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1

QRS complex duration enhancement as ventricular late potential indicator by signal-averaged ECG using time-amplitude alignments.  

PubMed

Ventricular late potentials (VLPs) are small-amplitude waves with a short duration that appear at the end part of the QRS complex, making a QRS complex duration larger. The signal-averaged electrocardiography (ECG) technique enhances VLPs and beats, assuming noise as the only random variable. However, ECG signals are not completely stationary and different elongations appear in both time and amplitude in each beat. This research proposes to use piecewise linear approximation to segment each beat and performs the alignment of the beats using the technique known as derivative dynamic time-warping to have beats better aligned and consequently enhance the presence of VLPs. We recorded high-resolution ECGs (HRECGs) from 50 subjects in supine position with no heart-stroke antecedents. VLPs were created synthetically and added to the HRECGs. Two cases were evaluated: (i) duration of the QRS complexes with VLPs without beats alignment, and (ii) duration of QRS complexes with VLPs using beats alignment in time and amplitude. Considering QRS duration as an indicative of VLP presence, results show that when using beats alignment in time and amplitude it is possible to reach a sensitivity of 0.96 and a specificity of 0.52, as opposed to 0.72 and 0.40, respectively, when using only averaging without beats alignment in time and amplitude. PMID:23446922

Avitia, Roberto L; Reyna, Marco A; Bravo-Zanoguera, Miguel E; Cetto, Lucio A

2013-04-01

2

QRS complex duration and dipyridamole gated SPECT findings in the left bundle branch block  

Microsoft Academic Search

Objective  The aim of this study was to investigate the relationship between QRS duration, artifactual perfusion abnormalities, and left\\u000a ventricular function in patients with left bundle branch block (LBBB) using dipyridamole technetium-99m sestamibi electrocardiography-gated\\u000a single-photon emission computed tomography (SPECT).\\u000a \\u000a \\u000a \\u000a Methods  Twenty-three patients (62 ± 12.2 years, 18 women, 5 men) with complete LBBB were analyzed. All patients underwent rest-dipyridamole\\u000a gated SPECT (1-day

Sabahat Inanir; Billur Caliskan; Sena Tokay; Ahmet Oktay

2008-01-01

3

Association between QRS Duration and Obstructive Sleep Apnea  

PubMed Central

Background: Both obstructive sleep apnea (OSA) and prolonged QRS duration are associated with hypertension, heart failure, and sudden cardiac death. However, possible links between QRS duration and OSA have not been explored. Methods: Cross-sectional study of 221 patients who underwent polysomnography at our center. Demographics, cardiovascular risk factors and ECG were collected to explore a relationship between OSA and QRS duration. Results: The apnea-hypopnea index (AHI) was positively correlated with QRS duration (r = 0.141, p = 0.03). Patients were divided into 3 groups: AHI < 5 (61), AHI 5-29 (104), and AHI > 30 (55). The mean QRS duration prolonged significantly as OSA worsened (AHI < 5, 85 ± 9.5; AHI 5-29, 89 ± 11.9; and AHI > 30, 95 ± 19.9 ms, p = 0.001). QRS ? 100 ms was present in 12.7% of patients with severe OSA compared with 0% in the rest of the sample (p < 0.0001). After adjustment for age, race, and cardiovascular risk factors, this association remained significant in women but not in men. Conclusion: QRS duration and OSA were significantly associated. Severity of OSA independently predicted prolonged QRS in women but not men. Nevertheless, prolongation of QRS duration in either sex may potentiate arrhythmic risks associated with OSA. Citation: Gupta S; Cepeda-Valery B; Romero-Corral A; Shamsuzzaman A; Somers VK; Pressman GS. Association between QRS duration and obstructive sleep apnea. J Clin Sleep Med 2012;8(6):649-654.

Gupta, Shuchita; Cepeda-Valery, Beatriz; Romero-Corral, Abel; Shamsuzzaman, Abu; Somers, Virend K.; Pressman, Gregg S.

2012-01-01

4

Wavelet transform-based QRS complex detector.  

PubMed

In this paper, we describe a QRS complex detector based on the dyadic wavelet transform (Dy WT) which is robust to time-varying QRS complex morphology and to noise. We design a spline wavelet that is suitable for QRS detection. The scales of this wavelet are chosen based on the spectral characteristics of the electrocardiogram (ECG) signal. We illustrate the performance of the Dy WT-based QRS detector by considering problematic ECG signals from the American Heart Association (AHA) data base. Seventy hours of data was considered. We also compare the performance of Dy WT-based QRS detector with detectors based on Okada, Hamilton-Tompkins, and multiplication of the backward difference algorithms. From the comparison, results we observed that although no one algorithm exhibited superior performance in all situations, the Dy WT-based detector compared well with the standard techniques. For multiform premature ventricular contractions, bigeminy, and couplets tapes, the Dy WT-based detector exhibited excellent performance. PMID:10396902

Kadambe, S; Murray, R; Boudreaux-Bartels, G F

1999-07-01

5

Electrocardiographic manifestations: narrow QRS complex tachycardias  

Microsoft Academic Search

Narrow QRS complex tachycardia is a common dysrhythmia in Emergency Medicine practice. Diagnosis and mechanism often can be made by 12-lead electrocardiographic (EKG) analysis but may subsequently require electrophysiologic testing. The clinical manifestations are varied and dependent upon heart rate, prior cardiac disease, and general physiologic status. Patient management is directed towards the etiology and mechanism of the dysrhythmia and

Marc L Pollack; William J Brady; Theodore C Chan

2003-01-01

6

Narrow QRS complex tachycardia presenting as palpitation.  

PubMed

Atrial fibrillation is the most common sustained cardiac arrhythmia. The rhythm in atrial fibrillation is irregular. Correct interpretation of the electrocardiogram (ECG) is essential. Atrial flutter can present as regular or irregular narrow QRS complex tachycardia. Knowledge of the ECG features of atrial flutter will help to differentiate it from paroxysmal supraventricular tachycardia. The treatment strategy in atrial fibrillation should focus on rhythm control vs. rate control, and anticoagulation should be started based on the calculated risk of systemic embolisation. Atrial flutter is a unique arrhythmia that has similar management strategies to those of atrial fibrillation; however, radiofrequency ablation is increasingly preferred due to its higher rate of efficacy and safety compared to pharmacological therapy. PMID:21808955

Singh, D; Teo, S G; Kireyev, D; Poh, K K

2011-07-01

7

Cardiac resynchronisation therapy in patients with heart failure and a normal QRS duration: the RESPOND study  

Microsoft Academic Search

ObjectivesTo evaluate the clinical response to cardiac resynchronisation therapy (CRT) in patients with heart failure and a normal QRS duration (<120 ms).SettingSingle centre.Patients60 patients with heart failure and a normal QRS duration receiving optimal pharmacological treatment (OPT).InterventionsPatients were randomly assigned to CRT (n=29) or to a control group (OPT, n=31). Cardiovascular magnetic resonance was used in order to avoid scar

Paul W X Foley; Kiran Patel; Nick Irwin; John E Sanderson; Michael P Frenneaux; Russell E A Smith; Berthold Stegemann; Francisco Leyva

2011-01-01

8

The prognostic significance of a fragmented QRS complex after primary percutaneous coronary intervention.  

PubMed

Fragmented QRS (fQRS) may occur due to non-homogeneous activation of ischemic ventricles. We want to investigate the prognostic significance of a fQRS complex in a patient who had undergone primary percutaneous coronary intervention (PCI). Eighty-five patients with no history of coronary artery disease who underwent primary PCI were included in the study. Of these patients, 34 who were found to have a fQRS at the 48th hour after primary PCI were defined as group 1, and 51 who were found not to have a fQRS were defined as group 2. Both groups were monitored for adverse cardiac events. At 6.6 ± 2.3 months of follow-up, major adverse cardiac events (MACE) was found significantly higher in the fQRS group [group 1:10 (29.4%) vs. group 2:3 (5.9%); p:0.003]. In multivariate Cox regression analysis; the duration of chest pain (HR:1.02, CI:1.004-1.05; p = 0.03) and fQRS at 48th hour (HR 7.16, CI 3.17-20.11; p = 0.006) were predictors of MACE. In the group 2, event-free survival rate was found significantly higher; however, Q wave and QRS distortion were found to be insignificant with regard to demonstrating event-free survival. Compared to both Q wave and QRS distortion, fQRS showed high sensitivity and specificity in demonstrating MACE (sensitivity 0.77; specificity 0.67; AUC 0.71 (0.57-0.86); p 0.01). fQRS had 73% sensitivity and 49% specificity and Q wave had 58% sensitivity and 85% specificity for demonstrating the presence of scar on myocardial perfusion scintigraphy with ROC curve analysis. The presence of a fQRS at the 48th hour is a significant predictor of MACE in patients with ST elevation myocardial infarction who have undergone primary PCI. (ClinicalTrials.gov number: NCT01136837). PMID:21344317

Ari, Hasan; Cetinkaya, Seçkin; Ari, Selma; Koca, Vedat; Bozat, Tahsin

2011-02-23

9

[Factors producing increase of QRS complex amplitude during hemodialysis].  

PubMed

An increase of total amplitudes of QRS complexes induced by the hemodialysis (HD) procedure is a common phenomenon in hemodialysed patients. The aim of the study was to define factors responsible for the growth of QRS complex amplitude as a result of HD. The study was carried out on a group of 48 patients. Before and after HD procedure basic biochemical blood tests were performed and the following parameters calculated for each patient: (a) the total amplitude of QRS complex, (b) the total volume of body water (TBW), the extracellular volume (ECW), and the intracellular volume (ICW), as well as the TBW, ECW and ICW indices standardized against the patient body weight. The levels of albumin, total protein, intact PTH (iPTH), interleukin-6 (IL-6), and tumor necrosis factor alpha (TNF-alpha) were determined before HD. The rates of Kt/V and normalized protein catabolic rate (nPCR) were calculated. The total amplitude of QRS complexes before HD was 13.09 +/- 3.3 mV and it increased significantly after HD to the value of 17.68 +/- 4.03 mV (p<0.001). An increase of QRS amplitude was observed in 35 patients (72.92%). The results of the study revealed, that the most important factor responsible for the growth of the total amplitude of QRS complexes after HD procedure is the value and changes in the ECW volume. The validation of the correlations disclosed in our study between the increase of the total amplitude of QRS complexes and IL-6 )positive correlation), and the nPCR value (negative correlation) require further studies on large groups of HD patients as well as a retrospective analysis of patients' survival rates. PMID:16334530

Jaroszy?ski, Andrzej J; Za?uska, Wojciech; Bober, Ewa; Ksiazek, Andrzej

2005-01-01

10

Redefining Performance Evaluation Tools for Real-Time QRS Complex Classification Systems  

Microsoft Academic Search

In a heartbeat classification procedure, the detection of QRS complex waveforms is necessary. In many studies, this heartbeat extraction function is not considered: the inputs of the classifier are assumed to be correctly identified. This communication aims to redefine classical performance evaluation tools in entire QRS complex classification systems and to evaluate the effects induced by QRS detection errors on

Philippe Ravier; Frederic Leclerc; Cedric Dumez-Viou; Guy Lamarque

2007-01-01

11

Several common variants modulate heart rate, PR interval and QRS duration  

Microsoft Academic Search

Electrocardiographic measures are indicative of the function of the cardiac conduction system. To search for sequence variants that modulate heart rate, PR interval and QRS duration in individuals of European descent, we performed a genome-wide association study in ?10,000 individuals and followed up the top signals in an additional ?10,000 individuals. We identified several genome-wide significant associations (with P <

Daniel F Gudbjartsson; David O Arnar; Gudmar Thorleifsson; Gudmundur Thorgeirsson; Hrafnhildur Stefansdottir; Sigurjon A Gudjonsson; Aslaug Jonasdottir; Ellisiv B Mathiesen; Inger Njølstad; Audhild Nyrnes; Tom Wilsgaard; Erin M Hald; Kristian Hveem; Camilla Stoltenberg; Maja-Lisa Løchen; Augustine Kong; Unnur Thorsteinsdottir; Hilma Holm; Kari Stefansson

2010-01-01

12

Prolonged Electrocardiogram QRS Duration Independently Predicts Long-Term Mortality in Patients Hospitalized for Heart Failure With Preserved Systolic Function  

PubMed Central

Background Prolonged electrocardiogram (ECG) QRS duration (?120 ms) is a risk factor for death in systolic heart failure, but its effects in heart failure with preserved systolic function (HFPSF) have not been extensively studied. We hypothesized that prolonged ECG QRS duration would independently predict long-term mortality in hospitalized HFPSF patients. Methods and Results We analyzed 872 HFPSF patients (defined as left ventricular ejection fraction ?50%) admitted to Michigan community hospitals between 2002 and 2004 and followed for a median of 660 days. We used Cox proportional hazards models to assess mortality hazard for prolonged QRS duration (?120 ms) on the last available predischarge ECG, first on a univariable basis and then after multivariable adjustment for other known risk factors. Prolonged QRS duration increased univariable all-cause mortality (HR 1.71; 95% CI 1.33–2.19, P < .001) and after multivariable adjustment (HR 1.31; 95% CI 1.01–1.71, P = .04). The univariable effect size was larger in younger patients. In multivariable models, there was no significant interaction between prolonged QRS and age, hypertension, or coronary artery disease status. Conclusions Prolonged QRS duration (?120 ms) on a predischarge ECG is an independent and consistent predictor of long-term mortality in hospitalized HFPSF patients.

HUMMEL, SCOTT L.; SKORCZ, STEPHEN; KOELLING, TODD M.

2013-01-01

13

QRS Duration on Electrocardiography and Cardiovascular Mortality (from the National Health and Nutrition Examination Survey-III).  

PubMed

The relation of bundle branch block (BBB) with adverse outcome is controversial. We hypothesized that increased QRS duration is an independent predictor of cardiovascular (CV) mortality in a cross-sectional US population. This is a retrospective cohort study on prospectively collected data to assess the relationship between QRS duration on routine ECG and CV mortality. Participants included 8,527 patients with ECG data available from the National Health and Nutrition Examination Survey data set, representing 74,062,796 individuals in the United States. Mean age was 60.5 ± 13.6 years. Most subjects were white (87%) and women (53%). During the follow-up period of 106,244.6 person-years, 1,433 CV deaths occurred. Multivariate analysis revealed that the highest quartile of QRS duration was associated with higher CV mortality than lowest quartile (hazard ratio [HR] 1.3, 95% confidence interval [CI] 1.01 to 1.7, p = 0.04) after adjustment for established risk factors. Both left BBB (HR 2.4, 95% CI 1.3 to 4.7, p = 0.009) and right BBB (HR 1.90, 95% CI 1.2 to 3.0, p = 0.008) were significantly associated with increased CV mortality. The addition of the QRS duration in 10-millisecond increments to the Framingham Risk Score model resulted in 4.4% overall net reclassification improvement (95% CI 0.02 to 0.04; p = 0.00006). In conclusion, increased QRS duration was found to be an independent predictor of CV mortality in this cross-sectional US population. A model including QRS duration in addition to traditional risk factors was associated with improved CV risk prediction. PMID:23726176

Badheka, Apurva Omkar; Singh, Vikas; Patel, Nileshkumar Jasmatbhai; Deshmukh, Abhishek; Shah, Neeraj; Chothani, Ankit; Mehta, Kathan; Grover, Peeyush; Savani, Ghanshyambhai Tulsibhai; Gupta, Sandeepkumar; Rathod, Ankit; Marzouka, George Robert; Mitrani, Raul David; Moscucci, Mauro; Cohen, Mauricio Gabriel

2013-05-29

14

A new approach of QRS complex detection based on matched filtering and triangle character analysis.  

PubMed

QRS complex detection usually provides the fundamentals to automated electrocardiogram (ECG) analysis. In this paper, a new approach of QRS complex detection without the stage of noise suppression was developed and evaluated, which was based on the combination of two techniques: matched filtering and triangle character analysis. Firstly, a template of QRS complex was selected automatically by the triangle character in ECG, and then it was time-reversed after removing its direct current component. Secondly, matched filtering was implemented at low computational cost by finite impulse response, which further enhanced QRS complex and attenuated non-QRS regions containing P-wave, T-wave and various noise components. Subsequently, triangle structure-based threshold decision was processed to detect QRS complexes. And RR intervals and triangle structures were further analyzed for the reduction of false-positive and false-negative detections. Finally, the performance of the proposed algorithm was tested on all 48 records of the MIT-BIH Arrhythmia Database. The results demonstrated that the detection rate reached 99.62 %, the sensitivity got 99.78 %, and the positive prediction was 99.85 %. In addition, the proposed method was able to identify QRS complexes reliably even under the condition of poor signal quality. PMID:22806315

Li, Yanjun; Yan, Hong; Hong, Feng; Song, Jinzhong

2012-07-18

15

Standardization of QRS duration measurement and LBBB criteria in CRT trials and clinical practice.  

PubMed

Based on the clinical trials so far, there is a major controversy regarding the benefit of CRT in patients with QRS?150 milliseconds. Some studies have shown that a fair number of patients with QRS?150 milliseconds benefit from CRT and it is needless to say that careful attention should be paid to CRT non-responders considering the risk of complications and cost-benefit ratio. Lack of uniformity in QRS measurement in all these trials could have a major influence on variable study outcomes. This is of concern because when the QRS is close to 120 milliseconds in patients with NYHA class III/IV symptoms or QRS close to 150 milliseconds in NYHA class I/II patients, the decision to recommend CRT implantation or undertake further risk stratification investigations is critically dependent on the EKG interpretation. In this paper we intent to raise the important question for need of standardized electrocardiographic criteria (QRS measurement and LBBB) in patients enrolled in CRT trials considering the variability in study results, high rates of CRT non response in the eligible population and the associated health care cost burden. PMID:23116056

Turagam, Mohit K; Velagapudi, Poonam; Kocheril, Abraham G

2013-02-01

16

Usefulness of spatial dispersion of QRS duration in predicting mortality in patients with mild to moderate chronic heart failure.  

PubMed

To prospectively evaluate the prognostic significance of spatial dispersion of QRS duration (S-QRSd) on a signal-averaged electrocardiogram in patients with chronic heart failure (CHF), we studied 114 consecutive stable outpatients with radionuclide left ventricular ejection fraction <40%. Cardiac and sudden deaths were significantly more often observed in patients with than without abnormal S-QRSd. S-QRSd is a powerful prognostic marker of the mortality in patients with mild to moderate CHF. PMID:15464690

Yamada, Takahisa; Shimonagata, Tsuyoshi; Misaki, Naoyuki; Asai, Mitsutoshi; Makino, Nobuhiko; Kioka, Hidetaka; Tamaki, Shunsuke; Fukunami, Masatake

2004-10-01

17

Methodology for automated detection of fragmentation in QRS complex of Standard 12-lead ECG.  

PubMed

Fragmented QRS (f-QRS) has been found to have higher sensitivity and/or specificity values for several diseases including remote and acute myocardial infarction, cardiac sarcoidosis etc, compared to other conventional bio-markers viz. Q-wave, ST-elevation etc. Several of these diseases do not have a reliable bio-marker and hence, patients suffering from them have to undergo expensive and sometimes invasive tests for diagnosis viz. myocardial biopsy, cardiac catheterization etc. This paper proposes automation of fragmentation detection which will lead to a more reliable diagnosis and therapy reducing human error, time consumption and thereby alleviating the need of enormous training required for detection of fragmentation. In this paper, we propose a novel approach to detect the discontinuities present in QRS complex of standard 12-lead ECG, known as fragmented QRS, using Discrete Wavelet transform (DWT) targeting both hospital-based and remote health monitoring environments. Fragmentation Detection Algorithm (FDA) was designed and modeled using PhysioNet's PTBDB and upon reiterative refinements it successfully detected all discontinuities in the QRS complex. The QRS complexes of 31 patients obtained randomly from PhysioNet's PTBDB were examined by two experienced cardiologists and the measurements obtained were compared with the results of our proposed FDA leading to 89.8% agreement among them. PMID:24110556

Maheshwari, Sidharth; Acharyya, Amit; Puddu, Paolo Emilio; Schiariti, Michele

2013-07-01

18

A FPGA system for QRS complex detection based on Integer Wavelet Transform  

NASA Astrophysics Data System (ADS)

Due to complexity of their mathematical computation, many QRS detectors are implemented in software and cannot operate in real time. The paper presents a real-time hardware based solution for this task. To filter ECG signal and to extract QRS complex it employs the Integer Wavelet Transform. The system includes several components and is incorporated in a single FPGA chip what makes it suitable for direct embedding in medical instruments or wearable health care devices. It has sufficient accuracy (about 95%), showing remarkable noise immunity and low cost. Additionally, each system component is composed of several identical blocks/cells what makes the design highly generic. The capacity of today existing FPGAs allows even dozens of detectors to be placed in a single chip. After the theoretical introduction of wavelets and the review of their application in QRS detection, it will be shown how some basic wavelets can be optimized for easy hardware implementation. For this purpose the migration to the integer arithmetic and additional simplifications in calculations has to be done. Further, the system architecture will be presented with the demonstrations in both, software simulation and real testing. At the end, the working performances and preliminary results will be outlined and discussed. The same principle can be applied with other signals where the hardware implementation of wavelet transform can be of benefit.

Stojanovi?, R.; Karadagli?, D.; Mirkovi?, M.; Miloševi?, D.

2011-01-01

19

Idiopathic ventricular fibrillation with fragmented QRS complex and J wave in resting electrocardiogram  

PubMed Central

Objective To describe the clinical characteristics of idiopathic ventricular fibrillation (IVF) with fragmented QRS complex (f-QRS) and J wave in resting electrocardiogram. Methods We reviewed data from 21 case subjects in our hospital who were resuscitated after cardiac arrest due to IVF and assessed the prevalence of f-QRS and J wave in resting electrocardiogram (ECG). All the case subjects were classified among three groups based on the electrocardiographic morphology: group I, both f-QRS and J wave were observed (n = 6), group II, only J wave was observed (n = 9), group III, neither f-QRS nor J wave was observed (n = 6). Population characteristics, history of syncope or sudden cardiac arrest, incidence of ventricular fibrillation (VF), and circumstance of VF were evaluated among the three groups. Results The incidence of index events (syncope, survived cardiac arrest and VF episodes recorded in implantable cardioverter defibrillator (ICD) or pacemakers) was 13.4 ± 5.6 per-year in group I, 10.8 ± 3.9 per-year in group II, and 9.8 ± 4.2 per-year in group III. There were significant differences in incidences among the three groups, the most frequent index events were observed in group I. The hazard ratio for incidence was 3.2 (95%CI, 1.1–7.9; P = 0.01). The history and circumstance of the index events were different among the groups. In group I, all the index events occurred during sleep in early morning. In group II, four subjects suffered VF during strenuous physical activities or agitation state, two during sleep in early morning, three in usual activity. In group III, one subject suffered VF during sleep in early morning, one in agitation state, four in usual activity. Conclusions This study suggests that the IVF patients with the combined appearance of f-QRS and J wave in the resting ECG suffer an increased risk of VF, this subgroup of IVF patients has a unique clinical feature.

Wang, Jing; Tang, Min; Mao, Ke-Xiu; Chu, Jian-Min; Hua, Wei; Jia, Yu-He; Zhao, Ying-Jie; Wei, Wei; Chen, Xu-Hua; Pu, Jie-Lin; Zhang, Shu

2012-01-01

20

The prolongation of QRS-duration resulting from delayed recovery of ventricular excitability. A new mechanism for intraventricular conduction disturbance. A preliminary note.  

PubMed

Chlorpromazine (1, 5, and 20 mg/Kg) was injected intravenously to anesthetized and open-chest dogs under artificial respiration. Using right atrial pacing, the heart rate was increased stepwise from intrinsic sinus rate to higher rate where the A-V block first developed. ECG (II) was recorded simultaneously with arterial blood pressure, ventricular monophasic action potentials and left atrial electrogram. In the control, QRS-duration was constant (46.9 +/- 0.8 msec) irrespective of heart rate. After the drug injection, however, the duration increased significantly with increasing heart rate, the effect depending on the injected dosage (r==0.283, P less than 0.1 in 1 mg/Kg; r==0.406, P less than 0.01 in t mg/Kg; r==0.631, P less than 0.001 in 20 mg/Kg). During the drug action, QRS-duration of atrial premature beats was also longer than that of sinus beats, and the lengthening increased with shortening of preceding cycle length. The observed QRS-prolongations were due to neither incomplete ventricular repolarization nor bundle branch block. The mechanism of prolongation was attributed to delayed or time-dependent recovery of ventricular excitability, i.e., slowed removal of inactivation in rapid sodium system in the ventricular muscle fibers. PMID:1011369

Nagamoto, Y; Arita, M; Saikawa, T

1976-11-01

21

Association of fragmented QRS complex with myocardial reperfusion in acute ST-elevated myocardial infarction.  

PubMed

In this study, we aimed to evaluate the relationship between TIMI myocardial perfusion (TMP) grade, as an indicator of myocardial reperfusion, and fragmented QRS (fQRS) in standard 12-lead electrocardiogram. Also, we evaluate fQRS is an additional indicator of myocardial reperfusion. One hundred patients admitted with first STEMI to Coronary Intensive Care Unit and who were used thrombolytic therapy was included in this retrospective study. Standard 12-lead electrocardiogram records of patients simultaneous with coronary angiography (second day) were assessed and analysed for the presence of fQRS. Also, coronary angiography images were analyzed to identify the infarct related artery, TIMI grade of infarct related artery and TMP grade of infarct related artery. The patients with fQRS demonstrated a significantly lower TMP grade, TIMI grade and ejection fraction compared with the non-fQRS patients (P = 0.004, P = 0.003, P = 0.02 respectively). The patients with inadequate myocardial reperfusion demonstrated a significantly higher fQRS compared with the adequate myocardial reperfusion patients. (56.9% versus 23.5%, P = 0.002 respectively). On correlation analysis, there was a significant negative correlation between fQRS and left ventricular ejection fraction (r = -232, P = 0.02) TMP grade and adequate myocardial reperfusion (TMP 3) showed significant negative correlation with fQRS (r = -0.370, P = 0.000; r = -0.318, P = 0.001 respectively). Presence of fragmented QRS in STEMI patients was associated with inadequate myocardial reperfusion and it can be used as a simple, noninvasive parameter to evaluate myocardial reperfusion. PMID:23347028

Erdem, Fatma Hizal; Tavil, Yusuf; Yazici, Hüseyin; Aygül, Nazif; Abaci, Adnan; Boyaci, Bülent

2012-11-22

22

Predictive value of the fragmented QRS complex in 6-month mortality and morbidity following acute coronary syndrome  

PubMed Central

Background Fragmented QRS encompasses different RSR’ patterns showing various morphologies of the QRS complexes with or without the Q wave on a resting 12-lead electrocardiogram. It has been shown possibly to cause adverse cardiac outcomes in patients with some heart diseases, including coronary artery disease. In view of the need for risk stratification of patients presenting with acute coronary syndrome in the most efficacious and cost-effective way, we conducted this study to clarify the value of developing fragmented QRS in a cohort of patients presenting with their first acute coronary syndrome in predicting 6-month mortality and morbidity. Methods One hundred consecutive patients admitted to the coronary care unit at Shahid Madani Heart Center in Tabriz from December 2008 to March 2009 with their first acute coronary syndrome were enrolled in this prospective study. Demographic and electrocardiographic data on admission, inhospital mortality, and need for revascularization were recorded. Electrocardiography performed 2 months after the index event was examined for development of fragmented QRS. Mortality and morbidity was evaluated at 6-month follow-up in all patients. Results The patients were of mean age 57.7 ± 12.8 years, and 84% were men. The primary diagnosis was unstable angina in 17 (17%) patients, non-ST elevation myocardial infarction (MI) in 11 (11%), anterior or inferior ST elevation MI in 66 (66%), and postero-inferior MI in six (6%). Fragmented QRS was present in 30 (30%) patients during the first admission, which increased to 44% at the 2-month follow-up and to 53% at the 6-month follow-up. The presence of various coronary risk factors and drug therapy given, including fibrinolytic agents, had no effect on development of fragmented QRS. Mortality was significantly higher (P = 0.032) and left ventricular ejection fraction was significantly lower (P = 0.001) in the fragmented QRS group at the 6-month follow-up. Conclusion This study strongly suggests that fragmented QRS on initial presentation with acute coronary syndrome is not predictive of subsequent events but, if present 6 months later, could be predictive of an adverse outcome.

Akbarzadeh, Fariborz; Pourafkari, Leili; Ghaffari, Samad; Hashemi, Mohammad; Sadeghi-Bazargani, Homayoun

2013-01-01

23

Fragmented QRS complexes are not hallmarks of myocardial injury as detected by cardiac magnetic resonance imaging in patients with acute myocardial infarction.  

PubMed

BACKGROUND: Q waves on a 12-lead electrocardiography (ECG) are considered to be classic hallmarks of prior myocardial infarction. However, one study suggested that the fragmented QRS complex (fQRS) on ECG is a highly sensitive and specific marker of myocardial scarring on a nuclear stress test. The study aimed to investigate the diagnostic accuracy of fragmented QRS complexes compared with Q waves for myocardial injury detected by delayed contrast-enhanced cardiovascular magnetic resonance imaging (DE-CMRI) in subjects with acute myocardial infarction. METHODS: Electrocardiograms of 190 subjects with myocardial infarction who underwent DE-CMR were analyzed. fQRS was defined by the presence of an additional R wave (R?), or notching of the S wave, or more than one R' in two contiguous leads. RESULTS: Delayed enhancement was observed in 180 (94.7%) patients. Transmural enhancement was noted in 78 (43.3%) and subendocardial enhancement in 102 (56.7%) patients. The sensitivity and specificity of Q waved and fQRS for diagnosing delayed enhancement were 59.4% vs. 66.7% and 90.0% vs. 40.0%. The area under the receiver-operator characteristics curve of delayed enhancement was 0.75 for Q waves and 0.53 for fQRS (p=0.04). The areas under the ROC curves of the transmurality of delayed enhancement were 0.44 for fQRS and 0.58 for Q waves (p=0.73). CONCLUSIONS: fQRS has poor accuracy for the detection of myocardial injury compared with Q waves. fQRS and Q waves are not valuable tools for the diagnosis transmural irreversible myocardial injury in acute myocardial infarction. PMID:23336958

Ahn, Min-Soo; Kim, Jin-Bae; Yoo, Byung-Su; Lee, Jun-Won; Lee, Ji Hyun; Youn, Young Jin; Ahn, Sung Gyun; Kim, Jang-Young; Lee, Seung-Hwan; Yoon, Junghan; Choe, Kyung-Hoon

2013-01-18

24

[A study on frequency characteristics of filter for detecting high frequency components of QRS complex and its application to the intraventricular conduction system].  

PubMed

A method to detect the high frequency component of QRS complex was developed and the mode of intraventricular conduction was analyzed from its sequential changes. An originally developed subtraction method was used to diminish the transient phenomenon related to phase shift and to obtain easily changeable filtering characteristics. The subjects included normal healthy persons (N), persons having right or left bundle branch block (R and L) and ventricular premature contraction of R or L type (VR and VL). Three components, initial low, mid high and terminal low amplitude were obtained in the N group. In the R group, mid component was lower and duration of the terminal component was longer than in the N group. In the L group, mid and terminal components were not clearly discriminated. Further, their amplitudes were low and duration of each component was markedly prolonged. In the VR and VL groups, the amplitude of the initial component was low and its duration was prolonged. From these findings, the excitation wave through the normal conduction system was short in duration and relatively high in amplitude and includes high frequency component. As contrasted, the duration was prolonged and the amplitude was low in conduction disturbance, seen in bundle branch block or ventricular premature contraction. Thus, the mode of intraventricular conduction could be defined by this newly developed method. PMID:7535364

Nanke, T

1995-02-01

25

Design of a unified framework for analyzing long-duration ambulatory ECG: Application for extracting QRS geometrical features  

Microsoft Academic Search

Purpose  Since ambulatory electrocardiogram (ECG) signal is always accompanied by strong noise, high amplitude baseline wandering,\\u000a impulsive artifacts, arrhythmic outliers and some discontinuities, these effects reduce the accuracy of a computerized cardiac-originated\\u000a events detection-delineation algorithm. The aim of this study is to describe a multi-aspect robust structure of a solution\\u000a designed for detection-delineation of major events of the long-duration holter ECG

Mohammad R. Homaeinezhad; Ali Ghaffari; S. Abbas Atyabi

2011-01-01

26

Adverse effect of ventricular pacing on heart failure and atrial fibrillation among patients with normal baseline QRS duration in a clinical trial of pacemaker therapy for sinus node dysfunction  

Microsoft Academic Search

Background—Dual-chamber (DDDR) pacing preserves AV synchrony and may reduce heart failure (HF) and atrial fibrillation (AF) compared with ventricular (VVIR) pacing in sinus node dysfunction (SND). However, DDDR pacing often results in prolonged QRS durations (QRSd) as the result of right ventricular stimulation, and ventricular desynchronization may result. The effect of pacing-induced ventricular desynchronization in patients with normal baseline QRSd

Michael O. Sweeney; Anne S. Hellkamp; Kenneth A. Ellenbogen

2003-01-01

27

Low Cost, Low Power QRS Detection Module Using PIC  

Microsoft Academic Search

This paper presents an efficient, low cost, low power QRS complexes detection module for ECG analysis. In past lot of research on algorithms for QRS detection has been carried out. All such methods mostly rely on a priori knowledge of the shape of the QRS complexes and general aspects of the ECG. Most of approaches require more CPU time and

Praveen Kumar; Monika Jain; Sagar Chandra

2011-01-01

28

Relation between right ventricular enlargement, QRS duration, and right ventricular function in patients with tetralogy of Fallot and pulmonary regurgitation after surgical repair  

Microsoft Academic Search

OBJECTIVEIn patients with repaired tetralogy of Fallot, to examine (1) a possible relation between right ventricular enlargement and QRS prolongation, and (2) the effect of right ventricular enlargement caused by pulmonary regurgitation on the right ventricular ejection fraction, evaluated by three dimensional echocardiography, and global function, evaluated by the myocardial performance index.DESIGN AND PATIENTS40 patients with repaired tetralogy were studied.

M Y Abd El Rahman; H Abdul-Khaliq; M Vogel; V Alexi-Meskishvili; M Gutberlet; P E Lange

2000-01-01

29

QRS amplitude and shape variability in magnetocardiograms.  

PubMed

In magnetocardiography, averaging of QRS complexes is often used to improve the signal-to-noise ratio. However, averaging of QRS complexes ignores the variation in amplitude and shape of the signals caused, for example, by respiration. This may lead to suppression of signal portions within the QRS complexes. Furthermore, for inverse source, reconstructions of dipoles and of current density distributions errors in the spacial arrangement may occur. To overcome these problems we developed a method for separating and selective averaging QRS complexes with different shapes and amplitudes. The method is based on a spline interpolation of the QRS complex averaged by a standard procedure. This spline function then is fitted to each QRS complex in the raw data by means of nonlinear regression (Levenberg-Marquardt method). Five regression parameters are applied: a linear amplitude scaling, two parameters describing the baseline drift, a time scaling parameter, and a time shift parameter. We found that both amplitude and shape of the QRS complex are influenced by respiration. The baseline shows a weaker influence of the respiration. The regression parameters of two neighboring measurement channels correlate linearly. Thus, selective averaging of a larger number of sensors can be performed simultaneously. PMID:10709232

Huck, M; Haueisen, J; Hoenecke, O; Fritschi, T; Leder, U; Nowak, H

2000-02-01

30

A new revised cardiac risk index incorporating fragmented QRS complex as a prognostic marker in patients undergoing noncardiac vascular surgery.  

PubMed

The aim of this study was to investigate the value of a new Revised Cardiac Risk Index (RCRI) that includes consideration of QRS fragmentation (fQRS) as a predictor of cardiac events in patients undergoing noncardiac vascular surgery. Four hundred sixty-seven consecutive patients admitted for noncardiac vascular surgery were studied. Patients were allocated to RCRI 0, 1, 2, or ?3 groups according to the sum of diabetes, renal insufficiency, and histories of ischemic heart disease, congestive heart failure, and cerebrovascular disease. They were then reallocated to fragmented RCRI (fRCRI) 0, 1, 2, or ?3 groups after including a score of 1 or 0 corresponding to the presence or absence of fQRS. A major adverse cardiac event (MACE) was defined as a composite of death, myocardial infarction, congestive heart failure, and percutaneous coronary intervention before noncardiac vascular surgery. During index hospitalization, MACE developed in 38 patients (8.1%). fQRS was present in 169 (36.2%), and it was significantly greater in patients with MACE than in those without MACE (63.2% vs 34.3%, p <0.001). The proportions of RCRI 0, 1, 2, and ?3 were 46.9% (n = 219), 35.3% (n = 165), 12.4% (n = 58), and 5.4% (n = 25), respectively. When fRCRI data were included, 28 patients (48.3%) in RCRI 2 were reclassified as fRCRI ?3. By multivariate logistic regression analysis, fRCRI (odds ratio 1.529, 95% confidence interval 1.035 to 2.258, p = 0.033) and a left ventricular ejection fraction <50% independently predicted in-hospital MACE. In conclusion, fRCRI is an independent predictor of in-hospital MACE in patients undergoing noncardiac vascular surgery. PMID:23768543

Bae, Myung Hwan; Jang, Se Yong; Choi, Won Suk; Kim, Kyun Hee; Park, Sun Hee; Lee, Jang Hoon; Kim, Hyung Kee; Yang, Dong Heon; Huh, Seung; Park, Hun Sik; Cho, Yongkeun; Chae, Shung Chull

2013-07-01

31

Relation of fragmented QRS complex to right ventricular fibrosis detected by late gadolinium enhancement cardiac magnetic resonance in adults with repaired tetralogy of fallot.  

PubMed

Fragmented QRS (fQRS) on 12-lead electrocardiography reflects conduction delay caused by myocardial fibrosis and dysfunction. Ventricular fibrosis detected by late gadolinium enhancement (LGE) cardiac magnetic resonance (CMR) is reportedly correlated with worse clinical outcomes in adults with repaired tetralogy of Fallot (TOF). The aim of this study was to assess whether the presence of fQRS is associated with right ventricular (RV) fibrosis or dysfunction in this patient group. In 37 consecutive patients (median age 30 years, median age at repair 6.6 years), the number of leads showing fQRS, defined as the presence of >2 notches on the R/S wave in ?2 contiguous leads, was counted. RV systolic function, dilatation, and LGE score were measured using LGE CMR. Ventricular LGE was observed mainly at the previous surgical sites: the RV outflow tract (33 of 37), ventricular septal defect patch region (15 of 37), and RV anterior wall (11 of 37). Fragmented QRS was found mostly in the right and mid precordial leads. The fQRS group (n = 20) demonstrated higher RV LGE scores (p <0.001) and lower RV ejection fractions (p = 0.02) and a trend toward larger RV end-diastolic and end-systolic volumes (p = 0.12 and p = 0.06, respectively) compared to the non-fQRS group (n = 17). The number of electrocardiographic leads showing fQRS was positively correlated with RV LGE score (r = 0.75, p <0.001). The presence of fQRS remained independently associated with the presence of supramedian RV LGE score, even after adjusting for relevant parameters. In conclusion, fQRS was closely associated with more extensive RV fibrosis and dysfunction in adults with repaired tetralogy of Fallot. PMID:21962997

Park, Seung-Jung; On, Young Keun; Kim, June Soo; Park, Seung Woo; Yang, Ji-Hyuk; Jun, Tae-Gook; Kang, I-Seok; Lee, Heung Jae; Choe, Yeon Hyeon; Huh, June

2011-09-29

32

An automated algorithm for online detection of fragmented QRS and identification of its various morphologies.  

PubMed

Fragmented QRS (f-QRS) has been proven to be an efficient biomarker for several diseases, including remote and acute myocardial infarction, cardiac sarcoidosis, non-ischaemic cardiomyopathy, etc. It has also been shown to have higher sensitivity and/or specificity values than the conventional markers (e.g. Q-wave, ST-elevation, etc.) which may even regress or disappear with time. Patients with such diseases have to undergo expensive and sometimes invasive tests for diagnosis. Automated detection of f-QRS followed by identification of its various morphologies in addition to the conventional ECG feature (e.g. P, QRS, T amplitude and duration, etc.) extraction will lead to a more reliable diagnosis, therapy and disease prognosis than the state-of-the-art approaches and thereby will be of significant clinical importance for both hospital-based and emerging remote health monitoring environments as well as for implanted ICD devices. An automated algorithm for detection of f-QRS from the ECG and identification of its various morphologies is proposed in this work which, to the best of our knowledge, is the first work of its kind. Using our recently proposed time-domain morphology and gradient-based ECG feature extraction algorithm, the QRS complex is extracted and discrete wavelet transform (DWT) with one level of decomposition, using the 'Haar' wavelet, is applied on it to detect the presence of fragmentation. Detailed DWT coefficients were observed to hypothesize the postulates of detection of all types of morphologies as reported in the literature. To model and verify the algorithm, PhysioNet's PTB database was used. Forty patients were randomly selected from the database and their ECG were examined by two experienced cardiologists and the results were compared with those obtained from the algorithm. Out of 40 patients, 31 were considered appropriate for comparison by two cardiologists, and it is shown that 334 out of 372 (89.8%) leads from the chosen 31 patients complied favourably with our proposed algorithm. The sensitivity and specificity values obtained for the detection of f-QRS were 0.897 and 0.899, respectively. Automation will speed up the detection of fragmentation, reducing the human error involved and will allow it to be implemented for hospital-based remote monitoring and ICD devices. PMID:24132202

Maheshwari, Sidharth; Acharyya, Amit; Puddu, Paolo Emilio; Mazomenos, Evangelos B; Leekha, Gourav; Maharatna, Koushik; Schiariti, Michele

2013-10-16

33

A new QRS detection method using wavelets and artificial neural networks.  

PubMed

We present a new method for detection and classification of QRS complexes in ECG signals using continuous wavelets and neural networks. Our wavelet method consists of four wavelet basis functions that are suitable in detection of QRS complexes within different QRS morphologies in the signal and thresholding technique for denoising and feature extraction. The results demonstrate that the proposed method is not only efficient for normal ECG signal analysis but also for various types of arrhythmic cardiac signals embedded in noise. For the classification stage, a feedforward neural network was trained with standard backpropagation algorithm. The classifier input features consisted of compact wavelet coefficients of QRS complexes that resulted in higher classification rates. We demonstrate the efficiency of our method with the average accuracy 97.2% in classification of normal and abnormal QRS complexes. PMID:20703782

Abibullaev, Berdakh; Seo, Hee Don

2010-01-20

34

The Spatial QRS-T Angle: Implications in Clinical Practice.  

PubMed

The ventricular gradient (VG) as a concept was conceived in the 1930s and its calculation yielded information that was not otherwise obtainable. The VG was not utilized by clinicians at large because it was not easy to understand and its computation time-consuming. The contemporary spatial QRS-T angle is based on the concept of the VG and defined as its mathematical and physiological integral. Its current major clinical use is to assess the cardiac primary repolarization abnormalities in 3-dimensional spatial vectorial plans which are normally untraced in the presence of secondary electrophysiological activity in a 2-dimensional routine electrocardiogram (ECG). Currently the calculation of the spatial QRS-T angle can be easily computed on the basis of a classical ECG and contributes to localization of arrhythmogenic areas in the heart by assessing overall and local heterogeneity of the myocardial ventricular action potention duration. Recent population-based studies suggest that the spatial QRS-T angle is a dominant ECG predictor of future cardiovascular events and death and it is superior to more conventional ECG parameters. Its assessment warrants consideration for intensified primary and secondary cardiovascular prevention efforts and should be included in everyday clinical practice. This review addresses the nature and diagnostic potential of the spatial QRS-T angle. The main focus is its role in ECG assessment of dispersion of repolarization, a key factor in arrythmogeneity. PMID:23909632

Voulgari, Christina; Pagoni, Stamatina; Tesfaye, Solomon; Tentolouris, Nicholas

2013-08-01

35

Absence and Resolution of Fragmented QRS Predict Reversible Myocardial Ischemia With Higher Probability of ST Segment Resolution in Patients With ST Segment Elevation Myocardial Infarction  

PubMed Central

Background and Objectives Fragmented QRS complexes (fQRS) are associated with increased morbidity and mortality. The causative relationship between fQRS and cardiac fibrosis has been shown, but whether the presence and the number of fQRS on admission of electrocardiogram (ECG) predicts ST segment resolution in patients undergoing primary percutaneous coronary intervention (p-PCI) has not been investigated until now. Subjects and Methods This study included one hundred and eighty-four consecutive patients with ST elevation myocardial infarction (STEMI) who underwent p-PCI. The presence or absence of fQRS on pre and post-PCI ECG and their relation with myocardial infarction and reperfusion parameters were investigated. Results Patients with fQRS on admission of ECG or newly developed fQRS after p-PCI had increased inflammatory markers, higher cardiac enzyme levels, increased pain to balloon time, prolonged QRS time, more extended coronary involvement and more frequent Q waves on ECG in comparison to patients with absence or resolved fQRS. The presence and higher number of fQRS on admission or post-PCI ECGs were significantly related with low percent of ST resolution and myocardial reperfusion parameters. The area under the receiver operating characteristics curve values for the presence and number of fQRS to detect Thrombolysis in Myocardial Infarction Blush Grade 0 and 1, were 0.682 and 0.703. Conclusion In our study, fQRS was significantly related to infarction and myocardial reperfusion parameters before and after p-PCI. Successful myocardial reperfusion by p-PCI caused the reduction in number of fQRS and QRS time with higher ST resolution. fQRS may be useful in identifying the patients at higher cardiac risk with increased ischemic jeopardized or infarcted myocardium, and persistent or newly developed fQRS may predict low percent of ST segment resolution in patients undergoing p-PCI.

Cetin, Mustafa; Kiris, Tuncay; Erdogan, Turan; Canga, Aytun; Durakoglugil, Murtaza Emre; Cicek, Yuksel; Dogan, Sitki; Satiroglu, Omer

2012-01-01

36

The development of mental models for auditory events: Relational complexity and discrimination of pitch and duration  

Microsoft Academic Search

This experiment investigated relational complexity and relational shift in judgments of auditory patterns. Pitch and duration values were used to construct two-note perceptually similar sequences (unary relations) and four-note relationally similar sequences (binary relations). It was hypothesized that 5-, 8- and 11-year-old children would perform unary level pitch and duration discrimination tasks accurately. Relational shift predicted a poorer performance of

Catherine Stevens; Melinda Gallagher

2004-01-01

37

QRS width and its impact on inducibility of ventricular arrhythmia at the time of electrophysiology study.  

PubMed Central

The inducibility of sustained ventricular arrhythmia by programmed electrical stimulation is a well-established marker of an increased risk of ventricular tachyarrhythmia. The purpose of this investigation was to determine whether there was a significant difference in the QRS duration or ejection fraction (EF) amongst patients who could be induced and those who could not be induced into ventricular arrhythmia at the time of standard electrophysiology study (EPS). All the patients who were studied for inducibility of ventricular arrhythmias between March 2003 and March 2004 (a total of 137 patients) were included in the study. An EF less than or equal to 30% was used to define decreased EF, and a QRS width greater than 120 ms was used to define widened QRS width. Patients were studied using standard EPS protocol after obtaining informed consent. In the univariate analysis, increasing age, male gender and low EF were predictors of inducibility, while widened QRS width did not have any predictive value. With multivariate analysis, there was a significant increase in the odds of inducibility with decreasing EF and widened QRS width. Interestingly, males had significantly more numbers of positive results.

Ashwath, Mahi Lakshmi; Okosun, Ike; Sogade, Felix O.

2005-01-01

38

QRS width and its impact on inducibility of ventricular arrhythmia at the time of electrophysiology study.  

PubMed

The inducibility of sustained ventricular arrhythmia by programmed electrical stimulation is a well-established marker of an increased risk of ventricular tachyarrhythmia. The purpose of this investigation was to determine whether there was a significant difference in the QRS duration or ejection fraction (EF) amongst patients who could be induced and those who could not be induced into ventricular arrhythmia at the time of standard electrophysiology study (EPS). All the patients who were studied for inducibility of ventricular arrhythmias between March 2003 and March 2004 (a total of 137 patients) were included in the study. An EF less than or equal to 30% was used to define decreased EF, and a QRS width greater than 120 ms was used to define widened QRS width. Patients were studied using standard EPS protocol after obtaining informed consent. In the univariate analysis, increasing age, male gender and low EF were predictors of inducibility, while widened QRS width did not have any predictive value. With multivariate analysis, there was a significant increase in the odds of inducibility with decreasing EF and widened QRS width. Interestingly, males had significantly more numbers of positive results. PMID:15926647

Ashwath, Mahi Lakshmi; Okosun, Ike; Sogade, Felix O

2005-05-01

39

The available force in long-duration memory complex systems and its statistical physical properties  

NASA Astrophysics Data System (ADS)

A new concept of the available force in long-duration memory complex systems is proposed. The relationship between the available force in different time intervals and the correlation parameters of complex systems is described. It is found that when the correlation parameters satisfy a determined condition, the trajectory where the velocity is divergent but the displacement is convergent can be well described and that the long-duration memory, anomalous diffusion, and q-Gaussian type distribution of complex systems can also be well described by the correlation parameters in different cases. In addition, by utilizing the velocity of time series randomly and analyzing its probability distribution of displacement, it is explained that when there exists a long-duration memory in complex systems, the fat-tail distributions will show up. The results obtained show that the relationship between the available force and the correlation parameters may be used to investigate the statistical physical properties in long-duration memory complex systems.

Huang, Zhifu; Ou, Congjie; Lin, Bihong; Su, Guozhen; Chen, Jincan

2013-07-01

40

Detection of P, QRS, and T Components of ECG using wavelet transformation  

Microsoft Academic Search

Electrocardiogram (ECG) signals are composed of five important waves: P, Q, R, S, and T. Sometimes, a sixth wave (U) may follow T. Q, R, and S are grouped together to form the QRS-complex. Detection of these waves is a vital step in ECG signal analysis to extract hidden patterns. Many prior studies have focused only on detection of the

A. Al Raoof Bsoul; Soo-Yeon Ji; K. Ward; K. Najarian

2009-01-01

41

Superior QRS axis in ventricular septal defect.  

PubMed Central

The relation between the superior orientation of the QRS axis and the anatomical site of the defect in the ventricular septum in patients with a ventricular septal defect was studied. Of 1031 patients with a ventricular septal defect, 64 (6.2%) had a superior axis on their electrocardiogram. In 59% of these patients the defect was in the inlet portion of the ventricular septum or affected this area. None of the cases was classified as an isolated ventricular septal defect of the persistent atrioventricular canal type. While there is an association between a superior axis and perimembranous inlet ventricular septal defect, a superior QRS axis does not characterise a ventricular septal defect as being of the atrioventricular canal type.

Shaw, N J; Godman, M J; Hayes, A; Sutherland, G R

1989-01-01

42

[Expert assessment of operations' complexity and its interrelationship with lethal outcomes and duration of treatment].  

PubMed

The aim of the work was to carry out expert assessment of complexity of operations and to study interrelationship of the average score of complexity of the interventions with lethal outcome and duration of treatment in the Intensive Care Unit (exemplified by comparison with the outcomes of operations on cardiac valves performed in 2009 in the setting of artificial circulation in adult patients). Complexity was assessed by a total of 13 cardiovascular surgeons specialized in operations aimed at correcting valve defects (4 of them were from the A. N. Bakulev Scientific Centre for Cardiovascular Surgery), with none of the participants being aware of the therapeutic outcomes of each type of the operation performed. An average expert-defined score was assigned for each of the 33 names of the operations. The Kendall coefficient of concordance for all operations amounted to 0.29 (p<0.001); consensus in the complexity-score (from 69 to 85%) was achieved for 48.5% of the operations thus considered. The values of the mean scores of complexity of operations, defined by the specialists form the SCCS (2.02±0.54) were significantly lower (Wilcoxon's test; p<0.001) as compared with the average score assigned by specialists from other facilities (2.28±0.43). The duration of the stay at the ICU of the patients subdivided into groups depending on the expert score was found to differ significantly (p=0.007). The area under the ROC curve using the EuroSCORE (0.59) is suggestive of its lower accuracy in assessing the lethal outcome as compared to the expert score (0.68). The obtained findings strongly suggest advisability of using expert score of operations' complexity for solving complicated non-formalized tasks on allied problems of cardiovascular surgery and organization of public health care (accrediting of medical facilities, formation of the government order, and planning of the budget of medical facilities). PMID:21389961

Bokeriia, L A; Samorodskaia, I V; Skopin, I I; Mironenko, V A; Kambarov, S Iu; Myrzakulov, E S

2010-01-01

43

New Hampshire Quality Rating System: QRS Profile. The Child Care Quality Rating System (QRS) Assessment  

ERIC Educational Resources Information Center

|This paper presents a profile of New Hampshire's Quality Rating System prepared as part of the Child Care Quality Rating System (QRS) Assessment Study. The profile consists of several sections and their corresponding descriptions including: (1) Program Information; (2) Rating Details; (3) Quality Indicators for Center-Based Programs; (4)…

Child Trends, 2010

2010-01-01

44

Relations between QRS|T Angle, Cardiac Risk Factors, and Mortality in the Third National Health and Nutrition Examination Survey (NHANES III)  

PubMed Central

On the surface electrocardiogram (ECG), an abnormally wide QRS|T angle reflects changes in regional action potential duration profiles and in direction of repolarization sequence which is thought to increase the risk of ventricular arrhythmia. We investigated the relationship between abnormal QRS|T angle and mortality in a nationally representative sample of individuals without clinically evident heart disease. We studied 7,052 participants ? 40 years of age in the Third National Health and Nutrition Examination Survey (NHANES III) with 12-lead ECGs. Individuals with self-report or ECG evidence of a prior myocardial infarction, QRS duration ?120 msec, or history of heart failure were excluded. Borderline and abnormal spatial QRS|T angle were defined according to sex-specific 75th and 95th percentiles of frequency distributions. All-cause (n=1093 women, n=1191 men) and cardiovascular mortality (n=462 women, n=455 men) over 14 years was assessed through linkage with the National Death Index. In multivariable analyses, abnormal spatial QRS|T angle was associated with an increased hazard ratio (HR) for cardiovascular mortality in women (HR 1.82, 95% CI 1.05-3.14) and men (HR 2.21, 95% CI 1.32-3.68). An abnormal QRS|T angle was also associated with increased multivariable adjusted HRs for all-cause mortality in women (HR 1.30, 95% CI 0.95-1.78) and men (HR 1.87, 95% CI 1.29-2.7). Borderline QRS|T angle was not associated with increased risk for all-cause or cardiovascular mortality. In conclusion, abnormal QRS|T angle, as measured on a 12-lead ECG, was associated with increased risk for cardiovascular and all-cause mortality in this population-based sample without known heart disease.

Whang, William; Shimbo, Daichi; Levitan, Emily B.; Newman, Jonathan D.; Rautaharju, Pentti M.; Davidson, Karina W.; Muntner, Paul

2012-01-01

45

Variation in canopy duration in the perennial biofuel crop Miscanthus reveals complex associations with yield.  

PubMed

Energy crops can provide a sustainable source of power and fuels, and mitigate the negative effects of CO2 emissions associated with fossil fuel use. Miscanthus is a perennial C4 energy crop capable of producing large biomass yields whilst requiring low levels of input. Miscanthus is largely unimproved and therefore there could be significant opportunities to increase yield. Further increases in yield will improve the economics, energy balance, and carbon mitigation of the crop, as well as reducing land-take. One strategy to increase yield in Miscanthus is to maximize the light captured through an extension of canopy duration. In this study, canopy duration was compared among a diverse collection of 244 Miscanthus genotypes. Canopy duration was determined by calculating the number of days between canopy establishment and senescence. Yield was positively correlated with canopy duration. Earlier establishment and later senescence were also both separately correlated with higher yield. However, although genotypes with short canopy durations were low yielding, not all genotypes with long canopy durations were high yielding. Differences of yield between genotypes with long canopy durations were associated with variation in stem and leaf traits. Different methodologies to assess canopy duration traits were investigated, including visual assessment, image analysis, light interception, and different trait thresholds. The highest correlation coefficients were associated with later assessments of traits and the use of quantum sensors for canopy establishment. A model for trait optimization to enable yield improvement in Miscanthus and other bioenergy crops is discussed. PMID:23599277

Robson, Paul R H; Farrar, Kerrie; Gay, Alan P; Jensen, Elaine F; Clifton-Brown, John C; Donnison, Iain S

2013-04-18

46

Prosodic Planning: Effects of Phrasal Length and Complexity on Pause Duration  

PubMed Central

Research on pause duration has mainly focused on the impact of syntactic structure on the duration of pauses within an utterance and on the impact of syntax, discourse, and prosodic structure on the likelihood of pause occurrence. Relatively little is known about what factors play a role in determining the duration of pauses between utterances or phrases. Two experiments examining the effect of prosodic structure and phrase length on pause duration are reported. Subjects read sentences varying along the following parameters: a) the length in syllables of the intonational phrase preceding and following the pause, and b) the prosodic structure of the intonational phrase preceding and following the pause, specifically whether or not the intonational phrase branches into smaller phrases. In order to minimize variability due to speech rate and individual differences, speakers read sentences synchronously in dyads. The results showed a significant post-boundary effect of prosodic branching and significant pre- and post-boundary phrase length effects. The results are discussed in terms of production units.

Krivokapi, Jelena

2007-01-01

47

QRS width in right bundle branch block. Accuracy and reproducibility of manual measurement  

Microsoft Academic Search

Background: The QRS prolongation and its relation to malignant ventricular arrhythmias are topics of interest. Controversies exist about the methodology of measuring the QRS. The aim of this study was to assess the accuracy and reproducibility of manual measurement of the QRS in standard electrocardiograms in patients with right bundle branch block and compare results with computer reading. Methods and

Berardo Sarubbi; Wei Li; Jane Somerville

2000-01-01

48

A neural network to differentiate wide QRS tachycardias  

Microsoft Academic Search

The development of a neural network designed to perform the differentiation of wide QRS tachycardias in superventricular tachycardia (SVT) vs. ventricular tachycardia (VT) is described. Artificial neural networks are formed by a large number of simulated artificial neurons, interconnected much like the brain's neurons. Rather than following programmed rules like in classical programs or expert systems, they learn by example.

W. R. M. Dassen; R. Mulleneers; K. den Dulk; J. Smeets; P. Brugada; H. J. J. Wellens

1990-01-01

49

QRS pattern and improvement in right and left ventricular function after cardiac resynchronization therapy: a radionuclide study  

PubMed Central

Background Predicting response to cardiac resynchronization therapy (CRT) remains a challenge. We evaluated the role of baseline QRS pattern to predict response in terms of improvement in biventricular ejection fraction (EF). Methods Consecutive patients (pts) undergoing CRT implantation underwent radionuclide angiography at baseline and at mid-term follow-up. The relationship between baseline QRS pattern and mechanical dyssynchrony using phase analysis was evaluated. Changes in left and right ventricular EF (LVEF and RVEF) were analyzed with regard to baseline QRS pattern. Results We enrolled 56 pts, 32 with left bundle branch block (LBBB), 4 with right bundle branch block (RBBB) and 20 with non-specific intraventricular conduction disturbance (IVCD). A total of 48 pts completed follow-up. LBBB pts had significantly greater improvement in LVEF compared to RBBB or non-specific IVCD pts (+9.6 ± 10.9% vs. +2.6 ± 7.6%, p = 0.003). Response (defined as ? 5% increase in LVEF) was observed in 68% of LBBB vs. 24% of non-specific IVCD pts (p = 0.006). None of the RBBB pts were responders. RVEF was significantly improved in LBBB (+5.0 ± 9.0%, p = 0.007), but not in non-specific IVCD and RBBB pts (+0.4 ± 5.8%, p = 0.76). At multivariate analysis, LBBB was the only predictor of LVEF response (OR, 7.45; 95% CI 1.80-30.94; p = 0.006), but not QRS duration or extent of mechanical dyssynchrony. Conclusions Presence of a LBBB is a marker of a positive response to CRT in terms of biventricular improvement. Pts with non-LBBB pattern show significantly less benefit from CRT than those with LBBB.

2012-01-01

50

[Study of suitable analyzed signal duration and criteria for abnormal signal averaged electrocardiogram on frequency-domain analysis in patients with Duchenne's muscular dystrophy].  

PubMed

We investigated the optimal condition to detect abnormalities on the fast-Fourier transformation of the signal-averaged electrocardiogram (SA-ECG) by studying the effects of analyzed signal duration, attenuation of low frequency components by using filtering processing and the criteria for abnormal SA-ECG. Subjects were 23 patients with Duchenne's muscular dystrophy (DMD) and were divided into two groups by the presence of ventricular tachycardia (VT). Age-matched healthy volunteers were obtained as controls. Abnormal SA-ECG was identified from the data in the controls as over 97 percentile of H/L ratio. Frequency domain analysis from last 40 ms of QRS wave to 80 ms of ST segment was most capable to distinguish the DMD patients with VT from the patients without VT, compared to analysis from last 20 ms. Whereas, analysis from QRS onset failed to detect VT patients. Although filter processing reduce the power of low frequency and increase the H/L ratio, sensitivity for predicting VT was not enhanced significantly. In conclusion, the frequency-domain analysis during the terminal 40 ms of the QRS complex and 80 ms of ST segment was most optimal condition to distinguish the DMD patients with VT. PMID:8256047

Kubo, M; Matsuoka, S; Ushiroguchi, Y; Tatara, K; Matsuka, Y; Kuroda, Y

1993-11-01

51

Chromosome passenger complexes control anaphase duration and spindle elongation via a kinesin-5 brake  

PubMed Central

During mitosis, chromosome passenger complexes (CPCs) exhibit a well-conserved association with the anaphase spindle and have been implicated in spindle stability. However, their precise effect on the spindle is not clear. In this paper, we show, in budding yeast, that a CPC consisting of CBF3, Bir1, and Sli15, but not Ipl1, is required for normal spindle elongation. CPC mutants slow spindle elongation through the action of the bipolar kinesins Cin8 and Kip1. The same CPC mutants that slow spindle elongation also result in the enrichment of Cin8 and Kip1 at the spindle midzone. Together, these findings argue that CPCs function to organize the spindle midzone and potentially switch motors between force generators and molecular brakes. We also find that slowing spindle elongation delays the mitotic exit network (MEN)–dependent release of Cdc14, thus delaying spindle breakdown until a minimal spindle size is reached. We propose that these CPC- and MEN-dependent mechanisms are important for coordinating chromosome segregation with spindle breakdown and mitotic exit.

Rozelle, Daniel K.; Hansen, Scott D.

2011-01-01

52

QRS complex recovery during one year after acute myocardial infarction.  

PubMed

The recovery of the ECG signs of anterior myocardial infarction has been studied in 70 patients. A significant increase in R-wave amplitude and decrease in Q-wave amplitude on 24-lead precordial mapping was observed during one year after infarction. Patients with lower initial heart rate showed a greater recovery of R- and Q-wave amplitudes, as did patients with smaller infarcts, as assessed by peak heat-stable lactate dehydrogenase (LDH). PMID:3545575

Richter, A; Herlitz, J; Hjalmarson, A

1987-01-01

53

A real-time microprocessor QRS detector system with a 1-ms timing accuracy for the measurement of ambulatory HRV  

Microsoft Academic Search

The design, test methods, and results of an ambulatory QRS detector are presented. The device is intended for the accurate measurement of heart rate variability (HRV) and reliable QRS detection in both ambulatory and clinical use. The aim of the design work was to achieve high QRS detection performance in terms of timing accuracy and reliability, without compromising the size

Antti Ruha; Sami Sallinen; S. Nissila

1997-01-01

54

Limitations of a QRS scoring system to assess left ventricular function and prognosis at hospital discharge after myocardial infarction  

Microsoft Academic Search

The value of a QRS scoring system derived from 12 lead electrocardiograms to estimate left ventricular ejection fraction was assessed in a prospective study of 285 hospital survivors of myocardial infarction. In these patients both the QRS score and ejection fraction were measured by radionuclide ventriculography at discharge. The correlation between ejection fraction and QRS score was weak. In 22

P Fioretti; R W Brower; E Lazzeroni; M L Simoons; W Wijns; J H Reiber; R J Bos; P G Hugenholtz

1985-01-01

55

A fast and accurate FPGA based QRS detection system.  

PubMed

An accurate Field Programmable Gate Array (FPGA) based ECG Analysis system is described in this paper. The design, based on a popular software based QRS detection algorithm, calculates the threshold value for the next peak detection cycle, from the median of eight previously detected peaks. The hardware design has accuracy in excess of 96% in detecting the beats correctly when tested with a subset of five 30 minute data records obtained from the MIT-BIH Arrhythmia database. The design, implemented using a proprietary design tool (System Generator), is an extension of our previous work and uses 76% resources available in a small-sized FPGA device (Xilinx Spartan xc3s500), has a higher detection accuracy as compared to our previous design and takes almost half the analysis time in comparison to software based approach. PMID:19163797

Shukla, Ashish; Macchiarulo, Luca

2008-01-01

56

A real-time QRS detection method based on moving-averaging incorporating with wavelet denoising  

Microsoft Academic Search

In this paper, a simple moving average-based computing method for real-time QRS detection is proposed. In addition, for signal preprocessing our detection algorithm also incorporates a wavelet-based denoising procedure to effectively reduce the noise level for electrocardiogram (ECG) data. The overall computational structure of the proposed algorithm allows the QRS detection to be performed and implemented in real-time with high

Szi-wen Chen; Hsiao-chen Chen; Hsiao-lung Chan

2006-01-01

57

District of Columbia Going for the Gold Tiered Rate Reimbursement System. QRS Profile. The Child Care Quality Rating System (QRS) Assessment  

ERIC Educational Resources Information Center

|This paper presents a profile of District of Columbia's Going for the Gold Tiered Rate Reimbursement Systemp repared as part of the Child Care Quality Rating System (QRS) Assessment Study. The profile consists of several sections and their corresponding descriptions including: (1) Program Information; (2) Rating Details; (3) Quality Indicators…

Child Trends, 2010

2010-01-01

58

District of Columbia Going for the Gold Tiered Rate Reimbursement System. QRS Profile. The Child Care Quality Rating System (QRS) Assessment  

ERIC Educational Resources Information Center

This paper presents a profile of District of Columbia's Going for the Gold Tiered Rate Reimbursement Systemp repared as part of the Child Care Quality Rating System (QRS) Assessment Study. The profile consists of several sections and their corresponding descriptions including: (1) Program Information; (2) Rating Details; (3) Quality Indicators for…

Child Trends, 2010

2010-01-01

59

Value of the frontal planar QRS-T angle on cardiac dysfunction in patients with old myocardial infarction  

PubMed Central

Objectives: To explore a method of surface electrocardiogram for assessing cardiac dysfunction in patients with old myocardial infarction. Methods: 1000 patients with old myocardial infarction in Anzhen hospital were analyzed retrospectively. The planar QRS-T angle was calculated automatically according to QRS-wave and T-wave vectors by the electrocardiogram machine. Results: Among these 1000 patients, 822 (82.2%) were male and 178 (17.8%) were female, the mean age was 59.3±10.5 years (34~89 years). The average planar QRS-T angle was 88.5±50.6°. The planar QRS-T angle and LVEF was negative correlation (r=-0.406, p<0.01), the lower the LVEF, the better the relationship with planar QRS-T angle. QRS-T angle>90° had optimal sensitivity and specificity (76%, 74%) in diagnosis of cardiac dysfunction. Conclusion: The planar QRS-T angle and LVEF of patients with old myocardial infarction is negative correlation, the larger the planar QRS-T angle, the lower the LVEF. The planar QRS-T angle may be an easier and more feasible index for assessing cardiac dysfunction in patients with old myocardial infarction.

Li, Yan-Hong; Ren, Xue-Jun; Han, Zhi-Hong; Wang, Yun-Long; Wang, Ye; Zhang, Jin-Rong; Chen, Fang

2013-01-01

60

Information recall of younger and older skilled athletes: The role of display complexity, attentional resources and visual exposure duration  

Microsoft Academic Search

This study was concerned with the interactive role of experience of athletic skill with other relevant environmental variables (display complexity, attentional resources, exposure time of stimuli) on perception (recall) of structured handball game situations. Nineteen experienced (older) and 19 less experienced (younger) handball players were assigned randomly either to ball?bouncing (diverted attention) or to calm seated (focused attention) conditions. In

Gershon Tenenbaum; Robert Weinberg

1994-01-01

61

Usefulness of electrocardiographic frontal QRS-T angle to predict increased morbidity and mortality in patients with chronic heart failure.  

PubMed

The risk of death in heart failure (HF) is high. The electrocardiographic spatial QRS-T angle reflects changes in the direction of the repolarization sequence and predicts death in the general population. The frontal QRS-T angle is simple to measure but has not been evaluated in a large chronic HF cohort. We examined the significance of the frontal QRS-T angle in predicting the clinical outcome in a large cohort of patients with HF. The QRS-T angle was calculated from the frontal QRS and T axis of the baseline 12-lead surface electrocardiogram. The patients were followed for cardiac-related hospitalizations and death; 5,038 patients with HF were evaluated. The mean follow-up period was 576 days; 51% were men. Overall survival during the follow-up period was 83%. Cox regression analysis after adjustment for significant predictors, including age, gender, ischemic heart disease, hypertension, atrial fibrillation, body mass index, pulse, serum hemoglobin, sodium, estimated glomerular filtration rate, and urea levels, demonstrated that the QRS-T angle was an incremental predictor of increased mortality in both genders. For women, a QRS-T angle of ?60° had a hazard ratio of 1.35 (95% confidence interval 1.04 to 1.75; p <0.05) and a QRS-T angle of ?120° had a hazard ratio of 1.45 (95% confidence interval 1.10 to 1.92, p <0.01). For men, a QRS-T angle of ?130° had a hazard ratio of 1.53 (95% confidence interval 1.14 to 2.06, p <0.01). For the whole cohort, a QRS-T angle of ?125° gave a hazard ratio of 1.47 (95% confidence interval 1.20 to 1.80, p <0.0001). The QRS-T angle was also a predictor of increased cardiac-related hospitalizations. The QRS-T angle was a predictor in patients with reduced and preserved left ventricular function and in patients with a normal QRS interval. In conclusion, the QRS-T angle was a powerful predictor of outcome in patients with HF. We believe the QRS-T angle should be a part of the electrocardiographic evaluation of patients with HF. PMID:23453457

Gotsman, Israel; Keren, Andre; Hellman, Yaron; Banker, Jeffrey; Lotan, Chaim; Zwas, Donna R

2013-02-27

62

[ECG QRS signal detection and control system design of ventricular assist device].  

PubMed

In order to achieve auxiliary timing of ventricular assisting device to automatically track the ECG signals, we designed a set of ECG acquisition circuit in our study for the first time. Then we carried out ECG acquisition, smoothing filter and QRS detection on the LabVIEW. With the QRS signal as a benchmark, the control system immediately triggered ventricular assisting device to trigger the heart to contract for ejection for about 300 ms, and then to assist to make it relax. The practical effects of the experiment proved that ECG acquisition circuit had the feature of strong anti-interference, and control system had no false QRS detection and no false triggering of assist device. This achieves the auxiliary timing which could automatically track the ECG signal. PMID:23865330

Liao, Huogen; Yang, Ming; Zhuang, Xiaoqi; Huang, Huan

2013-06-01

63

Fast QRS Detection with an Optimized Knowledge-Based Method: Evaluation on 11 Standard ECG Databases.  

PubMed

The current state-of-the-art in automatic QRS detection methods show high robustness and almost negligible error rates. In return, the methods are usually based on machine-learning approaches that require sufficient computational resources. However, simple-fast methods can also achieve high detection rates. There is a need to develop numerically efficient algorithms to accommodate the new trend towards battery-driven ECG devices and to analyze long-term recorded signals in a time-efficient manner. A typical QRS detection method has been reduced to a basic approach consisting of two moving averages that are calibrated by a knowledge base using only two parameters. In contrast to high-accuracy methods, the proposed method can be easily implemented in a digital filter design. PMID:24066054

Elgendi, Mohamed

2013-09-16

64

Fast QRS Detection with an Optimized Knowledge-Based Method: Evaluation on 11 Standard ECG Databases  

PubMed Central

The current state-of-the-art in automatic QRS detection methods show high robustness and almost negligible error rates. In return, the methods are usually based on machine-learning approaches that require sufficient computational resources. However, simple-fast methods can also achieve high detection rates. There is a need to develop numerically efficient algorithms to accommodate the new trend towards battery-driven ECG devices and to analyze long-term recorded signals in a time-efficient manner. A typical QRS detection method has been reduced to a basic approach consisting of two moving averages that are calibrated by a knowledge base using only two parameters. In contrast to high-accuracy methods, the proposed method can be easily implemented in a digital filter design.

Elgendi, Mohamed

2013-01-01

65

Supraventricular tachycardias: proposal of a diagnostic algorithm for the narrow complex tachycardias.  

PubMed

The narrow complex tachycardias (NCTs) are defined by the presence in a 12-lead electrocardiogram (ECG) of a QRS complex duration less than 120ms and a heart rate greater than 100 beats per minute; those are typically of supraventricular origin, although rarely narrow complex ventricular tachycardias have been reported in the literature. As some studies document, to diagnose correctly the NCTs is an arduous exercise because sometimes those have similar presentation on the ECG. In this paper, we have reviewed the physiopathological, clinical, and ECG findings of all known supraventricular tachycardias and, in order to reduce the possible diagnostic errors on the ECG, we have proposed a quick and accurate diagnostic algorithm for the differential diagnosis of NCTs. PMID:23473762

Buttà, Carmelo; Tuttolomondo, Antonino; Di Raimondo, Domenico; Milio, Glauco; Miceli, Salvatore; Attanzio, Maria Tereza; Giarrusso, Lucia; Licata, Giuseppe; Pinto, Antonio

2013-03-06

66

The QRS phasic characteristics of right ventricular hypertrophy in precordial leads.  

PubMed

The QRS apparent phase in some electrocardiograms (ECGs) progresses in opposite directions in the two halves of the precordial leads. The genesis of the waveforms leading to such bidirectional phase properties may be given in terms of the particular shapes of the horizontal vector loops. Such phasic properties associate themselves with right ventricular hypertrophy (RVH) of type A and type C although the reverse is not necessarily true. Schematic diagrams are generally used in this article for clarity in illustration, but the method has been tried on some well-documented cases of RVH, reported by Chou and Helm, 3 with promising results. PMID:1151193

Lee, T Y

1975-01-01

67

Factors of importance for QRS complex recovery after acute myocardial infarction.  

PubMed

The regression of the ECG signs of myocardial infarction has been studied in 101 patients. A significant increase in R wave amplitude and decrease in Q wave depth on the standard ECG was observed over three months. In 21% of the patients, Q waves disappeared completely. In inferior infarction, these changes were more apparent in the lateral V leads than in the inferior limb leads. Patients with intraventricular conduction defects were excluded. Two factors associated with the Q and R wave changes have been identified. Lower heart rates appeared to facilitate the recovery of R waves, and smaller infarcts, as assessed by peak LDH, showed greater ECG recovery. This study raises the interesting possibility that modification of the heart rate may affect favourably the healing process after an acute myocardial infarction. PMID:7044048

Yusuf, S; Estrada-Yamamoto, E; Reyes, C P; Herlitz, J; Hjalmarson, A

1982-05-01

68

Analysis of the QRS complex for apnea-bradycardia characterization in preterm infants  

Microsoft Academic Search

This work presents an analysis of the information content of new features derived from the electrocardiogram (ECG) for the characterization of apnea-bradycardia events in preterm infants. Automatic beat detection and segmentation methods have been adapted to the ECG signals from preterm infants, through the application of two evolutionary algorithms. ECG data acquired from 32 preterm infants with persistent apnea-bradycardia have

M. Altuve; G. Carrault; J. Cruz; A. Beuchee; P. Pladys; A. Hernandez

2009-01-01

69

Use of the Questionnaire on Resources and Stress (QRS-F) with parents of young children with autism  

Microsoft Academic Search

The Questionnaire on Resources and Stress (Friedrich, short form: QRS-F) has been used widely with parents of children with disabilities. However, its psychometric properties in parents of young children with autism have not been established. Here, 174 mothers and 43 fathers of children under 6 years with autism spectrum disorder were studied by two independent research teams. Each parent completed

Emma Honey; Richard P. Hastings; Helen Mcconachie

2005-01-01

70

Long-term effectiveness of cardiac resynchronization therapy in patients with refractory heart failure and “narrow” QRS  

Microsoft Academic Search

ObjectivesThe aim of the study was to evaluate the effectiveness of cardiac resynchronization therapy (CRT) in patients with refractory heart failure (HF) and incomplete left bundle branch block (“narrow” QRS), together with echocardiographic evidence of interventricular and intraventricular asynchrony.

Augusto Achilli; Massimo Sassara; Sabina Ficili; Daniele Pontillo; Paola Achilli; Claudio Alessi; Stefano De Spirito; Roberto Guerra; Nicolino Patruno; Francesco Serra

2003-01-01

71

Duration tuning across vertebrates.  

PubMed

Signal duration is important for identifying sound sources and determining signal meaning. Duration-tuned neurons (DTNs) respond preferentially to a range of stimulus durations and maximally to a best duration (BD). Duration-tuned neurons are found in the auditory midbrain of many vertebrates, although studied most extensively in bats. Studies of DTNs across vertebrates have identified cells with BDs and temporal response bandwidths that mirror the range of species-specific vocalizations. Neural tuning to stimulus duration appears to be universal among hearing vertebrates. Herein, we test the hypothesis that neural mechanisms underlying duration selectivity may be similar across vertebrates. We instantiated theoretical mechanisms of duration tuning in computational models to systematically explore the roles of excitatory and inhibitory receptor strengths, input latencies, and membrane time constant on duration tuning response profiles. We demonstrate that models of duration tuning with similar neural circuitry can be tuned with species-specific parameters to reproduce the responses of in vivo DTNs from the auditory midbrain. To relate and validate model output to in vivo responses, we collected electrophysiological data from the inferior colliculus of the awake big brown bat, Eptesicus fuscus, and present similar in vivo data from the published literature on DTNs in rats, mice, and frogs. Our results support the hypothesis that neural mechanisms of duration tuning may be shared across vertebrates despite species-specific differences in duration selectivity. Finally, we discuss how the underlying mechanisms of duration selectivity relate to other auditory feature detectors arising from the interaction of neural excitation and inhibition. PMID:22553042

Aubie, Brandon; Sayegh, Riziq; Faure, Paul A

2012-05-01

72

Icon Duration and Development.  

ERIC Educational Resources Information Center

|In this study, developmental changes in duration of the icon (visual sensory store) were investigated with three converging tachistoscopic tasks. (1) Stimulus interuption detection (SID), a variation of the two-flash threshold method, was performed by 29 first- and 32 fifth-graders, and 32 undergraduates. Icon duration was estimated by stimulus…

Gummerman, Kent; And Others

73

The natural history of right bundle branch block and frontal plane QRS axis in apparently healthy men.  

PubMed

We examined the characteristics, long-term follow-up, and prognosis of right bundle branch block (RBBB) detected on a routine ECG in men with no apparent heart disease. During the 29-year period, 59 cases of RBBB were observed in men with a mean age of 44.4 +/- 1.9 years. Because marked right or left axis deviation may identify cases with concomitant involvement of the left bundle branch system, subsets of frontal plane QRS (A QRS) were examined. Comparisons were made with groups of similar ages who were free of RBBB. Cases with RBBB were observed for 936 person-years (mean 15.9 +/- 1.6 years per case), showing no excess ischemic heart disease incidence, no cases of progression to advanced AV block (second- or third-degree), or sudden death. Right bundle branch block was associated with a greater proportion of both right axis (greater than or equal to +90 degrees) and marked left axis (-45 degrees to -90 degrees) deviation compared with those of the same age without this conduction disturbance. In apparently healthy men, RBBB had no adverse long-term prognosis regardless of frontal plane QRS axis. PMID:7249765

Rabkin, S W; Mathewson, F A; Tate, R B

1981-08-01

74

Dietary fat and sleep duration in Chinese men and women  

Microsoft Academic Search

Background:Many recent studies have highlighted the complex interaction between sleep duration, food intake and metabolic balance. Although a causal link is yet to be established, emerging evidence suggests that short sleep duration may alter the balance between energy intake and energy expenditure. Thus far, most research has focussed on the link between sleep duration and carbohydrate metabolism. The role of

Z Shi; M McEvoy; J Luu; J Attia

2008-01-01

75

Electrocardiographic spatial QRS-T angle and incident cardiovascular disease in HIV-infected patients (from the Strategies for the Management of Antiretroviral Therapy [SMART] study).  

PubMed

Widening of the electrocardiographic (ECG) spatial QRS-T angle has been predictive of cardiovascular disease (CVD) events in the general population. However, its prognostic significance in human immunodeficiency virus (HIV)-infected patients remains unknown. The spatial QRS-T angle was derived from the baseline resting 12-lead electrocardiogram of 4,453 HIV-infected patients aged 43.5 ± 9.3 years from the Strategies for Management of Antiretroviral Therapy (SMART) trial. CVD events were identified during a median follow-up of 28.7 months. Quartiles of the spatial QRS-T angle was calculated for men and women separately, and values in the upper quartile were considered as a widened angle (values >74° for women and >93° for men). A multivariate Cox proportional hazards analysis was used to examine the association between a widened baseline spatial QRS-T angle and incident CVD events. During 11,965 person-years of follow-up, 152 CVD events occurred at a rate of 1.27 events/100 person-years. The rate of CVD events in those with a widened spatial QRS-T angle was almost double the rate in those with a normal spatial QRS-T angle (rate ratio 1.94, 95% confidence interval 1.40 to 2.69; p <0.001). In a model adjusted for study treatment arm, demographics, CVD risk factors, HIV characteristics, inflammatory markers, and other ECG abnormalities, a widened spatial QRS-T angle was associated with a >50% increased risk of CVD events compared to a normal spatial QRS-T angle (hazard ratio 1.53, 95% confidence interval 1.07 to 2.17; p = 0.02). No interaction was seen by SMART trial arm (p value for interaction = 0.37) or gender (p value for interaction = 0.84). In conclusion, a widened spatial QRS-T angle was independently predictive of CVD events in HIV-infected patients receiving antiretroviral therapy. This highlights the potential role of routine electrocardiography as a simple noninvasive CVD risk-screening tool in HIV-infected patients. PMID:23062314

Dawood, Farah Z; Khan, Faraaz; Roediger, Mollie P; Zhang, Zhu-Ming; Swaminathan, Shobha; Klinker, Hartwig; Hoy, Jennifer; Lundgren, Jens D; Neaton, James D; Soliman, Elsayed Z

2012-10-09

76

Impact of response duration on multisensory integration  

PubMed Central

Multisensory neurons in the superior colliculus (SC) have been shown to have large receptive fields that are heterogeneous in nature. These neurons have the capacity to integrate their different sensory inputs, a process that has been shown to depend on the physical characteristics of the stimuli that are combined (i.e., spatial and temporal relationship and relative effectiveness). Recent work has highlighted the interdependence of these factors in driving multisensory integration, adding a layer of complexity to our understanding of multisensory processes. In the present study our goal was to add to this understanding by characterizing how stimulus location impacts the temporal dynamics of multisensory responses in cat SC neurons. The results illustrate that locations within the spatial receptive fields (SRFs) of these neurons can be divided into those showing short-duration responses and long-duration response profiles. Most importantly, discharge duration appears to be a good determinant of multisensory integration, such that short-duration responses are typically associated with a high magnitude of multisensory integration (i.e., superadditive responses) while long-duration responses are typically associated with low integrative capacity. These results further reinforce the complexity of the integrative features of SC neurons and show that the large SRFs of these neurons are characterized by vastly differing temporal dynamics, dynamics that strongly shape the integrative capacity of these neurons.

Barnett, Zachary P.; Wallace, Mark T.

2012-01-01

77

Effects of resting ischemia assessed by thallium scintigraphy on QRS scoring system for estimating left ventricular function quantified by radionuclide angiography in acute myocardial infarction patients  

SciTech Connect

The purpose of this study was to determine whether resting ischemia limits the usefulness of the QRS scoring system in predicting left ventricular (LV) ejection fraction (EF) in patients with acute infarction. We studied 48 patients after acute infarction by means of 12-lead ECG, thallium-201 scintigraphy, and radionuclide angiography. The thallium-201 scintigrams showed fixed defects in 25 patients, perfusion defects with partial or complete redistribution in the delayed images in 19 patients, and normal images in the remaining four patients. In the 48 patients there was a significant correlation between the QRS score and LVEF (r . -0.67; p less than 0.001). Patients with fixed defects showed a better correlation than patients with resting ischemia (r . -0.77 vs r . -0.60). A QRS score of 3 or less was used to separate patients with LVEF of 40% or greater from those with lower LVEF in patients with fixed defects (p . 0.0005), but this cutoff did not categorize patients with resting ischemia as to LVEF. Thus the presence of rest ischemia in patients with acute infarction may affect the correlation between QRS score and LVEF.

DePace, N.L.; Hakki, A.H.; Iskandrian, A.S.

1984-06-01

78

Transitory or permanent regular wide QRS complex tachycardia induced by atrial stimulation in patients without apparent heart disease. Significance  

Microsoft Academic Search

Objectives. – The purpose of the study was to evaluate the frequency of transitory or permanent bundle branch block (BBB) associated with a paroxysmal tachycardia induced by atrial stimulation in patients without heart disease and its significance.Methods. – Esophageal atrial stimulation was performed in 447 patients suspected to have supraventricular tachycardias (SVT). Sustained regular tachycardia was induced in all of them

B Brembilla-Perrot; D Beurrier; P Houriez; O Claudon; J Rizk; C Lemoine; P Gregoire; M Nippert

2003-01-01

79

Duration Judgments Over Multiple Elements  

PubMed Central

We investigated the limits of the number of events observers can simultaneously time. For single targets occurring in one of eight positions sensitivity to duration was improved for spatially pre-cued items as compared to post-cued items indicating that exogenous driven attention can improve duration discrimination. Sensitivity to duration for pre-cued items was also marginally better for single items as compared to eight items indicating that even after the allocation of focal attention, distractor items can interfere with the encoding of duration. For an eight item array discrimination was worse for post-cued locations as compared to pre-cued locations indicating both that attention can improve duration discrimination performance and that it was not possible to access a perfect memory trace of the duration of eight elements. The interference from the distractors in the pre-cued eight item array may reflect some mandatory averaging of target and distractor events. To further explore duration averaging we asked subjects to explicitly compare average durations of multiple item arrays against a single item standard duration. Duration discrimination thresholds were significantly lower for single elements as compared to multiple elements, showing that averaging, either automatically or intentionally, impairs duration discrimination. There was no set size effect. Performance was the same for averages of two and eight items, but performance with even an average of two items was worse than for one item. This was also true for sequential presentation indicating poor performance was not due to limits on the division of attention across items. Rather performance appears to be limited by an inability to remember or aggregate duration information from two or more items. Although it is possible to manipulate perceived duration locally, there appears to be no perceptual mechanisms for aggregating local durations across space.

Ayhan, Inci; Revina, Yulia; Bruno, Aurelio; Johnston, Alan

2012-01-01

80

Task switching and subjective duration  

Microsoft Academic Search

Three experiments investigated the effects of switching from a nontiming task (addition of rapidly presented digits) to estimation of the duration of short tones or visual stimuli (Experiments 1 and 2), or the production of time intervals (Experiment 3). In general, compared with trials without a task-switch, trials involving a switch resulted in shorter duration estimates, but longer productions. The

J. H. Wearden; Susan C. ORourke; Claire Matchwick; Zhang Min; Sharon Maeers

2010-01-01

81

Infant Ventricular Fibrillation After ST-Segment Changes and QRS Widening: A New Cause of Sudden Infant Death?  

PubMed

Background- Ventricular arrhythmia-related sudden cardiac arrest in infants with structurally normal hearts is rare. There have been no previously published reports of infants <3 months of age with ventricular fibrillation in which a primary diagnosis could not be defined. Methods and Results- Retrospective chart review of 3 unrelated infants <2 months of age from 3 different tertiary care centers within the United States and Australia was conducted. All 3 infants survived sudden cardiac arrest secondary to multiple episodes of polymorphic ventricular tachycardia and ventricular fibrillation. Each infant demonstrated unique and transient ECG findings consisting of ST changes and QRS widening before arrhythmia onset, which have not been previously reported. Amiodarone, sedation, sodium channel-blocking agents, and ventricular pacing were effective in suppressing acute events. Despite thorough investigation, including genetic testing, the cause of ventricular arrhythmias in each of these infants remains unclear. Conclusions- This is the first report of idiopathic ventricular fibrillation in young infants preceded by stereotypical transient ECG changes. These findings may represent a new, potentially treatable cause of sudden infant death. Recognition of these prodromal changes may be important in future management and survival of these infants. PMID:23748209

Miyake, Christina Y; Davis, Andrew M; Motonaga, Kara S; Dubin, Anne M; Berul, Charles I; Cecchin, Frank

2013-06-07

82

Intra-QRS high-frequency ECG changes with ischemia. Is it possible to evaluate these changes using the signal-averaged Holter ECG in dogs?  

PubMed

The purpose of this experiment is to study the possibility of intra-QRS high-frequency electrocardiographic (HFECG) changes for the evaluation of and recovery from myocardial ischemia in both the time-domain and spectral-turbulence analyses on the signal-averaged ECG using the Holter ECG monitoring (Holter SAECG) system. A balloon catheter was inserted into the left anterior descending coronary artery (LAD of 8 mongrel dogs and was maintained inflated for 2 hours to occlude the LAD and then was deflated to allow for reperfusion. The cardiac signal from the three orthogonal leads of the surface ECG (X, Y, and Z) was recorded and analyzed with a Del Mar Avionics (model 459, Irvine, CA) recorder and analyzer (model 563). The Holter SAECG was assessed before the LAD occlusion phase (control), during the coronary occlusion phase (ischemia), after the reperfusion phase (recovery). To evaluate intra-QRS ECG changes in the time-domain analysis, root-mean-square (RMS) voltage of the entire QRS in 40-250 HZ (40 RMS), 100-250 Hz (100 RMS), and 150-250 Hz (150 RMS) were studied and the vector magnitude of the QRS was depicted. In the spectral-turbulence analysis and spectrocardiogram to study the discordance of the ECG wave front velocity by fast Fourier transformation analysis, the interslice correlation mean (IC mean) and interslice correlation standard deviation (IC SD), which were calculated as the mean and standard deviation of the Pearson correlation coefficient of each time slice with its neighbor, were investigated. In the time-domain analysis, the LAD occlusion by balloon catheter at ischemia produced a reduction in 40 RMS, 100 RMS, and 150 RMS, while a restoration was seen at recovery in 40 RMS and 100 RMS. In the spectral-turbulence analysis, LAD occlusion at ischemia caused a decrease in IC mean and an increase in IC SD. The waveform of the vector magnitude and the spectrocardiogram seen at control showed changes with ischemia and was restored at recovery with the coronary reperfusion. It was thought possible to capture the intra-QRS HFECG changes that occur during myocardial ischemia and recovery from it in the time-domain analysis and spectral-turbulence analysis on the Holter SAECG system in spite of the limitation of this methodology. To evaluate myocardial ischemia and recovery, this method should be useful clinically. PMID:8656120

Yakubo, S; Ozawa, Y; Komaki, K

1995-01-01

83

Clustering ECG complexes using Hermite functions and self-organizing maps  

Microsoft Academic Search

:An integrated method for identifying and classifying ECG complexes in the MIT-BIH ArrhythmiaDatabase is presented. The QRS complexes are extracted and the RR intervals are calculatedin an autonomous way. Each complex is subsequently decomposed into Hermite basis functions,from which the resulting coefficients and widths are used to represent the beats. By means ofthis representation, unsupervised self-organizing neural networks are employed

M. Lagerholm; C. Peterson; G. Braccini; L. Edenbrandt; L. Sornmo

2000-01-01

84

Clinical correlates and heritability of QT interval duration in African Americans: the Jackson Heart Study  

PubMed Central

Background Electrocardiographic QT interval prolongation is a risk factor for sudden cardiac death (SCD) and drug-induced arrhythmia. The clinical correlates and heritability of QT interval duration in African Americans have not been well studied despite their higher risk for SCD compared to non-Hispanic whites. We sought to investigate potential correlates of the QT interval and estimate its heritability in the Jackson Heart Study (JHS). Methods and Results The JHS comprises a sample of African Americans residing in Jackson, Mississippi, of whom 5302 individuals with data at the baseline examination were available for study. JHS participants on QT-altering medications, with bundle branch block, paced rhythm, atrial fibrillation/flutter or other arrhythmias were excluded resulting in a sample of 4660 individuals eligible for analyses. The relation between QT and potential covariates was tested using multivariable stepwise linear regression. Heritability was estimated using SOLAR in a subset of 1297 JHS participants in 292 families; the remaining sample included unrelated individuals. In stepwise multivariable linear regression analysis, covariates significantly associated with QT interval duration included RR interval, female sex, QRS duration, age, lower potassium, hypertension, body mass index, coronary heart disease, diuretic use, and Sokolow-Lyon voltage (p ? 0.01 for all). The heritability of QT interval duration in age-, sex- and RR-interval-adjusted and fully-adjusted models was 0.41 (SE 0.07) and 0.40 (SE 0.07, p<10?11 for both), respectively. Conclusions There is substantial heritability of adjusted QT interval in African Americans supporting the need for further investigation to identify its genetic determinants.

Akylbekova, Ermeg L.; Crow, Richard S.; Johnson, William D.; Buxbaum, Sarah G.; Njemanze, Stephanie; Fox, Ervin; Sarpong, Daniel F.; Taylor, Herman A.; Newton-Cheh, Christopher

2009-01-01

85

On Minimum Duration Project Schedule  

Microsoft Academic Search

In order to facilitate building decision support system relative to project crashing, Minimum Duration Project Schedule Problem (MDPSP) is worthy of further research as a case of project crashing. In this paper, MDPSP is formulated using a bi-level programming model, and an algorithm named mfmc-A is presented to find maximum flow & minimum cut set in network with lower &

Fanrong Xie; Renan Jia; Guangxing Zeng

2010-01-01

86

JACEE long duration balloon flights  

NASA Astrophysics Data System (ADS)

JACEE balloon-borne emulsion chamber detectors are used to observe the spectra and interactions of cosmic ray protons and nuclei in the energy range 1 to 100A TeV. Experiments with long duration mid-latitude balloon flights and characteristics of the detector system that make it ideal for planned Antarctic balloon flights are discussed.

Burnett, T.; Iwai, J.; Dake, S.; Derrickson, J.; Fountain, W.; Fuki, M.; Gregory, J.; Hayashi, T.; Holynski, R.; Jones, W. V.

1990-01-01

87

Statistical Considerations in Duration of Load Research.  

National Technical Information Service (NTIS)

Duration of load factors is the most significant factor that reduces allowable design stresses for lumber. The paper discusses statistical considerations for the design of duration of load tests and for analysis of the resulting data. Duration of load fac...

C. L. Link

1988-01-01

88

Duration in the Digital Economy  

Microsoft Academic Search

We examine the drivers of Internet firm survival using a multi-method survival analysis. Based on previous literature on business failure and recent IS research on e-commerce business models, we test the impact of sector-, firm- and e-commerce-specific factors on an Internet firm's duration after its IPO. We first provide a descriptive analysis of Internet firm survival using non-parametric survival analysis,

Robert J. Kauffman; Bin Wang

2003-01-01

89

Sleep duration, asthma and obesity.  

PubMed

Abstract Background: Obesity is more prevalent in asthmatics. Sleep duration is a novel risk factor for obesity in general populations. Objective: We tested the association of sleep duration and asthma characteristics with obesity. Methods: Adults at tertiary clinics were surveyed on asthma symptoms and habitual sleep duration. Medical records were used to assess asthma severity step (1-4), extract height and weight, current medications and diagnosed comorbid conditions. BMI ?30?kg/m(2) defined obesity. Habitual sleep was categorized as <6 (very short), 6 to <7?h (short), 7-8?h (normal), >8 to ?9?h (long) and >9?h (very long). Inhaled corticosteroid doses were categorized as low, moderate and high. Results: Among 611 participants (mean BMI 30?±?8), 249 (41%) were obese. After adjustment for covariates, obesity was associated with short and very long sleep: as compared to normal sleepers, the odds of being obese were on an average 66% higher ([95% CI: 1.07-2.57], p?=?0.02) among short and 124% higher ([1.08-1.65], p?=?0.03) among very long sleepers, and the association with very short sleep approached significance (1.74 [0.96-3.14], p?=?0.06). Obesity was also significantly related to highest asthma step (1.87 [1.09-3.21], p?=?0.02) and psychopathology (1.64 [1.08-2.48], p?=?0.02), and a trend was seen with high-dose inhaled corticosteroids (1.82 [0.93-3.56], p?=?0.08). Conclusions: Obesity in asthmatics is associated with shorter and very long sleep duration, worse asthma severity, psychopathology and high-dose inhaled corticosteroids. Although this cross-sectional study cannot prove causality, we speculate that further investigation of sleep may provide new opportunities to reduce the rising prevalence of obesity among asthmatics. PMID:23923994

Teodorescu, Mihaela; Polomis, David A; Gangnon, Ronald E; Consens, Flavia B; Chervin, Ronald D; Teodorescu, Mihai C

2013-09-20

90

A Hybrid Framework for ECG Interpretation by Computer and its Evaluation Platform  

Microsoft Academic Search

In this article, firstly we present a new approach for detecting QRS complex which integrates the multi- scale idea of watershed into differentiation and template matching technologies. In order to make this algorithm accurate and robust, simultaneous multichannel detection and fusion techniques are also adopted. Then, several features such as RR intervals and QRS durations of a certain ECG segment

Jianwei Dong; Shi Zhang; Yapeng Wan

2008-01-01

91

Distortion of the Terminal Portion of the QRS on the Admission Electrocardiogram in Acute Myocardial Infarction and Correlation With Infarct Size and Long-Term Prognosis (Thrombolysis In Myocardial Infarction 4 Trial) * * This study was supported in part by a grant from SmithKline Beecham, Philadelphia, Pennsylvania  

Microsoft Academic Search

Previous studies have shown an association between distortion of the terminal portion of the QRS (QRS[+] pattern: emergence of the J point ?50% of the R wave in leads with qR configuration, or disappearance of the S wave in leads with an Rs configuration) on admission and in-hospital mortality in acute myocardial infarction (AMI). However, the mechanism for this association

Yochai Birnbaum; Robert A. Kloner; Samuel Sclarovsky; Christopher P. Cannon; Carolyn H. McCabe; Vicki G. Davis; Barry L. Zaret; Frans J. Th. Wackers; Eugene Braunwald

1996-01-01

92

The Duration of Patent Examination at the European Patent Office  

Microsoft Academic Search

We analyze the duration and outcomes of patent examination at the European Patent Office utilizing an unusually rich data set covering a random sample of 215,265 applications filed between 1982 and 1998. In our empirical analysis, we distinguish between three groups of determinants: applicant characteristics, indicators of patent quality and value, and determinants that affect the complexity of the examination

Dietmar Harhoff; Stefan Wagner

2009-01-01

93

Significance of QRS morphology in determining the prevalence of mechanical dyssynchrony in heart failure patients eligible for cardiac resynchronization: particular focus on patients with right bundle branch block with and without coexistent left-sided conduction defects  

Microsoft Academic Search

Aims The aim of this study was to assess the significance of QRS morphology in determining the preva- lence of mechanical dyssynchrony in heart failure (HF) patients considered eligible for cardiac resyn- chronization. Methods and results A total of 200 consecutive HF patients (158 males, mean age 56 + 13.5 years) with standard indications for cardiac resynchronization therapy (CRT) were

Majid Haghjoo; Ataallah Bagherzadeh; Maryam Moshkani Farahani; Zahra Ojaghi Haghighi; Mohammad Ali Sadr-Ameli

94

Business Cycle Duration Dependence: A Parametric Approach  

Microsoft Academic Search

This paper reexamines duration dependence in U.S. business cycles using parametric hazard models. Positive duration dependence would indicate that expansions or contractions are more likely to end as they become \\

Daniel E Sichel

1991-01-01

95

Duration Sensitivity Depends on Stimulus Familiarity  

Microsoft Academic Search

When people are asked to assess or compare the value of experienced or hypothetical events, one of the most intriguing observations is their apparent insensitivity to event duration. The authors propose that duration insensitivity occurs when stimuli are evaluated in isolation because they typically lack comparison information. People should be able to evaluate the duration of stimuli in isolation, however,

Carey K. Morewedge; Karim S. Kassam; Christopher K. Hsee; Eugene M. Caruso

2009-01-01

96

Probabilistic Temporal Planning with Uncertain Durations  

Microsoft Academic Search

Few temporal planners handle both concurrency and uncer- tain durations, but these features commonly co-occur in real- world domains. In this paper, we discuss the challenges caused by concurrent, durative actions whose durations are uncertain. We present five implemented algorithms, includ- ing DURprun, a planner guaranteed to find the optimal pol- icy. An empirical comparison reveals that DURexp, our fastest

Mausam; Daniel S. Weld

2006-01-01

97

Mortality and Duration of Hemodialysis Treatment  

Microsoft Academic Search

Decrease in the average duration of hemodialysis treatment time is a continuing phenomenon. We investigated the relationship of 3-year mortality to duration of dialysis in a 1984-1985 national random sample of 600 hemodialysis patients from 36 dialysis units. Mortality was negatively associated with duration of dialysis treatments, as shown by the Cox model, adjusted for other patient and dialysis unit

Philip J. Held; Nathan W. Levin; Randall R. Bovbjerg; Mark V. Pauly; Louis H. Diamond

2010-01-01

98

Prevalence and inter-relationship of different Doppler measures of dyssynchrony in patients with heart failure and prolonged QRS: a report from CARE-HF  

PubMed Central

Background Cardiac resynchronisation therapy (CRT) improves mortality and morbidity in heart failure patients with wide QRS. Observational studies suggest that patients having more left ventricular dyssynchrony pre-implantation obtain greater benefit on ventricular function and symptoms with CRT. Aim To provide an analysis of the prevalence and type of dyssynchrony in patients included in the CARE-HF trial. Methods 100 patients 67 (58 to 71) years were examined with echocardiography including tissue doppler imaging before receiving a CRT-pacemaker. Atrio-ventricular dyssynchrony (LVFT/RR) was defined as left ventricular filling time <40% of the RR-interval. Inter-ventricular mechanical delay (IVMD) was measured as the difference in onset of Doppler-flow in the pulmonary and aortic outflow tracts >40 ms. Intra-ventricular (regional) dyssynchrony in a 16-segment model was expressed either as a delayed longitudinal contraction (DLC) during the postsystolic phase or by tissue synchronisation imaging (TSI) with a predefined time-difference in systolic maximal velocities >85 ms. Results LVFT/RR was present in 34% and IVMD in 60% of patients while intra-ventricular dyssynchrony was present in 85% (DLC) and 86% (TSI) with a high agreement between the measures (Kappascore 0.86–1.00), indicating the methods being interchangeable. Patients with cardiomyopathy (53%) were more likely to have LVFT/RR <40% (45% vs. 21% (p= 0.02)) and more segments affected by intra-ventricular dyssynchrony 4(3, 5) vs. 3(1, 4), p = 0.002, compared to patients with ischemic heart disease. Conclusion The prevalence of intra-ventricular dyssynchrony is high in patients with heart failure, wide QRS and depressed systolic function. Most important, TSI appears to be a fast and reliable method to identify patients with intra-ventricular dyssynchrony likely to benefit from CRT.

Edner, Magnus; Kim, Yong; Hansen, Knud Norregaard; Nissen, Henrik; Espersen, Geert; La Rosee, Karl; Maru, Fikru; Freemantle, Nick; Cleland, John; Sogaard, Peter

2009-01-01

99

Tilt changes of short duration  

USGS Publications Warehouse

Section I of this report contains a classification scheme for short period tilt data. For convenience, all fluctuations in the local tilt field of less than 24 hours duration will be designated SP (i.e., short period) tilt events. Three basic categories of waveshape appearance are defined, and the rules for naming the waveforms are outlined. Examples from tilt observations at four central California sites are provided. Section II contains some coseismic tilt data. Fourteen earthquakes in central California, ranging in magnitude from 2.9 to 5.2, were chosen for study on four tiltmeters within 10 source dimensions of the epicenters. The raw records from each of the four tiltmeters at the times of the earthquakes were photographed and are presented in this section. Section III contains documentation of computer programs used in the analysis of the short period tilt data. Program VECTOR computes the difference vector of a tilt event and displays the sequence of events as a head-to-tail vector plot. Program ONSTSP 1) requires two component digitized tilt data as input, 2) scales and plots the data, and 3) computes and displays the amplitude, azimuth, and normalized derivative of the tilt amplitude. Program SHARPS computes the onset sharpness, (i.e., the normalized derivative of the tilt amplitude at the onset of the tilt event) as a function of source-station distance from a model of creep-related tilt changes. Program DSPLAY plots the digitized data.

McHugh, Stuart

1976-01-01

100

Sentence durations and accentedness judgments  

NASA Astrophysics Data System (ADS)

Talkers in a second language can frequently be identified as speaking with a foreign accent. It is not clear to what degree a foreign accent represents specific deviations from a target language versus more general characteristics. We examined the identifications of native and non-native talkers by listeners with various amount of knowledge of the target language. Native and non-native speakers of Latvian provided materials. All the non-native talkers spoke Russian as their first language and were long-term residents of Latvia. A listening test, containing sentences excerpted from a short recorded passage, was presented to three groups of listeners: native speakers of Latvian, Russians for whom Latvian was a second language, and Americans with no knowledge of either of the two languages. The listeners were asked to judge whether each utterance was produced by a native or non-native talker. The Latvians identified the non-native talkers very accurately, 88%. The Russians were somewhat less accurate, 83%. The American listeners were least accurate, but still identified the non-native talkers at above chance levels, 62%. Sentence durations correlated with the judgments provided by the American listeners but not with the judgments provided by native or L2 listeners.

Bond, Z. S.; Stockmal, Verna; Markus, Dace

2003-04-01

101

Control of responding by stimulus duration1  

PubMed Central

Pigeons were trained on a procedure in which the key was white for 30 sec, alternating with periods of darkness, or timeout. In a nondifferential training procedure, timeout duration was held constant at either 9 or 21 sec for different animals, and pecks on the white key were reinforced on a variable-interval 36-sec schedule. After 30 sessions an extinction generalization test was conducted where the duration of the timeout was varied from 3 to 27 sec. This test showed no differences in responding following timeouts of different durations. In a differential training procedure, timeout durations of either 9 or 21 sec were randomly scheduled for each animal. The variable-internal schedule was in effect following the same timeout duration as in the prior nondifferential procedure. No pecks were reinforced after the other timeout duration. In 40 sessions, differences in response rates following the two durations gradually developed. A maintained generalization procedure was then imposed in which timeout durations were varied from 3 to 27 sec, with the variable-interval schedule in effect following only the same duration as in the previous procedures. The first maintained generalization session showed that the prior differential training had established control of the animals' behavior by the timeout duration. In continued training on the maintained generalization procedure, control by the timeout duration decreased.

Elsmore, Timothy F.

1971-01-01

102

Control of responding by stimulus duration.  

PubMed

Pigeons were trained on a procedure in which the key was white for 30 sec, alternating with periods of darkness, or timeout. In a nondifferential training procedure, timeout duration was held constant at either 9 or 21 sec for different animals, and pecks on the white key were reinforced on a variable-interval 36-sec schedule. After 30 sessions an extinction generalization test was conducted where the duration of the timeout was varied from 3 to 27 sec. This test showed no differences in responding following timeouts of different durations. In a differential training procedure, timeout durations of either 9 or 21 sec were randomly scheduled for each animal. The variable-internal schedule was in effect following the same timeout duration as in the prior nondifferential procedure. No pecks were reinforced after the other timeout duration. In 40 sessions, differences in response rates following the two durations gradually developed. A maintained generalization procedure was then imposed in which timeout durations were varied from 3 to 27 sec, with the variable-interval schedule in effect following only the same duration as in the previous procedures. The first maintained generalization session showed that the prior differential training had established control of the animals' behavior by the timeout duration. In continued training on the maintained generalization procedure, control by the timeout duration decreased. PMID:16811537

Elsmore, T F

1971-07-01

103

The Effect of Predictability on Subjective Duration  

PubMed Central

Events can sometimes appear longer or shorter in duration than other events of equal length. For example, in a repeated presentation of auditory or visual stimuli, an unexpected object of equivalent duration appears to last longer. Illusions of duration distortion beg an important question of time representation: when durations dilate or contract, does time in general slow down or speed up during that moment? In other words, what entailments do duration distortions have with respect to other timing judgments? We here show that when a sound or visual flicker is presented in conjunction with an unexpected visual stimulus, neither the pitch of the sound nor the frequency of the flicker is affected by the apparent duration dilation. This demonstrates that subjective time in general is not slowed; instead, duration judgments can be manipulated with no concurrent impact on other temporal judgments. Like spatial vision, time perception appears to be underpinned by a collaboration of separate neural mechanisms that usually work in concert but are separable. We further show that the duration dilation of an unexpected stimulus is not enhanced by increasing its saliency, suggesting that the effect is more closely related to prediction violation than enhanced attention. Finally, duration distortions induced by violations of progressive number sequences implicate the involvement of high-level predictability, suggesting the involvement of areas higher than primary visual cortex. We suggest that duration distortions can be understood in terms of repetition suppression, in which neural responses to repeated stimuli are diminished.

Pariyadath, Vani; Eagleman, David

2007-01-01

104

Duration matters: Dissociating neural correlates of detection and evaluation of social gaze  

Microsoft Academic Search

The interpretation of interpersonal gaze behavior requires the use of complex cognitive processes and guides social interactions. Among a variety of different gaze characteristics, gaze direction and gaze duration modulate crucially the meaning of the “social gaze”. Nevertheless, prior neuroimaging studies disregarded the relevance of gaze duration by focusing on gaze direction only.The present functional magnetic resonance imaging (fMRI) study

Bojana Kuzmanovic; Alexandra L. Georgescu; Simon B. Eickhoff; Nadim J. Shah; Gary Bente; Gereon R. Fink; Kai Vogeley

2009-01-01

105

COMPLEX TRAUMA, COMPLEX REACTIONS: ASSESSMENT AND TREATMENT  

Microsoft Academic Search

Complex trauma occurs repeatedly and escalates over its duration. In families, it is exemplified by domestic violence and child abuse and in other situations by war, prisoner of war or refugee status, and human trafficking. Complex trauma also refers to situations such as acute\\/chronic illness that requires intensive medical intervention or a single traumatic event that is calamitous. Complex trauma

Christine A. Courtois

2004-01-01

106

Complex Trauma, Complex Reactions: Assessment and Treatment  

Microsoft Academic Search

Complex trauma occurs repeatedly and escalates over its duration. In families, it is exemplified by domestic violence and child abuse and in other situations by war, prisoner of war or refugee status, and human trafficking. Complex trauma also refers to situations such as acute\\/chronic illness that requires intensive medical intervention or a single traumatic event that is calamitous. Complex trauma

Christine A. Courtois

2008-01-01

107

IDF relationships for short duration rainfall  

NASA Astrophysics Data System (ADS)

The intensity-duration-frequency (IDF) relationships bound rainfall intensity to duration and return period. These relationships are commonly used as an input in design of many hydraulic structures and drainage systems. Empirical IDF are estimated on the basis of recorded maximum annual precipitation of given durations, often ranging from 1 h to 24 h. For shorter durations, extrapolations are applied. In this paper, maximum annual precipitation for durations shorter than 1 h (namely, 30 min and 10 min) are evaluated using a rainfall disaggregation model and then used for the evaluation of the IDF relationship. A comparison of values obtained with the extrapolated values is then performed, and the results are discussed. Keywords: intensity-duration-frequency curves, rainfall disaggregation, entropy.

Montesarchio, Valeria; Napolitano, Francesco; Russo, Fabio; Spina, S.

2013-10-01

108

Differences in Organizational Factors by Lean Duration  

Microsoft Academic Search

The aim of this paper is to explore whether employees’ perceptions towards perceived organisational support and participative\\u000a decision-making vary by lean duration (i.e., the duration of lean production in operation), and whether managers’ perceptions\\u000a towards propensity for participative decision-making vary by the lean duration. For the study, quantitative research methodology\\u000a was used and data was collected from 616 shop-floor employees

Dharmasri Wickramasinghe; Vathsala Wickramasinghe

109

An optimization principle for determining movement duration.  

PubMed

Movement duration is an integral component of motor control, but nearly all extant optimization models of motor planning prefix duration instead of explaining it. Here we propose a new optimization principle that predicts movement duration. The model assumes that the brain attempts to minimize movement duration under the constraint of meeting an accuracy criterion. The criterion is task and context dependent but is fixed for a given task and context. The model determines a unique duration as a trade-off between speed (time optimality) and accuracy (acceptable endpoint scatter). We analyzed the model for a linear motor plant, and obtained a closed-form equation for determining movement duration. By solving the equation numerically with specific plant parameters for the eye and arm, we found that the model can reproduce saccade duration as a function of amplitude (the main sequence), and arm-movement duration as a function of the ratio of target distance to size (Fitts's law). In addition, it explains the dependency of peak saccadic speed on amplitude and the dependency of saccadic duration on initial eye position. Furthermore, for arm movements, the model predicts a scaling relationship between peak velocity and distance and a reduction in movement duration with a moderate increase in viscosity. Finally, for a linear plant, our model predicts a neural control signal identical to that of the minimum-variance model set to the same movement duration. This control signal is a smooth function of time (except at the endpoint), in contrast to the discontinuous bang-bang control found in the time-optimal control literature. We suggest that one aspect of movement planning, as revealed by movement duration, may be to assign an endpoint accuracy criterion for a given task and context. PMID:16571740

Tanaka, Hirokazu; Krakauer, John W; Qian, Ning

2006-03-29

110

Incorporating Duration Information in Activity Recognition  

NASA Astrophysics Data System (ADS)

Activity recognition has become a key issue in smart home environments. The problem involves learning high level activities from low level sensor data. Activity recognition can depend on several variables; one such variable is duration of engagement with sensorised items or duration of intervals between sensor activations that can provide useful information about personal behaviour. In this paper a probabilistic learning algorithm is proposed that incorporates episode, time and duration information to determine inhabitant identity and the activity being undertaken from low level sensor data. Our results verify that incorporating duration information consistently improves the accuracy.

Chaurasia, Priyanka; Scotney, Bryan; McClean, Sally; Zhang, Shuai; Nugent, Chris

111

Botulinum toxin: examining duration of effect in facial aesthetic applications.  

PubMed

Patient satisfaction with botulinum toxin treatment is a key success factor in aesthetic procedures and is governed by the interaction of numerous variables. Duration of effect is important because it influences retreatment intervals as well as affecting cost and convenience to the patient. In order to review the evidence on the duration of benefit associated with various commercial formulations of botulinum toxin, MEDLINE was searched using the following terms: 'botulinum' and 'duration'/'retreatment' (limits: 'clinical trials,' 'meta-analyses,' 'English'). I also searched my existing reference files, reference lists of identified articles, and meeting/conference abstracts to ensure completeness. The focus was on clinical medicine and aesthetic trials. To be eligible for the analysis, studies had to include efficacy assessments at multiple timepoints. To estimate duration of benefit, the following outcomes were examined and summarized: responder rates, mean wrinkle severity scores at various timepoints (with or without changes from baseline), and relapse rates. Duration at both repose and maximum attempted muscle contraction was considered when provided. Where possible, duration was assessed by formulation and dose. The initial search yielded 164 articles. Of these, 35 included an adequate measure of duration in aesthetic indications. The majority of these (22) were on the glabellar area. Study designs and endpoints were highly heterogeneous, and duration of effect varied between studies. Several studies with the BOTOX Cosmetic (onabotulinumtoxinA; Allergan, Inc., Irvine, CA, USA) formulation of botulinum toxin type A (BoNTA) included relapse rates, defined conservatively as return to baseline levels of line severity for two consecutive visits approximately 30 days apart (at repose and maximum contraction). In these studies, duration of effect ranged from 3 to 5 months in female patients and from 4 to 6 months in male patients. Individual patients had longer durations of response. Across all studies providing relapse rates, most patients relapsed by 6 months. In studies assessing patient satisfaction, satisfaction remained high throughout the duration of the studies ( approximately 4 months). With the Dysport formulation (abobotulinumtoxinA, clostridium botulinum type A toxin-hemagglutinin complex; Ipsen Biopharm Ltd, Wrexham, England), retreatment intervals were estimated at a mean of 3.9 months (median = 3.3 months). These results were consistent with responder rates from another Dysport study in which the active treatment differed from placebo at 3 but not 4 months. A single comparative study demonstrated that the proportion of patients relapsing at week 16 was 23% (95% CI 11.5, 41.6) in the BOTOX Cosmetic group as compared with 40% (95% CI 25.2, 60.1) in the Dysport group. Myobloc (rimabotulinumtoxinB, botulinum toxin type B; Solstice Neurosciences, Inc., South San Francisco, CA, USA) was associated with shorter durations of action (2-3 months). Data from facial areas other than the glabella, although more limited, supported a duration of at least 3-4 months. The addition of BoNTA to dermal fillers or light/laser therapy appeared to increase the degree of effect. Repeated BoNTA treatments may prolong duration of effect or potentiate the effect. In conclusion, patients can expect treatments to last > or =3 months but often as many as 4-5 months depending on the facial area, dose, and formulation. Additional research should help clarify the impact of age, baseline rhytid severity, patient sex, repeated treatments, and combination treatment on longevity of effect. PMID:20369902

Flynn, Timothy Corcoran

2010-01-01

112

NMDAR-Dependent Control of Call Duration in Xenopus laevis  

PubMed Central

Many rhythmic behaviors, such as locomotion and vocalization, involve temporally dynamic patterns. How does the brain generate temporal complexity? Here, we use the vocal central pattern generator (CPG) of Xenopus laevis to address this question. Isolated brains can elicit fictive vocalizations, allowing us to study the CPG in vitro. The X. laevis advertisement call is temporally modulated; calls consist of rhythmic click trills that alternate between fast (?60 Hz) and slow (?30 Hz) rates. We investigated the role of two CPG nuclei—the laryngeal motor nucleus (n.IX–X) and the dorsal tegmental area of the medulla (DTAM)—in setting rhythm frequency and call durations. We discovered a local field potential wave in DTAM that coincides with fictive fast trills and phasic activity that coincides with fictive clicks. After disrupting n.IX–X connections, the wave persists, whereas phasic activity disappears. Wave duration was temperature dependent and correlated with fictive fast trills. This correlation persisted when wave duration was modified by temperature manipulations. Selectively cooling DTAM, but not n.IX–X, lengthened fictive call and fast trill durations, whereas cooling either nucleus decelerated the fictive click rate. The N-methyl-d-aspartate receptor (NMDAR) antagonist dAPV blocked waves and fictive fast trills, suggesting that the wave controls fast trill activation and, consequently, call duration. We conclude that two functionally distinct CPG circuits exist: 1) a pattern generator in DTAM that determines call duration and 2) a rhythm generator (spanning DTAM and n.IX–X) that determines click rates. The newly identified DTAM pattern generator provides an excellent model for understanding NDMAR-dependent rhythmic circuits.

Katzen, Abraham W.; Rhodes, Heather J.; Yamaguchi, Ayako

2010-01-01

113

Stimulus Intensity and the Perception of Duration  

ERIC Educational Resources Information Center

|This article explores the widely reported finding that the subjective duration of a stimulus is positively related to its magnitude. In Experiments 1 and 2 we show that, for both auditory and visual stimuli, the effect of stimulus magnitude on the perception of duration depends upon the background: Against a high intensity background, weak…

Matthews, William J.; Stewart, Neil; Wearden, John H.

2011-01-01

114

Determinants of Breastfeeding Duration in Peninsular Malaysia  

Microsoft Academic Search

The health benefits of breastfeeding to infants and mothers have been well recognised. This study applies linear regression analysis to assess the determinants of breastfeeding duration of first born using data from the Second Malaysian Family Life Survey. The proportion of women who breastfed their first child is 82 percent, of which 97 percent reported their breastfeeding duration. The distribution

Halimah Awang; Abdul Latif Haji Salleh

2000-01-01

115

Transition-event durations in one-dimensional activated processes  

NASA Astrophysics Data System (ADS)

Despite their importance in activated processes, transition-event durations-which are much shorter than first passage times-have not received a complete theoretical treatment. The authors therefore study the distribution ?b(t) of durations of transition events over a barrier in a one-dimensional system undergoing overdamped Langevin dynamics. The authors show that ?b(t) is determined by a Fokker-Planck equation with absorbing boundary conditions and obtain a number of results, including (i) the analytic form of the asymptotic short-time transient behavior, which is universal and independent of the potential function; (ii) the first nonuniversal correction to the short-time behavior leading to an estimate of a key physical time scale; (iii) following previous work, a recursive formulation for calculating, exactly, all moments of ?b based solely on the potential function-along with approximations for the distribution based on a small number of moments; and (iv) a high-barrier approximation to the long-time (t-->?) behavior of ?b(t). The authors also find that the mean event duration does not depend simply on the barrier-top frequency (curvature) but is sensitive to details of the potential. All of the analytic results are confirmed by transition-path-sampling simulations implemented in a novel way. Finally, the authors discuss which aspects of the duration distribution are expected to be general for more complex systems.

Zhang, Bin W.; Jasnow, David; Zuckerman, Daniel M.

2007-02-01

116

Heritability of initiation and duration of breastfeeding behavior.  

PubMed

Breastfeeding is considered the best and most natural way of feeding infants during the first months of life. Breastfeeding has multiple short- and long-term benefits for the health of the mother and babies, and from an evolutionist standpoint, it would be a behavior worth preserving throughout time. The aim of the present study was to explore the relative influence of genetic and environmental factors in this behavior. Three hundred and ninety pairs of adult female twins provided information about whether they breastfed their children and for how long. Three variables were analyzed: initiation and duration for the first baby, and mean duration for the complete offspring. Polychoric correlations were consistently higher for monozygotic twins, supporting a role for genetic factors (0.49 vs. 0.22 for initiation; 0.44 vs. 0.22 for duration in the first newborn; and 0.52 vs. 0.31 for duration on average). Model-fitting analyses found that in the best-fitting model, variance was explained by additive genetic and non-shared environmental factors, with estimated heritabilities ranging from 0.39 to 0.52 in the measures studied. The rest of the variance would be due to unique environmental factors. We conclude that genetic factors have a significant impact on the complex behavior of breastfeeding. PMID:23398685

Colodro-Conde, Lucia; Sánchez-Romera, Juan F; Ordoñana, Juan R

2013-02-11

117

Subjective Duration Distortions Mirror Neural Repetition Suppression  

PubMed Central

Background Subjective duration is strongly influenced by repetition and novelty, such that an oddball stimulus in a stream of repeated stimuli appears to last longer in duration in comparison. We hypothesize that this duration illusion, called the temporal oddball effect, is a result of the difference in expectation between the oddball and the repeated stimuli. Specifically, we conjecture that the repeated stimuli contract in duration as a result of increased predictability; these duration contractions, we suggest, result from decreased neural response amplitude with repetition, known as repetition suppression. Methodology/Principal Findings Participants viewed trials consisting of lines presented at a particular orientation (standard stimuli) followed by a line presented at a different orientation (oddball stimulus). We found that the size of the oddball effect correlates with the number of repetitions of the standard stimulus as well as the amount of deviance from the oddball stimulus; both of these results are consistent with a repetition suppression hypothesis. Further, we find that the temporal oddball effect is sensitive to experimental context – that is, the size of the oddball effect for a particular experimental trial is influenced by the range of duration distortions seen in preceding trials. Conclusions/Significance Our data suggest that the repetition-related duration contractions causing the oddball effect are a result of neural repetition suppression. More generally, subjective duration may reflect the prediction error associated with a stimulus and, consequently, the efficiency of encoding that stimulus. Additionally, we emphasize that experimental context effects need to be taken into consideration when designing duration-related tasks.

Pariyadath, Vani; Eagleman, David M.

2012-01-01

118

Thermoresponsive nanogels for prolonged duration local anesthesia  

PubMed Central

Nanogels based on poly(N-isopropylacrylamide) are attractive vehicles for prolonged duration local anesthesia because of their tunable size, number of functional groups, thermoresponsiveness, and their anionic charge. Nerve block durations of up to nine hours were achieved using acrylic acid-loaded nanogels loaded with bupivacaine. Increasing the anionic charge density of the nanogels or (for more highly acid-functionalized nanogels) decreasing the nanogel size facilitated longer duration anesthetic release. Small (<300 nm diameter) nanogels formed dense aggregates upon injection in vivo and induced only mild inflammatory responses, while large (>500 nm diameter) nanogels typically remained as liquid-like residues in vivo and induced more severe inflammatory reactions.

Hoare, Todd; Young, Stuart; Lawlor, Michael W.; Kohane, Daniel S.

2012-01-01

119

Long Duration Exposure Facility Space Optics Handbook.  

National Technical Information Service (NTIS)

This handbook provides a user a space optics design guide to materials based on the Long Duration Exposure Facility (LDEF) Space Optics Experiments. The materials covered are refractive optics, coatings, filters, mirrors, second surface mirrors, quartz mi...

C. Bloemker E. Taylor F. White G. Rensner W. T. Kemp

1993-01-01

120

18 CFR 430.33 - Duration.  

Code of Federal Regulations, 2013 CFR

...BASIN COMMISSION SPECIAL REGULATIONS GROUND WATER PROTECTION AREA: PENNSYLVANIA § 430.33 Duration. The delineation and declaration of the Southeastern Pennsylvania Ground Water Protected Area made pursuant to this regulation,...

2013-04-01

121

[Duration of antibiotic therapy in intraabdominal infections].  

PubMed

The duration of antibiotic treatment in patients with an infectious process is based on empirical considerations and those with intraabdominal infections are no exception. Therefore, the recommended duration of antibiotic therapy in intraabdominal infection is controversial and no consensus has been reached due to the lack of controlled studies that would provide sufficient scientific evidence. Excessive duration of antibiotic therapy can increase the risk of developing bacterial resistance as well as treatment-associated costs. These considerations have led to the exploration of "short-term treatment" strategies, lasting 3-5 days, with encouraging results. However, the development of biomarkers such as procalcitonin opens the door to individualized treatment that might allow the duration of antibiotic treatment in intraabdominal and other infections to be individually tailed to patient response. PMID:21130930

Maseda, Emilio; Gilsanz, Fernando

2010-09-01

122

14 CFR 21.181 - Duration.  

Code of Federal Regulations, 2013 CFR

...FAA; (iii) The aircraft has no unsafe condition...and (iv) The aircraft is registered in the...States. (4) An experimental certificate for...The duration of an experimental certificate issued...operating amateur-built aircraft, exhibition,...

2013-01-01

123

Electrocardiogram of Clinically Healthy Mithun (Bos frontalis): Variation among Strains.  

PubMed

A study was conducted to establish the normal electrocardiogram in four different genetic strains of mithun (Bos frontalis). Electrocardiography, cardiac electrical axis, heart rate, rectal temperature and respiration rate were recorded in a total of 32 adult male mithun of four strains (n = 8 each). It was found that the respiration and heart rates were higher (P < .05) in Manipur than other three strains. Amplitude (P < .05) and duration of P wave and QRS complex differed (P < .01) among the strains. Mizoram strain had the highest amplitude and duration of P wave and QRS complex. On the other hand, higher (P < .05) amplitude and duration of T wave were recorded in Arunachalee and Mizoram strains. The mean electrical axis of QRS complex that were recorded for Arunachalee and Manipur strains were similar to that reported for other bovine species; whereas the electrical axis of QRS for Nagamese and Mizoram strains were more close to feline and caprine species, respectively. In conclusion, electrocardiogram of mithun revealed that the amplitude and duration of P wave, QRS complex and T wave were different among four different genetic strains of mithun and the electrical axis of QRS complex for Nagamese and Mizoram mithuns are dissimilar to bovine species. PMID:20886013

Sanyal, Sagar; Das, Pradip Kumar; Ghosh, Probal Ranjan; Das, Kinsuk; Vupru, Kezha V; Rajkhowa, Chandan; Mondal, Mohan

2010-09-22

124

Electrocardiogram of Clinically Healthy Mithun (Bos frontalis): Variation among Strains  

PubMed Central

A study was conducted to establish the normal electrocardiogram in four different genetic strains of mithun (Bos frontalis). Electrocardiography, cardiac electrical axis, heart rate, rectal temperature and respiration rate were recorded in a total of 32 adult male mithun of four strains (n = 8 each). It was found that the respiration and heart rates were higher (P < .05) in Manipur than other three strains. Amplitude (P < .05) and duration of P wave and QRS complex differed (P < .01) among the strains. Mizoram strain had the highest amplitude and duration of P wave and QRS complex. On the other hand, higher (P < .05) amplitude and duration of T wave were recorded in Arunachalee and Mizoram strains. The mean electrical axis of QRS complex that were recorded for Arunachalee and Manipur strains were similar to that reported for other bovine species; whereas the electrical axis of QRS for Nagamese and Mizoram strains were more close to feline and caprine species, respectively. In conclusion, electrocardiogram of mithun revealed that the amplitude and duration of P wave, QRS complex and T wave were different among four different genetic strains of mithun and the electrical axis of QRS complex for Nagamese and Mizoram mithuns are dissimilar to bovine species.

Sanyal, Sagar; Das, Pradip Kumar; Ghosh, Probal Ranjan; Das, Kinsuk; Vupru, Kezha V.; Rajkhowa, Chandan; Mondal, Mohan

2010-01-01

125

Duration channels mediate human time perception  

PubMed Central

The task of deciding how long sensory events seem to last is one that the human nervous system appears to perform rapidly and, for sub-second intervals, seemingly without conscious effort. That these estimates can be performed within and between multiple sensory and motor domains suggest time perception forms one of the core, fundamental processes of our perception of the world around us. Given this significance, the current paucity in our understanding of how this process operates is surprising. One candidate mechanism for duration perception posits that duration may be mediated via a system of duration-selective ‘channels’, which are differentially activated depending on the match between afferent duration information and the channels' ‘preferred’ duration. However, this model awaits experimental validation. In the current study, we use the technique of sensory adaptation, and we present data that are well described by banks of duration channels that are limited in their bandwidth, sensory-specific, and appear to operate at a relatively early stage of visual and auditory sensory processing. Our results suggest that many of the computational principles the nervous system applies to coding visual spatial and auditory spectral information are common to its processing of temporal extent.

Heron, James; Aaen-Stockdale, Craig; Hotchkiss, John; Roach, Neil W.; McGraw, Paul V.; Whitaker, David

2012-01-01

126

Acute effects of caffeine ingestion on signal-averaged electrocardiograms  

Microsoft Academic Search

Background Although moderate caffeine ingestion has not been shown to be arrhythmogenic, caffeine toxicity can cause severe cardiac arrhythmias, including atrial fibrillation and ventricular tachycardia. Atrial fibrillation and ventricular tachycardia have been associated with prolongation of P-wave and QRS complex durations on signal-averaged electrocardiograms. This study investigated acute effects of caffeine ingestion on signal-averaged P-wave and QRS complexes. Methods and

Richard L. Donnerstein; David Zhu; Ricardo Samson; Alyse M. Bender; Stanley J. Goldberg

1998-01-01

127

Sample-duration effects on pigeons' delayed matching as a function of predictability of duration.  

PubMed Central

Three experiments assessed the impact of sample duration on pigeons' delayed matching as a function of whether or not the samples themselves signaled how long they would remain on. When duration was uncorrelated with the sample appearing on each matching trial, the typical effect of duration was observed: Choice accuracy was higher with long (15-s) than with short (5-s) durations. By contrast, this difference either disappeared or reversed when the 5- and 15-s durations were correlated with the sample stimuli. Sample duration itself cued comparison choice by some birds in the latter (predictable) condition when duration was also correlated with the reinforced choice alternatives. However, even when duration could not provide a cue for choice, pigeons matched predictably short-duration samples as accurately as, or more accurately than, predictably long-duration samples. Moreover, this result was observed independently of whether the contextual conditions of the retention interval were the same as, or different from, those of the intertrial interval. These results strongly support the view that conditional stimulus control by the samples is partly a function of their conditioned reinforcing properties, as determined by the relative reduction in overall delay to reinforcement that they signal.

Urcuioli, P J; DeMarse, T B; Lionello, K M

1999-01-01

128

The effects of cold acclimation on electrocardiogram parameters in five species of turtles.  

PubMed

The effects of thermal acclimation at 25 or 5 degrees C on electrical activity in the heart were investigated in Pseudemys scripta, Terrapene carolina, Chrysemys picta marginata, Chrysemys picta dorsalis, Chelydra serpentina, and Sternotherus odoratus. The durations of the QRS complex and P-R, R-T and R-R intervals were found to increase with decreasing body temperature in all animals tested. The amplitudes of the P and T waves and QRS complex were dependent upon both acclimation temperature and test temperature. Differences between acclimation groups in the change in QRS amplitudes between 20 and 0 degrees C were statistically significant for all species. PMID:2886260

Risher, J F; Claussen, D L

1987-01-01

129

Microcontroller uses in Long-Duration Ballooning  

NASA Astrophysics Data System (ADS)

This paper discusses how microcontrollers are being utilized to fulfill the demands of long duration ballooning (LDB) and the advantages of doing so. The Columbia Scientific Balloon Facility (CSBF) offers the service of launching high altitude balloons (120k ft) which provide an over the horizon telemetry system and platform for scientific research payloads to collect data. CSBF has utilized microcontrollers to address multiple tasks and functions which were previously performed by more complex systems. A microcontroller system has been recently developed and programmed in house to replace our previous backup navigation system which is used on all LDB flights. A similar microcontroller system was developed to be independently launched in Antarctica before the actual scientific payload. This system's function is to transmit its GPS position and a small housekeeping packet so that we can confirm the upper level float winds are as predicted from satellite derived models. Microcontrollers have also been used to create test equipment to functionally check out the flight hardware used in our telemetry systems. One test system which was developed can be used to quickly determine if our communication link we are providing for the science payloads is functioning properly. Another system was developed to provide us with the ability to easily determine the status of one of our over the horizon communication links through a closed loop system. This test system has given us the capability to provide more field support to science groups than we were able to in years past. The trend of utilizing microcontrollers has taken place for a number of reasons. By using microcontrollers to fill these needs, it has given us the ability to quickly design and implement systems which meet flight critical needs, as well as perform many of the everyday tasks in LDB. This route has also allowed us to reduce the amount of time required for personnel to perform a number of the tasks required during the initial fabrication and also refurbishing processes of flight hardware systems. The recent use of microcontrollers in the design of both LDB flight hardware and test equipment has shown some examples of the adaptability and usefulness they have provided for our workplace.

Jones, Joseph

130

Duration of immunity to norovirus gastroenteritis.  

PubMed

The duration of immunity to norovirus (NoV) gastroenteritis has been believed to be from 6 months to 2 years. However, several observations are inconsistent with this short period. To gain better estimates of the duration of immunity to NoV, we developed a mathematical model of community NoV transmission. The model was parameterized from the literature and also fit to age-specific incidence data from England and Wales by using maximum likelihood. We developed several scenarios to determine the effect of unknowns regarding transmission and immunity on estimates of the duration of immunity. In the various models, duration of immunity to NoV gastroenteritis was estimated at 4.1 (95% CI 3.2-5.1) to 8.7 (95% CI 6.8-11.3) years. Moreover, we calculated that children (<5 years) are much more infectious than older children and adults. If a vaccine can achieve protection for duration of natural immunity indicated by our results, its potential health and economic benefits could be substantial. PMID:23876612

Simmons, Kirsten; Gambhir, Manoj; Leon, Juan; Lopman, Ben

2013-08-01

131

Unemployment durations and the pattern of duration dependence over the business cycle of British males  

Microsoft Academic Search

This paper examines the relationship between the business cycle and individuals’ duration in unemployment. I use multi-spell\\u000a unemployment duration data of British males and monthly series of regional vacancies over unemployment, referred to as labour\\u000a market tightness, to control for the business cycle. In line with most previous studies I find that the observed negative\\u000a duration dependence on an aggregate

Adriaan Kalwij

2010-01-01

132

Statistical analysis of random duration times  

SciTech Connect

This report presents basic statistical methods for analyzing data obtained by observing random time durations. It gives nonparametric estimates of the cumulative distribution function, reliability function and cumulative hazard function. These results can be applied with either complete or censored data. Several models which are commonly used with time data are discussed, and methods for model checking and goodness-of-fit tests are discussed. Maximum likelihood estimates and confidence limits are given for the various models considered. Some results for situations where repeated durations such as repairable systems are also discussed.

Engelhardt, M.E.

1996-04-01

133

LONG-DURATION LOW-FREQUENCY TYPE III BURSTS AND SOLAR ENERGETIC PARTICLE EVENTS  

SciTech Connect

We analyzed the coronal mass ejections (CMEs), flares, and type II radio bursts associated with a set of three complex, long-duration, low-frequency (<14 MHz) type III bursts from active region 10588 in 2004 April. The durations were measured at 1 and 14 MHz using data from Wind/WAVES and were well above the threshold value (>15 minutes) normally used to define these bursts. One of the three type III bursts was not associated with a type II burst, which also lacked a solar energetic particle (SEP) event at energies >25 MeV. The 1 MHz duration of the type III burst (28 minutes) for this event was near the median value of type III durations found for gradual SEP events and ground level enhancement events. Yet, there was no sign of an SEP event. On the other hand, the other two type III bursts from the same active region had similar duration but were accompanied by WAVES type II bursts; these bursts were also accompanied by SEP events detected by SOHO/ERNE. The CMEs for the three events had similar speeds, and the flares also had similar size and duration. This study suggests that the occurrence of a complex, long-duration, low-frequency type III burst is not a good indicator of an SEP event.

Gopalswamy, Nat; Maekelae, Pertti [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)

2010-09-20

134

Prolonged duration local anesthesia with minimal toxicity  

Microsoft Academic Search

Injectable local anesthetics that would last for many days could have a marked impact on periprocedural care and pain management. Formulations have often been limited in duration of action, or by systemic toxicity, local tissue toxicity from local anesthetics, and inflammation. To address those issues, we developed liposomal formulations of saxitoxin (STX), a compound with ultrapotent local anesthetic properties but

Hila Epstein-Barash; Iris Shichor; Albert H. Kwon; Sherwood Hall; Michael W. Lawlor; Robert Langer; Daniel S. Kohane

2009-01-01

135

Expectations, Rivalries, and Civil War Duration  

Microsoft Academic Search

What role have states involved in a rivalry with another state played in shaping the dynamics of their rival's civil wars? How can the existence of an interstate rival affect rebel calculations whether to continue fighting or stop the violence and negotiate? And to what extent does rival intervention differ in its impact on civil war duration from interventions by

Seden Akcinaroglu; Elizabeth Radziszewski

2005-01-01

136

A Short-Duration Gel Diffusion Experiment.  

ERIC Educational Resources Information Center

Described is a gel diffusion experiment that permits the completion of duplicate diffusion runs within a three-hour laboratory session. Information included for the short-duration gel diffusion experiment is the diffusion cell, the experiment, data treatment, and the expected results of the experiment. (Author/DS)

Mulcahy, D. E.

1980-01-01

137

Display duration and stereoscopic depth discrimination.  

PubMed

We investigated the role of display duration in stereoscopic depth perception. The display consisted of a dynamic random-dot stereogram, with two disparity-defined squares (1.9 degrees x 1.9 degrees), one on the left and one on the right of a central (Nonius) fixation stimulus. The sign of the disparity (crossed or uncrossed) was always the same for both squares, and the magnitude of disparity was 0.25 degree for one square and either 0.125 degree or 0.375 degree for the other square. Participants indicated which square appeared closer. The display duration was varied adaptively between 20 and 1000 ms until participants performed at 75% accuracy. Results confirmed large individual differences in the display duration required for stereoscopic depth perception. Approximately half of the 100 naive participants were able to perform the task at 20 ms, while the remaining participants required up to 1000 ms to perform at criterion. The present study shows that display duration is a critical variable in explaining wide differences in reported abilities of individuals to process stereoscopic depth information. PMID:9655014

Tam, W J; Stelmach, L B

1998-03-01

138

Duration of antiviral immunity after smallpox vaccination  

Microsoft Academic Search

Although naturally occurring smallpox was eliminated through the efforts of the World Health Organization Global Eradication Program, it remains possible that smallpox could be intentionally released. Here we examine the magnitude and duration of antiviral immunity induced by one or more smallpox vaccinations. We found that more than 90% of volunteers vaccinated 25–75 years ago still maintain substantial humoral or

Erika Hammarlund; Matthew W Lewis; Scott G Hansen; Lisa I Strelow; Jay A Nelson; Gary J Sexton; Jon M Hanifin; Mark K Slifka

2003-01-01

139

Microcontroller uses in Long-Duration Ballooning  

Microsoft Academic Search

This paper discusses how microcontrollers are being utilized to fulfill the demands of long duration ballooning (LDB) and the advantages of doing so. The Columbia Scientific Balloon Facility (CSBF) offers the service of launching high altitude balloons (120k ft) which provide an over the horizon telemetry system and platform for scientific research payloads to collect data. CSBF has utilized microcontrollers

Joseph Jones

2008-01-01

140

Long Duration Balloon Data Acquisition Stack Upgrade  

Microsoft Academic Search

The Long Duration Balloon Data Acquisition Stack (LDB DAQ) has not been updated since earlier in this decade. It is desired to replace obsolete or unavailable components and redesign for modern applications. This includes the combination of two conventional LDB DAQ decks, the Timed Command Deck (TCMD) and the Housekeeping Deck (HSK) into one Telemetry Deck. The CSBF CAP II

Jacob Gilbert

2008-01-01

141

20 CFR 336.2 - Duration of normal unemployment benefits.  

Code of Federal Regulations, 2010 CFR

...2009-04-01 false Duration of normal unemployment benefits. 336.2 Section 336...BOARD REGULATIONS UNDER THE RAILROAD UNEMPLOYMENT INSURANCE ACT DURATION OF NORMAL...Benefits § 336.2 Duration of normal unemployment benefits. (a) 130...

2009-04-01

142

20 CFR 336.2 - Duration of normal unemployment benefits.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 false Duration of normal unemployment benefits. 336.2 Section 336...BOARD REGULATIONS UNDER THE RAILROAD UNEMPLOYMENT INSURANCE ACT DURATION OF NORMAL...Benefits § 336.2 Duration of normal unemployment benefits. (a) 130...

2010-04-01

143

Durational Correlates of Quantity in Swedish, Finnish and Estonian: Cross-Language Evidence for a Theory of Adaptive Dispersion  

Microsoft Academic Search

Audio recordings of lively conversational speech produced by 3 Swedish, 4 Finnish and 3 Estonian speakers were analyzed for durational correlates of quantity distinctions. The data suggest that duration contrasts are maintained more consistently by Finnish and Estonian than by Swedish speakers. This is attributed to the unusually complex structure of the Finnish and Estonian quantity systems, and to the

Olle Engstrand; Diana Krull

1994-01-01

144

The employment service and vacancy durations.  

PubMed

In the literature, there are few examples of studies analyzing the impact of labor market programs on vacancies. This article presents the results of a study of the impact of personnel increase at Swedish employment offices on vacancy durations. The evaluation method in the study is quasi-experimental. The main results of the study are as follows: (a) The increase of employment office staff members reduced their vacancy durations by approximately 2 days, and the probability that a vacancy is cancelled from the register is 1.17 times higher for the program offices; and (b) this effect is too small for the increase of staff members to represent a socially efficient use of resources and for a positive outcome in a public finance context. PMID:12465572

Behrenz, Lars

2002-12-01

145

Frequency analysis of short?duration rainfalls  

Microsoft Academic Search

An investigation was carried out to determine the appropriateness of a probability distribution and fitting technique commonly used in Canada for rainfall frequency analysis.The extreme value type 1 (EV1) distribution was assessed for three long?term Canadian stations: Victoria, St Thomas and Québec. The EV1 distribution appears to provide a reasonable fit for durations varying from 5 min to 6 h,

W. Edgar Watt

1983-01-01

146

A hidden Markov modelwith binned duration algorithm  

Microsoft Academic Search

The hidden Markov model with duration (HMMD) is critically important when the distributions on state intervals deviate significantly from the geometric distribution, such as for multimodal distributions and heavy-tailed distributions. Heavy-tailed distributions, in particular, are widespread in describing phenomena across the sciences, where the log-normal, student's-T, and Pareto distributions are heavy-tailed distributions that are almost as common as the normal

Stephen Winters-Hilt; Zuliang Jiang

2010-01-01

147

Strength–duration properties in diabetic polyneuropathy  

Microsoft Academic Search

We sought to examine the changes in the strength–duration time constant (SDTC) of the median nerve in diabetic polyneuropathy. The SDTC is a measure of axonal excitability and depends on the biophysical properties of the axonal membrane. It may provide some information about Na+ channel functioning. Forty-nine diabetic patients (30 men, 19 women; mean age, 54.6±9.4 years) and 15 age-matched

Deniz Yerdelen; Filiz Koç; Hilmi Uysal; Yakup Sarica

2007-01-01

148

Fitting the empirical distribution of intertrade durations  

NASA Astrophysics Data System (ADS)

Based on the analysis of a tick-by-tick data set used in the previous work by one of the authors (DJIA stocks traded at NYSE in October 1999), in this paper, we reject the hypothesis that tails of the empirical intertrade distribution are described by a power law. We further argue that the Tsallis q-exponentials are a viable tool for fitting and describing the unconditional distribution of empirical intertrade durations and they compare well to the Weibull distribution.

Politi, Mauro; Scalas, Enrico

2008-03-01

149

The nominal duration of TIPS bonds  

Microsoft Academic Search

This paper studies the price responsiveness (effective duration) of U.S. government issued inflation-indexed bonds, known by the acronym TIPS (Treasury Inflation-Protected Securities), to changes in nominal interest rates, real interest rates, and expected inflation. Using the TIPS pricing formula derived by Laatsch and Klein [Q. Rev. Econ. Finance 43 (2002) 405], we first confirm that TIPS bonds have zero sensitivity

Francis E. Laatsch; Daniel P. Klein

2005-01-01

150

Brief subjective durations contract with repetition.  

PubMed

Neural responses to a repeated stimulus typically diminish, an effect known as repetition suppression. We here demonstrate what appear to be parallel effects of repetition on subjective duration, even when stimuli are presented too rapidly for explicit temporal judgments. When a brief visual stimulus (e.g., a letter, word, object, or face) was serially flashed in different locations, several stimuli appeared to be present simultaneously due to persistence of vision-we term this the Proliferation Effect. Critically, fewer stimuli were perceived to be simultaneously present when the same stimulus was flashed repeatedly than when a different stimulus was used for each flash, indicating that persistence of vision (and hence subjective duration) shrinks for predictable stimuli. These short-timescale experiments demonstrate that subjective durations are computed at a preconscious and implicit level of processing, thereby changing the temporal interpretation of visual scenes. Further, these findings suggest a new, instant diagnostic test for deficits in repetition suppression, such as those found in schizophrenia. PMID:19146277

Pariyadath, Vani; Eagleman, David M

2008-12-22

151

ON THE DURATION OF BLAZAR SYNCHROTRON FLARES  

SciTech Connect

A semi-analytical model is presented that describes the temporal development of a blazar synchrotron flare for the case of a broadband synchrotron power spectrum. We examine three different injection scenarios and present its influence on the synchrotron flare. An accurate approximation of the half-life of a synchrotron flare is analytically computed and we give some illustrative examples of the time evolution of the emergent synchrotron intensity by using a numerical integration method. The synchrotron flare starts at all photon energies right after the injection of ultrarelativistic electrons into the spherical emission volume of radius R and its duration exceeds the light travel time 2R/c in the low energy regime. Furthermore, the flare duration extends by the period of injection of relativistic electrons into the emission knot. However, the energetic and spatial distribution of these injected electrons has no significant influence on the flare duration. We obtain a temporal behavior that agrees most favorably with the observations of PKS 2155-304 on 2006 July 29-30 and it differs considerably from the results that were recently achieved by using a monochromatic approximation of the synchrotron power.

Eichmann, B.; Schlickeiser, R. [Institut fuer Theoretische Physik, Lehrstuhl IV: Weltraum- und Astrophysik, Ruhr-Universitaet Bochum, 44780 Bochum (Germany); Rhode, W. [Experimentelle Physik V, Technische Universitaet Dortmund, 44221 Dortmund (Germany)

2012-01-10

152

16 CFR 613.1 - Duration of active duty alerts.  

Code of Federal Regulations, 2010 CFR

...2009-01-01 false Duration of active duty alerts. 613.1 Section 613.1 Commercial...CREDIT REPORTING ACT DURATION OF ACTIVE DUTY ALERTS § 613.1 Duration of active duty alerts. The duration of an active duty alert...

2009-01-01

153

16 CFR 613.1 - Duration of active duty alerts.  

Code of Federal Regulations, 2010 CFR

...2010-01-01 false Duration of active duty alerts. 613.1 Section 613.1 Commercial...CREDIT REPORTING ACT DURATION OF ACTIVE DUTY ALERTS § 613.1 Duration of active duty alerts. The duration of an active duty alert...

2010-01-01

154

Caffeine intake reduces sleep duration in adolescents.  

PubMed

In our study, we hypothesized that higher caffeine intake would be associated with lower sleep duration among 13-year-old adolescents. In addition, we aimed to identify food sources of caffeine intake in this sample. Eligible participants were adolescents who were born in 1990 and attended school in Porto, Portugal, in 2003/2004. Self-administered questionnaires were used, and diet was evaluated using a food frequency questionnaire. From the 2160 eligible participants, only 1522 with valid information regarding their diet were included in this study. In our sample, the median intake of caffeine was 23.1 mg/d, with soft drinks being the major source. Ice tea presented the highest median (25th-75th percentiles) contribution (33.1% [14.0-52.1]), followed by cola (21.1% [6.4-37.6]). Regarding cocoa products, chocolate bars presented a median contribution of 5.1% (1.0-14.0), and snacks containing chocolate had a contribution of 3.0% (0.5-7.2). Coffee and tea presented a negligible contribution. Adolescents who reported less sleep duration and those who spent more time watching TV during the weekend had a significantly higher caffeine intake. Overall, boys had higher intakes of caffeine from soft drinks, and private school attendees, those who had parents with more education, who reported less television viewing time and had lower body mass index presented higher intakes of caffeine from chocolate. Considering sleeping more than 9.5 hours as a reference class, for each increase of 10 mg/d in caffeine intake, we found that the odds ratio of sleeping 8.5 hours or less was 1.12 (95% confidence interval, 1.06-1.19). Our results support the hypothesis that caffeine intake was inversely associated with sleep duration in adolescents. PMID:24034572

Lodato, Francesca; Araújo, Joana; Barros, Henrique; Lopes, Carla; Agodi, Antonella; Barchitta, Martina; Ramos, Elisabete

2013-08-01

155

Long duration human exposure to microgravity  

NASA Astrophysics Data System (ADS)

Looking toward the era of long duration manned spaceflight, questions remain regarding human adaptation to the weightless environment. In particular, bone calcium loss, cardiovascular deconditioning, and effects of radiation require further study. NASA has undertaken a series of experiments to increase the knowledge base of human adaptation to spaceflight. To date, results in the area of cardiovascular deconditioning countermeasures are the furthest advanced. The results from the upcoming SLS-1 mission will enhance knowledge in all areas. With continued research, there is every confidence that astronauts will be able to be kept healthy for long periods of time.

Huntoon, C. L.

156

Effect of Adrenergic Stimulation on Action Potential Duration Restitution in Humans  

Microsoft Academic Search

Background—Enhanced sympathetic activity facilitates complex ventricular arrhythmias and fibrillation. The restitution properties of action potential duration (APD) are important determinants of electrical stability in the myocardium. Steepening of the slope of APD restitution has been shown to promote wave break and ventricular fibrillation. The effect of adrenergic stimulation on APD restitution in humans is unknown. Methods and Results—Monophasic action potentials

Peter Taggart; Peter Sutton; Zaid Chalabi; Mark R. Boyett; Ron Simon; Donna Elliott; Jaswinder S. Gill

2003-01-01

157

Modelling Patient Duration of Stay to Facilitate Resource Management of Geriatric Hospitals  

Microsoft Academic Search

A fundamental aspect of health care management is the effective allocation of resources. This is of particular importance in geriatric hospitals where elderly patients tend to have more complex needs. Hospital managers would benefit immensely if they had advance knowledge of patient duration of stay in hospital. Managers could assess the costs of patient care and make allowances for these

A. H. Marshall; S. I. McClean; C. M. Shapcott; P. H. Millard

2002-01-01

158

On the discriminability of stimulus duration.  

PubMed Central

The performance of pigeons trained to detect differences in the duration of stimuli was analysed using a matching model of signal detection. Two white stimuli, S1 and S2, differing in duration, were arranged with equal probability on the center key of a three-key chamber. S1 was systematically varied from 5 seconds to 25 seconds while S2 remained constant at 30 seconds. On completion of the center-key stimulus, a peck on the center key turned on the two red side keys. A left-key response was "correct" when S1 had been in effect on the center key and a right-key response was "correct" on S2 trials. A correct response produced a 3-second magazine light accompanied intermittently by food. Incorrect responses produced 3-second blackouts. Detection performance was measured under two procedures. In the first, the obtained reinforcement ratio was uncontrolled by allowing the number of food reinforcements obtained for correct left- and right-key responses to vary as the stimuli were changed. In the second procedure, the presentation of food reinforcement was controlled by holding the obtained reinforcement ratio constant. Discriminability changed as a function of stimulus differences under both procedures. No such trend was found in response bias.

McCarthy, D; Davison, M

1980-01-01

159

CONCORDIASI, Long Duration Stratospheric Balloons over Antarctica  

NASA Astrophysics Data System (ADS)

CNES, the French space agency, has been developing and operating stratospheric balloons for scientific purposes for many years. One particular type of balloon has been designed for ultra long duration flights in the lowermost stratosphere: the superpressure balloon. A constellation of typically 10 to 20 balloons, fitted with light payloads can be deployed, forming a regional airborne observatory. The first use of this kind of observation system has been for atmospheric sciences, each of the balloons carrying various sets of scientific instruments. Concordiasi is the latest program built on the use of this observation system in its most recent development stage. 19 balloons were released from McMurdo Station Antarctica over September to October 2010 in the Winter Polar Vortex. It carried a variety of instruments, for remote and in-situ measurement of the atmosphere. The average flight duration of the balloons was 69 days, cumulating to 1316 days over the whole balloon constellation. We will present briefly the scientific objectives of the project; describe the flight system and the flight campaign, including the launch phase and the long flight monitoring through the control centres. Flight results will be presented, with an overview of the scientific results, but focussing mainly on the technical achievements and on lessons that can be drawn from this project.

Cocquerez, Philippe

2012-07-01

160

Estimating potential diapause duration in Calanus finmarchicus  

NASA Astrophysics Data System (ADS)

Deep basins in the Gulf of Maine act as refuge for a large population of diapausing Calanus finmarchicus during the summer and fall. This population acts as the primary seed population for Georges Bank in the spring and is thought to be composed primarily of individuals that developed during the previous spring bloom. The factors affecting growth and mortality in the summer-fall population are not well understood, however, and loss terms from advection and starvation may be large. To assess the potential energetic limitation and loss of C. finmarchicus from the Gulf of Maine basins, a new nitrogen-specific respiration model has been developed for the resting stage of the species. Stage C5 C. finmarchicus were collected during July, September, and December 2003 from Wilkinson and Georges Basins. Animals were collected using both MOCNESS tows and zooplankton samplers on the Johnson Sea Link II submersible. Metabolic rates were measured using a Micro-Oxymax gas analyzer and Winkler incubation techniques both at sea and on animals kept in culture on shore. Respiration rates measured in the field were not significantly different from those measured on shore, with a mean of 130 ?mol O 2 gN -1 h -1 (14.4 ?mol O 2 gC -1 h -1) at 0 °C and a Q10 of 2.77 (2.58 for carbon-specific respiration). Using the nitrogen-specific rates in conjunction with visual estimates of nitrogen weight and lipid stores, we derived a discrete function for predicting potential diapause duration based on an animal's length, oil sac volume, and the in situ temperature. The maximum potential diapause duration for a C5 C. finmarchicus is predicted to range from 280 days at 0 °C to approximately 90 days at 11 °C. The maximum potential diapause duration in the Gulf of Maine is predicted to be between 3.5 and 5.5 months. These results suggest that energetic limitation may play a role in controlling the population dynamics of diapausing C. finmarchicus in the Gulf of Maine. A reassessment of the importance of summer production to the Gulf of Maine C. finmarchicus population may be required to account for its year-round presence on the Northeast American Shelf.

Saumweber, Whitley J.; Durbin, Edward G.

2006-11-01

161

On the role of storm duration in the mapping of rainfall to flood return periods  

NASA Astrophysics Data System (ADS)

While the correspondence of rainfall return period TP and flood return period TQ is at the heart of the design storm procedure, their relationship is still poorly understood. The purpose of this paper is to shed light on the controls on this relationship. To better understand the interplay of the controlling factors we assume a simplified world with block rainfall, constant runoff coefficient and linear catchment response. We use an analytical derived flood frequency approach in which, following design practise, TP is defined as the return period of the intensity-duration-frequency (IDF) curve given storm duration and depth. Results suggest that the main control on the mapping of rainfall to flood return periods is the ratio of storm duration and catchment response time, as would be expected. In the simple world assumed in this work, TQ is always smaller or equal than TP of the associated storm, i.e. TQTP?1. This is because of the difference in the selectiveness of the rectangular filters used to construct the IDF curves and the unit hydrograph (UH) together with the fact that different rectangular filters are used when evaluating the storm return periods. The critical storm duration that maximises TQTP is, in descending importance, a function of the catchment response time and the distribution of storm duration, while the maximum value of TQTP is mainly a function of the coefficient of variation of storm duration. The study provides the basis for future analyses, where more complex cases will be examined.

Viglione, A.; Blöschl, G.

2008-12-01

162

Duration tuning in the inferior colliculus of the mustached bat.  

PubMed

We studied duration tuning in neurons of the inferior colliculus (IC) of the mustached bat. Duration-tuned neurons in the IC of the mustached bat fall into three main types: short (16 of 136), band (34 of 136), and long (29 of 136) pass. The remaining 51 neurons showed no selectivity for the duration of sounds. The distribution of best durations was double peaked with maxima around 3 and 17 ms, which correlate with the duration of the short frequency-modulated (FM) and the long constant-frequency (CF) signals emitted by Pteronotus parnellii. Since there are no individual neurons with a double-peaked duration response profile, both types of temporal processing seem to be well segregated in the IC. Most short- and band-pass units with best frequency in the CF2 range responded to best durations > 9 ms (66%, 18 of 27 units). However, there is no evidence for a bias toward longer durations as there is for neurons tuned to the frequency range of the FM component of the third harmonic, where 83% (10 of 12 neurons) showed best durations longer than 9 ms. In most duration-tuned neurons, response areas as a function of stimulus duration and intensity showed either V or U shape, with duration tuning retained across the range of sound levels tested. Duration tuning was affected by changes in sound pressure level in only six neurons. In all duration-tuned neurons, latencies measured at the best duration were longer than best durations, suggesting that behavioral decisions based on analysis of the duration of the pulses would not be expected to be complete until well after the stimulus has occurred. PMID:21917994

Macías, Silvio; Mora, Emanuel C; Hechavarría, Julio C; Kössl, Manfred

2011-09-14

163

Long Duration Balloon Data Acquisition Stack Upgrade  

NASA Astrophysics Data System (ADS)

The Long Duration Balloon Data Acquisition Stack (LDB DAQ) has not been updated since earlier in this decade. It is desired to replace obsolete or unavailable components and redesign for modern applications. This includes the combination of two conventional LDB DAQ decks, the Timed Command Deck (TCMD) and the Housekeeping Deck (HSK) into one Telemetry Deck. The CSBF CAP II telemetry module has the desired functionality however it is not in the proper physical package to be of use with the rest of the DAS Stack decks. This paper will describe the repackaging operation in terms of hardware, both components and layout. The firmware running on the Altera FPGA should need no update since the hardware will have the exact same physical functionality as the CAP II telemetry module.

Gilbert, Jacob

164

Long duration backlighter experiments at Omega  

SciTech Connect

We have successfully demonstrated a 7.5 ns duration pinhole-apertured backlighter at the Omega laser facility. Pinhole-apertured point-projection backlighting for 8 ns will be useful for imaging evolving features in experiments at the National Ignition Facility. The backlighter consisted of a 20 {mu}m diameter pinhole in a 75 {mu}m thick Ta substrate separated from a Zn emitter (9 keV) by a 400 {mu}m thick high-density carbon piece. The carbon prevented the shock from the laser-driven surface from reaching the substrate before 8 ns and helped minimize x-ray ablation of the pinhole substrate. Grid wires in x-ray framing camera images of a gold grid have a source-limited resolution significantly smaller than the pinhole diameter due to the high aspect ratio of the pinhole, but do not become much smaller at late times.

Reighard, A. B.; Glendinning, S. G.; Young, P. E.; Hsing, W. W.; Foord, M.; Schneider, M.; Lu, K.; Dittrich, T.; Wallace, R.; Sorce, C. [Lawrence Livermore National Laboratory, Livermore, California 94551 (United States)

2008-10-15

165

Long Duration Backlighter Experiments at Omega  

SciTech Connect

We have successfully demonstrated a 7.5 ns-duration pinhole-apertured backlighter at the Omega laser facility. Pinhole-apertured point-projection backlighting for 8 ns will be useful for imaging evolving features in experiments at the National Ignition Facility. The backlighter consisted of a 20 {micro}m diameter pinhole in a 75 {micro}m thick Ta substrate separated from a Zn emitter (9 keV) by a 400 {micro}m thick high-density carbon piece. The carbon prevented the shock from the laser-driven surface from reaching the substrate before 8 ns and helped minimize x-ray ablation of the pinhole substrate. Grid wires in x-ray framing camera images of a gold grid have a source-limited resolution significantly smaller than the pinhole diameter due to the high aspect ratio of the pinhole, but do not become much smaller at late times.

Reighard, A; Glendinning, S; Young, P; Hsing, W; Foord, M; Schneider, M; Lu, K; Dittrich, T; Wallace, R; Sorce, C

2008-05-01

166

Architectural considerations for lunar long duration habitat  

NASA Astrophysics Data System (ADS)

The future of space exploration science and technology is expected to move toward long duration missions. During this long duration missions the most important factor to success will be the habitation system, the place that crew will live and work. The broad range of future space exploration, new advances in technology and increasing demand for space travel and space tourism will create great opportunities for architects to use their special abilities and skills in the realm of space. The lunar habitat is defined as a multidisciplinary task and cannot be considered an independent project from the main module. Therefore, habitability will become the most important aspect of future human exploration. A successful design strategy should integrate architecture, structure and other disciplines and should bring in elements such as psychological and physiological factors, human interfaces, and privacy. The current research provides "Habitat Architectural Design System (HADS)" in order to evaluate lunar habitat concepts based on habitability, functional optimization, and human factors. HADS helps to promote parametric studied and evaluation of habitat concepts. It will provide a guideline dependent upon mission objectives to standardize architectural needs within the engineering applications and scientific demands. The significance of this research is the process of developing lunar habitat concepts using an architectural system to evaluate the quality of each concept via habitability aspects. This process can be employed during the early stage of design development and is flexible enough to be adjusted by different parameters according to the objectives of lunar mission, limitations, and cost. It also emphasizes the importance of architecture involvement in space projects, especially habitats.

Bahrami, Payam

167

QT-Interval Duration and Mortality Rate  

PubMed Central

Background Extreme prolongation or reduction of the QT interval predisposes patients to malignant ventricular arrhythmias and sudden cardiac death, but the association of variations in the QT interval within a reference range with mortality end points in the general population is unclear. Methods We included 7828 men and women from the Third National Health and Nutrition Examination Survey. Baseline QT interval was measured via standard 12-lead electrocardiographic readings. Mortality end points were assessed through December 31, 2006 (2291 deaths). Results After an average follow-up of 13.7 years, the association between QT interval and mortality end points was U-shaped. The multivariate-adjusted hazard ratios comparing participants at or above the 95th percentile of age-, sex-, race-, and R-R interval–corrected QT interval (?439 milliseconds) with participants in the middle quintile (401 to <410 milliseconds) were 2.03 (95% confidence interval, 1.46-2.81) for total mortality, 2.55 (1.59-4.09) for mortality due to cardiovascular disease (CVD), 1.63 (0.96-2.75) for mortality due to coronary heart disease, and 1.65 (1.16-2.35) for non-CVD mortality. The corresponding hazard ratios comparing participants with a corrected QT interval below the fifth percentile (<377 milliseconds) with those in the middle quintile were 1.39 (95% confidence interval, 1.02-1.88) for total mortality, 1.35 (0.77-2.36) for CVD mortality, 1.02 (0.44-2.38) for coronary heart disease mortality, and 1.42 (0.97-2.08) for non-CVD mortality. Increased mortality also was observed with less extreme deviations of QT-interval duration. Similar, albeit weaker, associations also were observed with Bazett-corrected QT intervals. Conclusion Shortened and prolonged QT-interval durations, even within a reference range, are associated with increased mortality risk in the general population.

Zhang, Yiyi; Post, Wendy S.; Dalal, Darshan; Blasco-Colmenares, Elena; Tomaselli, Gordon F.; Guallar, Eliseo

2012-01-01

168

Prediction of Daily Flow Duration Curves and Streamflow for Ungauged Catchments Using Regional Flow Duration Curves  

EPA Science Inventory

This study presents a method to predict flow duration curves (FDCs) and streamflow for ungauged catchments in the Mid-Atlantic Region, USA. We selected 29 catchments from the Appalachian Plateau, Ridge and Valley, and Piedmont physiographic provinces to develop and test the propo...

169

20 CFR 655.158 - Duration of positive recruitment.  

Code of Federal Regulations, 2012 CFR

... false Duration of positive recruitment. 655.158 Section 655.158...655.158 Duration of positive recruitment. Except as otherwise noted, the obligation to engage in positive recruitment described in §§...

2012-04-01

170

7 CFR 953.78 - Duration of immunities.  

Code of Federal Regulations, 2013 CFR

... 2013-01-01 false Duration of immunities. 953.78 Section 953.78 Agriculture...Miscellaneous Provisions § 953.78 Duration of immunities. The benefits, privileges, and immunities conferred upon any person by virtue of...

2013-01-01

171

7 CFR 915.67 - Duration of immunities.  

Code of Federal Regulations, 2013 CFR

... 2013-01-01 false Duration of immunities. 915.67 Section 915.67 Agriculture...Miscellaneous Provisions § 915.67 Duration of immunities. The benefits, privileges, and immunities conferred upon any person by virtue of...

2013-01-01

172

7 CFR 925.66 - Duration of immunities.  

Code of Federal Regulations, 2013 CFR

... 2013-01-01 false Duration of immunities. 925.66 Section 925.66 Agriculture...Miscellaneous Provisions § 925.66 Duration of immunities. The benefits, privileges, and immunities conferred upon any person by virtue of...

2013-01-01

173

7 CFR 932.71 - Duration of immunities.  

Code of Federal Regulations, 2013 CFR

... 2013-01-01 false Duration of immunities. 932.71 Section 932.71 Agriculture...Miscellaneous Provisions § 932.71 Duration of immunities. The benefits, privileges, and immunities conferred upon any person by virtue of...

2013-01-01

174

7 CFR 929.72 - Duration of immunities.  

Code of Federal Regulations, 2013 CFR

... 2013-01-01 false Duration of immunities. 929.72 Section 929.72 Agriculture...Miscellaneous Provisions § 929.72 Duration of immunities. The benefits, privileges, and immunities conferred upon any person by virtue...

2013-01-01

175

7 CFR 982.84 - Duration of immunities.  

Code of Federal Regulations, 2013 CFR

... 2013-01-01 false Duration of immunities. 982.84 Section 982.84 Agriculture...Miscellaneous Provisions § 982.84 Duration of immunities. The benefits, privileges, and immunities conferred upon any person by virtue of...

2013-01-01

176

7 CFR 981.88 - Duration of immunities.  

Code of Federal Regulations, 2013 CFR

... 2013-01-01 false Duration of immunities. 981.88 Section 981.88 Agriculture...Miscellaneous Provisions § 981.88 Duration of immunities. The benefits, privileges, and immunities conferred upon any person by virtue of...

2013-01-01

177

7 CFR 947.83 - Duration of immunities.  

Code of Federal Regulations, 2013 CFR

... 2013-01-01 false Duration of immunities. 947.83 Section 947.83 Agriculture...Miscellaneous Provisions § 947.83 Duration of immunities. The benefits, privileges, and immunities conferred upon any persons by virtue...

2013-01-01

178

7 CFR 905.85 - Duration of immunities.  

Code of Federal Regulations, 2013 CFR

... 2013-01-01 false Duration of immunities. 905.85 Section 905.85 Agriculture...Miscellaneous Provisions § 905.85 Duration of immunities. The benefits, privileges, and immunities conferred upon any person by virtue of...

2013-01-01

179

7 CFR 966.87 - Duration of immunities.  

Code of Federal Regulations, 2013 CFR

... 2013-01-01 false Duration of immunities. 966.87 Section 966.87 Agriculture...Miscellaneous Provisions § 966.87 Duration of immunities. The benefits, privileges, and immunities conferred upon any person by virtue of...

2013-01-01

180

7 CFR 956.91 - Duration of immunities.  

Code of Federal Regulations, 2013 CFR

... 2013-01-01 false Duration of immunities. 956.91 Section 956.91 Agriculture...Miscellaneous Provisions § 956.91 Duration of immunities. The benefits, privileges, and immunities conferred upon any person by virtue of...

2013-01-01

181

7 CFR 930.86 - Duration of immunities.  

Code of Federal Regulations, 2013 CFR

... 2013-01-01 false Duration of immunities. 930.86 Section 930.86 Agriculture...Miscellaneous Provisions § 930.86 Duration of immunities. The benefits, privileges, and immunities conferred upon any person by virtue of...

2013-01-01

182

7 CFR 946.73 - Duration of immunities.  

Code of Federal Regulations, 2013 CFR

... 2013-01-01 false Duration of immunities. 946.73 Section 946.73 Agriculture...Miscellaneous Provisions § 946.73 Duration of immunities. The benefits, privileges, and immunities conferred upon any person by virtue of...

2013-01-01

183

7 CFR 987.80 - Duration of immunities.  

Code of Federal Regulations, 2013 CFR

... 2013-01-01 false Duration of immunities. 987.80 Section 987.80 Agriculture...Miscellaneous Provisions § 987.80 Duration of immunities. The benefits, privileges, and immunities conferred upon any person by virtue of...

2013-01-01

184

7 CFR 958.83 - Duration of immunities.  

Code of Federal Regulations, 2013 CFR

... 2013-01-01 false Duration of immunities. 958.83 Section 958.83 Agriculture...Miscellaneous Provisions § 958.83 Duration of immunities. The benefits, privileges, and immunities conferred upon any person by virtue of...

2013-01-01

185

7 CFR 985.69 - Duration of immunities.  

Code of Federal Regulations, 2013 CFR

... 2013-01-01 false Duration of immunities. 985.69 Section 985.69 Agriculture...Miscellaneous Provisions § 985.69 Duration of immunities. The benefits, privileges, and immunities conferred upon any person by virtue of...

2013-01-01

186

7 CFR 945.86 - Duration of immunities.  

Code of Federal Regulations, 2013 CFR

... 2013-01-01 false Duration of immunities. 945.86 Section 945.86 Agriculture...Miscellaneous Provisions § 945.86 Duration of immunities. The benefits, privileges, and immunities conferred upon any person by virtue of...

2013-01-01

187

7 CFR 920.66 - Duration of immunities.  

Code of Federal Regulations, 2013 CFR

... 2013-01-01 false Duration of immunities. 920.66 Section 920.66 Agriculture...Miscellaneous Provisions § 920.66 Duration of immunities. The benefits, priviliges, and immunities conferred upon any person by virtue of...

2013-01-01

188

7 CFR 922.67 - Duration of immunities.  

Code of Federal Regulations, 2013 CFR

... 2013-01-01 false Duration of immunities. 922.67 Section 922.67 Agriculture...Miscellaneous Provisions § 922.67 Duration of immunities. The benefits, privileges, and immunities conferred upon any person by virtue of...

2013-01-01

189

7 CFR 989.88 - Duration of immunities.  

Code of Federal Regulations, 2013 CFR

... 2013-01-01 false Duration of immunities. 989.88 Section 989.88 Agriculture...Miscellaneous Provisions § 989.88 Duration of immunities. The benefits, privileges, and immunities conferred upon any person by virtue of...

2013-01-01

190

7 CFR 923.67 - Duration of immunities.  

Code of Federal Regulations, 2013 CFR

... 2013-01-01 false Duration of immunities. 923.67 Section 923.67 Agriculture...Miscellaneous Provisions § 923.67 Duration of immunities. The benefits, privileges, and immunities conferred upon any person by virtue of...

2013-01-01

191

7 CFR 959.87 - Duration of immunities.  

Code of Federal Regulations, 2013 CFR

... 2013-01-01 false Duration of immunities. 959.87 Section 959.87 Agriculture...Miscellaneous Provisions § 959.87 Duration of immunities. The benefits, privileges, and immunities conferred upon any person by virtue of...

2013-01-01

192

7 CFR 917.65 - Duration of immunities.  

Code of Federal Regulations, 2013 CFR

... 2013-01-01 false Duration of immunities. 917.65 Section 917.65 Agriculture...Miscellaneous Provisions § 917.65 Duration of immunities. The benefits, privileges, and immunities conferred by virtue of the...

2013-01-01

193

7 CFR 993.87 - Duration of immunities.  

Code of Federal Regulations, 2013 CFR

... 2013-01-01 false Duration of immunities. 993.87 Section 993.87 Agriculture...Miscellaneous Provisions § 993.87 Duration of immunities. The benefits, privileges, and immunities conferred upon any person by virtue of...

2013-01-01

194

7 CFR 927.72 - Duration of immunities.  

Code of Federal Regulations, 2013 CFR

... 2013-01-01 false Duration of immunities. 927.72 Section 927.72 Agriculture...Miscellaneous Provisions § 927.72 Duration of immunities. The benefits, privileges, and immunities conferred by virtue of this subpart...

2013-01-01

195

7 CFR 955.82 - Duration of immunities.  

Code of Federal Regulations, 2013 CFR

... 2013-01-01 false Duration of immunities. 955.82 Section 955.82 Agriculture...Miscellaneous Provisions § 955.82 Duration of immunities. The benefits, privileges, and immunities conferred upon any person by virtue of...

2013-01-01

196

7 CFR 906.58 - Duration of immunities.  

Code of Federal Regulations, 2013 CFR

... 2013-01-01 false Duration of immunities. 906.58 Section 906.58 Agriculture...Miscellaneous Provisions § 906.58 Duration of immunities. The benefits, privileges, and immunities conferred upon any person by virtue of...

2013-01-01

197

7 CFR 984.87 - Duration of immunities.  

Code of Federal Regulations, 2013 CFR

... 2013-01-01 false Duration of immunities. 984.87 Section 984.87 Agriculture...Miscellaneous Provisions § 984.87 Duration of immunities. The benefits, privileges, and immunities conferred upon any person by virtue of...

2013-01-01

198

Overview of the capabilities of long duration balloon flight ground station equipment of the National Scientific Balloon Facility  

Microsoft Academic Search

Long duration balloon (LDB) flights are very complex endeavors. They require months of preparation on the part of the scientific team members as well as personnel from the National Scientific Balloon Facility (NSBF), the Physical Science Laboratory at New Mexico State University and other organizations, which vary with the flight specifics. Much of this complexity is due to the wide

S. Breeding; B. Stilwell

2002-01-01

199

38 CFR 21.73 - Duration of employment assistance programs.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Duration of employment assistance programs. 21.73 Section...EDUCATION Vocational Rehabilitation and Employment Under 38 U.S.C. Chapter 31 Duration...Rehabilitation Programs § 21.73 Duration of employment assistance programs. (a)...

2013-07-01

200

Time in Language: Event Duration in Language Comprehension  

ERIC Educational Resources Information Center

|This work investigates how we process and represent event duration in on-line language comprehension. Specifically, it examines how events of different duration are processed and what type of knowledge underlies their representations. Studies 1-4 examined verbs and phrases in different contexts. They showed that durative events took longer to…

Coll-Florit, Marta; Gennari, Silvia P.

2011-01-01

201

Analyzing sunlight duration and optimum shading using a sky map  

Microsoft Academic Search

A method of predicting the sunlight duration on windows in a densely packed building environment is presented. This method is based on dividing the hemispherical sky into small patches of 5°×5° and determining (using long-term climatic data) the probable sunlight duration with the sun locating in each sky patch. Hence, a sky map is constructed which gives the sunlight duration

H. D. Cheung; T. M. Chung

2007-01-01

202

When do auditory\\/visual differences in duration judgements occur?  

Microsoft Academic Search

Four experiments examined judgements of the duration of auditory and visual stimuli. Two used a bisection method, and two used verbal estimation. Auditory\\/visual differences were found when durations of auditory and visual stimuli were explicitly compared and when durations from both modalities were mixed in partition bisection. Differences in verbal estimation were also found both when people received a single

J. H. Wearden; N. P. M. Todd; L. A. Jones

2006-01-01

203

An exploratory hazard-based analysis of highway incident duration  

Microsoft Academic Search

The statistical analysis of highway incident duration has become an increasingly import research topic due to the impact that highway incidents (vehicle accidents and disablements) have on traffic congestion. In addition, there is a growing need to evaluate incident management programs that seek to reduce incident duration and incident-induced traffic congestion. We apply hazard-based duration models to statistically evaluate the

Doohee Nam; Fred Mannering

2000-01-01

204

Third-party Interventions and the Duration of Intrastate Conflicts  

Microsoft Academic Search

Recent research has begun to focus on the role of outside interventions in the duration of civil conflicts. Assuming that interventions are a form of conflict management, ex ante expectations would be that they would reduce a conflict's expected duration. Hypotheses relating the type and timing of outside interventions to the duration of civil conflicts are tested. The data incorporate

PATRICK M. REGAN

2002-01-01

205

Duration neglect by numbers—And its elimination by graphs  

Microsoft Academic Search

People tend to neglect duration when retrospectively evaluating aversive experiences, causing memories to be at odds with experienced pain. However, memory was not involved in the original demonstration of duration neglect. Instead, people evaluated others’ experiences represented by lists of discomfort ratings. Duration was said to be neglected because attention was focused on peak and end ratings. Three experiments are

Michael J. Liersch; Craig R. M. McKenzie

2009-01-01

206

Determinants of Unemployment Duration For Men and Women  

Microsoft Academic Search

There are few studies on unemployment duration in developing countries. This is the first study on duration aspect of unemployment in Turkey. We use the results of the Household Labor Force Surveys of 2000 and 2001 to construct a cross-section of durations of unemployment spells. We analyze the determinants of probability of leaving unemployment or the hazard rate. The effects

Aysit Tansel; H. Mehmet Tasci

2003-01-01

207

Determinants of Unemployment Duration for Men and Women in Turkey  

Microsoft Academic Search

There are few studies on unemployment duration in developing countries. This is the first study on duration aspect of unemployment in Turkey. We use the results of the Household Labor Force Surveys of 2000 and 2001 to construct a cross-section of durations of unemployment spells. We analyze the determinants of probability of leaving unemployment or the hazard rate. The effects

Aysit Tansel; H. Mehmet Tasci

2004-01-01

208

Synthetic regional flow duration curve for southern Taiwan  

Microsoft Academic Search

The primary purpose of this study is to develop the regional flow duration curves for southern Taiwan. To define homogeneous regions for developing regional flow duration curves, multivariate statistical analysis (principal component and cluster analysis) was applied to daily flow data from 34 stream-gauged stations in southern Taiwan. Two kinds of clustering variables, the dimensionless flow duration curve and specific

Pao-Shan Yu; Tao-Chang Yang

1996-01-01

209

Dietary nutrients associated with short and long sleep duration. Data from a nationally representative sample.  

PubMed

Short sleep duration is associated with weight gain and obesity, diabetes, cardiovascular disease, psychiatric illness, and performance deficits. Likewise, long sleep duration is also associated with poor physical and mental health. The role of a healthy diet in habitual sleep duration represents a largely unexplored pathway linking sleep and health. This study evaluated associations between habitual sleep parameters and dietary/nutritional variables obtained via the National Health and Nutrition Examination Survey (NHANES), 2007-2008. We hypothesized that habitual very short (<5h) short (5-6h) and long (9+h) sleep durations are associated with intake of a number of dietary nutrient variables. Overall, energy intake varied across very short (2036kcal), short (2201kcal), and long (1926kcal) sleep duration, relative to normal (2151kcal) sleep duration (p=0.001). Normal sleep duration was associated with the greatest food variety (17.8), compared to very short (14.0), short (16.5) and long (16.3) sleep duration (p<0.001). Associations between sleep duration were found across nutrient categories, with significant associations between habitual sleep duration and proteins, carbohydrates, vitamins and minerals. In stepwise analyses, significant contributors of unique variance included theobromine (long sleep RR=0.910, p<0.05), vitamin C (short sleep RR=0.890, p<0.05), tap water (short sleep RR=0.952, p<0.001; very short (<5h) sleep RR=0.941, p<0.05), lutein+zeaxanthin (short sleep RR=1.123, p<0.05), dodecanoic acid (long sleep RR=0.812, p<0.05), choline (long sleep RR=0.450, p=0.001), lycopene (very short (<5h) sleep RR=0.950, p<0.05), total carbohydrate (very short (<5h) sleep RR=0.494, p<0.05; long sleep RR=0.509, p<0.05), selenium (short sleep RR=0.670, p<0.01) and alcohol (long sleep RR=1.172, p<0.01). Overall, many nutrient variables were associated with short and/or long sleep duration, which may be explained by differences in food variety. Future studies should assess whether these associations are due to appetite dysregulation, due to short/long sleep and/or whether these nutrients have physiologic effects on sleep regulation. In addition, these data may help us better understand the complex relationship between diet and sleep and the potential role of diet in the relationship between sleep and obesity and other cardiometabolic risks. PMID:23339991

Grandner, Michael A; Jackson, Nicholas; Gerstner, Jason R; Knutson, Kristen L

2013-01-20

210

Bound Duration Theorem and DCPM Network Reduction  

Microsoft Academic Search

Decision critical path method (DCPM) is an extend method of CPM. The advantage of DCPM is that one network can provide a wide range of options to decision-maker. However, there exist plenty of decision activities in DCPM network, which make DCPM network very complex and hard to compute, which restricts its application in practice. Through the study we found that,

L. H. Zhang; Xiaoli Liu; Gang Zhong

2009-01-01

211

Local and Duration Magnitudes in Western Anatolia  

NASA Astrophysics Data System (ADS)

Kandilli Observatory and Earthquake Research Institute (KOERI) National Earthquake Monitoring Center (NEMC) has a well-designed broadband seismic network throughout Turkey. The network consists of 107 broadband seismometers (CMG-3T, CMG-3ESP/C, CMG-40T). Two types of magnitude scales used for broadband stations at NEMC. Local magnitude (Ml) and duration magnitude (Md) are calibrated using broadband stations. From 2006 through 2010, we calculate Ml values for western Anatolia earthquakes using maximum amplitudes on digital records from synthetic Wood-Anderson seismographs. We determine empirical Ml station corrections that minimize differences between Ml’s calculated from different type of broadband sensors. Application of these station corrections, in combination with distance corrections from Richter (1958) which have been in use at NEMC since 2003, produces Ml values that do not show any significant distance dependence. Ml determinations for western Anatolia (Marmara and Aegean regions) for 2006-2010 using our station corrections and Richter’s distance corrections have provided a reliable data set for recalibrating the Md scales for these regions. Our revised Ml values are consistent with available moment magnitude determinations for the western Anatolia earthquakes. Finally Md is calibrated against revised Ml and empirical equations are determined both magnitude scales.

Gorgun, E.; Comoglu, M.; Koseoglu Kusmezer, A.; Kekovali, K.; Kalafat, D.

2010-12-01

212

Strength-duration properties in diabetic polyneuropathy.  

PubMed

We sought to examine the changes in the strength-duration time constant (SDTC) of the median nerve in diabetic polyneuropathy. The SDTC is a measure of axonal excitability and depends on the biophysical properties of the axonal membrane. It may provide some information about Na(+) channel functioning. Forty-nine diabetic patients (30 men, 19 women; mean age, 54.6+/-9.4 years) and 15 age-matched healthy subjects (11 men, 4 women; mean age, 53.1+/-7.6 years) participated in the study. SDTC and rheobase values were 384.5+/-97.9 micros and 4.6+/-2.4 mA in patients and 313.8+/-46.7 micros and 6.0+/-2.6 mA in controls. The SDTC was found to be significantly different between the two groups (P=.009 for SDTC and P=.066 for rheobase). Fasting glucose and HbA1c levels of patients were 206.6+/-88.7 mg/dL and 8.8+/-2.4%, and these were not correlated with SDTC or rheobase (P<.05). We suggest that longer SDTC, indicating increased axonal excitability may develop in patients with polyneuropathy associated with uncontrolled diabetes. PMID:17408800

Yerdelen, Deniz; Koç, Filiz; Uysal, Hilmi; Sarica, Yakup

2007-04-03

213

Immune changes during short-duration missions.  

PubMed

Spaceflight materially influences the immune mechanism of humans and animals. Effects resulting from missions of less than 1 month are examined. Effects from longer missions are discussed in the companion paper by Konstantinova et al. Most immunology studies have involved analyses of subjects and samples from subjects obtained after flight, with the data being compared with similar data obtained before flight. These studies have demonstrated that short-duration missions can result in a postflight depression in blast cell transformation, major changes in cytokine function, and alterations in the relative numbers of immune cell populations. In addition to these post- vs. preflight studies, some data have been produced in flight. However, these in vitro analyses have been less than satisfactory because of differences between in-flight and ground-control conditions. Recently, both the U.S. and Russian space programs have started collecting in-flight, in vivo, cell-mediated immunity data. These studies have confirmed that the human cell-mediated immune system is blunted during spaceflight. PMID:8371049

Taylor, G R

1993-09-01

214

NASA long duration balloon capability development project  

NASA Astrophysics Data System (ADS)

The potential benefits of a Long Duration Balloon (LDB) capability have long been recognized and some modest efforts have previously been undertaken by the National Center for Atmospheric Research (NCAR), the National Scientific Balloon Facility (NSBF), et. al., going back to the late 1960's. In 1988, the National Aeronautics and Space Administration (NASA) made a decision to dedicate significant resources toward this effort and a technical and management approach was established. The objective of the project is to develop a near global LDB capability for both Antarctic and mid-latitude applications, including the required telecommunications, navigation and positioning, power, data processing and control systems necessary to conduct flights of scientific experiments weighing 1500 pounds or more on conventional balloons for periods of up to three weeks. The first operational use of the new capability is planned in support of Solar Max experiments in Antarctica during the 1991-1992 austral summer. Development of the Antarctica support system configuration has been initiated and the first test flight was conducted from McMurdo Station in December 1989 - January 1990. The progress, status and future plans for development of the new LDB capability will be discussed.

Stuchlik, D.; Craddock, W.

1993-02-01

215

Duration comparison: relative stimulus differences stimulus age, and stimulus predictiveness.  

PubMed Central

Under a psychophysical trials procedure, pigeons were presented with a red light of one duration followed by a green light of a second duration. Eight geometrically spaced base durations were paired with one of four shorter and four longer durations as the alternate member of a duration pair, with different pairs randomly intermixed. One choice was reinforced if red had lasted longer than green, and a second choice was reinforced if green had lasted longer. Performance was compared when all the base durations and their pair members were included (entire-range condition) or when only the four longest base durations and their comparison durations (restricted-range condition) were used. Discrimination sensitivity decreased for longer duration pairs under both conditions, supporting a memory-based account. Sensitivity was lower under the restricted-range condition. Under both conditions, a bias to report "green as longer" increased as the second green duration increased. Bias changed as a matching function of the green-duration predictiveness of the correct choice. The results are related to a quantitative model of timing and remembering proposed by Staddon.

Stubbs, D A; Dreyfus, L R; Fetterman, J G; Boynton, D M; Locklin, N; Smith, L D

1994-01-01

216

Dependence on pulse duration and foil thickness in high-contrast-laser proton acceleration  

NASA Astrophysics Data System (ADS)

Experimental measurements of proton acceleration with high intensity and high-contrast short laser pulses have been carried out over an order of magnitude range in target thickness and laser pulse duration. The dependence of the maximum proton energy with these parameters is qualitatively supported by two-dimensional particle-in-cell simulations. They evidence that two regimes of proton acceleration can take place, depending on the ratio between the density gradient and the hot electron Debye length at the rear target surface. As this ratio can be affected by the target thickness, a complex interplay between pulse duration and target thickness is observed. Measurements and simulations support unexpected variations in the laser absorption and hot electron temperature with the pulse duration and laser intensity, for which density profile modification at the target front surface is the controlling parameter.

Flacco, A.; Sylla, F.; Veltcheva, M.; Carrié, M.; Nuter, R.; Lefebvre, E.; Batani, D.; Malka, V.

2010-03-01

217

Organizational Determinants of Outpatient Substance Abuse Treatment Duration in Women  

PubMed Central

Longer treatment duration has consistently been related to improved substance use outcomes. This study examined how tailored women's programming and organizational characteristics were related to duration in outpatient substance abuse treatment in women. Data were from two waves of a national outpatient substance abuse treatment unit survey (n=571 in 1999/2000, n=566 in 2005). Analyses were conducted separately for methadone and non-methadone programs. Negative binomial regressions tested associations between organizational determinants, tailored programming, and women's treatment duration. Of the tailored programming services, childcare was significantly related to longer duration in the non-methadone programs, but few other organizational factors were. Tailored programming was not associated to treatment duration in methadone programs, but ownership, affiliation, and accreditation were related to longer duration. Study findings suggest evidence for how external relationships related to resources, treatment constraints, and legitimacy may influence women's treatment duration. Methadone programs may be more vulnerable to external influences.

Alexander, Jeffrey A.; Lemak, Christy Harris

2009-01-01

218

Neurons in the inferior colliculus of the mustached bat are tuned both to echo-delay and sound duration.  

PubMed

Echolocation in bats requires a precise temporal processing of complex signals. This processing of time includes the encoding of echo-delay, which gives an estimation of target distance, and sound duration, which is considered to be important for own sound or echo recognition. In this study, we report that delay-tuned neurons in the inferior colliculus of the mustached bat (Pteronotus parnellii) are also tuned to sound duration. Collicular delay-tuned neurons showed three types of duration tuning: short-pass (12 of 64), band-pass (16 of 64), and long-pass (17 of 64). The remaining 19 delay-tuned neurons are not selective for sound duration. All short-pass and 10 band-pass neurons' characteristic delays were similar to characteristic duration. In six band-pass neurons, characteristic delay was different from characteristic duration. Neurons processing unmatched delay and durations could be participating in complex kinds of processing where the same neuron has different functions depending on the activated neural network. PMID:23492868

Macías, Silvio; Hechavarría, Julio C; Kössl, Manfred; Mora, Emanuel C

2013-05-29

219

Effect of exercise intensity and duration on postexercise energy expenditure.  

PubMed

The purpose of this study was to examine 1) the effect of two exercise intensities of equal caloric output on the magnitude (kcal) and duration of excess postexercise oxygen consumption (EPOC) and 2) the effect of exercise of equal intensity but varying duration on EPOC. Ten trained male triathletes performed three cycle ergometer exercises: high intensity-short duration (HS), low intensity-short duration (LS), and low intensity-long duration (LL). Baseline VO2 was measured for 1 h prior to each exercise condition. Postexercise VO2 was measured continuously until baseline VO2 was achieved. The duration of EPOC was similar for HS (33 +/- 10 min) and LL (28 +/- 14 min), and both were significantly longer (P less than 0.05) than the EPOC following LS (20 +/- 5 min). However, total net caloric expenditure was significantly more (P less than 0.05) for HS (29 +/- 8 kcal) than for either LS (14 +/- 6 kcal) or LL (12 +/- 7 kcal). The exercise conditions used in this study did not produce a prolonged EPOC. However, the exercise intensity was shown to affect both the magnitude and duration of EPOC, whereas the exercise duration affected only the duration of EPOC. Moreover, the duration of EPOC and the subsequent caloric expenditure were not necessarily related. Based on the resulting magnitude of the postexercise energy expenditure, it is possible that EPOC may be of some value for weight control over the long term. PMID:2626089

Sedlock, D A; Fissinger, J A; Melby, C L

1989-12-01

220

Personal growth following long-duration spaceflight  

NASA Astrophysics Data System (ADS)

IntroductionSalutogenesis and posttraumatic growth represent personal growth and improved functioning as a result of experiencing major challenging events. These developments are not simply resilience (a return to a baseline level of well-being), but positive change in such characteristics as self-understanding, relations with others, personal values, and life goals. Space agencies and space psychologists, primarily concerned with deleterious effects and their countermeasures, have not paid much attention to such beneficial long-term aftereffects of spaceflight. PurposeTo document what changes veterans of the Soviet/Russian space program report as a consequence of their experiences. MethodTwenty retired male cosmonauts Mir and/or ISS cosmonauts filled out relevant self-report questionnaires. Results: Although there was little change in the relative rankings of a list of values, the scale showed an overall increase in the rated importance of all personal values, although only the increase in Self-Direction reached statistical significance. Responses to one of two post-space growth questionnaires based on the Post-Traumatic Growth Inventory (PTGI) were compared to the means of two comparison groups: 152 first-time mothers, and 926 respondents who had experienced various forms of trauma. The cosmonauts reported higher scores on the dimension of New Possibilities when compared to the new mothers and the traumatized group, and higher scores on Personal Strength and Overall PTG compared to the latter. Respondents who had spent more than a year in space, and those who flew on both Mir and ISS, were the most likely to report positive change in the domain Appreciation of Life. The other post-space career questionnaire reflected major changes in Perceptions of the Earth and of Space, and increases on a number of other dimensions, including New Possibilities and Changes in Daily Life, with positive scores that significantly exceeded the original report. DiscussionIt appears that cosmonauts do experience various aspects of positive personal growth following their space flights. As long-duration missions are (and will remain) the norm, it is important for the space agencies and the voyagers themselves to develop a better understanding and possible enhancement of this phenomenon.

Suedfeld, Peter; Brcic, Jelena; Johnson, Phyllis J.; Gushin, Vadim

2012-10-01

221

Ethnic polarization and the duration of civil wars  

Microsoft Academic Search

In this paper we analyze the relationship between ethnic polarization and the duration of civil wars. Several recent papers\\u000a have argued that the uncertainty about the relative power of the contenders in a war will tend to increase its duration. In\\u000a these models, uncertainty is directly related to the relative size of the contenders. We argue that the duration of

Jose G. Montalvo; Marta Reynal-Querol

2010-01-01

222

50 W thin-disk laser with variable pulse duration  

Microsoft Academic Search

The laser system is based on an Yb:YAG thin-disk regenerative amplifier, which is operated in different operation modes in order to address broad spectrum of pulse durations. It is especially interesting for application development tasks, when different pulse durations can be tested to find the application optimum. For sub-picosecond pulse duration the dispersion of the regenerative amplifier output is compensated

Mikhail Larionov; Friedrich Dausinger

2011-01-01

223

Modeling the frequency and duration of microbial contamination events  

Microsoft Academic Search

The frequency and duration of microbial contamination events in the environment in which ready-to-eat (RTE) foods are exposed for processing and packaging is subject to uncertainty and variability. Variability, within-model parameter uncertainty, and uncertainty regarding model selection are formally considered in modeling the frequency and duration of such contamination events by Listeria species. The estimated duration of contamination events represents

Mark R. Powell

2006-01-01

224

Finite Horizon Job Search, Null Offers and the Duration of Search Unemployment  

Microsoft Academic Search

The predictions of job-search theory for an analysis of unemployment have long been of interest (e.g. see Lippman and McCall (1976 b), Barron (1975) and Feinberg (1977)). In particular an important question is with regard to the duration of search unemployment and its determinants. Unfortunately robust results in this area are few. The reason for this being the complexity of

Martin Chalkley

1982-01-01

225

Factors that Influence Weekday Sleep Duration in European Children  

PubMed Central

Study Objectives: To compare nocturnal sleep duration in children from 8 European countries and identify its determinants. Design: Cross-sectional. Setting: Primary schools and preschools participating in the IDEFICS study. Participants: 8,542 children aged 2 to 9 years from 8 European countries with complete information on nocturnal sleep duration. Interventions: Not applicable. Measurements: Nocturnal sleep duration was assessed by means of a computer based parental 24-h recall. Data on personal, social, environmental, and behavioral factors were collected by means of standardized parental questionnaire. Physical activity was surveyed with accelerometers. Results: Nocturnal sleep duration in the participating countries ranged from 9.5 h (SD 0.8) in Estonia to 11.2 h (SD 0.7) in Belgium and differed significantly between countries (P < 0.001) in univariate as well as in multivariate analyses, with children from northern countries sleeping the longest. Sleep duration decreased by about 6 min with each year of age over all countries. No effect of season, daylight duration, overweight, parental education level, or lifestyle factors could be seen. Conclusion: Sleep duration differs significantly between countries. Our findings allow for the conclusion that regional affiliation, including culture and environmental characteristics, seems to overlay individual determinants of sleep duration. Citation: Hense S; Barba G; Pohlabeln H; De Henauw S; Marild S; Molnar D; Moreno LA; Hadjigeorgiou C; Veidebaum T; Ahrens W. Factors that influence weekday sleep duration in European children. SLEEP 2011;34(5):633-639.

Hense, Sabrina; Barba, Gianvincenzo; Pohlabeln, Hermann; De Henauw, Stefaan; Marild, Staffan; Molnar, Denes; Moreno, Luis A.; Hadjigeorgiou, Charalampos; Veidebaum, Toomas; Ahrens, Wolfgang

2011-01-01

226

On the role of storm duration in the mapping of rainfall to flood return periods  

NASA Astrophysics Data System (ADS)

While the correspondence of rainfall return period TP and flood return period TQ is at the heart of the design storm procedure, their relationship is still poorly understood. The purpose of this paper is to shed light on the controls on this relationship. To better understand the interplay of the controlling factors we assume a simplified world with block rainfall, constant runoff coefficient and linear catchment response. We use an analytical derived flood frequency approach in which, following design practise, TP is defined as the return period of the intensity-duration-frequency (IDF) curve given storm duration and depth. Results suggest that the main control on the mapping of rainfall to flood return periods is the ratio of storm duration and catchment response time, as would be expected. In the simple world assumed in this work, TQ is always smaller or equal than TP of the associated storm, i.e., TQ/TP?1. This is because of the difference in the selectiveness of the rectangular filters used to construct the IDF curves and the unit hydrograph (UH) together with the fact that different rectangular filters are used when evaluating the storm return periods. The critical storm duration that maximises TQ/TP is, in descending importance, a function of the catchment response time and the distribution of storm duration, while the maximum value of TQ/TP is mainly a function of the coefficient of variation of storm duration. The study provides the basis for future analyses, where more complex cases will be examined.

Viglione, A.; Blöschl, G.

2009-02-01

227

Changes in SEMG during the Long Duration Cycling Exercise  

Microsoft Academic Search

Identification of muscle fatigue using surface electromyogram (SEMG) has always been both desirable and difficult for the engineering and medical community. Changes in SEMG are already established by authors when fatigue occurs as a result of short duration, supramaximal dynamic contraction. But most of the contractions that we have during a days work are not supramaximal and short duration, they

Vijay P Singh; Dinesh K Kumar; Barbara Polus; Sonia Lo Guidice; Steve Fraser

2006-01-01

228

Correcting Memory Improves Accuracy of Predicted Task Duration  

Microsoft Academic Search

People are often inaccurate in predicting task duration. The memory bias explanation holds that this error is due to people having incorrect memories of how long previous tasks have taken, and these biased memories cause biased predictions. Therefore, the authors examined the effect on increasing predictive accuracy of correcting memory through supplying feedback for actual task duration. For Experiments 1

Michael M. Roy; Scott T. Mitten; Nicholas J. S. Christenfeld

2008-01-01

229

Internal Clock Processes and the Filled-Duration Illusion  

ERIC Educational Resources Information Center

|In 3 experiments, the authors compared duration judgments of filled stimuli (tones) with unfilled ones (intervals defined by clicks or gaps in tones). Temporal generalization procedures (Experiment 1) and verbal estimation procedures (Experiments 2 and 3) all showed that subjective durations of the tones were considerably longer than those of…

Wearden, John H.; Norton, Roger; Martin, Simon; Montford-Bebb, Oliver

2007-01-01

230

45 CFR 1180.58 - Duration of grants.  

Code of Federal Regulations, 2011 CFR

... 2011-10-01 false Duration of grants. 1180.58 Section 1180.58 Public...INSTITUTE OF MUSEUM AND LIBRARY SERVICES GRANTS REGULATIONS General Conditions Which...Responsibilities § 1180.58 Duration of grants. The grantee may use grant funds...

2011-10-01

231

Chronic schizophrenics with positive symptomatology have shortened EEG microstate durations  

Microsoft Academic Search

Objective: In young, first-episode, never-treated schizophrenics compared with controls, (a) generally shorter durations of EEG microstates were reported (Koukkou et al., Brain Topogr 6 (1994) 251; Kinoshita et al., Psychiatry Res Neuroimaging 83 (1998) 58), and (b) specifically, shorter duration of a particular class of microstates (Koenig et al., Eur Arch Psychiatry Clin Neurosci 249 (1999) 205). We now examined

V Strelets; P. L Faber; J Golikova; V Novototsky-Vlasov; T Koenig; L. R. R Gianotti; J. H Gruzelier; D Lehmann

2003-01-01

232

7 CFR 948.87 - Duration of immunities.  

Code of Federal Regulations, 2013 CFR

...2013-01-01 2013-01-01 false Duration of immunities. 948.87 Section 948.87 Agriculture...Miscellaneous Provisions § 948.87 Duration of immunities. The benefits, privileges and immunities conferred upon any person by virtue of...

2013-01-01

233

Optimization of commercial bank's value based on random duration  

Microsoft Academic Search

Bank's net cash flow and income approach was chosen to analyze the optimization of commercial bank's value on the study of the nature of commercial bank's value, enterprise value theories and evaluation approaches, bank's interest rate risks and their assessment methods. Financial instrument's random duration based on continuous time was defined. Furthermore, the random duration method was applied to manage

Ying Yin; Liang-rong Song

2011-01-01

234

Short sleep duration and obesity among Australian children  

Microsoft Academic Search

BACKGROUND: There is limited information on sleep duration and obesity among Australian children. The objective of the study is to cross-sectionally examine the relationship between sleep duration and obesity in Australian children aged 5 to 15 years. METHODS: Data were collected using the South Australian Monitoring and Surveillance System between January 2004 and December 2008. Each month a representative random

Zumin Shi; Anne W Taylor; Tiffany K Gill; Jane Tuckerman; Robert Adams; James Martin

2010-01-01

235

Political Institutions, Coercive Diplomacy, and the Duration of Economic Sanctions  

Microsoft Academic Search

A theory of sanction duration that focuses on differences between democratic and nondemocratic states in the structure of leaders’ support coalitions is tested, using a hazard model to analyze a data set of 47 sanction events with 272 observations. Results show that leadership change strongly affects the duration of sanctions only in the case of nondemocratic states. Leadership change in

Fiona McGillivray; Allan C. Stam

2004-01-01

236

A three-site comparison of fade-duration measurements  

Microsoft Academic Search

Important elements in the design of Ka-band communication systems are the duration of fade and nonfade events at a particular fade depth. The choice of modulation and forward error correcting codes will depend on both the fading time dynamics and annual fade occurrence statistics. This paper examines the fade duration measured at locations in three of the Advanced Communications Technology

H. Helmken; R. E. Henning; J. Feil; L. J. Ippolito; C. E. Mayer

1997-01-01

237

The duration analysis of the checked tones in Cantonese speech  

Microsoft Academic Search

It is well known that the duration reflects the difference between checked tone's syllables and other syllables in Cantonese. In this paper, aiming at improving the naturalness of the Cantonese TTS system, we use two concepts, the voice blank and pitch contour blank, to examine the particularity of the checked tone's duration with a serial designed experiments in Cantonese speech.

Xiaoying Xu; Jianhua Tao; Ling Zhang; Yingchao Lu

2010-01-01

238

Initiation of primary explosives by electron pulses of microsecond duration  

Microsoft Academic Search

The explosive decomposition of initiating explosives, namely, lead, silver, cadmium, and thallium azides, potassium picrate, lead styphnate, mercury fulminate, and tetrazene, on irradiation by electron pulses of various durations was studied. The critical parameters of electron pulses that initiate specimen explosions are determined. The critical energy density in pulses of microsecond duration is shown to be less than that in

S. M. Ryabykh; V. P. Zhulanova; N. V. Kholodkovskaya; V. G. Shakhovalov

1996-01-01

239

Unemployment Insurance and Male Unemployment Duration in Canada  

Microsoft Academic Search

A model of unemployment duration is estimated with weekly micro data on Canadian men. Ent itlement provisions in the unemployment insurance program and demand conditions are found to have a significant effect on the probability of leaving unemployment. The probability of a worker leaving unemploy ment declines with the duration of unemployment, holding unemployment insurance entitlement constant. When entitlement is

John C. Ham

1987-01-01

240

Contingent Durations in Temporal CSPs: From Consistency to Controllabilities  

Microsoft Academic Search

Temporal Constraint Networks (TCSP) allow to ex- press minimal and maximal durations between time- points. Though being used in many research areas, this model disregards the contingent nature of some constraints, whose eective duration cannot be decided by the system but is provided by the external world. We propose an extension of TCSP in which the classi- cal network consistency

Thierry Vidal; Hélène Fargier

1997-01-01

241

Non-segmental duration feature extraction for prosodic classification  

Microsoft Academic Search

This paper presents a set of novel duration features for detecting pitch accent and phrase boundaries, which depend on articula- tory timing rather than segmental duration information. The features are computed from the detected syllable nuclei and boundaries, using peaks and valleys in an energy contour but also leveraging information from a simple HMM phone man- ner class recognizer to

Amy Dashiell; Brian Hutchinson; Anna Margolis; Mari Ostendorf

2008-01-01

242

The role of tone duration in dichotic temporal order judgment.  

PubMed

Over the past two decades, a number of studies have been based on the dichotic temporal order judgment (TOJ) paradigm, to compare auditory temporal processing in various subpopulations to that of young, normal controls. The reported estimates of dichotic TOJ thresholds, expressed as the interstimulus intervals (ISIs) for 75 % accuracy among the controls, have varied. In the present study, we examined the influence of tone duration, within the 10- to 40-msec range, on dichotic TOJ accuracy and threshold. The results indicated that increases in either ISI or tone duration increased dichotic TOJ accuracy similarly, implying that changes in tone duration may affect dichotic TOJs simply by adding to the delay between onset of the tone at the lead ear and onset of the tone at the lag ear. The dichotic TOJ thresholds from three published studies that had used tones as stimuli and the dichotic thresholds from the present study all fell within 0.5 standard deviations from the theoretical line of a 10-msec reduction in threshold for every 10-msec increase in tone duration. When the dichotic TOJ threshold data from the present study and from the published studies were converted to stimulus onset asynchronies (SOAs) and plotted as a function of tone duration, they fell very close to or on a zero-slope line, indicating that when ISI and duration are summed to yield an SOA, dichotic TOJ thresholds are invariant to tone duration within the range of 10-40 msec. PMID:23572206

Babkoff, Harvey; Fostick, Leah

2013-05-01

243

Sequential forecast of incident duration using Artificial Neural Network models.  

PubMed

This study creates an adaptive procedure for sequential forecasting of incident duration. This adaptive procedure includes two adaptive Artificial Neural Network-based models as well as the data fusion techniques to forecast incident duration. Model A is used to forecast the duration time at the time of incident notification, while Model B provides multi-period updates of duration time after the incident notification. These two models together provide a sequential forecast of incident duration from the point of incident notification to the incident road clearance. Model inputs include incident characteristics, traffic data, time gap, space gap, and geometric characteristics. The model performance of mean absolute percentage error for forecasted incident duration at each time point of forecast are mostly under 40%, which indicates that the proposed models have a reasonable forecast ability. With these two models, the estimated duration time can be provided by plugging in relevant traffic data as soon as an incident is reported. Thereby travelers and traffic management units can better understand the impact of the existing incident. Based on the model effect assessments, this study shows that the proposed models are feasible in the Intelligent Transportation Systems (ITS) context. PMID:17303059

Wei, Chien-Hung; Lee, Ying

2007-02-14

244

Modulation of tactile duration judgments by emotional pictures  

PubMed Central

Judging the duration of emotional stimuli is known to be influenced by their valence and arousal values. However, whether and how perceiving emotion in one modality affects time perception in another modality is still unclear. To investigate this, we compared the influence of different types of emotional pictures—a picture of threat, disgust, or a neutral picture presented at the start of a trial—on temporal bisection judgments of the duration of a subsequently presented vibrotactile stimulus. We found an overestimation of tactile duration following exposure to pictures of threat, but not pictures of disgust (even though these scored equally high on arousal), in a short-range temporal bisection task (range 300/900 ms). Follow-up experiments revealed that this duration lengthening effect was abolished when the range to be bisected was increased (1000/1900 ms). However, duration overestimation was maintained in the short-range bisection task regardless of whether the interval between the visual and tactile events was short or long. This pattern is inconsistent with a general arousal interpretation of duration distortion and suggests that crossmodal linkages in the processing of emotions and emotional regulation are two main factors underlying the manifestation of crossmodal duration modulation.

Shi, Zhuanghua; Jia, Lina; Muller, Hermann J.

2012-01-01

245

The effects of duration of in vitro maturation of bovine oocytes on subsequent development, quality and transfer of embryos  

Microsoft Academic Search

We examined the effects of IVM duration on rates of Korean Native Cow (KNC) first polar body extrusion, embryo development and offspring. Cumulus oocytes complexes were cultured in vitro for up to 24h. Extrusion of the first polar body was highest at 16h. At selected times during IVM, oocytes were fertilized and in vitro development was compared to blastocysts collected

Yong-Soo Park; So-Seob Kim; Jae-Myeoung Kim; Hum-Dai Park; Myung-Dae Byun

2005-01-01

246

Long-Tailed Duration Distributions for Disability in Aged People  

NASA Astrophysics Data System (ADS)

Long tails of the duration distributions for disabilities in the aged are analyzed. Log-normal distribution shows excellent fit with various data on the durations of disabilities, irrespective of their severity. Persisting long tails suggest the fractal nature of disability distributions. For approximately 60% of the patients, the duration distributions are also mimicked by the first passage time distribution (FPTD) of one-dimensional Brownian motion. The finding that the data fit the log-normal distribution very well and FPTD fairly well reveals disability for the aged to be a stochastic process of suffering successively from various endogenous diseases, i.e., multiple pathology.

Moriyama, Osamu; Itoh, Hiroto; Matsushita, Satoru; Matsushita, Mitsugu

2003-10-01

247

Leaf surface wetness duration measurements by radiogauge and electronic techniques  

SciTech Connect

Comparative measurements of leaf surface wetness duration were made by a beta-ray gauge and an electronic sensor under various wind conditions in the laboratory. Under certain conditions, surface wetness duration measured by the electronic sensor was about 35 minutes shorter than that by the beta-ray gauge. Fair agreement between the sensors at low wind speeds was achieved when the wire grid of the electronic sensor was mounted on a microscope cover glass. Realistic leaf surface wetness duration can be obtained with a beta-ray gauge as it utilizes the attached leaf surfaces rather than artificial ones used on the electronic sensor.

Barthakur, N.N.

1987-01-01

248

JWST: Pathfinder for Long-Duration Solar System Missions  

NASA Astrophysics Data System (ADS)

The James Webb Space Telescope (JWST) will not only explore the secrets of the distant universe but it may provide the key to the exploration of our solar system for both manned and unmanned long-duration missions.

Chu, W. K.; Clark, P.; Cox, R. T.; Scharfstein, G.; Winglee, R.

2011-03-01

249

7 CFR 983.85 - Duration of immunities.  

Code of Federal Regulations, 2013 CFR

...MARKETING AGREEMENTS AND ORDERS; FRUITS, VEGETABLES, NUTS), DEPARTMENT OF AGRICULTURE PISTACHIOS GROWN IN CALIFORNIA, ARIZONA, AND NEW MEXICO Miscellaneous Provisions § 983.85 Duration of immunities. The benefits, privileges, and...

2013-01-01

250

5 CFR 352.704 - Duration of reemployment rights.  

Code of Federal Regulations, 2013 CFR

... Reemployment Rights of Former Bureau of Indian Affairs and Indian Health Service...Employees After Service Under the Indian Self-Determination...352.704 Duration of reemployment rights...reemployment terminates at the end of 6 years following...

2013-01-01

251

Controlling Vibrational Excitations in C60 by Laser Pulse Durations  

NASA Astrophysics Data System (ADS)

Two similar off-resonant ultrafast laser experiments in C60 have reported two different vibrational modes that dominate the relaxation process: one predicts the Ag modes while the other the Hg modes. A systematical simulation presented here reveals that this experimental discrepancy results from the laser pulse duration. The numerical results show that since each mode ? has a distinctive optimal duration ??o, the Ag modes are strongly suppressed for durations longer than 40fs, while the Hg modes start to grow. For the off-resonant and low-intensity excitations, the period ?o? of the dominant mode and ??o satisfy the relation ?o?/??o?3.4. By carefully scanning the laser frequencies and pulse durations, a comprehensive excitation diagram is constructed, which can be used to guide experiments to selectively excite the Ag and Hg modes in C60 by an ultrafast laser. Its potential impact is also discussed.

Zhang, G. P.; George, Thomas F.

2004-09-01

252

Radiation Shielding Requirements on Long-Duration Space Missions.  

National Technical Information Service (NTIS)

An analysis of radiation shielding requirements on long duration space missions is presented. The report finds the principal radiation hazards to be galactic cosmic radiation (cosmic rays) and radiation from solar flares. Galactic cosmic radiation is a co...

J. R. Letaw S. Clearwater

1986-01-01

253

Improving Prediction of Surgery Duration using Operational and Temporal Factors  

PubMed Central

Inherent uncertainties in surgery durations impact many critical metrics about the performance of an operating room (OR) environment. OR schedules that are robust to natural variability in surgery durations require surgery duration estimates that are unbiased, with high accuracy, and with few cases with large absolute errors. Earlier studies have shown that factors such as patient severity, personnel, and procedure type greatly affect the accuracy of such estimations. In this paper we investigate whether operational and temporal factors can be used to improve these estimates further. We present an adjustment method based on a combination of these operational and temporal factors. We validate our method with two years of detailed operational data from an electronic medical record. We conclude that while improving estimates of surgery durations is possible, the inherent variability in such estimates remains high, necessitating caution in their use when optimizing OR schedules.

Kayis, Enis; Wang, Haiyan; Patel, Meghna; Gonzalez, Tere; Jain, Shelen; Ramamurthi, RJ; Santos, Cipriano; Singhal, Sharad; Suermondt, Jaap; Sylvester, Karl

2012-01-01

254

14 CFR 65.92 - Inspection authorization: Duration.  

Code of Federal Regulations, 2013 CFR

...AIRMEN CERTIFICATION: AIRMEN OTHER THAN FLIGHT CREWMEMBERS Mechanics § 65.92 Inspection authorization: Duration. ...that authorization only while he holds a currently effective mechanic certificate with both a currently effective airframe...

2013-01-01

255

7 CFR 1450.205 - Duration of contracts.  

Code of Federal Regulations, 2013 CFR

...Agriculture (Continued) COMMODITY CREDIT CORPORATION, DEPARTMENT OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS BIOMASS CROP ASSISTANCE PROGRAM (BCAP) Establishment Payments and Annual Payments § 1450.205 Duration of contracts....

2013-01-01

256

7 CFR 3430.709 - Duration of awards.  

Code of Federal Regulations, 2013 CFR

...AGRICULTURE COMPETITIVE AND NONCOMPETITIVE NON-FORMULA FEDERAL ASSISTANCE PROGRAMS-GENERAL AWARD ADMINISTRATIVE PROVISIONS Biomass Research and Development Initiative § 3430.709 Duration of awards. The term of a Federal assistance award made...

2013-01-01

257

Job Search Behavior: An Empirical Analysis of Unemployment Duration.  

National Technical Information Service (NTIS)

The study seeks to empirically verify the propositions regarding unemployment duration derived from theoretical analysis of job search behavior. The major thrust of the study is to identify not only individual but also household characteristics that affec...

S. Malhotra

1976-01-01

258

14 CFR 1203.407 - Duration of classification.  

Code of Federal Regulations, 2012 CFR

... Section 1203.407 Aeronautics and Space NATIONAL AERONAUTICS AND SPACE ADMINISTRATION INFORMATION SECURITY PROGRAM Guides for Original Classification § 1203.407 Duration of classification. (a) Information shall be classified as...

2012-01-01

259

Restitution of Action Potential Duration at the Purkinjeventricular Interface.  

National Technical Information Service (NTIS)

Regional differences in the restitution of action potential duration may be arrhythmogenic. Though such a difference exists at the Purkinje- ventricular interface, restitution kinetics have not yet been defined between coupled Purkinje and ventricular cel...

D. J. Huelsing

2001-01-01

260

A Road Map of Interval Temporal Logics and Duration Calculi  

Microsoft Academic Search

Abstract We survey main developments, results, and open problems on interval temporal logics and duration calculi We present various formal systems studied in the literature and discuss their distinctive features, emphasizing on expressiveness, axiomatic systems, and (un)decidability results

Valentin Goranko; Angelo Montanari; Guido Sciavicco

2004-01-01

261

Advanced Water Recovery Technologies for Long Duration Space Exploration Missions.  

National Technical Information Service (NTIS)

Extended-duration space travel and habitation require recovering water from wastewater generated in spacecrafts and extraterrestrial outposts since the largest consumable for human life support is water. Many wastewater treatment technologies used for ter...

S. X. Liu

2005-01-01

262

43 CFR 3140.5 - Duration of the lease.  

Code of Federal Regulations, 2012 CFR

...BUREAU OF LAND MANAGEMENT, DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) LEASING IN SPECIAL TAR SAND AREAS Conversion of Existing Oil and Gas Leases and Valid Claims Based on Mineral Locations § 3140.5 Duration of the lease. A...

2012-10-01

263

36 CFR 72.33 - Timing and duration of projects.  

Code of Federal Regulations, 2013 CFR

...Program Development, Rehabilitation and Innovation § 72.33 Timing and duration of...components of either Rehabilitation or Innovation proposals will be limited to three...federal government. Any component of an Innovation proposal which is to provide...

2013-07-01

264

Passive Stabilization of the Long Duration Exposure Facility (Ldef).  

National Technical Information Service (NTIS)

The results of a study on the application of the magnetically anchored rate damper to gravity gradient stabilization of the Long Duration Exposure Facility (LDEF) are presented. The analyses and simulations required to investigate the use of an existing v...

A. Das

1974-01-01

265

Analysis of the Swift Gamma-Ray Bursts duration  

SciTech Connect

Two classes of gamma-ray bursts have been identified in the BATSE catalogs characterized by durations shorter and longer than about 2 seconds. There are, however, some indications for the existence of a third type of burst. Swift satellite detectors have different spectral sensitivity than pre-Swift ones for gamma-ray bursts. Therefore it is worth to reanalyze the durations and their distribution and also the classification of GRBs. Using The First BAT Catalog the maximum likelihood estimation was used to analyzed the duration distribution of GRBs. The three log-normal fit is significantly (99.54% probability) better than the two for the duration distribution. Monte-Carlo simulations also confirm this probability (99.2%)

Horvath, I.; Veres, P. [Dept. of Physics, Bolyai Military University, H-1581 Budapest, POB 15 (Hungary); Balazs, L. G.; Kelemen, J. [Konkoly Observatory, H-l525 Budapest, POB 67 (Hungary); Bagoly, Z. [Dept. of Physics of Complex Systems, Eoetvoes University, H-1117 Budapest, Pazmany P. s. 1/A (Hungary); Tusnady, G. [Renyi Institute of Mathematics, Hungarian Academy of Sciences, H-1364 Budapest, POB 127 (Hungary)

2008-10-22

266

42 CFR 460.34 - Duration of PACE program agreement.  

Code of Federal Regulations, 2012 CFR

...DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) PACE Program Agreement § 460.34 Duration of PACE program...

2012-10-01

267

KIVA-I Extended Duration MHD Generator Development.  

National Technical Information Service (NTIS)

An extended duration magnetohydrodynamic (MHD) generator system was developed. This system consists of the MHD combustor, nozzle, generator channel, diffuser, high speed data acquisition system and high voltage converter. Two steady-state generator channe...

H. W. Hehn J. K. Lytle L. W. Buechler R. A. Nimmo R. V. Shanklin

1975-01-01

268

40 CFR 85.2303 - Duration of model year.  

Code of Federal Regulations, 2013 CFR

...ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF AIR POLLUTION FROM MOBILE SOURCES Determination...Under Section 177 and Part A of Title II of the Clean Air Act § 85.2303 Duration of model year....

2013-07-01

269

Vocalization frequency and duration are coded in separate hindbrain nuclei  

PubMed Central

Temporal patterning is an essential feature of neural networks producing precisely timed behaviours such as vocalizations that are widely used in vertebrate social communication. Here we show that intrinsic and network properties of separate hindbrain neuronal populations encode the natural call attributes of frequency and duration in vocal fish. Intracellular structure/function analyses indicate that call duration is encoded by a sustained membrane depolarization in vocal prepacemaker neurons that innervate downstream pacemaker neurons. Pacemaker neurons, in turn, encode call frequency by rhythmic, ultrafast oscillations in their membrane potential. Pharmacological manipulations show prepacemaker activity to be independent of pacemaker function, thus accounting for natural variation in duration which is the predominant feature distinguishing call types. Prepacemaker neurons also innervate key hindbrain auditory nuclei thereby effectively serving as a call-duration corollary discharge. We propose that premotor compartmentalization of neurons coding distinct acoustic attributes is a fundamental trait of hindbrain vocal pattern generators among vertebrates.

Chagnaud, Boris P.; Baker, Robert; Bass, Andrew H.

2011-01-01

270

Long Duration Hot Hydrogen Exposure of Nuclear Thermal Rocket Materials.  

National Technical Information Service (NTIS)

An arc-heater driven hyper-thermal convective environments simulator was recently developed and commissioned for long duration hot hydrogen exposure of nuclear thermal rocket materials. This newly established non-nuclear testing capability uses a high-pow...

C. Dobson J. P. Foote R. Hickman R. J. Litchford S. Clifton

2007-01-01

271

Preliminary Long Duration Exposure Facility (LDEF) Materials Data Base.  

National Technical Information Service (NTIS)

A preliminary Long Duration Exposure Facility (LDEF) Materials Data Base was developed by the LDEF Materials Special Investigation Group (MSIG). The LDEF Materials Data Base is envisioned to eventually contain the wide variety and vast quantity of materia...

J. G. Funk J. W. Strickland J. M. Davis

1992-01-01

272

15 CFR 255.6 - Duration of fellowships.  

Code of Federal Regulations, 2013 CFR

...2013-01-01 2013-01-01 false Duration of fellowships. 255.6 Section 255.6 Commerce...AND TECHNOLOGY, DEPARTMENT OF COMMERCE FELLOWSHIPS AND RESEARCH ASSOCIATES FELLOWSHIPS IN LABORATORY STANDARDIZATION AND...

2013-01-01

273

Saturated and Short Pulse Duration X-Ray Lasers  

NASA Astrophysics Data System (ADS)

The basis of a model of the relationship between gain and output laser intensity is reviewed and the measurement of the duration of X-ray lasing with a streak camera with 700 fs temporal resolution is described. Combined with a temporal smearing due to the spectrometer employed, we have measured X-ray laser pulse durations for Ni-like silver at 13.9 nm and Ne-like nickel at 23.1 nm with a total time resolution of 1.1 ps. An extension of the model is shown to consistently relate the measured X-ray laser pulse duration to estimates of the gain duration obtained by temporally resolving resonance line emission from states near in energy to the upper lasing level.

Tallents, G. J.; Abou-Ali, Y.; Edwards, M.; King, R. E.; Pert, G. J.; Pestehe, S. J.; Strati, F.; Keenan, R.; Lewis, C. L. S.; Topping, S.

2002-11-01

274

Duration of neurofibrillary changes in the hippocampal pyramidal neurons  

Microsoft Academic Search

The total number of neurons with and without neurofibrillary changes in sectors CA1 to CA4, subiculum, and dentate gyrus of 16 subjects with Alzheimer disease (AD) was estimated. The duration of neurofibrillary changes was calculated on the basis of regressions between the duration of AD and neuronal numbers. In the CA1 and subiculum, it takes 3.4 and 5.4 years, respectively,

Maciej Bobinski; Jerzy Wegiel; Michal Tarnawski; Margaret Bobinski; Mony J de Leon; Barry Reisberg; Douglas C Miller; Henryk M Wisniewski

1998-01-01

275

A long-duration propulsive lunar landing testbed  

Microsoft Academic Search

Affordable test articles for descent and landing are crucial for developing commercial lunar landing capability. To ensure successful lunar landing, flight software must be tested over mission-length durations on hardware exhibiting dynamics analogous to those of true flight articles. Energetic and structural constraints typically preclude affordable long- duration lander tests. This paper details a first-in-kind propulsive lunar lander testbed designed

Krishna Shankar; Kevin Peterson; Heather Jones; Justin Moidel; William Whittaker

2011-01-01

276

Striatal neurons encoded temporal information in duration discrimination task  

Microsoft Academic Search

To clarify the roles of the basal ganglia in time perception, single-unit activity was recorded from both sides of the striatum\\u000a of a monkey performing a duration discrimination task. In the task, two visual cues were presented successively in different\\u000a durations (0.2?1.6 s). Each cue presentation was followed by a 1-s delay period. The subject was instructed to choose a longer

Atsushi Chiba; Ken-ichi Oshio; Masahiko Inase

2008-01-01

277

Distribution Of Febrile Seizure Duration And Associations With Development  

PubMed Central

Objectives In prior studies of febrile seizures (FS), prolonged FS are defined, absent empirical evidence, as lasting 10 or 15 minutes or more. We assessed the distribution of FS duration in a cohort with first FS, and the association between FS duration and baseline characteristics of the children. Methods We calculated the observed cumulative probability, S(t), that a FS would last at least t minutes, S(t) = exp(?t/ ?) . Data were also fit using a model obtained as the sum of two exponential distributions [S(t) = ?exp(?t/?1)+(1-?)exp(?t/?2)]. After assessing the best fit, the cut off defining long FS was determined. Logisitic regression was used to examine associations between long FS and baseline characteristics, behavior and development. Results In 158 children with a first FS, median duration was 4.0 minutes. Duration of FS was best fit by a two-component mixture exponential model. Using this model we identified one population that accounts for 82.3% of FS and has a mean duration of 3.8 minutes (short FS) and a second population that accounts for 17.7% of FS and has a mean duration of 39.8 minutes (long FS). Long FS were significantly associated with developmental delay (p=0.010) and delays and younger age at first FS (p=0.048). Interpretation Like the distribution of afebrile seizure duration in children, the distribution of first FS duration is best modeled by assuming two populations. Developmental delay and younger age are associated with prolonged FS. Our data lend further support to defining 10 minutes as the upper limit for a simple FS.

Hesdorffer, Dale C.; Benn, Emma K.T.; Bagiella, Emilia; Nordli, Douglas; Pellock, John; Hinton, Veronica; Shinnar, Shlomo

2011-01-01

278

Brain natriuretic peptide and P wave duration in dialysis patients  

Microsoft Academic Search

Objectives  P wave duration and dispersion, defined as the difference between the maximum and minimum P duration, are regarded as very\\u000a important non-invasive ECG markers for assessing atrial arrhythmia risk. Plasma brain natriuretic peptide (BNP) level is an\\u000a independent predictor of recurrence of atrial fibrillation. We compared the effects of hemodialysis (HD) and continuous ambulatory\\u000a peritoneal dialysis (CAPD) on P wave

M. Cagatay Taskapan; Soner Senel; Ozkan Ulutas; Yuksel Aksoy; Ibrahim Sahin; Feridun Kosar; Hulya Taskapan

2007-01-01

279

Electrical Modeling for Laser Testing with Different Pulse Durations  

Microsoft Academic Search

This paper presents a simple electrical model of laser-induced currents in a single MOS transistor for different laser pulse durations. This model is validated by mixed-mode device simulations of a laser-induced fault in an SRAM cell for different laser pulse durations ranging from 100fs to 10ns. This model can be used for netlist level simulation of pulsed laser online testing

A. Douin; V. Pouget; D. Lewis; P. Fouillat; Philippe Perdu

2005-01-01

280

Signal-Averaged Electrocardiography in Normal Newborn infants  

Microsoft Academic Search

Signal-averaged electrocardiograms (SAECGs) were recorded with bipolar orthogonal and standard 12-lead settings in 29 term healthy newborn infants. SAECGs performed with the two lead configurations were similar in quality and quantity. For the duration of the QRS complex (QRSD), the upper limit of normality for newborn infants can be set to 100 ms. It is similar in individual bipolar orthogonal and

R. G. Bennhagen; L. Sörnmo; O. Pahlm; E. Pesonen

2004-01-01

281

Epicardial ECG signals following global myocardial ischaemia  

Microsoft Academic Search

Summary Experiments were performed on 10 dog hearts undergone 15 to 90-minute normothermic arrests and 60-minute reperfusion in a special heart-lung model. The purpose of the experiments was to characterize the global ischaemic effects recorded on epicardial electrograms. The duration of QRS complexes and of RR intervals, the integral of ST segment shifts (?ST), the number of points showed ST

B. Török; E. Röth; B. Mezey; S. Szabados; T. Simor

1983-01-01

282

Duration discrimination: effects of probability of stimulus presentation.  

PubMed

Monkeys initiated a stimulus by pressing on the center of three levers and the stimulus terminated independently of behavior 60, 80, 90, or 100 sec later. Presses on the right lever were reinforced with food following the three briefer durations, and presses on the left lever, following the 100-sec duration. Incorrect responses produced a 10-sec timeout. Probability of presenting the 100-sec duration was manipulated in the range from 0.25 to 0.75, with the probabilities of the briefer durations remaining equal and summing to one minus the probability of the 100-sec duration. Percentage of responses on either side lever was functionally related to both the probability of presenting the 100-sec stimulus and to stimulus duration. An analysis of the data based on the theory of signal detection resulted in operating characteristics that were linear when plotted on normal-normal coordinates. The percentage of responses on either lever approximated the optimal values for maximizing reinforcement probability in each condition of the experiment. PMID:16811638

Elsmore, T F

1972-11-01

283

Duration discrimination: effects of probability of stimulus presentation  

PubMed Central

Monkeys initiated a stimulus by pressing on the center of three levers and the stimulus terminated independently of behavior 60, 80, 90, or 100 sec later. Presses on the right lever were reinforced with food following the three briefer durations, and presses on the left lever, following the 100-sec duration. Incorrect responses produced a 10-sec timeout. Probability of presenting the 100-sec duration was manipulated in the range from 0.25 to 0.75, with the probabilities of the briefer durations remaining equal and summing to one minus the probability of the 100-sec duration. Percentage of responses on either side lever was functionally related to both the probability of presenting the 100-sec stimulus and to stimulus duration. An analysis of the data based on the theory of signal detection resulted in operating characteristics that were linear when plotted on normal-normal coordinates. The percentage of responses on either lever approximated the optimal values for maximizing reinforcement probability in each condition of the experiment.

Elsmore, Timothy F.

1972-01-01

284

Duration of Lactation and Maternal Adipokines at 3 Years Postpartum  

PubMed Central

OBJECTIVE Lactation has been associated with reduced maternal risk of type 2 diabetes, the metabolic syndrome, and cardiovascular disease. We examined the relationship between breastfeeding duration and maternal adipokines at 3 years postpartum. RESEARCH DESIGN AND METHODS We used linear regression to relate the duration of lactation to maternal leptin, adiponectin, ghrelin, and peptide YY (PYY) at 3 years postpartum among 570 participants with 3-year postpartum blood samples (178 fasting), prospectively collected lactation history, and no intervening pregnancy in Project Viva, a cohort study of mothers and children. RESULTS A total of 88% of mothers had initiated breastfeeding, 26% had breastfed ?12 months, and 42% had exclusively breastfed for ?3 months. In multivariate analyses, we found that duration of total breastfeeding was directly related to PYY and ghrelin, and exclusive breastfeeding duration was directly related to ghrelin (predicted mean for never exclusively breastfeeding: 790.6 pg/mL vs. ?6 months of exclusive breastfeeding: 1,008.1 pg/mL; P < 0.01) at 3 years postpartum, adjusting for pregravid BMI, gestational weight gain, family history of diabetes, parity, smoking status, and age. We found a nonlinear pattern of association between exclusive breastfeeding duration and adiponectin in multivariate-adjusted models. CONCLUSIONS In this prospective cohort study, we found a direct relationship between the duration of lactation and both ghrelin and PYY at 3 years postpartum.

Stuebe, Alison M.; Mantzoros, Christos; Kleinman, Ken; Gillman, Matthew W.; Rifas-Shiman, Sheryl; Gunderson, Erica P.; Rich-Edwards, Janet

2011-01-01

285

Procedures used for assessment of stuttering frequency and stuttering duration.  

PubMed

Abstract Frequency of stuttered syllables and their durations were assessed using different procedures. The experiment examined overall syllable counts, counts of stuttered syllables and measures of stutter durations when they were made simultaneously or successively. Samples of speech with associated syllable, stuttered syllable and duration measurements of stuttering events were employed in reference transcriptions. Samples contained a minimum of 200 syllables. Ten participants assessed these samples for syllables, stuttered syllables and duration in an experiment. The responses of these participants were stored in alignment with the speech recordings for analysis. Performance was significantly more accurate (relative to transcriptions) for measures other than duration when the successive procedure was used as opposed to the simultaneous procedure. Although the successive method was more accurate, accuracy of stutter event identification was low for most participants. The procedure that allowed listeners to replay a speech sample and count the syllables, stuttered syllables and durations in three passes yielded more accurate syllable and stuttered syllable counts than procedures that required these judgments to be made in one pass. PMID:23848369

Jani, Leanne; Huckvale, Mark; Howell, Peter

2013-07-12

286

Factors influencing breastfeeding duration: a survey in a Turkish population.  

PubMed

Breastfeeding provides perfect nutrition for infants and is a source of many health benefits for both mother and baby. To obtain the maximum beneficial effects of breast milk, it is necessary to prolong the breastfeeding duration. In this study, we investigated the factors influencing the duration of breastfeeding. We conducted a 32-question survey of mothers with children aged 2-4 years, who presented to our medical school's pediatric outpatient clinics. The questionnaire solicited information on demographics and breastfeeding attitudes. We found correlations between total duration of breastfeeding and the time the mother and baby spent together (sharing a room to sleep at night) and the father's engagement in breastfeeding. Breastfeeding duration inversely correlated with maternal employment. Total duration of breastfeeding did not correlate with breastfeeding education by health personnel, the mother's education level, the gender of the child, regular prenatal care visits, the use of a pacifier, the interval between birth and the onset of breastfeeding, gestational age, method of delivery, or the birth weight of the infant. Conclusion: Our findings suggest several strategies to increase the duration of breastfeeding, including educating fathers along with mothers, supporting a shared bedroom until the child is 2 years of age, and promoting measures that allow mothers to be with their children during working hours. PMID:23793140

Sencan, Irfan; Tekin, O?uz; Tatli, Mustafa Mansur

2013-06-22

287

Exercise-triggered transient R-wave enhancement and ST-segment elevation in II, III, and aVF ECG leads: a testament to the "plasticity" of the QRS complex during ischemia.  

PubMed

We describe a patient with coronary artery disease who showed transiently augmented R-waves in his electrocardiogram (ECG) during the course of an exercise treadmill test (ETT), an ECG pattern occasionally associated with the hyperacute phase of myocardial infarction and variant angina. This change in the R-waves was noted in II, III, and aVF ECG leads and was associated with ST-segment elevation; both changed gradually and were normalized during the recovery period. Cardiac enzymes after ETT were negative, and arteriography revealed 3-vessel coronary artery disease, with a completely occluded right coronary artery. The ventriculogram showed very mild hypokinesis of the inferior left ventricular wall, while the global ejection fraction was 75%. These ECG changes, noted previously during ETT in precordial ECG leads, are herein reported to occur also in II, III, and aVF ECG leads. The generation of these ECG changes, which hinges upon a late unopposed depolarization occurring in the course and at the site of severe ischemic injury, constitutes a transient focal ventricular conduction abnormality. PMID:15127379

Madias, John E; Attari, Mehran

2004-04-01

288

Note: Measurement of extreme-short current pulse duration of runaway electron beam in atmospheric pressure air  

SciTech Connect

This note reports the time-amplitude characteristic of the supershort avalanche electron beam with up to 20 ps time resolution. For the first time it is shown that the electron beam downstream of small-diameter diaphragms in atmospheric pressure air has a complex structure which depends on the interelectrode gap width and cathode design. With a spherical cathode and collimator the minimum duration at half maximum of the supershort avalanche electron beam current pulse was shown to be {approx}25 ps. The minimum duration at half maximum of one peak in the pulses with two peaks can reach {approx}25 ps too.

Tarasenko, V. F.; Rybka, D. V.; Burachenko, A. G.; Lomaev, M. I.; Balzovsky, E. V. [Institute of High Current Electronics SB RAS, 2/3 Akademichesky Ave., 634055 Tomsk (Russian Federation)

2012-08-15

289

Lessons Learned from Biosphere 2: When Viewed as a Ground Simulation\\/Analogue for Long Duration Human Space Exploration and Settlement  

Microsoft Academic Search

A human mission to Mars, or a base on the Moon or Mars, is a longer and more complex mission than any space endeavor undertaken to date. Ground simulations provide a relevant, analogous environment for testing technologies and learning how to manage complex, long duration missions, while addressing inherent mission risks. Multiphase human missions and settlements that may preclude a

T. MacCallum; J. Poynter; D. Bearden

2004-01-01

290

Segmental durations in connected speech signals: preliminary results.  

PubMed

The data base, methods for a study of the durations of phonetic units in connected speech, and some preliminary results are described. From readings of two scripts by many talkers, two sets of seven talkers each were selected, based on total reading time, to form a fast group and a slow group of talkers. Using computer graphics and digital playback procedures, the recordings were segmented into breath groups and pauses, and the first four sentences in each script were segmented into phones. The hold and release (that is, plosion and/or frication) portions of stops were identified and measured; less than 50% of the stops included releases. To establish the usefulness of the data base, the first-order statistics of the phonetic segments were determined, and a variety of durational characteristics were compared to existing reports. Analysis of number of breath groups, phonation time, and pause characterized the difference between so-called average fast and average slow talkers; however, no script-independent measure of these variables was found which would accurately predict the classification of individual talkers. The mean durations of various phonetic categories showed essentially the same percentage change when the fast and slow talkers were compared. Preliminary analyses of contextual influences on durations showed some expected changes, and also indicated that certain traditional predictions may not hold for informal connected speech. Gamma functions were fitted to the distributions of durations of various gross categories. PMID:7130529

Crystal, T H; House, A S

1982-09-01

291

The Association of Urbanicity with Infant Sleep Duration  

PubMed Central

Short sleep duration is associated with multiple adverse child outcomes. We examined associations of the built environment with infant sleep duration among 1226 participants in a pre-birth cohort. From residential addresses, we used a geographic information system to determine urbanicity, population density, and closeness to major roadways. The main outcome was mother’s report of her infant’s average daily sleep duration at 1 year of age. We ranked urbanicity and population density as quintiles, categorized distance to major roads into 8 categories, and used linear regression adjusted for socio-demographic characteristics, smoking during pregnancy, gestational age, fetal growth, and television viewing at 1 year. In this sample, mean (SD) sleep duration at age 1 year was 12.8 (1.6) hours/day. In multivariable adjusted analyses, children living in the highest quintile of urbanicity slept ?19.2 minutes/day (95% CI: ?37.0, ?1.50) less than those living in the lowest quintile. Neither population density nor closeness to major roadways was associated with infant sleep duration after multivariable adjustment. Our findings suggest that living in more urban environments may be associated with reduced infant sleep.

Bottino, Clement J.; Rifas-Shiman, Sheryl L.; Kleinman, Ken P.; Oken, Emily; Redline, Susan; Gold, Diane; Schwartz, Joel; Melly, Steven J.; Koutrakis, Petros; Gillman, Matthew W.; Taveras, Elsie M.

2012-01-01

292

Effectiveness and duration of intramuscular antimotion sickness medications.  

PubMed

Motion sickness inhibits gastric motility, making the oral route ineffective for medications. The intramuscular route is an effective alternative. The rotating chair was used to produce the M 111 level of motion sickness on the Graybiel Symptom Scale. The intramuscular medications given 30 minutes before rotation were compared with placebo (saline, 1 mL) for effectiveness and duration in increasing the number of tolerated head movements. Average placebo number of head movements was 294. Promethazine 25 mg increased head movements by 78% (P < .05), with a duration of 12 hours. Scopolamine 0.2 mg increased head movements by 91% (P < .05), with a duration of 4 hours. The effect of caffeine 250 mg and ephedrine 25 mg was not significant. When combined with scopolamine, ephedrine produced an 32% additive effect. Scopolamine 0.08 mg, 0.1 mg, and 0.2 mg and also promethazine 12.5 mg and 25 mg were significant (P < .05). Promethazine appears to be the drug of choice for intramuscular use because of a longer duration and a high level of effectiveness. Scopolamine was of high effectiveness, but had a duration of 4 hours. It was eight times as potent by the intramuscular as by the oral route. PMID:1474161

Wood, C D; Stewart, J J; Wood, M J; Mims, M

1992-11-01

293

The association of urbanicity with infant sleep duration.  

PubMed

Short sleep duration is associated with multiple adverse child outcomes. We examined associations of the built environment with infant sleep duration among 1226 participants in a pre-birth cohort. From residential addresses, we used a geographic information system to determine urbanicity, population density, and closeness to major roadways. The main outcome was mother's report of her infant's average daily sleep duration at 1 year of age. We ranked urbanicity and population density as quintiles, categorized distance to major roads into 8 categories, and used linear regression adjusted for socio-demographic characteristics, smoking during pregnancy, gestational age, fetal growth, and television viewing at 1 year. In this sample, mean (SD) sleep duration at age 1 year was 12.8 (1.6)h/day. In multivariable adjusted analyses, children living in the highest quintile of urbanicity slept -19.2 min/day (95% CI:-37.0, -1.50) less than those living in the lowest quintile. Neither population density nor closeness to major roadways was associated with infant sleep duration after multivariable adjustment. Our findings suggest that living in more urban environments may be associated with reduced infant sleep. PMID:22795497

Bottino, Clement J; Rifas-Shiman, Sheryl L; Kleinman, Ken P; Oken, Emily; Redline, Susan; Gold, Diane; Schwartz, Joel; Melly, Steven J; Koutrakis, Petros; Gillman, Matthew W; Taveras, Elsie M

2012-06-28

294

Meisenheimer Complexes (sigma Complexes).  

National Technical Information Service (NTIS)

Meisenheimer complexes are known to form in aromatic nucleophilic substitution reactions. The purpose of the present study is to collect as much information as possible in this important field of organic chemistry. The interaction of nitro aromatics with ...

A. S. Mirza

1990-01-01

295

Aerosol-induced signal in sunshine duration records: A review of evidences  

NASA Astrophysics Data System (ADS)

Aerosols play a complex and crucial role in the Earth's radiation budget, by enhancing the absorption and scattering of incoming solar radiation. Consequently, knowledge of the interannual and decadal changes of the atmospheric turbidity induced by aerosols is fundamental for a better understanding of the climate variability and change since pre-industrial times. However, there is a little knowledge regarding changes in aerosol concentrations in the atmosphere on decadal time scales, especially before 1980s, when both ground-based platforms (spectrophotometers) and satellite-borne measurements were available. Nevertheless, sunshine duration observations may be affected by changes in atmospheric aerosol loading, therefore they may provide an adequate proxy measurement for turbidity from the late 19th century up to present. This work reviews publications reporting the suitability of the sunshine duration records measured by Campbell-Stokes instruments to detect changes in atmospheric turbidity, with special emphasis on decadal time scales. In addition, some possible directions for future research are also suggested, particularly pointing out that analyses based on sunshine duration measurements could be extended worldwide since the 1950s due to the availability of records; for some regions, these data are available since as far as the late 19th century.

Sanchez-Romero, Alejandro; Sanchez-Lorenzo, Arturo; Azorin-Molina, Cesar; Calbó, Josep; González, Josep-Abel

2013-04-01

296

How do changes in speed affect the perception of duration?  

PubMed

Six experiments investigated how changes in stimulus speed influence subjective duration. Participants saw rotating or translating shapes in three conditions: constant speed, accelerating motion, and decelerating motion. The distance moved and average speed were the same in all three conditions. In temporal judgment tasks, the constant-speed objects seemed to last longer than the decelerating objects, which in turn seemed to last longer than the accelerating stimuli. In temporal reproduction tasks, the difference between accelerating and decelerating stimuli disappeared; furthermore, watching an accelerating shape lengthened the apparent duration of the subsequent (static) display. These results (a) suggest that temporal judgment and reproduction can dissociate for moving stimuli because the stimulus influences the apparent duration of the subsequent interval, and (b) constrain theories of time perception, including those which emphasize memory storage, those which emphasize the existence of a pacemaker-accumulator timing system, and those which emphasize the division of attention between temporal and non-temporal information processing. PMID:21517218

Matthews, William J

2011-10-01

297

Perceived duration of visual motion increases with speed.  

PubMed

Despite wide recognition that a moving object is perceived to last longer, scientists do not yet agree as to how this illusion occurs. In the present study, we conducted two experiments using two experimental methods, namely duration matching and reproduction, and systematically manipulated the temporal frequency, spatial frequency, and speed of the stimulus, to identify the determinant factor of the illusion. Our results indicated that the speed of the stimulus, rather than temporal frequency or spatial frequency per se, best described the perceived duration of a moving stimulus, with the apparent duration proportionally increasing with log speed (Experiments 1 and 2). However, in an additional experiment, we found little or no change in onset and offset reaction times for moving stimuli (Experiment 3). Arguing that speed information is made explicit in higher stages of visual information processing in the brain, we suggest that this illusion is primarily mediated by higher level motion processing stages in the dorsal pathway. PMID:19761329

Kaneko, Sae; Murakami, Ikuya

2009-07-22

298

Articulatory duration in single-word speech production.  

PubMed

Three different speech production paradigms assessed C. T. Kello, D. C. Plaut, and B. MacWhinney's (2000) claim that the characteristics of speech production flexibly vary between staged and cascaded modes depending on task demand. All experiments measured response latencies and durations of single words without and with a response deadline. Experiment 1 used a picture-word interference task; Experiment 2 blocked pictures either by semantic category or by word-initial overlap; and Experiment 3 used a Stroop paradigm. In all cases, systematic effects of semantic and form relatedness were obtained on latencies but not on response durations. These results support the assumption that articulation, as assessed by response duration, is never influenced by central cognitive processes once a response has been initiated. PMID:12776752

Damian, Markus F

2003-05-01

299

Fade durations in satellite-path mobile radio propagation  

NASA Astrophysics Data System (ADS)

Fades on satellite to land mobile radio links are caused by several factors, the most important of which are multipath propagation and vegetative shadowing. Designers of vehicular satellite communications systems require information about the statistics of fade durations in order to overcome or compensate for the fades. Except for a few limiting cases, only the mean fade duration can be determined analytically, and all other statistics must be obtained experimentally or via simulation. This report describes and presents results from a computer program developed at Virginia Tech to simulate satellite path propagation of a mobile station in a rural area. It generates rapidly-fading and slowly-fading signals by separate processes that yield correct cumulative signal distributions and then combines these to simulate the overall signal. This is then analyzed to yield the statistics of fade duration.

Schmier, Robert G.; Bostian, Charles W.

1986-12-01

300

A stochastic index flow model of flow duration curves  

NASA Astrophysics Data System (ADS)

Annual flow duration curves (AFDCs) are used increasingly because unlike traditional period of record flow duration curves (FDCs), they provide confidence intervals for the median AFDC, they enable one to assign return periods to individual AFDCs, and they offer opportunities for developing a generalized stochastic model of daily streamflow. Previous stochastic models of FDCs and AFDCs were unable to reproduce the variance of AFDCs. We introduce an index flow approach to modeling the relationship between an FDC and AFDCs of daily streamflow series, which is able to reproduce the FDC, as well as the mean, median, and variance of the AFDCs without resorting to assumptions regarding the seasonal or persistence structure of daily streamflow series. Our approach offers additional opportunities for the regionalization of flow duration curves and for the generation of time series of daily streamflows at ungauged sites. Our approach is tested on three river basins in eastern central Italy.

Castellarin, Attilio; Vogel, Richard M.; Brath, Armando

2004-03-01

301

A major depression prognosis calculator based on episode duration  

PubMed Central

Background Epidemiological data have shown that the probability of recovery from an episode declines with increasing episode duration, such that the duration of an episode may be an important factor in determining whether treatment is required. The objective of this study is to incorporate episode duration data into a calculator predicting the probability of recovery during a specified interval of time. Methods Data from two Canadian epidemiological studies were used, both studies were components of a program undertaken by the Canadian national statistical agency. One component was a cross-sectional psychiatric epidemiological survey (n = 36,984) and the other was a longitudinal study (n = 17,262). Results A Weibull distribution provided a good description of episode durations reported by subjects with major depression in the cross-sectional survey. This distribution was used to develop a discrete event simulation model for episode duration calibrated using the longitudinal data. The resulting estimates were then incorporated into a predictive calculator. During the early weeks of an episode, recovery probabilities are high. The model predicts that approximately 20% will recover in the first week after diagnostic criteria for major depression are met. However, after six months of illness, recovery during a subsequent week is less than 1%. Conclusion The duration of an episode is relevant to the probability of recovery. This epidemiological feature of depressive disorders can inform prognostic judgments. Watchful waiting may be an appropriate strategy for mild episodes of recent onset, but the risks and benefits of this strategy must be assessed in relation to time since onset of the episode.

2006-01-01

302

Duration of liquid water habitats on early Mars  

NASA Astrophysics Data System (ADS)

The duration of ice-covered lakes after the initial freezing of the early Mars is presently estimated via a climate model whose critical parameter is the existence of peak seasonal temperatures above freezing, and in which the variability of insolation is included. Under conditions in which meltwater was supplied by an ice source, it is found that water habitats could have been maintained under relatively thin ice sheets for as many as 700 million years after the onset of below-freezing global temperatures. The duration of such habitats on the early Mars therefore exceeds the upper limit of the time envisioned for the emergence of aquatic life on earth.

McKay, C. P.; Davis, W. L.

1991-04-01

303

Atom interferometry using ?-kicked and finite-duration pulse sequences  

NASA Astrophysics Data System (ADS)

We investigate an atom interferometer in which large momentum differences between the arms are obtained by using quantum resonances in the atom-optics ?-kicked rotor. The interferometer can potentially measure the Talbot time (from which h/m can be deduced) and the local gravitational field or can serve as a narrow velocity filter. We present an analytical analysis in the short pulse limit and a numerical investigation for finite pulse durations. The sensitivity of the interferometer is improved by a moderate violation of the short pulse limit. Remarkably simple relations predict the optimal pulse duration and the sensitivity of the interferometer.

Daszuta, Boris; Andersen, Mikkel F.

2012-10-01

304

Expectation Maximization and Complex Duration Distributions for Continuous Time Bayesian Networks  

Microsoft Academic Search

Continuous time Bayesian networks (CTBNs) describe structured stochastic processes with finitely many states that evolve over continuous time. A CTBN is a directed (possibly cyclic) de- pendency graph over a set of variables, each of which represents a finite state continuous time Markov process whose transition model is a function of its parents. We address the prob- lem of learning

Uri Nodelman; Christian R. Shelton; Daphne Koller

2005-01-01

305

How preview space/time translates into preview cost/benefit for fixation durations during reading.  

PubMed

Eye-movement control during reading depends on foveal and parafoveal information. If the parafoveal preview of the next word is suppressed, reading is less efficient. A linear mixed model (LMM) reanalysis of McDonald (2006) confirmed his observation that preview benefit may be limited to parafoveal words that have been selected as the saccade target. Going beyond the original analyses, in the same LMM, we examined how the preview effect (i.e., the difference in single-fixation duration, SFD, between random-letter and identical preview) depends on the gaze duration on the pretarget word and on the amplitude of the saccade moving the eye onto the target word. There were two key results: (a) The shorter the saccade amplitude (i.e., the larger preview space), the shorter a subsequent SFD with an identical preview; this association was not observed with a random-letter preview. (b) However, the longer the gaze duration on the pretarget word, the longer the subsequent SFD on the target, with the difference between random-letter string and identical previews increasing with preview time. A third pattern-increasing cost of a random-letter string in the parafovea associated with shorter saccade amplitudes-was observed for target gaze durations. Thus, LMMs revealed that preview effects, which are typically summarized under "preview benefit", are a complex mixture of preview cost and preview benefit and vary with preview space and preview time. The consequence for reading is that parafoveal preview may not only facilitate, but also interfere with lexical access. PMID:22515948

Kliegl, Reinhold; Hohenstein, Sven; Yan, Ming; McDonald, Scott A

2012-04-19

306

Measurement of Differential Rupture Durations as Constraints on Source Finiteness of Deep-Focus Tonga Earthquakes  

NASA Astrophysics Data System (ADS)

One of the basic issues regarding the physical mechanism for deep earthquakes is the extent to which they occur on pre-existing faults: Do deep earthquakes reactivate faults that formed in the oceanic plate prior to subduction? A previous study of the Tonga subduction zone (Jiao et al., 2000) compared nodal plane distributions of outer-rise events to events as deep as 450 km depth, and found them to be very similar. While this comparison provides some support for the pre-existing fault hypothesis, a more stringent test of the hypothesis is available by identifying the actual rupture planes of the deep-focus events. We are developing the methodology to perform such a test. Between 1990 and 2002, the IRIS FARM database contains approximately 200~earthquakes with mb ?~5.5 in the region studied by Jiao et al. The Harvard CMT focal mechanism identifies two possible fault planes, and our goal is to distinguish the true fault plane using observations of source finiteness. Source finiteness is observable on seismograms at different azimuths and distances, for unilateral ruptures, as variations in the apparent rupture duration and, for complex ruptures, as differences in the travel-time delay between subevents. For each earthquake, the rupture duration (or travel-time delay) will be shortest in the direction of rupture propagation and longest in the opposite direction. Rather than measuring the actual rupture duration at each station, we use a cross-correlation technique that includes a stretching factor to measure the differential rupture duration between each pair of stations. These differential measurements then allow us to identify the rupture direction and fault plane for each earthquake. A comparison of the distribution of rupture-plane orientations of deep-focus and outer-rise seismicity allows us to determine whether or not deep seismicity occurs on reactivated faults.

Warren, L. M.; Silver, P. G.

2004-12-01

307

Predicting temporary threshold shifts in a bottlenose dolphin (Tursiops truncatus): the effects of noise level and duration.  

PubMed

Noise levels in the ocean are increasing and are expected to affect marine mammals. To examine the auditory effects of noise on odontocetes, a bottlenose dolphin (Tursiops truncatus) was exposed to octave-band noise (4-8 kHz) of varying durations (<2-30 min) and sound pressures (130-178 dB re 1 microPa). Temporary threshold shift (TTS) occurrence was quantified in an effort to (i) determine the sound exposure levels (SELs) (dB re 1 microPa(2) s) that induce TTS and (ii) develop a model to predict TTS onset. Hearing thresholds were measured using auditory evoked potentials. If SEL was kept constant, significant shifts were induced by longer duration exposures but not for shorter exposures. Higher SELs were required to induce shifts in shorter duration exposures. The results did not support an equal-energy model to predict TTS onset. Rather, a logarithmic algorithm, which increased in sound energy as exposure duration decreased, was a better predictor of TTS. Recovery to baseline hearing thresholds was also logarithmic (approximately -1.8 dB/doubling of time) but indicated variability including faster recovery rates after greater shifts and longer recoveries necessary after longer duration exposures. The data reflected the complexity of TTS in mammals that should be taken into account when predicting odontocete TTS. PMID:19275338

Mooney, T Aran; Nachtigall, Paul E; Breese, Marlee; Vlachos, Stephanie; Au, Whitlow W L

2009-03-01

308

Typing keystroke duration changed after submaximal isometric finger exercises.  

PubMed

A repeated-measures laboratory experiment tested whether keystroke duration during touch-typing changes after a finger performs submaximal isometric flexion exercises. Fourteen right-handed touch-typists used right ring finger to perform three 15-min exercise conditions, two isometric exercises and a no-force condition, each on a separate day. Before and after each exercise condition, typing keystroke duration and isometric force elicited by electrical stimulation were measured for right ring finger. Keystroke duration of right ring finger decreased by 5% (6 ms, P < 0.05) immediately after the exercises but not after the no-force condition. Peak isometric finger force elicited by electrical stimulation decreased by 17-26% (P < 0.05) for the flexor digitorum superficialis and decreased by 4-8% for the extensor digitorum communis after the isometric exercises. After the finger was exposed to isometric exercises, changes in typing keystroke duration coincided with changes in the physiological state of the finger flexor and extensor muscles. PMID:18853179

Joe Chang, Che-Hsu; Johnson, Peter W; Katz, Jeffrey N; Eisen, Ellen A; Dennerlein, Jack T

2008-10-14

309

A new duration modeling approach for Mandarin speech  

Microsoft Academic Search

In this paper, a new duration modeling approach for Mandarin speech is proposed. It explicitly takes several major af- fecting factors as multiplicative companding factors (CFs) and esti- mates all model parameters by an EM algorithm. Besides, the three basic Tone 3 patterns (i.e., full tone, half tone and sandhi tone) are also properly considered via using three different CFs

Sin-horng Chen; Wen-hsing Lai; Yih-ru Wang

2003-01-01

310

How Do Changes in Speed Affect the Perception of Duration?  

ERIC Educational Resources Information Center

|Six experiments investigated how changes in stimulus speed influence subjective duration. Participants saw rotating or translating shapes in three conditions: constant speed, accelerating motion, and decelerating motion. The distance moved and average speed were the same in all three conditions. In temporal judgment tasks, the constant-speed…

Matthews, William J.

2011-01-01

311

The Effect of Congenital Deafness on Duration Judgment  

ERIC Educational Resources Information Center

Objective: Congenital deafness provides the opportunity to study how atypical sensory and language experiences affect different aspects of information processing, e.g., time perception. Methods: Using two methods of temporal estimation, reproduction (Exp. 1) and production (Exp. 2), the effect of deafness on duration judgment was investigated…

Kowalska, Joanna; Szelag, Elzbieta

2006-01-01

312

The duration of new job matches in east and west  

Microsoft Academic Search

This paper studies the duration of new job matches in east and west Germany using data from the German Socio-economic Panel. Non-parametric estimates of the survival probability show that, except for the first years of the east German transition process, job matches are less stable in east Germany. Results from a proportional hazards model that controls for important covariates imply

Joachim Wolff

313

Attention, Exposure Duration, and Gaze Shifting in Naming Performance  

ERIC Educational Resources Information Center

|Two experiments are reported in which the role of attribute exposure duration in naming performance was examined by tracking eye movements. Participants were presented with color-word Stroop stimuli and left- or right-pointing arrows on different sides of a computer screen. They named the color attribute and shifted their gaze to the arrow to…

Roelofs, Ardi

2011-01-01

314

Duration Models and Proportional Hazards in Political Science  

Microsoft Academic Search

In recent years political scientists have increasingly adopted a wide range oftechniques for modeling duration data. A key assumption of all these approaches isthat the hazard ratios (i.e., the conditional relative risks across substrata) areproportional to one another, and that this proportionality is maintained over time.Estimation of proportional hazards (PH) models when in fact hazards are nonproportionalresults in coefficient biases

Janet M. Box-steffensmeier; Christopher J. W. Zorn

2001-01-01

315

Breastfeeding in Iran: prevalence, duration and current recommendations  

Microsoft Academic Search

BACKGROUND: The need to promote breastfeeding is unquestionable for the health and development of infants. The aim of this study was to investigate prevalence, duration and promotion of breastfeeding status in Iran with respect to the Baby Friendly Hospital, government actions and activities by the Breastfeeding Promotion Society including comparison with European countries. METHODS: This retrospective study is based on

Beheshteh Olang; Khalil Farivar; Abtin Heidarzadeh; Birgitta Strandvik; Agneta Yngve

2009-01-01

316

The duration of exercise as a regulator of bone mass  

Microsoft Academic Search

Exercise is associated with increased peak bone mineral density (BMD). To determine the relationship between the duration of exercise and BMD, we measured BMD of the axial and appendicular skeleton by dual-energy X-ray absorptiometry (DXA), and speed of sound (SOS), broadband attenuation (BUA), and stiffness index by quantitative ultrasound (QUS) of the calcaneus, in 67 active male national soccer players

M. K Karlsson; H Magnusson; C Karlsson; E Seeman

2001-01-01

317

Influence of subpicosecond laser pulse duration on proton acceleration  

NASA Astrophysics Data System (ADS)

The influence of pulse duration on proton acceleration using subpicosecond (30-300 fs), ultraintense (from 3.6×1018 to 3.6×1019 W/cm2), constant energy (0.14 J) laser pulses is studied using two-dimensional simulations. The entire pulse duration is modeled so that during the rising edge of the pulse a preplasma can naturally expand from the target front and rear surfaces into vacuum, altering respectively laser absorption and electrostatic field generation. In this paper, we study this effect for two target profiles (sharp-edge profile and smooth density gradient at the front side) and we point out the existence of a weak optimum pulse duration for proton acceleration. For the different pulse durations we consider, we first show that the maximum proton energy variations are similar to those of the rear side electrostatic field amplitude. The energy variations, however, are smaller than expected from the field variations, and we explain this effect by characteristic proton acceleration time.

Carrié, M.; Lefebvre, E.; Flacco, A.; Malka, V.

2009-05-01

318

Breast-feeding in Geneva: Prevalence, duration and determinants  

Microsoft Academic Search

Summary A telephone survey was carried out with the objective of measuring the prevalence, duration and determinants of breast-feeding in the canton of Geneva, between August and December 1993. The participants were 278 out of 320 families with a telephone number in Geneva, from a random sample of families in which a child had been born in Geneva in the

Paul Bouvier; André Rougemont

1998-01-01

319

Conflict and the Duration of Peace in Enduring Internal Rivalries  

Microsoft Academic Search

The question of how conflicts affect the nature of the peace forms a puzzle for students of civil conflict.Theoretical arguments and empirical evidence exist supporting the conclusion that increased violence leads to longer or shorter peace durations. Applying a model of rivalry that includes public support of conflict, this paper hypothesizes that the greater the concentration in fighting, the longer

Daniel S. Morey

2009-01-01

320

New Ways In Determining The Earth Fault Duration  

Microsoft Academic Search

One of the major problems in determining the duration of a single-pole earth fault in compensated networks is to detect the moment of arc extinction. Currently this problem is solved by analysing the time course of the displacement voltage and identifying the moment when the amplitude is rising above or falling below a certain critical value. However, solving the issue

E. Fuchs; G. Achleitner; C. Obkircher; L. Fickert; M. Sakulin

2010-01-01

321

Estimating duration in partnership studies: issues, methods and examples  

PubMed Central

Background and objectives Understanding the time course of sexual partnerships is important for understanding sexual behaviour, transmission risks for sexually transmitted infections (STI) and development of mathematical models of disease transmission. Study design The authors describe issues and biases relating to censoring, truncation and sampling that arise when estimating partnership duration. Recommendations for study design and analysis methods are presented and illustrated using data from a sexual-behaviour survey that enrolled individuals from an adolescent-health clinic and two STD clinics. Survey participants were queried, for each of (up to) four partnerships in the last 3 months, about the month and year of first sex, the number of days since last sex and whether partnerships were limited to single encounters. Participants were followed every 4 months for up to 1 year. Results After adjustment for censoring and truncation, the estimated median duration of sexual partnerships declined from 9 months (unadjusted) to 1.6 months (adjusted). Similarly, adjustment for censoring and truncation reduced the bias in relative risks for the effect of age in a Cox model. Other approaches, such as weighted estimation, also reduced bias in the estimated duration distribution. Conclusion Methods are available for estimating partnership duration from censored and truncated samples. Ignoring censoring, truncation and other sampling issues results in biased estimates.

Burington, Bart; Hughes, James P; Whittington, William L H; Stoner, Brad; Garnett, Geoff; Aral, Sevgi O; Holmes, King K

2011-01-01

322

The Long Duration Exposure Facility (LDEF). Mission 1 Experiments.  

ERIC Educational Resources Information Center

The Long Duration Exposure Facility (LDEF) has been designed to take advantage of the two-way transportation capability of the space shuttle by providing a large number of economical opportunities for science and technology experiments that require modest electrical power and data processing while in space and which benefit from postflight…

Clark, Lenwood G., Ed.; And Others

323

49 CFR 92.27 - Duration of deductions.  

Code of Federal Regulations, 2011 CFR

...27 Section 92.27 Transportation Office of the Secretary of Transportation RECOVERING DEBTS TO THE UNITED STATES BY SALARY OFFSET § 92.27 Duration of deductions. Debts shall be collected in one lump sum where possible. However, if the...

2011-10-01

324

The Effects of Duration of Caregiving on Institutionalization  

ERIC Educational Resources Information Center

|Purpose: Our objective in this analysis was to determine how the duration of caregiving interacts with key care demands (i.e., severity of problem behaviors) to influence the institutionalization of individuals suffering from dementia. Methods: We utilized multiregional data from 4,761 caregivers of individuals with dementia over a 3-year period.…

Gaugler, Joseph E.; Kane, Robert L.; Kane, Rosalie A.; Clay, Ted; Newcomer, Robert C.

2005-01-01

325

Phrasing not duration differs in French questions and statements  

Microsoft Academic Search

Six native speakers of metropolitan French were recorded reading sets of statements and questions for an acoustic study of durational patterning. In order to maximize comparability, ten sets of sentences were created in which the sentences in each set were as similar as possible except for varying sentence type. Each set included a statement and a lexically identical, syntactically-unmarked \\

Caroline L. Smith

2008-01-01

326

Visual duration threshold as a function of word-probability  

Microsoft Academic Search

The results of two experiments using 75 words demonstrated that the visual duration of a word, measured tachistoscopically by an ascending method of limits, was related linearly to the logarithm of the relative frequency with which that word appeared in the Thorndike-Lorge word counts. When certain physical characteristics and component letters of the words were corrected empirically the product-moment correlations

Davis H. Howes; R. L. Solomon

1951-01-01

327

Impact of breastfeeding duration on age at menarche.  

PubMed

The study aims to assess the relation between breastfeeding duration and age at menarche. Analysis was based on a cohort of 994 Filipino girls born in 1983-1984 and followed up from infancy to adulthood by the Cebu Longitudinal Health and Nutrition Survey. The main outcome was self-reported age at menarche. Cox regression was used to investigate the relation between duration of exclusive and any breastfeeding with age at menarche with adjustment sequentially for specific sets of known socioeconomic, maternal, genetic, and prenatal confounders. The estimated median of age at menarche was 13.08 years. After adjustment for potential confounders of the association of breastfeeding with age at menarche, exclusive breastfeeding duration retained an independent and significant association with age at menarche. An increase in 1 month of exclusive breastfeeding decreases the hazard of attaining earlier menarche by 6% (hazard ratio = 0.94, 95% confidence interval: 0.90, 0.98). Any breastfeeding duration was not associated with age at menarche. Although this is the first longitudinal study that reveals a negative association between exclusive breastfeeding and early menarche, the relation is still elusive. Further longitudinal studies within different contexts are warranted to assess the generalizability of these findings. PMID:21430189

Al-Sahab, Ban; Adair, Linda; Hamadeh, Mazen J; Ardern, Chris I; Tamim, Hala

2011-03-23

328

Sleep duration and overweight among Australian children and adolescents  

Microsoft Academic Search

Aim: To examine the association between sleep and overweight and waist circumference (WC) in children and adolescents. Methods: Data were from a nationally representative sample of 6324 7 ? 15-y-old males and females from the Australian Health and Fitness Survey. Associations between sleep duration and body mass index (BMI) and WC were examined by analysis of covariance, linear regression, and

JOEY C. EISENMANN; Panteleimon Ekkekakis; Megan Holmes

2006-01-01

329

Strength of cardiac conditioned responses with varying unconditioned stimulus durations  

Microsoft Academic Search

No relationship has been found in human Ss between conditioned heart rate response magnitude and a wide range of shock US durations. Under the assumption that cardiac disturbance is an index of fear, this fact is related to a deduction from a drive-reduction theory of fear, according to which a signal followed by a brief noxious stimulus should require the

Norma Wegner; David Zeaman

1958-01-01

330

Exposure duration: Effects on eyewitness accuracy and confidence  

Microsoft Academic Search

The current study examined the relationship between the length of exposure to a face in an eyewitness setting and identié cation accuracy and coné dence. A sample of 164 young (ages 17- 25) and older (ages 59- 81) adults viewed a simulated crime in which they saw the culprit's face for a short (12s) or long (45s) duration. They were

Amina Memon; Lorraine Hope; Ray Bull

2003-01-01

331

Attention, Exposure Duration, and Gaze Shifting in Naming Performance  

ERIC Educational Resources Information Center

Two experiments are reported in which the role of attribute exposure duration in naming performance was examined by tracking eye movements. Participants were presented with color-word Stroop stimuli and left- or right-pointing arrows on different sides of a computer screen. They named the color attribute and shifted their gaze to the arrow to…

Roelofs, Ardi

2011-01-01

332

The effects of duration of intractable epilepsy on memory function.  

PubMed

We assessed whether duration (time since diagnosis) of intractable epilepsy is associated with progressive memory loss in 250 individuals with left or right temporal lobe epilepsy and those diagnosed with psychogenic nonepileptic seizures. Verbal and nonverbal memory function was assessed using several memory assessment measures administered to all individuals as part of a larger neuropsychological assessment. Multivariate multiple regression analyses demonstrated that duration of temporal lobe epilepsy and age of seizure onset are significantly related to verbal memory deficits in patients with epilepsy. The interaction between duration of epilepsy and diagnostic group was nonsignificant, as was the interaction between age at spell onset and diagnostic group. As measured by several neuropsychological memory tests, duration of disease adversely affects verbal memory performance in patients diagnosed with temporal lobe epilepsy. Our study also supports the notion that age at seizure onset significantly affects verbal memory performance in this population. These results have implications for the strategy of treatment and counseling of patients with intractable temporal lobe epilepsy. PMID:16931163

Kent, Glenn P; Schefft, Bruce K; Howe, Steven R; Szaflarski, Jerzy P; Yeh, Hwa-Shain; Privitera, Michael D

2006-08-23

333

Fixed-Duration Therapy in Leprosy: Limitations and Opportunities  

PubMed Central

Leprosy has been considered a curable disease after the implementation of multidrug therapy (MDT), which has been proven to be safe and effective, by bringing about a significant change in the global and national scenario of leprosy by upgrading the control of leprosy to the next stage of eradication. Since its introduction, the MDT regimens for the treatment of leprosy have undergone several changes especially with regard to the duration of treatment. The advantages of shortened duration of treatment need to be balanced against the risk of relapse and a lot of controversies exist pertaining to this aspect. The fixed-duration (FD) therapy is not popular among academicians and private practitioners who prefer precise diagnosis and treatment with superior MDT regimens and for a longer duration. On the contrary, from a public health-care point of view, precise diagnosis and a longer treatment schedule are not cost effective and not feasible to be implemented in elimination programs. Hence, a fine balance needs to be maintained between achieving a cure for the patient and protecting the society at risk, and this review discusses the various limitations and opportunities of FD therapy with a note on the newer MDT regimens.

Malathi, Munisamy; Thappa, Devinder Mohan

2013-01-01

334

Reservation Wages, Search Duration, and Accepted Wages in Europe  

Microsoft Academic Search

This paper uses data from the European Community Household Panel, 1994-99, to investigate the arrival rate of job offers, the determinants of reservation wages, transitions out of unemployment, and accepted wages. In this exploratory treatment, we report that the arrival rate of job offers declines precipitously with jobless duration and age; that reservation wages do decline with the jobless spell

John T. Addison; Mario Centeno; Pedro Portugal

2004-01-01

335

Retrievable payload carrier: Next generation Long Duration Exposure Facility  

Microsoft Academic Search

This paper describes the Retrievable Payload Carrier (RPC), which is a multi-experiment, free flyer spacecraft being privately developed to make in-space experimentation more accessible and economically feasible for research and development organizations. The carrier concept was derived from NASA's highly successful and flight proven Long Duration Exposure Facility (LDEF). The LDEF capabilities have been enhanced to meet new customer requirements.

Arthur T. Perry

1992-01-01

336

Recent activities for long duration flight systems in Japan  

NASA Astrophysics Data System (ADS)

For the feasibility studies of the long duration balloon systems in recent times in Japan, the forces was on following items. • An analysis to utilize the Pumpkin Balloons for the over pressurized balloons, and to develop the simple automatic gas pressure control systems for the long duration flights. • Test flights by the balloon group of the Institute of Space and Astronautical Science (ISAS) to see the performance of the balloons of new films of EVAL (Ethylene-Vinyl-Alcohol) having strong absorption bands of the infra-red between 7-14 microns. We expect that this absorption prevents the cooling of the lifting gas after the sun-sets, and thus save the ballast consumption. • A sea recovery system beyond 100-200 km from the Pacific coast by using helicopters with ARGOS/GPS. The situation would be applicable to the sea recovery of payloads after the long duration flights at the turn-around period launched from Sanriku Balloon Center. The flight performances have already been proved in the 1975 and 77 achieving the duration of 55, 65, 80 hrs keeping the locations of payloads within 200 km from the sea coast. • Studies on the high altitude balloons with thin polyethylene films are also reported in this paper.

Nishimura, J.

337

Does short sleep duration favor abdominal adiposity in children?  

PubMed

The main aim of this cross-sectional study was to determine whether the increased body mass index (BMI) characterizing short-duration sleeping children is related to an increased predisposition to abdominal adiposity. A total of 422 children (211 boys and 211 girls) involved in the "Québec en Forme" Project were tested for body weight, height, waist circumference, and sleep duration. As there was no gender interaction with the other factors, a partial regression of waist circumference on hours of sleep was performed for both genders combined, adjusting for age, sex, BMI, parental obesity, parental education, total annual family income, frequency of taking breakfast, watching television, playing videogames, computer use, and frequency of practicing sports activities outside of school. Sleep duration had an independent effect on waist circumference, with the correlation between these variables remaining significant after adjustment for BMI and the several other covariates (r=- 0.17, p<0.001). In conclusion, these results suggest that short sleep duration favors abdominal adiposity in children. This finding is of particular concern since abdominal obesity is an important feature of the metabolic syndrome. PMID:17999284

Chaput, Jean-Philippe; Tremblay, Angelo

2007-01-01

338

Mediating Civil War Settlements and the Duration of Peace  

Microsoft Academic Search

In this article, we examine the impact of international mediation attempts during civil war on the duration of peace once the war has ended. We include several aspects of the mediation attempt in our theoretical framework and our empirical tests, but we also control for other characteristics of the conflict and the country. While studies often find that decisive victories

Mehmet Gurses; Nicolas Rost; Patrick McLeod

2008-01-01

339

Subjective shortening: A model of pigeons' memory for event duration  

Microsoft Academic Search

Investigated memory for event duration using a delayed matching-to-sample procedure in 4 experiments with 10 Silver King pigeons. When a retention interval of variable length intervened between sample and comparison stimuli, Ss responded as though long samples had been short after retention intervals of 10 sec or more. This \\

Marcia L. Spetch; Donald M. Wilkie

1983-01-01

340

Fixed-duration therapy in leprosy: limitations and opportunities.  

PubMed

Leprosy has been considered a curable disease after the implementation of multidrug therapy (MDT), which has been proven to be safe and effective, by bringing about a significant change in the global and national scenario of leprosy by upgrading the control of leprosy to the next stage of eradication. Since its introduction, the MDT regimens for the treatment of leprosy have undergone several changes especially with regard to the duration of treatment. The advantages of shortened duration of treatment need to be balanced against the risk of relapse and a lot of controversies exist pertaining to this aspect. The fixed-duration (FD) therapy is not popular among academicians and private practitioners who prefer precise diagnosis and treatment with superior MDT regimens and for a longer duration. On the contrary, from a public health-care point of view, precise diagnosis and a longer treatment schedule are not cost effective and not feasible to be implemented in elimination programs. Hence, a fine balance needs to be maintained between achieving a cure for the patient and protecting the society at risk, and this review discusses the various limitations and opportunities of FD therapy with a note on the newer MDT regimens. PMID:23716796

Malathi, Munisamy; Thappa, Devinder Mohan

2013-03-01

341

7 CFR 3430.1011 - Duration of awards.  

Code of Federal Regulations, 2013 CFR

...FEDERAL ASSISTANCE PROGRAMS-GENERAL AWARD ADMINISTRATIVE PROVISIONS Sun Grant Program § 3430.1011 Duration of awards. The term of a Federal assistance award made under the Sun Grant Program shall not exceed 5 years. No-cost extensions of...

2013-01-01

342

Correcting Memory Improves Accuracy of Predicted Task Duration  

ERIC Educational Resources Information Center

|People are often inaccurate in predicting task duration. The memory bias explanation holds that this error is due to people having incorrect memories of how long previous tasks have taken, and these biased memories cause biased predictions. Therefore, the authors examined the effect on increasing predictive accuracy of correcting memory through…

Roy, Michael M.; Mitten, Scott T.; Christenfeld, Nicholas J. S.

2008-01-01

343

Bias and Accuracy in Estimates of Task Duration  

Microsoft Academic Search

When asked to estimate the duration of various academic-type tasks (e.g., the time needed to complete a writing assignment, solve a series of problems, or read a manuscript), subjects demonstrated a marked tendency to trade accuracy in favor of minimizing cognitive effort in their selection of planning strategies. This tendency resulted in a drastic underestimation of the time required to

Robert A. Josephs; Eugene D. Hahn

1995-01-01

344

Temporal Context in Concurrent Chains: I. Terminal-Link Duration  

ERIC Educational Resources Information Center

|Two experiments are reported in which the ratio of the average times spent in the terminal and initial links ("Tt/Ti") in concurrent chains was varied. In Experiment 1, pigeons responded in a three-component procedure in which terminal-link variable-interval schedules were in constant ratio, but their average duration increased across components…

Grace, Randolph C.

2004-01-01

345

The Long Duration Exposure Facility (LDEF). Mission 1 Experiments.  

ERIC Educational Resources Information Center

|The Long Duration Exposure Facility (LDEF) has been designed to take advantage of the two-way transportation capability of the space shuttle by providing a large number of economical opportunities for science and technology experiments that require modest electrical power and data processing while in space and which benefit from postflight…

Clark, Lenwood G., Ed.; And Others

346

Short duration sporadic e and discrete auroral events. Final report  

SciTech Connect

The relationship that exists between the occurrence of sporadic E and the incidence of visual aurora is utilized as the basis for the determination of the lifetimes of discrete auroral events in the range of > or = 15 minutes from measurements of durations of sporadic E ionization. Intercomparisons of optical and ionosonde data from aircraft and ground-based installations are presented.

Krukonis, A.P.; Whalen, J.A.; Reilly, A.E.

1979-01-04

347

The Effect Of Benefit Sanctions On The Duration Of Unemployment  

Microsoft Academic Search

This paper investigates the effectiveness of unemployment benefit sanctions in reducing unem-ployment duration. Swiss data on benefit sanctions allow us to separate the effect of a warning that a person is not complying with eligibility requirements from the effect of the actual enforce-ment of a benefit sanction. Moreover, public employment services are given substantial leeway in setting the monitoring intensity.

Rafael Lalive; Josef Zweimüller

2005-01-01

348

Duration or Disadvantage? Exploring Nativity, Ethnicity, and Health in Midlife  

Microsoft Academic Search

Objectives . This study examined nativity as a risk factor for poor physical and emotional health for an ethnically di- verse population making the transition into retirement. The authors addressed whether the health disadvantage observed for immigrants lessens with increased time spent in the country (supporting theories of assimilation) or increases with duration of residence (supporting theories of cumulative disadvantage).

Jacqueline L. Angel; Cynthia J. Buckley; Art Sakamoto

2001-01-01

349

The preliminary Long Duration Exposure Facility (LDEF) materials data base  

Microsoft Academic Search

A preliminary Long Duration Exposure Facility (LDEF) Materials Data Base was developed by the LDEF Materials Special Investigation Group (MSIG). The LDEF Materials Data Base is envisioned to eventually contain the wide variety and vast quantity of materials data generated for LDEF. The data is searchable by optical, thermal, and mechanical properties, exposure parameters (such as atomic oxygen flux), and

J. G. Funk; J. W. Strickland; J. M. Davis

1992-01-01

350

Transition Edge Sensors for Long Duration Balloon experiments  

Microsoft Academic Search

Transition Edge Sensors (TES) bolometers are the state of the art of the detectors for experiments working at mm and sub-mm wavelengths. In this paper we briefly review the current experimental situation focusing the attention on the use of TES for Long Duration Balloon experiments.

E. S. Battistelli; A. Cruciani; S. Masi

2008-01-01

351

External Interventions and the Duration of Civil Wars  

Microsoft Academic Search

September 2000Previous studies have argued that longer civil wars have been caused by ethnically polarized societies, since rebel cohesion is easier and more lasting with polarization. This study shows that external interventions tend to reduce the cost of coordinating a rebellion (or of fighting a rebellion), thereby lengthening the duration of civil wars even in societies that are not ethnically

Nicholas Sambanis; Ibrahim A. Elbadawi

2000-01-01

352

Role of heterochromatin in the control of cell cycle duration  

Microsoft Academic Search

RECENTLY Bennett has demonstrated that most annual plants have less nuclear DNA than perennial plants1. Since there is a positive correlation between DNA content and minimum duration of the mitotic cell cycle2, Bennett suggested that low DNA content and short cycles might be factors determining the generation time of short-lived plants. These assumptions also fit the general findings that DNA

W. Nagl

1974-01-01

353

Parallel female preferences for call duration in a diploid ancestor of an allotetraploid treefrog  

PubMed Central

The gray treefrog species complex (Hyla chrysoscelis and H. versicolor) comprises a single allotetraploid species (H. versicolor) that arose multiple times from hybrid matings between an extant diploid species (H. chrysoscelis) and at least two other extinct diploid treefrogs. While previous studies have investigated female preferences for call duration in the tetraploid, we know little about these preferences in its putative diploid anscestors. Here, I report results from two-choice phonotaxis experiments investigating call duration preferences in H. chrysoscelis. Females preferred an average-length call over shorter-than-average calls (0.5–2.0 standard deviations [SD] below average), and they preferred longer-than-average calls over average or shorter-than-average calls if the difference in pulse number was at least 2.0 SD. When the amplitude of the longer alternative was attenuated by 6 dB, females still preferred an average-length call over a shorter-than-average call, but there was no preference for longer-than-average calls over an average call. In the presence of chorus noise, female preferences for both average and longer-than-average calls over shorter alternatives were weakened or reversed. Together, the results from this study reveal patterns of female preferences for call duration that are strikingly similar among two members of a species complex with a novel evolutionary history. In both species, female preferences are directional, nonlinear, and limited by environmental noise. Furthermore, these results also highlight the need for caution in studies of sexual selection when extrapolating from patterns of female preference obtained under ideal laboratory conditions to conclusions about how those preferences are expressed in the real world.

Bee, Mark A.

2008-01-01

354

38 CFR 21.6070 - Basic duration of a vocational training program.  

Code of Federal Regulations, 2010 CFR

...Basic duration of a vocational training program. 21.6070 Section 21.6070 Pensions, Bonuses, and Veterans' Relief DEPARTMENT...Pension Recipients Duration of Training § 21.6070 Basic duration of a vocational training...

2009-07-01

355

38 CFR 21.6070 - Basic duration of a vocational training program.  

Code of Federal Regulations, 2010 CFR

...Basic duration of a vocational training program. 21.6070 Section 21.6070 Pensions, Bonuses, and Veterans' Relief DEPARTMENT...Pension Recipients Duration of Training § 21.6070 Basic duration of a vocational training...

2010-07-01

356

Sleep Duration, Nap Habits, and Mortality in Older Persons  

PubMed Central

Objective: To examine the effect of nighttime sleep duration on mortality and the effect modification of daytime napping on the relationship between nighttime sleep duration and mortality in older persons. Design: Prospective survey with 20-yr mortality follow-up. Setting: The Cross-Sectional and Longitudinal Aging Study, a multidimensional assessment of a stratified random sample of the older Jewish population in Israel conducted between 1989-1992. Participants: There were 1,166 self-respondent, community-dwelling participants age 75-94 yr (mean, 83.40, standard deviation, 5.30). Measurements: Nighttime sleep duration, napping, functioning (activities of daily living, instrumental activities of daily living, Orientation Memory Concentration Test), health, and mortality. Results: Duration of nighttime sleep of more than 9 hr was significantly related to increased mortality in comparison with sleeping 7-9 hr (hazard ratio [HR] = 1.31, P < 0.01) after adjusting for demographic, health, and function variables, whereas for short nighttime sleep of fewer than 7 hr mortality did not differ from that of 7-9 hr of sleep. For those who nap, sleeping more than 9 hr per night significantly increased mortality risk (HR = 1.385, P < 0.05) and shorter nighttime sleep reduced mortality significantly in the unadjusted model (HR = 0.71, P < 0.001) but only approached significance in the fully adjusted model (HR = 0.82, P = 0.054). For those who do not or sometimes nap, a short amount of sleep appears to be harmful up to age 84 yr and may be protective thereafter (HR = 1.51, confidence interval [CI] = 1.13-2.02, P < 0.01; HR = 0.76, CI = 0.49-1.17, in the fully adjusted model, respectively). Conclusions: The findings are novel in demonstrating the protective effect of short nighttime sleep duration in individuals who take daily naps and suggest that the examination of the effect of sleep needs to take into account sleep duration per 24 hr, rather than daytime napping or nighttime sleep per se. Citation: Cohen-Mansfield J; Perach R. Sleep duration, nap habits, and mortality in older persons. SLEEP 2012;35(7):1003–1009.

Cohen-Mansfield, Jiska; Perach, Rotem

2012-01-01

357

Duration ratio discrimination in pigeons: a criterion-setting analysis.  

PubMed

Pigeons received trials beginning with a sequence of two colors (blue-->yellow) on the center key of a three-key array. The colors lasted different lengths of time. At the end of the sequence pigeons chose between two keys based on a criterial ratio of the temporal sequence. One choice was reinforced if the time ratio was less than the criterion and the alternate choice was reinforced if the time ratio was greater than the criterion. The criterial ratios (first to second duration) were 1:1, 1.5:1, and 3:1. The same set of intervals was used for the different criterion ratios, producing a balanced distribution of time ratios for the 1.5:1 condition, and unbalanced distributions for the 1:1 and 3:1 conditions. That is, for the 1.5:1 condition half of the duration pairs were less than the criterion and half were greater. However, for the 1:1 and 3:1 conditions, more duration pairs were less than (3:1) or greater than (1:1) the criterion. Accuracy was similar across criterion ratios, but response bias was influenced by the asymmetries of time ratios in the 1:1 and 3:1 conditions. When these asymmetries were controlled, the response biases were reduced or eliminated. These results indicate that pigeons are flexible in establishing a criterion for discriminating duration ratios, unlike humans, who are less flexible and are bound to categorical distinctions in the discrimination of duration ratios. PMID:16343807

Fetterman, J Gregor

2005-12-15

358

Short-duration electrical immobilization of lake trout  

USGS Publications Warehouse

Chemical anesthetics induce stress responses, and most leave residues in fish tissues that require a certain withdrawal time before the animal can be released into the environment. Therefore, alternatives are needed in cases when fish must be released immediately, for example, during egg-collecting operations or after implanting elastomer tags. To evaluate pulsed direct current as an alternative method of immobilization, individual lake trout Salvelinus namaycush were electrically immobilized using various pulsed-DC voltage gradients and shock durations. Duration of opercular recovery and narcosis were measured for individual fish. Fish were euthanized 24 h after electrical immobilization and processed for lateral radiograph analysis and assessment of perivertebral hemorrhaging by dissection. Survival of lake trout after electrical immobilization at 0.6 V/cm for 30 or 40 s or 0.8 V/cm for 5 or 15 s was monitored for 81 or 84 d after immobilization. Mean narcosis duration increased with voltage gradient and shock duration. Larger fish had longer periods of narcosis at the same combination of voltage gradient and shock duration. Radiological evaluation indicated that 9 of 28 fish in the oldest age-class tested had detectable injuries of the vertebral column, but all but one were in the lowest injury category. Although vertebral column injuries were observed in most small fish, the majority of vertebral column injuries were minor compressions involving two to seven vertebrae. Of the 82 lake trout electrically immobilized to assess long-term survival, only 5 died (6%). Our data suggest that lake trout could be electrically immobilized for a sufficient period to allow field workers to collect length and weight data and implant visible implant tags or colored elastomer tags. The technique we used, however, is probably not appropriate for procedures that require immobilization for more than 2a??3 min.

Gaikowski, Mark P.; Gingerich, William H.; Gutreuter, Steve

2001-01-01

359

Shortened Sleep Duration does not Predict Obesity in Adolescents  

PubMed Central

Obesity continues to be a major public health issue. In adolescents, there are limited studies on the relationship between obesity and sleep duration. We hypothesied that average sleep duration of less than 6 hours in adolescents was associated with obesity. Data was from the National Longitudinal Study of Adolescent Health (ADD Health); survey of 90,000 youths, ages 12 – 18 years; surveyed in several waves. The sample population for our study was 13,568. Weighted multiple logistic regression was used to identify relationship between obesity at Wave II and sleep duration, having adjusted for skipping breakfast ? 2/week; race, gender, parental income, TV ? 2hrs/day, depression, and obesity at Wave I. At Wave I, mean age 15.96±0.11 yrs; mean sleep hours 7.91±0.04. 10.6% and 11.2% of adolescents were obese at Waves I and II, respectively. Adjusted analyses suggest that effect of shortened sleep duration in Wave I was not significantly predictive of obesity in Wave II (p<0.218).Longitudinally, depression and TV ? 2hrs/day at Wave I was associated with higher risk of obesity at Wave II in adjusted analyses. Depressed adolescents were almost twice as likely to be obese (OR=1.84, 95% CI=1.25–2.72); adolescents who watched TV ? 2hrs/day were 37% more likely to be obese (OR=1.37, 95% CI=1.09–1.72).Environmental factors including TV ? 2hrs/day and depression were significantly associated with obesity; shortened sleep duration was not. Future longitudinal studies in adolescents are needed to determine whether timing of television watching directly influences sleep patterns, and ultimately obesity.

Calamaro, Christina J.; Park, Sunhee; Mason, Thornton B. A.; Marcus, Carole L.; Weaver, Terri E.; Pack, Allan; Ratcliffe, Sarah J.

2010-01-01

360

Rats' Memory for Time and Relational Responding in the Duration-Comparison Procedure  

ERIC Educational Resources Information Center

|Rats were trained in a duration-comparison task to press one lever if the comparison duration ("c") was 1.2-s shorter than a standard duration ("s"), and another lever if c was 1.2-s longer than s. The interval between s and c duration was 1 s. The 10 duration pairs used during training controlled for the absolute duration of "c" and the total…

Santi, Angelo; Hoover, Claire; Simmons, Sabrina

2011-01-01

361

Effects of Internal Clock and Memory Disorders on Duration Reproductions and Duration Productions in Patients with Parkinson's Disease  

ERIC Educational Resources Information Center

|Patients with Parkinson's disease (PD) exhibit deficits in perceptual and motor timing as well as impairments in memory and attentional processes that are related to dysfunction of dopaminergic systems in the basal ganglia. The aim of the present study was to assess the relationships existing between impaired duration judgments and defective…

Perbal, S.; Deweer, B.; Pillon, B.; Vidailhet, M.; Dubois, B.; Pouthas, V.

2005-01-01

362

[Comparative study on the characteristics of electrocardiac signals in time domain and frequency domain].  

PubMed

There are two methods (time domain and frequency domain) for the analysis of electrocardiac signals. In this paper is reported a study on them by way of comparison. With the use of filtering method in frequency domain, certain low frequency components were filtered, the time domain waveform was retrieved by IFFT, and the biphase T wave appeared in time domain. After some high frequency components were filtered, time domain wave was retrieved by IFFT, and amplified, the time domain representation of high frequency ECS could be shown obviously, i.e. there was no evident structure in time domain representation of high frequency components in P- and T-waves, but there was evident structure in high frequency components in QRS complex. The duration of QRS depended upon high frequency components, and it was prolonged by filtering certain high frequency components. The slurring of QRS complex was caused by increasing high frequency components, on ventricular depolarized QRS-complex, there were both triangular pulse-like and atriangular pulse-like waveforms, and their power spectrum had both types of feature, single peak and inversepower spectrum. There was no regularity in the spectrum of entire cycle, P- and T-waves, but these was some structure in QRS wave. PMID:11791318

He, W

2001-12-01

363

Integrated approach for fetal QRS detection.  

PubMed

Fetal magnetocardiography provides reliable signals of the fetal heart dynamics with high temporal resolution that can be used in a clinical setting. We present a robust Hilbert transform method for extraction of the fetal heart rate. Our method may be applied to signals derived from a single channel or an array of channels. In the case of multichannel data, the channels can be combined to improve signal-to-noise ratio for the extraction of fetal heart data. The method is inherently insensitive to fetal position or movement and, in addition, can be automated. We demonstrate that the determination of R-wave timing is relatively insensitive to waveform morphology. The method can also be applied if the data were preprocessed by independent component analysis (ICA). We compared the Hilbert method, ICA, ICA + Hilbert, and raw signals and found that the Hilbert method gave the best overall performance. We demonstrated that there were approximately 171 errors in 46,789 fetal heart beats. PMID:18713688

Wilson, James D; Govindan, R B; Hatton, Jeff O; Lowery, Curtis L; Preissl, Hubert

2008-09-01

364

Integrated Approach for Fetal QRS Detection  

PubMed Central

Fetal magnetocardiography provides reliable signals of the fetal heart dynamics with high temporal resolution that can be used in a clinical setting. We present a robust Hilbert transform method for extraction of the fetal heart rate. Our method may be applied to signals derived from a single channel or an array of channels. In the case of multichannel data, the channels can be combined to improve signal-to-noise ratio for the extraction of fetal heart data. The method is inherently insensitive to fetal position or movement and, in addition, can be automated. We demonstrate that the determination of R-wave timing is relatively insensitive to waveform morphology. The method can also be applied if the data were preprocessed by independent component analysis (ICA). We compared the Hilbert method, ICA, ICA + Hilbert, and raw signals and found that the Hilbert method gave the best overall performance. We demonstrated that there were approximately 171 errors in 46 789 fetal heart beats.

Govindan, R. B.; Hatton, Jeff O.; Lowery, Curtis L.; Preissl, Hubert

2010-01-01

365

Hypothesis: Smoking decreases breast feeding duration by suppressing prolactin secretion.  

PubMed

A number of studies, including new data summarized here, conclude that breast feeding duration is lower in smoking mothers. Although some have suggested that this merely reflects poor health motivation in those prone to smoke, several lines of evidence support the view that chronic smoking does indeed compromise breast feeding by suppressing prolactin secretion and thereby lowering breast milk volume. Moreover, a recent clinical trial shows that an effective smoking cessation program can boost breast feeding duration in smokers. An analysis of pertinent rodents studies suggests that chronic nicotine administration boosts dopaminergic activity in the tuberoinfundibular tract which functions to inhibit prolactin release; this increase in dopaminergic activity, in turn, may reflect a nicotine-mediated suppression of hypothalamic opioid activity. PMID:23948597

Bahadori, Babak; Riediger, Natalie D; Farrell, Sharla M; Uitz, Elisabeth; Moghadasian, Mohammed F

2013-08-12

366

SHORT-DURATION LENSING EVENTS. II. EXPECTATIONS AND PROTOCOLS  

SciTech Connect

Ongoing microlensing observations by OGLE and MOA regularly identify lensing events with Einstein diameter crossing time, {tau}{sub E}, of 16 or fewer days. Events with estimated values of {tau}{sub E} of one to two days have been detected. Short-duration events tend to be generated by low-mass lenses or by lenses with high transverse velocities. We compute the expected rates, demonstrate the expected ranges of parameters for lenses of different mass, and develop a protocol for observing and modeling short-duration events. Relatively minor additions to the procedures presently used will increase the rate of planet discovery, and also discover or place limits on the population of high-speed dim stars and stellar remnants in the vicinity of the Sun.

Di Stefano, Rosanne [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)

2012-08-01

367

Test flights of the NASA ultra-long duration balloon  

NASA Astrophysics Data System (ADS)

The National Aeronautics and Space Administration (NASA) Ultra-Long Duration Balloon development project is attempting to extend the potential flight durations for large scientific balloon payloads. The culmination of each of the development steps has been the fabrication and test flight of progressively larger balloons. This new super-pressure balloon is a pumpkin balloon design. This paper concentrates on the super-pressure balloon development test flights that have been, and are currently being planned by the NASA Balloon Program Office at Goddard Space Flight Center's Wallops Flight Facility. Descriptions of two test flights from early 2001 are presented along with lessons learned. Results are also presented of a July 2002 test flight of a full-scale 610,500 m 3 balloon with a 2800 kg suspended load that incorporated the lessons learned.

Cathey, H. M.

2004-01-01

368

Definition of disease duration in ankylosing spondylitis: reassessing the concept  

PubMed Central

The concept and definition of disease duration in patients with ankylosing spondylitis is ambiguous, and often many years pass between the onset of symptoms and diagnosis. Members of the Assessment in Ankylosing Spondylitis (ASAS) International Working Group by consensus recently recommended identifying specific components of the medical history to better define and document the concept of disease duration. These include (1) the time of onset of the first symptoms of axial manifestations (including inflammatory back pain); (2) the time of onset of the first symptoms of each individual manifestation, which may be an extra?axial sign or symptom of ankylosing spondylitis, such as peripheral arthritis and enthesitis; (3) the time of onset of associated diseases belonging to the spondyloarthritides, in particular acute anterior uveitis, inflammatory bowel disease and psoriasis; and (4) the time since actual diagnosis by a healthcare provider. Such uniformity in data collection will ensure comparability across studies and facilitate future research.

Davis, J C; Dougados, M; Braun, J; Sieper, J; van der Heijde, D; van der Linden, S

2006-01-01

369

Coronal mass ejections and associated X-ray flare durations  

SciTech Connect

It is found that 22 percent of a sample of M1 or greater impulsive soft X-ray flares were associated with coronal mass ejections (CMEs) observed in the Solwind coronagraph. These flares were more energetic than similar impulsive flares without CMEs, and the associated CMEs were narrow (5-40 deg) in angular width. A survey of all CMEs associated with M1 or greater X-ray flares reveals a good correlation between flare duration CME angular width. The H-alpha characteristics of impulsive, CME-associated flares suggest that they are not the dynamic or eruptive flares presumed to be associated with CMEs, but rather, are confined flares. The H-alpha flare locations are neither centered under the CME legs. The disparity in size scales between the CMEs and their associated flares leaves the basis of the correlation between CME width and X-ray flare duration unresolved. 29 refs.

Kahler, S.W.; Sheeley, N.R. Jr.; Liggett, M. (Emmanuel College, Boston, MA (USA); E. O. Hulbert Center for Space Research, Washington, DC (USA); Big Bear Solar Observatory, Pasadena, CA (USA))

1989-09-01

370

Rhythm measures and dimensions of durational variation in speech.  

PubMed

Patterns of durational variation were examined by applying 15 previously published rhythm measures to a large corpus of speech from five languages. In order to achieve consistent segmentation across all languages, an automatic speech recognition system was developed to divide the waveforms into consonantal and vocalic regions. The resulting duration measurements rest strictly on acoustic criteria. Machine classification showed that rhythm measures could separate languages at rates above chance. Within-language variability in rhythm measures, however, was large and comparable to that between languages. Therefore, different languages could not be identified reliably from single paragraphs. In experiments separating pairs of languages, a rhythm measure that was relatively successful at separating one pair often performed very poorly on another pair: there was no broadly successful rhythm measure. Separation of all five languages at once required a combination of three rhythm measures. Many triplets were about equally effective, but the confusion patterns between languages varied with the choice of rhythm measures. PMID:21568427

Loukina, Anastassia; Kochanski, Greg; Rosner, Burton; Keane, Elinor; Shih, Chilin

2011-05-01

371

Pauses and durations exhibit a serial position effect.  

PubMed

This article reports evidence of two kinds of serial position effects in immediate serial recall: One involves interresponse pauses, and the other response durations. In forward and backward recall, responding was faster at initial and final positions than at center positions, exhibitinga bow-shaped function relative to serial position. These data were obtained in a spoken recall study in which ungrouped lists of four to six words and postcuing of recall direction were used. The pause pattern is consistent with several models of serial memory, including a distinctiveness model (Brown, Neath, & Chater, 2002) and a version of the ACT-R model augmented with a spontaneous grouping strategy (Maybery, Parmentier, & Jones, 2002). The duration pattern suggests that response articulation depends on the processing context, rather than being modular. PMID:15945208

Haberlandt, Karl; Lawrence, Holly; Krohn, Talia; Bower, Katherine; Thomas, J Graham

2005-02-01

372

Short Sleep Duration and Weight Gain: A Systematic Review  

Microsoft Academic Search

Objective:The recent obesity epidemic has been accompanied by a parallel growth in chronic sleep deprivation. Physiologic studies suggest sleep deprivation may influence weight through effects on appetite, physical activity, and\\/or thermoregulation. This work reviews the literature regarding short sleep duration as an independent risk factor for obesity and weight gain.Methods and Procedures:A literature search was conducted for all articles published

Sanjay R. Patel; Frank B. Hu

2008-01-01

373

The Duration of Exercise as a Regulator of Bone Turnover  

Microsoft Academic Search

The relationship between duration of exercise and serum remodeling markers of bone turnover was evaluated by osteocalcin (OC), carboxy-terminal propeptide of type I collagen (PICP), total and bone-specific alkaline phosphatase (ALP) and carboxyterminal cross-linked telopeptide of type I collagen (ICTP) in 24 male premier league soccer players exercising 12 hours\\/week (range 8–18), 19 third league players exercising 8 hours\\/week (range

K. M. Karlsson; C. Karlsson; H. G. Ahlborg; Ö. Valdimarsson; S. Ljunghall

2003-01-01

374

[Duration of rehabilitation and fate of patients with cerebral infarction].  

PubMed

We studied 61 patients with a first stroke, admitted in our rehabilitation center. Functional evolution is usually good, 84% of patients are able to return at home, after a mean of 4.6 months of rehabilitation. Age, sex, severity of the initial deficit, shoulder-hand syndrome, etiology and localisation of stroke are the factors which determine the functional recovery and duration of hospitalisation. PMID:8480116

Cachin, C; Saudan, Y

1993-03-01

375

Factors Influencing the Duration of International Buyer–Seller Relationships  

Microsoft Academic Search

This paper focuses on factors influencing the duration of buyer–seller relationships. Based on transaction cost economics and relational exchange theory, we discuss key constructs describing long-term relationships and develop hypotheses that can explain differences between long-term and short-term relationships. By using longitudinal data from relationships between Norwegian exporters of farmed salmon and importers in the United States and Japan, we

Sven A. Haugland

1999-01-01

376

Lipopolysaccharide prolongs action potential duration in HL-1 mouse cardiomyocytes  

PubMed Central

Sepsis has deleterious effects on cardiac function including reduced contractility. We have shown previously that lipopolysaccharides (LPS) directly affect HL-1 cardiac myocytes by inhibiting Ca2+ regulation and by impairing pacemaker “funny” current, If. We now explore further cellular mechanisms whereby LPS inhibits excitability in HL-1 cells. LPS (1 ?g/ml) derived from Salmonella enteritidis decreased rate of firing of spontaneous action potentials in HL-1 cells, and it increased their pacemaker potential durations and decreased their rates of depolarization, all measured by whole cell current clamp. LPS also increased action potential durations and decreased their amplitude in cells paced at 1 Hz with 0.1 nA, and 20 min were necessary for maximal effect. LPS decreased the amplitude of a rapidly inactivating inward current attributed to Na+ and of an outward current attributed to K+; both were measured by whole cell voltage clamp. The K+ currents displayed a resurgent outward tail current, which is characteristic of the rapid delayed-rectifier K+ current, IKr. LPS accordingly reduced outward currents measured with pipette Cs+ substituted for K+ to isolate IKr. E-4031 (1 ?M) markedly inhibited IKr in HL-1 cells and also increased action potential duration; however, the direct effects of E-4031 occurred minutes faster than the slow effects of LPS. We conclude that LPS increases action potential duration in HL-1 mouse cardiomyocytes by inhibition of IKr and decreases their rate of firing by inhibition of INa. This protracted time course points toward an intermediary metabolic event, which either decreases available mouse ether-a-go-go (mERG) and Na+ channels or potentiates their inactivation.

Graves, Bridget M.; Li, Chuanfu; Williams, David L.

2012-01-01

377

Test flights of the NASA ultra long duration balloon  

NASA Astrophysics Data System (ADS)

The NASA Ultra Long Duration Balloon development project is attempting to extend the potential flight durations for large scientific balloon payloads. The culmination of each of the development steps has been the fabrication and test flight of progressively larger balloons. This new super-pressure balloon is a pumpkin balloon design. This paper concentrates on the super-pressure balloon development test flights that have been, and are currently being planned by the National Aeronautics and Space Administration (NASA) Balloon Program Office at Goddard Space Flight Center's Wallops Flight Facility. Two Ultra Long Duration balloon test flights took place from Australia in early 2001. The results from these flights, as well as the challenges presented, will be discussed. With these lessons learned and incorporating both material and design improvements, a test flight of a full-scale 610,500m3 balloon with a 2,800 kg suspended load will be completed in Spring of 2002 from Ft. Sumner, New Mexico. This balloon, the largest single celled super- pressure balloon ever flown, has been sized to satisfy the requirements for the planned ULDB CREAM mission in late 2003. A description of the balloon design, including the modifications made as a result of the lessons learned from the two Australia flights, will be presented. The results, highlighting balloon performance, from the Spring 2002 test flight will be presented. This will include information related to the balloon preparation, flight operations, and flight performance. A review of the radiative environmental influences on the balloon related to this flight will be presented. A second test flight of a full-scale Ultra Long Duration Balloon is scheduled for December of 2002. This flight is expected to be one orbit or approximately 15 days. The plans for this Southern Hemisphere, Australia launched, global flight will also be presented.

Cathey, H.

378

Short duration of sleep increases risk of colorectal adenoma  

PubMed Central

Background Short duration and poor quality of sleep have been associated with increased risks of obesity, cardiovascular disease, diabetes mellitus, and total mortality. However, few studies have investigated their associations with risk of colorectal neoplasia. Methods In a screening colonoscopy-based case-control study, the Pittsburg Sleep Quality Index (PSQI) was administered to 1,240 study participants prior to their colonoscopy. Results Three hundred and thirty eight (27.3%) of the participants were diagnosed with incident colorectal adenomas. Although there was no appreciable difference in the overall PSQI score between cases and adenoma-free controls (5.32 vs. 5.11; p=0.37), we found a statistically significant association of colorectal adenoma with the PSQI component 3, which corresponds to sleep duration (p=0.02). Cases were more likely to average less than 6 hours of sleep per night (28.9% vs. 22.1% in controls, p=0.01). In multivariate regression analysis adjusted for age, gender, race, smoking, family history of colorectal cancer, and waist-to-hip ratio, individuals averaging less than 6 hours per night had an almost 50% increase in risk of colorectal adenomas (OR=1.47, CI =1.05-2.06, p for trend=0.02) as compared with individuals sleeping at least 7 hours per night. Cases were also more likely to report of being diagnosed with sleep apnea (9.8% vs. 6.5%, p=0.05) and more likely to have worked alternate shifts (54.0% vs. 46.1%, p=0.01), although these differences were not significant in multivariate models. Conclusions Shorter duration of sleep significantly increases risk of colorectal adenomas. Our results suggest sleep duration as a novel risk factor for colorectal neoplasia.

Thompson, Cheryl L.; Larkin, Emma K.; Patel, Sanjay; Berger, Nathan A.; Redline, Susan; Li, Li

2010-01-01

379

Outage rates and outage durations of opportunistic relaying systems  

Microsoft Academic Search

Opportunistic relaying is a simple yet efficient cooperation scheme that\\u000aachieves full diversity and preserves the spectral efficiency among the\\u000aspatially distributed stations. However, the stations' mobility causes temporal\\u000acorrelation of the system's capacity outage events, which gives rise to its\\u000aimportant second-order outage statistical parameters, such as the average\\u000aoutage rate (AOR) and the average outage duration (AOD). This

Zoran Hadzi-Velkov; Nikola Zlatanov

2010-01-01

380

Racial disparities in short sleep duration by occupation and industry.  

PubMed

Short sleep duration, which is associated with increased morbidity and mortality, has been shown to vary by occupation and industry, but few studies have investigated differences between black and white populations. By using data from a nationally representative sample of US adult short sleepers (n = 41,088) in the National Health Interview Survey in 2004-2011, we estimated prevalence ratios for short sleep duration in blacks compared with whites for each of 8 industry categories by using adjusted Poisson regression models with robust variance. Participants' mean age was 47 years; 50% were women and 13% were black. Blacks were more likely to report short sleep duration than whites (37% vs. 28%), and the black-white disparity was widest among those who held professional occupations. Adjusted short sleep duration was more prevalent in blacks than whites in the following industry categories: finance/information/real estate (prevalence ratio (PR) = 1.44, 95% confidence interval (CI): 1.30, 1.59); professional/administrative/management (PR = 1.30, 95% CI: 1.18, 1.44); educational services (PR = 1.39, 95% CI: 1.25, 1.54); public administration/arts/other services (PR = 1.30, 95% CI: 1.21, 1.41); health care/social assistance (PR = 1.23, 95% CI: 1.14, 1.32); and manufacturing/construction (PR = 1.14, 95% CI: 1.07, 1.20). Short sleep generally increased with increasing professional responsibility within a given industry among blacks but decreased with increasing professional roles among whites. Our results suggest the need for further investigation of racial/ethnic differences in the work-sleep relationship. PMID:24018914

Jackson, Chandra L; Redline, Susan; Kawachi, Ichiro; Williams, Michelle A; Hu, Frank B

2013-09-09

381

Sleep Duration and Risk of Ischemic Stroke in Postmenopausal Women  

PubMed Central

Background Many studies have shown a U-shape association between sleep duration and mortality, but epidemiological evidence linking cardiovascular diseases (CVD) with habitual sleep patterns is limited and mixed. Methods We conducted a prospective study on 93175 older women (aged 50–79 years) in the Women’s Health Initiative Observational Study cohort to examine the risk of ischemic stroke in relation to self-reported sleep duration. Cox models were used to investigate the putative associations, adjusting for multiple sociodemographic and lifestyle factors, depression, snoring, sleepiness symptoms, and other CVD-related clinical characteristics. Results At baseline, 8.3% of subjects had their reported sleep duration ?5h/night and 4.6% with long sleep (?9h/night). After an average of 7.5 years of follow-up, 1166 cases of ischemic stroke had occurred. Multivariable-adjusted relative risks (RR; 95% confidence intervals) for ischemic stroke (using a sleep time of 7h/night as the reference) were 1.14 (0.97, 1.33), 1.24 (1.04, 1.47) and 1.70 (1.32, 2.21) for women reporting 6 or less, 8, and 9 or more hours of sleep. A modestly stronger association with sleep duration ? 6h/night (RR=1.22; 1.03, 1.44) was noted among women without prevalent CVD at baseline. Our analyses also reveal that the adverse effect of long sleep is likely independent of the increased risk for ischemic stroke associated with frequent snoring and sleepiness (RR=1.31; 1.00, 1.72). Conclusions Habitual sleep patterns are important neurobehavioral determinants of risk for ischemic stroke in postmenopausal women. The underlying neurobiology and mechanistic mediators for the putative adverse effect of long sleep (?9h/night) need further elucidation.

Chen, Jiu-Chiuan; Brunner, Robert L.; Ren, Hong; Wassertheil-Smoller, Sylvia; Larson, Joseph C.; Levine, Douglas W.; Allison, Matthew; Naughton, Michelle J.; Stefanick, Marcia L.

2008-01-01

382

Streamer Duration Optimization: Material and Length-to-Width Ratio  

Microsoft Academic Search

The effectiveness of various materials and length-to-width ratios was tested for streamer duration competition. Sixteen streamers, 4 inches wide and 40 inches long, were prepared from crepe paper, cellophane wrapping paper, yellow tracing paper, 16-lb. white bond paper, Micafilm, 1 mil electrostatic discharge Mylar® packaging film, 1.5 mil Mylar, and DragStrip ™ Mylar. Eight additional streamers were prepared from 1.5

Chris Kidwell

383

Fatigue life duration prediction for welded spots by volumetric method  

Microsoft Academic Search

The mechanical behavior of spot-welds under tensile-shear for one, three and five spot-welds is investigated in detail. Volumetric approach is applied to find fatigue life duration of welded spots. The three-dimensional finite element models for different geometries, including gap effects and non-linear features of materials are applied to obtain fatigue life. The elastic–plastic stress distribution at edge of hot spot-weld

H. Adib; J. Gilgert; G. Pluvinage

2004-01-01

384

Phenotypic responses of Spartina anglica to duration of tidal immersion  

Microsoft Academic Search

Although Spartina anglica C.E. Hubbard continues to be invasive in many countries, this species has experienced a drastic decline in coastal China\\u000a over the last decade. We hypothesize that changes in the duration of tidal immersion were responsible for this decline because\\u000a the elevation of the S. anglica-dominated area in coastal China has increased greatly over the last decade. We

Hongli Li; Guangchun Lei; Yingbiao Zhi; Peter Bridgewater; Lei Zhao; Yu Wang; Zifa Deng; Yuhong Liu; Fude Liu; Shuqing An

2011-01-01

385

Criteria for heat and cold wave duration indexes  

Microsoft Academic Search

Many areas of society are susceptible to the effects of extreme temperatures. Without an adequate definition of what constitutes\\u000a heat and cold waves, it is impossible to assess either their changes in the past or their possible consequences for the future.\\u000a The Intergovernmental Panel on Climate Change recommended criteria for heat wave duration indexes based on two arbitrarily\\u000a defined constants.

Djuro Radinovic; Mladjen ?uri?

2011-01-01

386

Development overview of the revised NASA Ultra Long Duration Balloon  

NASA Astrophysics Data System (ADS)

The desire for longer duration stratospheric flights at constant float altitudes for heavy payloads has been the focus of the development of the National Aeronautics and Space Administration’s (NASA) Ultra Long Duration Balloon (ULDB) effort. Recent efforts have focused on ground testing and analysis to understand the previously observed issue of balloon deployment. A revised approach to the pumpkin balloon design has been tested through ground testing of model balloons and through two test flights. The design approach does not require foreshortening, and will significantly reduce the balloon handling during manufacture reducing the chances of inducing damage to the envelope. Successful ground testing of model balloons lead to the fabrication and test flight of a ˜176,000 m3 (˜6.2 MCF Million Cubic Foot) balloon. Pre-flight analytical predictions predicted that the proposed flight balloon design to be stable and should fully deploy. This paper provides an overview of this first test flight of the revised Ultra Long Duration Balloon design which was a short domestic test flight from Ft. Sumner, NM, USA. This balloon fully deployed, but developed a leak under pressurization. After an extensive investigation to the cause of the leak, a second test flight balloon was fabricated. This ˜176,000 m3 (˜6.2 MCF) balloon was flown from Kiruna, Sweden in June of 2006. Flight results for both test flights, including flight performance are presented.

Cathey, H. M.

2008-11-01

387

Guided waves for monitoring heat treatment duration and material hardness  

NASA Astrophysics Data System (ADS)

Elastic properties of materials can be easily determined from the ultrasonic wave velocity measurement. However, material hardness cannot be obtained from the ultrasonic wave speed. Heat treatment and aging affect the microstructure of materials changing their hardness and strength. In this study it is investigated how the attenuation of ultrasonic guided waves is affected by the duration of heat treatment and varying material hardness. To this aim six identical Aluminum 2024 alloy plate specimens were subjected to different durations of heat treatment at 150°C and were inspected nondestructively propagating Lamb waves through the specimens. Attenuation of the Lamb wave was found to be inversely related to the hardness. Rockwell Hardness test was performed to corroborate the ultrasonic observations. In comparison to Rockwell hardness test the ultrasonic inspection was found to be more sensitive to the heat treatment duration. From these results it is concluded that guided wave inspection method is a reliable and probably more desirable alternative for characterizing the hardness of heat treated materials.

Korde, Nilesh; Kundu, Tribikram

2012-03-01

388

Duration of Loxosceles reclusa Venom Detection by ELISA from Swabs  

PubMed Central

BACKGROUND Diagnosis of Loxosceles reclusa envenomations is currently based upon clinical presentation. An enzyme-linked immunosorbent assay (ELISA) can detect surface Loxosceles venom at the envenomation site, allowing diagnostic confirmation. The length of time that venom on the skin is recoverable non-invasively is unknown. MATERIALS AND METHODS To investigate duration of recoverable venom antigen, whole venom and fractionated sphingomyelinase D venom aliquots were injected subcutaneously in New Zealand White rabbits. Cotton and Dacron swabs were compared for venom recovery over a 21-day period using a surface swab technique. RESULTS Significant amounts of Loxosceles reclusa antigen were found on the surface of rabbit skin after experimental injection of whole venom and sphingomyelinase D. The duration of recoverable antigen using this experimental model appears to be at least two weeks and as long as 21 days in some cases. CONCLUSIONS Because the duration of the recoverable antigen is seen to be at least two weeks, the ELISA venom test appears capable of detecting venom on most patients presenting with Loxosceles envenomations. This detection system will allow the physician more accurate determination of whether the lesion is from a brown recluse spider or some other agent that can cause this type of necrotic ulcer.

McGLASSON, DAVID L; GREEN, JONATHON A; STOECKER, WILLIAM V; BABCOCK, JAMES L; CALCARA, DAVID A

2011-01-01

389

The interdigestive colonic motor complex of the dog.  

PubMed

Interdigestive colonic motor patterns of conscious dogs chronically implanted with strain gauge force transducers showed regularly recurring motor complexes. These motor complexes consisted of a sequence of 8-12 tonic contractions (frequency: 1.3/min), on which phasic contractions (frequency: 5-6/min) were superimposed. Complex duration was about 7 min, cycle duration about 32 min. These interdigestive motor complexes of the canine colon were not related to the small intestinal motor complexes and must therefore be considered as a unique and organ-specific motor pattern. PMID:7447571

Schuurkes, J A; Tukker, J J

1980-10-01

390

The role of emotions on pacing strategies and performance in middle and long duration sport events.  

PubMed

Thepacing strategy may be defined as the process in which the total energy expenditure during exercise is regulated on a moment-to-moment basis in order to ensure that the exercise bout can be completed in a minimum time and without a catastrophic biological failure. Experienced athletes develop a stable template of the power outputs they are able to sustain for different durations of exercise, but it is not known how they originally develop this template or how that template changes with training and experience. While it is understood that the athlete's physiological state makes an important contribution to this process, there has been much less interest in the contribution that the athlete's emotional status makes. The aim of this review is to evaluate the literature of physiological, neurophysiological and perceptual responses during exercise in order to propose a complex model interpretation of this process which may be a critical factor determining success in middle- and long-duration sporting competitions. We describe unconscious/physiological and conscious/emotional mechanisms of control, the focus of which are to ensure that exercise terminates before catastrophic failure occurs in any bodily system. We suggest that training sessions teach the athlete to select optimal pacing strategies by associating a level of emotion with the ability to maintain that pace for exercise of different durations. That pacing strategy is then adopted in future events. Finally, we propose novel perspectives to maximise performance and to avoid overtraining by paying attention also to the emotional state in training process. PMID:19553226

Baron, B; Moullan, F; Deruelle, F; Noakes, T D

2009-06-23

391

Standard metabolic rate is associated with gestation duration, but not clutch size, in speckled cockroaches Nauphoeta cinerea  

PubMed Central

Summary Metabolic rate varies significantly between individuals, and these differences persist even when the wide range of biotic and abiotic factors that influence metabolism are accounted for. It is important to understand the life history implications of variation in metabolic rate, but they remain poorly characterised despite a growing body of work examining relationships between metabolism and a range of traits. In the present study we used laboratory-bred families (one sire to three dams) of Nauphoeta cinerea (Olivier) (speckled cockroaches) to examine the relationship between standard metabolic rate (SMR) and reproductive performance (number of offspring and gestation duration). We show that SMR is negatively associated with female gestation duration. Age at mating is negatively associated with gestation duration for females, and mass is negatively associated with the average gestation duration of the females a male was mated with. In addition to the results in the current literature, the results from the present study suggest that the association between metabolism and life history is more complex than simple relationships between metabolism and various fitness traits. Future work should consider longitudinal, ontogenetic as well as selective and quantitative genetic breeding approaches to fully examine the associations between metabolism and fitness.

Schimpf, Natalie G.; Matthews, Philip G. D.; White, Craig R.

2012-01-01

392

Short sleep duration and obesity among Australian children  

PubMed Central

Background There is limited information on sleep duration and obesity among Australian children. The objective of the study is to cross-sectionally examine the relationship between sleep duration and obesity in Australian children aged 5 to 15 years. Methods Data were collected using the South Australian Monitoring and Surveillance System between January 2004 and December 2008. Each month a representative random sample of South Australians are selected from the Electronic White Pages with interviews conducted using Computer Assisted Telephone Interviewing (CATI). Within each household, the person who was last to have a birthday was selected for interview. Parents reported the number of hours their children slept each day. Obesity was defined according to the International Obesity Task Force (IOTF) definition based on BMI calculated from reported body weight and height. Results Overall, parents of 3495 children aged 5-15 years (mean 10.7 years, 50.3% boys) were interviewed. The prevalence of obesity was 7.7% (8.9% in boys, 6.6% in girls). In multivariate analysis after adjusting for sociodemographic variables, intake of fruit and vegetables, physical activity and inactivity, the odds ratio (OR) for obesity comparing sleeping <9 hours with ?10 hours was 2.23 (95% CI 1.04-4.76) among boys, 1.70(0.78-3.73) among girls, and 1.97(1.15-3.38) in both genders. The association between short sleep (<9 hours) and obesity was stronger in the younger age group. No significant association between short sleep and obesity was found among children aged 13-15. There was also an additive interaction between short sleep and low level of physical activity. Conclusion Short sleep duration is associated with increased obesity in children especially among younger age groups and boys.

2010-01-01

393

Smoking duration, intensity, and risk of Parkinson disease  

PubMed Central

Objective: To evaluate the relative importance of smoking duration vs intensity in reducing the risk of Parkinson disease (PD). Methods: The study included 305,468 participants of the NIH-AARP Diet and Health cohort, of whom 1,662 had a PD diagnosis after 1995. We estimated odds ratios (OR) and 95% confidence intervals from multivariate logistic regression models. Results: Compared with never smokers, the multivariate ORs were 0.78 for past smokers and 0.56 for current smokers. Among past smokers, a monotonic trend toward lower PD risk was observed for all indicators of more smoking. Stratified analyses indicated that smoking duration was associated with lower PD risk within fixed intensities of smoking. For example, compared with never smokers, the ORs among past smokers who smoked >20 cigarettes/day were 0.96 for 1–9 years of smoking, 0.78 for 10–19 years, 0.64 for 20–29 years, and 0.59 for 30 years or more (p for trend = 0.001). In contrast, at fixed duration, the typical number of cigarettes smoked per day in general was not related to PD risk. Close examination of smoking behaviors in early life showed that patients with PD were less likely to be smokers at each age period, but if they smoked, they smoked similar numbers of cigarettes per day as individuals without PD. Conclusions: This large study suggests that long-term smoking is more important than smoking intensity in the smoking–Parkinson disease relationship. GLOSSARY CI = confidence interval; DH = Diet and Health; OR = odds ratio; PD = Parkinson disease.

Chen, H.; Huang, X.; Guo, X.; Mailman, R. B.; Park, Y.; Kamel, F.; Umbach, D. M.; Xu, Q.; Hollenbeck, A.; Schatzkin, A.; Blair, A.

2010-01-01

394

Duration of optimal therapy for idiopathic focal segmental glomerulosclerosis.  

PubMed

We conducted a retrospective study to evaluate the duration of optimal steroid therapy in idiopathic focal segmental glomerulosclerosis (FSGS). We evaluated 93 adult patients (n=65 males) with biopsy proven FSGS. Mean proteinuria was 5.4 +/- 2.8 gm/dL. Twelve patients were lost at follow-up. Of the remaining 81 patients, nephrotic range proteinuria was present in 48 (59%), and 21 (26%) presented with renal insufficiency. Of these patients, three (3.9%) experienced spontaneous remission. Seven patients were managed symptomatically with ACE inhibitors and never received steroids. Of the 71 patients, 32 received >16 weeks of steroid therapy, while 39 received <16 weeks of steroid therapy. Twenty-four patients (75%) who received >16 weeks of steroid therapy had a complete or partial remission, while only 18 (46%) of those with <16 weeks of steroid therapy had a steroid response (p=0.001). Patients with more than 25% interstitial fibrosis at biopsy also showed significantly lower remission rates (p=0.02). Hypertension, hematuria and degree of proteinuria did not significantly affect the response to steroid therapy. Univariate logistic regression analysis showed that the factors predictive of remission were: (1) steroid therapy duration (p=0.001); (2) serum creatinine (Cr) at onset (p=0.001) and; (3) presence of interstitial fibrosis (>25%) at initial biopsy (p=0.02). Multivariate logistic regression analysis showed that the only factor predictive of remission was steroid therapy duration >16 weeks (p=0.001). Therefore, we concluded that patients with idiopathic FSGS required treatment for at least 16 weeks, before labeling them as steroid non-responsive. Patients with interstitial fibrosis have a significantly poor response to therapy. PMID:14733415

Pokhariyal, Saurabh; Gulati, Sanjeev; Prasad, Narayan; Sharma, Raj Kumar; Singh, Uttam; Gupta, Ramesh Kumar; Mittal, Sanjay; Mehta, Bhavna

395

Predictors of Smoking Cessation and Duration: Implication for Smoking Prevention  

PubMed Central

Background: There are few articles studding the factors associated with successful smoking cessation in Iranian smokers. The aim of this study is to clarify the association between socio-demographic factors and smoking behavior, such as number of failed smoking cessation and duration of abstinence in Iranian population. Methods: A self-administered questionnaire survey of 673 participants was conducted in a local government health-care center. The questionnaire included items on socio-demographic information including, age, marital status, education, income, and job. Furthermore, information on smoking cigarettes including number of smoking per day, duration of smoking, cigarettes brand, nicotine concentration, and history of cessation was obtained. Results: Mean ± SD of age and daily cigarette consumption were 39.7 ± 1.1 and 22.1 ± 1.1 respectively. Failure rate of smoking cessation was higher in the lower age group (odds ratios [OR] 2.9; 95% confidence intervals [CI] 1.1, 7.7) and less than 10 numbers smoking per day (OR 2.4; 95% CI 1.3, 4.5) and duration of smoking more than 30 years (OR 3.4; 95% CI 1.2, 9.3) and foreign cigarette brand (OR 1.8; 95% CI 1.1, 2.7). Length time of cessation was prominent in participants with lower age group (OR 5.4; 95% CI 1.3, 22.1), and less than 10 numbers smoking per day (OR 2.7; 95% CI 1.5, 4.9) and lower in smokers with duration of smoking more than 10 and 10-19 years (OR 0.32; 95% CI 0.12, 0.89), (OR 0.34; 95% CI 0.17, 0.76), respectively. Conclusions: The above results suggest that there are a significant association between socio-demographic factors and smoking-related behaviors in the Iranian population, consistent with previous reports world-wide. These factors should be considered to have appropriate public-health and policy response.

Meamar, Rokhsareh; Etedali, Farshad; Sereshti, Nafiseh; Sabour, Elnaz; Samani, Marzieh Dehghani; Ardakani, Mohammad Reza Piri; Mirhosseini, Seyyed Mohammad Mahdy; Maracy, Mohammad

2013-01-01

396

Psychology and culture during long-duration space missions  

NASA Astrophysics Data System (ADS)

The objective of this paper is twofold: (a) to review the current knowledge of cultural, psychological, psychiatric, cognitive, interpersonal, and organizational issues that are relevant to the behavior and performance of astronaut crews and ground support personnel and (b) to make recommendations for future human space missions, including both transit and planetary surface operations involving the Moon or Mars. The focus will be on long-duration missions lasting at least six weeks, when important psychological and interpersonal factors begin to take their toll on crewmembers. This information is designed to provide guidelines for astronaut selection and training, in-flight monitoring and support, and post-flight recovery and re-adaptation.

Kanas, N.; Sandal, G.; Boyd, J. E.; Gushin, V. I.; Manzey, D.; North, R.; Leon, G. R.; Suedfeld, P.; Bishop, S.; Fiedler, E. R.; Inoue, N.; Johannes, B.; Kealey, D. J.; Kraft, N.; Matsuzaki, I.; Musson, D.; Palinkas, L. A.; Salnitskiy, V. P.; Sipes, W.; Stuster, J.; Wang, J.

2009-04-01

397

Infant feeding practices and breastfeeding duration in Japan: A review  

PubMed Central

The Japanese health system places great emphasis on healthy development. However, the prevalence of Exclusive Breastfeeding at one month postpartum between 1980 and 2005 has remained unchanged, fluctuating between 42% and 49%. At the same time, the Any Breastfeeding prevalence has gradually increased from about 80% to 95%. In 2010, the latest national breastfeeding report showed that ‘exclusive’ and ‘any’ breastfeeding rates have improved. However, as the World Health Organization (WHO) definition of breastfeeding practices was not used in this study or in other national surveys, it is difficult to interpret these latest results. While the Japanese government has launched several promotion projects, there have been few studies and reviews of risk factors that influence breastfeeding duration. The objectives of this review were to summarise the factors that have influenced the duration of breastfeeding in Japan to provide information relevant to breastfeeding promotion programs. A search of electronic databases in Japanese and English was undertaken up to 2011. The inclusion criteria for this review were studies that focused on infant feeding practices and targeted Japanese mothers, fathers, or health professionals, but excluded mothers’ friends and peer groups. In total, 12 articles were selected for the final analysis. Smoking status, low birth weight of infants and maternal perceptions of insufficient breast milk supply were negative influences on breastfeeding duration, while support from husbands/partners is associated with continued breastfeeding. Some factors that have been found to be associated with breastfeeding in other countries, including maternal age, family income, maternal educational levels, and living with grandparents of infants have not been confirmed in Japan. While the national breastfeeding rates were higher than other countries of similar health status, inconsistent knowledge of breastfeeding benefits and inappropriate hospital practices remain in Japan may be associated with increased the use of infant formula and reduced breastfeeding duration. Most of the studies reviewed were cross-sectional in design, with only a limited number of cohort studies. Also many published studies used small sample sizes. Cohort studies of infant feeding practices with larger sample sizes are required to monitor trends in rates and risk factors for breastfeeding outcomes.

2012-01-01

398

Fixed Duration Pursuit-Evasion Differential Game with Integral Constraints  

NASA Astrophysics Data System (ADS)

We investigate a pursuit-evasion differential game of countably many pursuers and one evader. Integral constraints are imposed on control functions of the players. Duration of the game is fixed and the payoff of the game is infimum of the distances between the evader and pursuers when the game is completed. Purpose of the pursuers is to minimize the payoff and that of the evader is to maximize it. Optimal strategies of the players are constructed, and the value of the game is found. It should be noted that energy resource of any pursuer may be less than that of the evader.

I, Ibragimov G.; Sh, Kuchkarov A.

2013-04-01

399

Laser duration and intensity limits in plasma backward Raman amplifiers  

NASA Astrophysics Data System (ADS)

The shortest duration and the largest non-focused intensity of laser pulses produced by means of backward Raman amplification (BRA) in plasmas are calculated. These limits occur in moderately undercritical plasmas and are imposed by combined effects of moderately small group velocity dispersion and relativistic electron nonlinearity of the amplified pulses. The efficient BRA range covered by this theory is broader than one known previously. This can be useful for BRA of x-ray pulses in regular or compressed solids and ultra-powerful optical pulses in the lowest density solids.

Malkin, V. M.; Toroker, Z.; Fisch, N. J.

2012-02-01

400

The duration of enzyme induction in orocaecal transit time measurements  

Microsoft Academic Search

Objective:In this study, the duration of enzyme induction provoked by unlabelled lactose ureide (LU) in orocaecal transit time (OCTT) measurements with lactose-[13C]ureide (13C-LU) was evaluated.Design:Experimental study.Setting:University of Rostock, Children's Hospital, Research Laboratory.Subjects:Fifteen healthy adults aged 19–54 years.Intervention:One-half gram of 13C-LU was administered together with a continental breakfast. After 1 week, the test was repeated after pre-dosing of 5 × 100

K D Wutzke; M Schütt

2007-01-01

401

Exercise Intensity and Duration Affect Blood-Soluble HSP72  

Microsoft Academic Search

\\u000a Extracellular Hsp72 (eHsp72) is elevated during and after acute bouts of exercise. Concentrations of eHsp72 in plasma or serum\\u000a are dependent on the duration and intensity of exercise. Active secretory processes rather than passive release due to cell\\u000a damage are considered to function in the exercise-induced release of eHsp72. Up-regulation of eHsp72 in the circulation following\\u000a acute exercise may contribute

Kishiko Ogawa; Elvira Fehrenbach

402

Explanation of power law behavior of autoregressive conditional duration processes based on the random multiplicative process  

NASA Astrophysics Data System (ADS)

Autoregressive conditional duration (ACD) processes, which have the potential to be applied to power law distributions of complex systems found in natural science, life science, and social science, are analyzed both numerically and theoretically. An ACD(1) process exhibits the singular second order moment, which suggests that its probability density function (PDF) has a power law tail. It is verified that the PDF of the ACD(1) has a power law tail with an arbitrary exponent depending on a model parameter. On the basis of theory of the random multiplicative process a relation between the model parameter and the power law exponent is theoretically derived. It is confirmed that the relation is valid from numerical simulations. An application of the ACD(1) to intervals between two successive transactions in a foreign currency market is shown.

Sato, Aki-Hiro

2004-04-01

403

Explanation of power law behavior of autoregressive conditional duration processes based on the random multiplicative process.  

PubMed

Autoregressive conditional duration (ACD) processes, which have the potential to be applied to power law distributions of complex systems found in natural science, life science, and social science, are analyzed both numerically and theoretically. An ACD(1) process exhibits the singular second order moment, which suggests that its probability density function (PDF) has a power law tail. It is verified that the PDF of the ACD(1) has a power law tail with an arbitrary exponent depending on a model parameter. On the basis of theory of the random multiplicative process a relation between the model parameter and the power law exponent is theoretically derived. It is confirmed that the relation is valid from numerical simulations. An application of the ACD(1) to intervals between two successive transactions in a foreign currency market is shown. PMID:15169127

Sato, Aki-Hiro

2004-04-26

404

Effects of different temperatures and duration on germination of caper (Capparis ovata) seeds.  

PubMed

Caperseed has poor germination because of the seed coat dormancy Germination of caperseeds are complex traits affected by a wide range of intemal and environmental influences. The effects of temperature preconditioning and period on germination of Capparis ovata were examined. Experiments were conducted in order to investigate germination behaviour of caperseeds subjected to different temperature and duration. The experiment revealed that the different temperature treatments were effective on mean germination percentage. The highest mean germination were obtained at 0 degree C 29.52% and 10 degrees C with 27.17% and the lowest mean germination were obtained at control seeds with 8.39%. Dry heat treatments effected germination rate, but it was not enough for removing germination obstacle of caper seed completely. PMID:20120507

Basbag, Mehmet; Toncer, Ozlem; Basbag, Sema

2009-07-01

405

COP9 signalosome subunit Csn8 is involved in maintaining proper duration of the G1 phase.  

PubMed

The COP9 signalosome (CSN) is a conserved protein complex known to be involved in developmental processes of eukaryotic organisms. Genetic disruption of a CSN gene causes arrest during early embryonic development in mice. The Csn8 subunit is the smallest and the least conserved subunit, being absent from the CSN complex of several fungal species. Nevertheless, Csn8 is an integral component of the CSN complex in higher eukaryotes, where it is essential for life. By characterizing the mouse embryonic fibroblasts (MEFs) that express Csn8 at a low level, we found that Csn8 plays an important role in maintaining the proper duration of the G1 phase of the cell cycle. A decreased level of Csn8, either in Csn8 hypomorphic MEFs or following siRNA-mediated knockdown in HeLa cells, accelerated cell growth rate. Csn8 hypomorphic MEFs exhibited a shortened G1 duration and affected expression of G1 regulators. In contrast to Csn8, down-regulation of Csn5 impaired cell proliferation. Csn5 proteins were found both as a component of the CSN complex and outside of CSN (Csn5-f), and the amount of Csn5-f relative to CSN was increased in the Csn8 hypomorphic cells. We conclude that CSN harbors both positive and negative regulators of the cell cycle and therefore is poised to influence the fate of a cell at the crossroad of cell division, differentiation, and senescence. PMID:23689509

Liu, Cheng; Guo, Li-Quan; Menon, Suchithra; Jin, Dan; Pick, Elah; Wang, Xuejun; Deng, Xing Wang; Wei, Ning

2013-05-20

406

Word-Initial Letters Influence Fixation Durations during Fluent Reading  

PubMed Central

The present study examined how word-initial letters influence lexical access during reading. Eye movements were monitored as participants read sentences containing target words. Three factors were independently manipulated. First, target words had either high or low constraining word-initial letter sequences (e.g., dwarf or clown, respectively). Second, targets were either high or low in frequency of occurrence (e.g., train or stain, respectively). Third, targets were embedded in either biasing or neutral contexts (i.e., targets were high or low in their predictability). This 2 (constraint)?×?2 (frequency)?×?2 (context) design allowed us to examine the conditions under which a word’s initial letter sequence could facilitate processing. Analyses of fixation duration data revealed significant main effects of constraint, frequency, and context. Moreover, in measures taken to reflect “early” lexical processing (i.e., first and single fixation duration), there was a significant interaction between constraint and context. The overall pattern of findings suggests lexical access is facilitated by highly constraining word-initial letters. Results are discussed in comparison to recent studies of lexical features involved in word recognition during reading.

Hand, Christopher J.; O'Donnell, Patrick J.; Sereno, Sara C.

2012-01-01

407

Sleep duration and quality associated with obesity among Arab children.  

PubMed

The link between sleep duration and obesity has been well established in adults, but several epidemiological studies revealed inconsistent findings in adolescents and younger children. This study aimed to investigate the relationship between sleep length and obesity in Saudi students. A total of 5,877 Saudi students, boys (55.2%) and girls (44.8%), aged between 10 and 19 years were randomly selected from elementary, intermediate, and secondary schools in different regions of Riyadh. A questionnaire on sleep behaviors was given. Anthropometry included BMI and waist and hip circumferences. Sleeping duration and poor sleep quality are significantly associated with obesity among Arab youth. Further studies need to employ more objective measures of sleep, such as actigraphy, and examine the mechanism of these associations. PMID:19498352

Bawazeer, Nahla M; Al-Daghri, Nasser M; Valsamakis, George; Al-Rubeaan, Khalid A; Sabico, Shaun Louie B; Huang, Terry T-K; Mastorakos, George P; Kumar, Sudhesh

2009-06-04

408

Duration of therapy in metastatic breast cancer: management using Herceptin.  

PubMed

Despite progressive developments in therapeutic interventions, including surgery, radiotherapy and chemotherapy, there has been no major improvement in the survival of women with metastatic breast cancer (MBC). Based on knowledge of tumor growth patterns, approaches addressing this issue have included increasing chemotherapy dose or dose density and extending the duration of therapy. However, only the latter approach has resulted in improved clinical benefit, although not survival; and its use is restricted by the cumulative toxicity of chemotherapeutic agents. Therefore, the best hope for improved survival lies with new classes of anticancer drug and particularly biological agents. This review focuses on the first oncogene-targeted therapy for human epidermal growth factor receptor-2 (HER2)+ MBC patients. The humanized anti-HER2 monoclonal antibody Herceptin has proven clinical benefits in HER2+ MBC patients, most importantly improved survival, and is rapidly becoming a standard of care for these patients. In contrast to the fixed number of cycles used for chemotherapeutic agents, Herceptin is administered until disease progression, with some data suggesting that continuation beyond disease progression should be investigated. The preclinical and clinical findings on which the current recommended duration of Herceptin therapy are based are reviewed and alternative strategies are discussed. PMID:11487711

Bell, R

2001-08-01

409

On pulse duration of self-terminating lasers  

SciTech Connect

The problem of the maximum pulse duration {tau}{sub max} of self-terminating lasers is considered. It is shown that the duration depends on the transition probability in the laser channel, on the decay rate of the resonant state in all other channels, and on the excitation rate of the metastable state. As a result, {tau}{sub max} is found to be significantly shorter than previously estimated. The criteria for converting the 'self-terminating' lasing to quasi-cw lasing are determined. It is shown that in the case of nonselective depopulation of the metastable state, for example in capillary lasers or in a fast flow of the active medium gas, it is impossible to obtain continuous lasing. Some concrete examples are considered. It is established that in several studies of barium vapour lasers ({lambda} = 1.5 {mu}m) and nitrogen lasers ({lambda} = 337 nm), collisional lasing is obtained by increasing the relaxation rate of the metastable state in collisions with working particles (barium atoms and nitrogen molecules). (lasers)

Bokhan, P A [A.V. Rzhanov Institute of Semiconductor Physics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk (Russian Federation)

2011-02-28

410

Duration of pulmonary function adaptation to ozone in humans  

SciTech Connect

The duration of pulmonary function adaptation subsequent to cessation of a 5-day repeated ozone (O/sub 3/) exposure was studied in 24 nonsmoking human subjects. A three-week, 3 hr/day study ws conducted. The subjects received filtered air on Week 1 and 0.4 ppm O/sub 3/ on Week 2. During Week 3, 13 subjects were re-exposed to O/sub 3/ on Friday and 11 were re-exposed to O/sub 3/ on Tuesday. Spirometric measurements (FVC and FEV/sub 1/) and bronchial reactivity to methacholine showed adapation within 2-3 days of the repeated daily exposures (Week 2). Although the duration of adaptation seen with bronchial reactivity appears longer than 7-days, the FVC and FEV/sub 1/ clearly demonstrated complete loss of adaptation by 7 days, with a trend toward significance by 4 days. We concluded, therefore, the loss of ozone adaptation in pulmonary function is a gradual phenomenon lasting less than 7 days following cessation of repeated daily exposures.

Kulle, T.J.; Sauder, L.R.; Kerr, H.D.; Farrell, B.P.; Bermel, M.S.; Smith, D.M.

1982-11-01

411

Effects of botulinum toxin on strength-duration properties.  

PubMed

Axonal excitability studies have been used in several diseases to investigate the underlying pathophysiology. The threshold tracking technique was developed to measure noninvasively several indices of axonal excitability, such as strength-duration properties. This study investigated the possible effects of botulinum toxin on strength-duration time constant (SDTC) in patients with the symptoms and signs of botulism. The clinical and electrophysiological findings of 13 patients who were admitted to the authors' clinic with botulism signs and symptoms were evaluated in a 5-day period after exposure to the toxin prospectively. After routine diagnostic electroneuromyographic examinations and electromyogram with repetitive nerve stimulation at 20-50 Hz, SDTC was studied. The results were compared with 13 age- and sex-matched healthy volunteers. The SDTCs were 381 +/- 60 micros and 471 +/- 84 micros in patients and controls, respectively. There was a statistical difference between the two groups (p = .003, Mann Whitney U test). These findings suggest a possible effect of botulinum toxin, known to be effective at neuromuscular junction, on Na(+)/K(+) pump activity, and Na(+) or K(+) conductance. PMID:17729156

Yerdelen, Deniz; Koc, Filiz; Sarica, Yakup

2007-10-01

412

Exposure duration: effects on eyewitness accuracy and confidence.  

PubMed

The current study examined the relationship between the length of exposure to a face in an eyewitness setting and identification accuracy and confidence. A sample of 164 young (ages 17-25) and older (ages 59-81) adults viewed a simulated crime in which they saw the culprit's face for a short (12 s) or long (45 s) duration. They were then tested with a target absent (a line-up not containing the culprit) or target present line-up. Identification accuracy rates for both young and older participants were significantly higher under the long exposure condition. In the short exposure condition, witnesses who had made a correct identification of the target were more confident than incorrect witnesses. In the long exposure condition the confidence ratings of accurate and inaccurate witnesses did not differ. Discussion focuses on the extent to which extended exposure may inflate confidence judgments and variables that may moderate the relationship between exposure duration and face recognition accuracy. PMID:14511547

Memon, Amina; Hope, Lorraine; Bull, Ray

2003-08-01

413

Activities for a long duration flight system in Japan  

NASA Astrophysics Data System (ADS)

The balloon group in the Institute of Space and Astronomical Science (ISAS) has been spending many efforts to long duration balloon flights for scientific observations. One of those achievements is the of Boomerang Balloon system. The system has been successfully applied to many scientific observations in Japan during these 20 years. Recent achievements along this line are ``Satellite linked Boomerang Balloons'' This is to recover the payloads after several days of flights over the Pacific Ocean. ISAS and the Communication Research Laboratory have been conducting this program. The Polar Patrol Balloon at Antarctica has been established already to perform the circumpolar flight at level altitude taking almost 3 weeks. The National Institute for Polar Research and ISAS have been conducting this program. Summarizing those activities, in this paper we mainly refer to some recent results of feasibility studies of the Over Pressurized Pumpkin Shaped Balloons and of the balloons with new possible balloon films (EVAL, Ethylene-Vinyl-Alcohol) of specific IR absorptivity for the long duration flights.

Nishimura, J.

414

Anticoagulation after venous thromboembolism. Deciding on the optimal duration.  

PubMed

Deciding on the optimal duration of anticoagulation is based on the risk of recurrent venous thromboembolism (VTE) and of bleeding during anticoagulation. The duration of anticoagulation should be at least three months since shorter courses double the recurrence rates. At three months anticoagulation can be stopped in patients with a VTE provoked by a transient risk factor, as the recurrence risk is expected to be lower than the bleeding risk during anticoagulation. Patients with unprovoked VTE are at higher risk of recurrence and prolonged anticoagulation is currently recommended. However, attempts are made to stratify these patients according to their recurrence risk and to identify those with a low recurrence risk who would not benefit from extended anticoagulation. Novel approaches to optimize the management of patients with unprovoked VTE are the use of prediction models which link clinical patient characteristics with laboratory testing to discriminate between patients with a low risk (who may discontinue anticoagulation) and those with high risk (in whom long term anticoagulation is justified). Moreover, new antithrombotic concepts including new oral anticoagulants or aspirin both of which potentially confer a lower bleeding risk and are more convenient for the patients have been explored for extended thromboprophylaxis. PMID:23719863

Eichinger, S

2013-05-29

415

Long Duration Performance of High Temperature Irradiation Resistant Thermocouples  

SciTech Connect

Many advanced nuclear reactor designs require new fuel, cladding, and structural materials. Data are needed to characterize the performance of these new materials in high temperature, radiation conditions. However, traditional methods for measuring temperature inpile degrade at temperatures above 1100 ºC. To address this instrumentation need, the Idaho National Laboratory (INL) developed and evaluated the performance of a high temperature irradiation-resistant thermocouple that contains alloys of molybdenum and niobium. To verify the performance of INL’s recommended thermocouple design, a series of high temperature (from 1200 to 1800 ºC) long duration (up to six months) tests has been initiated. This paper summarizes results from the tests that have been completed. Data are presented from 4000 hour tests conducted at 1200 and 1400 ºC that demonstrate the stability of this thermocouple (less than 2% drift). In addition, post test metallographic examinations are discussed which confirm the compatibility of thermocouple materials throughout these long duration, high temperature tests.

Rempe, Joy L; Knudson, D. L.; Condie, K. G.; Wilkins, S. C.

2007-05-01

416

An evaluation of factors affecting duration of orthodontic treatment.  

PubMed

One of the first questions asked by new orthodontic patients is: How long will I need to wear my braces? A multitude of factors have the potential to influence the answer to this question. The purpose of this retrospective study was to identify some of the primary factors that influence orthodontic treatment duration. Few studies have attempted to evaluate these factors. Data were gathered from 140 consecutively completed, comprehensive treatment patient records in five orthodontic offices. Thirty-one variables related to patient characteristics, diagnostic factors, modality of treatment, and patient cooperation were evaluated. Average treatment time was 28.6 months with a range of 23.4 to 33.4 months among the five offices. Nearly half (46.9%) of the variation in treatment duration was explained by a five-step multiple regression analysis. Included in the regression equation were the number of missed appointments, the number of replaced brackets and bands, the number of treatment phases, the number of negative chart entries regarding oral hygiene, and the prescription of headgear wear during treatment. An additional 6.7% of the variance was explained by variation among the five offices. Six of the 31 variables examined made a statistically significant (alpha =.01) contribution to the explanation of variation in treatment time. The quality of the finished cases and the appropriateness of the original diagnosis and treatment plan were not evaluated. Developing an objective assessment to evaluate these areas may be important for increasing our understanding of treatment time variation. PMID:10194290

Beckwith, F R; Ackerman, R J; Cobb, C M; Tira, D E

1999-04-01

417

Enhancing Team Performance for Long-Duration Space Missions.  

National Technical Information Service (NTIS)

Success of exploration missions will depend on skilled performance by a distributed team that includes both the astronauts in space and Mission Control personnel. Coordinated and collaborative teamwork will be required to cope with challenging complex pro...

J. M. Orasanu

2009-01-01

418

Division of labor between left and right human auditory cortices during the processing of intensity and duration.  

PubMed

Intensity and duration are important parameters for the processing of speech and music. Neuroimaging results on the processing of these parameters in tasks involving the discrimination of stimuli based on these parameters are controversial. Depending on the experimental approach, varying hypotheses on the involvement of the left and right auditory cortices (ACs) have been put forward. The aim of the present functional magnetic resonance imaging (fMRI) study was to find differences and commonalities in location and strength of brain activity during the processing of intensity and duration when the same stimuli have to be actively categorized according to these two parameters. For this we used a recently introduced method to determine lateralized processing in the AC with contralateral noise. Harmonic frequency modulated (FM) tone complexes were presented monaurally without and with contralateral noise. During categorization of the tones according to their intensity, contralateral noise increased activity mainly in the left AC, suggesting a special role for the left AC in this task. During categorization of tones according to their duration, contralateral noise increased activity in both the left and the right AC. This suggests that active categorization of FM tones according to their duration does not involve only the left AC as has been suggested, but also the right AC to a substantial degree. The area around Heschl's sulcus seems to be the most strongly involved during both intensity and duration categorization, albeit with different lateralization. Altogether the results of the present study support the view that the lateralized processing of the same stimuli in the human AC is strongly modulated by the given task (top-down effect). PMID:23831528

Angenstein, Nicole; Brechmann, André

2013-07-03

419

Effect of Observing Session Duration on Static GPS Velocity Estimation  

NASA Astrophysics Data System (ADS)

The effect of the observing session duration on static GPS positional accuracies has previously been detected. This study further investigates this effect on the estimated velocities. This is especially important for tectonic/deformation monitoring studies that use GPS observations shorter than 24 h. A sample has been made from 13 IGS stations that cover the earth globally. GIPSY research software has been used for the processing. GPS velocities have been estimated from GPS campaigns using the time series of 15-year length on average. The sampling rate was chosen as one observation per year as still used by some of the tectonic studies today. The solutions from 24 h data were taken as the truth and the velocities estimated from the shorter sessions were assessed. We show how the coefficient of multiple determination R-squared can successfully be used to assess the accuracy of GPS velocities from campaign measurements. Results based on this assessment indicate that vertical velocities are affected most when observation sessions shorter than 24 h are used. An accuracy improvement of 12% on average on the vertical velocity is gained as the observation session is extended from 8 h to 12 h. Individual solutions show that this improvement can be as high as 32%. Similarly, the improvement in horizontal velocities is 3% on average but it could be as high as 13% for some stations. A further amount of improvement at similar levels can only be obtained when observing session duration is extended from 12 h to 18 h which is not practical when one needs to use the advantage of the day light. This suggests us that the lowest limit for the session length of GPS campaigns needs to be 12 h rather than 6-8 h which have typically been applied conventionally by many research groups up to date. Using 12 h of GPS observations, 90% of the vertical deformation pattern is recovered. The percentages for the same duration are 96 and 100 for the longitudinal and latitudinal deformations respectively.

Sanli, D. U.; Akarsu, V.; Arslan, E.

2011-12-01

420

Indications for cardiac resynchronization therapy: 2011 update from the Heart Failure Society of America Guideline Committee.  

PubMed

Cardiac resynchronization therapy (CRT) improves survival, symptoms, quality of life, exercise capacity, and cardiac structure and function in patients with New York Heart Association (NYHA) functional class II or ambulatory class IV heart failure (HF) with wide QRS complex. The totality of evidence supports the use of CRT in patients with less severe HF symptoms. CRT is recommended for patients in sinus rhythm with a widened QRS interval (?150 ms) not due to right bundle branch block (RBBB) who have severe left ventricular (LV) systolic dysfunction and persistent NYHA functional class II-III symptoms despite optimal medical therapy (strength of evidence A). CRT may be considered for several other patient groups for whom evidence of benefit is clinically significant but less substantial, including patients with a QRS interval of ?120 to <150 ms and severe LV systolic dysfunction who have persistent mild to severe HF despite optimal medical therapy (strength of evidence B), some patients with atrial fibrillation, and some with ambulatory class IV HF. Several evidence gaps remain that need to be addressed, including the ideal threshold for QRS duration, QRS morphology, lead placement, degree of myocardial scarring, and the modality for evaluating dyssynchrony. Recommendations will evolve over time as additional data emerge from completed and ongoing clinical trials. PMID:22300776

Stevenson, William G; Hernandez, Adrian F; Carson, Peter E; Fang, James C; Katz, Stuart D; Spertus, John A; Sweitzer, Nancy K; Tang, W H Wilson; Albert, Nancy M; Butler, Javed; Westlake Canary, Cheryl A; Collins, Sean P; Colvin-Adams, Monica; Ezekowitz, Justin A; Givertz, Michael M; Hershberger, Ray E; Rogers, Joseph G; Teerlink, John R; Walsh, Mary N; Stough, Wendy Gattis; Starling, Randall C

2012-02-01

421

Update on imatinib for gastrointestinal stromal tumors: duration of treatment.  

PubMed

Gastrointestinal stromal tumors (GISTs) are the most common sarcoma of the gastrointestinal tract, with transformation typically driven by activating mutations of c-KIT and less commonly platelet-derived growth factor receptor alpha (PDGFRA). Successful targeting of c-KIT and PDGFRA with imatinib, a tyrosine kinase inhibitor (TKI), has had a major impact in advanced GIST and as an adjuvant and neoadjuvant treatment. If treatment with imatinib fails, further lines of TKI therapy have a role, but disease response is usually only measured in months, so strategies to maximize the benefit from imatinib are paramount. Here, we provide an overview of the structure and signaling of c-KIT coupled with a review of the clinical trials of imatinib in GIST. In doing so, we make recommendations about the duration of imatinib therapy and suggest how best to utilize imatinib in order to improve patient outcomes in the future. PMID:23935374

Linch, Mark; Claus, Jeroen; Benson, Charlotte

2013-07-30

422

The Mars Environment Analogue Platform long duration balloon flight  

NASA Astrophysics Data System (ADS)

The MEAP (Mars Environment Analogue Platform) mission was to fly a stratospheric balloon on a semicircular trajectory around the North Pole in summer 2008. The balloon platform carried the high-resolution neutral gas mass spectrometer P-BACE (Polar Balloon Atmospheric Composition Experiment) as scientific payload. MEAP/P-BACE is a joint project between the Esrange Space Center, Sweden, the University of Bern, Switzerland and the Swedish Institute of Space Physics (IRF), Kiruna, Sweden. Mission objectives were to validate the platform for future long duration flights around the North pole, to validate the P-BACE instrument design for planetary mission applications (conditions in the Earth stratosphere are similar to the conditions at the Mars surface), to study variation of the stratospheric composition during the flight and to gain experience in balloon based mass spectrometry. All objectives were fulfilled.

Wieser, Martin; Kalla, Leif; Barabash, Stas; Hedqvist, Tomas; Kemi, Stig; Widell, Ola; Abplanalp, Dominic; Wurz, Peter

2009-08-01

423

Active shielding for long duration interplanetary manned missions  

NASA Astrophysics Data System (ADS)

For long duration interplanetary manned missions the protection of astronauts from cosmic radiation is an unavoidable problem that has been considered by many space agencies. In Europe, during 2002-2004, the European Space Agency supported two research programs on this thematic: one was the constitution of a dedicated study group (on the thematic 'Shielding from cosmic radiation for interplanetary missions: active and passive methods') in the framework of the 'life and physical sciences' report, and the other an industrial study concerning the 'radiation exposure and mission strategies for interplanetary manned missions to Moon and Mars'. Both programs concluded that, outside the protection of the magnetosphere and in the presence of the most intense and energetic solar events, the protection cannot rely solely on the mechanical structures of the spacecraft, but a temporary shelter must be provided. Because of the limited mass budget, the shelter should be based on the use of superconducting magnetic systems. For long duration missions the astronauts must be protected from the much more energetic galactic cosmic rays during the whole mission period. This requires the protection of a large habitat where they could live and work, and not the temporary protection of a small volume shelter. With passive absorbers unable to play any significant role, the use of active shielding is mandatory. The possibilities offered by superconducting magnets are discussed, and recommendations are made about the needed R&D. The technical developments that have occurred in the meanwhile and the evolving panorama of possible near future interplanetary missions, require revising the pioneering studies of the last decades and the adoption of a strategy that considers long lasting human permanence in 'deep' space, moreover not only for a relatively small number of dedicated astronauts but also for citizens conducting there 'normal' activities.

Spillantini, Piero

2010-04-01

424

Cardiovascular autonomic control after short-duration spaceflights  

NASA Astrophysics Data System (ADS)

After spaceflight, astronauts sometimes suffer a variable degree of reduced orthostatic tolerance. Although many studies have addressed this problem, many aspects remain unclear. Also, it is unknown how long the cardiovascular system needs to recover from short duration spaceflights. The scope of the present study was to determine a long-term follow-up of cardiovascular control up to 25 days after spaceflight under control conditions in five astronauts using heart rate variability, blood pressure variability and baroreflex sensitivity (BRS) indices. In standing position heart rate after spaceflight was significantly higher compared with pre-flight (R+1: 99 (SD 9) BPM vs L-30: 77 (SD 3) BPM; p<0.001). At the same time high frequency modulation of heart rate was extremely depressed (R+1: 70 (SD 334) ms 2 vs L-30: 271 (SD 68) ms 2; p<0.01), as was BRS: (R+1: 5 (SD 1) vs L-30: 10 (SD 2) ms/mmHg, p<0.05). These changes had largely recovered after 4 days upon return to Earth. Orthostatic blood pressure control was well maintained from the first day after landing. The decrease in BRS and in vagal heart rate modulation following short-duration spaceflight appear to constitute an adequate autonomic neural response to restored gravity. After 4 days upon return to Earth, vagal heart rate modulation is almost completely recovered to the pre-flight level. The findings of the present study demonstrate that the decrease in vagal heart rate modulation in standing position should not be characterised as some kind of cardiovascular deconditioning, but rather as the normal response to orthostatic stress after spaceflight.

Beckers, Frank; Verheyden, Bart; Liu, Jiexin; Aubert, André E.

2009-09-01

425

Does Treatment Duration Affect Outcome After Radiotherapy for Prostate Cancer?  

SciTech Connect

Purpose: The protraction of external beam radiotherapy (RT) time is detrimental in several disease sites. In prostate cancer, the overall treatment time can be considerable, as can the potential for treatment breaks. We evaluated the effect of elapsed treatment time on outcome after RT for prostate cancer. Methods and Materials: Between April 1989 and November 2004, 1,796 men with prostate cancer were treated with RT alone. The nontreatment day ratio (NTDR) was defined as the number of nontreatment days divided by the total elapsed days of RT. This ratio was used to account for the relationship between treatment duration and total RT dose. Men were stratified into low risk (n = 789), intermediate risk (n = 798), and high risk (n = 209) using a single-factor model. Results: The 10-year freedom from biochemical failure (FFBF) rate was 68% for a NTDR <33% vs. 58% for NTDR {>=}33% (p = 0.02; BF was defined as a prostate-specific antigen nadir + 2 ng/mL). In the low-risk group, the 10-year FFBF rate was 82% for NTDR <33% vs. 57% for NTDR {>=}33% (p = 0.0019). The NTDR was independently predictive for FFBF (p = 0.03), in addition to T stage (p = 0.005) and initial prostate-specific antigen level (p < 0.0001) on multivariate analysis, including Gleason score and radiation dose. The NTDR was not a significant predictor of FFBF when examined in the intermediate-risk group, high-risk group, or all risk groups combined. Conclusions: A proportionally longer treatment duration was identified as an adverse factor in low-risk patients. Treatment breaks resulting in a NTDR of {>=}33% (e.g., four or more breaks during a 40-fraction treatment, 5 d/wk) should be avoided.

D'Ambrosio, David J. [Department of Radiation Oncology, Fox Chase Cancer Center, Philadelphia, PA (United States); Li Tianyu [Department of Biostatistics, Fox Chase Cancer Center, Philadelphia, PA (United States); Horwitz, Eric M. [Department of Radiation Oncology, Fox Chase Cancer Center, Philadelphia, PA (United States); Chen, David Y.T. [Department of Surgical Oncology, Fox Chase Cancer Center, Philadelphia, PA (United States); Pollack, Alan [Department of Radiation Oncology, Fox Chase Cancer Center, Philadelphia, PA (United States); Buyyounouski, Mark K. [Department of Radiation Oncology, Fox Chase Cancer Center, Philadelphia, PA (United States)], E-mail: mark.buyyounouski@fccc.edu

2008-12-01

426

Does exercise duration affect Fatmax in overweight boys?  

PubMed

To compare the assessment of Fat(max) using a single graded exercise test with 3 min stages against 30 min prolonged exercise bouts in overweight boys. Ten overweight boys (8-12 years) attended the laboratory on seven separate occasions. On the first visit, body anthropometrics and peak aerobic capacity ([Formula: see text]O(2peak)) were assessed. Following this, each participant attended the laboratory after an overnight fast for six morning cycling sessions. During the first session, participants completed a continuous, submaximal graded exercise protocol with seven 3 min stages (GRAD) at 35, 40, 45, 50, 55, 60 and 65% [Formula: see text]O(2peak). The final five visits consisted of a 30 min bout of prolonged exercise (PROL) performed in a counterbalanced order at 40, 45, 50, 55 and 60% [Formula: see text]O(2peak). There was no effect of exercise duration on Fat(max) or the absolute rate of fat oxidation during PROL (p > 0.05). At the group level, GRAD and PROL provided similar estimates of Fat(max) (GRAD: 53 ± 10% [Formula: see text]O(2peak); PROL: 53 ± 10% [Formula: see text]O(2peak); p = 0.995); however, individual variation between the two protocols is shown by a systematic bias and residual error of 0 ± 11% [Formula: see text]O(2peak). Fat oxidation rates remained stable across 30 min of steady-state exercise in overweight boys. Furthermore, Fat(max) was similar at 3, 10, 20 and 30 min of exercise, suggesting that for exercise lasting ? 30 min, exercise duration does not affect Fat(max). However, Fat(max) determined with GRAD may need to be interpreted with caution at the individual level given the variation in Fat(max) between protocols. PMID:22075644

Crisp, Nicole A; Guelfi, Kym J; Licari, Melissa K; Braham, Rebecca; Fournier, Paul A

2011-11-11

427

Factors influencing initiation and duration of breast feeding in Ireland.  

PubMed

The aim of this research was to identify factors associated with mothers breast feeding and to identify, for those who breast fed, factors associated with breast feeding for as long as planned. BACKGROUND: breast feeding rates in Ireland are amongst the lowest in Europe. Research evidence indicates that in order for mothers to be successful at breast feeding, multiplicities of supports are necessary for both initiation and duration. The nature of these supports in tandem with other influencing factors requires analysis from an Irish perspective. DESIGN: cross-sectional study involving public health nurses and mothers in Ireland. This paper presents the results of the mothers' evaluation. METHOD: mothers (n=1715) with children less than three years were offered a choice of completing the self-report questionnaires online or by mail. Data were analysed and reported using descriptive and inferential statistics. FINDINGS: four in every five participants breast fed their infant and two thirds of them breast fed as long as planned. The multivariate logistic regression analysis identified that third level education, being a first time mother or previously having breast fed, participating online, having more than two public health nurse visits, and having a positive infant feeding attitude were independently and statistically significantly associated with breast feeding. Among mothers who breast fed, being aged at least 35 years, participating online, having a positive infant feeding attitude and high breast feeding self-efficacy were independently and statistically significantly associated with breast feeding for as long as planned. CONCLUSIONS: findings from this study reinforce health inequalities therefore there needs to be a renewed commitment to reducing health inequalities in relation to breast feeding. RELEVANCE TO CLINICAL PRACTICE: this study has identified factors associated with initiation and duration of breast feeding that are potentially modifiable through public health interventions. PMID:23473933

Leahy-Warren, Patricia; Mulcahy, Helen; Phelan, Agnes; Corcoran, Paul

2013-03-01

428

45 CFR 1311.5 - Duration of Fellowships and status of Head Start Fellows.  

Code of Federal Regulations, 2010 CFR

...false Duration of Fellowships and status of Head Start Fellows. 1311.5 Section 1311.5 Public Welfare...ADMINISTRATION FOR CHILDREN, YOUTH AND FAMILIES, HEAD START PROGRAM HEAD START FELLOWS PROGRAM § 1311.5 Duration of...

2010-10-01

429

38 CFR 21.6072 - Extending the duration of a vocational training program.  

Code of Federal Regulations, 2013 CFR

...Extending the duration of a vocational training...Relief DEPARTMENT OF VETERANS AFFAIRS (CONTINUED) VOCATIONAL... Temporary Program of Vocational Training...6072 Extending the duration of a vocational...identified before the end of the first 24...

2013-07-01

430

19 CFR 360.105 - Duration of the steel import licensing requirement.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 false Duration of the steel import licensing requirement. 360...ADMINISTRATION, DEPARTMENT OF COMMERCE STEEL IMPORT MONITORING AND ANALYSIS SYSTEM § 360.105 Duration of the steel import licensing requirement....

2013-04-01

431

7 CFR 400.702 - Confidentiality of submission and duration of confidentiality.  

Code of Federal Regulations, 2010 CFR

...2010-01-01 false Confidentiality of submission and duration of confidentiality. ...GENERAL ADMINISTRATIVE REGULATIONS Submission of Policies, Provisions of Policies...Premium § 400.702 Confidentiality of submission and duration of confidentiality....

2010-01-01

432

34 CFR 1100.32 - What is the duration of a fellowship?  

Code of Federal Regulations, 2013 CFR

... false What is the duration of a fellowship? 1100.32 Section 1100.32 ...INSTITUTE FOR LITERACY: LITERACY LEADER FELLOWSHIP PROGRAM What Conditions Must Be Met...1100.32 What is the duration of a fellowship? (a) The Institute...

2013-07-01

433

29 CFR 825.603 - Special rules for school employees, duration of FMLA leave.  

Code of Federal Regulations, 2013 CFR

... false Special rules for school employees, duration of FMLA...DEPARTMENT OF LABOR OTHER LAWS THE FAMILY AND MEDICAL LEAVE...Rules Applicable to Employees of Schools § 825.603 Special rules for school employees, duration of...

2013-07-01

434

Melt season duration on Canadian Arctic ice caps, 2000-2004  

Microsoft Academic Search

The extent and duration of summer melt on ice caps in the Queen Elizabeth Islands (QEI), Nunavut, Canada, in 2000-2004 were mapped using enhanced resolution QuikSCAT (QSCAT) scatterometer images. The mean melt duration depends mainly on surface elevation and distance from Baffin Bay. Over most ice caps, inter-annual variations in melt duration and the variation in melt duration with elevation

L. Wang; M. J. Sharp; B. Rivard; S. Marshall; D. Burgess

2005-01-01

435

Melt season duration on Canadian Arctic ice caps, 2000–2004  

Microsoft Academic Search

The extent and duration of summer melt on ice caps in the Queen Elizabeth Islands (QEI), Nunavut, Canada, in 2000–2004 were mapped using enhanced resolution QuikSCAT (QSCAT) scatterometer images. The mean melt duration depends mainly on surface elevation and distance from Baffin Bay. Over most ice caps, inter-annual variations in melt duration and the variation in melt duration with elevation

L. Wang; M. J. Sharp; B. Rivard; S. Marshall; D. Burgess

2005-01-01

436

Aging, Texture Segmentation, and Exposure Duration: Evidence for a Deficit Is Preattentive Processing  

Microsoft Academic Search

Younger and older observers were asked to detect the presence and identify the orientation of an orientation-based texture target presented at durations ranging from 15 to 75 ms. In Experiment 1a, an age by duration interaction indicated that older adults were less able to process the displays at short durations. In Experiment 1b, a group of younger adults was given

2001-01-01

437

DISTRIBUTION OF PATH DURATIONS IN MOBILE AD-HOC NETWORKS - PALM'S THEOREM AT WORK  

Microsoft Academic Search

We first study the distribution of path duration in multi-hop wireless networks. We show that as the number of hops along a path increases, the path duration distribution can be accurately approximated by an exponential distribution under a set of mild conditions, even when the link duration distributions are not identical. Then, we develop an approximate model for the Random

Yijie Han; Richard J. La; Armand M. Makowski

2004-01-01

438

Distribution of path durations in mobile ad-hoc networks - Palm's Theorem to the rescue  

Microsoft Academic Search

We first study the distribution of path duration in multi-hop wireless networks. We show that as the number of hops along a path increases, the path duration distribution can be ac- curately approximated by an exponential distribution under a set of mild conditions, even when the link duration distributions are not identical. The n, we develop an approximate model for

Yijie Han; Richard J. La; Armand M. Makowski; Seungjoon Lee

2006-01-01

439

26 CFR 54.4980B-7 - Duration of COBRA continuation coverage.  

Code of Federal Regulations, 2010 CFR

... 2010-04-01 false Duration of COBRA continuation coverage. 54.4980B-7...TAXES § 54.4980B-7 Duration of COBRA continuation coverage. The following...questions-and-answers address the duration of COBRA continuation coverage: Q-1: How...

2010-04-01

440

26 CFR 54.4980B-7 - Duration of COBRA continuation coverage.  

Code of Federal Regulations, 2010 CFR

... 2009-04-01 false Duration of COBRA continuation coverage. 54.4980B-7...TAXES § 54.4980B-7 Duration of COBRA continuation coverage. The following...questions-and-answers address the duration of COBRA continuation coverage: Q-1: How...

2009-04-01

441

Forecasting the frequency of changes in quoted foreign exchange prices with the autoregressive conditional duration model  

Microsoft Academic Search

This paper applies the Autorecressive Conditional Duration model to Foreign Exchange quotes arriving on Reuters screens. The Autoregressive Conditional Duration model, developed in Engle and Russell (1995) [Engle, R., Russell, J., 1995. Autoregressive conditional duration; a new model for irregularly spaced time series data, University of California, San Diego, unpublished manuscript.], is a new statistical model for the analysis of

Robert F. Engle; Jeffrey R. Russell

1997-01-01

442

Duration of illness in Huntington's disease is not related to age at onset  

Microsoft Academic Search

The age at onset and duration of illness were studied in patients with Huntington's disease in the Leiden Roster which at 1 July 1990 contained 2787 patients. Of 1106 patients, 800 deceased and 306 alive, the age at onset was known. The median duration was 16.2 (range 2-45) years. In contrast to the current opinion, the median duration was independent

R A Roos; J Hermans; M Vegter-van der Vlis; G J van Ommen; G W Bruyn

1993-01-01

443

Cold-Shock-Induced Division Delay of Synchronized Tetrahymena: Temperature-Duration Relationship.  

National Technical Information Service (NTIS)

Synchronized Tetrahymena were subjected to temperatures around 0C and around 10C for various durations. Cell division was delayed in excess of the duration of the cold shock in an almost all-or-none fashion: with intermediate durations of cold shocks, som...

D. S. Nachtwey

1968-01-01

444

Long Period, Long Duration Seismic Events during Hydraulic Fracture Stimulation of a Shale Gas Reservoir  

NASA Astrophysics Data System (ADS)

We report a series of long period and long duration (LPLD) seismic events observed during hydraulic fracturing in a gas shale reservoir located in West Texas. These unusual events, 10-100 seconds in duration, are observed most clearly in the frequency band of 10-80 Hz and are similar in appearance to tectonic tremor sequences which have been observed at depth in several subduction zones and continental strike slip faults. These complex but coherent wave trains have finite move-outs obtained from waveform cross-correlation. The move-out direction of the events confirms that they originate in the reservoir from the area where the fracturing is going on. Clear P- and S-wave arrivals cannot be resolved within the LPLD episodes, but in some cases, small micro-earthquakes occur in the sequences. Whether these micro-earthquakes are causal or coincidental is being studied. It has also been observed that in three contiguous frac-stages, all LPLD events appear to come from two distinct places along one of two hypothetical fracture planes. Interestingly, the stages which have the largest number of LPLD events also have the highest observed pumping pressures during fracturing, the highest density of natural fractures and the greatest number of microearthquakes. One possible explanation of these LPLD events is that the high pore fluid pressure during hydraulic fracturing stimulates slow slip on pre-existing fault planes that are poorly-oriented for slip in the ambient stress field. In the absence of elevated pressure, slip would not be expected on these planes. Slip on these fault planes appears to be occurring because the fluid pressure is close to the magnitude of the least principal stress. We observe a few events between pumping cycles perhaps indicating that once triggered, these planes continue to slip due to the high transient pressure within the fault planes after pumping has stopped.

Das, I.; Zoback, M. D.

2011-12-01

445

Developmental duration and morphology of the sea star asterias amurensis, in tongyeong, Korea  

NASA Astrophysics Data System (ADS)

The process of embryogenesis and larval development of the asteroid sea star Asterias amurensis (Lütken) was observed, with special attention paid to morphological change and larval duration. In reproductive season, mature sea stars were collected under floating net cages, located in Tongyeong, southern Korea. The mature eggs are 138 ?m in average diameter, semi-translucent and orange in color, sperms in good condition appear light cream to white-gray in color. Embryos develop through the holoblastic equal cleavage stage and a wrinkled blastula stage that lasts about 9 hours after fertilization. Gastrulae bearing an expanded archenteron hatch from the fertilization envelope 22 hours after fertilization. At the end of gastrulation, rudiments of the left and right coelom are formed. By day 2, larvae possess complete alimentary canal and begin to feed. At this stage, the larva is called early bipinnaria. In 6day-old larvae, the pre- and post- oral ciliated bands form complete circuits and the bipinnarial processes start to develop. By day 12, the lateral and anterior projection of the larval wall processes along the ciliated bands begins to thicken and curl, and the ciliated bands become more prominent. By day 32, early brachiolaria are presented with three pairs of brachiolar arms. Advanced brachiolaria with a well-developed brachiolar complex (three pairs of brachia and central adhesive disc) occur 6 weeks after fertilization. In the field, spawning of the sea star was observed in April to May, settlement form larvae and just settlements seem to occur from June to July, and early juveniles occur from August to September. Although we had not described the end of brachiolaria stage, it can be tentatively estimated that the duration of the pelagic stage of A. amurensis is 40 to 50 days.

Paik, Sang-Gyu; Park, Heung-Sik; Yi, Soon Kil; Yun, Sung Gyu

2005-09-01

446

Melt season duration on Canadian Arctic ice caps, 2000-2004  

NASA Astrophysics Data System (ADS)

The extent and duration of summer melt on ice caps in the Queen Elizabeth Islands (QEI), Nunavut, Canada, in 2000-2004 were mapped using enhanced resolution QuikSCAT (QSCAT) scatterometer images. The mean melt duration depends mainly on surface elevation and distance from Baffin Bay. Over most ice caps, inter-annual variations in melt duration and the variation in melt duration with elevation are closely related to variations in the July 500 hPa height over the QEI. Pressure-related variability in the vertical gradient of near-surface air temperature appears to be a major control on the inter-annual variations in average melt duration.

Wang, L.; Sharp, M. J.; Rivard, B.; Marshall, S.; Burgess, D.

2005-10-01

447

Dam effects on droughts magnitude and duration in a transboundary basin: The Lower River Tagus, Spain and Portugal  

NASA Astrophysics Data System (ADS)

This study examines the effects of a large dam on hydrological droughts in the transboundary Tagus River, central Spain and Portugal. The magnitude and duration of droughts are analyzed by comparing a monthly drought index calculated for the flow series upstream and downstream of the Alcántara reservoir. The dam was built in 1969, and the reservoir is the second largest in Europe (3,162 hm3). Water management in the area is complex because of large seasonal and interannual variability in the flow regime, which is characteristic of Mediterranean environments. This paper demonstrates that, as a result of exploitation of the Alcántara reservoir, (1) during periods of water scarcity, the releases in winter and spring are reduced dramatically and the magnitude and duration of summer low flow show a slight increase and (2) the nature of droughts along the Tagus river basin downstream of the dam has shown severe changes since construction of the dam. In fact, during the predam period (1943-1969), droughts were longer and more intense in the Spanish part of the basin than that in the Portuguese part. Since the construction of the Alcántara dam, however, the Portuguese part of the basin has experienced more severe droughts than did the upstream part in terms of both magnitude and duration.

López-Moreno, J. I.; Vicente-Serrano, S. M.; BegueríA, S.; GarcíA-Ruiz, J. M.; Portela, M. M.; Almeida, A. B.

2009-02-01

448

Voltage noise influences action potential duration in cardiac myocytes  

PubMed Central

Stochastic gating of ion channels introduces noise to membrane currents in cardiac muscle cells (myocytes). Since membrane currents drive membrane potential, noise thereby influences action potential duration (APD) in myocytes. To assess the influence of noise on APD, membrane potential is in this study formulated as a stochastic process known as a diffusion process, which describes both the current-voltage relationship and voltage noise. In this framework, the response of APD voltage noise and the dependence of response on the shape of the current-voltage relationship can be characterized analytically. We find that in response to an increase in noise level, action potential in a canine ventricular myocytes is typically prolonged and that distribution of APDs becomes more skewed towards long APDs, which may lead to an increased frequency of early after-depolarization formation. This is a novel mechanism by which voltage noise may influence APD. The results are in good agreement with those obtained from more biophysically-detailed mathematical models, and they suggest that increased voltage noise (due to gating noise) may partially underlie an increased incidence of early after-depolarizations in heart failure.

Tanskanen, Antti J.; Alvarez, Luis H.R.

2008-01-01

449

Circadian rhythms in a long-term duration space flight  

NASA Astrophysics Data System (ADS)

In order to maintain cosmonaut health and performance, it is important for the work-rest schedule to follow human circadian rhythms (CR). What happens with CR in space flight? Investigations of CR in mammals revealed, that the circadian phase in flight is less stable, probably due to a displacement of the range of entrainment, resulting from internal period change (the latter was confirmed on insects). The circadian period may be a gravity-dependent parameter. If so, the basic biological requirement for the day length might be different in weightlessness. On this basis, a higher risk of desynchronosis is expected in a long-duration space flight. As a countermeasure, a non-24-hr day length could be suggested, being close to the internal circadian period (in humans about 25 hr). Taking into account a possible displacement of period in weightlessness, it seems reasonable to establish a flexible work-rest schedule, capable to follow the body temperature CR by means of biofeedback.

Alpatov, Alexey M.

450

Radiation exposure predictions for short-duration stay Mars missions.  

PubMed

The human radiation environment for several short-duration stay manned Mars missions is predicted using the Mission Radiation Calculation (MIRACAL) program, which was developed at NASA Langley Research Center. This program provides dose estimates for galactic cosmic rays (GCR) and large and ordinary solar proton flare events for various amounts of effective spacecraft shielding (both operational and storm shelter thicknesses) and a given time history of the spacecraft's heliocentric position. The results of this study show that most of the missions can survive the most recent large flares (if they were to occur at the missions' perihelion) if a 25 g/cm2 storm shelter is assumed. The dose predictions show that missions during solar minima (when solar flare activity is the lowest) are not necessarily the minimum dose cases, due to increased GCR contribution during this time period. The direct transfer mission studied has slightly lower doses than the outbound Venus swingby mission [on the order of 10-20 centi-Sieverts (cSv) lower], with the greatest dose differences for the assumed worst case scenario (when the large flares occur at perihelion). The GCR dose for a mission can be reduced by having the crew spend some fraction of its day nominally in the storm shelter (other than during flare events). PMID:11538210

Striepe, S A; Nealy, J E; Simonsen, L C

451

The impact of pulse duration on composite WATERGATE pulse  

NASA Astrophysics Data System (ADS)

As an effective method for solvent suppression, WATERGATE is widely used in high resolution NMR spectroscopy. It is usually composed of a number of pulses separated by constant intervals. However, theoretical and experimental analyses indicate that narrower bandwidth and lower intensities around the secondary suppression points occur in the excitation profile of the composite WATERGATE. The excitation profile distortion is caused by the chemical shift evolution during the RF pulses. The higher the ratio of pulse duration to the inter-pulse delay is, the severer the profile distorts. Therefore, in high magnetic fields, the effect will be serious when WATERGATE is applied to some biological samples whose resonances distribute over a wide range. As can be seen obviously by applying WATERGATE to detect a RNA-protein mixture sample in an 800 MHz spectrometer, the resonances of the imino protons were partially suppressed by showing decreased intensities, though the intended secondary suppression points were set far away from them. In this article, we proposed an optimized WATERGATE that could effectively compensate the chemical shift evolution during the RF pulses, and relieve the excitation profile distortion. The optimized experiment will be a good way to retain the imino signal intensities when WATERGATE is applied to detect the RNA samples in high magnetic field.

Wang, Jingjing; Zhang, Xu; Sun, Peng; Jiang, Xianwang; Jiang, Bin; Cao, Chunyang; Liu, Maili

2010-10-01

452

Predicting nucleosome positioning using a duration Hidden Markov Model  

PubMed Central

Background The nucleosome is the fundamental packing unit of DNAs in eukaryotic cells. Its detailed positioning on the genome is closely related to chromosome functions. Increasing evidence has shown that genomic DNA sequence itself is highly predictive of nucleosome positioning genome-wide. Therefore a fast software tool for predicting nucleosome positioning can help understanding how a genome's nucleosome organization may facilitate genome function. Results We present a duration Hidden Markov model for nucleosome positioning prediction by explicitly modeling the linker DNA length. The nucleosome and linker models trained from yeast data are re-scaled when making predictions for other species to adjust for differences in base composition. A software tool named NuPoP is developed in three formats for free download. Conclusions Simulation studies show that modeling the linker length distribution and utilizing a base composition re-scaling method both improve the prediction of nucleosome positioning regarding sensitivity and false discovery rate. NuPoP provides a user-friendly software tool for predicting the nucleosome occupancy and the most probable nucleosome positioning map for genomic sequences of any size. When compared with two existing methods, NuPoP shows improved performance in sensitivity.

2010-01-01

453

Action potential duration gradient protects the right atrium from fibrillating.  

PubMed

Atrial fibrillation (AF) is the most common cardiac arrhythmia. It is characterized by rapid and disorganized electrical activity in the atria. Atrial arrhythmias can be triggered from an ectopic focus, i.e., an abnormal impulse originating in an area other than the sinus node, generating reentrant waves. The regional ionic heterogeneities found in the atria cause a gradual shortening of the action potential duration (APD) with increased distance from the sinoatrial node. It is generally thought that the only electrophysiological consequence of the spatial dispersion of cardiac action potentials (AP) is the enhancement of reentry. This paper investigates the effect of a gradient in APD on arrhythmogenesis via computer simulations. A gradient of ionic properties was introduced into a computationally efficient computer model of the canine atria to produce a smooth distribution of APDs. The window of vulnerability for ectopic beat-induction of reentry was determined for both left atrium (LA) and the right atrium (RA) stimulation, with and without an APD gradient. The shortened windows of vulnerability in the RA, due to the addition of the APD gradient, suggests a protective mechanism against AF. The left atrial window of vulnerability was slightly longer from ionic dispersion. PMID:17947064

Ridler, Marc; McQueen, David M; Peskin, Charles S; Vigmond, Edward

2006-01-01

454

Host Galaxies of Long-Duration Gamma-Ray Bursts  

NASA Astrophysics Data System (ADS)

Long-duration gamma-ray bursts (GRBs) are associated with the deaths of massive, short-lived stars, and thus may be useful in tracking star formation in the universe. However, GRB progenitor models suggest that they might occur only in low-metallicity environments, introducing a bias into star formation studies. Presented here are the high-resolution spectra of two GRB host galaxies, one at z 0.03 and the other at z 0.7. The nearby galaxy, the host of GRB 060218, has a low metallicity, but one that is comparable to local galaxies of similar luminosity. It has little to no extinction and a star formation rate of 2x10-2 M?yr-1. The metallicity of the more distant galaxy, the host of GRB 991208, is not well constrained because the H? and [N II] lines are redshifted into the near infrared and were not observed. It has a star formation rate of 1-9 M?yr-1 and, unlike the majority of GRB hosts, is dusty. These two galaxies will eventually be a part of a larger sample of GRB hosts. This work was conducted by a Research Experience for Undergraduates (REU) position at the University of Hawai'i's Institute for Astronomy and funded by the NSF.

Bagley, Megan; Kewley, L. J.; Levesque, E. M.

2009-01-01

455

Toxicity of urban highway runoff with respect to storm duration.  

PubMed

The toxicity of stormwater runoff during various time-based stages was measured in both grab and composite samples collected from three highly urbanized highway sites in Los Angeles, California between 2002 and 2005. Stormwater runoff samples were tested for toxicity using three freshwater species (the water flea Ceriodaphnia dubia, the fathead minnow Pimephales promelas, and the green algae Pseudokirchneriella subcapitatum) and two marine species (the purple sea urchin Strongylocentrotus purpuratus, and the luminescent bacteria Photobacterium phosphoreum using Microtox. Toxicity results varied substantially throughout the storm events for both freshwater and marine species toxicity tests. In general, however, the first few samples were found to be more toxic compared with those collected during later stages of each storm event. In most cases, more than 40% of the toxicity was associated with the first 20% of discharged runoff volume. Furthermore, on average, 90% of the toxicity was observed during the first 30% of storm duration. Toxicity identification evaluation results found copper and zinc to be the primary cause of toxicity in about 90% of the samples evaluated with these procedures. Surfactants were also found to be the cause of toxicity in less than 10% of the samples. PMID:17920106

Kayhanian, M; Stransky, C; Bay, S; Lau, S-L; Stenstrom, M K

2007-10-24

456

Climatic changes and flooding durations in relation with public health  

NASA Astrophysics Data System (ADS)

Climatic Changes, and more generaly Global Changes, play a major role in environmental modifications in relation with public health. Modifications of temperatures, precipitations... influence ecological habitats. These habitats can be adapted for some animals species, responsable of certain pandemics. Mosquitoes and birds represent for certain pandemics the essential elements of virus transmission. Abundance of mosquitoes and birds species, is heavily conditioned by flooded areas extent and specific habitats and their variations. The study we carried, has been done in South of France. We show present status of ecological habitats and flooded durations and future previsions. We reach environment impact for certain virus like West Nile virus. This virus affects bird, horse and sometimes man. Presence of the virus is conditioned by different factors, primarily including vector distribution (mosquitoes). We show how it's possible to localise favorable areas for the virus and to predict its future expansion areas. We present maps of the possibilities for future concerning previsions of bioclimatic steps variations. Thanks to the latest remote sensing and spatial analysis techniques. Our maps may be used as precious tools to help decision makers when faced with mosquito related problems.

Sandoz, A.; Roumieux, C.; Trouillet, A.

2009-04-01

457

Distributional Effects of Word Frequency on Eye Fixation Durations  

PubMed Central

Recent research using word recognition paradigms such as lexical decision and speeded pronunciation has investigated how a range of variables affect the location and shape of response time distributions, using both parametric and non-parametric techniques. In this article, we explore the distributional effects of a word frequency manipulation on fixation durations in normal reading, making use of data from two recent eye movement experiments (Drieghe, Rayner, & Pollatsek, 2008; White, 2008). The ex-Gaussian distribution provided a good fit to the shape of individual subjects’ distributions in both experiments. The frequency manipulation affected both the shift and skew of the distributions, in both experiments, and this conclusion was supported by the non-parametric vincentizing technique. Finally, a new experiment demonstrated that White’s (2008) frequency manipulation also affects both shift and skew in RT distributions in the lexical decision task. These results argue against models of eye movement control in reading that propose that word frequency influences only a subset of fixations, and support models in which there is a tight connection between eye movement control and the progress of lexical processing.

Staub, Adrian; White, Sarah J.; Drieghe, Denis; Hollway, Elizabeth C.; Rayner, Keith

2009-01-01

458

Evidence for Long-Duration Magnetic Reconnection in Saturn's Magnetotail  

NASA Astrophysics Data System (ADS)

On 20 August 2006 the Cassini spacecraft was 32 Rs from Saturn in the northern magnetotail at a latitude of 13 deg and a local time of 21.9. At this time, a fast, sunward, magnetic-field-aligned beam of ions was observed, lasting approximately 1 hour. The beam was observed as the spacecraft crossed from the tail lobe into the plasma sheet, during an interval characterized by a slight northward turning of the magnetic field, followed by a strong dipolarization. CAPS observations show that the bulk of the ions, from a few to around 10 keV were almost exclusively H+, whereas at higher energies MIMI observed both H+ and O+. In analogy to the Earth's plasma-sheet boundary layer, the likeliest source of such ion beams traveling from the more distant tail toward Saturn is a region of magnetic reconnection tailward of the spacecraft. The persistence of the beam for an hour demonstrates that such reconnection can be of long duration in Saturn's magnetotail. The sequence of plasma and field observations for this event will be presented, and the implications for Saturn's magnetotail dynamics will be examined.

McAndrews, H. J.; Thomsen, M. F.; Leisner, J. S.; Mitchell, D. G.; Tokar, R. L.; Russell, C. T.

2009-05-01

459

The application of waste management systems for long duration spaceflight.  

PubMed

In the future planned interplanetary expedition mission to Mars, spaceflight crewmembers will be exposed to an environment that is completely unique from anything they are accustomed to on Earth. Due to the characteristics of these missions, a challenge will be to design an environment that allows crewmembers to easily work and live in for extended durations. One of the challenges associated with these future missions is supplying the crew with essential resources for survivability such as food and water. In this case, the waste management system can play