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1

Beyond the measurement of QRS complex toward mechanical dyssynchrony: cardiac resynchronisation therapy in heart failure patients with a normal QRS duration  

PubMed Central

Mechanical systolic dyssynchrony exists in many patients with heart failure, irrespective of QRS duration, and so more patients may derive benefit from cardiac resynchronisation therapy than previously considered PMID:15084530

Auricchio, A; Yu, C M

2004-01-01

2

QRS duration and mortality in patients with congestive heart failure  

Microsoft Academic Search

Background and Objectives It has been suggested that prolongation of the QRS duration (>120 ms) is an independent risk factor for mortality in patients with cardiomyopathy. The purpose of this study was to examine the association between QRS duration and survival in patients with heart failure. Methods We performed a retrospective analysis to examine the association between QRS prolongation (?120

Stephen Iuliano; Susan G. Fisher; Pamela E. Karasik; Ross D. Fletcher; Steven N. Singh

2002-01-01

3

Relation of QRS duration to response to cardiac resynchronization therapy.  

PubMed

Left bundle branch block (LBBB) is the most reliable electrocardiographic predictor of responsiveness to cardiac resynchronization therapy (CRT). However, not all patients with LBBB will respond to CRT. Our aim was to investigate the interaction between QRS duration, LBBB-type morphology, and the responsiveness to CRT. We retrospectively analyzed electrocardiograms of 243 patients who underwent CRT implantation according to current clinical indications. A 6-month reduction of left ventricular end-systolic volume >15% was used to identify CRT responders. The clinical end point consisted of death, hospitalization for heart failure and sustained rapid ventricular tachyarrhythmias. An LBBB morphology was present in 169 patients (70%) and 101 of these (60%) were responders to CRT. Analyzing the interaction between QRS duration and CRT responsiveness in patients with LBBB, a "U shaped" distribution resulted, with nonresponders clustered between 120 and 130 ms and above 180 ms. The receiver operating characteristic curve analysis identified 178 ms as the optimal cut-off value of QRS to predict a nonresponsiveness to CRT (area under the curve = 0.67 [95% confidence interval 0.57 to 0.76]). At multivariate analysis, only an ischemic cause and a QRS ?178 ms were independent predictors of nonresponsiveness to CRT (area under the curve = 0.75). Patients with LBBB with QRS ?178 ms had greater likelihood of adverse clinical events during a mean follow-up of 32 months (p = 0.049). In conclusion, in patients with LBBB undergoing CRT, a marked QRS widening (i.e., ?178 ms) is related to worse echocardiographic responsiveness and lower event free survival rate compared with patients with an intermediate QRS widening. PMID:25465934

Sassone, Biagio; Gambetti, Simona; Bertini, Matteo; Beltrami, Matteo; Mascioli, Giosuè; Bressan, Sabrina; Fucà, Giuseppe; Pacchioni, Federico; Pedaci, Mario; Michelotti, Federica; Bacchi Reggiani, Maria Letizia; Padeletti, Luigi

2015-01-15

4

Assessment of Left Ventricular Dyssynchrony in Heart Failure Patients Regarding Underlying Etiology and QRS Duration  

PubMed Central

Background: Left ventricular (LV) dyssynchrony is a prevalent feature in heart failure (HF) patients. The current study aimed to evaluate the prevalence of inter and intraventricular dyssynchrony in HF patients with regard to the QRS duration and etiology. Methods: The available data on the tissue Doppler imaging (TDI) of 230 patients with refractory HF were analyzed. The patients were divided into three groups according to the QRS duration: QRS duration < 120 ms; 120–150 ms; and ? 150 ms and the patients were re-categorized into two subgroups depending on the underlying etiology: ischemic cardiomyopathy (ICM) or dilated cardiomyopathy (DCM). The time-to-peak myocardial sustained systolic velocity (Ts) in six basal and six middle segments of the LV was measured manually using the velocity curves from TDI. LV dyssynchrony was defined as interventricular mechanical delay ? 40 ms and tissue Doppler velocity all segments delay ? 105 ms; standard deviation (SD) of all segments ? 34.4 ms; basal segments delay ? 78 ms; SD of basal segments ? 34.5 ms; and opposing wall delay ? 65 ms. Results: After adjustment for the possible confounders, interventricular dyssynchrony was more prevalent in the patients with QRS duration ? 150 ms than in those with QRS duration 120–150 ms and < 120 ms. The patients with DCM also had a higher percentage of interventricular dyssynchrony than those with ICM in the wide QRS groups. Turning to the intraventricular dyssynchrony indices, the patients with QRS duration ? 150 ms and 120–150 ms revealed a significantly greater delay between Ts at the basal and all segments than did those with QRS duration < 120 ms, while etiology did not influence the frequency of these indices in each QRS group. Conclusion: The prevalence of both inter and intraventricular dyssynchrony indices was greater in the patients with wide QRS than in those with narrow QRS duration. The underlying etiology may affect the frequency of interventricular but not intraventricular dyssynchrony indices. PMID:23074368

Montazeri, Mahdi; Rezvanfard, Mehrnaz; Kazemisaeid, Ali; Lotfi Tokaldany, Masoumeh; Mardanloo, Azam Safir; Darabi, Farzad; Fathollahi, Mahmood Sheikh; Sadeghian, Hakimeh

2011-01-01

5

A real time QRS complex classification method using Mahalanobis distance  

Microsoft Academic Search

An unsupervised method to recognize and classify QRS complexes was developed in order to create an automatic cardiac beat classifier in real time. After exhaustive analysis, four features extracted from the QRS complex in the time domain were selected as the ones presenting the best results: width, total sum of the areas under the positive and negative curves, total sum

J. C. T. B. Moraes; M. O. Seixas; F. N. Vilani; E. V. Costa

2002-01-01

6

Detecting drug-induced prolongation of the QRS complex: New insights for cardiac safety assessment  

SciTech Connect

Background: Drugs slowing the conduction of the cardiac action potential and prolonging QRS complex duration by blocking the sodium current (I{sub Na}) may carry pro-arrhythmic risks. Due to the frequency-dependent block of I{sub Na}, this study assesses whether activity-related spontaneous increases in heart rate (HR) occurring during standard dog telemetry studies can be used to optimise the detection of class I antiarrhythmic-induced QRS prolongation. Methods: Telemetered dogs were orally dosed with quinidine (class Ia), mexiletine (class Ib) or flecainide (class Ic). QRS duration was determined standardly (5 beats averaged at rest) but also prior to and at the plateau of each acute increase in HR (3 beats averaged at steady state), and averaged over 1 h period from 1 h pre-dose to 5 h post-dose. Results: Compared to time-matched vehicle, at rest, only quinidine and flecainide induced increases in QRS duration (E{sub max} 13% and 20% respectively, P < 0.01–0.001) whereas mexiletine had no effect. Importantly, the increase in QRS duration was enhanced at peak HR with an additional effect of + 0.7 ± 0.5 ms (quinidine, NS), + 1.8 ± 0.8 ms (mexiletine, P < 0.05) and + 2.8 ± 0.8 ms (flecainide, P < 0.01) (calculated as QRS at basal HR-QRS at high HR). Conclusion: Electrocardiogram recordings during elevated HR, not considered during routine analysis optimised for detecting QT prolongation, can be used to sensitise the detection of QRS prolongation. This could prove useful when borderline QRS effects are detected. Analysing during acute increases in HR could also be useful for detecting drug-induced effects on other aspects of cardiac function. -- Highlights: ? We aimed to improve detection of drug-induced QRS prolongation in safety screening. ? We used telemetered dogs to test class I antiarrhythmics at low and high heart rate. ? At low heart rate only quinidine and flecainide induced an increase in QRS duration. ? At high heart rate the effects of two out of three antiarrhythmics were enhanced. ? Detection of a drug-induced prolongation of QRS was improved at high heart rate.

Cros, C., E-mail: caroline.cros@hotmail.co.uk [Safety Pharmacology, Global Safety Assessment, Safety Assessment UK, AstraZeneca R and D, Alderley Park, Macclesfield, SK10 4TG (United Kingdom); Skinner, M., E-mail: Matthew.Skinner@astrazeneca.com [Safety Pharmacology, Global Safety Assessment, Safety Assessment UK, AstraZeneca R and D, Alderley Park, Macclesfield, SK10 4TG (United Kingdom); Moors, J. [Safety Pharmacology, Global Safety Assessment, Safety Assessment UK, AstraZeneca R and D, Alderley Park, Macclesfield, SK10 4TG (United Kingdom)] [Safety Pharmacology, Global Safety Assessment, Safety Assessment UK, AstraZeneca R and D, Alderley Park, Macclesfield, SK10 4TG (United Kingdom); Lainee, P. [Sanofi-Aventis R and D, 371, rue du Pr Joseph Blayac, 34184 Montpellier Cedex 04 (France)] [Sanofi-Aventis R and D, 371, rue du Pr Joseph Blayac, 34184 Montpellier Cedex 04 (France); Valentin, J.P. [Safety Pharmacology, Global Safety Assessment, Safety Assessment UK, AstraZeneca R and D, Alderley Park, Macclesfield, SK10 4TG (United Kingdom)] [Safety Pharmacology, Global Safety Assessment, Safety Assessment UK, AstraZeneca R and D, Alderley Park, Macclesfield, SK10 4TG (United Kingdom)

2012-12-01

7

The value of electrocardiography for differential diagnosis in wide QRS complex tachycardia.  

PubMed

Correct diagnosis in wide QRS complex tachycardia remains a challenge. Differential diagnosis between ventricular and supraventricular tachycardia has important therapeutic and prognostic implications, and although data from clinical history and physical examination may suggest a particular origin, it is the 12-lead surface electrocardiogram that usually enables this differentiation. Since 1978, various electrocardiographic criteria have been proposed for the differential diagnosis of wide complex tachycardias, particularly the presence of atrioventricular dissociation, and the axis, duration and morphology of QRS complexes. Despite the wide variety of criteria, diagnosis is still often difficult, and errors can have serious consequences. To reduce such errors, several differential diagnosis algorithms have been proposed since 1991. However, in a small percentage of wide QRS tachycardias the diagnosis remains uncertain and in these the wisest decision is to treat them as ventricular tachycardias. The authors' objective was to review the main electrocardiographic criteria and differential diagnosis algorithms of wide QRS tachycardia. PMID:24656320

Sousa, Pedro A; Pereira, Salomé; Candeias, Rui; de Jesus, Ilídio

2014-03-01

8

Common variants in 22 loci are associated with QRS duration and cardiac ventricular conduction  

PubMed Central

QRS interval on the electrocardiogram reflects ventricular depolarization and conduction time, and is a risk factor for mortality, sudden death, and heart failure. We performed a genome-wide association meta-analysis in 40,407 European-descent individuals from 14 studies, with further genotyping in 7170 additional Europeans, and identified 22 loci associated with QRS duration (P < 5 × 10?8). These loci map in or near genes in pathways with established roles in ventricular conduction such as sodium channels, transcription factors, and calcium-handling proteins, but also point to novel biologic processes, such as kinase inhibitors and genes related to tumorigenesis. We demonstrate that SCN10A, a gene at our most significant locus, is expressed in the mouse ventricular conduction system, and treatment with a selective SCN10A blocker prolongs QRS duration. These findings extend our current knowledge of ventricular depolarization and conduction. PMID:21076409

Sotoodehnia, Nona; Isaacs, Aaron; de Bakker, Paul I.W.; Dörr, Marcus; Newton-Cheh, Christopher; Nolte, Ilja M.; van der Harst, Pim; Müller, Martina; Eijgelsheim, Mark; Alonso, Alvaro; Hicks, Andrew A.; Padmanabhan, Sandosh; Hayward, Caroline; Smith, Albert Vernon; Polasek, Ozren; Giovannone, Steven; Fu, Jingyuan; Magnani, Jared W.; Marciante, Kristin D.; Pfeufer, Arne; Gharib, Sina A.; Teumer, Alexander; Li, Man; Bis, Joshua C.; Rivadeneira, Fernando; Aspelund, Thor; Köttgen, Anna; Johnson, Toby; Rice, Kenneth; Sie, Mark P.S.; Wang, Amanda Ying; Klopp, Norman; Fuchsberger, Christian; Wild, Sarah H.; Leach, Irene Mateo; Estrada, Karol; Völker, Uwe; Wright, Alan F.; Asselbergs, Folkert W.; Qu, Jiaxiang; Chakravarti, Aravinda; Sinner, Moritz F.; Kors, Jan A.; Petersmann, Astrid; Harris, Tamara B.; Soliman, Elsayed Z.; Munroe, Patricia B.; Psaty, Bruce M.; Oostra, Ben A.; Cupples, L. Adrienne; Perz, Siegfried; de Boer, Rudolf A.; Uitterlinden, André G.; Vözke, Henry; Spector, Timothy D.; Liu, Fang-Yu; Boerwinkle, Eric; Dominiczak, Anna F.; Rotter, Jerome I.; van Herpen, Gé; Levy, Daniel; Wichmann, H.-Erich; van Gilst, Wiek H.; Witteman, Jacqueline C.M.; Kroemer, Heyo K.; Kao, W.H. Linda; Heckbert, Susan R.; Meitinger, Thomas; Hofman, Albert; Campbell, Harry; Folsom, Aaron R.; van Veldhuisen, Dirk J.; Schwienbacher, Christine; O’Donnell, Christopher J.; Volpato, Claudia Beu; Caulfield, Mark J.; Connell, John M.; Launer, Lenore; Lu, Xiaowen; Franke, Lude; Fehrmann, Rudolf S.N.; Meerman, Gerard te; Groen, Harry J.M.; Weersma, Rinse K.; van den Berg, Leonard H.; Wijmenga, Cisca; Ophoff, Roel A.; Navis, Gerjan; Rudan, Igor; Snieder, Harold; Wilson, James F.; Pramstaller, Peter P.; Siscovick, David S.; Wang, Thomas J.; Gudnason, Vilmundur; van Duijn, Cornelia M.; Felix, Stephan B.; Fishman, Glenn I.; Jamshidi, Yalda; Stricker, Bruno H Ch; Samani, Nilesh J.; Kääb, Stefan; Arking, Dan E.

2010-01-01

9

Correlation between Mitral Regurgitation and Myocardial Mechanical Dyssynchrony and QRS Duration in Patients with Cardiomyopathy  

PubMed Central

Abstract Background: Several competing geometric and hemodynamic factors are suggested as contributing mechanisms for functional mitral regurgitation (MR) in heart failure patients. We aimed to study the relationships between the severity of MR and the QRS duration and dyssynchrony markers in patients with ischemic or dilated cardiomyopathy. Methods: We prospectively evaluated 251 heart failure patients with indications for echocardiographic evaluation of possible cardiac resynchronization therapy. All the patients were subjected to transthoracic echocardiography and tissue Doppler imaging to evaluate the left ventricular (LV) synchronicity. The patients were divided into two groups according to the severity of MR: ? mild MR and ? moderate MR. The effects of different dyssynchrony indices were adjusted for global and regional left ventricular remodeling parameters. Results: From the 251 patients (74.5% male, mean age = 53.38 ± 16.68 years), 130 had ? mild MR and 121 had ? moderate MR. There were no differences between the groups regarding the mean age, frequency of sex, and etiology of cardiomyopathy. The LV systolic and diastolic dimensions were greater in the patients with ? moderate MR (all p values < 0.001). Among the different echocardiographic factors, the QRS duration (150.75 ± 34.66 vs. 126.77 ± 29.044 ms; p value = 0.050) and interventricular mechanical delay (41.60 ± 29.50 vs. 35.00 ms ± 22.01; p value = 0.045) were significantly longer in the patients with ? mild MR in the univariate analysis. After adjusting the effect of these parameters on the severity of MR for the regional and global LV remodeling parameters, no significant impact of the QRS duration and dyssynchrony indices was observed. Conclusion: Our results showed that the degree of functional MR was not associated with the QRS duration and inter- and intraventricular dyssynchrony in our patients with cardiomyopathy. No association was found between the severity of MR and the ischemic or dilated etiology for cardiomyopathy.

Sardari, Akram; Ashraf, Haleh; Khorsand, Mani; Zoroufian, Arezou; Sahebjam, Mohammad; Jalali, Arash; Sadeghian, Hakimeh

2014-01-01

10

Long-term effect of pulmonary valve replacement on QRS duration in patients with corrected tetralogy of Fallot  

Microsoft Academic Search

Objective: To analyse the long-term course of QRS duration after pulmonary valve replacement in patients with a previous correction for tetralogy of Fallot.Setting: Tertiary referral centres.Methods: In a retrospective study, 99 adult patients with tetralogy of Fallot, who had undergone a first pulmonary valve replacement late after initial total correction, were identified from the CONCOR (CONgenital CORvitia) registry. Computer-generated QRS

Thomas Oosterhof; Hubert W Vliegen; Folkert J Meijboom; Aeilko H Zwinderman; Berto Bouma; Barbara J M Mulder

2007-01-01

11

Pulmonary regurgitation is a powerful factor influencing QRS duration in patients after surgical repair of tetralogy of Fallot  

Microsoft Academic Search

Summary\\u000a \\u000a Aims\\u000a   QRS prolongation is a negative prognostic factor for the development of ventricular arrhythmia after repair of tetralogy of\\u000a Fallot (TOF). In this MRI study, we performed a multivariate analysis to determine the influence of volumetric and functional\\u000a parameters as well as time factors on QRS duration.\\u000a \\u000a \\u000a \\u000a \\u000a Methods and results\\u000a   Sixty-seven patients after surgical repair of TOF were studied

Matthias Grothoff; B. Spors; H. Abdul-Khaliq; M. Abd El Rahman; V. Alexi-Meskishvili; P. Lange; R. Felix; M. Gutberlet

2006-01-01

12

Identification of three novel genetic variations associated with electrocardiographic traits (QRS duration and PR interval) in East Asians.  

PubMed

The electrocardiogram has several advantages in detecting cardiac arrhythmia-it is readily available, noninvasive and cost-efficient. Recent genome-wide association studies have identified single-nucleotide polymorphisms that are associated with electrocardiogram measures. We performed a genome-wide association study using Korea Association Resource data for the discovery phase (Phase 1, n = 6805) and two consecutive replication studies in Japanese populations (Phase 2, n = 2285; Phase 3, n = 5010) for QRS duration and PR interval. Three novel loci were identified: rs2483280 (PRDM16 locus) and rs335206 (PRDM6 locus) were associated with QRS duration, and rs17026156 (SLC8A1 locus) correlated with PR interval. PRDM16 was recently identified as a causative gene of left ventricular non-compaction and dilated cardiomyopathy in 1p36 deletion syndrome, which is characterized by heart failure, arrhythmia and sudden cardiac death. Thus, our finding that a PRDM16 SNP is linked to QRS duration strongly implicates PRDM16 in cardiac function. In addition, C allele of rs17026156 increases PR interval (beta ± SE, 2.39 ± 0.40 ms) and exists far more frequently in East Asians (0.46) than in Europeans and Africans (0.05 and 0.08, respectively). PMID:25035420

Hong, Kyung-Won; Lim, Ji Eun; Kim, Jong Wook; Tabara, Yasuharu; Ueshima, Hirotsugu; Miki, Tetsuro; Matsuda, Fumihiko; Cho, Yoon Shin; Kim, Yeonjung; Oh, Bermseok

2014-12-15

13

Predicting the QRS complex and detecting small changes using principal component analysis.  

PubMed

In this paper, a new method for QRS complex analysis and estimation based on principal component analysis (PCA) and polynomial fitting techniques is presented. Multi-channel ECG signals were recorded and QRS complexes were obtained from every channel and aligned perfectly in matrices. For every channel, the covariance matrix was calculated from the QRS complex data matrix of many heartbeats. Then the corresponding eigenvectors and eigenvalues were calculated and reconstruction parameter vectors were computed by expansion of every beat in terms of the principal eigenvectors. These parameter vectors show short-term fluctuations that have to be discriminated from abrupt changes or long-term trends that might indicate diseases. For this purpose, first-order poly-fit methods were applied to the elements of the reconstruction parameter vectors. In healthy volunteers, subsequent QRS complexes were estimated by calculating the corresponding reconstruction parameter vectors derived from these functions. The similarity, absolute error and RMS error between the original and predicted QRS complexes were measured. Based on this work, thresholds can be defined for changes in the parameter vectors that indicate diseases. PMID:17313328

Khawaja, Antoun; Dössel, Olaf

2007-02-01

14

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

PubMed Central

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 been used for quantitative evaluation. The adaptation procedure led to an improved sensitivity and positive predictive value, and a reduced jitter for the detection of the R-wave, QRS onset, QRS offset, and iso-electric level. Additionally, time series representing the RR interval, R-wave amplitude and QRS duration, were automatically extracted for periods at rest, before, during and after apnea-bradycardia episodes. Significant variations (p<0.05) were observed for all time-series when comparing the difference between values at rest versus values just before the bradycardia event, with the difference between values at rest versus values during the bradycardia event. These results reveal changes in the R-wave amplitude and QRS duration, appearing at the onset and termination of apnea-bradycardia episodes, which could be potentially useful for the early detection and characterization of these episodes. PMID:19963984

Altuve, Miguel; Carrault, Guy; Cruz, Julio; Beuchée, Alain; Pladys, Patrick; Hernandez, Alfredo I.

2009-01-01

15

The impact of changing oedematous states on the QRS duration: implications for cardiac resynchronization therapy and implantable cardioverter/defibrillator implantation.  

PubMed

Increased ECG QRS duration (QRSd) in patients with dilated cardiomyopathy (DCM) or heart failure (HF) is a well-known phenomenon. The QRSd is not a static ECG measurement but shows fluctuations, and its recent inclusion among the parameters used in referring patients for implantable cardioverter/defibrillators (ICDs) or cardiac resynchronization therapy (CRT) has led to renewed interest in its natural course and its determinants. Although clinical deterioration has been traditionally associated with increasing QRSd, its changes often are left unexplained. Also, the recent description of a decrease in QRSd, well correlated with attenuated amplitude of QRS complexes in patients with peripheral oedema (PERO) in the context of a variety of illnesses, has added complexity to the matter. This communication aims at calling attention to the importance of a few clinical and ECG parameters when documenting changes in the QRSd in serial ECGs. Thus, presence or absence of PERO and change in the patients' weight, along with alteration in the amplitude of QRS complexes and shifts to/from incomplete/complete bundle branch block patterns, all should be considered when assessing changes in QRSd for meaningful follow-up of patients with DCM or CHF, or referral for ICD or CRT. Evaluation of the QRSd as a selection parameter for referring patients suitable for device implantation should continue along with the employment of mechanical analysis of ventricular dyssynchrony. Although reference here is made to QRSd particularly in connection with DCM and HF, the above apply to other oedematous states (i.e. patients with chronic renal failure, or those undergoing haemodialysis). PMID:15763531

Madias, John E

2005-03-01

16

Simultaneous wide and narrow QRS complex tachycardia: what is the mechanism?  

PubMed

We present the case of a 50-year-old patient with several episodes of syncope and documented simultaneous wide and narrow QRS complex tachycardia. We then review this tacharrhythmia, focusing on electrophysiological findings and pathophysiology, diagnosis and treatment. PMID:23688775

Rodríguez-Mañero, Moisés; Bayrak, Fatih; Namdar, Mehdi; Casado-Arroyo, Rubén; Ricciardi, Danilo; Chierchia, Gian-Battista; Sarkozy, Andrea; de Asmundis, Carlo; Brugada, Pedro

2013-05-01

17

An efficient unsupervised fetal QRS complex detection from abdominal maternal ECG.  

PubMed

Non-invasive fetal heart rate is of great relevance in clinical practice to monitor fetal health state during pregnancy. To date, however, despite significant advances in the field of electrocardiography, the analysis of abdominal fetal ECG is considered a challenging problem for biomedical and signal processing communities. This is mainly due to the low signal-to-noise ratio of fetal ECG and difficulties in cancellation of maternal QRS complexes, motion and electromyographic artefacts. In this paper we present an efficient unsupervised algorithm for fetal QRS complex detection from abdominal multichannel signal recordings combining ICA and maternal ECG cancelling, which outperforms each single method. The signal is first pre-processed to remove impulsive artefacts, baseline wandering and power line interference. The following steps are then applied: maternal ECG extraction through independent component analysis (ICA); maternal QRS detection; maternal ECG cancelling through weighted singular value decomposition; enhancing of fetal ECG through ICA and fetal QRS detection. We participated in the Physionet/Computing in Cardiology Challenge 2013, obtaining the top official scores of the challenge (among 53 teams of participants) of event 1 and event 2 concerning fetal heart rate and fetal interbeat intervals estimation section. The developed algorithms are released as open-source on the Physionet website. PMID:25069520

Varanini, M; Tartarisco, G; Billeci, L; Macerata, A; Pioggia, G; Balocchi, R

2014-08-01

18

Progressive loss in circulating volume during haemodialysis can be monitored by time voltage integral area of QRS complex: pilot study  

PubMed Central

Introduction Time voltage area of QRS is a parameter that showed a close association with modifications in endoventricular volume. The aim of the study was to investigate the efficacy of this parameter in identifying progressive reduction in circulating blood volume (BV) during haemodialytic treatment (HT). Material and methods Thirteen uraemic patients were studied. XYX like leads were monitored before, during and after HT. Summation of areas of each QRS complex was named QRS total area (TA). Results Increase in QRS TA and decrease in BV were found after vs. before HT. Progressive increase in QRS TA is strongly linked to a progressive reduction of BV during HT. Conclusions These findings encourage use of ECG monitoring during HT with a dual purpose: rhythm and haemodynamic control. In fact, excessive or insufficient subtractions of water, with consequent hypotensive or cardiorespiratory crisis, are the most frequent complications in these patients. PMID:23847680

Castro, Claudia; Cammarota, Camillo; Tonnarini, Gianfranco; Pasquali, Marzia

2013-01-01

19

On the relationship between block of the cardiac Na+ channel and drug-induced prolongation of the QRS complex  

PubMed Central

BACKGROUND AND PURPOSE Inhibition of the human cardiac Na+ channel (hNav1.5) can prolong the QRS complex and has been associated with increased mortality in patients with underlying cardiovascular disease. The safety implications of blocking hNav1.5 channels suggest the need to test for this activity early in drug discovery in order to design out any potential liability. However, interpretation of hNav1.5 blocking potency requires knowledge of how hNav1.5 block translates into prolongation of the QRS complex. EXPERIMENTAL APPROACH We tested Class I anti-arrhythmics, other known QRS prolonging drugs and drugs not reported to prolong the QRS complex. Their block of hNav1.5 channels (as IC50 values) was measured in an automated electrophysiology-based assay. These IC50 values were compared with published reports of the corresponding unbound (free) plasma concentrations attained during clinical use (fCmax) to provide an IC50 : fCmax ratio. KEY RESULTS For 42 Class I anti-arrhythmics and other QRS prolonging drugs, 67% had IC50 : fCmax ratios <30. For 55 non-QRS prolonging drugs tested, 72% had ratios >100. Finally, we determined the relationship between the IC50 value and the free drug concentration associated with prolongation of the QRS complex in humans. For 37 drugs, QRS complex prolongation was observed at free plasma concentrations that were about 15-fold lower than the corresponding IC50 at hNav1.5 channels. CONCLUSIONS AND IMPLICATIONS A margin of 30- to 100-fold between hNav1.5 IC50 and fCmax appears to confer an acceptable degree of safety from QRS prolongation. QRS prolongation occurs on average at free plasma levels 15-fold below the IC50 at hNav1.5 channels. LINKED ARTICLE This article is commented on by Gintant et al., pp. 254–259 of this issue. To view this commentary visit http://dx.doi.org/10.1111/j.1476-5381.2011.01433.x PMID:21480866

Harmer, AR; Valentin, J-P; Pollard, CE

2011-01-01

20

Fragmented QRS: What Is The Meaning?  

PubMed Central

Fragmented QRS (fQRS) is a convenient marker of myocardial scar evaluated by 12-lead electrocardiogram (ECG) recording. fQRS is defined as additional spikes within the QRS complex. In patients with CAD, fQRS was associated with myocardial scar detected by single photon emission tomography and was a predictor of cardiac events. fQRS was also a predictor of mortality and arrhythmic events in patients with reduced left ventricular function. The usefulness of fQRS for detecting myocardial scar and for identifying high-risk patients has been expanded to various cardiac diseases, such as cardiac sarcoidosis, arrhythmogenic right ventricular cardiomyopathy, acute coronary syndrome, Brugada syndrome, and acquired long QT syndrome. fQRS can be applied to patients with wide QRS complexes and is associated with myocardial scar and prognosis. Myocardial scar detected by fQRS is associated with subsequent ventricular dysfunction and heart failure and is a substrate for reentrant ventricular tachyarrhythmias. PMID:23071383

Take, Yutaka; Morita, Hiroshi

2012-01-01

21

Radial dyssynchrony assessed by cardiovascular magnetic resonance in relation to left ventricular function, myocardial scarring and QRS duration in patients with heart failure  

PubMed Central

Background Intuitively, cardiac dyssynchrony is the inevitable result of myocardial injury. We hypothezised that radial dyssynchrony reflects left ventricular remodeling, myocardial scarring, QRS duration and impaired LV function and that, accordingly, it is detectable in all patients with heart failure. Methods 225 patients with heart failure, grouped according to QRS duration of <120 ms (A, n = 75), between 120-149 ms (B, n = 75) or ?150 ms (C, n = 75), and 50 healthy controls underwent assessment of radial dyssynchrony using the cardiovascular magnetic resonance tissue synchronization index (CMR-TSI = SD of time to peak inward endocardial motion in up to 60 myocardial segments). Results Compared to 50 healthy controls (21.8 ± 6.3 ms [mean ± SD]), CMR-TSI was higher in A (74.8 ± 34.6 ms), B (92.4 ± 39.5 ms) and C (104.6 ± 45.6 ms) (all p < 0.0001). Adopting a cut-off CMR-TSI of 34.4 ms (21.8 plus 2xSD for controls) for the definition of dyssynchrony, it was present in 91% in A, 95% in B and 99% in C. Amongst patients in NYHA class III or IV, with a LVEF<35% and a QRS>120 ms, 99% had dyssynchrony. Amongst those with a QRS<120 ms, 91% had dyssynchrony. Across the study sample, CMR-TSI was related positively to left ventricular volumes (p < 0.0001) and inversely to LVEF (CMR-TSI = 178.3 e (-0.033 LVEF) ms, p < 0.0001). Conclusion Radial dyssynchrony is almost universal in patients with heart failure. This vies against the notion that a lack of response to CRT is related to a lack of dyssynchrony. PMID:19930713

2009-01-01

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. PMID:23761979

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

2013-01-01

23

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

2013-01-01

24

Transient attenuation of the amplitude of the QRS complexes in the diagnosis of Takotsubo syndrome  

PubMed Central

Background and objectives: Currently, there are no specific diagnostic electrocardiogram (ECG) signs for Takotsubo syndrome (TTS) to differentiate it from acute coronary syndromes (ACS). Myocardial oedema has been detected by cardiac magnetic resonance imaging in patients with TTS. Recently it has been postulated that myocardial oedema may be the cause of low QRS voltage (LQRSV) in the admission ECG and attenuation of the amplitude of the QRS complexes (AAQRS) in serial ECGs, noted in a few published cases of patients with TTS. The objective of this study was to evaluate whether the admission ECG of patients with documented TTS reveals LQRSV and whether AAQRS is found when serial ECGs are compared in such patients. Methods: This study evaluated the prevalence of LQRSV in the admission ECG and AAQRS in serial ECGs in patients with TTS. ECGs of 368 patients with TTS from published reports in the international literature were evaluated for LQRSV (?5 mm in limb leads and/or ?10 mm in precordial leads) and AAQRS in serial ECGs. Results: LQRSV was seen in 91.5% of 200 patients with TTS and one ECG, with a distribution of 49.0, 42.8, 51.0, 52.0, and 46.9%, in lead aVR, and inferior, anterior, lateral, and high lateral ECG lead groups, respectively. AAQRS was seen in 93.5% of 168 patients with TTS and two or more ECGs, with a distribution of 78.3, 74.5, 60.1, 70.7, and 74.5% in lead aVR, and inferior, anterior, lateral, and high lateral ECG lead groups, respectively. Conclusions: LQRSV and AAQRS are highly prevalent ECG signs in patients with TTS, and should be useful in aiding in its diagnosis and differentiation from ACS, on first contact with the patient on admission to the hospital, and the ensuing 24 hours, in conjunction with echocardiography and coronary arteriography. PMID:24562801

2014-01-01

25

Influence of QRS complex detection errors on entropy algorithms. Application to heart rate variability discrimination.  

PubMed

Signal entropy measures such as approximate entropy (ApEn) and sample entropy (SampEn) are widely used in heart rate variability (HRV) analysis and biomedical research. In this article, we analyze the influence of QRS detection errors on HRV results based on signal entropy measures. Specifically, we study the influence that QRS detection errors have on the discrimination power of ApEn and SampEn using the cardiac arrhythmia suppression trial (CAST) database. The experiments assessed the discrimination capability of ApEn and SampEn under different levels of QRS detection errors. The results demonstrate that these measures are sensitive to the presence of ectopic peaks: from a successful classification rate of 100%, down to a 75% when spikes are present. The discriminating capability of the metrics degraded as the number of misdetections increased. For an error rate of 2% the segmentation failed in a 12.5% of the experiments, whereas for a 5% rate, it failed in a 25%. PMID:23246085

Molina-Picó, Antonio; Cuesta-Frau, David; Miró-Martínez, Pau; Oltra-Crespo, Sandra; Aboy, Mateo

2013-04-01

26

A multi-step method with signal quality assessment and fine-tuning procedure to locate maternal and fetal QRS complexes from abdominal ECG recordings.  

PubMed

Non-invasive monitoring of fetal electrocardiogram (fECG) plays an important role in detecting and diagnosing fetal diseases. This study aimed to develop a multi-step method for locating both maternal and fetal QRS complexes from abdominal ECG (aECG) recordings. The proposed method included four major steps: abdominal ECG pre-processing, maternal QRS complex locating, maternal ECG cancellation and fetal QRS complex locating. Signal quality assessment (SQA) and fine-tuning for maternal ECG (FTM) were implemented in the first and third steps, respectively. The method was then evaluated using 75 non-invasive 4-channel aECG recordings provided by the PhysioNet/Computing in Cardiology Challenge 2013. The F1 measure, which is a new index introduced by Behar et al (2013 Proc. Comput. Cardiol. 40 297-300), was used to assess the locating accuracy. The other two indices, mean squared error of heart rate (MSE_HR) between the fetal HR signals estimated from the reference and our method (MSE_HR in bpm(2)) and root mean squared difference between the corresponding fetal RR intervals (MSE_RR in ms) were also used to assess the locating accuracy. Overall, for the maternal QRS complex, the F1 measure was 98.4% from the method without the implementation of SQA, and it was improved to 99.8% with SQA. For the fetal QRS complex, the F1 measure, MSE_HR and MSE_RR were 84.9%, 185.6?bpm(2) and 19.4?ms for the method without both SQA and FTM procedures. They were improved to 93.9%, 47.5?bpm(2) and 7.6?ms with both SQA and FTM procedures. These improvements were observed from each individual subject. It can be concluded that implementing both SQA and FTM procedures could achieve better performance for locating both maternal and fetal QRS complexes. PMID:25069817

Liu, Chengyu; Li, Peng; Di Maria, Costanzo; Zhao, Lina; Zhang, Henggui; Chen, Zhiqing

2014-08-01

27

Diminution of QRS complexes caused by anasarca after an acute myocardial infarction: A case report and a discussion of the plausible underlying pathophysiological mechanisms  

Microsoft Academic Search

We describe the case of an 81-year-old man with an acute anterior myocardial infarction (MI), complicated by anoxic encephalopathy, respiratory, and acute renal failure, who developed gradually marked reduction in the QRS complexes of his electrocardiogram (ECG) in the process of gaining 44 pounds, due to anasarca. Such ECG pattern has been recently associated with marked peripheral edema in the

John E. Madias; Virenjan Narayan

2003-01-01

28

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

29

Design of a cardiac monitor in terms of parameters of QRS complex.  

PubMed

Objective. To design a portable cardiac monitor system based on the available ordinary ECG machine and works on the basis of QRS parameters. Method. The 80196 single chip microcomputer was used as the central microprocessor and real time electrocardiac signal was collected and analyzed [correction of analysized] in the system. Result. Apart from the performance of an ordinary monitor, this machine possesses also the following functions: arrhythmia analysis, HRV analysis, alarm, freeze, and record of automatic papering. Convenient in carrying, the system is powered by AC or DC sources. Stability, low power and low cost are emphasized in the hardware design; and modularization method is applied in software design. Conclusion. Popular in usage and low cost made the portable monitor system suitable for use under simple conditions. PMID:12422858

Chen, Zhen-cheng; Ni, Li-li; Su, Ke-ping; Wang, Hong-yan; Jiang, Da-zong

2002-08-01

30

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

31

QRS Complex Enlargement as a Predictor of Ventricular Arrhythmias in Patients Affected by Surgically Treated Tetralogy of Fallot: A Comprehensive Literature Review and Historical Overview  

PubMed Central

Tetralogy of Fallot (TOF) is a congenital heart disease frequently treated by surgical repair to relieve symptoms and improve survival. However, despite the performing of an optimal surgical repair, TOF patients are at times characterized by a poor long-term survival rate, likely due to cardiac causes such as ventricular arrhythmias, with subsequent sudden death. In the 80s it was irrefutably demonstrated that QRS prolongation ?180?msec at basal electrocardiogram is a strong predictor for refining risk stratification for ventricular tachycardia in these patients. The aim of this research was to undertake a review of all studies conducted to assess the impact of QRS duration on the development of life-threatening ventricular arrhythmias in repaired TOF subjects. PMID:23509638

Bassareo, Pier Paolo; Mercuro, Giuseppe

2013-01-01

32

High Frequency QRS ECG Accurately Detects Cardiomyopathy  

NASA Technical Reports Server (NTRS)

High frequency (HF, 150-250 Hz) analysis over the entire QRS interval of the ECG is more sensitive than conventional ECG for detecting myocardial ischemia. However, the accuracy of HF QRS ECG for detecting cardiomyopathy is unknown. We obtained simultaneous resting conventional and HF QRS 12-lead ECGs in 66 patients with cardiomyopathy (EF = 23.2 plus or minus 6.l%, mean plus or minus SD) and in 66 age- and gender-matched healthy controls using PC-based ECG software recently developed at NASA. The single most accurate ECG parameter for detecting cardiomyopathy was an HF QRS morphological score that takes into consideration the total number and severity of reduced amplitude zones (RAZs) present plus the clustering of RAZs together in contiguous leads. This RAZ score had an area under the receiver operator curve (ROC) of 0.91, and was 88% sensitive, 82% specific and 85% accurate for identifying cardiomyopathy at optimum score cut-off of 140 points. Although conventional ECG parameters such as the QRS and QTc intervals were also significantly longer in patients than controls (P less than 0.001, BBBs excluded), these conventional parameters were less accurate (area under the ROC = 0.77 and 0.77, respectively) than HF QRS morphological parameters for identifying underlying cardiomyopathy. The total amplitude of the HF QRS complexes, as measured by summed root mean square voltages (RMSVs), also differed between patients and controls (33.8 plus or minus 11.5 vs. 41.5 plus or minus 13.6 mV, respectively, P less than 0.003), but this parameter was even less accurate in distinguishing the two groups (area under ROC = 0.67) than the HF QRS morphologic and conventional ECG parameters. Diagnostic accuracy was optimal (86%) when the RAZ score from the HF QRS ECG and the QTc interval from the conventional ECG were used simultaneously with cut-offs of greater than or equal to 40 points and greater than or equal to 445 ms, respectively. In conclusion 12-lead HF QRS ECG employing RAZ scoring is a simple, accurate and inexpensive screening technique for cardiomyopathy. Although HF QRS ECG is highly sensitive for cardiomyopathy, its specificity may be compromised in patients with cardiac pathologies other than cardiomyopathy, such as uncomplicated coronary artery disease or multiple coronary disease risk factors. Further studies are required to determine whether HF QRS might be useful for monitoring cardiomyopathy severity or the efficacy of therapy in a longitudinal fashion.

Schlegel, Todd T.; Arenare, Brian; Poulin, Gregory; Moser, Daniel R.; Delgado, Reynolds

2005-01-01

33

Stability analysis of QRS features to evaluate signal quality for multi-lead QRS dectection.  

PubMed

In automated ECG monitoring, QRS detection performance is dependent on noise measurements on individual leads. A new signal quality measurement based on stability analysis of QRS complex features has been developed to assess individual ECG lead quality. The new method was evaluated on the records of the MIT-BIH arrhythmia and NST databases. Results showed that the new signal quality measurement can be used to accurately assess ECG signal quality and can be easily incorporated into an existing multi-lead QRS detection algorithm for performance improvement. PMID:22255159

Zhang, Zhe; Lall, Carolyn; Chen, Yu

2011-01-01

34

Examining visual complexity and its influence on perceived duration.  

PubMed

We investigated whether visual complexity of novel abstract patterns affects perceived duration. Previous research has reported that complex visual stimuli led to an underestimation of durations. However, to clarify the nature of the time estimation process, it is necessary to establish which component of image complexity, spatial or semantic, plays the critical role. Here we tested the impact of specific spatial properties. We used unfamiliar and abstract patterns made using black-and-white checkerboards in which the difference between stimuli was exclusively in configuration. Visual complexity was quantified by the GIF index based on a compression algorithm, which scanned the pattern in both horizontal and vertical directions. This metric correlated positively with subjective complexity (Experiment 1A). In the second study, we increased variability in the stimuli by changing the number of items across patterns while keeping overall size constant. A high positive correlation was found between objective and subjective complexity (r = 0.95) (Experiment 2A). In Experiments 1B and 2B, observers estimated pattern durations in seconds using a continuous scale. A multilevel linear analysis found that perceived duration was not predicted by visual complexity for either of the two sets of stimuli. These results provide new constraints to theories of time perception, hypothesizing that complexity leads to an underestimation of duration when it reduces attention to time. PMID:25487112

Palumbo, Letizia; Ogden, Ruth; Makin, Alexis D J; Bertamini, Marco

2014-01-01

35

A Randomized Controlled Trial to Evaluate the Safety and Efficacy of Cardiac Contractility Modulation in Patients With Moderately Reduced Left Ventricular Ejection Fraction and a Narrow QRS Duration: Study Rationale and Design  

PubMed Central

Cardiac contractility modulation (CCM) signals are nonexcitatory electrical signals delivered during the cardiac absolute refractory period that enhance the strength of cardiac muscular contraction. The FIX-HF-5 study was a prospective randomized study comparing CCM plus optimal medical therapy (OMT) to OMT alone that included 428 New York Heart Association (NYHA) functional class III or IV heart failure patients with ejection fraction (EF) ?45% according to core laboratory assessment. The study met its primary safety end point, but did not reach its primary efficacy end point: a responders analysis of changes in ventilatory anaerobic threshold (VAT). However, in a prespecified subgroup analysis, significant improvements in primary and secondary end points, including the responder VAT end point, were observed in patients with EFs ranging from 25% to 45%, who constituted about one-half of the study subjects. We therefore designed a new study to prospectively confirm the efficacy of CCM in this population. A hierarchic bayesian statistical analysis plan was developed to take advantage of the data already available from the first study. In addition, based on technical difficulties encountered in reliably quantifying VAT and the relatively large amount of nonquantifiable studies, the primary efficacy end point was changed to peak VO2, with significant measures incorporated to minimize the influence of placebo effect. In this paper, we provide the details and rationale of the FIX-HF-5C study design to study CCM plus OMT compared with OMT alone in subjects with normal QRS duration, NYHA functional class III or IV, and EF 25%–45%. This study is registered on www.clinicaltrials.gov with identifier no. NCT01381172. PMID:25285748

ABRAHAM, WILLIAM T.; LINDENFELD, JOANN; REDDY, VIVEK Y.; HASENFUSS, GERD; KUCK, KARL-HEINZ; BOSCARDIN, JOHN; GIBBONS, ROBERT; BURKHOFF, DANIEL

2015-01-01

36

Real-time, high frequency QRS electrocardiograph  

NASA Technical Reports Server (NTRS)

Real time cardiac electrical data are received from a patient, manipulated to determine various useful aspects of the ECG signal, and displayed in real time in a useful form on a computer screen or monitor. The monitor displays the high frequency data from the QRS complex in units of microvolts, juxtaposed with a display of conventional ECG data in units of millivolts or microvolts. The high frequency data are analyzed for their root mean square (RMS) voltage values and the discrete RMS values and related parameters are displayed in real time. The high frequency data from the QRS complex are analyzed with imbedded algorithms to determine the presence or absence of reduced amplitude zones, referred to herein as RAZs. RAZs are displayed as go, no-go signals on the computer monitor. The RMS and related values of the high frequency components are displayed as time varying signals, and the presence or absence of RAZs may be similarly displayed over time.

Schlegel, Todd T. (Inventor); DePalma, Jude L. (Inventor); Moradi, Saeed (Inventor)

2006-01-01

37

The Spatial QRS-T Angle: Implications in Clinical Practice  

PubMed Central

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

2013-01-01

38

The relation of QRS amplitude to the frontal QRS axis and the heart-electrode distance.  

NASA Technical Reports Server (NTRS)

The relation between QRS amplitude, QRS axis deviation and heart position was studied in 360 subjects, using the 12-lead EKG. The height of the V sub 6 R wave was used as the measure of QRS amplitude. The distance from the left lateral border of the heart was used to indicate heart position. The frontal and horizontal QRS axes were determined by noting the isoelectric limb and precordial leads, measured according to Schmitt's values.

Dougherty, J. D.

1971-01-01

39

QRS detection using S-Transform and Shannon energy.  

PubMed

This paper presents a novel method for QRS detection in electrocardiograms (ECG). It is based on the S-Transform, a new time frequency representation (TFR). The S-Transform provides frequency-dependent resolution while maintaining a direct relationship with the Fourier spectrum. We exploit the advantages of the S-Transform to isolate the QRS complexes in the time-frequency domain. Shannon energy of each obtained local spectrum is then computed in order to localize the R waves in the time domain. Significant performance enhancement is confirmed when the proposed approach is tested with the MIT-BIH arrhythmia database (MITDB). The obtained results show a sensitivity of 99.84%, a positive predictivity of 99.91% and an error rate of 0.25%. Furthermore, to be more convincing, the authors illustrated the detection parameters in the case of certain ECG segments with complicated patterns. PMID:24856322

Zidelmal, Z; Amirou, A; Ould-Abdeslam, D; Moukadem, A; Dieterlen, A

2014-08-01

40

Interesting ECG Narrow QRS Tachycardia with Alternate Wide QRS Beats: What is the Mechanism?  

Microsoft Academic Search

A 44-year old lady underwent electrophysiology study for recurrent palpitations and documented narrow QRS regular tachycardia. The baseline ECG showed subtle preexcitation that was easily manifest on atrial pacing. The retrograde atrial activation sequence during ventricular pacing was eccentric suggesting retrograde conduction over the accessory pathway. A regular narrow QRS tachycardia with cycle length 280 ms was easily inducible on

Kartikeya Bhargava; Rajesh Jindal; Tarlochan S Kler

41

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

42

Purkinje-cell plasticity and cerebellar motor learning are graded by complex-spike duration.  

PubMed

Behavioural learning is mediated by cellular plasticity, such as changes in the strength of synapses at specific sites in neural circuits. The theory of cerebellar motor learning relies on movement errors signalled by climbing-fibre inputs to cause long-term depression of synapses from parallel fibres to Purkinje cells. However, a recent review has called into question the widely held view that the climbing-fibre input is an 'all-or-none' event. In anaesthetized animals, there is wide variation in the duration of the complex spike (CS) caused in Purkinje cells by a climbing-fibre input. Furthermore, the amount of plasticity in Purkinje cells is graded according to the duration of electrically controlled bursts in climbing fibres. The duration of bursts depends on the 'state' of the inferior olive and therefore may be correlated across climbing fibres. Here we provide a potential functional context for these mechanisms during motor learning in behaving monkeys. The magnitudes of both plasticity and motor learning depend on the duration of the CS responses. Furthermore, the duration of CS responses seems to be a meaningful signal that is correlated across the Purkinje-cell population during motor learning. We suggest that during learning, longer bursts in climbing fibres lead to longer-duration CS responses in Purkinje cells, more calcium entry into Purkinje cells, larger synaptic depression, and stronger learning. The same graded impact of instructive signals for plasticity and learning might occur throughout the nervous system. PMID:24814344

Yang, Yan; Lisberger, Stephen G

2014-06-26

43

Revisiting QRS Detection Methodologies for Portable, Wearable, Battery-Operated, and Wireless ECG Systems  

PubMed Central

Cardiovascular diseases are the number one cause of death worldwide. Currently, portable battery-operated systems such as mobile phones with wireless ECG sensors have the potential to be used in continuous cardiac function assessment that can be easily integrated into daily life. These portable point-of-care diagnostic systems can therefore help unveil and treat cardiovascular diseases. The basis for ECG analysis is a robust detection of the prominent QRS complex, as well as other ECG signal characteristics. However, it is not clear from the literature which ECG analysis algorithms are suited for an implementation on a mobile device. We investigate current QRS detection algorithms based on three assessment criteria: 1) robustness to noise, 2) parameter choice, and 3) numerical efficiency, in order to target a universal fast-robust detector. Furthermore, existing QRS detection algorithms may provide an acceptable solution only on small segments of ECG signals, within a certain amplitude range, or amid particular types of arrhythmia and/or noise. These issues are discussed in the context of a comparison with the most conventional algorithms, followed by future recommendations for developing reliable QRS detection schemes suitable for implementation on battery-operated mobile devices. PMID:24409290

Elgendi, Mohamed; Eskofier, Björn; Dokos, Socrates; Abbott, Derek

2014-01-01

44

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

ERIC Educational Resources Information Center

This paper presents a profile of Iowa's Child Care Quality Rating System prepared as part of the Child Care Quality Rating System (QRS) Assessment Study. The profile is divided into the following categories: (1) Program Information; (2) Rating Details; (3) Quality Indicators for Center-Based Programs; (4) Indicators for Family Child Care Programs;…

Child Trends, 2010

2010-01-01

45

North Carolina Star Rated License System: QRS Profile. The Child Care Quality Rating System (QRS) Assessment  

ERIC Educational Resources Information Center

This paper presents a profile of North Carolina's Star Rated License 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

46

Real-Time 12-Lead High-Frequency QRS Electrocardiography for Enhanced Detection of Myocardial Ischemia and Coronary Artery Disease  

NASA Technical Reports Server (NTRS)

Several studies have shown that diminution of the high-frequency (HF; 150-250 Hz) components present within the central portion of the QRS complex of an electrocardiogram (ECG) is a more sensitive indicator for the presence of myocardial ischemia than are changes in the ST segments of the conventional low-frequency ECG. However, until now, no device has been capable of displaying, in real time on a beat-to-beat basis, changes in these HF QRS ECG components in a continuously monitored patient. Although several software programs have been designed to acquire the HF components over the entire QRS interval, such programs have involved laborious off-line calculations and postprocessing, limiting their clinical utility. We describe a personal computer-based ECG software program developed recently at the National Aeronautics and Space Administration (NASA) that acquires, analyzes, and displays HF QRS components in each of the 12 conventional ECG leads in real time. The system also updates these signals and their related derived parameters in real time on a beat-to-beat basis for any chosen monitoring period and simultaneously displays the diagnostic information from the conventional (low-frequency) 12-lead ECG. The real-time NASA HF QRS ECG software is being evaluated currently in multiple clinical settings in North America. We describe its potential usefulness in the diagnosis of myocardial ischemia and coronary artery disease.

Schlegel, Todd T.; Kulecz, Walter B.; DePalma, Jude L.; Feiveson, Alan H.; Wilson, John S.; Rahman, M. Atiar; Bungo, Michael W.

2004-01-01

47

Do patients with heart failure and right bundle branch block need biventricular pacing? A case of significant QRS narrowing by right ventricular pacing alone.  

PubMed

We report the case of a 56-year-old male with ischemic cardiomyopathy, severe left ventricular dysfunction and right bundle branch block (RBBB) with a wide QRS duration (180ms) who received dual-chamber implantable cardioverter-defibrillator for primary prevention of sudden death. After having placed the right ventricular lead in the middle of the inter-ventricular septum, a significant narrowing of QRS duration was observed, thus obtaining "de facto" a cardiac resynchronization therapy (CRT). This type of cardiac pacing could be an alternative to conventional CRT with left ventricular pacing in patients with wide QRS due to RBBB. The long-term effects of this RV only pacing strategy with ICD in patients with heart failure yet remain to be determined. PMID:25464987

Crea, Pasquale; Andò, Giuseppe; Zagari, Domenico; Giordano, Antonio; Picciolo, Giuseppe; Oreto, Giuseppe

2015-01-01

48

Noninvasive fetal QRS detection using an echo state network and dynamic programming.  

PubMed

We address a classical fetal QRS detection problem from abdominal ECG recordings with a data-driven statistical machine learning approach. Our goal is to have a powerful, yet conceptually clean, solution. There are two novel key components at the heart of our approach: an echo state recurrent neural network that is trained to indicate fetal QRS complexes, and several increasingly sophisticated versions of statistics-based dynamic programming algorithms, which are derived from and rooted in probability theory. We also employ a standard technique for preprocessing and removing maternal ECG complexes from the signals, but do not take this as the main focus of this work. The proposed approach is quite generic and can be extended to other types of signals and annotations. Open-source code is provided. PMID:25069892

Lukoševi?ius, Mantas; Marozas, Vaidotas

2014-08-01

49

A joint QRS detection and data compression scheme for wearable sensors.  

PubMed

This paper presents a novel electrocardiogram (ECG) processing technique for joint data compression and QRS detection in a wireless wearable sensor. The proposed algorithm is aimed at lowering the average complexity per task by sharing the computational load among multiple essential signal-processing tasks needed for wearable devices. The compression algorithm, which is based on an adaptive linear data prediction scheme, achieves a lossless bit compression ratio of 2.286x. The QRS detection algorithm achieves a sensitivity (Se) of 99.64% and positive prediction (+P) of 99.81% when tested with the MIT/BIH Arrhythmia database. Lower overall complexity and good performance renders the proposed technique suitable for wearable/ambulatory ECG devices. PMID:25073164

Deepu, C J; Lian, Y

2015-01-01

50

Real-time, high frequency QRS electrocardiograph with reduced amplitude zone detection  

NASA Technical Reports Server (NTRS)

Real time cardiac electrical data are received from a patient, manipulated to determine various useful aspects of the ECG signal, and displayed in real time in a useful form on a computer screen or monitor. The monitor displays the high frequency data from the QRS complex in units of microvolts, juxtaposed with a display of conventional ECG data in units of millivolts or microvolts. The high frequency data are analyzed for their root mean square (RMS) voltage values and the discrete RMS values and related parameters are displayed in real time. The high frequency data from the QRS complex are analyzed with imbedded algorithms to determine the presence or absence of reduced amplitude zones, referred to herein as ''RAZs''. RAZs are displayed as ''go, no-go'' signals on the computer monitor. The RMS and related values of the high frequency components are displayed as time varying signals, and the presence or absence of RAZs may be similarly displayed over time.

Schlegel, Todd T. (Inventor); DePalma, Jude L. (Inventor); Moradi, Saeed (Inventor)

2009-01-01

51

QRS detection based ECG quality assessment.  

PubMed

Although immediate feedback concerning ECG signal quality during recording is useful, up to now not much literature describing quality measures is available. We have implemented and evaluated four ECG quality measures. Empty lead criterion (A), spike detection criterion (B) and lead crossing point criterion (C) were calculated from basic signal properties. Measure D quantified the robustness of QRS detection when applied to the signal. An advanced Matlab-based algorithm combining all four measures and a simplified algorithm for Android platforms, excluding measure D, were developed. Both algorithms were evaluated by taking part in the Computing in Cardiology Challenge 2011. Each measure's accuracy and computing time was evaluated separately. During the challenge, the advanced algorithm correctly classified 93.3% of the ECGs in the training-set and 91.6 % in the test-set. Scores for the simplified algorithm were 0.834 in event 2 and 0.873 in event 3. Computing time for measure D was almost five times higher than for other measures. Required accuracy levels depend on the application and are related to computing time. While our simplified algorithm may be accurate for real-time feedback during ECG self-recordings, QRS detection based measures can further increase the performance if sufficient computing power is available. PMID:22902864

Hayn, Dieter; Jammerbund, Bernhard; Schreier, Günter

2012-09-01

52

Fetal QRS extraction from abdominal recordings via model-based signal processing and intelligent signal merging.  

PubMed

Noninvasive fetal ECG (fECG) monitoring has potential applications in diagnosing congenital heart diseases in a timely manner and assisting clinicians to make more appropriate decisions during labor. However, despite advances in signal processing and machine learning techniques, the analysis of fECG signals has still remained in its preliminary stages. In this work, we describe an algorithm to automatically locate QRS complexes in noninvasive fECG signals obtained from a set of four electrodes placed on the mother's abdomen. The algorithm is based on an iterative decomposition of the maternal and fetal subspaces and filtering of the maternal ECG (mECG) components from the fECG recordings. Once the maternal components are removed, a novel merging technique is applied to merge the signals and detect the fetal QRS (fQRS) complexes. The algorithm was trained and tested on the fECG datasets provided by the PhysioNet/CinC challenge 2013. The final results indicate that the algorithm is able to detect fetal peaks for a variety of signals with different morphologies and strength levels encountered in clinical practice. PMID:25069479

Haghpanahi, Masoumeh; Borkholder, David A

2014-08-01

53

Value of the Qrs-T Angle in Predicting the Induction of Ventricular Tachyarrhythmias in Patients with Chagas Disease.  

PubMed

Background: The QRS-T angle correlates with prognosis in patients with heart failure and coronary artery disease, reflected by an increase in mortality proportional to an increase in the difference between the axes of the QRS complex and T wave in the frontal plane. The value of this correlation in patients with Chagas heart disease is currently unknown. Objective: Determine the correlation of the QRS-T angle and the risk of induction of ventricular tachycardia / ventricular fibrillation (VT / VF) during electrophysiological study (EPS) in patients with Chagas disease. Methods: Case-control study at a tertiary center. Patients without induction of VT / VF on EPS were used as controls. The QRS-T angle was categorized as normal (0-105º), borderline (105-135º) or abnormal (135-180º). Differences between groups for continuous variables were analyzed with the t test or Mann-Whitney test, and for categorical variables with Fisher's exact test. P values < 0.05 were considered significant. Results: Of 116 patients undergoing EPS, 37.9% were excluded due to incomplete information / inactive records or due to the impossibility to correctly calculate the QRS-T angle (presence of left bundle branch block and atrial fibrillation). Of 72 patients included in the study, 31 induced VT / VF on EPS. Of these, the QRS-T angle was normal in 41.9%, borderline in 12.9% and abnormal in 45.2%. Among patients without induction of VT / VF on EPS, the QRS-T angle was normal in 63.4%, borderline in 14.6% and abnormal in 17.1% (p = 0.04). When compared with patients with normal QRS-T angle, those with abnormal angle had a fourfold higher risk of inducing ventricular tachycardia / ventricular fibrillation on EPS [odds ratio (OR) 4; confidence interval (CI) 1.298-12.325; p = 0.028]. After adjustment for other variables such as age, ejection fraction (EF) and QRS size, there was a trend for the abnormal QRS-T angle to identify patients with increased risk of inducing VT / VF during EPS (OR 3.95; CI 0.99-15.82; p = 0.052). The EF also emerged as a predictor of induction of VT / VF: for each point increase in EF, there was a 4% reduction in the rate of sustained ventricular arrhythmia on EPS. Conclusions: Changes in the QRS-T angle and decreases in EF were associated with an increased risk of induction of VT / VF on EPS.Fundamento: O ângulo QRS-T mostra correlação com prognóstico em pacientes com insuficiência cardíaca e doença coronariana, traduzido por um aumento na mortalidade proporcional ao aumento na diferença entre os eixos do complexo QRS e da onda T no plano frontal. Até hoje, nenhuma informação a este respeito foi obtida em pacientes com cardiopatia chagásica. Objetivo: Correlacionar o ângulo QRS-T com a indução de taquicardia ventricular / fibrilação ventricular (TV / FV) em chagásicos durante estudo eletrofisiológico (EEF). Métodos: Estudo caso-controle em centro terciário. Pacientes sem indução de TV / FV ao EEF foram utilizados como controles. O ângulo QRS-T foi categorizado como normal (0-105º), limítrofe (105-135º) e anormal (135-180º). As diferenças entre os grupos foram analisadas pelo teste t ou teste de Mann-Whitney para variáveis contínuas, e teste exato de Fisher ou qui-quadrado para variáveis categóricas. Valores de p < 0,05 foram considerados significativos. Resultados: De 116 pacientes submetidos ao EEF, 37,9% foram excluídos por estarem com dados incompletos / prontuários inativos ou pela impossibilidade de se calcular corretamente o ângulo QRS-T (presença de bloqueio de ramo esquerdo e fibrilação atrial). De 72 pacientes incluídos, 31 induziram TV / FV ao EEF. Destes, o ângulo QRS-T se encontrava normal em 41,9%, limítrofe em 12,9% e anormal em 45,2%. No grupo de pacientes sem indução de TV / FV, o ângulo QRS-T se encontrava normal em 63,4%, limítrofe em 14,6% e anormal em 17,1% (p = 0,04). Quando comparados aos pacientes com ângulo QRS-T normal, o risco de indução de TV / FV nos pacientes com ângulo anormal foi quatro vezes maior [odds ratio (OR) 4; intervalo de confia

Zampa, Hugo Bizetto; Moreira, Dalmo Ar; Ferreira Filho, Carlos Alberto Brandão; Souza, Charles Rios; Menezes, Camila Caldas; Hirata, Henrique Seichii; Armaganijan, Luciana Vidal

2014-10-28

54

Month-to-month and year-to-year reproducibility of high frequency QRS ECG signals.  

PubMed

High frequency electrocardiography analyzing the entire QRS complex in the frequency range of 150 to 250 Hz may prove useful in the detection of coronary artery disease, yet the long-term stability of these waveforms has not been fully characterized. Therefore, we prospectively investigated the reproducibility of the root mean squared voltage, kurtosis, and the presence versus absence of reduced amplitude zones in signal averaged 12-lead high frequency QRS recordings acquired in the supine position one month apart in 16 subjects and one year apart in 27 subjects. Reproducibility of root mean squared voltage and kurtosis was excellent over these time intervals in the limb leads, and acceptable in the precordial leads using both the V-lead and CR-lead derivations. The relative error of root mean squared voltage was 12% month-to-month and 16% year-to-year in the serial recordings when averaged over all 12 leads. Reduced amplitude zones were also reproducible up to a rate of 87% and 81%, respectively, for the month-to-month and year-to-year recordings. We conclude that 12-lead high frequency QRS electrocardiograms are sufficiently reproducible for clinical use. PMID:15484157

Batdorf, Niles J; Feiveson, Alan H; Schlegel, Todd T

2004-10-01

55

QRS slopes for assessment of myocardial damage in chronic chagasic patients  

NASA Astrophysics Data System (ADS)

In this study the slopes of the QRS complex are evaluated for determination of the degree of myocardial damage in chronic chagasic patients. Previous studies have demonstrated the ability of the slope indices to reflect alterations in the conduction velocity of the cardiac impulse. Results obtained in the present study show that chronic chagasic patients have significantly flatter QRS slopes as compared to healthy subjects. Not only that but the extent of slope lessening turns out to be proportional to the degree of myocardial damage caused by the disease. Additionally, when incorporating the slope indices into a classification analysis together with other indices indicative of the presence of ventricular late potentials obtained from high resolution electrocardiography, results show that the percentages of correct classification increase up to 62.5%, which means eight points above the percentages obtained prior to incorporation of the slope indices. It can be concluded that QRS slopes have great potential for assessing the degree of severity associated with Chagas' disease.

Pueyo, E.; Laciar, E.; Anzuola, E.; Laguna, P.; Jané, R.

2007-11-01

56

Month-to-Month and Year-to-Year Reproducibility of High Frequency QRS ECG signals  

NASA Technical Reports Server (NTRS)

High frequency (HF) electrocardiography analyzing the entire QRS complex in the frequency range of 150 to 250 Hz may prove useful in the detection of coronary artery disease, yet the long-term stability of these waveforms has not been fully characterized. We therefore prospectively investigated the reproducibility of the root mean squared (RMS) voltage, kurtosis, and the presence versus absence of reduced amplitude zones (RAzs) in signal averaged 12-lead HF QRS recordings acquired in the supine position one month apart in 16 subjects and one year apart in 27 subjects. Reproducibility of RMS voltage and kurtosis was excellent over these time intervals in the limb leads, and acceptable in the precordial leads using both the V-lead and CR-lead derivations. The relative error of RMS voltage was 12% month-to-month and 16% year-to-year in the serial recordings when averaged over all 12 leads. RAzs were also reproducible at a rate of up to 87% and 8 1 %, respectively, for the month-to-month and year-to-year recordings. We conclude that 12-lead HF QRS electrocardiograms are sufficiently reproducible for clinical use.

Batdorf, Niles; Feiveson, Alan H.; Schlegel, Todd T.

2006-01-01

57

Month-to-month and year-to-year reproducibility of high frequency QRS ECG signals  

NASA Technical Reports Server (NTRS)

High frequency electrocardiography analyzing the entire QRS complex in the frequency range of 150 to 250 Hz may prove useful in the detection of coronary artery disease, yet the long-term stability of these waveforms has not been fully characterized. Therefore, we prospectively investigated the reproducibility of the root mean squared voltage, kurtosis, and the presence versus absence of reduced amplitude zones in signal averaged 12-lead high frequency QRS recordings acquired in the supine position one month apart in 16 subjects and one year apart in 27 subjects. Reproducibility of root mean squared voltage and kurtosis was excellent over these time intervals in the limb leads, and acceptable in the precordial leads using both the V-lead and CR-lead derivations. The relative error of root mean squared voltage was 12% month-to-month and 16% year-to-year in the serial recordings when averaged over all 12 leads. Reduced amplitude zones were also reproducible up to a rate of 87% and 81%, respectively, for the month-to-month and year-to-year recordings. We conclude that 12-lead high frequency QRS electrocardiograms are sufficiently reproducible for clinical use.

Batdorf, Niles J.; Feiveson, Alan H.; Schlegel, Todd T.

2004-01-01

58

Low power adder based digital filter for QRS detector.  

PubMed

Most of the Biomedical applications use dedicated processors for the implementation of complex signal processing. Among them, sensor network is also a type, which has the constraint of low power consumption. Since the processing elements are the most copiously used operations in the signal processors, the power consumption of this has the major impact on the system level application. In this paper, we introduce low power concept of transistor stacking to reduce leakage power; and new architectures based on stacking to implement the full adder and its significance at the digital filter level for QRS detector are implemented. The proposed concept has lesser leakage power at the adder as well as filter level with trade-off in other quality metrics of the design. This enabled the design to be dealt with as the low-power corner and can be made adaptable to any level of hierarchical abstractions as per the requirement of the application. The proposed architectures are designed, modeled at RTL level using the Verilog-HDL, and synthesized in Synopsys Design Compiler by mapping the design to 65 nm technology library standard cells. PMID:24895649

Murali, L; Chitra, D; Manigandan, T

2014-01-01

59

Low Power Adder Based Digital Filter for QRS Detector  

PubMed Central

Most of the Biomedical applications use dedicated processors for the implementation of complex signal processing. Among them, sensor network is also a type, which has the constraint of low power consumption. Since the processing elements are the most copiously used operations in the signal processors, the power consumption of this has the major impact on the system level application. In this paper, we introduce low power concept of transistor stacking to reduce leakage power; and new architectures based on stacking to implement the full adder and its significance at the digital filter level for QRS detector are implemented. The proposed concept has lesser leakage power at the adder as well as filter level with trade-off in other quality metrics of the design. This enabled the design to be dealt with as the low-power corner and can be made adaptable to any level of hierarchical abstractions as per the requirement of the application. The proposed architectures are designed, modeled at RTL level using the Verilog-HDL, and synthesized in Synopsys Design Compiler by mapping the design to 65?nm technology library standard cells. PMID:24895649

Murali, L.; Chitra, D.; Manigandan, T.

2014-01-01

60

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

PubMed Central

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.

2013-01-01

61

QRS Fragmentation and Sudden Cardiac Death in the Obese and Overweight  

PubMed Central

Background Obesity has been associated with significantly greater risk of sudden cardiac death (SCD); however, identifying the obese patient at highest risk remains a challenge. We evaluated the association between QRS fragmentation on the 12?lead electrocardiogram and SCD, in obese/overweight subjects. Methods and Results In the ongoing prospective, community?based Oregon Sudden Unexpected Death Study (population approximately 1 million), we performed a case?control analysis, comparing obese/overweight SCD victims with obese/overweight controls from the same geographic region. Archived ECGs prior and unrelated to the SCD event were used for cases and all ECG measurements were assessed in blinded fashion. Fragmentation was defined as the presence of RSR’ patterns and/or notching of the R/S wave in at least 2 contiguous leads. Analysis was limited to ECGs with QRS duration <120 ms. Overall prevalence of fragmentation was higher in cases (n=185; 64.9±13.8 years; 67.0% male) compared with controls (n=405; 64.9±11.0 years; 64.7% male) (34.6% versus 26.9%, P=0.06). Lateral fragmentation was significantly more frequent in cases (8.1% versus 2.5%; P<0. 01), with non?significant differences in anterior and inferior territories. Fragmentation in multiple territories (?2) was also more likely to be observed in cases (9.7% versus 4.9%, P=0.02). In multivariable analysis with consideration of established SCD risk factors, lateral fragmentation was significantly associated with SCD (OR 2.84; 95% CI 1.01 to 8.02; P=0.05). Conclusion QRS fragmentation, especially in the lateral territory is a potential risk marker for SCD independent of the ejection fraction, among obese/overweight subjects in the general population. PMID:25762804

Narayanan, Kumar; Zhang, Lin; Kim, Candice; Uy?Evanado, Audrey; Teodorescu, Carmen; Reinier, Kyndaron; Zheng, Zhi?Jie; Gunson, Karen; Jui, Jonathan; Chugh, Sumeet S.

2015-01-01

62

Aviation System Analysis Capability (ASAC) Quick Response System (QRS) Test Report  

NASA Technical Reports Server (NTRS)

This document is the Aviation System Analysis Capability (ASAC) Quick Response System (QRS) Test Report. The purpose of this document is to present the results of the QRS unit and system tests in support of the ASAC QRS development effort. This document contains an overview of the project background and scope, defines the QRS system and presents the additions made to the QRS this year, explains the assumptions, constraints, and approach used to conduct QRS Unit and System Testing, and presents the schedule used to perform QRS Testing. The document also presents an overview of the Logistics Management Institute (LMI) Test Facility and testing environment and summarizes the QRS Unit and System Test effort and results.

Roberts, Eileen; Villani, James A.; Ritter, Paul

1997-01-01

63

Adaptive threshold QRS detector with best channel selection based on a noise rating system  

Microsoft Academic Search

QRS detection performance can depend on the type of noise present in each lead involved in the overall processing. A common approach to QRS detection is based on a QRS enhanced signal obtained from the derivatives of the pre-filtered leads. However, the signal pre-filtering cannot be able to perform a complete noise rejection and the use of derivatives can enhance

F. Chiarugi; V. Sakkalis; D. Emmanouilidou; T. Krontiris; M. Varanini; I. Tollis

2007-01-01

64

Progress in resolving the duration of magmatism in the Paleoproterozoic Bushveld Complex  

NASA Astrophysics Data System (ADS)

Determining precise crystallization ages and assessing the duration of magmatism associated with the Paleoproterozoic Bushveld Complex, the world's largest layered intrusion located in the northern Kaapvaal craton of South Africa, is critical for establishing the genetic relations among its different rock units (Rustenburg Layered Suite, overlying Rooiberg Group felsic volcanic rocks, intrusive Rashoop Granophyres). We report chemical abrasion ID-TIMS U-Pb zircon results (weighted 207Pb/206Pb ages) for samples spanning the uppermost ~3/4 of the igneous stratigraphy of the layered mafic rocks and the roof. The temporal relationship between the Upper Zone and the roof from the Eastern Limb is constrained by the age of a diorite ~52 m below the roof (2056.52 ± 0.81 Ma; n = 6 single grains) and a granodiorite mixed with hornfels (40:60) and interpreted as partially melted roof material (2054.83 ± 0.86 Ma; n = 7). The slightly younger age of the granodiorite may indicate that the overlying melt sheet was kept molten due to continued influx of the latent heat of crystallization from the underlying 8 km-thick stack of cooling cumulates. The PGE-rich Merensky Reef and the UG2 chromitite occur in the Upper Critical Zone above the ultramafic rocks that comprise the base of the complex. Two samples from the Merensky Reef, separated by ~300 km, have overlapping ages: a sample from Farm Driekop in the Eastern Limb yields an age of 2055.30 ± 0.61 Ma (n = 10) and a sample from the Rustenburg mining section in the Western Limb an age of 2056.13 ± 0.70 Ma (n = 8; age revised from [1]). These ages are indistinguishable from the Upper Zone diorite indicating rapid construction of the upper 2/3 of the Bushveld Complex at ca. 2056 Ma. Preliminary results for zircon from a feldspathic orthopyroxenite immediately beneath the UG2 chromitite (Middelpunt mine, Eastern Limb), ~380 m below the Merensky Reef, reveal unusual U-Pb systematics with low U concentrations (2-27 ppm), exceptionally high Th/U (7.3-28.1) and a range of 207Pb/206Pb ages (2057.8 to 2075.0 Ma; n = 6, all results concordant). These results may reflect a combination of the compositional effects of co-existing U-bearing accessory phases (apatite, rutile) and formation by metasomatism and partial melting of the pyroxenite protolith by rising hydrous interstitial melt that accumulated beneath the impermeable chromitite layer [2]. The ages for additional samples in progress will also be presented to further test the proposal that 15-25% of the original magma volume in the intrusion was expelled to form the Upper Rooiberg Group lavas or Rashoop granophyres [3]. [1] Scoates & Friedman (2008) Economic Geology 103, 465-471; [2] Mathez & Mey (2005) Economic Geology 100, 1616-1630; [3] VanTongeren et al. (2010) Journal of Petrology 51, 1891-1912.

Scoates, J. S.; Wall, C. J.; Friedman, R. M.; VanTongeren, J. A.; Mathez, E. A.

2011-12-01

65

The complex duration perception of emotional faces: effects of face direction  

PubMed Central

The perceived duration of emotional face stimuli strongly depends on the expressed emotion. But, emotional faces also differ regarding a number of other features like gaze, face direction, or sex. Usually, these features have been controlled by only using pictures of female models with straight gaze and face direction. Doi and Shinohara (2009) reported that an overestimation of angry faces could only be found when the model’s gaze was oriented toward the observer. We aimed at replicating this effect for face direction. Moreover, we explored the effect of face direction on the duration perception sad faces. Controlling for the sex of the face model and the participant, female and male participants rated the duration of neutral, angry, and sad face stimuli of both sexes photographed from different perspectives in a bisection task. In line with current findings, we report a significant overestimation of angry compared to neutral face stimuli that was modulated by face direction. Moreover, the perceived duration of sad face stimuli did not differ from that of neutral faces and was not influenced by face direction. Furthermore, we found that faces of the opposite sex appeared to last longer than those of the same sex. This outcome is discussed with regards to stimulus parameters like the induced arousal, social relevance, and an evolutionary context. PMID:25852589

Kliegl, Katrin M.; Limbrecht-Ecklundt, Kerstin; Dürr, Lea; Traue, Harald C.; Huckauf, Anke

2015-01-01

66

Real Time QRS Detection Based on M-ary Likelihood Ratio Test on the DFT Coefficients  

PubMed Central

This paper shows an adaptive statistical test for QRS detection of electrocardiography (ECG) signals. The method is based on a M-ary generalized likelihood ratio test (LRT) defined over a multiple observation window in the Fourier domain. The motivations for proposing another detection algorithm based on maximum a posteriori (MAP) estimation are found in the high complexity of the signal model proposed in previous approaches which i) makes them computationally unfeasible or not intended for real time applications such as intensive care monitoring and (ii) in which the parameter selection conditions the overall performance. In this sense, we propose an alternative model based on the independent Gaussian properties of the Discrete Fourier Transform (DFT) coefficients, which allows to define a simplified MAP probability function. In addition, the proposed approach defines an adaptive MAP statistical test in which a global hypothesis is defined on particular hypotheses of the multiple observation window. In this sense, the observation interval is modeled as a discontinuous transmission discrete-time stochastic process avoiding the inclusion of parameters that constraint the morphology of the QRS complexes. PMID:25356628

Górriz, Juan Manuel; Ramírez, Javier; Olivares, Alberto; Padilla, Pablo; Puntonet, Carlos G.; Cantón, Manuel; Laguna, Pablo

2014-01-01

67

Los Angeles County Steps to Excellence Project: QRS Profile. The Child Care Quality Rating System (QRS) Assessment  

ERIC Educational Resources Information Center

This paper presents a profile of Los Angeles County's Steps to Excellence Project 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;…

Child Trends, 2010

2010-01-01

68

Atlantis Time-Lapse Move to KSC Visitor Complex - Duration: 3:21.  

NASA Video Gallery

Time-lapse cameras captured space shuttle Atlantis making a 10-mile trek from the Vehicle Assembly Building at NASA's Kennedy Space Center in Florida to the Kennedy Space Center Visitor Complex whe...

69

High frequency QRS ECG predicts ischemic defects during myocardial perfusion imaging  

NASA Technical Reports Server (NTRS)

Background: Changes in high frequency QRS components of the electrocardiogram (HF QRS ECG) (150-250 Hz) are more sensitive than changes in conventional ST segments for detecting myocardial ischemia. We investigated the accuracy of 12-lead HF QRS ECG in detecting ischemia during adenosine tetrofosmin myocardial perfusion imaging (MPI). Methods and Results: 12-lead HF QRS ECG recordings were obtained from 45 patients before and during adenosine technetium-99 tetrofosmin MPI tests. Before the adenosine infusions, recordings of HF QRS were analyzed according to a morphological score that incorporated the number, type and location of reduced amplitude zones (RAZs) present in the 12 leads. During the adenosine infusions, recordings of HF QRS were analyzed according to the maximum percentage changes (in both the positive and negative directions) that occurred in root mean square (RMS) voltage amplitudes within the 12 leads. The best set of prospective HF QRS criteria had a sensitivity of 94% and a specificity of 83% for correctly identifying the MPI result. The sensitivity of simultaneous ST segment changes (18%) was significantly lower than that of any individual HF QRS criterion (P<0.001). Conclusions: Analysis of 12-lead HF QRS ECG is highly sensitive and specific for detecting ischemic perfusion defects during adenosine MPI stress tests and significantly more sensitive than analysis of conventional ST segments.

Rahman, Atiar

2006-01-01

70

High frequency QRS ECG predicts ischemic defects during myocardial perfusion imaging  

NASA Technical Reports Server (NTRS)

Changes in high frequency QRS components of the electrocardiogram (HF QRS ECG) (150-250 Hz) are more sensitive than changes in conventional ST segments for detecting myocardial ischemia. We investigated the accuracy of 12-lead HF QRS ECG in detecting ischemia during adenosine tetrofosmin myocardial perfusion imaging (MPI). 12-lead HF QRS ECG recordings were obtained from 45 patients before and during adenosine technetium-99 tetrofosmin MPI tests. Before the adenosine infusions, recordings of HF QRS were analyzed according to a morphological score that incorporated the number, type and location of reduced amplitude zones (RAZs) present in the 12 leads. During the adenosine infusions, recordings of HF QRS were analyzed according to the maximum percentage changes (in both the positive and negative directions) that occurred in root mean square (RMS) voltage amplitudes within the 12 leads. The best set of prospective HF QRS criteria had a sensitivity of 94% and a specificity of 83% for correctly identifying the MPI result. The sensitivity of simultaneous ST segment changes (18%) was significantly lower than that of any individual HF QRS criterion (P less than 0.00l). Analysis of 12-lead HF QRS ECG is highly sensitive and specific for detecting ischemic perfusion defects during adenosine MPI stress tests and significantly more sensitive than analysis of conventional ST segments.

2004-01-01

71

Real-Time, High-Frequency QRS Electrocardiograph  

NASA Technical Reports Server (NTRS)

An electronic system that performs real-time analysis of the low-amplitude, high-frequency, ordinarily invisible components of the QRS portion of an electrocardiographic signal in real time has been developed. Whereas the signals readily visible on a conventional electrocardiogram (ECG) have amplitudes of the order of a millivolt and are characterized by frequencies <100 Hz, the ordinarily invisible components have amplitudes in the microvolt range and are characterized by frequencies from about 150 to about 250 Hz. Deviations of these high-frequency components from a normal pattern can be indicative of myocardial ischemia or myocardial infarction

Schlegel, Todd T.; DePalma, Jude L.; Moradi, Saeed

2003-01-01

72

Monitoring complex trace-gas mixtures by long-path laser absorption spectrometry. [in long duration manned mission closed environments  

NASA Technical Reports Server (NTRS)

Laser-based spectrophotometric methods, which have been proposed for the detection of trace concentrations of gaseous contaminants, include Raman and passive radiometry. The paper discusses a simple long-path laser absorption method which is capable of resolving complex mixtures of closely related trace contaminants at ppm levels. A number of species were selected which are most likely to accumulate in closed environments, such as submarines or long-duration manned space flights. Absorption coefficients at CO2 laser wavelengths were measured, accurate to + 3 per cent or better, for each of these species. This data base was then used to determine the presence and concentration of the contaminants in prepared mixtures of 12 to 15 gases. Computer programs have been developed which will permit a real-time analysis of the monitored atmosphere. Minimum detectable concentrations for individual species are generally in the ppm range, and are not seriously degraded by interferences even in complex mixtures. Estimates of the dynamic range of this monitoring technique for various system configurations and comparison with other methods of analysis are discussed

Green, B. D.; Steinfeld, J. I.

1976-01-01

73

Electrocardiographic assessment of left ventricular hypertrophy with time-voltage QRS and QRST-wave areas.  

PubMed

The sum of time-voltage QRS areas in the 12-lead electrocardiogram (ECG) has outperformed other 12-lead ECG indices for detection of left ventricular hypertrophy (LVH). We assessed indices of time-voltage QRS and T-wave (QRST) areas from body surface potential mapping (BSPM) for detection of and quantitation of the degree of LVH. We studied 42 patients with echocardiographic LVH (LVH group) and 11 healthy controls (controls). QRST area sums were calculated from 123-lead BSPM and from the 12-lead ECG for comparison. Leadwise discriminant indices and correlation coefficients were used to identify optimal recording locations for QRST area-based LVH assessment. BSPM QRS area sum was greater in the LVH group than in controls (3752 +/- 1259 vs 2278 +/- 627 microV s, respectively; P<0.001) and at 91% specificity showed 74% sensitivity for LVH detection. The 12-lead QRS area sum performed similarly. Taking T-wave areas into account did not improve the results. QRS area sum from two most informative leads (located in the upper and lower right precordium) also separated the LVH group from controls (61.1 +/- 23.5 vs 27.8 +/- 6.5 microV s, respectively; P<0.00001). This 2-lead QRS area sum showed 90% sensitivity with 100% specificity for LVH detection and maintained high correlation to indexed left ventricular mass (r=0.732; P<0.001). In conclusion, the BSPM QRS area sum compared to 12-lead QRS area sum does not substantially improve LVH assessment. The 2-lead QRS area sum may improve ECG QRS area-based LVH assessment. PMID:14688808

Oikarinen, L; Karvonen, M; Viitasalo, M; Takala, P; Kaartinen, M; Rossinen, J; Tierala, I; Hänninen, H; Katila, T; Nieminen, M S; Toivonen, L

2004-01-01

74

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

75

QRS artifact elimination on full night sleep EEG.  

PubMed

Spectral analysis is now a standard procedure for analyzing the electroencephalograms (EEG) obtained by polysomnographic recordings. These numerical methods assume an artifact-free EEG since artifacts create spurious spectral components. Our aim was the development of a QRS artifact removal technique that might be applied to full night EEG with a minimal human intervention. This technique should handle one EEG channel, with or without use of one ECG channel. Variance minimization, independent component analysis (ICA), morphological filters (MF) have been implemented. Careful attention has been given to define the MF structuring element. The tests on artifact-simulated and real data were checked on the residual ECG spectral components present in the cleaned EEG. The best results are obtained by the MF when the structuring element is an artifact template defined either directly on the EEG or on the ICA ECG component. Further developments are required to identify and subtract the T-wave artifacts. PMID:15939658

Lanquart, J-P; Dumont, M; Linkowski, P

2006-03-01

76

Development of a Multi-Channel, High Frequency QRS Electrocardiograph  

NASA Technical Reports Server (NTRS)

With the advent of the ISS era and the potential requirement for increased cardiovascular monitoring of crewmembers during extended EVAs, NASA flight surgeons would stand to benefit from an evolving technology that allows for a more rapid diagnosis of myocardial ischemia compared to standard electrocardiography. Similarly, during the astronaut selection process, NASA flight surgeons and other physicians would also stand to benefit from a completely noninvasive technology that, either at rest or during maximal exercise tests, is more sensitive than standard ECG in identifying the presence of ischemia. Perhaps most importantly, practicing cardiologists and emergency medicine physicians could greatly benefit from such a device as it could augment (or even replace) standard electrocardiography in settings where the rapid diagnosis of myocardial ischemia (or the lack thereof) is required for proper clinical decision-making. A multi-channel, high-frequency QRS electrocardiograph is currently under development in the Life Sciences Research Laboratories at JSC. Specifically the project consisted of writing software code, some of which contained specially-designed digital filters, which will be incorporated into an existing commercial software program that is already designed to collect, plot and analyze conventional 12-lead ECG signals on a desktop, portable or palm PC. The software will derive the high-frequency QRS signals, which will be analyzed (in numerous ways) and plotted alongside of the conventional ECG signals, giving the PC-viewing clinician advanced diagnostic information that has never been available previously in all 12 ECG leads simultaneously. After the hardware and software for the advanced digital ECG monitor have been fully integrated, plans are to use the monitor to begin clinical studies both on healthy subjects and on patients with known coronary artery disease in both the outpatient and hospital settings. The ultimate goal is to get the technology out into the clinical world, where it has the potential to save lives.

DePalma, Jude L.

2003-01-01

77

A 0.83- ?W QRS detection processor using quadratic spline wavelet transform for wireless ECG acquisition in 0.35- ?m CMOS.  

PubMed

Healthcare electronics count on the effectiveness of the on-patient signal preprocessing unit to moderate the wireless data transfer for better power efficiency. In order to reduce the system power in long-time ECG acquisition, this work describes an on-patient QRS detection processor for arrhythmia monitoring. It extracts the concerned ECG part, i.e., the RR-interval between the QRS complex for evaluating the heart rate variability. The processor is structured by a scale-3 quadratic spline wavelet transform followed by a maxima modulus recognition stage. The former is implemented via a symmetric FIR filter, whereas the latter includes a number of feature extraction steps: zero-crossing detection, peak (zero-derivative) detection, threshold adjustment and two finite state machines for executing the decision rules. Fabricated in 0.35-?m CMOS the 300-Hz processor draws only 0.83 ?W, which is favorably comparable with the prior arts. In the system tests, the input data is placed via an on-chip 10-bit SAR analog-to-digital converter, while the output data is emitted via an off-the-shelf wireless transmitter (TI CC2500) that is configurable by the processor for different data transmission modes: 1) QRS detection result, 2) raw ECG data or 3) both. Validated with all recordings from the MIT-BIH arrhythmia database, 99.31% sensitivity and 99.70% predictivity are achieved. Mode 1 with solely the result of QRS detection exhibits 6× reduction of system power over modes 2 and 3. PMID:23853259

Ieong, Chio-In; Mak, Pui-In; Lam, Chi-Pang; Dong, Cheng; Vai, Mang-I; Mak, Peng-Un; Pun, Sio-Hang; Wan, Feng; Martins, Rui P

2012-12-01

78

Mechanical Dyssynchrony Precedes QRS Widening in ATP?Sensitive K+ Channel–Deficient Dilated Cardiomyopathy  

PubMed Central

Background Contractile discordance exacerbates cardiac dysfunction, aggravating heart failure outcome. Dissecting the genesis of mechanical dyssynchrony would enable an early diagnosis before advanced disease. Methods and Results High?resolution speckle?tracking echocardiography was applied in a knockout murine surrogate of adult?onset human cardiomyopathy caused by mutations in cardioprotective ATP?sensitive K+ (KATP) channels. Preceding the established criteria of cardiac dyssynchrony, multiparametric speckle?based strain resolved nascent erosion of dysfunctional regions within cardiomyopathic ventricles of the KATP channel–null mutant exposed to hemodynamic stress. Not observed in wild?type counterparts, intraventricular disparity in wall motion, validated by the degree, direction, and delay of myocardial speckle patterns, unmasked the disease substrate from asymptomatic to overt heart failure. Mechanical dyssynchrony preceded widening of the QRS complex and exercise intolerance and progressed into global myocardial discoordination and decompensated cardiac pump function, precipitating a low output syndrome. Conclusions The present study, with the use of high?resolution imaging, prospectively resolved the origin and extent of intraventricular motion disparity in a KATP channel–knockout model of dilated cardiomyopathy. Mechanical dyssynchrony established as an early marker of cardiomyopathic disease offers novel insight into the pathodynamics of dyssynchronous heart failure. PMID:24308936

Yamada, Satsuki; Arrell, D. Kent; Kane, Garvan C.; Nelson, Timothy J.; Perez?Terzic, Carmen M.; Behfar, Atta; Purushothaman, Saranya; Prinzen, Frits W.; Auricchio, Angelo; Terzic, Andre

2013-01-01

79

Real-time electrocardiogram P-QRS-T detection-delineation algorithm based on quality-supported analysis of characteristic templates.  

PubMed

The main objective of this study is to introduce a simple, low-latency, and accurate algorithm for real-time detection of P-QRS-T waves in the electrocardiogram (ECG) signal. In the proposed method, real-time signal preprocessing, which includes high frequency noise filtering and baseline wander reduction, is performed by applying discrete wavelet transform (DWT). A method based on signal first-order derivative and adaptive threshold adjustment is employed for real-time detection of the QRS complex. Moreover, detection and delineation of P- and T-waves are achieved by correlation analysis conducted between signal and their templates. Besides, signal quality is investigated online, and if the quality of the analysis window is unacceptable, then the algorithm will guess (estimate) the locations of P- and T-waves. The operating characteristics of the proposed algorithm are evaluated by its implementation to an artificially generated ECG signal whose quality is adjustable from the best (Quality, 100%) to the worst (Quality, ?40%) cases based on the random-walk noise theory. The algorithm was applied to the MIT-BIH arrhythmia database, QT database, and Physionet/CinC challenge 2011competition database. The obtained results, which were based on the QT database, showed sensitivity and positive predictivity of Se=99.63% and P+=99.83%, Se=99.83% and P+=99.98%, and Se=99.74% and P+=99.89% for the detection of P-, QRS-, and T-waves, respectively, and the obtained results, which were based on the MIT-BIH arrhythmia database, showed Se=99.81% and P+=99.70% for the detection of the QRS complex. Moreover, it will be shown that the results of the proposed method are reliable for a minimum signal quality value of 70%. According to numerical assessments, 8-ms after the occurrence of R-wave, its location will be identified by the computer code of the proposed algorithm. This parameter is 198-ms and 177-ms for P- and T-waves, respectively. PMID:25063881

Karimipour, Atiyeh; Homaeinezhad, Mohammad Reza

2014-09-01

80

Fetal QRS detection and heart rate estimation: a wavelet-based approach.  

PubMed

Fetal heart rate monitoring is used for pregnancy surveillance in obstetric units all over the world but in spite of recent advances in analysis methods, there are still inherent technical limitations that bound its contribution to the improvement of perinatal indicators. In this work, a previously published wavelet transform based QRS detector, validated over standard electrocardiogram (ECG) databases, is adapted to fetal QRS detection over abdominal fetal ECG. Maternal ECG waves were first located using the original detector and afterwards a version with parameters adapted for fetal physiology was applied to detect fetal QRS, excluding signal singularities associated with maternal heartbeats. Single lead (SL) based marks were combined in a single annotator with post processing rules (SLR) from which fetal RR and fetal heart rate (FHR) measures can be computed. Data from PhysioNet with reference fetal QRS locations was considered for validation, with SLR outperforming SL including ICA based detections. The error in estimated FHR using SLR was lower than 20 bpm for more than 80% of the processed files. The median error in 1 min based FHR estimation was 0.13 bpm, with a correlation between reference and estimated FHR of 0.48, which increased to 0.73 when considering only records for which estimated FHR > 110 bpm. This allows us to conclude that the proposed methodology is able to provide a clinically useful estimation of the FHR. PMID:25070210

Almeida, Rute; Gonçalves, Hernâni; Bernardes, João; Rocha, Ana Paula

2014-08-01

81

Linear prediction modeling for evaluating abnormal intra QRS potentials in the high-resolution electrocardiogram  

Microsoft Academic Search

The purpose of this paper is to obtain abnormal intra-QRS potentials (AIQP) from a signal-averaged electrocardiogram (SAECG) have been proposed to indicate the risk of ventricular arrhythmias. However, the major limitation of current autoregressive moving average modeling is that the model order depends on the database. This study presented a new method based on the linear prediction modeling to improve

C. C. Lin

2005-01-01

82

Linear Prediction Modeling for Evaluating Abnormal Intra QRS Potentials in the High-Resolution Electrocardiogram  

Microsoft Academic Search

Background: The abnormal intra-QRS potentials (AIQP) from a signal-averaged electrocardiogram (SAECG) have been proposed to indicate the risk of ventricular arrhythmias. However, the major limitation of current autoregressive moving average modeling is that the model order depends on the database. This study presented a new method based on the linear prediction modeling to improve the limits in AIQP analysis. Materials

CC Lin

2008-01-01

83

Influence of crude protein content, ingredient complexity, feed form, and duration of feeding of the Phase I diets on productive performance and nutrient digestibility of Iberian pigs.  

PubMed

The influence of CP content and ingredient complexity, feed form, and duration of feeding of the Phase I diets on growth performance and total tract apparent digestibility (TTAD) of energy and nutrients was studied in Iberian pigs weaned at 28 d of age. There were 12 dietary treatments with 2 type of feeds (high-quality, HQ; and low-quality, LQ), 2 feed forms (pellets vs. mash), and 3 durations (7, 14, and 21 d) of supply of the Phase I diets. From d 7, 14, or 21 (depending on treatment) to d 35, all pigs received a common diet in mash form. Each treatment was replicated 3 times (6 pigs/pen). For the entire experiment, ADG (P < 0.05) and ADFI (P < 0.01) were less with the HQ than the LQ Phase I diets, but G:F was not affected. Pelleting of the Phase I diets did not affect ADG but improved G:F (P < 0.01). Feeding the Phase I diets from d 0 to 21 improved G:F (P < 0.05) but decreased ADG (P < 0.01) as compared with 7 or 14 d of feeding. Postweaning diarrhea (PWD) tended to be greater (P = 0.06) for pigs fed the HQ diets than pigs fed the LQ diets and pigs fed pellets than those fed mash (P < 0.001). Also, PWD was greater for pigs fed the Phase I diet for 14 or 21 d than those fed the diet for 7 d (P < 0.01). From d 0 to 21, ADG and G:F were not affected (P > 0.10) by feed quality, but feeding pellets or increasing the duration of feeding the Phase I diets improved G:F (P < 0.01). Also, in this period, PWD was greater with pellets than with mash and for pigs fed the Phase I diets for 14 or 21 d than for pigs fed the diet for only 7 d (P < 0.01). From d 21 to 35, pigs previously fed the LQ diet had greater ADG than pigs fed the HQ Phase I diets (P < 0.001). Also, pigs fed the Phase I diets for 21 d had decreased ADG (P < 0.05) and ADFI (P < 0.001) and reduced G:F (P < 0.05) than pigs fed these diets for 7 or 14 d. Organic matter digestibility was greater for pigs fed the HQ Phase I diets than pigs fed the LQ Phase I diets (P < 0.05). Pelleting improved TTAD of all nutrients (P < 0.01). It is concluded that HQ Phase I diets increased TTAD of nutrients but not feed efficiency of Iberian pigs from d 0 to 35. Also, pelleting improved energy and nutrient digestibility and feed efficiency. Increasing the duration of supply of the Phase I diets from 7 to 21 d improved feed efficiency but reduced ADG. Therefore, the use of LQ Phase I diets in pellet form for no more than 7 d after weaning is recommended in Iberian pigs. PMID:23307842

Berrocoso, J D; Saldaña, B; Serrano, M P; Cámara, L; Ibáñez, M A; Mateos, G G

2013-03-01

84

Comparative effectiveness of cardiac resynchronization therapy in combination with implantable defibrillator in patients with heart failure and wide QRS duration.  

PubMed

Several clinical trials have established that cardiac resynchronization therapy in combination with an implantable cardioverter-defibrillator improves survival and alleviates heart failure symptoms in appropriately selected patients. Recent guidelines have expanded the indications to include patients with less severe heart failure. The aim of this study was to examine the extent to which cardiac resynchronization therapy in combination with an implantable cardioverter-defibrillator improves survival and reduces risk for heart failure hospitalization in United States Medicare patients who met class I or class IIa recommendations. Propensity score methods were used to assess survival and rehospitalization outcomes in Medicare patients. Among patients who met class I recommendations, those with combined cardiac resynchronization therapy had significantly lower risk for death (hazard ratio [HR] 0.83, 95% confidence interval [CI] 0.77 to 0.88, p <0.0001) and lower risk for rehospitalization (HR 0.88, 95% CI 0.83 to 0.94, p <0.0001). Among patients who met class IIa recommendations, the relative hazard of death for patients with combined cardiac resynchronization therapy was lower (HR 0.90, 95% CI 0.85 to 0.96, p = 0.0015), but there was no significant difference in the risk for rehospitalization for heart failure (HR 1.03, 95% CI 0.97 to 1.10, p = 0.2600). In conclusion, cardiac resynchronization therapy in combination with an implantable cardioverter-defibrillator resulted in improved survival among Medicare patients meeting class I criteria and most patients meeting class IIa criteria as outlined in the current guidelines for device-based therapy in heart failure, although the effect sizes were lower than those demonstrated in recent trials. PMID:25240510

Bilchick, Kenneth C; Stukenborg, George J

2014-11-15

85

Does Maturity Affect Cephalic Perfusion and T/QRS Ratio during Prolonged Umbilical Cord Occlusion in Fetal Sheep?  

PubMed Central

T/QRS ratio monitoring is used to help identify fetal asphyxia. However, immature animals have greater capacity to maintain blood pressure during severe asphyxia, raising the possibility that they may show an attenuated T/QRS increase during asphyxia. Chronically instrumented fetal sheep at 0.6 of gestation (0.6?GA; n = 12), 0.7?GA (n = 12), and 0.8?GA (n = 8) underwent complete umbilical cord occlusion for 30?min, 25?min, or 15?min, respectively. Cord occlusion was associated with progressive metabolic acidosis and initial hypertension followed by severe hypotension, with a more rapid fall in mean arterial blood pressure (MAP) and carotid blood flow (CaBF) with advancing gestation. T/QRS ratio rose after occlusion more rapidly at 0.8?GA than in immature fetuses, to a similar final peak at all ages, followed by a progressive fall that was slower at 0.8?GA than in the immature fetuses. The increase in T/QRS ratio correlated with initial hypertension at 0.8?GA (P < 0.05, R2 = 0.38), and conversely, its fall correlated closely with falling MAP in all gestational groups (P < 0.01, R2 = 0.67). In conclusion, elevation of the T/QRS ratio is an index of onset of severe asphyxia in the last third of gestation, but not of fetal compromise. PMID:24693290

Drury, Paul P.; Gunn, Eleanor R.; Bennet, Laura; Gunn, Alistair J.

2014-01-01

86

Association of the Frontal QRS-T Angle with Adverse Cardiac Remodeling, Impaired Left and Right Ventricular Function, and Worse Outcomes in Heart Failure with Preserved Ejection Fraction  

PubMed Central

Background No prior studies have investigated the association of QRS-T angle with cardiac structure/function and outcomes in heart failure with preserved ejection fraction (HFpEF). We hypothesized that increased frontal QRS-T angle is associated with worse cardiac function/remodeling and adverse outcomes in HFpEF. Methods We prospectively studied 376 patients with HFpEF (i.e. symptomatic HF with left ventricular [LV] ejection fraction >50%.) The frontal QRS-T angle was calculated from the 12-lead electrocardiogram. Patients were divided into tertiles by frontal QRS-T angle (0–26°, 27–75°, and 76–179°), and clinical, laboratory, and echocardiographic data were compared among groups. Cox proportional hazards analyses were performed to determine the association between QRS-T angle and outcomes. Results The mean age of the cohort was 64±13 years, 65% were women, and the mean QRS-T angle was 61±51°. Patients with increased QRS-T angle were older, had a lower body-mass index, more frequently had coronary artery disease, diabetes, chronic kidney disease, and atrial fibrillation, and had higher B-type natriuretic peptide (BNP) levels (P<0.05 for all comparisons). After multivariable adjustment, patients with increased QRS-T angle had higher BNP levels in addition to higher LV mass index, worse diastolic function parameters, more right ventricular (RV) remodeling, and worse RV systolic function (P<0.05 for all associations). QRS-T angle was independently associated with the composite outcome of cardiovascular hospitalization or death on multivariable analysis, even after adjusting for BNP (HR for the highest QRS-T tertile = 2.0, 95% CI 1.2–3.4; P=0.008). Conclusions In HFpEF, increased QRS-T angle is independently associated with worse left and right ventricular function/remodeling and adverse outcomes. PMID:24075945

Selvaraj, Senthil; Ilkhanoff, Leonard; Burke, Michael A.; Freed, Benjamin H.; Lang, Roberto M.; Martinez, Eva E.; Shah, Sanjiv J.

2013-01-01

87

Quantifying QRS changes during myocardial ischemia: Insights from high frequency electrocardiography.  

PubMed

Over four decades of high frequency electrocardiography research have provided a body of knowledge about QRS changes during myocardial ischemia, and the techniques to measure and quantify them. High-frequency QRS (HFQRS) components, being closely related to the pattern of ventricular depolarization, carry valuable clinical information. Changes in HFQRS amplitude and morphology have been shown to be sensitive diagnostic markers of myocardial ischemia, often superior to measures of ST-T segment changes. Clinical studies in patients undergoing exercise testing have consistently demonstrated the incremental diagnostic value of HFQRS analysis in detection of demand ischemia. In 6 studies that evaluated the HyperQ™ technology, the average sensitivity and specificity of HFQRS analysis were 75%±6% and 80%±6%, respectively, compared to average sensitivity 48%±16% and average specificity 70%±15% of ST segment analysis. In patients with acute supply ischemia, recent studies characterized and quantified the ischemic HFQRS patterns. HFQRS morphology index was found to be higher in patients with acute coronary syndrome (ACS), compared to non-ischemic, with good sensitivity in patients without ST elevation. These research findings may be translated into commercially-available ECG systems and be used in clinical practice for improved diagnosis and monitoring of myocardial ischemia. PMID:24795285

Amit, Guy; Granot, Yair; Abboud, Shimon

2014-01-01

88

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

89

A ROBUST METHOD FOR QRS DETECTION BASED ON MODIFIED P-SPECTRUM , and K. J. Ray Liu2  

E-print Network

on the mod- i ed p-spectrum to detect heart beats in ECG signals, which is also referred as QRS detection in [5]. The p- spectrum, also known as the periodicity spectrum, is a robust method for periodicity on the data singularity, the p-spectrum of a peri- odic signal will have high sharp peaks. Also, the p-spectrum

Liu, K. J. Ray

90

When Deriving the Spatial QRS-T Angle from the 12-lead ECG, which Transform is More Frank: Regression or Inverse Dower?  

NASA Technical Reports Server (NTRS)

Our primary objective was to ascertain which commonly used 12-to-Frank-lead transformation yields spatial QRS-T angle values closest to those obtained from simultaneously collected true Frank-lead recordings. Simultaneous 12-lead and Frank XYZ-lead recordings were analyzed for 100 post-myocardial infarction patients and 50 controls. Relative agreement, with true Frank-lead results, of 12-to-Frank-lead transformed results for the spatial QRS-T angle using Kors regression versus inverse Dower was assessed via ANOVA, Lin s concordance and Bland-Altman plots. Spatial QRS-T angles from the true Frank leads were not significantly different than those derived from the Kors regression-related transformation but were significantly smaller than those derived from the inverse Dower-related transformation (P less than 0.001). Independent of method, spatial mean QRS-T angles were also always significantly larger than spatial maximum (peaks) QRS-T angles. Spatial QRS-T angles are best approximated by regression-related transforms. Spatial mean and spatial peaks QRS-T angles should also not be used interchangeably.

Schlegel, Todd T.; Cortez, Daniel

2010-01-01

91

A 300-mV 220-nW event-driven ADC with real-time QRS detection for wearable ECG sensors.  

PubMed

This paper presents an ultra-low-power event-driven analog-to-digital converter (ADC) with real-time QRS detection for wearable electrocardiogram (ECG) sensors in wireless body sensor network (WBSN) applications. Two QRS detection algorithms, pulse-triggered (PUT) and time-assisted PUT (t-PUT), are proposed based on the level-crossing events generated from the ADC. The PUT detector achieves 97.63% sensitivity and 97.33% positive prediction in simulation on the MIT-BIH Arrhythmia Database. The t-PUT improves the sensitivity and positive prediction to 97.76% and 98.59% respectively. Fabricated in 0.13 ?m CMOS technology, the ADC with QRS detector consumes only 220 nW measured under 300 mV power supply, making it the first nanoWatt compact analog-to-information (A2I) converter with embedded QRS detector. PMID:25608283

Zhang, Xiaoyang; Lian, Yong

2014-12-01

92

Usefulness of electrocardiographic QRS/T angles with versus without bundle branch blocks to predict heart failure (from the Atherosclerosis Risk in Communities Study).  

PubMed

Repolarization abnormalities in the setting of bundle branch blocks (BBB) are generally ignored. We used Cox regression models to determine hazard ratios (HRs) with 95% confidence intervals (CIs) for incident heart failure (HF) associated with wide spatial and frontal QRS/T angle (upper twenty-fifth percentile of each) in men and women with and without BBB. This analysis included 14,478 participants (54.6% women, 26.4% blacks, 377 [2.6%] with BBB) from the Atherosclerosis Risk in Communities Study who were free of HF at baseline. Using No-BBB with normal spatial QRS/T angle as the reference group, the risk for HF in multivariable adjusted models was increased 51% for No-BBB with wide spatial QRS/T angle (HR 1.51, 95% CI 1.37 to 1.66), 48% for BBB with normal spatial QRS/T angle (HR 1.48, 95% CI 1.17 to 1.88), and the risk for incident HF was increased more than threefold for BBB with wide spatial QRS/T angle (HR 3.37, 95% CI 2.47 to 4.60). The results were consistent across subgroups by gender. Similar results were observed for the frontal plane QRS/T angle. In the pooled BBB group excluding right BBB, a positive T wave in lead aVR and heart rate 70 bpm and higher were also potent predictors of incident HF similar to the QRS/T angles. In conclusion, both BBB and wide QRS/T angles are predictive of HF, and concomitant presence of both carries a much higher risk than for either predictor alone. These findings suggest that repolarization abnormalities in the setting of BBB should not be considered benign or an expected consequence of BBB. PMID:24929625

Zhang, Zhu-ming; Rautaharju, Pentti M; Prineas, Ronald J; Loehr, Laura; Rosamond, Wayne; Soliman, Elsayed Z

2014-08-01

93

Electrocradiographic Qrs Axis, Q Wave and T-wave Changes in 2nd and 3rd Trimester of Normal Pregnancy  

PubMed Central

Background: Pregnancy although a physiological phenomena affects all the functions of the maternal body and brings about remarkable changes in the cardiovascular system. The cardiovascular changes and many of the physiological adaptations of normal pregnancy alter the physical findings thus, sometimes misleading the diagnosis of heart disease. Pregnancy also brings about various changes in the electrocardiogram, further confusing with that of heart disease. This study is undertaken to highlight the effect of normal pregnancy on the QRS axis, Q wave and T-wave of the Electrocardiogram and thereby helps us to distinguish it from that of pathological changes. Objectives: To study the effect of normal pregnancy on the QRS axis, Q wave and T-wave in the electrocardiogram and to compare with that of normal non pregnant women. Materials and Methods: Fifty normal pregnant women in 2nd and 3rd trimester each between 20– 35 y of age and 50 normal non pregnant women of the same age group were selected for the study. A 12 lead ECG was recorded by using ECG machine with special emphasis on QRS axis, Q wave and T-wave changes and all the parameters were analysed. Results: The ECG changes observed in our study include, deviation of QRS axis towards left as pregnancy advanced, significant increased incidence of occurrence of prominent Q waves in lead II, III and avF in pregnant group (p < 0.05 ) and, T-wave abnormalities like flat and inverted T-waves in lead III, V1 – V3 were more frequent in pregnant group ( p<0.05 ) than in non pregnant group. Conclusion:Normal pregnancy brings about various changes in ECG. These changes during pregnancy should be interpretated with caution by the physicians. It is necessary to understand the normal physiological changes which in turn help us in better management of those with cardiac disease. PMID:25386425

S., Chandrasekharappa; Brid, S.V

2014-01-01

94

A vector-free ECG interpretation with P, QRS & T waves as unbalanced transitions between stable configurations of the heart electric field during P-R, S-T & T-P segments  

PubMed Central

Since cell membranes are weak sources of electrostatic fields, this ECG interpretation relies on the analogy between cells and electrets. It is here assumed that cell-bound electric fields unite, reach the body surface and the surrounding space and form the thoracic electric field that consists from two concentric structures: the thoracic wall and the heart. If ECG leads measure differences in electric potentials between skin electrodes, they give scalar values that define position of the electric field center along each lead. Repolarised heart muscle acts as a stable positive electric source, while depolarized heart muscle produces much weaker negative electric field. During T-P, P-R and S-T segments electric field is stable, only subtle changes are detectable by skin electrodes. Diastolic electric field forms after ventricular depolarization (T-P segments in the ECG recording). Telediastolic electric field forms after the atria have been depolarized (P-Q segments in the ECG recording). Systolic electric field forms after the ventricular depolarization (S-T segments in the ECG recording). The three ECG waves (P, QRS and T) can then be described as unbalanced transitions of the heart electric field from one stable configuration to the next and in that process the electric field center is temporarily displaced. In the initial phase of QRS, the rapidly diminishing septal electric field makes measured potentials dependent only on positive charges of the corresponding parts of the left and the right heart that lie within the lead axes. If more positive charges are near the "DOWN" electrode than near the "UP" electrode, a Q wave will be seen, otherwise an R wave is expected. Repolarization of the ventricular muscle is dampened by the early septal muscle repolarization that reduces deflection of T waves. Since the "UP" electrode of most leads is near the usually larger left ventricle muscle, T waves are in these leads positive, although of smaller amplitude and longer duration than the QRS wave in the same lead. The proposed interpretation is applied to bundle branch blocks, fascicular (hemi-) blocks and changes during heart muscle ischemia. PMID:24506945

2014-01-01

95

A vector-free ECG interpretation with P, QRS & T waves as unbalanced transitions between stable configurations of the heart electric field during P-R, S-T & T-P segments.  

PubMed

Since cell membranes are weak sources of electrostatic fields, this ECG interpretation relies on the analogy between cells and electrets. It is here assumed that cell-bound electric fields unite, reach the body surface and the surrounding space and form the thoracic electric field that consists from two concentric structures: the thoracic wall and the heart. If ECG leads measure differences in electric potentials between skin electrodes, they give scalar values that define position of the electric field center along each lead. Repolarised heart muscle acts as a stable positive electric source, while depolarized heart muscle produces much weaker negative electric field. During T-P, P-R and S-T segments electric field is stable, only subtle changes are detectable by skin electrodes.Diastolic electric field forms after ventricular depolarization (T-P segments in the ECG recording). Telediastolic electric field forms after the atria have been depolarized (P-Q segments in the ECG recording). Systolic electric field forms after the ventricular depolarization (S-T segments in the ECG recording). The three ECG waves (P, QRS and T) can then be described as unbalanced transitions of the heart electric field from one stable configuration to the next and in that process the electric field center is temporarily displaced. In the initial phase of QRS, the rapidly diminishing septal electric field makes measured potentials dependent only on positive charges of the corresponding parts of the left and the right heart that lie within the lead axes. If more positive charges are near the "DOWN" electrode than near the "UP" electrode, a Q wave will be seen, otherwise an R wave is expected. Repolarization of the ventricular muscle is dampened by the early septal muscle repolarization that reduces deflection of T waves. Since the "UP" electrode of most leads is near the usually larger left ventricle muscle, T waves are in these leads positive, although of smaller amplitude and longer duration than the QRS wave in the same lead. The proposed interpretation is applied to bundle branch blocks, fascicular (hemi-) blocks and changes during heart muscle ischemia. PMID:24506945

Kurbel, Sven

2014-01-01

96

Implications of Franciscan Complex graywacke geochemistry for sediment transport, provenance determination, burial-exposure duration, and fluid exchange with cosubducted metabasites  

NASA Astrophysics Data System (ADS)

of graywacke provenance has long been used to evaluate the record of tectonic process in orogenic belts. Our geochemical data from graywackes of the Franciscan subduction complex, California, show that the connection between sedimentary record and geologic processes may be more complex than previously believed. Trace elements and Nd-Sr-Pb isotopes of Franciscan graywackes indicate two sources types. One group lacking negative Eu anomaly (Eu/Eu* > 0.9), shows slightly concave-up heavy rare earth elements, arc-like trace element patterns, and western Pacific island arc-like Pb isotopes, reflecting derivation from older accreted oceanic-arc terranes in the Sierra Nevada-Klamath Mountains. The other group displays small negative Eu anomalies, with trace element patterns resembling post-Archean Australian shale and Pb isotopes similar to Jurassic-Cretaceous Sierran batholith. There is no systematic separation of these two groups by depositional ages. Thus, geochemistry of the graywackes may partly reflect variation in location of sediment delivery systems, rather than solely reflecting evolution of the neighboring arc. Variation of Nd-Sr isotopes with stratigraphic-age for the graywackes mimics the trends of the coeval Great Valley Group clastic-rocks, suggesting that (1) they share the same sediment sources, (2) there are no "exotic" sediment sources that fed the Franciscan trench, and (3) burial-exposure cycles for Franciscan clastic rocks were comparatively brief. Comparison of Franciscan graywacke and metabasite geochemistry corroborates earlier conclusions that metabasites had little or no chemical exchange with fluids from cosubducted graywacke. Detrital zircon age populations, major element chemistry, and detrital framework modes, when compared to our data suggest that the former three parameters underrepresent the mafic component of clastic sediment provenance.

Ghatak, Arundhuti; Basu, Asish R.; Wakabayashi, John

2013-09-01

97

Impacts of Coulomb Interactions on the Magnetic Responses of Excitonic Complexes in Single Semiconductor Nanostructures  

PubMed Central

We report on the diamagnetic responses of different exciton complexes in single InAs/GaAs self-assembled quantum dots (QDs) and quantum rings (QRs). For QDs, the imbalanced magnetic responses of inter-particle Coulomb interactions play a crucial role in the diamagnetic shifts of excitons (X), biexcitons (XX), and positive trions (X?). For negative trions (X?) in QDs, anomalous magnetic responses are observed, which cannot be described by the conventional quadratic energy shift with the magnetic field. The anomalous behavior is attributed to the apparent change in the electron wave function extent after photon emission due to the strong Coulomb attraction by the hole in its initial state. In QRs, the diamagnetic responses of X and XX also show different behaviors. Unlike QDs, the diamagnetic shift of XX in QRs is considerably larger than that of X. The inherent structural asymmetry combined with the inter-particle Coulomb interactions makes the wave function distribution of XX very different from that of X in QRs. Our results suggest that the phase coherence of XX in QRs may survive from the wave function localization due to the structural asymmetry or imperfections. PMID:20672111

2010-01-01

98

Complex Solar Eruption - Duration: 0:03.  

NASA Video Gallery

On August 1, 2010 around 0855 UT, Earth orbiting satellites detected a C3-class solar flare. The origin of the blast was sunspot 1092. At about the same time, an enormous magnetic filament stretchi...

99

Is subjective duration a signature of coding efficiency?  

PubMed Central

Perceived duration is conventionally assumed to correspond with objective duration, but a growing literature suggests a more complex picture. For example, repeated stimuli appear briefer in duration than a novel stimulus of equal physical duration. We suggest that such duration illusions appear to parallel the neural phenomenon of repetition suppression, and we marshal evidence for a new hypothesis: the experience of duration is a signature of the amount of energy expended in representing a stimulus, i.e. the coding efficiency. This novel hypothesis offers a unified explanation for almost a dozen illusions in the literature in which subjective duration is modulated by properties of the stimulus such as size, brightness, motion and rate of flicker. PMID:19487187

Eagleman, David M.; Pariyadath, Vani

2009-01-01

100

Long duration flights management  

NASA Astrophysics Data System (ADS)

Long duration flights (LDF) require a special management to take the best decisions in terms of ballast consumption and instant of separation. As a contrast to short duration flights, where meteorological conditions are relatively well known, for LDF we need to include the meteorological model accuracy in trajectory simulations. Dispersions on the fields of model (wind, temperature and IR fluxes) could make the mission incompatible with safety rules, authorized zones and others flight requirements. Last CNES developments for LDF act on three main axes: 1. Although ECMWF-NCEP forecast allows generating simulations from a 4D point (altitude, latitude, longitude and UT time), result is not statistical, it is determinist. To take into account model dispersion a meteorological NCEP data base was analyzed. A comparison between Analysis (AN) and Forecast (FC) for the same time frame had been done. Result obtained from this work allows implementing wind and temperature dispersions on balloon flight simulator. 2. For IR fluxes, NCEP does not provide ascending IR fluxes in AN mode but only in FC mode. To obtain the IR fluxes for each time frame, satellite images are used. A comparison between FC and satellites measurements had been done. Results obtained from this work allow implementing flux dispersions on balloon flight simulator. 3. An improved cartography containing a vast data base had been included in balloon flight simulator. Mixing these three points with balloon flight dynamics we have obtained two new tools for observing balloon evolution and risk, one of them is called ASTERISK (Statistic Tool for Evaluation of Risk) for calculations and the other one is called OBERISK (Observing Balloon Evolution and Risk) for visualization. Depending on the balloon type (super pressure, zero pressure or MIR) relevant information for the flight manager is different. The goal is to take the best decision according to the global situation to obtain the largest flight duration with a minimum risk for population. Telemetry system is based on satellite communication technologies. Housekeeping data and GPS data are transferred to the Ground Station by IRIDIUM network. Gondola is interrogated automatically each hour and all data stocked onboard are downloaded to ground station. Communication takes a few minutes to transfer all data stocked from last request. Tools had been used in SCOUT-MIR campaign 2008 for the first time. The results obtained encourage CNES teams to improve ergonomics and functionalities of these prototype.

Sosa-Sesma, Sergio; Letrenne, Gérard; Spel, Martin; Charbonnier, Jean-Marc

101

The Latest Developments in NASA's Long Duration Balloon Systems  

NASA Astrophysics Data System (ADS)

The Latest Developments in NASA’s Long Duration Balloon Systems Bryan D. Stilwell, bryan.stilwell@csbf.nasa.gov Columbia Scientific Balloon Facility, Palestine, Texas, USA The Columbia Scientific Balloon Facility, located in Palestine, Texas offers the scientific community a high altitude balloon based communications platform. Scientific payload mass can exceed 2722 kg with balloon float altitudes on average of 40000 km and flight duration of up to 100 days. Many developments in electrical systems have occurred over the more than 25 years of long duration flights. This paper will discuss the latest developments in electronic systems related to long duration flights. Over the years, the long duration flights have increased in durations exceeding 56 days. In order to support these longer flights, the systems have had to increase in complexity and reliability. Several different systems that have been upgraded and/or enhanced will be discussed.

Stilwell, Bryan D.

102

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

103

Long duration ash probe  

DOEpatents

A long duration ash probe includes a pressure shell connected to a port in a combustor with a sample coupon mounted on a retractable carriage so as to retract the sample coupon within the pressure shell during soot blowing operation of the combustor. A valve mounted at the forward end of the pressure shell is selectively closeable to seal the sample coupon within the shell, and a heating element in the shell is operable to maintain the desired temperature of the sample coupon while retracted within the shell. The carriage is operably mounted on a pair of rails within the shell for longitudinal movement within the shell. A hollow carrier tube connects the hollow cylindrical sample coupon to the carriage, and extends through the carriage and out the rearward end thereof. Air lines are connected to the rearward end of the carrier tube and are operable to permit coolant to pass through the air lines and thence through the carrier tube to the sample coupon so as to cool the sample coupon. 8 figs.

Hurley, J.P.; McCollor, D.P.; Selle, S.J.

1994-07-26

104

Long duration ash probe  

DOEpatents

A long duration ash probe includes a pressure shell connected to a port in a combustor with a sample coupon mounted on a retractable carriage so as to retract the sample coupon within the pressure shell during sootblowing operation of the combustor. A valve mounted at the forward end of the pressure shell is selectively closeable to seal the sample coupon within the shell, and a heating element in the shell is operable to maintain the desired temperature of the sample coupon while retracted within the shell. The carriage is operably mounted on a pair of rails within the shell for longitudinal movement within the shell. A hollow carrier tube connects the hollow cylindrical sample coupon to the carriage, and extends through the carriage and out the rearward end thereof. Air lines are connected to the rearward end of the carrier tube and are operable to permit coolant to pass through the air lines and thence through the carrier tube to the sample coupon so as to cool the sample coupon.

Hurley, John P. (Grand Forks, ND); McCollor, Don P. (Grand Forks, ND); Selle, Stanley J. (Grand Forks, MN)

1994-01-01

105

The time and duration of meiosis.  

PubMed

Ever since meiosis was recognized as a process there has been a continuing interest in its temporal aspects. Two main types of meiotic timing experiments have been conducted: first, experiments to estimate the duration of meiosis (and sometimes its stages); second, experiments to locate the sensitive stage(s) when exposure of meiocytes to various treatments can affect meiotic chromosome behaviour (e.g. pairing or recombination). Such experiments have played an important role in increasing our understanding of the meiotic process. The duration of meiosis has been estimated in about 70 organisms, including two prokaryotes (yeast and Chlamydomonas) and the following eukaryotes: 1 Basidiomycete (Coprinus lagopus), 2 Gymnosperms (Larix decidua and Thuja plicata gracilis). at least 39 angiosperms, and at least 26 animal species. The duration of female meiosis has been estimated in far fewer species than male meiosis. However, estimates of the duration of female meiosis are available for 6 angiosperms. Drosophila melanogaster, Xenopus laevis, and several mammals. Comparison of these data shows that the duration of meiosis is one of the most variable aspects of the meiotic process, ranging from less than 6 h in yeast to more than 40 years in the human female. Developmental holds at different stages of meiosis are common in plants and animals, and inevitably prolong the meiotic division. However, even among species without developmental holds, the duration of meiosis is very variable. For instance, in animals it ranges from about 1-2 days in male Drosophila melanogaster to more than 24 days in male Homo sapiens and several Orthopterans. Despite the large variation in the duration of meiosis three generalizations can be made: (i) first prophase is always very long compared with the remaining meiotic stages, (ii) the rate of meiotic development is very slow compared with the rate of development in dividing somatic meristem cells of the same organisms under the same conditions, (iii) the duration of meiosis is characteristic of the genotype and species. Four main factors have been recognized which effect or determine the duration of meiosis, namely (1) environmental factors (e.g. temperature); (2) nuclear DNA content; (3) ploidy level of the organism; and, (4) the genotype. Because nuclear DNA content plays a major role in determining the duration of meiosis, it has been suggested that DNA influences the rate of meiotic development in two ways: first through its informational content (the genotype), and second indirectly by the physical and mechanical effects of its mass independently of its informational content (i.e. the nucleotype). Thus, the observed duration of meiosis is the result of a complex genotype-nucleotype-environment interaction. With the obvious exception of variation caused by developmental holds, changes in the duration of meiosis usually involve proportional changes in the durations of all its stages... PMID:16285

Bennett, M D

1977-03-21

106

ESTIMATING THE DURATION OF SPECIATION FROM PHYLOGENIES  

PubMed Central

Speciation is not instantaneous but takes time. The protracted birth–death diversification model incorporates this fact and predicts the often observed slowdown of lineage accumulation toward the present. The mathematical complexity of the protracted speciation model has barred estimation of its parameters until recently a method to compute the likelihood of phylogenetic branching times under this model was outlined (Lambert et al. 2014). Here, we implement this method and study using simulated phylogenies of extant species how well we can estimate the model parameters (rate of initiation of speciation, rate of extinction of incipient and good species, and rate of completion of speciation) as well as the duration of speciation, which is a combination of the aforementioned parameters. We illustrate our approach by applying it to a primate phylogeny. The simulations show that phylogenies often do not contain enough information to provide unbiased estimates of the speciation-initiation rate and the extinction rate, but the duration of speciation can be estimated without much bias. The estimate of the duration of speciation for the primate clade is consistent with literature estimates. We conclude that phylogenies combined with the protracted speciation model provide a promising way to estimate the duration of speciation. PMID:24758256

Etienne, Rampal S; Morlon, Hélène; Lambert, Amaury

2014-01-01

107

Duration of an elastic collision  

NASA Astrophysics Data System (ADS)

With a pedagogical goal, this paper deals with a study of the duration of an elastic collision of an inflatable spherical ball on a planar surface suitable for undergraduate studies. First, the force generated by the deformed spherical ball is obtained under assumptions that are discussed. The study of the motion of the spherical ball colliding with the planar surface allows us to determine the duration of the elastic collision. In order to check the theoretical model, an experiment is proposed to measure the duration of the collision. A more refined model built with masses and springs gives good agreement between theoretical and experimental values.

de Izarra, Charles

2012-07-01

108

Duration of the 2011 Tohoku earthquake ground motions  

NASA Astrophysics Data System (ADS)

We compared several different duration measures for the 2011 M9.0 Tohoku earthquake sequence, because empirical duration models are of great interest for purposes of correlation with structural damage, and the Tohoku mainshock was remarkable for its long duration. Among the three considered definitions, RMS duration (McCann and Shah, Bull Seism Soc Am 69: 1253-1265, 1979) is best able to predict the duration within which pulses or groups of pulses of energy arrive; it is particularly suitable for the Tohoku mainshock, for which source complexity caused time-series with multiple-phase arrivals. Two other considered definitions, both of which tend to underestimate the observed duration, are: (i) duration defined by random vibration theory (RVT); and (ii) the significant duration as defined by the interval between 5 and 75 % or 95 % of the integral of the square of the ground acceleration (known as "Arias intensity" (Arias 1970)) or velocity (known as "energy integral" (Anderson 2004)). In the Tohoku mainshock, significant amplitudes precede the 5 % of the Arias intensity marker; we need to use 0.3 % of the maximum of the accumulated energy as the lower bound marker to appropriately estimate the duration using the significant duration definition. The RVT duration (used in stochastic simulations) can be estimated easily from the 5-75 % of the Arias intensity (significant duration) definition as the two measures give very similar durations. Overall, the significant duration of ground motions observed during the 2011 M9.0 Tohoku earthquake increases with distance as 0.19 R cd for the horizontal components or 0.33 R cd for the vertical component, where R cd is the closest distance to the fault plane. By comparison, the duration of four aftershocks ( M4.5-7.7) increases with distance as ~0.10 R hypo where R hypo is the hypocentral distance. For the mainshock, the distance-dependent slope term is greater, presumably due to the large fault plane size.

Ghofrani, Hadi; Atkinson, Gail M.

2015-01-01

109

Value and limitations of adenosine in the diagnosis and treatment of narrow and broad complex tachycardias  

Microsoft Academic Search

The diagnostic and therapeutic potential of intravenous adenosine was studied in 64 patients during 92 episodes of regular sustained tachycardia. In 40 patients who had narrow complex tachycardias (QRS less than 0.12 s) adenosine (2.5-25 mg) restored sinus rhythm in 25 with junctional tachycardias (46 of 48 episodes) and produced atrioventricular block to reveal atrial or sinus tachycardia in 15.

A C Rankin; K G Oldroyd; E Chong; A P Rae; S M Cobbe

1989-01-01

110

JACEE long duration balloon flights  

NASA Technical Reports Server (NTRS)

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

1989-01-01

111

Duration of an Elastic Collision  

ERIC Educational Resources Information Center

With a pedagogical goal, this paper deals with a study of the duration of an elastic collision of an inflatable spherical ball on a planar surface suitable for undergraduate studies. First, the force generated by the deformed spherical ball is obtained under assumptions that are discussed. The study of the motion of the spherical ball colliding…

de Izarra, Charles

2012-01-01

112

JACEE long duration balloon flights  

SciTech Connect

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--100{ital A} TeV. Experience 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.; Dake, S.; Derrickson, J.; Fountain, W.; Fuki, M.; Gregory, J.; Hayashi, T.; Holynski, R.; Iwai, J.; Jones, W.V.; Jurak, A.; Lord, J.J.; Miyamura, O.; Oda, H.; Ogata, T.; Parnell, T.A.; Roberts, E.; Strausz, S.; Tabuki, T.; Takahashi, Y.; Tominaga, Y.; Watts, J.W.; Wefel, J.P.; Wilczynska, B.; Wilczynski, H.; Wilkes, R.J.; Wolter, W.; Wosiek, B. (ICR, Tokyo (Japan) Kobe Univ., Kobe (Japan) Osaka University, Osaka (Japan) Matsusho Gakuen Junior College, Matsumoto (Japan) NASA, Washington, DC (USA) University of Alabama at Huntsville, Huntsville, AL (USA) Louisiana State University, Baton Rouge, LA (USA) NASA/Marshall Space Flight Ctr., Huntsville, AL (USA) University of Washington, Seattle, WA (USA) INP, Krakow (Poland)); JACEE Collaboration

1990-01-15

113

Curricular internship Timing and Duration  

E-print Network

1 Art.1 Curricular internship Art.2 Objectives Art.3 Timing and Duration Art.4 Choice of Employer Art.5 Pertinence of the internship Art.6 Internship Search GRADUATE INTERNSHIP GUIDELINES Faculties training or work experience, herein referred to as `internship', is one of the graduation requirements. 2

Krause, Rolf

114

Voice attractiveness: influence of stimulus duration and type.  

PubMed

Voice attractiveness is a relatively new area of research. Some aspects of the methodology used in this domain deserve particular attention. Especially, the duration of voice samples is often neglected as a factor and happens to be manipulated without the perceptual consequences of these manipulations being known. Moreover, the type of voice stimulus varies from a single vowel to complex sentences. The aim of this experiment was to investigate the extent to which stimulus duration (nonmanipulated vs. normalized) and type (vowel vs. word) influence perceived voice attractiveness. Twenty-seven male and female raters made attractiveness judgments of 30 male and female voice samples. Voice samples included a single vowel /a/, a three-vowel series /i a o/, and the French word "bonjour" (i.e., "hello"). These samples were presented in three conditions: nonmanipulated, shortened, and lengthened duration. Duration manipulation was performed using the pitch synchronous overlap and add (PSOLA) algorithm implemented in Praat. Results for the effect of stimulus type showed that word length samples were more attractive to the opposite sex than vowels. Results for the effect of duration showed that the nonmanipulated sound sample duration was not predictive of perceived attractiveness. Duration manipulation, on the other hand, altered perceived attractiveness for the lengthening condition. In particular, there was a linear decrease in attractiveness as a function of modification percentage (especially for the word, as compared with the vowels). Recommendations for voice sample normalization with the PSOLA algorithm are thus to prefer shortening over lengthening and, if not possible, to limit the extent of duration manipulation-for example, by normalizing to the mean sample duration. PMID:23239065

Ferdenzi, C; Patel, S; Mehu-Blantar, I; Khidasheli, M; Sander, D; Delplanque, S

2013-06-01

115

The Case for Durative Actions: A Commentary on PDDL2.1  

NASA Technical Reports Server (NTRS)

The addition of durative actions to PDDL2.1 sparked some controversy. Fox and Long argued that actions should be considered as instantaneous, but can start and stop processes. Ultimately, a limited notion of durative actions was incorporated into the language. I argue that this notion is impoverished, and that the underlying philosophical position of regarding durative actions as being a shorthand for a start action, process, and stop action ignores the realities of modelling and execution for complex systems.

Smith, David E.

2003-01-01

116

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. PMID:20886013

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

2010-01-01

117

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

2010-01-01

118

Intensity-duration-frequency curves  

NASA Astrophysics Data System (ADS)

Intensity-duration-frequency (IDF) curves, or tables, are perhaps the most commonly used method for presentation of the characteristics of extreme rainfall events. This chapter provides an historical overview of developments in modeling and representation of IDF curves. Direction is provided to sources of information for IDF curve estimation, and alternative methods of modeling and representation of IDF relationships are discussed. Finally, this chapter provides an overview of contemporary IDF studies that are currently underway, as well as brief discussions of some emerging technologies that are leading to improvements in IDF curve estimation.

Durrans, S. Rocky

119

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

120

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

121

Effect of Study Design on the Reported Effect of Cardiac Resynchronization Therapy (CRT) on Quantitative Physiological Measures: Stratified Meta?Analysis in Narrow?QRS Heart Failure and Implications for Planning Future Studies  

PubMed Central

Background Biventricular pacing (CRT) shows clear benefits in heart failure with wide QRS, but results in narrow QRS have appeared conflicting. We tested the hypothesis that study design might have influenced findings. Method and Results We identified all reports of CRT?P/D therapy in subjects with narrow QRS reporting effects on continuous physiological variables. Twelve studies (2074 patients) met these criteria. Studies were stratified by presence of bias?resistance steps: the presence of a randomized control arm over a single arm, and blinded outcome measurement. Change in each endpoint was quantified using a standardized effect size (Cohen's d). We conducted separate meta?analyses for each variable in turn, stratified by trial quality. In non?randomized, non?blinded studies, the majority of variables (10 of 12, 83%) showed significant improvement, ranging from a standardized mean effect size of +1.57 (95%CI +0.43 to +2.7) for ejection fraction to +2.87 (+1.78 to +3.95) for NYHA class. In the randomized, non?blinded study, only 3 out of 6 variables (50%) showed improvement. For the randomized blinded studies, 0 out of 9 variables (0%) showed benefit, ranging from ?0.04 (?0.31 to +0.22) for ejection fraction to ?0.1 (?0.73 to +0.53) for 6?minute walk test. Conclusions Differences in degrees of resistance to bias, rather than choice of endpoint, explain the variation between studies of CRT in narrow?QRS heart failure addressing physiological variables. When bias?resistance features are implemented, it becomes clear that these patients do not improve in any tested physiological variable. Guidance from studies without careful planning to resist bias may be far less useful than commonly perceived. PMID:25564370

Jabbour, Richard J.; Shun?Shin, Matthew J.; Finegold, Judith A.; Afzal Sohaib, S. M.; Cook, Christopher; Nijjer, Sukhjinder S.; Whinnett, Zachary I.; Manisty, Charlotte H.; Brugada, Josep; Francis, Darrel P.

2015-01-01

122

Health care delivery system for long duration manned space operations  

NASA Technical Reports Server (NTRS)

Specific requirements for medical support of a long-duration manned facility in a low earth orbit derive from inflight medical experience, projected medical scenarios, mission related spacecraft and environmental hazards, health maintenance, and preventive medicine. A sequential buildup of medical capabilities tailored to increasing mission complexity is proposed. The space station health maintenance facility must provide preventive, diagnostic, and therapeutic medical support as immediate rescue capability may not exist.

Logan, J. S.; Shulman, E. L.; Johnson, P. C.

1983-01-01

123

Extended Duration Orbiter Medical Project  

NASA Technical Reports Server (NTRS)

Biomedical issues have presented a challenge to flight physicians, scientists, and engineers ever since the advent of high-speed, high-altitude airplane flight in the 1940s. In 1958, preparations began for the first manned space flights of Project Mercury. The medical data and flight experience gained through Mercury's six flights and the Gemini, Apollo, and Skylab projects, as well as subsequent space flights, comprised the knowledge base that was used to develop and implement the Extended Duration Orbiter Medical Project (EDOMP). The EDOMP yielded substantial amounts of data in six areas of space biomedical research. In addition, a significant amount of hardware was developed and tested under the EDOMP. This hardware was designed to improve data gathering capabilities and maintain crew physical fitness, while minimizing the overall impact to the microgravity environment. The biomedical findings as well as the hardware development results realized from the EDOMP have been important to the continuing success of extended Space Shuttle flights and have formed the basis for medical studies of crew members living for three to five months aboard the Russian space station, Mir. EDOMP data and hardware are also being used in preparation for the construction and habitation of International Space Station. All data sets were grouped to be non-attributable to individuals, and submitted to NASA s Life Sciences Data Archive.

Sawin, Charles F. (Editor); Taylor, Gerald R. (Editor); Smith, Wanda L. (Editor); Brown, J. Travis (Technical Monitor)

1999-01-01

124

Icing Encounter Duration Sensitivity Study  

NASA Technical Reports Server (NTRS)

This paper describes a study performed to investigate how aerodynamic performance degradation progresses with time throughout an exposure to icing conditions. It is one of the first documented studies of the effects of ice contamination on aerodynamic performance at various points in time throughout an icing encounter. Both a 1.5 and 6 ft chord, two-dimensional, NACA-23012 airfoils were subjected to icing conditions in the NASA Icing Research Tunnel for varying lengths of time. At the end of each run, lift, drag, and pitching moment measurements were made. Measurements with the 1.5 ft chord model showed that maximum lift and pitching moment degraded more rapidly early in the exposure and degraded more slowly as time progressed. Drag for the 1.5 ft chord model degraded more linearly with time, although drag for very short exposure durations was slightly higher than expected. Only drag measurements were made with the 6 ft chord airfoil. Here, drag for the long exposures was higher than expected. Novel comparison of drag measurements versus an icing scaling parameter, accumulation parameter times collection efficiency was used to compare the data from the two different size model. The comparisons provided a means of assessing the level of fidelity needed for accurate icing simulation.

Addy, Harold E., Jr.; Lee, Sam

2011-01-01

125

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

126

A quantal step function in duration discrimination  

Microsoft Academic Search

The difference threshold for duration, for the case of empty time intervals bounded by brief auditory pulses, is an increasing\\u000a function of base duration. For base durations between 100 and 1,480 msec, Weber’s law describes the function quite well and\\u000a a Weber ratio of .05 is obtained. These results in the present paper conform closely to results that have been

Alfred B. Kristofferson

1980-01-01

127

Training for long duration space missions  

NASA Technical Reports Server (NTRS)

The successful completion of an extended duration manned mission to Mars will require renewed research effort in the areas of crew training and skill retention techniques. The current estimate of inflight transit time is about nine months each way, with a six month surface visit, an order of magnitude beyond previous U.S. space missions. Concerns arise when considering the level of skill retention required for highly critical, one time operations such as an emergency procedure or a Mars orbit injection. The factors responsible for the level of complex skill retention are reviewed, optimal ways of refreshing degraded skills are suggested, and a conceptual crew training design for a Mars mission is outlined. Currently proposed crew activities during a Mars mission were reviewed to identify the spectrum of skills which must be retained over a long time period. Skill retention literature was reviewed to identify those factors which must be considered in deciding when and which tasks need retraining. Task, training, and retention interval factors were identified. These factors were then interpreted in light of the current state of spaceflight and adaptive training systems.

Goldberg, Joseph H.

1987-01-01

128

Sleep Duration and Adolescent Obesity  

PubMed Central

OBJECTIVES: Short sleep has been associated with adolescent obesity. Most studies used a cross-sectional design and modeled BMI categories. We sought to determine if sleep duration was associated with BMI distribution changes from age 14 to 18. METHODS: Adolescents were recruited from suburban high schools in Philadelphia when entering ninth grade (n = 1390) and were followed-up every 6 months through 12th grade. Height and weight were self-reported, and BMIs were calculated (kg/m2). Hours of sleep were self-reported. Quantile regression was used to model the 10th, 25th, 50th, 75th, and 90th BMI percentiles as dependent variables; study wave and sleep were the main predictors. RESULTS: BMI increased from age 14 to 18, with the largest increase observed at the 90th BMI percentile. Each additional hour of sleep was associated with decreases in BMI at the 10th (–0.04; 95% confidence interval [CI]: –0.11, 0.03), 25th (–0.12; 95% CI: –0.20, –0.04), 50th (–0.15; 95% CI: –0.24, –0.06), 75th (–0.25; 95% CI: –0.38, –0.12), and 90th (–0.27; 95% CI: -0.45, -0.09) BMI percentiles. The strength of the association was stronger at the upper tail of the BMI distribution. Increasing sleep from 7.5 to 10.0 hours per day at age 18 predicted a reduction in the proportion of adolescents >25 kg/m2 by 4%. CONCLUSIONS: More sleep was associated with nonuniform changes in BMI distribution from age 14 to 18. Increasing sleep among adolescents, especially those in the upper half of the BMI distribution, may help prevent overweight and obesity. PMID:23569090

Rodriguez, Daniel; Schmitz, Kathryn H.; Audrain-McGovern, Janet

2013-01-01

129

Role of echocardiography in differential diagnosis of broad complex tachycardia.  

PubMed Central

It is not always easy to distinguish between supraventricular tachycardia with aberration and ventricular tachycardia by electrocardiographic analysis alone. M mode echocardiography can often help by providing direct or indirect evidence of the relation between atrial and ventricular contraction. Sixteen consecutive patients with spontaneous sustained broad QRS complex tachycardia with heart rates of 120-225 beats/minute were examined. Echocardiographic evidence of 1:1 conduction was seen in three cases and 2:1 atrioventricular conduction in one (all four had supraventricular tachycardia, confirmed by intracardiac electrocardiography in three). Evidence of retrograde block was seen in 12 (all had ventricular tachycardia, with electrophysiological confirmation in 10). Satisfactory views of the mitral valve were obtained in all patients. Patients with ventricular tachycardia had a variable mitral valve opening time (range 42-110%) compared with those who had supraventricular tachycardia (9-15%). Aortic root and left atrial views gave direct evidence of atrial contraction in three cases, and subcostal right atrial wall views were diagnostic in four of five cases. Seven patients with ventricular tachycardia had been wrongly diagnosed elsewhere as having supraventricular tachycardia. This study confirms that echocardiography is a simple and rapid aid to accurate diagnosis in patients with broad QRS complex tachycardia. Images PMID:4015926

Wren, C; Campbell, R W; Hunter, S

1985-01-01

130

Estimating averages from distributions of tone durations.  

PubMed

We examined whether estimating average duration was influenced by the distribution peak location. We presented participants with samples of various tone durations and then presented comparison tone durations. Participants judged whether each comparison duration was longer than the average sample duration. Estimates of the averages were inferred from the psychophysical functions. The durations were sampled from three distributions: one positively skewed, one symmetric, and one negatively skewed. In Experiment 1, every participant was presented with every distribution. Estimates of the averages were unbiased for the symmetric distribution but were biased toward the long tail of each skewed distribution. This would occur if participants combined the sample to be judged with the previous, irrelevant samples, or with the comparison durations. In Experiment 2, each participant was presented with samples from only one of the distributions. Estimates of the averages were still biased toward the long tails of the skewed distributions. This would occur if participants combined the sample to be judged with the comparison durations, which were the same for the three distributions. In Experiment 3, each participant was presented with only one distribution, and each distribution was tested with its own comparison durations, selected as percentiles from the distribution. The estimates were accurate for the smallest population mean (positively skewed distribution) but underestimated the larger means. These results could be explained by subjective shortening of the durations in memory, with a simple equation from scalar timing theory. This equation correctly predicted two results: The estimated averages were a linear function of the stimulus means, and the variances were a linear function of the squared stimulus means. Neither prediction was dependent on the skewness of the stimulus durations. PMID:24264515

Schweickert, Richard; Han, Hye Joo; Yamaguchi, Motonori; Fortin, Claudette

2014-02-01

131

Sleep duration and personality in Croatian twins.  

PubMed

The objective of this study was to examine which genetic and environmental influences contribute to individual differences in sleep duration in a sample of Croatian adolescent/early adult twins, as well as to investigate the relationship between personality and sleep duration. Participants included 339 twin pairs (105 monozygotic and 234 dizygotic) aged between 15 and 22 years. They reported on their average sleep duration and personality. The broad heritability estimate (additive and non-additive genetic influences) for sleep duration was 0.63, while personality estimates ranged between 0.47 and 0.62. Significant negative phenotypic associations with neuroticism and openness were mainly genetically mediated 100 and 80%, respectively. Only 6% of the sleep duration variance was explained by genetic influences shared with neuroticism and openness. In regression analysis, age, gender and five personality traits explained 5% of sleep duration variance, with neuroticism and openness as significant predictors. Comparison of short, moderate and long sleepers showed that participants in the short sleepers group had significantly higher neuroticism scores than groups of moderate and long sleepers, as well as a significantly higher openness score than the group of long sleepers. This indicates that personality traits of neuroticism and openness contribute to the prediction of sleep duration due to overlapping genetic influences that contribute to both these personality traits and sleep duration. However, as phenotypic overlap of personality and sleep duration is relatively weak, heritability of sleep duration is not only related to individual differences in personality traits, so future research needs to examine other phenotypic correlates of sleep duration. PMID:24635510

Butkovic, Ana; Vukasovic, Tena; Bratko, Denis

2014-04-01

132

Repair of Electronics for Long Duration Spaceflight  

NASA Technical Reports Server (NTRS)

To reduce mission risk, long duration spaceflight and exploration activities will require greater degrees of self-sufficiency with regards to repair capability than have ever been employed before in space exploration. The current repair paradigm of replacing Orbital Replacement Units (ORUs) of malfunctioning avionics and electronic hardware will be impractical, since carrying all of the spares that could possibly be needed for a long duration mission would require upmass and volume at unprecedented and unacceptable levels. A strategy of component-level repair for electronics, however, could significantly reduce the mass and volume necessary for spares and enhance mission safety via a generic contingency capability. This approach is already used to varying degrees by the U.S. Navy, where vessels at sea experience some similar constraints such as the need for self sufficiency for moderately long time periods, and restrictions on volume of repair spares and infrastructure. The concept of conducting component-level repairs of electronics in spacecraft requires the development of design guidelines for future avionics (to enable repair), development of diagnostic techniques to allow an astronaut to pinpoint the faulty component aboard a vastly complex vehicle, and development of tools and methodologies for dealing with the physical processes of replacing the component. This physical process includes tasks such as conformal coating removal and replacement, component removal, replacement, and alignment--all in the difficulty of a reduced gravity environment. Further, the gravitational effects on the soldering process must be characterized and accounted for to ensure reliability of the newly repaired components. The Component-Level Electronics-Assembly Repair (CLEAR) project under the NASA Supportability program was established to develop and demonstrate the practicality of this repair approach. CLEAR involves collaborative efforts between NASA s Glenn Research Center, Langley Research Center, Johnson Space Center, the National Center for Space Exploration Research, and the U.S. Navy. The project goals are 1) develop and demonstrate a manually-operated electronics repair capability to be conducted in a spacecraft environment; and 2) develop guidelines for designs of electronics that facilitates component-level repair for future space exploration efforts. This multi-faceted program utilizes a cross-disciplinary approach to examine pre- and post-repair diagnostics, conformal coating removal and replacement, component soldering, and electronics design for supportability. These areas are investigated by a combination of trade studies, ground based testing, reduced gravity aircraft testing, and actual spaceflight testing on the International Space Station (ISS) in multiple experiments. This paper details the efforts of this program, with emphasis on early trade study results, ground-based efforts, and two upcoming ISS experiments.

Pettegrew, Richard D.; Easton, John; Struk, Peter

2007-01-01

133

Duration Sensitivity Depends on Stimulus Familiarity  

ERIC Educational Resources Information Center

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…

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

2009-01-01

134

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 stimuli…

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

2011-01-01

135

Mortality Associated With Sleep Duration and Insomnia  

Microsoft Academic Search

Background: Patients often complain about insuffi- cient sleep or chronic insomnia in the belief that they need 8 hours of sleep. Treatment strategies may be guided by what sleep durations predict optimal survival and whether insomnia might signal mortality risks. Methods: In 1982, the Cancer Prevention Study II of the American Cancer Society asked participants about their sleep duration and

Daniel F. Kripke; Lawrence Garfinkel; Deborah L. Wingard; Melville R. Klauber; Matthew R. Marler

2002-01-01

136

Estimated Duration of Events Annotation Guidelines  

E-print Network

for situations that happen or occur (e.g., killed in the following sample article); we also consider as events is swimming is much longer than the duration of the girl is actually seeing it swim. The dolphin began swimming from the time it was born. The girl might not have been around during the entire duration

Hobbs, Jerry R.

137

Retinotopic adaptation-based visual duration compression  

E-print Network

Retinotopic adaptation-based visual duration compression Cognitive, Perceptual and Brain Sciences of whether adaptation-based duration compression (A. Johnston, D. H. Arnold, & S. Nishida, 2006) takes place temporal frequency. However, using an adaptation schedule that minimizes any effect of adaptation

Johnston, Alan

138

The duration derby: a comparison of duration based strategies in asset liability management  

Microsoft Academic Search

The Macaulay duration matched strategy is a key tool in bond portfolio immunization. It is well known that if term structures are not flat or changes are not parallel, then the Macaulay duration matched portfolio can not guarantee adequate immunization. In the paper the approximate duration is proposed to measure the bond price sensitivity to changes of interest rates of

H. Zheng; L. C. Thomas; D. E. Allen

2002-01-01

139

The Duration Derby: A Comparison of Duration Based Strategies in Asset Liability Management  

Microsoft Academic Search

Macaulay duration matched strategy is a key tool in bond portfolio immunization. It is well known that if term structures are not flat or changes are not parallel, then Macaulay duration matched portfolio can not guarantee adequate immunization. In this paper the approximate duration is proposed to measure the bond price sensitivity to changes of interest rates of nonflat term

Harry Zheng; L. C. Thomas; David E. Allen

2001-01-01

140

The electrocardiogram of European shrews.  

PubMed

A recording method of electrocardiograms in resting animals is described. The electrocardiograms of Crocidura russula, Crocidura leucodon, Crocidura suaveolens, Neomys fodiens and Sorex araneus are similar to those of other small mammals. T-wave directly follows the QRS-complex. The duration of electrocardiograms depends on heart mass and body temperature. Heart rate shows no influence on the duration of electrocardiograms. PMID:2870871

Nagel, A

1986-01-01

141

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

142

Exogenous visual attention prolongs perceived duration  

Microsoft Academic Search

Previous studies have shown that spatial attention prolongs the perceived duration of visual stimuli. Chen and O’Neill (Perception & Psychophysics, 63, 1229–1238, 2001) reported, however, the reversed result and thus challenged the generality of this attention effect. We therefore reinvestigated\\u000a the influence of spatial attention on the perceived duration of visual stimuli in various experimental settings. In five experiments,\\u000a perceived

Tanja Seifried; Rolf Ulrich

2011-01-01

143

Rainfall intensity-duration-frequency formulas.  

USGS Publications Warehouse

A new general rainfall intensity-duration-frequency formula is presented, utilizing a method similar to, but more accurate than one previously developed. The previously developed formula was based on the average depth-duration ratio of about 40% and the mean depth-frequency ratio of 1.48. It is shown that this formula is only a particular form of the writer's more general formulation. -from Author

Chen, C.-L.

1983-01-01

144

Ambiguities in sound-duration selectivity by neurons in the inferior colliculus of the bat Molossus molossus from Cuba.  

PubMed

This study examines duration selectivity in auditory neurons of the inferior colliculus of the bat Molossus molossus (Molossidae, Chiroptera) from Cuba. Three main types of duration selectivity, short-, band-, and long-pass, as previously described in other species, are present in M. molossus. The range of best durations in the inferior colliculus of this species approximates the durations of their echolocation calls, suggesting that, as has been shown in other species of bats and frogs, the filter mechanism that produces duration tuning is selective for species-specific sounds relevant to behavior. Duration coding in M. molossus is not unambiguous because approximately 30% of the short- and band-pass neurons respond best to two different stimulus durations. This bimodal duration selectivity could be explained by time delayed excitatory inputs that coincide with an inhibitory rebound. In addition, the effect of stimulus intensity on duration selectivity was tested. For most of the neurons (78%), duration selectivity was affected by absolute sound pressure level and/or small changes of sound pressure. In this respect, the processing of stimulus duration by collicular neurons seems to be more complex in M. molossus than in other species studied so far. PMID:14711975

Mora, Emanuel C; Kössl, Manfred

2004-05-01

145

Differences in duration discrimination of filled and empty auditory intervals as a function of base duration  

Microsoft Academic Search

In the present experiments, participants were presented with two time intervals that were marked by auditory signals, and\\u000a their task was to decide which of the two was longer in duration. In Experiment 1, the base durations were 50 and 1,000msec,\\u000a whereas in Experiment 2, seven different base durations ranging from 50 to 1,000 msec were employed. It was found

Thomas H. Rammsayer

2010-01-01

146

Effect of Bolus Volume and Consistency on Swallowing Events Duration in Healthy Subjects  

PubMed Central

Background/Aims Swallowing is a complex function with the control of the swallowing center being located in the brain stem. Our aim in this investigation was to evaluate, in healthy volunteers, the oral and pharyngeal transit of 2 bolus volumes and 2 consistencies, and the influence of these boluses on the proportion of pharyngeal clearance duration/hyoid movement duration. Methods Videofluoroscopic evaluation of swallows was performed in 30 healthy volunteers, aged 29–77 years (mean 58 years). The subjects swallowed in duplicate of 5 mL and 10 mL of thick liquid barium and honey thick barium. We measured the duration of oral transit, pharyngeal transit, pharyngeal clearance, upper esophageal sphincter opening, hyoid movement, oropharyngeal transit, and the relation pharyngeal clearance duration/hyoid movement duration. Results A 10 mL bolus volume caused a longer UES opening duration than a 5 mL bolus volume, for both consistencies. The pharyngeal transit was longer for honey thick bolus consistency than for thick liquid, with both the volumes of 5 mL and 10 mL. For pharyngeal clearance, the difference was significant only with the 10 mL bolus volume. There was no difference associated with bolus volume or consistency in the relation between pharyngeal clearance duration and hyoid movement duration. Conclusions Increase in the swallowed bolus volume causes a longer UES opening duration and an increase in bolus consistency from thick liquid to honey thick causes a longer pharyngeal transit duration. The proportion between pharyngeal clearance and hyoid movement does not change with bolus volume or bolus consistency. PMID:25540944

Nascimento, Weslania V; Cassiani, Rachel A; Santos, Carla M; Dantas, Roberto O

2015-01-01

147

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

148

Sleep duration, cardiovascular disease, and proinflammatory biomarkers  

PubMed Central

Habitual sleep duration has been associated with cardiometabolic disease, via several mechanistic pathways, but few have been thoroughly explored. One hypothesis is that short and/or long sleep duration is associated with a proinflammatory state, which could increase risk for cardiovascular and metabolic diseases. This hypothesis has been largely explored in the context of experimental sleep deprivation studies which have attempted to demonstrate changes in proinflammatory markers following acute sleep loss in the laboratory. Despite the controlled environment available in these studies, samples tend to lack generalization to the population at large and acute sleep deprivation may not be a perfect analog for short sleep. To address these limitations, population based studies have explored associations between proinflammatory markers and habitual sleep duration. This review summarizes what is known from experimental and cross-sectional studies about the association between sleep duration, cardiovascular disease, and proinflammatory biomarkers. First, the association between sleep duration with both morbidity and mortality, with a focus on cardiovascular disease, is reviewed. Then, a brief review of the potential role of proinflammatory markers in cardiovascular disease is presented. The majority of this review details specific findings related to specific molecules, including tumor necrosis factor-?, interleukins-1, -6, and -17, C-reactive protein, coagulation molecules, cellular adhesion molecules, and visfatin. Finally, a discussion of the limitations of current studies and future directions is provided. PMID:23901303

Grandner, Michael A; Sands-Lincoln, Megan R; Pak, Victoria M; Garland, Sheila N

2013-01-01

149

Duration of nucleation process in supercooled halide melts  

NASA Astrophysics Data System (ADS)

We present a model allowing to estimate the so-called time lag of nucleating halide melts using electrical conductivity measurements. Due to the complex-forming nature of molten halide salts we suppose two basic types of charge carriers in the melt: complexes (playing the role of monomers—building units) and clusters of a newly forming solid phase. Within context of the nonstationary nucleation theory we determined a formula expressing the time dependency of electrical conductivity of such a system and compared this result with the experimental data obtained for the melts of PbBr2, PbCl2, and KPb2Cl5. In terms of this formula the time lag of nucleation may be estimated. This important quantity characterizing the moment from which the nucleated clusters only grow to the macroscopic sizes has been found to be approximately 75% of the total duration of the nucleation process itself.

Demo, P.; Sveshnikov, A. M.; Nitsch, K.; Rodová, M.; Kožíšek, Z.

2005-08-01

150

Slow Wave Sleep and Long Duration Spaceflight  

NASA Technical Reports Server (NTRS)

While ground research has clearly shown that preserving adequate quantities of sleep is essential for optimal health and performance, changes in the progression, order and /or duration of specific stages of sleep is also associated with deleterious outcomes. As seen in Figure 1, in healthy individuals, REM and Non-REM sleep alternate cyclically, with stages of Non-REM sleep structured chronologically. In the early parts of the night, for instance, Non-REM stages 3 and 4 (Slow Wave Sleep, or SWS) last longer while REM sleep spans shorter; as night progresses, the length of SWS is reduced as REM sleep lengthens. This process allows for SWS to establish precedence , with increases in SWS seen when recovering from sleep deprivation. SWS is indeed regarded as the most restorative portion of sleep. During SWS, physiological activities such as hormone secretion, muscle recovery, and immune responses are underway, while neurological processes required for long term learning and memory consolidation, also occur. The structure and duration of specific sleep stages may vary independent of total sleep duration, and changes in the structure and duration have been shown to be associated with deleterious outcomes. Individuals with narcolepsy enter sleep through REM as opposed to stage 1 of NREM. Disrupting slow wave sleep for several consecutive nights without reducing total sleep duration or sleep efficiency is associated with decreased pain threshold, increased discomfort, fatigue, and the inflammatory flare response in skin. Depression has been shown to be associated with a reduction of slow wave sleep and increased REM sleep. Given research that shows deleterious outcomes are associated with changes in sleep structure, it is essential to characterize and mitigate not only total sleep duration, but also changes in sleep stages.

Whitmire, Alexandra; Orr, Martin; Arias, Diana; Rueger, Melanie; Johnston, Smith; Leveton, Lauren

2012-01-01

151

Contextual Effects on the Perception of Duration  

PubMed Central

In the experiments reported here, listeners categorized and discriminated speech and non-speech analogue stimuli in which the durations of a vowel and a following consonant or their analogues were varied orthogonally. The listeners’ native languages differed in how these durations covary in speakers’ productions of such sequences. Because auditorist and autonomous models of speech perception hypothesize that the auditory qualities evoked by both kinds of stimuli determine their initial perceptual evaluation, they both predict that listeners from all the languages will respond similarly to non-speech analogues as they do to speech in both tasks. Because neither direct realist nor interactive models hypothesize such a processing stage, they predict instead that in the way in which vowel and consonant duration covary in the listeners’ native languages will determine how they categorize and discriminate the speech stimuli, and that all listeners will categorize and discriminate the non-speech differently from the speech stimuli. Listeners’ categorization of the speech stimuli did differ as a function of how these durations covary in their native languages, but all listeners discriminated the speech stimuli in the same way, and they all categorized and discriminated the non-speech stimuli in the same way, too. These similarities could arise from listeners adding the durations of the vowel and consonant intervals (or their analogues) in these tasks with these stimuli; they do so when linguistic experience does not influence them to perceive these durations otherwise. These results support an autonomous rather than interactive model in which listeners either add or apply their linguistic experience at a post-perceptual stage of processing. They do not however support an auditorist over a direct realist model because they provide no evidence that the signal’s acoustic properties are transformed during the hypothesized prior perceptual stage. PMID:20161112

Kingston, John; Kawahara, Shigeto; Chambless, Della; Mash, Daniel; Brenner-Alsop, Eve

2009-01-01

152

Slow Wave Sleep and Long Duration Spaceflight  

NASA Technical Reports Server (NTRS)

To review the literature on slow wave sleep (SWS) in long duration space flight, and place this within the context of the broader literature on SWS particularly with respect to analogous environments such as the Antarctic. Explore how SWS could be measured within the International Space Station (ISS) context with the aim to utilize the ISS as an analog for future extra-orbital long duration missions. Discuss the potential use of emergent minimally intrusive wireless technologies like ZEO for integrated prelaunch, flight, and return to Earth analysis and optimization of SWS (and general quality of sleep).

Orr, M.; Whitmire, A.; Arias, D.; Leveton, L.

2011-01-01

153

Monitoring Seizure Duration During Electroconvulsive Therapy.  

PubMed

Three alternative monitoring methods for assessing the duration of seizures during electroconvulsive therapy were studied. The mean integrated amplitude of the electroencephalogram, facial muscle electromyogram, and "cuff method" were compared with the reference single-channel unprocessed electroencephalogram in 78 sessions with 17 patients. The measures of seizure duration differed significantly (p < 0.001). The mean integrated electroence phalographic amplitude differences were small and an artifact of the sampling procedure. Larger, but clinically unimportant, discrepancies were obtained with the facial electromyogram amplitude. In contrast, there were marked differences between the electroencephalogram and the "cuff method," which suggest that the latter technique may be of limited usefulness. PMID:11940966

Couture, Lawrence J.; Lucas, Linda F.; Lippmann, Steven B.; Shaltout, Taher; Paloheimo, Markku P. J.; Edmonds, Harvey L.

1988-01-01

154

The Burst Time Duration in Micropillar Deformation  

NASA Astrophysics Data System (ADS)

Plastic flow of single crystal micropillars proceeds through a sequence of intermittent burst slips. The burst time durations are investigated based on an extended theoretical model which incorporates the observed power-law distribution of burst sizes in compression experiments of micropillars. The results show that the burst time durations exhibit a powerlaw behavior with an exponential cutoff, suggesting the same scaling behaviors as the burst sizes. In addition, the predicted scaling exponent is found to converge to a value of ~1.6. It is demonstrated that our results are consistent with the experimental data.

Zhang, Xu; Shang, Fu-Lin

2014-02-01

155

Legal Minimum Wages and Employment Duration  

Microsoft Academic Search

We estimate the effect of minimum wages on employment duration using event history data from the 1988–1994 rounds of the National Longitudinal Survey of Youth. Existing literature takes two alternative tracks: Some studies predict reduced turnover due to rents created by minimum wages, others focus on the expected increase in turnover due to reduced job amenities and imperfect information. We

Adam J. Grossberg; Paul Sicilian

2004-01-01

156

The Duration of Deliberation Scott D. Anderson  

E-print Network

National Park. Because the re ghters plan how to put out the re while the re is burning, there is time and the resulting quality. Clearly, quality can be di cult to de ne and highly dependent on the domain. Duration and puts unwanted noise in data from large experiments in which trials are run on many di erent machines

Southern California, University of

157

Sleep Duration and Breast Cancer Phenotype  

PubMed Central

Emerging evidence suggests that short sleep is associated with an increased risk of cancer; however, little has been done to study the role of sleep on tumor characteristics. In this study, we evaluated the relationship between sleep duration and tumor phenotype in 972 breast cancer patients. Sleep duration was inversely associated with tumor grade (univariate P = 0.032), particularly in postmenopausal women (univariate P = 0.018). This association did not reach statistical significance after adjustments for age, race, body mass index, hormone replacement therapy use, alcohol consumption, smoking, and physical activity in the entire study sample (P = 0.052), but it remained statistically significant (P = 0.049) among post-menopausal patients. We did not observe a statistically significant association between sleep duration and stage at diagnosis, ER, or HER2 receptor status. These results present a modest association between short duration of sleep and higher grade breast cancer in post-menopausal women. Further work needs to be done to validate these findings. PMID:24319459

Khawaja, Ali; Rao, Santosh; Li, Li; Thompson, Cheryl L.

2013-01-01

158

The Remembering of Auditory Event Durations  

Microsoft Academic Search

Three experiments examined the incidental remembering of event durations. In each study, Ss engaged in an initial learning phase in which they performed a set of perceptual ratings on events for a varying number of trials. These events consisted of tonal sequences or ecological sounds that varied in their internal structure and ending. Ss were then given a surprise memory

Marilyn G. Boltz

1992-01-01

159

Perception of duration in the parvocellular system  

PubMed Central

Both theoretical and experimental evidence suggests that duration perception is mediated preferentially by the color-blind but high temporally sensitive luminance pathway. In this experiment we tested whether color modulated stimuli and high spatial frequency luminance modulated stimuli, which are known to be relayed mostly by the slow parvocellular system, are able to elicit reliable sense of duration. We show that ramped color modulated stimuli seem to last less than luminance modulated stimuli matched for visibility. The effect is large, about 200 ms and is constant at all durations tested (range 500–1100 ms). However, high spatial frequency luminance stimuli obtain duration matches similar to those of low spatial frequency luminance modulated stimuli. The results at various levels of contrast and temporal smoothing indicate that equiluminant stimuli have higher contrast thresholds to activate the mechanisms which time visual stimuli. Overall the results imply that both the magnocellular and the parvocellular systems access reliably the timing mechanisms with a difference only in the way these are engaged. PMID:22470323

Cicchini, Guido M.

2012-01-01

160

The ATIC long duration balloon project  

Microsoft Academic Search

Long Duration Balloon (LDB) scientific experiments, launched to circumnavigate the south pole over Antarctica, have particular advantages compared to Shuttle or other Low Earth Orbit (LEO) missions in terms of cost, weight, scientific “duty factor” and work force development. The Advanced Thin Ionization Calorimeter (ATIC) cosmic-ray astrophysics experiment is a good example of a university-based project that takes full advantage

T. G. Guzik; J. H. Adams; H. S. Ahn; G. Bashindzhagyan; J. Chang; M. Christl; A. R. Fazely; O. Ganel; D. Granger; R. Gunasingha; Y. J. Han; J. B. Isbert; H. J. Kim; K. C. Kim; S. K. Kim; E. Kouznetsov; M. Panasyuk; A. Panov; B. Price; G. Samsonov; W. K. H. Schmidt; E. S. Seo; R. Sina; N. Sokolskaya; M. Stewart; A. Voronin; J. Z. Wang; J. P. Wefel; J. Wu; V. Zatsepin

2004-01-01

161

Alternating cycle durations in dwarf novae  

Microsoft Academic Search

The cycle durationC in some dwarf novae underwent abrupt significant changes, as was found by using our own photometric data and the published moments of maxima. For the analysis, the DMRT method (Dumontet al., 1978) as well as least-squares (LS) routine were used. The DMRT method is more appropriate for a search for ‘mean period’, if the cycle numeration is

I. L. Andronov; L. I. Shakun

1990-01-01

162

Short-Duration Simulations from Measurements.  

SciTech Connect

A method is presented that ascribes proper statistical variability to simulations that are derived from longer-duration measurements. This method is applicable to simulations of either real-value or integer-value data. An example is presented that demonstrates the applicability of this technique to the synthesis of gamma-ray spectra.

Mitchell, Dean J.; Enghauser, Michael

2014-08-01

163

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

164

How risks affect a project duration  

Microsoft Academic Search

In a fast-changing world, industry and especially soft- ware industry faces the challenge of more and more de- manding clients in terms of quality, delays, etc.. One mean to achieve this goal is to use risk management. In our research, we focused on how risks affect the du- ration of a project and how we can foreseen this duration at

Emmanuel Chauveau

165

Duration of storage of cyropreserved human embryos  

Microsoft Academic Search

Summary The incidence of cell injury, embryo survival, and implantation following cryopreservation of zygotes and two- to five-cell embryos was studied in 100 patients in order to evaluate the effect of duration of storage. The incidence of individual cell survival was 58% regardless of the length of time kept in liquid nitrogen or the stage of the embryo at freezing.

J. Cohen; K. L. Inge; S. R. Wiker; G. Wright; C. B. Fehilly; T. G. Turner

1988-01-01

166

16 CFR 613.1 - Duration of active duty alerts.  

Code of Federal Regulations, 2012 CFR

...2012-01-01 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...

2012-01-01

167

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

168

16 CFR 613.1 - Duration of active duty alerts.  

Code of Federal Regulations, 2011 CFR

...2011-01-01 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...

2011-01-01

169

Sound duration as a perceptual cue influencing vocal behavior of male bullfrogs  

Microsoft Academic Search

Female frogs of several species use the temporal cue of sound duration to aid in mate choice. Little is known, however, about the sensitivity of male frogs to this cue. Male bullfrogs emit a complex advertisement call to attract females for mating, and to announce territory occupation to other males. In two experiments, the sensitivity of vocalizing male bullfrogs to

Andrea M. Simmons

2002-01-01

170

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

171

Great expectations: Past wages and unemployment durations?  

PubMed Central

Decomposing wages into worker and firm wage components, we find that firm-fixed components are sizeable parts of workers' wages. If workers can only imperfectly observe the extent of firm-fixed components in their wages, they might be misled about the overall wage distribution. Such misperceptions may lead to unjustified high reservation wages, resulting in overly long unemployment durations. We examine the influence of previous wages on unemployment durations for workers after exogenous lay-offs and, using Austrian administrative data, we find that younger workers are, in fact, unemployed longer if they profited from high firm-fixed components in the past. We interpret our findings as evidence for overconfidence generated by imperfectly observed productivity. PMID:22211003

Böheim, Renè; Horvath, Gerard Thomas; Winter-Ebmer, Rudolf

2011-01-01

172

Extended duration Orbiter life support definition  

NASA Technical Reports Server (NTRS)

Extending the baseline seven-day Orbiter mission to 30 days or longer and operating with a solar power module as the primary source for electrical power requires changes to the existing environmental control and life support (ECLS) system. The existing ECLS system imposes penalties on longer missions which limit the Orbiter capabilities and changes are required to enhance overall mission objectives. Some of these penalties are: large quantities of expendables, the need to dump or store large quantities of waste material, the need to schedule fuel cell operation, and a high landing weight penalty. This paper presents the study ground rules and examines the limitations of the present ECLS system against Extended Duration Orbiter mission requirements. Alternate methods of accomplishing ECLS functions for the Extended Duration Orbiter are discussed. The overall impact of integrating these options into the Orbiter are evaluated and significant Orbiter weight and volume savings with the recommended approaches are described.

Kleiner, G. N.; Thompson, C. D.

1978-01-01

173

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

174

Sleep Duration and Circulating Adipokine Levels  

PubMed Central

Introduction: Short sleep duration is associated with systemic inflammation and diabetes; however the mechanisms by which reduced sleep leads to these complications are unclear. One possibility is sleep may impact secretion of adipocyte derived hormones that regulate inflammation and insulin resistance. In this study we assessed the association between sleep duration and 3 adipokine levels. Methods: A total of 561 adults from the Cleveland Family Study underwent standardized laboratory polysomnography followed by a morning fasting blood draw assayed for leptin, visfatin, and retinol binding protein-4 (RBP4) levels. Results: The cohort had an age of 44.5 (16.1) years and total sleep time (TST) of 6.2 (1.3) hours (mean [SD]). Each hour reduction in TST was associated with a 10% increase in leptin (P = 0.01) and a 14% increase in visfatin levels (P = 0.03) in analyses adjusted for age, gender, and race. After additional adjustment for obesity, sleep apnea severity, hypertension, and diabetes, each hour reduction in TST was associated with a 6% increase in leptin (P = 0.01) and a 14% increase in visfatin levels (P = 0.02). Leptin increased by 15% (P = 0.01) and visfatin increased by 31% (P = 0.05) for every 1-h decrease in REM sleep. In contrast, no association between sleep duration and RBP4 was found. Conclusions: Reduced sleep and reduced REM sleep are associated with elevations in leptin and visfatin, 2 adipokines associated with inflammation and insulin resistance. Further investigation of the effect of sleep on adipose tissue function should be pursued. Citation: Hayes AL; Xu F; Babineau D; Patel SR. Sleep duration and circulating adipokine levels. SLEEP 2011;34(2):147–152. PMID:21286230

Hayes, Amanda L.; Xu, Fang; Babineau, Denise; Patel, Sanjay R.

2011-01-01

175

Duration of action of depot-corticosteroids  

Microsoft Academic Search

Thirteen patients, eleven of whom had asthma, were treated with ordinary therapeutic dosages of Celeston Chronodose (a mixture of disodium phosphate and of acetate of betamethasone) or Depo-Medrol (6-methylprednisolone acetate). Duration of the effect of one single intramuscular injection lasted from 1–6 days, if judged by clinical improvement and by suppression of plasma 11-OHCS and by the blood eosinophil count.

Harald Frey; Nils Norman

1970-01-01

176

Evaluation of Long Duration Flight on Venus  

NASA Technical Reports Server (NTRS)

An analysis was performed to evaluate the potential of utilizing either an airship or aircraft as a flight platform for long duration flight within the atmosphere of Venus. In order to achieve long-duration flight, the power system for the vehicle had to be capable of operating for extended periods of time. To accomplish these, two types of power systems were considered, a solar energy-based power system utilizing a photovoltaic array as the main power source and a radioisotope heat source power system utilizing a Stirling engine as the heat conversion device. Both types of vehicles and power systems were analyzed to determine their flight altitude range. This analysis was performed for a station-keeping mission where the vehicle had to maintain a flight over a location on the ground. This requires the vehicle to be capable of flying faster than the wind speed at a particular altitude. An analysis was also performed to evaluate the altitude range and maximum duration for a vehicle that was not required to maintain station over a specified location. The results of the analysis show that each type of flight vehicle and power system was capable of flight within certain portions of Venus s atmosphere. The aircraft, both solar and radioisotope power proved to be the most versatile and provided the greatest range of coverage both for station-keeping and non-station-keeping missions.

Landis, Geoffrey A.; Colozza, Anthony J.

2006-01-01

177

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

178

Intensity-duration-frequency curves from scaling representations of rainfall  

NASA Astrophysics Data System (ADS)

We develop methods to estimate the intensity-duration-frequency (IDF) curves for three rainfall models with local multifractal behavior and varying complexity. The models use the classical notion of exterior and interior process, respectively, for the variation of rainfall intensity at (approximately) storm and substorm scales. The exterior process is nonscaling and differs in the three models, whereas the interior process is stationary multifractal in all cases. The model-based IDF curves are robust, against outliers, and can be obtained from only very few years of rainfall data. In an application to a 24-year rainfall record from Florence, Italy, the models closely reproduce the empirical IDF curves and make similar extrapolations for return periods longer than the historical record.

Langousis, Andreas; Veneziano, Daniele

2007-02-01

179

Antenatal breastfeeding education for increasing breastfeeding duration  

PubMed Central

Background Breastfeeding (BF) is well recognised as the best food for infants. The impact of antenatal BF education on the duration of BF has not been evaluated. Objectives To evaluate the effectiveness of antenatal BF education for increasing BF initiation and duration. Search methods We searched the Cochrane Pregnancy and Childbirth Group’s Trials Register (21 April 2010), CENTRAL (The Cochrane Library 2010, Issue 2), MEDLINE (1966 to April 2010) and SCOPUS (January 1985 to April 2010). We contacted experts and searched reference lists of retrieved articles. We updated the search of the Pregnancy and Childbirth Group’s Trials Register on 28 September 2011 and added the results to the awaiting classification section of the review. Selection criteria All identified published, unpublished and ongoing randomised controlled trials (RCTs) assessing the effect of formal antenatal BF education or comparing two different methods of formal antenatal BF education, on duration of BF. We excluded RCTs that also included intrapartum or postpartum BF education. Data collection and analysis We assessed all potential studies identified as a result of the search strategy. Two review authors extracted data from each included study using the agreed form and assessed risk of bias. We resolved discrepancies through discussion. Main results We included 17 studies with 7131 women in the review and 14 studies involving 6932 women contributed data to the analyses. We did not do any meta-analysis because there was only one study for each comparison. Five studies compared a single method of BF education with routine care. Peer counselling significantly increased BF initiation. Three studies compared one form of BF education versus another. No intervention was significantly more effective than another intervention in increasing initiation or duration of BF. Seven studies compared multiple methods versus a single method of BF education. Combined BF educational interventions were not significantly better than a single intervention in initiating or increasing BF duration. However, in one trial a combined BF education significantly reduced nipple pain and trauma. One study compared different combinations of interventions. There was a marginally significant increase in exclusive BF at six months in women receiving a booklet plus video plus lactation consultation (LC) compared with the booklet plus video only. Two studies compared multiple methods of BF education versus routine care. The combination of BF booklet plus video plus LC was significantly better than routine care for exclusive BF at three months. Authors’ conclusions Because there were significant methodological limitations and the observed effect sizes were small, it is not appropriate to recommend any antenatal BF education. There is an urgent need to conduct RCTs study with adequate power to evaluate the effectiveness of antenatal BF education. PMID:22071830

Lumbiganon, Pisake; Martis, Ruth; Laopaiboon, Malinee; Festin, Mario R; Ho, Jacqueline J; Hakimi, Mohammad

2014-01-01

180

Space Complexity Algorithms & Complexity  

E-print Network

Space Complexity Algorithms & Complexity Space Complexity Nicolas Stroppa Patrik Lambert - plambert@computing.dcu.ie CA313@Dublin City University. 2008-2009. December 4, 2008 #12;Space Complexity Hierarchy of problems #12;Space Complexity NP-intermediate Languages If P = NP, then are there languages which neither in P

Way, Andy

181

Association between Total Sleep Duration and Suicidal Ideation among the Korean General Adult Population  

PubMed Central

Study Objectives: Examine the association between sleep duration and suicidal ideation in Korean adults. Design: Cross-sectional survey. Setting: Data obtained by the Korea National Health and Nutrition Examination Survey IV (2007-2009) using a rolling sampling design involving a complex, stratified, multistage, and probability-cluster survey of civilian non-institutionalized Korean residents. Participants: A total of 15,236 subjects (6,638 males and 8,598 females) ? 19 years old. Measurements and Results: The weighted prevalence of self-reported short sleep duration (? 5 h/day) was 11.7% in males and 15% in females, and of long sleep duration (? 9 h/day) was 6.7% in males and 8.9% in females. A U-shaped relationship existed, with both short and long sleep durations associated with a higher suicidal ideation risk. Multiple logistic regression analysis was used to analyze the relationship between sleep duration and suicidal ideation, adjusting for sociodemographic factors, health behavior, and health status. After controlling for covariates, people with short sleep were 38.1% more likely to have suicidal ideation (OR = 1.381, 95% CI 1.156-1.650) than people with sleep duration of 7 h/day. Suicidal ideation was 1.196 times higher (95% CI: 0.950-1.507) in long-sleeping people than people sleeping 7 h/day, although statistically not significant. Inclusion of depressive mood (a potential confounder) in multiple logistic regression models attenuated but did not eliminate the sleep duration/suicidal ideation association. Limitations: Sleep duration and suicidal ideation were assessed only by self-report. Conclusions: The sleep duration/suicidal ideation relationship is U-shaped in the Korean adult population. Self-reported habitual sleep duration may be a useful behavioral indicator for both individual and societal suicidal ideation risk. Citation: Kim JH; Park EC; Cho WH; Park JY; Choi WJ; Chang HS. Association between total sleep duration and suicidal ideation among the Korean general adult population. SLEEP 2013;36(10):1563-1572. PMID:24082316

Kim, Jae-Hyun; Park, Eun-Cheol; Cho, Woo-Hyun; Park, Jong-Yeon; Choi, Won-Jung; Chang, Hoo-Sun

2013-01-01

182

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

PubMed Central

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 (<5 h) short (5–6 h) and long (9+ h) sleep durations are associated with intake of a number of dietary nutrient variables. Overall, energy intake varied across very short (2036 kcal), short (2201 kcal), and long (1926 kcal) sleep duration, relative to normal (2151 kcal) 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 (<5 h) 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 (<5 h) sleep RR = 0.950, p <0.05), total carbohydrate (very short (<5 h) 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.

2013-01-01

183

Value and limitations of adenosine in the diagnosis and treatment of narrow and broad complex tachycardias.  

PubMed

The diagnostic and therapeutic potential of intravenous adenosine was studied in 64 patients during 92 episodes of regular sustained tachycardia. In 40 patients who had narrow complex tachycardias (QRS less than 0.12 s) adenosine (2.5-25 mg) restored sinus rhythm in 25 with junctional tachycardias (46 of 48 episodes) and produced atrioventricular block to reveal atrial or sinus tachycardia in 15. In 24 patients with broad complex tachycardias (QRS greater than or equal to 0.12 s) adenosine terminated the tachycardias in six patients and revealed atrial or sinus arrhythmias in four. The tachycardias persisted in 14 patients despite doses up to 20 mg, but adenosine allowed the diagnosis of ventricular tachycardia with retrograde atrial activation in two patients by producing transient ventriculoatrial dissociation. Diagnosis based on adenosine induced atrioventricular nodal block was correct in all patients with narrow complex tachycardias and in 92% of those with broad complex tachycardias, compared with correct electrocardiographic diagnoses in 90% and 75% respectively. Adenosine gave diagnostic information additional to the electrocardiogram in 25%. The response to adenosine in broad complex tachycardias identified those of supraventricular origin with 90% sensitivity, 93% specificity, and 92% predictive accuracy. Adenosine restored sinus rhythm in all patients with junctional reentrant tachycardias, but in 10 (35%) the arrhythmias recurred within two minutes. Symptomatic side effects (dyspnoea, chest pain, flushing, headache) were reported by 40 (63%) patients and, although transient, were severe in 23 (36%). There were ventricular pauses of over 2 s in 16% of patients, the longest pause being 6.1 s. Adenosine is of value in the diagnosis and treatment of narrow and broad complex tachycardias, but its use is limited by symptomatic side effects, a tenfold range in minimal effective dosage, occasional action at sites other than the atrioventricular node, and early recurrence or arrhythmia. PMID:2789911

Rankin, A C; Oldroyd, K G; Chong, E; Rae, A P; Cobbe, S M

1989-09-01

184

Differences in duration discrimination of filled and empty auditory intervals as a function of base duration.  

PubMed

In the present experiments, participants were presented with two time intervals that were marked by auditory signals, and their task was to decide which of the two was longer in duration. In Experiment 1, the base durations were 50 and 1,000 msec, whereas in Experiment 2, seven different base durations ranging from 50 to 1,000 msec were employed. It was found that filled intervals (continuous tones) were discriminated more accurately than empty intervals (with onset and offset marked by clicks) at the 50-msec base duration, whereas no performance differences could be shown for longer ones. The findings are consistent with the notion of a unitary timing mechanism that governs the timing of both filled and empty auditory intervals, independent of base durations. A likely conceptual framework that could explain better performance with filled as compared with empty intervals represents an information-processing model of interval timing that evolved from scalar timing theory. According to this account, a performance decrement observed with empty intervals may be due to a misassignment of pulses generated by an internal pacemaker. PMID:20675803

Rammsayer, Thomas H

2010-08-01

185

25 CFR 211.27 - Duration of leases.  

Code of Federal Regulations, 2013 CFR

...Duration of leases. 211.27 Section 211.27 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR ENERGY AND MINERALS LEASING OF TRIBAL LANDS FOR MINERAL DEVELOPMENT How To Acquire Leases § 211.27 Duration of leases....

2013-04-01

186

25 CFR 211.27 - Duration of leases.  

Code of Federal Regulations, 2011 CFR

...Duration of leases. 211.27 Section 211.27 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR ENERGY AND MINERALS LEASING OF TRIBAL LANDS FOR MINERAL DEVELOPMENT How To Acquire Leases § 211.27 Duration of leases....

2011-04-01

187

25 CFR 211.27 - Duration of leases.  

Code of Federal Regulations, 2014 CFR

...Duration of leases. 211.27 Section 211.27 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR ENERGY AND MINERALS LEASING OF TRIBAL LANDS FOR MINERAL DEVELOPMENT How To Acquire Leases § 211.27 Duration of leases....

2014-04-01

188

25 CFR 212.27 - Duration of leases.  

Code of Federal Regulations, 2011 CFR

...Duration of leases. 212.27 Section 212.27 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR ENERGY AND MINERALS LEASING OF ALLOTTED LANDS FOR MINERAL DEVELOPMENT How To Acquire Leases § 212.27 Duration of leases....

2011-04-01

189

25 CFR 212.27 - Duration of leases.  

Code of Federal Regulations, 2012 CFR

...Duration of leases. 212.27 Section 212.27 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR ENERGY AND MINERALS LEASING OF ALLOTTED LANDS FOR MINERAL DEVELOPMENT How To Acquire Leases § 212.27 Duration of leases....

2012-04-01

190

25 CFR 212.27 - Duration of leases.  

Code of Federal Regulations, 2013 CFR

...Duration of leases. 212.27 Section 212.27 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR ENERGY AND MINERALS LEASING OF ALLOTTED LANDS FOR MINERAL DEVELOPMENT How To Acquire Leases § 212.27 Duration of leases....

2013-04-01

191

25 CFR 212.27 - Duration of leases.  

Code of Federal Regulations, 2010 CFR

...Duration of leases. 212.27 Section 212.27 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR ENERGY AND MINERALS LEASING OF ALLOTTED LANDS FOR MINERAL DEVELOPMENT How To Acquire Leases § 212.27 Duration of leases....

2010-04-01

192

25 CFR 212.27 - Duration of leases.  

Code of Federal Regulations, 2014 CFR

...Duration of leases. 212.27 Section 212.27 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR ENERGY AND MINERALS LEASING OF ALLOTTED LANDS FOR MINERAL DEVELOPMENT How To Acquire Leases § 212.27 Duration of leases....

2014-04-01

193

25 CFR 211.27 - Duration of leases.  

Code of Federal Regulations, 2012 CFR

...Duration of leases. 211.27 Section 211.27 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR ENERGY AND MINERALS LEASING OF TRIBAL LANDS FOR MINERAL DEVELOPMENT How To Acquire Leases § 211.27 Duration of leases....

2012-04-01

194

47 CFR 2.1509 - Environmental and duration tests.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 false Environmental and duration tests. 2.1509 Section 2.1509 Telecommunication...EPIRBs) Environmental and Operational Test Procedures § 2.1509 Environmental and duration tests. The environmental and operational...

2010-10-01

195

7 CFR 1430.211 - Duration of contracts.  

Code of Federal Regulations, 2010 CFR

... 2010-01-01 false Duration of contracts. 1430.211 Section 1430.211 Agriculture Regulations of the Department...DAIRY PRODUCTS Milk Income Loss Contract Program § 1430.211 Duration of contracts. (a) Except as...

2010-01-01

196

24 CFR 203.267 - Duration of periodic MIP.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 2010-04-01 false Duration of periodic MIP. 203.267 Section 203.267 ...Obligations Mortgage Insurance Premiums-Periodic Payment § 203.267 Duration of periodic MIP. The mortgagee shall pay the...

2010-04-01

197

5 CFR 831.642 - Marriage duration requirements.  

Code of Federal Regulations, 2010 CFR

...2010-01-01 2010-01-01 false Marriage duration requirements. 831.642...Annuities Eligibility § 831.642 Marriage duration requirements. ...or (2) A child was born of the marriage, as explained in paragraph (c)...

2010-01-01

198

Neural oscillatory correlates of duration maintenance in working memory.  

PubMed

Working memory (WM) is a core element of temporal information processing, but little is known about the internal representation and neuronal underpinnings of the duration maintenance in WM. The neural oscillations during maintenance of duration in WM were examined using electroencephalogram (EEG) recordings. The EEG results showed that theta amplitude was not modulated by the length of duration retained in WM, while alpha amplitude decreased in a 4-s duration condition compared with 1-s, 2-s, and 3-s duration conditions. The amplitude of alpha power positively correlated with accuracy for the 3-s duration condition. The results suggest that alpha activity is involved in duration maintenance in WM. Our study provides electrophysiological evidence that different internal representations are retained in WM for durations below and above about 3s. PMID:25637487

Chen, Y G; Chen, X; Kuang, C W; Huang, X T

2015-04-01

199

19 CFR 141.34 - Duration of power of attorney.  

Code of Federal Regulations, 2014 CFR

...2014-04-01 2014-04-01 false Duration of power of attorney. 141.34 Section 141.34...TREASURY (CONTINUED) ENTRY OF MERCHANDISE Powers of Attorney § 141.34 Duration of power of attorney. Powers of attorney...

2014-04-01

200

19 CFR 141.34 - Duration of power of attorney.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 2013-04-01 false Duration of power of attorney. 141.34 Section 141.34...TREASURY (CONTINUED) ENTRY OF MERCHANDISE Powers of Attorney § 141.34 Duration of power of attorney. Powers of attorney...

2013-04-01

201

19 CFR 141.34 - Duration of power of attorney.  

Code of Federal Regulations, 2011 CFR

...2011-04-01 2011-04-01 false Duration of power of attorney. 141.34 Section 141.34...TREASURY (CONTINUED) ENTRY OF MERCHANDISE Powers of Attorney § 141.34 Duration of power of attorney. Powers of attorney...

2011-04-01

202

19 CFR 141.34 - Duration of power of attorney.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 2010-04-01 false Duration of power of attorney. 141.34 Section 141.34...TREASURY (CONTINUED) ENTRY OF MERCHANDISE Powers of Attorney § 141.34 Duration of power of attorney. Powers of attorney...

2010-04-01

203

19 CFR 141.34 - Duration of power of attorney.  

Code of Federal Regulations, 2012 CFR

...2012-04-01 2012-04-01 false Duration of power of attorney. 141.34 Section 141.34...TREASURY (CONTINUED) ENTRY OF MERCHANDISE Powers of Attorney § 141.34 Duration of power of attorney. Powers of attorney...

2012-04-01

204

Time perception: paradigms, methods, target duration and individual differences   

E-print Network

The present study assessed the role of the time judgement paradigms of prospective and retrospective durations, the length of durations and the effects of the states of mood and arousal in time perception. The role of ...

McFarlane, Henriett A

2008-06-27

205

32 CFR 2001.12 - Duration of classification.  

Code of Federal Regulations, 2010 CFR

...Review” or its acronym “MR;” “DCI Only;” “DNI Only;” and any other marking indicating an indefinite duration...with an indefinite duration, such as “DCI Only” or “DNI Only,” shall be established by the Director of National...

2010-07-01

206

20 CFR 655.158 - Duration of positive recruitment.  

Code of Federal Regulations, 2010 CFR

...false Duration of positive recruitment. 655.158 Section 655...STATES Labor Certification Process for Temporary Agricultural...158 Duration of positive recruitment. Except as otherwise noted...obligation to engage in positive recruitment described in §§...

2010-04-01

207

47 CFR 2.1509 - Environmental and duration tests.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 false Environmental and duration tests. 2.1509 Section 2.1509 Telecommunication...EPIRBs) Environmental and Operational Test Procedures § 2.1509 Environmental and duration tests. The environmental and operational...

2011-10-01

208

Short-Duration Gamma-Ray Bursts  

NASA Astrophysics Data System (ADS)

Gamma-ray bursts (GRBs) display a bimodal duration distribution with a separation between the short- and long-duration bursts at about 2 s. The progenitors of long GRBs have been identified as massive stars based on their association with Type Ic core-collapse supernovae (SNe), their exclusive location in star-forming galaxies, and their strong correlation with bright UV regions within their host galaxies. Short GRBs have long been suspected on theoretical grounds to arise from compact object binary mergers (neutron star-neutron star or neutron star-black hole). The discovery of short GRB afterglows in 2005 provided the first insight into their energy scale and environments, as well as established a cosmological origin, a mix of host-galaxy types, and an absence of associated SNe. In this review, I summarize nearly a decade of short GRB afterglow and host-galaxy observations and use this information to shed light on the nature and properties of their progenitors, the energy scale and collimation of the relativistic outflow, and the properties of the circumburst environments. The preponderance of the evidence points to compact object binary progenitors, although some open questions remain. On the basis of this association, observations of short GRBs and their afterglows can shed light on the on- and off-axis electromagnetic counterparts of gravitational wave sources from the Advanced LIGO/Virgo experiments.

Berger, Edo

2014-08-01

209

Influences of electrocardiographic ischaemia grades and symptom duration on outcomes in patients with acute myocardial infarction treated with thrombolysis versus primary percutaneous coronary intervention: results from the DANAMI?2 trial  

PubMed Central

Objective To determine whether ischaemia grade (GI) on the presenting ECG and duration of symptoms can identify subgroups of patients who would derive more benefit than the general population of patients with ST segment elevation acute myocardium infarction (STEMI) from primary percutaneous coronary intervention (pPCI) over thrombolytic treatment (TT) in reducing mortality or reinfarction. Methods 1319 DANAMI?2 (Danish trial in Acute Myocardial Infarction?2) patients were classified as having grade 2 ischaemia (GI2; ST segment elevation without terminal QRS distortion) or grade 3 ischaemia (GI3; ST segment elevation with terminal QRS distortion in ??2 adjacent leads), and were divided into early and late groups split by the median time (3?h) from symptom onset to treatment. Outcomes were 30?day mortality and reinfarction. Results Mortality was significantly higher for GI3 than for GI2 (9.7% v 4.8%, p?duration in both GI2 and GI3. pPCI may be especially beneficial for patients with GI3 presenting early, whereas patients with GI3 presenting late and treated with TT are at particular risk of reinfarction. PMID:16740918

Sejersten, M; Birnbaum, Y; Ripa, R S; Maynard, C; Wagner, G S; Clemmensen, P

2006-01-01

210

Course Location Duration Admission Places for non-EU  

E-print Network

'Offerta Formativa A.A. 2012/2013 08/06/2012 #12;Course Location Duration (years) Admission Places for non-EUCourse Location Duration (years) Admission Places for non-EU students (total) Places for Chinese places reserved for spring entrance test) 5 0 Course Location Duration (years) Admission Places for non-EU

Schenato, Luca

211

Course Location Duration Admission Places for non-EU  

E-print Network

Course Location Duration (years) Admission Places for non-EU students (total) Places for Chinese (195 places) 5 2 Course Location Duration (years) Admission Places for non-EU students (total) Places Certificazione dell'Offerta Formativa A.A. 2012/2013 08/06/2012 #12;Course Location Duration (years) Admission

Schenato, Luca

212

Evaluating observational methods to quantify snow duration under diverse forest canopies  

NASA Astrophysics Data System (ADS)

Forests cover almost 40% of the seasonally snow-covered regions in North America. However, operational snow networks are located primarily in forest clearings, and optical remote sensing cannot see through tree canopies to detect forest snowpack. Due to the complex influence of the forest on snowpack duration, ground observations in forests are essential. We therefore consider the effectiveness of different strategies to observe snow-covered area under forests. At our study location in the Pacific Northwest, we simultaneously deployed fiber-optic cable, stand-alone ground temperature sensors, and time-lapse digital cameras in three diverse forest treatments: control second-growth forest, thinned forest, and forest gaps (one tree height in diameter). We derived fractional snow-covered area and snow duration metrics from the colocated instruments to assess optimal spatial resolution and sampling configuration, and snow duration differences between forest treatments. The fiber-optic cable and the cameras indicated that mean snow duration was 8 days longer in the gap plots than in the control plots (p < 0.001). We conducted Monte Carlo experiments for observing mean snow duration in a 40 m forest plot, and found the 95% confidence interval was ±5 days for 10 m spacing between instruments and ±3 days for 6 m spacing. We further tested the representativeness of sampling one plot per treatment group by observing snow duration across replicated forest plots at the same elevation, and at a set of forest plots 250 m higher. Relative relationships between snow duration in the forest treatments are consistent between replicated plots, elevation, and two winters of data.

Dickerson-Lange, Susan E.; Lutz, James A.; Martin, Kael A.; Raleigh, Mark S.; Gersonde, Rolf; Lundquist, Jessica D.

2015-02-01

213

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

214

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...

215

Supercomputing the Climate - Duration: 5:43.  

NASA Video Gallery

Goddard Space Flight Center is the home of a state-of-the-art supercomputing facility called the NASA Center for Climate Simulation (NCCS) that is capable of running highly complex models to help s...

216

Launch of Juno! - Duration: 2:11.  

NASA Video Gallery

An Atlas V rocket lofted the Juno spacecraft toward Jupiter from Space Launch Complex-41. The 4-ton Juno spacecraft will take five years to reach Jupiter on a mission to study its structure and dec...

217

Shuttle Showcase: STS-124 - Duration: 61 seconds.  

NASA Video Gallery

The second in a series of flights to assemble the Japanese segment of the International Space Station saw the mammoth Kibo module delivered to the complex complements of Discovery and its crew on t...

218

Aquarius: Tower Rollback - Duration: 2:14.  

NASA Video Gallery

The mobile service tower at NASA's Launch Complex-2 at Vandenberg Air Force Base in California is being moved away from the ULA Delta II rocket with the Aquarius/SAC-D spacecraft atop, in preparati...

219

HIAD at NFAC - Duration: 9 seconds.  

NASA Video Gallery

Timelapse video of a six-meter (19.7 ft), inflatable Hypersonic Inflatable Aerodynamic Decelerator (HIAD) article being prepared for testing in the National Full-Scale Aerodynamic Complex at Moffet...

220

Inference in Hidden Markov Models with Explicit State Duration Distributions  

E-print Network

In this letter we borrow from the inference techniques developed for unbounded state-cardinality (nonparametric) variants of the HMM and use them to develop a tuning-parameter free, black-box inference procedure for Explicit-state-duration hidden Markov models (EDHMM). EDHMMs are HMMs that have latent states consisting of both discrete state-indicator and discrete state-duration random variables. In contrast to the implicit geometric state duration distribution possessed by the standard HMM, EDHMMs allow the direct parameterisation and estimation of per-state duration distributions. As most duration distributions are defined over the positive integers, truncation or other approximations are usually required to perform EDHMM inference.

Dewar, Michael; Wood, Frank

2012-01-01

221

Duration of Nocturnal Hypoglycemia Before Seizures  

PubMed Central

OBJECTIVE—Despite a high incidence of nocturnal hypoglycemia documented by the use of continuous glucose monitoring (CGM), there are no reports in the literature of nocturnal hypoglycemic seizures while a patient is wearing a CGM device. RESEARCH DESIGN AND METHODS—In this article, we describe four such cases and assess the duration of nocturnal hypoglycemia before the seizure. RESULTS—In the cases where patients had a nocturnal hypoglycemic seizure while wearing a CGM device, sensor hypoglycemia (<60 mg/dl) was documented on the CGM record for 2.25–4 h before seizure activity. CONCLUSIONS—Even with a subcutaneous glucose lag of 18 min when compared with blood glucose measurements, glucose sensors have time to provide clinically meaningful alarms. Current nocturnal hypoglycemic alarms need to be improved, however, since patients can sleep through the current alarm systems. PMID:18694975

Buckingham, Bruce; Wilson, Darrell M.; Lecher, Todd; Hanas, Ragnar; Kaiserman, Kevin; Cameron, Fergus

2008-01-01

222

Short Duration Base Heating Test Improvements  

NASA Technical Reports Server (NTRS)

Significant improvements have been made to a short duration space launch vehicle base heating test technique. This technique was first developed during the 1960's to investigate launch vehicle plume induced convective environments. Recent improvements include the use of coiled nitrogen buffer gas lines upstream of the hydrogen / oxygen propellant charge tubes, fast acting solenoid valves, stand alone gas delivery and data acquisition systems, and an integrated model design code. Technique improvements were successfully demonstrated during a 2.25% scale X-33 base heating test conducted in the NASA/MSFC Nozzle Test Facility in early 1999. Cost savings of approximately an order of magnitude over previous tests were realized due in large part to these improvements.

Bender, Robert L.; Dagostino, Mark G.; Engel, Bradley A.; Engel, Carl D.

1999-01-01

223

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

224

Short duration thermal metamorphism in CR chondrites  

NASA Astrophysics Data System (ADS)

CR chondrites are considered as one of the most primitive classes of meteorites. Most of them experienced a mild aqueous alteration and show no evidence of significant effect of thermal metamorphism. We present here a search for low degree metamorphic effects in CR chondrites. We studied 15 CR chondrites using different metamorphic indicators: (1) structure and Ni content of metal grains; (2) hydration state of matrix; (3) structure and composition of organic matter. The different metamorphic indicators show that two of the analyzed CR chondrites, GRA 06100 and GRO 03116, experienced thermal metamorphism. Indeed, all of the metal grains in GRA 06100 and half of the metal grains in GRO 03116 show Ni-rich phases; the matrix of GRA 06100 is almost completely dehydrated, and the matrix of GRO 03116 is partially dehydrated; Raman spectra of organic matter in these two meteorites are clearly different from those obtained for organic matter in the other CR chondrites, which resemble Raman spectra of organic matter in unmetamorphosed, CM2 meteorites; IR spectra of insoluble organic matter extracted from GRA 06100 and GRO 03116 show lower carbonyl abundance and higher CH2/CH3 ratio with respect to organic matter of unmetamorphosed chondrites. The other CR chondrites analyzed here lack these characteristics and only show a few metal grains with Ni-rich inclusions. Our results also show that the metamorphic effects observed in GRA 06100 and GRO 03116 are different from those observed in type 3 chondrites, which experienced long-duration metamorphism of radiogenic origin. We infer that thermal processing in these two CRs extended over a short duration and was triggered by impacts.

Briani, G.; Quirico, E.; Gounelle, M.; Paulhiac-Pison, M.; Montagnac, G.; Beck, P.; Orthous-Daunay, F.-R.; Bonal, L.; Jacquet, E.; Kearsley, A.; Russell, S. S.

2013-12-01

225

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

226

Duration of patients’ visits to the hospital emergency department  

PubMed Central

Background Length of stay is an important indicator of quality of care in Emergency Departments (ED). This study explores the duration of patients’ visits to the ED for which they are treated and released (T&R). Methods Retrospective data analysis and multivariate regression analysis were conducted to investigate the duration of T&R ED visits. Duration for each visit was computed by taking the difference between admission and discharge times. The Healthcare Cost and Utilization Project (HCUP) State Emergency Department Databases (SEDD) for 2008 were used in the analysis. Results The mean duration of T&R ED visit was 195.7 minutes. The average duration of ED visits increased from 8 a.m. until noon, then decreased until midnight at which we observed an approximately 70-minute spike in average duration. We found a substantial difference in mean duration of ED visits (over 90 minutes) between Mondays and other weekdays during the transition time from the evening of the day before to the early morning hours. Black / African American patients had a 21.4-minute longer mean duration of visits compared to white patients. The mean duration of visits at teaching hospitals was substantially longer than at non-teaching hospitals (243.8 versus 175.6 minutes). Hospitals with large bed size were associated with longer duration of visits (222.2 minutes) when compared to hospitals with small bed size (172.4 minutes) or those with medium bed size (166.5 minutes). The risk-adjusted results show that mean duration of visits on Mondays are longer by about 4 and 9 percents when compared to mean duration of visits on non-Monday workdays and weekends, respectively. Conclusions The duration of T&R ED visits varied significantly by admission hour, day of the week, patient volume, patient characteristics, hospital characteristics and area characteristics. PMID:23126473

2012-01-01

227

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

228

Long Duration Space Materials Exposure (LDSE)  

NASA Technical Reports Server (NTRS)

The Center on Materials for Space Structures (CMSS) at Case Western Reserve University is one of seventeen Commercial Centers for the Development of Space. It was founded to: (1) produce and evaluate materials for space structures; (2) develop passive and active facilities for materials exposure and analysis in space; and (3) develop improved material systems for space structures. A major active facility for materials exposure is proposed to be mounted on the exterior truss of the Space Station Freedom (SSF). This Long Duration Space Materials Exposure (LDSE) experiment will be an approximately 6 1/2 ft. x 4 ft. panel facing into the velocity vector (RAM) to provide long term exposure (up to 30 years) to atomic oxygen, UV, micro meteorites, and other low earth orbit effects. It can expose large or small active (instrumented) or passive samples. These samples may be mounted in a removable Materials Flight Experiment (MFLEX) carrier which may be periodically brought into the SSF for examination by CMSS's other SSF facility, the Space Materials Evaluation Facility (SMEF), which will contain a Scanning Electron Microscope, a Variable Angle & Scanning Ellipsometer, a Fourier Transform Infrared Spectrometer, and other analysis equipment. These facilities will allow commercial firms to test their materials in space and promptly obtain information on their materials survivability in the LEO environment.

Allen, David; Schmidt, Robert

1992-01-01

229

Immune changes during short-duration missions  

NASA Technical Reports Server (NTRS)

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.

Taylor, G. R.

1993-01-01

230

Svarna - vanga - a short duration toxicity study.  

PubMed

Swarna - Vanga, an Ayurvedic preparation, is used in the treatment mainly of Pramehas (genitor urinary and metabolic disorders), Sveta Pradara (Leucorrhoea), Kasa - Swasa (Respiratory disorders), etc. The drug contains tin and sulphur as major components along with traces of mercury, iron and aluminum. According to modern point of view certain metals have been claimed toxic to both human and animal. Since Svarna - Vanga contains these metals, it is essential to screen out its toxic effect, if any, although it is claimed in Ayurveda that when a metal is processed as prescribed, it become non - toxic or the least toxic. Considering the above facts, an animal experiment was carried out for short duration (14 days) to screen the toxic effects of Svarna - Vanga (SV) in increasing doses of the drug starting from the maximum therapeutic dose (12.5 mg / 100 gm b.wt / day). The drug was found to have no toxic effects in tissues of the animal at doses of 12.5 mg and 25 mg / 100 gm b.wt. / day. Fine fatty vacuolization in liver and focal superficial mucosal degeneration and necrosis of small intestine confined to one animal each at dose of 50 mg / 100gm b.wt. and 100 mg/ 100 gm. b.wt. / day were observed. Our study indicates that the drug has no toxic effect on tissues at therapeutic dose. PMID:22557505

Sharma; Gyaneshwar; Joshi, D; Aryya, N C; Pandey, V B

1985-10-01

231

Shortening ocular pain duration following intravitreal injections.  

PubMed

Purpose. To determine ocular pain duration after routine in-office intravitreal injection and to determine whether topical eyedrops are beneficial in increasing patient comfort. Methods. Forty injection-naïve patients receiving routine intravitreal injections of bevacizumab for age-related macular degeneration were randomized into 3 groups: group 1 (control, no drops), group 2 (generic artificial tears), and group 3 (ketorolac tromethamine 0.4% eyedrops). Those who received topical medications were given a Visual Analog Pain score survey and asked to record their pain on a scale from 0 (no distress) to 10 (unbearable distress) daily until a score of 0 was achieved, at which point they were instructed to discontinue use of their given drops. Self-reported pain scores were assessed. Results. Pain after routine intravitreal injection lasts on average between 3 and 7 days. Patients receiving topical ketorolac eyedrops reported the fewest average number of pain days (2.25±1.22) vs patients receiving artificial tears (3.54±1.13) or those who received no postprocedure eyedrops (5.13±1.25); p<0.05. At most, patients receiving ketorolac eyedrops reported 3 days of recordable pain. Those who received artificial tears reported at most 5 days of recordable pain, and patients who did not receive any postprocedure eyedrops reported at most 7 days of recordable pain. Conclusions. Pain after intravitreal injection is generally mild, may be reduced by postinjection topical ketorolac eyedrops, and lasts less than 1 week. PMID:22562296

Rifkin, Lana; Schaal, Shlomit

2012-04-24

232

Long Duration Richtmyer-Meshkov Instability Experiments  

NASA Astrophysics Data System (ADS)

This experimental study investigates the Richtmyer-Meshkov (RM) instability of an interface between incompressible, miscible liquids with an initial 2-D sinusoidal perturbation. The experiments are conducted in NASA Glenn Research Center's 2.2 Second Drop Tower. The experimental rig is isolated from aerodynamic drag by a surrounding drag shield. The rig falls 7 1/2 inches relative to the drag shield during the 79 ft fall of the system. An internal spring-driven sled impacting a clay ball provides the impulsive acceleration while the package is at the top of the drop tower, with the package timed to release just after the impulsive acceleration is complete. The instability evolves for 2.2 seconds until the package impacts an air bag at the bottom of the drop tower. The increased duration of these experiments provides for more than twice the observation time of the RM instability in the non-linear regime that will allow for better experimental comparison with asymptotic theories of perturbation amplitude and velocity.

Hunyadi, Sarah; Niederhaus, Charles; Jacobs, Jeffrey

2004-11-01

233

Long Duration Richtmyer-Meshkov Instability Experiments  

NASA Astrophysics Data System (ADS)

This experimental study investigates the Richtmyer-Meshkov (RM) instability of an interface between incompressible, miscible liquids with an initial 2-D sinusoidal perturbation. The experiments are conducted in NASA Glenn Research Center's 2.2 Second Drop Tower. The experimental rig is isolated from aerodynamic drag by a surrounding drag shield. The rig falls 7 1/2 inches relative to the drag shield during the 79 ft fall of the system. An internal spring-driven sled impacting a clay ball provides the impulsive acceleration while the package is at the top of the drop tower, with the package timed to release just after the impulsive acceleration is complete. The instability evolves for 2.2 seconds until the package impacts an air bag at the bottom of the drop tower. The increased duration of these experiments provides for more than twice the observation time of the RM instability in the non-linear regime that will allow for better experimental comparison with asymptotic theories of perturbation amplitude and velocity.

Niederhaus, Charles; Hunyadi, Sarah; Jacobs, Jeffrey

2003-11-01

234

Prolonged duration local anesthesia with minimal toxicity  

PubMed Central

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 little or no cytotoxicity. In vitro, the release of bupivacaine and STX from liposomes depended on the lipid composition and on whether dexamethasone was incorporated. In cell culture, bupivacaine, but not STX, was myotoxic (to C2C12 cells) and neurotoxic (to PC12 cells) in a concentration- and time-dependent manner. Liposomal formulations containing combinations of the above compounds produced sciatic nerve blockade lasting up to 7.5 days (with STX + dexamethasone liposomes) in male Sprague–Dawley rats. Systemic toxicity only occurred where high loadings of dexamethasone increased the release of liposomal STX. Mild myotoxicity was only seen in formulations containing bupivacaine. There was no nerve injury on Epon-embedded sections, and these liposomes did not up-regulate the expression of 4 genes associated with nerve injury in the dorsal root ganglia. These results suggest that controlled release of STX and similar compounds can provide very prolonged nerve blocks with minimal systemic and local toxicity. PMID:19365067

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

2009-01-01

235

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

236

Rainfall intensity-duration-frequency relationships derived from large partial duration series  

NASA Astrophysics Data System (ADS)

SummaryA procedure is proposed for basing intensity-duration-frequency (IDF) curves on partial duration series (PDS) which are substantially larger than those commonly used for this purpose. The PDS are derived from event maxima series (EMS), composed of the maximum average intensities, over a given duration, determined for all rainfall events recorded at a station. The generalized Pareto distribution (GP) is fitted to many PDS nested within the EMS and the goodness-of-fit is determined by the Anderson-Darling test. The best fitted distribution is selected for predicting intensities associated with the given duration and with a number of recurrence intervals. This procedure was repeated for eleven rainfall durations, from 5 to 240 min, at four stations of the Israel Meteorological Service. For comparison, the GP and the generalized extreme value (GEV) distributions were fitted to annual maxima series (AMS) and the Gumbel and lognormal distributions were fitted to the PDS and to the AMS at these stations. In almost all cases, the GP distribution well fits to ranges of PDS within an EMS, while in a few cases the best fit is fair only. Another result is that the GP distribution does not fit to AMS and to EMS. The GEV distribution well fits to most AMS, and fairly fits to the others. The Gumbel and the lognormal distributions well fit to most of the AMS and to a very few PDS. In most cases of good fits of different distributions, the predicted values by the different distributions are not much different from one another. This indicates the importance of good fit of the distribution and of the power of the AD test used for determining it. In most cases the best fit of the GP distribution is to a PDS series substantially larger than its corresponding AMS. In most cases, the standard error of the estimated 100-year intensity, through the best fitted GP to PDS, is smaller than that estimated through the GEV fitted to the corresponding AMS. All these make the proposed procedure superior to the current ones. It also enables interpolated predictions down to recurrence intervals of N/ n years ( N is number of years of complete records and n is PDS size). The use of large samples would reduce the sensitivity of predicted intensities to sampling variations.

Ben-Zvi, Arie

2009-03-01

237

Intertrial interval and unconditioned stimulus durations in autoshaping  

Microsoft Academic Search

Four groups of pigeons were exposed to an autoshaping procedure in which a 20-sec key illumination preceded the presentation\\u000a of response-independent grain, The groups differed according to the duration of feeder access and the intertriai intervals,\\u000a If feeder durations are not included in the time between trials, two of the groups had identical intertriai intervals. If\\u000a feeder durations are included,

Peter D. Balsam; David Payne

1979-01-01

238

On energy-dependent cues in duration discrimination  

Microsoft Academic Search

We consider the possibility that, in a duration discrimination task involving very short empty time intervals, T and T + ‡T,\\u000a bounded by brief auditory pulses, there may be a critical value of the base duration T within the range 50–300 msec below\\u000a which duration is coded on the basis of sensory interactions between the markers which bound the interval.

R. M. Carbotte; A. B. Kristofferson

1973-01-01

239

Enhancing Team Performance for Long-Duration Space Missions  

NASA Technical Reports Server (NTRS)

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 problems in a hostile environment. While thorough preflight training and procedures will equip creW'S to address technical problems that can be anticipated, preparing them to solve novel problems is much more challenging. This presentation will review components of effective team performance, challenges to effective teamwork, and strategies for ensuring effective team performance. Teamwork skills essential for successful team performance include the behaviors involved in developing shared mental models, team situation awareness, collaborative decision making, adaptive coordination behaviors, effective team communication, and team cohesion. Challenges to teamwork include both chronic and acute stressors. Chronic stressors are associated with the isolated and confined environment and include monotony, noise, temperatures, weightlessness, poor sleep and circadian disruptions. Acute stressors include high workload, time pressure, imminent danger, and specific task-related stressors. Of particular concern are social and organizational stressors that can disrupt individual resilience and effective mission performance. Effective team performance can be developed by training teamwork skills, techniques for coping with team conflict, intracrew and intercrew communication, and working in a multicultural team; leadership and teamwork skills can be fostered through outdoor survival training exercises. The presentation will conclude with an evaluation of the special requirements associated with preparing crews to function autonomously in long-duration missions.

Orasanu, Judith M.

2009-01-01

240

The CarD/CarG regulatory complex is required for the action of several members of the large set of Myxococcus xanthus extracytoplasmic function ? factors.  

PubMed

Extracytoplasmic function (ECF) ? factors are critical players in signal transduction networks involved in bacterial response to environmental changes. The Myxococcus xanthus genome reveals ?45 putative ECF-? factors, but for the overwhelming majority, the specific signals or mechanisms for selective activation and regulation remain unknown. One well-studied ECF-?, CarQ, binds to its anti-?, CarR, and is inactive in the dark but drives its own expression from promoter P(QRS) on illumination. This requires the CarD/CarG complex, the integration host factor (IHF) and a specific CarD-binding site upstream of P(QRS). Here, we show that DdvS, a previously uncharacterized ECF-?, activates its own expression in a CarD/CarG-dependent manner but is inhibited when specifically bound to the N-terminal zinc-binding anti-? domain of its cognate anti-?, DdvA. Interestingly, we find that the autoregulatory action of 11 other ECF-? factors studied here depends totally or partially on CarD/CarG but not IHF. In silico analysis revealed possible CarD-binding sites that may be involved in direct regulation by CarD/CarG of target promoter activity. CarD/CarG-linked ECF-? regulation likely recurs in other myxobacteria with CarD/CarG orthologous pairs and could underlie, at least in part, the global regulatory effect of the complex on M.?xanthus gene expression. PMID:24428729

Abellón-Ruiz, Javier; Bernal-Bernal, Diego; Abellán, María; Fontes, Marta; Padmanabhan, S; Murillo, Francisco J; Elías-Arnanz, Montserrat

2014-08-01

241

Sleep Duration and Depressive Symptoms: A Gene-Environment Interaction  

PubMed Central

Objective: We used quantitative genetic models to assess whether sleep duration modifies genetic and environmental influences on depressive symptoms. Method: Participants were 1,788 adult twins from 894 same-sex twin pairs (192 male and 412 female monozygotic [MZ] pairs, and 81 male and 209 female dizygotic [DZ] pairs] from the University of Washington Twin Registry. Participants self-reported habitual sleep duration and depressive symptoms. Data were analyzed using quantitative genetic interaction models, which allowed the magnitude of additive genetic, shared environmental, and non-shared environmental influences on depressive symptoms to vary with sleep duration. Results: Within MZ twin pairs, the twin who reported longer sleep duration reported fewer depressive symptoms (ec = -0.17, SE = 0.06, P < 0.05). There was a significant gene × sleep duration interaction effect on depressive symptoms (a'c = 0.23, SE = 0.08, P < 0.05), with the interaction occurring on genetic influences that are common to both sleep duration and depressive symptoms. Among individuals with sleep duration within the normal range (7-8.9 h/night), the total heritability (h2) of depressive symptoms was approximately 27%. However, among individuals with sleep duration within the low (< 7 h/night) or high (? 9 h/night) range, increased genetic influence on depressive symptoms was observed, particularly at sleep duration extremes (5 h/night: h2 = 53%; 10 h/night: h2 = 49%). Conclusion: Genetic contributions to depressive symptoms increase at both short and long sleep durations. Citation: Watson NF; Harden KP; Buchwald D; Vitiello MV; Pack AI; Stachan E; Goldberg J. Sleep duration and depressive symptoms: a gene-environment interaction. SLEEP 2014;37(2):351-358. PMID:24497663

Watson, Nathaniel F.; Harden, Kathryn Paige; Buchwald, Dedra; Vitiello, Michael V.; Pack, Allan I.; Strachan, Eric; Goldberg, Jack

2014-01-01

242

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

243

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

244

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

245

Neuronal representation of duration discrimination in the monkey striatum  

PubMed Central

Functional imaging and lesion studies in humans and animals suggest that the basal ganglia are crucial for temporal information processing. To elucidate neuronal mechanisms of interval timing in the basal ganglia, we recorded single-unit activity from the striatum of two monkeys while they performed a visual duration discrimination task. In the task, blue and red cues of different durations (0.2–2.0 sec) were successively presented. Each of the two cues was followed by a 1.0 sec delay period. The animals were instructed to choose the longer presented colored stimulus after the second delay period. A total of 498 phasically active neurons were recorded from the striatum, and 269 neurons were defined as task related. Two types of neuronal activity were distinguished during the delay periods. First, the activity gradually changed depending on the duration of the cue presented just before. This activity may represent the signal duration for later comparison between two cue durations. The activity during the second cue period also represented duration of the first cue. Second, the activity changed differently depending on whether the first or second cue was presented longer. This activity may represent discrimination results after the comparison between the two cue durations. These findings support the assumption that striatal neurons represent timing information of sensory signals for duration discrimination. PMID:25677545

Chiba, Atsushi; Oshio, Ken-ichi; Inase, Masahiko

2015-01-01

246

Is 2Week Duration Sufficient for Stenting in Endopyelotomy?  

Microsoft Academic Search

PurposeInternal stenting is an integral part of endopyelotomy. Studies in animals show good healing after 1 to 2 weeks of ureterotomy. Inherent stent related problems warrant a minimum possible duration of stenting without compromising the results of endopyelotomy. We performed a prospective randomized trial to evaluate the optimum duration of stenting after endopyelotomy.

ANIL MANDHANI; RAKESH KAPOOR; WAHEED ZAMAN; ANANT KUMAR; MAHENDRA BHANDARI; SANJAY GAMBHIR

2003-01-01

247

Internal Clock Processes and the Filled-Duration Illusion  

Microsoft Academic Search

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 unfilled intervals defined either by clicks or gaps, with the

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

2007-01-01

248

Correcting memory improves accuracy of predicted task duration.  

PubMed

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 (paper-counting task) and 2 (essay-writing task), college students were supplied with duration information about their previous performance on a similar task before predicting task duration. For Experiment 3, participants were recruited at various locations, such as fast food restaurants and video arcades, and supplied with average task duration for others before predicting how long the task would take. In all 3 experiments, supplying feedback increased predictive accuracy. Overall, results indicate that, when predicting duration, people do well when they rely not on memory of past task duration but instead on measures of actual duration, whether their own or that of others. PMID:18808280

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

2008-09-01

249

5 CFR 843.303 - Marriage duration requirements.  

Code of Federal Regulations, 2010 CFR

...2010-01-01 2010-01-01 false Marriage duration requirements. 843.303...Former Spouse Benefits § 843.303 Marriage duration requirements. (a) The...or (2) A child was born of the marriage, as explained in paragraph (c)...

2010-01-01

250

Stimulus Duration Preference at Electrode Sites Yielding Elicited Behavior  

NASA Technical Reports Server (NTRS)

The latency to display eating or drinking during hypothalamic stimulation was compared with the preferred duration of the same stimulus intensity in a self-stimulation situation. All the animals preferred longer stimulus durations than those required to elicit eating or drinking

Cox, V. C.

1970-01-01

251

DURATION OF LIFE INSURANCE LIABILITIES AND ASSET LIABILITY MANAGEMENT  

Microsoft Academic Search

The scope of this paper is to analyse duration as a risk measure of life insurance liabilities from traditional life insurance products using a simple model to assess the problem. First, the liabilities are defined. Then the concept of Macauley duration as a measure for interest rate risk with respect to life insurance liabilities is derived. This concept is discussed

RALPH HONEGGER; CHRISTIANE MATHIS

252

Lifetime Risk and Duration of Chronic Disease and Disability  

Microsoft Academic Search

Objective: To estimate risk and duration of chronic conditions and disability for all older Americans and demographic subgroups. Method: Analysis of National Mortality Followback Survey data for survivors to age 65 to project lifetime risk and duration of selected conditions and examine their relationship with life expectancy and disability. Results: For women, Blacks, and non-Blacks, arthritis is most common and

Christopher M. Murtaugh; Brenda C. Spillman

2011-01-01

253

SEIZURE DURATION AND RELATED ISSUES IN ECT FOR ENDOGENOUS DEPRESSION  

PubMed Central

SUMMARY In a study comparing sinusoidal wave and brief-pulse ECT in endogenous depression, seizure duration was monitored by the cuff method in 29 patients over 180 treatment sessions. Mean seizure duration across all treatments was 26.5 secs, and the mean for individual patients across their ECT course ranged from a minimum of 15.7 secs to maximum of38.5 secs. Regression analysis found no variable which significantly predicted mean seizure duration. Of the 22 good responders in the study, response to ECT was associated with a mean seizure duration of secs in 1 patient, ando cs in 11 patients; as just 2 of 7poor responders to ECT had a mean seizure duration of <20 secs in 1 patients, <25 secs in 11 patients, of the 22 good responders in the study; as just 2 of 7 poor responders to ECT had a mean seizure duration of <25 secs, it appears that a cuff seizure duration of over 20 secs may suffice for the seizure to be therapeutic in depression. With (constant current) brief pulse ECT, seizure threshold significantly increased with successive ECTs; thresholds did not however differ between the good and poor responders. There was a trend for seizure duration to decrease over time; again, good and poor responders did not differ. These findings provide little support for the anticonvulsant hypothesis for the antidepressant effect of ECT, but support the literature that ECT exerts an anticonvulsant effect. PMID:21776168

Andrade, Chittaranjan

1993-01-01

254

Duration of Sleep and ADHD Tendency among Adolescents in China  

ERIC Educational Resources Information Center

Objective: This study investigates the association between duration of sleep and ADHD tendency among adolescents. Method: This population-based health survey uses a two-stage random cluster sampling design. Participants ages 13 to 17 are recruited from the total population of adolescents attending high school in one city of China. Duration of…

Lam, Lawrence T.; Yang, L.

2008-01-01

255

40 CFR 85.2303 - Duration of model year.  

Code of Federal Regulations, 2010 CFR

... 2010-07-01 false Duration of model year. 85.2303 Section 85.2303...FROM MOBILE SOURCES Determination of Model Year for Motor Vehicles and Engines Used...Clean Air Act § 85.2303 Duration of model year. A specific model year...

2010-07-01

256

Timing, Intensity, and Duration of Rehabilitation for Hip and Stroke  

E-print Network

Timing, Intensity, and Duration of Rehabilitation for Hip and Stroke Fracture BETHESDA, MD on rehabilitation for stroke and hip fracture was held August 4 by the National Center for Medical Rehabilitation, intensity, and duration of rehabilitation. Stroke and hip fracture were included together because these two

Rau, Don C.

257

The long duration response to levodopa in Parkinson's disease  

Microsoft Academic Search

The duration of effect of levodopa has been reported by some authors to be shorter in fluctuating parkinsonian patients with long standing disease than in stable patients. Other authors report no difference in the two groups of patients. We assessed motor fluctuations and response duration in 15 Parkinson's disease patients. Three patterns of response were observed: deterioration within one day

D. L Madden; J. G. L Morris; S. J Graham; M Katekar; D. N Wade

1995-01-01

258

Bayesian comparison of different rainfall depth-duration-frequency relationships  

E-print Network

. An empirical model based on the Generalized Extreme Value Distribution is presented for hourly maximum rainfall rainfall data. The model is then divided into two sub-models for the short and long rainfall durationsBayesian comparison of different rainfall depth-duration-frequency relationships Aurélie Muller (1

Paris-Sud XI, Université de

259

Endogenous attention prolongs dominance durations in binocular rivalry  

E-print Network

performed several tasks while viewing rival stimuli to ensure and control deployment of attention. We found that endogenous attention can prolong dominance durations of attended stimulus. We developed a novel single durations of the attended stimulus. Using this procedure, we showed that paying attention to the stimulus

Tadin, Duje

260

School of Agricultural Sciences and Veterinary Medicine Course Location Duration  

E-print Network

Places for non-EU students (total) Places for Chinese students Veterinary Medicine Legnaro (PD) 5 limited (65 places) 10 3 Law School Course Location Duration (years) Admission Places for non-EU students Certificazione dell'Offerta Formativa A.A. 2013/2014 #12;School of Engineering Course Location Duration (years

Schenato, Luca

261

Course Location Duration Admission Places for non-EU  

E-print Network

Course Location Duration (years) Admission Places for non-EU students (total) Places for Chinese. Agriculture Sciences Servizio Regolamento Didattico di Ateneo e Certificazione dell'Offerta Formativa A.A. 2012/2013 08/06/2012 #12;Course Location Duration (years) Admission Places for non-EU students (total

Schenato, Luca

262

Course Location Duration Admission Places for non-EU  

E-print Network

Course Location Duration (years) Admission Places for non-EU students (total) Places for Chinese Certificazione dell'Offerta Formativa A.A. 2013/2014 #12;Course Location Duration (years) Admission Places for non-EU students (total) Places for Chinese students Economic Law Rovigo 3 entrance test 4 2 Economics

Schenato, Luca

263

A STUDY ON THE DURATION OF STRONG EARTHQUAKE GROUND MOTION  

Microsoft Academic Search

A simple definition of the duration of strong earthquake ground motion based on the mean-square integral of motion has been presented. It is closely related to that part of the strong motion which contributes significantly to the seismic energy as recorded at a point and to the related spectral amplitudes. Correlations have been established between the duration of strong-motion acceleration,

MI D. TRIFUNAC; A. G. BRADY

1975-01-01

264

Depth-duration frequency of precipitation for Texas  

USGS Publications Warehouse

The U.S. Geological Survey, in cooperation with the Texas Department of Transportation, conducted a study of the depth-duration frequency of precipitation for Texas. Depth-duration frequency is an estimate of the depth of precipitation for a specified duration and frequency or recurrence interval. For this report, precipitation durations of 15, 30, and 60 minutes; 1, 2, 3, 6, 12, and 24 hours; and 1, 2, 3, 5, and 7 days were investigated. The recurrence intervals for the frequencies range from 2 to 500 years. The time series of precipitation annual maxima for 173 fifteen-minute, 274 hourly, and 865 daily National Weather Service precipitation stations with at least 10 years of record in Texas provide the basis of depth-duration frequency for each identified duration. In total, about 3,030; 10,160; and 38,120 cumulative years of record are available for the 15-minute, hourly, and daily stations, respectively. L-moment statistics of the precipitation annual maxima were calculated for each duration and for each station using unbiased L-moment estimators. The statistics calculated were the mean, L-scale, L-coefficient of variation, L-skew, and L-kurtosis. The mean for each station and duration was corrected for the bias associated with fixed-interval recording of precipitation. The generalized logistic distribution was determined, using L-moment ratio diagrams, as an appropriate probability distribution for modeling the frequency of annual maxima for durations of 15 minutes to 24 hours; whereas, the generalized extreme-value distribution was determined as appropriate for durations of 1 to 7 days. The location, scale, and shape parameters of the distributions for each duration and each station were calculated from the L-moments. These parameters were contoured using spatial interpolation, based on the geostatistical method of kriging, to produce 37 maps that depict the spatial variation and magnitude of each parameter. Contour maps of the shape parameter for the generalized extreme-value distribution for durations of 1 to 7 days are not presented; the root mean square errors of preliminary maps for 1- to 7-day shape parameters were not appreciably smaller than the statewide standard deviation. Therefore, a single statewide mean shape parameter was used for 1- to 7-day durations. The depth-duration frequency for any location in Texas can be estimated using the contour maps and the equation of the corresponding distribution.

Asquith, William H.

1998-01-01

265

Overshadowing by fixed- and variable-duration stimuli.  

PubMed

Two experiments investigated the effect of the temporal distribution form of a stimulus on its ability to produce an overshadowing effect. The overshadowing stimuli were either of the same duration on every trial, or of a variable duration drawn from an exponential distribution with the same mean duration as that of the fixed stimulus. Both experiments provided evidence that a variable-duration stimulus was less effective than a fixed-duration cue at overshadowing conditioning to a target conditioned stimulus (CS); moreover, this effect was independent of whether the overshadowed CS was fixed or variable. The findings presented here are consistent with the idea that the strength of the association between CS and unconditioned stimulus (US) is, in part, determined by the temporal distribution form of the CS. These results are discussed in terms of time-accumulation and trial-based theories of conditioning and timing. PMID:25203812

Bonardi, Charlotte; Mondragón, Esther; Brilot, Ben; Jennings, Dómhnall J

2015-03-01

266

Diurnal variation of overdense meteor echo duration and ozone  

NASA Technical Reports Server (NTRS)

The diurnal variation of the median duration of overdense sporadic radar meteor echoes is examined. The meteors recorded in August, December, and January by the Ondrejov meteor radar during the period 1958-1990 were used for the analysis. A maximum median echo duration 1-3 hours after the time of local sunrise in the meteor region confirms the already known sunrise effect. Minimum echo duration occurring at the time of sunset seems to be the most important point of diurnal variation of the echo duration, when ozone is no longer dissociated by solar UV radiation. The effect of diurnal changes of the echo duration should be considered when the mass distribution of meteor showers is analyzed.

Simek, Milos

1992-01-01

267

Electrocardiograms of bottlenose dolphins (Tursiops truncatus) out of water: habituated collection versus wild postcapture animals.  

PubMed

Electrocardiography (ECG) was performed on captured free-ranging bottlenose dolphins (Tursiops truncatus) during a health assessment exercise and compared with that of a Navy collection of dolphins habituated to handling out of water in order to assess possible cardiovascular impacts of capture and handling. Six-lead recordings (I, II, III, aVr, aVl, and aVf) in the frontal plane and direct thorax leads were collected from both groups, with a modified base-apex lead additionally employed with the Navy collection dolphins. Measured and calculated parameters included amplitudes of P, R, S, and T waves and total QRS complex; T:S and T:QRS ratios; heart rate; durations of P wave; QRS complex, PR, QT, and RR intervals; maximum minus minimum RR interval; ST segment elevation-depression; and mean electrical axis (MEA). Physiologically minor but statistically significant differences were detected in S wave amplitude, PR interval, QRS duration, and MEA. The PR interval, QRS duration, and S wave amplitude were slightly greater and the MEA oriented slightly rightward in wild postcapture dolphins compared to Navy collection dolphins. There were no differences in heart rate or maximum minus minimum RR interval, which serves as a proxy for the expected sinus arrhythmia of dolphins. The base-apex lead resulted in greater QRS amplitude than lead II, as expected for the category B ventricular activation of dolphins. The left-side direct thorax lead was more consistent than that of the right side. Clinically, ECG was a useful adjunct to auscultation and thoracic palpation for monitoring heart rate and rhythm and generated a record for archiving. Safe capture and handling protocols in place, under which dolphins are immediately returned to the water at progressive signs of distress, may make cardiovascular decompensation less likely to be detected by ECG. It appears that the dolphin cardiovascular system compensates suitably well to capture, as measured by ECG under the conditions of this study. PMID:24450057

Harms, Craig A; Jensen, Eric D; Townsend, Forrest I; Hansen, Larry J; Schwacke, Lori H; Rowles, Teresa K

2013-12-01

268

Functional and biochemical rationales for the 24-hour-long duration of action of olodaterol.  

PubMed

?(2)-Adrenoceptor (?(2)-AR) agonists are powerful bronchodilators and play a pivotal role in the management of pulmonary obstructive diseases, such as asthma and chronic obstructive pulmonary disease. Although these agents first were used many years ago, progress in drug development has resulted in better tolerated, long-acting ?(2)-AR agonists (LABAs), such as formoterol and salmeterol. Although LABAs have been on the market for several years, relatively little is known on the rationale(s) behind their long duration of action. In this study, we focused on olodaterol (previously known as BI1744CL), a novel inhaled LABA, which provides a bronchodilating effect lasting 24 h and is currently in Phase III clinical trials. To understand the rationale behind its long duration of action, different aspects of olodaterol were analyzed (i.e., its lipophilicity and propensity to accumulate in the lipid bilayer as well as its tight binding to the ?(2)-AR). In line with its physicochemical properties, olodaterol associated moderately with lipid bilayers. Instead, kinetic as well as equilibrium binding studies indicated the presence of a stable [(3)H]olodaterol/?(2)-AR complex with a dissociation half-life of 17.8 h due to ternary complex formation. The tight binding of olodaterol to the human ?(2)-AR and stabilization of the ternary complex were confirmed in functional experiments monitoring adenylyl cyclase activity after extensive washout. Taken together, binding, kinetic, and functional data support the existence of a stable complex with the ?(2)-AR that, with a dissociation half-life >17 h, might indeed be a rationale for the 24-h duration of action of olodaterol. PMID:21357659

Casarosa, Paola; Kollak, Ines; Kiechle, Tobias; Ostermann, Angela; Schnapp, Andreas; Kiesling, Ralf; Pieper, Michael; Sieger, Peter; Gantner, Florian

2011-06-01

269

Stimulus Compounding in Interval Timing: The ModalityDuration Relationship of the Anchor Durations Results in Qualitatively Different  

E-print Network

. In these rats, initiation of responding to the compound stimulus appeared to be controlled by the visual stimulus only, whereas response terminations reflected control by both modal stimuli. These latter dataStimulus Compounding in Interval Timing: The Modality­Duration Relationship of the Anchor Durations

Matell, Matthew S.

270

Asymmetrical control of fixation durations in scene viewing.  

PubMed

In two experiments we investigated the control of fixation durations in naturalistic scene viewing. Empirical evidence from the scene onset delay paradigm and numerical simulations of such data with the CRISP model [Psychological Review 117 (2010) 382-405] have suggested that processing related difficulties may lead to prolonged fixation durations. Here, we ask whether processing related facilitation may lead to comparable decreases to fixation durations. Research in visual search and reading have reported only uni-directional shifts. To address the question of unidirectional (slow down) as opposed to bidirectional (slow down and speed up) adjustment of fixation durations in the context of scene viewing, we used a saccade-contingent display change method to either reduce or increase the luminance of the scene during prespecified critical fixations. Degrading the stimulus by shifting luminance down resulted in an immediate increase to fixation durations. However, clarifying the stimulus by shifting luminance upwards did not result in a comparable decrease to fixation durations. These results suggest that the control of fixation durations in scene viewing is asymmetric, as has been reported for visual search and reading. PMID:24726565

Calen Walshe, R; Nuthmann, Antje

2014-07-01

271

Examining Duration of Binge Eating Episodes in Binge Eating Disorder  

PubMed Central

Objective The primary goal of this paper is to examine and clarify characteristics of binge eating in individuals with binge eating disorder (BED), particularly the duration of binge eating episodes, as well as potential differences between individuals with shorter compared to longer binge eating episodes. Method Two studies exploring binge eating characteristics in BED were conducted. Study 1 examined differences in clinical variables among individuals (N = 139) with BED who reported a short (< 2 hours) versus long (? 2 hours) average binge duration. Study 2 utilized an ecological momentary assessment (EMA) design to examine the duration and temporal pattern of binge eating episodes in the natural environment in a separate sample of nine women with BED. Results Participants in Study 1 who were classified as having long duration binge eating episodes displayed greater symptoms of depression and lower self-esteem, but did not differ on other measures of eating disorder symptoms, compared to those with short duration binge eating episodes. In Study 2, the average binge episode duration was approximately 42 minutes, and binge eating episodes were most common during the early afternoon and evening hours, as well as more common on weekdays versus weekends. Discussion Past research on binge episode characteristics, particularly duration, has been limited to studies of binge eating episodes in BN. This study contributes to the existing literature on characteristics of binge eating in BED. PMID:23881639

Schreiber-Gregory, Deanna N.; Lavender, Jason M.; Engel, Scott G.; Wonderlich, Steve A.; Crosby, Ross D.; Peterson, Carol B.; Simonich, Heather; Crow, Scott; Durkin, Nora; Mitchell, James E.

2013-01-01

272

Forecasting the duration of volcanic eruptions: an empirical probabilistic model  

NASA Astrophysics Data System (ADS)

The ability to forecast future volcanic eruption durations would greatly benefit emergency response planning prior to and during a volcanic crises. This paper introduces a probabilistic model to forecast the duration of future and on-going eruptions. The model fits theoretical distributions to observed duration data and relies on past eruptions being a good indicator of future activity. A dataset of historical Mt. Etna flank eruptions is presented and used to demonstrate the model. The data have been compiled through critical examination of existing literature along with careful consideration of uncertainties on reported eruption start and end dates between the years 1300 AD and 2010. Data following 1600 is considered to be reliable and free of reporting biases. The distribution of eruption duration between the years 1600 and 1669 is found to be statistically different from that following it and the forecasting model is run on two datasets of Mt. Etna flank eruption durations: 1600-2010 and 1670-2010. Each dataset is modelled using a log-logistic distribution with parameter values found by maximum likelihood estimation. Survivor function statistics are applied to the model distributions to forecast (a) the probability of an eruption exceeding a given duration, (b) the probability of an eruption that has already lasted a particular number of days exceeding a given total duration and (c) the duration with a given probability of being exceeded. Results show that excluding the 1600-1670 data has little effect on the forecasting model result, especially where short durations are involved. By assigning the terms `likely' and `unlikely' to probabilities of 66 % or more and 33 % or less, respectively, the forecasting model based on the 1600-2010 dataset indicates that a future flank eruption on Mt. Etna would be likely to exceed 20 days (± 7 days) but unlikely to exceed 86 days (± 29 days). This approach can easily be adapted for use on other highly active, well-documented volcanoes or for different duration data such as the duration of explosive episodes or the duration of repose periods between eruptions.

Gunn, L. S.; Blake, S.; Jones, M. C.; Rymer, H.

2014-01-01

273

Introduction to duration concepts: application to bank management  

E-print Network

of Bonds and Duration Pane Table 2 ? Balance Sheet with Duration Gap Equal to 3 Years Table 3 ? Balance Sheet from Table 2 After Increase in Interest Rates by 25 Basis Points. Table 4 ? Balance Sheet with Duration Gap Equal to 1 1/2 Years . 9 Table 5... ? Balance Sheet from Table 4 After Increase in Interest Rates by 25 Basis Points. 10 Table 6 ? Summary of Statistical Analysis. Appendix A 24 Table A. l ? Probability Distributions for Three Interest Rate Scenarios 31 Appendix B Table B. l Table B...

Meyers, Alison J.

1985-01-01

274

7 CFR 925.66 - Duration of immunities.  

Code of Federal Regulations, 2013 CFR

... AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS AND ORDERS; FRUITS, VEGETABLES, NUTS), DEPARTMENT OF AGRICULTURE GRAPES GROWN IN A DESIGNATED AREA OF SOUTHEASTERN CALIFORNIA Miscellaneous Provisions § 925.66 Duration of immunities....

2013-01-01

275

7 CFR 989.88 - Duration of immunities.  

Code of Federal Regulations, 2011 CFR

...MARKETING SERVICE (Marketing Agreements and Orders; Fruits, Vegetables, Nuts), DEPARTMENT OF AGRICULTURE RAISINS PRODUCED FROM GRAPES GROWN IN CALIFORNIA Order Regulating Handling Miscellaneous Provisions § 989.88 Duration of immunities. The...

2011-01-01

276

43 CFR 3140.5 - Duration of the lease.  

Code of Federal Regulations, 2011 CFR

...Continued) 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...

2011-10-01

277

43 CFR 3140.5 - Duration of the lease.  

Code of Federal Regulations, 2014 CFR

...Continued) 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...

2014-10-01

278

43 CFR 3140.5 - Duration of the lease.  

Code of Federal Regulations, 2013 CFR

...Continued) 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...

2013-10-01

279

43 CFR 3140.5 - Duration of the lease.  

Code of Federal Regulations, 2012 CFR

...Continued) 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...

2012-10-01

280

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. PMID:21673667

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

2011-01-01

281

Pelagic larval duration of 10 temperate cryptobenthic fishes  

E-print Network

-041 Lisboa, Portugal (Received 1 June 2006, Accepted 17 February 2007) The pelagic larval duration (DPL's DPL ranged between 14 and 39 days, and Parablennius pilicornis (Blenniidae) had an average of 33 days

282

5 CFR 352.704 - Duration of reemployment rights.  

Code of Federal Regulations, 2013 CFR

...2013-01-01 false Duration of reemployment rights. 352.704 Section 352.704 Administrative...Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS REEMPLOYMENT RIGHTS Reemployment Rights of Former Bureau of Indian Affairs...

2013-01-01

283

5 CFR 352.704 - Duration of reemployment rights.  

Code of Federal Regulations, 2011 CFR

...2011-01-01 false Duration of reemployment rights. 352.704 Section 352.704 Administrative...Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS REEMPLOYMENT RIGHTS Reemployment Rights of Former Bureau of Indian Affairs...

2011-01-01

284

5 CFR 352.704 - Duration of reemployment rights.  

Code of Federal Regulations, 2014 CFR

...2014-01-01 false Duration of reemployment rights. 352.704 Section 352.704 Administrative...Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS REEMPLOYMENT RIGHTS Reemployment Rights of Former Bureau of Indian Affairs...

2014-01-01

285

5 CFR 352.704 - Duration of reemployment rights.  

Code of Federal Regulations, 2012 CFR

...2012-01-01 false Duration of reemployment rights. 352.704 Section 352.704 Administrative...Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS REEMPLOYMENT RIGHTS Reemployment Rights of Former Bureau of Indian Affairs...

2012-01-01

286

14 CFR 65.92 - Inspection authorization: Duration.  

Code of Federal Regulations, 2013 CFR

...Mechanics § 65.92 Inspection authorization: Duration. (a) Each inspection authorization expires on March 31 of each odd-numbered year. However, the holder may exercise the privileges of that authorization only while he holds a currently...

2013-01-01

287

14 CFR 65.92 - Inspection authorization: Duration.  

Code of Federal Regulations, 2012 CFR

...Mechanics § 65.92 Inspection authorization: Duration. (a) Each inspection authorization expires on March 31 of each odd-numbered year. However, the holder may exercise the privileges of that authorization only while he holds a currently...

2012-01-01

288

14 CFR 65.92 - Inspection authorization: Duration.  

Code of Federal Regulations, 2010 CFR

...Mechanics § 65.92 Inspection authorization: Duration. (a) Each inspection authorization expires on March 31 of each odd-numbered year. However, the holder may exercise the privileges of that authorization only while he holds a currently...

2010-01-01

289

14 CFR 65.92 - Inspection authorization: Duration.  

Code of Federal Regulations, 2014 CFR

...Mechanics § 65.92 Inspection authorization: Duration. (a) Each inspection authorization expires on March 31 of each odd-numbered year. However, the holder may exercise the privileges of that authorization only while he holds a currently...

2014-01-01

290

14 CFR 65.92 - Inspection authorization: Duration.  

Code of Federal Regulations, 2011 CFR

...Mechanics § 65.92 Inspection authorization: Duration. (a) Each inspection authorization expires on March 31 of each odd-numbered year. However, the holder may exercise the privileges of that authorization only while he holds a currently...

2011-01-01

291

7 CFR 3430.1011 - Duration of awards.  

Code of Federal Regulations, 2014 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...

2014-01-01

292

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

293

7 CFR 3430.1011 - Duration of awards.  

Code of Federal Regulations, 2012 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...

2012-01-01

294

7 CFR 3430.1011 - Duration of awards.  

Code of Federal Regulations, 2011 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...

2011-01-01

295

Long Duration Exposure Facility (LDEF). Mission 1 Experiments  

NASA Technical Reports Server (NTRS)

Spaceborne experiments using the space shuttle payload known as the Long Duration Exposure Facility are described. Experiments in the fields of materials, coatings, thermal systems, power and propulsion, electronic, and optics are discussed.

Clark, L. G. (editor); Kinard, W. H. (editor); Carter, D. L., Jr. (editor); Jones, J. L., Jr. (editor)

1984-01-01

296

49 CFR 385.715 - Duration of safety monitoring system.  

Code of Federal Regulations, 2010 CFR

...Monitoring System for Non-North American Carriers § 385...Duration of safety monitoring system. (a) Each non-North America-domiciled carrier subject...remain in the safety monitoring system for at least 18 months...

2010-10-01

297

Glioblastoma and Increased Survival with Longer Chemotherapy Duration  

E-print Network

Background: The five year survival for patients with glioblastoma (GBM) is low at approximately 4.7%. Radiotherapy plus concomitant and adjuvant temozolomide (TMZ) remain the standard of care. The optimal duration of therapy with TMZ is unknown...

Aboujaoude, Dory

2013-05-31

298

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

299

10 CFR 451.6 - Duration of incentive payments.  

Code of Federal Regulations, 2011 CFR

...Section 451.6 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION RENEWABLE ENERGY PRODUCTION INCENTIVES § 451.6 Duration...payments under this part with respect to a qualified renewable energy facility for 10 consecutive fiscal...

2011-01-01

300

10 CFR 451.6 - Duration of incentive payments.  

Code of Federal Regulations, 2012 CFR

...Section 451.6 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION RENEWABLE ENERGY PRODUCTION INCENTIVES § 451.6 Duration...payments under this part with respect to a qualified renewable energy facility for 10 consecutive fiscal...

2012-01-01

301

45 CFR 2400.53 - Duration of stipend.  

Code of Federal Regulations, 2011 CFR

...stipend. 2400.53 Section 2400.53 Public Welfare Regulations Relating to Public Welfare (Continued) JAMES MADISON MEMORIAL FELLOWSHIP FOUNDATION FELLOWSHIP PROGRAM REQUIREMENTS Fellowship Stipend § 2400.53 Duration of...

2011-10-01

302

45 CFR 2400.53 - Duration of stipend.  

Code of Federal Regulations, 2010 CFR

...stipend. 2400.53 Section 2400.53 Public Welfare Regulations Relating to Public Welfare (Continued) JAMES MADISON MEMORIAL FELLOWSHIP FOUNDATION FELLOWSHIP PROGRAM REQUIREMENTS Fellowship Stipend § 2400.53 Duration of...

2010-10-01

303

45 CFR 2400.53 - Duration of stipend.  

Code of Federal Regulations, 2014 CFR

...stipend. 2400.53 Section 2400.53 Public Welfare Regulations Relating to Public Welfare (Continued) JAMES MADISON MEMORIAL FELLOWSHIP FOUNDATION FELLOWSHIP PROGRAM REQUIREMENTS Fellowship Stipend § 2400.53 Duration of...

2014-10-01

304

45 CFR 2400.53 - Duration of stipend.  

Code of Federal Regulations, 2012 CFR

...stipend. 2400.53 Section 2400.53 Public Welfare Regulations Relating to Public Welfare (Continued) JAMES MADISON MEMORIAL FELLOWSHIP FOUNDATION FELLOWSHIP PROGRAM REQUIREMENTS Fellowship Stipend § 2400.53 Duration of...

2012-10-01

305

45 CFR 2400.53 - Duration of stipend.  

Code of Federal Regulations, 2013 CFR

...stipend. 2400.53 Section 2400.53 Public Welfare Regulations Relating to Public Welfare (Continued) JAMES MADISON MEMORIAL FELLOWSHIP FOUNDATION FELLOWSHIP PROGRAM REQUIREMENTS Fellowship Stipend § 2400.53 Duration of...

2013-10-01

306

10 CFR 451.6 - Duration of incentive payments.  

Code of Federal Regulations, 2014 CFR

...Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION RENEWABLE ENERGY PRODUCTION INCENTIVES § 451.6 Duration of...payments under this part with respect to a qualified renewable energy facility for 10 consecutive fiscal...

2014-01-01

307

38 CFR 60.7 - Duration of temporary lodging.  

Code of Federal Regulations, 2012 CFR

...60.7 Section 60.7 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS (CONTINUED) FISHER HOUSES AND OTHER TEMPORARY LODGING § 60.7 Duration of temporary lodging. Temporary lodging may be furnished to...

2012-07-01

308

38 CFR 60.7 - Duration of temporary lodging.  

Code of Federal Regulations, 2011 CFR

...60.7 Section 60.7 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS (CONTINUED) FISHER HOUSES AND OTHER TEMPORARY LODGING § 60.7 Duration of temporary lodging. Temporary lodging may be furnished to...

2011-07-01

309

38 CFR 60.7 - Duration of temporary lodging.  

Code of Federal Regulations, 2010 CFR

...60.7 Section 60.7 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS (CONTINUED) FISHER HOUSES AND OTHER TEMPORARY LODGING § 60.7 Duration of temporary lodging. Temporary lodging may be furnished to...

2010-07-01

310

45 CFR 400.113 - Duration of eligibility.  

Code of Federal Regulations, 2011 CFR

...HUMAN SERVICES REFUGEE RESETTLEMENT PROGRAM Child Welfare Services § 400.113 Duration of eligibility...IV-B plan prescribes for the availability of child welfare services to any other child in the...

2011-10-01

311

45 CFR 400.113 - Duration of eligibility.  

Code of Federal Regulations, 2013 CFR

...HUMAN SERVICES REFUGEE RESETTLEMENT PROGRAM Child Welfare Services § 400.113 Duration of eligibility...IV-B plan prescribes for the availability of child welfare services to any other child in the...

2013-10-01

312

45 CFR 400.113 - Duration of eligibility.  

Code of Federal Regulations, 2010 CFR

...HUMAN SERVICES REFUGEE RESETTLEMENT PROGRAM Child Welfare Services § 400.113 Duration of eligibility...IV-B plan prescribes for the availability of child welfare services to any other child in the...

2010-10-01

313

45 CFR 400.113 - Duration of eligibility.  

Code of Federal Regulations, 2014 CFR

...HUMAN SERVICES REFUGEE RESETTLEMENT PROGRAM Child Welfare Services § 400.113 Duration of eligibility...IV-B plan prescribes for the availability of child welfare services to any other child in the...

2014-10-01

314

45 CFR 400.113 - Duration of eligibility.  

Code of Federal Regulations, 2012 CFR

...HUMAN SERVICES REFUGEE RESETTLEMENT PROGRAM Child Welfare Services § 400.113 Duration of eligibility...IV-B plan prescribes for the availability of child welfare services to any other child in the...

2012-10-01

315

Volume-Duration-Frequencies for Ungaged Catchments in Texas  

E-print Network

. Separate methodologies were developed for small and large watersheds. Regression equations were developed for twelve regions to estimate flood volumes for different durations and recurrence intervals. "Window Test" was conducted to establish a methodology...

Devulapalli, Ravi S.; Valdes, Juan B.

316

The Pros of Procalcitonin: Reducing Antibiotic Duration in the ICU  

E-print Network

with carbapenemase producing Klebsiella pneumoniae than susceptible K.pneumoniae ii. Nosocomial superinfections 1,3 1. Hospital-acquired pneumonia treatment based on one clinical trial 4 2. Treatment durations

Pillow, Jonathan

317

Vocal Corollary Discharge Communicates Call Duration to Vertebrate Auditory System  

PubMed Central

Corollary discharge is essential to an animal's ability to filter self-generated from external stimuli. This includes acoustic communication, although direct demonstration of a corollary discharge that both conveys a vocal motor signal and informs the auditory system about the physical attributes of a self-generated vocalization has remained elusive for vertebrates. Here, we show the underlying synaptic activity of a neuronal vocal corollary discharge pathway in the hindbrain of a highly vocal species of fish. Neurons carrying the vocal corollary discharge are specifically adapted for the transmission of duration information, a predominant acoustic cue. The results reveal that vertebrates, like some insects, have a robust corollary discharge conveying call duration. Along with evidence for the influence of vocal duration on auditory encoding in mammals, these new findings suggest that linking vocal motor and corollary discharge pathways with pattern generating, call duration neurons is a shared network character across the animal kingdom. PMID:24285884

2013-01-01

318

49 CFR 385.715 - Duration of safety monitoring system.  

Code of Federal Regulations, 2011 CFR

...FEDERAL MOTOR CARRIER SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION FEDERAL MOTOR CARRIER SAFETY REGULATIONS SAFETY FITNESS PROCEDURES Safety Monitoring System for Non-North American Carriers § 385.715 Duration of safety monitoring...

2011-10-01

319

49 CFR 385.117 - Duration of safety monitoring system.  

Code of Federal Regulations, 2014 CFR

...FEDERAL MOTOR CARRIER SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION FEDERAL MOTOR CARRIER SAFETY REGULATIONS SAFETY FITNESS PROCEDURES Safety Monitoring System for Mexico-Domiciled Carriers § 385.117 Duration of safety monitoring...

2014-10-01

320

49 CFR 385.715 - Duration of safety monitoring system.  

Code of Federal Regulations, 2014 CFR

...FEDERAL MOTOR CARRIER SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION FEDERAL MOTOR CARRIER SAFETY REGULATIONS SAFETY FITNESS PROCEDURES Safety Monitoring System for Non-North American Carriers § 385.715 Duration of safety monitoring...

2014-10-01

321

49 CFR 385.117 - Duration of safety monitoring system.  

Code of Federal Regulations, 2012 CFR

...FEDERAL MOTOR CARRIER SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION FEDERAL MOTOR CARRIER SAFETY REGULATIONS SAFETY FITNESS PROCEDURES Safety Monitoring System for Mexico-Domiciled Carriers § 385.117 Duration of safety monitoring...

2012-10-01

322

14 CFR 1203.702 - Duration of classification.  

Code of Federal Regulations, 2010 CFR

...PROGRAM Foreign Government Information § 1203.702 Duration of classification. Unless the guidelines for the systematic review of 30-year old foreign government information developed pursuant to § 1203.603(b) prescribe dates or...

2010-01-01

323

7 CFR 930.86 - Duration of immunities.  

Code of Federal Regulations, 2012 CFR

...OF AGRICULTURE TART CHERRIES GROWN IN THE STATES OF MICHIGAN, NEW YORK, PENNSYLVANIA, OREGON, UTAH, WASHINGTON, AND WISCONSIN Order Regulating Handling Miscellaneous Provisions § 930.86 Duration of immunities. The benefits,...

2012-01-01

324

7 CFR 930.86 - Duration of immunities.  

Code of Federal Regulations, 2014 CFR

...OF AGRICULTURE TART CHERRIES GROWN IN THE STATES OF MICHIGAN, NEW YORK, PENNSYLVANIA, OREGON, UTAH, WASHINGTON, AND WISCONSIN Order Regulating Handling Miscellaneous Provisions § 930.86 Duration of immunities. The benefits,...

2014-01-01

325

10 CFR 451.6 - Duration of incentive payments.  

Code of Federal Regulations, 2010 CFR

...Section 451.6 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION RENEWABLE ENERGY PRODUCTION INCENTIVES § 451.6 Duration...payments under this part with respect to a qualified renewable energy facility for 10 consecutive fiscal...

2010-01-01

326

10 CFR 52.26 - Duration of permit.  

Code of Federal Regulations, 2010 CFR

...AND APPROVALS FOR NUCLEAR POWER PLANTS Early Site Permits § 52.26 Duration of...b) of this section, an early site permit issued under this subpart...date of issuance. (b) An early site permit continues to be...

2010-01-01

327

36 CFR 72.33 - Timing and duration of projects.  

Code of Federal Regulations, 2011 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...

2011-07-01

328

36 CFR 72.33 - Timing and duration of projects.  

Code of Federal Regulations, 2010 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...

2010-07-01

329

5 CFR 352.704 - Duration of reemployment rights.  

Code of Federal Regulations, 2010 CFR

...2010-01-01 false Duration of reemployment rights. 352.704 Section 352.704 Administrative...MANAGEMENT CIVIL SERVICE REGULATIONS REEMPLOYMENT RIGHTS Reemployment Rights of Former Bureau of Indian Affairs and...

2010-01-01

330

Duration, Pitch and Diphones in the CSTR TTS System   

E-print Network

descriptors whose locations are given in terms of syntactically-determined prosodic domains. A pitch contour is computed by converting the descriptors into a sequence of abstract targets whose absolute values depend on a specific speaker model. Duration...

Campbell, Nick; Isard, Stephen; Monaghan, Alex; Verhoeven, J.

331

7 CFR 917.65 - Duration of immunities.  

Code of Federal Regulations, 2010 CFR

...MARKETING SERVICE (Marketing Agreements and Orders; Fruits, Vegetables, Nuts), DEPARTMENT OF AGRICULTURE FRESH PEARS AND PEACHES GROWN IN CALIFORNIA Order Regulating Handling Miscellaneous Provisions § 917.65 Duration of immunities. The...

2010-01-01

332

42 CFR 61.13 - Duration and continuation.  

Code of Federal Regulations, 2011 CFR

...13 Section 61.13 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES FELLOWSHIPS, INTERNSHIPS, TRAINING FELLOWSHIPS Regular Fellowships § 61.13 Duration and continuation. An award period may be any...

2011-10-01

333

42 CFR 61.38 - Duration of service fellowships.  

Code of Federal Regulations, 2014 CFR

...38 Section 61.38 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES FELLOWSHIPS, INTERNSHIPS, TRAINING FELLOWSHIPS Service Fellowships § 61.38 Duration of service fellowships. Initial...

2014-10-01

334

42 CFR 61.13 - Duration and continuation.  

Code of Federal Regulations, 2014 CFR

...13 Section 61.13 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES FELLOWSHIPS, INTERNSHIPS, TRAINING FELLOWSHIPS Regular Fellowships § 61.13 Duration and continuation. An award period may be any...

2014-10-01

335

42 CFR 61.13 - Duration and continuation.  

Code of Federal Regulations, 2013 CFR

...13 Section 61.13 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES FELLOWSHIPS, INTERNSHIPS, TRAINING FELLOWSHIPS Regular Fellowships § 61.13 Duration and continuation. An award period may be any...

2013-10-01

336

42 CFR 61.13 - Duration and continuation.  

Code of Federal Regulations, 2012 CFR

...13 Section 61.13 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES FELLOWSHIPS, INTERNSHIPS, TRAINING FELLOWSHIPS Regular Fellowships § 61.13 Duration and continuation. An award period may be any...

2012-10-01

337

42 CFR 61.38 - Duration of service fellowships.  

Code of Federal Regulations, 2010 CFR

...38 Section 61.38 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES FELLOWSHIPS, INTERNSHIPS, TRAINING FELLOWSHIPS Service Fellowships § 61.38 Duration of service fellowships. Initial...

2010-10-01

338

Performance and alertness of railroad engineers on long duration trips  

E-print Network

The present study investigated the performance and alertness of 8 healthy male participants between the age of 31 years and 65 years old in nighttime, long duration simulated train operation. Participants completed the ...

Karnali, Leona D., 1978-

2004-01-01

339

32 CFR 2001.12 - Duration of classification.  

Code of Federal Regulations, 2013 CFR

...intelligence source or key design concepts of weapons of mass destruction, an original classification authority shall...be expected to reveal key design concepts of weapons of mass destruction, the duration shall be up to 75 years and...

2013-07-01

340

32 CFR 2001.12 - Duration of classification.  

Code of Federal Regulations, 2011 CFR

...intelligence source or key design concepts of weapons of mass destruction, an original classification authority shall...be expected to reveal key design concepts of weapons of mass destruction, the duration shall be up to 75 years and...

2011-07-01

341

32 CFR 2001.12 - Duration of classification.  

Code of Federal Regulations, 2014 CFR

...intelligence source or key design concepts of weapons of mass destruction, an original classification authority shall...be expected to reveal key design concepts of weapons of mass destruction, the duration shall be up to 75 years and...

2014-07-01

342

32 CFR 2001.12 - Duration of classification.  

Code of Federal Regulations, 2012 CFR

...intelligence source or key design concepts of weapons of mass destruction, an original classification authority shall...be expected to reveal key design concepts of weapons of mass destruction, the duration shall be up to 75 years and...

2012-07-01

343

Sucking and allosucking duration in farmed red deer ( Cervus elaphus)  

Microsoft Academic Search

Sucking duration in ungulates does not only mean milk transfer, but is also associated with maternal care in general. It seems to be a reflection of offspring demand rather than solely milk transfer rate. Thus, the objective of this study was to discriminate between sucking and allosucking (i.e. sucking non-maternal hind) behaviour in red deer according to the sucking duration.We

Jorga Drabkovaa; Jitka Bartošová; Lud?k Bartoš; Radim Kotrba; Jan Pluhá?ek; Ludmila Švecová; Adam Dušek; Tomáš Kott

2008-01-01

344

Temporal discrimination as a function of marker duration  

Microsoft Academic Search

In a series of three experiments, the effect of marker duration on temporal discrimination was evaluated with empty auditory\\u000a intervals bounded by markers ranging from 3 to 300 msec or presented as a gap within a continuous tone. As a measure of performance,\\u000a difference thresholds in relation to a base duration of 50 msec were computed. Performance on temporal discrimination

Thomas H. Rammsayer; Detlev Leutner

1996-01-01

345

Development of long-duration ballooning in Antarctica  

SciTech Connect

Following four successful long-duration test flights from Australia to South America, a new flight support system with global tracking, command, and telemetry capability is being developed to support long-duration balloon flights of relatively sophisticated instruments at both mid-latitudes and in Antarctica. The first test flight for the joint NASA-NSF program to support flights in Antarctica is scheduled from McMurdo in December 1989, with operational capability two years later.

Jones, W.V. (National Aeronautics and Space Administration, Code ES, Space Physics Division, Washington, DC 20546 (USA))

1990-03-20

346

Strategies for crew selection for long duration missions  

NASA Technical Reports Server (NTRS)

Issues surrounding psychological reactions to long duration spaceflight are discussed with respect to the definition of criteria for selecting crewmembers for such expeditions. Two broad dimensions of personality and behavior are defined - Instrumentality including achievement orientation, leadership, and ability to perform under pressure and Expressivity encompassing interpersonal sensitivity and competence. A strategy for validating techniques to select in candidates with the optimum psychological profile to perform successfully on long duration missions is described.

Helmreich, Robert L.; Holland, Albert W.; Santy, Patricia A.; Rose, Robert M.; Mcfadden, Terry J.

1990-01-01

347

Planning in Time: Windows and Durations for Activities and Goals  

Microsoft Academic Search

A general purpose automated planner\\/scheduler is described which generates parallel plans to achieve goals with imposed time con-straints. Both durations and start time windows may be specified for sets of goal conditions. The parallel plans consist of not just actions but also of events (triggered by circumstances), inferences, and scheduled events (completely beyond the actor's control). Deterministic dura-tions of all

Steven A. Vere

1983-01-01

348

Effects of stimulus duration on audio-visual synchrony perception.  

PubMed

The integration of visual and auditory inputs in the human brain occurs only if the components are perceived in temporal proximity, that is, when the intermodal time difference falls within the so-called subjective synchrony range. We used the midpoint of this range to estimate the point of subjective simultaneity (PSS). We measured the PSS for audio-visual (AV) stimuli in a synchrony judgment task, in which subjects had to judge a given AV stimulus using three response categories (audio first, synchronous, video first). The relevant stimulus manipulation was the duration of the auditory and visual components. Results for unimodal auditory and visual stimuli have shown that the perceived onset shifts to relatively later positions with increasing stimulus duration. These unimodal shifts should be reflected in changing PSS values, when AV stimuli with different durations of the auditory and visual components are used. The results for 17 subjects showed indeed a significant shift of the PSS for different duration combinations of the stimulus components. Because the shifts were approximately equal for duration changes in either of the components, no net shift of the PSS was observed as long as the durations of the two components were equal. This result indicates the need to appropriately account for unimodal timing effects when quantifying intermodal synchrony perception. PMID:22821079

Kuling, I A; van Eijk, R L J; Juola, J F; Kohlrausch, A

2012-09-01

349

Procedures used for assessment of stuttering frequency and stuttering duration.  

PubMed

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

2013-12-01

350

50 W thin-disk laser with variable pulse duration  

NASA Astrophysics Data System (ADS)

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 with a pair of diffraction gratings. Pulses with a full width at half maximum of 334 fs at an output power level of 30 W can be produced using a nonlinear spectrum broadening during amplification. Tuning of the distance between gratings or abandoning of the compressor allows for output pulse durations of several picoseconds with an output power of 60 W. A second seed source allows for pulse durations up to several nanoseconds. Further, the amplifier was operated in cavity-dumped or in Q-switched mode just by changing of the electrical control of the Pockels cell in the amplifier. The pulse durations range is extended, correspondingly, to 100 ns and even to microseconds.

Larionov, Mikhail; Dausinger, Friedrich

2011-02-01

351

Association of sleep duration and insulin resistance in Taiwanese vegetarians  

PubMed Central

Background Short sleep duration has been reported to associate with increased insulin resistance. However, no studies have investigated whether such association exists in vegetarians. The aim of this study was to investigate the association between sleep duration and insulin resistance in Taiwanese vegetarians. Methods A total of 1290 individuals were recruited from a regional hospital in south Taiwan during their regular routine physical examination. Only individuals who described themselves as Buddhist vegetarians were included in the study. Demographic information and clinical characteristics were collected and multiple logistic regression analysis was used to evaluate the association between sleep duration and insulin resistance. Results A total of 433 vegetarians were included in the study. Results from univariate logistic regression indicated that insulin resistance was significantly associated with male sex, greater waist circumference, higher triglyceride levels, lower high-density lipoprotein cholesterol levels, higher plasma creatinine levels, higher alanine transaminase levels, greater energy expenditure, and sleep duration of more than 8 hours per night. Multiple logistic regression revealed that insulin resistance was significantly and independently associated with sleep duration of more than 8 hours per night (odd ratios?=?2.27, 95% confidence interval?=?1.24, 4.11) after adjusting for waist circumference and levels of alanine transaminase. Conclusions Sleep duration of more than 8 hours per night is an independent risk factor associated with increased insulin resistance in vegetarians. PMID:22898005

2012-01-01

352

Asymmetric processing of durational differences - electrophysiological investigations in Bengali.  

PubMed

Duration is used contrastively in many languages to distinguish word meaning (e.g. in Bengali, [pata] 'leaf' vs. [pat:a] 'whereabouts'). While there is a large body of research on other contrasts in speech perception (e.g. vowel contrasts and consonantal place features), little work has been done on how durational information is used in speech processing. In non-linguistic studies of low-level processing, such as visual and non-linguistic acoustic pop-out tasks, an asymmetry is found where additional information is more readily detected than missing information. In this study, event-related potentials were recorded during two cross-modal auditory-visual semantic priming studies, where nonword mispronunciations of spoken prime words were created by changing the duration of a medial consonant (real word [dana] 'seed'>nonword [dan:a]). N400 amplitudes showed an opposite asymmetric pattern of results, where increases in consonantal duration were tolerated and led to priming of the visual target, but decreases in consonantal duration were not accepted. This asymmetrical pattern of acceptability is attributed to the fact that a longer consonant includes all essential information for the recognition of the original word with a short medial consonant (a possible default category) and any additional information can be ignored. However, when a consonant is shortened, it lacks the required durational information to activate the word with the original long consonant. PMID:24726333

Roberts, Adam C; Kotzor, Sandra; Wetterlin, Allison; Lahiri, Aditi

2014-05-01

353

New method development in prehistoric stone tool research: evaluating use duration and data analysis protocols.  

PubMed

Lithic microwear is a research field of prehistoric stone tool (lithic) analysis that has been developed with the aim to identify how stone tools were used. It has been shown that laser scanning confocal microscopy has the potential to be a useful quantitative tool in the study of prehistoric stone tool function. In this paper, two important lines of inquiry are investigated: (1) whether the texture of worn surfaces is constant under varying durations of tool use, and (2) the development of rapid objective data analysis protocols. This study reports on the attempt to further develop these areas of study and results in a better understanding of the complexities underlying the development of flexible analytical algorithms for surface analysis. The results show that when sampling is optimised, surface texture may be linked to contact material type, independent of use duration. Further research is needed to validate this finding and test an expanded range of contact materials. The use of automated analytical protocols has shown promise but is only reliable if sampling location and scale are defined. Results suggest that the sampling protocol reports on the degree of worn surface invasiveness, complicating the ability to investigate duration related textural characterisation. PMID:25041833

Evans, Adrian A; Macdonald, Danielle A; Giusca, Claudiu L; Leach, Richard K

2014-10-01

354

40 CFR 80.48 - Augmentation of the complex emission model by vehicle testing.  

Code of Federal Regulations, 2012 CFR

...Augmentation of the complex emission model by vehicle...ADDITIVES Reformulated Gasoline § 80.48 Augmentation of the complex emission model by vehicle...all reformulated gasolines. (h) Duration of acceptance of emission effects...

2012-07-01

355

40 CFR 80.48 - Augmentation of the complex emission model by vehicle testing.  

Code of Federal Regulations, 2010 CFR

...Augmentation of the complex emission model by vehicle...ADDITIVES Reformulated Gasoline § 80.48 Augmentation of the complex emission model by vehicle...all reformulated gasolines. (h) Duration of acceptance of emission effects...

2010-07-01

356

40 CFR 80.48 - Augmentation of the complex emission model by vehicle testing.  

Code of Federal Regulations, 2013 CFR

...Augmentation of the complex emission model by vehicle...ADDITIVES Reformulated Gasoline § 80.48 Augmentation of the complex emission model by vehicle...all reformulated gasolines. (h) Duration of acceptance of emission effects...

2013-07-01

357

40 CFR 80.48 - Augmentation of the complex emission model by vehicle testing.  

Code of Federal Regulations, 2014 CFR

...Augmentation of the complex emission model by vehicle...ADDITIVES Reformulated Gasoline § 80.48 Augmentation of the complex emission model by vehicle...all reformulated gasolines. (h) Duration of acceptance of emission effects...

2014-07-01

358

40 CFR 80.48 - Augmentation of the complex emission model by vehicle testing.  

Code of Federal Regulations, 2011 CFR

...Augmentation of the complex emission model by vehicle...ADDITIVES Reformulated Gasoline § 80.48 Augmentation of the complex emission model by vehicle...all reformulated gasolines. (h) Duration of acceptance of emission effects...

2011-07-01

359

Depth-Duration Frequency of Precipitation for Oklahoma  

USGS Publications Warehouse

A regional frequency analysis was conducted to estimate the depth-duration frequency of precipitation for 12 durations in Oklahoma (15, 30, and 60 minutes; 1, 2, 3, 6, 12, and 24 hours; and 1, 3, and 7 days). Seven selected frequencies, expressed as recurrence intervals, were investigated (2, 5, 10, 25, 50, 100, and 500 years). L-moment statistics were used to summarize depth-duration data and to determine the appropriate statistical distributions. Three different rain-gage networks provided the data (15minute, 1-hour, and 1-day). The 60-minute, and 1-hour; and the 24-hour, and 1-day durations were analyzed separately. Data were used from rain-gage stations with at least 10-years of record and within Oklahoma or about 50 kilometers into bordering states. Precipitation annual maxima (depths) were determined from the data for 110 15-minute, 141 hourly, and 413 daily stations. The L-moment statistics for depths for all durations were calculated for each station using unbiased L-mo-ment estimators for the mean, L-scale, L-coefficient of variation, L-skew, and L-kur-tosis. The relation between L-skew and L-kurtosis (L-moment ratio diagram) and goodness-of-fit measures were used to select the frequency distributions. The three-parameter generalized logistic distribution was selected to model the frequencies of 15-, 30-, and 60-minute annual maxima; and the three-parameter generalized extreme-value distribution was selected to model the frequencies of 1-hour to 7-day annual maxima. The mean for each station and duration was corrected for the bias associated with fixed interval recording of precipitation amounts. The L-scale and spatially averaged L-skew statistics were used to compute the location, scale, and shape parameters of the selected distribution for each station and duration. The three parameters were used to calculate the depth-duration-frequency relations for each station. The precipitation depths for selected frequencies were contoured from weighted depth surfaces to produce maps from which the precipitation depth-duration-frequency curve for selected storm durations can be determined for any site in Oklahoma.

Tortorelli, Robert L.; Rea, Alan; Asquith, William H.

1999-01-01

360

Self-Reported Sleep Duration and Weight-Control Strategies Among US High School Students  

PubMed Central

Study Objective: To determine if self-reported sleep duration was associated with weight-control behaviors among US high school students. Design: National Youth Risk Behavior Survey. Setting: United States, 2007. Participants: US high school students (N = 12,087). Measurements: Students were asked if they had engaged in several weight-control behaviors during the 30 days before the survey to lose or maintain weight. Self-reported sleep duration categories included very short (? 5 h), short (6 or 7 h), referent moderate (8 or 9 h), and long (? 10 h). Sex-specific logistic regression analyses with race/ethnicity, grade, and body mass index category as covariates were conducted using SUDAAN to account for complex study design. Results: Approximately half the students reported short sleep duration (51.8% of males and 54.3% of females), whereas very short sleep durations were reported by another 14.8% of males and 16.9% of females. Among males, very short sleepers were significantly (P < 0.05) more likely than moderate sleepers to report dieting (36.3% versus 26.1%), fasting (14.2% versus 4.3%), and purging (4.3% versus 1.1%) to lose or maintain weight during the 30 days before the survey. Among females, the respective very short, short, and moderate sleepers varied (P < 0.05) in dieting (59.9%, 55.0%, and 47.5% respectively), fasting (28.3%, 15.2%, and 10.3%, respectively), and taking diet pills (13.3%, 6.8%, and 4.3%, respectively). Prevalence of purging was significantly higher only for very short sleepers (12.3%, 6.0%, and 3.9%, respectively). Conclusion: Self-reported short sleep duration was associated with dieting and three unhealthy weight-control behaviors in this population. If our findings are confirmed, intervention studies should be conducted to examine the effect of educational interventions. Citation: Wheaton AG; Perry GS; Chapman DP; Croft JB. Self-reported sleep duration and weight-control strategies among US high school students. SLEEP 2013;36(8):1139-1145. PMID:23904673

Wheaton, Anne G.; Perry, Geraldine S.; Chapman, Daniel P.; Croft, Janet B.

2013-01-01

361

Formulation of Intensity-Duration-Frequency Curves Incorporating Non-Stationarity  

NASA Astrophysics Data System (ADS)

The methodology behind the formulation of Intensity-Duration-Frequency (IDF) curves dates back to the 1930's. They are a commonly used tool in the planning and design of water-related projects. The principle of any IDF formula is to find the relationship between three variables of rainfall events: the intensity of the event, its duration, and its expected frequency. The general IDF methodology proposed by Koutsoyiannis et al. (1998) provides a simple expression of the relationship between the intensity of rainfall with its duration and frequency. The use of this general relationship has become increasingly popular in the literature, due to how it eliminates the complexity involved with other alternative relationships. Current research advances recognize the existence of non-stationarity in records of hydroclimatic variables, rendering it necessary for it to be incorporated into analyses involving these variables. Non-stationarity is caused by the changes in climate and environment across the world. Numerous studies have proven that neglecting to incorporate non-stationarity does have an impact on the results of modeling hydroclimatic variables. Examples of models worked with previously, taking non-stationarity into consideration, are Flood-Duration-Frequency (QDF) and Flood-Frequency-Analysis (FFA). The purpose of this study is to incorporate the non-stationarity that exists in rainfall records into the general IDF relationship, by making the parameters involved in it time-dependent. The Generalized Extreme Value (GEV) distribution is proposed as the distribution function to be used with the time dependent numerator of the general IDF relationship. Generalized Maximum Likelihood (GML) estimators are proposed to be used for determining the parameters of the GEV function, based on the work of El Adlouni et al. (2007).

Yousef, L. A.; Ouarda, T.

2013-12-01

362

Biological component of life support systems for a crew in long-duration space expeditions  

NASA Astrophysics Data System (ADS)

Creation of effective life support systems (LSSs) is one of the main tasks of medico-biological support of long-duration space flight. Principles of development of such an LSS will be defined on the basis of number of parameters, including mass-overall and energetic limitations of interplanetary spacecraft, duration of expedition and crew size. It is obvious that including biological subsystems in LSS of long-duration interplanetary space flights will help to form a full-fledged environment for humans in the spacecraft. It would be an appropriate solution for long-term biological needs of humans and important for elimination of possible negative consequences of their long stay under artificial (abiogenous) environment. Experiments with higher plants, conducted on board "MIR" orbital complex and Russian segment of ISS, showed that plant organisms are capable of long-duration normal growth, full development and reproduction without deviations under real space flight environment. These results allow us to assume that greenhouses are potential candidates to be a biological subsystem to be included in the LSS for interplanetary space flight. Inclusion of greenhouse equipment in the spacecrafts will require a number of corrective actions in functional schemes of the existing LSS, i.e. it will lead to redistribution of material streams inside an LSS and increase in functional load of authorized systems. Furthermore, involvement of greenhouse in an LSS of an interplanetary spacecraft requires a number of technical tasks to be cleared. In the present review, we discuss the constructive, technological and mass-transfer characteristics of greenhouse as a component part of the LSS for crews of long-term interplanetary missions, in particular, Mars expedition.

Sychev, Vladimir N.; Levinskikh, Margarita A.; Podolsky, Igor G.

363

Effect of propagation distance on aircraft flyover sound duration  

NASA Astrophysics Data System (ADS)

In the past, NOISEMAP and other aircraft noise contouring programs incorporating single event, time-integrated measures such as Sound Exposure Level (SEL) or Effective Perceived Noise Level (EPNL) assumed that the sound duration for flyovers doubled for each doubling of the distance between the source and a receiver. This simplifying assumption considers only the losses due to the spherical divergence of a sound wave as it propagates over distance. Mathematically this meant that in calculating SEL or EPNL versus distance functions, a "duration" term was introduced that was proportional to multiplying the logarithm of the ratio in propagation distances between two points by a coefficient of 10. Controlled level flyover noise tests were conducted on A-10, C-135A, C-141, E-3A, F-5E, F-15 and F-18 aircraft to directly measure sound duration as a function of propagation distance. Data were also acquired during a dedicated series of C-130E actual takeoffs and landings. Our findings show the duration coefficient varies between 5 and 7 for different aircraft types. Clearly the old coefficient of 10 is wrong. Data are included that also show that the sound attenuation mechanisms controlling this duration coefficient are basically independent of the frequency content of the aircraft noise.

Speakman, J. D.

1981-05-01

364

Competing risks mixture model for traffic incident duration prediction.  

PubMed

Traffic incident duration is known to result from a combination of multiple factors, including covariates such as spatial and temporal characteristics, traffic conditions, and existence of secondary accidents but also the clearance method itself. In this paper, a competing risks mixture model is used to investigate the influence of clearance methods and various covariates on the duration of traffic incidents and predict traffic incident duration. The proposed mixture model considers the uncertainty in any of five clearance methods that occurred. The probability of the clearance method is specified in the mixture by using a multinomial logistic model. Three candidate distributions, namely, generalized gamma, Weibull, and log-logistic are tested to determine the most appropriate probability density function of the parametric survival analysis model. The unobserved heterogeneity is also incorporated into the mixture model in a way that allows parameters to vary across observations based on the three candidate distributions. The methods are illustrated with incident data from Singaporean expressways from January 2010 to December 2011. Regression analysis reveals that the probability of different clearance methods and the duration of traffic incidents are both significantly affected by various factors, such as traffic conditions and incident characteristics. Results show that the proposed mixture model is better than the traditional accelerated failure time model, and it predicts traffic incident duration with reasonable accuracy, as shown by the mean average percent error. PMID:25485730

Li, Ruimin; Pereira, Francisco C; Ben-Akiva, Moshe E

2015-02-01

365

Scaling model of a rainfall intensity-duration-frequency relationship  

NASA Astrophysics Data System (ADS)

Intensity-duration-frequency (IDF) relationships are currently constructed based on an at-site frequency analysis of rainfall data separately for different durations. These relationships are not accurate and reliable since they depend on many assumptions such as distribution selection for each duration; they require a large number of parameters, and are not time-independent.In this study, scaling properties of extreme rainfall are examined to establish scaling behaviour of statistical non-central moments over different durations. A scale invariance concept is explored for disaggregation (or downscaling) of rainfall intensity from low to high resolution and is applied to the derivation of scaling IDF curves. These curves are developed for gauged sites based on scaling of the generalized extreme value (GEV) and Gumbel probability distributions.Numerical analysis was performed on annual maximum rainfall series for the province of Ontario, for storm durations of 5, 10, 15, and 30 min (the typical time of concentration for small urban catchments) and 1, 2, 6, 12, and 24 h (the typical time of concentration for larger rural watersheds).Results show that rainfall does follow a simple scaling process. Estimates found from the scaling procedure are comparable to estimates obtained from traditional techniques; however, the scaled approach was more efficient and gives more accurate estimates compared with the observed rainfall total at all stations. Copyright

Bougadis, John; Adamowski, Kaz

2006-11-01

366

Building a Shared Definitional Model of Long Duration Human Spaceflight  

NASA Technical Reports Server (NTRS)

In 1956, on the eve of human space travel Strughold first proposed a simple classification of the present and future stages of manned flight that identified key factors, risks and developmental stages for the evolutionary journey ahead. As we look to optimize the potential of the ISS as a gateway to new destinations, we need a current shared working definitional model of long duration human space flight to help guide our path. Initial search of formal and grey literature augmented by liaison with subject matter experts. Search strategy focused on both the use of term long duration mission and long duration spaceflight, and also broader related current and historical definitions and classification models of spaceflight. The related sea and air travel literature was also subsequently explored with a view to identifying analogous models or classification systems. There are multiple different definitions and classification systems for spaceflight including phase and type of mission, craft and payload and related risk management models. However the frequently used concepts of long duration mission and long duration spaceflight are infrequently operationally defined by authors, and no commonly referenced classical or gold standard definition or model of these terms emerged from the search. The categorization (Cat) system for sailing was found to be of potential analogous utility, with its focus on understanding the need for crew and craft autonomy at various levels of potential adversity and inability to gain outside support or return to a safe location, due to factors of time, distance and location.

Orr, M.; Whitmire, A.; Sandoval, L.; Leveton, L.; Arias, D.

2011-01-01

367

Effectiveness and duration of intramuscular antimotion sickness medications  

NASA Technical Reports Server (NTRS)

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.

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

1992-01-01

368

Incident Duration Modeling Using Flexible Parametric Hazard-Based Models  

PubMed Central

Assessing and prioritizing the duration time and effects of traffic incidents on major roads present significant challenges for road network managers. This study examines the effect of numerous factors associated with various types of incidents on their duration and proposes an incident duration prediction model. Several parametric accelerated failure time hazard-based models were examined, including Weibull, log-logistic, log-normal, and generalized gamma, as well as all models with gamma heterogeneity and flexible parametric hazard-based models with freedom ranging from one to ten, by analyzing a traffic incident dataset obtained from the Incident Reporting and Dispatching System in Beijing in 2008. Results show that different factors significantly affect different incident time phases, whose best distributions were diverse. Given the best hazard-based models of each incident time phase, the prediction result can be reasonable for most incidents. The results of this study can aid traffic incident management agencies not only in implementing strategies that would reduce incident duration, and thus reduce congestion, secondary incidents, and the associated human and economic losses, but also in effectively predicting incident duration time. PMID:25530753

2014-01-01

369

Earth-Space Links and Fade-Duration Statistics  

NASA Technical Reports Server (NTRS)

In recent years, fade-duration statistics have been the subject of several experimental investigations. A good knowledge of the fade-duration distribution is important for the assessment of a satellite communication system's channel dynamics: What is a typical link outage duration? How often do link outages exceeding a given duration occur? Unfortunately there is yet no model that can universally answer the above questions. The available field measurements mainly come from temperate climatic zones and only from a few sites. Furthermore, the available statistics are also limited in the choice of frequency and path elevation angle. Yet, much can be learned from the available information. For example, we now know that the fade-duration distribution is approximately lognormal. Under certain conditions, we can even determine the median and other percentiles of the distribution. This paper reviews the available data obtained by several experimenters in different parts of the world. Areas of emphasis are mobile and fixed satellite links. Fades in mobile links are due to roadside-tree shadowing, whereas fades in fixed links are due to rain attenuation.

Davarian, Faramaz

1996-01-01

370

Earth-space links and fade-duration statistics  

NASA Technical Reports Server (NTRS)

In recent years, fade-duration statistics have been the subject of several experimental investigations. A good knowledge of the fade-duration distribution is important for the assessment of a satellite communication system's channel dynamics: What is a typical link outage duration? How often do link outages exceeding a given duration occur? Unfortunately there is yet no model that can universally answer the above questions. The available field measurements mainly come from temperate climatic zones and only from a few sites. Furthermore, the available statistics are also limited in the choice of frequency and path elevation angle. Yet, much can be learned from the available information. For example, we now know that the fade-duration distribution is approximately lognormal. Under certain conditions, we can even determine the median and other percentiles of the distribution. This paper reviews the available data obtained by several experimenters in different parts of the world. Areas of emphasis are mobile and fixed satellite links. Fades in mobile links are due to roadside-tree shadowing, whereas fades in fixed links are due to rain attenuation.

Davarian, Faramaz

1995-01-01

371

Effect of measurement duration on accuracy of pulse-counting  

PubMed Central

In this study, the relation between the measurement duration and accuracy of pulse-counting was quantitatively examined with special reference to low-frequency fluctuations in heart rate variability. The interbeat intervals of 70 healthy male subjects were measured in standing, sitting and supine positions. Pulse rates for various durations were calculated by objective-scoring simulation based on the heartbeat recordings of the subjects. The duration of pulse-counting continuously varied from 6 to 60 s in the simulation. Simulated pulse rates were compared with the rate calculated from the 60 s that includes the given duration, and the absolute difference between the two rates was defined as the error. Average errors of pulse-counting for 15 s were 1.89, 1.89 and 1.80 bpm for standing, sitting and supine positions, respectively. No difference in error was observed between standing and sitting positions; however, smaller errors were observed in the supine position. Practitioner Summary: This study provides information on the degree of error that will occur when pulse rates are objectively scored for various durations, for example 10, 15 or 30 s, instead of a full minute. This useful information may be beneficial for physicians, nurses and medical practitioners. PMID:24117167

Kobayashi, Hiromitsu

2013-01-01

372

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. 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.

2012-01-01

373

Prolonging the expression duration of ultrasound-mediated gene transfection using PEI nanoparticles.  

PubMed

Ultrasound (US) irradiation has been found to facilitate the inward transport of genetic materials across cell membranes (sonoporation). However, its transfection efficiency is generally low, and the expression duration of transfected gene is short. Polyethylenimine (PEI), a cationic polymer, has been shown to aggregate plasmid DNA and facilitate its internalization. The purpose of this study is to determine whether PEI can also prolong the expression duration after US-mediated transfection. A mixture of pCMViLUC and 22-kDa linear PEI was transfected to cultured cells or mouse muscle by exposure to 1-MHz pulsed US. The duration of expression was assessed periodically following US treatment. As expected, strong expression of luciferase could be found 30days after the treatment of DNA-PEI complex with US exposure, both in vitro and in vivo. However, without US, only very low transfection level could be obtained in vivo. The DNA/PEI complex showed protective effect against digestion of DNase I enzymes as compared with groups without PEI or to which PEI was added following the mixing of plasmid DNA with DNase I. PEI enhanced the US transfection efficiency by increasing both the intracellular uptake of plasmid DNA and the percentage of transfected cells. Most of the DNA uptake occurred at 3h after US exposure, suggesting that endocytosis took place. Moreover, the PEI-facilitated US gene transfection depended on the ratio of PEI and DNA (N/P ratio), which was different for in-vitro and in-vivo conditions. This system could be applied in future human gene therapies. PMID:22465392

Lee, Jyun-Lin; Lo, Chia-Wen; Ka, Shuk-Man; Chen, Ann; Chen, Wen-Shiang

2012-05-30

374

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

375

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

376

Relationship Between Maximum Tsunami Amplitude and Duration of Signal  

NASA Astrophysics Data System (ADS)

All available tsunami observations at tide gauges situated along the North American coast were examined to determine if there is any clear relationship between maximum amplitude and signal duration. In total, 89 historical tsunami recordings generated by 13 major earthquakes between 1952 and 2011 were investigated. Tidal variations were filtered out of the signal and the duration between the arrival time and the time at which the signals drops and stays below 0.3 m amplitude was computed. The processed tsunami time series were evaluated and a linear least-squares fit with a 95 % confidence interval was examined to compare tsunami durations with maximum tsunami amplitude in the study region. The confidence interval is roughly 20 h over the range of maximum tsunami amplitudes in which we are interested. This relatively large confidence interval likely results from variations in local resonance effects, late-arriving reflections, and other effects.

Kim, Yoo Yin; Whitmore, Paul M.

2014-12-01

377

Correlates of work injury frequency and duration among firefighters.  

PubMed

This study examined demographic, personality, and economic incentive correlates of workplace injuries suffered by 171 firefighters over a 12-year period. Results showed that female firefighters experienced more injuries than male firefighters. Several Minnesota Multiphasic Personality Inventory (MMPI) scales (Conversion Hysteria, Psychopathic Deviate, and Social Introversion) were positively related to injury frequency. Regression analyses revealed that age, tenure, gender, marital status, type of injury, and wage variables were significant when predicting the duration of injuries as well as an interaction between marital status and gender. Two MMPI scales (Psychopathic Deviate and Schizophrenia) were also significantly related to injury duration. Indemnity cost estimates were calculated. The results underscore the importance of distinguishing the duration of injury from the occurrence of injury. PMID:11482634

Liao, H; Arvey, R D; Butler, R J; Nutting, S M

2001-07-01

378

Fade durations in satellite-path mobile radio propagation  

NASA Technical Reports Server (NTRS)

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.

1986-01-01

379

Long Duration Testing of Type C Thermocouples at 1500 °C  

SciTech Connect

Experience with Type C thermocouples operating for long periods in the 1400 to 1600 °C temperature range indicate that significant decalibration occurs, often leading to expensive downtime and material waste. As part of an effort to understand the mechanisms causing drift in these thermocouples, the Idaho National Laboratory conducted a long duration test at 1500 °C containing eight Type C thermocouples. As report in this document, results from this long duration test were adversely affected due to oxygen ingress. Nevertheless, results provide key insights about the impact of precipitate formation on thermoelectric response. Post-test examinations indicate that thermocouple signal was not adversely impacted by the precipitates detected after 1,000 hours of heating at 1,500 °C and suggest that the signal would not have been adversely impacted by these precipitates for longer durations (if oxygen ingress had not occurred in this test).

Joy L. Rempe; Darrell L. Knudson; J. E. Daw; S. C. Wilkins

2008-04-01

380

Release from retroactive retention interference for acoustic duration.  

PubMed

Listener retention of stimulus duration was studied. Measures of difference-limen-for-duration (DLD) between standard and comparison stimuli were obtained for intervals with and without intervening noise bursts, including an intervening condition with a lateralization cue. The DLD was significantly higher when intervening sounds were present, but a lateralization cue mitigated the interference, presumably by allowing attention to be more readily allocated to retention of the standard. General interference results are in keeping with those reported for pitch, loudness, and timbre retention, but not for retention of gap length. Release from interference with a lateralization cue is akin to that reported for pitch. Overall, the ramifications of retroactive interference on duration retention are more similar to those reported for pitch than for another temporal-based attribute--namely, gap length. PMID:25109012

Ries, Dennis T; Gadd, Danielle; Smith, Meghan

2014-01-01

381

Comparison of Postural Recovery Following Short and Long Duration Spaceflights  

NASA Technical Reports Server (NTRS)

INTRODUCTION: Post-flight postural ataxia reflects adaptive changes to vestibulo-spinal reflexes and control strategies adopted for movement in weightlessness. Quantitative measures obtained during computerized dynamic posturography (CDP) from US and Russian programs provide insight into the effect of spaceflight duration in terms of both the initial decrements and recovery of postural stability. METHODS: CDP was obtained on 117 crewmembers following Shuttle flights lasting 4-17 days, and on 64 crewmembers following long-duration missions lasting 48-380 days. Although the number and timing of sessions varied, the goal was to characterize postural recovery pooling similar measures from different research and flight medicine programs. This report focuses on eyes closed, head erect conditions with either a fixed or sway-referenced base of support. A smaller subset of subjects repeated the sway-referenced condition while making pitch head movements (+/- 20deg at 0.33Hz). Equilibrium scores were derived from peak-to-peak anterior-posterior sway. Fall probability was modeled using Bayesian statistical methods to estimate parameters of a logit function. RESULTS: The standard Romberg condition was the least sensitive. Longer duration flights led to larger decrements in stability with sway-reference support during the first 1-2 days, although the timecourse of recovery was similar across flight duration with head erect. Head movements led to increased incidence of falls during the first week, with a significantly longer recovery following long duration flights. CONCLUSIONS: The diagnostic assessment of postural instability, and differences in the timecourse of postural recovery between short and long flight durations, are more pronounced during unstable support conditions requiring active head movements.

Wood, S. J.; Fiedler, J.; Taylor, L. C.; Kozlovskaya, I.; Black, F. O.; Paloski, W. H.

2010-01-01

382

Secondhand Smoke Exposure, Restless Sleep, and Sleep Duration in Adolescents  

PubMed Central

Purpose. To examine whether secondhand smoke (SHS) exposure is associated with restless sleep and/or nighttime sleep duration among adolescents. Methods. Data were analyzed from 1,592 adolescents who completed an internet-delivered survey as part of the British Columbia Adolescent Substance Use Survey cohort study. Ordinal logistic and linear regression models were used to examine associations between frequency of SHS exposure in the past month and frequency of restless sleep and nighttime sleep duration, respectively. Results. SHS exposure was significantly positively associated with restless sleep and significantly negatively associated with sleep duration. In fully adjusted models, compared with students who reported never being exposed to SHS in the past month, students who reported a low, medium, or high frequency of SHS exposure were 1.53, 1.76, and 2.51 times as likely, respectively, to report more frequent restless sleep (OR = 1.53, 95% CI 1.08–2.16; OR = 1.76, 95% CI 1.22–2.53; OR = 2.51, 95% CI 1.59–3.98). With regard to sleep duration, as frequency of SHS exposure increased by one category, nighttime sleep duration during the week and weekend decreased by 4 minutes (B = ?0.06, 95% CI = ?0.01– ? 0.11) and 6 minutes (B = ?0.09, 95% CI = ?0.03– ? 0.14), respectively. Conclusions. This study suggests that frequency of SHS exposure has a significant dose-response relationship with restless sleep and sleep duration in adolescents. PMID:24808961

Bottorff, Joan L.

2014-01-01

383

A comparison of sunshine duration records from the Campbell-Stokes sunshine recorder and CSD3 sunshine duration sensor  

NASA Astrophysics Data System (ADS)

The purpose of this paper is to compare daily sunshine duration data measured using a Campbell-Stokes sunshine recorder (CS) and a CSD3 sunshine duration sensor (AUTO) as well as to attempt to explain discrepancies between the two data sets. The paper is based on heliographic data and cloudiness observations for 2007-2012. All the data come from the research station of the Jagiellonian University located in Krakow, Poland. Both instruments tend to produce similar sunshine duration data; however, the electronic sensor tends to show more sunshine duration than the CS. The difference may amount to several hours a day, especially on days with maximum solar radiation. The CSD3 sensor is twice as sensitive as the CS and reacts quickly to solar radiation. This is especially true for the first hour following sunrise, the last hour before sunset and when the Sun's disc becomes visible for short periods of time due to changes in cloudiness. However, there are days when the CSD3 registers less sunshine duration (up to an hour) than the CS. This happens with Cumulus clouds in the sky, which tend to pass the Sun's disc very quickly. The CSD3 sensor does not register sunshine in the presence of thick Altostratus and Cirrostratus clouds due to the relative lack of direct radiation. The sunshine recorder, on the other hand, registers this low level of sunshine.

Matuszko, Dorota

2015-02-01

384

Believing Is Seeing: Fixation Duration Predicts Implicit Negative Attitudes  

PubMed Central

A prototypical finding of social cognition is that social experiences influence later performance even though those experiences are not introspectively available. Building on social cognition research on implicit attitudes, we evaluate whether ethnic category/attribute pairs influence eye movements during the Implicit Association Test (IAT, Greenwald, McGhee, & Schwartz 1998). Results show that fixation duration predicted implicit attitudes such that when the category/attribute pairs disconfirmed one's implicit negative attitude fixation duration toward that pair increased. The present research provides evidence that eye movements and implicit processes inherent in the IAT are more broadly connected than previously thought. PMID:25133639

2014-01-01

385

Building a Shared Definitional Model of Long Duration Human Spaceflight  

NASA Technical Reports Server (NTRS)

Objective: To establish the need for a shared definitional model of long duration human spaceflight, that would provide a framework and vision to facilitate communication, research and practice In 1956, on the eve of human space travel, Hubertus Strughold first proposed a "simple classification of the present and future stages of manned flight" that identified key factors, risks and developmental stages for the evolutionary journey ahead. As we look to new destinations, we need a current shared working definitional model of long duration human space flight to help guide our path. Here we describe our preliminary findings and outline potential approaches for the future development of a definition and broader classification system

Arias, Diana; Orr, Martin; Whitmire, Alexandra; Leveton, Lauren; Sandoval, Luis

2012-01-01

386

Crew productivity issues in long-duration space flight  

NASA Technical Reports Server (NTRS)

Considerable evidence suggests the importance of teamwork, coordination, and conflict resolution to the performance and survival of isolated, confined groups in high-technology environments. With the advent of long-duration space flight, group-related issues of crew functioning will take on added significance. This paper discusses the influence of crew roles, status, leadership, and norms on the performance of small, confined groups, and offers guidelines and suggestions regarding organizational design, crew selection, training, and team building for crew productivity and social well-being in long-duration spaceflight.

Nicholas, John M.; Foushee, H. Clayton; Ulschak, Francis L.

1988-01-01

387

Cognitive Assessment in Long-Duration Space Flight  

NASA Technical Reports Server (NTRS)

This slide presentation reviews the development and use of a tool for assessing spaceflight cognitive ability in astronauts. This tool. the Spaceflight Cognitive Assessment Tool for Windows (WinSCAT) has been used to provide ISS flight surgeons with an objective clinical tool to monitor the astronauts cognitive status during long-duration space flight and allow immediate feedback to the astronaut. Its use is medically required for all long-duration missions and it contains a battery of five cognitive assessment subtests that are scheduled monthly and compared against the individual preflight baseline.

Kane, Robert; Seaton, Kimberly; Sipes, Walter

2011-01-01

388

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. PMID:18713688

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

2010-01-01

389

Prolonged Signal-Averaged P-wave Duration as an Intermediate Phenotype for Familial Atrial Fibrillation  

PubMed Central

OBJECTIVES To perform a genome-wide linkage analysis in a large atrial fibrillation (AF) kindred using AF and abnormally prolonged signal-averaged (SA) P-wave duration as the phenotype. BACKGROUND While inherited forms of AF exist, phenotypic complexity has limited efforts to ascertain mutation carriers and thus identify causal genes. The identification of intermediate or endophenotypes may accelerate this effort. METHODS A genome-wide linkage analysis was performed in a 4-generation AF kindred of 27 individuals, 8 with AF documented by ECG. The analysis was performed using AF as the phenotype, and repeated using an abnormally prolonged SA P-wave duration as the phenotype. RESULTS Linkage analysis and fine mapping generated a maximum multipoint logarithm of the odds (LOD) score of 3.0 at chromosome 5p15 between markers D5S406 and D5S635. Importantly, eight heterozygous carriers had a prolonged SA P-wave (203±21 msec) compared with 17 non-carriers (116±12 msec, P<0.00001). Using prolonged SA P-wave (conventionally defined as >155 msec) as an endophenotype, a maximum LOD score of 3.6 was obtained in the same region of chromosome 5p15, a span of 5.75 cM. CONCLUSIONS In a large AF kindred, we have identified a novel AF locus on chromosome 5p15 and demonstrated that affected individuals with AF and mutation carriers can be identified by a prolonged SA P-wave duration. Importantly, identification of an endophenotype in this kindred not only aided ascertainment of additional family members but also increased the LOD score providing increased support for linkage at this locus. Identification of the causal gene, mapped to chromosome 5p15, will advance our understanding of the molecular basis of AF. Condensed Abstract While inherited forms of atrial fibrillation (AF) exist, phenotypic complexity has limited efforts to ascertain mutation carriers and identify causal genes. In a large AF kindred, we have identified a new AF locus on chromosome 5p15 and demonstrated that that affected individuals with AF and mutation carriers can be identified by a prolonged signal-averaged (SA) P-wave duration. Identification of an intermediate or endophenotype not only aided ascertainment of additional family members but also increased the LOD score and will accelerate identification of the causal gene in this kindred. PMID:18342226

Darbar, Dawood; Hardy, Amanda; Haines, Jonathan L; Roden, Dan M

2008-01-01

390

CRISP: A Computational Model of Fixation Durations in Scene Viewing  

ERIC Educational Resources Information Center

Eye-movement control during scene viewing can be represented as a series of individual decisions about where and when to move the eyes. While substantial behavioral and computational research has been devoted to investigating the placement of fixations in scenes, relatively little is known about the mechanisms that control fixation durations.…

Nuthmann, Antje; Smith, Tim J.; Engbert, Ralf; Henderson, John M.

2010-01-01

391

Long Duration Space Missions: Human Subsystem Risks and Requirements  

NASA Technical Reports Server (NTRS)

This viewgraph presentation reviews the human health and performance risks associated with long duration space flight beyond low earth orbit. The contents include: 1) Human Research Program; 2) Human Subsystem Risks; 3) Human Exploration Framework Team (HEFT) Architecture Elements; 4) Potentially Unacceptable Risks -1; 5) Potentially Unacceptable Risks-2; and 6) Major Mission Drivers of Risk.

Kundrot, Criag E.

2011-01-01

392

Bioassays of Shortened Duration for Drugs: Statistical Implications  

Microsoft Academic Search

Declining survival rates in rodent carcinogenesis bioassays have raised a concern that continuing the practice of terminating such studies at 24 months could result in too few live animals at termination for adequate pathological evaluation. One option for ensuring sufficient numbers of animals at the terminal sacrifice is to shorten the duration of the bioassay, but this approach is accompanied

Ralph L. Kodell; Karl K. Lin; Brett T. Thorn; James J. Chen

2000-01-01

393

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

394

Practitioner Empathy and the Duration of the Common Cold  

PubMed Central

Objective To assess the relationship of empathy in medical consultations to subsequent cold outcomes. Methods 350 subjects, ?12 years of age received either a standard or enhanced physician visit as part of a randomized controlled trial. The patient-scored Consultation and Relational Empathy (CARE) questionnaire assessed practitioner-patient interaction, especially empathy. Cold severity and duration were assessed from twice daily symptom reports. Nasal wash was performed to measure the immune cytokine IL-8. Results 84 individuals reported perfect (score of 50) CARE scores. They tended to be older with less education, but reported similar health status, quality of life, and levels of optimism. In those with perfect CARE scores, cold duration was shorter (mean 7.10 days vs. 8.01 days, p=0.032), and there was a trend towards reduced severity (mean AUC 240.40 vs. 284.49, p=0.118). After accounting for possible confounding variables, cold severity and duration were significantly lower in those reporting perfect CARE scores (p=0.037 and p=0.017 respectively). In these models, a perfect score also correlates with a larger increase in IL-8 levels (p=0.015). Conclusions Clinician empathy, as perceived by patients with the common cold, significantly predicts subsequent duration and severity of illness and is associated with immune system changes. PMID:19582635

Rakel, David P.; Hoeft, Theresa J.; Barrett, Bruce P.; Chewning, Betty A.; Craig, Benjamin M.; Niu, Min

2009-01-01

395

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

396

Tsunami early warning using earthquake rupture duration Anthony Lomax1  

E-print Network

Tsunami early warning using earthquake rupture duration Anthony Lomax1 and Alberto Michelini2] Effective tsunami early warning for coastlines near a tsunamigenic earthquake requires notification within 5, greater than about 50 s. Here we show that T0 gives more information on tsunami importance than moment

Rawlinson, Nick

397

The response of flow duration curves to afforestation  

Microsoft Academic Search

The hydrologic effect of replacing pasture or other short crops with trees is reasonably well understood on a mean annual basis. The impact on flow regime, as described by the annual flow duration curve (FDC) is less certain. A method to assess the impact of plantation establishment on FDCs was developed. The starting point for the analyses was the assumption

Alice E. Best; Klaus Hickel; Lu Zhang

2005-01-01

398

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

2011-05-01

399

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

400

A Duration Analysis of Democratic Transitions and Authoritarian Backslides  

Microsoft Academic Search

Recent theories of political development have emphasized redistributive demands as the main drivers of democratic transitions and consolidation. The authors employ Cox duration models to evaluate a number of economic, institutionalist, and sociological theories of regime transition, using global data from 1970 to 1999. This study suggests that demands for redistribution are insufficient explanators of political transitions. The authors find

José Alemán; David D. Yang

2011-01-01

401

MODELING SEGMENTAL DURATION IN GERMAN TEXT-TO-SPEECH SYNTHESIS  

E-print Network

by successively applied rules. Mod- els of this type have been developed for several languages including American is that the feature vector be computable from text. The prevalent type of duration model is a sequential rule system. The solution proposed by van Santen [19, 20, 23] is the applica- tion of a broad class of arithmetic models,

Möbius, Bernd

402

Duration of spermatogenesis in the bullfrog (Lithobates catesbeianus).  

PubMed

The bullfrog (Lithobates catesbeianus) has substantial economic importance and has also been used as an experimental model for biological studies in the fields of pharmacology, medicine, and reproductive biology, especially studies addressing gametogenesis. However, there is a lack of comprehensive information in the literature regarding testis structure and function in this amphibian. The main objective of the current study was to estimate the duration of the various phases of spermatogenesis in this vertebrate. Sixteen sexually mature bullfrogs received an intracoelomic administration of tritiated thymidine. Testes were analyzed at various times between 1h and 33 d after administration to detect the most advanced germ cell types labeled at each interval, as well as labeled preleptotene spermatocytes, which presumably originated from spermatogonial stem cells. The duration of the spermatogonial, spermatocytic, and spermiogenic phases of spermatogenesis in the bullfrog were approximately 18, 14, and 8 d, respectively. Thus, the total duration of the spermatogenesis process from early spermatogonia through to spermatozoa was 40 d in this species, similar to that of most previously investigated mammalian species. To our knowledge, this is the first reliable report on the duration of the full spermatogenic process in any amphibian species. These findings will be very useful for tracking the pace of germ cells in studies involving spermatogonial transplantation in lower vertebrates. PMID:19683337

Segatelli, T M; Batlouni, S R; França, L R

2009-10-15

403

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.

404

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

405

Fast Repetition Detection in TV streams using duration patterns  

E-print Network

the number of image descriptors that have to be computed. First, shot durations are used as hash keys in a video dataset. Most of this research was conducted with two main purposes in mind: video copy detection programs. Since we are looking for long repeated segments, that usually contain several shots, we propose

Paris-Sud XI, Université de

406

Duration Test Report for the Entegrity EW50 Wind Turbine  

SciTech Connect

This report summarizes the results of a duration test that NREL conducted on the Entegrity EW50 wind turbine. This test was conducted in accordance with the International Electrotechnical Commissions' (IEC) standard, Wind Turbine Generator System Part 2: Design requirements for small wind turbines, IEC 61400-2 Ed.2.0, 2006-03.

Smith, J.; Huskey, A.; Jager, D.; Hur, J.

2012-12-01

407

Project scheduling with alternative technologies: Incorporating varying activity duration variability  

Microsoft Academic Search

We look into project scheduling with expected-NPV objective and stochastic activity durations. Individual activities carry a risk of failure, and an activity's failure can cause the overall project to fail. More than one alternative may exist for reaching intermediate project deliverables, and these alternatives can be implemented either in parallel or sequentially. In this paper, optimal solutions to the scheduling

S. Creemers; R. Leus; B. De Reyck

2010-01-01

408

Human factors in long-duration space flight  

NASA Technical Reports Server (NTRS)

A study, covering the behavioral, psychological, physiological, and medical factors of long duration manned space flight, is presented. An attempt was made to identify and resolve major obstacles and unknowns associated with such a flight. The costs and maintenance of the spacecraft system are also explored.

1972-01-01

409

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

410

Designing dementia treatment studies: Diagnosis, efficacy criteria, and duration.  

PubMed

Development of treatments for dementia is beset by special problems in defining the diagnosis, establishing efficacy criteria, and specifying the necessary duration of study. There is need for agreement among clinicians and scientists on diagnostic subgroups of dementia. Similarly, there is a need for harmonization of the regulatory guidelines in Europe, Japan, and the United States regarding the decision set of variables on which to base efficacy claims. The duration of trials must be based upon the intended claim: transient symptomatic benefit, maintained symptomatic benefit, or a therapeutic effect on disease progression. Claims other than transient benefit require long-term trials, suggested to be of at least six months in duration. Problems with long-term studies include slow patient accrual, high dropout rates, changing milieu, low return on investment, and lack of unanimity regarding regulatory requirements. Regulatory authorities must come to some accord, consonant with current clinical/scientific wisdom and consensus, regarding diagnosis, efficacy criteria, and feasible study duration, in order to attract continued sponsor investment in the development of antidementia treatments. PMID:19698442

Spiegel, R; Irwin, P

1996-01-01

411

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

412

Estimation Under Inequality Constraints: Semiparametric Estimation of Conditional Duration Models  

Microsoft Academic Search

This article proposes a semiparametric estimator of the parameter in a conditional duration model when there are inequality constraints on some parameters and the error distribution may be unknown. We propose to estimate the parameter by a constrained version of an unrestricted semiparametrically efficient estimator. The main requirement for applying this method is that the initial unrestricted estimator converges in

Kulan Ranasinghe; Mervyn J. Silvapulle

2011-01-01

413

10 CFR 52.33 - Duration of renewal.  

Code of Federal Regulations, 2010 CFR

...AND APPROVALS FOR NUCLEAR POWER PLANTS Early Site Permits § 52.33 Duration of renewal. Each renewal of an early site permit may be for not less than...any remaining years on the early site permit then in effect before...

2010-01-01

414

20 CFR 410.213 - Duration of entitlement; child.  

Code of Federal Regulations, 2011 CFR

...FEDERAL COAL MINE HEALTH AND SAFETY ACT OF 1969, TITLE IV-BLACK LUNG BENEFITS (1969- ) Requirements for Entitlement; Duration...will be resumed effective with the month of such remarriage or death. In such event no action by or on behalf of such child is...

2011-04-01

415

20 CFR 410.213 - Duration of entitlement; child.  

Code of Federal Regulations, 2010 CFR

...FEDERAL COAL MINE HEALTH AND SAFETY ACT OF 1969, TITLE IV-BLACK LUNG BENEFITS (1969- ) Requirements for Entitlement; Duration...will be resumed effective with the month of such remarriage or death. In such event no action by or on behalf of such child is...

2010-04-01

416

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

417

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

418

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

419

CAVE CRICKET EXIT COUNTS: ENVIRONMENTAL INFLUENCES AND DURATION OF SURVEYS  

E-print Network

CAVE CRICKET EXIT COUNTS: ENVIRONMENTAL INFLUENCES AND DURATION OF SURVEYS FLOYD W. WECKERLY1 1.edu Abstract: Cave cricket abundance is used as an indicator of integrity of cave ecosystems. One means of monitoring cave cricket abundance is counting crickets as they emerge from cave entrances for two hours after

Aspbury, Andrea S. - Department of Biology, Texas State University

420

Duration of ultrasound bubbles enhanced cell membrane permeability  

Microsoft Academic Search

Purpose: Ultrasound (US) has shown the ability to modulate the cell membrane permeability in a process known as sonoporation. In addition, the sonoporation process has been proven to be amplified when US is associated with contrast microbubbles. The purpose of this study is to quantify the duration of the sonoporation process for external molecules with different sizes. Method: monolayers of

Annemieke van Wamel; Ayache Bouakaz; Nico de Jong

2003-01-01

421

Adaptive variability in the duration of critical windows of plasticity  

PubMed Central

Developmental plasticity underlies widespread associations between early-life exposures and many components of adult phenotype, including the risk of chronic diseases. Humans take almost two decades to reach reproductive maturity, and yet the ‘critical windows’ of physiological sensitivity that confer developmental plasticity tend to close during fetal life or infancy. While several explanations for lengthy human maturation have been offered, the brevity of physiological plasticity has received less attention. I argue that offspring plasticity is only viable within the niche of maternal care, and that as this protection is withdrawn, the offspring is obliged to canalize many developmental traits in order to minimize environmental disruptions. The schedule of maternal care may therefore shape the duration of critical windows, and since the duration of this care is subject to parent–offspring conflict, the resolution of this conflict may shape the duration of critical windows. This perspective may help understand (i) why windows close at different times for different traits, and (ii) why the duration of critical windows may vary across human populations. The issue is explored in relation to population differences in the association between infant weight gain and later body composition. The occupation of more stable environments by western populations may have favoured earlier closure of the critical window during which growth in lean mass is sensitive to nutritional intake. This may paradoxically have elevated the risk of obesity following rapid infant weight gain in such populations. PMID:25095791

Wells, Jonathan C. K.

2014-01-01

422

Plant pathology Influence of pre-hardening duration and dehardening  

E-print Network

Plant pathology Influence of pre-hardening duration and dehardening temperatures on varietal freezing resistance in faba beans ( Vicia faba L.) H. Herzog Institute of Crop Science and Plant Breeding — Hardening response of winter faba beans at 8/2°C (day/night) to pre-hardening periods at 15°C

Paris-Sud XI, Université de

423

Sugarcane Response to Month and Duration of Preharvest Flood  

Technology Transfer Automated Retrieval System (TEKTRAN)

Some Florida growers apply 1-day floods about 3 weeks prior to harvest to prevent fires that may ignite on organic soils during preharvest burning of sugarcane (Saccharum spp.). Extending these flood durations could improve sugarcane insect control, freeze protection, soil conservation, and reduce u...

424

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. PMID:22754047

Cohen-Mansfield, Jiska; Perach, Rotem

2012-01-01

425

Reduced heart rate variability during sleep in long-duration spaceflight.  

PubMed

Limited data are available to describe the regulation of heart rate (HR) during sleep in spaceflight. Sleep provides a stable supine baseline during preflight Earth recordings for comparison of heart rate variability (HRV) over a wide range of frequencies using both linear, complexity, and fractal indicators. The current study investigated the effect of long-duration spaceflight on HR and HRV during sleep in seven astronauts aboard the International Space Station up to 6 mo. Measurements included electrocardiographic waveforms from Holter monitors and simultaneous movement records from accelerometers before, during, and after the flights. HR was unchanged inflight and elevated postflight [59.6 ± 8.9 beats per minute (bpm) compared with preflight 53.3 ± 7.3 bpm; P < 0.01]. Compared with preflight data, HRV indicators from both time domain and power spectral analysis methods were diminished inflight from ultralow to high frequencies and partially recovered to preflight levels after landing. During inflight and at postflight, complexity and fractal properties of HR were not different from preflight properties. Slow fluctuations (<0.04 Hz) in HR presented moderate correlations with movements during sleep, partially accounting for the reduction in HRV. In summary, substantial reduction in HRV was observed with linear, but not with complexity and fractal, methods of analysis. These results suggest that periodic elements that influence regulation of HR through reflex mechanisms are altered during sleep in spaceflight but that underlying system complexity and fractal dynamics were not altered. PMID:23637139

Xu, D; Shoemaker, J K; Blaber, A P; Arbeille, P; Fraser, K; Hughson, R L

2013-07-15

426

Trip recovery strategies following perturbations of variable duration.  

PubMed

Appropriately responding to mechanical perturbations during gait is critical to maintain balance and avoid falls. Tripping perturbation onset during swing phase is strongly related to the use of different recovery strategies; however, it is insufficient to fully explain how strategies are chosen. The dynamic interactions between the foot and the obstacle may further explain observed recovery strategies but the relationship between such contextual elements and strategy selection has not been explored. In this study, we investigated whether perturbation onset, duration and side could explain strategy selection for all of swing phase. We hypothesized that perturbations of longer duration would elicit lowering and delayed-lowering strategies earlier in swing phase than shorter perturbations. We developed a custom device to trip subjects multiple times while they walked on a treadmill. Seven young, healthy subjects were tripped on the left or right side at 10% to 80% of swing phase for 150 ms, 250 ms or 350 ms. Strategies were characterized by foot motion post-perturbation and identified by an automated algorithm. A multinomial logistic model was used to investigate the effect of perturbation onset, side, and the interaction between duration and onset on recovery strategy selection. Side perturbed did not affect strategy selection. Perturbation duration interacted with onset, limiting the use of elevating strategies to earlier in swing phase with longer perturbations. The choice between delayed-lowering and lowering strategies was not affected by perturbation duration. Although these variables did not fully explain strategy selection, they improved the prediction of strategy used in response to tripping perturbations throughout swing phase. PMID:24894024

Shirota, Camila; Simon, Ann M; Kuiken, Todd A

2014-08-22

427

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

428

A General Investigation of Optimized Atmospheric Sample Duration  

SciTech Connect

ABSTRACT The International Monitoring System (IMS) consists of up to 80 aerosol and xenon monitoring systems spaced around the world that have collection systems sensitive enough to detect nuclear releases from underground nuclear tests at great distances (CTBT 1996; CTBTO 2011). Although a few of the IMS radionuclide stations are closer together than 1,000 km (such as the stations in Kuwait and Iran), many of them are 2,000 km or more apart. In the absence of a scientific basis for optimizing the duration of atmospheric sampling, historically scientists used a integration times from 24 hours to 14 days for radionuclides (Thomas et al. 1977). This was entirely adequate in the past because the sources of signals were far away and large, meaning that they were smeared over many days by the time they had travelled 10,000 km. The Fukushima event pointed out the unacceptable delay time (72 hours) between the start of sample acquisition and final data being shipped. A scientific basis for selecting a sample duration time is needed. This report considers plume migration of a nondecaying tracer using archived atmospheric data for 2011 in the HYSPLIT (Draxler and Hess 1998; HYSPLIT 2011) transport model. We present two related results: the temporal duration of the majority of the plume as a function of distance and the behavior of the maximum plume concentration as a function of sample collection duration and distance. The modeled plume behavior can then be combined with external information about sampler design to optimize sample durations in a sampling network.

Eslinger, Paul W.; Miley, Harry S.

2012-11-28

429

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. PMID:23259052

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

2012-01-01

430

The effect of pulse duration on the interplay of electron heat conduction and electron–phonon interaction: Photomechanical versus photo-thermal damage of metal targets  

Microsoft Academic Search

Here we present a theoretical work on short pulse laser interaction with metal targets. With the help of Two Temperature Model we consider in detail the interplay of two competitive mechanism of the laser deposited energy dissipation: the fast electron heat conduction and the electron–phonon interaction processes. For a range of pulse durations the modelling included a complex description of

D. S. Ivanov; B. Rethfeld

2009-01-01

431

Stiffness is more than just duration and severity: a qualitative exploration in people with rheumatoid arthritis  

PubMed Central

Objective. Stiffness is internationally recognized as an important indicator of inflammatory activity in RA but is poorly understood and difficult to measure. The aim of this study was to explore the experience of stiffness from the patient perspective. Methods. Semi-structured interviews conducted with 16 RA patients were analysed independently by researchers and pat.ient partners using inductive thematic analysis. Results. Six themes were identified. Part of having RA identified stiffness as a normal consequence of RA, perceived as associated with disease-related aspects such as fluctuating disease activity, other RA symptoms and disease duration. Local and widespread highlighted stiffness occurring not only in joints, but also over the whole body, being more widespread during the morning or flare. Linked to behaviour and environment illustrated factors that influence stiffness, including movement, medications and weather. Highly variable captured the fluctuating nature of stiffness within and between patients and in relation to temporality, duration and intensity. Impacts on daily life emphasized the effect of stiffness on a range of domains, including physical function, quality of life, psychological well-being, activities of daily living and participation in work and leisure activities. Requires self-management detailed self-management strategies targeting both the symptom and its consequences. Conclusion. Patients’ experiences of stiffness were varied, complex and not exclusive to the morning period. Importantly, stiffness was reported in terms of impact rather than the traditional measurement concepts of severity or duration. Based on these findings, further research is needed to develop a patient-centred measure that adequately reflects inflammatory activity. PMID:25231178

Dures, Emma; Kirwan, John; Pollock, Jon; Baker, Gill; Edmunds, Avis; Hewlett, Sarah

2015-01-01

432

Complex Numbers  

NSDL National Science Digital Library

This is a short study guide from the University of Maryland's Physics Education Research Group on introducing, interpreting, and using complex numbers. Mathematical equations are included to help students understand the nature of complex numbers.

2010-04-01

433

Critical ratios of beluga whales (Delphinapterus leucas) and masked signal duration.  

PubMed

This article examines the masking of a complex beluga vocalization by natural and anthropogenic noise. The call consisted of six 150 ms pulses exhibiting spectral peaks between 800 Hz and 8 kHz. Comparing the spectra and spectrograms of the call and noises at detection threshold showed that the animal did not hear the entire call at threshold. It only heard parts of the call in frequency and time. From the masked hearing thresholds in broadband continuous noises, critical ratios were computed. Fletcher critical bands were narrower than either 15 or 111 of an octave at the low frequencies of the call (<2 kHz), depending on which frequency the animal cued on. From the masked hearing thresholds in intermittent noises, the audible signal duration at detection threshold was computed. The intermittent noises differed in gap length, gap number, and masking, but the total audible signal duration at threshold was the same: 660 ms. This observation supports a multiple-looks model. The two amplitude modulated noises exhibited weaker masking than the unmodulated noises hinting at a comodulation masking release. PMID:19062860

Erbe, Christine

2008-10-01

434

Extended Duration of Transgene Expression from Pegylated POD Nanoparticles Enables Attenuation of Photoreceptor Degeneration  

PubMed Central

Retinitis pigmentosa (RP) is the most genetically heterogeneous disorder known to cause blindness, involving over 50 different genes. Previously, we have described nanoparticles (NPs) 150 nm in size, comprised of a 3.5 kD peptide (POD) complexed to PEG and DNA (PEGPOD DNA). These NPs expressing GDNF enabled rescue of photoreceptor degeneration in mice up to 11 days post injection. In the current study we examine use of scaffold/ matrix attachment regions (S/MARs), CpG depletion and titration of DNA content of PEGPOD DNA NPs to extend the duration of transgene expression. S/MARs and CpGs did not significantly influence the duration of transgene expression, but did influence its stability. These parameters enabled us to extend transgene expression from 48 hours to 10 weeks. At 77 days post injection, we observed a 76% rescue of the thickness of the retinal outer nuclear layer (ONL) and at 37 days post injection we observed 53% and 55% rescue of the A and B wave ERG amplitudes respectively and 60% rescue of the ONL. Our studies suggest that PEGPOD DNA NPs have potential as gene delivery vectors for the retina. PMID:24278479

Binder, Christina; Cashman, Siobhan M.; Kumar-Singh, Rajendra

2013-01-01

435

Extended Duration Orbiter (EDO) Improved Waste Collection System (IWCS)  

NASA Technical Reports Server (NTRS)

This overall front view shows the Extended Duration Orbiter (EDO) Waste Collection System (WCS) scheduled to fly aboard NASA's Endeavour, Orbiter Vehicle (OV) 105, for the STS-54 mission. Detailed Test Objective 662, Extended duration orbiter WCS evaluation, will verify the design of the new EDO WCS under microgravity conditions for a prolonged period. OV-105 has been modified with additional structures in the waste management compartment (WMC) and additional avionics to support/restrain the EDO WCS. Among the advantages the new IWCS is hoped to have over the currect WCS are greater dependability, better hygiene, virtually unlimited capacity, and more efficient preparation between shuttle missions. Unlike the previous WCS, the improved version will not have to be removed from the spacecraft to be readied for the next flight. The WCS was documented in JSC's Crew Systems Laboratory Bldg 7.

1992-01-01

436

Extended Duration Orbiter (EDO) Improved Waste Collection System (IWCS)  

NASA Technical Reports Server (NTRS)

This high angle overall view shows the top side components of the Extended Duration Orbiter (EDO) Waste Collection System (WCS) scheduled to fly aboard NASA's Endeavour, Orbiter Vehicle (OV) 105, for the STS-54 mission. Detailed Test Objective 662, Extended duration orbiter WCS evaluation, will verify the design of the new EDO WCS under microgravity conditions for a prolonged period. OV-105 has been modified with additional structures in the waste management compartment (WMC) and additional avionics to support/restrain the EDO WCS. Among the advantages the new IWCS is hoped to have over the currect WCS are greater dependability, better hygiene, virtually unlimited capacity, and more efficient preparation between shuttle missions. Unlike the previous WCS, the improved version will not have to be removed from the spacecraft to be readied for the next flight. The WCS was documented in JSC's Crew Systems Laboratory Bldg 7.

1992-01-01

437

Long Duration Hot Hydrogen Exposure of Nuclear Thermal Rocket Materials  

NASA Technical Reports Server (NTRS)

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-power, multi-gas, wall-stabilized constricted arc-heater to .produce high-temperature pressurized hydrogen flows representative of nuclear reactor core environments, excepting radiation effects, and is intended to serve as a low cost test facility for the purpose of investigating and characterizing candidate fuel/structural materials and improving associated processing/fabrication techniques. Design and engineering development efforts are fully summarized, and facility operating characteristics are reported as determined from a series of baseline performance mapping runs and long duration capability demonstration tests.

Litchford, Ron J.; Foote, John P.; Hickman, Robert; Dobson, Chris; Clifton, Scooter

2007-01-01

438

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

439

Fluency in Parkinson's disease: disease duration, cognitive status and age.  

PubMed

The objective of this study was to determine the frequency of occurrence and to characterize the typology of dysfluencies in individuals with Parkinson's disease (PD), including the variables age, gender, schooling, disease duration, score on the Hoehn and Yahr scale and cognitive status (score on Mini-Mental State Examination). A cross-sectional study of a sample comprising 60 adults matched for gender, age and schooling was conducted. Group I comprised 30 adults with idiopathic PD, and Group II comprised 30 healthy adults. For assessment of fluency of speech, subjects were asked to utter a narrative based on a sequence of drawings and a transcription of 200 fluent syllables was performed to identify speech dysfluencies. PD patients exhibited a higher overall number of dysfluencies in speech with a large number of atypical dysfluencies. Additionally, results showed an influence of the variables cognitive status, disease duration and age on occurrence of dysfluencies. PMID:24863510

Brabo, Natalia Casagrande; Minett, Thais Soares C; Ortiz, Karin Zazo

2014-05-01

440

Electronic Repair Concepts for Long-Duration Spaceflight  

NASA Technical Reports Server (NTRS)

Constraints on the mass and volume that can be allocated for electronics spares and repair equipment on long-duration space missions mean that NASA must look at repair strategies beyond the traditional approach, which has been to replace faulty subsystems in a modular form, termed Orbital Replacement Units or Line Replacement Units. Other possible strategies include component and board-level replacement, modular designs that allow reprogramming of less-critical systems to take the place of more critical failed systems, and a blended approach which uses elements of each of these approaches, along with a limited number of Line Replacement Units. This paper presents some of the constraints and considerations that affect the decision on how to approach electronics repair for long duration space missions, and discusses the benefits and limitations of each of the previously mentioned strategies.

Easton, John; Pettegrew, Richard D.; Struk, Peter M.

2007-01-01

441

Shorter spontaneous fixation durations in infants with later emerging autism  

PubMed Central

Little is known about how spontaneous attentional deployment differs on a millisecond-level scale in the early development of autism spectrum disorders (ASD). We measured fine-grained eye movement patterns in 6-to 9-month-old infants at high or low familial risk (HR/LR) of ASD while they viewed static images. We observed shorter fixation durations (i.e. the time interval between saccades) in HR than LR infants. Preliminary analyses indicate that these results were replicated in a second cohort of infants. Fixation durations were shortest in those infants who went on to receive an ASD diagnosis at 36 months. While these findings demonstrate early-developing atypicality in fine-grained measures of attentional deployment early in the etiology of ASD, the specificity of these effects to ASD remains to be determined. PMID:25655672

Wass, Sam V.; Jones, Emily J. H.; Gliga, Teodora; Smith, Tim J.; Charman, Tony; Johnson, Mark H.; Baron-Cohen, Simon; Bedford, Rachael; Bolton, Patrick; Chandler, Susie; Davies, Kim; Fernandes, Janice; Garwood, Holly; Hudry, Kristelle; Maris, Helen; Pasco, Greg; Pickles, Andrew; Ribiero, Helena; Tucker, Leslie; Volein, Agnes

2015-01-01

442

Temporal duration as a function of information processing.  

PubMed

Estimation of duration has been shown to be a function of the amount and manner of organization of information processed during an interval. It was assumed that the use of an organizational schema to encode information reduces the actual amount of information stored. It was predicted that the use of an organizational schema will result in relatively shorter estimates of duration. Eighteen undergraduate subjects made estimates of intervals (.58 to 3.0 sec.) during which they watched film animations of moving geometric forms. In a second condition the same subjects were instructed to organize the animation as representing social interaction. An interaction showed that the use of an organizational schema to encode information resulted in smaller estimates for the longer intervals. PMID:530800

Berg, M

1979-12-01

443

Habitability and Performance Issues for Long Duration Space Flights  

NASA Technical Reports Server (NTRS)

Advancing technology, coupled with the desire to explore space has resulted in increasingly longer manned space missions. Although the Long Duration Space Flights (LDSF) have provided a considerable amount of scientific research on human ability to function in extreme environments, findings indicate long duration missions take a toll on the individual, both physiologically and psychologically. These physiological and psychological issues manifest themselves in performance decrements; and could lead to serious errors endangering the mission, spacecraft and crew. The purpose of this paper is to document existing knowledge of the effects of LDSF on performance, habitability, and workload and to identify and assess potential tools designed to address these decrements as well as propose an implementation plan to address the habitability, performance and workload issues.

Whitmore, Mihriban; McQuilkin, Meredith L.; Woolford, Barbara J.

1997-01-01

444

Sleep Duration and Cardiovascular Responses to Stress in Undergraduate Men  

PubMed Central

Short sleep has been related to incident cardiovascular disease, but physiological mechanisms accounting for this relationship are largely unknown. This study examines sleep duration and cardiovascular stress responses in 79 healthy, young men. Sleep duration was assessed by wrist actigraphy for seven nights. Participants then completed a series of laboratory stress tasks while heart rate and blood pressure were monitored. Shorter total sleep time was related to a greater reduction in high-frequency heart rate variability during stress tasks, and to prolonged elevations in heart rate and diastolic pressure following tasks. Associations were independent of age, race, body mass index, caffeine intake, and smoking status. In sum, healthy young men with shorter actigraphy-assessed sleep exhibit less cardiac vagal activity, and poorer heart rate and diastolic blood pressure recovery, upon encountering stressful stimuli, than those with longer sleep. PMID:24016263

Mezick, Elizabeth J.; Matthews, Karen A.; Hall, Martica H.; Jennings, J. Richard; Kamarck, Thomas W.

2013-01-01

445

Space mechanisms needs for future NASA long duration space missions  

NASA Technical Reports Server (NTRS)

Future NASA long duration missions will require high performance, reliable, long lived mechanical moving systems. In order to develop these systems, high technology components, such as bearings, gears, seals, lubricants, etc., will need to be utilized. There has been concern in the NASA community that the current technology level in these mechanical component/tribology areas may not be adequate to meet the goals of long duration NASA mission such as Space Exploration Initiative (SEI). To resolve this concern, NASA-Lewis sent a questionnaire to government and industry workers (who have been involved in space mechanism research, design, and implementation) to ask their opinion if the current space mechanisms technology (mechanical components/tribology) is adequate to meet future NASA Mission needs and goals. In addition, a working group consisting of members from each NASA Center, DoD, and DOE was established to study the technology status. The results of the survey and conclusions of the working group are summarized.

Fusaro, Robert L.

1991-01-01

446

COP9 Signalosome Subunit Csn8 Is Involved in Maintaining Proper Duration of the G1 Phase*  

PubMed Central

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

2013-01-01

447

Combination of Rimonabant and Donepezil Prolongs Spatial Memory Duration  

Microsoft Academic Search

The observations that the cannabinoid1(CB1) receptor antagonist\\/inverse agonist, rimonabant, and the selective noncompetitive inhibitor of acetylcholinesterase (AChE), donepezil, improve performance in a variety of animal memory models, suggest that these neurochemical systems play integral roles in cognition. The present study tested whether each of these agents administered alone or in combination will prolong the duration of spatial memory. Rats were

Laura E Wise; Philip A Iredale; Rene J Stokes; Aron H Lichtman

2007-01-01

448

Configuration saliency revealed in short duration binocular rivalry  

Microsoft Academic Search

Supra-threshold spatial integration was studied by testing the saliency of multi-Gabor element configurations in short duration binocular rivalry (dichoptic masking) conditions. Dichoptic presentations allow for a competition between spatially overlapping supra-threshold stimuli that involve non-overlapping monocular receptive fields in the first stage of visual filtering. Different spatial configurations of Gabor patches (?=?=0.12°) were presented to one eye (target) together with

Yoram Bonneh; Dov Sagi

1999-01-01

449

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

2013-11-01

450

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

451

Plasma Cytokine Levels During Long-Duration Spaceflight  

NASA Technical Reports Server (NTRS)

Reduced T cell, granulocyte, NK and monocyte function have all been reported following both long and short duration spaceflight, however these data indicate crews are generally not experiencing inflammatory or adaptive immune activation during spaceflight. There appear to be varied individual crew responses, and specific relationships between cytokines and markers of iron status and muscle turnover that warrant further evaluation. Increases in growth factors and chemokines may indicate other types of adaptation occurring during spaceflight, such as attempts to overcome diminished immunocyte function.

Crucian, Brian E.; Zwart, Sara R.; Quiriarte, Heather A.; Smith, Scott M.; Sams, Clarence F.

2011-01-01

452

Shortening of Cardiac Action Potential Duration Near an Insulating Boundary  

PubMed Central

It is known, from both experiments and simulations, that cardiac action potentials are shortened near a nonconducting boundary. In the present paper, this effect is studied in a simple, two-current ionic model, with propagation restricted to a one-dimensional fiber. An asymptotic approximation for the dependence of action potential duration on distance to the boundary is derived. This estimate agrees well with simulations. PMID:18343886

Cain, John W.; Schaeffer, David G.

2008-01-01

453

Rabbit eyelid conditioning as a function of unconditioned stimulus duration  

Microsoft Academic Search

Reports eyelid conditioning data for 85 male New Zealand white rabbits, employing UCS durations of 50, 100, and 200 msec. Ss with a 50-sec UCS were slower to start conditioning than the 100- or 200-msec groups. The 200-msec group reached a lower terminal performance level than the other 2 groups. Results are related to drive-reduction theory and to possible technical

Peter W. Frey; Charles S. Butler

1973-01-01

454

Inductively stabilized, long pulse duration transverse discharge apparatus  

DOEpatents

An inductively stabilized, long pulse duration transverse discharge apparatus. The use of a segmented electrode where each segment is attached to an inductive element permits high-energy, high-efficiency, long pulsed laser outputs to be obtained. The apparatus has been demonstrated with rare gas halide lasing media. Orders of magnitude increase in pulse repetition frequency are obtained in lasing devices that do not utilize gas flow.

Sze, R.C.

1983-09-01

455

Inductively stabilized, long pulse duration transverse discharge apparatus  

DOEpatents

An inductively stabilized, long pulse duration transverse discharge apparatus. The use of a segmented electrode where each segment is attached to an inductive element permits high energy, high efficiency, long-pulsed laser outputs to be obtained. The present apparatus has been demonstrated with rare-gas halide lasing media. Orders of magnitude increase in pulse repetition frequency are obtained in lasing devices that do not utilize gas flow.

Sze, Robert C. (Santa Fe, NM)

1986-01-01

456

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.

457

Cognitive and motor function in long duration PARKIN PD  

PubMed Central

Importance The long term cognitive outcome in PARKIN-PD patients is unknown. This data may be meaningful when counseling PARKIN-PD patients. Objective Among early-onset PD (EOPD) patients with long disease durations, we assessed cognitive and motor performances, comparing compound heterozygote/homozygote PARKIN carriers to non-carriers Design Cross sectional study Setting Seventeen movement disorders centers Participants Forty-four participants in the Consortium on Risk for Early-Onset PD (CORE-PD) with PD duration greater than median (>14 years), including PARKIN compound heterozygotes/homozygotes combined (n=21), and non-carriers (n=23). Main outcome measures Unified Parkinson’s Disease Rating Scale Part III (UPDRS), Clinical Dementia Rating (CDR) and neuropsychological performance. Linear regression models were applied to assess the association between PARKIN mutation status and cognitive domain scores and UPDRS. Models were adjusted for age, education, disease duration, language, and levodopa equivalent daily dose. Results Compound heterozygote/homozygote PARKIN mutation carriers had earlier AAO of PD (p<0.001) and were younger (p=0.004) at time of examination than non-carriers. They performed better on the MMSE (p=0.010) and were more likely to receive lower scores on the CDR (p=0.003). In multivariate analyses, PARKIN compound heterozygotes/homozygotes performed better on the UPDRS Part III (p=0.017), and on tests of attention (p=0.022), memory (p=0.025) and visuospatial (p=0.024) domains. Conclusions and Relevance Cross-sectional analyses demonstrate better cognitive and motor performance in compound heterozygote/homozygote PARKIN EOPD carriers than non-carriers with long disease duration, suggesting slower disease progression. Longitudinal follow up is required to confirm these findings. PMID:24190026

Alcalay, RN; Caccappolo, E; Mejia-Santana, H; Tang, M–X; Rosado, L; Orbe Reilly, M; Ruiz, D; Louis, ED; Comella, C; Nance, M; Bressman, S; Scott, WK; Tanner, C; Mickel, S; Waters, C; Fahn, S; Cote, L; Frucht, S; Ford, B; Rezak, M; Novak, K; Friedman, JH; Pfeiffer, R; Marsh, L; Hiner, B; Payami, H; Molho, E; Factor, SA; Nutt, J; Serrano, C; Arroyo, M; Ottman, R; Pauciulo, M; Nichols, W; Clark, LN; Marder, K

2013-01-01

458

Sleep duration and risk of fatal and nonfatal stroke  

PubMed Central

Objective: To study the association between sleep duration and stroke incidence in a British population and to synthesize our findings with published results through a meta-analysis. Methods: The prospective study included 9,692 stroke-free participants aged 42–81 years from the European Prospective Investigation into Cancer–Norfolk cohort. Participants reported sleep duration in 1998–2000 and 2002–2004, and all stroke cases were recorded until March 31, 2009. For the meta-analysis, we searched Ovid Medline, EMBASE, and the Cochrane Library for prospective studies published until May 2014, and pooled effect estimates using a weighted random-effect model. Results: After 9.5 years of follow-up, 346 cases of stroke occurred. Long sleep was significantly associated with an increased risk of stroke (hazard ratio [HR] = 1.46 [95% confidence interval (CI) 1.08, 1.98]) after adjustment for all covariates. The association remained robust among those without preexisting diseases and those who reported sleeping well. The association for short sleep was smaller (and not statistically significant) (HR = 1.18 [95% CI 0.91, 1.53]). There was a higher stroke risk among those who reported persistently long sleep or a substantial increase in sleep duration over time, compared to those reporting persistently average sleep. These were compatible with the pooled HRs from an updated meta-analysis, which were 1.15 (1.07, 1.24) and 1.45 (1.30, 1.62) for short and long sleep duration, respectively. Conclusions: This prospective study and meta-analysis identified prolonged sleep as a potentially useful marker of increased future stroke risk in an apparently healthy aging population. PMID:25716357

Cappuccio, Francesco P.; Wainwright, Nick W.J.; Surtees, Paul G.; Luben, Robert; Brayne, Carol; Khaw, Kay-Tee

2015-01-01

459

Observations of short-duration gamma-ray bursts  

NASA Astrophysics Data System (ADS)

Gamma-ray bursts (GRB) are the most powerful cosmological catastrophes in the Universe, with energy releases of 1048 - 1053 erg within a few tens of seconds. It is widely believed that progenitors of the short-duration class of GRB can be merging relativistic binary systems such as a neutron star (NS) and a black hole (BH) or NS-NS. We review the physics of GRBs, their phenomenological properties and observational evidence of GRBs, emphasizing optical observations of GRBs from Mongolia.

Pozanenko, Alexei; Volnova, Alina; Tungalag, Namkhai; Elenin, Leonid; Molotov, Igor; Voropaev, Victor; Schmalz, Sergey

2014-09-01

460

The Prolonged Duration of Rocuronium in Chinese Patients  

Microsoft Academic Search

We compared the potency and duration of action of rocuronium in Chinese and Caucasian patients during general anesthesia. Thirty-six women (18 Caucasian and 18 Chinese) and 36 children (18 Caucasian and 18 Chinese) were evaluated during the administration of propofol\\/fentanyl anesthesia. Patients in each age group were randomized into three subgroups to re- ceive single doses of 0.06, 0.12, or

Linda M. Collins; Joan C. Bevan; David R. Bevan; Giselle C. P. Villar; Raymond Kahwaji; Michael F. Smith

2000-01-01

461

Duration Test Report for the Viryd CS8 Wind Turbine  

SciTech Connect

This report summarizes the results of a duration noise test that the National Renewable Energy Laboratory (NREL) conducted on the Viryd CS8 wind turbine. This test was conducted in accordance with Clause 9.4 of the International Electrotechnical Commission's (IEC) standard, Wind turbines - Part 2: Design requirements for small wind turbines, IEC 61400-2 Ed. 2.0:2006-03. NREL researchers evaluated the turbine based on structural integrity and material degradation, quality of environmental protection, and dynamic behavior.

Roadman, J.; Murphy, M.; van Dam, J.

2013-06-01

462

Astronaut adaptation to 1 G following long duration space flight  

NASA Technical Reports Server (NTRS)

The paper reviews the results of studies of changes undergone by several physiological systems (including the cardiovascular system, the fluid and electrolyte characteristics, the red blood cells, the bone and the muscle tissues, and the exercise capacity) due to the exposures to microgravity and to the adaptation to 1 G after a long-duration space flight. Special attention is given to the effects of various training protocols and countermeasures used to attenuate the physiological problems encountered upon return from space.

Walker, John; Greenisen, Michael; Cowell, Lynda L.; Squires, William G.

1991-01-01

463

Racial Disparities in Short Sleep Duration by Occupation and Industry  

PubMed Central

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