Morphogenesis of univentricular hearts.

PubMed Central

Anderson, R H; Becker, A E; Wilkinson, J L; Gerlis, L M

1976-01-01

Two main theories exist for the explanation of univentricular hearts. One states that the bulboventricular septum becomes realigned to form the interventricular septum, and that univentricular hearts are a consequence of failure of this realignment. The other states that bulboventricular and interventricular septa are different structures, and that the univentricular heart results from failure of formation of the posterior interventricular septum. Four hearts are described in which both the posterior septum and an anterior bulboventricular septum are present. In each heart, therefore, the right ventricular sinus is separated both from the left ventricular sinus and from a discrete outlet chamber which supports the pulmonary artery. It is argued that these findings militate strongly against theories proposing reorientation of the bulboventricular septum to form the definitive interventricular septum. They support strongly the concept that the definitive right ventricle is formed in part from the bulbus and in part from the primitive ventricle. On the basis of these findings, it is suggested that the distinctive feature of the univentricular heart is absence of the posterior septum. Such hearts can properly be termed 'primitive ventricle'. It is also suggested that hearts with atretic or straddling valves should be included within this category. Images PMID:1275986

Isolated noncompaction of myocardium associated with calcification in the interventricular septum.

PubMed

Nil, M; Mori, K; Yuasa, Y; Ichida, F

2003-01-01

We describe a 12-year-old male with isolated noncompaction of the myocardium and associated abnormal calcification in the basal interventricular septum, and we present a review of the literature. The patient has been healthy and free of symptoms. The electrocardiogram showed abnormal Q waves in III, V1, V2, and ST elevation in V1-V3. Exercise testing demonstrated ST depression in V4 and V5. Myocardial scintigraphic examination showed a regional reduction in iodine-1,2,3-beta-methyl-iodophenylpentadecanoic acid uptake in the basal interventricular septum. Since coronary angiography demonstrated normal coronary vessels and the trabeculations were not prominent in this region, we hypothesize that coronary microcirculatory dysfunction may cause subendocardial infarction associated with calcification in the same area.

Hydatid cyst of the interventricular septum and contribution of magnetic resonance imaging.

PubMed

Kulan, K; Tuncer, C; Kulan, C; Serce, K; Goldeli, O; Irhan, S; Komsuoglu, B

1995-01-01

Cardiac echinococcosis has not been reported frequently. Because of the risk of potentially lethal complications, early diagnosis and definitive treatment are very important. We report a case of a cardiac echinococcal cyst in the interventricular septum. The cyst that caused angina and showed ischemic changes in electrocardiogram was diagnosed by two-dimensional echocardiography and magnetic resonance imaging and was treated surgically.

Haemangiosarcoma of the interventricular septum in a dog.

PubMed

Thompson, D J; Cave, N J; Scrimgeour, A B; Thompson, K G

2011-11-01

Abstract A 5-year-old male neutered Labrador Retriever Afghan crossbred dog was examined after collapsing. The dog was recumbent, dyspnoeic and mildly tachypnoeic. There was a tachyarrhythmia (300 beats per minute) and subcutaneous oedema of the ventral neck and right forelimb. The dog had a sustained ventricular tachycardia originating in the right ventricle and on echocardiography a mass was identified in the interventricular septum. Due to the poor prognosis the owners agreed to euthanasia of the dog. A reddish-grey mass was found in the interventricular septum and smaller red foci found scattered throughout the myocardium. There was a single, raised, splenic nodule with several smaller red foci within the splenic parenchyma. Hepatic congestion, pancreatic oedema, ascites and subcutaneous oedema of the right forelimb and neck were present. Sections of the splenic nodule, interventricular septal mass and both ventricular-free walls showed neoplastic mesenchymal cells. Haemangiosarcoma of the myocardium and spleen with right-sided congestive heart failure. This case report describes an atypical location for haemangiosarcoma. The investigation supports the use of echocardiography as a component of the protocol for staging haemangiosarcoma even in the absence of apericardial effusion. It also provides further evidence for the inclusion of intracardiac neoplasia as a differential diagnosis for dogs with unexplained cardiac arrhythmias.

British randomised controlled trial of AV and VV optimization ("BRAVO") study: rationale, design, and endpoints.

PubMed

Whinnett, Zachary I; Sohaib, S M Afzal; Jones, Siana; Kyriacou, Andreas; March, Katherine; Coady, Emma; Mayet, Jamil; Hughes, Alun D; Frenneaux, Michael; Francis, Darrel P

2014-04-03

Echocardiographic optimization of pacemaker settings is the current standard of care for patients treated with cardiac resynchronization therapy. However, the process requires considerable time of expert staff. The BRAVO study is a non-inferiority trial comparing echocardiographic optimization of atrioventricular (AV) and interventricular (VV) delay with an alternative method using non-invasive blood pressure monitoring that can be automated to consume less staff resources. BRAVO is a multi-centre, randomized, cross-over, non-inferiority trial of 400 patients with a previously implanted cardiac resynchronization device. Patients are randomly allocated to six months in each arm. In the echocardiographic arm, AV delay is optimized using the iterative method and VV delay by maximizing LVOT VTI. In the haemodynamic arm AV and VV delay are optimized using non-invasive blood pressure measured using finger photoplethysmography. At the end of each six month arm, patients undergo the primary outcome measure of objective exercise capacity, quantified as peak oxygen uptake (VO2) on a cardiopulmonary exercise test. Secondary outcome measures are echocardiographic measurement of left ventricular remodelling, quality of life score and N-terminal pro B-type Natriuretic Peptide (NT-pro BNP). The study is scheduled to complete recruitment in December 2013 and to complete follow up in December 2014. If exercise capacity is non-inferior with haemodynamic optimization compared with echocardiographic optimization, it would be proof of concept that haemodynamic optimization is an acceptable alternative which has the potential to be more easily implemented. Clinicaltrials.gov NCT01258829.

[Cardiac resynchronization therapy for heart failure - from experimental pacing to evidence-based therapy].

PubMed

Götze, S; Butter, C; Fleck, E

2006-01-01

Within the last decade, cardiac resynchronization therapy (CRT) has become an evidence-based cornerstone for a subset of patients with chronic heart failure. For those, who suffer from ischemic or non-ischemic cardiomyopathies at NYHA III or IV, have sinus rhythm, a left bundle branch block and a left ventricular ejection fraction below 35%, CRT has evolved as an important treatment option with promising results. Numerous studies have shown that in these patients pacemaker-mediated correction of intra- and interventicular conduction disturbances can improve not only clinical symptoms, exercise tolerance and the frequency of hospitalizations, but even more important the overall mortality. These clinical results are due to several functional aspects. In the failing heart characteristic intra- and interventricular alterations in electrical conduction result in mechanical asynchrony that leads to an abnormal contraction of the left ventricle with delayed activation of the lateral wall, a paradoxical septal movement, a reduced diastolic filling and a mitral regurgitation due to dyssynchrony of papillary muscle activation. It is conceivable that these functional changes have fatal consequences for the failing heart. AV-optimized left- or biventricular stimulation by modern pacemakers can correct the pathological dyssynchrony, thereby improving cardiac function and clinical outcome in these patients. Although tremendous progress in cardiac resynchronization therapy has been made during the last decade, a couple of questions still need to be resolved. Critical issues are the identification of patients, who will predictably benefit from CRT, the value of CRT-pacemakers versus CRT-ICDs, and the usefullness of CRT in patients with atrial fibrillation.

Biventricular pacemaker optimization guided by comprehensive echocardiography-preliminary observations regarding the effects on systolic and diastolic ventricular function and third heart sound.

PubMed

Taha, Nima; Zhang, Jing; Ranjan, Rupesh; Daneshvar, Samuel; Castillo, Edilzar; Guillen, Elizabeth; Montoya, Martha C; Velasquez, Giovanna; Naqvi, Tasneem Z

2010-08-01

Doppler echocardiography of mitral inflow or aortic outflow or both has been validated and advocated to guide biventricular (Biv) pacemaker optimization. A comprehensive and tailored Doppler echocardiographic evaluation may be required in patients with heart failure to assist with Biv pacemaker optimization. The third heart sound (S(3)), an acoustic cardiographic parameter, has been demonstrated to be a highly specific finding for hemodynamic evaluation in patients with heart failure. The aims of this study were to evaluate the use of comprehensive Doppler echocardiography as a guide during Biv pacemaker optimization in patients after cardiac resynchronization therapy and to evaluate the feasibility of S(3) intensity to be a cost-efficient parameter for Biv pacemaker optimization compared with Doppler echocardiography. Comprehensive Doppler echocardiographic evaluations were performed during Biv pacemaker optimization in 44 patients referred for pacemaker optimization (mean age, 71 + or - 12 years; mean left ventricular ejection fraction, 34 + or - 11%). Blinded assessment of S(3) intensity was performed simultaneously using acoustic cardiography. The correlation and improvement in cardiac hemodynamics were analyzed between the methods. Echocardiographically guided optimization resulted in significant improvements in the left ventricular outflow velocity-time integral (15.92 + or - 4.77 to 18.51 + or - 5.19 cm, P < .001), ejection time (278 + or - 40 to 293 + or - 40 ms, P < .001), myocardial performance index (0.57 + or - 0.19 to 0.44 + or - 0.14, P < .002), and peak pulmonary artery systolic pressure (42 + or - 13 to 36 + or - 11 mm Hg, P < .04) and decreased S(3) intensity from 4.81 + or - 1.84 at baseline to 3.96 + or - 1.22 after optimization (P < .02) for the overall study group and from 6.63 + or - 1.37 to 4.85 + or - 1.13 (P < .001) in the 18 patients with baseline S(3) intensity > 5.0. The correlation between echocardiographic and acoustic cardiographic S(3) intensity for optimal atrioventricular delay was 0.86 (P < .001) and for optimal interventricular delay was 0.64 (P < .001). Optimal atrioventricular delay was identical by echocardiographic and acoustic cardiographic S(3) intensity in 56%, and optimal interventricular delay was identical in 75% of patients. Pacemakers were permanently programmed on the basis of echocardiographic evaluation. In 35 patients available for follow up, the mean New York Heart Association class reduced from 2.55 + or - 0.81 to 1.77 + or - 0.90 (P < .001) and the mean quality-of-life score as assessed by Minnesota Living With Heart Failure Questionnaire improved from 45 + or - 28 to 32 + or - 28 (P = .08) at 2.5 + or - 2.1 months. Comprehensive echocardiographically guided Biv pacemaker optimization produces significant improvement in Doppler echocardiographic hemodynamics, a reduction in S(3) intensity, and an improvement in functional class in patients after cardiac resynchronization therapy. Copyright 2010 American Society of Echocardiography. Published by Mosby, Inc. All rights reserved.

Large Lipomatous Hypertrophy of the Interventricular Septum

PubMed Central

Ak, Koray; Isbir, Selim; Kepez, Alper; Turkoz, Kemal; Elci, Emre; Arsan, Sinan

2014-01-01

We present the case of a 58-year-old woman who had large lipomatous hypertrophy of the interventricular septum, a condition that is reported very infrequently. Preoperative cardiac magnetic resonance images revealed an inhomogeneous, infiltrating mass that was suppressed in fat-suppression mode. The extensive mass was causing right ventricular dysfunction, so we excised it through a right ventricular approach. The findings on histologic analysis of the mass were consistent with lipomatous hypertrophy. The patient died of septic shock on the 28th postoperative day. In addition to the patient's case, we discuss the characteristics and diagnosis of this rare entity. PMID:24808791

[Anterior infarction of the left ventricle and infarct of the posterior wall of the right ventricle caused by thrombosis of the anterior interventricular artery].

PubMed

Penther, P; Boschat, J; Etienne, Y; Le Potier, J

1988-01-01

The association: anterior infarction of the left ventricle-posterior infarction of the right ventricle, is a rare entity. The authors report the case of a 64 year-old woman, who died on the fifth day of an extended anterior myocardial infarction, present on electrocardiograms; there were however immediate signs of right heart failure unexplained by a pericardial effusion. At the autopsy, the unusual length and distribution of the anterior interventricular artery which was completely obstructed near its origin by a thrombosis occurring on a severe atheromatous and calcified stenosis, explain this association.

Echocardiography for cardiac resynchronization therapy: recommendations for performance and reporting--a report from the American Society of Echocardiography Dyssynchrony Writing Group endorsed by the Heart Rhythm Society.

PubMed

Gorcsan, John; Abraham, Theodore; Agler, Deborah A; Bax, Jeroen J; Derumeaux, Genevieve; Grimm, Richard A; Martin, Randy; Steinberg, Jonathan S; Sutton, Martin St John; Yu, Cheuk-Man

2008-03-01

Echocardiography plays an evolving and important role in the care of heart failure patients treated with biventricular pacing, or cardiac resynchronization therapy (CRT). Numerous recent published reports have utilized echocardiographic techniques to potentially aide in patient selection for CRT prior to implantation and to optimized device settings afterwards. However, no ideal approach has yet been found. This consensus report evaluates the contemporary applications of echocardiography for CRT including relative strengths and technical limitations of several techniques and proposes guidelines regarding current and possible future clinical applications. Principal methods advised to qualify abnormalities in regional ventricular activation, known as dyssynchrony, include longitudinal velocities by color-coded tissue Doppler and the difference in left ventricular to right ventricular ejection using routine pulsed Doppler, or interventricular mechanical delay. Supplemental measures of radial dynamics which may be of additive value include septal-to-posterior wall delay using M-mode in patients with non-ischemic disease with technically high quality data, or using speckle tracking radial strain. A simplified post-CRT screening for atrioventricular optimization using Doppler mitral inflow velocities is also proposed. Since this is rapidly changing field with new information being added frequently, future modification and refinements in approach are anticipated to continue.

A systematic approach to designing reliable VV optimization methodology: assessment of internal validity of echocardiographic, electrocardiographic and haemodynamic optimization of cardiac resynchronization therapy.

PubMed

Kyriacou, Andreas; Li Kam Wa, Matthew E; Pabari, Punam A; Unsworth, Beth; Baruah, Resham; Willson, Keith; Peters, Nicholas S; Kanagaratnam, Prapa; Hughes, Alun D; Mayet, Jamil; Whinnett, Zachary I; Francis, Darrel P

2013-08-10

In atrial fibrillation (AF), VV optimization of biventricular pacemakers can be examined in isolation. We used this approach to evaluate internal validity of three VV optimization methods by three criteria. Twenty patients (16 men, age 75 ± 7) in AF were optimized, at two paced heart rates, by LVOT VTI (flow), non-invasive arterial pressure, and ECG (minimizing QRS duration). Each optimization method was evaluated for: singularity (unique peak of function), reproducibility of optimum, and biological plausibility of the distribution of optima. The reproducibility (standard deviation of the difference, SDD) of the optimal VV delay was 10 ms for pressure, versus 8 ms (p=ns) for QRS and 34 ms (p<0.01) for flow. Singularity of optimum was 85% for pressure, 63% for ECG and 45% for flow (Chi(2)=10.9, p<0.005). The distribution of pressure optima was biologically plausible, with 80% LV pre-excited (p=0.007). The distributions of ECG (55% LV pre-excitation) and flow (45% LV pre-excitation) optima were no different to random (p=ns). The pressure-derived optimal VV delay is unaffected by the paced rate: SDD between slow and fast heart rate is 9 ms, no different from the reproducibility SDD at both heart rates. Using non-invasive arterial pressure, VV delay optimization by parabolic fitting is achievable with good precision, satisfying all 3 criteria of internal validity. VV optimum is unaffected by heart rate. Neither QRS minimization nor LVOT VTI satisfy all validity criteria, and therefore seem weaker candidate modalities for VV optimization. AF, unlinking interventricular from atrioventricular delay, uniquely exposes resynchronization concepts to experimental scrutiny. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Investigation of a novel algorithm for synchronized left-ventricular pacing and ambulatory optimization of cardiac resynchronization therapy: results of the adaptive CRT trial.

PubMed

Martin, David O; Lemke, Bernd; Birnie, David; Krum, Henry; Lee, Kathy Lai-Fun; Aonuma, Kazutaka; Gasparini, Maurizio; Starling, Randall C; Milasinovic, Goran; Rogers, Tyson; Sambelashvili, Alex; Gorcsan, John; Houmsse, Mahmoud

2012-11-01

In patients with sinus rhythm and normal atrioventricular conduction, pacing only the left ventricle with appropriate atrioventricular delays can result in superior left ventricular and right ventricular function compared with standard biventricular (BiV) pacing. To evaluate a novel adaptive cardiac resynchronization therapy ((aCRT) algorithm for CRT pacing that provides automatic ambulatory selection between synchronized left ventricular or BiV pacing with dynamic optimization of atrioventricular and interventricular delays. Patients (n = 522) indicated for a CRT-defibrillator were randomized to aCRT vs echo-optimized BiV pacing (Echo) in a 2:1 ratio and followed at 1-, 3-, and 6-month postrandomization. The study met all 3 noninferiority primary objectives: (1) the percentage of aCRT patients who improved in their clinical composite score at 6 months was at least as high in the aCRT arm as in the Echo arm (73.6% vs 72.5%, with a noninferiority margin of 12%; P = .0007); (2) aCRT and echo-optimized settings resulted in similar cardiac performance, as demonstrated by a high concordance correlation coefficient between aortic velocity time integrals at aCRT and Echo settings at randomization (concordance correlation coefficient = 0.93; 95% confidence interval 0.91-0.94) and at 6-month postrandomization (concordance correlation coefficient = 0.90; 95% confidence interval 0.87-0.92); and (3) aCRT did not result in inappropriate device settings. There were no significant differences between the arms with respect to heart failure events or ventricular arrhythmia episodes. Secondary end points showed similar benefit, and right-ventricular pacing was reduced by 44% in the aCRT arm. The aCRT algorithm is safe and at least as effective as BiV pacing with comprehensive echocardiographic optimization. Copyright © 2012 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Nonlinear excited waves on the interventricular septum

NASA Astrophysics Data System (ADS)

Bekki, Naoaki; Harada, Yoshifumi; Kanai, Hiroshi

2012-11-01

Using a novel ultrasonic noninvasive imaging method, we observe some phase singularities in propagating excited waves on a human cardiac interventricular septum (IVS) for a healthy young male. We present a possible physical model explaining one-dimensional dynamics of phase singularities in nonlinearly excited waves on the IVS. We show that at least one of the observed phase singularities in the excited waves on the IVS can be explained by the Bekki-Nozaki hole solution of the complex Ginzburg-Landau equation without any adjustable parameters. We conclude that the complex Ginzburg-Landau equation is such a suitable model for one-dimensional dynamics of cardiac phase singularities in nonlinearly excited waves on the IVS.

Morphology and Classification of Right Ventricular Bands in the Domestic Dog (Canis familiaris).

PubMed

Cope, L A

2017-10-01

Ventricular bands, also designated as 'false tendons', are described as single or multiple strands that cross the ventricles and have no connection to valvular cusps. Previous work indicates these strands are present in the ventricles of humans and some animal hearts and not always associated with cardiac pathologies. Despite these previous studies, the published literature is limited in documenting the morphology of these strands and incidence in animals. In this study, examination of 89 hearts showed six types of ventricular bands in the right ventricle of the domestic dog. These bands were classified according to their prevalence and points of attachment. Type I extended from the interventricular septum to the ventricular free wall, type II connected a musculus papillaris parvus to the ventricular free wall and type III connected trabeculae carneae on the interventricular septum. Type IV connected the trabeculae carneae on the ventricular free wall, type V interconnected papillary muscles and type VI connected the interventricular septum to a papillary muscle. While the study of these ventricular bands provided additional information on the cardiac anatomy of the domestic dog, it also showed their clinical importance. Several studies have proposed that their position in the ventricle may interfere with cardiac catheterization and pacemaker lead placement or be misinterpreted during echocardiography. © 2017 Blackwell Verlag GmbH.

New congenital coronary artery anomaly - double supply of single left anterior descending coronary artery from the left and right coronary sinuses: a case report.

PubMed

Daralammouri, Yunis; Ghannam, Malik; Lauer, Bernward

2016-08-02

A normal anatomy of coronary arteries is important to have adequate cardiac muscle blood supply especially during extraneous physical activities. This case report describes a rare coronary anomaly in which the accessory coronary artery arose from the right coronary artery, reentered the left anterior descending coronary artery, and then ran as a single vessel. We present a case of a coronary anomaly in a 47-year-old white man who presented with atypical angina. Computed tomographic angiography and coronary angiography showed a variant of dual left anterior descending coronary artery not previously described. Our patient's accessory coronary artery arose from his right coronary artery. It took an intramuscular course beneath the right ventricular outflow tract in the interventricular septal area to the anterior interventricular sulcus, giving off septal perforators that reentered his medial left anterior descending coronary artery. Both vessels ran after the anastomosis in the anterior interventricular sulcus as a single vessel. We propose that this anomaly represents a new variant of coronary artery anomaly. This coronary artery anomaly does not cause ischemia. Recognition of this coronary anomaly is important in patients undergoing percutaneous coronary intervention or coronary artery bypass graft operations.

Right atrial pacing impairs cardiac function during resynchronization therapy: acute effects of DDD pacing compared to VDD pacing.

PubMed

Bernheim, Alain; Ammann, Peter; Sticherling, Christian; Burger, Peter; Schaer, Beat; Brunner-La Rocca, Hans Peter; Eckstein, Jens; Kiencke, Stephanie; Kaiser, Christoph; Linka, Andre; Buser, Peter; Pfisterer, Matthias; Osswald, Stefan

2005-05-03

We aimed to compare the hemodynamic effects of right-atrial-paced (DDD) and right-atrial-sensed (VDD) biventricular paced rhythm on cardiac resynchronization therapy (CRT). Cardiac resynchronization therapy improves hemodynamics in patients with severe heart failure and left ventricular (LV) dyssynchrony. However, the impact of active right atrial pacing on resynchronization therapy is unknown. Seventeen CRT patients were studied 10 months (range: 1 to 46 months) after implantation. At baseline, the programmed atrioventricular delay was optimized by timing LV contraction properly at the end of atrial contraction. In both modes the acute hemodynamic effects were assessed by multiple Doppler echocardiographic parameters. Compared to DDD pacing, VDD pacing resulted in much better improvement of intraventricular dyssynchrony assessed by the septal-to-posterior wall motion delay (VDD 106 +/- 83 ms vs. DDD 145 +/- 95 ms; p = 0.001), whereas the interventricular mechanical delay (difference between onset of pulmonary and aortic outflow) did not differ (VDD 20 +/- 21 ms vs. DDD 18 +/- 17 ms; p = NS). Furthermore, VDD pacing significantly prolonged the rate-corrected LV filling period (VDD 458 +/- 123 ms vs. DDD 371 +/- 94 ms; p = 0.0001) and improved the myocardial performance index (VDD 0.60 +/- 0.18 vs. DDD 0.71 +/- 0.23; p < 0.01). Our findings suggest that avoidance of right atrial pacing results in a higher degree of LV resynchronization, in a substantial prolongation of the LV filling period, and in an improved myocardial performance. Thus, the VDD mode seems to be superior to the DDD mode in CRT patients.

Quantification of ventricular resynchronization reserve by radionuclide phase analysis in heart failure patients: a prospective long-term study.

PubMed

Dauphin, Raphael; Nonin, Emilie; Bontemps, Laurence; Vincent, Madeleine; Pinel, Alain; Bonijoly, Serge; Barborier, Denis; Ribier, Arnaud; Fernandes, Christine Mestre; Bert-Marcaz, Patrick; Itti, Roland; Chevalier, Philippe

2011-03-01

Phase analysis, developed to assess dyssynchrony from ECG-gated radionuclide ventriculography, has shown promising results. We hypothesized that quantifying the cardiac resynchronization reserve, that is, the extent of response to cardiac resynchronization therapy (CRT), by radionuclide imaging could potentially identify patients who are best suited for CRT. Seventy-four patients ages 64.8±10.1 years were prospectively studied from July 2004 to July 2006, of whom 62.2% and 37.8%, respectively, were in New York Heart Association class 3 and 4. Mean QRS width was 173±25 ms. ECG-gated radionuclide ventriculography to quantify interventricular and intraventricular dyssynchrony was performed at baseline with and without CRT and at the 3-month follow-up visit. Amino-terminal-pro-brain natriuretic peptide (NT-pro-BNP) levels were also determined at baseline and at 3 months. During a mean follow-up of 10.1±7.6 months, there were 37 (50%) clinical events that defined the nonresponder group, including cardiac death or readmission for worsening heart failure. In multivariate Cox model analysis, higher NT-pro-BNP blood levels were associated with a significant increase in the risk for event (hazard ratio=1.085 for a 100 pg/L increase in NT-pro-BNP; 95% confidence interval, 1.014 to 1.161). Each 10° elevation in intraventricular dyssynchrony was associated with a decrease in the risk of events (hazard ratio=0.456, 95% confidence interval, 0.304 to 0.683). Receiver operating characteristic curve analysis demonstrated that an interventricular dyssynchrony cutoff value of 25.5° for intraventricular synchrony yielded 91.4% sensitivity and 84.4% specificity for predicting a good response to CRT. The quantification of interventricular dyssynchrony with radionuclide phase analysis suggests that early postimplantation interventricular dyssynchrony may provide identification of CRT responders.

Comparison of radiological and morphologic assessments of myocardial bridges.

PubMed

Ercakmak, Burcu; Bulut, Elif; Hayran, Mutlu; Kaymaz, Figen; Bilgin, Selma; Hazirolan, Tuncay; Bayramoglu, Alp; Erbil, Mine

2015-09-01

In this study we aimed to compare the findings of coronary dual-source computed tomography angiography of myocardial bridges with cadaveric dissections. Forty-one isolated, non-damaged fresh sheep hearts were used in this study. Myocardial bridges of the anterior interventricular branch of the left coronary artery were demonstrated and analyzed by a coronary dual-source computed tomography angiography. Dissections along the left anterior interventricular branch of the left coronary artery were performed by using Zeiss OPMI pico microscope and the length of the bridges were measured. The depths of the myocardial bridges were measured from the stained sections by using the light microscope (Leica DM 6000B). MBs were found in all 41 hearts (100%) during dissections. Dual-source computed tomography angiography successfully detected 87.8% (36 of the 41 hearts) of the myocardial bridges measured on left anterior interventricular branch of left coronary artery. The lengths of the myocardial bridges were found 5-40 and 8-50 mm with dissection and dual-source computed tomography angiography, respectively. And the depths were found 0.7-4.5 mm by dual-source computed tomography angiography and 0.745-4.632 mm morphologically. Comparison of the mean values of the lengths showed statistically significantly higher values (22.0 ± 8.5, 17.7 ± 7.7 mm, p = 0.003) for the dissections. Radiological assessment also effectively discriminated complete bridges from incomplete ones. Our study showed that coronary computed tomography angiography is reliable in evaluating the presence and depth of myocardial bridges.

Spatial distributions of Kv4 channels and KChip2 isoforms in the murine heart based on laser capture microdissection.

PubMed

Teutsch, Christine; Kondo, Richard P; Dederko, Dorothy A; Chrast, Jacqueline; Chien, Kenneth R; Giles, Wayne R

2007-03-01

Regional differences in repolarizing K(+) current densities and expression levels of their molecular components are important for coordinating the pattern of electrical excitation and repolarization of the heart. The small size of hearts from mice may obscure these interventricular and/or transmural expression differences of K(+) channels. We have examined this possibility in adult mouse ventricle using a technology that provides very high spatial resolution of tissue collection. Conventional manual dissection and laser capture microdissection (LCM) were utilized to dissect tissue from distinct ventricular regions. RNA was isolated from epicardial, mid-myocardial and endocardial layers of both the right and left ventricles. Real-time RT-PCR was used to quantify the transcript expression in these different regions. LCM revealed significant interventricular and transmural gradients for both Kv4.2 and the alpha-subunit of KChIP2. The expression profile of a second K(+) channel transcript, Kir2.1, which is responsible for the inwardly rectifying K(+) current I(k1), showed no interventricular or transmural gradients and therefore served as a negative control. Our findings are in contrast to previous reports of a relatively uniform left ventricular transmural pattern of expression of Kv4.2, Kv4.3 and KChIP2 in adult mouse heart, which appear to be different than that in larger mammals. Specifically, our results demonstrate significant epi- to endocardial differences in the patterns of expression of both Kv4.2 and KChIP2.

Partial rescue of defects in Cited2-deficient embryos by HIF-1alpha heterozygosity.

PubMed

Xu, Bing; Doughman, Yongqiu; Turakhia, Mona; Jiang, Weihong; Landsettle, Chad E; Agani, Faton H; Semenza, Gregg L; Watanabe, Michiko; Yang, Yu-Chung

2007-01-01

Hypoxia inducible factor-1 (HIF-1) initiates key cellular and tissue responses to physiological and pathological hypoxia. Evidence from in vitro and structural analyses supports a critical role for Cited2 in down-regulating HIF-1-mediated transcription by competing for binding with oxygen-sensitive HIF-1alpha to transcriptional co-activators CBP/p300. We previously detected elevated expression of HIF-1 target genes in Cited2(-/-) embryonic hearts, indicating that Cited2 inhibits HIF-1 transactivation in vivo. In this study, we show for the first time that highly hypoxic cardiac regions in mouse embryos corresponded to the sites of defects in Cited2(-/-) embryos and that defects of the outflow tract, interventricular septum, cardiac vasculature, and hyposplenia were largely rescued by HIF-1alpha haploinsufficiency. The hypoxia of the outflow tract and interventricular septum peaked at E13.5 and dissipated by E15.5 in wild-type hearts, but persisted in E15.5 Cited2(-/-) hearts. The persistent hypoxia and abnormal vasculature in the myocardium of interventricular septum in E15.5 Cited2(-/-) hearts were rescued with decreased HIF-1alpha gene dosage. Accordingly, mRNA levels of HIF-1-responsive genes were reduced in Cited2(-/-) embryonic hearts by HIF-1alpha heterozygosity. These findings suggest that a precise level of HIF-1 transcriptional activity critical for normal development is triggered by differential hypoxia and regulated through feedback inhibition by Cited2.

Regression equations for calculation of z scores for echocardiographic measurements of left heart structures in healthy Han Chinese children.

PubMed

Wang, Shan-Shan; Hong, Wen-Jing; Zhang, Yu-Qi; Chen, Shu-Bao; Huang, Guo-Ying; Zhang, Hong-Yan; Chen, Li-Jun; Wu, Lan-Ping; Shen, Rong; Liu, Yi-Qing; Zhu, Jun-Xue

2018-06-01

Clinical decision making in children with heart disease relies on detailed measurements of cardiac structures using two-dimensional and M-mode echocardiography. However, no echocardiographic reference values are available for the Chinese children. We aimed to establish z-score regression equations for left heart structures in a population-based cohort of healthy Chinese Han children. Echocardiography was performed in 545 children with a normal heart. The dimensions of the aortic valve annulus (AVA), aortic sinuses of Valsalva (ASV), sinotubular junction (STJ), ascending aorta (AAO), left atrium (LA), mitral valve annulus (MVA), interventricular septal end-diastolic thickness (IVSd), interventricular septal end-systolic thickness (IVSs), left ventricular end-diastolic diameter (LVIDd), left ventricular end-systolic diameter (LVIDs), left ventricular posterior wall end-diastolic thickness (LVPWd), left ventricular posterior wall end-systolic thickness (LVPWs) were measured. Regression analyses were conducted to relate the measurements of left heart structures to body surface area (BSA). Left ventricular ejection fraction (LVEF) and left ventricular fractional shortening (LVFS) were calculated. Several models were used, and the adjusted R2 values were compared for each model. AVA, ASV, STJ, AAO, LA, MVA, IVSd, IVSs, LVIDd, LVIDs, LVPWd, and LVPWs had a cubic relationship with BSA. LVEF and LVFS fell within a narrow range. Our results provide reference values for z scores and regression equations for left heart structures in Han Chinese children. These data may help make a quick and accurate judgment of the routine clinical measurement of left heart structures in children with heart disease. © 2018 Wiley Periodicals, Inc.

Value of mechanical dyssynchrony as assessed by radionuclide ventriculography to predict the cardiac resynchronization therapy response.

PubMed

Tournoux, Francois; Chequer, Renata; Sroussi, Marjorie; Hyafil, Fabien; Algalarrondo, Vincent; Cohen-Solal, Alain; Bodson-Clermont, Paule; Le Guludec, Dominique; Rouzet, Francois

2016-11-01

To assess the value of mechanical dyssynchrony measured by equilibrium radionuclide angiography (ERNA) in predicting long-term outcome in cardiac resynchronization therapy (CRT) patients. We reviewed 146 ERNA studies performed in heart failure patients between 2001 and 2011 at our institution. Long-term follow-up focused on death from any cause or heart transplantation. Phase images were computed using the first harmonic Fourier transform. Intra-ventricular dyssynchrony was calculated as the delay between the earliest and most delayed 20% of the left ventricular (LV) (IntraV-20/80) and inter-ventricular dyssynchrony as the difference between LV- and right ventricular (RV)-mode phase angles (InterV). Eighty-three patients (57%) were implanted with a CRT device after ERNA. Median follow-up was 35 [21-50] months. Twenty-four events were observed during the first 41 months. Median baseline ERNA dyssynchrony values were 28 [3 to 46] degrees for intraV-20/80 and 9 [-6 to 24] degrees for interV. Comparing survival between CRT and non-CRT patients according to dyssynchrony status, log-rank tests showed no difference in survival in patients with no ERNA dyssynchrony (P = 0.34) while a significant difference was observed in ERNA patients with high level of mechanical dyssynchrony (P = 0.004). ERNA mechanical dyssynchrony could be of value in CRT patient selection. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.

Giant cardiac hydatid cyst with rare adhesions.

PubMed

Poorzand, Hoorak; Teshnizi, Mohammad Abbasi; Baghini, Vahid Shojaei; Gifani, Mehrnoosh; Gholoobi, Arash; Zirak, Nahid

2014-01-01

We present a 29-year-old woman who was admitted to the emergency department with shortness of breath. Using echocardiography, a giant multi-cystic mass was detected in the right ventricle, attached to the septal leaflet of the tricuspid valve and basal portion of the interventricular septum. Serologic tests (hydatid cyst antibody) confirmed Echinococcus infection. Lung computed tomography with intravenous contrast showed involvement of the pulmonary vasculature. The patient underwent cardiac surgery and the large cardiac cyst and the one in the right pulmonary artery branch were both removed. The tricuspid valve was also replaced by a bioprosthetic one. Albendazole was started preoperatively and was continued for six months after surgery. The patient recovered uneventfully and was followed up for one year. This is a report of a rare case of a very large cardiac hydatid cyst complicated by pulmonary embolism with attachments to both the tricuspid valve and interventricular septum.

Myocardial bridges, neither rare nor isolated-Autopsy study.

PubMed

Teofilovski-Parapid, G; Jankovic, R; Kanjuh, V; Virmani, R; Danchin, N; Prates, N; Simic, D V; Parapid, B

2017-03-01

Myocardial bridge is a congenital anomaly with a markedly variable reported incidence on autopsy (4.7%-86%), likely related to geographical regions. Our previous retrospective study showed a prevalence of 0.8%, which we doubted to be the true one in the examined sample of the Serbian population. To assess the importance of the phenomenon we conducted a 2-year prospective study at the same institution. Ninety-six cadaver hearts from adult individuals of both genders (51 men, 45 women) who died from natural causes underwent special dissection. Tunneled coronary arteries and myocardium were examined using light microscopy. A total of 14 myocardial bridges were found in 13 (13.54%) hearts. This anomaly was insignificantly more common in men (13.72% vs. 13.33%, p>0.05). In one heart we noted two myocardial bridges (the left anterior interventricular artery and left marginal artery were overbridged). None of the myocardial bridges had been diagnosed during life. The most common causes of death were cardiac related. Myocardial bridges were located in the following areas: left anterior interventricular (50%), left circumflex artery (28.6%), left marginal artery (14.3%), and right coronary artery (7.1%). In 92.3% of cases, the right coronary artery was dominant. The only heart with a balanced-type had two bridges. Most of the myocardial bridges were long and deep. All tunneled coronary arteries, and although surrounded by "coronary cushion," were not protected from atherosclerosis. In 30.8% of hearts with myocardial bridges, we found additional coronary artery anomalies. Myocardial bridges were not rare in the examined sample of the Serbian population and were often associated with other coronary artery anomalies, rendering the carriers at higher risk. Copyright © 2016 Elsevier GmbH. All rights reserved.

Effects of milrinone and epinephrine or dopamine on biventricular function and hemodynamics in an animal model with right ventricular failure after pulmonary artery banding.

PubMed

Hyldebrandt, Janus Adler; Sivén, Eleonora; Agger, Peter; Frederiksen, Christian Alcaraz; Heiberg, Johan; Wemmelund, Kristian Borup; Ravn, Hanne Berg

2015-07-01

Right ventricular (RV) failure due to chronic pressure overload is a main determinant of outcome in congenital heart disease. Medical management is challenging because not only contractility but also the interventricular relationship is important for increasing cardiac output. This study evaluated the effect of milrinone alone and in combination with epinephrine or dopamine on hemodynamics, ventricular performance, and the interventricular relationship. RV failure was induced in 21 Danish landrace pigs by pulmonary artery banding. After 10 wk, animals were reexamined using biventricular pressure-volume conductance catheters. The maximum pressure in the RV increased by 113% (P < 0.0001) and end-diastolic volume by 43% (P < 0.002), while left ventricular (LV) pressure simultaneously decreased (P = 0.006). Concomitantly, mean arterial pressure (MAP; -16%, P = 0.01), cardiac index (CI; -23%, P < 0.0001), and mixed venous oxygen saturation (SvO2 ; -40%, P < 0.0001) decreased. Milrinone increased CI (11%, P = 0.008) and heart rate (HR; 21%, P < 0.0001). Stroke volume index (SVI) decreased (7%, P = 0.03), although RV contractility was improved. The addition of either epinephrine or dopamine further increased CI and HR in a dose-dependent manner but without any significant differences between the two interventions. A more pronounced increase in biventricular contractility was observed in the dopamine-treated animals. LV volume was reduced in both the dopamine and epinephrine groups with increasing doses In the failing pressure overloaded RV, milrinone improved CI and increased contractility. Albeit additional dose-dependent effects of both epinephrine and dopamine on CI and contractility, neither of the interventions improved SVI due to reduced filling of the LV. Copyright © 2015 the American Physiological Society.

Effects of milrinone and epinephrine or dopamine on biventricular function and hemodynamics in right heart failure after pulmonary regurgitation.

PubMed

Hyldebrandt, Janus Adler; Agger, Peter; Sivén, Eleonora; Wemmelund, Kristian Borup; Heiberg, Johan; Frederiksen, Christian Alcaraz; Ravn, Hanne Berg

2015-09-01

Right ventricular failure (RVF) secondary to pulmonary regurgitation (PR) impairs right ventricular (RV) function and interrupts the interventricular relationship. There are few recommendations for the medical management of severe RVF after prolonged PR. PR was induced in 16 Danish landrace pigs by plication of the pulmonary valve leaflets. Twenty-three pigs served as controls. At reexamination the effect of milrinone, epinephrine, and dopamine was evaluated using biventricular conductance and pulmonary catheters. Seventy-nine days after PR was induced, RV end-diastolic volume index (EDVI) had increased by 33% (P = 0.006) and there was a severe decrease in the load-independent measurement of contractility (PRSW) (-58%; P = 0.003). Lower cardiac index (CI) (-28%; P < 0.0001), mean arterial pressure (-15%; P = 0.01) and mixed venous oxygen saturation (SvO2) (36%; P < 0.0001) were observed compared with the control group. The interventricular septum deviated toward the left ventricle (LV). Milrinone improved RV-PRSW and CI and maintained systemic pressure while reducing central venous pressure (CVP). Epinephrine and dopamine further improved biventricular PRSW and CI equally in a dose-dependent manner. Systemic and pulmonary pressures were higher in the dopamine-treated animals compared with epinephrine-treated animals. None of the treatments improved stroke volume index (SVI) despite increases in contractility. Strong correlation was detected between SVI and LV-EDVI, but not SVI and biventricular contractility. In RVF due to PR, milrinone significantly improved CI, SvO2, and CVP and increased contractility in the RV. Epinephrine and dopamine had equal inotropic effect, but a greater vasopressor effect was observed for dopamine. SV was unchanged due to inability of both treatments to increase LV-EDVI. Copyright © 2015 the American Physiological Society.

An unusual location of a papillary fibroelastoma.

PubMed

Bajaj, Sharad; Nandigam, Harish; Gupta, Nishant; Alkhouri, Yazan; Galldin, Lars M; Parikh, Nalini S; Patel, Nilesh; Shamoon, Fayez

2014-03-01

Papillary fibroelastomas are benign, avascular tumors and 90 % of them are attached to the cardiac valves. We present an unusual case, where papillary fibroelastoma was found attached to the interventricular septum, flopping in and out of the left ventricular outflow tract.

Echocardiographic evaluation of cardiac dyssynchrony in patients with congestive heart failure.

PubMed

Qin, Chuan; Zhang, Li; Zhang, Zi-Ming; Wang, Bin; Ye, Zhou; Wang, Yong; Nanda, Navin C; Xie, Ming-Xing

2016-06-01

The present study investigated the application of echocardiography to evaluation of cardiac dyssynchrony in patients with congestive heart failure (CHF). A total of 348 consecutive CHF patients who were admitted for cardiac resynchronization (CRT) and presented with low ejection fraction (EF) and wide QRS duration were enrolled in this study, along with 388 healthy individuals. Dyssynchrony was assessed based on filling time ratio (FT/RR), left ventricular pre-ejection delay (PED), interventricular mechanical delay (IVMD), longitudinal opposing wall delay (LOWD) and radial septal to posterior wall delay (RSPWD). Response to CRT was defined as a ≥15% increase in EF. The results showed that FT/RR was decreased while PED, IVMD, LOWD and RSPWD were increased in the CHF group compared with the control group (P<0.01). In the CHF group, FT/RR was negatively correlated with the QRS duration, LV end-diastolic diameter (LVESd), LV end-diastolic volume (LVEDV) and LV end-systolic volume (LVESV) (P<0.01), but positively with the LVEF (P<0.01). Additionally, PED, IVMD, LOWD and RSPWD were positively correlated with the QRS duration, LVESd, LVEDV and LVESV (P<0.01), but negatively with the LVEF (P<0.01). The CHF group was divided into three subgroups according to the varying degrees of LVEF. FT/RR decreased successively from the LVEF-1 group to the LVEF-2 group to the LVEF-3 group, while the PED, IVMD, LOWD and RSPWD successively increased in the same order (P<0.01). The CHF group was divided into three subgroups according to the varying degrees of QRS duration, and FT/RR decreased successively in a sequence from the QRS-1 group to the QRS-2 group to the QRS-3 group, while the PED, IVMD, LOWD and RSPWD successively increased in the same order (P<0.01). Speckle tracking radial dyssynchrony ≥130 ms was predictive of an EF response in patients in QRS-1 group (78% sensitivity, 83% specificity), those in QRS-2 group (83% sensitivity, 77% specificity) and in QRS-3 group (89% sensitivity, 79% specificity). In conclusion, echocardiography is a convenient and sensitive method for evaluating cardiac dyssynchrony in patients with CHF.

Assessment of N-terminal prohormone B-type natriuretic peptide as a measure of vascular and ventricular function in pediatric pulmonary arterial hypertension

PubMed Central

Dunning, Jamie; Truong, Uyen; Ivy, D. Dunbar; Hunter, Kendall A.; Shandas, Robin

2015-01-01

Abstract Pulmonary arterial hypertension (PAH) is a progressive disease that puts excessive mechanical loads on the ventricle due to a gradual increase in pulmonary vascular impedance. We hypothesize that the increase in right ventricular (RV) afterload is reflected in the concentration of circulating biochemical markers of ventricular strain and stress (B-type natriuretic peptide [BNP] and N-terminal prohormone BNP [NT-proBNP]). We retrospectively analyzed right heart catheterization (RHC) and serum biochemical analysis data () for a pediatric PAH cohort with no sign of left ventricular dysfunction. Using RHC data, we computed an estimate of pulmonary vascular resistance (PVR), compliance, and ventricular-vascular coupling. We also compared how the early onset of interventricular decoupling (characterized as septal flattening) impacts serum NT-proBNP concentrations. Our data revealed correlated NT-proBNP expression with both the resistive and reactive components of RV afterload, an estimate of ventricular-vascular coupling, and a significant increase in biomarker expression in patients with a flattened interventricular septum. Furthermore, the strong correlation between PVR and NT-proBNP appears to break down under flat septum morphology. Over 80% of resistive RV afterload variance is reflected in serum NT-proBNP concentration in pediatric patients with PAH with no sign of left ventricular dysfunction. Reactive afterload appears to contribute to myocardial NT-proBNP release at advanced stages of PAH. Therefore, in mild-to-moderate PAH, resistive afterload is likely the greatest contributor to RV wall stress. These findings could also be used to estimate invasive RHC measurements from serum biochemical analysis, but more work is needed to improve correlations and overcome the issue of interventricular decoupling. PMID:26697173

Influence of Football on Physiological Cardiac Indexes in Professional and Young Athletes

PubMed Central

Francavilla, Cristian V.; Sessa, Francesco; Salerno, Monica; Albano, Giuseppe D.; Villano, Ines; Messina, Giovanni; Triolo, Fabio; Todaro, Lorenzo; Ruberto, Maria; Marsala, Gabriella; Cascio, Orazio; Mollica, Maria P.; Monda, Vincenzo; Cibelli, Giuseppe; Valenzano, Anna; Zammit, Christian; Monda, Marcellino; Messina, Antonietta

2018-01-01

Background: After long-term intensive training, considerable morphological and functional heart changes occur in professional athletes. Such changes arise progressively and regress upon interruption of the physical activity. Morphological and functional alterations on heart are known as “Athlete's heart” condition. Objective: This study aims to compare echocardiographic parameters in two different groups of professional athletes. Furthermore, a prospective study is performed analyzing the echocardiographic changes occurring in 12 professional players in 3 years of follow-up. Materials and Methods: 78 football players were examined from July 2011 to May 2016 (40 enrolled in Group A and 38 in Group B). Twelve players of GROUP A were followed for 3 consecutive seasons. The general clinical examination, the cardiopulmonary evaluation, the ECG, the ergometer stress test, the spirometric examination and the standard cardiac eco color doppler test were recorded. Results: Left ventricle dimensions, left atrium dimensions, and interventricular septum dimensions were higher in A players than in B players. Moreover, following up 12 players for 3 years, a statistically significant increase of such values was observed. Discussion: In A players, higher dimensions of the left chambers and the interventricular septum were observed, compared to B players. No statistically significant difference was found regarding the ejection fraction. The 3 years follow-up showed a statistically significant increase of both left chambers and interventricular septum dimensions, particularly in the second and third year. Conclusions: These findings demonstrated that A players have higher echocardiographic parameters respect to B players. The results of this study support the scientific theory that long-term intensive training influences heart function, inducing “athlete's heart” with morphological adaptations. No significant echocardiographic variation within the examined sample was observed for different roles (goalkeeper, defender, midfielder, or attacker) or skills of individual players. PMID:29541036

[Successful use of an AED following anterior myocardial infarction].

PubMed

Harding, Ulf; Reifferscheid, Florian; von Olshausen, Klaus

2007-05-01

A participant of the annual Hamburg marathon collapses on the finish line. Medics at the scene find a conscious patient and prepare transport to the finish area medical center. During transport the patient becomes unconscious and pulseless. The medics immediately perform basic life support and cardiopulmonary resuscitation (CPR). An automated external defibrillator (AED) is attached and after analysis of the patient}s heart rhythm the patient is defibrillated twice. The ambulance service reach the scene with a delay. The emergency physician}s ECG shows ventricular fibrillation (VF) and two more defibrillations are delivered. Return of spontaneous circulation can be achieved. After stabilisation the patient is taken to hospital by ambulance. The ECG shows an anterior myocardial infarction and right bundle-branch block. The coronary angioplasty (PTCA) shows single-vessel disease with complete stenosis of the proximal part of the anterior interventricular branch. Revasucarisation is successful and a coronary stent is applied. The patient survives neurologically intact. This case report demonstrates the importance of readily available AED and specially trained medics. By immediately using the AED this patient was defibrillated before the ambulance service and emergency physician arrived at the scene. Spontaneous circulation was restored.

Atrial electromechanical conduction delay in patients with neurocardiogenic syncope.

PubMed

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

2014-05-01

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

Transvenous versus open chest lead placement for resynchronization therapy in patients with heart failure: comparison of ventricular electromechanical synchronicity.

PubMed

Zhang, Hai-Bo; Meng, Xu; Han, Jie; Li, Yan; Zhang, Ye; Jiang, Teng-Yong; Zhao, Ying-Xin; Zhou, Yu-Jie

2017-04-01

Transvenous lead placement is the standard approach for left ventricular (LV) pacing in cardiac resynchronization therapy (CRT), while the open chest access epicardial lead placement is currently the most frequently used second choice. Our study aimed to compare the ventricular electromechanical synchronicity in patients with heart failure after CRT with these two different LV pacing techniques. We enrolled 33 consecutive patients with refractory heart failure secondly to dilated cardiomyopathy who were eligible for CRT in this study. Nineteen patients received transvenous (TV group) while 14 received open chest (OP group) LV lead pacing. Intra- and inter-ventricular electromechanical synchronicity was assessed by tissue Doppler imaging (TDI) before and one year after CRT procedure. Before CRT procedure, the mean QRS-duration, maximum time difference to systolic peak velocity among 12 left ventricle segments (LV Ts-12), standard deviation of time difference to systolic peak velocity of 12 left ventricle segments (LV Ts-SD), and inter-ventricular mechanical delay (IVMD) in OP and TV group were 166 ± 17 ms and 170 ± 21 ms, 391 ± 42 ms and 397 ± 36 ms, 144 ± 30 ms and 148 ± 22 ms, 58 ± 25 ms and 60 ± 36 ms, respectively (all P > 0.05). At one year after the CRT, the mean QRS-duration, LV Ts-12, LV Ts-SD, and IVMD in TV and OP group were 128 ± 14 ms and 141 ± 22 ms ( P = 0.031), 136 ± 37 ms and 294 ± 119 ms ( P = 0.023), 50 ± 22 ms and 96 ± 34 ms ( P = 0.015), 27 ± 11 ms and 27 ± 26 ms ( P = 0.86), respectively. The LV lead implantation procedure time was 53.4 ± 16.3 min for OP group and 136 ± 35.1 min for TV group ( P = 0.016). The mean LV pacing threshold increased significantly from 1.7 ± 0.6 V/0.5 ms to 2.3 ± 1.6 V/0.5 ms ( P < 0.05) in TV group while it remained stable in the OP group. Compared to conventional endovascular approach, open chest access of LV pacing for CRT leads to better improvement of the intraventricular synchronization.

Early Impairment of Cardiac Function and Asynchronization of Systemic Amyloidosis with Preserved Ejection Fraction Using Two-Dimensional Speckle Tracking Echocardiography.

PubMed

Huang, He; Jing, Xian-chao; Hu, Zhang-xue; Chen, Xi; Liu, Xiao-qin

2015-12-01

To observe the ventricular global and regional function of the patients with systemic amyloidosis using two-dimensional speckle tracking echocardiography. The study enrolled 31 consecutive biopsy-proved patients with systemic amyloidosis who underwent echocardiographic examination and EF ≥ 55% and 37 age- and gender-matched healthy controls. We compared systolic strain and strain rate, diastolic strain rate, time to peak strain, peak delay time in longitudinal, radial, circumferential directions in 16 left ventricular segments. The global peak systolic longitudinal and radial strain of left ventricle, peak systolic longitudinal strain and strain rate, diastolic strain rate of right ventricular free wall were also compared. (1) Global peak systolic longitudinal strain (GPSLS), peak systolic longitudinal strain (PSLS) and strain rate (PSLSR), peak early diastolic longitudinal strain rate (PELSR) in 16 segments were decreased in case (P < 0.05). (2) Peak systolic radial strain and strain rate of inferoseptum and inferolateral at the level of papillary muscle were lower (P < 0.05), and peak early diastolic radial strain rate (PERSR) was reduced (P < 0.05). (3) Peak early diastolic circumferential strain rate was lower (P < 0.05). (4) Time to peak systolic longitudinal, radial, circumferential strain was longer, and peak delay time at the same level retarded (P < 0.05). (5) Into right ventricular wall, PSLS and PSLSR at mid-segment, and PSLSR, PELSR, peak atrial systolic longitudinal strain rate (PALSR) at basal were reduced (P < 0.05). (6) Inverse correlation between interventricular septum (IVS) thickness and GPSLS and GPSRS was found (P < 0.05). Systolic and diastolic dysfunction existed in systemic amyloidosis with preserved EF. Mechanical contraction disorder may be one reason for systolic dysfunction. GPLSR and GPRSR were negatively related to IVS thickness. © 2015, Wiley Periodicals, Inc.

[Effect of down-regulation of IKs repolarization-reserve on ventricular arrhythmogenesis in a guinea pig model of cardiac hypertrophy].

PubMed

Wang, Hegui; Huang, Ting; Wang, Zheng; Ge, Nannan; Ke, Yongsheng

2018-04-28

To observe the changes of rapidly activated delayed rectifier potassium channel (IKr) and slowly activated delayed rectifier potassium channel (IKs) in cardiac hypertrophy and to evaluate the effects of IKr and IKs blocker on the incidence of ventricular arrhythmias in guinea pigs with left ventricular hypertrophy (LVH).
 Methods: Guinea pigs were divided into a sham operation group and a left ventricular hypertrophy (LVH) group. LVH model was prepared. Whole cell patch-clamp technique was used to record IKr and IKs tail currents in a guinea pig model with LVH. The changes of QTc and the incidence rate of ventricular arrhythmias in LVH guinea pigs were observed by using the IKr and IKs blockers.
 Results: Compared with cardiac cells in the control group, the interventricular septal thickness at end systole (IVSs), left ventricular posterior wall thickness at end systole (LVPWs), QTc interval and cell capacitance in guinea pigs with LVH were significantly increased (P<0.05); while IKs densities were significantly reduced [+60 mV: (0.36±0.03) pA/pF vs (0.58±0.05) pA/pF, P<0.01]. However, LVH exerted no significant effect on IKr densities. IKr blocker markedly prolonged the QTc interval (P<0.01) and increased the incidence of ventricular arrhythmias in guinea pigs with LVH compared with the control guinea pigs. In contrast, IKs blocker produced modest increase in QTc interval in guinea pigs of control group with no increase in LVH animals. IKs blocker did not induce ventricular arrhythmias incidence in either control or LVH animals.
 Conclusion: The cardiac hypertrophy-induced arrhythmogenesis is due to the down-regulation 
of IKs.

Allometric scaling of echocardiographic measurements in healthy Spanish foals with different body weight.

PubMed

Rovira, S; Muñoz, A; Rodilla, V

2009-04-01

Scaling in biology is usually allometric, and therefore, the size of the heart may be expressed as a power function of body weight (BW). The present research analyses the echocardiographic measurements in 68 healthy Spanish foals weighed between 70 and 347kg in order to determine the correct scaling exponent for the allometric equation. The echocardiographic parameters measured were: left ventricular internal dimensions (LVID), free wall thickness (LVFWT), interventricular septum thickness (IVST) at systole (s) and diastole (d), EPSS (distance between the point E of the mitral valve and the interventricular septum), and aorta diameters at the level of the aortic valve (AOD), base of valve leaflets (ABS), sinus of Valsalva (ASV) and sino-tubular junction (AJT). Indices of left ventricular performance were calculated. It was found that LVIDd, IVSTs, AOD, and ASV have a relationship to BW raised to 0.300-0.368 power, whereas left ventricular end-diastolic volume and stroke volume scaled to BW raised to 0.731-0.712 power. With these data, appropriate values can be calculated for normal Spanish foals.

Atrial and ventricular septal changes in ethanol vapour exposed chick embryos.

PubMed

Kamran, Kiran; Khan, Muhammad Yunus; Minhas, Liaqat Ali

2015-03-01

To study the effects of ethanol vapour exposure on development of atrial and ventricular septa of chick embryo. The experimental study was conducted at the College of Physicians and Surgeons, Islamabad, from 2006 to 2007. The experimental and control groups were further divided into three subgroups based on the day of sacrifice. The experimental group was exposed to ethanol vapours produced in a specially-designed vapour chamber and then compared with age-matched controls. There were 90 eggs in each of the two groups. The development of inter-ventricular septum completed at day 7 of development in chick embryo. Ethanol vapour exposure produced a small discontinuity at day 10 of development in a chick embryo which may be labelled as ventricular septal defect since ventricular development is completed by day 7. Interatrial septum formed till day 7 with small perforations which persisted till hatching. Ethanol vapour exposure may lead to ventricular septal defect.

Magnetic resonance characterization of septal bounce: findings of blood impact physiology.

PubMed

Angheloiu, George O; Rayarao, Geetha; Williams, Ronald; Yamrozik, June; Doyle, Mark; Biederman, Robert W W

2015-01-01

'Septal bounce' is a pathognomonic sign of constrictive pericarditis (CP). The objectives of the study are to resolve the etiology of the septal bounce, to generate septal bounce-related diagnostic tools, and to prove that its presence is related to the mechanical interaction between the atrioventricular inflow and the inter-ventricular septum. We compared steady state free precession four-chamber images between 11 CP patients and 11 controls via cardiac magnetic resonance. The septal bounce was composed of two movements observed during every cardiac cycle, simultaneous with the rapid filling and atrial systole respectively. Three parameters (measured at end-systole) were generated: right ventricular (RV) clamp (compression ratio of the RV)-greater in CP (0.88 ± 0.03) than controls (0.85 ± 0.03, p = 0.02), tri-septal angle between the tricuspid valve annulus plane and the interventricular septum (81° ± 9° vs. 91° ± 7°, p = 0.01), and impact angle between the tricuspid inflow vector and septum (8.6° ± 8.7° vs. 0° ± 6.6°, p = 0.01). The accuracy, positive predictive value, sensitivity and specificity of these parameters in differentiating CP from controls ranged from 100 to 82 %. A forth parameter-septal flow ratio, gauging the proportion of tricuspid inflow impacting the septum, was markedly higher in CP than controls (0.38 ± 0.19 vs. 0.01 ± 0.03, p < 0.0001) with 100 % sensitivity, specificity, positive and negative predictive value. The septal bounce consists of two sequential movements during each cardiac cycle, is time-related with the rapid ventricular filling and atrial systole, and likely represents a result of the tricuspid blood inflow impacting the interventricular septum. Four septal bounce-derived parameters have a good accuracy in differentiating CP from volunteers.

[Coronary circulation in asymmetrical hypertrophy of the interventricular septum. On a new pathogenic hypothesis].

PubMed

Sánchez, G; Orea, A; Trevethan, S; Martínez Ríos, M A

1984-01-01

Thirty-four patients with left ventricular hypertrophy were studied. In all cases the following parameters were analyzed: 1) Echocardiography:left ventricular diastolic and systolic diameters, ejection fraction, thickness and movement of interventricular septum and posterior wall of the left ventricle (LV) 2) Electrocardiography: R wave voltaje in precordial leads V2, V3 and V5 and electrical axis in frontal plane 3) Catheterization: intracavitary pressures in LV and aortic pressures 4) Left ventriculography: areas of altered contractility 5) Coronariography: distribution pattern of coronary arteries and number of first order branches of circumflex (CA) and anterior descending coronary arteries (ADCA). The population was divided into 2 groups. Group A (GA) was made up of 22 patients with concentric hypertrophy (CH) of the LV (15 with systemic hypertensive heart disease, 6 with aortic valvular stenosis and 1 idiopathic). Echocardiographic findings included posterior wall thickness (PWT) or septal thickness of 1.1. cm or more and interventricular septum-posterior wall thickness ratio (S/PW) of less than 1.3. Group B (GB) included 12 patients with asymmetric septal hypertrophy (ASH), idiopathic in 5, systemic hypertensive heart disease in 4 and aortic valvular stenosis in 3. In these patients the S/PW thickness ratio was greater than 1.3 and the thickness of either wall greater than 1.1. cm. When the data of the two groups were compared there were significant differences in relation to the presence of septal hypertrophy. The R wave voltage in V2, interventricular thickness and S/PW were greater in GB. In addition, septal movement was less in GB than in Group A (0.47 +/- 0.26 cm vs. 0.74 +/- 0.37 cm; P less than 0.05). PWT was also less in Group B than in A (B: 1.01 +/- 0.1 cm, A: 1.2 +/- 0.2 cm; P less than 0.001). The CA in Group B divided into fewer than 4 first order branches to the upper two thirds of the posterior and lateral walls of the LV in 91.6%. This distribution of circumflex branches was found in 31.8% of the patients in Group A (P less than 0.05). In Group B, the ADCA divided into septal branches with no more than 2 diagonal branches. The posterior descending artery dominated septal distribution in 100% of these cases (GA: 31.8%; P less than 0.05). The sum of the first order branches of the CA and the ADCA was 5.6 +/- 0.9 in Group A and 2.7 +/- 0.9 branches in Group B (P less than 0.01).(ABSTRACT TRUNCATED AT 400 WORDS)

Diastolic heart failure associated with hemangiosarcoma infiltrating left ventricular walls in a dog

PubMed Central

Osuga, Tatsuyuki; Nakamura, Kensuke; Morita, Tomoya; Kagawa, Yumiko; Ohta, Hiroshi; Takiguchi, Mitsuyoshi

2017-01-01

A 9-year-old Shetland sheepdog was diagnosed with cardiogenic pulmonary edema. Echocardiography revealed focally thickened left ventricular free wall and interventricular septum and left atrial dilation. Left ventricular systolic function was preserved. Doppler echocardiography of transmitral flow indicated restrictive left ventricular filling. Cardiac histopathology demonstrated hemangiosarcoma infiltrating the left ventricular walls. PMID:29089652

Diastolic heart failure associated with hemangiosarcoma infiltrating left ventricular walls in a dog.

PubMed

Osuga, Tatsuyuki; Nakamura, Kensuke; Morita, Tomoya; Kagawa, Yumiko; Ohta, Hiroshi; Takiguchi, Mitsuyoshi

2017-11-01

A 9-year-old Shetland sheepdog was diagnosed with cardiogenic pulmonary edema. Echocardiography revealed focally thickened left ventricular free wall and interventricular septum and left atrial dilation. Left ventricular systolic function was preserved. Doppler echocardiography of transmitral flow indicated restrictive left ventricular filling. Cardiac histopathology demonstrated hemangiosarcoma infiltrating the left ventricular walls.

Catheter ablation of ventricular ectopy with para-hisian origin: importance of mapping both sides of the interventricular septum and understanding when to stop ablating.

PubMed

Madaffari, Antonio; Große, Anett; Raffa, Santi; Frommhold, Markus; Fink, Agnes; Geller, J Christoph

2016-12-01

Catheter ablation of para-Hisian premature ventricular contractions (PVCs) still represents a challenge and is a compromise between success and inadvertent AV block. We describe a possible strategy to address PVCs from this location with high-amplitude His-bundle potentials at the site of earliest activation.

The Upper Limit of Cerebral Blood Flow Autoregulation Is Decreased with Elevations in Intracranial Pressure.

PubMed

Pesek, Matthew; Kibler, Kathleen; Easley, R Blaine; Mytar, Jennifer; Rhee, Christopher; Andropolous, Dean; Brady, Ken

2016-01-01

The upper limit of cerebrovascular pressure autoregulation (ULA) is inadequately characterized. We sought to delineate the ULA in a neonatal swine model. Neonatal piglets with sham surgery (n = 9), interventricular fluid infusion (INF; n = 10), controlled cortical impact (CCI; n = 10), or impact + infusion (CCI + INF; n = 11) had intracranial pressure monitoring and bilateral cortical laser-Doppler flux recordings during arterial hypertension until lethality. An increase in red cell flux as a function of cerebral perfusion pressure was determined by piecewise linear regression and static rates of autoregulation (SRoRs) were determined above and below this inflection. When identified, the ULA (median [interquartile range]) was as follows: sham group: 102 mmHg (97-109), INF group: 75 mmHg (52-84), CCI group: 81 mmHg (69-101), and CCI + INF group: 61 mmHg (52-57; p = 0.01). Both groups with interventricular infusion had significantly lower ULA compared with the sham group. Neonatal piglets without intracranial pathological conditions tolerated acute hypertension, with minimal perturbation of cerebral blood flow. Piglets with acutely elevated intracranial pressure, with or without trauma, demonstrated loss of autoregulation when subjected to arterial hypertension.

Prognostic significance of interventricular septal thickness in patients with AL amyloidosis.

PubMed

Cho, Hyunsoo; Kim, Soo-Jeong; Shim, Chi Young; Hong, Geu-Ru; Ha, Jong-Won; Kim, Yu Ri; Yang, Woo Ick; Chung, Haerim; Jang, Ji Eun; Cheong, June-Won; Min, Yoo Hong; Kim, Jin Seok

2017-09-01

The major prognostic determinant of immunoglobulin light chain (AL) amyloidosis is cardiac involvement. However, the role of interventricular septal thickness (IVST), which reflects the extent of cardiac involvement, remains unclear. Therefore, we analyzed 77 patients with newly diagnosed AL amyloidosis and evaluated the prognostic role of IVST. Fifty patients (64.9%) had cardiac involvement and 17 patients (22.1%) showed IVST >15mm. Among all patients, the revised Mayo Clinic Stage III-IV and IVST >15mm were independently associated with inferior overall survival (OS) in a multivariable analysis. IVST >15mm was also adversely prognostic for OS in a subgroup of advanced-stage (revised Mayo Clinic stage III-IV) patients in a multivariable analysis (P<0.001). Furthermore, advanced-stage patients with IVST >15mm did not show survival benefit from treatment with bortezomib-based regimens and/or autologous stem-cell transplantation (ASCT). Our study demonstrated that IVST >15mm is adversely prognostic independent of the revised Mayo Clinic staging system in patients with AL amyloidosis. In addition, the degree of IVST might be used as a useful prognostic indicator that can guide the management of patients with AL amyloidosis especially at an advanced stage. Copyright © 2017 Elsevier Ltd. All rights reserved.

Evaluation of prosthetic valve obstruction on electrocardiographically gated multidetector-row computed tomography--identification of subprosthetic pannus in the aortic position.

PubMed

Ueda, Tomohiro; Teshima, Hideki; Fukunaga, Shuji; Aoyagi, Shigeaki; Tanaka, Hiroyuki

2013-01-01

This study was performed to evaluate the diagnostic role of electrocardiographically gated multidetector-row computed tomography (MDCT) for prosthetic valve obstruction (PVO) in the aortic position. Between 2002 and 2006, 9 patients were diagnosed with PVO of an aortic bileaflet mechanical valve based on echocardiographic and cineradiographic criteria. These 9 patients were examined using MDCT before replacement of the mechanical valve, and intraoperative findings were compared to morphologic periprosthetic abnormalities observed on MDCT. CT attenuation (Hounsfield units; HU) of the periprosthetic abnormalities was measured to investigate the underlying cause of the PVO. MDCT showed subprosthetic masses extending beyond the prosthetic ring into the orifice of the valve. At reoperation, presence of subprosthetic pannus was confirmed in all of the 9 patients, but no periprosthetic thrombus was found. The mean CT attenuation of the subprosthetic pannus was 170 HU, and it was significantly greater than that obtained from the interventricular septum (108 HU; P<0.0001). MDCT can be used to clearly visualize subprosthetic pannus causing PVO and the mean CT attenuation of subprosthetic pannus is significantly higher than that of the interventricular septum on MDCT.

Phase analysis of gated blood pool SPECT for multiple stress testing assessments of ventricular mechanical dyssynchrony in a tachycardia-induced dilated cardiomyopathy canine model.

PubMed

Salimian, Samaneh; Thibault, Bernard; Finnerty, Vincent; Grégoire, Jean; Harel, François

2017-02-01

Stress-induced dyssynchrony has been shown to be independently correlated with clinical outcomes in patients with dilated cardiomyopathy (DCM) and narrow QRS complexes. However, the extent to which stress levels affect inter- and intraventricular dyssynchrony parameters remains unknown. Ten large dogs were submitted to tachycardia-induced DCM by pacing the right ventricular apex for 3-4 weeks to reach a target ejection fraction (EF) of 35% or less. Stress was then induced in DCM dogs by administering intravenous dobutamine up to a maximum of 20 μg·kg -1 ·min -1 . Hemodynamic and ventricular dyssynchrony data were analyzed by left ventricular (LV) pressure measurements and gated blood pool SPECT (GBPS) imaging. In order to assess mechanical dyssynchrony in DCM subjects and compare it with that of 8 normal counterparts, we extracted the following data: count-based indices of LV contraction homogeneity index (CHI), entropy and phase standard deviation, and interventricular dyssynchrony index. A significant LV intraventricular dyssynchrony (CHI: 96.4 ± 1.3% in control vs 78.6% ± 10.9% in DCM subjects) resulted in an intense LV dysfunction in DCM subjects (EF: 49.5% ± 8.4% in control vs 22.6% ± 6.0% in DCM), compared to control subjects. However, interventricular dyssynchrony did not vary significantly between the two groups. Under stress, DCM subjects showed a significant improvement in ventricular functional parameters at each level (EF: 22.6% ± 6.0% at rest vs 48.1% ± 5.8% at maximum stress). All intraventricular dyssynchrony indices showed a significant increase in magnitude of synchrony from baseline to stress levels of greater than or equal to 5 μg·kg -1 ·min -1 dobutamine. There were individual differences in the magnitude and pattern of change in interventricular dyssynchrony during the various levels of stress. Based on GBPS analyses, different levels of functional stress, even in close intervals, can have a significant impact on hemodynamic and intraventricular dyssynchrony parameters in a DCM model with narrow QRS complex.

Right Ventricular Outflow Tract Septal Pacing Is Superior to Right Ventricular Apical Pacing

PubMed Central

Zou, Cao; Song, Jianping; Li, Hui; Huang, Xingmei; Liu, Yuping; Zhao, Caiming; Shi, Xin; Yang, Xiangjun

2015-01-01

Background The effects of right ventricular apical pacing (RVAP) and right ventricular outflow tract (RVOT) septal pacing on atrial and ventricular electrophysiology have not been thoroughly compared. Methods and Results To identify a more favorable pacing strategy with fewer adverse effects, 80 patients who had complete atrioventricular block with normal cardiac function and who were treated with either RVAP (n=42) or RVOT septal pacing (n=38) were recruited after an average of 2 years of follow‐up. The data from electrocardiography and echocardiography performed before pacemaker implantation and at the end of follow‐up were collected. The patients in the RVOT septal pacing and RVAP groups showed similar demographic and clinical characteristics before pacing treatments. After a mean follow‐up of 2 years, the final maximum P‐wave duration; P‐wave dispersion; Q‐, R‐, and S‐wave complex duration; left atrial volume index; left ventricular end‐systolic diameter; ratio of transmitral early diastolic filling velocity to mitral annular early diastolic velocity; and interventricular mechanical delay in the RVOT septal pacing group were significantly less than those in the RVAP group (P<0.05). The final left ventricular ejection fraction of the RVOT septal pacing group was significantly higher than that of the RVAP group (P<0.05). Conclusions Compared with RVAP, RVOT septal pacing has fewer adverse effects regarding atrial electrical activity and structure in patients with normal cardiac function. PMID:25896891

The antiarrhythmic effect of vagal stimulation after acute coronary occlusion: Role of the heart rate.

PubMed

Manati, Waheed; Pineau, Julien; Doñate Puertas, Rosa; Morel, Elodie; Quadiri, Timour; Bui-Xuan, Bernard; Chevalier, Philippe

2018-01-03

Strong evidence suggests a causal link between autonomic disturbances and ventricular arrhythmias. However, the mechanisms underlying the antiarrhythmic effect of vagal stimulation are poorly understood. The vagal antiarrhythmic effect might be modulated by a decrease in heart rate. the proximal anterior interventricular artery was occluded in 16 pigs by clamping under general anaesthesia. Group 1: heart rates remained spontaneous (n = 6; 12 occlusions); Group 2: heart rates were fixed at 190 beats per minute (bpm) with atrial electrical stimulation (n = 10; 20 occlusions). Each pig received two occlusions, 30 min apart, one without and one with vagal stimulation (10 Hz, 2 ms, 5-20 mA). The antiarrhythmic effect of vagal activation was defined as the time to the appearance of ventricular fibrillation (VF) after occlusion. In Group 1, vagal stimulation triggered a significant decrease in basal heart rate (132 ± 4 vs. 110 ± 17 bpm, p < 0.05), and delayed the time to VF after coronary occlusion (1102 ± 85 vs. 925 ± 41 s, p < 0.05). In Group 2, vagal stimulation did not modify the time to VF (103 ± 39 vs. 91 ± 20 s). Analyses revealed that heart rate and the time to VF were positively linearly related. Maintaining a constant heart rate with atrial electrical stimulation in pigs prevented vagal stimulation from modifying the time to VF after acute coronary occlusion.

Concrete induced cardiac contusion.

PubMed Central

Curzen, N.; Brett, S.; Fox, K.

1997-01-01

A previously fit 22 year old man was struck in the chest by a concrete block dropped through the windscreen of his car while he was driving on the motorway. He suffered extensive chest wall trauma and lung contusion, which subsequently precipitated acute respiratory distress. On admission ECG showed right bundle branch block and left axis deviation. Three days later QRS duration was normal but there was anterior ST segment elevation and subsequent T wave change. There was a large rise in creatine kinase, and echocardiography revealed septal and apical hyokinesis as well as a mobile mass attached to the left side of the interventricular septum, which had the echogenic texture of myocardium. The patient had fixed perfusion defects in the areas of hypokinesis on thallium scanning but the coronary arteries were unobstructed at angiography. He was treated with warfarin in the short term and an angiotensin converting enzyme inhibitor in the longer term and has made an asymptomatic recovery. Outpatient echocardiography two months after the injury demonstrated some recovery in overall left ventricular systolic function and no evidence of the intracardiac mass. This case illustrates some of the typical features of non-fatal cardiac contusion associated with non-penetrating cardiac trauma, and was complicated by partial thickness avulsion of a strip of the myocardium in the interventricular septum. Images PMID:9391297

Pacemaker mediated tachycardia as a complication of the autointrinsic conduction search function.

PubMed

Dennis, Malcolm J; Sparks, Paul B

2004-06-01

The autointrinsic conduction search (AICS) option, featured on some DDD pacemakers, performs periodic assessments of atrioventricular (AV) conduction capability during a single beat AV delay extension. Demonstration of ventricular conduction during the prolonged AV delay, permits ongoing AV delay extension if the patient's intrinsic conduction is preferred to ventricular pacing. A case is presented where the wide separation of atrial and ventricular pacing during the conduction search permitted retrograde ventriculoatrial conduction, precipitating pacemaker mediated tachycardia (PMT) on seven occasions in one patient. Two onset patterns are reported, both attributable to the AICS option. Recommendations for prevention strategies are made.

Do right-ventricular trabeculae gain energetic advantage from having a greater velocity of shortening?

PubMed

Pham, Toan; Han, June-Chiew; Taberner, Andrew; Loiselle, Denis

2017-10-15

We designed a study to test whether velocity of shortening in right-ventricular tissue preparations is greater than that of the left side under conditions mimicking those encountered by the heart in vivo. Our experiments allowed us to explore whether greater velocity of shortening results in any energetic advantage. We found that velocity of shortening was higher in the rat right-ventricular trabeculae. These results at the tissue level seem paradoxical to the velocity of ventricular ejection at the organ level, and are not always in accord with shortening of unloaded cells. Despite greater velocity of shortening in right-ventricular trabeculae, they neither gained nor lost advantage with respect to both mechanical efficiency and the heat generated during shortening. Our study aimed to ascertain whether the interventricular difference of shortening velocity, reported for isolated cardiac tissues in vitro, affects interventricular mechano-energetic performance when tested under physiological conditions using a shortening protocol designed to mimic those in vivo. We isolated trabeculae from both ventricles of the rat, mounted them in a calorimeter, and performed experiments at 37°C and 5 Hz stimulus frequency to emulate conditions of the rat heart in vivo. Each trabecula was subjected to two experimental protocols: (i) isotonic work-loop contractions at a variety of afterloads, and (ii) isometric contractions at a variety of preloads. Velocity of shortening was calculated from the former protocol during the isotonic shortening phase of the contraction. Simultaneous measurements of force-length work and heat output allowed calculation of mechanical efficiency. The shortening-dependent thermal component was quantified from the difference in heat output between the two protocols. Our results show that both extent of shortening and velocity of shortening were higher in trabeculae from the right ventricle. Despite these differences, trabeculae from both ventricles developed the same stress, performed the same work, liberated the same amount of heat, and hence operated at the same mechanical efficiency. Shortening heat was also ventricle independent. The interventricular differences in velocity of shortening and extent of shortening of isolated trabeculae were not manifested in any index of energetics. These collective results underscore the absence of any mechano-energetic advantage or disadvantage conferred on right-ventricular trabeculae arising from their superior velocity of shortening. © 2017 The Authors. The Journal of Physiology © 2017 The Physiological Society.

Quantitative Analysis of Electro-Anatomical Maps: Application to an Experimental Model of Left Bundle Branch Block/Cardiac Resynchronization Therapy

PubMed Central

Duchateau, Nicolas; Kostantyn Butakov, Constantine Butakoff; Andreu, David; Fernández-Armenta, Juan; Bijnens, Bart; Berruezo, Antonio; Sitges, Marta; Camara, Oscar

2017-01-01

Electro-anatomical maps (EAMs) are commonly acquired in clinical routine for guiding ablation therapies. They provide voltage and activation time information on a 3-D anatomical mesh representation, making them useful for analyzing the electrical activation patterns in specific pathologies. However, the variability between the different acquisitions and anatomies hampers the comparison between different maps. This paper presents two contributions for the analysis of electrical patterns in EAM data from biventricular surfaces of cardiac chambers. The first contribution is an integrated automatic 2-D disk representation (2-D bull’s eye plot) of the left ventricle (LV) and right ventricle (RV) obtained with a quasi-conformal mapping from the 3-D EAM meshes, that allows an analysis of cardiac resynchronization therapy (CRT) lead positioning, interpretation of global (total activation time), and local indices (local activation time (LAT), surrogates of conduction velocity, inter-ventricular, and transmural delays) that characterize changes in the electrical activation pattern. The second contribution is a set of indices derived from the electrical activation: speed maps, computed from LAT values, to study the electrical wave propagation, and histograms of isochrones to analyze regional electrical heterogeneities in the ventricles. We have applied the proposed methods to look for the underlying physiological mechanisms of left bundle branch block (LBBB) and CRT, with the goal of optimizing the therapy by improving CRT response. To better illustrate the benefits of the proposed tools, we created a set of synthetically generated and fully controlled activation patterns, where the proposed representation and indices were validated. Then, the proposed analysis tools are used to analyze EAM data from an experimental swine model of induced LBBB with an implanted CRT device. We have analyzed and compared the electrical activation patterns at baseline, LBBB, and CRT stages in four animals: two without any structural disease and two with an induced infarction. By relating the CRT lead location with electrical dyssynchrony, we evaluated current hypotheses about lead placement in CRT and showed that optimal pacing sites should target the RV lead close to the apex and the LV one distant from it. PMID:29164019

Enhancement of delayed-rectifier potassium conductance by low concentrations of local anaesthetics in spinal sensory neurones

PubMed Central

Olschewski, Andrea; Wolff, Matthias; Bräu, Michael E; Hempelmann, Gunter; Vogel, Werner; Safronov, Boris V

2002-01-01

Combining the patch-clamp recordings in slice preparation with the ‘entire soma isolation' method we studied action of several local anaesthetics on delayed-rectifier K+ currents in spinal dorsal horn neurones.Bupivacaine, lidocaine and mepivacaine at low concentrations (1–100 μM) enhanced delayed-rectifier K+ current in intact neurones within the spinal cord slice, while exhibiting a partial blocking effect at higher concentrations (>100 μM). In isolated somata 0.1–10 μM bupivacaine enhanced delayed-rectifier K+ current by shifting its steady-state activation characteristic and the voltage-dependence of the activation time constant to more negative potentials by 10–20 mV.Detailed analysis has revealed that bupivacaine also increased the maximum delayed-rectifier K+ conductance by changing the open probability, rather than the unitary conductance, of the channel.It is concluded that local anaesthetics show a dual effect on delayed-rectifier K+ currents by potentiating them at low concentrations and partially suppressing at high concentrations. The phenomenon observed demonstrated the complex action of local anaesthetics during spinal and epidural anaesthesia, which is not restricted to a suppression of Na+ conductance only. PMID:12055132

Maps of interaural delay in the owl's nucleus laminaris

PubMed Central

Shah, Sahil; McColgan, Thomas; Ashida, Go; Kuokkanen, Paula T.; Brill, Sandra; Kempter, Richard; Wagner, Hermann

2015-01-01

Axons from the nucleus magnocellularis form a presynaptic map of interaural time differences (ITDs) in the nucleus laminaris (NL). These inputs generate a field potential that varies systematically with recording position and can be used to measure the map of ITDs. In the barn owl, the representation of best ITD shifts with mediolateral position in NL, so as to form continuous, smoothly overlapping maps of ITD with iso-ITD contours that are not parallel to the NL border. Frontal space (0°) is, however, represented throughout and thus overrepresented with respect to the periphery. Measurements of presynaptic conduction delay, combined with a model of delay line conduction velocity, reveal that conduction delays can account for the mediolateral shifts in the map of ITD. PMID:26224776

Analysis of cardiac interventricular septum motion in different respiratory states

NASA Astrophysics Data System (ADS)

Tautz, Lennart; Feng, Li; Otazo, Ricardo; Hennemuth, Anja; Axel, Leon

2016-03-01

The interaction between the left and right heart ventricles (LV and RV) depends on load and pressure conditions that are affected by cardiac contraction and respiration cycles. A novel MRI sequence, XD-GRASP, allows the acquisition of multi-dimensional, respiration-sorted and cardiac-synchronized free-breathing image data. In these data, effects of the cardiac and respiratory cycles on the LV/RV interaction can be observed independently. To enable the analysis of such data, we developed a semi-automatic exploration workflow. After tracking a cross-sectional line positioned over the heart, over all motion states, the septum and heart wall border locations are detected by analyzing the grey-value profile under the lines. These data are used to quantify septum motion, both in absolute units and as a fraction of the heart size, to compare values for different subjects. In addition to conventional visualization techniques, we used color maps for intuitive exploration of the variable values for this multi-dimensional data set. We acquired short-axis image data of nine healthy volunteers, to analyze the position and the motion of the interventricular septum in different breathing states and different cardiac cycle phases. The results indicate a consistent range of normal septum motion values, and also suggest that respiratory phase-dependent septum motion is greatest near end-diastolic phases. These new methods are a promising tool to assess LV/RV ventricle interaction and the effects of respiration on this interaction.

Double-outlet right ventricle revisited.

PubMed

Ebadi, Ameneh; Spicer, Diane E; Backer, Carl L; Fricker, F Jay; Anderson, Robert H

2017-08-01

Double-outlet right ventricle is a form of ventriculoarterial connection. The definition formulated by the International Society for Nomenclature of Paediatric and Congenital Heart Disease is based on hearts with both arterial trunks supported in their greater part by a morphologically right ventricle. Bilateral infundibula and ventricular septal defects are highly debated criteria. This study examines the anatomic controversies surrounding double-outlet right ventricle. We show that hearts with double-outlet right ventricle can have atrioventricular-to-arterial valvular continuity. We emphasize the difference between the interventricular communication and the zone of deficient ventricular septation. The hearts examined were from the University of Florida in Gainesville; Johns Hopkins All Children's Hospital, St Petersburg, Fla; and Lurie Children's Hospital, Chicago, Ill. Each specimen had at least 75% of both arterial roots supported by the morphologically right ventricle, with a total of 100 hearts examined. The morphologic method was used to assess anatomic features, including arterial-atrioventricular valvular continuity, subarterial infundibular musculature, and the location of the hole between the ventricles. Most hearts had fibrous continuity between one of the arterial valves and an atrioventricular valve, with bilateral infundibula in 23%, and intact ventricular septum in 5%. Bilateral infundibula are not a defining feature of double-outlet right ventricle, representing only 23% of the specimens in our sample. The interventricular communication can have a posteroinferior muscular rim or extend to become perimembranous (58%). Double-outlet right ventricle can exist with an intact ventricular septum. Copyright © 2017 The American Association for Thoracic Surgery. All rights reserved.

Myocardial fibrosis in rats exposed to low frequency noise.

PubMed

Antunes, Eduardo; Oliveira, Pedro; Borrecho, Gonçalo; Oliveira, Maria João R; Brito, José; Aguas, Artur; Martins, Dos Santos José

2013-06-01

Low frequency noise (LFN) characterized by large pressure amplitude (> or =90 dB SPL) and low frequency bands (< or =500 Hz) can lead to structural and ultrastructural modifications in the extracellular matrix of several tissues, with an abnormal proliferation of collagen and development of fibrosis. It is not known whether LFN induces similar structural alterations in the ventricular myocardium of rats. The aim of this study was to evaluate and measure the myocardial fibrosis induced by LFN. Two groups of rats were considered: group A with 26 rats continuously exposed to LFN during a period of 3 months; group B with 20 control rats.The hearts were sectioned from the ventricular apex to the atria and the mid-ventricular fragment was selected. Chromotrope-aniline blue (CAB) staining was used for histological observation. The measurement of fibrosis was performed using the computer image analysis Image J software. Histological observation with CAB staining showed the presence of collagen deposition between the cardiomyocytes. Fibrosis increased 97.5%, 81.5% and 83.7%, respectively, in the left ventricle, interventricular septum and right ventricle, in exposed rats (P <0.001).The ratio fibrosis/muscle in left ventricle, interventricular septum and right ventricle was significantly higher in LFN exposed rats (P< 0.001). Our study demonstrates a significant myocardial fibrosis induced by low frequency noise in rats. Our results reinforce the need for further experimental and clinical investigations concerning the effects of low frequency noise on the heart.

Arrhythmogenic substrate at the interventricular septum as a target site for radiofrequency catheter ablation of recurrent ventricular tachycardia in left dominant arrhythmogenic cardiomyopathy.

PubMed

Havranek, Stepan; Palecek, Tomas; Kovarnik, Tomas; Vitkova, Ivana; Psenicka, Miroslav; Linhart, Ales; Wichterle, Dan

2015-03-10

Left dominant arrhythmogenic cardiomyopathy (LDAC) is a rare condition characterised by progressive fibrofatty replacement of the myocardium of the left ventricle (LV) in combination with ventricular arrhythmias of LV origin. A thirty-five-year-old male was referred for evaluation of recurrent sustained monomorphic ventricular tachycardia (VT) of 200 bpm and right bundle branch block (RBBB) morphology. Cardiac magnetic resonance imaging showed late gadolinium enhancement distributed circumferentially in the epicardial layer of the LV free wall myocardium including the rightward portion of the interventricular septum (IVS). The clinical RBBB VT was reproduced during the EP study. Ablation at an LV septum site with absence of abnormal electrograms and a suboptimum pacemap rendered the VT of clinical morphology noninducible. Three other VTs, all of left bundle branch block (LBBB) pattern, were induced by programmed electrical stimulation. The regions corresponding to abnormal electrograms were identified and ablated at the mid-to-apical RV septum and the anteroseptal portion of the right ventricular outflow tract. No abnormalities were found at the RV free wall including the inferolateral peritricuspid annulus region. Histological examination confirmed the presence of abnormal fibrous and adipose tissue with myocyte reduction in endomyocardial samples taken from both the left and right aspects of the IVS. LDAC rarely manifests with sustained monomorphic ventricular tachycardia. In this case, several VTs of both RBBB and LBBB morphology were amenable to endocardial radiofrequency catheter ablation.

The effect of childhood obesity on cardiac functions.

PubMed

Üner, Abdurrahman; Doğan, Murat; Epcacan, Zerrin; Epçaçan, Serdar

2014-03-01

Obesity is a metabolic disorder defined as excessive accumulation of body fat, which is made up of genetic, environmental, and hormonal factors and has various social, psychological, and medical complications. Childhood obesity is a major indicator of adult obesity. The aim of this study is to evaluate the cardiac functions via electrocardiography (ECG), echocardiography (ECHO), and treadmill test in childhood obesity. A patient group consisting of 30 obese children and a control group consisting of 30 non-obese children were included in the study. The age range was between 8 and 17 years. Anthropometric measurements, physical examination, ECG, ECHO, and treadmill test were done in all patients. P-wave dispersion (PD) was found to be statistically significantly high in obese patients. In ECHO analysis, we found that end-diastolic diameter, end-systolic diameter, left ventricle posterior wall thickness, and interventricular septum were significantly greater in obese children. In treadmill test, exercise capacity was found to be significantly lower and the hemodynamic response to exercise was found to be defective in obese children. Various cardiac structural and functional changes occur in childhood obesity and this condition includes important cardiovascular risks. PD, left ventricle end-systolic and end-diastolic diameter, left ventricle posterior wall thickness, interventricular septum thickness, exercise capacity, and hemodynamic and ECG measurements during exercise testing are useful tests to determine cardiac dysfunctions and potential arrhythmias even in early stages of childhood obesity. Early recognition and taking precautions for obesity during childhood is very important to intercept complications that will occur in adulthood.

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

PubMed

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

2015-01-01

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

Effects of gestational and pregestational diabetes mellitus on the foetal heart: a cross-sectional study.

PubMed

Dervisoglu, Pinar; Kosecik, Mustafa; Kumbasar, Serkan

2018-04-01

We examined the foetal cardiac structural and functional characteristics in diabetic pregnancies versus non-diabetic, healthy pregnancies. Between August 2015 and April 2016, 32 pregnant women with pregestational diabetes, 36 pregnant women with gestational diabetes, and 42 healthy pregnant women were scheduled to have foetal echocardiograms to assess cardiac structure and function. In the diabetic groups, the foetal interventricular septum (IVS) thickness was significantly greater than in non-diabetics (p < .05) but none had an IVS >2 SD from normal. The peak velocity of tricuspid E, and the E/A ratio were significantly lower in the diabetic groups (p < .05). Tricuspid valve E a values and the E a /A a ratio were lower in the diabetic group than in the control group (p < .05) but there was no significant difference between the pre-GDM and GDM groups (p > .05). Interventricular septal hypertrophy is the most common structural abnormality in diabetic pregnancies. These changes do not pose a risk to the foetal unless they cause functional impairment. Thus, we believe that it is important for diabetic pregnant women to be monitored for foetal cardiac diastolic dysfunction. Impact statement What is already known on this subject? Pregestational insulin-dependent diabetes mellitus is a relatively common condition in pregnancy, affecting up to 0.5% of the pregnant population. Foetuses of diabetic mothers are at an increased risk of perinatal morbidity and death. Gestational diabetes mellitus is under-recognised and affects up to 4% of pregnancies. Although diabetes mellitus is known to increase the risk of cardiovascular defects and structural changes (myocardial hypertrophy and diastolic dysfunction) due to foetal hyperglycaemia and hyperinsulinism, similar data in women with gestational diabetes is scarce. Moreover, the effect of maternal hyperglycaemia on foetal cardiac structure and function is unclear because of discordant results from previous studies. What do the results of this study add? In this study, we have used foetal echocardiography, two-dimensional US, pulsed wave Doppler and TDI to characterise the foetal cardiac structure and function in normal pregnancies as well as in the pregnancies complicated by GDM, and pregestational DM. Interventricular septum thickness is increased in women with pregestational diabetes mellitus and impaired diastolic function. The dominant right ventricle of the foetal circulation was affected earlier than the left ventricle. What are the implications of these findings for clinical practice and/or further research? Large population-based studies are required to establish the absolute risk of congenital heart defects in patients with pregestational diabetes and pregestational diabetes in the utility of routine screening.

Association between frequent cardiac resynchronization therapy optimization and long-term clinical response: a post hoc analysis of the Clinical Evaluation on Advanced Resynchronization (CLEAR) pilot study.

PubMed

Delnoy, Peter Paul; Ritter, Philippe; Naegele, Herbert; Orazi, Serafino; Szwed, Hanna; Zupan, Igor; Goscinska-Bis, Kinga; Anselme, Frederic; Martino, Maria; Padeletti, Luigi

2013-08-01

The long-term clinical value of the optimization of atrioventricular (AVD) and interventricular (VVD) delays in cardiac resynchronization therapy (CRT) remains controversial. We studied retrospectively the association between the frequency of AVD and VVD optimization and 1-year clinical outcomes in the 199 CRT patients who completed the Clinical Evaluation on Advanced Resynchronization study. From the 199 patients assigned to CRT-pacemaker (CRT-P) (New York Heart Association, NYHA, class III/IV, left ventricular ejection fraction <35%), two groups were retrospectively composed a posteriori on the basis of the frequency of their AVD and VVD optimization: Group 1 (n = 66) was composed of patients 'systematically' optimized at implant, at 3 and 6 months; Group 2 (n = 133) was composed of all other patients optimized 'non-systematically' (less than three times) during the 1 year study. The primary endpoint was a composite of all-cause mortality, heart failure-related hospitalization, NYHA functional class, and Quality of Life score, at 1 year. Systematic CRT optimization was associated with a higher percentage of improved patients based on the composite endpoint (85% in Group 1 vs. 61% in Group 2, P < 0.001), with fewer deaths (3% in Group 1 vs. 14% in Group 2, P = 0.014) and fewer hospitalizations (8% in Group 1 vs. 23% in Group 2, P = 0.007), at 1 year. These results further suggest that AVD and VVD frequent optimization (at implant, at 3 and 6 months) is associated with improved long-term clinical response in CRT-P patients.

Contingency Tracking during Unsignaled Delayed Reinforcement

ERIC Educational Resources Information Center

Keely, Josue; Feola, Tyler; Lattal, Kennon A.

2007-01-01

Three experiments were conducted with rats in which responses on one lever (labeled the functional lever) produced reinforcers after an unsignaled delay period that reset with each response during the delay. Responses on a second, nonfunctional, lever did not initiate delays, but, in the first and third experiments, such responses during the last…

Advanced Transport Delay Compensation Algorithms: Results of Delay Measurement and Piloted Performance Tests

NASA Technical Reports Server (NTRS)

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

2007-01-01

This report summarizes the results of delay measurement and piloted performance tests that were conducted to assess the effectiveness of the adaptive compensator and the state space compensator for alleviating the phase distortion of transport delay in the visual system in the VMS at the NASA Langley Research Center. Piloted simulation tests were conducted to assess the effectiveness of two novel compensators in comparison to the McFarland predictor and the baseline system with no compensation. Thirteen pilots with heterogeneous flight experience executed straight-in and offset approaches, at various delay configurations, on a flight simulator where different predictors were applied to compensate for transport delay. The glideslope and touchdown errors, power spectral density of the pilot control inputs, NASA Task Load Index, and Cooper-Harper rating of the handling qualities were employed for the analyses. The overall analyses show that the adaptive predictor results in slightly poorer compensation for short added delay (up to 48 ms) and better compensation for long added delay (up to 192 ms) than the McFarland compensator. The analyses also show that the state space predictor is fairly superior for short delay and significantly superior for long delay than the McFarland compensator.

Oscillation, Conduction Delays, and Learning Cooperate to Establish Neural Competition in Recurrent Networks

PubMed Central

Kato, Hideyuki; Ikeguchi, Tohru

2016-01-01

Specific memory might be stored in a subnetwork consisting of a small population of neurons. To select neurons involved in memory formation, neural competition might be essential. In this paper, we show that excitable neurons are competitive and organize into two assemblies in a recurrent network with spike timing-dependent synaptic plasticity (STDP) and axonal conduction delays. Neural competition is established by the cooperation of spontaneously induced neural oscillation, axonal conduction delays, and STDP. We also suggest that the competition mechanism in this paper is one of the basic functions required to organize memory-storing subnetworks into fine-scale cortical networks. PMID:26840529

Test Report Emission Test Program EPA Information Collection Request for Delayed Coking Units 736 Coker Unit

EPA Pesticide Factsheets

ARI Environmental, Inc. (ARI) was retained by Houston Refining LP (HRO) to conduct an emission test program at their refinery located in Houston, Texas. The testing was conducted on on the 736 Delayed Coking Unit (DCU) in response to EPA's ICR.

Electrophysiologic studies in atrial fibrillation. Slow conduction of premature impulses: a possible manifestation of the background for reentry.

PubMed

Cosio, F G; Palacios, J; Vidal, J M; Cocina, E G; Gómez-Sánchez, M A; Tamargo, L

1983-01-01

Extrastimulus-induced intraatrial conduction delays were measured in 12 patients with documented episodes of atrial fibrillation (AF) by recording atrial electrograms at the high right atrium, His bundle region, and coronary sinus. Seventeen patients with and without heart disease, but without atrial arrhythmias served as the control group. During baseline-paced atrial rhythms, a conduction delay zone could be delineated, near the atrial effective refractory period, during which all extrastimuli produced conduction delays. When compared at the same paced cycle lengths (500 to 650 ms), the patients with AF had shorter atrial effective refractory periods (mean +/- standard deviation 206 +/- 24.1 versus 233 +/- 28.2 in control patients, p less than 0.02), wider conduction delay zones (79 +/- 21.7 ms versus 52 +/- 21 in control patients, p less than 0.01), and longer conduction delays both to the His bundle region (64 +/- 18.3 ms versus 35 +/- 21.7 in control patients, p less than 0.005) and the coronary sinus (76 +/- 18.9 ms versus 35 +/- 16.1 in control patients, p less than 0.001). Repetitive atrial responses were recorded in 6 patients with AF and in 9 control subjects. Sinus nodal function abnormalities were detected in 6 of the patients with fibrillation. Patients with AF had a higher tendency than control subjects to develop slow intraatrial conduction, as well as shorter effective refractory periods. Since both features would favor reentry, they may be the electrophysiologic manifestations of the abnormalities making these patients prone to atrial reentrant arrhythmias. Repetitive atrial responses were of no predictive value. Sinus nodal dysfunction was frequently found, but was not essential for the occurrence of AF.

Molecular Basis of Cardiac Delayed Rectifier Potassium Channel Function and Pharmacology.

PubMed

Wu, Wei; Sanguinetti, Michael C

2016-06-01

Human cardiomyocytes express 3 distinct types of delayed rectifier potassium channels. Human ether-a-go-go-related gene (hERG) channels conduct the rapidly activating current IKr; KCNQ1/KCNE1 channels conduct the slowly activating current IKs; and Kv1.5 channels conduct an ultrarapid activating current IKur. Here the authors provide a general overview of the mechanistic and structural basis of ion selectivity, gating, and pharmacology of the 3 types of cardiac delayed rectifier potassium ion channels. Most blockers bind to S6 residues that line the central cavity of the channel, whereas activators interact with the channel at 4 symmetric binding sites outside the cavity. Copyright © 2016 Elsevier Inc. All rights reserved.

Unusual mechanism of tricuspid regurgitation in ventricular septal defect.

PubMed

Desai, Ravi V; Seghatol-Eslami, Frank; Nabavizadeh, Fatemeh; Lloyd, Steven G

2011-02-01

A 37-year-old woman was diagnosed to have a small ventricular septal defect (VSD) with high velocity tricuspid regurgitation (TR) that was attributed to atrio-VSD (Gerbode). Cardiac MR revealed a small subaortic VSD in the membranous portion of the interventricular septum. The atrioventricular portion was intact. Cardiac MR clearly showed flow jet through the VSD, impinging on the anterior tricuspid leaflet during systole, and bouncing back into the right atrium as TR. This ricochet mechanism of TR in VSD may be misinterpreted as Gerbode defect or as evidence of pulmonary hypertension. © 2011, Wiley Periodicals, Inc.

Flail Tricuspid Valve in an Adult Patient with Congenitally Corrected Transposition of the Great Arteries.

PubMed

Meloni, Luigi; Abbruzzese, Piero A.; Pirisi, Raimondo; Cherchi, Angelo

1997-01-01

We describe a case of a 50-year-old woman with congenitally corrected transposition of the great vessels, in whom severe left-sided tricuspid (systemic atrioventricular) valve insufficiency was the only associated anomaly. The tricuspid valve was dysplastic and abnormally oriented toward the interventricular septum, without the downward displacement of Ebstein's anomaly. The mechanism of atrioventricular regurgitation was unusual in that it consisted of the rupture of chordae tendineae of both the anterior and septal leaflets. The left-sided tricuspid valve was replaced with a St. Jude prosthesis and the postoperative course was uneventful.

Echocardiographic detection of ventricular septal defects in large animals.

PubMed

Pipers, F S; Reef, V; Wilson, J

1985-10-15

Ventricular septal defects in a foal, a 2-year-old filly, and 2 calves were demonstrated with M-mode and two-dimensional real-time echocardiography. The studies were performed with the animals unsedated, either standing or in lateral recumbency. Cardiac windows were located between the 4th and 7th intercostal spaces, approximately at the level of the olecranon. In each case, the septal defect was visualized high in the membranous portion of the interventricular septum. Defects were visualized by use of sector scanning or linear-array ultrasonic equipment, with transducer frequencies of 2.25 to 3.5 MHz.

A randomized pilot study of optimization of cardiac resynchronization therapy in sinus rhythm patients using a peak endocardial acceleration sensor vs. standard methods.

PubMed

Ritter, Philippe; Delnoy, Peter Paul H M; Padeletti, Luigi; Lunati, Maurizio; Naegele, Herbert; Borri-Brunetto, Alberto; Silvestre, Jorge

2012-09-01

Non-response rate to cardiac resynchronization therapy (CRT) might be decreased by optimizing device programming. The Clinical Evaluation on Advanced Resynchronization (CLEAR) study aimed to assess the effects of CRT with automatically optimized atrioventricular (AV) and interventricular (VV) delays, based on a Peak Endocardial Acceleration (PEA) signal system. This multicentre, single-blind study randomized patients in a 1 : 1 ratio to CRT optimized either automatically by the PEA-based system, or according to centres' usual practices, mostly by echocardiography. Patients had heart failure (HF) New York Heart Association (NYHA) functional class III/IV, left ventricular ejection fraction (LVEF) <35%, QRS duration >150 or >120 ms with mechanical dyssynchrony. Follow-up was 1 year. The primary endpoint was the proportion of patients who improved their condition at 1 year, based on a composite of all-cause death, HF hospitalizations, NYHA class, and quality of life. In all, 268 patients in sinus rhythm (63% men; mean age: 73.1 ± 9.9 years; mean NYHA: 3.0 ± 0.3; mean LVEF: 27.1 ± 8.1%; and mean QRS duration: 160.1 ± 22.0 ms) were included and 238 patients were randomized, 123 to PEA and 115 to the control group. At 1 year, 76% of patients assigned to PEA were classified as improved, vs. 62% in the control group (P= 0.0285). The percentage of patients with improved NYHA class was significantly (P= 0.0020) higher in the PEA group than in controls. Fatal and non-fatal adverse events were evenly distributed between the groups. PEA-based optimization of CRT in HF patients significantly increased the proportion of patients who improved with therapy, mainly through improved NYHA class, after 1 year of follow-up.

[Comparison of 64 MDCT coronary CTA and coronary angiography in the detection of coronary artery stenosis in low risk patients with stable angina and acute coronary syndrome].

PubMed

Cazalas, G; Sarran, A; Amabile, N; Chaumoitre, K; Marciano-Chagnaud, S; Jacquier, A; Paganelli, F; Panuel, M

2009-09-01

To determine the accuracy of 64 MDCT coronary CTA (CCTA) compared to coronary angiography in low risk patients with stable angina and acute coronary syndrome and determine the number of significant coronary artery stenoses ( 50%) in these patients. Materials and methods. Fifty-five patients underwent CCTA using a 32 MDCT unit with z flying focus allowing the acquisition of 64 slices of 0.6 mm thickness as well as coronary angiography (gold standard). Nine patients were excluded due to prior coronary artery bypass surgery (n=4), insufficient breath hold (n=3), calcium scoring>1000 (n=1) and delay between both examinations over 4 months (n=1). Forty-six patients: 27 males and 19 females were included. CCTA results were compared to coronary angiography per segment and artery with threshold detection of stenoses 50%. The degree of correlation between both examinations was performed using a regression analysis with a Pearson correlation coefficient<0.05 considered significant. The overall accuracy of CCTA was 90%; limitations related to the presence of calcifications, motion artifacts or insufficient vessel opacification. The correlation for all analyzed segments was 96.4%. Thirty-eight of 50 significant stenoses seen on coronary angiography were correctly detected on CCTA. Sensitivity, specificity, PPVC and NPV for detection of stenoses 50% were 76%, 98.3%, 80.3% and 97.7% respectively. Evaluation per segment had a NPV of 96.8% (interventricular and diagonal segments) to 100% (main trunk). Our results for specificity and NPV are similar to reports from the literature. This suggests that CCTA in this clinical setting may replace coronary angiography.

Conduction Delay Learning Model for Unsupervised and Supervised Classification of Spatio-Temporal Spike Patterns

PubMed Central

Matsubara, Takashi

2017-01-01

Precise spike timing is considered to play a fundamental role in communications and signal processing in biological neural networks. Understanding the mechanism of spike timing adjustment would deepen our understanding of biological systems and enable advanced engineering applications such as efficient computational architectures. However, the biological mechanisms that adjust and maintain spike timing remain unclear. Existing algorithms adopt a supervised approach, which adjusts the axonal conduction delay and synaptic efficacy until the spike timings approximate the desired timings. This study proposes a spike timing-dependent learning model that adjusts the axonal conduction delay and synaptic efficacy in both unsupervised and supervised manners. The proposed learning algorithm approximates the Expectation-Maximization algorithm, and classifies the input data encoded into spatio-temporal spike patterns. Even in the supervised classification, the algorithm requires no external spikes indicating the desired spike timings unlike existing algorithms. Furthermore, because the algorithm is consistent with biological models and hypotheses found in existing biological studies, it could capture the mechanism underlying biological delay learning. PMID:29209191

Conduction Delay Learning Model for Unsupervised and Supervised Classification of Spatio-Temporal Spike Patterns.

PubMed

Matsubara, Takashi

2017-01-01

Precise spike timing is considered to play a fundamental role in communications and signal processing in biological neural networks. Understanding the mechanism of spike timing adjustment would deepen our understanding of biological systems and enable advanced engineering applications such as efficient computational architectures. However, the biological mechanisms that adjust and maintain spike timing remain unclear. Existing algorithms adopt a supervised approach, which adjusts the axonal conduction delay and synaptic efficacy until the spike timings approximate the desired timings. This study proposes a spike timing-dependent learning model that adjusts the axonal conduction delay and synaptic efficacy in both unsupervised and supervised manners. The proposed learning algorithm approximates the Expectation-Maximization algorithm, and classifies the input data encoded into spatio-temporal spike patterns. Even in the supervised classification, the algorithm requires no external spikes indicating the desired spike timings unlike existing algorithms. Furthermore, because the algorithm is consistent with biological models and hypotheses found in existing biological studies, it could capture the mechanism underlying biological delay learning.

Effects of graded doses of epinephrine on regional myocardial blood flow during cardiopulmonary resuscitation in swine

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

Brown, C.G.; Werman, H.A.; Davis, E.A.

1987-02-01

Although epinephrine has been shown to improve myocardial blood flow during cardiopulmonary resuscitation (CPR), the effects of standard as well as larger doses of epinephrine on regional myocardial blood flow have not been examined. In this study we compared the effects of various doses of epinephrine on regional myocardial blood flow after a 10 min arrest in a swine preparation. Fifteen swine weighing greater than 15 kg each were instrumented for regional myocardial blood flow measurements with tracer microspheres. Regional blood flow was measured during normal sinus rhythm. After 10 min of ventricular fibrillation, CPR was begun and regional myocardialmore » blood flow was determined. Animals were then randomly assigned to receive 0.02, 0.2, or 2.0 mg/kg epinephrine by peripheral injection. One minute after drug administration, regional myocardial blood flow measurements were repeated. The adjusted regional myocardial blood flows (ml/min/100 g) for animals given 0.02, 0.2, and 2.0 mg/kg epinephrine, respectively, were as follows: left atrium, 0.9, 67.4, and 58.8; right atrium, 0.3, 46.2, and 38.5; right ventricle, 0.7, 82.3, and 66.9; right interventricular septum, 1.7, 125.5, and 99.1; left interventricular septum, 2.8, 182.8, 109.5; mesointerventricular septum, 16.8, 142.2, and 79.2; left ventricular epicardium, 19.2, 98.5 and 108.7; left ventricular mesocardium, 22.8, 135.0, and 115.8; and left ventricular endocardium, 2.5, 176.1, and 132.9). All comparisons between the groups receiving 0.02 and 0.2 mg/kg epinephrine were statistically significant (p less than .05).« less

Magnetic Resonance Imaging as a Predictor of Survival Free of Life-Threatening Arrhythmias and Transplantation in Cardiac Sarcoidosis.

PubMed

Ekström, Kaj; Lehtonen, Jukka; Hänninen, Helena; Kandolin, Riina; Kivistö, Sari; Kupari, Markku

2016-05-02

Cardiac magnetic resonance imaging has a key role in today's diagnosis of cardiac sarcoidosis. We set out to investigate whether cardiac magnetic resonance imaging also helps predict outcome in cardiac sarcoidosis. Our work involved 59 patients with cardiac sarcoidosis (38 female, mean age 46±10 years) seen at our hospital since February 2004 and followed up after contrast-enhanced cardiac magnetic resonance imaging. The extent of myocardial late gadolinium enhancement (measured as percentage of left ventricular mass), the volumes and ejection fractions of the left and right ventricles, and the thickness of the basal interventricular septum were determined and analyzed for prognostic significance. By April 2015, 23 patients had reached the study's end point, consisting of a composite of cardiac death (n=3), cardiac transplantation (n=1), and occurrence of life-threatening ventricular tachyarrhythmias (n=19; ventricular fibrillation in 5 and sustained ventricular tachycardia in 14 patients). In univariate analysis, myocardial extent of late gadolinium enhancement predicted event-free survival, as did scar-like thinning (<4 mm) of the basal interventricular septum and the ejection fraction of the right ventricle (P<0.05 for all). In multivariate Cox regression analysis, extent of late gadolinium enhancement was the only independent predictor of outcome events on cardiac magnetic resonance imaging, with a hazard ratio of 2.22 per tertile (95% CI 1.07-4.59). An extent of late gadolinium enhancement >22% (third tertile) had positive and negative predictive values for serious cardiac events of 75% and 76%, respectively. Findings on cardiac magnetic resonance imaging and the extent of myocardial late gadolinium enhancement in particular help predict serious cardiac events in cardiac sarcoidosis. © 2016 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

Evaluation of electrical propagation delay with cardiomyocytes by photosensitization reaction in vitro

NASA Astrophysics Data System (ADS)

Doi, Marika; Ogawa, Emiyu; Arai, Tsunenori

2017-02-01

In order to study cardiomyocyte electrical conduction damage by a photosensitization reaction (PR) mostly comes from outside of the cells in a few minutes after the PR, we studied propagation delay of contact action potential with cardiomyocyte by the PR. To determine appropriate PR condition for tachyarrhythmia ablation, a precise electrophysiological experiment in vitro has been preferable. We measured the contact action potential using a microelectrode array system of which information may be correct than conventional Ca2+ measurement. We investigated the propagation delays of an evoked potential to evaluate the electrical conduction damage by the PR. Rat cardiomyocytes were cultivated for 5-7 days on a dish with which 64 electrodes were patterned, in an incubator controlled to 37°C, 5% CO2. The following conditions were used for the PR: 40 μg/ml talapordfin sodium and 290 mW/cm2, 40-78 J/cm2 for an irradiation. A 2D map was obtained to visualize the propagation delays of the evoked potential. The propagation speed, which was calculated based on the measured propagation delays, was decreased by about 30-50% on average of all electrodes after the PR. Therefore, we think 2D propagation delays measurement of the evoked potential with contact action potential measuring system might be available to evaluate the acute electrical conduction damage of cardiomyocyte by the PR.

77 FR 47705 - Open Meeting of the Taxpayer Advocacy Panel Return Processing Delays Project Committee

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-09

... Return Processing Delays Project Committee AGENCY: Internal Revenue Service (IRS), Treasury. ACTION... Project Committee will be conducted. The Taxpayer Advocacy Panel is soliciting public comments, ideas, and... Processing Delays Project Committee will be held Tuesday, September 04, 2012, at 9:30 a.m. Pacific Time via...

77 FR 2611 - Open Meeting of the Taxpayer Advocacy Panel Return Processing Delays Project Committee

Federal Register 2010, 2011, 2012, 2013, 2014

2012-01-18

... Return Processing Delays Project Committee AGENCY: Internal Revenue Service (IRS) Treasury. ACTION... Project Committee will be conducted. The Taxpayer Advocacy Panel is soliciting public comments, ideas, and... Processing Delays Project Committee will be held Tuesday, February 7, 2012, at 9:30 a.m. Pacific Time via...

Cardioembolic strokes resulting from a self-inflicted needle puncture involving both sides of the heart.

PubMed

Tan, Mark Zheng Yi; Brunswicker, Annemarie; Abdelraheem, Shamsaldeen; Sheehan, Alison

2017-04-01

Foreign bodies in the heart are rare occurrences with a limited evidence base to guide recommendations on management. We report a case of multiple cardioembolic strokes as a result of a self-inflicted sewing needle puncture from the anterior chest through the right ventricle and interventricular septum with its tip in the left ventricle close to the subvalvular apparatus in a 39-year-old psychiatric patient. We discuss issues surrounding decision making and ongoing care and highlight the importance of further follow-up and reporting of cases to form a robust evidence base to guide future recommendations. © 2017, Wiley Periodicals, Inc.

Familial diagnostic experiences in paediatric oncology.

PubMed

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

2015-01-06

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

Using Time Delay to Teach Literacy to Students with Severe Developmental Disabilities

ERIC Educational Resources Information Center

Browder, Diane; Ahlgrim-Delzell, Lynn; Spooner, Fred; Mims, Pamela J.; Baker, Joshua N.

2009-01-01

A review of the literature was conducted for articles published between 1975 and 2007 on the application of time delay as an instructional procedure to teach word and picture recognition to students with severe developmental disabilities in an effort to evaluate time delay as an evidence-based practice. A total of 30 experiments were analyzed…

COGNITIVE FUNCTIONING AND TOLERANCE FOR DELAY OF GRATIFICATION.

ERIC Educational Resources Information Center

ZIMILES, HERBERT

TWO EXPERIMENTS WERE CONDUCTED TO STUDY THE RELATIONSHIP BETWEEN A CHILD'S TOLERANCE FOR DELAY OF GRATIFICATION AND HIS ABILITY TO CONSERVE NUMBER AND PICTURES. OTHER MEASURES OF COGNITION ALSO WERE USED. TOLERANCE FOR DELAY OF GRATIFICATION WAS MEASURED BY THE CHILD'S DECISION TO RECEIVE A PACK OF CANDY AND A TOY ON THE DAY OF TESTING OR TO…

Timing and delay in children vaccination; evaluation of expanded program of immunization in outskirt of Iranian cities.

PubMed

Rejali, Mehri; Mohammadbeigi, Abolfazl; Mokhtari, Mohsen; Zahraei, Seyed Mohsen; Eshrati, Babak

2015-01-01

Most studies evaluated the vaccine coverage, but the time of vaccination is important as coverage. This study was conducted to evaluate the Expanded Program of Immunization (EPI) in outskirt of Iranian cities regarding to incidence of delay vaccination among children less than 4 years. This cross sectional descriptive study was conducted among children 24-47 months old, living in the suburbs of five metropolises of Iran. Totally, 3610 eligible children selected with proportioned cluster sampling method and data of vaccination card extracted after interview with child parents. Delayed incidence rate reported and predictive factors assessed by Chi square test and Multivariate logistic regression. Overall, 56.6% to 93.2% vaccines were administered out of time. Delayed vaccination incidence with more than one-week delay varies from 5.5% to 74.9% for polio at birth and MMR2 at 18 month, respectively. Mother's educational level and birth order were the most important predictors of delayed vaccination. Incidence of delayed vaccination was enlarged by increasing birth order and decreased in lower educated mothers. Incidence rate of delayed vaccination is more than expectation. Regarding to high coverage vaccines in Iran, heath officers and health policy makers should attempt for on-time vaccination beside of high immunization coverage especially in slum areas with more concentrated immigrants due to low literature and crowded families.

Local conduction during acute myocardial infarction in rats: Interplay between central sympathetic activation and endothelin.

PubMed

Kolettis, Theofilos M; Kontonika, Marianthi; La Rocca, Vassilios; Vlahos, Antonios P; Baltogiannis, Giannis G; Kyriakides, Zenon S

2017-04-01

We investigated the effects of autonomic dysfunction and endothelin on local conduction and arrhythmogenesis during myocardial infarction. We recorded ventricular tachyarrhythmias, monophasic action potentials, and activation sequences in wild-type and ET B -deficient rats displaying high endothelin levels. Central sympathetic inputs were examined after clonidine administration. Clonidine mitigated early and delayed arrhythmogenesis in ET B -deficient and wild-type rats, respectively. The right ventricular activation delay increased in clonidine-treated ET B -deficient rats and slightly decreased in wild-type rats. The left ventricular voltage rise decreased in all groups, whereas the activation delay increased mainly in clonidine-treated ET B -deficient rats. Central sympathetic activation and endothelin modulate ischemia-induced arrhythmogenesis. Ischemia alters excitability, whereas endothelin impairs local conduction, an action partly counterbalanced by central sympathetic activity.

Feedback and feedforward adaptation to visuomotor delay during reaching and slicing movements.

PubMed

Botzer, Lior; Karniel, Amir

2013-07-01

It has been suggested that the brain and in particular the cerebellum and motor cortex adapt to represent the environment during reaching movements under various visuomotor perturbations. It is well known that significant delay is present in neural conductance and processing; however, the possible representation of delay and adaptation to delayed visual feedback has been largely overlooked. Here we investigated the control of reaching movements in human subjects during an imposed visuomotor delay in a virtual reality environment. In the first experiment, when visual feedback was unexpectedly delayed, the hand movement overshot the end-point target, indicating a vision-based feedback control. Over the ensuing trials, movements gradually adapted and became accurate. When the delay was removed unexpectedly, movements systematically undershot the target, demonstrating that adaptation occurred within the vision-based feedback control mechanism. In a second experiment designed to broaden our understanding of the underlying mechanisms, we revealed similar after-effects for rhythmic reversal (out-and-back) movements. We present a computational model accounting for these results based on two adapted forward models, each tuned for a specific modality delay (proprioception or vision), and a third feedforward controller. The computational model, along with the experimental results, refutes delay representation in a pure forward vision-based predictor and suggests that adaptation occurred in the forward vision-based predictor, and concurrently in the state-based feedforward controller. Understanding how the brain compensates for conductance and processing delays is essential for understanding certain impairments concerning these neural delays as well as for the development of brain-machine interfaces. © 2013 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

Monophasic action potentials of right atrium and electrophysiological properties of AV conducting system in patients with hypothyroidism.

PubMed Central

Gavrilescu, S; Luca, C; Streian, C; Lungu, G; Deutsch, G

1976-01-01

In 12 patients with manifest hypothyroidism right atrial monophasic action potentials showed a significant prolongation in comparison with data from normal or euthyroid patients. Atrial effective refractory periods were also significantly prolonged. After thyroid treatment the monophasic action potential duration and the effective refractory period of the right atrium were within normal ranges. In 6 hypothyroid patients studies of AV conduction with the aid of His bundle electrography and atrial pacing showed a supraHisian conduction delay which was manifest in one case and latent in another two. InfraHisian conduction delay was encountered in 2 cases. PMID:1008978

Time-Resolved IR-Absorption Spectroscopy of Hot-Electron Dynamics in Satellite and Upper Conduction Bands in GaP

NASA Technical Reports Server (NTRS)

Cavicchia, M. A.; Alfano, R. R.

1995-01-01

The relaxation dynamics of hot electrons in the X6 and X7 satellite and upper conduction bands in GaP was directly measured by femtosecond UV-pump-IR-probe absorption spectroscopy. From a fit to the induced IR-absorption spectra the dominant scattering mechanism giving rise to the absorption at early delay times was determined to be intervalley scattering of electrons out of the X7 upper conduction-band valley. For long delay times the dominant scattering mechanism is electron-hole scattering. Electron transport dynamics of the upper conduction band of GaP has been time resolved.

Barriers to help-seeking in men diagnosed with benign colorectal diseases.

PubMed

Oberoi, Devesh V; Jiwa, Moyez; McManus, Alexandra; Hodder, Rupert

2015-01-01

To explore the help-seeking pathway for lower bowel symptoms in men diagnosed with benign bowel diseases. Semi-structured interviews were conducted. The data were analyzed thematically using Andersen's Model of Patient Delay as the theoretical framework. The major delaying factors were attribution of symptoms to self-limiting conditions, failure to make time to visit a GP, low expectation of help from the GP, fear of cancer diagnosis and embarrassment. The major causes of delay in help-seeking were related to the participants, whereas factors associated with treatment delay were less prominent in diagnostic delay.

Gender and Geographic Differences in Developmental Delays among Young Children: Analysis of the Data from the National Registry in Taiwan

ERIC Educational Resources Information Center

Lai, Der-Chung; Tseng, Yen-Cheng; Guo, How-Ran

2011-01-01

Although developmental delays are not uncommon in children, the incidence is seldom assessed, and the reported prevalence varies widely. In Taiwan, the government mandates the reporting of suspected cases. Using the national registry data, we conducted a study to estimate the incidence and prevalence of developmental delays in young children in…

Relations between Self Regulation, Future Time Perspective and the Delay of Gratification in University Students

ERIC Educational Resources Information Center

Avci, Suleyman

2013-01-01

The present study was conducted on 508 (331 female, 144 male) first grade university students in order to investigate the relations between self regulation, the future time perspectives, and the delay of gratification in the academic field. A future time perspective scale, an academic delay of gratification scale and a motivational strategies for…

Structural and Functional Aspects of Social Support for Mothers of Children with and without Cognitive Delays in Vietnam

ERIC Educational Resources Information Center

Park, So-Youn; Glidden, Laraine M.; Shin, Jin Y.

2010-01-01

Background: This study reports development of a social support scale appropriate to the Vietnamese culture and the impact of social support on mothers of children with cognitive delays by using the developing scale. Method: Interview surveys were conducted with 225 mothers of children with and without cognitive delays in Vietnam. The structural…

[Diagnosis delay of pleural and pulmonary tuberculosis].

PubMed

Cherif, J; Mjid, M; Ladhar, A; Toujani, S; Mokadem, S; Louzir, B; Mehiri, N; Béji, M

2014-08-01

Tuberculosis (TB) is still being endemic in our country. Time until management determines both evolution and prognosis of this condition. The aim of this work is to evaluate the delay in diagnosis of TB in a respiratory unit from a university hospital series. The authors conducted a cross-sectional study including patients with pulmonary TBC and/or pleural. An evaluation of time management was conducted from the beginning of symptoms and various consultations with reference to the date of hospitalization and treatment set up. One hundred patients were included (pulmonary TB: 68 cases, pleural TB 23 cases, miliary pulmonary TB: 4 cases, pulmonary TB associated with other extrathoracic locations: 5 cases). The mean time of patient delay and total delay institution were respectively 43.6, 25.7 and 69.3 days. Variables responsible for long delays were: number of consultations more than 3 before hospitalization, empirical antibiotic therapy, of a regional hospital first consultation and the presence of extra-respiratory impairment. The patient delay was considered long. A reorganization of the TB control program, in particular by partial decentralization of care and health education is imperative in order to improve the quality of tuberculosis management in our country. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Bilingualism as a strategy to delay the onset of Alzheimer’s disease

PubMed Central

Klimova, Blanka; Valis, Martin; Kuca, Kamil

2017-01-01

The purpose of this study is to explore original studies which provide evidence about the effects of bilingualism on the delay of the onset of dementia, specifically Alzheimer’s disease (AD). A literature review was conducted in the world’s acknowledged databases: Web of Science, Scopus, and MEDLINE. Altogether, 14 original studies focusing on the research topic were detected. These included six prospective cohort studies and eight retrospective studies. Both types of studies suggest different conclusions. The findings from the prospective cohort studies state that there is no association between bilingualism and the delay of the onset of AD, while the retrospective studies claim the opposite. Despite the negative results of the prospective cohort studies, more research should be conducted on bilingualism and its impact on the delay of the onset of AD, since the brain studies have brought positive findings as far as the enhancement of cognitive reserve is concerned. PMID:29089747

Bilingualism as a strategy to delay the onset of Alzheimer's disease.

PubMed

Klimova, Blanka; Valis, Martin; Kuca, Kamil

2017-01-01

The purpose of this study is to explore original studies which provide evidence about the effects of bilingualism on the delay of the onset of dementia, specifically Alzheimer's disease (AD). A literature review was conducted in the world's acknowledged databases: Web of Science, Scopus, and MEDLINE. Altogether, 14 original studies focusing on the research topic were detected. These included six prospective cohort studies and eight retrospective studies. Both types of studies suggest different conclusions. The findings from the prospective cohort studies state that there is no association between bilingualism and the delay of the onset of AD, while the retrospective studies claim the opposite. Despite the negative results of the prospective cohort studies, more research should be conducted on bilingualism and its impact on the delay of the onset of AD, since the brain studies have brought positive findings as far as the enhancement of cognitive reserve is concerned.

Barriers to emergency obstetric care services: accounts of survivors of life threatening obstetric complications in Malindi District, Kenya.

PubMed

Echoka, Elizabeth; Makokha, Anselimo; Dubourg, Dominique; Kombe, Yeri; Nyandieka, Lillian; Byskov, Jens

2014-01-01

Pregnancy-related mortality and morbidity in most low and middle income countries can be reduced through early recognition of complications, prompt access to care and appropriate medical interventions following obstetric emergencies. We used the three delays framework to explore barriers to emergency obstetric care (EmOC) services by women who experienced life threatening obstetric complications in Malindi District, Kenya. A facility-based qualitative study was conducted between November and December 2010. In-depth interviews were conducted with 30 women who experienced obstetric "near miss" at the only public hospital with capacity to provide comprehensive EmOC services in the district. Findings indicate that pregnant women experienced delays in making decision to seek care and in reaching an appropriate care facility. The "first" delay was due to lack of birth preparedness, including failure to identify a health facility for delivery services regardless of antenatal care and to seek care promptly despite recognition of danger signs. The "second" delay was influenced by long distance and inconvenient transport to hospital. These two delays resulted in some women arriving at the hospital too late to save the life of the unborn baby. Delays in making the decision to seek care when obstetric complications occur, combined with delays in reaching the hospital, contribute to ineffective treatment upon arrival at the hospital. Interventions to reduce maternal mortality and morbidity must adequately consider the pre-hospital challenges faced by pregnant women in order to influence decision making towards addressing the three delays.

A simulation study of the effects of communication delay on air traffic control

DOT National Transportation Integrated Search

1990-09-01

This study was conducted to examine the impacts of voice communications delays : characteristic of Voice Switching and Control System (VSCS) and satellite : communications systems on air traffic system performance, controller stress : and workload, a...

Delays affecting ITS projects : summary of findings

DOT National Transportation Integrated Search

2003-11-01

This report documents the findings of a program review conducted from October 2002 to September 2003 that investigated what delays continue to affect ITS projects. The program review also identified what actions staffs at state DOTs are taking to add...

The Results of a Simulator Study to Determine the Effects on Pilot Performance of Two Different Motion Cueing Algorithms and Various Delays, Compensated and Uncompensated

NASA Technical Reports Server (NTRS)

Guo, Li-Wen; Cardullo, Frank M.; Telban, Robert J.; Houck, Jacob A.; Kelly, Lon C.

2003-01-01

A study was conducted employing the Visual Motion Simulator (VMS) at the NASA Langley Research Center, Hampton, Virginia. This study compared two motion cueing algorithms, the NASA adaptive algorithm and a new optimal control based algorithm. Also, the study included the effects of transport delays and the compensation thereof. The delay compensation algorithm employed is one developed by Richard McFarland at NASA Ames Research Center. This paper reports on the analyses of the results of analyzing the experimental data collected from preliminary simulation tests. This series of tests was conducted to evaluate the protocols and the methodology of data analysis in preparation for more comprehensive tests which will be conducted during the spring of 2003. Therefore only three pilots were used. Nevertheless some useful results were obtained. The experimental conditions involved three maneuvers; a straight-in approach with a rotating wind vector, an offset approach with turbulence and gust, and a takeoff with and without an engine failure shortly after liftoff. For each of the maneuvers the two motion conditions were combined with four delay conditions (0, 50, 100 & 200ms), with and without compensation.

A TDR-Based Soil Moisture Monitoring System with Simultaneous Measurement of Soil Temperature and Electrical Conductivity

PubMed Central

Skierucha, Wojciech; Wilczek, Andrzej; Szypłowska, Agnieszka; Sławiński, Cezary; Lamorski, Krzysztof

2012-01-01

Elements of design and a field application of a TDR-based soil moisture and electrical conductivity monitoring system are described with detailed presentation of the time delay units with a resolution of 10 ps. Other issues discussed include the temperature correction of the applied time delay units, battery supply characteristics and the measurement results from one of the installed ground measurement stations in the Polesie National Park in Poland. PMID:23202009

Quantification of the Arrhythmogenic Effects of Spontaneous Atrial Extrasystole Using High-Resolution Epicardial Mapping.

PubMed

Teuwen, Christophe P; Kik, Charles; van der Does, Lisette J M E; Lanters, Eva A H; Knops, Paul; Mouws, Elisabeth M J P; Bogers, Ad J J C; de Groot, Natasja M S

2018-01-01

Atrial extrasystoles (AES) can initiate atrial fibrillation. However, the impact of spontaneous AES on intra-atrial conduction is unknown. The aims of this study were to examine conduction disorders provoked by AES and to correlate these conduction differences with patient characteristics, mapping locations, and type of AES. High-resolution epicardial mapping (electrodes N=128 or N=192; interelectrode distance, 2 mm) of the entire atrial surface was performed in patients (N=164; 69.5% male; age 67.2±10.5 years) undergoing open-chest cardiac surgery. AES were classified as premature, aberrant, or prematurely aberrant. Conduction delay and conduction block were quantified during sinus rhythm and AES and subsequently compared. Median incidence of conduction delay and conduction block during sinus rhythm was 1.2% (interquartile, 0%-2.3%) and 0.4% (interquartile, 0%-2.1%). In comparison, the median incidence of conduction delay and conduction block during 339 AES was respectively 2.8% (interquartile, 1.3%-4.6%) and 2.2% (interquartile, 0.3%-5.1%) and differed between the types of AES (prematurely aberrant>aberrant>premature). The degree of prematurity was not associated with a higher incidence of conduction disorders ( P >0.05). In contrast, a higher degree of aberrancy was associated with a higher incidence of conduction disorders; AES emerging as epicardial breakthrough provoked most conduction disorders ( P ≥0.002). AES caused most conduction disorders in patients with diabetes mellitus and left atrial dilatation ( P <0.05). Intraoperative high-resolution epicardial mapping showed that conduction disorders are mainly provoked by prematurely aberrant AES, particularly in patients with left atrial dilation and diabetes mellitus or emerging as epicardial breakthrough. © 2017 American Heart Association, Inc.

Ventricular tachycardia storm originating from interventricular septum successfully treated with surgical cryoablation with electroanatomic and electrophysiological mapping before dual valve replacement.

PubMed

Kawamura, Iwanari; Fukamizu, Seiji; Miyazawa, Satoshi; Hojo, Rintaro; Ito, Fusahiko; Watanabe, Masazumi; Nishizaki, Mitsuhiro; Sakurada, Harumizu; Hiraoka, Masayasu

2018-02-01

A 58-year-old man with dilated cardiomyopathy was admitted with heart failure. He had a history of two catheter ablation procedures for ventricular tachycardia (VT) originating from the intraventricular septum (IVS). Before dual valve replacement (DVR), he suffered a VT storm. An electrophysiological study revealed an extended low-voltage area at the IVS with the exit of the induced VT at the anterior side. Radiofrequency application was performed at the VT exit as a landmark for surgical cryoablation (SA). During the DVR, SA was performed at the IVS using this landmark. After SA, the patient had no ventricular tachyarrhythmia.

Signal functions in delayed reinforcement

PubMed Central

Lattal, Kennon A.

1984-01-01

Three experiments were conducted with pigeons to examine the role of the signal in delay-of-reinforcement procedures. In the first, a blackout accompanying a period of nonreinforcement increased key-peck response rates maintained by immediate reinforcement. The effects of dissociating the blackout from the delay interval were examined in the second experiment. In three conditions, blackouts and unsignaled delays were negatively correlated or occurred randomly with respect to one another. A signaled delay and an unsignaled delay that omitted the blackouts were studied in two other conditions. All delay-of-reinforcement conditions generally produced response rates lower than those produced by immediate reinforcement. Signaled delays maintained higher response rates than did any of the various unsignaled-delay conditions, with or without dissociated blackouts. The effects of these latter conditions did not differ systematically from one another. The final experiment showed that response rates varied as a function of the frequency with which a blackout accompanied delay intervals. By eliminating a number of methodological difficulties present in previous delay-of-reinforcement experiments, these results suggest the importance of the signal in maintaining responding during delay-of-reinforcement procedures and, conversely, the importance of the delay interval in decreasing responding. PMID:16812387

Sources of delayed provision of neurosurgical care in a rural kenyan setting

PubMed Central

Mansouri, Alireza; Chan, Vivien; Njaramba, Veronica; Cadotte, David W.; Albright, A. Leland; Bernstein, Mark

2015-01-01

Background: Delay to neurosurgical care can result in significant morbidity and mortality. In this study, we aim to identify and quantify the sources of delay to neurosurgical consultation and care at a rural setting in Kenya. Methods: A mixed-methods, cross-sectional analysis of all patients admitted to the neurosurgical department at Kijabe Hospital (KH) was conducted: A retrospective analysis of admissions from October 1 to December 31, 2013 and a prospective analysis from June 2 to June 20, 2014. Sources of delay were categorized and quantified. The Kruskal–Wallis test was used to identify an overall significant difference among diagnoses. The Mann–Whitney U test was used for pairwise comparisons within groups; the Bonferroni correction was applied to the alpha level of significance (0.05) according to the number of comparisons conducted. IBM SPSS version 22.0 (SPSS, Chicago, IL) was used for statistical analyses. Results: A total of 332 admissions were reviewed (237 retrospective, 95 prospective). The majority was pediatric admissions (median age: 3 months). Hydrocephalus (35%) and neural tube defects (NTDs; 27%) were most common. At least one source of delay was identified in 192 cases (58%); 39 (12%) were affected by multiple sources. Delay in primary care (PCPs), in isolation or combined with other sources, comprised 137 of total (71%); misdiagnosis or incorrect management comprised 46 (34%) of these. Finances contributed to delays in 25 of 95 prospective cases. At a median delay of 49 and 200.5 days, the diagnoses of hydrocephalus and tumors were associated with a significantly longer delay compared with NTDs (P < 0.001). Conclusion: A substantial proportion of patients experienced delays in procuring pediatric neurosurgical care. Improvement in PCP knowledge base, implementation of a triage and referral process, and development of community-based funding strategies can potentially reduce these delays. PMID:25745587

Reasons for delay in decision making and reaching health facility among obstetric fistula and pelvic organ prolapse patients in Gondar University hospital, Northwest Ethiopia.

PubMed

Adefris, Mulat; Abebe, Solomon Mekonnen; Terefe, Kiros; Gelagay, Abebaw Addis; Adigo, Azmeraw; Amare, Selamawit; Lazaro, Dorothy; Berhe, Aster; Baye, Chernet

2017-08-22

Obstetric fistula and pelvic organ prolapse remain highly prevalent in sub-Saharan Africa, where women have poor access to modern health care. Women having these problems tend to stay at home for years before getting treatment. However, information regarding the reasons contributing to late presentation to treatment is scarce, especially at the study area. The objective of this study was to assess the reasons whywomen with obstetric fistula and pelvic organ prolapse at Gondar University Hospital delay treatment. A hospital based cross-sectional study was conducted among 384 women. Delay was evaluated by calculating symptom onset and time of arrival to get treatment at Gondar University Hospital. Regression analysis was conducted to elicit predictors of delay for treatment. Of the total 384 participants, 311 (80.9%) had pelvic organ prolapse and 73(19.1%) obstetric fistula. The proportion of women who delayed treatment of pelvic organ prolapse was 82.9% and that of obstetric fistula 60.9%. Fear of disclosing illness due to social stigma (AOR = 2; 1.03, 3.9) and lack of money (AOR = 1.97; 1.01, 3.86) were associated with the delay of treatment for pelvic organ prolapse,while increasing age (AOR =1.12; 1.01, 1.24) and divorce (AOR = 16.9; 1.75, 165.5) were were responsible for delaying treatment forobstetric fistula. A large numberof women with pelvic organ prolapse and obstetric fistula delayed treatment. Fear of disclosure due to social stigma and lack of moneywere the major factors that contributed to thedelay to seek treatment for pelvic organ prolapse,while increasing age and divorce were the predictors for delaying treatment for obstetric fistula.

Mechanisms of Firing Patterns in Fast-Spiking Cortical Interneurons

PubMed Central

Golomb, David; Donner, Karnit; Shacham, Liron; Shlosberg, Dan; Amitai, Yael; Hansel, David

2007-01-01

Cortical fast-spiking (FS) interneurons display highly variable electrophysiological properties. Their spike responses to step currents occur almost immediately following the step onset or after a substantial delay, during which subthreshold oscillations are frequently observed. Their firing patterns include high-frequency tonic firing and rhythmic or irregular bursting (stuttering). What is the origin of this variability? In the present paper, we hypothesize that it emerges naturally if one assumes a continuous distribution of properties in a small set of active channels. To test this hypothesis, we construct a minimal, single-compartment conductance-based model of FS cells that includes transient Na+, delayed-rectifier K+, and slowly inactivating d-type K+ conductances. The model is analyzed using nonlinear dynamical system theory. For small Na+ window current, the neuron exhibits high-frequency tonic firing. At current threshold, the spike response is almost instantaneous for small d-current conductance, g d, and it is delayed for larger g d. As g d further increases, the neuron stutters. Noise substantially reduces the delay duration and induces subthreshold oscillations. In contrast, when the Na+ window current is large, the neuron always fires tonically. Near threshold, the firing rates are low, and the delay to firing is only weakly sensitive to noise; subthreshold oscillations are not observed. We propose that the variability in the response of cortical FS neurons is a consequence of heterogeneities in their g d and in the strength of their Na+ window current. We predict the existence of two types of firing patterns in FS neurons, differing in the sensitivity of the delay duration to noise, in the minimal firing rate of the tonic discharge, and in the existence of subthreshold oscillations. We report experimental results from intracellular recordings supporting this prediction. PMID:17696606

Mechanisms of firing patterns in fast-spiking cortical interneurons.

PubMed

Golomb, David; Donner, Karnit; Shacham, Liron; Shlosberg, Dan; Amitai, Yael; Hansel, David

2007-08-01

Cortical fast-spiking (FS) interneurons display highly variable electrophysiological properties. Their spike responses to step currents occur almost immediately following the step onset or after a substantial delay, during which subthreshold oscillations are frequently observed. Their firing patterns include high-frequency tonic firing and rhythmic or irregular bursting (stuttering). What is the origin of this variability? In the present paper, we hypothesize that it emerges naturally if one assumes a continuous distribution of properties in a small set of active channels. To test this hypothesis, we construct a minimal, single-compartment conductance-based model of FS cells that includes transient Na(+), delayed-rectifier K(+), and slowly inactivating d-type K(+) conductances. The model is analyzed using nonlinear dynamical system theory. For small Na(+) window current, the neuron exhibits high-frequency tonic firing. At current threshold, the spike response is almost instantaneous for small d-current conductance, gd, and it is delayed for larger gd. As gd further increases, the neuron stutters. Noise substantially reduces the delay duration and induces subthreshold oscillations. In contrast, when the Na(+) window current is large, the neuron always fires tonically. Near threshold, the firing rates are low, and the delay to firing is only weakly sensitive to noise; subthreshold oscillations are not observed. We propose that the variability in the response of cortical FS neurons is a consequence of heterogeneities in their gd and in the strength of their Na(+) window current. We predict the existence of two types of firing patterns in FS neurons, differing in the sensitivity of the delay duration to noise, in the minimal firing rate of the tonic discharge, and in the existence of subthreshold oscillations. We report experimental results from intracellular recordings supporting this prediction.

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

NASA Technical Reports Server (NTRS)

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

1986-01-01

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

Functional morphology and patterns of blood flow in the heart of Python regius.

PubMed

Starck, J Matthias

2009-06-01

Brightness-modulated ultrasonography, continuous-wave Doppler, and pulsed-wave Doppler-echocardiography were used to analyze the functional morphology of the undisturbed heart of ball pythons. In particular, the action of the muscular ridge and the atrio-ventricular valves are key features to understand how patterns of blood flow emerge from structures directing blood into the various chambers of the heart. A step-by-step image analysis of echocardiographs shows that during ventricular diastole, the atrio-ventricular valves block the interventricular canals so that blood from the right atrium first fills the cavum venosum, and blood from the left atrium fills the cavum arteriosum. During diastole, blood from the cavum venosum crosses the muscular ridge into the cavum pulmonale. During middle to late systole the muscular ridge closes, thus prohibiting further blood flow into the cavum pulmonale. At the same time, the atrio-ventricular valves open the interventricular canal and allow blood from the cavum arteriosum to flow into the cavum venosum. In the late phase of ventricular systole, all blood from the cavum pulmonale is pressed into the pulmonary trunk; all blood from the cavum venosum is pressed into both aortas. Quantitative measures of blood flow volume showed that resting snakes bypass the pulmonary circulation and shunt about twice the blood volume into the systemic circulation as into the pulmonary circulation. When digesting, the oxygen demand of snakes increased tremendously. This is associated with shunting more blood into the pulmonary circulation. The results of this study allow the presentation of a detailed functional model of the python heart. They are also the basis for a functional hypothesis of how shunting is achieved. Further, it was shown that shunting is an active regulation process in response to changing demands of the organism (here, oxygen demand). Finally, the results of this study support earlier reports about a dual pressure circulation in Python regius.

Ten-year outcome of enzyme replacement therapy with agalsidase beta in patients with Fabry disease.

PubMed

Germain, Dominique P; Charrow, Joel; Desnick, Robert J; Guffon, Nathalie; Kempf, Judy; Lachmann, Robin H; Lemay, Roberta; Linthorst, Gabor E; Packman, Seymour; Scott, C Ronald; Waldek, Stephen; Warnock, David G; Weinreb, Neal J; Wilcox, William R

2015-05-01

Fabry disease results from deficient α-galactosidase A activity and globotriaosylceramide accumulation causing renal insufficiency, strokes, hypertrophic cardiomyopathy and early demise. We assessed the 10-year outcome of recombinant α-galactosidase A therapy. The outcomes (severe clinical events, renal function, cardiac structure) of 52/58 patients with classic Fabry disease from the phase 3 clinical trial and extension study, and the Fabry Registry were evaluated. Disease progression rates for patients with low renal involvement (LRI, n=32) or high renal involvement (HRI, n=20) at baseline were assessed. 81% of patients (42/52) did not experience any severe clinical event during the treatment interval and 94% (49/52) were alive at the end of the study period. Ten patients reported a total of 16 events. Patients classified as LRI started therapy 13 years younger than HRI (mean 25 years vs 38 years). Mean slopes for estimated glomerular filtration rate for LRI and HRI were -1.89 mL/min/1.73 m(2)/year and -6.82 mL/min/1.73 m(2)/year, respectively. Overall, the mean left ventricular posterior wall thickness and interventricular septum thickness remained unchanged and normal. Patients who initiated treatment at age ≥ 40 years exhibited significant increase in left ventricular posterior wall thickness and interventricular septum thickness. Mean plasma globotriaosylceramide normalised within 6 months. This 10-year study documents the effectiveness of agalsidase beta (1 mg/kg/2 weeks) in patients with Fabry disease. Most patients remained alive and event-free. Patients who initiated treatment at a younger age and with less kidney involvement benefited the most from therapy. Patients who initiated treatment at older ages and/or had advanced renal disease experienced disease progression. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Ten-year outcome of enzyme replacement therapy with agalsidase beta in patients with Fabry disease

PubMed Central

Germain, Dominique P; Charrow, Joel; Desnick, Robert J; Guffon, Nathalie; Kempf, Judy; Lachmann, Robin H; Lemay, Roberta; Linthorst, Gabor E; Packman, Seymour; Scott, C Ronald; Waldek, Stephen; Warnock, David G; Weinreb, Neal J; Wilcox, William R

2015-01-01

Background Fabry disease results from deficient α-galactosidase A activity and globotriaosylceramide accumulation causing renal insufficiency, strokes, hypertrophic cardiomyopathy and early demise. We assessed the 10-year outcome of recombinant α-galactosidase A therapy. Methods The outcomes (severe clinical events, renal function, cardiac structure) of 52/58 patients with classic Fabry disease from the phase 3 clinical trial and extension study, and the Fabry Registry were evaluated. Disease progression rates for patients with low renal involvement (LRI, n=32) or high renal involvement (HRI, n=20) at baseline were assessed. Results 81% of patients (42/52) did not experience any severe clinical event during the treatment interval and 94% (49/52) were alive at the end of the study period. Ten patients reported a total of 16 events. Patients classified as LRI started therapy 13 years younger than HRI (mean 25 years vs 38 years). Mean slopes for estimated glomerular filtration rate for LRI and HRI were −1.89 mL/min/1.73 m2/year and −6.82 mL/min/1.73 m2/year, respectively. Overall, the mean left ventricular posterior wall thickness and interventricular septum thickness remained unchanged and normal. Patients who initiated treatment at age ≥40 years exhibited significant increase in left ventricular posterior wall thickness and interventricular septum thickness. Mean plasma globotriaosylceramide normalised within 6 months. Conclusions This 10-year study documents the effectiveness of agalsidase beta (1 mg/kg/2 weeks) in patients with Fabry disease. Most patients remained alive and event-free. Patients who initiated treatment at a younger age and with less kidney involvement benefited the most from therapy. Patients who initiated treatment at older ages and/or had advanced renal disease experienced disease progression. PMID:25795794

Analysis of transit time flow of the right internal thoracic artery anastomosed to the left anterior descending artery compared to the left internal thoracic artery

PubMed Central

Milani, Rodrigo; de Moraes, Daniela; Sanches, Aline; Jardim, Rodrigo; Lumikoski, Thais; Miotto, Gabriela; Santana, Vitor Hugo; Brofman, Paulo Roberto

2014-01-01

Introduction We evaluated with transit time flow the performance of the right and left thoracic arteries when used as a graft for the left anterior descending artery. Methods Fifty patients undergoing surgery for myocardial revascularization without cardiopulmonary bypass were divided into two groups. In group A patients received graft of right internal mammary artery to the anterior interventricular branch. In group B patients received graft of left internal mammary artery to the same branch. At the end of the operation the flow was assessed by measuring transit time. Results In group A, mean age was 60.6±9.49 years. The average height and weight of the group was 80.4±10.32 kg and 169.2±6.86 cm. The average number of grafts per patient in this group was 3.28±1.49. The mean flow and distal resistance obtained in right internal thoracic artery was 42.1±23.4 ml/min and 2.8±0.9 respectively. In group B, the mean age was 59.8±9.7 years. The average height and weight of this group was 77.7±14.22 kg and 166.0±8.2 cm. The average number of grafts per patient in this group was 3.08 ±0.82. The mean flow and distal resistance observed in this group was 34.2±19.1 ml/min and 2.0±0.7. There were no deaths in this series. Conclusion Right internal mammary artery presented a similar behavior to left internal mammary artery when anastomosed to the anterior interventricular branch of the left coronary artery. There was no statistical difference between the measured flow obtained between both arteries. PMID:25140463

Evolution and Development of Ventricular Septation in the Amniote Heart

PubMed Central

Poelmann, Robert E.; Groot, Adriana C. Gittenberger-de; Vicente-Steijn, Rebecca; Wisse, Lambertus J.; Bartelings, Margot M.; Everts, Sonja; Hoppenbrouwers, Tamara; Kruithof, Boudewijn P. T.; Jensen, Bjarke; de Bruin, Paul W.; Hirasawa, Tatsuya; Kuratani, Shigeru; Vonk, Freek; van de Put, Jeanne M. M. S.; de Bakker, Merijn A.; Richardson, Michael K.

2014-01-01

During cardiogenesis the epicardium, covering the surface of the myocardial tube, has been ascribed several functions essential for normal heart development of vertebrates from lampreys to mammals. We investigated a novel function of the epicardium in ventricular development in species with partial and complete septation. These species include reptiles, birds and mammals. Adult turtles, lizards and snakes have a complex ventricle with three cava, partially separated by the horizontal and vertical septa. The crocodilians, birds and mammals with origins some 100 million years apart, however, have a left and right ventricle that are completely separated, being a clear example of convergent evolution. In specific embryonic stages these species show similarities in development, prompting us to investigate the mechanisms underlying epicardial involvement. The primitive ventricle of early embryos becomes septated by folding and fusion of the anterior ventricular wall, trapping epicardium in its core. This folding septum develops as the horizontal septum in reptiles and the anterior part of the interventricular septum in the other taxa. The mechanism of folding is confirmed using DiI tattoos of the ventricular surface. Trapping of epicardium-derived cells is studied by transplanting embryonic quail pro-epicardial organ into chicken hosts. The effect of decreased epicardium involvement is studied in knock-out mice, and pro-epicardium ablated chicken, resulting in diminished and even absent septum formation. Proper folding followed by diminished ventricular fusion may explain the deep interventricular cleft observed in elephants. The vertical septum, although indistinct in most reptiles except in crocodilians and pythonidsis apparently homologous to the inlet septum. Eventually the various septal components merge to form the completely septated heart. In our attempt to discover homologies between the various septum components we aim to elucidate the evolution and development of this part of the vertebrate heart as well as understand the etiology of septal defects in human congenital heart malformations. PMID:25192012

Using a whole-body 31P birdcage transmit coil and 16-element receive array for human cardiac metabolic imaging at 7T

PubMed Central

Dragonu, Iulius; Almujayyaz, Salam; Batzakis, Alex; Young, Liam A. J.; Purvis, Lucian A. B.; Clarke, William T.; Wichmann, Tobias; Lanz, Titus; Neubauer, Stefan; Robson, Matthew D.; Klomp, Dennis W. J.; Rodgers, Christopher T.

2017-01-01

Purpose Cardiac phosphorus magnetic resonance spectroscopy (31P-MRS) provides unique insight into the mechanisms of heart failure. Yet, clinical applications have been hindered by the restricted sensitivity of the surface radiofrequency-coils normally used. These permit the analysis of spectra only from the interventricular septum, or large volumes of myocardium, which may not be meaningful in focal disease. Löring et al. recently presented a prototype whole-body (52 cm diameter) transmit/receive birdcage coil for 31P at 7T. We now present a new, easily-removable, whole-body 31P transmit radiofrequency-coil built into a patient-bed extension combined with a 16-element receive array for cardiac 31P-MRS. Materials and methods A fully-removable (55 cm diameter) birdcage transmit coil was combined with a 16-element receive array on a Magnetom 7T scanner (Siemens, Germany). Electro-magnetic field simulations and phantom tests of the setup were performed. In vivo maps of B1+, metabolite signals, and saturation-band efficiency were acquired across the torsos of eight volunteers. Results The combined (volume-transmit, local receive array) setup increased signal-to-noise ratio 2.6-fold 10 cm below the array (depth of the interventricular septum) compared to using the birdcage coil in transceiver mode. The simulated coefficient of variation for B1+ of the whole-body coil across the heart was 46.7% (surface coil 129.0%); and the in vivo measured value was 38.4%. Metabolite images of 2,3-diphosphoglycerate clearly resolved the ventricular blood pools, and muscle tissue was visible in phosphocreatine (PCr) maps. Amplitude-modulated saturation bands achieved 71±4% suppression of phosphocreatine PCr in chest-wall muscles. Subjects reported they were comfortable. Conclusion This easy-to-assemble, volume-transmit, local receive array coil combination significantly improves the homogeneity and field-of-view for metabolic imaging of the human heart at 7T. PMID:29073228

Nonsurgical reduction of the interventricular septum in patients with hypertrophic cardiomyopathy.

PubMed

Shamim, Waqar; Yousufuddin, Mohammed; Wang, Duolao; Henein, Michael; Seggewiss, Hubert; Flather, Marcus; Coats, Andrew J S; Sigwart, Ulrich

2002-10-24

In patients with hypertrophic cardiomyopathy and obstruction of the left ventricular outflow tract, nonsurgical reduction of the septum is a treatment option when medical therapy has failed. We investigated the long-term effects of nonsurgical reduction of the septum on functional capacity and electrocardiographic and echocardiographic characteristics. Sixty-four consecutive patients with hypertrophic cardiomyopathy and a mean (+/-SD) age of 48.5+/-17.2 years underwent nonsurgical reduction of the septum by injection of ethanol into the septal perforator branch of the left anterior descending coronary artery. These patients were assessed by exercise testing, electrocardiography, and resting and dobutamine (stress-induced) echocardiography after a mean period of 3.0+/-1.3 years. At follow-up, patients had significant improvements in New York Heart Association class, peak oxygen consumption (from 18.4+/-5.8 to 30.0+/-4.4 ml per kilogram of body weight per minute, P<0.001), and left ventricular outflow tract gradients (resting gradient, from 64+/-36 to 16+/-15 mm Hg; P<0.001; stress-induced gradient, from 132+/-34 to 45+/-19 mm Hg; P<0.001). Procedure-related complications included right bundle-branch block in all patients, complete heart block in 31 patients (48 percent), and significant increases in QRS and corrected QT intervals. Seventeen patients (27 percent) required permanent pacing. R-wave amplitude was significantly decreased (from 32+/-8 to 17+/-7 mV, P<0.001). The dimensions of the left ventricular cavity increased, and the interventricular septal thickness was reduced. Nonsurgical septal reduction leads to sustained improvements in both subjective and objective measures of exercise capacity in association with a persistent reduction in resting and stress-induced left ventricular outflow tract gradients. It is also associated with a high incidence of procedure-related complete heart block, however, often requiring permanent pacing. Copyright 2002 Massachusetts Medical Society

Impact of aerobic interval training and continuous training on left ventricular geometry and function: a SAINTEX-CAD substudy.

PubMed

Van De Heyning, Caroline M; De Maeyer, Catherine; Pattyn, Nele; Beckers, Paul J; Cornelissen, Véronique A; Goetschalckx, Kaatje; Possemiers, Nadine; Van Craenenbroeck, Emeline M; Voigt, Jens-Uwe; Vanhees, Luc; Shivalkar, Bharati

2018-04-15

Increase of exercise capacity (peak VO 2 ) after cardiac rehabilitation improves outcome in patients with coronary artery disease (CAD). Systolic and diastolic function have been associated with peak VO 2 , but their role towards improvement of exercise capacity remains unclear. It is unknown which exercise intensity has the most beneficial impact on left ventricular (LV) geometry and function in CAD patients without heart failure. 200 stable CAD patients without heart failure were randomized to 3months of aerobic interval training (AIT) or aerobic continuous training (ACT). Cardiopulmonary exercise test and transthoracic echocardiography were scheduled before and after 3months of training. At baseline, a higher peak VO 2 correlated with lower LV posterior wall thickness (p=0.002), higher LV ejection fraction (p=0.008), better LV global longitudinal strain (p=0.043) and lower E/e' (0=0.001). After multivariate stepwise regression analysis only E/é remained an independent predictor of peak VO 2 (p=0.042). Improvement of peak VO 2 after 3months of training correlated with reverse remodeling of the interventricular septum (p=0.005), enlargement of LV diastolic volume (p=0.007) and increase of LV stroke volume (p=0.018) but not with other indices of systolic or diastolic function. Significant reduction of the interventricular septum thickness after cardiac rehabilitation was observed (p=0.012), with a trend towards more reverse remodeling after ACT compared to AIT (p=0.054). In contrast, there were no changes in other parameters of LV geometry, diastolic or systolic function. Systolic and diastolic function are determinants of baseline exercise capacity in CAD patients without heart failure, but do not seem to mediate improvement of peak VO 2 after either AIT or ACT. Copyright © 2017 Elsevier B.V. All rights reserved.

Glue septal ablation: A promising alternative to alcohol septal ablation

PubMed Central

Aytemir, Kudret; Oto, Ali

2016-01-01

Hypertrophic cardiomyopathy (HCM) is defined as myocardial hypertrophy in the absence of another cardiac or systemic disease capable of producing the magnitude of present hypertrophy. In about 70% of patients with HCM, there is left ventricular outflow tract (LVOT) obstruction (LVOTO) and this is known as obstructive type of hypertrophic cardiomyopathy (HOCM). Cases refractory to medical treatment have had two options either surgical septal myectomy or alcohol septal ablation (ASA) to alleviate LVOT gradient. ASA may cause some life-threatening complications including conduction disturbances and complete heart block, hemodynamic compromise, ventricular arrhythmias, distant and massive myocardial necrosis. Glue septal ablation (GSA) is a promising technique for the treatment of HOCM. Glue seems to be superior to alcohol due to some intrinsic advantageous properties of glue such as immediate polymerization which prevents the leak into the left anterior descending coronary artery and it is particularly useful in patients with collaterals to the right coronary artery in whom alcohol ablation is contraindicated. In our experience, GSA is effective and also a safe technique without significant complications. GSA decreases LVOT gradient immediately after the procedure and this reduction persists during 12 months of follow-up. It improves New York Heart Association functional capacity and decrease interventricular septal wall thickness. Further studies are needed in order to assess the long-term efficacy and safety of this technique. PMID:27011786

Assessment of atrial conduction time in patients with polycystic ovary syndrome.

PubMed

Zehir, Regayip; Karabay, Can Yucel; Kocabay, Gonenc; Kalayci, Arzu; Kaymaz, Ozge; Aykan, Ahmet Cagrı; Karabay, Emre; Kirma, Cevat

2014-11-01

Polycystic ovary syndrome (PCOS) is closely related to increased cardiovascular risk in women of reproductive age. Atrial conduction abnormalities in these patients have not been investigated in terms of atrial electromechanical delay measured by tissue Doppler imaging (TDI) as an early predictor of atrial fibrillation development. The aim of this study was to evaluate whether TDI-derived atrial conduction time is prolonged in PCOS. The study included 51 patients with PCOS and 48 age-matched healthy controls. P-wave dispersion (PWD) was calculated on the 12-lead surface electrocardiogram. Systolic and diastolic left ventricular (LV) functions, atrial electromechanical coupling, intraatrial and interatrial electromechanical delays were measured with conventional echocardiography and TDI. PWD was higher in PCOS women (50.45 ± 3.7 vs 34.73 ± 6.7 ms, p = 0.008). Interatrial and intraatrial electromechanical delay were found longer in patients with PCOS compared to controls (41.9 ± 9.0 vs 22.2 ± 6.6 ms, p < 0.001; 22.6 ± 5.8 vs 5.9 ± 4.7 ms, p < 0.001, respectively). Left atrial (LA) volume index and LV diastolic parameters were significantly different between the groups. PWD was correlated with interatrial electromechanical delay (r = 0.54, p < 0.01). Interatrial electromechanical delay was strongly correlated with homeostatic model assessment insulin resistance index and high-sensitivity C-reactive protein levels (r = 0.68, p < 0.001; r = 0.53, p < 0.001, respectively). Interatrial electromechanical delay was positively correlated with LA volume index and deceleration time (r = 0.31, p = 0.04; r = 0.37, p = 0.021, respectively) and negatively correlated with flow propagation velocity (r = -0.38, p = 0.014). This study shows that atrial electromechanical delay is prolonged in PCOS patients. Atrial electromechanical delay prolongation is related to low-grade inflammation, insulin resistance, and LV diastolic dysfunction in PCOS.

The influence of ground conductivity on the structure of RF radiation from return strokes

NASA Technical Reports Server (NTRS)

Levine, D. M.; Gesell, L.

1984-01-01

The combination of the finite conductivity of the Earth plus the propagation of the return stroke current up the channel which results in an apparent time delay between the fast field changes and RF radiation for distant observers is shown. The time delay predicted from model return strokes is on the order of 20 micro and the received signal has the characteristics of the data observed in Virginia and Florida. A piecewise linear model for the return stroke channel and a transmission line model for current propagation on each segment was used. Radiation from each segment is calculated over a flat Earth with finite conductivity using asymptotics approximations for the Sommerfeld integrals. The radiation at the observer is processed by a model AM radio receiver. The output voltage was calculated for several frequencies between HF-UHF assuming a system bandwidth (300 kHz) characteristic of the system used to collect data in Florida and Virginia. Comparison with the theoretical fast field changes indicates a time delay of 20 microns.

Do executive deficits and delay aversion make independent contributions to preschool attention-deficit/hyperactivity disorder symptoms?

PubMed

Sonuga-Barke, Edmund J S; Dalen, Lindy; Remington, Bob

2003-11-01

To test whether deficits in executive function and delay aversion make independent contributions to levels of attention-deficit/hyperactivity disorder (ADHD) symptoms exhibited by preschool children. One hundred fifty-six children between 3 and 5.5 years old (78 girls and 78 boys) selected from the community completed an age-appropriate battery of tests measuring working memory, set shifting, planning, delay of gratification, and preference for delayed rewards. Parents completed a clinical interview about their children's ADHD symptoms. Analysis of test performance revealed two factors: executive dysfunction and delay aversion. Multivariate analysis demonstrated that when other factors (i.e., age, IQ, and conduct problems) were controlled, executive dysfunction and delay aversion each made significant independent contributions to predictions of ADHD symptoms. Preschool ADHD symptoms are psychologically heterogeneous. Executive dysfunction and delay aversion may represent two distinct and early appearing neurodevelopmental bases for ADHD symptoms.

On the delay factors of the private construction projects in Medan city

NASA Astrophysics Data System (ADS)

Perwira Mulia Tarigan, A.; Subroto

2018-03-01

The delay in construction projects undertaken by contractors is impeding the economic growth of a region. Medan city which is one of the big cities in Indonesia is suffering from it. This study aims to identify the dominant factors causing delays in construction projects conducted by private contractors. The interview method with questionnaires is used to involve 20 contractors, 10 consultants, and 10 owner representatives in the study. From the 45 identified factors causing delays, the highest ranking is the change of work demand by the project owners with 71.84% importance index.

Achievement motivation and memory: achievement goals differentially influence immediate and delayed remember-know recognition memory.

PubMed

Murayama, Kou; Elliot, Andrew J

2011-10-01

Little research has been conducted on achievement motivation and memory and, more specifically, on achievement goals and memory. In the present research, the authors conducted two experiments designed to examine the influence of mastery-approach and performance-approach goals on immediate and delayed remember-know recognition memory. The experiments revealed differential effects for achievement goals over time: Performance-approach goals showed higher correct remember responding on an immediate recognition test, whereas mastery-approach goals showed higher correct remember responding on a delayed recognition test. Achievement goals had no influence on overall recognition memory and no consistent influence on know responding across experiments. These findings indicate that it is important to consider quality, not just quantity, in both motivation and memory, when studying relations between these constructs.

Tuberculosis related stigma and its effect on the delay for sputum examination under the Revised National Tuberculosis Control Program in India.

PubMed

Chakrabartty, Arupkumar; Basu, Pampa; Ali, Kazi Monjur; Sarkar, Aditi Kishore; Ghosh, Debidas

2018-04-01

One major barrier to achieve goal of tuberculosis (TB) control program globally, is the stigma attached to the disease. Perceived stigma can delay sputum test in time. Delay will lead to spread of infection in the community. There is no scientific information available in India exactly looking into the association between delay in sputum examination and stigma. We conducted a study in rural West Bengal among persons with cough for 2 weeks or more to assess their level of stigma, its influence on delay for sputum test and identify factors those shape the level of stigma. A community based cross sectional survey was conducted from February to June 2015 in West Bengal, India. We interviewed 135 persons of 15-60 years. Data were collected using a pretested structured questionnaire. Chi-square and logistic regression analysis were done using SPSS 23.0 statistical software. Among the 'lower stigma' group (score 4-24), 'delay' (14-25 days) is found among 46.2% respondents and 'much delay' (26-120 days) among 53.8%. Among the 'higher stigma' (score 25-36) group, 'delay' is found among 20.5% respondents and 'much delay' among 79.5%. Persons with lower stigma are 0.17 times likely to delay than persons with higher stigma [adjusted odds ratio (AOR): 0.17 (0.044-0.668), p=0.011)]. Important influencers of stigma are caste [AOR: 5.90 (1.66-20.90), p=0.006], number of family members [AOR: 3.46 (1.08-11.06), p=0.009] and residence in urban or rural [AOR: 3.97 (1.03-15.27), p=0.045]. Revised National Tuberculosis Control Program in India should de-stigmatize the community giving priorities to lower castes, big families and rural areas. Copyright © 2017 Tuberculosis Association of India. Published by Elsevier B.V. All rights reserved.

Delay in seeking medical help following Transient Ischemic Attack (TIA) or "mini-stroke": a qualitative study.

PubMed

Mc Sharry, Jennifer; Baxter, Alison; Wallace, Louise M; Kenton, Anthony; Turner, Andrew; French, David P

2014-01-01

Prompt treatment following Transient Ischemic Attack (TIA) can reduce the risk of subsequent stroke and disability. However, many patients delay in making contact with medical services. This study aimed to explore TIA patients' accounts of delay between symptom onset and contacting medical services including how decisions to contact services were made and the factors discussed in relation to delay. Twenty interviews were conducted with TIA patients in England. Using a previous systematic review as an initial framework, interview data were organised into categories of symptom recognition, presence of others and type of care sought. A thematic analysis was then conducted to explore descriptions of care-seeking relevant to each category. Delay in contacting medical services varied from less than an hour to eight days. Awareness of typical stroke symptoms could lead to urgent action when more severe TIA symptoms were present but could lead to delay when experienced symptoms were less severe. The role of friends and family varied widely from deciding on and enacting care-seeking decisions to simply providing transport to the GP practice. When family or friends played a greater role, and both made and enacted care-seeking decisions, delays were often shorter, even when patients themselves failed to identify symptoms. Healthcare professionals also impacted on patients' care-seeking with greater delays in seeking further care for the same episode described when patients perceived a lack of urgency during initial healthcare interactions. This study provides new information on patients' decisions to contact medical services following TIA and identifies overlapping factors that can lead to delay in receiving appropriate treatment. While recognition of symptoms may contribute to delay in contacting medical services, additional factors, including full responsibility being taken by others and initial healthcare interactions, can over-ride or undermine the importance of patients' own identification of TIA.

Delay in Seeking Medical Help following Transient Ischemic Attack (TIA) or “Mini-Stroke”: A Qualitative Study

PubMed Central

Mc Sharry, Jennifer; Baxter, Alison; Wallace, Louise M.; Kenton, Anthony; Turner, Andrew; French, David P.

2014-01-01

Background Prompt treatment following Transient Ischemic Attack (TIA) can reduce the risk of subsequent stroke and disability. However, many patients delay in making contact with medical services. This study aimed to explore TIA patients' accounts of delay between symptom onset and contacting medical services including how decisions to contact services were made and the factors discussed in relation to delay. Methods Twenty interviews were conducted with TIA patients in England. Using a previous systematic review as an initial framework, interview data were organised into categories of symptom recognition, presence of others and type of care sought. A thematic analysis was then conducted to explore descriptions of care-seeking relevant to each category. Results Delay in contacting medical services varied from less than an hour to eight days. Awareness of typical stroke symptoms could lead to urgent action when more severe TIA symptoms were present but could lead to delay when experienced symptoms were less severe. The role of friends and family varied widely from deciding on and enacting care-seeking decisions to simply providing transport to the GP practice. When family or friends played a greater role, and both made and enacted care-seeking decisions, delays were often shorter, even when patients themselves failed to identify symptoms. Healthcare professionals also impacted on patients' care-seeking with greater delays in seeking further care for the same episode described when patients perceived a lack of urgency during initial healthcare interactions. Conclusions This study provides new information on patients' decisions to contact medical services following TIA and identifies overlapping factors that can lead to delay in receiving appropriate treatment. While recognition of symptoms may contribute to delay in contacting medical services, additional factors, including full responsibility being taken by others and initial healthcare interactions, can over-ride or undermine the importance of patients' own identification of TIA. PMID:25137185

Evaluation of Empirical Tropospheric Models Using Satellite-Tracking Tropospheric Wet Delays with Water Vapor Radiometer at Tongji, China

PubMed Central

Wang, Miaomiao; Li, Bofeng

2016-01-01

An empirical tropospheric delay model, together with a mapping function, is commonly used to correct the tropospheric errors in global navigation satellite system (GNSS) processing. As is well-known, the accuracy of tropospheric delay models relies mainly on the correction efficiency for tropospheric wet delays. In this paper, we evaluate the accuracy of three tropospheric delay models, together with five mapping functions in wet delays calculation. The evaluations are conducted by comparing their slant wet delays with those measured by water vapor radiometer based on its satellite-tracking function (collected data with large liquid water path is removed). For all 15 combinations of three tropospheric models and five mapping functions, their accuracies as a function of elevation are statistically analyzed by using nine-day data in two scenarios, with and without meteorological data. The results show that (1) no matter with or without meteorological data, there is no practical difference between mapping functions, i.e., Chao, Ifadis, Vienna Mapping Function 1 (VMF1), Niell Mapping Function (NMF), and MTT Mapping Function (MTT); (2) without meteorological data, the UNB3 is much better than Saastamoinen and Hopfield models, while the Saastamoinen model performed slightly better than the Hopfield model; (3) with meteorological data, the accuracies of all three tropospheric delay models are improved to be comparable, especially for lower elevations. In addition, the kinematic precise point positioning where no parameter is set up for tropospheric delay modification is conducted to further evaluate the performance of tropospheric delay models in positioning accuracy. It is shown that the UNB3 model is best and can achieve about 10 cm accuracy for the N and E coordinate component while 20 cm accuracy for the U coordinate component no matter the meteorological data is available or not. This accuracy can be obtained by the Saastamoinen model only when meteorological data is available, and degraded to 46 cm for the U component if the meteorological data is not available. PMID:26848662

Singer's preferred acoustic condition in performance in an opera house and self-perception of the singer's voice

NASA Astrophysics Data System (ADS)

Noson, Dennis; Kato, Kosuke; Ando, Yoichi

2004-05-01

Solo singers have been shown to over estimate the relative sound pressure level of a delayed, external reproduction of their own voice, singing single syllables, which, in turn, appears to influence the preferred delay of simulated stage reflections [Noson, Ph.D. thesis, Kobe University, 2003]. Bone conduction is thought to be one factor separating singer versus instrumental performer judgments of stage acoustics. Using a parameter derived from the vocal signal autocorrelation function (ACF envelope), the changes in singer preference for delayed reflections is primarily explained by the ACF parameter, rather than internal bone conduction. An auditory model of a singer's preferred reflection delay is proposed, combining the effects of acoustical environment (reflection amplitude), bone conduction, and performer vocal overestimate, which may be applied to the acoustic design of reflecting elements in both upstage and forestage environments of opera stages. For example, soloists who characteristically underestimate external voice levels (or overestimate their own voice) should be provided shorter distances to reflective panels-irrespective of their singing style. Adjustable elements can be deployed to adapt opera houses intended for bel canto style performances to other styles. Additional examples will also be discussed. a)Now at Kumamoto Univ., Kumamoto, Japan. b)Now at: 1-10-27 Yamano Kami, Kumamoto, Japan.

Effects of stomatal development on stomatal conductance and on stomatal limitation of photosynthesis in Syringa oblata and Euonymus japonicus Thunb.

PubMed

Wu, Bing-Jie; Chow, Wah Soon; Liu, Yu-Jun; Shi, Lei; Jiang, Chuang-Dao

2014-12-01

During leaf development, the increase in stomatal conductance cannot meet photosynthetic demand for CO2, thus leading to stomatal limitation of photosynthesis (Ls). Considering the crucial influences of stomatal development on stomatal conductance, we speculated whether stomatal development limits photosynthesis to some extent. To test this hypothesis, stomatal development, stomatal conductance and photosynthesis were carefully studied in both Syringa oblata (normal greening species) and Euonymus japonicus Thunb (delayed greening species). Our results show that the size of stomata increased gradually with leaf expansion, resulting in increased stomatal conductance up to the time of full leaf expansion. During this process, photosynthesis also increased steadily. Compared to that in S. oblata, the development of chloroplasts in E. japonicus Thunb was obviously delayed, leading to a delay in the improvement of photosynthetic capacity. Further analysis revealed that before full leaf expansion, stomatal limitation increased rapidly in both S. oblata and E. japonicus Thunb; after full leaf expansion, stomatal limitation continually increased in E. japonicus Thunb. Accordingly, we suggested that the enhancement of photosynthetic capacity is the main factor leading to stomatal limitation during leaf development but that stomatal development can alleviate stomatal limitation with the increase of photosynthesis by controlling gas exchange. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Prevalence of conduction delay of the right atrium in patients with SSS: implications for pacing site selection.

PubMed

Verlato, Roberto; Zanon, Francesco; Bertaglia, Emanuele; Turrini, Pietro; Baccillieri, Maria Stella; Baracca, Enrico; Bongiorni, Maria Grazia; Zampiero, Aldo; Zonzin, Pietro; Pascotto, Pietro; Venturini, Diego; Corbucci, Giorgio

2007-09-01

To evaluate the prevalence of severe right atrial conduction delay in patients with sinus node dysfunction (SND) and atrial fibrillation (AF) and the effects of pacing in the right atrial appendage (RAA) and in the inter-atrial septum (IAS). Forty-two patients (15 male, 72 +/- 7 years) underwent electrophysiologic study to measure the difference between the conduction time from RAA to coronary sinus ostium during stimulation at 600 ms and after extrastimulus (DeltaCTos). Patients were classified as group A if DeltaCTos > 60 ms and group B if < 60 ms. Each Group was randomized to RAA/IAS pacing and algorithms ON/OFF. Fifteen patients (36%, group A) had DeltaCTos = 76 +/- 11 ms and 27 patients (64%, group B) had DeltaCTos = 36 +/- 20 ms. Twenty-two patients were paced at the RAA and 20 at the IAS. During the study, no AF recurrences were reported in 11 of 42 (26%) patients, independently of RAA or IAS pacing. Patients from group A and RAA pacing had 0.79 +/- 0.81 episodes of AF/day during DDD, which increased to 1.52 +/- 1.41 episodes of AF/day during DDDR + Alg (P = 0.046). Those with IAS pacing had 0.5 +/- 0.24 episodes of AF/day during DDD, which decreased to 0.06 +/- 0.08 episodes of AF/day during DDDR + Alg (P = 0.06). In group B, no differences were reported between pacing sites and pacing modes. Severe right atrial conduction delay is present in one-third of patients with SND and AF: continuous pacing at the IAS is superior to RAA for AF recurrences. In patients without severe conduction delay, no differences between pacing site or mode were observed.

Evaluation of P-Wave Dispersion, Diastolic Function, and Atrial Electromechanical Conduction in Pediatric Patients with Subclinical Hypothyroidism.

PubMed

Irdem, Ahmet; Aydın Sahin, Derya; Kervancioglu, Mehmet; Baspinar, Osman; Sucu, Murat; Keskin, Mehmet; Kilinc, Metin

2016-09-01

This study aimed to evaluate ventricular diastolic dysfunction, inter- and intraatrial conduction delay, and P-wave dispersion in pediatric patients with subclinical hypothyroidism. The study comprised a total of 30 pediatric patients with subclinical hypothyroidism (SH) (mean age 7.8 ± 3.2 years) and 30 healthy children (mean age 8.4 ± 3.6 years) as the control group. A SH diagnosis was made in the event of increased serum thyroid-stimulating hormone (TSH) and decreased serum free triiodothyronine (T3 ) and free thyroxine (T4 ) concentrations. Conventional Doppler imaging (TDI) showed low mitral early diastolic E-wave velocity and E/A ratio (P < 0.001) and significantly higher mitral late diastolic A-wave velocity (P = 0.001) in hypothyroidism patients. Moreover, patients with hypothyroidism had significantly lower left ventricular (LV) septal Em velocity and Em /Am ratios compared with the control group (P < 0.001), whereas Am velocity was higher in hypothyroidism patients (P = 0.018). LV lateral Em velocity and Em /Am ratio were significantly lower in patients with hypothyroidism compared with the control group (P < 0.001). With regard to atrial electromechanical conduction, atrial electromechanical delay (PA) lateral, PA septum, PA tricuspid, and each of interatrial and intraatrial conduction delay were significantly prolonged in hypothyroidism patients as compared with the control group (P < 0.001, P < 0.001, P = 0.023, P = 0.002, and P = 0.003, respectively). P-wave dispersion was significantly different in the pediatric patients with hypothyroidism (P < 0.001). This study demonstrated atrial electromechanical conduction delay, abnormal P-wave dispersion, and ventricle diastolic dysfunction in pediatric patients with hypothyroidism. © 2016, Wiley Periodicals, Inc.

Cognitive Function in Individuals with Atypical Pubertal Development.

ERIC Educational Resources Information Center

Rovet, Joanne F.; And Others

A study of 55 growth-disturbed children, aged 8-17, was conducted to assess how rate of physical maturation and pubertal development influences cognitive and neuropsychological functioning. The sample included 27 boys with short stature and delayed pubertal development (SSB), 15 girls with delayed puberty (DPG), and 13 girls with precocious…

Parenting Stress and Depression in Children with Mental Retardation and Developmental Disabilities.

ERIC Educational Resources Information Center

Kobe, Frank H.

1994-01-01

This study of 29 children with developmental delays found that parent ratings of children's depression were significantly associated with maternal depression, negative self-image, anxiety, and conduct problems. Data suggest that children with developmental delays exhibit a similar pattern of symptoms and associated characteristics to those found…

Mitigating Communication Delays in Remotely Connected Hardware-in-the-loop Experiments

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

Cale, James; Johnson, Brian; Dall'Anese, Emiliano

Here, this paper introduces a potential approach for mitigating the effects of communication delays between multiple, closed-loop hardware-in-the-loop experiments which are virtually connected, yet physically separated. The method consists of an analytical method for the compensation of communication delays, along with the supporting computational and communication infrastructure. The control design leverages tools for the design of observers for the compensation of measurement errors in systems with time-varying delays. The proposed methodology is validated through computer simulation and hardware experimentation connecting hardware-in-the-loop experiments conducted between laboratories separated by a distance of over 100 km.

Mitigating Communication Delays in Remotely Connected Hardware-in-the-loop Experiments

DOE PAGES

Cale, James; Johnson, Brian; Dall'Anese, Emiliano; ...

2018-03-30

Here, this paper introduces a potential approach for mitigating the effects of communication delays between multiple, closed-loop hardware-in-the-loop experiments which are virtually connected, yet physically separated. The method consists of an analytical method for the compensation of communication delays, along with the supporting computational and communication infrastructure. The control design leverages tools for the design of observers for the compensation of measurement errors in systems with time-varying delays. The proposed methodology is validated through computer simulation and hardware experimentation connecting hardware-in-the-loop experiments conducted between laboratories separated by a distance of over 100 km.

Cardiac Delayed Rectifier Potassium Channels in Health and Disease.

PubMed

Chen, Lei; Sampson, Kevin J; Kass, Robert S

2016-06-01

Cardiac delayed rectifier potassium channels conduct outward potassium currents during the plateau phase of action potentials and play pivotal roles in cardiac repolarization. These include IKs, IKr and the atrial specific IKur channels. In this article, we will review their molecular identities and biophysical properties. Mutations in the genes encoding delayed rectifiers lead to loss- or gain-of-function phenotypes, disrupt normal cardiac repolarization and result in various cardiac rhythm disorders, including congenital Long QT Syndrome, Short QT Syndrome and familial atrial fibrillation. We will also discuss the prospect of using delayed rectifier channels as therapeutic targets to manage cardiac arrhythmia. Copyright © 2016 Elsevier Inc. All rights reserved.

Cardiac Delayed Rectifier Potassium Channels in Health and Disease

PubMed Central

Chen, Lei; Sampson, Kevin J.; Kass, Robert S.

2016-01-01

Cardiac delayed rectifier potassium channels conduct outward potassium currents during the plateau phase of action potentials and play pivotal roles in cardiac repolarization. These include IKs, IKr and the atrial specific IKur channels. In this chapter, we will review the molecular identities and biophysical properties of these channels. Mutations in the genes encoding delayed rectifiers lead to loss- or gain-of-function phenotypes, disrupt normal cardiac repolarization and result in various cardiac rhythm disorders, including congenital Long QT Syndrome, Short QT Syndrome and familial atrial fibrillation. We will also discuss the possibility and prospect of using delayed rectifier channels as therapeutic targets to manage cardiac arrhythmia. PMID:27261823

Behaviour of fractional loop delay zero crossing digital phase locked loop (FR-ZCDPLL)

NASA Astrophysics Data System (ADS)

Nasir, Qassim

2018-01-01

This article analyses the performance of the first-order zero crossing digital phase locked loops (FR-ZCDPLL) when fractional loop delay is added to loop. The non-linear dynamics of the loop is presented, analysed and examined through bifurcation behaviour. Numerical simulation of the loop is conducted to proof the mathematical analysis of the loop operation. The results of the loop simulation show that the proposed FR-ZCDPLL has enhanced the performance compared to the conventional zero crossing DPLL in terms of wider lock range, captured range and stable operation region. In addition, extensive experimental simulation was conducted to find the optimum loop parameters for different loop environmental conditions. The addition of the fractional loop delay network in the conventional loop also reduces the phase jitter and its variance especially when the signal-to-noise ratio is low.

Manipulation of peripheral neural feedback loops alters human corticomuscular coherence

PubMed Central

Riddle, C Nicholas; Baker, Stuart N

2005-01-01

Sensorimotor EEG shows ∼20 Hz coherence with contralateral EMG. This could involve efferent and/or afferent components of the sensorimotor loop. We investigated the pathways responsible for coherence genesis by manipulating nervous conduction delays using cooling. Coherence between left sensorimotor EEG and right EMG from three hand and two forearm muscles was assessed in healthy subjects during the hold phase of a precision grip task. The right arm was then cooled to 10°C for ∼90 min, increasing peripheral motor conduction time (PMCT) by ∼35% (assessed by F-wave latency). EEG and EMG recordings were repeated, and coherence recalculated. Control recordings revealed a heterogeneous subject population. In 6/15 subjects (Group A), the corticomuscular coherence phase increased linearly with frequency, as expected if oscillations were propagated along efferent pathways from cortex to muscle. The mean corticomuscular conduction delay for intrinsic hand muscles calculated from the phase–frequency regression slope was 10.4 ms; this is smaller than the delay expected for conduction over fast corticospinal pathways. In 8/15 subjects (Group B), the phase showed no dependence with frequency. One subject showed both Group A and Group B patterns over different frequency ranges. Following cooling, averaged corticomuscular coherence was decreased in Group A subjects, but unchanged for Group B, even though both groups showed comparable slowing of nervous conduction. The delay calculated from the slope of the phase–frequency regression was increased following cooling. However, the size of this increase was around twice the rise in PMCT measured using the F-wave (regression slope 2.33, 95% confidence limits 1.30–3.36). Both afferent and efferent peripheral nerves will be slowed by similar amounts following cooling. The change in delay calculated from the coherence phase therefore better matches the rise in total sensorimotor feedback loop time caused by cooling, rather than just the change in the efferent limb. A model of corticomuscular coherence which assumes that only efferent pathways contribute cannot be reconciled to these results. The data rather suggest that afferent feedback pathways may also play a role in the genesis of corticomuscular coherence. PMID:15919711

Reduction of Weather-Related Terminal Area Delays in the Free-Flight Era

NASA Technical Reports Server (NTRS)

Johnson, Sally C.; Chin, David K.; Rovinsky, Robert B.; Kostiuk, Peter F.; Lee, David A.; Hemm, Robert V.; Wingrove, Earl R., III

1996-01-01

While much of the emphasis of the free-flight movement has been concentrated on reducing en-route delays, airport capacity is a major bottleneck in the current airspace system, particularly during bad weather. According to the Air Transport Association (ATA) Air Carrier Delay Reports, ground delays (gate-hold, taxi-in, and taxi-out) comprise 75 percent of total delays. It is likely that the projected steady growth in traffic will only exacerbate these losses. Preliminary analyses show that implementation of the terminal area technologies and procedures under development in NASA s Terminal Area Productivity program can potentially save the airlines at least $350M annually in weather-related delays by the year 2005 at Boston Logan and Detroit airports alone. This paper briefly describes the Terminal Area Productivity program, outlines the costhenefit analyses that are being conducted in support of the program, and presents some preliminary analysis results.

Delays in using chromatic and luminance information to correct rapid reaches.

PubMed

Kane, Adam; Wade, Alex; Ma-Wyatt, Anna

2011-09-07

People can use feedback to make online corrections to movements but only if there is sufficient time to integrate the new information and make the correction. A key variable in this process is therefore the speed at which the new information about the target location is coded. Conduction velocities for chromatic signals are lower than for achromatic signals so it may take longer to correct reaches to chromatic stimuli. In addition to this delay, the sensorimotor system may prefer achromatic information over the chromatic information as delayed information may be less valuable when movements are made under time pressure. A down-weighting of chromatic information may result in additional latencies for chromatically directed reaches. In our study, participants made online corrections to reaches to achromatic, (L-M)-cone, and S-cone stimuli. Our chromatic stimuli were carefully adjusted to minimize stimulation of achromatic pathways, and we equated stimuli both in terms of detection thresholds and also by their estimated neural responses. Similar stimuli were used throughout the subjective adjustments and final reaching experiment. Using this paradigm, we found that responses to achromatic stimuli were only slightly faster than responses to (L-M)-cone and S-cone stimuli. We conclude that the sensorimotor system treats chromatic and achromatic information similarly and that the delayed chromatic responses primarily reflect early conduction delays.

76 FR 77891 - Open Meeting of the Taxpayer Advocacy Panel Return Processing Delays Project Committee

Federal Register 2010, 2011, 2012, 2013, 2014

2011-12-14

... Return Processing Delays Project Committee AGENCY: Internal Revenue Service (IRS), Treasury. ACTION... Project Committee will be conducted. The Taxpayer Advocacy Panel is soliciting public comments, ideas, and... Project Committee will be held Tuesday, January 03, 2012, at 9:30 a.m. Pacific Time via telephone...

77 FR 40409 - Open Meeting of the Taxpayer Advocacy Panel Return Processing Delays Project Committee

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-09

... Return Processing Delays Project Committee AGENCY: Internal Revenue Service (IRS), Treasury. ACTION... Project Committee will be conducted. The Taxpayer Advocacy Panel is soliciting public comments, ideas, and... Project Committee will be held Tuesday, August 7, 2012, at 9:30 a.m. Pacific Time via telephone conference...

77 FR 55525 - Open Meeting of the Taxpayer Advocacy Panel Return Processing Delays Project Committee

Federal Register 2010, 2011, 2012, 2013, 2014

2012-09-10

... Return Processing Delays Project Committee AGENCY: Internal Revenue Service (IRS), Treasury. ACTION... Project Committee will be conducted. The Taxpayer Advocacy Panel is soliciting public comments, ideas, and... Project Committee will be held Tuesday, October 2, 2012, at 9:30 a.m. Pacific Time via telephone...

77 FR 37103 - Open Meeting of the Taxpayer Advocacy Panel Return Processing Delays Project Committee

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-20

... Project Committee will be conducted. The Taxpayer Advocacy Panel is soliciting public comments, ideas, and... Project Committee will be held Tuesday, July 03, 2012, at 9:30 a.m. Pacific Time via telephone conference... Return Processing Delays Project Committee AGENCY: Internal Revenue Service (IRS), Treasury. ACTION...

Maternal Obesity: Risks for Developmental Delays in Early Childhood.

PubMed

Duffany, Kathleen O'Connor; McVeigh, Katharine H; Kershaw, Trace S; Lipkind, Heather S; Ickovics, Jeannette R

2016-02-01

To assess the risk for neurodevelopmental delays for children of mothers who were obese (≥200 pounds) prior to pregnancy, and to characterize delays associated with maternal obesity among children referred to and found eligible to receive Early Intervention Program services. We conducted a retrospective cohort study (N = 541,816) using a population-based New York City data warehouse with linked birth and Early Intervention data. Risks for children suspected of a delay and 'significantly delayed', with two moderate or one severe delay, were calculated. Among the group of children eligible by delay for Early Intervention, analyses assessed risk for being identified with a moderate-to-severe delay across each of five functional domains as well as risks for multiple delays. Children of mothers who were obese were more likely to be suspected of a delay (adjusted RR 1.19 [CI 1.15-1.22]) and borderline association for 'significantly delayed' (adjusted RR 1.01 [CI 1.00-1.02). Among children eligible by delay, children of mothers who were obese evidenced an increased risk for moderate-to-severe cognitive (adjusted RR 1.04 [CI 1.02-1.07]) and physical (adjusted RR 1.04 [CI 1.01-1.08]) delays and for global developmental delay (adjusted RR 1.05 [CI 1.01-1.08]). Maternal obesity is associated with increased risk of developmental delay in offspring. Among children with moderate or severe delays, maternal obesity is associated with increased risk of cognitive and physical delays as well as with increased risk for global developmental delay. While causation remains uncertain, this adds to the growing body of research reporting an association between maternal obesity and neurodevelopmental delays in offspring.

Autoignition study of binary blends of n- dodecane/1-methylnaphthalene and iso- cetane/1-methylnaphthalene

DOE PAGES

Kukkadapu, Goutham; Sung, Chih-Jen

2017-11-24

An experimental study on autoignition of two binary blends, n-dodecane/1-methylnaphthalene and iso-cetane/1-methylnaphthalene, has been conducted using a rapid compression machine. Specifically, the ignition delays of the stoichiometric blend+air mixtures were measured at elevated pressures of P C = 15 bar and 30 bar, compressed temperatures of T C = 626–944 K, and varying blending ratios of the constituents. For a given set of P C and T C, a nonlinear response of the blend reactivity with respect to the relative amount of the constituents was observed. Since a comprehensive chemical kinetic model for the blends investigated here is under development,more » the current ignition delay datasets serve as the needed targets for model validation. For selected conditions, ignition delay simulations were conducted to highlight and discuss the deficiencies of the literature models and the potential areas for model improvements, especially at low temperatures. In conclusion, further chemical kinetic analyses were conducted to gain understanding of the blending behavior predicted by the available model.« less

Autoignition study of binary blends of n- dodecane/1-methylnaphthalene and iso- cetane/1-methylnaphthalene

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

Kukkadapu, Goutham; Sung, Chih-Jen

An experimental study on autoignition of two binary blends, n-dodecane/1-methylnaphthalene and iso-cetane/1-methylnaphthalene, has been conducted using a rapid compression machine. Specifically, the ignition delays of the stoichiometric blend+air mixtures were measured at elevated pressures of P C = 15 bar and 30 bar, compressed temperatures of T C = 626–944 K, and varying blending ratios of the constituents. For a given set of P C and T C, a nonlinear response of the blend reactivity with respect to the relative amount of the constituents was observed. Since a comprehensive chemical kinetic model for the blends investigated here is under development,more » the current ignition delay datasets serve as the needed targets for model validation. For selected conditions, ignition delay simulations were conducted to highlight and discuss the deficiencies of the literature models and the potential areas for model improvements, especially at low temperatures. In conclusion, further chemical kinetic analyses were conducted to gain understanding of the blending behavior predicted by the available model.« less

The effect of antithyroid treatment on atrial conduction times in patients with subclinical hyperthyroidism.

PubMed

Nacar, Alper Buğra; Acar, Gürkan; Yorgun, Hikmet; Akçay, Ahmet; Özkaya, Mesut; Canpolat, Uğur; Akkoyun, Murat; Tuncer, Cemal

2012-09-01

Prolonged atrial conduction time measured by tissue Doppler imaging (TDI) has been associated with increased risk of atrial fibrillation. We aimed to evaluate the effect of subclinical hyperthyroidism (SH) and antithyroid treatment on atrial conduction time. A total of 30 patients with SH (26 females; mean age 34.8 ± 8.5 years) and 30 age- and gender-matched controls were included. Using TDI, atrial conduction time was measured from the lateral mitral annulus, septal mitral annulus, and lateral tricuspid annulus. Intra- and interatrial conduction delay were calculated. TDI and thyroid hormone levels were studied at the time of enrollment and after achievement of euthyroid state with propylthiouracil treatment. Patients were followed for 14 ± 3 weeks. Atrial conduction time at the lateral and septal mitral annulus were significantly higher in patients with SH compared to controls. Both inter-, right, and left intraatrial electromechanical delay were prolonged in patients with SH compared to control subjects (21.3 ± 6.1 vs. 13.9 ± 4.3, P < 0.001 and 4.2 ± 3.5 vs. 2.3 ± 1.9, P = 0.014 and 17.1 ± 6.0 vs. 11.6 ± 3.8, P < 0.001, respectively). After achievement of euthyroid state, inter- and left intraatrial electromechanical delay were significantly decreased compared to baseline values and approximated to the values of the control group (P < 0.001). SH is associated with prolonged atrial conduction time. After achievement of euthyroid state, decrement in atrial conduction time may reveal how the antithyroid treatment may prevent the development of atrial fibrillation in these patients. © 2012, Wiley Periodicals, Inc.

High frequency modulation circuits based on photoconductive wide bandgap switches

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

Sampayan, Stephen

Methods, systems, and devices for high voltage and/or high frequency modulation. In one aspect, an optoelectronic modulation system includes an array of two or more photoconductive switch units each including a wide bandgap photoconductive material coupled between a first electrode and a second electrode, a light source optically coupled to the WBGP material of each photoconductive switch unit via a light path, in which the light path splits into multiple light paths to optically interface with each WBGP material, such that a time delay of emitted light exists along each subsequent split light path, and in which the WBGP materialmore » conducts an electrical signal when a light signal is transmitted to the WBGP material, and an output to transmit the electrical signal conducted by each photoconductive switch unit. The time delay of the photons emitted through the light path is substantially equivalent to the time delay of the electrical signal.« less

Minimization of Delay Costs in the Realization of Production Orders in Two-Machine System

NASA Astrophysics Data System (ADS)

Dylewski, Robert; Jardzioch, Andrzej; Dworak, Oliver

2018-03-01

The article presents a new algorithm that enables the allocation of the optimal scheduling of the production orders in the two-machine system based on the minimum cost of order delays. The formulated algorithm uses the method of branch and bounds and it is a particular generalisation of the algorithm enabling for the determination of the sequence of the production orders with the minimal sum of the delays. In order to illustrate the proposed algorithm in the best way, the article contains examples accompanied by the graphical trees of solutions. The research analysing the utility of the said algorithm was conducted. The achieved results proved the usefulness of the proposed algorithm when applied to scheduling of orders. The formulated algorithm was implemented in the Matlab programme. In addition, the studies for different sets of production orders were conducted.

Young pigs exhibit differential exploratory behavior during novelty preference tasks in response to age, sex, and delay.

PubMed

Fleming, Stephen A; Dilger, Ryan N

2017-03-15

Novelty preference paradigms have been widely used to study recognition memory and its neural substrates. The piglet model continues to advance the study of neurodevelopment, and as such, tasks that use novelty preference will serve especially useful due to their translatable nature to humans. However, there has been little use of this behavioral paradigm in the pig, and previous studies using the novel object recognition paradigm in piglets have yielded inconsistent results. The current study was conducted to determine if piglets were capable of displaying a novelty preference. Herein a series of experiments were conducted using novel object recognition or location in 3- and 4-week-old piglets. In the novel object recognition task, piglets were able to discriminate between novel and sample objects after delays of 2min, 1h, 1 day, and 2 days (all P<0.039) at both ages. Performance was sex-dependent, as females could perform both 1- and 2-day delays (P<0.036) and males could perform the 2-day delay (P=0.008) but not the 1-day delay (P=0.347). Furthermore, 4-week-old piglets and females tended to exhibit greater exploratory behavior compared with males. Such performance did not extend to novel location recognition tasks, as piglets were only able to discriminate between novel and sample locations after a short delay (P>0.046). In conclusion, this study determined that piglets are able to perform the novel object and location recognition tasks at 3-to-4 weeks of age, however performance was dependent on sex, age, and delay. Copyright © 2016 Elsevier B.V. All rights reserved.

Motivational Climate, Motor-Skill Development, and Perceived Competence: Two Studies of Developmentally Delayed Kindergarten Children

ERIC Educational Resources Information Center

Valentini, Nadia; Rudisill, Mary E.

2004-01-01

Two studies were conducted to examine the effects of motivational climate on motor-skill development and perceived physical competence in kindergarten children with developmental delays. In Experiment 1, two intervention groups were exposed to environments with either high (mastery climate) or low autonomy for 12 weeks. Results showed that the…

Effects of delayed wrapping and moisture content on intake and digestibility of ryegrass silage by growing lambs

USDA-ARS?s Scientific Manuscript database

Baling silage provides an alternative method for preserving forage quality in areas where hay production can be compromised because of the risk of rain exposure and humidity. This study was conducted to examine the effects of moisture content at baling and delayed wrapping intervals on the intake an...

Spontaneous ignition characteristics of gaseous hydrocarbon-air mixtures

NASA Technical Reports Server (NTRS)

Freeman, G.; Lefebvre, A. H.

1984-01-01

Experiments are conducted to determine the spontaneous ignition delay times of gaseous propane, kerosine vapor, and n-heptane vapor in mixtures with air, and oxygen-enriched air, at atmospheric pressure. Over a range of equivalence ratios from 0.2 to 0.8 it is found that ignition delay times are sensibly independent of fuel concentration. However, the results indicate a strong dependence of delay times on oxygen concentration. The experimental data for kerosine and propane demonstrate very close agreement with the results obtained previously by Mullins and Lezberg respectively.

The effect of response-delay on estimating reachability.

PubMed

Gabbard, Carl; Ammar, Diala

2008-11-01

The experiment was conducted to compare visual imagery (VI) and motor imagery (MI) reaching tasks in a response-delay paradigm designed to explore the hypothesized dissociation between vision for perception and vision for action. Although the visual systems work cooperatively in motor control, theory suggests that they operate under different temporal constraints. From this perspective, we expected that delay would affect MI but not VI because MI operates in real time and VI is postulated to be memory-driven. Following measurement of actual reach, right-handers were presented seven (imagery) targets at midline in eight conditions: MI and VI with 0-, 1-, 2-, and 4-s delays. Results indicted that delay affected the ability to estimate reachability with MI but not with VI. These results are supportive of a general distinction between vision for perception and vision for action.

Predictors of healthcare seeking delays among children with chronic musculoskeletal disorders in Nepal.

PubMed

LeBrun, Drake G; Talwar, Divya; Pham, Tuyetnhi A; Banskota, Bibek; Spiegel, David A

2017-12-01

Healthcare seeking behaviors among children with musculoskeletal disorders are poorly understood. We sought to analyze healthcare seeking delays among children with chronic musculoskeletal conditions in Nepal and identify predictors of clinically significant delays. A cross-sectional study was conducted at a large pediatric musculoskeletal rehabilitation center in Nepal. Baseline sociodemographic data and healthcare seeking behaviors were assessed via interviews with 75 randomly selected caregivers. Delays of at least 3 months between disease recognition and presentation to a health worker were considered clinically significant. Predictors of significant delay were assessed via multivariable logistic regression. Clubfoot was the most common condition seen in the study sample (N = 33; 37%). Mean and median presentation delays were 33 months and 14 months, respectively. Sixty-seven percent of children were delayed at least 3 months and 40% were delayed at least 2 years. Caregiver occupation in agriculture or unskilled labor was associated with an increased risk of delayed presentation (adjusted OR = 4.05; 95% CI: 1.36-12.09). Children with chronic musculoskeletal disorders in Nepal face significant delays in accessing healthcare. This poses a major clinical problem as the delayed diagnosis and treatment of childhood musculoskeletal disorders can complicate management options and decrease long-term quality of life. Copyright © 2017 Ministry of Health, Saudi Arabia. Published by Elsevier Ltd. All rights reserved.

Delay in Presentation, Diagnosis, and Treatment for Breast Cancer Patients in Jordan.

PubMed

Abu-Helalah, Ahmad Munir; Alshraideh, Hussam Ahmad; Al-Hanaqtah, Mo'tasem; Da'na, Moh'd; Al-Omari, Asim; Mubaidin, Rasmi

2016-01-01

Breast cancer is the most common cancer, and one of the leading causes of death for females in Jordan and many countries in the world. Studies have shown that delay in symptoms presentation, diagnosis or treatment would result in poor prognosis. There has been no published study from Jordan on delays in patient presentation, delays in diagnosis, or delays in treatment. Therefore, we conducted this study to assess these important quality indicators aiming to improve prognosis for breast cancer patients in Jordan. This project was a cross-sectional study on female breast cancer patients in Jordan. The total number of participants was 327. The proportion of patients with presentation delay, diagnosis delay, and treatment delay was 32.2%, 49.1%, or 32.4%, respectively. The main reported reasons for delay in presentation were ignorance of the nature of the problem (65.6%), limited/lack of knowledge that symptoms were suggestive of cancer diagnosis (16.7%), and misdiagnosis (16.7%). Predictors of delay and mean time for presentation, diagnosis, and treatment were identified. Our results reveal that breast cancer patients in Jordan are experiencing delays in presentation, diagnosis, and treatment. This could justify the advanced stages at diagnosis and poor outcomes for breast cancer patients in Jordan. We recommend revising the current early detection and down-staging programs in Jordan. © 2015 Wiley Periodicals, Inc.

[Right ventricular hypertrophic cardiomyopathy in the fetus --may it be caused by chronic oral tocolysis with fenoterol?].

PubMed

Hamela-Olkowska, Anita; Szymkiewicz-Dangel, Joanna; Własienko, Paweł; Majewska, Urszula; Bokiniec, Renata

2012-02-01

The use of fenoterol in the treatment of preterm labor is associated with the risk of many complications in the mother and the fetus. We present a case of a multipara treated with oral fenoterol due to threatening preterm labor 14 weeks. At 35 weeks of gestation the fetus was diagnosed with hypertrophic cardiomyopathy with severe impairment of the right ventricle. The only factor that might have caused such a state of the fetal circulatory system was fenoterol, used from 21 weeks of gestation. After the withdrawal of the fenoterol the fetal right ventricular function improved gradually. However fetal cardiac hypertrophy persisted until the birth at 39 weeks of gestation. Concentric hypertrophy of the right ventricular wall and interventricular septum were confirmed in the newborn.

Effects of septum and pericardium on heart-lung interactions in a cardiopulmonary simulation model.

PubMed

Karamolegkos, Nikolaos; Albanese, Antonio; Chbat, Nicolas W

2017-07-01

Mechanical heart-lung interactions are often overlooked in clinical settings. However, their impact on cardiac function can be quite significant. Mechanistic physiology-based models can provide invaluable insights into such cardiorespiratory interactions, which occur not only under external mechanical ventilatory support but in normal physiology as well. In this work, we focus on the cardiac component of a previously developed mathematical model of the human cardiopulmonary system, aiming to improve the model's response to the intrathoracic pressure variations that are associated with the respiratory cycle. Interventricular septum and pericardial membrane are integrated into the existing model. Their effect on the overall cardiac response is explained by means of comparison against simulation results from the original model as well as experimental data from literature.

Estimates of delays in diagnosis of cervical cancer in Nepal

PubMed Central

2014-01-01

Background Cervical cancer is the leading cause of cancer related deaths among women in Nepal. The long symptom to diagnosis interval means that women have advanced disease at presentation. The aim of this study was to identify, estimate and describe the extent of different delays in diagnosis of cervical cancer in Nepal. Methods A cross-sectional descriptive study was conducted in two tertiary cancer hospitals of Nepal. Face to face interview and medical records review were carried out among 110 cervical cancer patients. Total diagnostic delay was categorized into component delays: patient delay, health care providers delay, referral delay and diagnostic waiting time. Results Total 110 patients recruited in the study represented 40 districts from all three ecological regions of the country. Median total diagnostic delay was 157 days with more than three fourth (77.3%) of the patients having longer total diagnostic delay of >90 days. Out of the total diagnostic delay, median patient delay, median health care provider delay, median referral delay and median diagnostic waiting time were 68.5 days, 40 days, 5 days and 9 days respectively. Majority of the patients had experienced longer delay of each type except referral delay. Fifty seven percent of the patients had experienced longer patient delay of >60 days, 90% had suffered longer health care provider delay of >1 week, 31.8% had longer referral delay of >1 week and 66.2% had waited >1 week at diagnostic center for final diagnosis. Variation in each type of delay was observed among women with different attributes and in context of health care service delivery. Conclusions Longer delays were observed in all the diagnostic pathways except for referral delay and diagnostic waiting time. Among the delays, patient delay is of crucial importance because of its longer span, although health care provider delay is equally important. In the context of limited screening services in Nepal, the efforts should be to reduce the diagnostic delay especially patient and health care provider delay for early detection and reduction of mortality rate of cervical cancer. PMID:24533670

Developmental pattern of ANF gene expression reveals a strict localization of cardiac chamber formation in chicken.

PubMed

Houweling, Arjan C; Somi, Semir; Van Den Hoff, Maurice J B; Moorman, Antoon F M; Christoffels, Vincent M

2002-02-01

In mouse, atrial natriuretic factor (ANF) gene expression was shown to be a marker for chamber formation within the embryonic heart. To gain insight into the process of chamber formation in the chicken embryonic heart, we analyzed the expression pattern of cANF during development. We found cANF to be specifically expressed in the myocardium of the morphologically distinguishable atrial and ventricular chambers, similar to ANF in mouse. cANF expression was never detected in the myocardium of the atrioventricular canal (AVC), inner curvature, and outflow tract (OFT), which is lined by endocardial cushions. Expression was strictly excluded from the interventricular myocardium and most proximal part of the bundle branches, as identified by the expression of Msx-2, whereas the rest of the bundle branches, trabeculae, and surrounding working myocardium did express cANF. The myocardium that forms de novo within the cushions after looping did not express cANF. At HH9 cANF expression was first observed in a subset of cardiomyocytes, which was localized ventrally in the fused heart tube and laterally in the unfused cardiac sheets. Together, these results show that cANF expression can be used to distinguish differentiated chamber (working) myocardium, including the peripheral ventricular conduction system, from embryonic myocardium. We conclude that differentiation of chamber myocardium takes place already at HH9 at the ventral side of the linear heart tube, possibly preceded by latero-medial signals in the unfused cardiac sheets. Copyright 2002 Wiley-Liss, Inc.

"Why doesn't she seek help for partner abuse?" An exploratory study with South Asian immigrant women.

PubMed

Ahmad, Farah; Driver, Natasha; McNally, Mary Jane; Stewart, Donna E

2009-08-01

This study explores why South Asian immigrant women with experiences of partner abuse delay seeking help from professionals. Three focus groups were conducted in Hindi language with South Asian immigrant women in Toronto. Twenty-two women participated with a mean age of 46 years (range 29-68 years). Thematic analysis was conducted on the transcribed data using constant comparison techniques within and across the groups. We found that three major themes emerged from the discussions: reasons for delayed help-seeking, turning points and talking to professionals. Women expressed delaying help-seeking to the point when "Pani sar se guzar jata he" (water crosses over your head). Their dominant reasons for delayed help-seeking were social stigma, rigid gender roles, marriage obligations, expected silence, loss of social support after migration and limited knowledge about available resources and myths about partner abuse. Women usually turned for help only after experiencing pronounced mental and physical health problems. The findings are interpreted in light of participants' immigration context and the socio-cultural norms of patriarchy, collectivism and familism. Prevention approaches to address partner abuse and delayed help-seeking among South Asian immigrant women should include tailored community education, social services to reduce vulnerability, and cultural competency of professionals. Further research and program evaluation is needed to advance the field.

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

PubMed Central

Li, Dong; Zhou, Changsong

2011-01-01

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

Delayed healing of lower limb fractures with bisphosphonate therapy.

PubMed

Yue, B; Ng, A; Tang, H; Joseph, S; Richardson, M

2015-07-01

Bisphosphonate therapy (BT) is used commonly in the management of osteoporosis. A systematic review was conducted investigating delayed union of lower limb, long bone fractures in patients on BT. We specifically assessed whether BT increases the risk of delayed union or non-union in lower limb, long bone fractures. A literature search was conducted in the PubMed and Embase™ on 4 November 2014. Articles that investigated lower limb fractures, history of BT and fracture union were included in the review. A total of 9,809 papers were retrieved and 14 were deemed suitable for this review. The mean time to union in patients on BT was 8.5 months. A longer time to union was reported in a study investigating BT users versus controls (6.5 vs 4.8 months respectively). The mean rate of delayed or non-union for BT associated atypical fractures was 20% per fracture. Specifically in one study, delayed union was more common in the cohort with more than three years of BT (67%) than in the group with less than three years of BT (26%). Surgical fixation was associated with improved outcomes compared with non-operative management. BT has been described to be associated with multiple adverse outcomes related to atypical fractures. Current evidence recommends operative management for this patient group. Further investigation is required to evaluate the exact effects of BT on lower limb fractures, in particular typical femoral fractures.

Churg-Strauss syndrome associated with rapid deterioration of left ventricular diastolic dysfunction and conduction disturbance.

PubMed

Chin, Jung Yeon; Yi, Jeong Eun; Youn, Ho-Joong

2013-10-01

Cardiac involvement in Churg-Strauss syndrome (CSS) is a major cause of mortality. Here we report a case of a 75-year-old woman with eosinophilic endomyocarditis due to CSS. An electrocardiogram showed intraventricular conduction delay, and echocardiography showed an impaired relaxation pattern and biventricular apical thickening. Magnetic resonance imaging revealed subendocardial delayed enhancement with biventricular apical thrombi. Endomyocardial biopsy showed perivascular eosinophilic infiltration. Despite resolution of the hypereosinophilia after steroid therapy, her left ventricular (LV) diastolic function worsened into a restrictive pattern and she died with a ventricular escape rhythm on her 14th day in the hospital. This case is unusual in that there was rapid progression of the LV diastolic dysfunction and conduction disturbance due to CSS. © 2013, Wiley Periodicals, Inc.

Impact of Morphometry, Myelinization and Synaptic Current Strength on Spike Conduction in Human and Cat Spiral Ganglion Neurons

PubMed Central

Rattay, Frank; Potrusil, Thomas; Wenger, Cornelia; Wise, Andrew K.; Glueckert, Rudolf; Schrott-Fischer, Anneliese

2013-01-01

Background Our knowledge about the neural code in the auditory nerve is based to a large extent on experiments on cats. Several anatomical differences between auditory neurons in human and cat are expected to lead to functional differences in speed and safety of spike conduction. Methodology/Principal Findings Confocal microscopy was used to systematically evaluate peripheral and central process diameters, commonness of myelination and morphology of spiral ganglion neurons (SGNs) along the cochlea of three human and three cats. Based on these morphometric data, model analysis reveales that spike conduction in SGNs is characterized by four phases: a postsynaptic delay, constant velocity in the peripheral process, a presomatic delay and constant velocity in the central process. The majority of SGNs are type I, connecting the inner hair cells with the brainstem. In contrast to those of humans, type I neurons of the cat are entirely myelinated. Biophysical model evaluation showed delayed and weak spikes in the human soma region as a consequence of a lack of myelin. The simulated spike conduction times are in accordance with normal interwave latencies from auditory brainstem response recordings from man and cat. Simulated 400 pA postsynaptic currents from inner hair cell ribbon synapses were 15 times above threshold. They enforced quick and synchronous spiking. Both of these properties were not present in type II cells as they receive fewer and much weaker (∼26 pA) synaptic stimuli. Conclusions/Significance Wasting synaptic energy boosts spike initiation, which guarantees the rapid transmission of temporal fine structure of auditory signals. However, a lack of myelin in the soma regions of human type I neurons causes a large delay in spike conduction in comparison with cat neurons. The absent myelin, in combination with a longer peripheral process, causes quantitative differences of temporal parameters in the electrically stimulated human cochlea compared to the cat cochlea. PMID:24260179

System for sensing droplet formation time delay in a flow cytometer

DOEpatents

Van den Engh, Ger; Esposito, Richard J.

1997-01-01

A droplet flow cytometer system which includes a system to optimize the droplet formation time delay based on conditions actually experienced includes an automatic droplet sampler which rapidly moves a plurality of containers stepwise through the droplet stream while simultaneously adjusting the droplet time delay. Through the system sampling of an actual substance to be processed can be used to minimize the effect of the substances variations or the determination of which time delay is optimal. Analysis such as cell counting and the like may be conducted manually or automatically and input to a time delay adjustment which may then act with analysis equipment to revise the time delay estimate actually applied during processing. The automatic sampler can be controlled through a microprocessor and appropriate programming to bracket an initial droplet formation time delay estimate. When maximization counts through volume, weight, or other types of analysis exists in the containers, the increment may then be reduced for a more accurate ultimate setting. This may be accomplished while actually processing the sample without interruption.

Influence of age on delayed surgical treatment of proximal femoral fractures

PubMed Central

Gomes, Lisiane Pinto; do Nascimento, Leandra Delfim; Campos, Tulio Vinicius de Oliveira; Paiva, Edson Barreto; de Andrade, Marco Antonio Percope; Guimarães, Henrique Cerqueira

2015-01-01

ABSTRACT OBJECTIVE : To investigate the influence of patients' age on the delay between diagnosis and surgical treatment of proximal femoral fractures METHODS : This is a retrospective study, con-ducted at a tertiary university hospital, including all patients admitted with proximal femoral fractures between March 2013 and March 2014. The participants were categorized into four groups according to age levels. The groups were compared according to demographics, comorbidities, fracture type, trau-ma circumstances, and time between diagnosis and surgical procedure RESULTS : One hundred and sixty one patients were included, 37 adults and 124 elderly. Among adults, the mean delay between diagnosis and surgical procedure was 6.4±5.3 days; among elderly the delay was 9.5±7.6 days. There was a progressive increase in the delay from the young-adults group through the elderly individuals (Kruskal-Wallis: 13.7; p=0.003) CONCLUSION : In spite of being the patients most susceptible to complications due to surgical delay, the elderly individuals pre-sented the longest delays from admission to surgical treatment. Level of Evidence III, Retrospective Study. PMID:27057145

Working Towards Safe Motherhood: Delays and Barriers to Prenatal Care for Women in Rural and Peri-Urban Areas of Georgia.

PubMed

Meyer, Erika; Hennink, Monique; Rochat, Roger; Julian, Zoë; Pinto, Meredith; Zertuche, Adrienne D; Spelke, Bridget; Dott, Andrew; Cota, Pat

2016-07-01

Objectives Georgia has the highest rate of maternal mortality in the United States, and ranks 40th for infant mortality. The Georgia Maternal and Infant Health Research Group was formed to investigate and address the shortage of obstetric care providers outside the Atlanta area. Because access to prenatal care (PNC) can improve maternal and infant health outcomes, we used qualitative methods to identify the access barriers experienced by women who live in rural and peri-urban areas of the state. Methods We conducted semi-structured, in-depth interviews with 24 mothers who gave birth between July and August 2013, and who live in either shortage or non-shortage obstetric care service areas. We also conducted key informant interviews with four perinatal case managers, and analyzed all data using applied thematic analysis. We then utilized Thaddeus and Maine's "Three Delays to Care" theoretical framework structure to describe the recognized barriers to care. Results We identified delays in a woman's decision to seek PNC (such as awareness of pregnancy and stigma); delays in accessing an appropriate healthcare facility (such as choosing a doctor and receiving insurance coverage); and delays in receiving adequate and appropriate care (such as continuity of care and communication). Moreover, many participants perceived low self-worth and believed this influenced their PNC exchanges. Conclusion As a means of supporting Georgia's pregnant women who face barriers and delays to PNC, these data provide a rationale for developing contextually relevant solutions to both mothers and their providers.

Stigma is Associated with Delays in Seeking Care Among HIV-Infected People in India

PubMed Central

Steward, Wayne T.; Bharat, Shalini; Ramakrishna, Jayashree; Heylen, Elsa; Ekstrand, Maria L.

2012-01-01

Background Stigma shapes the lives of people living with HIV and may affect their willingness to seek medical care. But treatment delays can compromise health and increase the risk of transmission to others. Purpose To examine whether four stigma manifestations—enacted (discrimination), vicarious (hearing stories of discrimination), felt normative (perceptions of stigma’s prevalence) and internalized (personal endorsement of stigma beliefs)—were linked with delays in seeking care among HIV-infected people in India. Methods A cross-sectional survey was conducted with 961 HIV-positive men and women in Mumbai and Bengaluru. Results Enacted and internalized stigmas were correlated with delays in seeking care after testing HIV-positive. Depression symptoms mediated the associations of enacted and internalized stigmas with care seeking delays, whereas efforts to avoiding disclosing HIV status mediated only the association between internalized stigma and care seeking delays. Conclusions It is vital to develop stigma reduction interventions to ensure timely receipt of care. PMID:22282878

Causes of shortage and delay in material supply: a preliminary study

NASA Astrophysics Data System (ADS)

Rahman, M. M.; Yap, Y. H.; Ramli, N. R.; Dullah, M. A.; Shamsuddin, M. S. W.

2017-11-01

Shortage and delay in materials supply is argued to be one of the most important factors that lead to delay in construction project delivery globally. However, the relevant underlying reasons vary from country to country. As such, this paper summarises the outcomes of a study that targeted identifying causes of shortage and delay in materials supply in Brunei Darussalam. The study was conducted through fifteen semi-structured interviews of contractors and materials suppliers in Brunei. The study identified six causes of shortageof materials and nine causes of delay in materials supply in Brunei. The most importantcausefor shortage of materials relates to the origin or availability of construction materials. On the other hand, the most influential cause of delay in material supply was found to be poor materials procurement and inventory management system, which has other underlying reasons such as late identification of the type of materials needed. The observations are expected to help in formulating or reviewing relevant policies, in order to ensure on-time project delivery.

Factors Associated with Delayed Childbearing: From the Voices of Expectant Latina Adults and Teens in California

ERIC Educational Resources Information Center

Biggs, M. Antonia; Ralph, Lauren; Minnis, Alexandra M.; Arons, Abigail; Marchi, Kristen S.; Lehrer, Jocelyn A.; Braveman, Paula A.; Brindis, Claire D.

2010-01-01

There has been limited research on the protective factors that help Latinas delay childbearing until adulthood. In-depth interviews were conducted with 65 pregnant Latina teenage and adult women in California who were about to have their first child. Lack of or inconsistent birth control use as teens was attributed to wanting or ambivalence toward…

Contextual-Specificity of Short-Delay Extinction in Humans: Renewal of Fear-Potentiated Startle in a Virtual Environment

ERIC Educational Resources Information Center

Alvarez, Ruben P.; Johnson, Linda; Grillon, Christian

2007-01-01

A recent fear-potentiated startle study in rodents suggested that extinction was not context dependent when extinction was conducted after a short delay following acquisition, suggesting that extinction can lead to erasure of fear learning in some circumstances. The main objective of this study was to attempt to replicate these findings in humans…

A Microdata Model of Delayed Entry Program (DEP) Behavior. Technical Report 666.

ERIC Educational Resources Information Center

Phillips, Chester E.; Schmitz, Edward J.

High personnel loss rates among recruits who have signed up for the Army's Delayed Entry Program (DEP) are becoming an increasing problem for DEP program managers. Therefore, a research project was conducted to examine DEP loss as a function of sociodemography and policy variables at the microdata level. Two DEP loss models were created. The first…

The Effects of Imitation Instruction Using a Mirror on the Emergence of Duplicative Responses by Preschool Students Diagnosed with Developmental Delays

ERIC Educational Resources Information Center

Moreno, Jalene Donica

2012-01-01

Using pre-and post-intervention non-concurrent multiple probe designs across participants, I conducted 2 experiments that tested the effects of imitation instruction using a mirror on the emergence of both basic and advanced forms of generalized imitation (GI) involving physical actions with preschool students diagnosed with developmental delays.…

The Effects of Social Skills Groups for Young Children with Social Delays

ERIC Educational Resources Information Center

Koyama, Takanori

2011-01-01

This study was conducted as a program evaluation of an existing social skills program. A review of literature identified a limited number of empirical studies on group-based social skills training for young children with social delays. The purpose of this study was to examine the effects of social skills groups as well as the effects of homework…

Teaching Generalized Reading of Product Warning Labels to Young Adults with Autism Using the Constant Time Delay Procedure

ERIC Educational Resources Information Center

Dogoe, Maud S.; Banda, Devender R.; Lock, Robin H.; Feinstein, Rita

2011-01-01

This study examined the effectiveness of the constant timed delay procedure for teaching two young adults with autism to read, define, and state the contextual meaning of keywords on product warning labels of common household products. Training sessions were conducted in the dyad format using flash cards. Results indicated that both participants…

Effects of simulator motion and visual characteristics on rotorcraft handling qualities evaluations

NASA Technical Reports Server (NTRS)

Mitchell, David G.; Hart, Daniel C.

1993-01-01

The pilot's perceptions of aircraft handling qualities are influenced by a combination of the aircraft dynamics, the task, and the environment under which the evaluation is performed. When the evaluation is performed in a groundbased simulator, the characteristics of the simulation facility also come into play. Two studies were conducted on NASA Ames Research Center's Vertical Motion Simulator to determine the effects of simulator characteristics on perceived handling qualities. Most evaluations were conducted with a baseline set of rotorcraft dynamics, using a simple transfer-function model of an uncoupled helicopter, under different conditions of visual time delays and motion command washout filters. Differences in pilot opinion were found as the visual and motion parameters were changed, reflecting a change in the pilots' perceptions of handling qualities, rather than changes in the aircraft model itself. The results indicate a need for tailoring the motion washout dynamics to suit the task. Visual-delay data are inconclusive but suggest that it may be better to allow some time delay in the visual path to minimize the mismatch between visual and motion, rather than eliminate the visual delay entirely through lead compensation.

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

PubMed

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

2017-12-01

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

Predictors of the Persistence of Conduct Difficulties in Children with Cognitive Delay

ERIC Educational Resources Information Center

Emerson, Eric; Einfeld, Stewart; Stancliffe, Roger J.

2011-01-01

Background: High rates of conduct difficulties have been reported among children with borderline intellectual disabilities or intellectual disabilities. Little is known about predictors of the persistence of conduct difficulties in the pre-adolescent period in this high-risk group. Methods: Secondary analysis of data from the first three waves of…

Robust stability for stochastic bidirectional associative memory neural networks with time delays

NASA Astrophysics Data System (ADS)

Shu, H. S.; Lv, Z. W.; Wei, G. L.

2008-02-01

In this paper, the asymptotic stability is considered for a class of uncertain stochastic bidirectional associative memory neural networks with time delays and parameter uncertainties. The delays are time-invariant and the uncertainties are norm-bounded that enter into all network parameters. The aim of this paper is to establish easily verifiable conditions under which the delayed neural network is robustly asymptotically stable in the mean square for all admissible parameter uncertainties. By employing a Lyapunov-Krasovskii functional and conducting the stochastic analysis, a linear matrix inequality matrix inequality (LMI) approach is developed to derive the stability criteria. The proposed criteria can be easily checked by the Matlab LMI toolbox. A numerical example is given to demonstrate the usefulness of the proposed criteria.

Radiation from lightning return strokes over a finitely conducting earth

NASA Technical Reports Server (NTRS)

Le Vine, D. M.; Gesell, L.; Kao, Michael

1986-01-01

The effects of the conductivity of the earth on radiation from lightning return strokes are examined theoretically using a piecewise linear transmission line model for the return stroke. First, calculations are made of the electric field radiated during the return stroke, and then this electric field is used to compute the response of conventional AM radio receivers and electric field change systems during the return stroke. The calculations apply to the entire transient waveform (they are not restricted to the initial portions of the return stroke) and yield fast field changes and RF radiation in agreement with measurements made during real lightning. This research was motivated by measurements indicating that a time delay exists between the time of arrival of the fast electric field change and the RF radiation from first return strokes. The time delay is on the order of 20 microsec for frequencies in the HF-UHF range for lightning in Florida. The time delay is obtained theoretically in this paper. It occurs when both the effects of attenuation due to conductivity of the earth, and the finite velocity of propagation of the current pulse up the return stroke channel, are taken into account in the model.

Altering impulsive decision making with an acceptance-based procedure.

PubMed

Morrison, Kate L; Madden, Gregory J; Odum, Amy L; Friedel, Jonathan E; Twohig, Michael P

2014-09-01

Delay discounting is one facet of impulsive decision making and involves subjectively devaluing a delayed outcome. Steeply discounting delayed rewards is correlated with substance abuse and other problematic behaviors. To the extent that steep delay discounting underlies these clinical disorders, it would be advantageous to find psychosocial avenues for reducing delay discounting. Acceptance-based interventions may prove useful as they may help to decrease the distress that arises while waiting for a delayed outcome. The current study was conducted to determine if a 60-90 minute acceptance-based training would change delay discounting rates among 30 undergraduate university students in comparison to a waitlist control. Measures given at pre- and posttraining included a hypothetical monetary delay discounting task, the Acceptance and Action Questionnaire-II (AAQ-II), and the Distress Tolerance Scale. Those assigned to the treatment group decreased their discounting of delayed money, but not distress intolerance or psychological inflexibility when compared to the waitlist control group. After the waiting period, the control group received the intervention. Combining all participants' pre- to posttreatment data, the acceptance-based treatment significantly decreased discounting of monetary rewards and increased distress tolerance. The difference in AAQ-II approached significance. Acceptance-based treatments may be a worthwhile option for decreasing delay discounting rates and, consequently, affecting the choices that underlie addiction and other problematic behaviors. Copyright © 2014. Published by Elsevier Ltd.

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

NASA Technical Reports Server (NTRS)

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

1987-01-01

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

Escaping the impulse to immediate gratification: the prospect concept promotes a future-oriented mindset, prompting an inclination towards delayed gratification.

PubMed

Cheng, Ying-Yao; Shein, Paichi Pat; Chiou, Wen-Bin

2012-02-01

People's willingness to postpone receiving an immediate reward in order to gain additional benefits in the future, that is, a tendency to shallow delay discounting, is closely related to one's health, wealth, and happiness. We conducted two experiments investigating how the prospect concept can induce a future-oriented mindset and induce people to behave accordingly. We found that engaging in prospective imagery led the participants to focus on delayed utility over immediate utility in financial decisions (Experiment 1). Participants who received the prospect prime via a scrambled-sentence task decreased their desire to pursue hedonic activities for instant gratification (Experiment 2). Moreover, a state of future orientation mediated the effect of the prospect prime on measures of delayed gratification (Experiments 1 and 2). Thus, reminders of prospect may activate a mindset for future orientation by which delayed gratification is strengthened. ©2011 The British Psychological Society.

Echocardiographic variables after left ventricular assist device implantation associated with adverse outcome.

PubMed

Topilsky, Yan; Hasin, Tal; Oh, Jae K; Borgeson, Daniel D; Boilson, Barry A; Schirger, John A; Clavell, Alfredo L; Frantz, Robert P; Tsutsui, Rayji; Liu, Mingya; Maltais, Simon; Kushwaha, Sudhir S; Pereira, Naveen L; Park, Soon J

2011-11-01

Operative mortality after left ventricular assist device (LVAD) implantation is heavily influenced by patient selection and the technical difficulty of surgery. However, how we treat our patients and LVAD setting may affect the patient outcome beyond this period. We postulated that the presence of echocardiographic variables 1 month after surgery suggesting appropriate degree of LV unloading and an adequate forward flow would be important in determining clinical outcomes after the initial successful LVAD implantation. We retrospectively analyzed various variables in echocardiographic examinations performed 30 days after LVAD implant in 76 consecutive patients receiving continuous flow device for their association with a compound end point (90-day mortality, readmission for heart failure, or New York Heart Association class III or higher at the end of the 90-day period). The echocardiographic associations examined included estimated LVAD flow, with and without native LV contribution, interventricular septal position, the status of aortic valve opening, an estimated left atrial pressure (ELAP), the mitral flow E-wave deceleration time, and the ratio of deceleration time to E-wave velocity (mitral deceleration index [MDI]). Four patients died during the 30- to 90-day period, 6 patients were readmitted for heart failure, and 25 patients were considered to have New York Heart Association class III or higher at the end of the 90-day period. Variables associated with adverse outcome included increased ELAP (odds ratio, 1.30 [1.16-1.48]; P<0.0001), MDI <2 ms/[cm/s] (odds ratio, 4.4 implantation [1.22-18]; P=0.02) and decreased tricuspid lateral annulus velocity (odds ratio, 0.70 implantation [0.48-0.95]; P=0.02). A leftward deviation of interventricular septum was associated with a worse outcome (odds ratio, 3.03 implantation [1.21-13.3]; P=0.01). Mortality and heart failure after LVAD surgery appear to be predominantly determined by echocardiographic evidence of inefficient unloading of the left ventricle and persistence of right ventricular dysfunction. Increased estimated LA pressure and short MDI are associated with worse mid term outcome. Leftward deviation of the septum is associated with worse outcome as well.

Four-dimensional ultrasonography of the fetal heart with spatiotemporal image correlation.

PubMed

Gonçalves, Luís F; Lee, Wesley; Chaiworapongsa, Tinnakorn; Espinoza, Jimmy; Schoen, Mary Lou; Falkensammer, Peter; Treadwell, Marjorie; Romero, Roberto

2003-12-01

This study was undertaken to describe a new technique for the examination of the fetal heart using four-dimensional ultrasonography with spatiotemporal image correlation (STIC). Volume data sets of the fetal heart were acquired with a new cardiac gating technique (STIC), which uses automated transverse and longitudinal sweeps of the anterior chest wall. These volumes were obtained from 69 fetuses: 35 normal, 16 with congenital anomalies not affecting the cardiovascular system, and 18 with cardiac abnormalities. Dynamic multiplanar slicing and surface rendering of cardiac structures were performed. To illustrate the STIC technique, two representative volumes from a normal fetus were compared with volumes obtained from fetuses with the following congenital heart anomalies: atrioventricular septal defect, tricuspid stenosis, tricuspid atresia, and interrupted inferior vena cava with abnormal venous drainage. Volume datasets obtained with a transverse sweep were utilized to demonstrate the cardiac chambers, moderator band, interatrial and interventricular septae, atrioventricular valves, pulmonary veins, and outflow tracts. With the use of a reference dot to navigate the four-chamber view, intracardiac structures could be simultaneously studied in three orthogonal planes. The same volume dataset was used for surface rendering of the atrioventricular valves. The aortic and ductal arches were best visualized when the original plane of acquisition was sagittal. Volumes could be interactively manipulated to simultaneously visualize both outflow tracts, in addition to the aortic and ductal arches. Novel views of specific structures were generated. For example, the location and extent of a ventricular septal defect was imaged in a sagittal view of the interventricular septum. Furthermore, surface-rendered images of the atrioventricular valves were employed to distinguish between normal and pathologic conditions. Representative video clips were posted on the Journal's Web site to demonstrate the diagnostic capabilities of this new technique. Dynamic multiplanar slicing and surface rendering of the fetal heart are feasible with STIC technology. One good quality volume dataset, obtained from a transverse sweep, can be used to examine the four-chamber view and the outflow tracts. This novel method may assist in the evaluation of fetal cardiac anatomy.

The slant path atmospheric refraction calibrator - An instrument to measure the microwave propagation delays induced by atmospheric water vapor

NASA Technical Reports Server (NTRS)

Walter, Steven J.; Bender, Peter L.

1992-01-01

The water vapor-induced propagation delay experienced by a radio signal traversing the atmosphere is characterized by the Slant Path Atmospheric Refraction Calibrator (SPARC), which measures the difference in the travel times between an optical and a microwave signal propagating along the same atmospheric path with an accuracy of 15 picosec or better. Attention is given to the theoretical and experimental issues involved in measuring the delay induced by water vapor; SPARC measurements conducted along a 13.35-km ground-based path are presented, illustrating the instrument's stability, precision, and accuracy.

Perceived Discrimination and Reported Delay of Pharmacy Prescriptions and Medical Tests

PubMed Central

Van Houtven, Courtney Harold; Voils, Corrine I; Oddone, Eugene Z; Weinfurt, Kevin P; Friedman, Joëlle Y; Schulman, Kevin A; Bosworth, Hayden B

2005-01-01

BACKGROUND Access to health care varies according to a person's race and ethnicity. Delaying treatment is one measure of access with important health consequences. OBJECTIVE Determine whether perceptions of unfair treatment because of race or ethnicity are associated with reported treatment delays, controlling for economic constraints, self-reported health, depression, and demographics. DESIGN Cross-sectional, observational study. PARTICIPANTS A randomly selected community sample of 181 blacks, 148 Latinos, and 193 whites in Durham County, NC. MEASUREMENTS A phone survey conducted in 2002 to assess discrimination, trust in medical care, quality of care, and access to care. Treatment delays were measured by whether or not a person reported delaying or forgoing filling a prescription and delaying or forgoing having a medical test/treatment in the past 12 months. Perceived discrimination was measured as unfair treatment in health care and as racism in local health care institutions. RESULTS The odds of delaying filling prescriptions were significantly higher (odds ratio (OR)=2.02) for persons who perceived unfair treatment, whereas the odds of delaying tests or treatments were significantly higher (OR=2.42) for persons who thought racism was a problem in health care locally. People with self-reported depression and people who reported not working had greater odds of delaying both types of care. CONCLUSIONS A prospective cohort study with both personal and macro measures of discrimination, as well as more refined measures of treatment delays, would help us better understand the relationship between perceived discrimination and treatment delays. PMID:16050850

Axonal Conduction Delays, Brain State, and Corticogeniculate Communication

PubMed Central

2017-01-01

Thalamocortical conduction times are short, but layer 6 corticothalamic axons display an enormous range of conduction times, some exceeding 40–50 ms. Here, we investigate (1) how axonal conduction times of corticogeniculate (CG) neurons are related to the visual information conveyed to the thalamus, and (2) how alert versus nonalert awake brain states affect visual processing across the spectrum of CG conduction times. In awake female Dutch-Belted rabbits, we found 58% of CG neurons to be visually responsive, and 42% to be unresponsive. All responsive CG neurons had simple, orientation-selective receptive fields, and generated sustained responses to stationary stimuli. CG axonal conduction times were strongly related to modulated firing rates (F1 values) generated by drifting grating stimuli, and their associated interspike interval distributions, suggesting a continuum of visual responsiveness spanning the spectrum of axonal conduction times. CG conduction times were also significantly related to visual response latency, contrast sensitivity (C-50 values), directional selectivity, and optimal stimulus velocity. Increasing alertness did not cause visually unresponsive CG neurons to become responsive and did not change the response linearity (F1/F0 ratios) of visually responsive CG neurons. However, for visually responsive CG neurons, increased alertness nearly doubled the modulated response amplitude to optimal visual stimulation (F1 values), significantly shortened response latency, and dramatically increased response reliability. These effects of alertness were uniform across the broad spectrum of CG axonal conduction times. SIGNIFICANCE STATEMENT Corticothalamic neurons of layer 6 send a dense feedback projection to thalamic nuclei that provide input to sensory neocortex. While sensory information reaches the cortex after brief thalamocortical axonal delays, corticothalamic axons can exhibit conduction delays of <2 ms to 40–50 ms. Here, in the corticogeniculate visual system of awake rabbits, we investigate the functional significance of this axonal diversity, and the effects of shifting alert/nonalert brain states on corticogeniculate processing. We show that axonal conduction times are strongly related to multiple visual response properties, suggesting a continuum of visual responsiveness spanning the spectrum of corticogeniculate axonal conduction times. We also show that transitions between awake brain states powerfully affect corticogeniculate processing, in some ways more strongly than in layer 4. PMID:28559382

Effects of iron on the lattice thermal conductivity of Earth's deep mantle and implications for mantle dynamics

NASA Astrophysics Data System (ADS)

Hsieh, Wen-Pin; Deschamps, Frédéric; Okuchi, Takuo; Lin, Jung-Fu

2018-04-01

Iron may critically influence the physical properties and thermochemical structures of Earth's lower mantle. Its effects on thermal conductivity, with possible consequences on heat transfer and mantle dynamics, however, remain largely unknown. We measured the lattice thermal conductivity of lower-mantle ferropericlase to 120 GPa using the ultrafast optical pump-probe technique in a diamond anvil cell. The thermal conductivity of ferropericlase with 56% iron significantly drops by a factor of 1.8 across the spin transition around 53 GPa, while that with 8–10% iron increases monotonically with pressure, causing an enhanced iron substitution effect in the low-spin state. Combined with bridgmanite data, modeling of our results provides a self-consistent radial profile of lower-mantle thermal conductivity, which is dominated by pressure, temperature, and iron effects, and shows a twofold increase from top to bottom of the lower mantle. Such increase in thermal conductivity may delay the cooling of the core, while its decrease with iron content may enhance the dynamics of large low shear-wave velocity provinces. Our findings further show that, if hot and strongly enriched in iron, the seismic ultralow velocity zones have exceptionally low conductivity, thus delaying their cooling.

Effects of iron on the lattice thermal conductivity of Earth's deep mantle and implications for mantle dynamics.

PubMed

Hsieh, Wen-Pin; Deschamps, Frédéric; Okuchi, Takuo; Lin, Jung-Fu

2018-04-17

Iron may critically influence the physical properties and thermochemical structures of Earth's lower mantle. Its effects on thermal conductivity, with possible consequences on heat transfer and mantle dynamics, however, remain largely unknown. We measured the lattice thermal conductivity of lower-mantle ferropericlase to 120 GPa using the ultrafast optical pump-probe technique in a diamond anvil cell. The thermal conductivity of ferropericlase with 56% iron significantly drops by a factor of 1.8 across the spin transition around 53 GPa, while that with 8-10% iron increases monotonically with pressure, causing an enhanced iron substitution effect in the low-spin state. Combined with bridgmanite data, modeling of our results provides a self-consistent radial profile of lower-mantle thermal conductivity, which is dominated by pressure, temperature, and iron effects, and shows a twofold increase from top to bottom of the lower mantle. Such increase in thermal conductivity may delay the cooling of the core, while its decrease with iron content may enhance the dynamics of large low shear-wave velocity provinces. Our findings further show that, if hot and strongly enriched in iron, the seismic ultralow velocity zones have exceptionally low conductivity, thus delaying their cooling.

The Effects of Constant Time Delay Embedded into Teaching Activities for Teaching the Names of Clothes for Preschool Children with Developmental Disabilities

ERIC Educational Resources Information Center

Odluyurt, Serhat

2011-01-01

The general purpose of this study was to examine the effectiveness of constant time delay embedded in activities for teaching clothes name for preschool children with developmental disabilities. This study included four participants having Down syndrome with an age range of 43-46 months. All experimental sessions were conducted in one to one…

A Tutorial on the Use of Excel 2010 and Excel for Mac 2011 for Conducting Delay-Discounting Analyses

ERIC Educational Resources Information Center

Reed, Derek D.; Kaplan, Brent A.; Brewer, Adam T.

2012-01-01

In recent years, researchers and practitioners in the behavioral sciences have profited from a growing literature on delay discounting. The purpose of this article is to provide readers with a brief tutorial on how to use Microsoft Office Excel 2010 and Excel for Mac 2011 to analyze discounting data to yield parameters for both the hyperbolic…

Improving Early Reading Skills in Young Children through an iPad App: Small-Group Instruction and Observational Learning

ERIC Educational Resources Information Center

Chai, Zhen

2017-01-01

This study evaluated the effectiveness of using a researcher-developed iPad app with a 0- to 5-s constant time delay procedure to improve phonological awareness skills of young children with mild developmental delays in a small-group arrangement in a rural public elementary school in Southwest United States. The study was conducted using a…

The acoustic sensor for rapid analysis of bacterial cells in the conductive suspensions.

PubMed

Borodina, I A; Zaitsev, B D; Guliy, O; Teplykh, A A; Shikhabudinov, A M

2017-11-01

The possibility of using the acoustic sensor on the basis of a two-channel delay line for rapid analysis of bacterial cells in the conductive suspensions was investigated. The dependencies of change in phase and insertion loss of output signal of the sensor on conductivity of buffer solution with various concentrations of cells due to a specific interaction "bacterial cells - mini-antibodies" for electrically open and electrically shorted channels of delay line were measured. It has been found that these changes have the most values for the electrically open channel. It has been also shown that the sensor rapidly responds to the specific interaction and the time stabilization of the phase and insertion loss of output signal is less than 10min. Copyright © 2017 Elsevier B.V. All rights reserved.

Regulation of Aedes aegypti Population Dynamics in Field Systems: Quantifying Direct and Delayed Density Dependence

PubMed Central

Walsh, Rachael K.; Aguilar, Cristobal L.; Facchinelli, Luca; Valerio, Laura; Ramsey, Janine M.; Scott, Thomas W.; Lloyd, Alun L.; Gould, Fred

2013-01-01

Transgenic strains of Aedes aegypti have been engineered to help control transmission of dengue virus. Although resources have been invested in developing the strains, we lack data on the ecology of mosquitoes that could impact the success of this approach. Although studies of intra-specific competition have been conducted using Ae. aegypti larvae, none of these studies examine mixed age cohorts at densities that occur in the field, with natural nutrient levels. Experiments were conducted in Mexico to determine the impact of direct and delayed density dependence on Ae. aegypti populations. Natural water, food, and larval densities were used to estimate the impacts of density dependence on larval survival, development, and adult body size. Direct and delayed density-dependent factors had a significant impact on larval survival, larval development, and adult body size. These results indicate that control methods attempting to reduce mosquito populations may be counteracted by density-dependent population regulation. PMID:23669230

Diagnostic Delay among Adults with Pulmonary Tuberculosis in a High Gross Domestic Product Per Capita Country: Reasons and Magnitude of the Problem.

PubMed

Ibrahim, Wanis H; Alousi, Faraj H; Al-Khal, Abdulatif; Bener, Abdulbari; AlSalman, Ahmed; Aamer, Aaiza; Khaled, Ahmed; Raza, Tasleem

2016-01-01

To determine the mean and median delays in pulmonary tuberculosis (PTB) diagnosis among adults in one of the world's highest gross domestic product per capita countries and identify patient and health system-related reasons for these delays. This is a cross-sectional, face-to-face, prospective study of 100 subjects with confirmed PTB, conducted at main tuberculosis (TB) admitting facilities in Qatar. The mean and median diagnostic delays were measured. The Chi-square test with two-sided P < 0.05 was considered to determine the association between factors and diagnostic delay. The mean and median total diagnostic delays of PTB were 53 (95% confidence interval [CI] 42.61-63.59) and 30 (interquartile range; Q1-Q3, 15-60) days, respectively. The mean patient factor delay was 45.7 (95% CI 28.1-63.4) days, and the median was 30 (interquartile range; Q1-Q3, 15-60) days. The mean health system factor delay was 46.3 (95% CI 35.46-57.06) days, and the median was 30 (interquartile range; Q1-Q3, 18-60) days. The most common cause of patient factor delay was neglect of TB symptoms by patients (in 39% of cases), and for health-care system factor delay was a failure (mostly at general and private care levels) to suspect PTB by doctors (in 57% of cases). There were no significant associations between the presence of language barrier, patient occupation or nationality, and diagnostic delay. Despite a favorable comparison to other countries, there is a substantial delay in the diagnosis of PTB in Qatar. Relevant actions including health education on TB are required to minimize this delay.

Diagnostic delay among pulmonary tuberculosis patients in Sarawak, Malaysia: a cross-sectional study.

PubMed

Chang, Ching Thon; Esterman, Adrain

2007-01-01

Delayed diagnosis of tuberculosis (TB) can lead to an increased period of infectivity in the community, a delay in treatment and a severe form of the disease. The objective of this study was to determine the length of delay, and factors linking the delay from the onset of symptoms of pulmonary tuberculosis (PTB) until the commencement of treatment in Sarawak, Malaysia. An institution based cross-sectional study was conducted in 10 TB clinics in randomly selected divisions in Sarawak from June 2003 to May 2004. Delay was analyzed from two perspectives: (1) period between the onset of TB symptoms to any first medical consultation (patients' delay); and (2) period between the first medical consultation to the diagnosis of TB (diagnosis delay). Patients were interviewed on diagnosis or within the admission period using a semi-structured questionnaire. A total of 316 new smear-positive PTB patients participated in the study. The median patient interval was 30 days. Gender was found to be significantly associated with patient delay. The median diagnosis interval was 22 days. Respondents' incomes, health-care professional first consulted and actions taken by the health-care providers during the first consultation were significantly associated with diagnosis delay. The medium treatment interval was 0 days. Both patients and health providers played a role in delaying TB diagnosis. Females appeared to have longer delay. Respondents living above the poverty line had diagnosis delay as they made more visits to GPs or different government clinics without proper investigations for TB. A mechanism is needed to increase all health-care providers' suspicion of TB so that proper investigations can be done during first consultation.

Semiclassical relation between open trajectories and periodic orbits for the Wigner time delay.

PubMed

Kuipers, Jack; Sieber, Martin

2008-04-01

The Wigner time delay of a classically chaotic quantum system can be expressed semiclassically either in terms of pairs of scattering trajectories that enter and leave the system or in terms of the periodic orbits trapped inside the system. We show how these two pictures are related on the semiclassical level. We start from the semiclassical formula with the scattering trajectories and derive from it all terms in the periodic orbit formula for the time delay. The main ingredient in this calculation are correlations between scattering trajectories which are due to trajectories that approach the trapped periodic orbits closely. The equivalence between the two pictures is also demonstrated by considering correlation functions of the time delay. A corresponding calculation for the conductance gives no periodic orbit contributions in leading order.

Compounding diagnostic delays: a qualitative study of point-of-care testing in South Africa.

PubMed

Engel, Nora; Davids, Malika; Blankvoort, Nadine; Pai, Nitika Pant; Dheda, Keertan; Pai, Madhukar

2015-04-01

Successful point-of-care (POC) testing (completion of test-and-treat cycle in one patient encounter) has immense potential to reduce diagnostic and treatment delays, and improve patient and public health outcomes. We explored what tests are done and how in public/private, rural/urban hospitals and clinics in South Africa and whether they can ensure successful POC testing. This qualitative research study examined POC testing across major diseases in Cape Town, Durban and Eastern Cape. We conducted 101 semi-structured interviews and seven focus group discussions with doctors, nurses, community health workers, patients, laboratory technicians, policymakers, hospital managers and diagnostic manufacturers. In South Africa, diagnostics are characterised by a centralised system. Most tests conducted on the spot can be made to work successfully as POC tests. The majority of public/private clinics and smaller hospitals send samples via couriers to centralised laboratories and retrieve results the same way, via internet, fax or phone. The main challenge to POC testing lies in transporting samples and results, while delays risk patient loss from diagnostic/treatment pathways. Strategies to deal with associated delays create new problems, such as artificially prolonged turnaround times, strains on human resources and quality of testing, compounding additional diagnostic and treatment delays. For POC testing to succeed, particular characteristics of diagnostic ecosystems and adaptations of professional practices to overcome associated challenges must be taken into account. © 2014 John Wiley & Sons Ltd.

A dual-loop adaptive control for minimizing time response delay in real-time structural vibration control with magnetorheological (MR) devices

NASA Astrophysics Data System (ADS)

Chen, Xi; Li, Yancheng; Li, Jianchun; Gu, Xiaoyu

2018-01-01

Time delay is a challenge issue faced by the real-time control application of the magnetorheological (MR) devices. Not to deal with it properly may jeopardize the effectiveness of the control, even lead to instability of the control system or catastrophic failure. This paper proposes a dual-loop adaptive control to address the response time delay associated with MR devices. In the proposed dual-loop control, the inner loop is designed to compensate the time delay of MR device induced by the PWM current driver. While the outer loop control can be any structural control algorithm with aims to reducing structural responses of a building during extreme loadings. Here an adaptive control strategy is adopted. To verify the proposed dual-loop control, a smart base isolation system employing magnetorheological elastomer base isolators is used as an example to illustrate the control effect. Numerical study is then conducted using a 5 -storey shear building model equipped with smart base isolation system. The result shows that with the implementation of the inner loop, the control current can instantly follow the control command which reduce the possibility of instability caused by the time delay. Comparative studies are conducted between three control strategies, i.e. dual-loop control, Lyapunov’s direct method based control and optimal passive base isolation control. The results of the study have demonstrated that the proposed dual-loop control strategy can achieve much better performance than the other two control strategies.

Delayed healing of lower limb fractures with bisphosphonate therapy

PubMed Central

Ng, A; Tang, H; Joseph, S; Richardson, M

2015-01-01

Introduction Bisphosphonate therapy (BT) is used commonly in the management of osteoporosis. A systematic review was conducted investigating delayed union of lower limb, long bone fractures in patients on BT. We specifically assessed whether BT increases the risk of delayed union or non-union in lower limb, long bone fractures. Methods A literature search was conducted in the PubMed and Embase™ on 4 November 2014. Articles that investigated lower limb fractures, history of BT and fracture union were included in the review. Results A total of 9,809 papers were retrieved and 14 were deemed suitable for this review. The mean time to union in patients on BT was 8.5 months. A longer time to union was reported in a study investigating BT users versus controls (6.5 vs 4.8 months respectively). The mean rate of delayed or non-union for BT associated atypical fractures was 20% per fracture. Specifically in one study, delayed union was more common in the cohort with more than three years of BT (67%) than in the group with less than three years of BT (26%). Surgical fixation was associated with improved outcomes compared with non-operative management. Conclusions BT has been described to be associated with multiple adverse outcomes related to atypical fractures. Current evidence recommends operative management for this patient group. Further investigation is required to evaluate the exact effects of BT on lower limb fractures, in particular typical femoral fractures. PMID:26264082

A comparison of control modes for time-delayed remote manipulation

NASA Technical Reports Server (NTRS)

Starr, G. P.

1982-01-01

Transmission time delay in the communication channel of a manual control system is investigated. A time delay can exist in remote manipulation systems, caused by long communication distances or bandwidth limitations. Ferrell 1 conducted the first research in time-delayed manipulation using a two degree-of-freedom manipulator. His subjects, working at time delays of 1.0, 2.1, and 3.2 s, could accomplish tasks even requiring great accuracy. The subjects spontaneously adopted a pattern of moving cautiously, then waiting to see the results of their actions. In experiments with a six degree-of-freedom master-slave manipulator system and time delays of 1.0 to 6 s, Black 2 saw that subjects tried to use the move-and-wait strategy; but there were often difficulties. The subjects seemed to have a problem in holding the master arm stationary while waiting for feedback. Any undesired drifting of the master arm introduced a discrepancy between the positions of the master and slave. This discrepancy was not perceived because of the time delay. The subject would then begin his next move with an inherent error. The difficulty of effectively using the move-and-wait strategy with a master-slave manipulator suggested that rate control might be a more effective control mode with time delay.

[Factors linked to delayed diagnosis of tuberculosis in Conakry (Guinea)].

PubMed

Camara, A; Diallo, A; Camara, L M; Fielding, K; Sow, O Y; Chaperon, J

2006-03-01

Untreated smear-positive pulmonary tuberculosis constitutes a reservoir of infection which is highly contagious. The present study was conducted in Conakry, Guinea, to determine the different options which are available when seeking treatment or care, and to ascertain the average delay in diagnosis of pulmonary tuberculosis and the main factors linked to the delay in diagnosis after the initial onset of symptoms. Through a cross-sectional study, 113 consecutive patients with smear-positive pulmonary tuberculosis were interviewed through the use of a questionnaire. The median total delay from the onset of symptoms of pulmonary tuberculosis until the diagnosis was 11 weeks. This delay period exceeded 4 weeks for 90 of the patients (80%). The average delay linked to the conventional health care system was double that of the one at the fault of the patient (6 weeks versus 3 weeks, respectively). 54% of the patients had initially resorted to non-conventional care. To shorten this mean delay period, it is necessary to both strengthen the professional abilities and skills which train for one to better to detect tuberculosis and to sensitize the population to the subject matter and information on the illness and its symptoms.

Hydrogen-Induced Delayed Cracking in TRIP-Aided Lean-Alloyed Ferritic-Austenitic Stainless Steels.

PubMed

Papula, Suvi; Sarikka, Teemu; Anttila, Severi; Talonen, Juho; Virkkunen, Iikka; Hänninen, Hannu

2017-06-03

Susceptibility of three lean-alloyed ferritic-austenitic stainless steels to hydrogen-induced delayed cracking was examined, concentrating on internal hydrogen contained in the materials after production operations. The aim was to study the role of strain-induced austenite to martensite transformation in the delayed cracking susceptibility. According to the conducted deep drawing tests and constant load tensile testing, the studied materials seem not to be particularly susceptible to delayed cracking. Delayed cracks were only occasionally initiated in two of the materials at high local stress levels. However, if a delayed crack initiated in a highly stressed location, strain-induced martensite transformation decreased the crack arrest tendency of the austenite phase in a duplex microstructure. According to electron microscopy examination and electron backscattering diffraction analysis, the fracture mode was predominantly cleavage, and cracks propagated along the body-centered cubic (BCC) phases ferrite and α'-martensite. The BCC crystal structure enables fast diffusion of hydrogen to the crack tip area. No delayed cracking was observed in the stainless steel that had high austenite stability. Thus, it can be concluded that the presence of α'-martensite increases the hydrogen-induced cracking susceptibility.

Hydrogen-Induced Delayed Cracking in TRIP-Aided Lean-Alloyed Ferritic-Austenitic Stainless Steels

PubMed Central

Papula, Suvi; Sarikka, Teemu; Anttila, Severi; Talonen, Juho; Virkkunen, Iikka; Hänninen, Hannu

2017-01-01

Susceptibility of three lean-alloyed ferritic-austenitic stainless steels to hydrogen-induced delayed cracking was examined, concentrating on internal hydrogen contained in the materials after production operations. The aim was to study the role of strain-induced austenite to martensite transformation in the delayed cracking susceptibility. According to the conducted deep drawing tests and constant load tensile testing, the studied materials seem not to be particularly susceptible to delayed cracking. Delayed cracks were only occasionally initiated in two of the materials at high local stress levels. However, if a delayed crack initiated in a highly stressed location, strain-induced martensite transformation decreased the crack arrest tendency of the austenite phase in a duplex microstructure. According to electron microscopy examination and electron backscattering diffraction analysis, the fracture mode was predominantly cleavage, and cracks propagated along the body-centered cubic (BCC) phases ferrite and α’-martensite. The BCC crystal structure enables fast diffusion of hydrogen to the crack tip area. No delayed cracking was observed in the stainless steel that had high austenite stability. Thus, it can be concluded that the presence of α’-martensite increases the hydrogen-induced cracking susceptibility. PMID:28772975

Delaying first birth: an analysis of household survey data from rural Southern Tanzania.

PubMed

Sedekia, Yovitha; Nathan, Rose; Church, Kathryn; Temu, Silas; Hanson, Claudia; Schellenberg, Joanna; Marchant, Tanya

2017-01-31

Currently, family planning metrics derived from nationally-representative household surveys such as the Demographic and Health Surveys (DHS) categorise women into those desiring to space or limit (permanently stop) births, or according to their age in the case of young women. This conceptualisation potentially ignores a large and growing group of young women who desire to delay a first birth. This study uses household survey data to investigate the characteristics and needs for family planning of women who want to delay their first birth. The research was conducted in two rural districts in southern Tanzania (Tandahimba and Newala), and nested within the Expanded Quality Management Using Information Power (EQUIP) study. Data were collected as part of a repeated cross sectional household survey conducted between September 2013 and April 2014. The socio-demographic characteristics, including parity, contraceptive practices and fertility intentions of 2128 women aged 13-49 were analysed. The association between women's life stages of reproduction (delayers of first birth, spacers of subsequent pregnancies and limiters of future birth) and selected contraceptive outcomes (current use, unmet need and demand for modern contraceptives) was assessed using the point estimates and 95% confidence intervals for each indicator, adjusted for the survey design. Overall, four percent of women surveyed were categorised as 'delayers of first birth', i.e. sexually active but not started childbearing. Among this group, the majority were younger than 20 years old (82%) and unmarried (88%). Fifty-nine percent were currently using a modern method of contraception and injectables dominated their contraceptive use. Unmet need for contraception was higher among delayers (41%; 95% CI 32-51) and limiters (41%; 95% CI 35-47) compared to spacers (19%; 95% CI 17-22). Delayers of first birth have very high unmet needs for modern contraceptives and they should be routinely and separately categorised and measured within nationally-representative surveys such as Demographic and Health Survey and Multiple Indicator Cluster surveys. Acknowledging their unique needs could help catalyse a programmatic response.

[DEFORMITY OF LEFT VENTRICLE WALLS IN PATIENTS WITH AORTAL VALVE STENOSIS].

PubMed

Trembovetskaya, E M

2015-04-01

Parameters of longitudinal deformity of left ventricle walls in patients, suffering aortal valve stenosis (AVS), were analyzed. While the process of heart contraction in norm and in AVS occurs, longitudinal deformity is expressed maximally in its apical divisions. AVS deformity of apical divisions of left ventricle, as well as middle divisions of interventricular septum and lower wall, practically did not differ from such in norm, and deformity of basal divisions of all walls and middle divisions of posterior, lateral and anterior walls of left ventricle was trustworthy less than a norm. Thus, a reduction of the deformity indices in basal divisions of left ventricle and middle segments of its posterior, lateral and anterior walls in patients, suffering AVS with preserved output fraction, precedes the disorders of its hemodynamics and constitutes a predictor for the cardiac output reduction.

[Echocardiography in diagnosis of primary cardiac tumors in pediatrics].

PubMed

Erdmenger Orellana, Julio; Vázquez, Clara; Ortega Maldonado, Jesús

2005-01-01

We report the experience in the diagnosis of primary cardiac tumor during the period from 1999 to 2004, 8500 studies were revised echocardiographic carried out. We found 21 patients, 11 of female sex (55%). In 15/21 (71%), the age of presentation was less than 1 year. In 9/21 the tumor was multiple (42.8%), lodged in the ventricle right in 2/21 (9.5%), in the ventricle left 3 (14.2%), 8 in the septum interventricular (38%) and 4 compromised the auriculas. They were classified like rabdomiomas 14 (66%), 5 associates with sclerosis tuberosa, 4 mixomas (19%), 2 fibromas (9.5%) and 1 rabdomiosarcoma (4.7%). In five patients the diagnosis was prenatal. The global mortality went of 9.5%. The echocardiograpy is a good diagnosis method in our series the rabdomioma occupied the first place in frequency.

Assessment of atrial electromechanical delay in children with acute rheumatic fever.

PubMed

Ciftel, Murat; Turan, Ozlem; Simşek, Ayşe; Kardelen, Fırat; Akçurin, Gayaz; Ertuğ, Halil

2014-02-01

There may be an increase in the risk of atrial arrhythmia due to left atrial enlargement and the influence on conduction system in acute rheumatic fever. The aim of this study is to investigate atrial electromechanical delay and P-wave dispersion in patients with acute rheumatic fever. A total of 48 patients diagnosed with acute rheumatic fever and 40 volunteers of similar age, sex, and body mass index were included in the study. The study groups were compared for M-mode echocardiographic parameters, interatrial electromechanical delay, intra-atrial electromechanical delay, and P-wave dispersion. Maximum P-wave duration, P-wave dispersion, and interatrial electromechanical delay were significantly higher in patients with acute rheumatic fever compared with the control group (p < 0.001). However, there was no difference in terms of intra-atrial electromechanical delay (p > 0.05). For patients with acute rheumatic fever, a positive correlation was identified between the left atrium diameter and the P-wave dispersion and interatrial electromechanical delay (r = 0.524 and p < 0.001, and r = 0.351 and p = 0.014, respectively). Furthermore, an important correlation was also identified between the P-wave dispersion and the interatrial electromechanical delay (r = 0.494 and p < 0.001). This study shows the prolongation of P-wave dispersion and interatrial electromechanical delay in acute rheumatic fever. Left atrial enlargement can be one of the underlying reasons for the increase in P-wave dispersion and interatrial electromechanical delay.

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

PubMed

Black, Anne C; Rosen, Marc I

2011-01-01

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

Early and late components of EEG delay activity correlate differently with scene working memory performance

PubMed Central

Ng, Kenneth; Reichert, Chelsea P.

2017-01-01

Sustained and elevated activity during the working memory delay period has long been considered the primary neural correlate for maintaining information over short time intervals. This idea has recently been reinterpreted in light of findings generated from multiple neural recording modalities and levels of analysis. To further investigate the sustained or transient nature of activity, the temporal-spectral evolution (TSE) of delay period activity was examined in humans with high density EEG during performance of a Sternberg working memory paradigm with a relatively long six second delay and with novel scenes as stimuli. Multiple analyses were conducted using different trial window durations and different baseline periods for TSE computation. Sensor level analyses revealed transient rather than sustained activity during delay periods. Specifically, the consistent finding among the analyses was that high amplitude activity encompassing the theta range was found early in the first three seconds of the delay period. These increases in activity early in the delay period correlated positively with subsequent ability to distinguish new from old probe scenes. Source level signal estimation implicated a right parietal region of transient early delay activity that correlated positively with working memory ability. This pattern of results adds to recent evidence that transient rather than sustained delay period activity supports visual working memory performance. The findings are discussed in relation to synchronous and desynchronous intra- and inter-regional neural transmission, and choosing an optimal baseline for expressing temporal-spectral delay activity change. PMID:29016657

Effect of delay in hospital presentation on clinical and imaging findings in acute pulmonary thromboembolism.

PubMed

Jenab, Yaser; Alemzadeh-Ansari, Mohammad Javad; Fehri, Seyedeh Arezoo; Ghaffari-Marandi, Neda; Jalali, Arash

2014-04-01

There is limited information on the extent and clinical importance of the delay in hospital presentation of acute pulmonary thromboembolism (PTE). The aim of this study was to investigate the delay in hospital presentation of PTE and its association with clinical and imaging findings in PTE. This prospective study was conducted on patients admitted to our hospital with a diagnosis of acute PTE between September 2007 and September 2011. Relationships between delay in hospital presentation and clinical findings, risk factors, imaging findings, and in-hospital mortality were analyzed. Of the 195 patients enrolled, 84 (43.1%) patients presented 3 days after the onset of symptoms. Patients with chest pain, history of immobility for more than 3 days, recent surgery, and estrogen use had significantly less delayed presentation. Right ventricular dysfunction was significantly more frequent in patients with delayed presentation (odds ratio [OR] = 2.38; 95% confidence interval [CI] 1.27-4.44; p = 0.006); however, no relationship was found between delay in presentation and pulmonary computed tomographic angiography or color Doppler sonography findings. Patients with delayed presentation were at higher risk of in-hospital mortality (OR = 4.32; 95% CI 1.12-16.49; p = 0.021). Our study showed that a significant portion of patients with acute PTE had delayed presentation. Also, patients with delayed presentation had worse echocardiographic findings and higher in-hospital mortality. Copyright © 2014 Elsevier Inc. All rights reserved.

Early Changes in Atrial Electromechanical Coupling in Patients with Hypertension: Assessment by Tissue Doppler Imaging.

PubMed

Avci, Burcak Kilickiran; Gulmez, Oyku; Donmez, Guclu; Pehlivanoglu, Seckin

2016-06-05

Hypertension (HT) is associated with atrial electrophysiological abnormalities. Echocardiographic pulsed wave tissue Doppler imaging (TDI) is one of the noninvasive methods for evaluation of atrial electromechanical properties. The aims of our study were to investigate the early changes in atrial electromechanical conduction in patients with HT and to assess the parameters that affect atrial electromechanical conduction. Seventy-six patients with HT (41 males, mean age 52.6 ± 9.0 years) and 41 controls (22 males, mean age 49.8 ± 7.9 years) were included in the study. Atrial electromechanical coupling at the right (PRA), left (PLA), interatrial septum (PIS) were measured with TDI. Intra- (right: PIS-PRA, left: PLA-PIS) and inter-atrial (PLA-PRA) electromechanical delays were calculated. Maximum P-wave duration (Pmax) was calculated from 12-lead electrocardiogram. Atrial electromechanical coupling at PLA (76.6 ± 14.1 ms vs. 82.9 ± 15.8 ms, P = 0.036), left intra-atrial (10.9 ± 5.0 ms vs. 14.0 ± 9.7 ms, P = 0.023), right intra-atrial (10.6 ± 7.8 ms vs. 14.5 ± 10.1 ms, P = 0.035), and interatrial electromechanical (21.4 ± 9.8 ms vs. 28.3 ± 12.7 ms, P = 0.003) delays were significantly longer in patients with HT. The linear regression analysis showed that left ventricular (LV) mass index and Pmax were significantly associated with PLA (P = 0.001 and P = 0.002, respectively), and the LV mass index was the only related factor for interatrial delay (P = 0.001). Intra- and interatrial electromechanical delay, PLA were significantly prolonged in hypertensive patients. LV mass index and Pmax were significantly associated with PLA, and the LV mass index was the only related factor for interatrial delay. The atrial TDI can be a valuable method to assess the early changes of atrial electromechanical conduction properties in those patients.

Early Changes in Atrial Electromechanical Coupling in Patients with Hypertension: Assessment by Tissue Doppler Imaging

PubMed Central

Avci, Burcak Kilickiran; Gulmez, Oyku; Donmez, Guclu; Pehlivanoglu, Seckin

2016-01-01

Background: Hypertension (HT) is associated with atrial electrophysiological abnormalities. Echocardiographic pulsed wave tissue Doppler imaging (TDI) is one of the noninvasive methods for evaluation of atrial electromechanical properties. The aims of our study were to investigate the early changes in atrial electromechanical conduction in patients with HT and to assess the parameters that affect atrial electromechanical conduction. Methods: Seventy-six patients with HT (41 males, mean age 52.6 ± 9.0 years) and 41 controls (22 males, mean age 49.8 ± 7.9 years) were included in the study. Atrial electromechanical coupling at the right (PRA), left (PLA), interatrial septum (PIS) were measured with TDI. Intra- (right: PIS-PRA, left: PLA-PIS) and inter-atrial (PLA-PRA) electromechanical delays were calculated. Maximum P-wave duration (Pmax) was calculated from 12-lead electrocardiogram. Results: Atrial electromechanical coupling at PLA (76.6 ± 14.1 ms vs. 82.9 ± 15.8 ms, P = 0.036), left intra-atrial (10.9 ± 5.0 ms vs. 14.0 ± 9.7 ms, P = 0.023), right intra-atrial (10.6 ± 7.8 ms vs. 14.5 ± 10.1 ms, P = 0.035), and interatrial electromechanical (21.4 ± 9.8 ms vs. 28.3 ± 12.7 ms, P = 0.003) delays were significantly longer in patients with HT. The linear regression analysis showed that left ventricular (LV) mass index and Pmax were significantly associated with PLA (P = 0.001 and P = 0.002, respectively), and the LV mass index was the only related factor for interatrial delay (P = 0.001). Conclusions: Intra- and interatrial electromechanical delay, PLA were significantly prolonged in hypertensive patients. LV mass index and Pmax were significantly associated with PLA, and the LV mass index was the only related factor for interatrial delay. The atrial TDI can be a valuable method to assess the early changes of atrial electromechanical conduction properties in those patients. PMID:27231168

Pigeons' Memory for Number of Events: Effects of Intertrial Interval and Delay Interval Illumination

ERIC Educational Resources Information Center

Hope, Chris; Santi, Angelo

2004-01-01

In Experiment 1, pigeons were trained at a 0-s baseline delay to discriminate sequences of light flashes (illumination of the feeder) that varied in number but not time (2f/4s and 8f/4s). During training, the intertrial interval was illuminated by the houselight for Group Light, but it was dark for Group Dark. Testing conducted with dark delay…

MyoR Modulates Cardiac Conduction by Repressing Gata4

PubMed Central

Harris, John P.; Bhakta, Minoti; Bezprozvannaya, Svetlana; Wang, Lin; Lubczyk, Christina; Olson, Eric N.

2014-01-01

The cardiac conduction system coordinates electrical activation through a series of interconnected structures, including the atrioventricular node (AVN), the central connection point that delays impulse propagation to optimize cardiac performance. Although recent studies have uncovered important molecular details of AVN formation, relatively little is known about the transcriptional mechanisms that regulate AV delay, the primary function of the mature AVN. We identify here MyoR as a novel transcription factor expressed in Cx30.2+ cells of the AVN. We show that MyoR specifically inhibits a Cx30.2 enhancer required for AVN-specific gene expression. Furthermore, we demonstrate that MyoR interacts directly with Gata4 to mediate transcriptional repression. Our studies reveal that MyoR contains two nonequivalent repression domains. While the MyoR C-terminal repression domain inhibits transcription in a context-dependent manner, the N-terminal repression domain can function in a heterologous context to convert the Hand2 activator into a repressor. In addition, we show that genetic deletion of MyoR in mice increases Cx30.2 expression by 50% and prolongs AV delay by 13%. Taken together, we conclude that MyoR modulates a Gata4-dependent regulatory circuit that establishes proper AV delay, and these findings may have wider implications for the variability of cardiac rhythm observed in the general population. PMID:25487574

Latitude-dependent delay in the responses of the equatorial electrojet and Sq currents to X-class solar flares

NASA Astrophysics Data System (ADS)

Nogueira, Paulo A. B.; Abdu, Mangalathayil A.; Souza, Jonas R.; Denardini, Clezio M.; Barbosa Neto, Paulo F.; Serra de Souza da Costa, João P.; Silva, Ana P. M.

2018-01-01

We have analyzed low-latitude ionospheric current responses to two intense (X-class) solar flares that occurred on 13 May 2013 and 11 March 2015. Sudden intensifications, in response to solar flare radiation impulses, in the Sq and equatorial electrojet (EEJ) currents, as detected by magnetometers over equatorial and low-latitude sites in South America, are studied. In particular we show for the first time that a 5 to 8 min time delay is present in the peak effect in the EEJ, with respect that of Sq current outside the magnetic equator, in response to the flare radiation enhancement. The Sq current intensification peaks close to the flare X-ray peak, while the EEJ peak occurs 5 to 8 min later. We have used the Sheffield University Plasmasphere-Ionosphere Model at National Institute for Space Research (SUPIM-INPE) to simulate the E-region conductivity enhancement as caused by the flare enhanced solar extreme ultraviolet (EUV) and soft X-rays flux. We propose that the flare-induced enhancement in neutral wind occurring with a time delay (with respect to the flare radiation) could be responsible for a delayed zonal electric field disturbance driving the EEJ, in which the Cowling conductivity offers enhanced sensitivity to the driving zonal electric field.

Left ventricular approach for recording His bundle potential in man.

PubMed

Lee, Y S; Lien, W P

1975-06-01

The electrical potentials of the His bundle (HB) were recorded from the left ventricular endocardial surface in 28 patients ranging from 16 to 63 years of age. In 14 of the patients the left bundle branch (LB) potentials were also obtained. Placement of a bipolar electrode catheter tip toward the interventricular septum, right at and also 1 to 2 cm below the aortic valve, resulted in stable recordings of both potentials in successive cardiac cycles even at performing atrial or HB pacing from the right heart. The following intervals were measured in milliseconds (msec): P-A, A-H, H, H-V, LB, and LB-V. The average values in 12 patients (average age 26 plus or minus 7 years and average heart rate 90 plus or minus 16 beats per minute) with normal A-V conduction were as follows: P-A 28 plus or minus 7, A-H 76 plus or minus 16, H 19 plus or minus 3 and H-V 45 plus or minus 6 msec. The average values for LB and LB-V in 10 of these 12 patients were 15 plus or minus 3 and 25 plus or minus 3 msec respectively. Validation of the His bundle electrogram (HBE) from the left ventricular endocardial surface was based on simultaneous recordings of the intracardiac electrograms from both left and right sides of the heart in 18 patients. The individual average values for the intervals obtained from both sides of the heart in these patients were statistically not different, except that the H potential was slightly longer in duration fr m the left heart (P equals 0.05). Among these, 16 showed simultaneous onset of the H potentials, and the LB-V and RB-V conduction times from comparable points were almost the same. Indications for the left sided electro-physiologic studies include the following situations: (a) inability to record H from the right of the heart; (b) giant right atrium; and (c) possibly during atrial fibrillation.

Defining the Value of Future Research to Identify the Preferred Treatment of Meniscal Tear in the Presence of Knee Osteoarthritis

PubMed Central

Losina, Elena; Dervan, Elizabeth E.; Paltiel, A. David; Dong, Yan; Wright, R. John; Spindler, Kurt P.; Mandl, Lisa A.; Jones, Morgan H.; Marx, Robert G.; Safran-Norton, Clare E.; Katz, Jeffrey N.

2015-01-01

Background Arthroscopic partial meniscectomy (APM) is extensively used to relieve pain in patients with symptomatic meniscal tear (MT) and knee osteoarthritis (OA). Recent studies have failed to show the superiority of APM compared to other treatments. We aim to examine whether existing evidence is sufficient to reject use of APM as a cost-effective treatment for MT+OA. Methods We built a patient-level microsimulation using Monte Carlo methods and evaluated three strategies: Physical therapy (‘PT’) alone; PT followed by APM if subjects continued to experience pain (‘Delayed APM’); and ‘Immediate APM’. Our subject population was US adults with symptomatic MT and knee OA over a 10 year time horizon. We assessed treatment outcomes using societal costs, quality-adjusted life years (QALYs), and calculated incremental cost-effectiveness ratios (ICERs), incorporating productivity costs as a sensitivity analysis. We also conducted a value-of-information analysis using probabilistic sensitivity analyses. Results Calculated ICERs were estimated to be $12,900/QALY for Delayed APM as compared to PT and $103,200/QALY for Immediate APM as compared to Delayed APM. In sensitivity analyses, inclusion of time costs made Delayed APM cost-saving as compared to PT. Improving efficacy of Delayed APM led to higher incremental costs and lower incremental effectiveness of Immediate APM in comparison to Delayed APM. Probabilistic sensitivity analyses indicated that PT had 3.0% probability of being cost-effective at a willingness-to-pay (WTP) threshold of $50,000/QALY. Delayed APM was cost effective 57.7% of the time at WTP = $50,000/QALY and 50.2% at WTP = $100,000/QALY. The probability of Immediate APM being cost-effective did not exceed 50% unless WTP exceeded $103,000/QALY. Conclusions We conclude that current cost-effectiveness evidence does not support unqualified rejection of either Immediate or Delayed APM for the treatment of MT+OA. The amount to which society would be willing to pay for additional information on treatment outcomes greatly exceeds the cost of conducting another randomized controlled trial on APM. PMID:26086246

Understanding the delayed prescribing of antibiotics for respiratory tract infection in primary care: a qualitative analysis.

PubMed

Ryves, R; Eyles, C; Moore, M; McDermott, L; Little, P; Leydon, G M

2016-11-18

To identify general practitioner (GP) views and understanding on the use of delayed prescribing in primary care. Qualitative semistructured telephone interview study. Primary care general practices in England. 32 GPs from identified high-prescribing and low-prescribing general practices in England. Semistructured telephone interviews were conducted with GPs identified from practices within clinical commissioning groups with the highest and lowest prescribing rates in England. A thematic analysis of the data was conducted to generate themes. All GPs had a good understanding of respiratory tract infection (RTI) management and how the delayed prescribing approach could be used in primary care. However, GPs highlighted factors that were influential as to whether delayed prescribing was successfully carried out during the consultation. These included the increase in evidence of antimicrobial resistance, and GPs' prior experiences of using delayed prescribing during the consultation. The patient-practitioner relationship could also influence treatment outcomes for RTI, and a lack of an agreed prescribing strategy within and between practices was considered to be of significance to GPs. Participants expressed that a lack of feedback on prescribing data at an individual and practice level made it difficult to know if delayed prescribing strategies were successful in reducing unnecessary consumption. GPs agreed that coherent and uniform training and guidelines would be of some benefit to ensure consistent prescribing throughout the UK. Delayed prescribing is encouraged in primary care, but is not always implemented successfully. Greater uniformity within and between practices in the UK is needed to operationalise delayed prescribing, as well as providing feedback on the uptake of antibiotics. Finally, GPs may need further guidance on how to answer the concerns of patients without interpreting these questions as a demand for antibiotics, as well as educating the patient about antimicrobial resistance and supporting a good patient-practitioner relationship. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Delayed Hospital Discharges of Older Patients: A Systematic Review on Prevalence and Costs.

PubMed

Landeiro, Filipa; Roberts, Kenny; Gray, Alastair Mcintosh; Leal, José

2017-05-23

To determine the prevalence of delayed discharges of elderly inpatients and associated costs. We searched Medline, Embase, Global Health, CAB Abstracts, Econlit, Web of Knowledge, EBSCO - CINAHL, The Cochrane Library, Health Management Information Consortium, and SCIE - Social Care Online for evidence published between 1990 and 2015 on number of days or proportion of delayed discharges for elderly inpatients in acute hospitals. Descriptive and regression analyses were conducted. Data on proportions of delayed discharges were pooled using a random effects logistic model and the association of relevant factors was assessed. Mean costs of delayed discharge were calculated in USD adjusted for Purchasing Power Parity (PPP). Of 64 studies included, 52 (81.3%) reported delayed discharges as proportions of total hospital stay and 9 (14.1%) estimated the respective costs for these delays. Proportions of delayed discharges varied widely, from 1.6% to 91.3% with a weighted mean of 22.8%. This variation was also seen in studies from the same country, for example, in the United Kingdom, they ranged between 1.6% and 60.0%. No factor was found to be significantly associated with delays. The mean costs of delayed discharge also varied widely (between 142 and 31,935 USD PPP adjusted), reflecting the variability in mean days of delay per patient. Delayed discharges occur in most countries and the associated costs are significant. However, the variability in prevalence of delayed discharges and available data on costs limit our knowledge of the full impact of delayed discharges. A standardization of methods is necessary to allow comparisons to be made, and additional studies are required-preferably by disease area-to determine the postdischarge needs of specific patient groups and the estimated costs of delays. © The Author 2017. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

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

PubMed

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

2016-01-01

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

Socio-economic, gender and health services factors affecting diagnostic delay for tuberculosis patients in urban Zambia.

PubMed

Needham, D M; Foster, S D; Tomlinson, G; Godfrey-Faussett, P

2001-04-01

In-depth interviews regarding health seeking behaviour were conducted with 202 adults registered with pulmonary tuberculosis at the centralized Chest Clinic in Lusaka, Zambia. The median (mean) diagnostic delay was 8.6 (9) weeks, and was significantly associated with the following factors: female sex, lower education, more than six instances of health-seeking encounters, outpatient diagnosis of tuberculosis, and visiting a private doctor or traditional healer. More effective tuberculosis control interventions require novel methods of accessing women and less educated people. Decentralization of public tuberculosis care and improved integration with private sector health providers may also reduce diagnostic delay.

The conduction block produced by oxcarbazepine in the isolated rat sciatic nerve: a comparison with lamotrigine.

PubMed

Guven, Mustafa; Kahraman, Ibrahim; Koc, Filiz; Bozdemir, Hacer; Sarica, Yakup; Gunay, Ismail

2011-01-01

Oxcarbazepine is an antiepileptic drug widely used for the treatment of neuropathic pain. In the present study, the effects of oxcarbazepine and lamotrigine on conduction properties in the rat sciatic nerves were examined. The experiments were conducted with in vitro sucrose-gap technique on the isolated wistar rat sciatic nerves. The compound action potentials were obtained by tonic (single) and phasic (10, 40, and 100 Hz) stimulation. Oxcarbazepine produced a significant concentration- and frequency-dependent reduction in the compound action potential amplitude. When the two drugs were applied at concentrations that produced equal levels of tonic (i.e., non-frequency-dependent) conduction block, oxcarbazepine produced the greatest phasic (i.e., frequency-dependent) conduction block, followed by lamotrigine. Oxcarbazepine and lamotrigine reduced the 4-aminopyridine-induced amplitude of delayed depolarization; however, oxcarbazepine had a significantly greater effect than lamotrigine. These results suggest that oxcarbazepine produces more potent frequency-dependent conduction block than lamotrigine, and suppresses the delayed depolarization which contributes to sensory signaling and may play a role in neuropathic pain. The findings provide insight into the mechanisms of action of oxcarbazepine and lamotrigine and may help in the development of novel therapies for neuropathic pain.

A 2:1 AV rhythm: an adverse effect of a long AV delay during DDI pacing and its prevention by the ventricular intrinsic preference algorithm in DDD mode.

PubMed

Minamiguchi, Hitoshi; Oginosawa, Yasushi; Kohno, Ritsuko; Tamura, Masahito; Takeuchi, Masaaki; Otsuji, Yutaka; Abe, Haruhiko

2012-07-01

A 91-year-old woman received a dual-chamber pacemaker for sick sinus syndrome and intermittently abnormal atrioventricular (AV) conduction. The pacemaker was set in DDI mode with a 350-ms AV delay to preserve intrinsic ventricular activity. She complained of palpitation during AV sequential pacing. The electrocardiogram showed a 2:1 AV rhythm from 1:1 ventriculoatrial (VA) conduction during ventricular pacing in DDI mode with a long AV interval. After reprogramming of the pacemaker in DDD mode with a 250-ms AV interval and additional 100-ms prolongation of the AV interval by the ventricular intrinsic preference function, VA conduction disappeared and the patient's symptom were alleviated without increasing unnecessary right ventricular pacing. ©2011, The Authors. Journal compilation ©2011 Wiley Periodicals, Inc.

Interpretation of symptoms as a cause of delays in patients with acute myocardial infarction, Istanbul, Turkey.

PubMed

Koc, Sema; Durna, Zehra; Akin, Semiha

2017-06-14

This cross-sectional study aimed to assess interpretation of symptoms as a cause of delays in patients with acute myocardial infarction (AMI). It was conducted at a university hospital in Istanbul, Turkey. The sample included 93 patients: 73 male, mean age 57.89 (12.13) years. Prehospital delay time ranged from 15 minutes to 10 days, with a median of 2 hours (interquartile range: 9.50). Patients waited for pain to go away (48.4%) and tried to calm down (39.8%). Most patients attributed AMI-related symptoms to a reason other than heart disease. In a multivariate logistic regression analysis, the type of AMI was classified based on electrocardiography findings (odds ratio 5.18, 95% confidence interval: 1.69-15.91, P=0.004) and was independently associated with a long prehospital delay time, indicating that patients with ST segment elevation MI would seek early medical care. Misinterpretation of symptoms and misconceptions about emergency treatment during AMI cause delays in admission and may affect treatment.

Advanced techniques for mitigating the effects of temporal distortions in human in the loop control systems

NASA Astrophysics Data System (ADS)

Guo, Liwen

The desire to create more complex visual scenes in modern flight simulators outpaces recent increases in processor speed. As a result, the simulation transport delay remains a problem. Because of the limitations shown in the three prominent existing delay compensators---the lead/lag filter, the McFarland compensator and the Sobiski/Cardullo predictor---new approaches of compensating the transport delay in a flight simulator have been developed. The first novel compensator is the adaptive predictor making use of the Kalman filter algorithm in a unique manner so that the predictor can provide accurately the desired amount of prediction, significantly reducing the large spikes caused by the McFarland predictor. Among several simplified online adaptive predictors it illustrates mathematically why the stochastic approximation algorithm achieves the best compensation results. A second novel approach employed a reference aircraft dynamics model to implement a state space predictor on a flight simulator. The practical implementation formed the filter state vector from the operator's control input and the aircraft states. The relationship between the reference model and the compensator performance was investigated in great detail, and the best performing reference model was selected for implementation in the final tests. Piloted simulation tests were conducted for assessing the effectiveness of the two novel compensators in comparison to the McFarland predictor and no compensation. Thirteen pilots with heterogeneous flight experience executed straight-in and offset approaches, at various delay configurations, on a flight simulator where different predictors were applied to compensate for transport delay. Four metrics---the glide slope and touchdown errors, power spectral density of the pilot control inputs, NASA Task Load Index, and Cooper-Harper rating on the handling qualities---were employed for the analyses. The overall analyses show that while the adaptive predictor results in slightly poorer compensation for short added delay (up to 48 ms) and better compensation for long added delay (up to 192 ms) than the McFarland compensator, the state space predictor is fairly superior for short delay and significantly superior for long delay to the McFarland compensator. The state space predictor also achieves better compensation than the adaptive predictor. The results of the evaluation on the effectiveness of these predictors in the piloted tests agree with those in the theoretical offline tests conducted with the recorded simulation aircraft states.

Determinants of delay in malaria care-seeking behaviour for children 15 years and under in Bata district, Equatorial Guinea.

PubMed

Romay-Barja, Maria; Cano, Jorge; Ncogo, Policarpo; Nseng, Gloria; Santana-Morales, Maria A; Valladares, Basilio; Riloha, Matilde; Benito, Agustin

2016-03-31

Malaria remains a major cause of morbidity and mortality in children under 5 years of age in Equatorial Guinea. Early appropriate treatment can reduce progression of the illness to severe stages, thus reducing of mortality, morbidity and onward transmission. The factors that contribute to malaria treatment delay have not been studied previously in Equatorial Guinea. The objective of this study was to assess the determinants of delay in seeking malaria treatment for children in the Bata district, in mainland Equatorial Guinea. A cross-sectional study was conducted in Bata district, in 2013, which involved 428 houses in 18 rural villages and 26 urban neighbourhoods. Household caregivers were identified in each house and asked about their knowledge of malaria and about the management of the last reported malaria episode in a child 15 years and younger under their care. Bivariate and multivariate statistical analyses were conducted to determine the relevance of socio-economic, geographical and behavioural factors on delays in care-seeking behaviour. Nearly half of the children sought treatment at least 24 h after the onset of the symptoms. The median delay in seeking care was 2.8 days. Children from households with the highest socio-economic status were less likely to be delayed in seeking care than those from households with the lowest socio-economic status (OR 0.37, 95% CI 0.19-0.72). Children that first received treatment at home, mainly paracetamol, were more than twice more likely to be delayed for seeking care, than children who did not first receive treatment at home (OR 2.36, 95% CI 1.45-3.83). Children living in a distance >3 km from the nearest health facility were almost two times more likely to be delayed in seeking care than those living closer to a facility but with non significant association once adjusted for other variables (OR 1.75, 95% CI 0.88-3.47). To decrease malaria morbidity and mortality in Bata district, efforts should be addressed to reduce household delays in seeking care. It is necessary to provide free access to effective malaria diagnosis and treatment, to reinforce malaria management at community level through community health workers and drug sellers and to increase awareness on the severity of malaria, the importance of early diagnosis and appropriate treatment.

Slowing light down by low magnetic fields: pulse delay by transient spectral hole-burning in ruby.

PubMed

Riesen, Hans; Rebane, Aleksander K; Szabo, Alex; Carceller, Ivana

2012-08-13

We report on the observation of slow light induced by transient spectral hole-burning in a solid, that is based on excited-state population storage. Experiments were conducted in the R1-line (2E←4A2 transition) of a 2.3 mm thick pink ruby (Al2O3:Cr(III) 130 ppm). Importantly, the pulse delay can be controlled by the application of a low external magnetic field B||c≤9 mT and delays of up to 11 ns with minimal pulse distortion are observed for ~55 ns Gaussian pulses. The delay corresponds to a group velocity value of ~c/1400. The experiment is very well modelled by linear spectral filter theory and the results indicate the possibility of using transient hole-burning based slow light experiments as a spectroscopic technique.

Longitudinal Models of Socio-Economic Status: Impact on Positive Parenting Behaviors

ERIC Educational Resources Information Center

Azad, Gazi; Blacher, Jan; Marcoulides, George

2014-01-01

Parenting research is frequently conducted without a thorough examination of socio-economic characteristics. In this study, longitudinal observations of positive parenting were conducted across six time points. Participants were 219 mothers of children with and without developmental delays. Mothers' positive parenting increased during early and…

12 CFR 19.5 - Authority of the administrative law judge.

Code of Federal Regulations, 2010 CFR

2010-01-01

... powers necessary to conduct a proceeding in a fair and impartial manner and to avoid unnecessary delay. (b) Powers. The administrative law judge shall have all powers necessary to conduct the proceeding in accordance with paragraph (a) of this section, including the following powers: (1) To administer oaths and...

Distinguishing fissions of 232Th, 237Np and 238U with beta-delayed gamma rays

DOE PAGES

Iyengar, A.; Norman, E. B.; Howard, C.; ...

2013-04-08

Measurements of beta-delayed gamma-ray spectra following 14-MeV neutron-induced fissions of 232Th, 238U, and 237Np were conducted at Lawrence Berkeley National Laboratory’s 88-Inch Cyclotron. Spectra were collected for times ranging from 1 minute to 14 hours after irradiation. Lastly, intensity ratios of gamma-ray lines were extracted from the data that allow identification of the fissioning isotope.

Bilingualism delays age at onset of dementia, independent of education and immigration status.

PubMed

Mortimer, James A

2014-05-27

Editors' Note: Mortimer argues that important confounding variables may have biased the conclusion by Alladi et al. on the role of bilingualism in delaying the onset of dementia. Following Mortimer’s comments, Alladi et al. conducted additional analysis of their data to support their conclusion. The attitude of "close enough" is not appropriate when determining brain death. Stadlan comments and supports Frank’s call for action regarding this sensitive issue.

Doppler-derived myocardial systolic strain rate is a strong index of left ventricular contractility

NASA Technical Reports Server (NTRS)

Greenberg, Neil L.; Firstenberg, Michael S.; Castro, Peter L.; Main, Michael; Travaglini, Agnese; Odabashian, Jill A.; Drinko, Jeanne K.; Rodriguez, L. Leonardo; Thomas, James D.; Garcia, Mario J.

2002-01-01

BACKGROUND: Myocardial fiber strain is directly related to left ventricular (LV) contractility. Strain rate can be estimated as the spatial derivative of velocities (dV/ds) obtained by tissue Doppler echocardiography (TDE). The purposes of the study were (1) to determine whether TDE-derived strain rate may be used as a noninvasive, quantitative index of contractility and (2) to compare the relative accuracy of systolic strain rate against TDE velocities alone. METHODS AND RESULTS: TDE color M-mode images of the interventricular septum were recorded from the apical 4-chamber view in 7 closed-chest anesthetized mongrel dogs during 5 different inotropic stages. Simultaneous LV volume and pressure were obtained with a combined conductance-high-fidelity pressure catheter. Peak elastance (Emax) was determined as the slope of end-systolic pressure-volume relationships during caval occlusion and was used as the gold standard of LV contractility. Peak systolic TDE myocardial velocities (Sm) and peak (epsilon'(p)) and mean (epsilon'(m)) strain rates obtained at the basal septum were compared against Emax by linear regression. Emax as well as TDE systolic indices increased during inotropic stimulation with dobutamine and decreased with the infusion of esmolol. A stronger association was found between Emax and epsilon'(p) (r=0.94, P<0.01, y=0.29x+0.46) and epsilon'(m) (r=0.88, P<0.01) than for Sm (r=0.75, P<0.01). CONCLUSIONS: TDE-derived epsilon'(p) and epsilon'(m) are strong noninvasive indices of LV contractility. These indices appear to be more reliable than S(m), perhaps by eliminating translational artifact.

Use of Intracardiac Echocardiography in Interventional Cardiology: Working With the Anatomy Rather Than Fighting It.

PubMed

Enriquez, Andres; Saenz, Luis C; Rosso, Raphael; Silvestry, Frank E; Callans, David; Marchlinski, Francis E; Garcia, Fermin

2018-05-22

The indications for catheter-based structural and electrophysiological procedures have recently expanded to more complex scenarios, in which an accurate definition of the variable individual cardiac anatomy is key to obtain optimal results. Intracardiac echocardiography (ICE) is a unique imaging modality able to provide high-resolution real-time visualization of cardiac structures, continuous monitoring of catheter location within the heart, and early recognition of procedural complications, such as pericardial effusion or thrombus formation. Additional benefits are excellent patient tolerance, reduction of fluoroscopy time, and lack of need for general anesthesia or a second operator. For these reasons, ICE has largely replaced transesophageal echocardiography as ideal imaging modality for guiding certain procedures, such as atrial septal defect closure and catheter ablation of cardiac arrhythmias, and has an emerging role in others, including mitral valvuloplasty, transcatheter aortic valve replacement, and left atrial appendage closure. In electrophysiology procedures, ICE allows integration of real-time images with electroanatomic maps; it has a role in assessment of arrhythmogenic substrate, and it is particularly useful for mapping structures that are not visualized by fluoroscopy, such as the interatrial or interventricular septum, papillary muscles, and intracavitary muscular ridges. Most recently, a three-dimensional (3D) volumetric ICE system has also been developed, with potential for greater anatomic information and a promising role in structural interventions. In this state-of-the-art review, we provide guidance on how to conduct a comprehensive ICE survey and summarize the main applications of ICE in a variety of structural and electrophysiology procedures. © 2018 American Heart Association, Inc.

Human-in-the-Loop Operations over Time Delay: NASA Analog Missions Lessons Learned

NASA Technical Reports Server (NTRS)

Rader, Steven N.; Reagan, Marcum L.; Janoiko, Barbara; Johnson, James E.

2013-01-01

Teams at NASA have conducted studies of time-delayed communications as it effects human exploration. In October 2012, the Advanced Exploration Systems (AES) Analog Missions project conducted a Technical Interchange Meeting (TIM) with the primary stakeholders to share information and experiences of studying time delay, to build a coherent picture of how studies are covering the problem domain, and to determine possible forward plans (including how to best communicate study results and lessons learned, how to inform future studies and mission plans, and how to drive potential development efforts). This initial meeting s participants included personnel from multiple NASA centers (HQ, JSC, KSC, ARC, and JPL), academia, and ESA. It included all of the known studies, analog missions, and tests of time delayed communications dating back to the Apollo missions including NASA Extreme Environment Mission Operations (NEEMO), Desert Research and Technology Studies (DRATS/RATS), International Space Station Test-bed for Analog Research (ISTAR), Pavilion Lake Research Project (PLRP), Mars 520, JPL Mars Orbiters/Rovers, Advanced Mission Operations (AMO), Devon Island analog missions, and Apollo experiences. Additionally, the meeting attempted to capture all of the various functional perspectives via presentations by disciplines including mission operations (flight director and mission planning), communications, crew, Capcom, Extra-Vehicular Activity (EVA), Behavioral Health and Performance (BHP), Medical/Surgeon, Science, Education and Public Outreach (EPO), and data management. The paper summarizes the descriptions and results from each of the activities discussed at the TIM and includes several recommendations captured in the meeting for dealing with time delay in human exploration along with recommendations for future development and studies to address this issue.

Impact of health care system delay in patients with ST-elevation myocardial infarction on return to labor market and work retirement.

PubMed

Laut, Kristina Grønborg; Hjort, Jacob; Engstrøm, Thomas; Jensen, Lisette Okkels; Tilsted Hansen, Hans-Henrik; Jensen, Jan Skov; Pedersen, Frants; Jørgensen, Erik; Holmvang, Lene; Pedersen, Alma Becic; Christensen, Erika Frischknecht; Lippert, Freddy; Lang-Jensen, Torsten; Jans, Henning; Hansen, Poul Anders; Trautner, Sven; Kristensen, Steen Dalby; Lassen, Jens Flensted; Lash, Timothy L; Clemmensen, Peter; Terkelsen, Christian Juhl

2014-12-15

System delay (delay from emergency medical service call to reperfusion with primary percutaneous coronary intervention [PPCI]) is acknowledged as a performance measure in ST-elevation myocardial infarction (STEMI), as shorter system delay is associated with lower mortality. It is unknown whether system delay also impacts ability to stay in the labor market. Therefore, the aim of the study was to evaluate whether system delay is associated with duration of absence from work or time to retirement from work among patients with STEMI treated with PPCI. We conducted a population-based cohort study including patients ≤67 years of age who were admitted with STEMI from January 1, 1999, to December 1, 2011 and treated with PPCI. Data were derived from Danish population-based registries. Only patients who were full- or part-time employed before their STEMI admission were included. Association between system delay and time to return to the labor market was analyzed using a competing-risk regression analysis. Association between system delay and time to retirement from work was analyzed using a Cox regression model. A total of 4,061 patients were included. Ninety-three percent returned to the labor market during 4 years of follow-up, and 41% retired during 8 years of follow-up. After adjustment, system delay >120 minutes was associated with reduced resumption of work (subhazard ratio 0.86, 95% confidence interval 0.81 to 0.92) and earlier retirement from work (hazard ratio 1.21, 95% confidence interval 1.08 to 1.36). In conclusion, system delay was associated with reduced work resumption and earlier retirement. This highlights the value of system delay as a performance measure in treating patients with STEMI. Copyright © 2014 Elsevier Inc. All rights reserved.

Prognosis and delay of diagnosis among Kaposi’s sarcoma patients in Uganda: a cross-sectional study

PubMed Central

2014-01-01

Background In low- and middle-income countries, the association between delay to treatment and prognosis for Kaposi’s sarcoma (KS) patients is yet to be studied. Methods This is a prospective study of HIV-infected adults with histologically-confirmed KS treated at the Uganda Cancer Institute (UCI). Standardized interviews were conducted in English or Luganda. Medical records were abstracted for KS stage at admission to UCI. Multivariable logistic regression assessed relationships between diagnostic delay and stage at diagnosis. Results Of 161 patients (90% response rate), 69% were men, and the mean age was 34.0 years (SD 7.7). 26% had been seen in an HIV clinic within 3 months, 72% were on antiretroviral therapy, and 26% had visited a traditional healer prior to diagnosis. 45% delayed seeking care at UCI for ≥3 months from symptom onset. Among those who delayed, 36% waited 6 months, and 25% waited 12 months. Common reasons for delay were lack of pain (48%), no money (32%), and distance to UCI (8%). In adjusted analysis patients who experienced diagnostic delay were more likely than those who did not delay to have poor-risk KS stage (OR 3.41, p = 0.002, 95% CI: 1.46-7.45). In adjusted analyses visiting a traditional healer was the only variable associated with greater likelihood of delay (OR 2.69, p = 0.020, 95% CI: 1.17-6.17). Conclusions Diagnostic delay was associated with poor-risk stage at diagnosis, and visiting a traditional healer was associated with higher odds of delay. The relationship between traditional and Western medicine presents a critical intervention point to improve KS-related outcomes in Uganda. PMID:24904686

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

PubMed Central

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

2016-01-01

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

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

PubMed

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

2016-11-01

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

Effect of metrology time delay on overlay APC

NASA Astrophysics Data System (ADS)

Carlson, Alan; DiBiase, Debra

2002-07-01

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

On the estimation of the reproduction number based on misreported epidemic data.

PubMed

Azmon, Amin; Faes, Christel; Hens, Niel

2014-03-30

Epidemic data often suffer from underreporting and delay in reporting. In this paper, we investigated the impact of delays and underreporting on estimates of reproduction number. We used a thinned version of the epidemic renewal equation to describe the epidemic process while accounting for the underlying reporting system. Assuming a constant reporting parameter, we used different delay patterns to represent the delay structure in our model. Instead of assuming a fixed delay distribution, we estimated the delay parameters while assuming a smooth function for the reproduction number over time. In order to estimate the parameters, we used a Bayesian semiparametric approach with penalized splines, allowing both flexibility and exact inference provided by MCMC. To show the performance of our method, we performed different simulation studies. We conducted sensitivity analyses to investigate the impact of misspecification of the delay pattern and the impact of assuming nonconstant reporting parameters on the estimates of the reproduction numbers. We showed that, whenever available, additional information about time-dependent underreporting can be taken into account. As an application of our method, we analyzed confirmed daily A(H1N1) v2009 cases made publicly available by the World Health Organization for Mexico and the USA. Copyright © 2013 John Wiley & Sons, Ltd.

The biological acoustic sensor to record the interactions of the microbial cells with the phage antibodies in conducting suspensions.

PubMed

Guliy, О I; Zaitsev, B D; Borodina, I A; Shikhabudinov, А М; Teplykh, A A; Staroverov, S A; Fomin, A S

2018-02-01

The acoustic biological sensor for the analysis of the bacterial cells in conducting suspension was developed. The sensor represented the two channel delay line based on the piezoelectric plate of Y-X lithium niobate thick of 0.2mm. Two pairs of the interdigital transducers (IDT) for the excitation and reception of shear horizontal acoustic wave of zero order (SH 0 ) in each channel were deposited by the method of photolithography. One channel of the delay line was electrically shorted by the deposition of thin aluminum film between IDTs. The second channel remained as electrically open. The liquid container with the volume of 5ml was fixed on the plate surface between IDTs by the glue, which did not cause the additional insertion loss. For the first time the influence of the conductivity of the cell suspension on the registration of the specific and nonspecific interactions of the bacterial cells with phage-antibodies (phage-Abs) was studied by means of the developed sensor. The dependencies of the change in insertion loss and phase of the output signal on the conductivity of the buffer solution at specific/nonspecific interactions for the electrically open and shorted channels of the delay line were obtained. It was shown that the sensor successfully registered the interactions of microbial cells with phage-Abs in the range of the conductivity of 2-20 μS/cm on the model samples A. brasilense Sp245 - specific phage-Abs. The sensor in the time regime of the operation fast reacted on the specific/nonspecific interaction and the time of the stabilization of the output parameters did not exceed 10min. Copyright © 2017 Elsevier B.V. All rights reserved.

Axonal Conduction Delays, Brain State, and Corticogeniculate Communication.

PubMed

Stoelzel, Carl R; Bereshpolova, Yulia; Alonso, Jose-Manuel; Swadlow, Harvey A

2017-06-28

Thalamocortical conduction times are short, but layer 6 corticothalamic axons display an enormous range of conduction times, some exceeding 40-50 ms. Here, we investigate (1) how axonal conduction times of corticogeniculate (CG) neurons are related to the visual information conveyed to the thalamus, and (2) how alert versus nonalert awake brain states affect visual processing across the spectrum of CG conduction times. In awake female Dutch-Belted rabbits, we found 58% of CG neurons to be visually responsive, and 42% to be unresponsive. All responsive CG neurons had simple, orientation-selective receptive fields, and generated sustained responses to stationary stimuli. CG axonal conduction times were strongly related to modulated firing rates (F1 values) generated by drifting grating stimuli, and their associated interspike interval distributions, suggesting a continuum of visual responsiveness spanning the spectrum of axonal conduction times. CG conduction times were also significantly related to visual response latency, contrast sensitivity (C-50 values), directional selectivity, and optimal stimulus velocity. Increasing alertness did not cause visually unresponsive CG neurons to become responsive and did not change the response linearity (F1/F0 ratios) of visually responsive CG neurons. However, for visually responsive CG neurons, increased alertness nearly doubled the modulated response amplitude to optimal visual stimulation (F1 values), significantly shortened response latency, and dramatically increased response reliability. These effects of alertness were uniform across the broad spectrum of CG axonal conduction times. SIGNIFICANCE STATEMENT Corticothalamic neurons of layer 6 send a dense feedback projection to thalamic nuclei that provide input to sensory neocortex. While sensory information reaches the cortex after brief thalamocortical axonal delays, corticothalamic axons can exhibit conduction delays of <2 ms to 40-50 ms. Here, in the corticogeniculate visual system of awake rabbits, we investigate the functional significance of this axonal diversity, and the effects of shifting alert/nonalert brain states on corticogeniculate processing. We show that axonal conduction times are strongly related to multiple visual response properties, suggesting a continuum of visual responsiveness spanning the spectrum of corticogeniculate axonal conduction times. We also show that transitions between awake brain states powerfully affect corticogeniculate processing, in some ways more strongly than in layer 4. Copyright © 2017 the authors 0270-6474/17/376342-17$15.00/0.

Temporary epicardial cardiac resynchronisation versus conventional right ventricular pacing after cardiac surgery: study protocol for a randomised control trial.

PubMed

Russell, Stuart J; Tan, Christine; O'Keefe, Peter; Ashraf, Saeed; Zaidi, Afzal; Fraser, Alan G; Yousef, Zaheer R

2012-02-20

Heart failure patients with stable angina, acute coronary syndromes and valvular heart disease may benefit from revascularisation and/or valve surgery. However, the mortality rate is increased- 5-30%. Biventricular pacing using temporary epicardial wires after surgery is a potential mechanism to improve cardiac function and clinical endpoints. A multi-centred, prospective, randomised, single-blinded, intervention-control trial of temporary biventricular pacing versus standard pacing. Patients with ischaemic cardiomyopathy, valvular heart disease or both, an ejection fraction ≤ 35% and a conventional indication for cardiac surgery will be recruited from 2 cardiac centres. Baseline investigations will include: an electrocardiogram to confirm sinus rhythm and measure QRS duration; echocardiogram to evaluate left ventricular function and markers of mechanical dyssynchrony; dobutamine echocardiogram for viability and blood tests for renal function and biomarkers of myocardial injury- troponin T and brain naturetic peptide. Blood tests will be repeated at 18, 48 and 72 hours. The principal exclusions will be subjects with permanent atrial arrhythmias, permanent pacemakers, infective endocarditis or end-stage renal disease.After surgery, temporary pacing wires will be attached to the postero-lateral wall of the left ventricle, the right atrium and right ventricle and connected to a triple chamber temporary pacemaker. Subjects will be randomised to receive either temporary biventricular pacing or standard pacing (atrial inhibited pacing or atrial-synchronous right ventricular pacing) for 48 hours.The primary endpoint will be the duration of level 3 care. In brief, this is the requirement for invasive ventilation, multi-organ support or more than one inotrope/vasoconstrictor. Haemodynamic studies will be performed at baseline, 6, 18 and 24 hours after surgery using a pulmonary arterial catheter. Measurements will be taken in the following pacing modes: atrial inhibited; right ventricular only; atrial synchronous-right ventricular; atrial synchronous-left ventricular and biventricular pacing. Optimisation of the atrioventricular and interventricular delay will be performed in the biventricular pacing group at 18 hours. The effect of biventricular pacing on myocardial injury, post operative arrhythmias and renal function will also be quantified. ClinicalTrials.gov: NCT01027299.

8p23.1 duplication syndrome differentiated from copy number variation of the defensin cluster at prenatal diagnosis in four new families

PubMed Central

2010-01-01

Background The 8p23.1 duplication syndrome and copy number variation of the 8p23.1 defensin gene cluster are cytogenetically indistinguishable but distinct at the molecular level. To our knowledge, the 8p23.1 duplication syndrome has been described at prenatal diagnosis only once and we report our experience with four further apparent duplications ascertained at prenatal diagnosis. Methods Additional material at band 8p23.1 was detected using conventional G-banded cytogenetics in each case. Multiplex Ligation-dependent Probe Amplification (MLPA) or Fluorescence In Situ Hybridisation (FISH) were used depending on whether only DNA (Cases 1 and 4) or cytogenetic preparations (Cases 2 and 3) were available from the laboratory of origin. The extent of the duplication in Case 1 was retrospectively determined using array Comparative Genomic Hybridisation (array CGH). Results Three cases of 8p23.1 duplication syndrome were found (Cases 1 to 3). Two were de novo and continued to term and the third, a paternally transmitted duplication, was terminated because of a previous child with psychomotor delay and 8p23.1 duplication syndrome. Case 1 was ascertained with a hypoplastic left heart but the ventricular septal and interventricular defects, in Cases 2 and 3 respectively, were found after ascertainment for advanced maternal age. By contrast, case 4 was a maternally transmitted copy number variation of the defensin cluster with normal outcome. Conclusions Our data underline the need to differentiate 8p23.1 duplications from copy number variation of the defensin cluster using FISH, MLPA or array CGH. Cardiac defects were ascertained by ultrasound in only one of the three duplication 8p23.1 pregnancies but were visible in two of the three at 21 to 22 weeks gestation. Our results provide further evidence that both deletion and duplication of the GATA4 transcription factor can give rise to a variety of conotruncal heart defects with variable penetrance and expressivity. PMID:20167067

The effects of computer-assisted cognitive rehabilitation on Alzheimer's dementia patients memories.

PubMed

Hwang, Jung-Ha; Cha, Hyun-Gyu; Cho, Young-Seok; Kim, Tae-Sue; Cho, Hyuk-Shin

2015-09-01

[Purpose] The purpose of the present study was to conduct Computer-Assisted Cognitive Rehabilitation (COMCOG) to examine the effects of COMCOG on Alzheimer's dementia patients' memories. [Subjects] Thirty-five patients diagnosed with Alzheimer's dementia received COMCOG for 30 minutes per day, five days per week for four weeks. [Methods] Before and after the COMCOG intervention, subjects' cognitive functions were evaluated using the Cognitive Assessment Reference Diagnosis System (CARDS) and Mini-Mental State Examination-Korea (MMSE-K) test. [Results] According to the results of the evaluation, among the CARDS scores of the subjects who received COMCOG, the scores of the delayed 10-word list, delayed 10-object list, recognition 10-object, and recent memory significantly increased while the scores of recognition 10-word significantly decreased after intervention compared to before intervention. In addition, among the MMSE-K items, the orientation, registration, and recall showed significant increases. [Conclusion] Based on these results, delay in the progress of memory deterioration can be expected when COMCOG is conducted for Alzheimer's dementia patients who show declines in cognitive functions.

Real life is different: a qualitative study of why women delay abortion until the second trimester in Vietnam.

PubMed

Gallo, Maria F; Nghia, Nguyen C

2007-05-01

Although legal and safe-induced abortion services are available on request in Vietnam, second-trimester abortion still occurs. Given the increased risks and higher costs associated with later-term abortions, we conducted a qualitative study to understand the determinants of delaying abortion until the second trimester. We used purposive sampling to conduct semi-structured face-to-face interviews with 60 women aged 14-47 receiving an abortion at 13-24 weeks of gestation in 5 health facilities in 3 provinces in Vietnam. We also interviewed 6 providers from the study facilities. Three broad categories for factors influencing delays in obtaining abortions emerged: most women failed to recognize their pregnancy during the first trimester; women described structural barriers to accessing services earlier; and some women either needed time to make a decision or only decided to abort after other events had transpired. A richer understanding of the factors that prevent women from obtaining an abortion during the first trimester could be useful for informing interventions that support women in receiving care earlier during their pregnancies.

[Are antioxidant supplements effective in reducing delayed onset muscle soreness? A systematic review].

PubMed

Candia-Luján, Ramón; De Paz Fernández, José Antonio; Costa Moreira, Osvaldo

2014-10-05

In recent years, antioxidant supplements have become popular to counter the effects of free radicals and muscle damage symptoms, including delayed onset muscle soreness (DOMS). To conduct a systematic review in different databases to determine the effects of antioxidant supplements on DOMS. We conducted a search in databases; Cochrane, Pubmed, Scopus and SportDiscus and Web of Science (WOS). The words and acronyms used were; Delayed onset muscle soreness, exercise induced muscle damage, DOMS, EIMD, antioxidant and oxidative stress. 54 articles were identified of which 48 were retreived, all in English, 17 related to vitamin C and E, supplements polyphenolic correspond to fourteen, eleven other antioxidant supplements and six to commercial supplements, all of them used to diminish the DOMS and other variables. Both vitamins and commercial supplements have low effectiveness in reducing DOMS, while polyphenols and other antioxidant supplements show moderate to good effectiveness in combating DOMS. However, most of the studies have effectiveness in reducing other symptoms of muscle damage besides helping in the post-exercise recovery. Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.

The Diagnostic Yield of Array Comparative Genomic Hybridization Is High Regardless of Severity of Intellectual Disability/Developmental Delay in Children.

PubMed

D'Arrigo, Stefano; Gavazzi, Francesco; Alfei, Enrico; Zuffardi, Orsetta; Montomoli, Cristina; Corso, Barbara; Buzzi, Erika; Sciacca, Francesca L; Bulgheroni, Sara; Riva, Daria; Pantaleoni, Chiara

2016-05-01

Microarray-based comparative genomic hybridization is a method of molecular analysis that identifies chromosomal anomalies (or copy number variants) that correlate with clinical phenotypes. The aim of the present study was to apply a clinical score previously designated by de Vries to 329 patients with intellectual disability/developmental disorder (intellectual disability/developmental delay) referred to our tertiary center and to see whether the clinical factors are associated with a positive outcome of aCGH analyses. Another goal was to test the association between a positive microarray-based comparative genomic hybridization result and the severity of intellectual disability/developmental delay. Microarray-based comparative genomic hybridization identified structural chromosomal alterations responsible for the intellectual disability/developmental delay phenotype in 16% of our sample. Our study showed that causative copy number variants are frequently found even in cases of mild intellectual disability (30.77%). We want to emphasize the need to conduct microarray-based comparative genomic hybridization on all individuals with intellectual disability/developmental delay, regardless of the severity, because the degree of intellectual disability/developmental delay does not predict the diagnostic yield of microarray-based comparative genomic hybridization. © The Author(s) 2015.

Delay and reward choice in ADHD: an experimental test of the role of delay aversion.

PubMed

Marco, Rafaela; Miranda, Ana; Schlotz, Wolff; Melia, Amanda; Mulligan, Aisling; Müller, Ueli; Andreou, Penny; Butler, Louise; Christiansen, Hanna; Gabriels, Isabel; Medad, Sheera; Albrecht, Bjorn; Uebel, Henrik; Asherson, Phillip; Banaschewski, Tobias; Gill, Michael; Kuntsi, Jonna; Mulas, Fernando; Oades, Robert; Roeyers, Herbert; Steinhausen, Hans-Christoph; Rothenberger, Aribert; Faraone, Stephen V; Sonuga-Barke, Edmund J S

2009-05-01

Children with attention deficit/hyperactivity disorder (ADHD) choose smaller sooner (SS) over larger later (LL) rewards more than controls. Here we assess the contributions of impulsive drive for immediate rewards (IDIR) and delay aversion (DAv) to this pattern. We also explore the characteristics of, and the degree of familiality in, ADHD SS responders. We had 360 ADHD probands; 349 siblings and 112 controls (aged between 6 to 17 years) chose between SS (1 point after 2 s) and LL reward (2 points after 30 s) outcomes on the Maudsley Index of Delay Aversion (Kuntsi, Oosterlaan, & Stevenson, 2001): Under one condition SS choice led to less overall trial delay under another it did not. ADHD participants chose SS more than controls under both conditions. This effect was larger when SS choice reduced trial delay. ADHD SS responders were younger, had lower IQ, more conduct disorder and had siblings who were more likely to be SS responders themselves. The results support a dual component model in which both IDIR and DAv contribute to SS choice in ADHD. SS choice may be a marker of an ADHD motivational subtype.

[Immediate and Long-term Results of the First in Russia of IntrocoronaryMetal Stent in the Coronary Artery].

PubMed

Babunashvili, A M; Navtsishvili, Z G; Konstantinov, B A

2016-02-01

The authors present immediate and long term results of the first in Russia implantation in coronary artery of Palmaz-Shatz metal stent. Indications for stenting were urgent after complicated dissection as a result of balloon dilation of discrete bifurcational stenosis of anterior interventricular artery (IVA). Immediate angiographic and clinical result was good. At control angiography after 13 years their was no restenosis in stented IVA. However novel narrowing was found in left main coronary artery (LMCA) in which drug eluting stent was implanted. Coronary angiography carried out after 7.5 years after stenting of LMCA and in 20 years after stent implantation in IVA revealed good patency of both stented segments without signs of restenosis. This case report demonstrates possibility of long term preservation of angiographic and clinical effect of staged endovascular treatment of coronary atherosclerosis.

The first signs of prospective memory.

PubMed

Ślusarczyk, Elżbieta; Niedźwieńska, Agnieszka; Białecka-Pikul, Marta

2018-06-05

We conducted a study to examine the impact of motivation and length of delay on performance on prospective memory (PM) tasks in 2-year of children. A total of 158 children aged exactly 24 months were asked to perform a naturalistic PM task. Length of delay (10 min; 35 min) and motivation (high; very high) were between-subjects factors. Two thirds of children had to be excluded from the analysis because of poor retrospective memory for the PM task instructions which were no longer remembered at the end of the session. For the children who did remember the instructions, both motivation and delay had significant effects on PM. Also, their PM performance was reliably above zero, even after the long delay. The findings indicate that when children as young as 24 months are able to remember the PM task instructions they can reliably succeed in PM tasks that are intrinsically motivating for them.

Separation attenuation in swept shock wave-boundary-layer interactions using different microvortex generator geometries

NASA Astrophysics Data System (ADS)

Martis, R. R.; Misra, A.

2017-09-01

A numerical study is conducted to determine the effectiveness of six different microvortex generator geometries in controlling swept shock wave/boundary-layer interactions. The geometries considered are base ramp, base ramp with declining angle of 45°, blunt ramp, split ramp, thick vanes, and ramped vanes. Microvortex generators with a gap were found to be better suited for delaying the separation. Thick vanes showed the largest delay in separation among the devices studied.

Investigation of the effects of bandwidth and time delay on helicopter roll-axis handling qualities

NASA Technical Reports Server (NTRS)

Pausder, Heinz-Juergen; Blanken, Chris L.

1992-01-01

Several years of cooperative research conducted under the U.S./German Memorandum of Understanding (MOU) in helicopter flight control has recently resulted in a successful handling qualities study. The focus of this cooperative research has been the effects on handling qualities due to time delays in combination with a high bandwidth vehicle. The jointly performed study included the use of U.S. ground-based simulation and German in-flight simulation facilities. The NASA-Ames Vertical Motion Simulator (VMS) was used to develop a high bandwidth slalom tracking task which took into consideration the constraints of the facilities. The VMS was also used to define a range of the test parameters and to perform initial handling qualities evaluations. The flight tests were conducted using DLR's variable-stability BO 105 S3 Advanced Technology Testing Helicopter System (ATTHeS). Configurations included a rate command and an attitude command response system with added time delays up to 160 milliseconds over the baseline and bandwidth values between 1.5 and 4.5 rad/sec. Sixty-six evaluations were performed in about 25 hr of flight time during 10 days of testing. The results indicate a need to more tightly constrain the allowable roll axis phase delay for the Level 1 and Level 2 requirements in the U.S. Army's specification for helicopter handling qualities, ADS-33C.

Investigation of the effects of bandwidth and time delay on helicopter roll-axis handling qualities

NASA Technical Reports Server (NTRS)

Blanken, Chris L.; Pausder, Heinz-Jurgen

1994-01-01

Several years of cooperative research conducted under the U.S./German Memorandum of Understanding (MOU) in helicopter aeromechanics have recently resulted in a successful handling qualities study. The focus of this cooperative research has been the effect of time delays in a high bandwidth vehicle on handling qualities. The jointly performed study included the use of U.S. ground-based simulation and German in-flight simulation facilities. The NASA-Ames Vertical Motion Simulator (VMS) was used to develop a high bandwidth slalom tracking task which took into consideration the constraints of the facilities. The VMS was used to define a range of the test parameters and to perform initial handling qualities evaluations. The flight tests were conducted using DLR's variable-stability BO 105 S3 Advanced Technology Testing Helicopter System (ATTHeS). Configurations included a rate command and an attitude command response system with added time delays of up to 160 milliseconds over the baseline and band width values between 1.5 and 4.5 rad/sec. Sixty-six evaluations were performed in about 25 hours of flight time during ten days of testing. The results indicate a need to more tightly constrain the allowable roll axis phase delay for the Level 1 and Level 2 requirements in the U.S. Army's specification for helicopter handling qualities Aeronautical Design Standard (ADS)-33C.

Investigation of the effects of bandwidth and time delay on helicopter roll-axis handling qualities

NASA Technical Reports Server (NTRS)

Pausder, Heinz-Juergen; Blanken, Chris L.

1993-01-01

Several years of cooperative research conducted under the U.S./German Memorandum of Understanding (MOU) in helicopter flight control has recently resulted in a successful handling qualities study. The focus of this cooperative research has been the effects on handling qualities due to time delays in combination with a high bandwidth vehicle. The jointly performed study included the use of U.S. ground-based simulation and German in-flight simulation facilities. The NASA-Ames Vertical Motion Simulator (VMS) was used to develop a high bandwidth slalom tracking task which took into consideration the constraints of the facilities. The VMS was also used to define a range of the test parameters and to perform initial handling qualities evaluations. The flight tests were conducted using DLR's variable-stability BO 105 S3 Advanced Technology Testing Helicopter System (ATTHeS). Configurations included a rate command and an attitude command response system with added time delays up to 160 milliseconds over the baseline and bandwidth values between 1.5 and 4.5 rad/sec. Sixty-six evaluations were performed in about 25 hours of flight time during ten days of testing. The results indicate a need to more tightly constrain the allowable roll axis phase delay for the Level 1 and Level 2 requirements in the U.S. Army's specification for helicopter handling qualities, ADS-33C.

Adult language use and infant comprehension of English: associations with encoding and generalization across cues at 20 months.

PubMed

Phung, Janice N; Milojevich, Helen M; Lukowski, Angela F

2014-11-01

Adult-provided language shapes event memory in children who are preverbal and in those who are able to discuss the past using language. The research conducted to date, however, has not yet established whether infant language comprehension abilities moderate the extent to which preverbal infants benefit from adult-provided supportive language. The present study was conducted to address this question by examining immediate imitation and 1-week delayed generalization across cues in 20-month-old infants as a function of (a) variability in adult-provided linguistic support at encoding and test, (b) infant language comprehension abilities, and (c) their interaction. The provision of supportive adult language at encoding and test was associated with delayed generalization across cues although supportive adult language at encoding did not influence performance at immediate imitation. Infant language comprehension abilities were associated with performance at immediate imitation and delayed generalization across cues. In addition, infant language comprehension abilities moderated the extent to which infants benefited from adult-provided supportive language at encoding and test. The findings contribute to the literature by demonstrating that adult language use and infant language comprehension are independently and differentially associated with immediate imitation and 1-week delayed generalization across cues but also serve to jointly structure event memory in the second year of life. Copyright © 2014 Elsevier Inc. All rights reserved.

[Hugo von Ziemssen poster award 2015].

PubMed

2015-12-01

Prize winner: Herr Dr. Stefano Bordignon, for the poster presentation "The SCAR-AF study: electroanatomial scar distribution and left atrial conduction delay in patients undergoing pulmonary vein isolation".

Reward: commentary. Temporal discounting in conduct disorder: toward an experience-adaptation hypothesis of the role of psychosocial insecurity.

PubMed

Sonuga-Barke, Edmund J S

2014-02-01

Young people with conduct disorder often experience histories of psychosocial adversity and socioeconomic insecurity. For these individuals, real-world future outcomes are not only delayed in their delivery but also highly uncertain. Under such circumstances, accentuated time preference (extreme favoring of the present over the future) is a rational response to the everyday reality of social and economic transactions. Building on this observation, the author sets out the hypothesis that the exaggerated temporal discounting displayed by individuals with conduct disorder reported by White et al. (2014) is an adaptation to chronic exposure to psychosocial insecurity during development. The author postulates that this adaptation leads to (a) a decision-making bias whereby delay and uncertainty are coded as inseparable characteristics of choice outcomes and/or (b) reprogramming of the brain networks regulating intertemporal decision making. Future research could explore the putative role of environmental exposures to adversity in the development of exaggerated temporal discounting in conduct disorder as well as the mediating role of putative cognitive and neurobiological adaptations.

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

NASA Astrophysics Data System (ADS)

Wang, Danyi

2007-12-01

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

Contextual-specificity of short-delay extinction in humans: Renewal of fear-potentiated startle in a virtual environment

PubMed Central

Alvarez, Ruben P.; Johnson, Linda; Grillon, Christian

2007-01-01

A recent fear-potentiated startle study in rodents suggested that extinction was not context dependent when extinction was conducted after a short delay following acquisition, suggesting that extinction can lead to erasure of fear learning in some circumstances. The main objective of this study was to attempt to replicate these findings in humans by examining the context specificity of short-delay extinction in an ABA renewal procedure using virtual reality environments. A second objective was to examine whether renewal, if any, would be influenced by context conditioning. Subjects underwent differential aversive conditioning in virtual context A, which was immediately followed by extinction in virtual context B. Extinction was followed by tests of renewal in context A and B, with the order counterbalanced across subjects. Results showed that extinction was context dependent. Evidence for renewal was established using fear-potentiated startle as well as skin conductance and fear ratings. In addition, although contextual anxiety was greater in the acquisition context than in the extinction context during renewal, as assessed with startle, context conditioning did not influence the renewal effect. These data do not support the view that extinction conducted shortly after acquisition is context independent. Hence, they do not provide evidence that extinction can lead to erasure of a fear memory established via Pavlovian conditioning. PMID:17412963

Semantic effects in sentence recall: the contribution of immediate vs delayed recall in language assessment.

PubMed

Polišenská, Kamila; Chiat, Shula; Comer, Amanda; McKenzie, Kirsty

2014-01-01

Sentence recall is increasingly used to assess language. It is widely debated what the task is actually testing, but one rarely explored aspect is the contribution of semantics to sentence recall. The few studies that have examined the role of semantics in sentence recall have employed an 'intrusion paradigm', following Potter and Lombardi (1990), and their paradigm relies on interference errors with conclusions based on an analysis of error patterns. We have instead manipulated the semantic plausibility of whole sentences to investigate the effects of semantics on immediate and delayed sentence recall. In Study 1, adults recalled semantically plausible and implausible sentences either immediately or after distracter tasks varying in lexical retrieval demands (backward counting and picture naming). Results revealed significant effects of plausibility, delay, and a significant interaction indicating increasing reliance on semantics as the demands of the distracter tasks increased. Study 2, conducted with 6-year-old children, employed delay conditions that were modified to avoid floor effects (delay with silence and forward counting) and a similar pattern of results emerged. This novel methodology provided robust evidence showing the effectiveness of delayed recall in the assessment of semantics and the effectiveness of immediate recall in the assessment of morphosyntax. The findings from our study clarify the linguistic mechanisms involved in immediate and delayed sentence recall, with implications for the use of recall tasks in language assessment. The reader will be able to: (i) define the difference between immediate and delayed sentence recall and different types of distractors, (ii) explain the utility of immediate and delayed recall sentence recall in language assessment, (iii) discuss suitability of delayed recall for the assessment of semantics. Copyright © 2014 Elsevier Inc. All rights reserved.

Genetic architecture of delayed senescence, biomass, and grain yield under drought stress in cowpea.

PubMed

Muchero, Wellington; Roberts, Philip A; Diop, Ndeye N; Drabo, Issa; Cisse, Ndiaga; Close, Timothy J; Muranaka, Satoru; Boukar, Ousmane; Ehlers, Jeffrey D

2013-01-01

The stay-green phenomenon is a key plant trait with wide usage in managing crop production under limited water conditions. This trait enhances delayed senescence, biomass, and grain yield under drought stress. In this study we sought to identify QTLs in cowpea (Vigna unguiculata) consistent across experiments conducted in Burkina Faso, Nigeria, Senegal, and the United States of America under limited water conditions. A panel of 383 diverse cowpea accessions and a recombinant inbred line population (RIL) were SNP genotyped using an Illumina 1536 GoldenGate assay. Phenotypic data from thirteen experiments conducted across the four countries were used to identify SNP-trait associations based on linkage disequilibrium association mapping, with bi-parental QTL mapping as a complementary strategy. We identified seven loci, five of which exhibited evidence suggesting pleiotropic effects (stay-green) between delayed senescence, biomass, and grain yield. Further, we provide evidence suggesting the existence of positive pleiotropy in cowpea based on positively correlated mean phenotypic values (0.34< r <0.87) and allele effects (0.07< r <0.86) for delayed senescence and grain yield across three African environments. Three of the five putative stay-green QTLs, Dro-1, 3, and 7 were identified in both RILs and diverse germplasm with resolutions of 3.2 cM or less for each of the three loci, suggesting that these may be valuable targets for marker-assisted breeding in cowpea. Also, the co-location of early vegetative delayed senescence with biomass and grain yield QTLs suggests the possibility of using delayed senescence at the seedling stage as a rapid screening tool for post-flowering drought tolerance in cowpea breeding. BLAST analysis using EST sequences harboring SNPs with the highest associations provided a genomic context for loci identified in this study in closely related common bean (Phaseolus vulgaris) and soybean (Glycine max) reference genomes.

Correlation Between Mothers' Depression and Developmental Delay in Infants Aged 6-18 Months.

PubMed

Vameghi, Roshanak; Amir Ali Akbari, Sedigheh; Sajjadi, Homeira; Sajedi, Firoozeh; Alavimajd, Hamid

2015-08-23

Regarding the importance of children's developmental status and various factors that delay their development, this study was conducted to examine the correlation between mothers' depression levels and the developmental delay in infants. This descriptive study was performed on 1053 mothers and their infants' age 6 to18 month-old in medical centers affiliated with Shahid Beheshti University of Medical Sciences, Iran, in 2014-2015. The participants were selected through multi-stage random sampling. The following instruments were used in this study: A demographic and obstetric specification questionnaire, infant specification questionnaire, the Beck Depression Inventory, and the Ages and Stages Questionnaire to determine the status of the children's development. The data were analyzed using SPSS19 software, Mann-Whitney; independent T-test and logistic-Regression tests were used. The results showed that 491 mothers (46.7%) suffered mild to extremely severe depression. The delay in infant development was 11.8%. The Mann-Whitney test showed a correlation between mothers' depression levels and developmental delay in infants (P=0.001). Moreover, there was a significant correlation between mothers' depression and developmental delays in gross-motor and problem-solving skills (P<0/05). In logistic model age of infants showed significant correlation with developmental delay (P=0.004 OR=1.07), but unwanted pregnancy, gender of infants, type of delivery and socioeconomic status had no correlation with developmental delay. Given the correlation between mothers' depression and infant development, it is recommended to screen mothers for depression in order to perform early interventions in developmental delay.

[Time perception in depressed and manic patients].

PubMed

Zhao, Qi-yuan; Ji, Yi-fu; Wang, Kai; Zhang, Lei; Liu, Ping; Jiang, Yu-bao

2010-02-02

To investigate the time perception in affective disorders by using neuropsychological tests and to try to elucidate its neurobiochemical mechanism. Using a time reproduction task, a comparative study was conducted for 28 depressive patients, 22 manic patients, and 26 age and education level matched healthy persons as healthy controls. Both depressive patients and manic patients are abnormal (P < 0.001), depressive patients over-reproduced the time interval than healthy controls (600 ms/delay 1 s: 1.6 +/- 0.6, P < 0.001; 600 ms/delay 5 s: 1.7 +/- 0.6, P < 0.001; 3 s/delay 1 s: 3.9 +/- 0.9, P < 0.001; 3 s/delay 5 s: 3.9 +/- 0.7, P < 0.001; 5 s/delay 1 s: 5.9 +/- 1.3, P < 0.001; 5 s/delay 5 s: 6.1 +/- 1.3, P < 0.001), yet manic patients under-reproduced the time interval (600 ms/delay 1 s: 0.7 +/- 0.2, P < 0.01; 600 ms/delay 5 s: 0.6 +/- 0.3, P < 0.001; 3 s/delay 1 s: 1.7 +/- 0.5, P < 0.001; 3 s/delay 5 s: 1.8 +/- 0.6, P < 0.001; 5 s/delay 1 s: 2.9 +/- 0.7, P < 0.001; 5 s/delay 5 s: 3.0 +/- 0.8, P < 0.001). The results of time reproduction task in patients were not related to age, education, duration of illness, number of admission (P > 0.05), but had some relation to severity of illness.And the results were positively correlated with the score of HAMD in depressive patients (six times: r = 0.44, 0.46, 0.73, 0.61, 0.55, 0.50, P < 0.05), but negatively with the score of BRMS in manic patients (six times: r = -0.57, -0.54, -0.71, -0.69, -0.80, -0.71, P < 0.05). Emotion will affect one's time perception. And the neurotransmitter in brain may participate in the processes of time perception.

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

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

Lionello, Roberto; Linker, Jon A.; Mikić, Zoran

The light curves of solar coronal loops often peak first in channels associated with higher temperatures and then in those associated with lower temperatures. The delay times between the different narrowband EUV channels have been measured for many individual loops and recently for every pixel of an active region observation. The time delays between channels for an active region exhibit a wide range of values. The maximum time delay in each channel pair can be quite large, i.e., >5000 s. These large time delays make-up 3%–26% (depending on the channel pair) of the pixels where a trustworthy, positive time delaymore » is measured. It has been suggested that these time delays can be explained by simple impulsive heating, i.e., a short burst of energy that heats the plasma to a high temperature, after which the plasma is allowed to cool through radiation and conduction back to its original state. In this paper, we investigate whether the largest observed time delays can be explained by this hypothesis by simulating a series of coronal loops with different heating rates, loop lengths, abundances, and geometries to determine the range of expected time delays between a set of four EUV channels. We find that impulsive heating cannot address the largest time delays observed in two of the channel pairs and that the majority of the large time delays can only be explained by long, expanding loops with photospheric abundances. Additional observations may rule out these simulations as an explanation for the long time delays. We suggest that either the time delays found in this manner may not be representative of real loop evolution, or that the impulsive heating and cooling scenario may be too simple to explain the observations, and other potential heating scenarios must be explored.« less

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

PubMed

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

2017-09-05

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

The difference of delay time in monitoring system of facial acupressure learning media using bluetooth, wireless and ethernet

NASA Astrophysics Data System (ADS)

Agustin, Eny Widhia; Hangga, Arimaz; Fahrian, Muhammad Iqbal; Azhari, Anis Fikri

2018-03-01

The implementation of monitoring system in the facial acupressure learning media could increase the students' proficiency. However the common learning media still has not implemented a monitoring system in their learning process. This research was conducted to implement monitoring system in the mannequin head prototype as a learning media of facial acupressure using Bluetooth, wireless and Ethernet. The results of the implementation of monitoring system in the prototype showed that there were differences in the delay time between Bluetooth and wireless or Ethernet. The results data showed no difference in the average delay time between the use of Bluetooth with wireless and the use of Bluetooth with Ethernet in monitoring system of facial acupressure learning media. From all the facial acupressure points, the forehead facial acupressure point has the longest delay time of 11.93 seconds. The average delay time in all 3 class rooms was 1.96 seconds therefore the use of Bluetooth, wireless and Ethernet is highly recommended in the monitoring system of facial acupressure.

Timing matters: negative emotion elicited 5 min but not 30 min or 45 min after learning enhances consolidation of internal-monitoring source memory.

PubMed

Wang, Bo; Bukuan, Sun

2015-05-01

Two experiments examined the time-dependent effects of negative emotion on consolidation of item and internal-monitoring source memory. In Experiment 1, participants (n=121) learned a list of words. They were asked to read aloud half of the words and to think about the remaining half. They were instructed to memorize each word and its associative cognitive operation ("reading" versus "thinking"). Immediately following learning they conducted free recall and then watched a 3-min either neutral or negative video clip when 5 min, 30 min or 45 min had elapsed after learning. Twenty-four hours later they returned to take surprise tests for item and source memory. Experiment 2 was similar to Experiment 1 except that participants, without conducting an immediate test of free recall, took tests of source memory for all encoded words both immediately and 24 h after learning. Experiment 1 showed that negative emotion enhanced consolidation of item memory (as measured by retention ratio of free recall) regardless of delay of emotion elicitation and that negative emotion enhanced consolidation of source memory when it was elicited at a 5 min delay but reduced consolidation of source memory when it was elicited at a 30 min delay; when elicited at a 45 min delay, negative emotion had little effect. Furthermore, Experiment 2 replicated the enhancement effect on source memory in the 5 min delay even when participants were tested on all the encoded words. The current study partially replicated prior studies on item memory and extends the literature by providing evidence for a time-dependent effect of negative emotion on consolidation of source memory based on internal monitoring. Copyright © 2015 Elsevier B.V. All rights reserved.

Health care strategies to promote earlier presentation of symptomatic breast cancer: perspectives of women and family physicians

PubMed Central

Heisey, R.; Clemons, M.; Granek, L.; Fergus, K.; Hum, S.; Lord, B.; McCready, D.R.; Fitzgerald, B.

2011-01-01

Background Many women with symptoms suggestive of a breast cancer diagnosis delay presentation to their family physician. Although factors associated with delay have been well described, there is a paucity of data on strategies to mitigate delay. Objectives We conducted a qualitative research project to examine factors related to delay and to identify health care system changes that might encourage earlier presentation. Methods Individual semi-structured interviews were conducted with women who sought care 12 weeks or more after self-detection of breast cancer symptoms and with family physicians whose practices included patients meeting that criterion. Results The women and physicians both suggested a need for clearer screening mammography guidelines for women 40–49 years of age and for better messaging concerning breast awareness. The use of additional hopeful testimonials from breast cancer survivors were suggested to help dispel the notion of cancer as a “death sentence.” Educational initiatives were proposed, aimed at both increasing awareness of “non-lump” breast cancer symptoms and advising women that a previous benign diagnosis does not ensure that future symptoms are not cancer. Women wanted empathic nonjudgmental access to care. Improved methods to track compliance with screening mammography and with periodic health exams and access to a rapid diagnostic process were suggested. Conclusions A list of “at-risk situations for delay” in diagnosis of breast cancer was developed for physicians to assist in identifying women who might delay. Health care system changes actionable both at the health policy level and in the family physician’s office were identified to encourage earlier presentation of women with symptomatic breast cancer. PMID:21980254

Surface acoustic wave devices as passive buried sensors

NASA Astrophysics Data System (ADS)

Friedt, J.-M.; Rétornaz, T.; Alzuaga, S.; Baron, T.; Martin, G.; Laroche, T.; Ballandras, S.; Griselin, M.; Simonnet, J.-P.

2011-02-01

Surface acoustic wave (SAW) devices are currently used as passive remote-controlled sensors for measuring various physical quantities through a wireless link. Among the two main classes of designs—resonator and delay line—the former has the advantage of providing narrow-band spectrum informations and hence appears compatible with an interrogation strategy complying with Industry-Scientific-Medical regulations in radio-frequency (rf) bands centered around 434, 866, or 915 MHz. Delay-line based sensors require larger bandwidths as they consists of a few interdigitated electrodes excited by short rf pulses with large instantaneous energy and short response delays but is compatible with existing equipment such as ground penetrating radar (GPR). We here demonstrate the measurement of temperature using the two configurations, particularly for long term monitoring using sensors buried in soil. Although we have demonstrated long term stability and robustness of packaged resonators and signal to noise ratio compatible with the expected application, the interrogation range (maximum 80 cm) is insufficient for most geology or geophysical purposes. We then focus on the use of delay lines, as the corresponding interrogation method is similar to the one used by GPR which allows for rf penetration distances ranging from a few meters to tens of meters and which operates in the lower rf range, depending on soil water content, permittivity, and conductivity. Assuming propagation losses in a pure dielectric medium with negligible conductivity (snow or ice), an interrogation distance of about 40 m is predicted, which overcomes the observed limits met when using interrogation methods specifically developed for wireless SAW sensors, and could partly comply with the above-mentioned applications. Although quite optimistic, this estimate is consistent with the signal to noise ratio observed during an experimental demonstration of the interrogation of a delay line buried at a depth of 5 m in snow.

The Efficacy of Parent Counseling and Support Groups on the Stress Levels, Self-Esteem and Degree of Coping of Parents of Developmentally Delayed or Handicapped Children Who Are Involved in an Infant Intervention Program.

ERIC Educational Resources Information Center

La Fountain, Rebecca; Geoffroy, Kevin

This study was conducted to investigate the effect that a parent support group and a counseling group had on the stress levels, self-esteem, and degree of coping of parents (N=48) of developmentally delayed or handicapped infants enrolled in an infant intervention program. It was hypothesized that, compared to parents in the control group, parents…

Analysis and correction of ground reflection effects in measured narrowband sound spectra using cepstral techniques

NASA Technical Reports Server (NTRS)

Miles, J. H.; Stevens, G. H.; Leininger, G. G.

1975-01-01

Ground reflections generate undesirable effects on acoustic measurements such as those conducted outdoors for jet noise research, aircraft certification, and motor vehicle regulation. Cepstral techniques developed in speech processing are adapted to identify echo delay time and to correct for ground reflection effects. A sample result is presented using an actual narrowband sound pressure level spectrum. The technique can readily be adapted to existing fast Fourier transform type spectrum measurement instrumentation to provide field measurements/of echo time delays.

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

PubMed

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

2017-06-19

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

The Role of Influenza in the Delay between Low Temperature and Ischemic Heart Disease: Evidence from Simulation and Mortality Data from Japan

PubMed Central

Imai, Chisato; Barnett, Adrian G.; Hashizume, Masahiro; Honda, Yasushi

2016-01-01

Many studies have found that cardiovascular deaths mostly occur within a few days of exposure to heat, whereas cold-related deaths can occur up to 30 days after exposure. We investigated whether influenza infection could explain the delayed cold effects on ischemic heart diseases (IHD) as they can trigger IHD. We hypothesized two pathways between cold exposure and IHD: a direct pathway and an indirect pathway through influenza infection. We created a multi-state model of the pathways and simulated incidence data to examine the observed delayed patterns in cases. We conducted cross-correlation and time series analysis with Japanese daily pneumonia and influenza (P&I) mortality data to help validate our model. Simulations showed the IHD incidence through the direct pathway occurred mostly within 10 days, while IHD through influenza infection peaked at 4–6 days, followed by delayed incidences of up to 20–30 days. In the mortality data from Japan, P&I lagged IHD in cross-correlations. Time series analysis showed strong delayed cold effects in the older population. There was also a strong delay on intense days of influenza which was more noticeable in the older population. Influenza can therefore be a plausible explanation for the delayed association between cold exposure and cardiovascular mortality. PMID:27136571

Timeliness and completeness of vaccination and risk factors for low and late vaccine uptake in young children living in rural southern Tanzania.

PubMed

Le Polain de Waroux, Olivier; Schellenberg, Joanna R Armstrong; Manzi, Fatuma; Mrisho, Mwifadhi; Shirima, Kizito; Mshinda, Hassan; Alonso, Pedro; Tanner, Marcel; Schellenberg, David M

2013-06-01

We studied coverage and timeliness of vaccination and risk factors for low and delayed vaccine uptake in children aged <2 years in rural Tanzania. We used data from a cluster survey conducted in 2004, which included 1403 children. Risk factors were analysed by log-binomial regression adjusted for the clustering. The analysis was restricted to BCG, first and third dose of Diphtheria-Tetanus-Pertussis vaccines (DTP-1 and DTP-3) and first dose of measles-containing vaccine (MCV-1). Coverage for BCG, DTP-1, DTP-3 and MCV-1 was 94%, 96%, 90% and 86%, respectively. Delayed vaccination (>1 month after the recommended age) occurred in 398/1205 (33%) children for BCG, 404/1189 (34%) for DTP-1, 683/990 (69%) for DTP-3 and 296/643 (46%) for MCV-1. Coverage was lower for all vaccines except DTP-1 in children living ≥5 km from a healthcare facility. Delayed uptake was associated with poverty. Low and delayed MCV-1 vaccination was associated with low maternal education. Delayed BCG vaccination was associated with ethnicity and rainy season. Despite reasonably high vaccination coverage, we observed substantial vaccination delays, particularly for DTP-3 and MCV-1. We found specific factors associated with low and/or delayed vaccine uptake. These findings can help to improve strategies to reach children who remain inadequately protected.

Autonomous Mission Operations

NASA Technical Reports Server (NTRS)

Frank, Jeremy; Spirkovska, Lilijana; McCann, Rob; Wang, Lui; Pohlkamp, Kara; Morin, Lee

2012-01-01

NASA's Advanced Exploration Systems Autonomous Mission Operations (AMO) project conducted an empirical investigation of the impact of time-delay on todays mission operations, and of the effect of processes and mission support tools designed to mitigate time-delay related impacts. Mission operation scenarios were designed for NASA's Deep Space Habitat (DSH), an analog spacecraft habitat, covering a range of activities including nominal objectives, DSH system failures, and crew medical emergencies. The scenarios were simulated at time-delay values representative of Lunar (1.2-5 sec), Near Earth Object (NEO) (50 sec) and Mars (300 sec) missions. Each combination of operational scenario and time-delay was tested in a Baseline configuration, designed to reflect present-day operations of the International Space Station, and a Mitigation configuration in which a variety of software tools, information displays, and crew-ground communications protocols were employed to assist both crews and Flight Control Team (FCT) members with the long-delay conditions. Preliminary findings indicate: 1) Workload of both crew members and FCT members generally increased along with increasing time delay. 2) Advanced procedure execution viewers, caution and warning tools, and communications protocols such as text messaging decreased the workload of both flight controllers and crew, and decreased the difficulty of coordinating activities. 3) Whereas crew workload ratings increased between 50 sec and 300 sec of time-delay in the Baseline configuration, workload ratings decreased (or remained flat) in the Mitigation configuration.

Investigating the Role of Interventricular Interdependence in Development of Right Heart Dysfunction During LVAD Support: A Patient-Specific Methods-Based Approach.

PubMed

Sack, Kevin L; Dabiri, Yaghoub; Franz, Thomas; Solomon, Scott D; Burkhoff, Daniel; Guccione, Julius M

2018-01-01

Predictive computation models offer the potential to uncover the mechanisms of treatments whose actions cannot be easily determined by experimental or imaging techniques. This is particularly relevant for investigating left ventricular mechanical assistance, a therapy for end-stage heart failure, which is increasingly used as more than just a bridge-to-transplant therapy. The high incidence of right ventricular failure following left ventricular assistance reflects an undesired consequence of treatment, which has been hypothesized to be related to the mechanical interdependence between the two ventricles. To investigate the implication of this interdependence specifically in the setting of left ventricular assistance device (LVAD) support, we introduce a patient-specific finite-element model of dilated chronic heart failure. The model geometry and material parameters were calibrated using patient-specific clinical data, producing a mechanical surrogate of the failing in vivo heart that models its dynamic strain and stress throughout the cardiac cycle. The model of the heart was coupled to lumped-parameter circulatory systems to simulate realistic ventricular loading conditions. Finally, the impact of ventricular assistance was investigated by incorporating a pump with pressure-flow characteristics of an LVAD (HeartMate II™ operating between 8 and 12 k RPM) in parallel to the left ventricle. This allowed us to investigate the mechanical impact of acute left ventricular assistance at multiple operating-speeds on right ventricular mechanics and septal wall motion. Our findings show that left ventricular assistance reduces myofiber stress in the left ventricle and, to a lesser extent, right ventricle free wall, while increasing leftward septal-shift with increased operating-speeds. These effects were achieved with secondary, potentially negative effects on the interventricular septum which showed that support from LVADs, introduces unnatural bending of the septum and with it, increased localized stress regions. Left ventricular assistance unloads the left ventricle significantly and shifts the right ventricular pressure-volume-loop toward larger volumes and higher pressures; a consequence of left-to-right ventricular interactions and a leftward septal shift. The methods and results described in the present study are a meaningful advancement of computational efforts to investigate heart-failure therapies in silico and illustrate the potential of computational models to aid understanding of complex mechanical and hemodynamic effects of new therapies.

Pregestational type 2 diabetes mellitus induces cardiac hypertrophy in the murine embryo through cardiac remodeling and fibrosis.

PubMed

Lin, Xue; Yang, Penghua; Reece, E Albert; Yang, Peixin

2017-08-01

Cardiac hypertrophy is highly prevalent in patients with type 2 diabetes mellitus. Experimental evidence has implied that pregnant women with type 2 diabetes mellitus and their children are at an increased risk of cardiovascular diseases. Our previous mouse model study revealed that maternal type 2 diabetes mellitus induces structural heart defects in their offspring. This study aims to determine whether maternal type 2 diabetes mellitus induces embryonic heart hypertrophy in a murine model of diabetic embryopathy. The type 2 diabetes mellitus embryopathy model was established by feeding 4-week-old female C57BL/6J mice with a high-fat diet for 15 weeks. Cardiac hypertrophy in embryos at embryonic day 17.5 was characterized by measuring heart size and thickness of the right and left ventricle walls and the interventricular septum, as well as the expression of β-myosin heavy chain, atrial natriuretic peptide, insulin-like growth factor-1, desmin, and adrenomedullin. Cardiac remodeling was determined by collagen synthesis and fibronectin synthesis. Fibrosis was evaluated by Masson staining and determining the expression of connective tissue growth factor, osteopontin, and galectin-3 genes. Cell apoptosis also was measured in the developing heart. The thicknesses of the left ventricle walls and the interventricular septum of embryonic hearts exposed to maternal diabetes were significantly thicker than those in the nondiabetic group. Maternal diabetes significantly increased β-myosin heavy chain, atrial natriuretic peptide, insulin-like growth factor-1, and desmin expression, but decreased expression of adrenomedullin. Moreover, collagen synthesis was significantly elevated, whereas fibronectin synthesis was suppressed, in embryonic hearts from diabetic dams, suggesting that cardiac remodeling is a contributing factor to cardiac hypertrophy. The cardiac fibrosis marker, galectin-3, was induced by maternal diabetes. Furthermore, maternal type 2 diabetes mellitus activated the proapoptotic c-Jun-N-terminal kinase 1/2 stress signaling and triggered cell apoptosis by increasing the number of terminal deoxynucleotidyl transferase 2'-deoxyuridine 5'-triphosphate nick end labeling-positive cells (10.4 ± 2.2% of the type 2 diabetes mellitus group vs 3.8 ± 0.7% of the nondiabetic group, P < .05). Maternal type 2 diabetes mellitus induces cardiac hypertrophy in embryonic hearts. Adverse cardiac remodeling, including elevated collagen synthesis, suppressed fibronectin synthesis, profibrosis, and apoptosis, is implicated as the etiology of cardiac hypertrophy. Copyright © 2017 Elsevier Inc. All rights reserved.

[Myocardial bridge as the only cause of acute coronary syndrome among the young patients].

PubMed

Miakinkova, Liudmila O; Teslenko, Yurii V; Tsyhanenko, Irina V

2018-01-01

Introduction: Myocardial bridge is an inborn anomaly of coronary artery development, when a part of it is submerged in a myocard, which is pressing the coronary artery to a systola and restrains coronary blood circulation. Generally this feature of coronary blood circulation does not cause any clinical symptoms because the 85% of coronary blood stream of the left ventricle is provided by diastolic filling. Hemodynamic changes in atherosclerosis, tahicardie, hypertrophie of myocard are leading to the manifestation of clinical symptoms of ischemia. The aim: The purpose of the investigation was to discover the features of clinical development of acute coronary syndrome caused by myocardial bridge of young patients without the features of atherosclerotical harm of coronary arteries. Materials and methods: Eight causes of acute coronary syndrome among patients of 28±8,5 years with myocardial bridge which was revealed during coronary angiography, were investigated. Standardized examination and conservative treatment of patients was held, except for three who have got interventional therapy. Results: According to our investigation, myocardial bridge of all investigated patients was located in the middle of the third front interventricular branch of the left coronary artery. Causes of acute coronary syndrome manifestation were tahicardia, spasms of coronary artery, inducted by iatrogenic factors hypertrophie of myocard, hypertrophic cardiomyopatie. Connection between the manifestation of clinical symptoms and length of tunneled segment which did not depend on the level of systolic compres was discovered. The results of conservative and interventional treatment were analyzed. Conclusions: Myocardial bridge can be the cause of myocardial ischemia among patients without signs of coronary atherosclerosis with additional hemodynamic risk facts such as tahicardia, spasms of coronary artery, hypertrophie of myocard. Clinical symptomatology of the acute coronary syndrome is more often observed among patients who's myocsrdial bridge is located in the middle of the third front interventricular branch of the left coronary artery. This is caused by perpendicular location of muscle fibers to coronary artery that increases systolic compression. Diastolic function and blood filling of coronary artery can be improved due to the medication beta-blockers therapy of patients with symptomatic myocardial bridge. A higher risk of appearance of restenosis of the stent is possible due to interventional treatment of young patients with myocardial bridge without atherosclerosis of coronary arteries.

Troponin T and NT ProBNP Levels in Gestational, Type 1 and Type 2 Diabetic Mothers and Macrosomic Infants.

PubMed

Mert, Mustafa Kurthan; Satar, Mehmet; Özbarlas, Nazan; Yaman, Akgün; Özgünen, Fatma Tuncay; Asker, Hüseyin Selim; Çekinmez, Eren Kale; Tetiker, Tamer

2016-01-01

This study compares NT proBNP and troponin T levels in umbilical cord arterial blood and postnatal echocardiographic findings for infants of gestational and pregestational diabetic mothers and macrosomic infants. Twenty-seven infants of pregestational diabetic mothers, 61 infants of gestational diabetic mothers and 37 macrosomic infants of nondiabetic mothers were prospectively enrolled in this study along with a control group of 58 healthy infants of mothers without any pregestational or gestational disorders as the control group. All enrollees were born after 34 weeks of gestation. For this study, umbilical cord blood was drawn during delivery to determine NT proBNP and troponin T levels. Echocardiography was performed 24-72 h after the delivery. Umbilical cord troponin T and NT proBNP levels were found to be higher in the diabetic and macrosomic groups than in the control group (all of them p < 0.001). NT proBNP levels were positively correlated with interventricular septum thickness in the pregestational and gestational infants of diabetic mothers groups (r = 0.564 and r = 0.560, respectively, p < 0.01). Both pregestational and gestational diabetic mothers were divided into two groups according to HbA1c levels in the third trimester as good (<6.1 %) and suboptimal (>6.1 %) metabolic control. In the good and suboptimal metabolic control diabetic groups, NT proBNP levels were also positively correlated with interventricular septum thickness (r = 0.536 and r = 0.576, respectively, p < 0.01). In the suboptimal metabolic control diabetic group, NT proBNP was only found to be positively correlated with the left ventricular mass index (r = 0.586, p < 0.01). While there was no correlation in the myocardial performance index between infants of diabetic mothers and the control group, the myocardial performance index of macrosomic infants was lower than that of the control group (p = 0.017). Cardiac biomarkers (NT proBNP and troponin T) were elevated in infants of diabetic mothers and macrosomic infants. While there was a positive correlation between NT proBNP levels and cardiac structure in infants of pregestational and gestational diabetic mothers, there was no relationship between NT proBNP levels and cardiac function.

A Study of Commuters’ Decision-Making When Delaying Departure for Work-Home Trips

NASA Astrophysics Data System (ADS)

Que, Fangjie; Wang, Wei

2017-12-01

Studies on the travel behaviors and patterns of residents are important to the arrangement of urban layouts and urban traffic planning. However, research on the characteristics of the decision-making behavior regarding departure time is not fully expanded yet. In this paper, the research focuses on commuters’ decision-making behavior regarding departure delay. According to the 2013 travel survey data of Suzhou City, a nested logit (NL) model was built to represent the probabilities of individual choices. Parameter calibration was conducted, so that the significant factors influencing the departure delay were obtained. Ultimately, the results of the NL model indicated that it performed better and with higher precision, compared to the traditional multinomial logit (MNL) model.

Second-Degree Interatrial Block in Hemodialysis Patients

PubMed Central

Enriquez, Andres; D'Amato, Anna; de Luna, Antoni Bayes; Baranchuk, Adrian

2015-01-01

Interatrial conduction delays manifest as a prolonged P-wave duration on surface ECG and the term interatrial block (IAB) has been coined. They are usually fixed, but cases of intermittent IAB have been described, suggesting functional conduction block at the Bachmann bundle region. We report 2 cases of patients on chronic hemodialysis therapy presenting with intermittent IAB. PMID:25755895

The Long-Term Effects of Functional Communication Training Conducted in Young Children's Home Settings

ERIC Educational Resources Information Center

Wacker, David P.; Schieltz, Kelly M.; Berg, Wendy K.; Harding, Jay W.; Padilla Dalmau, Yaniz C.; Lee, John F.

2017-01-01

This article describes the results of a series of studies that involved functional communication training (FCT) conducted in children's homes by their parents. The 103 children who participated were six years old or younger, had developmental delays, and engaged in destructive behaviors such as self-injury. The core procedures used in each study…

[Evaluation of the effect of varicella outbreak control measures through a discrete time delay SEIR model].

PubMed

Pan, Jin-ren; Huang, Zheng-qiang; Chen, Kun

2012-04-01

forecast the epidemic trend and to evaluate the effect of outbreak control measures by investigation of a varicella outbreak event with a discrete time delay SEIR model. A discrete time delay model was formulated by discretization method based on a continuous SEIR model with the consideration of the time delay effect on latent period and communicable period. The epidemic trend forecast was carried out based on the number of expected cases. The theoretical effect evaluation was assessed by comparing the results from different emergency control measures. Without any control measures, the theoretical attack rate was 30.16% (504/1671). The course of the epidemic lasted for 4 months and the peak epidemic time was 78 days after the onset of the first case. 'Generation' phenomenon had been observed in the course of the epidemic with the interval of two weeks. The actual number of cases was decreased by 89.48% (451/504) compared with the number of expected cases under no control measure scenario. With the rigorous quarantine measure for all cases on their onset day, when the measure was conducted on 0, 14, 28, 42 days after the onset of the first case, the total numbers of expected cases were 22, 59, 127 and 220 respectively. With the quarantine measure conducted on 14 days after the onset of the first case, when the proportion of quarantine was 30%, 50%, 70%, 90%, the total number of expected cases were 485, 457, 386 and 169, respectively. With the emergent vaccination for all persons, when the measure was conducted on 0, 14, 28, 42 days after the onset of the first case, the total numbers of expected cases were 7, 26, 81 and 202 respectively. With the emergent vaccination conducted on 14 days after the onset of the first case, when the immunization coverage rate was 30%, 50%, 70%, 90%, the total numbers of expected cases were 354, 246, 127 and 40, respectively. The number of expected cases can be regarded as the reference to evaluate the effect of control measures. The simulation results suggest that it will get more benefits to conduct control measures earlier in varicella outbreak events, and the effect of emergent vaccination is better than that of quarantine measure under the same conditions.

Reward type and behavioural patterns predict dogs’ success in a delay of gratification paradigm

PubMed Central

Brucks, Désirée; Soliani, Matteo; Range, Friederike; Marshall-Pescini, Sarah

2017-01-01

Inhibiting an immediate behaviour in favour of an alternative but more advantageous behaviour has been linked to individual success in life, especially in humans. Dogs, which have been living in the human environment for thousands of years, are exposed to daily situations that require inhibition different in context from other non-domesticated species. One task regularly used to study inhibitory control is the delay of gratification task, which requires individuals to choose between an immediate option of lower value and a delayed option of higher value. We tested sixteen dogs in a non-social delay of gratification task, conducting two different conditions: a quality and a quantity condition. While the majority of dogs failed to wait for more than 10 s, some dogs tolerated delays of up to 140 s, while one dog waited for 15 minutes. Moreover, dogs had more difficulties to wait if the reward increased in terms of quantity than quality. Interestingly, dogs were able to anticipate the delay duration and some dogs developed behavioural patterns that predicted waiting, which seems similar in some respects to ‘coping-strategies’ found in children, chimpanzees and parrots. Our results indicate that strategies to cope with impulsivity seem to be consistent and present across animal taxa. PMID:28272409

Mitigating delay and non-payment in the Malaysian construction industry

NASA Astrophysics Data System (ADS)

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

2018-02-01

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

Using theory to explore facilitators and barriers to delayed prescribing in Australia: a qualitative study using the Theoretical Domains Framework and the Behaviour Change Wheel.

PubMed

Sargent, Lucy; McCullough, Amanda; Del Mar, Chris; Lowe, John

2017-02-13

Delayed antibiotic prescribing reduces antibiotic use for acute respiratory infections in trials in general practice, but the uptake in clinical practice is low. The aim of the study was to identify facilitators and barriers to general practitioners' (GPs') use of delayed prescribing and to gain pharmacists' and the public's views about delayed prescribing in Australia. This study used the Theoretical Domains Framework and the Behaviour Change Wheel to explore facilitators and barriers to delayed prescribing in Australia. Forty-three semi-structured, face-to-face interviews with general practitioners, pharmacists and patients were conducted. Responses were coded into domains of the Theoretical Domains Framework, and specific criteria from the Behaviour Change Wheel were used to identify which domains were relevant to increasing the use of delayed prescribing by GPs. The interviews revealed nine key domains that influence GPs' use of delayed prescribing: knowledge; cognitive and interpersonal skills; memory, attention and decision-making processes; optimism; beliefs about consequences; intentions; goals; emotion; and social influences: GPs knew about delayed prescribing; however, they did not use it consistently, preferring to bring patients back for review and only using it with patients in a highly selective way. Pharmacists would support GPs and the public in delayed prescribing but would fill the prescription if people insisted. The public said they would delay taking their antibiotics if asked by their GP and given the right information on managing symptoms and when to take antibiotics. Using a theory-driven approach, we identified nine key domains that influence GPs' willingness to provide a delayed prescription to patients with an acute respiratory infection presenting to general practice. These data can be used to develop a structured intervention to change this behaviour and thus reduce antibiotic use for acute respiratory infections in general practice.

Effects of overweight and obesity on motor and mental development in infants and toddlers.

PubMed

Cataldo, R; Huang, J; Calixte, R; Wong, A T; Bianchi-Hayes, J; Pati, S

2016-10-01

A consequence of childhood obesity may be poor developmental outcomes. This study aimed to examine the relationship between weight and developmental delays in young children. We conducted a secondary analysis of the Early Childhood Longitudinal Study Birth Cohort data. Logistic regression models quantified the association between different weight statuses (normal weight <85th, overweight ≥90th, obese ≥95th percentile for weight) and delays in motor and mental development. Children classified as overweight in both waves had higher percentages of delays in wave 2 (motor [7.5 vs. 6.2-6.4%], mental [8.6 vs. 5.9-6.7%]), as well as wave 1 and/or wave 2 (motor [14.8 vs. 10.9-13.0%], mental [11.9 vs. 9.0-10.1%]), compared with other children. This association was also found in children who were obese at both time points in wave 2 (motor delay [8.9 vs. 4.9-7.3%], mental delay [10.3 vs. 6.0-7.2%]), as well as wave 1 and/or wave 2 (motor delay [14.5 vs. 10.9-12.9%], mental delay [14.1 vs. 9.4-10.1%]). In the adjusted models, children classified as always obese were more likely to have a mental delay in wave 2 (adjusted odds ratio [aOR] 1.89, 95% confidence interval [CI]: 1.21-2.95) as well as wave 1 and/or wave 2 (aOR 1.56, 95% CI: 1.08-2.26). These children were also more likely to have motor delay (aOR 1.47, 95% CI: 1.02-2.13) in wave 1 and/or wave 2. Overweight children are more likely than their normal-weight peers to have motor and mental developmental delays. Preventing obesity during infancy may facilitate reducing developmental delays in young children. © 2015 World Obesity.

Why the Wait? Delayed HIV Diagnosis among Men Who Have Sex with Men

PubMed Central

Thiede, Hanne; Hawes, Stephen E.; Golden, Matthew R.; Hutcheson, Rebecca; Carey, James W.; Kurth, Ann; Jenkins, Richard A.

2010-01-01

We sought to identify factors associated with delayed diagnosis of human immunodeficiency virus (HIV; testing HIV-seropositive 6 months or more after HIV seroconversion), by comparing delayed testers to non-delayed testers (persons who were diagnosed within 6 months of HIV seroconversion), in King County, Washington among men who have sex with men (MSM). Participants were recruited from HIV testing sites in the Seattle area. Delayed testing status was determined by the Serologic Testing Algorithm for Recent HIV Seroconversion or a self-reported previous HIV-negative test. Quantitative data on sociodemographic characteristics, health history, and drug-use and sexual behaviors were collected via computer-assisted self-interviews. Qualitative semi-structured interviews regarding testing and risk behaviors were also conducted. Multivariate analysis was used to identify factors associated with delayed diagnosis. Content analysis was used to establish themes in the qualitative data. Out of the 77 HIV-seropositive MSM in this sample, 39 (51%) had evidence of delayed diagnosis. Factors associated with delayed testing included being African-American, homeless, “out” to 50% or less people about male-male sex, and having only one sex partner in the past 6 months. Delayed testers often cited HIV-related sickness as their reason for testing and fear and wanting to be in denial of their HIV status as reasons for not testing. Delayed testers frequently did not identify as part of the MSM community, did not recognize that they were at risk for HIV acquisition, and did not feel a responsibility to themselves or others to disclose their HIV status. This study illustrates the need to further explore circumstances around delayed diagnosis in MSM and develop outreach methods and prevention messages targeted specifically to this potentially highly marginalized population in order to detect HIV infections earlier, provide HIV care, and prevent new infections. PMID:20186493

[Determinants of patient and health system delays for women with breast cancer in Morocco, 2013].

PubMed

Benbakhta, B; Tazi, M; Benjaafar, N; Khattabi, A; Maaroufi, A

2015-06-01

In Morocco, breast cancer is the first most common cancer in women. It is diagnosed in most cases at an advanced stage. Delay in diagnosis and access to treatment for breast cancer increases morbidity and mortality. The objective of this study was to determine the consultation delay (patient delay), diagnosis delay and access to treatment delay (health system delays) of women with breast cancer admitted at the National Institute of Oncology in Rabat. Factors associated with these delays were analyzed. We conducted a cross-sectional study from December 2012 to May 2013 at the National Institute of Oncology in Rabat. Two hundred eligible and consenting women were interviewed using a structured and pre-tested questionnaire. Stages I and II were identified as "early stages" and III and IV as "advanced stages". In our population, 54% were diagnosed at an early stage of breast cancer and 46% at an advanced stage. The median total delay was 120 days (interquartile interval [IIQ]=81-202 days). The patient delay (median=65 days, IIQ=31-121) was longer than the health system delay (median=50 days, IIQ=29-77). High risk for a long total delay (more than 4 months) was observed for women who were aged over 65 years (OR=1.30, 95% CI 1.10-4.20), illiterate (OR=4.50, 95% CI 2.10-6.20), rural residents (OR=3.40, 95% CI 1.23-8.13), in a lower socioeconomic category (OR=4.75, 95% CI 1.45-15.60), without knowledge about breast self-examination (OR=5.67, 95% CI 2.65-12.15) and seen more than 2 times before diagnosis (OR=7.70, 95% CI 2.88-20.50). A long total delay increased the risk of being diagnosed at an advanced stage (OR=5.62, 95% CI 3.03-10.45). Efforts should be directed to providing good information to the population at risk, better access to screening and continuing medical training to enable diagnosis and early treatment. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

AdVEGF-All6A+ Preconditioning of Murine Ischemic Skin Flaps Is Comparable to Surgical Delay.

PubMed

Gersch, Robert P; Fourman, Mitchell S; Phillips, Brett T; Nasser, Ahmed; McClain, Steve A; Khan, Sami U; Dagum, Alexander B; Bui, Duc T

2015-08-01

Surgical flap delay is commonly used in preconditioning reconstructive flaps to prevent necrosis. However, staged procedures are not ideal. Pharmacologic up-regulation of angiogenic and arteriogenic factors before flap elevation poses a nonsurgical approach to improve flap survival. Male Sprague Dawley rats were divided into control (n = 16), surgical delay (Delay), AdNull, AdEgr-1, and AdVEGF (n ≥ 9/group) groups. Delay rats had a 9 cm × 3 cm cranial based pedicle skin flap incised 10 days prior to elevation. Adenoviral groups received 28 intradermal injections (10(9) pu/animal total) throughout the distal two thirds of the flap 1 week prior to elevation. At postoperative day (POD) 0 flaps were elevated and silicone sheeting was placed between flap and wound bed. Perfusion analysis in arbitrary perfusion units of the ischemic middle third of the flap using laser Doppler imaging was conducted preoperatively and on POD 0, 3, and 7. Clinical and histopathologic assessments of the skin flaps were performed on POD 7. AdVEGF (50.8 ± 10.9 APU) and AdEgr-1 (39.3 ± 10.6 APU) perfusion levels were significantly higher than controls (16.5 ± 4.2 APU) on POD 7. Delay models were equivalent to controls (25.9 ± 6.8 APU). AdVEGF and Delay animals showed significantly more viable surface area on POD 7 (14.4 ± 1.3 cm(2), P < 0.01 and 12.4 ± 1.2 cm(2), P < 0.05, respectively) compared with Controls (8.7 ± 0.7 cm(2)). AdVEGF preconditioning resulted in flap survival comparable to surgical delay. Adenoviral preconditioning maintained perfusion levels postoperatively while surgical delay did not.

AdVEGF-All6A+ Preconditioning of Murine Ischemic Skin Flaps Is Comparable to Surgical Delay

PubMed Central

Gersch, Robert P.; Fourman, Mitchell S.; Phillips, Brett T.; Nasser, Ahmed; McClain, Steve A.; Khan, Sami U.; Dagum, Alexander B.

2015-01-01

Background: Surgical flap delay is commonly used in preconditioning reconstructive flaps to prevent necrosis. However, staged procedures are not ideal. Pharmacologic up-regulation of angiogenic and arteriogenic factors before flap elevation poses a nonsurgical approach to improve flap survival. Methods: Male Sprague Dawley rats were divided into control (n = 16), surgical delay (Delay), AdNull, AdEgr-1, and AdVEGF (n ≥ 9/group) groups. Delay rats had a 9 cm × 3 cm cranial based pedicle skin flap incised 10 days prior to elevation. Adenoviral groups received 28 intradermal injections (109 pu/animal total) throughout the distal two thirds of the flap 1 week prior to elevation. At postoperative day (POD) 0 flaps were elevated and silicone sheeting was placed between flap and wound bed. Perfusion analysis in arbitrary perfusion units of the ischemic middle third of the flap using laser Doppler imaging was conducted preoperatively and on POD 0, 3, and 7. Clinical and histopathologic assessments of the skin flaps were performed on POD 7. Results: AdVEGF (50.8 ± 10.9 APU) and AdEgr-1 (39.3 ± 10.6 APU) perfusion levels were significantly higher than controls (16.5 ± 4.2 APU) on POD 7. Delay models were equivalent to controls (25.9 ± 6.8 APU). AdVEGF and Delay animals showed significantly more viable surface area on POD 7 (14.4 ± 1.3 cm2, P < 0.01 and 12.4 ± 1.2 cm2, P < 0.05, respectively) compared with Controls (8.7 ± 0.7 cm2). Conclusions: AdVEGF preconditioning resulted in flap survival comparable to surgical delay. Adenoviral preconditioning maintained perfusion levels postoperatively while surgical delay did not. PMID:26495207

Early Compared With Delayed Physician Rounds on Patient Satisfaction of Postpartum Women: A Randomized Controlled Trial.

PubMed

Roberts, Robyn P; Blackwell, Sean C; Brown, Kelly M; Pedroza, Claudia; Sibai, Baha M; Tyson, Jon E

2016-08-01

To investigate whether delayed timing of physician rounds improves patient satisfaction for postpartum women. Women were randomized to early (5-7 AM) or delayed (8-10 AM) physician rounding. Women with stillbirth, high-risk pregnancy, or complications precluding delayed rounding were excluded. At discharge, women completed a modified Hospital Consumer Assessment of Healthcare Providers and Systems survey. The primary outcome was rating of the hospital. Secondary outcomes included patient assessment of patient-physician communication, various hospital experiences, and timing of maternal and neonatal discharge. We estimated that 74 women were needed to detect a 20% difference in rating of the hospital (0-10 score) between groups (assumption P=.05, power 90%). Given limited information on primary outcome, an a priori plan was in place to conduct the study for 2 months. One hundred fifty-two women were randomized (n=76 early rounding; n=76 delayed rounding). More women had a cesarean delivery in the early compared with the delayed rounding group (47.4% compared with 22.4%). Median rating of the hospital was higher in the delayed as compared with the early rounding group (9.0 [7.0-9.0] compared with 7.0 [6.0-8.0]; P<.01). Median scores regarding physician communication and perception of hospital experiences were higher in the delayed compared with the early group (8.0 [7.0-9.0] compared with 6.0 [5.0-7.0]; P<.001). Adjustment for delivery mode did not alter results (P<.01). No differences in timing of maternal (P=.47) or neonatal hospital discharge (P=.35) were observed. Postpartum women receiving delayed physician rounding were more satisfied with their hospital experience and patient-physician communication without prolonging maternal or neonatal discharge. ClinicalTrials.gov, https://clinicaltrials.gov, NCT02432573.

Prevalence and reasons for delaying and foregoing necessary care by the presence and type of disability among working-age adults.

PubMed

Reichard, Amanda; Stransky, Michelle; Phillips, Kimberly; McClain, Monica; Drum, Charles

2017-01-01

While it is commonly accepted that disparities in unmet need for care vary by age, race/ethnicity, income, education, and access to care, literature documenting unmet needs experienced by adults with different types of disabilities is developing. The main objective was to determine whether subgroups of people with disabilities are more likely than people without disabilities to delay/forgo necessary care, in general and among the insured. We used pooled Medical Expenditure Panel Survey data (2004-2010) to examine delaying or forgoing medical, dental, and pharmacy care among five disability subgroups (physical, cognitive, visual, hearing, multiple) and the non-disabled population. Logistic regression was conducted to examine delayed/forgone care, controlling for sociodemographic, health, and health care factors. Over 13% of all working-age adults delayed/forwent necessary care; lack of insurance was the strongest predictor of unmet needs. Among the insured, disability subgroups were greater than two times more likely to report delayed/forgone care than adults without disabilities. Insured working-age adults with multiple chronic conditions and those with ADL/IADL assistance needs had higher odds of delayed or forgone care than their peers without these characteristics. Reasons related to affordability were most often listed as leading to unmet needs, regardless of disability. Although insurance status most strongly predicted unmet needs for care, many people with insurance delayed/forewent necessary care. Even among the insured, all disability subgroups had significantly greater likelihood of having to delay/forgo care than those without disabilities. Differences also existed between the disability subgroups. Cost was most frequently cited reason for unmet needs. Published by Elsevier Inc.

Predictors of avoiding medical care and reasons for avoidance behavior.

PubMed

Kannan, Viji Diane; Veazie, Peter J

2014-04-01

Delayed medical care has negative health and economic consequences; interventions have focused on appraising symptoms, with limited success in reducing delay. To identify predictors of care avoidance and reasons for avoiding care. Using the Health Information National Trends Survey (2007), we conducted logistic regressions to identify predictors of avoiding medical visits deemed necessary by the respondents; and, we then conducted similar analyses on reasons given for avoidance behavior. Independent variables included geographic, demographic, socioeconomic, personal health, health behavior, health care system, and cognitive characteristics. Approximately one third of adults avoided doctor visits they had deemed necessary. Although unadjusted associations existed, avoiding needed care was not independently associated with geographic, demographic, and socioeconomic characteristics. Avoidance behavior is characterized by low health self-efficacy, less experience with both quality care and getting help with uncertainty about health, having your feelings attended to by your provider, no usual source of care, negative affect, smoking daily, and fatalistic attitude toward cancer. Reasons elicited for avoidance include preference for self-care or alternative care, dislike or distrust of doctors, fear or dislike of medical treatments, time, and money; respondents also endorsed discomfort with body examinations, fear of having a serious illness, and thoughts of dying. Distinct predictors distinguish each of these reasons. Interventions to reduce patient delay could be improved by addressing the health-related behavioral, belief, experiential, and emotional traits associated with delay. Attention should also be directed toward the interpersonal communications between patients and providers.

Testing the performance of superhydrophobic aluminum surfaces.

PubMed

Ruiz-Cabello, F Javier Montes; Ibáñez-Ibáñez, Pablo F; Gómez-Lopera, J Francisco; Martínez-Aroza, José; Cabrerizo-Vílchez, Miguel; Rodríguez-Valverde, Miguel A

2017-12-15

The analysis of wetting properties of superhydrophobic surfaces may be a difficult task due to the restless behavior of drops on this type of surfaces and the limitations of goniometry for high contact angles. A method to validate the performance of superhydrophobic surfaces, rather than standard goniometry, is required. In this work, we used bouncing drop dynamics as a useful tool to predict the water repellency of different superhydrophobic surfaces. From bouncing drop experiments conducted over a wide range of superhydrophobic surfaces, we found that those surfaces with a proper roughness degree and homogeneous chemical composition showed higher water-repellency. We also conducted a drop condensation study at saturating conditions aimed to determine whether there is direct correlation between water repellency and condensation delay. We found that the drop condensation process is strongly related to the surface topography, as well as the intrinsic wettability. The condensation is promoted on rough surfaces but it is delayed on intrinsically hydrophobic surfaces. However, the differences found in condensation delay between the superhydrophobic surfaces explored in this study cannot be justified by their chemical homogeneity nor their efficiency as water repellent surfaces, separately. Copyright © 2017 Elsevier Inc. All rights reserved.

Active feedforward noise control and signal tracking of headsets: Electroacoustic analysis and system implementation.

PubMed

Bai, Mingsian R; Pan, Weichi; Chen, Hungyu

2018-03-01

Active noise control (ANC) of headsets is revisited in this paper. An in-depth electroacoustic analysis of the combined loudspeaker-cavity headset system is conducted on the basis of electro-mechano-acoustical analogous circuits. Model matching of the primary path and the secondary path leads to a feedforward control architecture. The ideal controller sheds some light on the key parameters that affect the noise reduction performance. Filtered-X least-mean-squares algorithm is employed to implement the feedforward controller on a digital signal processor. Since the relative delay of the primary path and the secondary path is crucial to the noise reduction performance, multirate signal processing with polyphase implementation is utilized to minimize the effective analog-digital conversion delay in the secondary path. Ad hoc decimation and interpolation filters are designed in order not to introduce excessive phase delays at the cutoff. Real-time experiments are undertaken to validate the implemented ANC system. Listening tests are also conducted to compare the fixed controller and the adaptive controller in terms of noise reduction and signal tracking performance for three noise types. The results have demonstrated that the fixed feedforward controller achieved satisfactory noise reduction performance and signal tracking quality.

Acidosis slows electrical conduction through the atrio-ventricular node

PubMed Central

Nisbet, Ashley M.; Burton, Francis L.; Walker, Nicola L.; Craig, Margaret A.; Cheng, Hongwei; Hancox, Jules C.; Orchard, Clive H.; Smith, Godfrey L.

2014-01-01

Acidosis affects the mechanical and electrical activity of mammalian hearts but comparatively little is known about its effects on the function of the atrio-ventricular node (AVN). In this study, the electrical activity of the epicardial surface of the left ventricle of isolated Langendorff-perfused rabbit hearts was examined using optical methods. Perfusion with hypercapnic Tyrode's solution (20% CO2, pH 6.7) increased the time of earliest activation (Tact) from 100.5 ± 7.9 to 166.1 ± 7.2 ms (n = 8) at a pacing cycle length (PCL) of 300 ms (37°C). Tact increased at shorter PCL, and the hypercapnic solution prolonged Tact further: at 150 ms PCL, Tact was prolonged from 131.0 ± 5.2 to 174.9 ± 16.3 ms. 2:1 AVN block was common at shorter cycle lengths. Atrial and ventricular conduction times were not significantly affected by the hypercapnic solution suggesting that the increased delay originated in the AVN. Isolated right atrial preparations were superfused with Tyrode's solutions at pH 7.4 (control), 6.8 and 6.3. Low pH prolonged the atrial-Hisian (AH) interval, the AVN effective and functional refractory periods and Wenckebach cycle length significantly. Complete AVN block occurred in 6 out of 9 preparations. Optical imaging of conduction at the AV junction revealed increased conduction delay in the region of the AVN, with less marked effects in atrial and ventricular tissue. Thus acidosis can dramatically prolong the AVN delay, and in combination with short cycle lengths, this can cause partial or complete AVN block and is therefore implicated in the development of brady-arrhythmias in conditions of local or systemic acidosis. PMID:25009505

Acidosis slows electrical conduction through the atrio-ventricular node.

PubMed

Nisbet, Ashley M; Burton, Francis L; Walker, Nicola L; Craig, Margaret A; Cheng, Hongwei; Hancox, Jules C; Orchard, Clive H; Smith, Godfrey L

2014-01-01

Acidosis affects the mechanical and electrical activity of mammalian hearts but comparatively little is known about its effects on the function of the atrio-ventricular node (AVN). In this study, the electrical activity of the epicardial surface of the left ventricle of isolated Langendorff-perfused rabbit hearts was examined using optical methods. Perfusion with hypercapnic Tyrode's solution (20% CO2, pH 6.7) increased the time of earliest activation (Tact) from 100.5 ± 7.9 to 166.1 ± 7.2 ms (n = 8) at a pacing cycle length (PCL) of 300 ms (37°C). Tact increased at shorter PCL, and the hypercapnic solution prolonged Tact further: at 150 ms PCL, Tact was prolonged from 131.0 ± 5.2 to 174.9 ± 16.3 ms. 2:1 AVN block was common at shorter cycle lengths. Atrial and ventricular conduction times were not significantly affected by the hypercapnic solution suggesting that the increased delay originated in the AVN. Isolated right atrial preparations were superfused with Tyrode's solutions at pH 7.4 (control), 6.8 and 6.3. Low pH prolonged the atrial-Hisian (AH) interval, the AVN effective and functional refractory periods and Wenckebach cycle length significantly. Complete AVN block occurred in 6 out of 9 preparations. Optical imaging of conduction at the AV junction revealed increased conduction delay in the region of the AVN, with less marked effects in atrial and ventricular tissue. Thus acidosis can dramatically prolong the AVN delay, and in combination with short cycle lengths, this can cause partial or complete AVN block and is therefore implicated in the development of brady-arrhythmias in conditions of local or systemic acidosis.

Defective sensorimotor integration in preparation for reaction time tasks in patients with multiple sclerosis.

PubMed

Cabib, Christopher; Llufriu, Sara; Casanova-Molla, Jordi; Saiz, Albert; Valls-Solé, Josep

2015-03-01

Slowness of voluntary movements in patients with multiple sclerosis (MS) may be due to various factors, including attentional and cognitive deficits, delays in motor conduction time, and impairment of specific central nervous system circuits. In 13 healthy volunteers and 20 mildly disabled, relapsing-remitting MS patients, we examined simple reaction time (SRT) tasks requiring sensorimotor integration in circuits involving the corpus callosum and the brain stem. A somatosensory stimulus was used as the imperative signal (IS), and subjects were requested to react with either the ipsilateral or the contralateral hand (uncrossed vs. crossed SRT). In 33% of trials, a startling auditory stimulus was presented together with the IS, and the percentage reaction time change with respect to baseline SRT trials was measured (StartReact effect). The difference between crossed and uncrossed SRT, which requires interhemispheric conduction, was significantly larger in patients than in healthy subjects (P = 0.021). The StartReact effect, which involves activation of brain stem motor pathways, was reduced significantly in patients with respect to healthy subjects (uncrossed trials: P = 0.015; crossed trials: P = 0.005). In patients, a barely significant correlation was found between SRT delay and conduction abnormalities in motor and sensory pathways (P = 0.02 and P = 0.04, respectively). The abnormalities found specifically in trials reflecting interhemispheric transfer of information, as well as the evidence for reduced subcortical motor preparation, indicate that a delay in reaction time execution in MS patients cannot be explained solely by conduction slowing in motor and sensory pathways but suggest, instead, defective sensorimotor integration mechanisms in at least the two circuits examined. Copyright © 2015 The American Physiological Society.

Effect of Pressure on Piloted Ignition Delay of PMMA

NASA Technical Reports Server (NTRS)

McAllister, Sara; Lai, Janice; Scott, Sarah; Ramirez-Correa, Amelia; Fernandez-Pello, Carlos; Urban, David; Ruff, Gary

2008-01-01

In order to reduce the risk of decompression sickness associated with spacewalks, NASA is considering designing the next generation of exploration vehicles and habitats with a different cabin environment than used previously. The proposed environment uses a total cabin pressure of 52.7 to 58.6 kPa with an oxygen concentration of 30 to 34% by volume and was chosen with material flammability in mind. Because materials may burn differently under these conditions and there is little information on how this new environment affects the flammability of the materials onboard, it is important to conduct material flammability experiments at the intended exploration atmosphere. One method to evaluate material flammability is by its ease of ignition. To this end, piloted ignition delay tests were conducted in the Forced Ignition and Spread Test (FIST) apparatus subject to this new environment. In these tests, polymethylmethacylate (PMMA) was exposed to a range of oxidizer flow velocities and externally applied heat fluxes. The ultimate goal is to determine the individual effect of pressure and the combined effect of pressure and oxygen concentration on the ignition delay. Tests were conducted for a baseline case of normal pressure and oxygen concentration, low pressure (58.6 kPa) with normal oxygen (21%). Future work will focus on low pressure with 32% oxygen concentration (space exploration atmosphere - SEA) conditions. It was found that reducing the pressure while keeping the oxygen concentration at 21% reduced the ignition time by 17% on average. It was also noted that the critical heat flux for ignition decreases in low-pressure conditions. Because tests conducted in standard atmospheric conditions will underpredict the flammability of materials intended for use on spacecraft, fire safety onboard at exploration atmospheres may be compromised.

Piloted Ignition Delay of PMMA in Space Exploration Atmospheres

NASA Technical Reports Server (NTRS)

McAllister, Sara; Fernandez-Pello, Carlos; Urban, David; Ruff, Gary

2007-01-01

In order to reduce the risk of decompression sickness associated with extravehicular activity (EVA), NASA is designing the next generation of exploration vehicles and habitats with a different cabin environment than used previously. The proposed environment uses a total cabin pressure of 52.7 to 58.6 kPa with an oxygen concentration of 30 to 34% by volume and was chosen with material flammability in mind. Because materials may burn differently under these conditions and there is little information on how this new environment affects the flammability of the materials onboard, it is important to conduct material flammability experiments at the intended exploration atmosphere. One method to evaluate material flammability is by its ease of ignition. To this end, piloted ignition delay tests were conducted in the Forced Ignition and Spread Test (FIST) apparatus subject to this new environment. In these tests, polymethylmethacylate (PMMA) was exposed to a range of oxidizer flow velocities and externally applied heat fluxes. Tests were conducted for a baseline case of normal pressure and oxygen concentration, low pressure (58.6 kPa) with normal oxygen (21%), and low pressure with 32% oxygen concentration conditions to determine the individual effect of pressure and the combined effect of pressure and oxygen concentration on the ignition delay. It was found that reducing the pressure while keeping the oxygen concentration at 21% reduced the ignition time by 17% on average. Increasing the oxygen concentration at low pressures reduced the ignition time by an additional 10%. It was also noted that the critical heat flux for ignition decreases at exploration atmospheres. These results show that tests conducted in standard atmospheric conditions will underpredict the ignition of materials intended for use on spacecraft and that, at these conditions, materials are more susceptible to ignition than at current spacecraft atmospheres.

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

PubMed

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

2010-09-01

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

Effect of Interocular Delay on Disparity-Selective V1 Neurons: Relationship to Stereoacuity and the Pulfrich Effect

PubMed Central

Read, Jenny C. A.; Cumming, Bruce G.

2006-01-01

The temporal properties of disparity-sensitive neurons place important temporal constraints on stereo matching. We examined these constraints by measuring the responses of disparity-selective neurons in striate cortex of awake behaving monkeys to random-dot stereograms that contained interocular delays. Disparity selectivity was gradually abolished by increasing interocular delay (when the delay exceeds the integration time, the inputs from the 2 eyes become uncorrelated). The amplitude of the disparity-selective response was a Gaussian function of interocular delay, with a mean of 16 ms (±5 ms, SD). Psychophysical measures of stereoacuity, in both monkey and human observers, showed a closely similar dependency on time, suggesting that temporal integration in V1 neurons is what determines psychophysical matching constraints over time. There was a slight but consistent asymmetry in the neuronal responses, as if the optimum stimulus is one in which the right stimulus leads by about 4 ms. Because all recordings were made in the left hemisphere, this probably reflects nasotemporal differences in conduction times; psychophysical data are compatible with this interpretation. In only a few neurons (5/72), interocular delay caused a change in the preferred disparity. Such tilted disparity/delay profiles have been invoked previously to explain depth perception in the stroboscopic version of the Pulfrich effect (and other variants). However, the great majority of the neurons did not show tilted disparity/delay profiles. This suggests that either the activity of these neurons is ignored when viewing Pulfrich stimuli, or that current theories relating neuronal properties to perception in the Pulfrich effect need to be reevaluated. PMID:15788521

Performance of 2-year-old children after early surgery for congenital heart disease on the Bayley Scales of Infant and Toddler Development, Third Edition.

PubMed

Long, Suzanne H; Galea, Mary P; Eldridge, Beverley J; Harris, Susan R

2012-08-01

Previous research on developmental outcomes of infants with congenital heart disease (CHD) has shown delays in both cognitive and motor skills. To describe outcomes on the Bayley Scales of Infant and Toddler Development, 3rd edition (Bayley-III) for infants with CHD and to compare those findings to published results for similar samples of infants assessed on the 2nd edition of the Bayley Scales (BSID-II). Prospective cohort. Of 50 infants with CHD who participated in this longitudinal study (2006-2008) at the Royal Children's Hospital in Melbourne, Australia, 47 were assessed on the Bayley-III (median age=24.5 months), administered by a psychologist or neonatologist. Although neither assessor was blind to the CHD diagnosis, they were unaware of results of previous developmental assessments conducted in this longitudinal study. For the Bayley-III cognitive composite score, 17.0% of infants showed mild delays (1-2 SD below the mean), 2.1% had moderate delays (2-3 SD below the mean), and none had severe delays (greater than 3 SD below the mean). Motor composite scores showed mild delays in 10.9% of infants and moderate delays in 2.2%; none had severe motor delays. These findings differ from study results using the BSID-II in similar infants. The Bayley-III may underestimate developmental delay in 2-year-old children with CHD when compared to results of similar children tested at 12-36 months of age on the BSID-II. Copyright © 2012 Elsevier Ltd. All rights reserved.

Polypyrrole-chitosan conductive biomaterial synchronizes cardiomyocyte contraction and improves myocardial electrical impulse propagation.

PubMed

Cui, Zhi; Ni, Nathan C; Wu, Jun; Du, Guo-Qing; He, Sheng; Yau, Terrence M; Weisel, Richard D; Sung, Hsing-Wen; Li, Ren-Ke

2018-01-01

Background: The post-myocardial infarction (MI) scar interrupts electrical impulse propagation and delays regional contraction, which contributes to ventricular dysfunction. We investigated the potential of an injectable conductive biomaterial to restore scar tissue conductivity and re-establish synchronous ventricular contraction. Methods: A conductive biomaterial was generated by conjugating conductive polypyrrole (PPY) onto chitosan (CHI) backbones. Trypan blue staining of neonatal rat cardiomyocytes (CMs) cultured on biomaterials was used to evaluate the biocompatibility of the conductive biomaterials. Ca 2+ imaging was used to visualize beating CMs. A cryoablation injury rat model was used to investigate the ability of PPY:CHI to improve cardiac electrical propagation in the injured heart in vivo . Electromyography was used to evaluate conductivity of scar tissue ex vivo . Results: Cell survival and morphology were similar between cells cultured on biomaterials-coated and uncoated-control dishes. PPY:CHI established synchronous contraction of two distinct clusters of spontaneously-beating CMs. Intramyocardial PPY:CHI injection into the cryoablation-induced injured region improved electrical impulse propagation across the scarred tissue and decreased the QRS interval, whereas saline- or CHI-injected hearts continued to have delayed propagation patterns and significantly reduced conduction velocity compared to healthy controls. Ex vivo evaluation found that scar tissue from PPY:CHI-treated rat hearts had higher signal amplitude compared to those from saline- or CHI-treated rat heart tissue. Conclusions: The PPY:CHI biomaterial is electrically conductive, biocompatible and injectable. It improved synchronous contraction between physically separated beating CM clusters in vitro . Intra-myocardial injection of PPY:CHI following cardiac injury improved electrical impulse propagation of scar tissue in vivo .

Effective utility accommodation : final report.

DOT National Transportation Integrated Search

2009-12-08

The report presents research regarding methods to improve project delivery times and minimize construction delays due to utility coordination by conducting a study of the current best practices used by six (6) similar state transportation departments...

Brief Report: Methods for Acquiring Structural MRI Data in Very Young Children with Autism Without the Use of Sedation

PubMed Central

Simon, Tony J.; Zierhut, Cynthia; Solomon, Marjorie; Rogers, Sally J.; Amaral, David G.

2016-01-01

We describe a protocol with which we achieved a 93% success rate in acquiring high quality MRI scans without the use of sedation in 2.5–4.5 year old children with autism, developmental delays, and typical development. Our main strategy was to conduct MRIs during natural nocturnal sleep in the evenings after the child's normal bedtime. Alternatively, with some older and higher functioning children, the MRI was conducted while the child was awake and watching a video. Both strategies relied heavily on the creation of a child and family friendly MRI environment and the involvement of parents as collaborators in the project. Scanning very young children with autism, typical development, and developmental delays without the use of sedation or anesthesia was possible in the majority of cases. PMID:18157624

Segregation of the Brain into Gray and White Matter: A Design Minimizing Conduction Delays

PubMed Central

Wen, Quan; Chklovskii, Dmitri B

2005-01-01

A ubiquitous feature of the vertebrate anatomy is the segregation of the brain into white and gray matter. Assuming that evolution maximized brain functionality, what is the reason for such segregation? To answer this question, we posit that brain functionality requires high interconnectivity and short conduction delays. Based on this assumption we searched for the optimal brain architecture by comparing different candidate designs. We found that the optimal design depends on the number of neurons, interneuronal connectivity, and axon diameter. In particular, the requirement to connect neurons with many fast axons drives the segregation of the brain into white and gray matter. These results provide a possible explanation for the structure of various regions of the vertebrate brain, such as the mammalian neocortex and neostriatum, the avian telencephalon, and the spinal cord. PMID:16389299

Teenage driver licensing in relation to state laws.

PubMed

Williams, A F; Lund, A K; Preusser, D F

1985-04-01

Previous studies have shown that delaying licensure reduces motor vehicle injuries. This study examined the relationship between licensing laws and the timing of obtaining drivers licenses. The states studied have various laws, including minimum licensing ages of 15, 16 and 17; minimum learners permit ages of 15 and 16; and teenage night driving curfews. A questionnaire survey of 52,304 students was conducted in 75 high schools during the spring of 1983. The schools were selected from Orange County, California; rural Colorado; and most or all of Louisiana, Michigan, Mississippi, New Jersey and New York. The results indicated that the minimum age of licensure has obvious strong effects in delaying licensure. Setting the learners permit age later also apparently delays licensure. The night driving curfew in New York State (9 p.m.-5 a.m.) is seen by students as a factor in their decisions to delay obtaining licenses; Louisiana's 11 p.m.-5 a.m. curfew has a much smaller effect, if any.

Early-Onset LMNA-Associated Muscular Dystrophy with Later Involvement of Contracture.

PubMed

Lee, Younggun; Lee, Jung Hwan; Park, Hyung Jun; Choi, Young Chul

2017-10-01

The early diagnosis of LMNA-associated muscular dystrophy is important for preventing sudden arrest related to cardiac conduction block. However, diagnosing early-onset Emery-Dreifuss muscular dystrophy (EDMD) with later involvement of contracture and limb-girdle muscular dystrophy type 1B is often delayed due to heterogeneous clinical presentations. We aimed to determine the clinical features that contribute to a delayed diagnosis. We reviewed four patients who were recently diagnosed with LMNA-associated muscular dystrophy by targeted exome sequencing and who were initially diagnosed with nonspecific or other types of muscular dystrophy. Certain clinical features such as delayed contracture involvement and calf hypertrophy were found to contribute to a delayed diagnosis. Muscle biopsies were not informative for the diagnosis in these patients. Genetic testing of single or multiple genes is useful for confirming a diagnosis of LMNA-associated muscular dystrophy. Even EDMD patients could experience the later involvement of contracture, so clinicians should consider early genetic testing for patients with undiagnosed muscular dystrophy or laminopathy. Copyright © 2017 Korean Neurological Association

Direct simulation of phase delay effects on induced-charge electro-osmosis under large ac electric fields

NASA Astrophysics Data System (ADS)

Sugioka, Hideyuki

2016-08-01

The standard theory of induced-charge electro-osmosis (ICEO) often overpredicts experimental values of ICEO velocities. Using a nonsteady direct multiphysics simulation technique based on the coupled Poisson-Nernst-Planck and Stokes equations for an electrolyte around a conductive cylinder subject to an ac electric field, we find that a phase delay effect concerning an ion response provides a fundamental mechanism for electrokinetic suppression. A surprising aspect of our findings is that the phase delay effect occurs even at much lower frequencies (e.g., 50 Hz) than the generally believed charging frequency of an electric double layer (typically, 1 kHz) and it can decrease the electrokinetic velocities in one to several orders. In addition, we find that the phase delay effect may also cause a change in the electrokinetic flow directions (i.e., flow reversal) depending on the geometrical conditions. We believe that our findings move toward a more complete understanding of complex experimental nonlinear electrokinetic phenomena.

Delayed system response times affect immediate physiology and the dynamics of subsequent button press behavior.

PubMed

Kohrs, Christin; Hrabal, David; Angenstein, Nicole; Brechmann, André

2014-11-01

System response time research is an important issue in human-computer interactions. Experience with technical devices and general rules of human-human interactions determine the user's expectation, and any delay in system response time may lead to immediate physiological, emotional, and behavioral consequences. We investigated such effects on a trial-by-trial basis during a human-computer interaction by measuring changes in skin conductance (SC), heart rate (HR), and the dynamics of button press responses. We found an increase in SC and a deceleration of HR for all three delayed system response times (0.5, 1, 2 s). Moreover, the data on button press dynamics was highly informative since subjects repeated a button press with more force in response to delayed system response times. Furthermore, the button press dynamics could distinguish between correct and incorrect decisions and may thus even be used to infer the uncertainty of a user's decision. Copyright © 2014 Society for Psychophysiological Research.

Delayed norovirus epidemic in the 2009-2010 season in Japan: potential relationship with intensive hand sanitizer use for pandemic influenza.

PubMed

Inaida, S; Shobugawa, Y; Matsuno, S; Saito, R; Suzuki, H

2016-09-01

Norovirus (NoV) epidemics normally peak in December in Japan; however, the peak in the 2009-2010 season was delayed until the fourth week of January 2010. We suspected intensive hand hygiene that was conducted for a previous pandemic influenza in 2009 as the cause of this delay. We analysed the NoV epidemic trend, based on national surveillance data, and its associations with monthly output data for hand hygiene products, including alcohol-based skin antiseptics and hand soap. The delayed peak in the NoV incidence in the 2009-2010 season had the lowest number of recorded cases of the five seasons studied (2006-2007 to 2010-2011). GII.4 was the most commonly occurring genotype. The monthly relative risk of NoV and monthly output of both alcohol-based skin antiseptics and hand soap were significantly and negatively correlated. Our findings suggest an association between hand hygiene using these products and prevention of NoV transmission.

Identification of Mobile Phone and Analysis of Original Version of Videos through a Delay Time Analysis of Sound Signals from Mobile Phone Videos.

PubMed

Hwang, Min Gu; Har, Dong Hwan

2017-11-01

This study designs a method of identifying the camera model used to take videos that are distributed through mobile phones and determines the original version of the mobile phone video for use as legal evidence. For this analysis, an experiment was conducted to find the unique characteristics of each mobile phone. The videos recorded by mobile phones were analyzed to establish the delay time of sound signals, and the differences between the delay times of sound signals for different mobile phones were traced by classifying their characteristics. Furthermore, the sound input signals for mobile phone videos used as legal evidence were analyzed to ascertain whether they have the unique characteristics of the original version. The objective of this study was to find a method for validating the use of mobile phone videos as legal evidence using mobile phones through differences in the delay times of sound input signals. © 2017 American Academy of Forensic Sciences.

A Nonlinearity Mitigation Method for a Broadband RF Front-End in a Sensor Based on Best Delay Searching

PubMed Central

Zhao, Wen; Ma, Hong; Zhang, Hua; Jin, Jiang; Dai, Gang; Hu, Lin

2017-01-01

The cognitive radio wireless sensor network (CR-WSN) is experiencing more and more attention for its capacity to automatically extract broadband instantaneous radio environment information. Obtaining sufficient linearity and spurious-free dynamic range (SFDR) is a significant premise of guaranteeing sensing performance which, however, usually suffers from the nonlinear distortion coming from the broadband radio frequency (RF) front-end in the sensor node. Moreover, unlike other existing methods, the joint effect of non-constant group delay distortion and nonlinear distortion is discussed, and its corresponding solution is provided in this paper. After that, the nonlinearity mitigation architecture based on best delay searching is proposed. Finally, verification experiments, both on simulation signals and signals from real-world measurement, are conducted and discussed. The achieved results demonstrate that with best delay searching, nonlinear distortion can be alleviated significantly and, in this way, spectrum sensing performance is more reliable and accurate. PMID:28956860

A Fuel-Efficient Conflict Resolution Maneuver for Separation Assurance

NASA Technical Reports Server (NTRS)

Bowe, Aisha Ruth; Santiago, Confesor

2012-01-01

Automated separation assurance algorithms are envisioned to play an integral role in accommodating the forecasted increase in demand of the National Airspace System. Developing a robust, reliable, air traffic management system involves safely increasing efficiency and throughput while considering the potential impact on users. This experiment seeks to evaluate the benefit of augmenting a conflict detection and resolution algorithm to consider a fuel efficient, Zero-Delay Direct-To maneuver, when resolving a given conflict based on either minimum fuel burn or minimum delay. A total of twelve conditions were tested in a fast-time simulation conducted in three airspace regions with mixed aircraft types and light weather. Results show that inclusion of this maneuver has no appreciable effect on the ability of the algorithm to safely detect and resolve conflicts. The results further suggest that enabling the Zero-Delay Direct-To maneuver significantly increases the cumulative fuel burn savings when choosing resolution based on minimum fuel burn while marginally increasing the average delay per resolution.

The impact of social isolation on delayed hospital discharges of older hip fracture patients and associated costs.

PubMed

Landeiro, F; Leal, J; Gray, A M

2016-02-01

Delayed discharges represent an inefficient use of acute hospital beds. Social isolation and referral to a public-funded rehabilitation unit were significant predictors of delayed discharges while admission from an institution was a protective factor for older hip fracture patients. Preventing delays could save between 11.2 and 30.7 % of total hospital costs for this patient group. Delayed discharges of older patients from acute care hospitals are a major challenge for administrative, humanitarian, and economic reasons. At the same time, older people are particularly vulnerable to social isolation which has a detrimental effect on their health and well-being with cost implications for health and social care services. The purpose of the present study was to determine the impact and costs of social isolation on delayed hospital discharge. A prospective study of 278 consecutive patients aged 75 or older with hip fracture admitted, as an emergency, to the Orthopaedics Department of Hospital Universitário de Santa Maria, Portugal, was conducted. A logistic regression model was used to examine the impact of relevant covariates on delayed discharges, and a negative binomial regression model was used to examine the main drivers of days of delayed discharges. Costs of delayed discharges were estimated using unit costs from national databases. Mean age at admission was 85.5 years and mean length of stay was 13.1 days per patient. Sixty-two (22.3 %) patients had delayed discharges, resulting in 419 bed days lost (11.5 % of the total length of stay). Being isolated or at a high risk of social isolation, measured with the Lubben social network scale, was significantly associated with delayed discharges (odds ratio (OR) 3.5) as was being referred to a public-funded rehabilitation unit (OR 7.6). These two variables also increased the number of days of delayed discharges (2.6 and 4.9 extra days, respectively, holding all else constant). Patients who were admitted from an institution were less likely to have delayed discharges (OR 0.2) with 5.5 fewer days of delay. Total costs of delayed discharges were between 11.2 and 30.7 % of total costs (€2352 and €9317 per patient with delayed discharge) conditional on whether waiting costs for placement in public-funded rehabilitation unit were included. High risk of social isolation, social isolation and referral to public-funded rehabilitation units increase delays in patients' discharges from acute care hospitals.

Effects of the association of diabetes and pulmonary emphysema on cardiac structure and function in rats.

PubMed

Di Petta, Antonio; Simas, Rafael; Ferreira, Clebson L; Capelozzi, Vera L; Salemi, Vera M C; Moreira, Luiz F P; Sannomiya, Paulina

2015-10-01

Chronic obstructive pulmonary disease is often associated with chronic comorbid conditions of cardiovascular disease, diabetes mellitus and hypertension. This study aimed to investigate the effects of the association of diabetes and pulmonary emphysema on cardiac structure and function in rats. Wistar rats were divided into control non-diabetic instilled with saline (CS) or elastase (CE), diabetic instilled with saline (DS) or elastase (DE), DE treated with insulin (DEI) groups and echocardiographic measurements, morphometric analyses of the heart and lungs, and survival analysis conducted 50 days after instillation. Diabetes mellitus was induced [alloxan, 42 mg/kg, intravenously (iv)] 10 days before the induction of emphysema (elastase, 0.25 IU/100 g). Rats were treated with NPH insulin (4 IU before elastase plus 2 IU/day, 50 days). Both CE and DE exhibited similar increases in mean alveolar diameter, which are positively correlated with increases in right ventricular (RV) wall thickness (P = 0.0022), cavity area (P = 0.0001) and cardiomyocyte thickness (P = 0.0001). Diabetic saline group demonstrated a reduction in left ventricular (LV) wall, interventricular (IV) septum, cardiomyocyte thickness and an increase in cavity area, associated with a reduction in LV fractional shortening (P < 0.05), and an increase in LViv relaxation time (P < 0.05). Survival rate decreased from 80% in DS group to 40% in DE group. In conclusion, alloxan diabetes did not affect RV hypertrophy secondary to chronic emphysema, even in the presence of insulin. Diabetes per se induced left ventricular dysfunction, which was less evident in the presence of RV hypertrophy. Survival rate was substantially reduced as a consequence, at least in part, of the coexistence of RV hypertrophy and diabetic cardiomyopathy. © 2015 The Authors. International Journal of Experimental Pathology © 2015 International Journal of Experimental Pathology.

Olanzapine induced Q-Tc shortening.

PubMed

Shoja Shafti, Saeed; Fallah Jahromi, Parisa

2014-12-01

Prolongation of Q-Tc interval is commonly accepted as a surrogate marker for the ability of a drug to cause torsade de pointes. In the present study, safety of olanzapine versus risperidone was compared among a group of patients with schizophrenia to see the frequency of the electrocardiographic alterations induced by those atypical antipsychotics. Two hundred and sixty-eight female inpatients with schizophrenia entered in one of the two parallel groups to participate in an open study for random assignment to olanzapine (n = 148) or risperidone (n = 120). Standard 12-lead surface electrocardiogram (ECG) was taken from each patient at baseline, before initiation of treatment, and then at the end of management, just before discharge. The parameters that were assessed included heart rate (HR), P-R interval, QRS interval, Q-T interval (corrected = Q-Tc), ventricular activation time (VAT), ST segment, T wave, axis of QRS, and finally, interventricular conduction process. A total of 37.83% of cases in the olanzapine group and 30% in the risperidone group showed some Q-Tc changes; 13.51% and 24.32% of the patients in the olanzapine group showed prolongation and shortening of the Q-Tc, respectively, while changes in the risperidone group were restricted to only prolongation of Q-Tc. Comparison of means showed a significant increment in Q-Tc by risperidone (p = 0.02). Also, comparison of proportions in the olanzapine group showed significantly more cases with shortening of Q-Tc versus its prolongation (p = 0.01). No significant alterations with respect to other variables were evident. Olanzapine and risperidone had comparable potentiality for induction of Q-Tc changes, while production of further miscellaneous alterations in ECG was more observable in the olanzapine group compared with the risperidone group. Also shortening of Q-Tc was specific to olanzapine.

N-terminal pro-brain natriuretic peptide measurements in hemodynamically significant patent ductus arteriosus in preterm infants.

PubMed

Alenazi, Shehab Ahmed

2016-01-01

Evaluate the role of NT-proBNP levels in Preterm neonates suffering from PDA and used as a screening tool for predicting HsPDA and guiding physicians to consider early echocardiographic evaluation. This is a monocentric prospective blind study which was conducted at Arar Central Hospital, Ar'ar, Saudi Arabia, during the period between Jan 2014 to June 2014. Thirty-three (33) preterm infants born at less than 31 weeks of gestation or weighing less than 1200 g at birth infants were initially enrolled during a 6-month period. Blood samples were collected along with routine blood tests on days 1, 2, 3, and 7 of life for NT-proBNP analysis. Two echocardiographies were systematically performed on day two of life to ascertain about the status of Ductus Arteriosus. The Plasma NT-proBNP levels were high on day one of life and decline from day three to day seven of life except in those infants with significant hsPDA. Plasma NT-proNBP levels on day 2 of infants in the HsPDA group were significantly higher (<0.001) than those in non-HsPDA group. Echocardiogram parameters indicates the significant difference (p<0.002) in Left Atrial and Aortic ratio (LA/AO), Interventricular septum thickness (P<0.03), Left ventricular posterior wall thickness (p<0.05), diastole PDA gradient (p<0.005) between HsPDA and non-HsPDA. Plasma NT-proBNP level peaked during the first few days after birth and declined rapidly within a week. Therefore, its level may have a role as a screening tool to predict HsPDA and provide more information regarding its spontaneous closure or otherwise.

Short-Term Anticoagulant Therapy and Thrombus Location Are Independent Risk Factors for Delayed Recanalization of Deep Vein Thrombosis.

PubMed

Zhang, Chuanlin; Fu, Qining; Zhao, Yu; Mu, Shaoyu; Liu, Liping

2016-01-21

Prompt recanalization of the vein containing the thrombus is an important goal during the initial treatment of DVT, and risk factors for delayed recanalization in patients with deep vein thrombosis (DVT) in the lower extremities need to be determined. A total of 174 patients with DVT in lower extremities were recruited from June 2014 to March 2015 at our hospital. Duplex ultrasound scanning was conducted for all patients at 1 and 6 months after baseline evaluation. We divided the patients into recanalization and non-recanalization groups and analyzed risk factors for delayed recanalization. The univariate analysis revealed that an oral anticoagulant time of less than 3 months and venous thrombus location were risk factors for delayed recanalization (P<0.01). However, age, gender, hypertension, diabetes, pulmonary embolism, incidence factors, the use of catheter-directed thrombolytic (CDT) drugs, and inferior vena cava filter (IVCF) implantation had no influence on the incidence of delayed recanalization in patients with DVT (P>0.05). The multivariate analysis showed that patients with an anticoagulant time of less than 3 months had a lower incidence of recanalization than those with an anticoagulant time of more than 3 months (OR=2.358, P<0.05). The risk of delayed recanalization in patients with proximal DVT was 7 times higher than that in patients with distal DVT. Duration of anticoagulant treatment of less than 3 months and venous thrombus location are independent risk factors for delayed recanalization of DVT in the lower extremities.

Acute Cellular Rejection in ABO-Incompatible Renal Transplant Recipients Receiving Rituximab Is Associated with Delayed-Onset Neutropenia.

PubMed

Uchida, Junji; Iwai, Tomoaki; Nishide, Shunji; Kabei, Kazuya; Kuwabara, Nobuyuki; Yamasaki, Takeshi; Naganuma, Toshihide; Kumada, Norihiko; Takemoto, Yoshiaki; Nakatani, Tatsuya

2017-07-25

BACKGROUND Rituximab induces long-lasting B cell depletion in the peripheral blood and increases the levels of proinflammatory cytokines associated with regulatory B cell depletion. Previous reports showed that B cell-related cytokine release after administration of rituximab may induce acute cellular rejection (ACR) and delayed-onset neutropenia. The present study was conducted to investigate the correlation between acute rejection and delayed-onset neutropenia in ABO-incompatible renal transplant recipients who underwent administration of rituximab for 1 year after transplantation. MATERIAL AND METHODS From June 2006 to July 2015, 47 patients with chronic renal failure received ABO-incompatible renal transplant with rituximab induction at Osaka City University Hospital. All 47 patients underwent plasmapheresis due to removal of anti-A/B antibodies and administration of rituximab, and their transplants were carried out successfully. We investigated the correlation between ACR and delayed-onset neutropenia in ABO-incompatible renal transplant recipients who underwent administration of rituximab for 1 year after transplantation. RESULTS Fourteen patients (29.8%) experienced ACR (group A), and 33 recipients did not develop ACR (group B). The frequency of delayed-onset neutropenia was higher in group A than in group B (p=0.0503). Multivariate logistic regression analysis revealed that the frequency of ACR correlated significantly with the prevalence of delayed-onset neutropenia. CONCLUSIONS Our results indicated that ACR in ABO-incompatible renal transplant recipients receiving rituximab was associated with delayed-onset neutropenia.

Neuropsychological tests for predicting cognitive decline in older adults

PubMed Central

Baerresen, Kimberly M; Miller, Karen J; Hanson, Eric R; Miller, Justin S; Dye, Richelin V; Hartman, Richard E; Vermeersch, David; Small, Gary W

2015-01-01

Summary Aim To determine neuropsychological tests likely to predict cognitive decline. Methods A sample of nonconverters (n = 106) was compared with those who declined in cognitive status (n = 24). Significant univariate logistic regression prediction models were used to create multivariate logistic regression models to predict decline based on initial neuropsychological testing. Results Rey–Osterrieth Complex Figure Test (RCFT) Retention predicted conversion to mild cognitive impairment (MCI) while baseline Buschke Delay predicted conversion to Alzheimer’s disease (AD). Due to group sample size differences, additional analyses were conducted using a subsample of demographically matched nonconverters. Analyses indicated RCFT Retention predicted conversion to MCI and AD, and Buschke Delay predicted conversion to AD. Conclusion Results suggest RCFT Retention and Buschke Delay may be useful in predicting cognitive decline. PMID:26107318

Singer Responses to Sound Fields with a Simulated Reflection

NASA Astrophysics Data System (ADS)

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

2000-04-01

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

Factors Associated with Delayed Enrollment in HIV Medical Care among HIV-Positive Individuals in Odessa Region, Ukraine.

PubMed

Neduzhko, Oleksandr; Postnov, Oleksandr; Perehinets, Ihor; DeHovitz, Jack; Joseph, Michael; Odegaard, David; Kaplan, Robert; Kiriazova, Tetiana

In Ukraine, about one-third of identified HIV-positive individuals are not connected to care. We conducted a cross-sectional survey (n = 200) among patients registered at Odessa AIDS centers in October to December 2011. Factors associated with delayed enrollment in HIV care (>3 months since positive HIV test) were evaluated using logistic regression. Among study participants (mean age 35 ± 8.2 years, 47.5% female, 42.5% reported history of injecting drugs), 55% delayed HIV care enrollment. Odds of delayed enrollment were higher for those with lower educational attainment (adjusted odds ratio [aOR]: 2.65, 95% confidence interval [CI]: 1.04-6.76), not feeling ill (aOR: 2.98, 95% CI: 1.50-5.93), or not having time to go to the AIDS center (aOR: 3.89, 95% CI: 1.39-10.89); injection drug use was not associated with delayed enrollment. Programs linking HIV-positive individuals to specialized care should address enrollment barriers and include education on HIV care benefits and case management for direct linkage to care. HIV testing and treatment should be coupled to ensure a continuum of care.

Missed and Delayed Diagnosis of Dementia in Primary Care: Prevalence and Contributing Factors

PubMed Central

Bradford, Andrea; Kunik, Mark E.; Schulz, Paul; Williams, Susan P.; Singh, Hardeep

2009-01-01

Dementia is a growing public health problem for which early detection may be beneficial. Currently, the diagnosis of dementia in primary care is dependent mostly on clinical suspicion based on patient symptomsor caregivers’ concerns and is prone to be missed or delayed. We conducted a systematic review of the literature to ascertain the prevalence and contributing factors for missed and delayed dementia diagnoses in primary care. Prevalence of missed and delayed diagnosis was estimated by abstracting quantitative data from studies of diagnostic sensitivity among primary care providers. Possible predictors and contributory factors were determined from the text of quantitative and qualitative studies of patient-, caregiver-, provider-, and system-related barriers. Overall estimates of diagnostic sensitivity varied among studies and appeared to be in part a function of dementia severity, degree of patient impairment, dementia subtype, and frequency of patient-provider contact. Major contributory factors included problems with attitudes and patient-provider communication, educational deficits, and system resource constraints. The true prevalence of missed and delayed diagnoses of dementia is unknown but appears to be high. Until the case for dementia screening becomes more compelling, efforts to promote timely detection should focus on removing barriers to diagnosis. PMID:19568149

The effects of time delays on a telepathology user interface.

PubMed Central

Carr, D.; Hasegawa, H.; Lemmon, D.; Plaisant, C.

1992-01-01

Telepathology enables a pathologist to examine physically distant tissue samples by microscope operation over a communication link. Communication links can impose time delays which cause difficulties in controlling the remote device. Such difficulties were found in a microscope teleoperation system. Since the user interface is critical to pathologist's acceptance of telepathology, we redesigned the user interface for this system, built two different versions (a keypad whose movement commands operated by specifying a start command followed by a stop command and a trackball interface whose movement commands were incremental and directly proportional to the rotation of the trackball). We then conducted a pilot study to determine the effect of time delays on the new user interfaces. In our experiment, the keypad was the faster interface when the time delay is short. There was no evidence to favor either the keypad or trackball when the time delay was longer. Inexperienced participants benefitted by allowing them to move long distances over the microscope slide by dragging the field-of-view indicator on the touchscreen control panel. The experiment suggests that changes could be made to the trackball interface which would improve its performance. PMID:1482878

A Delay-Aware and Reliable Data Aggregation for Cyber-Physical Sensing

PubMed Central

Zhang, Jinhuan; Long, Jun; Zhang, Chengyuan; Zhao, Guihu

2017-01-01

Physical information sensed by various sensors in a cyber-physical system should be collected for further operation. In many applications, data aggregation should take reliability and delay into consideration. To address these problems, a novel Tiered Structure Routing-based Delay-Aware and Reliable Data Aggregation scheme named TSR-DARDA for spherical physical objects is proposed. By dividing the spherical network constructed by dispersed sensor nodes into circular tiers with specifically designed widths and cells, TSTR-DARDA tries to enable as many nodes as possible to transmit data simultaneously. In order to ensure transmission reliability, lost packets are retransmitted. Moreover, to minimize the latency while maintaining reliability for data collection, in-network aggregation and broadcast techniques are adopted to deal with the transmission between data collecting nodes in the outer layer and their parent data collecting nodes in the inner layer. Thus, the optimization problem is transformed to minimize the delay under reliability constraints by controlling the system parameters. To demonstrate the effectiveness of the proposed scheme, we have conducted extensive theoretical analysis and comparisons to evaluate the performance of TSR-DARDA. The analysis and simulations show that TSR-DARDA leads to lower delay with reliability satisfaction. PMID:28218668

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

PubMed

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

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

Application of a Modified Time Delay Spectrometry Technique in Modeling of Underwater Acoustic Propagation.

DTIC Science & Technology

1987-03-01

W.B. Anderson) 1 Keyport, Washington 98345 7. Director, David W. Taylor Naval Ships 1 and Development Center Detachment Puget Sound Attn: George...Monterey, California 93943-5000 Sa IIAME ’) F NDN1G, SPONSOQ;NG 8ab OF ,CE SvM9OL 9 PROCUJREMENT ,NSTR MET *DEN’ CATiON .,.M4[R ORCA ’.:ZAr ON j Iapplecaboe...analysis of sound propagating by multiple paths in an ocean at short ranges has been conducted using a Modified Time Delay Spectrometry (TDS) technique

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

PubMed

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

2016-06-07

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

[Diagnostic evaluation of the developmental level in children identified at risk of delay through the Child Development Evaluation Test].

PubMed

Rizzoli-Córdoba, Antonio; Campos-Maldonado, Martha Carmen; Vélez-Andrade, Víctor Hugo; Delgado-Ginebra, Ismael; Baqueiro-Hernández, César Iván; Villasís-Keever, Miguel Ángel; Reyes-Morales, Hortensia; Ojeda-Lara, Lucía; Davis-Martínez, Erika Berenice; O'Shea-Cuevas, Gabriel; Aceves-Villagrán, Daniel; Carrasco-Mendoza, Joaquín; Villagrán-Muñoz, Víctor Manuel; Halley-Castillo, Elizabeth; Sidonio-Aguayo, Beatriz; Palma-Tavera, Josuha Alexander; Muñoz-Hernández, Onofre

The Child Development Evaluation (or CDE Test) was developed in Mexico as a screening tool for child developmental problems. It yields three possible results: normal, slow development or risk of delay. The modified version was elaborated using the information obtained during the validation study but its properties according to the base population are not known. The objective of this work was to establish diagnostic confirmation of developmental delay in children 16- to 59-months of age previously identified as having risk of delay through the CDE Test in primary care facilities. A population-based cross-sectional study was conducted in one Mexican state. CDE test was administered to 11,455 children 16- to 59-months of age from December/2013 to March/2014. The eligible population represented the 6.2% of the children (n=714) who were identified at risk of delay through the CDE Test. For inclusion in the study, a block randomization stratified by sex and age group was performed. Each participant included in the study had a diagnostic evaluation using the Battelle Development Inventory, 2 nd edition. From the 355 participants included with risk of delay, 65.9% were male and 80.2% were from rural areas; 6.5% were false positives (Total Development Quotient ˃90) and 6.8% did not have any domain with delay (Domain Developmental Quotient <80). The proportion of delay for each domain was as follows: communication 82.5%; cognitive 80.8%; social-personal 33.8%; motor 55.5%; and adaptive 41.7%. There were significant differences in the percentages of delay both by age and by domain/subdomain evaluated. In 93.2% of the participants, developmental delay was corroborated in at least one domain evaluated. Copyright © 2015 Hospital Infantil de México Federico Gómez. Publicado por Masson Doyma México S.A. All rights reserved.

Project Amistad (Friendship), a Joint Venture between DHS and Family Outreach. Final Report: Innovations in Protective Services.

ERIC Educational Resources Information Center

Dennis-Small, Lucretia

Conducted by the Texas Department of Human Services (DHS), Project Amistad (Friendship) originally set out to recruit and train Black and Hispanic volunteers to conduct lay therapy sessions with Black and Hispanic families in which abuse and neglect of children had occurred. Start-up was significantly delayed due to personnel changes; as a result,…

Piloting Changes to Changing Aircraft Dynamics: What Do Pilots Need to Know?

NASA Technical Reports Server (NTRS)

Trujillo, Anna C.; Gregory, Irene M.

2011-01-01

An experiment was conducted to quantify the effects of changing dynamics on a subject s ability to track a signal in order to eventually model a pilot adapting to changing aircraft dynamics. The data will be used to identify primary aircraft dynamics variables that influence changes in pilot s response and produce a simplified pilot model that incorporates this relationship. Each run incorporated a different set of second-order aircraft dynamics representing short period transfer function pitch attitude response: damping ratio, frequency, gain, zero location, and time delay. The subject s ability to conduct the tracking task was the greatest source of root mean square error tracking variability. As for the aircraft dynamics, the factors that affected the subjects ability to conduct the tracking were the time delay, frequency, and zero location. In addition to creating a simplified pilot model, the results of the experiment can be utilized in an advisory capacity. A situation awareness/prediction aid based on the pilot behavior and aircraft dynamics may help tailor pilot s inputs more quickly so that PIO or an upset condition can be avoided.

Application of Time-Delay Absorber to Suppress Vibration of a Dynamical System to Tuned Excitation.

PubMed

El-Ganaini, W A A; El-Gohary, H A

2014-08-01

In this work, we present a comprehensive investigation of the time delay absorber effects on the control of a dynamical system represented by a cantilever beam subjected to tuned excitation forces. Cantilever beam is one of the most widely used system in too many engineering applications, such as mechanical and civil engineering. The main aim of this work is to control the vibration of the beam at simultaneous internal and combined resonance condition, as it is the worst resonance case. Control is conducted via time delay absorber to suppress chaotic vibrations. Time delays often appear in many control systems in the state, in the control input, or in the measurements. Time delay commonly exists in various engineering, biological, and economical systems because of the finite speed of the information processing. It is a source of performance degradation and instability. Multiple time scale perturbation method is applied to obtain a first order approximation for the nonlinear differential equations describing the system behavior. The different resonance cases are reported and studied numerically. The stability of the steady-state solution at the selected worst resonance case is investigated applying Runge-Kutta fourth order method and frequency response equations via Matlab 7.0 and Maple11. Time delay absorber is effective, but within a specified range of time delay. It is the critical factor in selecting such absorber. Time delay absorber is better than the ordinary one as from the effectiveness point of view. The effects of the different absorber parameters on the system behavior and stability are studied numerically. A comparison with the available published work showed a close agreement with some previously published work.

Parents who refuse or delay HPV vaccine: Differences in vaccination behavior, beliefs, and clinical communication preferences

PubMed Central

Gilkey, Melissa B.; Calo, William A.; Marciniak, Macary W.

2017-01-01

ABSTRACT Background: We sought to estimate the national prevalence of HPV vaccine refusal and delay in a nationally-representative sample of parents of adolescents. We also compared parents who refused versus delayed HPV vaccine in terms of their vaccination beliefs and clinical communication preferences. Methods: In 2014 to 2015, we conducted an online survey of 1,484 US parents who reported on an 11- to 17-year-old child in their household. We used weighted multinomial logistic regression to assess correlates of HPV vaccine refusal and delay. Results: Overall, 28% of parents reported that they had ever “refused or decided not to get” HPV vaccine for their child, and an additional 8% of parents reported that they had “delayed or put off getting” HPV vaccine. Compared to no refusal/delay, refusal was associated with lower confidence in adolescent vaccination (relative risk ratio [RRR] = 0.66, 95% confidence interval [CI], 0.48–0.91), lower perceived HPV vaccine effectiveness (RRR = 0.68, 95% CI, 0.50–0.91), and higher perceived harms (RRR = 3.49, 95% CI, 2.65–4.60). In contrast, delay was associated with needing more information (RRR = 1.76, 95% CI, 1.08–2.85). Most parents rated physicians and information sheets as helpful for making decisions about HPV vaccination, although parents who reported refusal endorsed these resources less often. Conclusions: Our findings suggest that HPV vaccine refusal is common among parents of adolescents and may have increased relative to previous estimates. Because the vaccination beliefs and communication preferences of parents who refuse appear to differ from those who delay, targeted communication strategies may be needed to effectively address HPV vaccine hesitancy. PMID:27763818

Maternal deaths in eastern Indonesia: 20 years and still walking: an ethnographic study

PubMed Central

2014-01-01

Background The delays in receiving adequate emergency maternal care described by Thaddeus and Maine twenty years ago are still occurring, as exemplified in this study of cases of maternal deaths in a subdistrict in rural eastern Indonesia. Methods An ethnographic design was conducted, recruiting eleven families who reported on cases of maternal deaths in one sub-district of Indonesia, as well as assessing the geographical and cultural context of the villages. Traditional birth attendants and village leaders provided information to the research team which was thematically and contextually analysed. Results Two stages to the first and second delays have been differentiated in this study. First, delays in the decision to seek care comprised time taken to recognise (if at all) that an emergency situation existed, followed by time taken to reach a decision to request care. The decision to request care resided variously with the family or cadre. Second, delays in reaching care comprised time taken to deliver the request for help and then time for help to arrive. A phone was not available to request care in many cases and so the request was delivered by walking or motorbike. In two cases where the decision to seek care and the delivery of the request happened in a timely way, help was delayed because the midwife and ambulance respectively were unavailable. Conclusions This study, although a small sample, confirmed that either a single delay or a sequence of delays can prove fatal. Delays were determined by both social and geographic factors, any of which alone could be limiting. Initiatives to improve maternal health outcomes need to address multiple factors: increased awareness of equitable access to maternal health care, village preparedness for emergency response, improved access to telecommunications and geographic access. PMID:24447873

Correlations between radiation-induced double strand breaks, cell division delay, and cyclin-dependent signaling in x-irradiated NIH3T3 fibroblasts

NASA Astrophysics Data System (ADS)

Cariveau, Mickael J.

2005-07-01

Molecular responses to radiation-induced DNA double strand breaks (DSB) are mediated by the phosphorylation of the histone variant H2AX which forms identifiable gamma-H2AX foci at the site of the DSB. This event is thought to be linked with the down-regulation of signaling proteins contributing to the checkpoints regulating cell cycle progression and, vis-a-vis , the induction of cell division delay. However, it is unclear whether this division delay is directly related to the number of DSB (gamma-H2AX foci) sustained by an irradiated cell and, if so, whether this number drives cells into cell cycle delay or apoptosis. For this reason, studies were conducted in the immortalized NIH/3T3 fibroblast cell in order to establish correlations between the temporal appearance of the gamma-H2AX foci (a DSB) and the expression of the cell cycle regulatory proteins, cyclin E, A, B1, and their cyclin kinase inhibitor, p21. Cell cycle kinetics and flow cytometry were used to establish radiation-induced division delay over a dose range of 1--6 Gy where a mitotic delay of 2.65 min/cGy was established. Correlations between the expression of cyclin E, A, B1, p21, and the generation of DSB were established in NIH/3T3 cells exposed to 2 or 4 Gy x-irradiation. The data suggest that the G1/S and S phase delay (cyclin E and cyclin A protein levels) are dependent on the dose of radiation while the G2/M (cyclin B1 protein levels) delay is dependent on the quantity of DSB sustained by the irradiated cell.

Delayed Breast Reconstruction on Patients With Upper Extremity Lymphedema: A Systematic Review of the Literature and Pooled Analysis.

PubMed

Siotos, Charalampos; Hassanein, Aladdin H; Bello, Ricardo J; Sebai, Mohamad E; Seal, Stella M; Manahan, Michele A; Cooney, Damon S; Cooney, Carisa M; Rosson, Gedge D

2018-06-26

Breast cancer-related lymphedema (BCRL) is a debilitating condition with morbidity, hindered quality of life, and increased health-related costs. Experimental studies support the use of musculocutaneous flaps for managing animal models with lymphedema. Although vascularized lymph node transfer (VLNT) and lymphovenous anastomosis are used to surgically treat patients with lymphedema, it is not known whether musculocutaneous or adipocutaneous flaps (eg, delayed autologous breast reconstruction) are effective for treating refractory upper extremity BCRL. We conducted a systematic review and pooled analysis to assess the impact of delayed breast reconstruction on developed BCRL. Following PRISMA guidelines, we systematically searched PubMed, Scopus, EMBASE, and Google Scholar databases for relevant studies published through November 11, 2016. We screened 934 unique articles. Of these, we conducted full-text and reference screening on 37 articles. We then performed a pooled and sensitivity analysis using random effects. Eight studies met our inclusion criteria. One study was a case report; 7 studies were case series with sample sizes ranging from 3 to 38 patients. According to our pooled analysis 58% of patients reported improvement after breast reconstruction with or without VLNT. Sensitivity analysis revealed that 84% (95% confidence interval, 0.74-0.95) of patients who underwent breast reconstruction and VLNT reported improvement, whereas only 22% (95% confidence interval, 0.12-0.32) of those who had breast reconstruction alone reported improvement. Our review summarizes the current evidence regarding the effect of delayed breast reconstruction on established lymphedema. The VLNT component of the autologous breast reconstruction procedures may be the largest contributing factor leading to lymphedema improvement.

RSR' pattern and the risk of mortality in men and women free of cardiovascular disease.

PubMed

O'Neal, Wesley T; Qureshi, Waqas; Li, Yabing; Soliman, Elsayed Z

2015-01-01

This study included 6,398 participants (mean age 55 ± 0.34 years; 54% female; 49% white; 22% black; 24% Mexican; 4.3% other) free of clinical cardiovascular disease (CVD) and major ECG abnormalities. Cox regression was used to examine the association between the RSR' (incomplete right bundle branch block (RBBB) or right ventricular conduction delay) pattern and CVD and all-cause mortalities. The RSR' pattern was not associated with an increased risk of CVD (HR=1.10; 95%CI=0.63, 1.91) mortality or all-cause (HR=0.95; 95%CI=0.66, 1.35) mortality. The results were similar when the RSR' pattern was further separated into incomplete RBBB and right ventricular conduction delay. In conclusion, the RSR' pattern is a benign finding in older adults free of clinical CVD. Copyright © 2015 Elsevier Inc. All rights reserved.

Patient and health service delay in pulmonary tuberculosis patients attending a referral hospital: a cross-sectional study.

PubMed

Kiwuwa, Mpungu S; Charles, Karamagi; Harriet, Mayanja Kizza

2005-11-24

Delays in diagnosis and initiation of effective treatment increase morbidity and mortality from tuberculosis as well as the risk of transmission in the community. The aim of this study was to determine the time taken for patients later confirmed as having TB to present with symptoms to the first health provider (patient delay) and the time taken between the first health care visit and initiation of tuberculosis treatment (health service delay). Factors relating to these 'delays' were analyzed. A cross-sectional survey, of 231 newly diagnosed smear-positive tuberculosis patients was conducted in Mulago National referral Hospital Kampala, from January to May 2002. Socio-demographic, lifestyle and health seeking factors were evaluated for their association with patient delay (> 2 weeks) and health service delay (> 4 weeks), using odds ratios with 95% confidence intervals (CI) including multivariate logistic regression. The median total delay to treatment initiation was 12 weeks. Patients often presented to drug shops or pharmacies (39.4%) and private clinics (36.8%) more commonly than government health units (14%) as initial contacts. Several independent predictors of 'patient delay' were identified: being hospitalized (odds ratio [0R] = 0.32; 95% CI: 0.12-0.80), daily alcohol consumption (OR = 3.7; CI: 1.57-9.76), subsistence farming (OR = 4.70; CI: 1.67-13.22), and perception of smoking as a cause of TB (OR = 5.54; CI: 2.26-13.58). Independent predictors of 'health service delay' were: > 2 health seeking encounters per month (OR = 2.74; CI: 1.10-6.83), and medical expenditure on TB related symptoms > 29 US dollars (OR = 3.88; CI: 1.19-12.62). Perceived TB stigma and education status was not associated with either form of delay. Delay in diagnosis of TB is prolonged at the referral centre with a significant proportion of Health service delay. More specific and effective health education of the general public on tuberculosis and seeking of appropriate medical consultation is likely to improve case detection. Certain specific groups require further attention. Alcoholics and subsistence farmers should be targeted to improve accessibility to TB treatment. Continuing medical education about TB management procedures for health providers and improvement in the capacity of TB control services should be undertaken.

Reversible acute axonal polyneuropathy associated with Wernicke-Korsakoff syndrome: impaired physiological nerve conduction due to thiamine deficiency?

PubMed

Ishibashi, S; Yokota, T; Shiojiri, T; Matunaga, T; Tanaka, H; Nishina, K; Hirota, H; Inaba, A; Yamada, M; Kanda, T; Mizusawa, H

2003-05-01

Acute axonal polyneuropathy and Wernicke-Korsakoff encephalopathy developed simultaneously in three patients. Nerve conduction studies (NCS) detected markedly decreased compound muscle action potentials (CMAPs) and sensory nerve action potentials (SNAPs) with minimal conduction slowing; sympathetic skin responses (SSRs) were also notably decreased. Sural nerve biopsies showed only mild axonal degeneration with scattered myelin ovoid formation. The symptoms of neuropathy lessened within two weeks after an intravenous thiamine infusion. CMAPs, SNAPs, and SSRs also increased considerably. We suggest that this is a new type of peripheral nerve impairment: physiological conduction failure with minimal conduction delay due to thiamine deficiency.

Phase delaying the human circadian clock with a single light pulse and moderate delay of the sleep/dark episode: no influence of iris color.

PubMed

Canton, Jillian L; Smith, Mark R; Choi, Ho-Sun; Eastman, Charmane I

2009-07-17

Light exposure in the late evening and nighttime and a delay of the sleep/dark episode can phase delay the circadian clock. This study assessed the size of the phase delay produced by a single light pulse combined with a moderate delay of the sleep/dark episode for one day. Because iris color or race has been reported to influence light-induced melatonin suppression, and we have recently reported racial differences in free-running circadian period and circadian phase shifting in response to light pulses, we also tested for differences in the magnitude of the phase delay in subjects with blue and brown irises. Subjects (blue-eyed n = 7; brown eyed n = 6) maintained a regular sleep schedule for 1 week before coming to the laboratory for a baseline phase assessment, during which saliva was collected every 30 minutes to determine the time of the dim light melatonin onset (DLMO). Immediately following the baseline phase assessment, which ended 2 hours after baseline bedtime, subjects received a 2-hour bright light pulse (~4,000 lux). An 8-hour sleep episode followed the light pulse (i.e. was delayed 4 hours from baseline). A final phase assessment was conducted the subsequent night to determine the phase shift of the DLMO from the baseline to final phase assessment.Phase delays of the DLMO were compared in subjects with blue and brown irises. Iris color was also quantified from photographs using the three dimensions of red-green-blue color axes, as well as a lightness scale. These variables were correlated with phase shift of the DLMO, with the hypothesis that subjects with lighter irises would have larger phase delays. The average phase delay of the DLMO was -1.3 +/- 0.6 h, with a maximum delay of ~2 hours, and was similar for subjects with blue and brown irises. There were no significant correlations between any of the iris color variables and the magnitude of the phase delay. A single 2-hour bright light pulse combined with a moderate delay of the sleep/dark episode delayed the circadian clock an average of ~1.5 hours. There was no evidence that iris color influenced the magnitude of the phase shift. Future studies are needed to replicate our findings that iris color does not impact the magnitude of light-induced circadian phase shifts, and that the previously reported differences may be due to race.

Factors associated with patient, and diagnostic delays in Chinese TB patients: a systematic review and meta-analysis.

PubMed

Li, Ying; Ehiri, John; Tang, Shenglan; Li, Daikun; Bian, Yongqiao; Lin, Hui; Marshall, Caitlin; Cao, Jia

2013-07-02

Delay in seeking care is a major impediment to effective management of tuberculosis (TB) in China. To elucidate factors that underpin patient and diagnostic delays in TB management, we conducted a systematic review and meta-analysis of factors that are associated with delays in TB care-seeking and diagnosis in the country. This review was prepared following standard procedures of the Cochrane Collaboration and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement and checklist. Relevant studies published up to November 2012 were identified from three major international and Chinese literature databases: Medline/PubMed, EMBASE and CNKI (China National Knowledge Infrastructure). We included 29 studies involving 38,947 patients from 17 provinces in China. Qualitative analysis showed that key individual level determinants of delays included socio-demographic and economic factors, mostly poverty, rural residence, lack of health insurance, lower educational attainment, stigma and poor knowledge of TB. Health facility determinants included limited availability of resources to perform prompt diagnosis, lack of qualified health workers and geographical barriers.Quantitative meta-analysis indicated that living in rural areas was a risk factor for patient delays (pooled odds ratio (OR) (95% confidence interval (CI)): 1.79 (1.62, 1.98)) and diagnostic delays (pooled OR (95% CI): 1.40 (1.23, 1.59)). Female patients had higher risk of patient delay (pooled OR (95% CI): 1.94 (1.13, 3.33)). Low educational attainment (primary school and below) was also a risk factor for patient delay (pooled OR (95% CI): 2.14 (1.03, 4.47)). The practice of seeking care first from Traditional Chinese Medicine (TMC) providers was also identified as a risk factor for diagnostic delay (pooled OR (95% CI): 5.75 (3.03, 10.94)). Patient and diagnostic delays in TB care are mediated by individual and health facility factors. Population-based interventions that seek to reduce TB stigma and raise awareness about the benefits of early diagnosis and prompt treatment are needed. Policies that remove patients' financial barriers in access to TB care, and integration of the informal care sector into TB control in urban and rural settings are central factors in TB control.

Relation of polymorphism of arsenic metabolism genes to arsenic methylation capacity and developmental delay in preschool children in Taiwan

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

Hsieh, Ru-Lan

Inefficient arsenic methylation capacity has been associated with developmental delay in children. The present study was designed to explore whether polymorphisms and haplotypes of arsenic methyltransferase (AS3MT), glutathione-S-transferase omegas (GSTOs), and purine nucleoside phosphorylase (PNP) affect arsenic methylation capacity and developmental delay. A case-control study was conducted from August 2010 to March 2014. All participants were recruited from the Shin Kong Wu Ho-Su Memorial Teaching Hospital. In total, 179 children with developmental delay and 88 children without delay were recruited. Urinary arsenic species, including arsenite (As{sup III}), arsenate (As{sup V}), monomethylarsonic acid (MMA{sup V}), and dimethylarsinic acid (DMA{sup V}) weremore » measured using a high-performance liquid chromatography-linked hydride generator and atomic absorption spectrometry. The polymorphisms of AS3MT, GSTO, and PNP were performed using the Sequenom MassARRAY platform with iPLEX Gold chemistry. Polymorphisms of AS3MT genes were found to affect susceptibility to developmental delay in children, but GSTO and PNP polymorphisms were not. Participants with AS3MT rs3740392 A/G + G/G genotype, compared with AS3MT rs3740392 A/A genotype, had a significantly lower secondary methylation index. This may result in an increased OR for developmental delay. Participants with the AS3MT high-risk haplotype had a significantly higher OR than those with AS3MT low-risk haplotypes [OR and 95% CI, 1.59 (1.08–2.34)]. This is the first study to show a joint dose-response effect of this AS3MT high-risk haplotype and inefficient arsenic methylation capacity on developmental delay. Our data provide evidence that AS3MT genes are related to developmental delay and may partially influence arsenic methylation capacity. - Highlights: • AS3MT genotypes were found to affect susceptibility to developmental delay. • AS3MT rs3740392 A/G and G/G genotype had a significantly low SMI (DMA/MMA) index. • AS3MT high-risk haplotype was significantly associated with developmental delay.« less

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

NASA Technical Reports Server (NTRS)

Walsh, Kevin R.

1992-01-01

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

Interventions for preventing, delaying the onset, or decreasing the burden of frailty: an overview of systematic reviews.

PubMed

Wilson, Michael G; Béland, François; Julien, Dominic; Gauvin, Lise; Guindon, G Emmanuel; Roy, Denis; Campbell, Kaitryn; Comeau, Donna G; Davidson, Heather; Raina, Parminder; Sattler, Deborah; Vrkljan, Brenda

2015-09-25

Many systematic reviews have evaluated the effectiveness of interventions to prevent, delay, or decrease frailty symptoms, but no effort has been made to identify, map, and synthesize the findings from reviews across the full spectrum of interventions. Our objectives are to (1) synthesize findings from all existing systematic reviews evaluating interventions for preventing, delaying the onset, or decreasing the burden of frailty symptoms; (2) examine different conceptualizations of frailty that have been used in the development and implementation of interventions; and (3) inform policy by convening a stakeholder dialogue with Canadian health-system leaders. We will conduct an overview of systematic reviews to identify and synthesize all of the systematic reviews addressing interventions to preventing, delaying the onset, or decreasing the burden of frailty symptoms. To identify relevant systematic reviews, we will conduct database searches for published and grey literature as well as contact key experts and search reference lists of included reviews. Two reviewers will independently review all search results for inclusion and then conceptually map, extract key findings (including the conceptualization/definition of frailty used) and assess the methodological quality of all included reviews. We will then synthesize the findings by producing a 'gap map' (i.e. mapping reviews in a matrix according to the interventions and outcomes assessed), and narratively synthesize the key messages across reviews related to type of interventions. Following the completion of the synthesis, we will use the findings to develop an evidence brief that mobilizes the best available evidence about the problem related to preventing, delaying the onset, or decreasing the burden of frailty symptoms in older adults, policy and programmatic options to address the problem and implementation considerations. The evidence brief will then be used as the input into a stakeholder dialogue, which will engage 18-22 Canadian health-system leaders (including policymakers, health providers, researchers, and other stakeholders) in 'off-the-record' deliberations to inform future actions and policymaking. PROSPERO CRD42015022082.

Effects of iso-octane/ethanol blend ratios on the observance of negative temperature coefficient behavior within the Ignition Quality Tester

DOE PAGES

Bogin, Jr., Gregory E.; Luecke, Jon; Ratcliff, Matthew A.; ...

2016-08-21

Here, an ignition delay study investigating the reduction in low temperature heat release (LTHR) and negative temperature coefficient (NTC) region with increasing ethanol concentration in binary blends of ethanol/isooctane was conducted in the Ignition Quality Tester (IQT). The IQT is advantageous for studying multi-component fuels such as iso-octane/ethanol which are difficult to study at lower temperatures covering the NTC region in traditional systems (e.g., shock tubes, rapid compression machines, etc.). The high octane numbers and concomitant long ignition delay times of ethanol and iso-octane are ideal for study in the IQT allowing the system to reach a quasi-homogeneous mixture; allowingmore » the effect of fuel chemistry on ignition delay to be investigated with minimal impact from the fuel spray due to the relatively long ignition times. NTC behavior from iso-octane/ethanol blends was observed for the first time using an IQT. Temperature sweeps of iso-octane/ethanol volumetric blends (100/0, 90/10, 80/20, 50/50, and 0/100) were conducted from 623 to 993 K at 0.5, 1.0 and 1.5 MPa and global equivalence ratios ranging from 0.7 to 1.0. Ignition of the iso-octane/ethanol blends in the IQT was also modeled using a 0-D homogeneous batch reactor model. Significant observations include: (1) NTC behavior was observed for ethanol/ iso-octane fuel blends up to 20% ethanol. (2) Ethanol produced shorter ignition delay times than iso-octane in the high temperature region. (3) The initial increase in ethanol from 0% to 10% had a lesser impact on ignition delay than increasing ethanol from 10% to 20%. (4) The 0-D model predicts that at 0.5 and 1.0 MPa ethanol produces the shortest ignition time in the high-temperature regime, as seen experimentally.« less

Once-daily MMX(®) mesalamine for endoscopic maintenance of remission of ulcerative colitis.

PubMed

D'Haens, Geert; Sandborn, William J; Barrett, Karen; Hodgson, Ian; Streck, Paul

2012-07-01

Treatment with mesalamine to maintain endoscopic remission (mucosal healing) of ulcerative colitis (UC) has been shown to reduce the risk of relapse and is the recommended first-line maintenance therapy. To improve treatment adherence, a mesalamine formulation that can be administered once-daily, MMX(®) mesalamine (Lialda; Shire Pharmaceuticals LLC, Wayne, PA), was developed. This study was conducted to determine the efficacy and safety of once-daily MMX mesalamine compared with twice-daily delayed-release mesalamine (Asacol; Warner Chilcott, Dublin, Ireland) for maintaining endoscopic remission in patients with UC. A multicenter, randomized, double-blind, 6-month, active-control trial was conducted to assess the non-inferiority of once-daily MMX mesalamine 2.4 g/day compared with twice-daily delayed-release mesalamine at a total daily dose of 1.6 g/day in patients with UC in endoscopic remission. The primary end point was maintenance of endoscopic remission at month 6 in the per-protocol (PP) population. Overall, 826 patients were randomized and dosed. The primary objective (non-inferiority) was met. At month 6, 83.7 and 77.8% of patients receiving MMX mesalamine in the PP and intent-to-treat (ITT) populations, respectively, had maintained endoscopic remission compared with 81.5% (PP) and 76.9% (ITT) of patients receiving delayed-release mesalamine (95% confidence interval for difference: -3.9%, 8.1% (PP); -5.0%, 6.9% (ITT)). Time to relapse was not significantly different between the two treatment groups (log-rank test, P=0.5116 (PP); P=0.5455 (ITT)). The proportion of patients with adverse events was 37.1 and 36.0% in patients receiving MMX mesalamine and delayed-release mesalamine, respectively. Once-daily dosing of MMX mesalamine 2.4 g/day was shown to be well tolerated and non-inferior to twice-daily dosing with delayed-release mesalamine 1.6 g/day for maintenance of endoscopic remission in patients with UC.

Effects of iso-octane/ethanol blend ratios on the observance of negative temperature coefficient behavior within the Ignition Quality Tester

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

Bogin, Jr., Gregory E.; Luecke, Jon; Ratcliff, Matthew A.

Here, an ignition delay study investigating the reduction in low temperature heat release (LTHR) and negative temperature coefficient (NTC) region with increasing ethanol concentration in binary blends of ethanol/isooctane was conducted in the Ignition Quality Tester (IQT). The IQT is advantageous for studying multi-component fuels such as iso-octane/ethanol which are difficult to study at lower temperatures covering the NTC region in traditional systems (e.g., shock tubes, rapid compression machines, etc.). The high octane numbers and concomitant long ignition delay times of ethanol and iso-octane are ideal for study in the IQT allowing the system to reach a quasi-homogeneous mixture; allowingmore » the effect of fuel chemistry on ignition delay to be investigated with minimal impact from the fuel spray due to the relatively long ignition times. NTC behavior from iso-octane/ethanol blends was observed for the first time using an IQT. Temperature sweeps of iso-octane/ethanol volumetric blends (100/0, 90/10, 80/20, 50/50, and 0/100) were conducted from 623 to 993 K at 0.5, 1.0 and 1.5 MPa and global equivalence ratios ranging from 0.7 to 1.0. Ignition of the iso-octane/ethanol blends in the IQT was also modeled using a 0-D homogeneous batch reactor model. Significant observations include: (1) NTC behavior was observed for ethanol/ iso-octane fuel blends up to 20% ethanol. (2) Ethanol produced shorter ignition delay times than iso-octane in the high temperature region. (3) The initial increase in ethanol from 0% to 10% had a lesser impact on ignition delay than increasing ethanol from 10% to 20%. (4) The 0-D model predicts that at 0.5 and 1.0 MPa ethanol produces the shortest ignition time in the high-temperature regime, as seen experimentally.« less

The delayed rectifier, IKI, is the major conductance in type I vestibular hair cells across vestibular end organs

NASA Technical Reports Server (NTRS)

Ricci, A. J.; Rennie, K. J.; Correia, M. J.

1996-01-01

Hair cells were dissociated from the semicircular canal, utricle, lagena and saccule of white king pigeons. Type I hair cells were identified morphologically based on the ratios of neck width to cuticular plate width (NPR < 0.72) as well as neck width to cell body width (NBR < 0.64). The perforated patch variant of the whole-cell recording technique was used to measure electrical properties from type I hair cells. In voltage-clamp, the membrane properties of all identified type I cells were dominated by a predominantly outward potassium current, previously characterized in semicircular canal as IKI. Zero-current potential, activation, deactivation, slope conductance, pharmacologic and steady-state properties of the complex currents were not statistically different between type I hair cells of different vestibular end organs. The voltage dependence causes a significant proportion of this conductance to be active about the cell's zero-current potential. The first report of the whole-cell activation kinetics of the conductance is presented, showing a voltage dependence that could be best fit by an equation for a single exponential. Results presented here are the first data from pigeon dissociated type I hair cells from utricle, saccule and lagena suggesting that the basolateral conductances of a morphologically identified population of type I hair cells are conserved between functionally different vestibular end organs; the major conductance being a delayed rectifier characterized previously in semicircular canal hair cells as IKI.

A Blood-Resistant Surgical Glue for Minimally Invasive Repair of Vessels and Heart Defects

PubMed Central

Lang, Nora; Pereira, Maria J.; Lee, Yuhan; Friehs, Ingeborg; Vasilyev, Nikolay V.; Feins, Eric N.; Ablasser, Klemens; O'Cearbhaill, Eoin D.; Xu, Chenjie; Fabozzo, Assunta; Padera, Robert; Wasserman, Steve; Freudenthal, Franz; Ferreira, Lino S.; Langer, Robert

2014-01-01

Currently, there are no clinically approved surgical glues that are nontoxic, bind strongly to tissue, and work well within wet and highly dynamic environments within the body. This is especially relevant to minimally invasive surgery that is increasingly performed to reduce postoperative complications, recovery times, and patient discomfort. We describe the engineering of a bioinspired elastic and biocompatible hydrophobic light-activated adhesive (HLAA) that achieves a strong level of adhesion to wet tissue and is not compromised by preexposure to blood. The HLAA provided an on-demand hemostatic seal, within seconds of light application, when applied to high-pressure large blood vessels and cardiac wall defects in pigs. HLAA-coated patches attached to the interventricular septum in a beating porcine heart and resisted supraphysiologic pressures by remaining attached for 24 hours, which is relevant to intracardiac interventions in humans. The HLAA could be used for many cardiovascular and surgical applications, with immediate application in repair of vascular defects and surgical hemostasis. PMID:24401941

Fetal Cardiac Impairment in Nitrofen-Induced Congenital Diaphragmatic Hernia: Postmortem Microcomputed Tomography Imaging Study.

PubMed

Pelizzo, Gloria; Calcaterra, Valeria; Lombardi, Claudio; Bussani, Rossana; Zambelli, Vanessa; De Silvestri, Annalisa; Custrin, Ana; Belgrano, Manuel; Zennaro, Floriana

2017-08-01

We assessed the post-mortem micro-CT utility to evaluate fetal cardiac impairment in nitrofen-induced congenital diaphragmatic hernia (CDH). At 9.5d postconception (dpc), pregnant rats were exposed to nitrofen. At +18 and +21dpc, fetuses were harvested by cesarean section. Postmortem micro-CT and autopsy were performed. Fetuses were assigned to three experimental groups: Control group (C), Nitrofen group (N, exposition to nitrofen without CDH), CDH group. Cardio-pulmonary indices were evaluated. An accurate morphological evaluation of the lung and heart was obtained. Early cardiac impairment was present in the N and CDH groups. At term pregnancy, an increased maximum diameter and decreased minimum diameter of the ventricles and increased interventricular septal thickness were noted in CDH. Histology showed a myocardial "disarray" and an high density of mitotic myocytes in CDH at midgestation. The potential utility of post-mortem fetal micro-CT examination in CDH was introduced. The results highlighted the presence of cardiac adaptation in affected fetuses.

[Long-term effects of hydroxychloroquine on metabolism of serum lipids and left ventricular structure and function in patients of systemic lupus erythematosus].

PubMed

Meng, Juan; Lu, Yuewu; Dong, Xin; Liu, Hongyan

2014-04-08

To observe the long-term effects of hydroxychloroquine treatment on blood lipids and left ventricular function of systemic lupus erythematosus (SLE) patients. A total of 72 SLE patients were randomly divided into 2 groups of hydroxychloroquine treatment (n = 36) and non-hydroxychloroquine (n = 36). The serum level of lipids, left ventricular end-diastolic diameter (LVEDD), left ventricular end-systolic diameter (LVESD), interventricular septum thickness (IVST), left ventricular posterior wall thickness (LVPWT), fractional shortening rate (FS), left ventricular ejection fraction (LVEF) and E/A ratio were measured before, 6 month, 12 month and 2 years after treatment. After long-term use of hydroxychloroquine, there were statistically differences in the levels of total cholesterol (TC), triglyceride (TG), low-density lipoprotein (LDL) and high-density lipoprotein (HDL). And LVEDD, LVWPT and E/A were statistically different (P < 0.05) before and after hydroxychloroquine dosing. The long-term use of hydroxychloroquine may improve lipid metabolism and left ventricular function in SLE patients.

Left phrenic nerve anatomy relative to the coronary venous system: Implications for phrenic nerve stimulation during cardiac resynchronization therapy.

PubMed

Spencer, Julianne H; Goff, Ryan P; Iaizzo, Paul A

2015-07-01

The objective of this study was to quantitatively characterize anatomy of the human phrenic nerve in relation to the coronary venous system, to reduce undesired phrenic nerve stimulation during left-sided lead implantations. We obtained CT scans while injecting contrast into coronary veins of 15 perfusion-fixed human heart-lung blocs. A radiopaque wire was glued to the phrenic nerve under CT, then we created three-dimensional models of anatomy and measured anatomical parameters. The left phrenic nerve typically coursed over the basal region of the anterior interventricular vein, mid region of left marginal veins, and apical region of inferior and middle cardiac veins. There was large variation associated with the average angle between nerve and veins. Average angle across all coronary sinus tributaries was fairly consistent (101.3°-111.1°). The phrenic nerve coursed closest to the middle cardiac vein and left marginal veins. The phrenic nerve overlapped a left marginal vein in >50% of specimens. © 2015 Wiley Periodicals, Inc.

Value of positive myocardial technetium-99m-pyrophosphate scintigraphy in the noninvasive diagnosis of cardiac amyloidosis

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

Wizenberg, T.A.; Muz, J.; Sohn, Y.H.

1982-04-01

Ten consecutive patients with tissue-proven amyloidosis, seven of whom presented with congestive heart failure, were found to exhibit intense diffuse uptake of technetium-99m-pyrophosphate (Tc-99m-PYP) on cardiac radionuclide imaging. The patients exhibited echocardiographic and systolic time interval abnormalities suggesting combined restrictive and congestive cardiomyopathic changes. On M-mode echocardiograms, there was symmetrically increased thickness of the interventricular septum and left ventricular (LV) posterior wall in diastole (10 of 10), decreased fractional shortening of the LV minor axis diameter in systole (eight of nine), and decreased percent thickening of the LV minor axis diameter in systole (eight of nine) and LV posterior wallmore » (10 of 10) in systole. Three patients demonstrated enlarged LV end-diastolic diameter. All 10 patients had abnormal PEP/LVET and eight had shortened LVETI. When combined with noninvasive tests of LV performance, positive myocardial pyrophosphate (PYP) scanning provides a new and useful adjunct in the diagnosis of amyloid heart disease.« less

Ultrasound imaging of propagation of myocardial contraction for non-invasive identification of myocardial ischemia

NASA Astrophysics Data System (ADS)

Matsuno, Yuya; Taki, Hirofumi; Yamamoto, Hiroaki; Hirano, Michinori; Morosawa, Susumu; Shimokawa, Hiroaki; Kanai, Hiroshi

2017-07-01

Non-invasive identification of ischemic regions is important for diagnosis and treatment of myocardial infarction. In the present study, ultrasound measurement was applied to the interventricular septum of three open-chest swine hearts. The properties of the myocardial contraction response of the septum were compared between normal and acute ischemic conditions, where the acute ischemic condition of the septum originated from direct avascularization of the left anterior descending (LAD) coronary artery. The result showed that the contraction response propagated from the basal side to the apical side along the septum. The estimated propagation velocities in the normal and acute ischemic conditions were 3.6 and 1.9 m/s, respectively. This finding indicates that acute ischemia which occurred 5 s after the avascularization of the LAD promptly suppressed the propagation velocity through the ventricular septum to about half the normal velocity. It was suggested that the myocardial ischemic region could be identified using the difference in the propagation velocity of the myocardial response to contraction.

Rhodotorula fungemia: Report of two cases in Sfax (Tunisia).

PubMed

Guidara, R; Trabelsi, H; Neji, S; Cheikhrouhou, F; Sellami, H; Makni, F; Ayadi, A

2016-06-01

Rhodotorula is emerging as an important cause of nosocomial and opportunistic infections. We present two cases of Rhodotorula mucilaginosa fungemia diagnosed at our hospital during the last decade. The first case was of a term neonate who presented congenital heart disease (interventricular communication) and body dysmorphic disorder. He was admitted for respiratory failure and sepsis. The second case involved in a 33-year-old woman that had Hodgkinien lymphoma associated to tuberculosis. Identification was performed using commercial systems and confirmed by PCR sequencing of internal transcribed spacer, ITS1 and ITS2 regions of rDNA. Antifungal susceptibility tested by sensititre yeast revealed susceptibility to amphotericin B and resistance to fluconazole for the two strains. These cases emphasize the emerging importance of Rhodotorula sp. as a pathogen and it must be considered a potential pathogen in patients with immunosupression and with central venous catheters. Correct identification is mandatory for appropriate management, as Rhodotorula spp. are resistant to antifungal agents, such as fluconazole. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Evaluation of segmental left ventricular wall motion by equilibrium gated radionuclide ventriculography.

PubMed

Van Nostrand, D; Janowitz, W R; Holmes, D R; Cohen, H A

1979-01-01

The ability of equilibrium gated radionuclide ventriculography to detect segmental left ventricular (LV) wall motion abnormalities was determined in 26 patients undergoing cardiac catheterization. Multiple gated studies obtained in 30 degrees right anterior oblique and 45 degrees left anterior oblique projections, played back in a movie format, were compared to the corresponding LV ventriculograms. The LV wall in the two projections was divided into eight segments. Each segment was graded as normal, hypokinetic, akinetic, dyskinetic, or indeterminate. Thirteen percent of the segments in the gated images were indeterminate; 24 out of 27 of these were proximal or distal inferior wall segments. There was exact agreement in 86% of the remaining segments. The sensitivity of the radionuclide technique for detecting normal versus any abnormal wall motion was 71%, with a specificity of 99%. Equilibrium gated ventriculography is an excellent noninvasive technique for evaluating segmental LV wall motion. It is least reliable in assessing the proximal inferior wall and interventricular septum.

Clinical-Physiological Considerations in Patients Undergoing Staged Palliation for a Functionally Single Ventricle.

PubMed

Penny, Daniel J; Krishnamurthy, Rajesh

2016-08-01

The objectives of this review are to discuss the pathophysiology of the circulation with a functionally univentricular heart, with a focus on the unique physiologic characteristics, which provide the underpinnings for the management of these complex patients. MEDLINE and PubMed. The circulation of the patient with a functionally univentricular heart displays unique physiologic characteristics, which are quite different from those of the normal biventricular circulation. There are profound differences within the heart itself in terms of ventricular function, interventricular interactions, and myocardial architecture, which are likely to have significant implications for the efficiency of ventricular ejection and metabolism. The coupling between the systemic ventricle and the aorta also displays unique features. The 3D orientation of the Fontan anastomosis itself can profoundly impact cardiac output, although the "portal" pulmonary arterial bed is a crucial determinant of overall cardiovascular function. As a result, disease-specific approaches to improve cardiovascular function are required at all stages during the care of these complex patients.

Stereological Cell Morphometry In Right Atrium Myocardium Of Primates

NASA Astrophysics Data System (ADS)

Mandarim-De-Lacerda, Carlos A...; Hureau, Jacques

1986-07-01

The mechanism by which the cardiac impulse is propagated in normal hearts from its origin in the sinus node to the atrio-ventricular node has not been agreed on fully. We studied the "internodal posterior tract" through the crista terminalis by light microscopy and stereological morphometry. The hearts of 12 Papio cynocephalus were perfused , after sacrifice,with phosphate-buffered formol saline. The regions of the crista terminalis (CT), interatrial septum (IAS), atrioventricular bundle (AVB) and interventricular septum (IVS) were cut off and embedded in paraplast and sectioned (10 4m). The multipurpose test system M 42 was superimposed over the photomicrographs (1,890 points test, ESR = 2%) to the stereological computing. The quantitative results show that the cells from CT were more closely relationed with IAS cells than others cells (IVS and AVB cells). This results are not a morphological evidence to establish the specificity of the "internodal posterior tract". The cellular arrangement and anatomical variation in CT myocardium is very important.

A test of water vapor radiometer-based troposphere calibration using VLBI observations on a 21-kilometer baseline

NASA Technical Reports Server (NTRS)

Linfield, R. P.; Teitelbaum, L. P.; Skjerve, L. J.; Keihm, S. J.; Walter, S. J.; Mahoney, M. J.; Treuhaft, R. N.

1995-01-01

Simultaneous very long baseline interferometry (VLBI) and water vapor radiometer (WVR) measurements on a 21 km baseline showed that calibration by WVRs removed a significant fraction of the effect of tropospheric delay fluctuations for these experiments. From comparison of the residual delay variations within scans and between scans, the total tropospheric contribution t the delay residuals for each of the three 5 to 20 hour sessions was estimated as 1, 17, and 10%, with the first value being uncertain. The observed improvement in rms residual delay from WVR calibration during these three sessions was 4, 16, and 2%, respectively. The improvement is consistent with the estimated 2 to 3 mm path delay precision of current WVRs. The VLBI measurements, of natural radio sources, were conducted in April and May 1993 at Goldstone, California. Dual-frequency (2.3 and 8.4 GHz) observations were employed to remove the effects of charged particles from the data. Measurements with co-pointed WVRs, located within 50 m of the axis of each antenna, were performed to test the ability of the WVRs to calibrate line-of-sight path delays. Factors that made WVR performance assessment difficult included (1) the fact that the level of tropospheric fluctuations was smaller than is typical for Goldstone during these experiments and (2) VLBI delay variations on longer time scales (i.e., over multiple scans) contained uncalibrated instrumental effects (probably a result of slow temperature variations in the VLBI hardware) that were larger than the tropospheric effects.

Ignition Delay of Combustible Materials in Normoxic Equivalent Environments

NASA Technical Reports Server (NTRS)

McAllister, Sara; Fernandez-Pello, Carlos; Ruff, Gary; Urban, David

2009-01-01

Material flammability is an important factor in determining the pressure and composition (fraction of oxygen and nitrogen) of the atmosphere in the habitable volume of exploration vehicles and habitats. The method chosen in this work to quantify the flammability of a material is by its ease of ignition. The ignition delay time was defined as the time it takes a combustible material to ignite after it has been exposed to an external heat flux. Previous work in the Forced Ignition and Spread Test (FIST) apparatus has shown that the ignition delay in the currently proposed space exploration atmosphere (approximately 58.6 kPa and32% oxygen concentration) is reduced by 27% compared to the standard atmosphere used in the Space Shuttle and Space Station. In order to determine whether there is a safer environment in terms of material flammability, a series of piloted ignition delay tests using polymethylmethacrylate (PMMA) was conducted in the FIST apparatus to extend the work over a range of possible exploration atmospheres. The exploration atmospheres considered were the normoxic equivalents, i.e. reduced pressure conditions with a constant partial pressure of oxygen. The ignition delay time was seen to decrease as the pressure was reduced along the normoxic curve. The minimum ignition delay observed in the normoxic equivalent environments was nearly 30% lower than in standard atmospheric conditions. The ignition delay in the proposed exploration atmosphere is only slightly larger than this minimum. Interms of material flammability, normoxic environments with a higher pressure relative to the proposed pressure would be desired.

Short-Term Anticoagulant Therapy and Thrombus Location Are Independent Risk Factors for Delayed Recanalization of Deep Vein Thrombosis

PubMed Central

Zhang, Chuanlin; Fu, Qining; Zhao, Yu; Mu, Shaoyu; Liu, Liping

2016-01-01

Background Prompt recanalization of the vein containing the thrombus is an important goal during the initial treatment of DVT, and risk factors for delayed recanalization in patients with deep vein thrombosis (DVT) in the lower extremities need to be determined. Material/Methods A total of 174 patients with DVT in lower extremities were recruited from June 2014 to March 2015 at our hospital. Duplex ultrasound scanning was conducted for all patients at 1 and 6 months after baseline evaluation. We divided the patients into recanalization and non-recanalization groups and analyzed risk factors for delayed recanalization. Results The univariate analysis revealed that an oral anticoagulant time of less than 3 months and venous thrombus location were risk factors for delayed recanalization (P<0.01). However, age, gender, hypertension, diabetes, pulmonary embolism, incidence factors, the use of catheter-directed thrombolytic (CDT) drugs, and inferior vena cava filter (IVCF) implantation had no influence on the incidence of delayed recanalization in patients with DVT (P>0.05). The multivariate analysis showed that patients with an anticoagulant time of less than 3 months had a lower incidence of recanalization than those with an anticoagulant time of more than 3 months (OR=2.358, P<0.05). The risk of delayed recanalization in patients with proximal DVT was 7 times higher than that in patients with distal DVT. Conclusions Duration of anticoagulant treatment of less than 3 months and venous thrombus location are independent risk factors for delayed recanalization of DVT in the lower extremities. PMID:26790571

Location in the right hemi-colon is an independent risk factor for delayed post-polypectomy hemorrhage: a multi-center case-control study.

PubMed

Buddingh, K Tim; Herngreen, Thomas; Haringsma, Jelle; van der Zwet, Wil C; Vleggaar, Frank P; Breumelhof, Ronald; Ter Borg, Frank

2011-06-01

Delayed hemorrhage is an infrequent, but serious complication of colonoscopic polypectomy. Large size is the only polyp-related factor that has been unequivocally proven to increase the risk of delayed bleeding. It has been suggested that location in the right hemi-colon is also a risk factor. The objective of this study was to determine whether polyp location is an independent risk factor for delayed post-polypectomy hemorrhage. A retrospective case-control study was conducted in two university hospitals and two community hospitals. Thirty-nine cases and 117 controls were identified. In multivariate analysis, size and location were found to be independent polyp-related risk factors for delayed type hemorrhage. The risk increased by 13% for every 1 mm increase in polyp diameter (odds ratio (OR) 1.13, 95% confidence interval (CI) 1.05-1.20, P<0.001). Polyps located in the right hemi-colon had an OR of 4.67 (1.88-11.61, P=0.001) for delayed hemorrhage. Polyps in the cecum seemed to be especially at high risk in univariate analysis (OR 13.82, 95% CI 2.66-71.73), but this could not be assessed in multivariate analysis as the number of cases was too small. Polyp type (sessile or pedunculated) was not a risk factor. Polyp location in the right hemi-colon seems to be an independent and substantial risk factor for delayed post-polypectomy hemorrhage. A low threshold for preventive hemostatic measures is advised when removing polyps from this region.

Relationship between time management in construction industry and project management performance

NASA Astrophysics Data System (ADS)

Nasir, Najuwa; Nawi, Mohd Nasrun Mohd; Radzuan, Kamaruddin

2016-08-01

Nowadays, construction industry particularly in Malaysia struggle in achieving status of eminent time management for construction project. Project managers have a great responsibility to keep the project success under time of project completion. However, studies shows that delays especially in Malaysian construction industry still unresolved due to weakness in managing the project. In addition, quality of time management on construction projects is generally poor. Due to the progressively extended delays issue, time performance becomes an important subject to be explored to investigate delay factors. The method of this study is review of literature towards issues in construction industry which affecting time performance of project in general by focusing towards process involved for project management. Based on study, it was found that knowledge, commitment, cooperation are the main criteria as an overall to manage the project into a smooth process during project execution until completion. It can be concluded that, the strength between project manager and team members in these main criteria while conducting the project towards good time performance is highly needed. However, there is lack of establishment towards factors of poor time performance which strongly related with project management. Hence, this study has been conducted to establish factors of poor time performance and its relations with project management.

Path integration of head direction: updating a packet of neural activity at the correct speed using axonal conduction delays.

PubMed

Walters, Daniel; Stringer, Simon; Rolls, Edmund

2013-01-01

The head direction cell system is capable of accurately updating its current representation of head direction in the absence of visual input. This is known as the path integration of head direction. An important question is how the head direction cell system learns to perform accurate path integration of head direction. In this paper we propose a model of velocity path integration of head direction in which the natural time delay of axonal transmission between a linked continuous attractor network and competitive network acts as a timing mechanism to facilitate the correct speed of path integration. The model effectively learns a "look-up" table for the correct speed of path integration. In simulation, we show that the model is able to successfully learn two different speeds of path integration across two different axonal conduction delays, and without the need to alter any other model parameters. An implication of this model is that, by learning look-up tables for each speed of path integration, the model should exhibit a degree of robustness to damage. In simulations, we show that the speed of path integration is not significantly affected by degrading the network through removing a proportion of the cells that signal rotational velocity.

Path Integration of Head Direction: Updating a Packet of Neural Activity at the Correct Speed Using Axonal Conduction Delays

PubMed Central

Walters, Daniel; Stringer, Simon; Rolls, Edmund

2013-01-01

The head direction cell system is capable of accurately updating its current representation of head direction in the absence of visual input. This is known as the path integration of head direction. An important question is how the head direction cell system learns to perform accurate path integration of head direction. In this paper we propose a model of velocity path integration of head direction in which the natural time delay of axonal transmission between a linked continuous attractor network and competitive network acts as a timing mechanism to facilitate the correct speed of path integration. The model effectively learns a “look-up” table for the correct speed of path integration. In simulation, we show that the model is able to successfully learn two different speeds of path integration across two different axonal conduction delays, and without the need to alter any other model parameters. An implication of this model is that, by learning look-up tables for each speed of path integration, the model should exhibit a degree of robustness to damage. In simulations, we show that the speed of path integration is not significantly affected by degrading the network through removing a proportion of the cells that signal rotational velocity. PMID:23526976

Risk assessment of underpass infrastructure project based on IS0 31000 and ISO 21500 using fishbone diagram and RFMEA (project risk failure mode and effects analysis) method

NASA Astrophysics Data System (ADS)

Purwanggono, Bambang; Margarette, Anastasia

2017-12-01

Completion time of highway construction is very meaningful for smooth transportation, moreover expected number of ownership motor vehicle will increase each year. Therefore, this study was conducted with to analyze the constraints that contained in an infrastructure development project. This research was conducted on Jatingaleh Underpass Project, Semarang. This research was carried out while the project is running, on the implementation, this project is experiencing delays. This research is done to find out what are the constraints that occur in execution of a road infrastructure project, in particular that causes delays. The method that used to find the root cause is fishbone diagram to obtain a possible means of mitigation. Coupled with the RFMEA method used to determine the critical risks that must be addressed immediately on road infrastructure project. The result of data tabulation in this study indicates that the most possible mitigation tool to make a Standard Operating Procedure (SOP) recommendations to disrupt utilities that interfere project implementation. Process of risk assessment has been carried out systematically based on ISO 31000:2009 on risk management and for determination of delayed variables, the requirements of process groups according to ISO 21500:2013 on project management were used.

Methodological issues and evidence of malfeasance in research purporting to show thimerosal in vaccines is safe.

PubMed

Hooker, Brian; Kern, Janet; Geier, David; Haley, Boyd; Sykes, Lisa; King, Paul; Geier, Mark

2014-01-01

There are over 165 studies that have focused on Thimerosal, an organic-mercury (Hg) based compound, used as a preservative in many childhood vaccines, and found it to be harmful. Of these, 16 were conducted to specifically examine the effects of Thimerosal on human infants or children with reported outcomes of death; acrodynia; poisoning; allergic reaction; malformations; auto-immune reaction; Well's syndrome; developmental delay; and neurodevelopmental disorders, including tics, speech delay, language delay, attention deficit disorder, and autism. In contrast, the United States Centers for Disease Control and Prevention states that Thimerosal is safe and there is "no relationship between [T]himerosal[-]containing vaccines and autism rates in children." This is puzzling because, in a study conducted directly by CDC epidemiologists, a 7.6-fold increased risk of autism from exposure to Thimerosal during infancy was found. The CDC's current stance that Thimerosal is safe and that there is no relationship between Thimerosal and autism is based on six specific published epidemiological studies coauthored and sponsored by the CDC. The purpose of this review is to examine these six publications and analyze possible reasons why their published outcomes are so different from the results of investigations by multiple independent research groups over the past 75+ years.

Methodological Issues and Evidence of Malfeasance in Research Purporting to Show Thimerosal in Vaccines Is Safe

PubMed Central

Kern, Janet; Geier, David; Haley, Boyd; King, Paul; Geier, Mark

2014-01-01

There are over 165 studies that have focused on Thimerosal, an organic-mercury (Hg) based compound, used as a preservative in many childhood vaccines, and found it to be harmful. Of these, 16 were conducted to specifically examine the effects of Thimerosal on human infants or children with reported outcomes of death; acrodynia; poisoning; allergic reaction; malformations; auto-immune reaction; Well's syndrome; developmental delay; and neurodevelopmental disorders, including tics, speech delay, language delay, attention deficit disorder, and autism. In contrast, the United States Centers for Disease Control and Prevention states that Thimerosal is safe and there is “no relationship between [T]himerosal[-]containing vaccines and autism rates in children.” This is puzzling because, in a study conducted directly by CDC epidemiologists, a 7.6-fold increased risk of autism from exposure to Thimerosal during infancy was found. The CDC's current stance that Thimerosal is safe and that there is no relationship between Thimerosal and autism is based on six specific published epidemiological studies coauthored and sponsored by the CDC. The purpose of this review is to examine these six publications and analyze possible reasons why their published outcomes are so different from the results of investigations by multiple independent research groups over the past 75+ years. PMID:24995277

Effect of silane concentration on the supersonic combustion of a silane/methane mixture

NASA Technical Reports Server (NTRS)

Northam, G. B.; Mclain, A. G.; Pellett, G. L.; Diskin, G. S.

1986-01-01

A series of direct connect combustor tests was conducted to determine the effect of silane concentration on the supersonic combustion characteristics of silane/methane mixtures. Shock tube ignition delay data indicated more than an order of magnitude reduction in ignition delay times for both 10 and 20 percent silane/methane mixtures as compared to methane. The ignition delay time of the 10 percent mixture was only a factor of 2.3 greater than that of the 20 percent mixture. Supersonic combustion tests were conducted with the fuel injected into a model scramjet combustor. The combustor was mounted at the exit of a Mach 2 nozzle and a hydrogen fired heater was used to provide a variation in test gas total temperature. Tests using the 20 percent silane/methane mixture indicated considerable combustion enhancement when compared to methane alone. This mixture had an autoignition total temperature of 1650 R. This autoignition temperature can be contrasted with 2330 R for hydrogen and 1350 R for a 20 percent silane/hydrogen mixture in similar hardware. Methane without the silane additive did not autoignite in this configuration at total temperatures as high as 3900 R, the maximum temperature at which tests were conducted. Supersonic combustion tests with the silane concentration reduced to 10 percent indicated little improvement in combustion performance over pure methane. The addition of 20 percent silane to methane resulted in a pyrophoric fuel with good supersonic combustion performance. Reducing the silane concentration below this level, however, yielded a less pyrophoric fuel that exhibited poor supersonic combustion performance.

Connected commercial vehicles-integrated truck project : vehicle build test report.

DOT National Transportation Integrated Search

2000-12-01

This paper examines the ways ITS is changing the way federal and state motor carrier agencies conduct business with the motor carrier industry. New technologies are streamlining credentialing operations, reducing delays for safe carriers, and improvi...

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

PubMed

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

2009-11-01

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

Relation of polymorphism of arsenic metabolism genes to arsenic methylation capacity and developmental delay in preschool children in Taiwan.

PubMed

Hsieh, Ru-Lan; Su, Chien-Tien; Shiue, Horng-Sheng; Chen, Wei-Jen; Huang, Shiau-Rung; Lin, Ying-Chin; Lin, Ming-I; Mu, Shu-Chi; Chen, Ray-Jade; Hsueh, Yu-Mei

2017-04-15

Inefficient arsenic methylation capacity has been associated with developmental delay in children. The present study was designed to explore whether polymorphisms and haplotypes of arsenic methyltransferase (AS3MT), glutathione-S-transferase omegas (GSTOs), and purine nucleoside phosphorylase (PNP) affect arsenic methylation capacity and developmental delay. A case-control study was conducted from August 2010 to March 2014. All participants were recruited from the Shin Kong Wu Ho-Su Memorial Teaching Hospital. In total, 179 children with developmental delay and 88 children without delay were recruited. Urinary arsenic species, including arsenite (As III ), arsenate (As V ), monomethylarsonic acid (MMA V ), and dimethylarsinic acid (DMA V ) were measured using a high-performance liquid chromatography-linked hydride generator and atomic absorption spectrometry. The polymorphisms of AS3MT, GSTO, and PNP were performed using the Sequenom MassARRAY platform with iPLEX Gold chemistry. Polymorphisms of AS3MT genes were found to affect susceptibility to developmental delay in children, but GSTO and PNP polymorphisms were not. Participants with AS3MT rs3740392 A/G+G/G genotype, compared with AS3MT rs3740392 A/A genotype, had a significantly lower secondary methylation index. This may result in an increased OR for developmental delay. Participants with the AS3MT high-risk haplotype had a significantly higher OR than those with AS3MT low-risk haplotypes [OR and 95% CI, 1.59 (1.08-2.34)]. This is the first study to show a joint dose-response effect of this AS3MT high-risk haplotype and inefficient arsenic methylation capacity on developmental delay. Our data provide evidence that AS3MT genes are related to developmental delay and may partially influence arsenic methylation capacity. Copyright © 2017 Elsevier Inc. All rights reserved.

A CCD Monolithic LMS Adaptive Analog Signal Processor Integrated Circuit.

DTIC Science & Technology

1980-03-01

adaptive filter with electrically- reprogrammable MOS analog conductance weights. I The analog and digital peripheral MOS on-chip circuits are provided with...electrically reprogrammable analog weights at tap positions along a CCD analog delay line in order to form a basic linear combiner for adaptive filtering...electrically reprogrammable analog conductance weights was introduced with the use of non-volatile MNOS memory 6-7 transistors biased in their triode

Effect of cochlear implantation on middle ear function: A three-month prospective study.

PubMed

Wasson, Joseph D; Campbell, Luke; Chambers, Scott; Hampson, Amy; Briggs, Robert J S; O'Leary, Stephen J

2018-05-01

To determine if cochlear implantation has a delayed effect on the middle ear conductive hearing mechanism by measuring laser Doppler vibrometry (LDV) of the tympanic membrane (TM) in both implanted and contralateral control ears preoperatively and 3 months postoperatively, and then comparing the relative change in LDV outcome measures between implanted and control ears. Prospective cohort study. Eleven preoperative adult unilateral cochlear implant recipients in previously unoperated ears with normal anatomy and aerated temporal bones were included in this study. The magnitude and phase angle of umbo velocity transfer function in response to air- conduction (AC) stimulus, and the magnitude of umbo velocity in response to bone- conduction (BC) stimulus were measured in the implant ear and the contralateral control ear preoperatively and 3 months postoperatively and compared. No significant changes in the magnitude or phase angle of TM velocity in response to either AC or BC stimulus were observed in the implanted ear relative to the contralateral control ear 3 months following cochlear implantation. From the results of LDV measurements, it can be said that cochlear implantation has no significant delayed effect on the middle ear conductive mechanism. 4. Laryngoscope, 128:1207-1212, 2018. © 2017 The American Laryngological, Rhinological and Otological Society, Inc.

A tutorial on the use of Excel 2010 and Excel for Mac 2011 for conducting delay-discounting analyses.

PubMed

Reed, Derek D; Kaplan, Brent A; Brewer, Adam T

2012-01-01

In recent years, researchers and practitioners in the behavioral sciences have profited from a growing literature on delay discounting. The purpose of this article is to provide readers with a brief tutorial on how to use Microsoft Office Excel 2010 and Excel for Mac 2011 to analyze discounting data to yield parameters for both the hyperbolic discounting model and area under the curve. This tutorial is intended to encourage the quantitative analysis of behavior in both research and applied settings by readers with relatively little formal training in nonlinear regression.

A TUTORIAL ON THE USE OF EXCEL 2010 AND EXCEL FOR MAC 2011 FOR CONDUCTING DELAY-DISCOUNTING ANALYSES

PubMed Central

Reed, Derek D; Kaplan, Brent A; Brewer, Adam T

2012-01-01

In recent years, researchers and practitioners in the behavioral sciences have profited from a growing literature on delay discounting. The purpose of this article is to provide readers with a brief tutorial on how to use Microsoft Office Excel 2010 and Excel for Mac 2011 to analyze discounting data to yield parameters for both the hyperbolic discounting model and area under the curve. This tutorial is intended to encourage the quantitative analysis of behavior in both research and applied settings by readers with relatively little formal training in nonlinear regression. PMID:22844143

Comparison of dual-k spacer and single-k spacer for single NWFET and 3-stack NWFET

NASA Astrophysics Data System (ADS)

Ko, Hyungwoo; Kim, Jongsu; Kim, Minsoo; Kang, Myounggon; Shin, Hyungcheol

2018-02-01

The investigation of the Dual-k spacer through comparative analysis of single nanowire-FET(NWFET)/3-stack NWFET and underlap/overlap channel is conducted. It is known that the dug 3-stack NWFET has better delay characteristics than single NWFET with the use of high permittivity material of Cin in Dual-k spacer structure. In addition, there is no difference of delay between overlap and underlap channel when it used Dual-k spacer structure but underlap channel of Dual-k 3-stack NWFET shows better short channel immunity.

Longitudinal and reciprocal relations between delay discounting and crime

PubMed Central

Lee, Christine A.; Derefinko, Karen J.; Milich, Richard; Lynam, Donald R.; DeWall, C. Nathan

2017-01-01

Theorists argue that self-control failure is the underlying cause of criminal behavior, with previous research linking poor self-control to delinquency and drug use. The path from self-control to crime is well-established, but less is known about whether criminal behavior contributes to self-control deficits over time. We investigated bi-directional relations between self-control assessed via a delay discounting task and self-reported crime over a three-year period. During their first, second (73.38% retention rate), and third (63.12% retention rate) years of college, 526 undergraduates completed a delay discounting task and reported on their criminal behavior. In order to maximize variability, participants with conduct problems were overrecruited, comprising 23.1% of the final sample. As expected, more discounting of hypothetical monetary rewards significantly predicted future property crime across a one and two-year period, even when controlling for initial levels of both. This study also demonstrated evidence of a bi-directional relationship; violent crime predicted higher rates of delay discounting one year later. These results suggest that bi-directional relations exist between self-control and types of crime. PMID:28970645

On delay adjustment for dynamic load balancing in distributed virtual environments.

PubMed

Deng, Yunhua; Lau, Rynson W H

2012-04-01

Distributed virtual environments (DVEs) are becoming very popular in recent years, due to the rapid growing of applications, such as massive multiplayer online games (MMOGs). As the number of concurrent users increases, scalability becomes one of the major challenges in designing an interactive DVE system. One solution to address this scalability problem is to adopt a multi-server architecture. While some methods focus on the quality of partitioning the load among the servers, others focus on the efficiency of the partitioning process itself. However, all these methods neglect the effect of network delay among the servers on the accuracy of the load balancing solutions. As we show in this paper, the change in the load of the servers due to network delay would affect the performance of the load balancing algorithm. In this work, we conduct a formal analysis of this problem and discuss two efficient delay adjustment schemes to address the problem. Our experimental results show that our proposed schemes can significantly improve the performance of the load balancing algorithm with neglectable computation overhead.

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

PubMed Central

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

2011-01-01

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

[Medical audit of neonatal deaths with the "three delay" model in a pediatric hospital in Ouagadougou].

PubMed

Kouéta, Fla; Ouédraogo Yugbaré, Solange Odile; Dao, Lassina; Dao, Fousséni; Yé, Diarra; Kam, Kobena Ludovic

2011-01-01

To determine the causes of neonatal deaths and their contributing factors. We used the "three-delay model" to conduct an audit of the neonatal deaths that occurred between January 2006 and December 2010 at the Charles de Gaulle University Pediatric Hospital, in Ouagadougou. The neonatal mortality rate was 12.3%. The main direct causes were infections (70%), cerebral distress (10%), respiratory distress (7%), congenital malformations (5.5%), prematurity (4.5%) and hemorrhagic syndromes (3%). All three delays were found: in decision making in 64.4% of cases, in access to health services in 77%, and in receiving appropriate care in 66.9%; they multiplied the risk of death by a factor of 4, 3 and 5, respectively. To reduce deaths of newborn babies, it is necessary to overcome the three delays that contribute to it, pending the improvement of socioeconomic conditions of populations. This combat requires optimizing the implementation of the subsidies for obstetric and neonatal emergency care and strengthening the involvement of all stakeholders, specifically, policy makers, the community and health professionals.

Arrival Metering Precision Study

NASA Technical Reports Server (NTRS)

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

2015-01-01

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

The continuing problem of missed test results in an integrated health system with an advanced electronic medical record.

PubMed

Wahls, Terry; Haugen, Thomas; Cram, Peter

2007-08-01

Missed results can cause needless treatment delays. However, there is little data about the magnitude of this problem and the systems that clinics use to manage test results. Surveys about potential problems related to test results management were developed and administered to clinical staff in a regional Veterans Administration (VA) health care network. The provider survey, conducted four times between May 2005 and October 2006, sampling VA staff physicians, physician assistants, nurse practitioners, and internal medicine trainees, asked questions about the frequency of missed results and diagnosis or treatment delays seen in the antecedent two weeks in their clinics, or if a trainee, the antecedent month. Clinical staff survey response rate was 39% (143 of 370), with 40% using standard operating procedures to manage test results. Forty-four percent routinely reported all results to patients. The provider survey response rate was 50% (441 of 884) overall, with responses often (37% overall; range 29% to 46%) indicating they had seen patients with diagnosis or treatment delays attributed to a missed result; 15% reported two or more such encounters. Even in an integrated health system with an advanced electronic medical record, missed test results and associated diagnosis or treatment delays are common. Additional study and measures of missed results and associated treatment delays are needed.

The measurement of atmospheric water vapor - Radiometer comparison and spatial variations

NASA Technical Reports Server (NTRS)

Rocken, C.; Johnson, J. M.; Ware, R. H.; Neilan, R. E.; Cerezo, M.; Jordan, J. R.; Falls, M. J..; Nelson, L. D.; Hayes, M.

1991-01-01

Two water vapor radiometer (WVR) experiments were conducted to evaluate whether such instruments are both suitable and necessary to correct for propagation effects that are induced by precipitable water vapor (PWV) on signals from GPS and VLBI. WVRs are suitable for these corrections if they provide wet path delays to better than 0.5 cm. They are needed if spatial variations of PWV result in complicated, direction-dependent propagation effects that are too complex to be parametrized in the GPS or VLBI geodetic solution. The suitability of radiometers was first addressed by comparing six airport WVRs for two weeks. While two WVRs showed an average wet path delay bias of only 0.1 cm, others were biased by 1-3 cm relative to each other and relative to radiosondes. The second experiment addressed the question whether radiometers are needed for the detection of inhomogeneities in the wet delay. Three JPL D-series radiometers were operated at three sites 50 km apart. The WVRs simultaneously sampled PWV at different azimuths and elevations in search of spatial variations of PWV. On one day of this second experiment evidence was found for spatial variations of the wet path delay as high as 20 percent of the total wet path delay.

Method and Apparatus for Monitoring the Integrity of a Geomembrane Liner using time Domain Reflectometry

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

Morris, John L.

1998-11-09

Leaks are detected in a multi-layered geomembrane liner by a two-dimensional time domain reflectometry (TDR) technique. The TDR geomembrane liner is constructed with an electrically conductive detection layer positioned between two electrically non-conductive dielectric layers, which are each positioned between the detection layer and an electrically conductive reference layer. The integrity of the TDR geomembrane liner is determined by generating electrical pulses within the detection layer and measuring the time delay for any reflected electrical energy caused by absorption of moisture by a dielectric layer.

Method and apparatus for monitoring the integrity of a geomembrane liner using time domain reflectometry

DOEpatents

Morrison, John L [Idaho Falls, ID

2001-04-24

Leaks are detected in a multi-layered geomembrane liner by a two-dimensional time domain reflectometry (TDR) technique. The TDR geomembrane liner is constructed with an electrically conductive detection layer positioned between two electrically non-conductive dielectric layers, which are each positioned between the detection layer and an electrically conductive reference layer. The integrity of the TDR geomembrane liner is determined by generating electrical pulses within the detection layer and measuring the time delay for any reflected electrical energy caused by absorption of moisture by a dielectric layer.

Cognitive and emotional factors affecting avoidable decision-making delay in acute myocardial infarction male adults.

PubMed

Vidotto, Giulio; Bertolotti, Giorgio; Zotti, AnnaMaria; Marchi, Stefano; Tavazzi, Luigi

2013-01-01

To study the potentially avoidable decision-making delay in acute myocardial infarction (AMI) adults male with different psychological characteristics a nationwide multicentre study was conducted in Italy by the 118 Coronary Care Units (CCUs). 929 AMI patients consecutively presented to the CCU in a conscious condition less than two hours, 2-6 hours, 6-12 hours, and more than 12 hours after symptom onset and completing the Disease Distress Questionnaire (DDQ) were enrolled in a multicentre case-control study. The DDQ collects information regarding the decision time to seek help, and includes a set of items assessing psychological factors and pain-related symptoms. The relationship between the perceived threat and the delay due to decision-making was evaluated by means of a multivariate model using LISREL 8 structural equation modelling. The delay significantly correlated with perceived threat, which was mainly related to somatic awareness. It was only slightly related to pain and was not associated with any of the other variables. Perceived threat was also related to psychological upset, fear and health worries, the first of which was considerably influenced by emotional instability. Somatic awareness is the main dimension affecting perceived threat, but subjective pain intensity affects the delay both directly and indirectly. The core of the model is the relationship between perceived threat and the delay due to decision-making. The importance of subjective pain intensity is well documented, but it is still not clear how subjective and objective pain interact.

Correlation study of real delay time and imaginary delay time in 1-dimensional weak disorder optical media

NASA Astrophysics Data System (ADS)

Sahay, Peeyush; Almabadi, Huda M.; Pradhan, Prabhakar

Real delay time (τr) provides a measure of the time spent by photons inside an optical system. The measurement of τr is conducted in terms of energy (E) derivative of the Wigner phase delay (φ) , as τr = dϕ / dE dϕ / cdk k and c represents wavenumber and the speed of light, respectively. The characterization of τr requires interferometric system to measure φ of the light waves scattering from the medium [ R =√{ r} exp (- iϕ) ]. We investigated the possibility of extracting the τr information from the intensity measurement of the backscattered waves. The study was performed on a 1D model of weak disordered optical system and short sample length by numerically evaluating the backscattered light intensity. An imaginary delay time (τi) , defined as τi = dθ / cdk , where θ represents an `imaginary phase', was obtained upon expressing the backscattered intensity as RR* =| R | 2 = r = exp (- θ) . The result shows a strong correlation between r and φ with τr and τi exhibiting similar statistical distribution but with a shift. The magnitude and variation of the mean and std values of τr, and the std values of τi with sample lengths are nearly the same, which indicates about one parameter theory of delay time. This work potentially paves way for extracting phase information from the intensity distribution without using interferometric systems.

Influence of the heart rate and atrioventricular delays on vortex evolution and blood transport inside the left ventricle

NASA Astrophysics Data System (ADS)

Hendabadi, Sahar; Martinez-Legazpi, Pablo; Benito, Yolanda; Bermejo, Javier; Del Alamo, Juan Carlos; Shadden, Shawn

2013-11-01

Cardiac resynchronization therapy (CRT) is used to help restore coordinated pumping of the ventricles by overcoming delays in electrical conduction due to cardiac disease. This is accomplished by a specialized cardiac pacemaker that is able to adjust the atrioventricular (AV) delay.A major clinical challenge is to adjust the pacing strategy to best coordinate the blood flow mechanics of ventricular filling and ejection. To this end, we have studied the difference in the vortex formation and its evolution inside the left ventricle (LV) for 4 different AV delays in a cohort of patients with implanted pacemakers. A reconstruction algorithm was used to obtain 2D velocity over the apical long-axis view of the LV from color Doppler and B-mode ultrasound data. To study blood transport, we have identified Lagrangian coherent structures to determine moving boundaries of the blood volumes injected to the LV in diastole and ejected to the aorta in systole. In all cases, we have analyzed the differences in filling and ejection patterns and the blood transport during the E-wave and A-wave formation.Finally we have assessed the influence of the AV delay on 2 indices of stasis, direct flow and residence time.The findings shed insight to the optimization of AV delays in patients undergoing CRT. NIH award 5R21HL108268 and grants PIS09/02603 and RD06/0010 from the Plan Nacional de Investigacion Cientifica, Spain.

Sensorimotor responsiveness and resolution in the giraffe.

PubMed

More, Heather L; O'Connor, Shawn M; Brøndum, Emil; Wang, Tobias; Bertelsen, Mads F; Grøndahl, Carsten; Kastberg, Karin; Hørlyck, Arne; Funder, Jonas; Donelan, J Maxwell

2013-03-15

The ability of an animal to detect and respond to changes in the environment is crucial to its survival. However, two elements of sensorimotor control - the time required to respond to a stimulus (responsiveness) and the precision of stimulus detection and response production (resolution) - are inherently limited by a competition for space in peripheral nerves and muscles. These limitations only become more acute as animal size increases. In this paper, we investigated whether the physiology of giraffes has found unique solutions for maintaining sensorimotor performance in order to compensate for their extreme size. To examine responsiveness, we quantified three major sources of delay: nerve conduction delay, muscle electromechanical delay and force generation delay. To examine resolution, we quantified the number and size distribution of nerve fibers in the sciatic nerve. Rather than possessing a particularly unique sensorimotor system, we found that our measurements in giraffes were broadly comparable to size-dependent trends seen across other terrestrial mammals. Consequently, both giraffes and other large animals must contend with greater sensorimotor delays and lower innervation density in comparison to smaller animals. Because of their unconventional leg length, giraffes may experience even longer delays compared with other animals of the same mass when sensing distal stimuli. While there are certainly advantages to being tall, there appear to be challenges as well - our results suggest that giraffes are less able to precisely and accurately sense and respond to stimuli using feedback alone, particularly when moving quickly.

The use of low-intensity pulsed ultrasound in treating delayed union of fifth metatarsal fractures.

PubMed

Teoh, Kar Hao; Whitham, Robert; Wong, Jenny F; Hariharan, Kartik

2018-01-31

There are no studies looking at the success rate of low-intensity pulsed ultrasound (LIPUS) in fifth metatarsal fracture delayed unions to our knowledge. The aim of this study is to investigate the use of LIPUS treatment for delayed union of fifth metatarsal fractures. A retrospective review of patients who were treated with LIPUS following a delayed union of fifth metatarsal fracture was conducted over a three-year period. There were thirty patients (9 males, 21 females) in this cohort. The average age was 39.3 years. Type 2 fractures made up 43% of our cohort. Twenty-seven (90%) patients went on to progress to union clinically and radiologically following LIPUS treatment. Smoking (p=0.014) was predictive of non-union. Assuming that there were 10 delayed unions a year and 6 went on to non-union as previously suggested by a systematic review, the cost savings of using LIPUS (90% success rate; 10 LIPUS machine and surgery for 1 non-union) vs operative intervention (surgery for 6 non-union) equates to a cost saving of £7765 a year. There is a role for the use of LIPUS in delayed union of fifth metatarsal fractures and can serve as an adjunct prior to consideration of surgery. The findings of this study also suggest the use of LIPUS to be a cost effective treatment modality compared to surgical management. Level 4. Copyright © 2018 Elsevier Ltd. All rights reserved.

Data Link Benefits Study: National Sector Survey Update

DOT National Transportation Integrated Search

1995-06-15

Numerous changes have occurred in the National Airspace System since the spring : of 1994 when data was gathered for the original National Sector Survey, : conducted to gauge the effects of ATC delays on system users. This update : reflects those cha...

The association of sleep disordered breathing with left ventricular remodeling in CAD patients: a cross-sectional study.

PubMed

Alonderis, Audrius; Raskauskiene, Nijole; Gelziniene, Vaidute; Mickuviene, Narseta; Brozaitiene, Julija

2017-09-18

There is still insufficient knowledge on the potential effect of mild to moderate sleep-disordered breathing (SDB) that is widely prevalent, often asymptomatic, and largely undiagnosed in patients with stable coronary artery disease (CAD). SDB affects 34% of men and 17% of women aged between 30 and 70. The objective of this study was to evaluate the association between SDB and left ventricular (LV) hypertrophy as well as structural remodeling in stable CAD patients. The study was based on a cross-sectional design. Echocardiography and polysomnography was performed in 772 patients with CAD and with untreated sleep apnea. All study participants underwent testing by Epworth Sleepiness Scale questionnaire. Their mean age, NYHA and left ventricular ejection fraction were, respectively: 57 ± 9 years, 2.1 ± 0.5 and 51 ± 8%, and 76% were men. Sleep apnea (SA) was defined as an apnea-hypopnea-index (AHI) ≥5 events/h, and, non-SA, as an AHI <5. Sleep apnea was present in 39% of patients, and a large fraction of those patients had no complaints on excessive daytime sleepiness. The patients with SA were older, with higher body mass and higher prevalence of hypertension. LV hypertrophy (LVH), defined by allometrically corrected (LV mass/height 2.7 ) gender-independent criteria, was more common among the patients with SA than those without (86% vs. 74%, p < 0.001). The frequency of LVH by wall thickness criteria (interventricular septal thickness or posterior wall thickness ≥ 12 mm: 49% vs. 33%, p < 0.001) and concentric LVH (61% vs. 47%, p = 0.001) was higher in CAD patients with SA. The patients with SA had significantly higher values of both interventricular septal thickness and posterior wall thickness. Multiple logistic regression analysis showed that even mild sleep apnea was an independent predictor for LVH by wall thickness criteria and concentric LVH (OR = 1.5; 95% CI 1.04-2.2 and OR = 1.9; 1.3-2.9 respectively). We concluded that unrecognized sleep apnea was highly prevalent among patients with stable CAD, and the majority of those patients did not report daytime sleepiness. Mild to moderate sleep apnea was associated with increased LV wall thickness, LV mass, and with higher prevalence of concentric LV hypertrophy independently of coexisting obesity, hypertension, diabetes mellitus or advancing age.

Characterizing the motor execution stage of speech production: consonantal effects on delayed naming latency and onset duration.

PubMed

Rastle, Kathleen; Croot, Karen P; Harrington, Jonathan M; Coltheart, Max

2005-10-01

The research described in this article had 2 aims: to permit greater precision in the conduct of naming experiments and to contribute to a characterization of the motor execution stage of speech production. The authors report an exhaustive inventory of consonantal and postconsonantal influences on delayed naming latency and onset acoustic duration, derived from a hand-labeled corpus of single-syllable consonant-vowel utterances. Five talkers produced 6 repetitions each of a set of 168 prepared monosyllables, a set that comprised each of the consonantal onsets of English in 3 vowel contexts. Strong and significant effects associated with phonetic characteristics of initial and noninitial phonemes were observed on both delayed naming latency and onset acoustic duration. Results are discussed in terms of the biomechanical properties of the articulatory system that may give rise to these effects and in terms of their methodological implications for naming experiments.

Understanding Housing Delays and Relocations Within the Housing First Model.

PubMed

Zerger, Suzanne; Pridham, Katherine Francombe; Jeyaratnam, Jeyagobi; Hwang, Stephen W; O'Campo, Patricia; Kohli, Jaipreet; Stergiopoulos, Vicky

2016-01-01

This study explores factors contributing to delays and relocations during the implementation of the Housing First model in Toronto, Ontario. While interruptions in housing tenure are expected en route to recovery and housing stability, consumer and service provider views on finding and keeping housing remain largely unknown. In-person interviews and focus groups were conducted with 48 study participants, including 23 case managers or housing workers and 25 consumers. The following three factors contributed to housing delays and transfers: (1) the effectiveness of communication and collaboration among consumers and service providers, (2) consumer-driven preferences and ambivalence, and (3) provider prioritization of consumer choice over immediate housing access. Two strategies--targeted communications and consumer engagement in housing searches--supported the housing process. Several factors affect the timing and stability of housing. Communication between and among providers and consumers, and a shared understanding of consumer choice, can further support choice and recovery.

Time-dependent in-vivo effects of interleukin-2 on neurotransmitters in various cortices: relationships with depressive-related and anxiety-like behaviour.

PubMed

Karrenbauer, B D; Müller, C P; Ho, Y J; Spanagel, R; Huston, J P; Schwarting, R K W; Pawlak, C R

2011-08-15

We investigated the impact of systemically injected IL-2 (2.5 μg/kg, i.p.) on serotonergic and dopaminergic neurotransmission in various cortical areas by in-vivo microdialysis. IL-2 lastingly reduced extracellular 5-HT levels in the medial prefrontal (-75%), occipital (-70%), and temporal cortices (-45%), whereas dopamine was only moderately reduced in the medial prefrontal cortex. Based on the serotonergic time profile, we conducted further experiments to test for acute and delayed (2 h post injection) depressive-related effects of systemic IL-2 (0-5.0 μg/kg) in a forced swim test and delayed effects on anxiety-like behaviour in the elevated plus-maze. IL-2 had dose-dependent effects on depressive-related behaviour after delayed but not acute testing, but no effects on anxiety-like behaviour. Copyright © 2011 Elsevier B.V. All rights reserved.

Zika Virus Testing and Outcomes during Pregnancy, Florida, USA, 2016

PubMed Central

Shiu, Colette; Starker, Rebecca; Kwal, Jaclyn; Bartlett, Michelle; Crane, Anise; Greissman, Samantha; Gunaratne, Naiomi; Lardy, Meghan; Picon, Michelle; Rodriguez, Patricia; Gonzalez, Ivan

2018-01-01

Zika virus infection during pregnancy can lead to congenital Zika syndrome. Implementation of screening programs and interpretation of test results can be particularly challenging during ongoing local mosquitoborne transmission. We conducted a retrospective chart review of 2,327 pregnant women screened for Zika virus in Miami–Dade County, Florida, USA, during 2016. Of these, 86 had laboratory evidence of Zika virus infection; we describe 2 infants with probable congenital Zika syndrome. Delays in receipt of laboratory test results (median 42 days) occurred during the first month of local transmission. Odds of screening positive for Zika virus were higher for women without health insurance or who did not speak English. Our findings indicate the increase in screening for Zika virus can overwhelm hospital and public health systems, resulting in delayed receipt of results of screening and confirmatory tests and the potential to miss cases or delay diagnoses. PMID:29260671

The Subjective Experience of Patients Diagnosed with Hereditary Hemorrhagic Telangiectasia: a Qualitative Study.

PubMed

Geerts, Laura; Fantini-Hauwel, Carole; Brugallé, Elodie; Boute, Odile; Frénois, Frédéric; Defrance, Lydie; Manouvrier-Hanu, Sylvie; Petit, Florence; Antoine, Pascal

2017-06-01

The aim of the present study was to understand the context and psychological impact for patients diagnosed with hereditary hemorrhagic telangiectasia (HHT). Semi-structured interviews were conducted with 9 patients affected by HHT, and the transcripts were analyzed using interpretative phenomenological analysis. The results of this study allowed us to propose a new hypothesis to explain the delay in diagnosis: the trivialization of symptoms associated with HHT. Moreover, the results showed that a genetic diagnosis of HHT results in emotional shock, uncertainty about the future, and worry about one's children in parents who are confronted with the dilemma of facing the reality of the diagnosis or delaying dealing with the diagnosis until disease onset. Family and personal perceptions of the disease influenced not only the delay in diagnosis but also the emotional and behavioral reactions of patients following a genetic diagnosis.

A Simulation Based Investigation of High Latency Space Systems Operations

NASA Technical Reports Server (NTRS)

Li, Zu Qun; Moore, Michael; Bielski, Paul; Crues, Edwin Z.

2017-01-01

This study was the first in a series of planned tests to use physics-based subsystem simulations to investigate the interactions between a spacecraft's crew and a ground-based mission control center for vehicle subsystem operations across long communication delays. The simulation models the life support system of a deep space habitat. It contains models of an environmental control and life support system, an electrical power system, an active thermal control systems, and crew metabolic functions. The simulation has three interfaces: 1) a real-time crew interface that can be use to monitor and control the subsystems; 2) a mission control center interface with data transport delays up to 15 minute each way; and 3) a real-time simulation test conductor interface used to insert subsystem malfunctions and observe the interactions between the crew, ground, and simulated vehicle. The study was conducted at the 21st NASA Extreme Environment Mission Operations (NEEMO) mission. The NEEMO crew and ground support team performed a number of relevant deep space mission scenarios that included both nominal activities and activities with system malfunctions. While this initial test sequence was focused on test infrastructure and procedures development, the data collected in the study already indicate that long communication delays have notable impacts on the operation of deep space systems. For future human missions beyond cis-lunar, NASA will need to design systems and support tools to meet these challenges. These will be used to train the crew to handle critical malfunctions on their own, to predict malfunctions and assist with vehicle operations. Subsequent more detailed and involved studies will be conducted to continue advancing NASA's understanding of space systems operations across long communications delays.

A Simulation Based Investigation of High Latency Space Systems Operations

NASA Technical Reports Server (NTRS)

Li, Zu Qun; Crues, Edwin Z.; Bielski, Paul; Moore, Michael

2017-01-01

This study was the first in a series of planned tests to use physics-based subsystem simulations to investigate the interactions between a spacecraft's crew and a ground-based mission control center for vehicle subsystem operations across long communication delays. The simulation models the life support system of a deep space habitat. It contains models of an environmental control and life support system, an electrical power system, an active thermal control system, and crew metabolic functions. The simulation has three interfaces: 1) a real-time crew interface that can be use to monitor and control the subsystems; 2) a mission control center interface with data transport delays up to 15 minute each way; and 3) a real-time simulation test conductor interface used to insert subsystem malfunctions and observe the interactions between the crew, ground, and simulated vehicle. The study was conducted at the 21st NASA Extreme Environment Mission Operations (NEEMO) mission. The NEEMO crew and ground support team performed a number of relevant deep space mission scenarios that included both nominal activities and activities with system malfunctions. While this initial test sequence was focused on test infrastructure and procedures development, the data collected in the study already indicate that long communication delays have notable impacts on the operation of deep space systems. For future human missions beyond cis-lunar, NASA will need to design systems and support tools to meet these challenges. These will be used to train the crew to handle critical malfunctions on their own, to predict malfunctions, and to assist with vehicle operations. Subsequent more detailed and involved studies will be conducted to continue advancing NASA's understanding of space systems operations across long communications delays.

Comparison of shipborne GNSS-derived precipitable water vapor with radiosonde in the western North Pacific and in the seas adjacent to Japan

NASA Astrophysics Data System (ADS)

Shoji, Yoshinori; Sato, Kazutoshi; Yabuki, Masanori; Tsuda, Toshitaka

2017-11-01

We installed two global navigation satellite system (GNSS) antennas on a research vessel, the RYOFU MARU of the Japan Meteorological Agency, and conducted experimental observations to assess the GNSS-derived precipitable water vapor (PWV) from October 19, 2016, to August 6, 2017. One antenna was set on the mast (MAST), while another antenna was set on the upper deck (DECK). The GNSS analysis was conducted using the precise point positioning procedure with a real-time GNSS orbit. A quality control (QC) procedure based on the amount of zenith tropospheric delay (ZTD) time variation was proposed. After the QC was applied, the retrieved PWVs were compared to 77 radiosonde observations. The PWVs of MAST agreed with the radiosonde observations with a 1.7 mm root mean square (RMS) difference, a - 0.7-mm bias, and 3.6% rejection rate, while that of DECK showed a 3.2, - 0.8 mm, and 15.7%. The larger RMS and higher rejection rate of DECK imply a stronger multi-path effect on the deck. The differences in the GNSS PWV versus radiosonde observations were compared to the atmospheric delay, the estimated altitude of the GNSS antenna, the vessel's moving speed, the wind speed, and the wave height. The atmospheric delay and GNSS antenna altitude showed moderate correlation with the differences. The results suggest the kinematic PPP's potential for practical water vapor monitoring over oceans worldwide. At the same time, from the growing negative biases with the PWV value and with estimated antenna altitude, it could be inferred that the difficulty grows in separating the signal delay from the vertical coordinate under high-humidity conditions.[Figure not available: see fulltext.

Effect of the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT) on Conduction System Disease.

PubMed

Dewland, Thomas A; Soliman, Elsayed Z; Davis, Barry R; Magnani, Jared W; Yamal, Jose-Miguel; Piller, Linda B; Haywood, L Julian; Alonso, Alvaro; Albert, Christine M; Marcus, Gregory M

2016-08-01

Cardiac conduction abnormalities are associated with an increased risk for morbidity and mortality, and understanding factors that accelerate or delay conduction system disease could help to identify preventive and therapeutic strategies. Antifibrotic and anti-inflammatory properties of angiotensin-converting enzyme inhibitors and treatment for hyperlipidemia may reduce the risk for incident conduction system disease. To identify the effect of pharmacologic therapy randomization and clinical risk factors on the incidence of conduction system disease. This secondary analysis of the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT) investigation acquired data from 623 North American centers. A total of 21 004 ambulatory individuals 55 years or older with hypertension and at least 1 other cardiac risk factor were included in the analysis. Participants were randomly assigned to receive amlodipine besylate, lisinopril, or chlorthalidone. Individuals with elevated fasting low-density lipoprotein cholesterol levels were also randomized to pravastatin sodium vs usual care. An electrocardiogram (ECG) was obtained at study enrollment and every 2 years of follow-up. The development of incident first-degree atrioventricular block, left anterior fascicular block, incomplete left bundle branch block (LBBB), LBBB, incomplete right bundle branch block (RBBB), RBBB, or intraventricular conduction delay was assessed by serial ECGs. The 21 004 participants (11 758 men [56.0%]; 9246 women [44.0%]; mean [SD] age, 66.5 [7.3] years) underwent a mean (SD) follow-up of 5.0 (1.2) years. Among the 1114 participants who developed any conduction defect, 389 developed LBBB, 570 developed RBBB, and 155 developed intraventricular conduction delay. Compared with chlorthalidone, randomization to lisinopril was associated with a significant 19% reduction in conduction abnormalities (hazard ratio [HR], 0.81; 95% CI, 0.69-0.95; P = .01). Treatment with amlodipine, however, was not associated with a significant difference in conduction outcome events (HR, 0.94; 95% CI, 0.81-1.09; P = .42). Similarly, pravastatin treatment was not associated with a reduced adjusted risk for incident disease compared with usual hyperlipidemia treatment (HR, 1.13; 95% CI, 0.95-1.35; P = .18). Increased age (HR, 1.47; 95% CI, 1.34-1.63; P < .001), male sex (HR, 0.59; 95% CI, 0.50-0.73; P < .001), white race (HR, 0.59; 95% CI, 0.50-0.70; P < .001), diabetes (HR, 1.23; 95% CI, 1.07-1.42; P = .003), and left ventricular hypertrophy (HR, 3.20; 95% CI, 2.61-3.94; P < .001) were also independently associated with increased risk for conduction system disease. Incident conduction system disease is significantly reduced by lisinopril therapy and is independently associated with multiple clinical factors. Further studies are warranted to determine whether pharmacologic treatment affects conduction abnormality outcomes, including pacemaker implantation. clinicaltrials.gov Identifier: NCT00000542.

Time Critical Targeting: Predictive Vs Reactionary Methods An Analysis For The Future

DTIC Science & Technology

2002-06-01

critical targets. To conduct the analysis, a four-step process is used. First, research is conducted to determine which future aircraft, spacecraft , and...the most promising aircraft, spacecraft , and weapons are determined , they are categorized for use in either the reactive or preemptive method. For...no significant delays, 292; Alan Vick et al., 17. 33 Ibid. 12 sensors are Electro-optical (EO) sensors, thermal imagers , and signal intelligence

Defense Acquisitions. Missile Defense Agency Fields Initial Capability but Falls Short of Original Goals

DTIC Science & Technology

2006-03-01

Implementation Plan MAP Missile Defense System Assurance Provisions MDA Missile Defense System NASA National Aeronautics and Space Administration NFIRE ...fourth element, KEI, also delayed some activities related to its Near Field Infrared Experiment ( NFIRE ), which is being conducted to gather data on the...to complete a number of tasks that would have enabled it to conduct the NFIRE experiment. The experiment places sensors aboard a satellite that

Magnetic transit-time flowmeter

DOEpatents

Forster, George A.

1976-07-06

The flow rate of a conducting fluid in a stream is determined by disposing two permanent-magnet flowmeters in the stream, one downstream of the other. Flow of the conducting fluid causes the generation of both d-c and a-c electrical signals, the a-c comprising flow noise. Measurement of the time delay between similarities in the a-c signals by cross-correlation methods provides a measure of the rate of flow of the fluid.

Delayed nausea and vomiting from carboplatin doublet chemotherapy

PubMed Central

Waqar, Saiama N.; Mann, Janelle; Baggstrom, Maria Q.; Waqar, Muhammad Atif; Chitneni, Pooja; Williams, Kristina; Gao, Feng; Morgensztern, Daniel; Govindan, Ramaswamy

2016-01-01

Background Delayed nausea and vomiting following administration of carboplatin containing chemotherapy regimen remains a clinically significant problem for patients with cancer despite administration of standard antiemetic prophylaxis comprising of a 5-HT3 antagonist and dexamethasone. We performed a prospective study to define the incidence and risk factors for delayed chemotherapy induced nausea and vomiting (CINV). Methods Previously untreated patients with newly diagnosed cancer scheduled to receive carboplatin containing chemotherapy (AUC 5 or above), but no prophylactic aprepitant were enrolled in the study. The primary endpoint was the incidence of delayed CINV after cycle 1 of chemotherapy. Secondary endpoints included the incidence of CINV with the third chemotherapy cycle and gender differences in incidence of CINV. Patients completed the Functional Living Index Emesis (FLIE) questionnaires 24, 48, 72 and 96 hours after receiving chemotherapy. Telephone interviews were conducted 24–48 hours following chemotherapy to assess the severity and need for breakthrough medications for CINV. Results Between December 2006 and July 2009, 105 patients were enrolled onto this study. Delayed emesis following cycle 1 of carboplatin was observed in 30% of patients. Of these, 14.1%, 22.4% and 23.5% of patients described CINV at 48 hours, 72 hours, and 96 hours respectively. The incidence of delayed CINV following cycle 3 dropped to 12.8%, 14.6% and 16% of patients at 48 hours, 72 hours and 96 hours respectively. No differences were observed in the incidence of CINV between men and women. A total of 20% of patients required use of breakthrough antiemetics with cycle 1. Conclusions Without prophylactic aprepitant administration, 30% of patients receiving carboplatin containing regimen had moderate to severe delayed CINV. PMID:27145068

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

PubMed

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

2009-01-01

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

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

PubMed

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

2005-05-01

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

Chromosomal Microarray With Clinical Diagnostic Utility in Children With Developmental Delay or Intellectual Disability.

PubMed

Lee, Jin Sook; Hwang, Hee; Kim, Soo Yeon; Kim, Ki Joong; Choi, Jin Sun; Woo, Mi Jung; Choi, Young Min; Jun, Jong Kwan; Lim, Byung Chan; Chae, Jong Hee

2018-09-01

Chromosomal microarray (CMA) testing is a first-tier test for patients with developmental delay, autism, or congenital anomalies. It increases diagnostic yield for patients with developmental delay or intellectual disability. In some countries, including Korea, CMA testing is not yet implemented in clinical practice. We assessed the diagnostic utility of CMA testing in a large cohort of patients with developmental delay or intellectual disability in Korea. We conducted a genome-wide microarray analysis of 649 consecutive patients with developmental delay or intellectual disability at the Seoul National University Children's Hospital. Medical records were reviewed retrospectively. Pathogenicity of detected copy number variations (CNVs) was evaluated by referencing previous reports or parental testing using FISH or quantitative PCR. We found 110 patients to have pathogenic CNVs, which included 100 deletions and 31 duplications of 270 kb to 30 Mb. The diagnostic yield was 16.9%, demonstrating the diagnostic utility of CMA testing in clinic. Parental testing was performed in 66 patients, 86.4% of which carried de novo CNVs. In eight patients, pathogenic CNVs were inherited from healthy parents with a balanced translocation, and genetic counseling was provided to these families. We verified five rarely reported deletions on 2p21p16.3, 3p21.31, 10p11.22, 14q24.2, and 21q22.13. This study demonstrated the clinical utility of CMA testing in the genetic diagnosis of patients with developmental delay or intellectual disability. CMA testing should be included as a clinical diagnostic test for all children with developmental delay or intellectual disability. © The Korean Society for Laboratory Medicine.

Randomized Controlled Trial of Early Versus Delayed Statin Therapy in Patients With Acute Ischemic Stroke: ASSORT Trial (Administration of Statin on Acute Ischemic Stroke Patient).

PubMed

Yoshimura, Shinichi; Uchida, Kazutaka; Daimon, Takashi; Takashima, Ryuzo; Kimura, Kazuhiro; Morimoto, Takeshi

2017-11-01

Several studies suggested that statins during hospitalization were associated with better disability outcomes in patients with acute ischemic stroke, but only 1 small randomized trial is available. We conducted a multicenter, open-label, randomized controlled trial in patients with acute ischemic strokes in 11 hospitals in Japan. Patients with acute ischemic stroke and dyslipidemia randomly received statins within 24 hours after admission in the early group or on the seventh day in the delayed group, in a 1:1 ratio. Statins were administered for 12 weeks. The primary outcome was patient disability assessed by modified Rankin Scale at 90 days. A total of 257 patients were randomized and analyzed (early 131, delayed 126). At 90 days, modified Rankin Scale score distribution did not differ between groups ( P =0.68), and the adjusted common odds ratio of the early statin group was 0.84 (95% confidence interval, 0.53-1.3; P =0.46) compared with the delayed statin group. There were 3 deaths at 90 days (2 in the early group, 1 in the delayed group) because of malignancy. Ischemic stroke recurred in 9 patients (6.9%) in the early group and 5 patients (4.0%) in the delayed group. The safety profile was similar between groups. Our randomized trial involving patients with acute ischemic stroke and dyslipidemia did not show any superiority of early statin therapy within 24 hours of admission compared with delayed statin therapy 7 days after admission to alleviate the degree of disability at 90 days after onset. URL: http://www.clinicaltrials.gov. Unique identifier: NCT02549846. © 2017 American Heart Association, Inc.

Initiation of nutritional support is delayed in critically ill obese patients: a multicenter cohort study.

PubMed

Borel, Anne-Laure; Schwebel, Carole; Planquette, Benjamin; Vésin, Aurélien; Garrouste-Orgeas, Maité; Adrie, Christophe; Clec'h, Christophe; Azoulay, Elie; Souweine, Bertrand; Allaouchiche, Bernard; Goldgran-Toledano, Dany; Jamali, Samir; Darmon, Michael; Timsit, Jean-François

2014-09-01

A high catabolic rate characterizes the acute phase of critical illness. Guidelines recommend an early nutritional support, regardless of the previous nutritional status. We aimed to assess whether the nutritional status of patients, which was defined by the body mass index (BMI) at admission in an intensive care unit (ICU), affected the time of nutritional support initiation. We conducted a cohort study that reported a retrospective analysis of a multicenter ICU database (OUTCOMEREA) by using data prospectively entered from January 1997 to October 2012. Patients who needed orotracheal intubation within the first 72 h and >3 d were included. Data from 3257 ICU stays were analyzed. The delay before feeding was different according to BMI groups (P = 0.035). The delay was longer in obese patients [BMI (in kg/m²) ≥30; n = 663] than in other patients with either low weight (BMI <20; n = 501), normal weight (BMI ≥20 and <25; n = 1135), or overweight (BMI ≥25 and <30; n = 958). The association between nutritional status and a delay in nutrition initiation was independent of potential confounding factors such as age, sex, and diabetes or other chronic diseases. In comparison with normal weight, the adjusted RR (95% CI) associated with a delayed nutrition initiation was 0.92 (0.86, 0.98) for patients with low weight, 1.00 (0.94, 1.05) for overweight patients, and 1.06 (1.00, 1.12) for obese patients (P = 0.004). The initiation of nutritional support was delayed in obese ICU patients. Randomized controlled trials that address consequences of early compared with delayed beginnings of nutritional support in critically ill obese patients are needed. © 2014 American Society for Nutrition.

Analysis of the diagnostic pathway and delay in patients with amyotrophic lateral sclerosis in the Valencian Community.

PubMed

Vázquez-Costa, J F; Martínez-Molina, M; Fernández-Polo, M; Fornés-Ferrer, V; Frasquet-Carrera, M; Sevilla-Mantecón, T

2018-06-11

Amyotrophic lateral sclerosis (ALS) is an insidious, clinically heterogeneous neurodegenerative disease associated with a diagnostic delay of approximately 12 months. No study conducted to date has analysed the diagnostic pathway in Spain. We gathered data on variables related to the diagnostic pathway and delay for patients diagnosed with ALS between October 2013 and July 2017. The study included 143 patients with ALS (57% men; 68% spinal onset). Patients were diagnosed in public centres in 86% of cases and in private centres in 14%.The mean diagnostic delay was 13.1 months (median 11.7). Patients were examined by neurologists a mean time of 7.9 months after symptom onset, with diagnosis being made 5.2 months later. Half of all patients underwent unnecessary diagnostic tests and multiple electrophysiological studies before diagnosis was established. Diagnostic delay was longer in cases of spinal onset (P = .008) due to onset of the disease in the lower limbs. No differences were found between the public and private healthcare systems (P = .897). The diagnostic delay in ALS in Spain is similar to that of neighboring countries and seems to depend on disease-related factors, not on the healthcare system. Patients with lower-limb onset ALS constitute the greatest diagnostic challenge. Misdiagnosis is frequent, and partly attributable to an incorrect approach or erroneous interpretation of electrophysiological studies. Specific training programmes for neurologists and general neurophysiologists and early referral to reference centers may help to reduce diagnostic delay. Copyright © 2018 Sociedad Española de Neurología. Publicado por Elsevier España, S.L.U. All rights reserved.

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

Lane, Taylor; Parma, Edward J.

Delayed fission gamma-rays play an important role in determining the time dependent ioniz- ing dose for experiments in the central irradiation cavity of the Annular Core Research Reactor (ACRR). Delayed gamma-rays are produced from both fission product decay and from acti- vation of materials in the core, such as cladding and support structures. Knowing both the delayed gamma-ray emission rate and the time-dependent gamma-ray energy spectrum is nec- essary in order to properly determine the dose contributions from delayed fission gamma-rays. This information is especially important when attempting to deconvolute the time-dependent neutron, prompt gamma-ray, and delayed gamma-ray contribution tomore » the response of a diamond photo-conducting diode (PCD) or fission chamber in time frames of milliseconds to seconds following a reactor pulse. This work focused on investigating delayed gamma-ray character- istics produced from fission products from thermal, fast, and high energy fission of Th-232, U-233, U-235, U-238, and Pu-239. This work uses a modified version of CINDER2008, a transmutation code developed at Los Alamos National Laboratory, to model time and energy dependent photon characteristics due to fission. This modified code adds the capability to track photon-induced transmutations, photo-fission, and the subsequent radiation caused by fission products due to photo-fission. The data is compared against previous work done with SNL- modified CINDER2008 [ 1 ] and experimental data [ 2 , 3 ] and other published literature, includ- ing ENDF/B-VII.1 [ 4 ]. The ability to produce a high-fidelity (7,428 group) energy-dependent photon fluence at various times post-fission can improve the delayed photon characterization for radiation effects tests at research reactors, as well as other applications.« less

High prevalence of developmental delay among children under three years of age in poverty-stricken areas of China.

PubMed

Wei, Q W; Zhang, J X; Scherpbier, R W; Zhao, C X; Luo, S S; Wang, X L; Guo, S F

2015-12-01

Poverty and its associated factors put children at risk for developmental delay. The aim of this study was to describe the neurodevelopment of children under three years of age in poverty-stricken areas of China and explore possible associated factors. A cross-sectional survey was conducted among 2837 children aged 1-35 months in poverty-stricken areas of China. Characteristics of the child, caregiver, and family were collected through face-to-face caregiver interviews. Developmental delay was explored with the five-domain, structured, parent-completed Ages and Stages Questionnaire. The Zung Self-rating Depression Scale was used to assess depressive symptoms of the caregivers. The Chi-squared test and multivariate logistic regression analyses were used to explore associated factors. Of the children, 39.7% (95% confidence interval, 37.9-41.5) had developmental delay in at least one of the five domains. For the domains of communication, gross motor, fine motor, problem solving, and personal-social skills, the prevalence was 11.5%, 18.5%, 21.4%, 18.4%, and 17.9%, respectively. Significant predictors of increased odds of developmental delay included the child having no toys (odds ratio [OR] = 2.31), the caregiver having depression (OR = 2.24), insufficient learning activities (OR = 1.65), and more children in the family (OR = 1.16). The high prevalence of developmental delay in children younger than three years in poverty-stricken areas of China and the presence of risk factors for developmental delay such as inadequate learning resources and activities in the home, caregiver depression, and low family income highlight the need for early identification and interventions. Copyright © 2015 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.

Intraspecific priority effects modify compensatory responses to changes in hatching phenology in an amphibian.

PubMed

Murillo-Rincón, Andrea P; Kolter, Nora A; Laurila, Anssi; Orizaola, Germán

2017-01-01

In seasonal environments, modifications in the phenology of life-history events can alter the strength of time constraints experienced by organisms. Offspring can compensate for a change in timing of hatching by modifying their growth and development trajectories. However, intra- and interspecific interactions may affect these compensatory responses, in particular if differences in phenology between cohorts lead to significant priority effects (i.e. the competitive advantage that early-hatching individuals have over late-hatching ones). Here, we conducted a factorial experiment to determine whether intraspecific priority effects can alter compensatory phenotypic responses to hatching delay in a synchronic breeder by rearing moor frog (Rana arvalis) tadpoles in different combinations of phenological delay and food abundance. Tadpoles compensated for the hatching delay by speeding up their development, but only when reared in groups of individuals with identical hatching phenology. In mixed phenology groups, strong competitive effects by non-delayed tadpoles prevented the compensatory responses and delayed larvae metamorphosed later than in single phenology treatments. Non-delayed individuals gained advantage from developing with delayed larvae by increasing their developmental and growth rates as compared to single phenology groups. Food shortage prolonged larval period and reduced mass at metamorphosis in all treatments, but it did not prevent compensatory developmental responses in larvae reared in single phenology groups. This study demonstrates that strong intraspecific priority effects can constrain the compensatory growth and developmental responses to phenological change, and that priority effects can be an important factor explaining the maintenance of synchronic life histories (i.e. explosive breeding) in seasonal environments. © 2016 The Authors. Journal of Animal Ecology © 2016 British Ecological Society.

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

PubMed

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

2015-07-06

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

Using the Three Delays Model to Examine Civil Registration Barriers in Indonesia.

PubMed

Bennouna, Cyril; Feldman, Brooke; Usman, Rahmadi; Adiputra, Rama; Kusumaningrum, Santi; Stark, Lindsay

2016-01-01

The Three Delays Model has proven a useful framework for examining barriers to seeking obstetric care and preventing maternal and child mortality. This article demonstrates the applicability of the Three Delays Model to the case of civil registration in rural Indonesia and examines ways that efforts to strengthen civil registration services can draw on lessons from maternal and child health programming. Twenty focus group discussions were conducted using a participatory ranking exercise in four Indonesian districts. Focus groups were stratified into four groups: (1) government officials involved in civil registration, (2) civil society organization members that assist communities in civil registration, and (3) female and (4) male community members. Transcripts were analyzed using constant comparative method and thematic analysis, revealing barriers that communities commonly faced in accessing civil registration services. In examining the categories and themes related to these barriers, the research team found a significant overlap with the factors and phases of the Three Delays Model. Participants were delayed from seeking registration services by a range of sociocultural factors and by the perceived inaccessibility and poor quality of services. Once they decided to seek care, long distances to services and poor transportation options delayed their access to registration offices. Finally, a series of bottlenecks in service provision created extended delays once applicants reached registration offices. Ownership of civil registration documents in Indonesia remains exceptionally low, with just over half of children and youth possessing a birth certificate. To strengthen civil registration and health systems more generally, it is important to understand the factors that enable and constrain civil registration, how these factors relate to one another, and how they change over a child's life.

Using the Three Delays Model to Examine Civil Registration Barriers in Indonesia

PubMed Central

Bennouna, Cyril; Feldman, Brooke; Usman, Rahmadi; Adiputra, Rama; Kusumaningrum, Santi

2016-01-01

The Three Delays Model has proven a useful framework for examining barriers to seeking obstetric care and preventing maternal and child mortality. This article demonstrates the applicability of the Three Delays Model to the case of civil registration in rural Indonesia and examines ways that efforts to strengthen civil registration services can draw on lessons from maternal and child health programming. Twenty focus group discussions were conducted using a participatory ranking exercise in four Indonesian districts. Focus groups were stratified into four groups: (1) government officials involved in civil registration, (2) civil society organization members that assist communities in civil registration, and (3) female and (4) male community members. Transcripts were analyzed using constant comparative method and thematic analysis, revealing barriers that communities commonly faced in accessing civil registration services. In examining the categories and themes related to these barriers, the research team found a significant overlap with the factors and phases of the Three Delays Model. Participants were delayed from seeking registration services by a range of sociocultural factors and by the perceived inaccessibility and poor quality of services. Once they decided to seek care, long distances to services and poor transportation options delayed their access to registration offices. Finally, a series of bottlenecks in service provision created extended delays once applicants reached registration offices. Ownership of civil registration documents in Indonesia remains exceptionally low, with just over half of children and youth possessing a birth certificate. To strengthen civil registration and health systems more generally, it is important to understand the factors that enable and constrain civil registration, how these factors relate to one another, and how they change over a child’s life. PMID:27992515

Extracorporeal shock wave therapy in treatment of delayed bone-tendon healing.

PubMed

Wang, Lin; Qin, Ling; Lu, Hong-bin; Cheung, Wing-hoi; Yang, Hu; Wong, Wan-nar; Chan, Kai-ming; Leung, Kwok-sui

2008-02-01

Extracorporeal shock wave therapy is indicated for treatment of chronic injuries of soft tissues and delayed fracture healing and nonunion. No investigation has been conducted to study the effect of shock wave on delayed healing at the bone-tendon junction. Shock wave promotes osteogenesis, regeneration of fibrocartilage zone, and remodeling of healing tissue in delayed healing of bone-tendon junction surgical repair. Controlled laboratory study. Twenty-eight mature rabbits were used for establishing a delayed healing model at the patella-patellar tendon complex after partial patellectomy and then divided into control and shock wave groups. In the shock wave group, a single shock wave treatment was given at week 6 postoperatively to the patella-patellar tendon healing complex. Seven samples were harvested at week 8 and 7 samples at week 12 for radiologic, densitometric, histologic, and mechanical evaluations. Radiographic measurements showed 293.4% and 185.8% more new bone formation at the patella-patellar tendon healing junction in the shock wave group at weeks 8 and 12, respectively. Significantly better bone mineral status was found in the week 12 shock wave group. Histologically, the shock wave group showed more advanced remodeling in terms of better alignment of collagen fibers and thicker and more mature regenerated fibrocartilage zone at both weeks 8 and 12. Mechanical testing showed 167.7% and 145.1% higher tensile load and strength in the shock wave group at week 8 and week 12, respectively, compared with controls. Extracorporeal shock wave promotes osteogenesis, regeneration of fibrocartilage zone, and remodeling in the delayed bone-to-tendon healing junction in rabbits. These results provide a foundation for future clinical studies toward establishment of clinical indication for treatment of delayed bone-to-tendon junction healing.

On an instability exhibited by the ballistic-diffusive heat conduction model of Xu and Hu

DOE PAGES

Christov, I. C.; Jordan, P. M.

2013-11-13

We show that the constitutive relation for the thermal flux proposed by Xu & Hu (2011) admits an unconditional instability. We also highlight the difference between mathematical models containing delay and those that include relaxation effects.

30 CFR 955.14 - Examination.

Code of Federal Regulations, 2010 CFR

2010-07-01

... CONDUCT OF SURFACE MINING OPERATIONS WITHIN EACH STATE CERTIFICATION OF BLASTERS IN FEDERAL PROGRAM STATES...(b) of this chapter, and shall include: (i) Objective questions; (ii) Blasting log problems; and (iii) Initiation system and delay sequence problems. (c) Reexamination. (1) Any person who fails the examination...

Transient current interruption mechanism in a magnetically delayed vacuum switch

NASA Technical Reports Server (NTRS)

Morris, Gibson, Jr.; Dougal, Roger A.

1993-01-01

The capacity of a magnetically delayed vacuum switch to conduct current depends on the density of plasma injected into the switch. Exceeding the current capacity results in the switch entering a lossy mode of operation characterized by a transient interruption of the main current (opening behavior) and a rapid increase of voltage across the vacuum gap. Streak and framing photographs of the discharge indicate that a decrease of luminosity near the middle of the gap preceeds the transition to the opening phase. The zone of low luminosity propagates toward the cathode. This evidence suggests that the mechanism causing the opening phase is erosion of the background plasma in a manner similar to that in a plasma-opening switch. The resulting ion depletion forces a space-charge-limited conduction mode. The switch inductance maintains a high discharge current even during the space-charge-limited conduction phase, thus producing high internal fields. The high accelerating voltage, in turn, produces electron and ion beams that heat the electrode surfaces. As a result of the heating, jets of electrode vapor issue from the electrodes, either cathode or anode, depending on the selection of electrode materials.

Electrical remodelling of the left and right atria due to rheumatic mitral stenosis.

PubMed

John, Bobby; Stiles, Martin K; Kuklik, Pawel; Chandy, Sunil T; Young, Glenn D; Mackenzie, Lorraine; Szumowski, Lukasz; Joseph, George; Jose, Jacob; Worthley, Stephen G; Kalman, Jonathan M; Sanders, Prashanthan

2008-09-01

To characterize the atrial remodelling in mitral stenosis (MS). Twenty-four patients with severe MS undergoing commissurotomy and 24 controls were studied. Electrophysiological evaluation was performed in 12 patients in each group by positioning multi-electrode catheters in both atria to determine the following: effective refractory period (ERP) at 10 sites at 600 and 450 ms; conduction time; conduction delay at the crista terminalis (CT); and vulnerability for atrial fibrillation (AF). P-wave duration (PWD) was determined on the surface ECG. In the remaining 12 patients in each group, electroanatomic maps of both atria were created to determine conduction velocity and identify regions of low voltage and electrical silence. Patients with MS had larger left atria (LA) (P < 0.0001); prolonged PWD (P = 0.0007); prolonged ERP in both LA (P < 0.0001) and right atria (RA) (P < 0.0001); reduced conduction velocity in the LA (P = 0.009) and RA (P < 0.0001); greater number (P < 0.0001) and duration (P< 0.0001) of bipoles along the CT with delayed conduction; lower atrial voltage in the LA (P < 0.0001) and RA (P < 0.0001); and more frequent electrical scar (P = 0.001) compared with controls. Five of twelve with MS and none of the controls developed AF with extra-stimulus (P = 0.02). Atrial remodelling in MS is characterized by LA enlargement, loss of myocardium, and scarring associated with widespread and site-specific conduction abnormalities and no change or an increase in ERP. These abnormalities were associated with a heightened inducibility of AF.

Reduced Sodium Current in the Lateral Ventricular Wall Induces Inferolateral J-Waves.

PubMed

Meijborg, Veronique M F; Potse, Mark; Conrath, Chantal E; Belterman, Charly N W; De Bakker, Jacques M T; Coronel, Ruben

2016-01-01

J-waves in inferolateral leads are associated with a higher risk for idiopathic ventricular fibrillation. We aimed to test potential mechanisms (depolarization or repolarization dependent) responsible for inferolateral J-waves. We hypothesized that inferolateral J-waves can be caused by regional delayed activation of myocardium that is activated late during normal conditions. Computer simulations were performed to evaluate how J-point elevation is influenced by reducing sodium current conductivity (GNa), increasing transient outward current conductivity (Gto), or cellular uncoupling in three predefined ventricular regions (lateral, anterior, or septal). Two pig hearts were Langendorff-perfused with selective perfusion with a sodium channel blocker of lateral or anterior/septal regions. Volume-conducted pseudo-electrocardiograms (ECG) were recorded to detect the presence of J-waves. Epicardial unipolar electrograms were simultaneously recorded to obtain activation times (AT). Simulation data showed that conduction slowing, caused by reduced sodium current, in lateral, but not in other regions induced inferolateral J-waves. An increase in transient outward potassium current or cellular uncoupling in the lateral zone elicited slight J-point elevations which did not meet J-wave criteria. Additional conduction slowing in the entire heart attenuated J-waves and J-point elevations on the ECG, because of masking by the QRS. Experimental data confirmed that conduction slowing attributed to sodium channel blockade in the left lateral but not in the anterior/septal ventricular region induced inferolateral J-waves. J-waves coincided with the delayed activation. Reduced sodium current in the left lateral ventricular myocardium can cause inferolateral J-waves on the ECG.

Roles of hippocampal subfields in verbal and visual episodic memory.

PubMed

Zammit, Andrea R; Ezzati, Ali; Zimmerman, Molly E; Lipton, Richard B; Lipton, Michael L; Katz, Mindy J

2017-01-15

Selective hippocampal (HC) subfield atrophy has been reported in older adults with mild cognitive impairment and Alzheimer's disease. The goal of this study was to investigate the associations between the volume of hippocampal subfields and visual and verbal episodic memory in cognitively normal older adults. This study was conducted on a subset of 133 participants from the Einstein Aging Study (EAS), a community-based study of non-demented older adults systematically recruited from the Bronx, N.Y. All participants completed comprehensive EAS neuropsychological assessment. Visual episodic memory was assessed using the Complex Figure Delayed Recall subtest from the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS). Verbal episodic memory was assessed using Delayed Recall from the Free and Cued Selective Reminding Test (FCSRT). All participants underwent 3T MRI brain scanning with subsequent automatic measurement of the hemispheric hippocampal subfield volumes (CA1, CA2-CA3, CA4-dente gyrus, presubiculum, and subiculum). We used linear regressions to model the association between hippocampal subfield volumes and visual and verbal episodic memory tests while adjusting for age, sex, education, and total intracranial volume. Participants had a mean age of 78.9 (SD=5.1) and 60.2% were female. Total hippocampal volume was associated with Complex Figure Delayed Recall (β=0.31, p=0.001) and FCSRT Delayed Recall (β=0.27, p=0.007); subiculum volume was associated with Complex Figure Delayed Recall (β=0.27, p=0.002) and FCSRT Delayed Recall (β=0.24, p=0.010); CA1 was associated with Complex Figure Delayed Recall (β=0.26, p<0.002) and FCSRT Delayed Recall (β=0.20, p=0.025). Our findings confirm previous research on the specific roles of CA1 and subiculum in episodic memory. Our results suggest that hippocampal subfields have sensitive roles in the process of visual and verbal episodic memory. Copyright © 2016 Elsevier B.V. All rights reserved.

System dynamics modeling in the evaluation of delays of care in ST-segment elevation myocardial infarction patients within a tiered health system.

PubMed

de Andrade, Luciano; Lynch, Catherine; Carvalho, Elias; Rodrigues, Clarissa Garcia; Vissoci, João Ricardo Nickenig; Passos, Guttenberg Ferreira; Pietrobon, Ricardo; Nihei, Oscar Kenji; de Barros Carvalho, Maria Dalva

2014-01-01

Mortality rates amongst ST segment elevation myocardial infarction (STEMI) patients remain high, especially in developing countries. The aim of this study was to evaluate the factors related with delays in the treatment of STEMI patients to support a strategic plan toward structural and personnel modifications in a primary hospital aligning its process with international guidelines. The study was conducted in a primary hospital localized in Foz do Iguaçu, Brazil. We utilized a qualitative and quantitative integrated analysis including on-site observations, interviews, medical records analysis, Qualitative Comparative Analysis (QCA) and System Dynamics Modeling (SD). Main cause of delays were categorized into three themes: a) professional, b) equipment and c) transportation logistics. QCA analysis confirmed four main stages of delay to STEMI patient's care in relation to the 'Door-in-Door-out' time at the primary hospital. These stages and their average delays in minutes were: a) First Medical Contact (From Door-In to the first contact with the nurse and/or physician): 7 minutes; b) Electrocardiogram acquisition and review by a physician: 28 minutes; c) ECG transmission and Percutaneous Coronary Intervention Center team feedback time: 76 minutes; and d) Patient's Transfer Waiting Time: 78 minutes. SD baseline model confirmed the system's behavior with all occurring delays and the need of improvements. Moreover, after model validation and sensitivity analysis, results suggested that an overall improvement of 40% to 50% in each of these identified stages would reduce the delay. This evaluation suggests that investment in health personnel training, diminution of bureaucracy, and management of guidelines might lead to important improvements decreasing the delay of STEMI patients' care. In addition, this work provides evidence that SD modeling may highlight areas where health system managers can implement and evaluate the necessary changes in order to improve the process of care.

Does Early Versus Delayed Active Range of Motion Affect Rotator Cuff Healing After Surgical Repair? A Systematic Review and Meta-analysis.

PubMed

Kluczynski, Melissa A; Isenburg, Maureen M; Marzo, John M; Bisson, Leslie J

2016-03-01

The timing of passive range of motion (ROM) after surgical repair of the rotator cuff (RC) has been shown to affect healing. However, it is unknown if early or delayed active ROM affects healing. To determine whether early versus delayed active ROM affects structural results of RC repair surgery. Systematic review and meta-analysis. A systematic review of articles published between January 2004 and April 2014 was conducted. Structural results were compared for early (<6 weeks after surgery) versus delayed (≥6 weeks after surgery) active ROM using chi-square and Fisher exact tests, as well as relative risks (RRs) and 95% CIs. The analyses were stratified by tear size and repair method. A total of 37 studies (2251 repairs) were included in the analysis, with 10 (649 repairs) in the early group and 27 (1602 repairs) in the delayed group. For tears ≤3 cm, the risk of a structural tendon defect was higher in the early versus delayed group for transosseous plus single-row suture anchor repairs (39.7% vs 24.3%; RR, 1.63 [95% CI, 1.28-2.08]). For tears >3 cm, the risk of a structural tendon defect was higher in the early versus delayed group for suture bridge repairs (48% vs 17.5%; RR, 2.74 [95% CI, 1.59-4.73]) and all repair methods combined (40.5% vs 26.7%; RR, 1.52 [95% CI, 1.17-1.97]). For tears >5 cm, the risk of structural tendon defect was higher in the early versus delayed group for suture bridge repairs (100% vs 16.7%; RR, 6.00 [95% CI, 1.69-21.26]). There were no statistically significant associations for tears measuring ≤1, 1-3, or 3-5 cm. Early active ROM was associated with increased risk of a structural defect for small and large RC tears, and thus might not be advisable after RC repair. © 2015 The Author(s).

Cost-effectiveness of early compared to late inhaled nitric oxide therapy in near-term infants.

PubMed

Armstrong, Edward P; Dhanda, Rahul

2010-12-01

The purpose of this study was to determine the cost-effectiveness of early versus late inhaled nitric oxide (INO) therapy in neonates with hypoxic respiratory failure initially managed on conventional mechanical ventilation. A decision analytic model was created to compare the use of early INO compared to delayed INO for neonates receiving mechanical ventilation due to hypoxic respiratory failure. The perspective of the model was that of a hospital. Patients who did not respond to either early or delayed INO were assumed to have been treated with extracorporeal membrane oxygenation (ECMO). The effectiveness measure was defined as a neonate discharged alive without requiring ECMO therapy. A Monte Carlo simulation of 10,000 cases was conducted using first and second order probabilistic analysis. Direct medical costs that differed between early versus delayed INO treatment were estimated until time to hospital discharge. The proportion of successfully treated patients and costs were determined from the probabilistic sensitivity analysis. The mean (± SD) effectiveness rate for early INO was 0.75 (± 0.08) and 0.61 (± 0.09) for delayed INO. The mean hospital cost for early INO was $21,462 (± $2695) and $27,226 (± $3532) for delayed INO. In 87% of scenarios, early INO dominated delayed INO by being both more effective and less costly. The acceptability curve between products demonstrated that early INO had over a 90% probability of being the most cost-effective treatment across a wide range of willingness to pay values. This analysis indicated that early INO therapy was cost-effective in neonates with hypoxic respiratory failure requiring mechanical ventilation compared to delayed INO by reducing the probability of developing severe hypoxic respiratory failure. There was a 90% or higher probability that early INO was more cost-effective than delayed INO across a wide range of willingness to pay values in this analysis.

Delays in Post-Remission Chemotherapy for Philadelphia Chromosome Negative Acute Lymphoblastic Leukemia are Associated with Inferior Outcomes in Patients who Undergo Allogeneic Transplant: an Analysis from ECOG 2993/MRC UK ALLXII

PubMed Central

Kumar, Anita J.; Rowe, Jacob M.; Goldstone, Anthony H; Fielding, Adele; Marks, David I; Litzow, Mark; Paietta, Elisabeth; Lazarus, Hillard M.; Tallman, Martin S.; Luger, Selina M.; Loren, Alison W.

2016-01-01

Adults with acute lymphoblastic leukemia (ALL) have a poorer prognosis than children due to a high risk of relapse. One explanation may be variable adherence to dose-intense chemotherapy. However, little is known about risk factors for delays in therapy and their impact on survival. We conducted an analysis of ECOG 2993/UKALLXII trial to study delays in post-remission chemotherapy in adults with newly-diagnosed ALL. Logistic regression was used to identify risk factors for a very long delay (>4 weeks, VLD) in start of intensification therapy. Cox regression was used to evaluate the impact of delays on overall and event-free survival (OS, EFS). We evaluated 1076 Philadelphia chromosome negative (Ph-) patients who completed induction chemotherapy, achieved complete remission, and started intensification. Factors independently associated with VLD included: duration of hospitalization (Odds Ratio (OR)=1.2, p<0.001) during Phase I; thrombocytopenia during Phase I (OR=1.16, p=0.004) or Phase II (OR 1.13, p=0.001); chemotherapy dose reductions during induction Phase I (OR=1.72, p<0.014); female sex (OR=1.53, p=0.010); Black (OR=3.24, p=0.003) and Asian (OR=2.26, p=0.021) race; and increasing age (OR=1.31, p<0.001). In multivariate Cox regression, patients who underwent allogeneic stem cell transplant (alloHCT) had significantly worse OS (HR 1.4, p=0.03) and EFS (HR 1.4, p=0.02) after experiencing a VLD compared to alloHCT patients who experienced <=4 weeks delay. Specific populations (female, older, Black, and Asian patients) were more likely to experience delays in chemotherapy, as were those with significant toxicity during induction. Very long delays in therapy negatively affected outcomes in patients undergoing allografting. PMID:27468137

Successful strategies for improving operating room efficiency at academic institutions.

PubMed

Overdyk, F J; Harvey, S C; Fishman, R L; Shippey, F

1998-04-01

In this prospective study, we evaluated the etiology of operating room (OR) delays in an academic institution, examined the impact of multidisciplinary strategies to improve OR efficiency, and established OR timing benchmarks for use in future OR efficiency studies. OR times and delay etiologies were collected for 94 cases during the initial phase of the study. Timing data and delay etiologies were analyzed, and 2 wk of multidisciplinary OR efficiency awareness education was conducted for the nursing, surgical, and anesthesia staff. After the education period, timing data were collected from 1787 cases, and monthly reports listing individual case delays and timing data were sent to the Chiefs of Service. For the first case of the day, patient in room, anesthesia ready, surgical preparation start, and procedure start time were significantly earlier (P < 0.01) in the posteducation period compared with the preeducation period, and the procedure start time for the first case of the day occurred, on average, 22 min earlier than all other procedures. For all cases combined, turnover time decreased, on average, by 16 min. Unavailability of surgeons, anesthesiologists, and residents decreased significantly (P < 0.05) as causes of OR delays. Anesthesia induction times were consistently longer for the vascular and cardiothoracic services, whereas surgical preparation time was increased for the neurosurgical and orthopedic services (P < 0.05). Identification of the etiology of OR inefficiency, combined with multidisciplinary awareness training and personal accountability, can improve OR efficiency. The time savings realized are probably most cost-effective when combined with more flexible OR staffing and improved OR scheduling. We achieved significant improvements in operating room efficiency by analyzing operating room data on causes of delays, devising strategies for minimizing the most common delays, and subsequently measuring delay data. Personal accountability, streamlining of procedures, interdisciplinary team work, and accurate data collection were all important contributors to improved efficiency.

System Dynamics Modeling in the Evaluation of Delays of Care in ST-Segment Elevation Myocardial Infarction Patients within a Tiered Health System

PubMed Central

de Andrade, Luciano; Lynch, Catherine; Carvalho, Elias; Rodrigues, Clarissa Garcia; Vissoci, João Ricardo Nickenig; Passos, Guttenberg Ferreira; Pietrobon, Ricardo; Nihei, Oscar Kenji; de Barros Carvalho, Maria Dalva

2014-01-01

Background Mortality rates amongst ST segment elevation myocardial infarction (STEMI) patients remain high, especially in developing countries. The aim of this study was to evaluate the factors related with delays in the treatment of STEMI patients to support a strategic plan toward structural and personnel modifications in a primary hospital aligning its process with international guidelines. Methods and Findings The study was conducted in a primary hospital localized in Foz do Iguaçu, Brazil. We utilized a qualitative and quantitative integrated analysis including on-site observations, interviews, medical records analysis, Qualitative Comparative Analysis (QCA) and System Dynamics Modeling (SD). Main cause of delays were categorized into three themes: a) professional, b) equipment and c) transportation logistics. QCA analysis confirmed four main stages of delay to STEMI patient’s care in relation to the ‘Door-in-Door-out’ time at the primary hospital. These stages and their average delays in minutes were: a) First Medical Contact (From Door-In to the first contact with the nurse and/or physician): 7 minutes; b) Electrocardiogram acquisition and review by a physician: 28 minutes; c) ECG transmission and Percutaneous Coronary Intervention Center team feedback time: 76 minutes; and d) Patient’s Transfer Waiting Time: 78 minutes. SD baseline model confirmed the system’s behavior with all occurring delays and the need of improvements. Moreover, after model validation and sensitivity analysis, results suggested that an overall improvement of 40% to 50% in each of these identified stages would reduce the delay. Conclusions This evaluation suggests that investment in health personnel training, diminution of bureaucracy, and management of guidelines might lead to important improvements decreasing the delay of STEMI patients’ care. In addition, this work provides evidence that SD modeling may highlight areas where health system managers can implement and evaluate the necessary changes in order to improve the process of care. PMID:25079362

FDA advisory committees meet January 26 on Salk HIV-1 immunogen.

PubMed

1995-01-06

Two advisory committees of the Food and Drug Administration (FDA) will meet to consider future trials of the HIV-1 immunogen developed by Dr. Jonas Salk. The Immune Response Corporation has already conducted several studies of the immunogen, and has found improvement in various immunological and other blood tests, and no adverse effects. However, the studies have not been large enough to show conclusively that the treatment has clinical benefit in delaying disease progression. The new, larger trials are intended to demonstrate a delay in disease progression and validate the use of blood-test markers of disease progression for studying an immune-based treatment.

Organic solar cells: evaluation of the stability of P3HT using time-delayed degradation

NASA Astrophysics Data System (ADS)

Poh, Chung-How; Poh, Chung-Kiak; Bryant, Glenn; Belcher, Warwick; Dastoor, Paul

2011-12-01

Despite the fact that the performance of organic solar cells is generally susceptible to degradation by moisture exposure, there has been suggestion that the photoactive layer (P3HT) is surprisingly resilient. This work attempts to confirm the stability of P3HT as an organic solar cell material by deliberately introducing water into the photoactive layer. A dramatic step drop in device performance during cell characterization is observed approximately one day after the device has been fabricated. The time-delayed step drop in output efficiency strongly suggests that moisture has little effect on the P3HT conducting polymer.

Pastoralism and delay in diagnosis of TB in Ethiopia

PubMed Central

Gele, Abdi A; Bjune, Gunnar; Abebe, Fekadu

2009-01-01

Background Tuberculosis (TB) is a major public health problem in the Horn of Africa with Ethiopia being the most affected where TB cases increase at the rate of 2.6% each year. One of the main contributing factors for this rise is increasing transmission due to large number of untreated patients, serving as reservoirs of the infection within the communities. Reduction of the time between onset of TB symptoms to diagnosis is therefore a prerequisite to bring the TB epidemic under control. The aim of this study was to measure duration of delay among pastoralist TB patients at TB management units in Somali Regional State (SRS) of Ethiopia. Methods A cross sectional study of 226 TB patients with pastoralist identity was conducted in SRS of Ethiopia from June to September 2007. Patients were interviewed using questionnaire based interview. Time between onset of TB symptoms and first visit to a professional health care provider (patient delay), and the time between first visits to the professional health care provider to the date of diagnosis (medical provider's delay) were analyzed. Both pulmonary and extrapulmonary TB patients were included in the study. Result A total of 226 pastoralist TB patients were included in this study; 93 (41.2%) were nomadic pastoralists and 133 (58.8%) were agro-pastoralists. Median patient delay was found to be 60 days with range of 10–1800 days (83 days for nomadic pastoralists and 57 days for agro-pastoralists). Median health care provider's delay was 6 days and median total delay was 70 days in this study. Patient delay constituted 86% of the total delay. In multivariate logistic regression analysis, nomadic pastoralism (aOR. 2.69, CI 1.47–4.91) and having low biomedical knowledge on TB (aOR. 2.02, CI 1.02–3.98) were significantly associated with prolonged patient delay. However, the only observed risk factor for very long patient delay >120 days was distance to health facility (aOR.4.23, CI 1.32–13.54). Extra-pulmonary TB was the only observed predictor for health care providers' delay (aOR. 3.39, CI 1.68–6.83). Conclusion Patient delay observed among pastoralist TB patients in SRS is one of the highest reported so far from developing countries, exceeding two years in some patients. This long patient delay appears to be associated with patient's inadequate knowledge of the disease and distance to health care facility with nomadic pastoralists being the most affected. Regional TB control programmes need to consider the exceptional circumstances of pastoralists, to maximise their access to TB services. PMID:19128498

Microwave bale moisture sensing: Field trial

USDA-ARS?s Scientific Manuscript database

A microwave moisture measurement technique was developed for moisture sensing of cotton bales after the bale press. The technique measures the propagation delay of a microwave signal that is transmitted through the cotton bale. This research conducted a field trial to test the sensor in a commercial...

Application of Reflected Global Navigation Satellite System (GNSS-R) Signals in the Estimation of Sea Roughness Effects in Microwave Radiometry

NASA Technical Reports Server (NTRS)

Voo, Justin K.; Garrison, James L.; Yueh, Simon H.; Grant, Michael S.; Fore, Alexander G.; Haase, Jennifer S.; Clauss, Bryan

2010-01-01

In February-March 2009 NASA JPL conducted an airborne field campaign using the Passive Active L-band System (PALS) and the Ku-band Polarimetric Scatterometer (PolSCAT) collecting measurements of brightness temperature and near surface wind speeds. Flights were conducted over a region of expected high-speed winds in the Atlantic Ocean, for the purposes of algorithm development for salinity retrievals. Wind speeds encountered were in the range of 5 to 25 m/s during the two weeks deployment. The NASA-Langley GPS delay-mapping receiver (DMR) was also flown to collect GPS signals reflected from the ocean surface and generate post-correlation power vs. delay measurements. This data was used to estimate ocean surface roughness and a strong correlation with brightness temperature was found. Initial results suggest that reflected GPS signals, using small low-power instruments, will provide an additional source of data for correcting brightness temperature measurements for the purpose of sea surface salinity retrievals.

Comparison study on disturbance estimation techniques in precise slow motion control

NASA Astrophysics Data System (ADS)

Fan, S.; Nagamune, R.; Altintas, Y.; Fan, D.; Zhang, Z.

2010-08-01

Precise low speed motion control is important for the industrial applications of both micro-milling machine tool feed drives and electro-optical tracking servo systems. It calls for precise position and instantaneous velocity measurement and disturbance, which involves direct drive motor force ripple, guide way friction and cutting force etc., estimation. This paper presents a comparison study on dynamic response and noise rejection performance of three existing disturbance estimation techniques, including the time-delayed estimators, the state augmented Kalman Filters and the conventional disturbance observers. The design technique essentials of these three disturbance estimators are introduced. For designing time-delayed estimators, it is proposed to substitute Kalman Filter for Luenberger state observer to improve noise suppression performance. The results show that the noise rejection performances of the state augmented Kalman Filters and the time-delayed estimators are much better than the conventional disturbance observers. These two estimators can give not only the estimation of the disturbance but also the low noise level estimations of position and instantaneous velocity. The bandwidth of the state augmented Kalman Filters is wider than the time-delayed estimators. In addition, the state augmented Kalman Filters can give unbiased estimations of the slow varying disturbance and the instantaneous velocity, while the time-delayed estimators can not. The simulation and experiment conducted on X axis of a 2.5-axis prototype micro milling machine are provided.

Determinants of Patient Delay in Seeking Diagnosis and Treatment among Moroccan Women with Cervical Cancer

PubMed Central

Hanchi, Zaki; Bekkali, Rachid; Ahid, Samir; Mesfioui, Abdelhalem

2016-01-01

Introduction. This study sought to investigate potential determinants of patient delay among Moroccan women with cervical cancer. Methods. A cross-sectional study was conducted from June 2014 to June 2015 at the National Institute of Oncology in Rabat. Data were collected using questionnaire among patients with cervical cancer locally advanced or metastatic (stages IIA–IVB). Medical records were abstracted to complete clinical information. An interval longer than 90 days between discovery of initial symptoms and presentation to a provider was defined as a patient delay. Results. Four hundred and one patients with cervical cancer enrolled in this study. The mean age was 52.4 years (SD = 11.5). 53.6% were illiterate. Abnormal vaginal bleeding was identified for 65.8% of patients. 60.1% were diagnosed at stages IIA-IIB. 55.4% were found having patient delay. The regression analyses showed the association between literacy (p < 0.001), distance of the place of the first consultation (p = 0.031), abnormal vaginal bleeding as an earlier symptom (p < 0.001), stage at diagnosis (p < 0.03), knowledge of symptoms (p < 0.001), knowledge of causes (p = 0.008), and practice of gynecological exam during the last three years (p = 0.018) and the patient delay. Conclusion. Educational messages should aim at increasing awareness of cervical cancer, assisting women in symptom recognition, and encouraging earlier presentation. PMID:27882055

Control of resting membrane potential by delayed rectifier potassium currents in ferret airway smooth muscle cells.

PubMed Central

Fleischmann, B K; Washabau, R J; Kotlikoff, M I

1993-01-01

1. In order to determine the physiological role of specific potassium currents in airway smooth muscle, potassium currents were measured in freshly dissociated ferret trachealis cells using the nystatin-permeabilized, whole-cell method, at 35 degrees C. 2. The magnitude of the outward currents was markedly increased as bath temperature was increased from 22 to 35 degrees C. This increase was primarily due to the increase in maximum potassium conductance (gK,max), although there was also a small leftward shift in the relationship between gK and voltage at higher temperatures. The maximum conductance and the kinetics of current activation and inactivation were also temperature dependent. At 35 degrees C, gating of the current was steeply voltage dependent between -40 and 0 mV. Current activation was well fitted by fourth-order kinetics; the mean time constants of activation (30 mV clamp step) were 1.09 +/- 0.17 and 1.96 +/- 0.27 ms at 35 and 22 degrees C, respectively. 3. Outward currents using the nystatin method were qualitatively similar to delayed rectifier currents recorded in dialysed cells with high calcium buffering capacity solutions. 4-Aminopyridine (4-AP; 2 mM), a specific blocker of delayed rectifier potassium channels in this tissue, inhibited over 80% of the outward current evoked by voltage-clamp steps to between -10 and +20 mV (n = 6). Less than 5% of the outward current was blocked over the same voltage range by charybdotoxin (100 nM; n = 15), a specific antagonist of large-conductance, calcium-activated potassium channels in this tissue. 4. The degree to which delayed rectifier and calcium-activated potassium conductances control resting membrane potential was examined in current-clamp experiments. The resting membrane potential of current clamped cells was -33.6 +/- 1.0 mV (n = 62). Application of 4-AP (2 mM) resulted in a 14.4 +/- 1.0 mV depolarization (n = 8) and an increase in input resistance. Charybdotoxin (100 nM) had no effect on resting membrane potential (n = 6). 5. Force measurements were made in isolated strips of trachealis muscle to determine the effect of pharmacological blockade of individual potassium conductances on resting tone. In the presence of tetrodotoxin (1 microM) and atropine (1 microM), 4-AP increased baseline tension in a dose-dependent manner, with an EC50 of 1.8 mM (n = 13); application of 5 mM 4-AP increased tone to 86.8 +/- 8.1% of that produced by 1 microM methacholine, and this tone was almost completely inhibited by nifedipine (1 microM).(ABSTRACT TRUNCATED AT 400 WORDS) PMID:8271220

The effects of resonances on time delay estimation for water leak detection in plastic pipes

NASA Astrophysics Data System (ADS)

Almeida, Fabrício C. L.; Brennan, Michael J.; Joseph, Phillip F.; Gao, Yan; Paschoalini, Amarildo T.

2018-04-01

In the use of acoustic correlation methods for water leak detection, sensors are placed at pipe access points either side of a suspected leak, and the peak in the cross-correlation function of the measured signals gives the time difference (delay) between the arrival times of the leak noise at the sensors. Combining this information with the speed at which the leak noise propagates along the pipe, gives an estimate for the location of the leak with respect to one of the measurement positions. It is possible for the structural dynamics of the pipe system to corrupt the time delay estimate, which results in the leak being incorrectly located. In this paper, data from test-rigs in the United Kingdom and Canada are used to demonstrate this phenomenon, and analytical models of resonators are coupled with a pipe model to replicate the experimental results. The model is then used to investigate which of the two commonly used correlation algorithms, the Basic Cross-Correlation (BCC) function or the Phase Transform (PHAT), is more robust to the undesirable structural dynamics of the pipe system. It is found that time delay estimation is highly sensitive to the frequency bandwidth over which the analysis is conducted. Moreover, it is found that the PHAT is particularly sensitive to the presence of resonances and can give an incorrect time delay estimate, whereas the BCC function is found to be much more robust, giving a consistently accurate time delay estimate for a range of dynamic conditions.

Early and delayed pinhole MIBI SPECT in detecting hyperfunctioning parathyroid glands: a comparison with peroperative γ probe.

PubMed

Gültekin, Salih Sinan; Kir, Metin; Tuğ, Tuğbay; Demirer, Seher; Genç, Yasemin

2011-10-01

This study was conducted to evaluate the early and delayed pinhole MIBI single photon emission computed tomography (pSPECT) images in detecting hyperfunctioning parathyroid glands, to make a comparison with peroperative γ probe (GP) findings. Planar, early, and delayed pSPECT scans and skin in-vivo and ex-vivo GP counts were obtained in 22 patients with hyperparathyroidism. All data were analyzed statistically on the basis of localization of the lesions, using the histopathological findings as the gold standard. Histopathological examinations revealed 18 of 44 adenomas, 18 of 44 hyperplasic glands, two of 44 lymph nodules, five of 44 thyroid nodules, and one of 44 normal parathyroid glands. Sensitivity and specificity were found to be 36 and 100% for planar, 69 and 75% for early pSPECT, 86 and 88% for delayed pSPECT scans, and similarly, 78 and 75% on skin, 92 and 75% in-vivo and 83 and 100% ex-vivo GP counts, respectively. For distinction ability of GP counts between three groups of lesions, there was a statistically significant difference among the three groups for ex-vivo GP counts but not between groups of adenomas and hyperplasic lesions for in-vivo GP counts. Early and delayed pSPECT scans play a complementary role on the planar scans. Delayed pSPECT scans and in-vivo GP counts are equally valuable to localize both single and multiple hyperfunctioning parathyroid glands. Ex-vivo GP counts seem to be better for making a distinction among types of lesions.

The study on achievement of motor milestones and associated factors among children in rural North India

PubMed Central

Gupta, Arti; Kalaivani, Mani; Gupta, Sanjeev Kumar; Rai, Sanjay K.; Nongkynrih, Baridalyne

2016-01-01

Background: Nearly 14% of children worldwide do not reach their developmental potential in early childhood. The early identification of delays in achieving milestones is critical. The World Health Organization (WHO) has developed normal age ranges for the achievement of motor milestones by healthy children. This study aimed to assess the gross motor developmental achievements and associated factors among children in rural India. Materials and Methods: A cross-sectional study was conducted with rural children in North India. A pretested questionnaire was used to collect the data. The median age at the time of the highest observed milestone was calculated and compared with the WHO windows of achievement. Results: Overall, 221 children aged 4–18 months were included in the study. The median age of motor development exhibited a 0.1–2.1-month delay compared to the WHO median age of motor milestone achievement. The prevalence of the gross motor milestone achievements for each of the six milestones ranged from 91.6% to 98.4%. Developmental delay was observed in 6.3% of the children. After adjusting for different variables, children with birth order of second or more were found to be significantly associated with the timely achievement of gross motor milestones. Conclusion: The apparently healthy children of the rural area of Haryana achieved gross motor milestones with some delay with respect to the WHO windows of achievement. Although the median value of this delay was low, awareness campaigns should be implemented to promote timely identification of children with development delays. PMID:27843845

Theoretical Prediction of Microgravity Ignition Delay of Polymeric Fuels in Low Velocity Flows

NASA Technical Reports Server (NTRS)

Fernandez-Pello, A. C.; Torero, J. L.; Zhou, Y. Y.; Walther, D.; Ross, H. D.

2001-01-01

A new flammability apparatus and protocol, FIST (Forced Flow Ignition and Flame Spread Test), is under development. Based on the LIFT (Lateral Ignition and Flame Spread Test) protocol, FIST better reflects the environments expected in spacebased facilities. The final objective of the FIST research is to provide NASA with a test methodology that complements the existing protocol and provides a more comprehensive assessment of material flammability of practical materials for space applications. Theoretical modeling, an extensive normal gravity data bank and a few validation space experiments will support the testing methodology. The objective of the work presented here is to predict the ignition delay and critical heat flux for ignition of solid fuels in microgravity at airflow velocities below those induced in normal gravity. This is achieved through the application of a numerical model previously developed of piloted ignition of solid polymeric materials exposed to an external radiant heat flux. The model predictions will provide quantitative results about ignition of practical materials in the limiting conditions expected in space facilities. Experimental data of surface temperature histories and ignition delay obtained in the KC-135 aircraft are used to determine the critical pyrolysate mass flux for ignition and this value is subsequently used to predict the ignition delay and the critical heat flux for ignition of the material. Surface temperature and piloted ignition delay calculations for Polymethylmethacrylate (PMMA) and a Polypropylene/Fiberglass (PP/GL) composite were conducted under both reduced and normal gravity conditions. It was found that ignition delay times are significantly shorter at velocities below those induced by natural convection.

Persistent Memory in Single Node Delay-Coupled Reservoir Computing.

PubMed

Kovac, André David; Koall, Maximilian; Pipa, Gordon; Toutounji, Hazem

2016-01-01

Delays are ubiquitous in biological systems, ranging from genetic regulatory networks and synaptic conductances, to predator/pray population interactions. The evidence is mounting, not only to the presence of delays as physical constraints in signal propagation speed, but also to their functional role in providing dynamical diversity to the systems that comprise them. The latter observation in biological systems inspired the recent development of a computational architecture that harnesses this dynamical diversity, by delay-coupling a single nonlinear element to itself. This architecture is a particular realization of Reservoir Computing, where stimuli are injected into the system in time rather than in space as is the case with classical recurrent neural network realizations. This architecture also exhibits an internal memory which fades in time, an important prerequisite to the functioning of any reservoir computing device. However, fading memory is also a limitation to any computation that requires persistent storage. In order to overcome this limitation, the current work introduces an extended version to the single node Delay-Coupled Reservoir, that is based on trained linear feedback. We show by numerical simulations that adding task-specific linear feedback to the single node Delay-Coupled Reservoir extends the class of solvable tasks to those that require nonfading memory. We demonstrate, through several case studies, the ability of the extended system to carry out complex nonlinear computations that depend on past information, whereas the computational power of the system with fading memory alone quickly deteriorates. Our findings provide the theoretical basis for future physical realizations of a biologically-inspired ultrafast computing device with extended functionality.

Analysis of vaccination status of preschool children in Teresina (PI), Brazil.

PubMed

Fernandes, Ana Catharina Nunes; Gomes, Keila Rejane Oliveira; de Araújo, Telma Maria Evangelista; Moreira-Araújo, Regilda Saraiva dos Reis

2015-01-01

Immunization is a priority action of the Ministry of Health for contributing to reducing child mortality; however, studies show increased vaccination delays and non-vaccination. This study aims to analyze the immunization status of preschool children in Teresina - PI. Cross-sectional study involving 542 children, aged 2-6 years, enrolled in local public schools in four Municipal Childhood Education Centers selected at random, following the proportional division by regions of the city. Data were collected through a pre-coded and pre-tested form, in addition to scanning the children's vaccination card. For univariate descriptive statistical analysis, Pearson's χ2 Test and Fisher's Exact Test were used, and for multivariate analysis, multiple logistic regression was conducted using SPSS version 17.0. The study complied with the ethical aspects in accordance with current legislation. The frequency of delayed vaccination/non-vaccination was 24.9%. The average of non-administered vaccines was 1.7 (SD ± 1.2) and of delayed vaccines was 3.3 (SD ± 1.6). The binomial logistic regression model showed a significant association (p < 0.05) between young caregivers (under 24 years) and low frequency in childcare consultations with delayed vaccination/non-vaccination. There was no association with the variables related to the experience of children in the vaccination room and with the implementation of the Family Health Strategy. Ensuring and strengthening primary healthcare actions are essential tools to reduce non-vaccination and vaccine delays. Professionals who care for children in vaccination rooms need to sensitize themselves to guide and encourage parents/caregivers to meet the vaccination schedules without delays or errors.

Persistent Memory in Single Node Delay-Coupled Reservoir Computing

PubMed Central

Pipa, Gordon; Toutounji, Hazem

2016-01-01

Delays are ubiquitous in biological systems, ranging from genetic regulatory networks and synaptic conductances, to predator/pray population interactions. The evidence is mounting, not only to the presence of delays as physical constraints in signal propagation speed, but also to their functional role in providing dynamical diversity to the systems that comprise them. The latter observation in biological systems inspired the recent development of a computational architecture that harnesses this dynamical diversity, by delay-coupling a single nonlinear element to itself. This architecture is a particular realization of Reservoir Computing, where stimuli are injected into the system in time rather than in space as is the case with classical recurrent neural network realizations. This architecture also exhibits an internal memory which fades in time, an important prerequisite to the functioning of any reservoir computing device. However, fading memory is also a limitation to any computation that requires persistent storage. In order to overcome this limitation, the current work introduces an extended version to the single node Delay-Coupled Reservoir, that is based on trained linear feedback. We show by numerical simulations that adding task-specific linear feedback to the single node Delay-Coupled Reservoir extends the class of solvable tasks to those that require nonfading memory. We demonstrate, through several case studies, the ability of the extended system to carry out complex nonlinear computations that depend on past information, whereas the computational power of the system with fading memory alone quickly deteriorates. Our findings provide the theoretical basis for future physical realizations of a biologically-inspired ultrafast computing device with extended functionality. PMID:27783690

A position- and time-sensitive photon-counting detector with delay- line read-out

NASA Astrophysics Data System (ADS)

Jagutzki, Ottmar; Dangendorf, Volker; Lauck, Ronald; Czasch, Achim; Milnes, James

2007-05-01

We have developed image intensifier tubes with delay-anode read-out for time- and position-sensitive photon counting. The timing precision is better than 1 ns with 1000x1000 pixels position resolution and up to one megacounts/s processing rate. Large format detectors of 40 and 75 mm active diameter with internal helical-wire delay-line anodes have been produced and specified. A different type of 40 and 25 mm tubes with semi-conducting screen for image charge read-out allow for an economic and robust tube design and for placing the read-out anodes outside the sealed housing. Two types of external delay-line anodes, i.e. pick-up electrodes for the image charge, have been tested. We present tests of the detector and anode performance. Due to the low background this technique is well suited for applications with very low light intensity and especially if a precise time tagging for each photon is required. As an example we present the application of scintillator read-out in time-of-flight (TOF) neutron radiography. Further applications so far are Fluorescence Life-time Microscopy (FLIM) and Astronomy.

Delay in Diagnosis and Treatment of Breast Cancer among Women Attending a Reference Service in Brazil

PubMed

Romeiro Lopes, Tiara Cristina; Gravena, Angela Andréia França; Demitto, Marcela de Oliveira; Borghesan, Deise Helena Pelloso; Dell`Agnolo, Cátia Millene; Brischiliari, Sheila Cristina Rocha; Carvalho, Maria Dalva de Barros; Pelloso, Sandra Marisa

2017-11-26

Background: Cancer is a major public health problem. Early diagnosis and treatment are essential for reducing mortality. This study aimed to analyze factors associated with delay in breast cancer diagnosis and treatment among women attending a reference cancer service. Methods: This retrospective, cross-sectional study was performed with data collected from medical records and interviews conducted with women diagnosed with breast cancer and treated from October 2013 to October 2014 at a cancer reference hospital in Paraná, Southern Brazil. Results: A total of 82 participants were enrolled during the study period; their average age was 58.2 ± 11.5 years. The average time taken for final diagnosis of breast cancer was 102.5 ± 165.5 days. Treatment onset was delayed in the majority of cases, and the average time elapsing from diagnostic biopsy to onset of primary treatment was 72.3 ± 54.0 days. The odds of treatment delay were higher among the women with a low educational level. Conclusions: The results underline the need for proposals aimed at early detection, identification of risk factors and timely provision of treatment by health managers that focus on this group. Creative Commons Attribution License

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

NASA Astrophysics Data System (ADS)

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

2017-02-01

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

Patient Reported Delays in Seeking Treatment for Tuberculosis among Adult and Pediatric TB Patients and TB Patients Co-Infected with HIV in Lima, Peru: A Qualitative Study

PubMed Central

Paz-Soldan, Valerie A.; Alban, Rebecca E.; Dimos Jones, Christy; Powell, Amy R.; Oberhelman, Richard A.

2014-01-01

Introduction: Tuberculosis (TB) remains a significant public health challenge worldwide, and particularly in Peru with one of the highest incidence rates in Latin America. TB patient behavior has a direct influence on whether a patient will receive timely diagnosis and successful treatment of their illness. Objectives: The objective was to understand the complex factors that can impact TB patient health seeking behavior. Methods: In-depth interviews were conducted with adult and parents of pediatric patients receiving TB treatment (n = 43), within that group a sub-group was also co-infected with HIV (n = 11). Results: Almost all of the study participants recognized delays in seeking either their child’s or their own diagnosis of their TB symptoms. The principal reasons for treatment-seeking delays were lack of knowledge and confusion of TB symptoms, fear and embarrassment of receiving a TB diagnosis, and a patient tendency to self-medicate prior to seeking formal medical attention. Conclusion: Health promotion activities that target patient delays have the potential to improve individual patient outcomes and mitigate the spread of TB at a community level. PMID:25566523

Skin testing of guinea pigs and footpad testing of mice with a new antigen for detecting delayed hypersensitivity to Cryptococcus neoformans.

PubMed

Murphy, J W; Gregory, J A; Larsh, H W

1974-02-01

This study was undertaken to evaluate the potential of a cryptococcal culture filtrate antigen, cryptococcin C184, for detecting delayed hypersensitivity in Cryptococcus neoformans-injected animals. The antigen was tested on guinea pigs which had received saline or C. neoformans and on animals sensitized to Histoplasma capsulatum, Blastomyces dermatitidis, Candida albicans, or Sporothrix schenckii. A delayed-type hypersensitivity response was elicited by cryptococcin C184 in C. neoformans-injected guinea pigs, whereas no indurations or erythemas were seen at 48 h after skin testing of saline controls or heterologously sensitized guinea pigs. Besides being specific for Cryptococcus, the antigen showed a high degree of sensitivity and was reproducible. Footpad tests were conducted with the antigen on mice which had previously received either 10(5) viable C. neoformans cells or saline. Delayed hypersensitivity was indicated in the C. neoformans-injected mice by the increase in thickness of antigen-injected footpads when compared with the saline-injected footpads. In control mice, antigen- and saline-injected footpads were comparable in thickness 24 h after injection. Mice sensitized to B. dermatitidis were footpad tested with C184, and no cross-reactivity was demonstrated.

Measurement method for determining the magnetic hysteresis effects of reluctance actuators by evaluation of the force and flux variation.

PubMed

Vrijsen, N H; Jansen, J W; Compter, J C; Lomonova, E A

2013-07-01

A measurement method is presented which identifies the magnetic hysteresis effects present in the force of linear reluctance actuators. The measurement method is applied to determine the magnetic hysteresis in the force of an E-core reluctance actuator, with and without pre-biasing permanent magnet. The force measurements are conducted with a piezoelectric load cell (Kistler type 9272). This high-bandwidth force measurement instrument is identified in the frequency domain using a voice-coil actuator that has negligible magnetic hysteresis and eddy currents. Specifically, the phase delay between the current and force of the voice-coil actuator is used for the calibration of the measurement instrument. This phase delay is also obtained by evaluation of the measured force and flux variation in the E-core actuator, both with and without permanent magnet on the middle tooth. The measured magnetic flux variation is used to distinguish the phase delay due to magnetic hysteresis from the measured phase delay between the current and the force of the E-core actuator. Finally, an open loop steady-state ac model is presented that predicts the magnetic hysteresis effects in the force of the E-core actuator.

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

PubMed

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

2011-06-01

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

Effects of cockpit lateral stick characteristics on handling qualities and pilot dynamics

NASA Technical Reports Server (NTRS)

Mitchell, David G.; Aponso, Bimal L.; Klyde, David H.

1992-01-01

This report presents the results of analysis of cockpit lateral control feel-system studies. Variations in feel-system natural frequency, damping, and command sensing reference (force and position) were investigated, in combination with variations in the aircraft response characteristics. The primary data for the report were obtained from a flight investigation conducted with a variable-stability airplane, with additional information taken from other flight experiments and ground-based simulations for both airplanes and helicopters . The study consisted of analysis of handling qualities ratings and extraction of open-loop, pilot-vehicle describing functions from sum-of-sines tracking data, including, for a limited subset of these data, the development of pilot models. The study confirms the findings of other investigators that the effects on pilot opinion of cockpit feel-system dynamics are not equivalent to a comparable level of added time delay, and until a more comprehensive set of criteria are developed, it is recommended that feel-system dynamics be considered a delay-inducing element in the aircraft response. The best correlation with time-delay requirements was found when the feel-system dynamics were included in the delay measurements, regardless of the command reference. This is a radical departure from past approaches.

Effect of the glucocorticoid receptor antagonist Org 34850 on fast and delayed feedback of corticosterone release.

PubMed

Spiga, Francesca; Harrison, Louise R; Wood, Susan A; MacSweeney, Cliona P; Thomson, Fiona J; Craighead, Mark; Grassie, Morag; Lightman, Stafford L

2008-02-01

We investigated the effect of the glucocorticoid receptor (GR) antagonist Org 34850 on fast and delayed inhibition of corticosterone secretion in response to the synthetic glucocorticoid methylprednisolone (MPL). Male rats were implanted with a catheter in the right jugular vein, for blood sampling and MPL administration, and with an s.c. cannula for Org 34850 administration. All experiments were conducted at the diurnal hormonal peak in the late afternoon. Rats were connected to an automated sampling system and blood samples were collected every 5 or 10 min. Org 34850 (10 mg/kg, s.c.) or vehicle (5% mulgofen in saline) was injected at 1630 h; 30 min later, rats received an injection of MPL (500 microg/rat, i.v.) or saline (0.1 ml/rat). We found that an acute administration of MPL rapidly decreased the basal corticosterone secretion and this effect was not prevented by acute pretreatment with Org 34850. However, blockade of GR with Org 34850 prevented delayed inhibition of MPL on corticosterone secretion measured between 4 and 12 h after MPL administration. Our data suggest an involvement of GR in modulating delayed, but not fast, inhibition induced by MPL on basal corticosterone secretion.

Developmental delay in the Amazon: The social determinants and prevalence among rural communities in Peru

PubMed Central

Alnasser, Yossef

2017-01-01

The consequences of poor child development are becoming increasingly recognized. Programs are being put in place around the world to improve child development by providing healthy and stimulating environments for children. However, these programs often have limited reach and little is known about the prevalence of developmental delay in under-developed communities. The current study set-out to better understand the prevalence of developmental delay in rural communities in the Amazon region of Peru. Also, it explores social determinants that are associated with any delay. Cross-sectional study by evaluating developmental delay in children under 4 years utilizing Ages and Stages Questionnaire (ASQ-3). Additionally, conducting a social determinants questionnaire answered by caretakers to identify social drivers for developmental delay. The data was analyzed with multi-variant analysis to measure association. The prevalence of developmental delay in the Amazonian communities was 26.7% (19.3% in communication, 11.4% in gross motor skills, 8% in both) (N = 596). The multivariate logistic regression analysis revealed significant associations between developmental delay and; level of education (OR 0.64, p = 0.009), age of mother during child’s birth (OR 0.96, p = 0.002), visits by community health agents (OR 0.73, p = 0.013), and river as primary water source (OR 2.39, p = 0.001). The social determinants questionnaire revealed that 39% of the mothers had their first child before the age of 17, nearly half stopped going to school before the age of 12 (52%), 29% gave birth at home, 13% breast fed for less than 7 months, and 50% of the children had diarrhea in the last month. There is still a great need to improve the conditions for child development in the Amazon region of Peru. One-fourth of the children suffer from developmental delay, which will likely impede their potentials for life unless something is done. The impact of education, age of mother at birth of the child, community health agents, and access to clean drinking water were important findings. Improvements can be made in these areas to create a large, cost-effective impact on the well-being of the communities. PMID:29023517

Developmental delay in the Amazon: The social determinants and prevalence among rural communities in Peru.

PubMed

Westgard, Christopher; Alnasser, Yossef

2017-01-01

The consequences of poor child development are becoming increasingly recognized. Programs are being put in place around the world to improve child development by providing healthy and stimulating environments for children. However, these programs often have limited reach and little is known about the prevalence of developmental delay in under-developed communities. The current study set-out to better understand the prevalence of developmental delay in rural communities in the Amazon region of Peru. Also, it explores social determinants that are associated with any delay. Cross-sectional study by evaluating developmental delay in children under 4 years utilizing Ages and Stages Questionnaire (ASQ-3). Additionally, conducting a social determinants questionnaire answered by caretakers to identify social drivers for developmental delay. The data was analyzed with multi-variant analysis to measure association. The prevalence of developmental delay in the Amazonian communities was 26.7% (19.3% in communication, 11.4% in gross motor skills, 8% in both) (N = 596). The multivariate logistic regression analysis revealed significant associations between developmental delay and; level of education (OR 0.64, p = 0.009), age of mother during child's birth (OR 0.96, p = 0.002), visits by community health agents (OR 0.73, p = 0.013), and river as primary water source (OR 2.39, p = 0.001). The social determinants questionnaire revealed that 39% of the mothers had their first child before the age of 17, nearly half stopped going to school before the age of 12 (52%), 29% gave birth at home, 13% breast fed for less than 7 months, and 50% of the children had diarrhea in the last month. There is still a great need to improve the conditions for child development in the Amazon region of Peru. One-fourth of the children suffer from developmental delay, which will likely impede their potentials for life unless something is done. The impact of education, age of mother at birth of the child, community health agents, and access to clean drinking water were important findings. Improvements can be made in these areas to create a large, cost-effective impact on the well-being of the communities.

Early Versus Delayed Passive Range of Motion After Rotator Cuff Repair: A Systematic Review and Meta-analysis.

PubMed

Kluczynski, Melissa A; Nayyar, Samir; Marzo, John M; Bisson, Leslie J

2015-08-01

Postoperative rehabilitation has been shown to affect healing of the rotator cuff after surgical repair. However, it is unknown whether an early or delayed rehabilitation protocol is most beneficial for healing. To determine whether early versus delayed passive range of motion (PROM) affects rotator cuff (RC) retear rates after surgery. Systematic review and meta-analysis. A systematic review of the literature published between January 2003 and February 2014 was conducted. Retear rates were compared for early (within 1 week after surgery) versus delayed (3-6 weeks after surgery) PROM using χ(2) or Fisher exact tests as well as relative risks (RR) and 95% CIs. In the first analysis, data from evidence level 1 studies that directly compared early versus delayed PROM were pooled; and in the second analysis, data from level 1 to 4 studies that did not directly compare early versus delayed PROM were pooled. The second analysis was stratified by tear size and repair method. Twenty-eight studies (1729 repairs) were included. The first analysis of level 1 studies did not reveal a significant difference in retear rates for early (13.7%) versus delayed (10.5%) PROM (P = .36; RR = 1.30 [95% CI, 0.74-2.30]). The second analysis revealed that for ≤3 cm tears, the risk of retear was lower for early versus delayed PROM for transosseous (TO) plus single-row anchor (SA) repairs (18.7% vs 28.2%, P = .02; RR = 0.66 [95% CI, 0.47-0.95]). For >5 cm tears, the risk of retear was greater for early versus delayed PROM for double-row anchor (DA) repairs (56.4% vs 20%, P = .002; RR = 2.82 [95% CI, 1.31-6.07]) and for all repair methods combined (52.2% vs 22.6%, P = .01; RR = 2.31 [95% CI, 1.16-4.61]). There were no statistically significant associations for tears measuring <1 cm, 1 to 3 cm, 3 to 5 cm, and >3 cm. Evidence is lacking with regard to the optimal timing of PROM after RC repair; however, this study suggests that tear size may be influential. © 2014 The Author(s).

Determinants of delayed care seeking for TB suggestive symptoms in Seru district, Oromiya region, Ethiopia: a community based unmatched case-control study.

PubMed

Yirgu, Robel; Lemessa, Firaol; Hirpa, Selamawit; Alemayehu, Abraham; Klinkenberg, Eveline

2017-04-20

Early tuberculosis (TB) case finding and adequate chemotherapy are essential for interrupting disease transmission and preventing complications due to delayed care seeking. This study was undertaken in order to provide insights into the magnitude and determinants of patient delay. The study was conducted in rural Seru district, employing a population based unmatched case-control study design. The WHO standardized TB screening tool was used to identify presumptive TB cases among the district population ages > 15 years. Presumptive TB cases who sought care in a health facility more than 14 days after the onset of symptoms were considered cases while those who sought care within the first 14 days were classified as controls. A structured interview questionnaire was used to capture socio demographic characteristics and health care service utilization related data from the study participants. A multiple binary logistic regression model was used to identify any factor associated with patient care seeking delay. A total of 9,782 individuals were screened, of which 980 (10%, 95% CI; 9.4-10.5%) presumptive TB cases were identified. From these cases 358 (76%, 95% CI; 75.6%-76.4%) sought care within the first 14 days of the onset of symptoms with a median patient delay of 15 days, IQR (5-30 days). The most common TB suggestive symptom mentioned by the participants was night sweat 754 (76.4%) while the least common was a history of contact with a confirmed TB case in the past one year 207 (21.1%). Individuals in the 45-54 age range had lower odds of delay (AOR 0.31, 95%CI 0.15, 0.61) as compared to those 15-24 years old. First TB treatment episode (AOR16.2, 95% CI 9.94, 26.26) and limited access to either traditional or modern modes of transportation (AOR 2.62, 95% CI 1.25, 5.49) were independently associated with patient care delay. Increasing community awareness about the risks of delayed care seeking and the importance of accessing health services close to the community can help decrease patient care delay.

Socio-cultural and service delivery dimensions of maternal mortality in rural central India: a qualitative exploration using a human rights lens.

PubMed

Jat, Tej Ram; Deo, Prakash R; Goicolea, Isabel; Hurtig, Anna-Karin; San Sebastian, Miguel

2015-01-01

Despite the avoidable nature of maternal mortality, unacceptably high numbers of maternal deaths occur in developing countries. Considering its preventability, maternal mortality is being increasingly recognised as a human rights issue. Integration of a human rights perspective in maternal health programmes could contribute positively in eliminating avertable maternal deaths. This study was conducted to explore socio-cultural and service delivery-related dimensions of maternal deaths in rural central India using a human rights lens. Social autopsies were conducted for 22 maternal deaths during 2011 in Khargone district in central India. The data were analysed using thematic analysis. The factors associated with maternal deaths were classified by using the 'three delays' framework and were examined by using a human rights lens. All 22 women tried to access medical assistance, but various factors delayed their access to appropriate care. The underestimation of the severity of complications by family members, gender inequity, and perceptions of low-quality delivery services delayed decisions to seek care. Transportation problems and care seeking at multiple facilities delayed reaching appropriate health facilities. Negligence by health staff and unavailability of blood and emergency obstetric care services delayed receiving adequate care after reaching a health facility. The study highlighted various socio-cultural and service delivery-related factors which are violating women's human rights and resulting in maternal deaths in rural central India. This study highlights that, despite the health system's conscious effort to improve maternal health, normative elements of a human rights approach to maternal health (i.e. availability, accessibility, acceptability, and quality of maternal health services) were not upheld. The data and analysis suggest that the deceased women and their relatives were unable to claim their entitlements and that the duty bearers were not successful in meeting their obligations. Based on the findings of our study, we conclude that to prevent maternal deaths, further concentrated efforts are required for better community education, women's empowerment, and health systems strengthening to provide appropriate and timely services, including emergency obstetric care, with good quality.

Interrupted Visual Searches Reveal Volatile Search Memory

ERIC Educational Resources Information Center

Shen, Y. Jeremy; Jiang, Yuhong V.

2006-01-01

This study investigated memory from interrupted visual searches. Participants conducted a change detection search task on polygons overlaid on scenes. Search was interrupted by various disruptions, including unfilled delay, passive viewing of other scenes, and additional search on new displays. Results showed that performance was unaffected by…

Computer Simulations and Clear Observations Do Not Guarantee Conceptual Understanding

ERIC Educational Resources Information Center

Renken, Maggie D.; Nunez, Narina

2013-01-01

Evidence for cognitive benefits of simulated versus physical experiments is unclear. Seventh grade participants (n = 147) reported their understanding of two simple pendulum problems (1) before conducting an experiment, (2) immediately following experimentation, and (3) after a 12-week delay. "Problem type" was manipulated within…

Evaluation of an adaptive traffic signal system : route 291 in Lee's Summit, Missouri.

DOT National Transportation Integrated Search

2010-03-01

An adaptive traffic signal system was installed on a 12-signal, 2.5-mi arterial in Lees Summit, Missouri in the Spring : of 2008. An evaluation of travel time, delay, number of stops, fuel consumption, and emissions was conducted, which : compared...

Immediate Postsession Feeding Reduces Operant Responding in Rats

ERIC Educational Resources Information Center

Smethells, John R.; Fox, Andrew T.; Andrews, Jennifer J.; Reilly, Mark P.

2012-01-01

Three experiments investigated the effects of immediate and delayed postsession feeding on progressive-ratio and variable-interval schedule performance in rats. During Experiments 1 and 2, immediate postsession feeding decreased the breakpoint, or largest completed ratio, under progressive-ratio schedules. Experiment 3 was conducted to extend the…

Correlation of Mechanical Properties in Bulk Metallic Glasses with 27Al NMR Characteristics

DTIC Science & Technology

2011-12-01

recycle delay of 300 ms. Magnetization measurements were conducted at room temperature using a Quantum Design SQUID magne- tometer. The magnetization of...Gangopadhyay A K, et al. First X-ray scattering studies on electrostatically levitated metallic liquids: Demonstrated influence of local icosahedral

Life in the Transition Economies.

ERIC Educational Resources Information Center

Lopus, Jane

1998-01-01

Reports on interviews conducted with Ukrainian teachers who were asked whether they and others they know are better, or worse, off since Ukrainian independence. Addresses inflation, private enterprise, delayed salaries, and new freedoms. Provides insights into the effects of the transition on people's lives and hopes for the future. (DSK)

An Annotated Bibliography of Hypobaric Decompression Sickness Research Conducted at the Crew Technology Division, USAF School of Aerospace Medicine, Brooks AFB, Texas from 1983 to 1988

DTIC Science & Technology

1990-06-01

AN ANNOTATED BIBLIOGRAPHY OF HYPOBARIC DECOMPRESSION SICKNESS RESEARCH CONDUCTED AT THE CREW TECHNOLOGY DIVISION, USAF SCHOOL OF AEROSPACE MEDICINE...190 man-flights to four selected altitudes (30000, 27500, 25000, and 22500 ft pressure equivalent) in a hypobaric chamber. The subjects’ ages ranged...conditions and two of these developed delayed sy~rtcms. Three of these five subjects underwent hyperbaric oxygen treatment. Conclusion. Female subjects

Haystack Observatory VLBI Correlator

NASA Technical Reports Server (NTRS)

Titus, Mike; Cappallo, Roger; Corey, Brian; Dudevoir, Kevin; Niell, Arthur; Whitney, Alan

2013-01-01

This report summarizes the activities of the Haystack Correlator during 2012. Highlights include finding a solution to the DiFX InfiniBand timeout problem and other DiFX software development, conducting a DBE comparison test following the First International VLBI Technology Workshop, conducting a Mark IV and DiFX correlator comparison, more broadband delay experiments, more u- VLBI Galactic Center observations, and conversion of RDV session processing to the Mark IV/HOPS path. Non-real-time e-VLBI transfers and engineering support of other correlators continued.

ONE SHAKE GATE FORMER

DOEpatents

Kalibjian, R.; Perez-Mendez, V.

1957-08-20

An improved circuit for forming square pulses having substantially short and precise durations is described. The gate forming circuit incorporates a secondary emission R. F. pentode adapted to receive input trigger pulses amd having a positive feedback loop comnected from the dynode to the control grid to maintain conduction in response to trigger pulses. A short circuited pulse delay line is employed to precisely control the conducting time of the tube and a circuit for squelching spurious oscillations is provided in the feedback loop.

Computational modelling of internally cooled wet (ICW) electrodes for radiofrequency ablation: impact of rehydration, thermal convection and electrical conductivity.

PubMed

Trujillo, Macarena; Bon, Jose; Berjano, Enrique

2017-09-01

(1) To analyse rehydration, thermal convection and increased electrical conductivity as the three phenomena which distinguish the performance of internally cooled electrodes (IC) and internally cooled wet (ICW) electrodes during radiofrequency ablation (RFA), (2) Implement a RFA computer model with an ICW which includes these phenomena and (3) Assess their relative influence on the thermal and electrical tissue response and on the coagulation zone size. A 12-min RFA in liver was modelled using an ICW electrode (17 G, 3 cm tip) by an impedance-control pulsing protocol with a constant current of 1.5 A. A model of an IC electrode was used to compare the ICW electrode performance and the computational results with the experimental results. Rehydration and increased electrical conductivity were responsible for an increase in coagulation zone size and a delay (or absence) in the occurrence of abrupt increases in electrical impedance (roll-off). While the increased electrical conductivity had a remarkable effect on enlarging the coagulation zone (an increase of 0.74 cm for differences in electrical conductivity of 0.31 S/m), rehydration considerably affected the delay in roll-off, which, in fact, was absent with a sufficiently high rehydration level. In contrast, thermal convection had an insignificant effect for the flow rates considered (0.05 and 1 mL/min). Computer results suggest that rehydration and increased electrical conductivity were mainly responsible for the absence of roll-off and increased size of the coagulation zone, respectively, and in combination allow the thermal and electrical performance of ICW electrodes to be modelled during RFA.

Delayed Carcass Deboning Results in Significantly Reduced Cook Yields of Boneless Skinless Chicken Thighs

USDA-ARS?s Scientific Manuscript database

Boneless skinless chicken thighs are a new deboned poultry product in the retail market. Three trials were conducted to investigate the effect of postmortem carcass deboning time on the cook yields of boneless skinless chicken thighs as well as boneless skinless chicken breasts. Broiler carcasses ...