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Sample records for biventricular pacing devices

  1. Impact of pacing modality and biventricular pacing on cardiac output and coronary conduit flow in the post-cardiotomy patient.

    LENUS (Irish Health Repository)

    Healy, David G

    2012-02-03

    We have previously demonstrated the role of univentricular pacing modalities in influencing coronary conduit flow in the immediate post-operative period in the cardiac surgery patient. We wanted to determine the mechanism of this improved coronary conduit and, in addition, to explore the possible benefits with biventricular pacing. Sixteen patients undergoing first time elective coronary artery bypass grafting who required pacing following surgery were recruited. Comparison of cardiac output and coronary conduit flow was performed between VVI and DDD pacing with a single right ventricular lead and biventricular pacing lead placement. Cardiac output was measured using arterial pulse waveform analysis while conduit flow was measured using ultrasonic transit time methodology. Cardiac output was greatest with DDD pacing using right ventricular lead placement only [DDD-univentricular 5.42 l (0.7), DDD-biventricular 5.33 l (0.8), VVI-univentricular 4.71 l (0.8), VVI-biventricular 4.68 l (0.6)]. DDD-univentricular pacing was significantly better than VVI-univentricular (P=0.023) and VVI-biventricular pacing (P=0.001) but there was no significant advantage to DDD-biventricular pacing (P=0.45). In relation to coronary conduit flow, DDD pacing again had the highest flow [DDD-univentricular 55 ml\\/min (24), DDD-biventricular 52 ml\\/min (25), VVI-univentricular 47 ml\\/min (23), VVI-biventricular 50 ml\\/min (26)]. DDD-univentricular pacing was significantly better than VVI-univentricular (P=0.006) pacing but not significantly different to VVI-biventricular pacing (P=0.109) or DDD-biventricular pacing (P=0.171). Pacing with a DDD modality offers the optimal coronary conduit flow by maximising cardiac output. Biventricular lead placement offered no significant benefit to coronary conduit flow or cardiac output.

  2. Association between frequency of atrial and ventricular ectopic beats and biventricular pacing percentage and outcomes in patients with cardiac resynchronization therapy

    DEFF Research Database (Denmark)

    Ruwald, Martin H; Mittal, Suneet; Ruwald, Anne-Christine

    2014-01-01

    -defibrillator device with data available on biventricular pacing percentage and pre-implantation 24-h Holter recordings were included. Using logistic regression, we estimated the influence of ectopic beats on the percentage of biventricular pacing. Reverse remodeling was measured as reductions in atrial and left.......001) in patients with >1.5% ectopic beats compared with those with reverse remodeling (percent reduction in LVESV 31 ± 15%) than patients with ... biventricular pacing (reverse remodeling and higher risk of HF/death and VTA. This supports pre-implantation Holter monitoring of patients selected for CRT for optimal outcome. (MADIT-CRT: Multicenter Automatic Defibrillator Implantation With Cardiac Resynchronization...

  3. Successful treatment with biventricular pacing in a patient with hypertrophic obstructive cardiomyopathy

    Institute of Scientific and Technical Information of China (English)

    HE Ji-qiang; JIANG Teng-yong; WANG Yun-long; WANG Yan; L(U) Shu-zheng

    2011-01-01

    We report the effects of biventricular pacing in a patient with hypertrophic obstructive cardiomyopathy (HOCM) refractory to medical therapy. A 58-year-old man with HOCM had suffered from dyspnea,chest pain and palpitation for 5 years. Cardiac catheterization showed a left ventricular outflow tract (LVOT) gradient of 80 mmHg. He refused septal myomectomy and the septal ablation was not available. Based on intraoperative pressure measurements,he was implanted with biventricular pacing and LVOT gradient decreased to 10 mmHg. During the follow-up period of 6 months, the patient's symptoms were markedly improved. Biventricular pacing may be an alternative therapy for patients with HOCM.

  4. Sequential biventricular pacing improves regional contractility, longitudinal function and dyssynchrony in patients with heart failure and prolonged QRS

    Directory of Open Access Journals (Sweden)

    Ring Margareta

    2010-04-01

    Full Text Available Abstract Aims Biventricular pacing (BiP is an effective treatment in systolic heart failure (HF patients with prolonged QRS. However, approximately 35% of the patients receiving BiP are classified as non-responders. The aim of this study is to evaluate the acute effects of VV-optimization on systolic heart function. Methods Twenty-one HF patients aged 72 (46-88 years, QRS 154 (120-190 ms, were studied with echocardiography, Tissue Doppler Imaging (TDI and 3D-echo the first day after receiving a BiP device. TDI was performed; during simultaneous pacing (LV-lead pacing 4 ms before the RV-lead and during sequential pacing (LV 20 and 40 ms before RV and RV 20 and 40 ms before LV-lead pacing. Systolic heart function was studied by tissue tracking (TT for longitudinal function and systolic maximal velocity (SMV for regional contractility and signs of dyssynchrony assessed by time-delays standard deviation of aortic valve opening to SMV, AVO-SMV/SD and tissue synchronization imaging (TSI. Results The TT mean value preoperatively was 4,2 ± 1,5 and increased at simultaneous pacing to 5,0 ± 1,2 mm (p Conclusions VV-optimization in the acute phase improves systolic heart function more than simultaneous BiP pacing. Long-term effects should be evaluated in prospective randomized trials.

  5. Recovery in ERG gene expression with biventricular pacing in a rabbit model of myocardial infarction

    Directory of Open Access Journals (Sweden)

    Saba S

    2013-05-01

    Full Text Available Samir Saba,* Haider Mehdi,* William Barrington, Fardeen Mehdi, Zahid Islam, Barry LondonCardiovascular Institute of the University of Pittsburgh Medical Center, Pittsburgh, PA, USA*These authors contributed equally to this workBackground: Improved clinical and echocardiographic parameters have been documented with biventricular (BIV pacing in patients after myocardial infarction (MI. We investigated the changes in gene expression in cardiac tissue with BIV pacing, using a rabbit model of MI.Method: New Zealand White rabbits were divided into four groups: sham-operated controls, MI with no pacing, MI with right ventricle (RV pacing (MI + RV, and MI with BIV pacing (MI + BIV. Pacing was initiated 1–2 weeks after the coronary ligation. At 5 weeks, the hearts were excised. The tissue extracted from the left ventricle (LV and RV underwent analysis for protein and messenger ribonucleic acid (mRNA levels.Results: The ether-a-go-go-related gene (ERG protein levels recovered from the base of the LV away from the MI area were two- to threefold lower in the MI and the MI + RV compared with the MI + BIV groups (P = 0.07. The ERG protein levels were similar between the MI + BIV and the control groups. However, the RNA levels were comparable between the four study groups, suggesting that a posttranscriptional mechanism accounted for the difference in protein levels.Conclusion: In this rabbit model of MI, we demonstrated a recovery in ERG protein levels with BIV pacing, after MI. This recovery may underlie some of the benefits seen with BIV pacing in ischemic cardiomyopathy.Keywords: heart failure, biventricular pacing, cardiac reverse remodeling, ether-a-go-go-related gene

  6. Portable pneumatic biventricular driver for the Thoratec ventricular assist device.

    Science.gov (United States)

    Farrar, D J; Buck, K E; Coulter, J H; Kupa, E J

    1997-01-01

    As patients with left ventricular (LVAD) and biventricular assist devices are supported for increasingly long durations while awaiting heart transplantation or cardiac recovery, there is a need to facilitate greater patient mobility and ambulation. To meet these needs, the authors have developed the Thoratec TLC-II Portable VAD Driver, which is a small brief-case sized (33 x 34 x 13 cm) pneumatic unit for Thoratec's paracorporeal and implantable VADs. The TLC-II consists of an electric motor driven air compressor for supplying both positive and negative air pressure, solenoid valves for switching between LVAD/RVAD filling and ejection, and microcontroller based electronics and firmware. Four power sources are provided: external power, two rechargeable lithium-ion battery packs, and an emergency battery that drives an independent electronic back-up system. The 8 kg TLC-II can be carried by hand, with a shoulder strap, or pushed on a wheeled mobility cart. Trend information stored in the TLC-II can be accessed by an external system computer with a color touchscreen mounted on a docking station, which also houses the battery charger. Control configurations (univentricular/biventricular operation, beat rates, etc.) are entered on the touchscreen and programmed into the TLC-II. In vitro testing demonstrates the ability to pump VAD outputs up to 7 L/min. By providing improved patient mobility, this small driver will enhance rehabilitation and improve the quality of life of VAD patients.

  7. Tissue Doppler echocardiography and biventricular pacing in heart failure: Patient selection, procedural guidance, follow-up, quantification of success

    Directory of Open Access Journals (Sweden)

    Baumann Gert

    2004-09-01

    Full Text Available Abstract Asynchronous myocardial contraction in heart failure is associated with poor prognosis. Resynchronization can be achieved by biventricular pacing (BVP, which leads to clinical improvement and reverse remodeling. However, there is a substantial subset of patients with wide QRS complexes in the electrocardiogram that does not improve despite BVP. QRS width does not predict benefit of BVP and only correlates weakly with echocardiographically determined myocardial asynchrony. Determination of asynchrony by Tissue Doppler echocardiography seems to be the best predictor for improvement after BVP, although no consensus on the optimal method to assess asynchrony has been achieved yet. Our own preliminary results show the usefulness of Tissue Doppler Imaging and Tissue Synchronization Imaging to document acute and sustained improvement after BVP. To date, all studies evaluating Tissue Doppler in BVP were performed retrospectively and no prospective studies with patient selection for BVP according to echocardiographic criteria of asynchrony were published yet. We believe that these new echocardiographic tools will help to prospectively select patients for BVP, help to guide implantation and to optimize device programming.

  8. In Heart Failure Patients with Left Bundle Branch Block Single Lead MultiSpot Left Ventricular Pacing Does Not Improve Acute Hemodynamic Response To Conventional Biventricular Pacing. A Multicenter Prospective, Interventional, Non-Randomized Study

    OpenAIRE

    Maciej Sterliński; Adam Sokal; Radosław Lenarczyk; Frederic Van Heuverswyn; Aldo Rinaldi, C.; Marc Vanderheyden; Vladimir Khalameizer; Darrel Francis; Joeri Heynens; Berthold Stegemann; Richard Cornelussen

    2016-01-01

    Introduction Recent efforts to increase CRT response by multiSPOT pacing (MSP) from multiple bipols on the same left ventricular lead are still inconclusive. Aim The Left Ventricular (LV) MultiSPOTpacing for CRT (iSPOT) study compared the acute hemodynamic response of MSP pacing by using 3 electrodes on a quadripolar lead compared with conventional biventricular pacing (BiV). Methods Patients with left bundle branch block (LBBB) underwent an acute hemodynamic study to determine the %change in...

  9. Cardiac Failure after Liver Transplantation Requiring a Biventricular Assist Device

    Directory of Open Access Journals (Sweden)

    Rita Jermyn

    2014-01-01

    Full Text Available Increased hepatic iron load in extrahepatic organs of cirrhotic patients with and without hereditary hemochromatosis portends a poorer long term prognosis after liver transplant. Hepatic as well as nonhepatic iron overload is associated with increased infectious and postoperative complications, including cardiac dysfunction. In this case report, we describe a cirrhotic patient with alpha 1 antitrypsin deficiency and nonhereditary hemochromatosis (non-HFE that developed cardiogenic shock requiring mechanical circulatory support for twenty days after liver transplant. Upon further investigation, she was found to have significant iron deposition in both the liver and heart biopsies. Her heart regained complete and sustained recovery following ten days of mechanical biventricular support. This case highlights the importance of preoperatively recognizing extrahepatic iron deposition in patients referred for liver transplantation irrespective of etiology of liver disease as this may prevent postoperative complications.

  10. Meta-analysis of randomized controlled trials comparing isolated left ventricular and biventricular pacing in patients with chronic heart failure.

    Science.gov (United States)

    Liang, Yixiu; Pan, Wenzhi; Su, Yangang; Ge, Junbo

    2011-10-15

    Cardiac resynchronization therapy (CRT) has been mostly achieved by biventricular pacing (BVP) in patients with chronic heart failure (CHF), although it can also be provided by left ventricular pacing (LVP). The superiority of BVP over LVP remains uncertain. The present meta-analysis of randomized controlled trials was performed to compare the effects of LVP to BVP in patients with CHF. Outcomes analyzed included clinical status (6-minute walk distance, peak oxygen consumption, quality of life, New York Heart Association class), LV function (LV ejection fraction), and LV remodeling (LV end-systolic volume). Five trials fulfilled criteria for inclusion in analysis, which included 574 patients with CHF indicated for CRT. After a midterm follow-up, pooled analysis demonstrated that LVP resulted in similar improvements in 6-minute walk distance (weighted mean difference [WMD] 11.25, 95% confidence interval [CI] -12.39 to 34.90, p = 0.35), quality of life (WMD 0.34, 95% CI -3.72 to 4.39, p = 0.87), peak oxygen consumption (WMD 1.00, 95% CI -0.84 to 2.85, p = 0.29), and New York Heart Association class (WMD -0.19, 95% CI -0.79 to 0.42, p = 0.54). There was a trend toward a superiority of BVP over LVP for LV ejection fraction (WMD 1.28, 95% CI -0.11 to 2.68, p = 0.07) and LV end-systolic volume (WMD -5.73, 95% CI -11.86 to 0.39, p = 0.07). In conclusion, LVP achieves similar improvement in clinical status as BVP in patients with CHF, whereas there was a trend toward superiority of BVP over LVP for LV reverse modeling and systolic function.

  11. Reverse left ventricular remodeling is more likely in non ischemic cardiomyopathy patients upgraded to biventricular stimulation after chronic right ventricular pacing

    Directory of Open Access Journals (Sweden)

    Morales Maria-Aurora

    2011-12-01

    Full Text Available Abstract Background Chronic right ventricular (RV apical pacing may lead to left ventricular (LV dyssynchrony and LV dysfunction. In heart failure due to RV pacing, upgrading to biventricular stimulation (CRT can improve NYHA Class and LV function. A proportion of patients do not respond to upgrading. Aim was to assess whether etiology of LV dysfunction accounts for responses to CRT in RV-paced patients. Methods Sixty-two patients treated by CRT, under RV pacing from 50.2 ± 5.4 months, were studied. Cause of LV dysfunction was non-ischemic (NIC in 28 and ischemic cardiomyopathy (IC in 34 patients. Clinical and conventional echocardiographic parameters were available within 1 month before RV pacing, within 1 month before CRT and at 12 ± 2 months of follow-up (FU. Results Decreased LVEF (from 37.0 ± 8.8 to 25.6 ± 6.1%, p 10% decrease in LVESD was observed in 24 patients: 5 with IC, 19 with NIC (p 10% decrease in LVESD remained highly significant (p Conclusions CRT improves functional class even after long-lasting pacing. Reverse remodeling is evident in a small population, more likely with NIC.

  12. Gastrointestinal bleeding in a patient with a continuous-flow biventricular assist device

    Institute of Scientific and Technical Information of China (English)

    Raymond V Mirasol; Jason J Tholany; Hasini Reddy; Billie S Fyfe-Kirschner; Christina L Cheng; Issam F Moubarak; John L Nosher

    2016-01-01

    The association between continuous-flow left ventricular assist devices(CF-LVADs)and gastrointestinal(GI)bleeding from angiodysplasia is well recognized.However,the association between continuous-flow biventricular assist devices(CF-BIVADs)and bleeding angiodysplasia is less understood.We report a case of GI bleeding from a patient with a CF-BIVAD.The location of GI bleeding was identified by nuclear red blood cell bleeding scan.The vascular malformation leading to the bleed was identified and localized on angiography and then by pathology.The intensity of bleeding,reflected by number of units of packed red blood cells needed for normalization of hemoglobin,as well as the time to onset of bleeding after transplantation,are similar to that seen in the literature for CF-LVADs and pulsatile BIVADs.While angiography only detected a dilated late draining vein,pathology demonstrated the presence of both arterial and venous dilation in the submucosa,vascular abnormalities characteristic of a late arteriovenous malformation.

  13. Prediction of survival in patients with cardiogenic shock and multiorgan failure treated with biventricular assist device.

    Science.gov (United States)

    Potapov, Evgenij V; Stepanenko, Alexander; Kukucka, Marian; Ba Fadhl, Faiz H; Qedra, Naser; Weng, Yuguo; Pasic, Miralem; Lehmkuhl, Hans B; Krabatsch, Thomas; Hetzer, Roland

    2010-01-01

    Mechanical circulatory support (MCS) is valuable in saving the lives of patients with severe cardiogenic shock. However, their survival is limited if multiorgan failure (MOF) proves to be irreversible. Although ventricular assist devices (VADs) have been shown to reverse end-organ failure in some patients, the pathophysiological mechanisms of end-organ failure and its regression are not fully understood, and clinical markers and thresholds for the "point of no return" are lacking. We investigated predictors of 30-day survival in patients supported with a biventricular assist device (BVAD). We studied 157 patients implanted with a Berlin Heart EXCOR BVAD between 1987 and 2006. Children younger than 10 years and cases with postcardiotomy syndrome and transplant failure were excluded from the analysis as well as patients with technical or bleeding problems requiring rethoracotomy. In total, 69 clinical, hemodynamic, echocardiographic, and laboratory parameters were evaluated. Most of the patients suffered from ischemic cardiomyopathy or acute myocardial infarction. In addition, the preoperative multiple organ dysfunction syndrome (MODS) and the sequential organ failure assessment (SOFA) scores were calculated. The patients were divided into two groups regarding procedural success: group I-survival >30 days or heart transplantation or weaning from device (n = 105) and group II-death on system shock and MOF do not predict survival on BVAD. As expected, older patients are at higher risk for death on BVAD. Acidosis and high MODS score predict unfavorable outcome. However, the prediction of clinical outcome in patients in severe cardiogenic shock supported by BVAD is possible in extreme situations only.

  14. Successful trans-Atlantic air ambulance transfer of a patient supported by a bi-ventricular assist device.

    Science.gov (United States)

    McLean, Neilson; Copeland, Ryan; Casey, Neil; Samoukovic, Gordon; Quigley, Robert

    2011-08-01

    The ventricular assist device (VAD) is a hemodynamic support device that augments cardiac output for patients with severe ventricular dysfunction. With improved reliability and technological advances, the use of VADs to support patients is increasing. Many VAD-dependent patients ultimately require heart transplants that are only available in specialized centers, necessitating an interhospital transfer. To date there are few reports of long-distance fixed wing aeromedical transport of patients dependent on a VAD. Here we describe the successful transfer of a patient supported by a biventricular assist device (BiVAD) from Cambridge, UK, to Durham, NC, via fixed-wing jet aircraft. During this transfer, we observed hemodynamic alterations secondary to gravitational forces, which should be anticipated and may be mitigated with simple maneuvers. With high-level logistical planning and appropriate medical oversight, patients dependant on BiVADs can be safely transported by fixed wing aircraft over long distances.

  15. A new transcutaneous energy transmission system with hybrid energy coils for driving an implantable biventricular assist device.

    Science.gov (United States)

    Okamoto, Eiji; Yamamoto, Yoshiro; Akasaka, Yuhta; Motomura, Tadashi; Mitamura, Yoshinori; Nosé, Yukihiko

    2009-08-01

    We have developed a new transcutaneous energy transmission (TET) system for a totally implantable biventricular assist device (BVAD) system in the New Energy and Industrial Development Organization (NEDO) artificial heart project. The TET system mainly consists of an energy transmitter, a hybrid energy coil unit, an energy receiver, an internal battery system, and an optical telemetry system. The hybrid energy coil unit consists of an air-core energy transmission coil and an energy-receiving coil having a ferrite core. Internal units of the TET system are encapsulated in a titanium alloy casing, which has a size of 111 mm in width, 73 mm in length, and 25 mm in height. In in vitro experiments, the TET system can transmit a maximum electric energy of 60 Watts, and it has a maximum transmission efficiency of 87.3%. A maximum surface temperature of 46.1 degrees C was measured at the ferrite core of the energy-receiving coil during an energy transmission of 20 Watts in air. The long-term performance test shows that the TET system has been able to operate stably for over 4 years with a decrease of energy-transmission efficiency from 85% to 80%. In conclusion, the TET system with the hybrid energy coil can overcome the drawback of previously reported TET systems, and it promises to be the highest performance TET system in the world.

  16. The comparison of the curative effect between the left univentricular pacing and the biventricular pacing in patients with chronic heart failure%单纯左室起搏与双心室起搏治疗慢性心力衰竭的疗效比较

    Institute of Scientific and Technical Information of China (English)

    王徐乐; 邱春光; 韩战营; 卢文杰; 陈晓杰; 秦石诚; 张瑞芳

    2011-01-01

    目的比较单纯左室起搏与双心室起搏治疗慢性心力衰竭(CHF)的可行性及临床效果.方法选择窦性心律、NYHA心功能分级Ⅲ~Ⅳ级、左室射血分数(LVEF)≤0.35、QRS波时限≥120 ms的CHF患者36例,成功植入心脏再同步化(CRT)起搏器后,随机分为两组,第一组先以右房左室起搏模式治疗(LV起搏模式)7天,然后以右房双室起搏模式治疗(Biv起搏模式)7天;第二组先以Biv治疗7天,然后以LV治疗7天.收集术前、术后第7天、第14天的临床资料,所有数据应用交叉设计资料方差分析及单变量一般线性模型分析.结果6 min步行距离、明尼苏达生活质量评分、体表心电图QRS波时限、左室舒张末期内径、左室射血分数、左室间隔部与侧壁基底段收缩期达峰时间差值等6种评价指标的结果相似:评价指标测量值在处理效应即LV、Biv两种起搏模式上、在顺序效应即两种起搏模式顺序上的差异均无统计学意义(P均>0.05);但在阶段效应即术后第7天、第14天两阶段上的差异有统计学意义(P<0.05).结论单纯左室起搏与双心室起搏治疗CHF的疗效相仿;对窦性心律、完全性左束支传导阻滞的CHF患者,单纯左室起搏可作为CRT的一种选择.%Objective To compare the curative effect of the left univentricular pacing with that of the biventricular pacing in patients with chronic heart failure(CHF). Methods Thirty-six patients who had left ventricular ejection fraction (LVEF) less than or equal to 0.35, a QRS duration greater than or equal to 0.12 seconds, sinus rhythm and New York Heart Association (NYHA) function Class Ⅲ or ambulatory Class Ⅳ heart failure symptoms with optimal medical therapy were divided into two groups randomly after the successful implantation of CRT/CRTD. The first group was wroking first with left univentricular pacing for 7 days, then the biventricular pacing for the next 7 days, and the second group was just the

  17. The association between biventricular pacing and cardiac resynchronization therapy-defibrillator efficacy when compared with implantable cardioverter defibrillator on outcomes and reverse remodelling

    DEFF Research Database (Denmark)

    Ruwald, Anne-Christine; Kutyifa, Valentina; Ruwald, Martin H;

    2015-01-01

    : Using Kaplan-Meier plots, we estimated the threshold of BIV pacing percentage needed for CRT-D to be superior to ICD on the end-point of heart failure (HF) or death in 1219 left bundle branch block (LBBB) patients in the MADIT-CRT trial. Patients were censored at the time of crossover. In multivariable...

  18. Normalisation of left ventricular systolic function after change from VVI pacing to biventricular pacing in a child with congenital complete atrioventricular block, long-QT syndrome, and congenital muscular dystrophy

    DEFF Research Database (Denmark)

    Ellesøe, Sabrina G; Reimers, Jesper I; Andersen, Henrik

    2013-01-01

    Development of dilated cardiomyopathy in patients with congenital complete atrioventricular block with or without pacemaker is well described. We report a case of dilated cardiomyopathy in a child with congenital complete atrioventricular block, long-QT syndrome, and VVI pacemaker. Temporary pacing...

  19. Biventricular Pacing Therapy for Heart Failure

    Institute of Scientific and Technical Information of China (English)

    Henry; Cheuk - Man Yu

    2001-01-01

    @@eart failure is a disease with high morbidity and mortality. It is also the commonest cause of medical ward admission. The incidence of heart failure has been increasing world-wide in the past decade.Studies observed that about 25 - 50 % of patients with heart failure had evidence of electromechanical delay,commonly in the form of left bundle branch block or intraventricular conduction delay on surface electrocardiogram. This condition results in dyssynchronous contraction, mitral regurgitation and was associated with a worse prognosis. These patients may therefore benefit from cardiac resynchronization therapy.

  20. Acute tamponade of the left paracorporeal pump house due to membrane defect in a patient with a Berlin Heart EXCOR biventricular assist device.

    Science.gov (United States)

    Völz, Sebastian; Holmberg, Michael; Redfors, Bengt; Dellgren, Göran

    2014-10-01

    We report a case of acute tamponade of the left paracorporeal pump house in a patient supported by a Berlin Heart EXCOR biventricular assist device (BiVAD) caused by mechanical defect in the membrane of the arterial chamber. A 36-year old male was admitted for composite graft surgery due to a large aortic regurgitation and consecutive heart failure, decompensated postoperatively and was rescued by with an extracorporeal membrane oxygenation (ECMO) device. He was accepted for heart transplantation, and a BiVAD (Berlin Heart EXCOR) was implanted as bridge-to-transplantation. Two months after discharge, he experienced dyspnoea and received error signals from his BiVAD. Relatives released him from his BiVAD companion driver, connected him to the hand pump and transported him to our institution. On arrival, he was in cardiogenic shock and was stabilized by ECMO. Inspection of the arterial chamber revealed a wear hole and delamination of the diaphragm, which had led to a tamponade by air insufflation into the three-layer membrane. New BiVAD paracorporeal pumps were connected, and the patient was subsequently successfully transplanted. The case depicts the difficulty of diagnosis in this specific patient setting. Despite transparent design of the BiVAD chambers, the development of a chamber tamponade remained undetected until explantation of the system.

  1. Bridging to Heart Transplantation from the Biventricular Pulsatile Berlin Heart EXCOR Assist Device Support in a Patient with Advanced End-Organ Failure

    Science.gov (United States)

    Tuba Demirozu, Zumrut; Suha Kucukaksu, Deniz

    2015-01-01

    Long-term mechanical circulatory support is a life-saving technology while briding to heart transplantation. It increases the quality of life and preserves end-organ function for patients with advanced heart failure. The number of patients with advanced heart failure scheduled for heart transplantation before comorbidities escalate is on the rise. However, the device function is complicated by the bleeding-thrombosis and infection paradigm, hence the interest in understanding device thrombosis and infection. We describe a 27-year-old man with idiopathic cardiomyopathy, advanced end-organ failure, and severe infection, who was bridged to heart transplantation after 8 months on the Berlin Heart EXCOR (Berlin Heart AG, Berlin, Germany) biventricular support. The patient was discharged from the hospital in the third postoperative week after the recovery of his end-organ functions. At 29 months’ post-transplantation follow-up, his last cardiac biopsy was grade 0, his ejection fraction was 60%, and he was enjoying a good quality of life. PMID:26985209

  2. Biventricular Pulsus Alternans

    Directory of Open Access Journals (Sweden)

    Param Vidwan

    2009-01-01

    Full Text Available Pulsus alternans is a rare hemodynamic condition characterized by beat-to-beat variability in systolic pressure. It is attributed to variations in stroke volume with alternate cardiac cycles and is typically seen in patients with advanced myopathic conditions. Left ventricular pulsus alternans is rare, and right ventricular pulsus alternans is even less common. There are only a few reports of biventricular pulsus alternans. We report the case of a 62-year-old female with a recent anterior wall myocardial infarction who had biventricular pulsus alternans at the time of cardiac catheterization.

  3. Current status of the gyro centrifugal blood pump--development of the permanently implantable centrifugal blood pump as a biventricular assist device (NEDO project).

    Science.gov (United States)

    Nosé, Yukihiko; Furukawa, Kojiro

    2004-10-01

    The New Energy and Industrial Technology Development Organization (NEDO) project was started in 1995. The goal is the development of a multipurpose, totally implantable biventricular assist device (BVAD) that can be used for any patient who suffers from severe heart failure. Our C1E3 (two-week pump) centrifugal pump, called the Gyro pump, has three design characteristics: a magnetic coupling and double pivot bearing system, an eccentric inlet port, and secondary vanes on the bottom of the impeller. The pump was miniaturized. The C1E3 evolved into the NEDO PI-601, a totally implantable centrifugal pump for BVAD. The current NEDO PI-710 pump (five-year pump) system includes a centrifugal pump with pivot bearings, a hydraulically-levitated impeller, an rpm-controlled miniaturized actuator (all-in-one actuator plus controller), an emergency clamp on the left outflow, and a Frank-Starling-type flow control. The final mass production model is now finalized, and the final animal study and two-year endurance studies are ongoing.

  4. Biventricular Takotsubo Cardiomyopathy

    Science.gov (United States)

    Daoko, Joseph; Rajachandran, Manu; Savarese, Ronald; Orme, Joseph

    2013-01-01

    Biventricular takotsubo cardiomyopathy is associated with more hemodynamic instability than is isolated left ventricular takotsubo cardiomyopathy; medical management is more invasive and the course of hospitalization is longer. In March 2011, a 62-year-old woman presented at our emergency department with abdominal pain, nausea, and vomiting. On hospital day 2, she experienced chest pain. An electrocardiogram and cardiac enzyme levels suggested an acute myocardial infarction. She underwent cardiac angiography and was found to have severe left ventricular systolic dysfunction involving the mid and apical segments, which resulted in a left ventricular ejection fraction of 0.10 to 0.15 in the absence of obstructive coronary artery disease. Her hospital course was complicated by cardiogenic shock that required hemodynamic support with an intra-aortic balloon pump and dobutamine. A transthoracic echocardiogram revealed akinesis of the mid-to-distal segments of the left ventricle and mid-to-apical dyskinesis of the right ventricular free wall characteristic of biventricular takotsubo cardiomyopathy. After several days of medical management, the patient was discharged from the hospital in stable condition. To the best of our knowledge, this is the first review of the literature on biventricular takotsubo cardiomyopathy that compares its hemodynamic instability and medical management requirements with those of isolated left ventricular takotsubo cardiomyopathy. Herein, we discuss the case of our patient, review the pertinent medical literature, and convey the prevalence and importance of right ventricular involvement in patients with takotsubo cardiomyopathy. PMID:23914028

  5. Ventricular Septal Perforation after Biventricular Takotsubo Cardiomyopathy Successfully Repaired with an Amplatzer Device: First Report in the Literature

    Directory of Open Access Journals (Sweden)

    Alfredo E. Rodríguez

    2016-01-01

    Full Text Available A 79-year-old female was admitted with sudden onset dyspnea, mild oppressive chest pain, and severe anxiety disorder. Patient had history of hypertension, dyslipidemia, smoking, and chronic obstructive pulmonary disease. On admission blood pressure was 160/90 and heart rate was 130 bpm. Transthoracic echocardiography (TE and contrast tomography showed a thin septum with an abnormal left and right ventricular contraction with an “apical ballooning” pattern and mild increase of cardiac enzymes. At the 4th day of admission, the patient presented symptoms and signs of congestive heart failure and developed cardiogenic shock. EKG showed an inversion of T waves in all precordial leads. In a new TE, a ventricular septal perforation (VSP in the apical portion of the septum was seen. Coronary angiogram showed angiographically “normal” coronary arteries. With a diagnosis of VSP in takotsubo cardiomyopathy, a percutaneous procedure to repair the VSP was performed 11 days after admission. The VSP was closed with an Amplatzer device. TE performed 24 hours after showed significant improvement of ventricular function and good apposition of the Amplatzer device. Three days later she was discharged from the hospital. To our knowledge, this is the first reported case of a VSP in a TCM repaired percutaneously with an occluder device.

  6. A comparative study of biventricular and right ventricular septum pacing in the patients with pacemaker dependant Jianping%双心室起搏与右心室间隔部起搏治疗起搏依赖房室传导阻滞的效果比较

    Institute of Scientific and Technical Information of China (English)

    葛智儒; 王璐; 赵汉君; 张晨君; 黄宇; 刘秋云; 邱建平

    2016-01-01

    <0�05),而组间各时间比较差异均无统计学意义(P 均>0�05)。结论与右心室间隔部起搏相比,双心室起搏对起搏依赖房室传导阻滞患者的生活质量和心功能影响未显示出优势。%Objective Respectively applying the treatment of biventricular pacing and right ventricular septal pacing in atrioventricular block,to compare the heart function influence of two kinds of pacing mode on pacemaker dependent patients, to provide evidence for the physiological pacing mode selection�Methods Enrolled 20 patients from January 2012 to March 2013 who should be placed in pacemakers, their primary disease was the second degree,high or third degree atrioventricular block,giving them three chamber pacemaker ( right atrial + biventricular ) each�Randomly divided into right ventricular septum pacing group ( group A, n=10) and biventricular pacing group( group B,n=10)�Twelve months later,each group crossed into the each other group and continued following⁃up for 12 months�After 24 months to obtain all the data to do the statistical analysis,including patients'6 min walking distance(6MWD),the Minnesota Heart Failure Quality of life score (MLHFQ),plasma N⁃terminal pro brain natriuretic peptide precursor(NT⁃proBNP),left ventricular ejection ejection fraction(LVEF),left ventricular diastolic end diastolic diameter(LVEDD),left ventricular contraction end diastolic diameter(LVESD),left ventricular twelve segmental 14W time standard deviation(Ts⁃12SD),left ventricular twelve segmental 14W time maximum delay(Ts⁃dif),the paced QRS qrsd�Results Compared with group B,the 6MWD and LVEF of 12,24 months after treatment of group A were significantly increased( ( 242�58 ±37�56) m vs�(347�42±36�59) m vs�(340�67±24�99) m;(39�97±5�84)% vs�(57�92±10�01)% vs�(60�50±10�06)%;P0�05)�Conclusion Compared with the right septal pacing,biventricular pacing is of no significant advantages on the

  7. Ventricular assist device

    Science.gov (United States)

    VAD; RVAD; LVAD; BVAD; Right ventricular assist device; Left ventricular assist device; Biventricular assist device; Heart pump; Left ventricular assist system; LVAS; Implantable ventricular assist device

  8. Optimized pacing mode for hypertrophic cardiomyopathy: Impact of ECG fusion during pacing

    NARCIS (Netherlands)

    Berruezo, A.; Penela, D.; Burgos, F.; Evertz, R.; Fernandez-Armenta, J.; Roca, J.; Doltra, A.; Acosta, J.; Francino, A.; Sitges, M.; Alsina, X.; Ordonez, A.; Villuendas, R.; Brugada, R.; Mont, L.; Brugada, J.

    2015-01-01

    BACKGROUND: Electrocardiographic (ECG) fusion with intrinsic QRS could reduce the benefit of atrial synchronous biventricular pacing (AS-BiVP) in patients with hypertrophic obstructive cardiomyopathy (HOCM). OBJECTIVES: The purpose of this study was to assess the benefit of AS-BiVP and the influence

  9. Effects of Biventricular and Left Ventricular Assist Devices on Ischemic Myocardium%左心室及双心室辅助装置对缺血心肌的影响

    Institute of Scientific and Technical Information of China (English)

    杨敏; 王一山; 叶椿秀; 朱洪生; 陈长志

    2001-01-01

    目的 比较左心室辅助装置(LVAD)和双心室辅助装置(BVAD)对缺血心肌再灌注后心脏血流动力学、心肌能量代谢物质和心肌超微结构中线粒体形态的影响。 方法 将16只绵羊随机分为LVAD组和BVAD组,每组8只,常温阻断升主动脉25分钟,造成双心室缺血损伤的动物模型。结扎右颈内动脉远端,在心脏复跳后应用转子泵分别行LVAD(左心室-右颈内动脉径路)和BVAD(左心室-右颈内动脉和右心室-肺动脉径路)辅助循环120分钟。测定血流动力学、心肌三磷酸腺苷、磷酸肌酸,观察心肌超微结构变化。 结果 施行BVAD或LVAD辅助循环的同时增加容量负荷能够显著改善心脏血流动力学,但LVAD组右心房压显著高于BVAD组(P<0.05);BVAD组右心室心肌三磷酸腺苷、磷酸肌酸含量和心肌线粒体比表面值均高于LVAD组(P<0.05)。 结论 BVAD比LVAD更有助于促进双心室缺血损伤心肌的功能恢复。%Objective To compare the effects of biventricular assist devices (BVAD) and left ventricular assist devices(LVAD) on enhancing the myocardial recovery in an acute ovine model of global myocardial ischemia. Methods Sixteen adult sheep were randomly divided into LVAD group (n=8) and BVAD group (n=8). BVAD group consisted of left ventricle-right carotid artery bypass and right ventricle-pulmonary artery bypass. Two roller pumps with heat exchanger were used. LVAD group was connected from the apex of left ventricle and returned blood flow to the right carotid artery, and a roller pump. The aorta was clamped 25 minutes to produce a global ischemic injury after cross clamp was released. In both BVAD and LVAD group, the bypass was continued for an additional 120 minutes of reperfusion before further measurements were done. Hemodynamic changes, adenosine triphosphate and creatine phosphate were measured. Myocardial ultrastructure were observed. Results LVAD could maintain nearly

  10. Acute left ventricular dysfunction secondary to right ventricular septal pacing in a woman with initial preserved contractility: a case report

    Directory of Open Access Journals (Sweden)

    Gribaa Rim

    2011-10-01

    Full Text Available Abstract Introduction Right ventricular apical pacing-related heart failure is reported in some patients after long-term pacing. The exact mechanism is not yet clear but may be related to left ventricular dyssynchrony induced by right ventricular apical pacing. Right ventricular septal pacing is thought to deteriorate left ventricular function less frequently because of a more normal left ventricular activation pattern. Case presentation We report the case of a 55-year-old Tunisian woman with preserved ventricular function, implanted with a dual-chamber pacemaker for complete atrioventricular block. Right ventricular septal pacing induced a major ventricular dyssynchrony, severe left ventricular ejection fraction deterioration and symptoms of congestive heart failure. Upgrading to a biventricular device was associated with a decrease in the symptoms and the ventricular dyssynchrony, and an increase of left ventricular ejection fraction. Conclusion Right ventricular septal pacing can induce reversible left ventricular dysfunction and heart failure secondary to left ventricular dyssynchrony. This complication remains an unpredictable complication of right ventricular septal pacing.

  11. NADH fluorescence imaging of isolated biventricular working rabbit hearts.

    Science.gov (United States)

    Asfour, Huda; Wengrowski, Anastasia M; Jaimes, Rafael; Swift, Luther M; Kay, Matthew W

    2012-07-24

    that alter the rate of myocyte metabolism or induce hypoxia or create a combination of the two. Hearts from New Zealand white rabbits were connected to a biventricular working heart system (Hugo Sachs Elektronik) and perfused with modified Krebs-Henseleit solution(16) at 37 °C. Aortic, LV, pulmonary artery, and left & right atrial pressures were recorded. Electrical activity was measured using a monophasic action potential electrode. To image fNADH, light from a mercury lamp was filtered (350±25 nm) and used to illuminate the epicardium. Emitted light was filtered (460±20 nm) and imaged using a CCD camera. Changes in the epicardial fNADH of biventricular working hearts during different pacing rates are presented. The combination of the heart model and fNADH imaging provides a new and valuable experimental tool for studying acute cardiac pathologies within the context of realistic physiological conditions.

  12. MECHANISMS OF RIGHT VENTRICULAR FAILURE AND BIVENTRICULAR MECHANICAL CIRCULATORY SUPPORT

    Directory of Open Access Journals (Sweden)

    G. P. Itkin

    2013-01-01

    Full Text Available The paper presents a review of the problems of mechanical circulatory support with left ventricular bypass in total cardiac failure. Dysfunction of right ventricular defines the high mortality on left ventricular device. One of the effective methods for solving this problem is the use of right ventricular assisted devices. There are considered of the basic physiological mechanisms of interaction between the right and left ventricles of the heart, affecting on the function of the right heart. Shows the need to assess right ventricular function before deciding on mechanical circulatory support. Provides examples of the estimation the predictors of the right ventricular failure. The basic methods and devices of biventricular circulatory support were con- sidered. 

  13. Biventricular Mural Endocarditis on the Intraventricular Septum.

    Science.gov (United States)

    Mori, Makoto; Hosoba, Soh; Yoshimura, Stephanie; Lattouf, Omar

    2015-10-28

    Mural endocarditis is an inflammation and disruption of the nonvalvular endocardial surface of the cardiac chambers. We present a rare case of mural endocarditis on the intraventricular (IV) septum on both the left and right ventricular side with intact valvular annulus. This case highlights the complexity of the operative and postoperative management in an unprecedented case of biventricular mural endocarditis.

  14. Biventricular Takotsubo cardiomyopathy in Graves hyperthyroidism.

    Science.gov (United States)

    Perkins, Matthew J; Schachter, David T

    2014-03-01

    Graves hyperthyroidism is commonly seen in clinical practice and Takotsubo stress cardiomyopathy is an increasingly recognized cardiac complication of physical or emotional stress. We report the rare case of a patient with Graves hyperthyroidism that was complicated by severe biventricular takotsubo cardiomyopathy, which was demonstrated on heart catheterization. After appropriate pharmacologic treatment of her hyperthyroidism, she had complete resolution of her cardiomyopathy.

  15. TEE-guided left ventricular epicardial pacing lead placement for cardiac resynchronization therapy

    Directory of Open Access Journals (Sweden)

    Rajesh Chand Arya

    2012-01-01

    Full Text Available Biventricular pacing has demonstrated improvement in cardiac functions in treating congestive cardiac failure patients. Recent trials have proven the clinical and functional benefits of cardiac resynchronization therapy in severe heart failure and intraventricular cardiac delays, mainly left bundle branch block. Biventricular pacing improves the exercise tolerance, quality of life, systolic heart function, reduces hospitalization and slows progression of the disease. A 54-year-old lady, a known case of dilated cardiomyopathy, was on biventricular pacing since 2 years. She presented in emergency with sudden deterioration of dyspnea to NYHA class III/IV. When investigated, the coronary sinus lead was found displaced; thus, left ventricle (LV was not getting paced. After multiple failures to reposition the coronary sinus lead, it was decided to surgically place the epicardial lead for LV pacing under general anesthesia. Lateral thoracotomy was done and LV pacing lead was placed at different sites with simultaneous monitoring of cardiac output (CO and stroke volume (SV by transesophageal echocardiography (TEE. Baseline CO and SV were 1.9 l/min and 19.48 ml respectively and increased at different sites of pacing at LV, the best CO and SV were 4.2 l/min and 42.39 ml respectively on lateral surface. Intraoperative TEE can calculate beat to beat stroke volume and thus CO and helps to choose optimal site for placement of epicardial pacing lead.

  16. Cardiac resynchronization therapy pacemaker: critical appraisal of the adaptive CRT-P device

    Directory of Open Access Journals (Sweden)

    Daoud GE

    2016-01-01

    Full Text Available Georges E Daoud,1 Mahmoud Houmsse2 1Department of the Biomedical Research, 2Division of Cardiovascular Medicine, The Ohio State University Wexner Medical Center, Columbus, OH, USA Abstract: Cardiac resynchronization therapy (CRT is an effective and well-established therapy for patients suffering with heart failure, left ventricular (LV systolic dysfunction (ejection fraction ≤35%, and electrical dyssynchrony, demonstrated by a surface QRS duration of ≥120 ms. Patients undergoing treatment with CRT have shown significant improvement in functional class, quality of life, LV ejection fraction, exercise capacity, hemodynamics, and reverse remodeling of LV, and ultimately, morbidity and mortality. However, 30%–40% of patients who receive a CRT device may not show improvement, and they are termed as nonresponders. The nonresponders have a poor prognosis; several methods have been developed to try to enhance response to CRT. Echocardiography-guided optimization of CRT has not resulted in significant clinical benefit, since it is done at rest with the patient in supine position. An ideal optimization strategy would provide continuous monitoring and adjustment of device pacing to provide maximal cardiac resynchronization, under a multitude of physiologic states. Intrinsic activation of the right ventricle (RV with paced activation of the RV, even in the setting of biventricular (BiV pacing, may result in an adverse effect on cardiac performance. With this physiology, the use of LV-only pacing may be preferred and may enhance CRT. Adaptive CRT is a novel device-based algorithm that was designed to achieve patient-specific adjustment in CRT so as to provide appropriate BiV pacing or LV-only pacing. This article will review the goals of CRT optimization, and implementation and outcomes associated with adaptive CRT. Keywords: heart failure, cardiac resynchronization, therapy, adaptive, left and biventricular pacing

  17. Biventricular Mechanical Circulatory Support Does Not Prevent Delayed Myocardial Ventricular Rupture following Myocardial Infarction

    Directory of Open Access Journals (Sweden)

    Yazhini Ravi

    2013-01-01

    Full Text Available Cardiogenic shock and myocardial rupture can complicate an acute myocardial infarction (AMI. A case is reported in which a 58-year-old male with an acute inferior myocardial infarction required placement of biventricular assist device for hemodynamic support eight days after the onset of his AMI; eleven days after his AMI, the patient developed abrupt onset of hemodynamic instability with massive bleeding from his chest tube due to delayed free wall myocardial rupture that was discovered when he was taking emergently to the operating room. Myocardial rupture in patients with a ventricular assist device should be considered in the differential diagnosis in the event of acute hemodynamic compromise. A high level of suspicion for such a complication should prompt aggressive and emergent actions including surgery. We present a case of delayed free wall myocardial rupture following an acute inferior wall myocardial infarction in a patient with biventricular mechanical circulatory support.

  18. Utility of a Novel Biofeedback Device for Within-Breath Modulation of Heart Rate in Rats: A Quantitative Comparison of Vagus Nerve vs. Right Atrial Pacing.

    Science.gov (United States)

    O'Callaghan, Erin L; Chauhan, Ashok S; Zhao, Le; Lataro, Renata M; Salgado, Helio C; Nogaret, Alain; Paton, Julian F R

    2016-01-01

    In an emerging bioelectronics era, there is a clinical need for physiological devices incorporating biofeedback that permits natural and demand-dependent control in real time. Here, we describe a novel device termed a central pattern generator (CPG) that uses cutting edge analog circuitry producing temporally controlled, electrical stimulus outputs based on the real time integration of physiological feedback. Motivated by the fact that respiratory sinus arrhythmia (RSA), which is the cyclical changes in heart rate every breath, is an essential component of heart rate variability (HRV) (an indicator of cardiac health), we have explored the versatility and efficiency of the CPG for producing respiratory modulation of heart rate in anesthetized, spontaneously breathing rats. Diaphragmatic electromyographic activity was used as the input to the device and its output connected to either the right cervical vagus nerve or the right atrium for pacing heart rate. We found that the CPG could induce respiratory related heart rate modulation that closely mimicked RSA. Whether connected to the vagus nerve or right atrium, the versatility of the device was demonstrated by permitting: (i) heart rate modulation in any phase of the respiratory cycle, (ii) control of the magnitude of heart rate modulation, and (iii) instant adaptation to changes in respiratory frequency. Vagal nerve pacing was only possible following transection of the nerve limiting its effective use chronically. Pacing via the right atrium permitted better flexibility and control of heart rate above its intrinsic level. This investigation now lays the foundation for future studies using this biofeedback technology permitting closer analysis of both the function and dysfunction of RSA.

  19. Utility of a novel biofeedback device for within-breath modulation of heart rate in rats: a quantitative comparison of vagus nerve versus right atrial pacing.

    Directory of Open Access Journals (Sweden)

    Erin Louise O'Callaghan

    2016-02-01

    Full Text Available In an emerging bioelectronics era, there is a clinical need for physiological devices incorporating biofeedback that permits natural and demand-dependent control in real time. Here, we describe a novel device termed a central pattern generator (CPG that uses cutting edge analogue circuitry producing temporally controlled, electrical stimulus outputs based on the real time integration of physiological feedback. Motivated by the fact that respiratory sinus arrhythmia (RSA, which is the cyclical changes in heart rate every breath, is an essential component of heart rate variability (an indicator of cardiac health, we have explored the versatility and efficiency of the CPG for producing respiratory modulation of heart rate in anaesthetised, spontaneously breathing rats. Diaphragmatic electromyographic activity was used as the input to the device and its output connected to either the right cervical vagus nerve or the right atrium for pacing heart rate. We found that the CPG could induce respiratory related heart rate modulation that closely mimicked RSA. Whether connected to the vagus nerve or right atrium, the versatility of the device was demonstrated by permitting: (i heart rate modulation in any phase of the respiratory cycle, (ii control of the magnitude of heart rate modulation and (iii instant adaptation to changes in respiratory frequency. Vagal nerve pacing was only possible following transection of the nerve limiting its effective use chronically. Pacing via the right atrium permitted better flexibility and control of heart rate above its intrinsic level. This investigation now lays the foundation for future studies using this biofeedback technology permitting closer analysis of both the function and dysfunction of RSA.

  20. [Advances in cardiac pacing].

    Science.gov (United States)

    de Carranza, María-José Sancho-Tello; Fidalgo-Andrés, María Luisa; Ferrer, José Martínez; Mateas, Francisco Ruiz

    2012-01-01

    This article contains a review of the current status of remote monitoring and follow-up involving cardiac pacing devices and of the latest developments in cardiac resynchronization therapy. In addition, the most important articles published in the last year are discussed.

  1. Temporary pacing

    Directory of Open Access Journals (Sweden)

    L.J. Workman

    1983-09-01

    Full Text Available Artificial cardiac pacing, the use of electrical stimuli to cause contraction of heart muscle, is a sophisticated therapeutic and diagnostic tool. Its rapid technologic improvement since first developed in the late 1930’s by Hyman, has made it possible not only to avoid certain cases of death due to heart block, but also to extend and improve the quality of life. Pacemaker therapy is generally used to treat heart rate or rhythm disturbances, being either tachy- or bradyarrhythmias that produce a detrimental drop in cardiac output. Of the many different types of pacemakers and electrodes currently available, ventricular demand pacing is the most commonly used.

  2. Total artificial heart in the pediatric patient with biventricular heart failure.

    Science.gov (United States)

    Park, S S; Sanders, D B; Smith, B P; Ryan, J; Plasencia, J; Osborn, M B; Wellnitz, C M; Southard, R N; Pierce, C N; Arabia, F A; Lane, J; Frakes, D; Velez, D A; Pophal, S G; Nigro, J J

    2014-01-01

    Mechanical circulatory support emerged for the pediatric population in the late 1980s as a bridge to cardiac transplantation. The Total Artificial Heart (TAH-t) (SynCardia Systems Inc., Tuscon, AZ) has been approved for compassionate use by the Food and Drug Administration for patients with end-stage biventricular heart failure as a bridge to heart transplantation since 1985 and has had FDA approval since 2004. However, of the 1,061 patients placed on the TAH-t, only 21 (2%) were under the age 18. SynCardia Systems, Inc. recommends a minimum patient body surface area (BSA) of 1.7 m(2), thus, limiting pediatric application of this device. This unique case report shares this pediatric institution's first experience with the TAH-t. A 14-year-old male was admitted with dilated cardiomyopathy and severe biventricular heart failure. The patient rapidly decompensated, requiring extracorporeal life support. An echocardiogram revealed severe biventricular dysfunction and diffuse clot formation in the left ventricle and outflow tract. The decision was made to transition to biventricular assist device. The biventricular failure and clot formation helped guide the team to the TAH-t, in spite of a BSA (1.5 m(2)) below the recommendation of 1.7 m(2). A computed tomography (CT) scan of the thorax, in conjunction with a novel three-dimensional (3D) modeling system and team, assisted in determining appropriate fit. Chest CT and 3D modeling following implantation were utilized to determine all major vascular structures were unobstructed and the bronchi were open. The virtual 3D model confirmed appropriate device fit with no evidence of compression to the left pulmonary veins. The postoperative course was complicated by a left lung opacification. The left lung anomalies proved to be atelectasis and improved with aggressive recruitment maneuvers. The patient was supported for 11 days prior to transplantation. Chest CT and 3D modeling were crucial in assessing whether the device would

  3. Keeping Pace

    Science.gov (United States)

    Henderson, Nancy

    2008-01-01

    This article describes the struggles of two tough moms who team up to start their own company. Fed up with a lack of stylish, properly-fitting shoes for their children with cerebral palsy, they established "Keeping Pace" which currently offers a selection of stylish girls' and boys' athletic sneakers and casual dress shoes for boys, all sold…

  4. The cardiac implantable electronic device power source: evolution and revolution.

    Science.gov (United States)

    Mond, Harry G; Freitag, Gary

    2014-12-01

    Although the first power source for an implantable pacemaker was a rechargeable nickel-cadmium battery, it was rapidly replaced by an unreliable short-life zinc-mercury cell. This sustained the small pacemaker industry until the early 1970s, when the lithium-iodine cell became the dominant power source for low voltage, microampere current, single- and dual-chamber pacemakers. By the early 2000s, a number of significant advances were occurring with pacemaker technology which necessitated that the power source should now provide milliampere current for data logging, telemetric communication, and programming, as well as powering more complicated pacing devices such as biventricular pacemakers, treatment or prevention of atrial tachyarrhythmias, and the integration of innovative physiologic sensors. Because the current delivery of the lithium-iodine battery was inadequate for these functions, other lithium anode chemistries that can provide medium power were introduced. These include lithium-carbon monofluoride, lithium-manganese dioxide, and lithium-silver vanadium oxide/carbon mono-fluoride hybrids. In the early 1980s, the first implantable defibrillators for high voltage therapy used a lithium-vanadium pentoxide battery. With the introduction of the implantable cardioverter defibrillator, the reliable lithium-silver vanadium oxide became the power source. More recently, because of the demands of biventricular pacing, data logging, and telemetry, lithium-manganese dioxide and the hybrid lithium-silver vanadium oxide/carbon mono-fluoride laminate have also been used. Today all cardiac implantable electronic devices are powered by lithium anode batteries.

  5. Evaluation of the effects of transvenous pacing site on left ventricular function and synchrony in healthy anesthetized dogs.

    Science.gov (United States)

    Maisenbacher, Herbert W; Estrada, Amara H; Prosek, Robert; Shih, Andre C; Vangilder, James M

    2009-04-01

    OBJECTIVE-To compare the acute effects of cardiac pacing from various transvenous pacing sites on left ventricular (LV) function and synchrony in clinically normal dogs. ANIMALS-10 healthy adult mixed-breed dogs. PROCEDURES-Dogs were anesthetized, and dual-chamber transvenous biventricular pacing systems were implanted. Dogs were paced in single-chamber mode from the right atrial appendage (RAA) alone and in dual-chamber mode from the right ventricular apex (RVA), from the left ventricular free wall (LVFW), and simultaneously from the RVA and LVFW (BiV). Standard ECG and echocardiographic measurements, cardiac output measured with the lithium dilution method (LiDCO), and tissue Doppler-derived measurements of LV synchrony were obtained during each of the pacing configurations. RESULTS-Placement of the biventricular pacing systems was possible in 8 of the 10 dogs. The QRS duration was significantly different among all pacing sites, and the order of increasing duration was RAA, BiV, LVFW, and RVA. Pacing sites did not differ with respect to fractional shortening; however, pacing from the RVA resulted in a significantly lower ejection fraction than pacing from all other sites. During RVA and LVFW pacing, LiDCO was significantly lower than that at other sites; there was no significant difference between RAA and BiV pacing with respect to LiDCO. Although the degree of dyssynchrony was significantly lower during pacing from the RAA versus other ventricular pacing sites, it was not significantly different among sites. CONCLUSIONS AND CLINICAL RELEVANCE-Ventricular activation by RAA pacing provided the best LV function and synchrony. Pacing from the RVA worsened LV function, and although pacing from the LVFW improved it, BiV pacing may provide additional improvement.

  6. Anastomose cavo-pulmonar associada ao suporte circulatório esquerdo comparada à assistência biventricular na falência cardíaca aguda Cavo-pulmonary anastomosis associated with left ventricular in comparison with biventricular circulatory support in acute heart failure

    Directory of Open Access Journals (Sweden)

    Luis Alberto Saraiva Santos

    2012-12-01

    Full Text Available OBJETIVO: Este estudo avaliou o desempenho hemodinâmico e as alterações miocárdicas decorrentes do emprego de dispositivos de assistência ventricular esquerda (DAVE, associado ou não à descompressão do ventrículo direito por meio de derivação cavo-pulmonar, sendo esses achados comparados ao emprego de assistência circulatória biventricular. MÉTODOS: Vinte e um suínos foram submetidos à indução de insuficiência cardíaca através de fibrilação ventricular, sendo a atividade circulatória mantida por DAVE durante 180 minutos. No grupo controle, foi apenas implantado o DAVE. No grupo derivação, além do DAVE foi realizada cirurgia de derivação cavo-pulmonar. No grupo biventricular, foi instituída assistência biventricular. Foram monitoradas as pressões intracavitárias por 3 horas de assistência e amostras do endocárdio dos dois ventrículos foram coletadas e analisadas à microscopia óptica e eletrônica. RESULTADOS: O lactato sérico foi significativamente menor no grupo biventricular (P=0,014. A diferença observada entre o fluxo do DAVE nos grupos derivação e controle (+55±14 ml/kg/min, P=0,072 não foi significativa, enquanto que o fluxo no grupo biventricular foi significativamente maior (+93±17 ml/kg/min, P=0,012 e se manteve estável durante o experimento. A pressão arterial média (PAM se manteve constante apenas no grupo biventricular (POBJECTIVE: Right ventricular (RV failure during left ventricular assist device (LVAD support can result in severe hemodynamic compromise with high mortality. This study investigated the acute effects of cavo-pulmonary anastomosis on LVAD performance and RV myocardial compromise in comparison with biventricular circulatory support, in a model of biventricular failure. METHODS: LVAD support was performed by centrifugal pump in 21 pigs with severe biventricular failure obtained by FV induction. Animals were randomized to be submitted to cavo-pulmonary anastomosis, to

  7. A design of body surface gastric pacing device with self-feedback%体外自主反馈式胃起搏装置设计

    Institute of Scientific and Technical Information of China (English)

    王伟; 王成章; 张汇泉; 李章勇; 郭毅军; 任永

    2012-01-01

    Objective A surface feedback-stimulation gastric-pacing device was designed to extract gastric surface information,determine the status of gastric and surface stimulation.Methods The characteristic parameters of gastric electrical formed by processing signal and extracting parameter.By that,the state of stomach could be confirmed,and stimulus signal of stomach pace-making in different frequency and intensity could be decided as needed.During the processes of the stimulation,the variations of gastric electrical parameters can be analyzed in real-time and the stimulation parameters could be modified to achieve the self-feedback mode.Results Self-feedback model in different gastric motility analog environment could be realized.Conclusion The preliminary validation of experimental results proved the effectiveness of self-feedback of gastric pacing devices and its application prospects in some areas.%目的 提供一种集体表胃电检测、胃蠕动状态分析和判断、体表胃刺激起搏于一体的自主反馈式胃起搏装置设计.方法 依据胃电的检测采集,通过信号处理与参数提取形成胃电特征参数,以此判断胃的运动状态并按需要发生不同频率、强度的胃起搏刺激信号.刺激过程中,可实时分析胃电特征参数的变化,修改刺激参数,实现自主反馈模式.结果 自主反馈模式在不同的胃运动模拟信号环境中得到实现.结论 初步验证实验证明了该自主反馈胃起搏装置工作的有效性,显示了一定的应用前景.

  8. Hemodynamic improvement by right ventricular septal pacing in elderly patients with chronic atrial fibrillation and slow ventricular response

    Institute of Scientific and Technical Information of China (English)

    Wei HUA; Shidong GUO; Shu ZHANG; Fangzheng WANG; Lida ZHI; Hongxia NIU; Xin CHEN

    2005-01-01

    Background and objectives Right ventricular apical (RVA) pacing has been reported impairing left ventricular (LV)performance. Alternative pacing sites in right ventricle (RV) has been explored to obtain better cardiac function. Our study was designed to compare the hemodynamic effects of right ventricular septal (RVS) pacing with RVA pacing. Methods Ten elderly patients with chronic atrial fibrillation (AF) and long RR interval or slow ventricular response (VR) received VVI pacing. The hemodynamic difference between RVS and RVA pacing were examined by transthoracic echocardiography (TTE). Results Pacing leads were implanted successfully at the RVA and then RVS in all patients without complication. The left ventricular (LV) parameters,measured during RVA pacing including left ventricular ejection fraction (LVEF), FS, stroke volume (SV) and peak E wave velocity (EV) were decreased significantly compared to baseline data, while during RVS pacing, they were significantly better than those during RVA pacing. However, after 3-6 weeks there was no statistical significant difference between pre- and post- RVS pacing.Conclusions The LV hemodynamic parameters during RVA pacing were significantly worse than baseline data. The short term LV hemodynamic parameters of RVS pacing were significantly better than those of RVA pacing; RVS pacing could improve the hemodynamic effect through maintaining normal ventricular activation sequence and biventricular contraction synchrony in patients with chronic AF and slow ventricular response.

  9. Machines versus medication for biventricular heart failure: focus on the total artificial heart.

    Science.gov (United States)

    Arabia, Francisco A; Moriguchi, Jaime D

    2014-09-01

    The medical/surgical management of advanced heart failure has evolved rapidly over the last few decades. With better understanding of heart failure pathophysiology, new pharmacological agents have been introduced that have resulted in improvements in survival. For those patients that fail to improve, mechanical circulatory support with left ventricular assist devices and total artificial hearts (TAHs) have served as a beneficial bridge to transplantation. The TAH has continued to play a significant role as a bridge to transplantation in patients with biventricular failure and more selected indications that could not be completely helped with left ventricular assist devices. Improved survival with the TAH has resulted in more patients benefiting from this technology. Improvements will eventually lead to a totally implantable device that will permanently replace the failing human heart.

  10. Echocardiographic estimation of acute haemodynamic response during optimization of multisite pace-maker using different pacing modalities and atrioventricular delays

    Directory of Open Access Journals (Sweden)

    Šalinger-Martinović Sonja

    2009-01-01

    Full Text Available Background/Aim. Cardiac resynchronization therapy (CRT improves ventricular dyssynchrony and is associated with an improvement in symptoms, quality of life and prognosis in patients with severe heart failure and intraventricular conduction delay. Different pacing modalities produce variable activation patterns and may be a cause of different haemodynamic changes. The aim of our study was to investigate acute haemodynamic changes with different CRT configurations during optimization procedure. Methods. This study included 30 patients with severe left ventricular systolic dysfunction and left bundle branch block with wide QRS (EF 24.33 ± 3.7%, QRS 159 ± 17.3 ms, New York Heart Association III/IV 25/5 with implanted CRT device. The whole group of patients had severe mitral regurgitation in order to measure dP/dt. After implantation and before discharge all the patients underwent optimization procedure guided by Doppler echocardiography. Left and right ventricular pre-ejection intervals (LVPEI and RVPEI, interventricular mechanical delay (IVD and the maximal rate of ventricular pressure rise during early systole (max dP/dt were measured during left and biventricular pacing with three different atrioventricular (AV delays. Results. After CRT device optimization, optimal AV delay and CRT mode were defined. Left ventricular pre-ejection intervals changed from 170.5 ± 24.6 to 145.9 ± 9.5 (p < 0.001, RVPEI from 102.4 ± 15.9 to 119.8 ± 10.9 (p < 0.001, IVD from 68.1 ± 18.3 to 26.5 ± 8.2 (p < 0.001 and dP/dt from 524.2 ± 67 to 678.2 ± 88.5 (p < 0.01. Conclusion. In patients receiving CRT echocardiographic assessment of the acute haemodynamic response to CRT is a useful tool in optimization procedure. The variability of Doppler parameters with different CRT modalities emphasizes the necessity of individualized approach in optimization procedure.

  11. Biventricular takotsubo cardiomyopathy: case study and review of literature.

    Science.gov (United States)

    Daoko, Joseph; Rajachandran, Manu; Savarese, Ronald; Orme, Joseph

    2013-01-01

    Biventricular takotsubo cardiomyopathy is associated with more hemodynamic instability than is isolated left ventricular takotsubo cardiomyopathy; medical management is more invasive and the course of hospitalization is longer. In March 2011, a 62-year-old woman presented at our emergency department with abdominal pain, nausea, and vomiting. On hospital day 2, she experienced chest pain. An electrocardiogram and cardiac enzyme levels suggested an acute myocardial infarction. She underwent cardiac angiography and was found to have severe left ventricular systolic dysfunction involving the mid and apical segments, which resulted in a left ventricular ejection fraction of 0.10 to 0.15 in the absence of obstructive coronary artery disease. Her hospital course was complicated by cardiogenic shock that required hemodynamic support with an intra-aortic balloon pump and dobutamine. A transthoracic echocardiogram revealed akinesis of the mid-to-distal segments of the left ventricle and mid-to-apical dyskinesis of the right ventricular free wall characteristic of biventricular takotsubo cardiomyopathy. After several days of medical management, the patient was discharged from the hospital in stable condition. To the best of our knowledge, this is the first review of the literature on biventricular takotsubo cardiomyopathy that compares its hemodynamic instability and medical management requirements with those of isolated left ventricular takotsubo cardiomyopathy. Herein, we discuss the case of our patient, review the pertinent medical literature, and convey the prevalence and importance of right ventricular involvement in patients with takotsubo cardiomyopathy.

  12. Cardiac resynchronization therapy: Dire need for targeted left ventricular lead placement and optimal device programming

    Institute of Scientific and Technical Information of China (English)

    Sokratis; Pastromas; Antonis; S; Manolis

    2014-01-01

    Cardiac resynchronization therapy(CRT) effected via biventricular pacing has been established as prime therapy for heart failure patients of New York Heart Association functional class Ⅱ, Ⅲ and ambulatory Ⅳ, reduced left ventricular(LV) function, and a widened QRS complex. CRT has been shown to improve symptoms, LV function, hospitalization rates, and survival. In order to maximize the benefit from CRT and reduce the number of non-responders, consideration should be given to target the optimal site for LV lead implantation away from myocardial scar and close to the latest LV site activation; and also to appropriately program the device paying particular attention to optimal atrioventricular and interventricular intervals. We herein review current data related to both optimal LV lead placement and device programming and their effects on CRT clinical outcomes.

  13. Pneumothorax in cardiac pacing

    DEFF Research Database (Denmark)

    Kirkfeldt, Rikke Esberg; Johansen, Jens Brock; Nohr, Ellen Aagaard;

    2012-01-01

    AIM: To identify risk factors for pneumothorax treated with a chest tube after cardiac pacing device implantation in a population-based cohort.METHODS AND RESULTS: A nationwide cohort study was performed based on data on 28 860 patients from the Danish Pacemaker Register, which included all Danish...... patients who received their first pacemaker (PM) or cardiac resynchronization device from 1997 to 2008. Multiple logistic regression was used to estimate adjusted odds ratios (aOR) with 95% confidence intervals for the association between risk factors and pneumothorax treated with a chest tube. The median...... age was 77 years (25th and 75th percentile: 69-84) and 55% were male (n = 15 785). A total of 190 patients (0.66%) were treated for pneumothorax, which was more often in women [aOR 1.9 (1.4-2.6)], and in patients with age >80 years [aOR 1.4 (1.0-1.9)], a prior history of chronic obstructive pulmonary...

  14. The Use of a Quadripolar Left Ventricular Lead Increases Successful Implantation Rates in Patients with Phrenic Nerve Stimulation and/or High Pacing Thresholds Undergoing Cardiac Resynchronisation Therapy with Conventional Bipolar Leads

    OpenAIRE

    Ohlow, Marc-Alexander; Lauer, Bernward; Brunelli, Michele; Daralammouri, Yunis; Geller, Christoph

    2013-01-01

    Background Phrenic nerve stimulation (PNS) and high pacing thresholds (HPT) hinder biventricular stimulation in patients (pts) undergoing cardiac resynchronization therapy (CRT). A new quadripolar left ventricular (LV) lead (Quartet 1458Q, St. Jude Medical) with increased number of pacing configuration, might overcome this problem. Methods All consecutive pts in whom a standard bipolar lead intraoperatively resulted in PNS and/or HPT (≥4.00V/1mV), received, during the same implant, a quadripo...

  15. Biventricular takotsubo cardiomyopathy: case report and general discussion.

    Science.gov (United States)

    Angelini, Paolo; Monge, Jorge; Simpson, Leo

    2013-01-01

    In recent years, our understanding of the physiologic mechanisms of transient takotsubo cardiomyopathy has improved because of the growing use of emergent heart catheterization in patients who present with severe ischemic syndromes. However, even this procedure has revealed only that, in most patients with takotsubo syndrome, the sudden onset of ventricular dysfunction is not due to fixed coronary artery occlusions. We present a case of transient takotsubo cardiomyopathy with an exceptional feature--uneven impairment of both right and left ventricular function, or biventricular takotsubo--and we discuss a novel, comprehensive theory that we have devised to explain the pathophysiology of this syndrome's many manifestations.

  16. Self-Paced Fortran.

    Science.gov (United States)

    Burnett, James

    1979-01-01

    This paper describes the instructional format of the lecture and the self-paced methods of teaching FORTRAN at Michigan State University and compares end-of-term grades of students taking a second computer science course based on whether they took the first course in the self-paced or the traditional lecture format. (Author/BB)

  17. Pacing for Dramaturgy

    OpenAIRE

    Pensjö, Jonas

    2014-01-01

    This thesis is a study on how game mechanics affect dramaturgy through pacing within the multiplayer MOBA genre of video games and serves as an addition to ease dramaturgic design for future games. The thesis contains an introduction of drama and some of related terms in addition to the MOBA game genre, its format and a short history of the genre. To compare the observations and analysis made in this study, previous work on both dramaturgy and pacing have been recollected.

  18. Large Right Ventricular Clot in Pulmonary Atresia With Intact Ventricular Septum: In Defense of Biventricular Approach.

    Science.gov (United States)

    Dutta, Nilanjan; Ghosh, Rajarshi; Awasthy, Neeraj; Iyer, Parvathi U; Girotra, Sumir; Iyer, Krishna S

    2016-09-01

    Thrombus formation within the right ventricle (RV) in the setting of pulmonary atresia with intact ventricular septum (PAIVS) is not a very common occurrence and can be catastrophic. We present the case of a seven-month-old child with PAIVS and RV clot who successfully underwent biventricular repair. We discuss the interesting case and the rationale for management by means of biventricular repair over single ventricle repair when feasible in such a setting.

  19. [Implantation of a biventricular ICD in a patient with dextrocardia with situs inversus].

    Science.gov (United States)

    Vurgun, Veysel Kutay; Gerede, Menekşe; Altın, Ali Timuçin; Candemir, Başar; Akyürek, Ömer

    2015-01-01

    In order to reduce sudden cardiac death and heart failure symptoms, biventricular implantable cardioverter defibrillator (ICD) implantation is a treatment method commonly used in selected patients with cardiomyopathy. The frequency of dextrocardia in congenital heart defects is approximately 0.4/10000. In this group, the frequency of cardiomyopathy development is rare. In this case report we present a patient with dextrocardia undergoing implantation of biventricular ICD.

  20. Pacing stress echocardiography

    Directory of Open Access Journals (Sweden)

    Agrusta Marco

    2005-12-01

    Full Text Available Abstract Background High-rate pacing is a valid stress test to be used in conjunction with echocardiography; it is independent of physical exercise and does not require drug administration. There are two main applications of pacing stress in the echo lab: the noninvasive detection of coronary artery disease through induction of a regional transient dysfunction; and the assessment of contractile reserve through peak systolic pressure/ end-systolic volume relationship at increasing heart rates to assess global left ventricular contractility. Methods The pathophysiologic rationale of pacing stress for noninvasive detection of coronary artery disease is obvious, with the stress determined by a controlled increase in heart rate, which is a major determinant of myocardial oxygen demand, and thereby tachycardia may exceed a fixed coronary flow reserve in the presence of hemodynamically significant coronary artery disease. The use of pacing stress echo to assess left ventricular contractile reserve is less established, but promising. Positive inotropic interventions are mirrored by smaller end-systolic volumes and higher end-systolic pressures. An increased heart rate progressively increases the force of ventricular contraction (Bowditch treppe or staircase phenomenon. To build the force-frequency relationship, the force is determined at different heart rate steps as the ratio of the systolic pressure (cuff sphygmomanometer/end-systolic volume index (biplane Simpson rule. The heart rate is determined from ECG. Conclusion Two-dimensional echocardiography during pacing is a useful tool in the detection of coronary artery disease. Because of its safety and ease of repeatability noninvasive pacing stress echo can be the first-line stress test in patients with permanent pacemaker. The force-frequency can be defined as up- sloping (normal when the peak stress pacing systolic pressure/end-systolic volume index is higher than baseline and intermediate stress

  1. PACE Status Update

    Energy Technology Data Exchange (ETDEWEB)

    M., Zimring,; Hoffman, I.; Fuller, M.

    2010-08-11

    The Federal Housing Finance Agency (FHFA) regulates Fannie Mae, Freddie Mac, and the 12 Federal Home Loan Banks (the government-sponsored enterprises - GSEs). On July 6, 2010, FHFA and the Office of the Comptroller of the Currency (OCC) concluded that Property Assessed Clean Energy (PACE) programs 'present significant safety and soundness concerns' to the housing finance industry. This statement came after a year of discussions with state and federal agencies in which PACE, a novel mechanism for financing energy efficiency and renewable energy improvements, has gone from receiving support from the White House, canonization as one of Scientific American's 'World Changing Ideas' and legislative adoption in 24 states to questionable relevance, at least in the residential sector. Whether PACE resumes its expansion as an innovative tool for financing energy efficiency and clean generation depends on outcomes in each of the three branches of government - discussions on a PACE pilot phase among federal agencies, litigation in federal court, and legislation in Congress - all highly uncertain. This policy brief addresses the practical impacts of these possible outcomes on existing and emerging PACE programs across the United States and potential paths forward.

  2. Feasibility of dual-chamber (DDD) pacing via a single-pass (VDD) pacing lead employing a floating atrial ring (dipole): case series, future considerations, and refinements.

    Science.gov (United States)

    Kassotis, John; Voigt, Louis; Mongwa, Mbu; Reddy, C V R

    2005-01-01

    The objective of this study was to assess the feasibility of DDD pacing from a standard single-pass VDD pacemaker system. Over the past 2 decades significant advances have been made in the development of single-pass VDD pacing systems. These have been shown in long-term prospective studies to effectively preserve atrioventricular (AV)synchrony in patients with AV block and normal sinus node function. What remains problematic is the development of a single-pass pacing system capable of DDD pacing. Such a lead configuration would be useful in those patients with peripheral venous anomalies and in younger patients with congenital anomalies, which may require lead revisions in the future. In addition, with the increased use of resynchronization (biventricular pacing) therapy, the availability of a reliable single-pass lead will minimize operative time, enhance patient safety, and minimize the amount of hardware within the heart. The feasibility of DDD pacing via a Medtronic Capsure VDD-2 (Model #5038) pacing lead was evaluated. Twenty patients who presented with AV block and normal sinus node function were recruited for this study. Atrial pacing thresholds and sensitivities were assessed intraoperatively in the supine position with various respiratory maneuvers. Five patients who agreed to participate in long-term follow-up received a dual-chamber generator and were evaluated periodically over a 12-month period. Mean atrial sensitivity was 2.35 +/- 0.83 mV at the time of implantation. Effective atrial stimulation was possible in all patients at the time of implantation (mean stimulation threshold 3.08 +/- 1.04 V at 0.5 ms [bipolar], 3.34 +/- 0.95 V at 0.5 ms [unipolar]). Five of the 20 patients received a Kappa KDR701 generator, and atrial electrical properties were followed up over a 1-year period. There was no significant change in atrial pacing threshold or incidence of phrenic nerve stimulation over the 1-year follow-up. A standard single-pass VDD pacing lead

  3. Graybar – pace project

    OpenAIRE

    Morillo Peres, Xavier

    2014-01-01

    Proyecto Final de Carrera en el se presenta una memoria del trabajo realizado en la empresa Graybar de implantación de un sistema de Gestión de la Cadena de Suministro Mètodes basat en investigació operativa per agilitzar la logística interna d´industries Graybar.Projecte PACE

  4. Recent developments in cardiac pacing.

    Science.gov (United States)

    Rodak, D J

    1995-10-01

    Indications for cardiac pacing continue to expand. Pacing to improve functional capacity, which is now common, relies on careful patient selection and technical improvements, such as complex software algorithms and diagnostic capabilities.

  5. TCP Pacing Developed

    Science.gov (United States)

    Ivancic, William D.

    2002-01-01

    Transmission control protocol (TCP) was conceived and designed to run over a variety of communication links, including wireless and high-bandwidth links. However, with recent technological advances in satellite and fiber-optic networks, researchers are reevaluating the flexibility of TCP. The TCP pacing and packet pair probing implementation may help overcome two of the major obstacles identified for efficient bandwidth utilization over communication links with large delay-bandwidth products.

  6. Total artificial heart implantation for biventricular failure due to eosinophilic myocarditis.

    Science.gov (United States)

    Kawabori, Masashi; Kurihara, Chitaru; Miller, Yair; Heck, Kent A; Bogaev, Roberta C; Civitello, Andrew B; Cohn, William E; Frazier, O H; Morgan, Jeffrey A

    2017-03-27

    Idiopathic hypereosinophilic syndrome is a condition of unknown etiology characterized by proliferation of eosinophils and their infiltration into tissues. Although cardiac involvement is rare, eosinophilic myocarditis can lead to life-threating fulminant congestive heart failure. Treatment of patients with eosinophilic myocarditis is challenging as heart failure can be caused by biventricular dysfunction. To our knowledge, this is the first case reported in the literature describing a patient with acute severe biventricular heart failure caused by eosinophilic myocarditis with mural left ventricular apical thrombus who was successfully treated with implantation of a total artificial heart as a bridge to heart transplant.

  7. Use of a Three Dimensional Printed Cardiac Model to Assess Suitability for Biventricular Repair.

    Science.gov (United States)

    Farooqi, Kanwal M; Gonzalez-Lengua, Carlos; Shenoy, Rajesh; Sanz, Javier; Nguyen, Khanh

    2016-05-01

    Three dimensional (3D) printing is rapidly gaining interest in the medical field for use in presurgical planning. We present the case of a seven-year-old boy with double outlet right ventricle who underwent a bidirectional Glenn anastomosis. We used a 3D cardiac model to assess his suitability for a biventricular repair. He underwent a left ventricle-to-aorta baffle with a right ventricle-to-pulmonary artery conduit placement. He did well postoperatively and was discharged home with no evidence of baffle obstruction and good biventricular function. A 3D printed model can provide invaluable intracardiac spatial information in these complex patients.

  8. Speckle-tracking echocardiography elucidates the effect of pacing site on left ventricular synchronization in the normal and infarcted rat myocardium.

    Directory of Open Access Journals (Sweden)

    Michal Mor

    Full Text Available BACKGROUND: Right ventricular (RV pacing generates regional disparities in electrical activation and mechanical function (ventricular dyssynchrony. In contrast, left ventricular (LV or biventricular (BIV pacing can improve cardiac efficiency in the setting of ventricular dyssynchrony, constituting the rationale for cardiac resynchronization therapy (CRT. Animal models of ventricular dyssynchrony and CRT currently relay on large mammals which are expensive and not readily available to most researchers. We developed a methodology for double-site epicardial pacing in conscious rats. Here, following post-operative recovery, we compared the effects of various pacing modes on LV dyssynchrony in normal rats and in rats with ischemic cardiomyopathy. METHODS: Two bipolar electrodes were implanted in rats as follows: Group A (n = 6 right atrial (RA and RV sites; Group B (n = 7 RV and LV sites; Group C (n = 8 as in group B in combination with left coronary artery ligation. Electrodes were exteriorized through the back. Following post-operative recovery, two-dimensional transthoracic echocardiography was performed during pacing through the different electrodes. Segmental systolic circumferential strain (Ecc was used to evaluate LV dyssynchrony. RESULTS: In normal rats, RV pacing induced marked LV dyssynchrony compared to RA pacing or sinus rhythm, as measured by the standard deviation (SD of segmental time to peak Ecc, SD of peak Ecc, and the average delay between opposing ventricular segments. LV pacing and, to a greater extend BIV pacing diminished the LV dyssynchrony compared to RV pacing. In rats with extensive MI, the effects of LV and BIV pacing were markedly attenuated, and the response of individual animals was variable. CONCLUSIONS: Rodent cardiac pacing mimics important features seen in humans. This model may be developed as a simple new tool to study the pathophysiology of ventricular dyssynchrony and CRT.

  9. Marathon pacing and elevation change

    CERN Document Server

    Elliott, J B

    2012-01-01

    An analysis of marathon pacing and elevation change is presented. It is based on an empirical observation of how the pace of elite and non-elite marathon runners change over the course of the marathon and a simple approximation of the energy cost of ascent and decent. It was observed that the pace of the runners slowed in a regular manner that could be broken up into four regions. That observation can be used to project target paces for a desired marathon finish time. However, that estimate fails to take in to account the energetic costs of elevation changes (hills) along the marathon course. Several approximations are made to give a coarse estimate of target paces for marathon run on courses with significant elevation changes, i.e. a hilly course. The 2012 Oakland Marathon course is used as and example of a hilly course and the times of 23 finishers are examined.

  10. Factors influencing pacing in triathlon.

    Science.gov (United States)

    Wu, Sam Sx; Peiffer, Jeremiah J; Brisswalter, Jeanick; Nosaka, Kazunori; Abbiss, Chris R

    2014-01-01

    Triathlon is a multisport event consisting of sequential swim, cycle, and run disciplines performed over a variety of distances. This complex and unique sport requires athletes to appropriately distribute their speed or energy expenditure (ie, pacing) within each discipline as well as over the entire event. As with most physical activity, the regulation of pacing in triathlon may be influenced by a multitude of intrinsic and extrinsic factors. The majority of current research focuses mainly on the Olympic distance, whilst much less literature is available on other triathlon distances such as the sprint, half-Ironman, and Ironman distances. Furthermore, little is understood regarding the specific physiological, environmental, and interdisciplinary effects on pacing. Therefore, this article discusses the pacing strategies observed in triathlon across different distances, and elucidates the possible factors influencing pacing within the three specific disciplines of a triathlon.

  11. Biventricular takotsubo cardiomyopathy in an elderly woman with uncontrolled type 2 diabetes: the biphasic echocardiographic and clinical pattern.

    Science.gov (United States)

    Kochanowski, Janusz; Piatkowski, Radoslaw; Budnik, Monika; Jasik, Mariusz; Roik, Marek; Opolski, Grzegorz

    2016-12-01

    We describe a case of an elderly woman who was diagnosed with a biventricular takotsubo cardiomyopathy (TTC) with combination of emotional stress and poorly controlled type 2 diabetes. We observed significant correlation between biphasic improvement of right (after 4 days) and left ventricle function (after 4 weeks) with normalization glycemic status. To our knowledge, this is the first reported case in the literature of biventricular TTC with such metabolic disturbances.

  12. A Clinical Review of Implantable Cardioverter Defibrillators and Bi-Ventricular Pacemakers at one Institute

    Directory of Open Access Journals (Sweden)

    Ahmad Nasir

    2010-01-01

    Full Text Available Background: ICD/BVP indications are expanding. They areexpensive devices and historically, morbidities associated withtheir use were high. The starting experience at the Gold CoastHospital is being reviewed.Methods: A retrospective chart review of all the ICD/BVPsimplanted in the Gold Coast Hospital from 06/07/2007 –17/06/2008, with special emphasis on device indications andcomplications.Results: Devices implanted were (31. Primary preventiondevices (67%, secondary prevention devices (33%.Indications were; Non-ischemic Dilated Cardiomyopathy(35%, Out-of-hospital Cardiac Arrest (26%, Conscious VT(13%, Ischemic Dilated Cardiomyopathy (10%, In-hospitalCardiac Arrest (6%, Long-QT Syndrome (6% andCatecholamine-related Polymorphic VT (3%. Majorcomplications reported; lung contusion (1, left haemothorax(1, failed coronary sinus lead positioning (2, lead repositioning(2, atrial lead removal (1, left subclavian veinthrombosis (1, lead malfunction leading to VT under sensingand syncope (1. Device-administered therapies were eight;Inappropriate discharges (5, Appropriate discharges (1,successful Anti-tachycardia Pacing (2.Conclusions: We believe that ICDs are very effective lifesavingdevices but unfortunately they still are very expensiveand their use can be associated with significant morbiditiesespecially during the learning curve.

  13. Factors influencing pacing in triathlon

    Directory of Open Access Journals (Sweden)

    Wu SSX

    2014-09-01

    Full Text Available Sam SX Wu,1 Jeremiah J Peiffer,2 Jeanick Brisswalter,3 Kazunori Nosaka,1 Chris R Abbiss1 1Centre for Exercise and Sports Science Research, School of Exercise and Health Sciences, Edith Cowan University, Perth, WA, Australia; 2School of Psychology and Exercise Science, Murdoch University, Perth, WA, Australia; 3Laboratory of Human Motricity, Education Sport and Health, University of Nice Sophia Antipolis, Nice, France Abstract: Triathlon is a multisport event consisting of sequential swim, cycle, and run disciplines performed over a variety of distances. This complex and unique sport requires athletes to appropriately distribute their speed or energy expenditure (ie, pacing within each discipline as well as over the entire event. As with most physical activity, the regulation of pacing in triathlon may be influenced by a multitude of intrinsic and extrinsic factors. The majority of current research focuses mainly on the Olympic distance, whilst much less literature is available on other triathlon distances such as the sprint, half-Ironman, and Ironman distances. Furthermore, little is understood regarding the specific physiological, environmental, and interdisciplinary effects on pacing. Therefore, this article discusses the pacing strategies observed in triathlon across different distances, and elucidates the possible factors influencing pacing within the three specific disciplines of a triathlon. Keywords: cycle, endurance, multisport, pacing strategy, run, swim

  14. Alternative technique for implantation of biventricular support with HeartWare implantable continuous flow pump.

    Science.gov (United States)

    Krabatsch, Thomas; Stepanenko, Alexander; Schweiger, Martin; Kukucka, Marian; Ewert, Peter; Hetzer, Roland; Potapov, Evgenij

    2011-01-01

    In this case report, we describe a modification of the biventricular implantation of the HeartWare HVAD. A 28-year-old man with dilative cardiomyopathy presented with biventricular decompensation. The patient underwent implantation of two HeartWare HVADs for biventricular support. Because of low flow of the right pump (2 L/min), a right ventricular angiogram and repeated transesophageal echocardiography (TEE) were done and showed that the pump was compressing the right ventricle. Operative revision was performed, resulting in removal of the right pump and placement into the right atrium, so that it was located in the right pleural cavity. The HVAD fixation ring on the free wall of the right ventricle was left in place, and the opening was closed with an individually designed titanium plug. The findings of this case are that implantation of the HeartWare HVAD for right ventricular (RV) support may be safely performed in atrial position, with individually designed plugs allowing safe and quick removal of the HeartWare pump. This might be used as a "bail-out" strategy when necessary.

  15. Biventricular Failure due to Stress Cardiomyopathy after Pericardiectomy for Constrictive Pericarditis

    Directory of Open Access Journals (Sweden)

    Elliott M. Groves

    2013-01-01

    Full Text Available Importance. Constrictive pericarditis is a rare clinical entity that frequently necessitates surgical intervention. Here we present a case of biventricular failure due to stress cardiomyopathy after pericardiectomy. This is an extremely rare complication that is not well described and does not have a definitive mechanism. Observations. A 40-year-old Ecuadorian woman who was found to have constrictive pericarditis due to Mycobacterium tuberculosis infection was referred to our institution. The presence of constrictive pericarditis was confirmed by echocardiography, computed tomography, magnetic resonance imaging, and cardiac catheterization. Following pericardiectomy, the patient developed biventricular failure consistent with stress cardiomyopathy (Takotsubo cardiomyopathy, based on the echocardiographic assessment of the ventricles, which demonstrated an akinetic apex and hyperactive base in both ventricles, the absence of significant epicardial coronary atherosclerosis, and prompt normalization of the cardiac function after intensive medical therapy. Conclusions and Relevance. Biventricular failure in the form of stress cardiomyopathy after pericardiectomy in the manner presented here has not been previously described in the literature. While postulations as to the cause of single ventricle dysfunction have been described, the exact mechanism is unclear and current theories do not explain the clinical features in this case of stress cardiomyopathy after pericardiectomy.

  16. Diagnostic accuracy of pace spikes in the electrocardiogram to diagnose paced rhythm

    DEFF Research Database (Denmark)

    Andersson, Hedvig; Hansen, Marco Bo; Thorsberger, Mads;

    2015-01-01

    OBJECTIVE: To determine how often cardiac resynchronization therapy (CRT) pacing systems generate visible pace spikes in the electrocardiogram (ECG). METHODS: In 46 patients treated with CRT pacing systems, we recorded ECGs during intrinsic rhythm, atrial pacing and ventricular pacing. ECGs were...

  17. Presentation Time Concerning System-Paced Multimedia Instructions and the Superiority of Learner Pacing

    Science.gov (United States)

    Stiller, Klaus D.; Petzold, Kirstin; Zinnbauer, Peter

    2011-01-01

    The superiority of learner-paced over system-paced instructions was demonstrated in multiple experiments. In these experiments, the system-paced presentations were highly speeded, causing cognitive overload, while the learner-paced instructions allowed adjustments of the presentational flow to the learner's needs by pacing facilities, mostly…

  18. The pace and shape of ageing

    DEFF Research Database (Denmark)

    Baudisch, Annette

    2011-01-01

    dimensions of age-specific change - the pace and the shape of ageing. 2.Based on the two axes of pace and shape, I introduce a new conceptual framework to classify how species age. 3.With this method, I rank species according to how strongly they age (shape) and how fast they age (pace). Depending on whether...... they are ranked by pace or by shape, species are ordered differently. 4.Alternative pace measures turn out to be highly correlated. Alternative shape measures are also highly correlated. The correlation between pace and shape ranking is negative but weak. Among the examples here, no species is long lived yet...

  19. Feasibility and safety of biventricular repair in neonates with hypoplastic left heart complex.

    Science.gov (United States)

    Bergonzini, S; Mendoza, A; Paz, M A; Garcia, E; Aguilar, J M; Arlati, F G; Galletti, L; Comas, J V

    2015-02-01

    Hypoplastic left heart syndrome is a spectrum of structural cardiac malformations characterized by variable underdevelopment of the left heart-aorta complex. A minority of patients having a milder degree of left ventricular hypoplasia, described as hypoplastic left heart complex (HLHC), may be selected for biventricular repair. The objective of this study was to assess the outcome of the biventricular approach in HLHC. We evaluated retrospectively 30 neonates diagnosed with HLHC from the "12 de Octubre" University Hospital, following established criteria. We analyzed the echocardiographic data recorded just after birth and at last follow-up after surgery. All patients were operated on in the neonatal period using various surgical techniques. There were no early deaths and only 1 late death after a mean follow-up of 62.9 ± 43.8 months. All patients presented a significant growth of the left ventricular structures, with a Z-score increase of 1.17 ± 1.05 for mitral annulus, 1.72 ± 1.23 for aortic annulus, and 1.33 ± 1.46 for left ventricular end-diastolic diameter. Postoperatively, 18 patients showed a left valvular stenosis, and 17 patients underwent a reoperation and/or an interventional procedure. Freedom from surgery or interventional catheterizations at 1, 3 and 5 years was 53, 49 and 43%, respectively. The 29 current survivors are all in a good functional status. In our experience, we achieved good results from biventricular repair in patients with HLHC, with a significant growth of left heart structures and an excellent clinical status at a medium-term follow-up. Nevertheless, there was a high rate of reoperations and/or interventional catheterizations.

  20. Correção biventricular em defeito do septo atrioventricular desbalanceado Corrección biventricular en defecto del septo atrioventricular desbalanceado Biventricular repair in unbalanced atrioventricular septal defect

    Directory of Open Access Journals (Sweden)

    Edmar Atik

    2009-04-01

    Full Text Available É apresentada a evolução favorável, após correção operatória biventricular, de criança com 2,5 anos de idade, com defeito do septo atrioventricular desbalanceado, com ventrículo esquerdo (VE pequeno (anel mitral de 10 mm em relação de 0,4 com o anel tricúspide, DDVE de 17 mm, Vd2 VE de 15 ml/m² e relação do índice longitudinal VE/VD de 0,71. Houve desenvolvimento normal do VE, verificado três meses após a operação (anel mitral de 22 mm, em relação de 0,84 com o da valva tricúspide e DDVE de 30 mm. Discutem-se os parâmetros atuais de utilização do ventrículo hipoplásico.Presenta evolución favorable después de corrección operatoria biventricular, de niño con 2,5 años de edad, con Defecto del Septo Atrioventricular Desbalanceado con ventrículo izquierdo (VI pequeño (anillo mitral de 10 mm en relación de 0,4 con el anillo tricúspide, DDVI de 17 mm, Vd2 VI de 15 ml/m2 y relación de ejes longitudinales VI/VD de 0,71. Hubo desarrollo normal del VI, verificado tres meses después de la operación (anillo mitral de 22 mm, en relación de 0,84 con el de la válvula tricúspide y DDVI de 30 mm. Se discuten los parámetros actuales de utilización del ventrículo hipoplásico.We present the case of a 2.5 year-old child with unbalanced atrioventricular septal defect due to a small left ventricle (LV (mitral annulus of 10mm and a 0.4 ratio in relation to the tricuspid annulus, LVDD: 17 mm, LV Vd2: 15 ml/m² and LV/RV long-axis ratio of 0.71; he had a favorable outcome after biventricular surgical repair. Normal LV development was observed three months after the operation (mitral annulus of 22 mm, with a 0.84 ratio in relation to the tricuspid annulus, and LVDD of 30 mm. Current parameters for utilization of the hypoplastic ventricle are discussed.

  1. Low atrial septum pacing in pacemaker patients

    NARCIS (Netherlands)

    Voogt, Willem Gijsbert de

    2006-01-01

    In patients with an indication for anti bradycardia pacing, atrial fibrillation (AF) is a common arrhythmia (30-50%) even in the absence of atrial tachy arrhythmias before pacemaker implantation. Pace prevention and pace intervention for atrial tachy arrhythmias could be an interesting adjuvant trea

  2. Biventricular diastolic function assessed by Doppler echocardiogram in children vertically infected with human immunodeficiency virus

    Directory of Open Access Journals (Sweden)

    Mauricio L. Silva

    2014-07-01

    Full Text Available OBJECTIVE: to determine, by Doppler-echocardiography, the frequency of cardiac diastolic dysfunction in asymptomatic and clinically stable pediatric patients with vertical infection by the human immunodeficiency virus (HIV, from the cardiovascular viewpoint. METHODS: this was an observational, prospective, and cross-sectional study, performed at a regional referral clinic for patients with HIV, in a convenience sample of 94 individuals, assessing biventricular diastolic function by Doppler-echocardiography, and weight, blood hemoglobin, and percentage of lymphocytes T-CD4+. RESULTS: fifty patients had diastolic dysfunction. Left ventricular dysfunction occurred in 38.7%, and the predominant type of dysfunction was decreased myocardial compliance. Right ventricular dysfunction was observed in 29.4% of the sample, and abnormal relaxation was the most prevalent type. Simultaneous biventricular dysfunction occurred in 14.1% of the individuals. There was no association between dysfunction and the immune status. CONCLUSIONS: diastolic dysfunction occurred, individually or simultaneously, with no association with immune status; decreased myocardial compliance was predominant in the left ventricle, and abnormal relaxation in the right ventricle.

  3. Is hydrotherapy an appropriate form of exercise for elderly patients with biventricular systolic heart failure?

    Institute of Scientific and Technical Information of China (English)

    Bente Grüer Sve(a)v1,; Margareta Scharin T(a)ng,; (A)sa Cider

    2012-01-01

    Hydrotherapy (exercise in warm water) is considered to be a safe and beneficial method to use in the rehabilitation of stable heart failure patients, but there is little information on the effect of the increased venous return and enhanced preload in elderly patients with biventricular heart failure. We present a case of an elderly man who was recruited to participate in a hydrotherapy study. We compared echocardiographic data during warm water immersion with land measurements, and observed increases in stroke volume from 32 mL (land) to 42 mL (water), left ventricular ejection fraction from 22% to 24%, left ventricular systolic velocity from 4.8 cm/s to 5.0 cm/s and left atrioventricular plane displacement from 2.1 mm to 2.2 mm. By contrast, right ventricular systolic velocity decreased from 11.2 cm/s to 8.4 cm/s and right atrioventricular plane displacement from 8.1 mm to 4.7 mm. The tricuspid pressure gradient rose from 18 mmHg on land to 50 mmHg during warm water immersion. Thus, although left ventricular systolic function was relatively unaffected during warm water immersion, we observed a decrease in right ventricular function with an augmented right ventricular pressure. We recommend further investigations to observe the cardiac effect of warm water immersion on patients with biventricular systolic heart failure and at risk of elevated right ventricular pressure.

  4. Is hydrotherapy an appropriate form of exercise for elderly patients with biventricular systolic heart failure?

    Science.gov (United States)

    Sveälv, Bente Grüner; Täng, Margareta Scharin; Cider, Asa

    2012-12-01

    Hydrotherapy (exercise in warm water) is considered to be a safe and beneficial method to use in the rehabilitation of stable heart failure patients, but there is little information on the effect of the increased venous return and enhanced preload in elderly patients with biventricular heart failure. We present a case of an elderly man who was recruited to participate in a hydrotherapy study. We compared echocardiographic data during warm water immersion with land measurements, and observed increases in stroke volume from 32 mL (land) to 42 mL (water), left ventricular ejection fraction from 22% to 24%, left ventricular systolic velocity from 4.8 cm/s to 5.0 cm/s and left atrioventricular plane displacement from 2.1 mm to 2.2 mm. By contrast, right ventricular systolic velocity decreased from 11.2 cm/s to 8.4 cm/s and right atrioventricular plane displacement from 8.1 mm to 4.7 mm. The tricuspid pressure gradient rose from 18 mmHg on land to 50 mmHg during warm water immersion. Thus, although left ventricular systolic function was relatively unaffected during warm water immersion, we observed a decrease in right ventricular function with an augmented right ventricular pressure. We recommend further investigations to observe the cardiac effect of warm water immersion on patients with biventricular systolic heart failure and at risk of elevated right ventricular pressure.

  5. Aspectos técnicos da cateterização do seio coronariano baseada no componente atrial do eletrograma intracavitário e anatomia radiológica durante o procedimento de implante de marcapasso biventricular Technical aspects of coronary sinus catheterization based on the atrial component of the intracavitary electrogram and radiological anatomy during the implantation procedure of a biventricular pacemaker

    Directory of Open Access Journals (Sweden)

    Fernando Sérgio Oliva de Souza

    2006-04-01

    Full Text Available OBJETIVO: Apresentar uma proposição técnica baseada na experiência de 130 implantes utilizando técnica simplificada para cateterização do seio coronariano, baseada no componente atrial do eletrograma intracavi-tário e anatomia radiológica. MÉTODOS: De outubro de 2001 a outubro de 2004 foram realiza-dos 130 implantes de marcapasso biventricular, utilizando-se anatomia radiológica e observação de eletrograma intracavitário, com prioridade ao componente atrial. RESULTADOS: O implante do sistema, utilizando-se a estimulação do ventrículo esquerdo via seio coronariano, não foi possível em 8 pacientes. Em 12 pacientes foram observadas dificuldades na canulação do óstio coronário e em 15 pacientes observaram-se dificuldades de progressão do eletrodo através do seio coronariano. O tempo médio de utilização de radioscopia foi de 18,69 min. CONCLUSÃO: A técnica de implante, utilizando a morfologia do componente atrial do eletrograma intracavitário e anatomia radiológica, demonstrou ser pouco trabalhosa, segura e eficaz para canulação do óstio do seio coronariano, necessitando de reduzido tempo de radioscopia.OBJECTIVE: To present a technical proposal based on the experience of 130 implantations using a simplified technique for coronary sinus catheterization, based on the atrial component of the intracavitary electrogram and radiological anatomy. METHODS: From October, 2001 to October, 2004, 130 biventricular pacemaker implantations were performed, using radiological anatomy and observation of the intracavitary electrogram, focusing on the atrial component. RESULTS: The implantation of the system using left ventricular pacing via coronary sinus was not possible in 8 patients. Difficulties on the cannulation of the coronary ostium were felt in 12 patients and difficulties of lead advancement through the coronary sinus were felt in 15 patients. The mean time of radioscopy utilization was 18.69 min. CONCLUSION: The

  6. Pacing during an ultramarathon running event in hilly terrain

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    Hugo A. Kerhervé

    2016-10-01

    Full Text Available Purpose The dynamics of speed selection as a function of distance, or pacing, are used in recreational, competitive, and scientific research situations as an indirect measure of the psycho-physiological status of an individual. The purpose of this study was to determine pacing on level, uphill and downhill sections of participants in a long (>80 km ultramarathon performed on trails in hilly terrain. Methods Fifteen ultramarathon runners competed in a  173 km event (five finished at  103 km carrying a Global-Positioning System (GPS device. Using the GPS data, we determined the speed, relative to average total speed, in level (LEV, uphill (UH and downhill (DH gradient categories as a function of total distance, as well as the correlation between overall performance and speed variability, speed loss, and total time stopped. Results There were no significant differences in normality, variances or means in the relative speed in 173-km and 103-km participants. Relative speed decreased in LEV, UH and DH. The main component of speed loss occurred between 5% and 50% of the event distance in LEV, and between 5% and 95% in UH and DH. There were no significant correlations between overall performance and speed loss, the variability of speed, or total time stopped. Conclusions Positive pacing was observed at all gradients, with the main component of speed loss occurring earlier (mixed pacing in LEV compared to UH and DH. A speed reserve (increased speed in the last section was observed in LEV and UH. The decrease in speed and variability of speed were more important in LEV and DH than in UH. The absence of a significant correlation between overall performance and descriptors of pacing is novel and indicates that pacing in ultramarathons in trails and hilly terrain differs to other types of running events.

  7. 640 X 480 Pace HgCdTe FPA

    Science.gov (United States)

    Kozlowski, Lester J.; Bailey, Robert B.; Cabelli, Scott A.; Cooper, Donald E.; McComas, Gail D.; Vural, Kadri; Tennant, William E.

    1992-12-01

    A hybrid HgCdTe 640 X 480 infrared (IR) focal plane array (FPA) that meets the sensitivity, resolution, and field-of-view requirements of high-performance medium wavelength infrared (MWIR) imaging systems has been developed. The key technology making this large, high sensitivity device producible is the epitaxial growth of HgCdTe on a CdTe-buffered, sapphire substrate (referred to as PACE, for Producible Alternative to CdTe for Epitaxy; PACE-I refers to sapphire). The device offers TV resolution with excellent sensitivity at temperatures below 120 K. Mean NE(Delta) T as low as 13 mK has been achieved at operating temperatures nonuniformity compensation.

  8. Biventricular noncompaction cardiomyopathy in a patient presenting with new onset seizure: case report.

    Science.gov (United States)

    Odiete, Oghenerukevwe; Nagendra, Ramanna; Lawson, Mark A; Okafor, Henry

    2012-01-01

    Ventricular noncompaction (VNC) of the myocardium is a rare genetic cardiomyopathy caused by a disorder during endocardial morphogenesis and could be accompanied by life-threatening complications. The major clinical manifestations of VNC are heart failure, arrhythmias, and embolic events. The left ventricle is the most commonly reported affected site, but a few cases of right ventricular involvement have also been reported. We report a case of biventricular noncompaction cardiomyopathy in a 31-year-old woman presenting with a new onset seizure. On the second day of her telemetry-monitored hospitalization, she suffered a witnessed ventricular fibrillation arrest requiring emergency direct-current cardioversion and induced hypothermia. Transthoracic echocardiography (TTE) showed isolated left ventricular (LV) noncompaction and depressed LV systolic function. Subsequent cardiac magnetic resonance imaging (MRI) revealed both left and right ventricular noncompaction. This unusual presentation highlights the importance of a complete and thorough evaluation of patients even when presenting with apparently noncardiac symptom(s).

  9. Ventricular Assist Device Support: for Management of Sustained Ventricular Arrhythmias

    OpenAIRE

    2002-01-01

    We describe herein the cases of 2 patients who had ventricular arrhythmias. In one, a short-term biventricular assist device, the ABIOMED BVS 5000, was placed because the patient had sustained ventricular tachycardia and could not be weaned from cardiopulmonary bypass. Excellent hemodynamic support was maintained for several days while the antiarrhythmic therapy was maximized. Sinus rhythm was restored, and the patient was successfully weaned from the ventricular assist device. However, the s...

  10. Surgical implantation of a cardiac resynchronization therapy device in a western lowland gorilla (Gorilla gorilla gorilla) with fibrosing cardiomyopathy.

    Science.gov (United States)

    Rush, Elizabeth Marie; Ogburn, Anna L; Hall, Jeffrey; Rush, Dwain; Lau, Yung; Dillon, A R; Garmon, Linda; Tillson, D M; Kay, G Neal

    2010-09-01

    A 24-yr-old, male western lowland gorilla (Gorilla gorilla gorilla) was diagnosed in March of 2003 with congestive heart failure (CHF). Transesophageal and transthoracic echocardiography demonstrated global left and right ventricular hypokinesia with a left ventricular ejection fraction of 0.20. At the time of diagnosis, the animal exhibited symptoms and signs of CHF with minimal exertion (New York Heart Association class III). Over a 16-mo period, the severity of CHF progressed to class IV (resting signs and symptoms) despite angiotensin-converting enzyme inhibition, beta-blockers, and diuretics. Because of intractable CHF and a QRS duration that was markedly prolonged compared with the normal range for this species, a cardiac resynchronization therapy (CRT) device was implanted using implantation techniques based on human surgical procedures. Placement of the right ventricular, right atrial, and left ventricular leads and pulse generator were accomplished in 5.5 hr. Telemetry of the device postoperatively via wand or remote radio frequency has allowed for noninvasive programming and interrogation. The clinical improvement in CHF with this therapy was immediate and dramatic for this animal. Six months after CRT device implantation, the device leads became dislodged during an altercation with another gorilla, with the rapid development of CHF upon cessation of biventricular pacing. A second procedure to replace the leads returned the gorilla to his previous level of activity. In 2007, the pulse generator was electively replaced for battery depletion with a device capable of remote radiofrequency programming and interrogation. CRT implantation, although requiring specialized equipment and surgical skill, appears to be a viable option for treatment of dilated cardiomyopathy in gorillas.

  11. Benefit of warm water immersion on biventricular function in patients with chronic heart failure

    Directory of Open Access Journals (Sweden)

    Kardassis Dimitris

    2009-07-01

    Full Text Available Abstract Background Regular physical activity and exercise are well-known cardiovascular protective factors. Many elderly patients with heart failure find it difficult to exercise on land, and hydrotherapy (training in warm water could be a more appropriate form of exercise for such patients. However, concerns have been raised about its safety. The aim of this study was to investigate, with echocardiography and Doppler, the acute effect of warm water immersion (WWI and effect of 8 weeks of hydrotherapy on biventricular function, volumes and systemic vascular resistance. A secondary aim was to observe the effect of hydrotherapy on brain natriuretic peptide (BNP. Methods Eighteen patients [age 69 ± 8 years, left ventricular ejection fraction 31 ± 9%, peakVO2 14.6 ± 4.5 mL/kg/min] were examined with echocardiography on land and in warm water (34°C. Twelve of these patients completed 8 weeks of control period followed by 8 weeks of hydrotherapy twice weekly. Results During acute WWI, cardiac output increased from 3.1 ± 0.8 to 4.2 ± 0.9 L/min, LV tissue velocity time integral from 1.2 ± 0.4 to 1.7 ± 0.5 cm and right ventricular tissue velocity time integral from 1.6 ± 0.6 to 2.5 ± 0.8 cm (land vs WWI, p There was no change in the cardiovascular response or BNP after 8 weeks of hydrotherapy. Conclusion Hydrotherapy was well tolerated by all patients. The main observed cardiac effect during acute WWI was a reduction in heart rate, which, together with a decrease in afterload, resulted in increases in systolic and diastolic biventricular function. Although 8 weeks of hydrotherapy did not improve cardiac function, our data support the concept that exercise in warm water is an acceptable regime for patients with heart failure.

  12. Permanent cardiac pacing in pediatric patients.

    Science.gov (United States)

    Lotfy, Wael; Hegazy, Ranya; AbdElAziz, Osama; Sobhy, Rodina; Hasanein, Hossam; Shaltout, Fawzan

    2013-02-01

    Pediatric pacemaker (PM) implants comprise less than 1 % of all PM implants. This study aimed to investigate permanent cardiac pacing among the pediatric population, identifying different indications and complications of pediatric cardiac pacing, especially focusing on the effect of the pacing sites, the PM lead type, and the indications for pacing. The current work is a cross-sectional study of 103 procedures for permanent PM insertion in pediatric patients between January 2001 and December 2010. The patients were followed up 1, 3, and 6 months after implantation, then every 6 months or as needed. Evaluation included routine clinical examination, electrocardiography, chest X-ray, echocardiography, and a full analysis of the pacing system measurements. The ages of the patients ranged from 0.09 to 12 years (median, 2.3 years). The most common indication for pacing was postoperative complete heart bock, noted in 54 patients (52.4 %). Transvenous endocardial PM insertion was performed in 92 procedures (89.3 %), whereas transthoracic epicardial insertion was performed in 11 procedures (10.7 %). The most common site of pacing was the right ventricular apex (n = 64, 62 %), followed by the right ventricular outflow tract (n = 25, 24.3 %). Transthoracic epicardial PM insertion was associated with a significantly higher percentage and greater severity of complications. In this study, 65 % of the patients with left ventricle (LV) dilation before pacing showed a significant improvement in LV dimensions and function after pacing. This was noted only in those with endocardially inserted PM leads in both the congenital and the postoperative groups regardless of the pacing site. Endocardial PM insertion in children is a safe procedure with fewer complications and a lower ventricular threshold than the epicardial route. Permanent single-chamber right ventricle pacing is safe and can lead to significant improvement in LV function and dimensions. However, long-term follow

  13. A novel association of biventricular cardiac noncompaction and diabetic embryopathy: case report and review of the literature.

    Science.gov (United States)

    Woo, Jennifer S; Perez-Rosendahl, Mari; Haydel, Dana; Perens, Gregory; Fishbein, Michael C

    2015-01-01

    Diabetic embryopathy refers to a constellation of congenital malformations arising in the setting of poorly controlled maternal diabetes mellitus. Cardiac abnormalities are the most frequently observed findings, with a 5-fold risk over normal pregnancies. Although a diverse spectrum of cardiac defects has been documented, cardiac noncompaction morphology has not been associated with this syndrome. In this report, we describe a novel case of biventricular cardiac noncompaction in a neonate of a diabetic mother. The patient was a late preterm female with right anotia, caudal dysgenesis, multiple cardiac septal and aortic arch defects, and biventricular cardiac noncompaction. Examination of both ventricles demonstrated spongy myocardium with increased myocardial trabeculation greater than 50% left ventricular thickness and greater than 75% right ventricular thickness, with hypoplasia of the bilateral papillary muscles, consistent with noncompaction morphology. Review of the literature highlights the importance of gene expression and epigenomic regulation in cardiac embryogenesis.

  14. HeartWare third-generation implantable continuous flow pump as biventricular support: mid-term follow-up.

    Science.gov (United States)

    Loforte, Antonio; Monica, Paola Lilla Della; Montalto, Andrea; Musumeci, Francesco

    2011-03-01

    A long-term mechanical biventricular support by HeartWare HVAS third-generation continuous flow pump (HeartWare, Inc, Miramar, FL, USA) was implanted in a Korean patient with a small chest size for treatment of a refractory end-stage heart failure due to an idiopathic dilative cardiomyopathy. We report our experience with a single patient and the early mid-term follow-up results with such a mechanical ventricular support.

  15. Update in cardiac arrhythmias and pacing.

    Science.gov (United States)

    García-Bolao, Ignacio; Ruiz-Mateas, Francisco; Bazan, Victor; Berruezo, Antonio; Alcalde, Oscar; Leal del Ojo, Juan; Acosta, Juan; Martínez Sellés, Manuel; Mosquera, Ignacio

    2015-03-01

    This article discusses the main advances in cardiac arrhythmias and pacing published between 2013 and 2014. Special attention is given to the interventional treatment of atrial fibrillation and ventricular arrhythmias, and on advances in cardiac pacing and implantable cardioverter defibrillators, with particular reference to the elderly patient.

  16. Percutaneously injectable fetal pacemaker: electronics, pacing thresholds, and power budget.

    Science.gov (United States)

    Nicholson, Adriana; Chmait, Ramen; Bar-Cohen, Yaniv; Zheng, Kaihui; Loeb, Gerald E

    2012-01-01

    We are developing a cardiac pacemaker that is designed to be implanted percutaneously into a fetus to treat complete heart block and consequent hydrops fetalis, which is otherwise fatal. One of the most significant considerations for this device is the technical challenges presented by the battery and charging system. The size of the device is limited to about 3 mm in diameter; batteries on this scale have very small charge capacities. The smaller capacity means that the device needs to be designed so that it uses as little current as possible and so that its battery can be recharged wirelessly. We determined the pacing thresholds for a simple relaxation oscillator that can be assembled from discrete, surface mount components and analyzed the power consumption of the device given different electrode configurations and stimulus parameters. An inductive recharging system will be required for some patients; it is feasible within the package constraints and under development.

  17. Pre-ejection period by radial artery tonometry supplements echo doppler findings during biventricular pacemaker optimization

    Directory of Open Access Journals (Sweden)

    Qamruddin Salima

    2011-07-01

    Full Text Available Abstract Background Biventricular (Biv pacemaker echo optimization has been shown to improve cardiac output however is not routinely used due to its complexity. We investigated the role of a simple method involving computerized pre-ejection time (PEP assessment by radial artery tonometry in guiding Biv pacemaker optimization. Methods Blinded echo and radial artery tonometry were performed simultaneously in 37 patients, age 69.1 ± 12.8 years, left ventricular (LV ejection fraction (EF 33 ± 10%, during Biv pacemaker optimization. Effect of optimization on echo derived velocity time integral (VTI, ejection time (ET, myocardial performance index (MPI, radial artery tonometry derived PEP and echo-radial artery tonometry derived PEP/VTI and PEP/ET indices was evaluated. Results Significant improvement post optimization was achieved in LV ET (286.9 ± 37.3 to 299 ± 34.6 ms, p Conclusion An acute shortening of PEP by radial artery tonometry occurs post Biv pacemaker optimization and correlates with improvement in hemodynamics by echo Doppler and may provide a cost-efficient approach to assist with Biv pacemaker echo optimization.

  18. Transferring PACE Assessments Upon Home Sale

    Energy Technology Data Exchange (ETDEWEB)

    National Renewable Energy Laboratory (NREL); Coughlin, Jason; Fuller, Merrian; Zimring, Mark

    2010-04-12

    A significant barrier to investing in renewable energy and comprehensive energy efficiency improvements to homes across the country is the initial capital cost. Property Assessed Clean Energy (PACE) financing is one of several new financial models broadening access to clean energy by addressing this upfront cost issue. Recently, the White House cited PACE programs as an important element of its 'Recovery through Retrofit' plan. The residential PACE model involves the creation of a special clean energy financing district that homeowners elect to opt into. Once opted in, the local government (usually at the city or county level) finances the upfront investment of the renewable energy installation and/or energy efficiency improvements. A special lien is attached to the property and the assessment is paid back as a line item on the property tax bill. As of April 2010, 17 states have passed legislation to allow their local governments to create PACE programs, two already have the authority to set up PACE programs, and over 10 additional states are actively developing enabling legislation. This policy brief analyzes one of the advantages of PACE, which is the transferability of the special assessment from one homeowner to the next when the home is sold. This analysis focuses on the potential for the outstanding lien to impact the sales negotiation process, rather than the legal nature of the lien transfer itself. The goal of this paper is to consider what implications a PACE lien may have on the home sales negotiation process so that it can be addressed upfront rather than risk a future backlash to PACE programs. If PACE programs do expand at a rapid rate, the chances are high that there will be other cases where prospective buyers uses PACE liens to negotiate lower home prices or require repayment of the lien as a condition of sale. As a result, PACE programs should highlight this issue as a potential risk factor for the sake of full disclosure. A good example

  19. Pollution Abatement and Control Expenditures Survey (PACE)

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Pollution Abatement Costs and Expenditures (PACE) survey is the most comprehensive national source of pollution abatement costs and expenditures related to...

  20. Cardiac pacing in pediatrics: Is still the right ventricle the optimal pacing site?

    Directory of Open Access Journals (Sweden)

    Michel Cabrera Ortega

    2015-10-01

    Full Text Available Permanent cardiac pacing is frequently indicated in pediatric patients due to atrioventricular block. Traditionally, the right ventricle has been the pacing site because it is readily accessible, and provides lead stability and optimal chronic pacing thresholds. However, it is associated with a dyssynchrony pattern of ventricular activation, that may cause remodeling and impairment of left ventricular function. In pediatric patients, paced from an early age and with a long life expectancy, the preservation of cardiac function is a premise. Therefore, the prevention of dyssynchrony, using possible alternative sites, is not just a priority, is a challenge. The aim of the article is to show the effects of chronic right ventricular pacing as well as the evidence of benefits provided by alternatives pacing sites in pediatric population and their clinical and practical implications.

  1. Optogenetic pacing in Drosophila melanogaster (Conference Presentation)

    Science.gov (United States)

    Alex, Aneesh; Li, Airong; Men, Jing; Jerwick, Jason; Tanzi, Rudolph E.; Zhou, Chao

    2016-03-01

    A non-invasive, contact-less cardiac pacing technology can be a powerful tool in basic cardiac research and in clinics. Currently, electrical pacing is the gold standard for cardiac pacing. Although highly effective in controlling the cardiac function, the invasive nature, non-specificity to cardiac tissues and possible tissue damage limits its capabilities. Optical pacing of heart is a promising alternative, which is non-invasive and more specific, has high spatial and temporal precision, and avoids shortcomings in electrical stimulation. Optical coherence tomography has been proved to be an effective technique in non-invasive imaging in vivo with ultrahigh resolution and imaging speed. In the last several years, non-invasive specific optical pacing in animal hearts has been reported in quail, zebrafish, and rabbit models. However, Drosophila Melanogaster, which is a significant model with orthologs of 75% of human disease genes, has rarely been studied concerning their optical pacing in heart. Here, we combined optogenetic control of Drosophila heartbeat with optical coherence microscopy (OCM) technique for the first time. The light-gated cation channel, channelrhodopsin-2 (ChR2) was specifically expressed by transgene as a pacemaker in drosophila heart. By stimulating the pacemaker with 472 nm pulsed laser light at different frequencies, we achieved non-invasive and more specific optical control of the Drosophila heart rhythm, which demonstrates the wide potential of optical pacing for studying cardiac dynamics and development. Imaging capability of our customized OCM system was also involved to observe the pacing effect visually. No tissue damage was found after long exposure to laser pulses, which proved the safety of optogenetic control of Drosophila heart.

  2. Synchronization of ventricular fibrillation with electrical pacing guided by optical signals: comparison of pacing locations

    Science.gov (United States)

    Hernandez, Heidy; Hwang, Gyo-Seung; Lin, Shien-Fong

    2006-02-01

    Wavefront synchronization is an important aspect preceding the termination of ventricular fibrillation (VF). We designed a novel approach using multi-electrode pacing that could reduce the energy consumption of successful defibrillation by more than 100-fold. We compared the efficacy of a synchronized pacing algorithm using optical recording-guided pacing at the right ventricle and the posterior left ventricle in isolated rabbit hearts. Two modes of pacing were used in the study. The electrodes were individually controlled (independent mode, ISyncP) or fired together (simultaneous mode, SSyncP) when triggered by tissue polarization at a reference site separate from the pacing sites. The hearts were stained with voltage-sensitive dye and illuminated with laser for epifluorescence imaging during pacing. The number of phase singularities of VF propagation was used to estimate the complexity of VF. A decrease in the number of PS signified a higher degree of VF organization. We found that the pacing algorithm was more effective if the pacing was applied to the posterior left ventricle than to the right ventricle. Pacing in the posterior left ventricle resulted in a 25.3% decrease in the number of PS for ISyncP and a 31% decrease for SSyncP. Pacing in the right ventricle resulted in a 29.0% decrease for ISyncP and a 2.3% increase for SSyncP. The 5mA current reflected a 27.8% decrease for ISyncP and a 32.2% decrease for SSyncP, whereas the 10mA current reflected a 27.2% decrease for ISyncP and a 5.2% increase for SSyncP. We conclude that synchronized pacing can induce VF organization, and the efficacy is higher when pacing in the left ventricle with 5 mA.

  3. The Manipulation of Pace within Endurance Sport

    Science.gov (United States)

    Skorski, Sabrina; Abbiss, Chris R.

    2017-01-01

    In any athletic event, the ability to appropriately distribute energy is essential to prevent premature fatigue prior to the completion of the event. In sport science literature this is termed “pacing.” Within the past decade, research aiming to better understand the underlying mechanisms influencing the selection of an athlete's pacing during exercise has dramatically increased. It is suggested that pacing is a combination of anticipation, knowledge of the end-point, prior experience and sensory feedback. In order to better understand the role each of these factors have in the regulation of pace, studies have often manipulated various conditions known to influence performance such as the feedback provided to participants, the starting strategy or environmental conditions. As with all research there are several factors that should be considered in the interpretation of results from these studies. Thus, this review aims at discussing the pacing literature examining the manipulation of: (i) energy expenditure and pacing strategies, (ii) kinematics or biomechanics, (iii) exercise environment, and (iv) fatigue development. PMID:28289392

  4. Early right ventricular fibrosis and reduction in biventricular cardiac reserve in the dystrophin-deficient mdx heart.

    Science.gov (United States)

    Meyers, Tatyana A; Townsend, DeWayne

    2015-02-15

    Duchenne muscular dystrophy (DMD) is a progressive disease of striated muscle deterioration. Respiratory and cardiac muscle dysfunction are particularly clinically relevant because they result in the leading causes of death in DMD patients. Despite the clinical and physiological significance of these systems, little has been done to understand the cardiorespiratory interaction in DMD. We show here that prior to the onset of global cardiac dysfunction, dystrophin-deficient mdx mice have increased cardiac fibrosis with the right ventricle being particularly affected. Using a novel biventricular cardiac catheterization technique coupled with cardiac stress testing, we demonstrate that both the right and left ventricles have significant reductions in both systolic and diastolic function in response to dobutamine. Unstimulated cardiac function is relatively normal except for a significant reduction in the ventricular pressure transient duration compared with controls. These biventricular analyses also reveal the absence of a dobutamine-induced increase in isovolumic relaxation in the right ventricle of control hearts. Simultaneous assessment of biventricular pressure demonstrates a dobutamine-dependent enhancement of coupling between the ventricles in control mice, which is absent in mdx mice. Furthermore, studies probing the passive-extension properties of the left ventricle demonstrate that the mdx heart is significantly more compliant compared with age-matched C57BL/10 hearts, which have an age-dependent stiffening that is completely absent from dystrophic hearts. These new results indicate that right ventricular fibrosis is an early indicator of the development of dystrophic cardiomyopathy, suggesting a mechanism by which respiratory insufficiency may accelerate the development of heart failure in DMD.

  5. 42 CFR 460.60 - PACE organizational structure.

    Science.gov (United States)

    2010-10-01

    ... planning a change in organizational structure must notify CMS and the State administering agency, in... 42 Public Health 4 2010-10-01 2010-10-01 false PACE organizational structure. 460.60 Section 460... ELDERLY (PACE) PACE Administrative Requirements § 460.60 PACE organizational structure. (a) A...

  6. Optimal pacing for symptomatic AV block: a comparison of VDD and DDD pacing.

    Science.gov (United States)

    Huang, Max; Krahn, Andrew D; Yee, Raymond; Klein, George J; Skanes, Allan C

    2004-01-01

    VDD pacing provides the physiological benefits of atrioventricular synchronous pacing with the convenience of a single lead system, but is hampered by uncertainty regarding long term atrial sensing and potential development of sinus node disease. To examine the long-term reliability and complication rates of VDD pacing, we compared the outcome of 112 consecutive patients (age 70 +/- 13 years, 59% men) with symptomatic AV block who received a single pass bipolar VDD system, to 80 patients (age 63 +/- 16 years, 70% men) who received DDD pacing for the same indication. All patients were judged to have intact sinus node function based on submitted ECGs and monitoring results at the time of implant. Implant time was reduced in VDD patients compared to DDD patients (63 +/- 20 vs 97 +/- 36 minutes, P DDD patients compared to 3 (3%) VDD patients (P = 0.15). The implant P wave was lower with VDD pacing compared to DDD patients (2.91 +/- 1.48 vs 4.0 +/- 1.7 mv, P DDD patients. Physiological atrioventricular activation was maintained in 94%-99% of beats throughout the follow-up period in the VDD group. VDD pacing is an excellent strategy for treatment of patients with symptomatic AV block. The lower cost, high reliability, and abbreviated implantation time suggest that VDD pacing is a viable alternative to DDD pacing in patients with high degree AV block and normal sinus node function.

  7. A Simulation Study of Paced TCP

    Science.gov (United States)

    Kulik, Joanna; Coulter, Robert; Rockwell, Dennis; Partridge, Craig

    2000-01-01

    In this paper, we study the performance of paced TCP, a modified version of TCP designed especially for high delay- bandwidth networks. In typical networks, TCP optimizes its send-rate by transmitting increasingly large bursts, or windows, of packets, one burst per round-trip time, until it reaches a maximum window-size, which corresponds to the full capacity of the network. In a network with a high delay-bandwidth product, however, Transmission Control Protocol's (TCPs) maximum window-size may be larger than the queue size of the intermediate routers, and routers will begin to drop packets as soon as the windows become too large for the router queues. The TCP sender then concludes that the bottleneck capacity of the network has been reached, and it limits its send-rate accordingly. Partridge proposed paced TCP as a means of solving the problem of queueing bottlenecks. A sender using paced TCP would release packets in multiple, small bursts during a round-trip time in which ordinary TCP would release a single, large burst of packets. This approach allows the sender to increase its send-rate to the maximum window size without encountering queueing bottlenecks. This paper describes the performance of paced TCP in a simulated network and discusses implementation details that can affect the performance of paced TCP.

  8. Case report of biventricular pacemaker implantation in a child with heart failure

    Directory of Open Access Journals (Sweden)

    Bockeria L.A.

    2013-03-01

    Full Text Available Heart failure is a complex of signs and symptoms appearing as a result of structural or functional disorders of heart that lead to inhibition of pump function. In newborns it's the heart failure causes death in 90 % of cases. Children with the isolated right ventricular apex cardiac pacing systems are exposed to risk of left ventricular failure due to myocardial dissynchrony caused by chronic pacing of right ventricle. In these patients cardiac resynchronization therapy is used as it favors the improvement of myocardial contractile function, increasing of ejection fraction and synchronous contraction of the left ventricular myocardium. These effects in turn contribute to clinical improvement. In children over 10 kg an endocardial approach is preferable. This method in some cases allows to avoid thoracotomy and general anesthesia. However, in unsuccessful cases or lead dislocation from the coronary sinus (accounts for up to 9 % combined or isolated surgical approaches are used. The former approach is characterized by the left ventricular lead positioned epicardially and other leads are implanted endocardially. The latter approach allows to implant all three pacing leads (atrial, right ventricular and left ventricular leads epicardially during standard operation.

  9. Dual Endothelin Receptor Blockade Abrogates Right Ventricular Remodeling and Biventricular Fibrosis in Isolated Elevated Right Ventricular Afterload.

    Directory of Open Access Journals (Sweden)

    Eva Amalie Nielsen

    Full Text Available Pulmonary arterial hypertension is usually fatal due to right ventricular failure and is frequently associated with co-existing left ventricular dysfunction. Endothelin-1 is a powerful pro-fibrotic mediator and vasoconstrictor that is elevated in pulmonary arterial hypertension. Endothelin receptor blockers are commonly used as pulmonary vasodilators, however their effect on biventricular injury, remodeling and function, despite elevated isolated right ventricular afterload is unknown.Elevated right ventricular afterload was induced by progressive pulmonary artery banding. Seven rabbits underwent pulmonary artery banding without macitentan; 13 received pulmonary artery banding + macitentan; and 5 did not undergo inflation of the pulmonary artery band (sham-operated controls.Right and left ventricular collagen content was increased with pulmonary artery banding compared to sham-operated controls and ameliorated by macitentan. Right ventricular fibrosis signaling (connective tissue growth factor and endothelin-1 protein levels; extra-cellular matrix remodeling (matrix-metalloproteinases 2 and 9, apoptosis and apoptosis-related peptides (caspases 3 and 8 were increased with pulmonary artery banding compared with sham-operated controls and decreased with macitentan.Isolated right ventricular afterload causes biventricular fibrosis, right ventricular apoptosis and extra cellular matrix remodeling, mediated by up-regulation of endothelin-1 and connective tissue growth factor signaling. These pathological changes are ameliorated by dual endothelin receptor blockade despite persistent elevated right ventricular afterload.

  10. Ventricular Assist Device Support

    Science.gov (United States)

    Fasseas, Panayotis; Kutalek, Steven P.; Samuels, Fania L.; Holmes, Elena C.; Samuels, Louis E.

    2002-01-01

    We describe herein the cases of 2 patients who had ventricular arrhythmias. In one, a short-term biventricular assist device, the ABIOMED BVS 5000, was placed because the patient had sustained ventricular tachycardia and could not be weaned from cardiopulmonary bypass. Excellent hemodynamic support was maintained for several days while the antiarrhythmic therapy was maximized. Sinus rhythm was restored, and the patient was successfully weaned from the ventricular assist device. However, the substrate for the arrhythmia persisted, and a recurrence, 1 week later, resulted in the patient's death. In the 2nd patient, the use of an implantable left ventricular assist device was successful in temporarily alleviating the ventricular tachycardia associated with ischemic cardiomyopathy. However, after 2 days of device assistance, the patient experienced a recurrence of the tachycardia, which degenerated into ventricular fibrillation with a marked deterioration in the patient's hemodynamics. The arrhythmia persisted despite multiple attempts at external cardioversion, and internal cardioversion and placement of an automatic implantable cardioverter-defibrillator were necessary. This treatment, along with repeated boluses of amiodarone, led to successful suppression of the arrhythmias, and the patient eventually underwent transplantation. The mechanical hemodynamic support of the circulation by ventricular assist devices was effective in supporting these 2 patients who had sustained ventricular arrhythmias. (Tex Heart Inst J 2002;29:33–6) PMID:11995847

  11. Minimally Invasive Treatment of Biventricular Hydrocephalus Caused by a Giant Basilar Apex Aneurysm via a Staged Combination of Endoscopy and Endovascular Embolization: A Case Report.

    Science.gov (United States)

    Setty, Pradeep; Volkov, Andrey; Richards, Boyd; Barrett, Ryan

    2015-01-01

    Biventricular hydrocephalus caused by a Giant Basilar Apex Aneurysm (GBAA) is a rare finding that presents unique and challenging treatment decisions. We report a case of GBAA causing a life-threatening biventricular hydrocephalus in which both the aneurysm and hydrocephalus were given definitive treatment through a staged, minimally invasive approach. An obtunded 82-year-old male was found to have biventricular hydrocephalus caused by an unruptured GBAA obstructing the foramina of Monro. The patient was treated via staged, minimally invasive technique that first involved endoscopic fenestration of the septum pellucidum to create communication between the lateral ventricles. A programmable ventriculo-peritoneal shunt was then placed with a high-pressure setting. The patient was then loaded with dual anti-platelet therapy prior to undergoing endovascular coiling of the GBAA with adjacent stenting of the Posterior Cerebral Artery. He remained on dual anti-platelet therapy and the shunt setting was lowered at the bedside to treat the hydrocephalus. At 6-month follow up, the patient had returned to his cognitive baseline, speaking fluently and appropriately. Biventricular hydrocephalus caused by a GBAA can successfully be treated in a minimally invasive fashion utilizing a combination of endoscopy and endovascular therapy, even when a stent-assisted coiling is needed.

  12. Self-Paced Instruction: Hello, Education

    Science.gov (United States)

    Leuba, Richard J.; Flammer, Gordon H.

    1975-01-01

    Answers criticisms of self-paced instruction (SPI) by citing advantages of SPI over lecture methods. Concludes that criticisms of SPI are useful since they indicate in which areas further research should be conducted to improve this method of instruction. (MLH)

  13. 42 CFR 460.122 - PACE organization's appeals process.

    Science.gov (United States)

    2010-10-01

    ...) PACE organization's written appeals process. The PACE organization must have a formal written appeals... process must include written procedures for the following: (1) Timely preparation and processing of a... writing. (e) Services furnished during appeals process. During the appeals process, the PACE...

  14. Visual aided pacing in respiratory maneuvers

    Energy Technology Data Exchange (ETDEWEB)

    Rambaudi, L R [Laboratorio de Biofisica y Fisiologia ' Antonio Sadi Frumento' (Argentina); Rossi, E [Catedra de Bioingenieria II (Argentina); Mantaras, M C [Catedra de Bioingenieria II (Argentina); Perrone, M S [Laboratorio de Biofisica y Fisiologia ' Antonio Sadi Frumento' (Argentina); Siri, L Nicola [Catedra de Bioingenieria II (Argentina)

    2007-11-15

    A visual aid to pace self-controlled respiratory cycles in humans is presented. Respiratory manoeuvres need to be accomplished in several clinic and research procedures, among others, the studies on Heart Rate Variability. Free running respiration turns to be difficult to correlate with other physiologic variables. Because of this fact, voluntary self-control is asked from the individuals under study. Currently, an acoustic metronome is used to pace respiratory frequency, its main limitation being the impossibility to induce predetermined timing in the stages within the respiratory cycle. In the present work, visual driven self-control was provided, with separate timing for the four stages of a normal respiratory cycle. This visual metronome (ViMet) was based on a microcontroller which power-ON and -OFF an eight-LED bar, in a four-stage respiratory cycle time series handset by the operator. The precise timing is also exhibited on an alphanumeric display.

  15. Multi-Leu PACE4 Inhibitor Retention within Cells Is PACE4 Dependent and a Prerequisite for Antiproliferative Activity

    Directory of Open Access Journals (Sweden)

    Frédéric Couture

    2015-01-01

    Full Text Available The overexpression as well as the critical implication of the proprotein convertase PACE4 in prostate cancer progression has been previously reported and supported the development of peptide inhibitors. The multi-Leu peptide, a PACE4-specific inhibitor, was further generated and its capability to be uptaken by tumor xenograft was demonstrated with regard to its PACE4 expression status. To investigate whether the uptake of this inhibitor was directly dependent of PACE4 levels, uptake and efflux from cancer cells were evaluated and correlations were established with PACE4 contents on both wild type and PACE4-knockdown cell lines. PACE4-knockdown associated growth deficiencies were established on the knockdown HepG2, Huh7, and HT1080 cells as well as the antiproliferative effects of the multi-Leu peptide supporting the growth capabilities of PACE4 in cancer cells.

  16. Almanac 2013: cardiac arrhythmias and pacing.

    Science.gov (United States)

    Liew, Reginald

    2013-10-01

    Important advances have been made in the past few years in the fields of clinical cardiac electrophysiology and pacing. Researchers and clinicians have a greater understanding of the pathophysiological mechanisms underlying atrial fibrillation (AF), which has transpired into improved methods of detection, risk stratification, and treatments. The introduction of novel oral anticoagulants has provided clinicians with alternative options in managing patients with AF at moderate to high thromboembolic risk and further data has been emerging on the use of catheter ablation for the treatment of symptomatic AF. Another area of intense research in the field of cardiac arrhythmias and pacing is in the use of cardiac resynchronisation therapy (CRT) for the treatment of patients with heart failure. Following the publication of major landmark randomised controlled trials reporting that CRT confers a survival advantage in patients with severe heart failure and improves symptoms, many subsequent studies have been performed to further refine the selection of patients for CRT and determine the clinical characteristics associated with a favourable response. The field of sudden cardiac death and implantable cardioverter defibrillators also continues to be actively researched, with important new epidemiological and clinical data emerging on improved methods for patient selection, risk stratification, and management. This review covers the major recent advances in these areas related to cardiac arrhythmias and pacing.

  17. Temporary emergency pacing-an orphan in district hospitals

    DEFF Research Database (Denmark)

    Gjesdal, Knut; Johansen, Jens Brock; Gadler, Fredrik

    2012-01-01

    This editorial discusses a report on the 1 year experience with temporary pacing, especially in the emergency setting, in several Norwegian district hospitals. The vast majority of the patients received transvenous temporary pacing, and the majority of leads were placed by noncardiologists....... The procedure times were long and complications were frequent. The organization of emergency pacing is discussed, and we suggest that unless qualified physicians can establish transvenous pacing, the patients who need that should be transferred with transcutaneous pacing as back-up during transport...

  18. Enact legislation supporting residential property assessed clean energy financing (PACE)

    Energy Technology Data Exchange (ETDEWEB)

    Saha, Devashree

    2012-11-15

    Congress should enact legislation that supports residential property assessed clean energy (PACE) programs in the nation’s states and metropolitan areas. Such legislation should require the Federal Housing Finance Agency (FHFA) to allow Fannie Mae and Freddie Mac to purchase residential mortgages with PACE assessments while at the same time providing responsible underwriting standards and a set of benchmarks for residential PACE assessments in order to minimize financial risks to mortgage holders. Congressional support of residential PACE financing will improve energy efficiency, encourage job creation, and foster economic growth in the nation’s state and metropolitan areas.

  19. POSTCARDIOTOMY SHOCK - CLINICAL-EVALUATION OF THE BVS-5000 BIVENTRICULAR SUPPORT SYSTEM

    NARCIS (Netherlands)

    GUYTON, RA; SCHONBERGER, JPAM; EVERTS, PAM; JETT, GK; GRAY, LA; GIELCHINSKY, [No Value; RAESS, DH; VLAHAKES, GJ; WOOLLEY, [No Value; GANGAHAR, DM; SOLTANZADEH, H; PICCIONE, WJ; VAUGHN, CC; BOONSTRA, PW; BUCKLEY, MJ

    1993-01-01

    This prospective trial evaluated the safety and efficacy of a new pulsatile, temporary ventricular assist device, the BVS 5000. Patients were eligible for treatment if they were hemodynamically unstable despite maximal pharmacologic and intraaortic balloon pump therapy, were free of concomitant comp

  20. Novel insights on effect of atrioventricular programming of biventricular pacemaker in heart failure – a case series

    Directory of Open Access Journals (Sweden)

    Rafique Asim M

    2006-10-01

    Full Text Available Abstract Background Echocardiography plays an integral role in the diagnosis of congestive heart failure including measurement of left heart pressure as well as mechanical dyssynchrony. Methods In this report we describe novel therapeutic uses of echo pulsed wave Doppler in atrioventricular pacemaker optimization in patients who had either not derived significant symptomatic benefit post biventricular pacemaker implantation or deteriorated after deriving initial benefit. In these patients atrioventricular optimization showed novel findings and improved cardiac output and symptoms. Results In 3 patients with Cheyne Stokes pattern of respiration echo Doppler showed worsening of mitral regurgitation during hyperpneac phase in one patient, marked E and A fusion in another patient and exaggerated ventricular interdependence in a third patient thus highlighting mechanisms of adverse effects of Cheyne Stokes respiration in patients with heart failure. All 3 patients required a very short atrioventricular delay programming for best cardiac output. In one patient with recurrent congestive heart failure post cardiac resynchronization, mitral inflow pulse wave Doppler showed no A wave until a sensed atrioventricular delay of 190 ms was reached and showed progressive improvement in mitral inflow pattern until an atrioventricular delay of 290 ms. In 2 patients atrioventricular delay as short as 50 ms was required to allow E and A separation and prevent diastolic mitral regurgitation. All patients developed marked improvement in congestive heart failure symptoms post echo-guided biv pacemaker optimization. Conclusion These findings highlight the value of echo-guided pacemaker optimization in symptomatic patients post cardiac resynchronization treatment.

  1. Non-invasive cardiac pacing with image-guided focused ultrasound

    Science.gov (United States)

    Marquet, Fabrice; Bour, Pierre; Vaillant, Fanny; Amraoui, Sana; Dubois, Rémi; Ritter, Philippe; Haïssaguerre, Michel; Hocini, Mélèze; Bernus, Olivier; Quesson, Bruno

    2016-11-01

    Currently, no non-invasive cardiac pacing device acceptable for prolonged use in conscious patients exists. High Intensity Focused Ultrasound (HIFU) can be used to perform remote pacing using reversibility of electromechanical coupling of cardiomyocytes. Here we described an extracorporeal cardiac stimulation device and study its efficacy and safety. We conducted experiments ex vivo and in vivo in a large animal model (pig) to evaluate clinical potential of such a technique. The stimulation threshold was determined in 10 different ex vivo hearts and different clinically relevant electrical effects such as consecutive stimulations of different heart chambers with a single ultrasonic probe, continuous pacing or the inducibility of ventricular tachycardia were shown. Using ultrasonic contrast agent, consistent cardiac stimulation was achievable in vivo for up to 1 hour sessions in 4 different animals. No damage was observed in inversion-recovery MR sequences performed in vivo in the 4 animals. Histological analysis revealed no differences between stimulated and control regions, for all ex vivo and in vivo cases.

  2. Ventricular assist device in univentricular heart physiology.

    Science.gov (United States)

    Brancaccio, Gianluca; Gandolfo, Fabrizio; Carotti, Adriano; Amodeo, Antonio

    2013-04-01

    The use of mechanical cardiac assistance is well established as a bridge to orthotopic heart transplantation (OHT) or to recovery for patients with congestive heart failure, however, the experience in single ventricle (SV) physiology is still limited. We report two cases of mechanical assistance in patients with SV physiology: a 2-year old male with hypoplastic left heart syndrome who underwent Norwood Stage I and II followed by HF and a 4-year old female with a univentricular heart who developed a severe right ventricular dysfunction 2 years after a cavopulmonary shunt. Mechanical support utilizing ventricular assist devices (VADs) is considered a valid tool to bridge patients with congestive heart failure to either OHT or to recovery. Increasing experience and improved outcomes utilizing this technology in children with biventricular hearts have led to considering employing these devices in failing SV treatment. We present 2 cases of terminally ill children with SV who were assisted with a VAD.

  3. Effect of atrial pacing therapy with selective pacing algorithms on paroxysmal atrial fibrillation

    Institute of Scientific and Technical Information of China (English)

    潘晓宏; 张雪华; 徐耕; 傅国胜; 单江

    2004-01-01

    @@ Atrial fibrillation (AF) is the most common cardiac arrhythmia among the elderly. Its incidence increases dramatically with increasing age and decreasing left ventricular function, peaking in subjects with overt congestive heart failure.1 Because of the unsatisfactory efficacy and possible serious side effects of clinically available anti-AF drugs for AF patients with sick sinus syndrome, pacing techniques have recently been applied in the treatment of AF. The cardiac pacemaker Vitatron Selection 900E has special AF diagnostic and prophylactic therapy algorithms. The objective of this study was to use the diagnostic information concerning the onset mechanisms of AF to program the preventive pacing algorithms for each patient individually and to find out whether a reduction in AF burden could be achieved.

  4. How do we perceive activity pacing in rheumatology care?

    DEFF Research Database (Denmark)

    Cuperus, N.; Vliet Vlieland, T.; Brodin, N.;

    2015-01-01

    Background: Activity pacing is a recommended non-pharmacological intervention for the management of rheumatic and musculoskeletal diseases in international clinical guidelines. In clinical practice, activity pacing aims at adapting daily activities, and is often an important component of self-management...

  5. PACE3 - front-end chip for the CMS Preshower

    CERN Multimedia

    Aspel, Paul

    2003-01-01

    This is PACE3 which is the front-end chip for the CMS Preshower. In fact PACE3 is the combination of two ASICs called Delta3 and PACEAM3. Delta3 is on the left and PACEAM3 is on the right. The two ASICs are bonded together and then packaged within a single 196 pin fpBGA package.

  6. Is Self-Paced Instruction Really Worth It?

    Science.gov (United States)

    Roberson, J. A.; Crowe, C. T.

    1975-01-01

    Describes a self-paced, learning-for-mastery course in undergraduate fluid mechanics. Includes the method of course assessment, method of student evaluation, and a description of the instructor's role and work load. Summarizes aspects of self-paced instruction considered favorable and unfavorable. (GS)

  7. Atrial-based pacing has no benefit over ventricular pacing in preventing atrial arrhythmias in adults with congenital heart disease

    NARCIS (Netherlands)

    Opic, P.; Yap, S.C.; Kranenburg, M. van; Dijk, A.P.J. van; Budts, W.; Vliegen, H.W.; Erven, L. van; Can, A.; Sahin, G.; Groot, N.M. de; Witsenburg, M.; Roos-Hesselink, J.W.

    2013-01-01

    AIMS: To determine whether atrial-based pacing prevents atrial arrhythmias in adults with congenital heart disease (CHD) compared with ventricular pacing. METHODS AND RESULTS: All adult CHD patients from four participating centres with a permanent pacemaker were identified. Patients with permanent a

  8. A comparison of single-lead atrial pacing with dual-chamber pacing in sick sinus syndrome

    DEFF Research Database (Denmark)

    Nielsen, Jens Cosedis; Thomsen, Poul Erik B; Højberg, Søren

    2011-01-01

    In patients with sick sinus syndrome, bradycardia can be treated with a single-lead pacemaker or a dual-chamber pacemaker. Previous trials have revealed that pacing modes preserving atrio-ventricular synchrony are superior to single-lead ventricular pacing, but it remains unclear if there is any ...

  9. Automatic Mode Switch (AMS Causes Less Synchronization

    Directory of Open Access Journals (Sweden)

    Jorat

    2016-03-01

    Full Text Available Introduction Cardiac resynchronization devices are part of modern heart failure management. After implantation, we analyze and program devices in an attempt to ensure their success. Biventricular pacing should be 98% or more for the lowest mortality and best symptom improvement. Case Presentation In this case series, we present a combination of far field sensing and automatic mode switching (AMS in six patients. It is found that this combination causes ventricular sensing (VS episodes with wide QRS and no synchronization. We turn off the AMS and alleviate the problem. Conclusions Switching AMS off may increase biventricular pacing in some patients.

  10. Pushing the pace of tree species migration.

    Directory of Open Access Journals (Sweden)

    Eli D Lazarus

    Full Text Available Plants and animals have responded to past climate changes by migrating with habitable environments, sometimes shifting the boundaries of their geographic ranges by tens of kilometers per year or more. Species migrating in response to present climate conditions, however, must contend with landscapes fragmented by anthropogenic disturbance. We consider this problem in the context of wind-dispersed tree species. Mechanisms of long-distance seed dispersal make these species capable of rapid migration rates. Models of species-front migration suggest that even tree species with the capacity for long-distance dispersal will be unable to keep pace with future spatial changes in temperature gradients, exclusive of habitat fragmentation effects. Here we present a numerical model that captures the salient dynamics of migration by long-distance dispersal for a generic tree species. We then use the model to explore the possible effects of assisted colonization within a fragmented landscape under a simulated tree-planting scheme. Our results suggest that an assisted-colonization program could accelerate species-front migration rates enough to match the speed of climate change, but such a program would involve an environmental-sustainability intervention at a massive scale.

  11. Altering embryonic cardiac dynamics with optical pacing.

    Science.gov (United States)

    Peterson, L M; McPheeters, M; Barwick, L; Gu, S; Rollins, A M; Jenkins, M W

    2012-01-01

    Several studies have shown that altering blood flow early in development leads to congenital heart defects. In these studies the perturbations to hemodynamics were very gross manipulations (vessel ligation, conotruncal banding, etc.) that would be inappropriate for probing the delicate mechanisms responsible for mechanically-transduced signaling. Also, these perturbations lacked feedback from a monitoring system to determine the exact degree of alteration and the location of its effect. Here, we employed optical pacing (OP) to alter the heart rate in quail embryos and optical coherence tomography (OCT) to measure the resultant shear forces on the endocardium. OP is a new technique utilizing pulsed 1.851 µm infrared laser light to noninvasively capture the heart rate to the pulse frequency of the laser without the use of exogenous agents. To measure shear stress on the endocardium, we extended our previous OCT algorithms to enable the production of 4-D shear maps. 4-D shear maps allowed observation of the spatial and temporal distribution of shear stress. Employing both OCT and OP, we were able to develop perturbation protocols that increase regurgitant flow and greatly modify the oscillatory shear index (OSI) in a region of the heart tube where future valves will develop. Regurgitant flow has been linked with valve development and precise perturbations may allow one to determine the role of hemodynamics in valvulogenesis.

  12. The evolution of pace in popular movies.

    Science.gov (United States)

    Cutting, James E

    2016-01-01

    Movies have changed dramatically over the last 100 years. Several of these changes in popular English-language filmmaking practice are reflected in patterns of film style as distributed over the length of movies. In particular, arrangements of shot durations, motion, and luminance have altered and come to reflect aspects of the narrative form. Narrative form, on the other hand, appears to have been relatively unchanged over that time and is often characterized as having four more or less equal duration parts, sometimes called acts - setup, complication, development, and climax. The altered patterns in film style found here affect a movie's pace: increasing shot durations and decreasing motion in the setup, darkening across the complication and development followed by brightening across the climax, decreasing shot durations and increasing motion during the first part of the climax followed by increasing shot durations and decreasing motion at the end of the climax. Decreasing shot durations mean more cuts; more cuts mean potentially more saccades that drive attention; more motion also captures attention; and brighter and darker images are associated with positive and negative emotions. Coupled with narrative form, all of these may serve to increase the engagement of the movie viewer.

  13. The road to right ventricular septal pacing: techniques and tools.

    Science.gov (United States)

    Mond, Harry G

    2010-07-01

    Prolonged right ventricular (RV) apical pacing is associated with progressive left ventricular dysfunction due to dysynchronous ventricular activation and contraction. RV septal pacing allows a narrower QRS compared to RV apical pacing, which might reflect a more physiological and synchronous ventricular activation. Previous clinical studies, which did not consistently achieve RV septal pacing, were not confirmatory and need to be repeated. This review summarizes the anatomy of the RV septum, the radiographic appearances of pacing leads in the RV, the electrocardiograph correlates of RV septal lead positioning, and the techniques and tools required for implantation of an active-fixation lead onto the RV septum. Using the described techniques and tools, conventional active-fixation leads can now be reliably secured to either the RV outflow tract septum or mid-RV septum with very low complication rates and good long-term performance. Even though physiologic and hemodynamic studies on true RV septal pacing have not been completed, the detrimental effects of long-term RV apical pacing are significant enough to suggest that it is now time to leave the RV apex and secure all RV leads onto the septum.

  14. Pacing: A Concept Analysis of a Chronic Pain Intervention

    Directory of Open Access Journals (Sweden)

    Kathryn Jamieson-Lega

    2013-01-01

    Full Text Available BACKGROUND: The intervention of pacing is regularly recommended for chronic pain patients. However, pacing is poorly defined and appears to be interpreted in varying, potentially contradictory manners within the field of chronic pain. This conceptual lack of clarity has implications for effective service delivery and for researchers’ ability to conduct rigorous study. An examination of the background literature demonstrates that while pacing is often one part of a multidisciplinary pain management program, outcome research is hindered by a lack of a clear and shared definition of this currently ill-defined construct.

  15. Fast Paced, Low Cost Projects at MSFC

    Science.gov (United States)

    Watson-Morgan, Lisa; Clinton, Raymond

    2012-01-01

    What does an orbiting microsatellite, a robotic lander and a ruggedized camera and telescope have in common? They are all fast paced, low cost projects managed by Marshall Space Flight Center (MSFC) teamed with successful industry partners. MSFC has long been synonymous with human space flight large propulsion programs, engineering acumen and risk intolerance. However, there is a growing portfolio/product line within MSFC that focuses on these smaller, fast paced projects. While launching anything into space is expensive, using a managed risk posture, holding to schedule and keeping costs low by stopping at egood enough f were key elements to their success. Risk is defined as the possibility of loss or failure per Merriam Webster. The National Aeronautics and Space Administration (NASA) defines risk using procedural requirement 8705.4 and establishes eclasses f to discern the acceptable risk per a project. It states a Class D risk has a medium to significant risk of not achieving mission success. MSFC, along with industry partners, has created a niche in Class D efforts. How did the big, cautious MSFC succeed on these projects that embodied the antithesis of its heritage in human space flight? A key factor toward these successful projects was innovative industry partners such as Dynetics Corporation, University of Alabama in Huntsville (UAHuntsville), Johns Hopkins Applied Physics Laboratory (JHU APL), Teledyne Brown Engineering (TBE), Von Braun Center for Science and Innovation (VCSI), SAIC, and Jacobs. Fast Affordable Satellite Technology (FastSat HSV01) is a low earth orbit microsatellite that houses six instruments with the primary scientific objective of earth observation and technology demonstration. The team was comprised of Dynetics, UAHuntsvile, SAIC, Goddard Space Flight Center (GSFC) and VCSI with the United States Air Force Space Test Program as the customer. The team completed design, development, manufacturing, environmental test and integration in

  16. Direct His-bundle pacing: present and future.

    Science.gov (United States)

    Deshmukh, Pramod M; Romanyshyn, Mary

    2004-06-01

    Direct His-bundle pacing (DHBP) produces rapid sequential multisite synchronous ventricular activation and, therefore, would be an ideal alternative to right ventricular apical (RVA) pacing. In 54 patients with cardiomyopathy, ejection fraction (EF) 0.23 +/- 0.11, persistent atrial fibrillation, and normal QRS Treppe effect) was investigated. Twelve patients who also received a RVA lead underwent cardiopulmonary testing. After a mean follow-up of 42 months, 29 patients are still alive with EF improving from 0.23 +/- 0.11 to 0.33 +/- 0.15. Functional class improved from 3.5 to 2.2. DP/dt increased at each pacing site (P Treppe effect and increased cardiopulmonary reserve when compared to RVA pacing.

  17. The Pace of Perceivable Extreme Climate Change

    Science.gov (United States)

    Tan, X.; Gan, T. Y.

    2015-12-01

    When will the signal of obvious changes in extreme climate emerge over climate variability (Time of Emergence, ToE) is a key question for planning and implementing measures to mitigate the potential impact of climate change to natural and human systems that are generally adapted to potential changes from current variability. We estimated ToEs for the magnitude, duration and frequency of global extreme climate represented by 24 extreme climate indices (16 for temperature and 8 for precipitation) with different thresholds of the signal-to-noise (S/N) ratio based on projections of CMIP5 global climate models under RCP8.5 and RCP4.5 for the 21st century. The uncertainty of ToE is assessed by using 3 different methods to calculate S/N for each extreme index. Results show that ToEs of the projected extreme climate indices based on the RCP4.5 climate scenarios are generally projected to happen about 20 years later than that for the RCP8.5 climate scenarios. Under RCP8.5, the projected magnitude, duration and frequency of extreme temperature on Earth will all exceed 2 standard deviations by 2100, and the empirical 50th percentile of the global ToE for the frequency and magnitude of hot (cold) extreme are about 2040 and 2054 (2064 and 2054) for S/N > 2, respectively. The 50th percentile of global ToE for the intensity of extreme precipitation is about 2030 and 2058 for S/N >0.5 and S/N >1, respectively. We further evaluated the exposure of ecosystems and human societies to the pace of extreme climate change by determining the year of ToE for various extreme climate indices projected to occur over terrestrial biomes, marine realms and major urban areas with large populations. This was done by overlaying terrestrial, ecoregions and population maps with maps of ToE derived, to extract ToEs for these regions. Possible relationships between GDP per person and ToE are also investigated by relating the mean ToE for each country and its average value of GDP per person.

  18. Effects of gastric pacing on gastric emptying and plasma motilin

    Institute of Scientific and Technical Information of China (English)

    Min Yang; Dian-Chun Fang; Qian-Wei Li; Nian-Xu Sun; Qing-Lin Long; Jian-Feng Sui; Lu Gan

    2004-01-01

    AIM: To invertigate the effects of gastric pacing on gastric emptying and plasma motilin level in a canine model of gastric motility disorders and the correlation between gastric emptying and plasma motilin level.METHODS: Ten healthy Mongrel dogs were divided into:experimental group of six dogs and control group of four dogs. A model of gastric motility disorders was established in the experimental group undergone truncal vagotomy combined with injection of glucagon. Gastric half-emptying time (GEt1/2) was monitored with single photon emission computerized tomography (SPECT), and the half-solid test meal was labeled with an isotope-99m Tc sulfur colloid. Plasma motilin concentration was measured with radioimmunoassay (RIA) kit. Surface gastric pacing at 1.1-1.2 times the intrinsic slow-wave frequency and a superimposed series of high frequency pulses (10-30 Hz) was performed for 45 min daily for a month in conscious dogs.RESULTS: After surgery, GEt1/2 in dogs undergone truncal vagotomy was increased significantly from 56.35±2.99 min to 79.42±l.91 min (P<0.001), but surface gastric pacing markedly accelerated gastric emptying and significantly decreased GEt1/2 to 64,94±l.75 min (P<0.001) in animals undergone vagotomy. There was a significant increase of plasma level of motilin at the phase of IMCⅢ (interdigertive myoelectrical complex, IMCⅢ) in the dogs undergone bilateral truncal vagotomy (baseline vs vagotomy, 184.29±9.81 pg/ml vs 242.09±17,22 pg/ml; P<0.01). But plasma motilin concentration (212.55±11.20 pg/ml; P<0.02) was decreased significantly after a long-term treatment with gastric pacing.Before gastric pacing, GEt1/2 and plasma motilin concentration of the dogs undergone vagotomy showed a positive correlation (r=0.867, P<0.01), but after a long-term gastric pacing, GEt1/2 and motilin level showed a negative correlation (r=-0.733, P<0,04).CONCLUSION: Surface gastric pacing with optimal pacing parameters can improve gastric emptying

  19. Right ventricular pacing: the best site is yet to be defined

    Institute of Scientific and Technical Information of China (English)

    Li ZHOU; Brian Olshansky

    2005-01-01

    @@ The right ventricular (RV) apex is the traditional site to provide stable and reliable chronic ventricular pacing. Interest in alternate site pacing has grown since RV apical pacing has been associated with increased mortality and morbidity compared to normal atrio-ventricular conduction. 1-4 Alternate pacing sites include the RV septum and outflow tract.

  20. T wave alternans during exercise and atrial pacing in humans

    Science.gov (United States)

    Hohnloser, S. H.; Klingenheben, T.; Zabel, M.; Li, Y. G.; Albrecht, P.; Cohen, R. J.

    1997-01-01

    INTRODUCTION: Evidence is accumulating that microvolt T wave alternans (TWA) is a marker of increased risk for ventricular tachyarrhythmias. Initially, atrial pacing was used to elevate heart rate and elicit TWA. More recently, a noninvasive approach has been developed that elevates heart rate using exercise. METHODS AND RESULTS: In 30 consecutive patients with a history of ventricular tachyarrhythmias, the spectral method was used to detect TWA during both atrial pacing and submaximal exercise testing. The concordance rate for the presence or absence of TWA using the two measurement methods was 84%. There was a patient-specific heart rate threshold for the detection of TWA that averaged 100 +/- 14 beats/min during exercise compared with 97 +/- 9 beats/min during right atrial pacing (P = NS). Beyond this threshold, there was a significant and comparable increase in level of TWA with decreasing pacing cycle length and increasing exercise heart rates. CONCLUSIONS: The present study is the first to demonstrate that microvolt TWA can be assessed reliably and noninvasively during exercise stress. There is a patient-specific heart rate threshold beyond which TWA continues to increase with increasing heart rates. Heart rate thresholds for the onset of TWA measured during atrial pacing and exercise stress were comparable, indicating that heart rate alone appears to be the main factor of determining the onset of TWA during submaximal exercise stress.

  1. Cardiac pacing in left bundle branch/ bifascicular block patients

    Directory of Open Access Journals (Sweden)

    Maddali Madan

    2010-01-01

    Full Text Available The primary concern in patients with bifascicular block is the increased risk of progression to complete heart block. Further, an additional first-degree A-V block in patients with bifascicular block or LBBB might increase the risk of block progression. Anesthesia, monitoring and surgical techniques can induce conduction defects and bradyarrhythmias in patients with pre-existing bundle branch block. In the setting of an acute MI, several different types of conduction disturbance may become manifest and complete heart block occurs usually in patients with acute myocardial infarction more commonly if there is pre-existing or new bundle branch block. The question that arises is whether it is necessary to insert a temporary pacing catheter in patients with bifascicular block undergoing anesthesia. It is important that an anesthesiologist should be aware of the indications for temporary cardiac pacing as well as the current recommendations for permanent pacing in patients with chronic bifascicular and trifascicular block. This article also highlights the recent guidelines for temporary transvenous pacing in the setting of acute MI and the different pacing modalities that are available for an anesthesiologist.

  2. Aspectos técnicos da cateterização do seio coronariano baseada no componente atrial do eletrograma intracavitário e anatomia radiológica durante o procedimento de implante de marcapasso biventricular Technical aspects of coronary sinus catheterization based on the atrial component of the intracavitary electrogram and radiological anatomy during the implantation procedure of a biventricular pacemaker

    OpenAIRE

    Fernando Sérgio Oliva de Souza; Nicola Luciano Mortati; Domingo Marcolino Braile; Reinaldo Wilson Vieira; Salomon Ordinola Rojas; Alessandre Caputo Rabelo; Januário Manuel de Souza; Sérgio Almeida de Oliveira

    2006-01-01

    OBJETIVO: Apresentar uma proposição técnica baseada na experiência de 130 implantes utilizando técnica simplificada para cateterização do seio coronariano, baseada no componente atrial do eletrograma intracavi-tário e anatomia radiológica. MÉTODOS: De outubro de 2001 a outubro de 2004 foram realiza-dos 130 implantes de marcapasso biventricular, utilizando-se anatomia radiológica e observação de eletrograma intracavitário, com prioridade ao componente atrial. RESULTADOS: O implante do sistema,...

  3. Optogenetics for in vivo cardiac pacing and resynchronization therapies.

    Science.gov (United States)

    Nussinovitch, Udi; Gepstein, Lior

    2015-07-01

    Abnormalities in the specialized cardiac conduction system may result in slow heart rate or mechanical dyssynchrony. Here we apply optogenetics, widely used to modulate neuronal excitability, for cardiac pacing and resynchronization. We used adeno-associated virus (AAV) 9 to express the Channelrhodopsin-2 (ChR2) transgene at one or more ventricular sites in rats. This allowed optogenetic pacing of the hearts at different beating frequencies with blue-light illumination both in vivo and in isolated perfused hearts. Optical mapping confirmed that the source of the new pacemaker activity was the site of ChR2 transgene delivery. Notably, diffuse illumination of hearts where the ChR2 transgene was delivered to several ventricular sites resulted in electrical synchronization and significant shortening of ventricular activation times. These findings highlight the unique potential of optogenetics for cardiac pacing and resynchronization therapies.

  4. Mechanical Circulatory Support Devices for Pediatric Patients With Congenital Heart Disease.

    Science.gov (United States)

    Chopski, Steven G; Moskowitz, William B; Stevens, Randy M; Throckmorton, Amy L

    2017-01-01

    The use of mechanical circulatory support (MCS) devices is a viable therapeutic treatment option for patients with congestive heart failure. Ventricular assist devices, cavopulmonary assist devices, and total artificial heart pumps continue to gain acceptance as viable treatment strategies for both adults and pediatric patients as bridge-to-transplant, bridge-to-recovery, and longer-term circulatory support alternatives. We present a review of the current and future MCS devices for patients having congenital heart disease (CHD) with biventricular or univentricular circulations. Several devices that are specifically designed for patients with complex CHD are in the development pipeline undergoing rigorous animal testing as readiness experiments in preparation for future clinical trials. These advances in the development of new blood pumps for patients with CHD will address a significant unmet clinical need, as well as generally improve innovation of the current state of the art in MCS technology.

  5. Biventricular Myocardial Noncompaction

    Directory of Open Access Journals (Sweden)

    Onder Ozturk

    2006-01-01

    Full Text Available The isolated noncompacted ventricular myocardium (NCVM, characterized by excessively prominent trabecular meshwork and deep intertrabecular recesses, is seen in the early period of embryogenesis. Clinical manifestations of NCVM are symptoms associated with depressed left ventricular systolic function, with ventricular arrhythmias, and with systemic embolization. Characteristics on echocardiography have been defined as absent coexisting cardiac abnormalities, non-compacted trabecular endocardium with deep endomyocardial spaces, predominant localisation of the trabeculation to mid-lateral, apical and mid-inferior segments, and a colour Doppler evidence of deep perfused intertrabecular recesses. We describe a case of isolated noncompaction of the left and right ventricular myocardium in a 17-year-old man who presented initially with palpitation and syncope.

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

    Science.gov (United States)

    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 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.

  7. In vivo mechanical study of helical cardiac pacing electrode interacting with canine myocardium

    Institute of Scientific and Technical Information of China (English)

    Xiangming Zhang; Nianke Ma; Hualin Fan; Guodong Niu; Wei Yang

    2007-01-01

    Cardiac pacing is a medical device to help human to overcome arrhythmia and to recover the regular beats of heart. A helical configuration of electrode tip is a new type of cardiac pacing lead distal tip. The helical electrode attaches itself to the desired site of heart by screwing its helical tip into the myocardium. In vivo experiments on anesthetized dogs were carried out to measure the acute interactions between helical electrode and myocardium during screw-in and pull-out processes. These data would be helpful for electrode tip design and electrode/myocardium adherence safety evaluation. They also provide reliability data for clinical site choice of human heart to implant and to fix the pacing lead.A special design of the helical tip using strain gauges is instrumented for the measurement of the screw-in and pull-out forces. We obtained the data of screw-in torques and pull-out forces for five different types of helical electrodes at nine designed sites on ten canine hearts. The results indicate that the screw-in torques increased steplike while the torque-time curves presente saw-tooth fashion. The maximum torque has a range of 0.3-1.9N mm. Obvious differences are observed for different types of helical tips and for different test sites.Large pull-out forces are frequently obtained at epicardium of left ventricle and right ventricle lateral wall, and the forces obtained at right ventricle apex and outflow tract of right ventricle are normally small. The differences in pull-out forces are dictated by the geometrical configuration of helix and regional structures of heart muscle.

  8. "Set the Pace": Nutrition Education DVD for Head Start Parents

    Science.gov (United States)

    Adedze, Pascasie; Orr, Robin A.; Chapman-Novakofski, Karen; Donovan, Sharon M.

    2013-01-01

    Childhood overweight remains a major public health problem and innovative nutrition education programs are still needed. Thus, the "Set the Pace" is a nutrition education DVD for Head Start parents which provides visual nutrition education and physical activities to incorporate in their daily routines. (Contains 1 table.)

  9. Entrainment of Activation during Ventricular Fibrillation (VF) by Distributed Pacing.

    Science.gov (United States)

    Gu, Yiping; Moghe, Sachin; Patwardhan, Abhijit

    2002-03-01

    Optical mapping and pacing studies show excitable gaps during VF. This observation supports entrainment of activation by spatially distributed pacing. Such pacing approach would be enhanced by availability of an index of spatio-temporal heterogeneity in activation. We use simulations to demonstrate feasibility of entraining activations and of using spatially averaged coherence as an index of uniformity in activation. We used a Luo-Rudy model to simulate VF in a matrix of 400x400 cells. Stimuli were delivered from 8 rows of electrodes. Trans-membrane voltages from nine locations spanning the entrained area were used to compute 6 time-coherencies. Average of 6 coherencies was used as an index of uniformity of activations. Results showed that when stimuli were delivered at cycle lengths slightly shorter than intrinsic activation intervals, activations during VF could be entrained into a planar pattern. As expected, average coherence was low during native VF and increased during entrainment. Thus, distributed pacing and time-coherence may be used to entrain and modify activation during VF.

  10. Self-Paced Instruction Methods in a Required Sophomore Course.

    Science.gov (United States)

    King, Franklin G.; Hossain, Muhammad A.

    1984-01-01

    Compares a personalized system of instruction (PSI) to the lecture method and linear self-paced instruction (LSPI) of teaching stoichiometry to undergraduate students. Discusses the methods used to assess student achievement which includes: the use of common midterms and final examinations; and modules, mini-courses and mini-course final exams.…

  11. Hardware packet pacing using a DMA in a parallel computer

    Science.gov (United States)

    Chen, Dong; Heidelberger, Phillip; Vranas, Pavlos

    2013-08-13

    Method and system for hardware packet pacing using a direct memory access controller in a parallel computer which, in one aspect, keeps track of a total number of bytes put on the network as a result of a remote get operation, using a hardware token counter.

  12. The pace of shifting climate in marine and terrestrial ecosystems

    DEFF Research Database (Denmark)

    Burrows, Michael T.; Schoeman, David S.; Buckley, Lauren B.

    2011-01-01

    Climate change challenges organisms to adapt or move to track changes in environments in space and time. We used two measures of thermal shifts from analyses of global temperatures over the past 50 years to describe the pace of climate change that species should track: the velocity of climate cha...

  13. 'Human paced' walking: Followers adopt stride time dynamics of leaders

    NARCIS (Netherlands)

    Marmelat, V.C.M.; Delignières, D.; Torre, K.; Beek, P.J.; Daffertshofer, A.

    2014-01-01

    Isochronous cueing is widely used in gait rehabilitation even though it alters the stride-time dynamics toward anti-persistent rather than the persistent, fractal fluctuations characteristic of human walking. In the present experiment we tested an alternative cueing method: pacing by a human. To thi

  14. Design Recommendations for Self-Paced Online Faculty Development Courses

    Science.gov (United States)

    Rizzuto, Melissa

    2017-01-01

    An increased need for self-paced, online professional development opportunities in higher education has emerged from a variety of factors including dispersed geographic locations of faculty, full teaching loads, and institutional evaluation requirements. This article is a report of the examination of the design and evaluation of a self-paced…

  15. 42 CFR 460.180 - Medicare payment to PACE organizations.

    Science.gov (United States)

    2010-10-01

    ... risk adjustment model. (5) CMS may adjust the monthly capitation amount to take into account other... or Federal workers' compensation, any no-fault insurance, or any liability insurance policy or plan, including a self-insured plan, the PACE organization may charge any of the following: (i) The...

  16. Gait coordination after stroke: Benefits of acoustically paced treadmill walking

    NARCIS (Netherlands)

    Roerdink, Melvyn; Lamoth, Claudine J.C.; Kwakkel, Gert; Van Wieringen, Piet C.W.; Beek, Peter J.

    2007-01-01

    Background and Purpose: Gait coordination often is compromised after stroke. The purpose of this study was to evaluate the efficacy of acoustically paced treadmill walking as a method for improving gait coordination in people after stroke. Participants: Ten people after stroke volunteered for the st

  17. Gait coordination after stroke: benefits of acoustically paced treadmill walking.

    NARCIS (Netherlands)

    Roerdink, M.; Lamoth, C.J.; Kwakkel, G.; Wieringen, P.C. van; Beek, P.J.

    2007-01-01

    BACKGROUND AND PURPOSE: Gait coordination often is compromised after stroke. The purpose of this study was to evaluate the efficacy of acoustically paced treadmill walking as a method for improving gait coordination in people after stroke. PARTICIPANTS: Ten people after stroke volunteered for the st

  18. SolarPaces: genealogy of an international research program; SolarPaces: genealogie d`un programme international de recherche

    Energy Technology Data Exchange (ETDEWEB)

    Pharabod, F.; Lede, J. [Centre National de la Recherche Scientifique (CNRS), 75 - Paris (France); Lefevre, P.; D`Humieres, B.; Forget, F.

    1998-07-01

    What are the stakes of SolarPaces, the solar research program of the International Energy Agency (IEA)? The explanations are given by Francais Pharabod and Jacques Lede which analyze the France joining conditions in this program and evoke the industrial repercussions. (O.M.)

  19. "U-Pace" Instruction: Improving Student Success by Integrating Content Mastery and Amplified Assistance

    Science.gov (United States)

    Reddy, Diane M.; Pfeiffer, Heidi M.; Fleming, Raymond; Ports, Katie A.; Pedrick, Laura E.; Barnack-Tavlaris, Jessica L.; Jirovec, Danielle L.; Helion, Alicia M.; Swain, Rodney A.

    2013-01-01

    "U-Pace," an instructional intervention, has potential for widespread implementation because student behavior recorded in any learning management system is used by "U-Pace" instructors to tailor coaching of student learning based on students' strengths and motivations. "U-Pace" utilizes an online learning environment…

  20. Effects of Modality and Pace on Achievement, Mental Effort, and Positive Affect in Multimedia Learning Environments

    Science.gov (United States)

    Izmirli, Serkan; Kurt, Adile Askim

    2016-01-01

    The purpose of the study was to examine the effects of instruction given with different multimedia modalities (written text + animation or narration + animation) on the academic achievement, cognitive load, and positive affect in different paces (learner-paced or system-paced); 97 freshmen university students divided into four groups taught in…

  1. The pace of vocabulary growth helps predict later vocabulary skill.

    Science.gov (United States)

    Rowe, Meredith L; Raudenbush, Stephen W; Goldin-Meadow, Susan

    2012-01-01

    Children vary widely in the rate at which they acquire words--some start slow and speed up, others start fast and continue at a steady pace. Do early developmental variations of this sort help predict vocabulary skill just prior to kindergarten entry? This longitudinal study starts by examining important predictors (socioeconomic status [SES], parent input, child gesture) of vocabulary growth between 14 and 46 months (n = 62) and then uses growth estimates to predict children's vocabulary at 54 months. Velocity and acceleration in vocabulary development at 30 months predicted later vocabulary, particularly for children from low-SES backgrounds. Understanding the pace of early vocabulary growth thus improves our ability to predict school readiness and may help identify children at risk for starting behind.

  2. De pace fidei: de la libertad a la tolerancia

    Directory of Open Access Journals (Sweden)

    Enzo Solari

    2012-01-01

    Full Text Available Este articulo resume las articulaciones fundamentales de De pace fidei, luego de lo cual muestra algunas de sus mejores interpretaciones recientes y plantea ciertas cuestiones que adn merece la pena explorar en aquella obra, particularmente la de su conexión con la filosofia de la libertad del Cusano y la del reflejo ya renacentista que tal filosofia halla en la oratio de Pico della Mirandola.This article summarizes the fundamental reasonings in De pace fidei and goes on to show some of their most relevant recent readings, to finally lay down some questions which are still worth exploring in the cited work, in particular its connection with the philosophy of freedom of the Cusanus and the reflection, with renaissance spirit, which such philosophy finds in the oratio of Pico della Mirandola.

  3. Quantification of biventricular myocardial function using cardiac magnetic resonance feature tracking, endocardial border delineation and echocardiographic speckle tracking in patients with repaired tetralogy of fallot and healthy controls

    Directory of Open Access Journals (Sweden)

    Kempny Aleksander

    2012-05-01

    Full Text Available Abstract Background Parameters of myocardial deformation have been suggested to be superior to conventional measures of ventricular function in patients with tetralogy of Fallot (ToF, but have required non-routine, tagged cardiovascular magnetic resonance (CMR techniques. We assessed biventricular myocardial function using CMR cine-based feature tracking (FT and compared it to speckle tracking echocardiography (STE and to simple endocardial border delineation (EBD. In addition, the relation between parameters of myocardial deformation and clinical parameters was assessed. Methods Overall, 28 consecutive adult patients with repaired ToF (age 40.4 ± 13.3 years underwent standard steady-state-free precession sequence CMR, echocardiography, and cardiopulmonary exercise testing. In addition, 25 healthy subjects served as controls. Myocardial deformation was assessed by CMR based FT (TomTec Diogenes software, CMR based EBD (using custom written software and STE (TomTec Cardiac Performance Analysis software. Results Feature tracking was feasible in all subjects. A close agreement was found between measures of global left (LV and right ventricular (RV global strain. Interobserver agreement for FT and STE was similar for longitudinal LV global strain, but FT showed better inter-observer reproducibility than STE for circumferential or radial LV and longitudinal RV global strain. Reproducibility of regional strain on FT was, however, poor. The relative systolic length change of the endocardial border measured by EBD yielded similar results to FT global strain. Clinically, biventricular longitudinal strain on FT was reduced compared to controls (P 2-slope. Conclusions Although neither the inter-study reproducibility nor accuracy of FT software were investigated, and its inter-observer reproducibility for regional strain calculation was poor, its calculations of global systolic strain showed similar or better inter-oberver reproducibility than those

  4. Alternate Pacing of Border-Collision Period-Doubling Bifurcations.

    Science.gov (United States)

    Zhao, Xiaopeng; Schaeffer, David G

    2007-11-01

    Unlike classical bifurcations, border-collision bifurcations occur when, for example, a fixed point of a continuous, piecewise C1 map crosses a boundary in state space. Although classical bifurcations have been much studied, border-collision bifurcations are not well understood. This paper considers a particular class of border-collision bifurcations, i.e., border-collision period-doubling bifurcations. We apply a subharmonic perturbation to the bifurcation parameter, which is also known as alternate pacing, and we investigate the response under such pacing near the original bifurcation point. The resulting behavior is characterized quantitatively by a gain, which is the ratio of the response amplitude to the applied perturbation amplitude. The gain in a border-collision period-doubling bifurcation has a qualitatively different dependence on parameters from that of a classical period-doubling bifurcation. Perhaps surprisingly, the differences are more readily apparent if the gain is plotted vs. the perturbation amplitude (with the bifurcation parameter fixed) than if plotted vs. the bifurcation parameter (with the perturbation amplitude fixed). When this observation is exploited, the gain under alternate pacing provides a useful experimental tool to identify a border-collision period-doubling bifurcation.

  5. Factors affecting the regulation of pacing: current perspectives

    Directory of Open Access Journals (Sweden)

    Mauger AR

    2014-09-01

    Full Text Available Alexis R Mauger Endurance Research Group, School of Sport and Exercise Sciences, Faculty of Science, University of Kent, Chatham, UK Abstract: During prolonged dynamic and rhythmic exercise, muscular pain and discomfort arises as a result of an increased concentration of deleterious metabolites. Sensed by peripheral nociceptors and transmitted via afferent feedback to the brain, this provides important information regarding the physiological state of the muscle. These sensations ultimately contribute to what is termed "exercise-induced pain". Despite being well recognized by athletes and coaches, and suggested to be integral to exercise performance, this construct has largely escaped attention in experimental work. This perspective article highlights the current understanding of pacing in endurance performance, and the causes of exercise-induced pain. A new perspective is described, which proposes how exercise-induced pain may be a contributing factor in helping individuals to regulate their work rate during exercise and thus provides an important construct in pacing. Keywords: pain, exercise-induced pain, discomfort, exercise performance, self-paced

  6. Unilateral Laryngeal Pacing System and Its Functional Evaluation

    Directory of Open Access Journals (Sweden)

    Taiping Zeng

    2017-01-01

    Full Text Available Goal. To establish a reliable instrumental system for synchronized reactivation of a unilaterally paralyzed vocal fold and evaluate its functional feasibility. Methods. Unilateral vocal fold paralysis model was induced by destruction of the left recurrent laryngeal nerve (RLN in anesthetized dogs. With a micro controller-based electronic system, electromyography (EMG signals from cricothyroid (CT muscle on the ipsilateral side were recorded and used to trigger pacing of paralyzed vocalis muscles. The dynamic movement of vocal folds was continuously monitored using an endoscope, and the opening and closing of the glottis were quantified with customized imaging processing software. Results. The recorded video images showed that left side vocal fold was obviously paralyzed after destructing the RLN. Using the pacing system with feedback triggering EMG signals from the ipsilateral CT muscle, the paralyzed vocal fold was successfully reactivated, and its movement was shown to be synchronized with the healthy side. Significance. The developed unilateral laryngeal pacing system triggered by EMG from the ipsilateral side CT muscle could be successfully used in unilateral vocal fold paralysis with the advantage of avoiding disturbance to the healthy side muscles.

  7. Combined obliquity and precession pacing of late Pleistocene deglaciations.

    Science.gov (United States)

    Huybers, Peter

    2011-12-08

    Milankovitch proposed that Earth resides in an interglacial state when its spin axis both tilts to a high obliquity and precesses to align the Northern Hemisphere summer with Earth's nearest approach to the Sun. This general concept has been elaborated into hypotheses that precession, obliquity or combinations of both could pace deglaciations during the late Pleistocene. Earlier tests have shown that obliquity paces the late Pleistocene glacial cycles but have been inconclusive with regard to precession, whose shorter period of about 20,000 years makes phasing more sensitive to timing errors. No quantitative test has provided firm evidence for a dual effect. Here I show that both obliquity and precession pace late Pleistocene glacial cycles. Deficiencies in time control that have long stymied efforts to establish orbital effects on deglaciation are overcome using a new statistical test that focuses on maxima in orbital forcing. The results are fully consistent with Milankovitch's proposal but also admit the possibility that long Southern Hemisphere summers contribute to deglaciation.

  8. Tropical birds have a slow pace of life.

    Science.gov (United States)

    Wiersma, Popko; Muñoz-Garcia, Agustí; Walker, Amy; Williams, Joseph B

    2007-05-29

    Tropical birds are relatively long-lived and produce few offspring, which develop slowly and mature relatively late in life, the slow end of the life-history axis, whereas temperate birds lie at the opposite end of this continuum. We tested the hypothesis that tropical birds have evolved a reduced basal metabolic rate (BMR). We measured BMR of 69 species of tropical birds, the largest data set amassed on metabolic rates of tropical birds, and compared these measurements with 59 estimates of BMR for temperate birds. Our analyses included conventional least squares regression, regressions based on phylogenetic independent contrasts, and a comparison of BMR of 13 phylogenetically matched pairs, one species from the tropics and one from northerly temperate areas. Our triptych showed that tropical birds had a reduced BMR, compelling evidence for a connection between the life history of tropical birds and a slow pace of life. Further, tropical migrants breeding in temperate habitats had a lower BMR than did temperate residents, suggesting that these migrants have physiological traits consistent with a slow pace of life. In addition, we determined that tropical birds had a lower cold-induced peak metabolic rate and thermogenic metabolic scope than temperate species, a finding that is consistent with the hypothesis that their environment has not selected for high levels of thermogenesis, or alternatively, that a slow pace of life may be incompatible with high thermogenic capacity. We conclude that physiological function correlates with the suite of life-history traits.

  9. Functional atrial undersensing associated with switching to a tracking mode of pacing.

    Science.gov (United States)

    Barold, S Serge; Van Heuverswyn, Frederic; Timmers, Liesbeth; Stroobandt, Roland X

    2012-10-01

    We have previously demonstrated that contemporary St. Jude devices (pacemakers and implantable cardioverter-defibrillators [ICDs]; St. Jude Medical, Sylmar, CA, USA) are designed to generate an extended postventricular atrial refractory period (PVARP) of 475 ms at the termination of conventional automatic mode switching (AMS) in response to atrial tachyarrhythmias . This response may cause functional atrial undersensing . A similar PVARP response unrelated to conventional AMS was found in four St. Jude devices (three ICDs and one pacemaker) whenever a nontracking pacing mode switched to a tracking DDD(R) mode. PVARP extension and functional atrial undersensing were observed when the VOO, VVI, and the DDI(R) modes (unrelated to conventional AMS) switched to the DDD(R) mode . In one patient the switch from the OOO mode (in the programmed noise reversion mode) to the DDD mode occurred after cessation of electromagnetic interference disturbing the ventricular channel. In this case PVARP extension was seen only in the corresponding markers because no P waves occurred coincidentally with the extended PVARP. The PVARP extension caused by a mode switch to the tracking function was designed to prevent sensing of a retrograde P wave on the first cycle of the reestablished tracking mode. The observed functional atrial undersensing is a normal manifestation of device function and must not be misinterpreted as a true atrial undersensing problem.

  10. 单纯左心室起搏与双心室起搏治疗心力衰竭伴宽QRS波疗效比较的Meta分析%Comparing of left ventricular pacing and biventricular pacing in patients with heart failure and wide QRS ;complex:a Meta-analysis

    Institute of Scientific and Technical Information of China (English)

    耿金; 张荣林; 马树人

    2013-01-01

    Objective To provid the evidence of non-inferiority of LVP compared to BVP in patients with heart failure and wide QRS complex. Methods The Pubmed, EMBASE and CNKI were searched for controlled trials on LVP versus BVP published from 2000 to 2013. Revman 5.1 were used to perform this meta-analysis and the main outcomes were left ventricular ejection fraction (LVEF), left ventricular end-systolic volume (LVESV), left ventricular end-diastolic dimension (LVEDD). Results 7 studies were included, and we got 742 patients with heart failure and wide QRS complex. Meta-analysis demonstrated that LVP was similar to BVP in LVEF(WMD -0.54, 95%CI -1.80 to 0.73, P=0.40),LVESV(WMD 1.39, 95%CI -8.96 to 11.74, P=0.79) and LVEDD(WMD 1.42, 95%CI -0.38 to 3.23, P=0.12). Conclusion LVP is similar to BVP on either LV systolic function or LV reverse remodeling in patients with heart failure and wide QRS complex.%目的:比较单纯左心室起搏(LVP)和双心室起搏(BVP)在窦性心律合并宽QRS波的慢性心力衰竭患者中的疗效。方法在Pubmed、EMBASE、中国知网数据库中检索2000年至2013年6月发表的比较LVP与BVP治疗心力衰竭患者的对照研究,并应用Revman 5.1对其进行Meta分析,分析的主要事件为随访结束后的左心室射血分数、左心室收缩末容积及左心室舒张末内径。结果7项研究最终入组,包括742例心力衰竭合并宽QRS波的患者。Meta分析显示LVP和BVP在左心室射血分数(WMD -0.54,95%CI -1.80~0.73,P=0.40)、左心室收缩末容积(WMD 1.39,95%CI -8.96~11.74,P=0.79)及左心室舒张末内径(WMD 1.42,95%CI -0.38~3.23,P=0.12)的疗效差异无统计学意义。结论对于窦性心律、宽QRS波的心力衰竭患者,LVP在左心室功能及心肌逆重构方面可取得与BVP相当的治疗效果。

  11. One step behind to step ahead – femoral approach to stabilize and to extract functional pacing lead to regain venous access

    OpenAIRE

    Maciąg, Aleksander; Syska, Paweł; Kuśmierski, Krzysztof; Broy, Beata; Sterliński, Maciej

    2013-01-01

    Transvenous lead extraction can be a method to regain venous access. We present the case of a man, aged 67, with indications to upgrade an ICD to a resynchronization therapy device. Since innominate vein occlusion was diagnosed and extraction of an abandoned ventricular pacing lead did not provide lumen regain, a functional atrial lead was extracted with the femoral approach to stabilization and venous access was regained. Asymptomatic vein wall damage but no other complications were recorded...

  12. Pajarito Aerosol Couplings to Ecosystems (PACE) Field Campaign Report

    Energy Technology Data Exchange (ETDEWEB)

    Dubey, M [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-03-01

    Laboratory (LANL) worked on the Pajarito Aerosol Couplings to Ecosystems (PACE) intensive operational period (IOP). PACE’s primary goal was to demonstrate routine Mobile Aerosol Observing System (MAOS) field operations and improve instrumental and operational performance. LANL operated the instruments efficiently and effectively with remote guidance by the instrument mentors. This was the first time a complex suite of instruments had been operated under the ARM model and it proved to be a very successful and cost-effective model to build upon.

  13. Acute impact of pacing at different cardiac sites on left ventricular rotation and twist in dogs.

    Directory of Open Access Journals (Sweden)

    Zhi-Wen Zhou

    Full Text Available We evaluated the acute impact of different cardiac pacing sites on two-dimensional speckle-tracking echocardiography (STE derived left ventricular (LV rotation and twist in healthy dogs.Twelve dogs were used in this study. The steerable pacing electrodes were positioned into right heart through the superior or inferior vena cava, into LV through aorta across the aortic valve. The steerable pacing electrodes were positioned individually in the right atrium (RA, right ventricular apex (RVA, RV outflow tract (RVOT, His bundle (HB, LV apex (LVA and LV high septum (LVS, individual pacing mode was applied at 10 minutes interval for at least 5 minutes from each position under fluoroscopy and ultrasound guidance and at stabilized hemodynamic conditions. LV short-axis images at the apical and basal levels were obtained during sinus rhythm and pacing. Offline STE analysis was performed. Rotation, twist, time to peak rotation (TPR, time to peak twist (TPT, and apical-basal rotation delay (rotational synchronization index, RSI values were compared at various conditions. LV pressure was monitored simultaneously.Anesthetic death occurred in 1 dog, and another dog was excluded because of bad imaging quality. Data from 10 dogs were analyzed. RVA, RVOT, HB, LVA, LVS, RARV (RA+RVA pacing resulted in significantly reduced apical and basal rotation and twist, significantly prolonged apical TPR, TPT and RSI compared to pre-pacing and RA pacing (all P<0.05. The apical and basal rotation and twist values were significantly higher during HB pacing than during pacing at ventricular sites (all P<0.05, except basal rotation at RVA pacing. The apical TPR during HB pacing was significantly shorter than during RVOT and RVA pacing (both P<0.05. The LV end systolic pressure (LVESP was significantly lower during ventricular pacing than during pre-pacing and RA pacing.Our results show that RA and HB pacing results in less acute reduction on LV twist, rotation and LVESP compared

  14. ECG Database Applicable for Development and Testing of Pace Detection Algorithms

    Directory of Open Access Journals (Sweden)

    Irena Jekova

    2014-12-01

    Full Text Available This paper presents an ECG database, named 'PacedECGdb' (available at http://biomed.bas.bg/bioautomation/2014/vol_18.4/files/PacedECGdb.zip, which contains different arrhythmias generated by HKP (Heidelberger Praxisklinik simulator, combined with artificially superimposed pacing pulses that cover the wide ranges of rising edge (from <10 µs to 100 µs and total pulse durations (from 100 µs to 2 ms and correspond to various pacemaker modes. It involves a total number of 1404 recordings - 780 representing 'pure' ECG with pacing pulses and 624 that comprise paced ECGs corrupted by tremor. The signals are recorded with 9.81 µV/LSB amplitude resolution at 128 kHz sampling rate in order to preserve the steep raising and trailing edges of the pace pulses. To the best of our knowledge, 'PacedECGdb' is the first publicly available paced ECG database. It could be used for development and testing of methods for pace detection in the ECG. The existence of ECGs corrupted by tremor (the only physiological noise that could compromise the methods for pacing pulses detection is an advantage, since such signals could be applied to define the signal-to-noise level for correct operation of the algorithm, or for improvement of the noise immunity of a method that is under development. The open access of the database makes it suitable for comparative studies including different algorithms.

  15. Ventricular assist device support for management of sustained ventricular arrhythmias.

    Science.gov (United States)

    Fasseas, Panayotis; Kutalek, Steven P; Samuels, Fania L; Holmes, Elena C; Samuels, Louis E

    2002-01-01

    We describe herein the cases of 2 patients who had ventricular arrhythmias. In one, a short-term biventricular assist device, the ABIOMED BVS 5000, was placed because the patient had sustained ventricular tachycardia and could not be weaned from cardiopulmonary bypass. Excellent hemodynamic support was maintained for several days while the antiarrhythmic therapy was maximized. Sinus rhythm was restored, and the patient was successfully weaned from the ventricular assist device. However, the substrate for the arrhythmia persisted, and a recurrence, 1 week later, resulted in the patient's death. In the 2nd patient, the use of an implantable left ventricular assist device was successful in temporarily alleviating the ventricular tachycardia associated with ischemic cardiomyopathy. However, after 2 days of device assistance, the patient experienced a recurrence of the tachycardia, which degenerated into ventricular fibrillation with a marked deterioration in the patient's hemodynamics. The arrhythmia persisted despite multiple attempts at external cardioversion, and internal cardioversion and placement of an automatic implantable cardioverter-defibrillator were necessary. This treatment, along with repeated boluses of amiodarone, led to successful suppression of the arrhythmias, and the patient eventually underwent transplantation. The mechanical hemodynamic support of the circulation by ventricular assist devices was effective in supporting these 2 patients who had sustained ventricular arrhythmias.

  16. Fusion beat in patients with heart failure treated with left ventricular pacing: may ECG morphology relate to mechanical synchrony? A pilot study

    Directory of Open Access Journals (Sweden)

    Sassone Biagio

    2008-01-01

    Full Text Available Abstract Background Electrical fusion between left ventricular pacing and spontaneous right ventricular activation is considered the key to resynchronisation in sinus rhythm patients treated with single-site left ventricular pacing. Aim Use of QRS morphology to optimize device programming in patients with heart failure (HF, sinus rhythm (SR, left bundle branch block (LBBB, treated with single-site left ventricular pacing. Methods and Results We defined the "fusion band" (FB as the range of AV intervals within which surface ECG showed an intermediate morphology between the native LBBB and the fully paced right bundle branch block patterns. Twenty-four patients were enrolled. Echo-derived parameters were collected in the FB and compared with the basal LBBB condition. Velocity time integral and ejection time did not improve significantly. Diastolic filling time, ejection fraction and myocardial performance index showed a statistically significant improvement in the FB. Interventricular delay and mitral regurgitation progressively and significantly decreased as AV delay shortened in the FB. The tissue Doppler asynchrony index (Ts-SD-12-ejection showed a non significant decreasing trend in the FB. The indications provided by the tested parameters were mostly concordant in that part of the FB corresponding to the shortest AV intervals. Conclusion Using ECG criteria based on the FB may constitute an attractive option for a safe, simple and rapid optimization of resynchronization therapy in patients with HF, SR and LBBB.

  17. Presence of notched QRS on paced electrocardiographs as a predictor of poor response to cardiac resynchronization therapy

    Institute of Scientific and Technical Information of China (English)

    Wang Jiayu; Zhang Ping; Li Xuebin; Zhu Tiangang; Li Hua; Wang Long; Li Ding

    2014-01-01

    Background Cardiac resynchronization therapy (CRT) on patients with advanced and refractory heart failure has made remarkable progress.Clinically,notched QRS (nQRS) is commonly seen on electrocardiographs (ECGs) with bundle branch block morphology and on paced ECGs after implantation of a CRT device,which may reflect the heterogeneity of ventricular myocardial depolarization and electrical activity.The aim of this study was to determine whether patients with more nQRS myocardial segments on paced ECGs had a worse response to CRT than patients with fewer nQRS myocardial segments.Methods We prospectively enrolled 56 patients of CRT with chronic heart failure from People's Hospital affiliated to Peking University from January 2007 to October 2013.Based on nQRS segments on ECGs before CRT,we allocated them to two groups:fewer nQRS (<2) myocardial segments (lateral,inferior,anterior segments) group (F-nQRS,G1,n=23) and more nQRS (≥2) myocardial segments group (M-nQRS,G2,n=33).Then according to nQRS segments on ECGs after CRT,we divided them into two groups similarly:fewer nQRS (<2) myocardial segments group (G3,n=24) and more nQRS (≥2) myocardial segments group (G4,n=32).This study was approved by the ethics committee of People's Hospital.Results At 6 months in the baseline-ECG group,there was a greater absolute increase in left ventricular ejection fraction (LVEF) in G2 than in G1 ((11.5±8.9)% vs.(5.5±10.4)%,P=0.023),with the incidence of nonresponse lower in G2than in G1 (9.1% vs.39.1%,P=0.018).In the paced-ECG group,the absolute increase in LVEF was less in G4 than in G3 ((6.4±8.8)% vs.(12.5±10.4)%,P=0.024) and the incidence of nonresponse was higher in G4 than in G3 (31.3% vs.8.3%,P=0.039).Multivariate analysis showed that fewer nQRS (<2) myocardial segments on paced ECGs (odds ratio 13.920) was a predictor of positive response to CRT.Conclusion nQRS ≥2 myocardial segments (lateral,inferior,anterior) on paced ECGs may predict a poor

  18. Paced QRS duration and myocardial scar amount: predictors of long-term outcome of right ventricular apical pacing.

    Science.gov (United States)

    Lee, Seung-Ah; Cha, Myung-Jin; Cho, Youngjin; Oh, Il-Young; Choi, Eue-Keun; Oh, Seil

    2016-07-01

    Long-term right ventricular apical pacing (RVAP) is reportedly associated with heart failure (HF) development. However, the predictors of pacing-induced HF (PHF) remained unclear. We retrospectively enrolled 234 patients without structural heart disease who underwent a permanent pacemaker implantation with RVAP between 1982 and 2004. RVAP-induced HF was defined as left ventricular ejection fraction decrease >5 % with HF symptom without other HF development etiology. The QRS duration of a paced beat (pQRSd) and myocardial scar score were analyzed from each patient's 12-lead ECG. During a mean 15.6 years (range 3.3-30.0 years), 48 patients (20.5 %) patients developed RVAP-induced HF. The PHF group patients had a longer pQRSd (192.4 ± 13.5 vs. 175.7 ± 14.7 ms in non-PHF patients, p scar score (5.2 ± 1.9 vs. 2.7 ± 1.9, respectively p scar score (HR 1.23, 95 % CI 1.03-1.49, p = 0.037), and a higher percentage of ventricular pacing (HR 1.31, 95 % CI 1.01-1.49, p = 0.010) were independent predictors of PHF. Based on the results of the receiver-operating characteristic (ROC) curve, the pQRSd cutoff was 185 ms (AUC 0.79, sensitivity 66.7 %, specificity 76.3 %) and myocardial scar score cutoff value was 4 (AUC 0.81, sensitivity 81.3 %, specificity 66.1 %). The pQRSd was positively correlated with scar score (r = 0.70, p scar score ≥4 might be independent long-term prognostic markers of PHF.

  19. Pilot trial of an age-paced parenting newsletter.

    Science.gov (United States)

    Keane, Brigid; Waterston, Tony; McConachie, Helen; Towner, Elizabeth; Cook, Margaret; Birks, Eileen

    2005-10-01

    Supporting parents in the first three years of a child's life has the potential to produce successful outcomes. Present government initiatives such as Sure Start focus on this age group. An American educational intervention, in the style of a monthly newsletter, was adapted for use in the UK for parents of young children. Topics were presented in an easy-to-read format and focused on infant emotional development, parent interaction and play. Newsletters, called Baby Express were posted at monthly intervals to the family home providing age-paced information which could meet the specific needs of parents at that stage of their child's life. The aim of the study was to determine the applicability of the newsletter to UK parents and evaluate their satisfaction. Sixty home-based interviews were conducted and 95 per cent of mothers reported reading all or part of the newsletter. Changes in parenting style were spontaneously reported by 28 per cent of mothers. This study found that an aged-paced parenting newsletter was an acceptable and useful method of supporting parents in the early months of a child's life and promotes positive changes in parenting behaviour.

  20. Self-paced model learning for robust visual tracking

    Science.gov (United States)

    Huang, Wenhui; Gu, Jason; Ma, Xin; Li, Yibin

    2017-01-01

    In visual tracking, learning a robust and efficient appearance model is a challenging task. Model learning determines both the strategy and the frequency of model updating, which contains many details that could affect the tracking results. Self-paced learning (SPL) has recently been attracting considerable interest in the fields of machine learning and computer vision. SPL is inspired by the learning principle underlying the cognitive process of humans, whose learning process is generally from easier samples to more complex aspects of a task. We propose a tracking method that integrates the learning paradigm of SPL into visual tracking, so reliable samples can be automatically selected for model learning. In contrast to many existing model learning strategies in visual tracking, we discover the missing link between sample selection and model learning, which are combined into a single objective function in our approach. Sample weights and model parameters can be learned by minimizing this single objective function. Additionally, to solve the real-valued learning weight of samples, an error-tolerant self-paced function that considers the characteristics of visual tracking is proposed. We demonstrate the robustness and efficiency of our tracker on a recent tracking benchmark data set with 50 video sequences.

  1. Social Interaction in Self-paced Distance Education

    Directory of Open Access Journals (Sweden)

    Terry Anderson

    2015-02-01

    Full Text Available In this paper we present a case study of a self-paced university course that was originally designed to support independent, self-paced study at distance. We developed a social media intervention, in design-based research terms, that allows these independent students to contribute archived content to enhance the course, to engage in discussions with other students and to share as little or as much personal information with each other as they wished. We describe the learning design for the intervention and present survey data of student and tutor perception of value and content analysis of the archived contributions. The results indicate that the intervention was positively received by tutors and by the majority (but not all students and that the archive created by the students’ contributions was adding value to the course. We conclude that the intervention was a modest, yet manageable example of a learning enhancement to a traditional cognitive-behavioral, course that has positive impact and potential with little negative impact on workload.

  2. Data reproducibility of pace strategy in a laboratory test run

    Science.gov (United States)

    de França, Elias; Xavier, Ana Paula; Hirota, Vinicius Barroso; Côrrea, Sônia Cavalcanti; Caperuto, Érico Chagas

    2016-01-01

    This data paper contains data related to a reproducibility test for running pacing strategy in an intermittent running test until exhaustion. Ten participants underwent a crossover study (test and retest) with an intermittent running test. The test was composed of three-minute sets (at 1 km/h above Onset Blood Lactate Accumulation) until volitional exhaustion. To assess pace strategy change, in the first test participants chose the rest time interval (RTI) between sets (ranging from 30 to 60 s) and in the second test the maximum RTI values were either the RTI chosen in the first test (maximum RTI value), or less if desired. To verify the reproducibility of the test, rating perceived exertion (RPE), heart rate (HR) and blood plasma lactate concentration ([La]p) were collected at rest, immediately after each set and at the end of the tests. As results, RTI, RPE, HR, [La]p and time to exhaustion were not statistically different (p>0.05) between test and retest, as well as they demonstrated good intraclass correlation. PMID:27081672

  3. Pacing a data transfer operation between compute nodes on a parallel computer

    Science.gov (United States)

    Blocksome, Michael A.

    2011-09-13

    Methods, systems, and products are disclosed for pacing a data transfer between compute nodes on a parallel computer that include: transferring, by an origin compute node, a chunk of an application message to a target compute node; sending, by the origin compute node, a pacing request to a target direct memory access (`DMA`) engine on the target compute node using a remote get DMA operation; determining, by the origin compute node, whether a pacing response to the pacing request has been received from the target DMA engine; and transferring, by the origin compute node, a next chunk of the application message if the pacing response to the pacing request has been received from the target DMA engine.

  4. Aspectos técnicos da cateterização do seio coronariano baseada no componente atrial do eletrograma intracavitário e anatomia radiológica durante o procedimento de implante de marcapasso biventricular

    OpenAIRE

    Souza, Fernando Sérgio Oliva de; Mortati,Nicola Luciano; Braile, Domingo Marcolino; Vieira, Reinaldo Wilson; Rojas,Salomon Ordinola; Rabelo,Alessandre Caputo; SOUZA Januário Manuel de; Sérgio Almeida de OLIVEIRA

    2006-01-01

    OBJETIVO: Apresentar uma proposição técnica baseada na experiência de 130 implantes utilizando técnica simplificada para cateterização do seio coronariano, baseada no componente atrial do eletrograma intracavi-tário e anatomia radiológica. MÉTODOS: De outubro de 2001 a outubro de 2004 foram realiza-dos 130 implantes de marcapasso biventricular, utilizando-se anatomia radiológica e observação de eletrograma intracavitário, com prioridade ao componente atrial. RESULTADOS: O implante do sistema,...

  5. Coronary grafts flow and cardiac pacing modalities: how to improve perioperative myocardial perfusion.

    LENUS (Irish Health Repository)

    D'Ancona, Giuseppe

    2012-02-03

    OBJECTIVE: Aim of this study was to investigate modifications of coronary grafts flow during different pacing modalities after CABG. MATERIALS AND METHODS: Two separate prospective studies were conducted in patients undergoing CABG and requiring intraoperative epicardial pacing. In a first study (22 patients) coronary grafts flows were measured during dual chamber pacing (DDD) and during ventricular pacing (VVI). In a second study (10 patients) flows were measured during DDD pacing at different atrio-ventricular (A-V) delay periods. A-V delay was adjusted in 25 ms increments from 25 to 250 ms and flow measurements were performed for each A-V delay increment. A transit time flowmeter was used for the measurements. RESULTS: An average of 3.4 grafts\\/patient were performed. In the first study, average coronary graft flow was 47.4+\\/-20.8 ml\\/min during DDD pacing and 41.8+\\/-18.2 ml\\/min during VVI pacing (P = 0.0004). Furthermore average systolic pressure was 94.3+\\/-10.1 mmHg during DDD pacing and 89.6+\\/-12.2 mmHg during VVV pacing (P = 0.0007). No significant differences in diastolic pressure were recorded during the two different pacing modalities. In the second study, maximal flows were achieved during DDD pacing with an A-V delay of 175 ms (54+\\/-9.6 ml\\/min) and minimal flows were detected at 25 ms A-V delay (38.1+\\/-4.7 ml\\/min) (P=ns). No significant differences in systolic or diastolic blood pressure were noticed during the different A-V delays. CONCLUSION: Grafts flowmetry provides an extra tool to direct supportive measures such as cardiac pacing after CABG. DDD mode with A-V delay around 175 ms. should be preferred to allow for maximal myocardial perfusion via the grafts.

  6. Controlling Spiral Dynamics in Excitable Media by a Weakly Localized Pacing

    Institute of Scientific and Technical Information of China (English)

    LI Bing-Wei; SUN Li-Li; CHEN Bin; YING He-Ping

    2007-01-01

    @@ Spiral dynamics controlled by a weakly localized pacing around the spiral tip is investigated. Numerical simulations show two distinct characteristics when the pacing is applied with the weak amplitude for suitable frequencies:for a rigidly rotating spiral, a transition from rigid rotation to meandering motion is observed, and for unstable spiral waves, spiral breakup can be prevented. Successfully preventing spiral breakup is relevant to the modulation of the tip trajectory induced by a localized pacing.

  7. Effects of Amiodarone plus Losartan on Electrical Remodeling in Rapid Atrial Pacing in Rabbits

    Institute of Scientific and Technical Information of China (English)

    Liye Wei; Yue Xia; Guoqing Qi; Qingwen Zhang

    2008-01-01

    Objectives To investigate the electrical remodeling and the effects of amiodarone and losartan on electrical remode-ling in rapid atrial pacing on rabbit model. Methods 40 normal rabbits were randomly divided into 4 groups: the sa-line group (control group), amiodarone group, losartan group, ami + los group. All rabbits were raised drugs in a week. The atrial effective refractory period (AERP) was measured. Then, take a rapid atrial pacing (600 bpm) and the AERP was measured after 0. 5, 1, 2, 4, 6 and 8 hours pacing and 30 minutes after the termination of rapid pacing. Results ① In control group, after 8 hours rapid pacing, AERP 200 and AERP 150 were significantly shortened 16. 11%± 3. 1% (P <0. 01) and 9. 99%±4. 2% (P <0. 01). And the degree of AERP shortening induced by rapid pacing was greater at basic cycle lengths of 200 ms (BCL200) than that at BCL150. The AERP of amiodarone, losartan group and anti + los group were not shortened during rapid pacing.② In the control group, after the termination of rapid pacing, the AERP gradually increased. The AERP at all of the BCLS examined recovered to almost the 95.78% and 96. 76% of baseline values within the first 10 minutes and recovered to almost the 99. 07% and 99. 39% of baseline values within the first 30 minutes. Condusions Short-term atrial rapid pacing can induce the atrial electrical remodeling. Amiodarone and losartan can prevent the electrical remodeling.

  8. Inhibition of bradycardia pacing caused by far-field atrial sensing in a third-generation cardioverter defibrillator with an automatic gain feature.

    Science.gov (United States)

    Curwin, J H; Roelke, M; Ruskin, J N

    1996-01-01

    The diagnostic accuracy of implantable cardioverter defibrillators may be improved by automatically adjusting gain algorithms, which in general reduce the likelihood of oversensing while maintaining the ability to detect the low amplitude signals associated with ventricular fibrillation. We present a patient with a third-generation device who developed prolonged ventricular asystole arising as a complication of the automatic gain feature. During asystole the device automatically increased sensitivity in order to prevent undersensing of ventricular fibrillation, which in this case resulted in far-field sensing of atrial activity and inhibition of ventricular pacing.

  9. Sex differences in pacing during ‘Ultraman Hawaii’

    Directory of Open Access Journals (Sweden)

    Beat Knechtle

    2016-09-01

    Full Text Available Background To date, little is known for pacing in ultra-endurance athletes competing in a non-stop event and in a multi-stage event, and especially, about pacing in a multi-stage event with different disciplines during the stages. Therefore, the aim of the present study was to examine the effect of age, sex and calendar year on triathlon performance and variation of performance by events (i.e., swimming, cycling 1, cycling 2 and running in ‘Ultraman Hawaii’ held between 1983 and 2015. Methods Within each sex, participants were grouped in quartiles (i.e., Q1, Q2, Q3 and Q4 with Q1 being the fastest (i.e., lowest overall time and Q4 the slowest (i.e., highest overall time. To compare performance among events (i.e., swimming, cycling 1, cycling 2 and running, race time in each event was converted in z score and this value was used for further analysis. Results A between-within subjects ANOVA showed a large sex × event (p = 0.015, η2 = 0.014 and a medium performance group × event interaction (p = 0.001, η2 = 0.012. No main effect of event on performance was observed (p = 0.174, η2 = 0.007. With regard to the sex × event interaction, three female performance groups (i.e., Q2, Q3 and Q4 increased race time from swimming to cycling 1, whereas only one male performance group (Q4 revealed a similar trend. From cycling 1 to cycling 2, the two slower female groups (Q3 and Q4 and the slowest male group (Q4 increased raced time. In women, the fastest group decreased (i.e., improved race time from swimming to cycling 1 and thereafter, maintained performance, whereas in men, the fastest group decreased race time till cycling 2 and increased it in the running. Conclusion In summary, women pace differently than men during ‘Ultraman Hawaii’ where the fastest women decreased performance on day 1 and could then maintain on day 2 and 3, whereas the fastest men worsened performance on day 1 and 2 but improved on day 3.

  10. Specific Intensity for Peaking: Is Race Pace the Best Option?

    Directory of Open Access Journals (Sweden)

    Munoz

    2015-09-01

    Full Text Available Background The peaking period for endurance competition is characterized for a relative increase of the intensity of training, after a longer period of training relatively dominated by lower intensity and higher volume Objectives The present study was designed to compare physiological and 10 km performance effects of high intensity training (HIT versus race pace interval training (RP during peaking for competition in well-trained runners. Patients and Methods 13 athletes took part in the study, they were divided into two groups: HIT and RP. HIT performed short intervals at ~105% of the maximal aerobic velocity (MAV, while RP trained longer intervals at a speed of ~90% of the MAV (a speed approximating 10 km race pace. After 12 weeks of baseline training, the athletes trained for 6 weeks under one of the two peaking regimes. Subjects performed 10 km prior to and after the intervention period. The total load of training was matched between groups during the treatment phase. Subjects completed a graded treadmill running test until volitional exhaustion prior to each 10 km race. MAV was determined as the minimal velocity eliciting maximal oxygen consumption (VO2max. Results Both groups significantly improved their 10 km time (35 minutes 29 seconds ± 1 minutes 41 seconds vs 34 minutes 53 seconds ± 1 minutes 55 seconds, P 0.05. In contrast, running economy decreased significantly after HIT (210 ± 6 ml.Kg-1.km-1 vs 218 ± 9, P < 0.05. Conclusions A 6 week period of training at either 105% of MAV or 90% of MAV yielded similar performance gains in a 10km race performed at ~90% MAV. Therefore, the physiological impact of HIT training seems to be positive for VO2max but negative for running economy.

  11. Right ventricular septal pacing: Safety and efficacy in a long term follow up

    Institute of Scientific and Technical Information of China (English)

    Eraldo; Occhetta; Gianluca; Quirino; Lara; Baduena; Rosaria; Nappo; Chiara; Cavallino; Emanuela; Facchini; Paolo; Pistelli; Andrea; Magnani; Miriam; Bortnik; Gabriella; Francalacci; Gabriele; Dell’Era; Laura; Plebani; Paolo; Marino

    2015-01-01

    AIM: To evaluate the safety and efficacy of the permanent high interventricular septal pacing in a long term follow up, as alternative to right ventricular apical pacing. METHODS: We retrospectively evaluated:(1) 244 patients(74 ± 8 years; 169 men, 75 women) implanted with a single(132 pts) or dual chamber(112 pts) pacemaker(PM) with ventricular screw-in lead placed at the right ventricular high septal parahisian site(SEPTAL pacing);(2) 22 patients with permanent pacemaker and low percentage of pacing(< 20%)(NO pacing);(3) 33 patients with high percentage(> 80%) right ventricular apical pacing(RVA). All patients had a narrow spontaneous QRS(101 ± 14 ms). We evaluated New York Heart Association(NYHA) class, quality of life(Qo L), 6 min walking test(6MWT) and left ventricular function(end-diastolic volume, LV-EDV; end-systolic volume, LVESV; ejection fraction, LV-EF) with 2D-echocardiography. RESULTS: Pacing parameters were stable duringfollow up(21 mo/patient). In SEPTAL pacing group we observed an improvement in NYHA class, Qo L score and 6MWT. While LV-EDV didn’t significantly increase(104 ± 40 m L vs 100 ± 37 m L; P = 0.35), LV-ESV slightly increased(55 ± 31 m L vs 49 ± 27 m L; P = 0.05) and LV-EF slightly decreased(49% ± 11% vs 53% ± 11%; P = 0.001) but never falling < 45%. In the RVA pacing control group we observed a worsening of NYHA class and an important reduction of LV-EF(from 56% ± 6% to 43% ± 9%, P < 0.0001).CONCLUSION: Right ventricular permanent high septal pacing is safe and effective in a long term follow up evaluation; it could be a good alternative to the conventional RVA pacing in order to avoid its deleterious effects.

  12. Self-forming nanoscale devices

    Directory of Open Access Journals (Sweden)

    Lars Samuelson

    2003-10-01

    The top-down approach limits the dimensions of devices to what is technically achievable using lithography. This is the means by which patterns can be drawn, either in stone as the Vikings did when they carved messages into granite, or into Si as the electronics industry does today to build integrated circuits. Lithographic techniques can create device features as narrow as 130 nm and the industry sees the road ahead pretty well drawn up for line-widths down to ∼50 nm. This continued progress does not come without a price; the cost of new fabs is growing extremely fast, at a pace that may limit continued progress, simply because devices and circuits become too expensive to be economically viable.

  13. Atrioventricular Left Ventricular Apical Pacing Improves Haemodynamic, Rotational, and Deformation Variables in Comparison to Pacing at the Lateral Wall in Intact Myocardium: Experimental Study

    Directory of Open Access Journals (Sweden)

    Savvas Toumanidis

    2014-01-01

    Full Text Available Aim. To assess the effect on left ventricular (LV function of atrioventricular (AV and ventricular pacing at the LV apical or lateral wall and to compare the normal torsional and deformation pattern of the intact LV myocardium with those created by the aforementioned LV pacing modes and sites. Methods. Experiments were conducted in pigs (n=21 with normal LV function to investigate the acute hemodynamic effects of epicardial AV and ventricular LV pacing at the LV apical or lateral wall. Torsional and deformation indices of LV function were assessed using speckle tracking echocardiography. Results. AV pacing at the apex revealed a significant reduction in the radial strain of the base (P<0.03, without affecting significantly the ejection fraction and the LV torsion or twist. In contrast, AV pacing at the lateral wall produced, in addition to the reduction of the radial strain of the base (P<0.01, significant reduction of the circumferential and the radial strain of the apex (both P<0.01 as well as of the ejection fraction (P<0.002 and twist (P<0.05. Conclusions. In pig hearts with intact myocardium, LV function is maintained at sinus rhythm level when AV pacing is performed at the LV apex.

  14. Effect of right ventricular pacing on ventricular rhythm during atrial fibrillation

    NARCIS (Netherlands)

    Wittkampf, F.H.M.; Jongste, M.J.L. de; Lie, H.I.; Meijler, F.L.

    1988-01-01

    In 13 patients with atrial fibrillation, the effect of right ventricular pacing at various rates on spontaneous RR intervals was studied. Five hundred consecutive RR intervals were recorded and measured before and during varying right ventricular pacing rates. As anticipated, all RR intervals longer

  15. The effect of work pace on workload, motor variability and fatigue during simulated light assembly work.

    Science.gov (United States)

    Bosch, T; Mathiassen, S E; Visser, B; de Looze, M P; van Dieën, J H

    2011-02-01

    This study investigated the effect of work pace on workload, motor variability and fatigue during light assembly work. Upper extremity kinematics and electromyography (EMG) were obtained on a cycle-to-cycle basis for eight participants during two conditions, corresponding to "normal" and "high" work pace according to a predetermined time system for engineering. Indicators of fatigue, pain sensitivity and performance were recorded before, during and after the task. The level and variability of muscle activity did not differ according to work pace, and manifestations of muscle fatigue or changed pain sensitivity were not observed. In the high work pace, however, participants moved more efficiently, they showed more variability in wrist speed and acceleration, but they also made more errors. These results suggest that an increased work pace, within the range addressed here, will not have any substantial adverse effects on acute motor performance and fatigue in light, cyclic assembly work. STATEMENT OF RELEVANCE: In the manufacturing industry, work pace is a key issue in production system design and hence of interest to ergonomists as well as engineers. In this laboratory study, increasing the work pace did not show adverse effects in terms of biomechanical exposures and muscle fatigue, but it did lead to more errors. For the industrial engineer, this observation suggests that an increase in work pace might diminish production quality, even without any noticeable fatigue being experienced by the operators.

  16. Beyond a Unitary Conception of Pedagogic Pace: Quantitative Measurement and Ethnographic Experience

    Science.gov (United States)

    Lefstein, Adam; Snell, Julia

    2013-01-01

    English education policy-makers have targeted classroom time as a key area for regulation and intervention, with "brisk pace" widely accepted as a feature of good teaching practice. We problematise this conventional wisdom through an exploration of objective and subjective dimensions of lesson pace in a corpus of 30 Key Stage 2 literacy…

  17. Right ventricular outflow and apical pacing comparably worsen the echocardioghraphic normal left ventricle

    NARCIS (Netherlands)

    T.J.F. ten Cate (Tim); M.G. Scheffer (Michael); G.R. Sutherland (George); J.F. Verzijlbergen (Fred); N.M. van Hemel (Norbert)

    2008-01-01

    textabstractAims: A depressed left ventricular function (LVF) is sometimes observed during right ventricular apical (RVA) pacing, but any prediction of this adverse effect cannot be done. Right ventricular outflow tract (RVOT) pacing is thought to deteriorate LVF less frequently because of a more no

  18. Effects of permanent dual chamber pacing on myocardial perfusion in symptomatic hypertrophic cardiomyopathy

    NARCIS (Netherlands)

    Posma, JL; Blanksma, PK; VanderWall, EE; Vaalburg, W; Crijns, HJGM; Lie, KI

    1996-01-01

    Objective-Angina and the presence of myocardial ischaemia are common in hypertrophic cardiomyopathy. Dual chamber pacing results in clinical improvement in these patients. This study evaluates the effects of permanent dual chamber pacing on absolute regional myocardial perfusion and perfusion reserv

  19. Self-Paced Economics Instruction: A Large-Scale Disaggregated Evaluation

    Science.gov (United States)

    Soper, John C.; Thorton, Richard M.

    1976-01-01

    This paper reports on an evaluation of the Sterling Institute self-paced macroeconomics course at Northern Illinois University. Results show that a completely self-paced teaching format for macroeconomics is inferior to a well-directed, concept-oriented, graduate-student instructed, lecture-discussion taught course. (Author/RM)

  20. New method for cardiac resynchronization therapy: Transapical endocardial lead implantation for left ventricular free wall pacing

    NARCIS (Netherlands)

    I. Kassai (Imre); C. Foldesi (Csaba); A. Szekely (Andrea); T. Szili-Torok (Tamas)

    2008-01-01

    textabstractCoronary sinus lead placement for transvenous left ventricular (LV) pacing in cardiac resynchronization therapy (CRT) has a significant failure rate at implant and a significant dislocation rate during follow-up. For these patients, epicardial pacing lead implantation is the most frequen

  1. Improvement of pacing induced regional myocardial ischemia by Solcoseryl in conscious dogs with coronary stenosis.

    Science.gov (United States)

    Shimada, T; Sasayama, S; Takahashi, M; Osakada, G; Kawai, C

    1984-02-01

    The effects of Solcoseryl on regional myocardial function were studied in 5 conscious dogs with partial coronary constriction, in which temporary ischemia was induced by rapid cardiac pacing. During the coronary artery constriction, the percent shortening of the ischemic segment decreased by 9%. When the heart rate was increased by pacing, the percent shortening of the ischemic segments was further reduced by 57%. On cessation of cardiac pacing, the early potentiation of dP/dt and of control segment shortening became evident and was followed by exponential decay in the subsequent several beats. In the ischemic segment, the percent shortening was significantly improved in the first post-pacing beat but was more severely depressed at five seconds. Thirty minutes after administration of Solcoseryl, the cardiac pacing was repeated in the same manner but the pacing-induced hypokinesia of the ischemic segment were less marked, the percent shortening being at an average of 9.1% during control pacing and 12.7% during the second pacing after Solcoseryl (p less than 0.05). Postpacing deterioration of the ischemic segment shortening was also significantly improved from 9.8 to 11.8% at 5 seconds (p less than 0.05). These findings indicate that Solcoseryl exerts protective effects on the ischemic myocardium by promoting a rapid recovery from ischemia, probably due to the improvement of oxygen utility through activated cellular respiration.

  2. Research on Electrical Remodeling After Short Term Pacing in Canine Model

    Institute of Scientific and Technical Information of China (English)

    Kebbati A Hafid; Huang Congxin; Wang Xi; Zhao Qingyan

    2007-01-01

    Objectives To evaluate the changes in atrial effective refractory period (AERP) proprieties and in ionic currents in PVs myocytes from dogs subjected to rapid atrial pacing in PVs and right atrial appendage (RAA) and to relate these changes to the ability to induce AF. Methods Twelve mongrel dogs in normal sinus rhythm were paced from the superior left PVs or RAA at 500 bpm for 4 hours. Electrophysiologic studies conducted to determine changes in AERP, dispersion and rhythm. Ionic currents were studies with the patch clamp technique in single PVs myocytes in sham operated dogs and compared with those from PVs pacing and RAA pacing groups. Results The presence of rapid atrial pacing was associated with a marked shortening in AERP in both PVs and RAA pacing group with a marked increase of AERP dispersion in PVs pacing. Both L-type calcium current (ICa, L) and the transient outward current (Ito)were reduced in both groups with an increased significance in PVs pacing group. The density of ICa-L WaS decreased significantly from ( - 6.03 ± 0.63 ) pA/pF in the control group to ( -3.21±0.34) pA/pF in PVs pacing group and ( - 4,75 ± 0.41 ) pA/pF in RAA pacing group (n = 6, P<0.05) while the density of Ito was decreased significantly from (8.45±0.71 ) pA/pF in the control group to (5.21 ±0.763 ) pA/pF in PVs pacing group and (6,84 ± 0.69) pA/pF in RAA pacing group (n = 6, P<0.05). Conclusions Our findings provide likely ionic mechanisms of shortened repolarization in induced atrial tachycardia with a decrease in Ica,L and Ito current densities which is the likely mechanism for a decrease in Action potential duration (APD) rate adaptation in the canine rapid pacing model more pronounced in PVs pacing group underlying the crucial role of PVs in initiating AF.

  3. Risk factors for lead complications in cardiac pacing

    DEFF Research Database (Denmark)

    Kirkfeldt, Rikke Esberg; Johansen, Jens Brock; Nøhr, Ellen Aagaard;

    2011-01-01

    Lead complications are the main reason for reoperation after implantation of pacemakers (PM) or cardiac resynchronization therapy (CRT-P) devices.......Lead complications are the main reason for reoperation after implantation of pacemakers (PM) or cardiac resynchronization therapy (CRT-P) devices....

  4. Effects of pacing site and stimulation history on alternans dynamics and the development of complex spatiotemporal patterns in cardiac tissue

    Directory of Open Access Journals (Sweden)

    Alessio eGizzi

    2013-04-01

    Full Text Available Alternans of action potential duration has been associated with T-wave alternans and the development of arrhythmias because it produces large gradients of repolarization. However, little is known about alternans dynamics in large mammalian hearts. Using optical mapping to record electrical activations simultaneously from the epicardium and endocardium of 9 canine right ventricles, we demonstrate novel arrhythmogenic complex spatiotemporal dynamics. (i Alternans predominantly develops first on the endocardium. (ii The postulated simple progression from normal rhythm to concordant to discordant alternans is not always observed; concordant alternans can develop from discordant alternans as the pacing period is decreased. (iii In contrast to smaller tissue preparations, multiple stationary nodal lines may exist and need not be perpendicular to the pacing site or to each other. (iv Alternans has fully three-dimensional dynamics and the epicardium and endocardium can show significantly different dynamics: multiple nodal surfaces can be transmural or intramural and can form concave/convex surfaces resulting in islands of discordant alternans. (v The complex spatiotemporal patterns observed during alternans are very sensitive to both the site of stimulation and the stimulation history. Alternans in canine ventricles not only exhibit larger amplitudes and persist for longer cycle length regimes compared those found in smaller mammalian hearts, but also show novel dynamics not previously described that enhance dispersion and show high sensitivity to initial conditions. This indicate some underlying predisposition to chaos and can help the design of new drugs and devices controlling and preventing arrhythmic events.

  5. Effects of right atrial and ventricular DDD pacing on cardiac function and ventricular contraction synchrony

    Institute of Scientific and Technical Information of China (English)

    支力大; 华伟; 张澍; 史蓉芳; 王方正; 陈新

    2004-01-01

    Background Right ventricular apical pacing has been reported to reduce cardiac performance. But there are few reports on the effects of dual chamber (DDD) pacing on cardiac function compared to sinus rhythm. In this study, we evaluated the effects of right atrial and ventricular DDD pacing on cardiac function and ventricular contraction synchrony using equilibrium radionuclide angiography.Methods Ten patients implanted with a right atrial and ventricular DDD pacemaker underwent equilibrium radionuclide angiography. The scintigraphic data were obtained during sinus rhythm and pacing rhythm. Cardiac function parameters were obtained semimanually. Phase analysis was used to study the ventricular activation sequence and ventricular synchrony.Results The left ventricular 1/3 ejection fraction decreased significantly during pacing compared with that during sinus rhythm[(23.4 ±6.1)% vs(27.7 ±4.5)%, P =0.01]. Regional ejection fraction also decreased during pacing, although the difference was not statistically significant. Phase analysis showed that the right ventricle was activated earlier than the left ventricle during pacing, and that the phase shift was significantly greater during pacing than that during sinus rhythm[64.13°±16.80° vs 52.88°± 9.26°, P =0.007]. The activation of both ventricles occurred simultaneously during sinus rhythm, with the activation sequence from proximal septum or base of left ventricle to apex. The earliest activation during pacing occurred at the right ventricular apex, and subsequently spread to the base and left ventricle.Conclusion Right atrial and ventricular DDD pacing impairs left ventricular systolic function and ventricular synchrony.

  6. Case study thoracic radiotherapy in an elderly patient with pacemaker: The issue of pacing leads

    Energy Technology Data Exchange (ETDEWEB)

    Kirova, Youlia M., E-mail: youlia.kirova@curie.net [Department of Radiation Oncology, Institut Curie, Paris (France); Menard, Jean; Chargari, Cyrus; Mazal, Alejandro [Department of Radiation Oncology, Institut Curie, Paris (France); Kirov, Krassen [Department of Anesthesiology and Reanimation, Institut Curie, Paris (France)

    2012-07-01

    To assess clinical outcome of patients with pacemaker treated with thoracic radiation therapy for T8-T9 paravertebral chloroma. A 92-year-old male patient with chloroma presenting as paravertebral painful and compressive (T8-T9) mass was referred for radiotherapy in the Department of Radiation Oncology, Institut Curie. The patient presented with cardiac dysfunction and a permanent pacemaker that had been implanted prior. The decision of Multidisciplinary Meeting was to deliver 30 Gy in 10 fractions for reducing the symptoms and controlling the tumor growth. The patient received a total dose of 30 Gy in 10 fractions using 4-field conformal radiotherapy with 20-MV photons. The dose to pacemaker was 0.1 Gy but a part of the pacing leads was in the irradiation fields. The patient was treated the first time in the presence of his radiation oncologist and an intensive care unit doctor. Moreover, the function of his pacemaker was monitored during the entire radiotherapy course. No change in pacemaker function was observed during any of the radiotherapy fractions. The radiotherapy was very well tolerated without any side effects. The function of the pacemaker was checked before and after the radiotherapy treatment by the cardiologist and no pacemaker dysfunction was observed. Although updated guidelines are needed with acceptable dose criteria for implantable cardiac devices, it is possible to treat patients with these devices and parts encroaching on the radiation field. This case report shows we were able to safely treat our patient through a multidisciplinary approach, monitoring the patient during each step of the treatment.

  7. Cycling in the Absence of Task-related Feedback: Effects on Pacing and Performance

    Directory of Open Access Journals (Sweden)

    Benjamin Smits

    2016-08-01

    Full Text Available Introduction. To achieve personal goals in exercise task completion, exercisers have to regulate, distribute and manage their effort. In endurance sports, it has become very commonplace for athletes to consult task-related feedback on external devices to do so. The aim of the present study was to explore the importance of the presence of this information by examining the influence of the absence of commonly available task-related feedback on effort distribution and performance in experienced endurance athletes.Methods. A 20-km cycling time trial was performed. 20 Participants from a homogenous cyclist population were appointed to a group that did not receive any feedback (NoF, or a group that could consult task-related feedback (i.e., speed, heart rate, power output, cadence, elapsed time and elapsed distance continuously during their trial (FF.Results. The distribution of power output (PO differed between groups. Most evident is the spurt at the end of the trial of FF, which was not incorporated by NoF. Nevertheless, no between-group differences were found in performance time (FF: 28.86 +/- 3.68 min vs. NoF: 30.95 +/- 2.77 min and mean PO controlled by body mass (FF: 3.61 +/- .60 W/kg vs. NoF: 3.43 +/- .38 W/kg. Also, no differences in rating of perceived exertion scores were found.Conclusion. The current study provides a first indication that prior knowledge of task demands together with reliance on bodily and environmental information can be sufficient for experienced athletes to come to comparable time trial performances. This questions the necessity of the presence of in-race instantaneous task-related feedback via external devices for maximising performance. Moreover, it seems that different pacing strategies emerge depending on sources of information available to experienced athletes.

  8. Electrical Pacing of Cardiac Tissue Including Potassium Inward Rectification.

    Science.gov (United States)

    Galappaththige, Suran; Roth, Bradley J

    2015-01-01

    In this study cardiac tissue is stimulated electrically through a small unipolar electrode. Numerical simulations predict that around an electrode are adjacent regions of depolarization and hyperpolarization. Experiments have shown that during pacing of resting cardiac tissue the hyperpolarization is often inhibited. Our goal is to determine if the inward rectifying potassium current (IK1) causes the inhibition of hyperpolarization. Numerical simulations were carried out using the bidomain model with potassium dynamics specified to be inward rectifying. In the simulations, adjacent regions of depolarization and hyperpolarization were observed surrounding the electrode. For cathodal currents the virtual anode produces a hyperpolarization that decreases over time. For long duration pulses the current-voltage curve is non-linear, with very small hyperpolarization compared to depolarization. For short pulses, the hyperpolarization is more prominent. Without the inward potassium rectification, the current voltage curve is linear and the hyperpolarization is evident for both long and short pulses. In conclusion, the inward rectification of the potassium current explains the inhibition of hyperpolarization for long duration stimulus pulses, but not for short duration pulses.

  9. Electrical Pacing of Cardiac Tissue Including Potassium Inward Rectification.

    Directory of Open Access Journals (Sweden)

    Suran Galappaththige

    Full Text Available In this study cardiac tissue is stimulated electrically through a small unipolar electrode. Numerical simulations predict that around an electrode are adjacent regions of depolarization and hyperpolarization. Experiments have shown that during pacing of resting cardiac tissue the hyperpolarization is often inhibited. Our goal is to determine if the inward rectifying potassium current (IK1 causes the inhibition of hyperpolarization. Numerical simulations were carried out using the bidomain model with potassium dynamics specified to be inward rectifying. In the simulations, adjacent regions of depolarization and hyperpolarization were observed surrounding the electrode. For cathodal currents the virtual anode produces a hyperpolarization that decreases over time. For long duration pulses the current-voltage curve is non-linear, with very small hyperpolarization compared to depolarization. For short pulses, the hyperpolarization is more prominent. Without the inward potassium rectification, the current voltage curve is linear and the hyperpolarization is evident for both long and short pulses. In conclusion, the inward rectification of the potassium current explains the inhibition of hyperpolarization for long duration stimulus pulses, but not for short duration pulses.

  10. High-resolution entrainment mapping of gastric pacing: a new analytical tool.

    Science.gov (United States)

    O'Grady, Gregory; Du, Peng; Lammers, Wim J E P; Egbuji, John U; Mithraratne, Pulasthi; Chen, Jiande D Z; Cheng, Leo K; Windsor, John A; Pullan, Andrew J

    2010-02-01

    Gastric pacing has been investigated as a potential treatment for gastroparesis. New pacing protocols are required to improve symptom and motility outcomes; however, research progress has been constrained by a limited understanding of the effects of electrical stimulation on slow-wave activity. This study introduces high-resolution (HR) "entrainment mapping" for the analysis of gastric pacing and presents four demonstrations. Gastric pacing was initiated in a porcine model (typical amplitude 4 mA, pulse width 400 ms, period 17 s). Entrainment mapping was performed using flexible multielectrode arrays (entrainment onset was quantified over successive waves in spatiotemporal detail. In the second demonstration, slow-wave velocity was accurately determined with HR field analysis, and paced propagation was found to be anisotropic (longitudinal 2.6 +/- 1.7 vs. circumferential 4.5 +/- 0.6 mm/s; P Entrainment mapping enables an accurate quantification of the effects of gastric pacing on slow-wave activity, offering an improved method to assess whether pacing protocols are likely to achieve physiologically and clinically useful outcomes.

  11. Differences in atrial septal activation with an intrasinoatrial nodal pacemaker and epicardial sinoatrial nodal pacing.

    Science.gov (United States)

    Goldberg, J M

    1979-01-01

    Changes in Intra-SA nodal pacemaker localization were produced through stimulation of the decentralized cervical vagi and stellate ganglia in the anesthetized dog. Shifts in pacemaker to the rostral, middle, or caudal regions of the SA node produced a change in the timing as well as a change in the sequence of activation of recording sites overlying the AV node. Epicardial pacing with a plaque electrode from either the rostral, middle, or caudal regions of the SA node produced the same activation sequence of the AV nodal electrodes irrespective of the epicardial SA nodal pacing site. The inability of epicardial SA nodal pacing to precisely reproduce the activation pattern of the atrial septum overlying the AV node observed with a natural SA nodal pacemaker can be explained by the geographic relationship of the pacemaker cells within the node to the preferential internodal pathways and the area of atrial tissue stimulated by pacing. Pacing activates a large mass of tissue, whereas an intrinsic pacemaker probably acts as a more localized focus. The inability of pacing to reproduce the activation pattern seen with spontaneous rhythm may be a determinant in the varied P wave morphology seen with coronary sinus or AV nodal junctional rhythms, as compared with more consistent morphology seen with pacing.

  12. [Competitive pacing in a patient with DDD pacemaker and bigeminal ventricular extrasystoles].

    Science.gov (United States)

    Carbone, Vincenzo; Candelmo, Fiore; Todaro, Chiara; Oreto, Giuseppe

    2008-11-01

    The ECG recorded from a patient with DDD pacemaker showed variable responses of the pacing system to bigeminal ventricular extrasystoles, dependent on the coupling interval of premature beats. For relatively short coupling intervals, the premature spontaneous event was detected by the pacemaker, inhibiting both atrial and ventricular output, and resulting in a relatively long pacing pause. In slightly less premature end-diastolic extrasystoles, in contrast, the pacing system delivered an atrial spike that was superimposed upon the spontaneous premature QRS complex (pseudo-pseudofusion); under these circumstances, the atrial spike was followed, at the end of the programmed atrioventricular interval, by a ventricular spike falling on the extrasystolic T wave apex (competitive ventricular pacing). This phenomenon, however, did not express a sensing malfunction, but was due to post-atrial ventricular blanking (PAVB), a short period initiated by the atrial spike during which ventricular sensing is temporarily disabled, so that no signal can be detected. Finally, whenever premature end-diastolic impulses occurred after PAVB, during the brief interval defined ventricular safety pacing, the spontaneous event was sensed, being followed by an earlier-than-expected ventricular spike, whose prematurity was aimed at avoiding the occurrence of an artificial impulse upon the T wave of extrasystole. In conclusion, despite several not sensed ventricular extrasystoles and competitive pacing, no sensing malfunction was present. This case demonstrates how complex can be the electrocardiographic analysis of a DDD pacemaker, owing to the many complicating phenomena related to this pacing mechanism.

  13. Cardiomyopathy induced by artificial cardiac pacing: myth or reality sustained by evidence?

    Directory of Open Access Journals (Sweden)

    Andrés Di Leoni Ferrari

    2014-09-01

    Full Text Available Implantable cardiac pacing systems are a safe and effective treatment for symptomatic irreversible bradycardia. Under the proper indications, cardiac pacing might bring significant clinical benefit. Evidences from literature state that the action of the artificial pacing system, mainly when the ventricular lead is located at the apex of the right ventricle, produces negative effects to cardiac structure (remodeling, dilatation and function (dissinchrony. Patients with previously compromised left ventricular function would benefit the least with conventional right ventricle apical pacing, and are exposed to the risk of developing higher incidence of morbidity and mortality for heart failure. However, after almost 6 decades of cardiac pacing, just a reduced portion of patients in general would develop these alterations. In this context, there are not completely clear some issues related to cardiac pacing and the development of this cardiomyopathy. Causality relationships among QRS widening with a left bundle branch block morphology, contractility alterations within the left ventricle, and certain substrates or clinical (previous systolic dysfunction, structural heart disease, time from implant or electrical conditions (QRS duration, percentage of ventricular stimulation are still subjecte of debate. This review analyses contemporary data regarding this new entity, and discusses alternatives of how to use cardiac pacing in this context, emphasizing cardiac resynchronization therapy.

  14. Facility Composer (Trademark) and PACES (Trademark) Integration: Development of an XML Interface Based on Industry Foundation Classes

    Science.gov (United States)

    2007-11-01

    Density Parameters. ...............................111 Figure C5. PACES Facilities Values editing screen, Shell Quantity Parameters...112 Figure C6. PACES Facilities Values editing screen, Shell Descriptive Parameters...........................113 Figure C7. PACES import... COCOA B1 12008 FL COCOA B2 12009 FL COCOA OC 12010 FL FT PIERCE 12011 FL JONATHAN 12012 FL MALABAR 12013 FL MELBOURN 12014 FL STUART 12015 FL

  15. Cardiogenic shock associated with loco-regional anesthesia rescued with left ventricular assist device implantation

    Directory of Open Access Journals (Sweden)

    Droogan Christopher

    2010-12-01

    Full Text Available Abstract A healthy 53 year old man developed profound cardiogenic shock following instillation of bupivacaine-lidocaine-epinephrine solution as a locoregional anesthetic for elective outpatient shoulder surgery. Intubation, resuscitation, and transfer to the nearby hospital were done: echocardiography showed profound biventricular dysfunction; cardiac catheterization showed normal coronary arteries. Despite placement of an intra-aortic balloon pump and intravenous vasoactive drugs, the patient remained in shock. Stabilization was achieved with emergent institution of cardiopulmonary bypass and placement of a temporary left ventricular assist device (LVAD. Twenty-four hours later, cardiac function normalized and the LVAD was removed. The patient was discharged five days later and remained with normal heart function in three-year follow-up.

  16. Obliquity-paced Pliocene West Antarctic ice sheet oscillations

    Science.gov (United States)

    Naish, T.; Powell, R.; Levy, R.; Wilson, G.; Scherer, R.; Talarico, F.; Krissek, L.; Niessen, F.; Pompilio, M.; Wilson, T.; Carter, L.; DeConto, R.; Huybers, P.; McKay, R.; Pollard, D.; Ross, J.; Winter, D.; Barrett, P.; Browne, G.; Cody, R.; Cowan, E.; Crampton, J.; Dunbar, G.; Dunbar, N.; Florindo, F.; Gebhardt, C.; Graham, I.; Hannah, M.; Hansaraj, D.; Harwood, D.; Helling, D.; Henrys, S.; Hinnov, L.; Kuhn, G.; Kyle, P.; Laufer, A.; Maffioli, P.; Magens, D.; Mandernack, K.; McIntosh, W.; Millan, C.; Morin, R.; Ohneiser, C.; Paulsen, T.; Persico, D.; Raine, I.; Reed, J.; Riesselman, C.; Sagnotti, L.; Schmitt, D.; Sjunneskog, C.; Strong, P.; Taviani, M.; Vogel, S.; Wilch, T.; Williams, T.

    2009-01-01

    Thirty years after oxygen isotope records from microfossils deposited in ocean sediments confirmed the hypothesis that variations in the Earth's orbital geometry control the ice ages, fundamental questions remain over the response of the Antarctic ice sheets to orbital cycles. Furthermore, an understanding of the behaviour of the marine-based West Antarctic ice sheet (WAIS) during the 'warmer-than-present' early-Pliocene epoch (???5-3 Myr ago) is needed to better constrain the possible range of ice-sheet behaviour in the context of future global warming. Here we present a marine glacial record from the upper 600 m of the AND-1B sediment core recovered from beneath the northwest part of the Ross ice shelf by the ANDRILL programme and demonstrate well-dated, ???40-kyr cyclic variations in ice-sheet extent linked to cycles in insolation influenced by changes in the Earth's axial tilt (obliquity) during the Pliocene. Our data provide direct evidence for orbitally induced oscillations in the WAIS, which periodically collapsed, resulting in a switch from grounded ice, or ice shelves, to open waters in the Ross embayment when planetary temperatures were up to ???3??C warmer than today and atmospheric CO 2 concentration was as high as ???400 p.p.m.v. (refs 5, 6). The evidence is consistent with a new ice-sheet/ice-shelf model that simulates fluctuations in Antarctic ice volume of up to +7 m in equivalent sea level associated with the loss of the WAIS and up to +3 m in equivalent sea level from the East Antarctic ice sheet, in response to ocean-induced melting paced by obliquity. During interglacial times, diatomaceous sediments indicate high surface-water productivity, minimal summer sea ice and air temperatures above freezing, suggesting an additional influence of surface melt under conditions of elevated CO2. ??2009 Macmillan Publishers Limited. All rights reserved.

  17. Pace: an advanced structure for handling multi-technique NDT; Pace: une structure avancee pour la gestion de donnees CND multitechniques

    Energy Technology Data Exchange (ETDEWEB)

    Mayos, M.; Guisnel, F.

    1995-08-01

    The growing extent and complexity of NDT data analysis has reached a stage where dedicated systems are required. In the context of a European research program, EDF participated from 1992 to 1994 in one of the first international projects in this field, TRAPPIST and, in 1993, began developing An application for the electricity generating industry, giving rise to the PACE project. The prime objective specially targets the French electricity generating industry, where PACE was to be the reference system for analysis of NDE data concerning EdF power plants. The second objective is to promote the adoption of PACE by other industrial sectors and other countries. The analysis of needs shows that the required system must be designed to analyze data from widely different sources. The PACE entry point consequently has to be a standard format compatible with geometrical data as well as those provided by NDT. The TRAPPIST format constitutes the first version of this standard and is the first step towards European standardization in this respect. Consideration of the different user modes defined for PACE led to the design of a 2-part user structure comprising a database management system (Ingres/Windows 4GL) and a display/processing tool (AVS), also usable to construct analysis scenarios. The structure of PACE is defined nd seems well suited to industrial requirements, but before it is possible to proceed further towards its adoption for actual power plant inspections, it has to be validated on a more realistic application, the eddy current and ultrasonic testing of a full-scale T-joint. This is already under way, whilst work on format standardization and industrialization preparatory procedures are proceeding in parallel. (authors). 4 refs., 6 figs.

  18. Insertion devices

    CERN Document Server

    Bahrdt, J

    2006-01-01

    The interaction of an insertion device with the electron beam in a storage ring is discussed. The radiation property including brightness, ux and polarization of an ideal and real planar and helical / elliptical device is described. The magnet design of planar, helical, quasiperiodic devices and of devices with a reduced on axis power density are resumed.

  19. Optical recording-guided pacing to create functional line of block during ventricular fibrillation

    Science.gov (United States)

    Ravi, Krishna; Nihei, Motoki; Willmer, Anjuli; Hayashi, Hideki; Lin, Shien-Fong

    2006-03-01

    Low-energy defibrillation is very desirable in cardiac rhythm management. We previously reported that ventricular fibrillation (VF) can be synchronized with a novel synchronized pacing technique (SyncP) using low-energy pacing pulses. This study sought to create a line of block during VF using SyncP. SyncP was performed in six isolated rabbit hearts during VF using optical recording to control the delivery of pacing pulses in real time. Four pacing electrodes with interelectrode distances of 5 mm were configured in a line along and across the myocardial fiber direction. The electrodes were controlled independently (independent mode) or fired together (simultaneous mode). Significant wavefront synchronization was observed along the electrode line as indicated by a decrease in variance. With the independent SyncP protocol, the decrease in the variance was 19.3 and 13.7% (Pventricular defibrillation.

  20. Transvenous right ventricular pacing in a patient with tricuspid mechanical prosthesis

    Directory of Open Access Journals (Sweden)

    Rubio José

    2008-07-01

    Full Text Available Abstract We report a patient in whom permanent endocardial pacing was accomplished by passage of the electrode through a mechanical tricuspid valve. Echocardiography study showed a minimal tricuspid regurgitation.

  1. Classifying running-related injuries based upon etiology, with emphasis on volume and pace

    DEFF Research Database (Denmark)

    Nielsen, Rasmus Oestergaard; Nohr, Ellen Aagaard; Rasmussen, Sten;

    2013-01-01

    of patellofemoral pain syndrome, iliotibial band syndrome, and patellar tendinopathy, while change in running pace may be associated with the development of achilles tendinopathy, gastrocnemius injuries, and plantar fasciitis. DISCUSSIONRELATION TO CLINICAL PRACTICE: If this assertion is correct, bias may...

  2. Photovoltaics (PV) as an Eligible Measure in Residential PACE Programs: Benefits and Challenges (Fact Sheet)

    Energy Technology Data Exchange (ETDEWEB)

    Coughlin, J.

    2010-06-01

    Property Assessed Clean Energy (PACE) financing is one of several new financial models broadening access to clean energy by addressing the barrier of initial capital cost. The majority of the PACE programs in the market today include PV as an eligible measure. PV appeals to homeowners as a way to reduce utility bills, self-generate sustainable power, increase energy independence and demonstrate a commitment to the environment. If substantial state incentives for PV exist, PV projects can be economic under PACE, especially when partnered with good net metering policies. At the same time, PV is expensive relative to other eligible measures with a return on investment horizon that might exceed program targets. This fact sheet reviews the benefits and potential challenges of including PV in PACE programs.

  3. Left ventricular pacing improves haemodynamic variables in patients with heart failure with a normal QRS duration

    Science.gov (United States)

    Turner, M S; Bleasdale, R A; Mumford, C E; Frenneaux, M P; Morris-Thurgood, J A

    2004-01-01

    Objectives: To assess whether patients with congestive heart failure (CHF) and a normal QRS duration can benefit from left ventricular (VDD-LV) pacing. Design: Cardiac resynchronisation is reserved for patients with a broad QRS duration on the premise that systolic resynchronisation is the mechanism of benefit, yet improvement from pacing correlates poorly with QRS duration. In CHF patients with a broad QRS duration, those with a high resting pulmonary capillary wedge pressure (PCWP) > 15 mm Hg benefit. In this acute haemodynamic VDD-LV pacing study, patients with CHF with a normal QRS duration were divided into two groups—patients with a resting PCWP > 15 mm Hg and patients with a resting PCWP 15 mm Hg (n  =  10), cardiac output increased from 3.9 (1.5) to 4.5 (1.65) l/min (p 15 mm Hg derive acute haemodynamic benefit from VDD-LV pacing. PMID:15084543

  4. Self-Paced Mathematics Instruction: How Effective Has it Been in Secondary and Postsecondary Schools?

    Science.gov (United States)

    Schoen, Harold L.

    1976-01-01

    Seventeen studies of self-paced instruction in algebra, geometry, trigonometry, and college mathematics courses are reviewed. In general these studies did not find the individualized programs to be superior to theregular instruction with which they were compared. (SD)

  5. Conditioning of the diaphragm by phrenic nerve pacing in primary alveolar hypoventilation.

    OpenAIRE

    Wilcox, P G; Paré, P D; Fleetham, J A

    1988-01-01

    A patient with respiratory muscle weakness due to alveolar hypoventilation was treated with nocturnal bilateral phrenic nerve pacing for one year. Treatment was associated with a progressive increase in diaphragmatic strength and endurance.

  6. EFFECT OF ADAPTIVE PACED CARDIOLOCOMOTOR SYNCHRONIZATION DURING RUNNING: A PRELIMINARY STUDY

    Directory of Open Access Journals (Sweden)

    Bill Phillips

    2013-09-01

    Full Text Available Cardiolocomotor synchronization (CLS has been well established for individuals engaged in rhythmic activity, such as walking, running, or cycling. When frequency of the activity is at or near the heart rate, entrainment occurs. CLS has been shown in many cases to improve the efficiency of locomotor activity, improving stroke volume, reducing blood pressure variability, and lowering the oxygen uptake (VO2. Instead of a 1:1 frequency ratio of activity to heart rate, an investigation was performed to determine if different harmonic coupling at other simple integer ratios (e.g. 1:2, 2:3, 3:2 could achieve any performance benefits. CLS was ensured by pacing the stride rate according to the measured heartbeat (i.e., adaptive paced CLS, or forced CLS. An algorithm was designed that determined the simplest ratio (lowest denominator that, when multiplied by the heart rate will fall within an individualized, predetermined comfortable pacing range for the user. The algorithm was implemented on an iPhone 4, which generated a 'tick-tock' sound through the iPhone's headphones. A sham-controlled crossover study was performed with 15 volunteers of various fitness levels. Subjects ran a 3 mile (4.83 km simulated training run at their normal pace on two consecutive days (randomized one adaptive pacing, one sham. Adaptive pacing resulted in faster runs run times, with subjects running an average of 26:03 ± 3:23 for adaptive pacing and 26:38 ± 3:31 for sham (F = 5.46, p < 0.05. The increase in heart rate from the start of the race as estimated by an exponential time constant was significantly longer during adaptive pacing, τ = 0.99 ± 0.30, compared to sham, τ = 1.53 ± 0.34 (t = -6.62, p < 0.01. Eighty-seven percent of runners found it easy to adjust their stride length to match the pacing signal with seventy-nine percent reporting that pacing helped their performance. These results suggest that adaptive paced CLS may have a beneficial effect on running

  7. The effect of visitor number and spice provisioning in pacing expression by jaguars evaluated through a case study

    Directory of Open Access Journals (Sweden)

    L. S. Vidal

    Full Text Available Abstract Captive animals exhibit stereotypic pacing in response to multiple causes, including the inability to escape from human contact. Environmental enrichment techniques can minimize pacing expression. By using an individual-based approach, we addressed whether the amount of time two males and a female jaguar (Panthera onca devote to pacing varied with the number of visitors and tested the effectiveness of cinnamon and black pepper in reducing pacing. The amount of time that all jaguars engaged in pacing increased significantly with the number of visitors. Despite the difference between the males regarding age and housing conditions, both devoted significantly less time to pacing following the addition of both spices, which indicates their suitability as enrichment techniques. Mean time devoted to pacing among the treatments did not differ for the female. Our findings pointed out to the validity of individual-based approaches, as they can reveal how suitable olfactory stimuli are to minimizing stereotypies irrespective of particular traits.

  8. The effect of visitor number and spice provisioning in pacing expression by jaguars evaluated through a case study.

    Science.gov (United States)

    Vidal, L S; Guilherme, F R; Silva, V F; Faccio, M C S R; Martins, M M; Briani, D C

    2016-06-01

    Captive animals exhibit stereotypic pacing in response to multiple causes, including the inability to escape from human contact. Environmental enrichment techniques can minimize pacing expression. By using an individual-based approach, we addressed whether the amount of time two males and a female jaguar (Panthera onca) devote to pacing varied with the number of visitors and tested the effectiveness of cinnamon and black pepper in reducing pacing. The amount of time that all jaguars engaged in pacing increased significantly with the number of visitors. Despite the difference between the males regarding age and housing conditions, both devoted significantly less time to pacing following the addition of both spices, which indicates their suitability as enrichment techniques. Mean time devoted to pacing among the treatments did not differ for the female. Our findings pointed out to the validity of individual-based approaches, as they can reveal how suitable olfactory stimuli are to minimizing stereotypies irrespective of particular traits.

  9. Paralympic athletes with cerebral palsy display altered pacing strategies in distance-deceived shuttle running trials.

    Science.gov (United States)

    Runciman, P; Tucker, R; Ferreira, S; Albertus-Kajee, Y; Derman, W

    2016-10-01

    This study investigated performance and physiology to understand pacing strategies in elite Paralympic athletes with cerebral palsy (CP). Six Paralympic athletes with CP and 13 able-bodied (AB) athletes performed two trials of eight sets of 10 shuttles (total 1600m). One trial was distance-deceived (DEC, 1000 m + 600 m) one trial was nondeceived (N-DEC, 1600 m). Time (s), heart rate (HR, bpm), ratings of perceived exertion (RPE, units), and electromyography of five bilateral muscles (EMG) were recorded for each set of both trials. The CP group ran slower than the AB group, and pacing differences were seen in the CP DEC trial, presenting as a flat pacing profile over the trial (P < 0.05). HR was higher and RPE was lower in the CP group in both trials (P < 0.05). EMG showed small differences between groups, sides, and trials. The present study provides evidence for a possible pacing strategy underlying exercise performance and fatigue in CP. The results of this study show (1) underperformance of the CP group, and (2) altered pacing strategy utilization in the CP group. We proposed that even at high levels of performance, the residual effects of CP may negatively affect performance through selection of conservative pacing strategies during exercise.

  10. Active avoidance but not activity pacing is associated with disability in fibromyalgia.

    Science.gov (United States)

    Karsdorp, Petra A; Vlaeyen, Johan W S

    2009-12-15

    Activity pacing has been suggested as a behavioural strategy that may protect patients with fibromyalgia (FM) against activity dysregulation and disability. The aim of the present study was to empirically test whether the construct of activity pacing is distinct from other behavioural strategies assessed with the Chronic Pain Coping Inventory (CPCI), such as guarding, resting, asking for assistance, relaxation, task persistence, exercise/stretch, seeking social support, and coping self-statements. The second objective was to test whether pacing was associated with physical disability when controlling for pain catastrophizing, pain severity and the other behavioural strategies as measured with CPCI. A random sample of patients with FM (N=409) completed the CPCI, the Pain Catastrophizing Scale (PCS), the Physical Index of the Fibromyalgia Impact Questionnaire (FIQ-PH) and the Pain Disability Index (PDI). The results demonstrated that the Dutch version of the CPCI including the pacing subscale has adequate internal consistency and construct validity. Moreover, guarding and asking for assistance, but not pacing, were associated with disability. These findings are in line with fear-avoidance models and suggest that specifically active avoidance behaviours are detrimental in FM. The authors recommend developing cognitive-behavioural and exposure-based interventions and challenge the idea that pacing as an intervention is essential in pain self-management programs.

  11. Climatic controls on the pace of glacier erosion

    Science.gov (United States)

    Koppes, Michele; Hallet, Bernard; Rignot, Eric; Mouginot, Jeremie; Wellner, Julia; Love, Katherine

    2016-04-01

    precipitation rates at the end of glaciations favor the production of water from rainfall, surface melting and internal melting, which promotes sliding, erosion and sediment production and evacuation from under the ice. Hence, climatic variation, more than the extent of ice cover or ice volume, controls the pace at which glaciers shape mountains.

  12. Photovoltaic device

    Energy Technology Data Exchange (ETDEWEB)

    Reese, Jason A; Keenihan, James R; Gaston, Ryan S; Kauffmann, Keith L; Langmaid, Joseph A; Lopez, Leonardo; Maak, Kevin D; Mills, Michael E; Ramesh, Narayan; Teli, Samar R

    2017-03-21

    The present invention is premised upon an improved photovoltaic device ("PV device"), more particularly to an improved photovoltaic device with a multilayered photovoltaic cell assembly and a body portion joined at an interface region and including an intermediate layer, at least one interconnecting structural member, relieving feature, unique component geometry, or any combination thereof.

  13. Photovoltaic device

    Science.gov (United States)

    Reese, Jason A.; Keenihan, James R.; Gaston, Ryan S.; Kauffmann, Keith L.; Langmaid, Joseph A.; Lopez, Leonardo C.; Maak, Kevin D.; Mills, Michael E.; Ramesh, Narayan; Teli, Samar R.

    2015-06-02

    The present invention is premised upon an improved photovoltaic device ("PV device"), more particularly to an improved photovoltaic device with a multilayered photovoltaic cell assembly and a body portion joined at an interface region and including an intermediate layer, at least one interconnecting structural member, relieving feature, unique component geometry, or any combination thereof.

  14. Photovoltaic device

    Science.gov (United States)

    Reese, Jason A.; Keenihan, James R.; Gaston, Ryan S.; Kauffmann, Keith L.; Langmaid, Joseph A.; Lopez, Leonardo C.; Maak, Kevin D.; Mills, Michael E.; Ramesh, Narayan; Teli, Samar R.

    2015-09-01

    The present invention is premised upon an improved photovoltaic device ("PV device"), more particularly to an improved photovoltaic device (10) with a multilayered photovoltaic cell assembly (100) and a body portion (200) joined at an interface region (410) and including an intermediate layer (500), at least one interconnecting structural member (1500), relieving feature (2500), unique component geometry, or any combination thereof.

  15. A fast-start pacing strategy speeds pulmonary oxygen uptake kinetics and improves supramaximal running performance.

    Directory of Open Access Journals (Sweden)

    Tiago Turnes

    Full Text Available The focus of the present study was to investigate the effects of a fast-start pacing strategy on running performance and pulmonary oxygen uptake (VO2 kinetics at the upper boundary of the severe-intensity domain. Eleven active male participants (28±10 years, 70±5 kg, 176±6 cm, 57±4 mL/kg/min visited the laboratory for a series of tests that were performed until exhaustion: 1 an incremental test; 2 three laboratory test sessions performed at 95, 100 and 110% of the maximal aerobic speed; 3 two to four constant speed tests for the determination of the highest constant speed (HS that still allowed achieving maximal oxygen uptake; and 4 an exercise based on the HS using a higher initial speed followed by a subsequent decrease. To predict equalized performance values for the constant pace, the relationship between time and distance/speed through log-log modelling was used. When a fast-start was utilized, subjects were able to cover a greater distance in a performance of similar duration in comparison with a constant-pace performance (constant pace: 670 m±22%; fast-start: 683 m±22%; P = 0.029; subjects also demonstrated a higher exercise tolerance at a similar average speed when compared with constant-pace performance (constant pace: 114 s±30%; fast-start: 125 s±26%; P = 0.037. Moreover, the mean VO2 response time was reduced after a fast start (constant pace: 22.2 s±28%; fast-start: 19.3 s±29%; P = 0.025. In conclusion, middle-distance running performances with a duration of 2-3 min are improved and VO2 response time is faster when a fast-start is adopted.

  16. Pacing-induced congenital heart defects assessed by OCT (Conference Presentation)

    Science.gov (United States)

    Ford, Stephanie M.; McPheeters, Matt T.; Wang, Yves T.; Gu, Shi; Doughman, Yong Qiu; Strainic, James P.; Rollins, Andrew M.; Watanabe, Michiko; Jenkins, Michael W.

    2016-03-01

    The role of hemodynamics in early heart development is poorly understood. In order to successfully assess the impact of hemodynamics on development, we need to monitor and perturb blood flow, and quantify the resultant effects on morphology. Here, we have utilized cardiac optical pacing to create regurgitant flow in embryonic hearts and OCT to quantify regurgitation percentage and resultant morphology. Embryonic quail in a shell-less culture were optically paced at 3 Hz (well above the intrinsic rate or 1.33-1.67 Hz) on day 2 of development (3-4 weeks human) for 5 minutes. The pacing fatigued the heart and led to a prolonged period (> 1 hour) of increased regurgitant flow. Embryos were kept alive until day 3 (cardiac looping - 4-5 weeks human) or day 8 (4 chambered heart - 8 weeks human) to quantify resultant morphologic changes with OCT. All paced embryos imaged at day 3 displayed cardiac defects. The extent of regurgitant flow immediately after pacing was correlated with cardiac cushion size 24-hours post pacing (p-value congenital heart defects (CHDs) including 11/18 with valve defects, 5/18 with ventricular septal defects and 5/18 with hypoplastic right ventricles. Our data suggests that regurgitant flow leads to smaller cushions, which develop into abnormal valves and septa. Our model produces similar phenotypes as found in our fetal alcohol syndrome and velo-cardio-facial/DiGeorge syndrome models suggesting that hemodynamics plays a role in these syndromes as well. Utilizing OCT and optical pacing to understand hemodynamics in development is an important step towards determining CHD mechanisms and ultimately developing earlier treatments.

  17. Diritto internazionale umanitario, guerra e pace, diritti delle persone

    Directory of Open Access Journals (Sweden)

    Giovanni Barberini

    2011-11-01

    Full Text Available SOMMARIO: 1. Il diritto umanitario nei conflitti armati - 2. La codificazione del diritto umanitario - 3. Diritto della guerra e diritto della pace - 4. L’articolo 11 della costituzione italiana - 5. La protezione internazionale dei diritti e delle libertà della persona - 6. Conclusioni. Abstract: The military operators must also assure the peace with the weapons and, above all, the persons responsible of the operations must give test of great sensibility because busy to conjugate laws and rules war with the objectives of pacification. The authorities responsible for the operations at any time they need to know what they can or must do and what orders impart; they must know what it cannot do or what should be avoided. The international humanitarian law, important part of the international law, is constituted by conventional and consuetudinary norms that are applied in the relationships among States with a specific objective: to protect in time of armed conflict the people who do not take part or do not take more part in hostilities and impose bans or limits to the use of means offensive, of sophisticated weapons and methods of warfare in situations of armed conflict in act or to avoid sleepwalking. The codification of the international humanitarian law is initiated in the century XIX, above all when it was tried to introduce with the Declaration of Petersbourg in 1868 a principle that individualized in the contrariety to the laws of the humanity the impassable limit to respect in the armed conflicts. The codification has received then force and importance after the second world conflict that the consciences of the people had struck with the systematic practice of the most merciless violence making to record million of deads. The fundamental importance of the 1949 Geneva four Conventions is unanimously recognized. They are based on ratio of the existence and the responsibilities of the Organization of United Nations; they have properly

  18. A biophysically-based finite state machine model for analysing gastric experimental entrainment and pacing recordings

    Science.gov (United States)

    Sathar, Shameer; Trew, Mark L.; Du, Peng; O’ Grady, Greg; Cheng, Leo K.

    2014-01-01

    Gastrointestinal motility is coordinated by slow waves (SWs) generated by the interstitial cells of Cajal (ICC). Experimental studies have shown that SWs spontaneously activate at different intrinsic frequencies in isolated tissue, whereas in intact tissues they are entrained to a single frequency. Gastric pacing has been used in an attempt to improve motility in disorders such as gastroparesis by modulating entrainment, but the optimal methods of pacing are currently unknown. Computational models can aid in the interpretation of complex in-vivo recordings and help to determine optical pacing strategies. However, previous computational models of SW entrainment are limited to the intrinsic pacing frequency as the primary determinant of the conduction velocity, and are not able to accurately represent the effects of external stimuli and electrical anisotropies. In this paper, we present a novel computationally efficient method for modelling SW propagation through the ICC network while accounting for conductivity parameters and fiber orientations. The method successfully reproduced experimental recordings of entrainment following gastric transection and the effects of gastric pacing on SW activity. It provides a reliable new tool for investigating gastric electrophysiology in normal and diseased states, and to guide and focus future experimental studies. PMID:24276722

  19. Physiological and psychological effects of deception on pacing strategy and performance: a review.

    Science.gov (United States)

    Jones, Hollie S; Williams, Emily L; Bridge, Craig A; Marchant, Dave; Midgley, Adrian W; Micklewright, Dominic; Mc Naughton, Lars R

    2013-12-01

    The aim of an optimal pacing strategy during exercise is to enhance performance whilst ensuring physiological limits are not surpassed, which has been shown to result in a metabolic reserve at the end of the exercise. There has been debate surrounding the theoretical models that have been proposed to explain how pace is regulated, with more recent research investigating a central control of exercise regulation. Deception has recently emerged as a common, practical approach to manipulate key variables during exercise. There are a number of ways in which deception interventions have been designed, each intending to gain particular insights into pacing behaviour and performance. Deception methodologies can be conceptualised according to a number of dimensions such as deception timing (prior to or during exercise), presentation frequency (blind, discontinuous or continuous) and type of deception (performance, biofeedback or environmental feedback). However, research evidence on the effects of deception has been perplexing and the use of complex designs and varied methodologies makes it difficult to draw any definitive conclusions about how pacing strategy and performance are affected by deception. This review examines existing research in the area of deception and pacing strategies, and provides a critical appraisal of the different methodological approaches used to date. It is hoped that this analysis will inform the direction and methodology of future investigations in this area by addressing the mechanisms through which deception impacts upon performance and by elucidating the potential application of deception techniques in training and competitive settings.

  20. Application of PACE Principles for Population Health Management of Frail Older Adults.

    Science.gov (United States)

    Stefanacci, Richard G; Reich, Shelley; Casiano, Alex

    2015-10-01

    To determine which practices would have the most impact on reducing hospital and emergency department admissions and nursing home placement among older adults with multiple comorbid conditions, a literature search and survey were conducted to identify and prioritize comprehensive care principles as practiced in the Program of All-inclusive Care for the Elderly (PACE). PACE medical directors and members of the PACE interdisciplinary team (IDT) were surveyed to gain their insights on the most impactful practices, which were identified as: End-of-Life Management, Caregiver Support, Management of Red Flags, Medication Management, Participant and Caregiver Health Care System Literacy, and Care Coordination. In addition, this research evaluated measures that could be used to assess an organization's level of success with regard to each of the 6 PACE practices identified. The results reported in this article, found through a survey with PACE medical directors and IDT members concerning effective interventions, can be viewed as strategies to improve care for older adults, enabling them to maintain their independence in the community, avoid the expense of facility-based care, and enhance their quality of life.

  1. Potential Effect of Physical Activity Calorie Equivalent (PACE Labeling on Adult Fast Food Ordering and Exercise.

    Directory of Open Access Journals (Sweden)

    Ray Antonelli

    Full Text Available Numeric calorie content labels show limited efficacy in reducing the number of calories ordered from fast food meals. Physical activity calorie equivalent (PACE labels are an alternative that may reduce the number of calories ordered in fast food meals while encouraging patrons to exercise.A total of 1000 adults from 47 US states were randomly assigned via internet survey to one of four generic fast food menus: no label, calories only, calories + minutes, or calories + miles necessary to walk to burn off the calories. After completing hypothetical orders participants were asked to rate the likelihood of calorie-only and PACE labels to influence (1 food choice and (2 physical activity.Respondents (n = 823 ordered a median of 1580 calories from the no-label menu, 1200 from the calories-only menu, 1140 from the calories + minutes menu, and 1210 from the calories + miles menu (p = 0.0001. 40% of respondents reported that PACE labels were "very likely" to influence food item choice vs. 28% for calorie-only labels (p<0.0001. 64% of participants reported that PACE labels were "somewhat likely" or "very likely" to influence their level of physical activity vs. 49% for calorie-only labels (p<0.0001.PACE labels may be helpful in reducing the number of calories ordered in fast food meals and may have the added benefit of encouraging exercise.

  2. Ventricular evoked response in patients with hypertrophic obstructive cardiomyopathy treated with DDD pacing

    Directory of Open Access Journals (Sweden)

    João Ricardo M. Sant'Anna

    1999-08-01

    Full Text Available OBJECTIVE: To assess the changes in ventricular evoked responses (VER produced by the decrease in left ventricular outflow tract gradient (LVOTG in patients with hypertrophic obstructive cardiomyopathy (HOCM treated with dual-chamber (DDD pacing. METHODS: A pulse generator Physios CTM (Biotronik, Germany was implanted in 9 patients with severe drug-refractory HOCM. After implantation, the following conditions were assessed: 1 Baseline evaluation: different AV delay (ranging from 150ms to 50 ms were sequentially programmed during 5 to 10 minutes, and the LVOTG (as determined by Doppler echocardiography and VER recorded; 2 standard evaluation, when the best AV delay (resulting in the lowest LVOTG programmed at the initial evaluation was maintained so that its effect on VER and LVOTG could be assessed during each chronic pacing evaluation. RESULTS: LVOTG decreased after DDD pacing, with a mean value of 59 ± 24 mmHg after dual chamber pacemaker, which was significantly less than the gradient before pacing (98 + 22mmHg. An AV delay >100ms produced a significantly lower decrease in VER depolarization duration (VER DD when compared to an AV delay <=100ms. Linear regression analyses showed a significant correlation between the LVOTG values and the magnitude of VER (r=0.69; p<0.05 in the 9 studied patients. CONCLUSION: The telemetry obtained intramyocardial electrogram is a sensitive means to assess left ventricular dynamics in patients with HOCM treated with DDD pacing.

  3. Provenance Context Entity (PaCE): Scalable Provenance Tracking for Scientific RDF Data.

    Science.gov (United States)

    Sahoo, Satya S; Bodenreider, Olivier; Hitzler, Pascal; Sheth, Amit; Thirunarayan, Krishnaprasad

    The Resource Description Framework (RDF) format is being used by a large number of scientific applications to store and disseminate their datasets. The provenance information, describing the source or lineage of the datasets, is playing an increasingly significant role in ensuring data quality, computing trust value of the datasets, and ranking query results. Current provenance tracking approaches using the RDF reification vocabulary suffer from a number of known issues, including lack of formal semantics, use of blank nodes, and application-dependent interpretation of reified RDF triples. In this paper, we introduce a new approach called Provenance Context Entity (PaCE) that uses the notion of provenance context to create provenance-aware RDF triples. We also define the formal semantics of PaCE through a simple extension of the existing RDF(S) semantics that ensures compatibility of PaCE with existing Semantic Web tools and implementations. We have implemented the PaCE approach in the Biomedical Knowledge Repository (BKR) project at the US National Library of Medicine. The evaluations demonstrate a minimum of 49% reduction in total number of provenance-specific RDF triples generated using the PaCE approach as compared to RDF reification. In addition, performance for complex queries improves by three orders of magnitude and remains comparable to the RDF reification approach for simpler provenance queries.

  4. Left ventricular performance during triggered left ventricular pacing in patients with cardiac resynchronization therapy and left bundle branch block

    DEFF Research Database (Denmark)

    Witt, Christoffer Tobias; Kronborg, Mads Brix; Nohr, Ellen Aagaard;

    2016-01-01

    PURPOSE: To assess the acute effect of triggered left ventricular pacing (tLVp) on left ventricular performance and contraction pattern in patients with heart failure, left bundle branch block (LBBB), and cardiac resynchronization therapy (CRT). METHODS: Twenty-three patients with pre-implant QRS...... conduction, tLVp, and BiV pacing and compared as paired data. Echocardiographic analysis was done blinded with respect to pacing mode. RESULTS: LVEF was significantly higher during BiV pacing (47 ± 11 %) compared with intrinsic conduction (43 ± 13 %, P = 0.001) and tLVp (44 ± 13 %, P = 0.001), while......V pacing. CONCLUSIONS: The acute effect of tLVp on LV systolic function and contraction pattern is significantly lower than the effect of BiV pacing and not different from intrinsic conduction in patients with LBBB and CRT....

  5. Microfluidic Device

    Science.gov (United States)

    Tai, Yu-Chong (Inventor); Zheng, Siyang (Inventor); Lin, Jeffrey Chun-Hui (Inventor); Kasdan, Harvey L. (Inventor)

    2017-01-01

    Described herein are particular embodiments relating to a microfluidic device that may be utilized for cell sensing, counting, and/or sorting. Particular aspects relate to a microfabricated device that is capable of differentiating single cell types from dense cell populations. One particular embodiment relates a device and methods of using the same for sensing, counting, and/or sorting leukocytes from whole, undiluted blood samples.

  6. NSTX ELM Pacing and L-H Threshold Experiments for ITER

    Science.gov (United States)

    Canik, J. M.; Maingi, R.; Sontag, A. C.; Gerhardt, S. P.; Kaye, S.; Bell, R. E.; Gates, D.; Goldston, R.; Leblanc, B. P.; Menard, J.; Park, J.-K.; Evans, T.; Osborne, T.; Sabbagh, S.; Unterberg, E. A.

    2009-11-01

    We present a summary of recent edge-localized mode (ELM) pacing and L-H power threshold (PLH) experiments performed in NSTX in support of ITER. ELM triggering using 3D magnetic perturbations was used to perform pacing during ELM-free H-modes induced by lithium conditioning, mitigating the impurity accumulation typically observed in these conditions. The waveform of the applied field has been tailored to provide high reliability triggering at frequencies of >60 Hz to reduce the average ELM size. ELM pacing was also performed using vertical position oscillations, with the ELM frequency increased to ˜30 Hz from a natural frequency of ˜15 Hz. PLH is reduced by ˜50% at low triangularity, and also decreased by ˜50% during discharge with thick lithium wall coatings. PLH was observed to increase strongly with plasma current during sustained H-modes. The influence of heating method, non-axisymmetric fields, and magnetic balance on PLH will be presented.

  7. Preparative activities in posterior parietal cortex for self-paced movement in monkeys.

    Science.gov (United States)

    Gemba, Hisae; Matsuura-Nakao, Kazuko; Matsuzaki, Ryuichi

    2004-02-26

    Cortical field potentials were recorded by electrodes implanted chronically on the surface and at a 2.0-3.0 mm depth in various cortices in monkeys performing self-paced finger, toe, mouth, hand or trunk movements. Surface-negative, depth-positive potentials (readiness potential) appeared in the posterior parietal cortex about 1.0 s before onset of every self-paced movement, as well as in the premotor, motor and somatosensory cortices. Somatotopical distribution was seen in the readiness potential in the posterior parietal cortex, although it was not so distinct as that in the motor or somatosensory cortex. This suggests that the posterior parietal cortex is involved in preparation for self-paced movement of any body part. This study contributes to the investigation of central nervous mechanisms of voluntary movements initiated by internal stimulus.

  8. The Influence of Mid-Event Deception on Psychophysiological Status and Pacing Can Persist across Consecutive Disciplines and Enhance Self-paced Multi-modal Endurance Performance

    Science.gov (United States)

    Taylor, Daniel; Smith, Mark F.

    2017-01-01

    Purpose: To examine the effects of deceptively aggressive bike pacing on performance, pacing, and associated physiological and perceptual responses during simulated sprint-distance triathlon. Methods: Ten non-elite, competitive male triathletes completed three simulated sprint-distance triathlons (0.75 km swim, 500 kJ bike, 5 km run), the first of which established personal best “baseline” performance (BL). During the remaining two trials athletes maintained a cycling power output 5% greater than BL, before completing the run as quickly as possible. However, participants were informed of this aggressive cycling strategy before and during only one of the two trials (HON). Prior to the alternate trial (DEC), participants were misinformed that cycling power output would equal that of BL, with on-screen feedback manipulated to reinforce this deception. Results: Compared to BL, a significantly faster run performance was observed following DEC cycling (p triathlon performance to be quicker during DEC (4339 ± 395 s) compared to HON (4356 ± 384 s), the only significant and almost certainly meaningful differences were between each of these trials and BL (4465 ± 420 s; p triathlon run. Conclusions: The present study is the first to show that mid-event pace deception can have a practically meaningful effect on multi-modal endurance performance, though the relative importance of different psychophysiological and emotional responses remains unclear. Whilst our findings support the view that some form of anticipatory “template” may be used by athletes to interpret levels of psychophysiological and emotional strain, and regulate exercise intensity accordingly, they would also suggest that individual constructs such as RPE and affect may be more loosely tied with pacing than previously suggested. PMID:28174540

  9. Estudo comparativo das estimulações ventricular direita e biventricular no pós-operatório de revascularização miocárdica

    Directory of Open Access Journals (Sweden)

    ALBUQUERQUE Luciano C.

    2002-01-01

    Full Text Available OBJETIVO: Nos anos recentes, a ressincronização ventricular tem sido proposta como adjuvante no tratamento da insuficiência cardíaca congestiva. O objetivo deste estudo é comparar as alterações eletrocardiográficas e o efeito hemodinâmico imediato das estimulações ventricular direita (EVD e biventricular (EBV, no pós-operatório de operação de revascularização miocárdica (CRM com circulação extracorpórea (CEC. CASUÍSTICA E MÉTODOS: Em um ensaio clínico cruzado, 13 pacientes com doença coronária multiarterial, e fração de ejeção inferior a 50%, foram submetidos a estimulação epicárdica temporária univentricular direita e biventricular, no 5° dia de pós-operatório. As variáveis analisadas foram duração do complexo QRS, dimensões do átrio esquerdo (AE e ventrículo esquerdo (VE, fração de encurtamento do VE (delta D e fração de ejeção do VE. Os grupos foram comparados através do teste de t de Student para amostras pareadas, considerando-se nível de significância de 0,05. RESULTADOS: A duração média do complexo QRS foi de 185±26 ms durante a EVD, e de 126±37 ms com a EBV (p<0,001. O diâmetro médio do AE com a EVD foi de 40±4 mm, e de 35±4 mm na EBV (p<0,001. As médias dos diâmetros diastólico e sistólico finais do VE foram, respectivamente, de 49±13 mm e 59±11 mm com a EVD, e de 42±12 mm e 52±10 mm durante a EBV (p<0,001. A delta D média do VE determinada pela EVD foi de 18±7%, e de 22±8% com a EBV (p=0,017. A fração de ejeção média do VE com a EVD foi de 33±14%, e de 46±17% durante a EBV (p<0,001. CONCLUSÃO: No modelo estudado, a estimulação biventricular temporária determinou melhora significativa do desempenho hemodinâmico, em comparação à estimulação ventricular direita, e um complexo QRS com duração próxima à fisiológica.

  10. Physiological demand and pacing strategy during the new combined event in elite pentathletes.

    Science.gov (United States)

    Le Meur, Yann; Dorel, Sylvain; Baup, Yann; Guyomarch, Jean Pierre; Roudaut, Christian; Hausswirth, Christophe

    2012-07-01

    To evaluate the physiological demands and effects of different pacing strategies on performance during the new combined event (CE) of the modern pentathlon (consisting of three pistol shooting sessions interspersed by three 1-km running legs). Nine elite pentathletes realised five tests: a free-paced CE during an international competition; an incremental running test to determine [Formula: see text] and its related velocity ([Formula: see text]) and three experimental time-trial CE, where the pacing strategy was manipulated (CE(ref), CE(100%), CE(105%)). CE(ref) reproduced the international competition strategy with a 170-m fast running start within the first 2 km. CE(100%) and CE(105%) imposed a constant strategy over km-1 and km-2 with a velocity of 100 and 105% of the mean speed adopted over the same sections during the international competition, respectively. Km-3 was always self-paced. The subjects ran CE(ref) at 99 ± 4% of [Formula: see text] and reached 100 ± 5, 100 ± 7, 99 ± 8% of [Formula: see text] at the end of kilometres 1, 2 and 3, respectively ([Formula: see text]: 72 ± 6 mL O(2) min(-1) kg(-1)), with a peak blood lactate concentration of 13.6 ± 1.5 mmol L(-1). No significant differences in overall performance were found between the pacing conditions (753 ± 30, 770 ± 39, 768 ± 27 s for CE(ref), CE(100%) and CE(105%), respectively, p = 0.63), but all of the shooting performance parameters were only stable in CE(ref). Completion of CE by elite pentathletes elicits a maximal aerobic contribution coupled with a high glycolytic supply. Manipulating the mean running speed over km-1 and km-2 had strong influence on the overall pacing strategy and induced minor differences in shooting performance, but it did not affect overall performance.

  11. Developmental Differences in Effects of Task Pacing on Implicit Sequence Learning

    Directory of Open Access Journals (Sweden)

    Amanda Sue Hodel

    2014-02-01

    Full Text Available Although there is now substantial evidence that developmental change occurs in implicit learning abilities over the lifespan, disparate results exist regarding the specific developmental trajectory of implicit learning skills. One possible reason for discrepancies across implicit learning studies may be that younger children show an increased sensitivity to variations in implicit learning task procedures and demands relative to adults. Studies using serial-reaction time (SRT tasks have suggested that in adults, measurements of implicit learning are robust across variations in task procedures. Most classic SRT tasks have used response-contingent pacing in which the participant’s own reaction time determines the duration of each trial. However, recent paradigms with adults and children have used fixed trial pacing, which leads to alterations in both response and attention demands, accuracy feedback, perceived agency, and task motivation for participants. In the current study, we compared learning on fixed-paced and self-paced versions of a spatial sequence learning paradigm in 4-year-old children and adults. Results indicated that preschool-aged children showed reduced evidence of implicit sequence learning in comparison to adults, regardless of the SRT paradigm used. In addition, we found the preschoolers showed significantly greater learning when stimulus presentation was self-paced. These data provide evidence for developmental differences in implicit sequence learning that are dependent on specific task demands such as stimulus pacing, which may be related to developmental changes in the impact of broader constructs such as attention and task motivation on implicit learning.

  12. First Observation Of ELM Pacing With Vertical Jogs In A Spherical Torus

    Energy Technology Data Exchange (ETDEWEB)

    Gerhardt, S P; Canik, J M; Maingi, R; Bell, R; Gates, d; Goldston, R; Hawryluk, R; Le Blanc, B P; Menard, J; Sontag, A C; Sabbagh, S

    2010-07-15

    Experiments in a number of conventional aspect ratio tokamaks have been successful in pacing edge localized modes (ELMs) by rapid vertical jogging of the plasma. This paper demonstrates the first pacing of ELMs in a spherical torus plasma. Applied 30 Hz vertical jogs synchronized the ELMs with the upward motion of the plasma. 45 Hz jogs also lead to an increase in the ELM frequency, though the synchronization of the ELMs and jogs was unclear. A reduction in the ELM energy was observed at the higher driven ELM frequencies. __________________________________________________

  13. First observation of ELM pacing with vertical jogs in a spherical torus

    Energy Technology Data Exchange (ETDEWEB)

    Gerhardt, S.P. [Princeton Plasma Physics Laboratory (PPPL); Ahn, Joon-Wook [Oak Ridge National Laboratory (ORNL); Canik, John [ORNL; Maingi, R. [Oak Ridge National Laboratory (ORNL); Bell, R. [Princeton Plasma Physics Laboratory (PPPL); Gates, D. [Princeton Plasma Physics Laboratory (PPPL); Goldston, R. [Princeton Plasma Physics Laboratory (PPPL); Hawryluk, R. [Princeton Plasma Physics Laboratory (PPPL); Le Blanc, B. P. [Princeton Plasma Physics Laboratory (PPPL); Menard, J. [Princeton Plasma Physics Laboratory (PPPL); Sontag, Aaron C [ORNL; Sabbagh, S. A. [Columbia University; Tritz, K. [Johns Hopkins University

    2010-01-01

    Experiments in a number of conventional aspect ratio tokamaks have been successful in pacing edge localized modes (ELMs) by rapid vertical jogging of the plasma. This paper demonstrates the first pacing of ELMs in a spherical torus plasma. Applied 30 Hz vertical jogs synchronized the ELMs with the upward motion of the plasma. 45 Hz jogs also lead to an increase in the ELM frequency, though the synchronization of the ELMs and jogs was unclear. A reduction in the ELM energy was observed at the higher driven ELM frequencies.

  14. First observation of ELM pacing with vertical jogs in a spherical torus

    Science.gov (United States)

    Gerhardt, S. P.; Ahn, J.-W.; Canik, J. M.; Maingi, R.; Bell, R.; Gates, D.; Goldston, R.; Hawryluk, R.; Le Blanc, B. P.; Menard, J.; Sontag, A. C.; Sabbagh, S.; Tritz, K.

    2010-06-01

    Experiments in a number of conventional aspect ratio tokamaks have been successful in pacing edge localized modes (ELMs) by rapid vertical jogging of the plasma. This paper demonstrates the first pacing of ELMs in a spherical torus plasma. Applied 30 Hz vertical jogs synchronized the ELMs with the upward motion of the plasma. 45 Hz jogs also lead to an increase in the ELM frequency, though the synchronization of the ELMs and jogs was unclear. A reduction in the ELM energy was observed at the higher driven ELM frequencies.

  15. Pacing Lead-Induced Granuloma in the Atrium: A Foreign Body Reaction to Polyurethane

    Directory of Open Access Journals (Sweden)

    Shinagawa Yoko

    2013-01-01

    Full Text Available We described a case of an 82-year-old male who presented with a granuloma entrapping the polyurethane-coated pacing lead at the site of contact on the atrium. He had been paced for 8 years without symptoms or signs suggestive of an allergic reaction to the pacemaker system and died from thrombosis of the superior mesenteric artery and heart failure. A histological examination of the nodule showed an incidental granuloma with multinucleated giant cells. No granuloma was found in the heart or the lung.

  16. MCTS self-paced training kit (exam 70-680) configuring Windows 7

    CERN Document Server

    McLean, Ian

    2010-01-01

    NOTE: The most recent printings of this title incorporate corrections to errors found in the earlier printings. This Self-Paced Training Kit is designed to help maximize your performance on 70-680, the required exam for the Microsoft® Certified Technology Specialist (MCTS): Windows 7, Configuration certification.This 2-in-1 kit includes the official Microsoft study guide, plus practice tests on CD to help you assess your skills. It comes packed with the tools and features exam candidates want most-including in-depth, self-paced training based on final exam content; rigorous, objective-by-obj

  17. Pacing the Cell: Walking and Productivity in the Work of Bruce Nauman

    Directory of Open Access Journals (Sweden)

    Ruth Burgon

    2016-12-01

    Full Text Available After graduating from art school in the late 1960s Bruce Nauman found himself pacing his studio, unsure how to produce work as a professional artist. Out of this practice arose several films and videos recording these performances of studio pacing. This paper draws upon Michel Foucault’s Discipline and Punish (1975, translated into English 1977 to shed light upon the aesthetic of confinement and incarceration found in Nauman’s use of the walking body in this early work.

  18. Unification of Frequency direction Pilot-symbol Aided Channel Estimation (PACE) for OFDM

    DEFF Research Database (Denmark)

    Rom, Christian; Manchón, Carles Navarro; Deneire, Luc

    2007-01-01

    Frequency direction Pilot-symbol Aided Channel Estimation (PACE) for Orthogonal Frequency Division Multiplexing (OFDM) is crucial in high-rate wireless systems. The choice of an estimator for upcoming standards, such as the Long Term Evolution (LTE) of UTRA, has to take into account their specifi......Frequency direction Pilot-symbol Aided Channel Estimation (PACE) for Orthogonal Frequency Division Multiplexing (OFDM) is crucial in high-rate wireless systems. The choice of an estimator for upcoming standards, such as the Long Term Evolution (LTE) of UTRA, has to take into account...

  19. Avaliar a correlação entre a concentração da hemoglobina e a medida ecográfica do diâmetro biventricular externo em fetos anêmicos de gestantes isoimunizadas

    Directory of Open Access Journals (Sweden)

    Rodrigues Rosangela Lopes Miranda

    2005-01-01

    Full Text Available OBJETIVO: Verificar se existe correlação significativa entre a medida ecográfica do diâmetro biventricular externo e a concentração sérica da hemoglobina fetal pré-transfusional e se essa medida ecográfica poderá vir a ser utilizada como marcador não invasivo da anemia fetal. MÉTODOS: Estudo transversal prospectivo, no qual foram selecionadas 65 cordocenteses realizadas em 36 fetos anêmicos de mães portadoras de isoimunização pelo fator Rh. Obteve-se a medida do diâmetro biventricular externo (DBVE, por meio do modo M, utilizando-se aparelho de ultra-som convencional. Anterior à transfusão foi obtida amostra de 0,5ml de sangue fetal, para dosagem da hemoglobina, sendo a medida imediatamente realizada através de espectrofotometria, no equipamento Hemocue®. Como análise estatística foi utilizada a regressão dos mínimos quadrados, aceitando-se p<0,05 e análise multivariada. RESULTADOS: Foram observadas correlação inversa entre a concentração da hemoglobina no sangue fetal no momento prévio à transfusão e a medida do DBVE e correlação direta entre a medida do DBVE e a idade gestacional, e, também, através da análise multivariada que, à medida que a concentração de hemoglobina fetal cai, o DBVE aumenta, independentemente da influência da idade gestacional nesse parâmetro. CONCLUSÃO: Existe correlação inversa entre a concentração da hemoglobina no sangue fetal e a medida do DBVE, independente da idade gestacional. Os achados sugerem que o DBVE poderá vir a ser um marcador ecográfico de predição do nível de hemoglobina de fetos de gestantes isoimunizadas.

  20. Diagnostic accuracy of metronome-paced tachypnea to detect dynamic hyperinflation

    NARCIS (Netherlands)

    Lahaije, A.J.M.C.; Willems, L.M.; Hees, H.W. van; Dekhuijzen, P.N.R.; Helvoort, H.A.C. van; Heijdra, Y.F.

    2013-01-01

    INTRODUCTION: This prospective study was carried out to investigate if metronome-paced tachypnea (MPT) can serve as an accurate diagnostic tool to identify patients with chronic obstructive pulmonary disease (COPD) who are susceptible to develop dynamic hyperinflation during exercise. Commonly, this

  1. Dynamic hyperinflation after metronome-paced hyperventilation in COPD--a 2 year follow-up.

    NARCIS (Netherlands)

    Hannink, J.D.C.; Lahaije, A.; Bischoff, E.W.M.A.; Helvoort, H.A.C. van; Dekhuijzen, R.; Schermer, T.R.J.; Heijdra, Y.F.

    2010-01-01

    In contrast to the decline in FEV(1), the behavior of dynamic hyperinflation (DH) over time is unknown in patients with COPD. Metronome-paced hyperventilation (MPH) is a simple applicable surrogate for exercise to detect DH. OBJECTIVE: To evaluate changes in MPH-induced DH during two years follow-up

  2. Pacing Behavior and Tactical Positioning in 500-and 1000-m Short-Track Speed Skating

    NARCIS (Netherlands)

    Noorbergen, Olaf S.; Konings, Marco J.; Micklewright, Dominic; Elferink-Gemser, Marge T.; Hettinga, Florentina J.

    2016-01-01

    Purpose: To explore pacing behavior and tactical positioning during the shorter 500- and 1000-m short-track competitions. Methods: Lap times and intermediate rankings of elite 500- and 1000-m short-track-skating competitors were collected over the 2012-13 season. First, lap times were analyzed using

  3. China's Manufacturing Expands at Slowest Pace in 28 Months

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    The manufacturing sector expanded at its slowest pace in 28 months in June, with the Purchasing Managers Index (PMI) falling 1.1 percentage points monthon-month to 50.9 percent, according to the China Federation of Logistics and Purchasing (CFLP).

  4. On the Cutting Edge (of Torpor): Innovation and the Pace of Change in American Higher Education

    Science.gov (United States)

    Murray, Gordon

    2008-01-01

    This article considers the pace of innovation and technology adoption in higher education and suggests that the rate of change on 21st century campuses is remarkably similar to earlier centuries when it may have taken over 30 years to introduce "modern" inventions like the telescope, microscope, and barometer to students. The literature shows that…

  5. Characterizing the concept of activity pacing as a non-pharmacological intervention in rheumatology care

    DEFF Research Database (Denmark)

    Cuperus, N; Vliet Vlieland, Tpm; Brodin, N;

    2016-01-01

    OBJECTIVE: To develop a consensual list of the most important aspects of activity pacing (AP) as an intervention within the context of non-pharmacological rheumatology care. METHOD: An international, multidisciplinary expert panel comprising 60 clinicians and/or healthcare providers experienced i...

  6. Self-Pacing a Gross Motor Skills Course: Crawler Tractor Operator, MOS 62E20.

    Science.gov (United States)

    Brennan, Mark F.; Taylor, John E.

    As part of the Army's emphasis on performance-oriented instruction in training centers, a study was conducted to determine the feasibility of using self-paced instruction in a gross motor skills course. The Crawler Tractor Operator Course, a seven-week heavy equipment course conducted at Fort Leonard Wood, Missouri was selected for the study…

  7. Molecular mechanisms of early atrial remodeling by rapid atrial pacing in rabbits

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Objective: To establish a rabbit atrial fibrillation model with rapid atrial pacing (RAP) and investigate its ultrastructural changes and expressions of L-type calcium channel subunits and potassium channel Ky4.3. Methods: Thirty-six rabbits were performed electrical stimulation through bipolar endocardial led by surgical technique, 600 beat per min from 0 to 48 h. Atrial ultrastructure was observed by transmission electron microscope (TEM) after different pacing times. mRNA were measured by reverse transcription-polymerase chain reaction (RT-PCR). Results: Atrial ultrastructure had alteration after 3 hours' pacing, such as mitochondria vacuolization, myofilament lysis and glucogen aggregation. The mRNA of the Ca2+ channel β1 and α1 subunits began to decrease after pacing of 6 h, which were paralleled with the change of Kv4.3 mRNA. But the auxiliary subunit α2 were not affected. Conclusion: Ultrastructural changes and mRNA levels of L-type calcium channel subunits and potassium channel Kv4.3 are decreased after RAP, with a mechanism of transcriptional down-regulation of underlying ion channels due to calcium overloading after RAP.

  8. Developmental Pacing as an Alternative to Ability Grouping in a Primary Setting.

    Science.gov (United States)

    Piel, John A.

    An alternative to ability grouping for instructional purposes exists. Cognitive developmental grouping (CDG), sometimes labeled "tracking" or "pacing," organizes students in terms of similar learning styles and takes into consideration the child's intellectual maturation rather than performance within a particular curriculum…

  9. Constitutive innate immunity is a component of the pace-of-life syndrome in tropical birds

    NARCIS (Netherlands)

    Tieleman, BI; Williams, JB; Ricklefs, RE; Klasing, KC; Williams, Joseph B.; Ricklefs, Robert E.; Klasing, Kirk C.

    2005-01-01

    We studied the relationship between one component of immune function and basal metabolic rate (BMR), an indicator of the 'pace-of-life syndrome', among 12 tropical bird species and among individuals of the tropical house wren (Troglodytes aedon), to gain insights into functional connections between

  10. Effects of wind application on thermal perception and self-paced performance

    NARCIS (Netherlands)

    Teunissen, L.P.J.; Haan, A. de; Koning, J.J. de; Daanen, H.A.M.

    2013-01-01

    Physiological and perceptual effects of wind cooling are often intertwined and have scarcely been studied in self-paced exercise. Therefore, we aimed to investigate (1) the independent perceptual effect of wind cooling and its impact on performance and (2) the responses to temporary wind cooling dur

  11. VDDR pacing after His-bundle ablation for paroxysmal atrial fibrillation : A pilot study

    NARCIS (Netherlands)

    Buys, EM; van Hemel, NM; Jessurun, ER; Bakema, L; Kingma, JH

    1998-01-01

    His-bundle ablation followed by pacemaker implantation is today a widely accepted therapeutic choice when drug refractoriness of symptomatic AF is evident. The selection of pacing mode in patients suffering from paroxysmal AF is still controversial. Preservation of AV synchrony is an attractive opti

  12. Exercise capacity in children with isolated congenital complete atrioventricular block: does pacing make a difference?

    NARCIS (Netherlands)

    Blank, A.C.; Hakim, S.; Strengers, J.L.; Tanke, R.B.; Veen, T.A. van; Vos, M.E. de; Takken, T.

    2012-01-01

    The management of patients with isolated congenital complete atrioventricular block (CCAVB) has changed during the last decades. The current policy is to pace the majority of patients based on a variety of criteria, among which is limited exercise capacity. Data regarding exercise capacity in this p

  13. Exercise Capacity in Children With Isolated Congenital Complete Atrioventricular Block : Does Pacing Make a Difference?

    NARCIS (Netherlands)

    Blank, A. Christian; Hakim, Sara; Strengers, Jan L.; Tanke, Ronald B.; van Veen, Toon A.; Vos, Marc A.; Takken, Tim

    2012-01-01

    The management of patients with isolated congenital complete atrioventricular block (CCAVB) has changed during the last decades. The current policy is to pace the majority of patients based on a variety of criteria, among which is limited exercise capacity. Data regarding exercise capacity in this p

  14. Investigating the Effects of Concurrent Performance of Physical and Cognitive Demanding Task in Paced Assembly Lines

    Directory of Open Access Journals (Sweden)

    Shakil Ahmed Shaikh

    2013-07-01

    Full Text Available The study was undertaken to investigate the effects of pacing on aspects of performance at an assembly task and on the operators' responses related to work behaviour, perceived workload and perceived stress. A particular objective of the study was to investigate whether physical and cognitive demands may interact in their influences on these effects. An assembly task was simulated in the laboratory and the level of pacing imposed, work height and memory load within the task were all varied. The results showed that the type of pacing commonly imposed (as is common with a lean manufacturing Takt time system in industry can significantly affect both performance and perceived workload and stress. Physical demands (through work height affecting posture and mental demand (through memory load were also found to have significant effects, as would be expected from the many studies of these in the literature. More importantly, some interactions were found between pacing and work height in their effects on quality of assembly and the operator's own rating of performance, and between work height and memory load in their effects on errors. These findings will need to be taken into account by companies when implementing Takt time systems.

  15. PERMANENT CARDIAC PACING IN CHILDREN - MORBIDITY AND EFFICACY OF FOLLOW-UP

    NARCIS (Netherlands)

    KERSTJENSFREDERIKSE, MWS; BINKBOELKENS, MTE; DEJONGSTE, MJL; VANDERHEIDE, JNH

    1991-01-01

    The data from 50 permanently paced children [mean standard deviation follow-up 5.3 +/- 3.7 years] were reviewed, with special attention being paid to the cause of complications and the efficacy of follow-up. The 5-year survival (SD) of the patients was 78 +/- 6%; mortality was mainly due to the unde

  16. Pacing, the missing piece of the puzzle to high-intensity interval training.

    Science.gov (United States)

    Zadow, E K; Gordon, N; Abbiss, C R; Peiffer, J J

    2015-03-01

    This study examined physiological and perceptual responses to matched work high-intensity interval training using all-out and 2 even-paced methodologies. 15 trained male cyclists performed 3 interval sessions of three 3-min efforts with 3 min of active recovery between efforts. The initial interval session was completed using all-out pacing, with the following 2 sessions being completed with computer- and athlete-controlled pacing in a randomised and semi-counterbalanced manner. Computer- and athlete-controlled intervals were completed at the mean power from the corresponding interval during the all-out trial. Oxygen consumption and ratings of perceived exertion were recorded during each effort. 20 min following each session, participants completed a 4-km time trial and provided sessional rating of perceived exertion. Oxygen consumption was greater during all-out (54.1±6.6 ml.kg(-1).min(-1); pintervals. Distribution of pace throughout high-intensity interval training can influence perceptual and metabolic stress along with subsequent performance and should be considered during the prescription of such training.

  17. Pacing Strategy, Muscle Fatigue and Technique in 1500m Speed Skating and Cycling Time-Trials

    NARCIS (Netherlands)

    Stoter, Inge K; MacIntosh, Brian R; Fletcher, Jared R; Pootz, Spencer; Zijdewind, Inge; Hettinga, Florentina J

    2016-01-01

    PURPOSE: To evaluate pacing behavior and peripheral and central contributions to muscle fatigue in 1500m speed skating and cycling time-trials, when a faster or slower start is instructed. METHODS: Nine speed skaters and nine cyclists, all competing at regional or national level, performed two 1500m

  18. Unusual QRS morphology on ECG: a rare condition and an interesting response to pacing.

    Science.gov (United States)

    Gula, Lorne J; Eckart, Robert E; Klein, George J; Peralta, Adelqui

    2005-08-01

    We present the interesting case of a young man with borderline wide QRS complexes noted on electrocardiogram (ECG). The diagnosis of an unusual form of preexcitation was reached using observations from intracardiac tracings at electrophysiology study. Atrial pacing consistently resulted in further widening of the first conducted QRS complex, and the physiology underlying this unusual finding is explored.

  19. Mobitz type I atrio-ventricular block in dengue myocarditis, requiring temporary pacing

    Directory of Open Access Journals (Sweden)

    S. de Mel

    2015-01-01

    Full Text Available We present a case of dengue myocarditis related Mobitz type I atrio-ventricular (A-V block. To our knowledge, this is the first report of such a patient requiring pacing. An early response to methylprednisolone suggests the possibility of a therapeutic role for steroids in these patients.

  20. Optimal Cardiac Resynchronization Therapy Pacing Rate in Non-Ischemic Heart Failure Patients

    DEFF Research Database (Denmark)

    Ghotbi, Adam Ali; Sander, Mikael; Køber, Lars;

    2015-01-01

    BACKGROUND: The optimal pacing rate during cardiac resynchronization therapy (CRT) is unknown. Therefore, we investigated the impact of changing basal pacing frequencies on autonomic nerve function, cardiopulmonary exercise capacity and self-perceived quality of life (QoL). METHODS: Twelve CRT...... patients with non-ischemic heart failure (NYHA class II-III) were enrolled in a randomized, double-blind, crossover trial, in which the basal pacing rate was set at DDD-60 and DDD-80 for 3 months (DDD-R for 2 patients). At baseline, 3 months and 6 months, we assessed sympathetic nerve activity...... by microneurography (MSNA), peak oxygen consumption (pVO2), N-terminal pro-brain natriuretic peptide (p-NT-proBNP), echocardiography and QoL. RESULTS: DDD-80 pacing for 3 months increased the mean heart rate from 77.3 to 86.1 (p = 0.001) and reduced sympathetic activity compared to DDD-60 (51±14 bursts/100 cardiac...

  1. Early Sensitivity to Discourse-Level Anomalies: Evidence from Self-Paced Reading

    Science.gov (United States)

    Stewart, Andrew J.; Kidd, Evan; Haigh, Matthew

    2009-01-01

    Two word-by-word, self-paced reading experiments investigated the speed with which readers were sensitive to discourse-level anomalies. An account arguing for delayed sensitivity (Guzman & Klin, 2000) was contrasted with one allowing for rapid sensitivity (Myers & O'Brien, 1998). Anomalies related to spatial information (Experiment 1) and…

  2. Evaluation of Parent and Child Enhancement (PACE) Program: Randomized Controlled Trial

    Science.gov (United States)

    Leung, Cynthia; Tsang, Sandra; Lo, Cyrus

    2017-01-01

    Objective: This study examined the efficacy of the Parent and Child Enhancement (PACE) program on child learning, child behavior problems, and parental stress, using randomized controlled trial design, in social services centers. Methods: Eligibility criteria were (1) children aged 2 years at program commencement, (2) low-income, new immigrant, or…

  3. Children's Use of Self-Paced Slideshows: An Extension of the Video Deficit Effect?

    Science.gov (United States)

    Sage, Kara D.; Baldwin, Dare

    2015-01-01

    Past research has established that children typically learn better from live demonstrations than from two-dimensional (2D) media. In the present set of experiments, we investigated the efficacy of a new 2D learning medium-the self-paced slideshow. A primary goal was to determine whether the "video deficit effect" extended to self-paced…

  4. Using "U-Pace" Instruction to Improve the Academic Performance of Economically Disadvantaged Undergraduates

    Science.gov (United States)

    Fleming, R.; Stoiber, L. C.; Pfeiffer, H. M.; Kienzler, S. E.; Fleming, R. R.; Pedrick, L. E.; Barth, D. J.; Reddy, D. .

    2016-01-01

    This study was undertaken to evaluate whether the student success associated with the "U-Pace" instructional approach, which integrates mastery-based learning with proactive instructor support in an online learning environment, would replicate for both economically disadvantaged students and students who are not economically…

  5. Effect of heat and heat acclimatization on cycling time trial performance and pacing

    DEFF Research Database (Denmark)

    Racinais, Sebastien; Périard, Julien D; Karlsen, Anders;

    2015-01-01

    PURPOSE: To determine the effects of heat-acclimatization on performance and pacing during outdoor cycling time-trials (TT, 43.4km) in the heat. METHODS: Nine cyclists performed 3 TTs in hot ambient conditions (TTH, ∼37ºC) on the first (TTH-1), sixth (TTH-2) and fourteenth (TTH-3) days of trainin...

  6. 完全性心内膜垫缺损合并右室双出口的双心室修复%Biventricular refair for endocardial cushion defects with double outlet right ventricle

    Institute of Scientific and Technical Information of China (English)

    李富骊; 尤斌; 李平; 郑铁; 许李力; 徐屹; 刘硕

    2011-01-01

    目的 总结完全性心内膜垫缺损合并右室双出口双心室修复的经验.方法 2006年7月至209年11月对6例完全性心内膜垫缺损合并右室双出口病人采用双片法修补完全性心内膜垫缺损,人工血管补片作右心室内隧道,连接室间隔缺损与主动脉口,引导左心室血经内隧道进入主动脉;应用牛心包补片扩大右室流出道;肺动脉瓣环小者用带瓣补片跨环修补右室流出道;心室内隧道有可能阻塞右室流出道造成重度梗阻者,右室流出道与主肺动脉之间安置带瓣管道(Rastelli手术).结果 术后死亡1例,占16.6%,其余病例恢复良好.结论 完全性心内膜垫缺损合并右室双出口一期双心室修复可获得良好效果.%Objective Double-outlet right ventricle,which often associated with total anomalous pulmonary venous connection and complete endocardial cushion defects,has been considered a risk factor for biventricular repair procedure.To reviewed cases treated by biventricular repair for endocardial cushion defects with double outlet right ventricle.Methods From July to November of 2009,6 patients (3 males and 3 females) aged from 7 to 24 (16.17±5.98) years and with endocardial cushion defects and double outlet right ventricle underwent operation of biventricular repair The duration of follow-up ranged from 10 days to 2 years(median,16 months).Endocardial cushion defects were repaired with a 2-patch technique.The artificial vascular patch was implanted to connect the ventricular septal defects and the aorta for draining the blood stream from the left ventricle to the aorta.The other patch was used to repair the ostium primum atrial septal defects.Right ventricular outflow tract obstructions was released and reconstructed by transplanting a bovine pericardium patch.If the size of pulmonary valve annulus was far more below the normal,a transannular pericardial patch was used.Rastelli procedure with a valved conduit between the right

  7. The effect of three recovery protocols on blood lactate clearance after race-paced swimming.

    Science.gov (United States)

    Lomax, Mitch

    2012-10-01

    The purpose of the present study was to assess the impact of 3 recovery protocols on blood lactate clearance after maximal intensity swimming. Thirty-three regional standard swimmers were tested throughout the course a year and were required to complete a race-paced 200-m swim in their main stroke or individual medley. After the race-paced swim, swimmers were assigned a self-paced continuous steady rate swim of 20 minutes (self-prescribed); a 20-minute coach-administered modified warm-up consisting of various swimming modes, intensities, and rest intervals (coach prescribed); or a 20-minute land-based recovery consisting of light-intensity walking, skipping, and stretching (land based). Blood lactate concentration was measured from the fingertip before and after the race-paced swim and after the recovery activity. The concentration of blood lactate was higher (p swimming (range of 10.5-11.0 mmol·L(-1)) compared with baseline (range 1.3-1.4 mmol·L(-1)). However, there were no differences (p > 0.05) between the groups (recovery protocols) at these time points. Conversely, differences were observed between groups after the recovery activities (p swimming protocols. The results of the present study suggest that it does not matter whether a self-paced continuous steady rate swimming velocity or a swimming recovery consisting of various strokes, intensities, and rest intervals is adopted as a recovery activity. As both swimming recoveries removed more blood lactate than the land-based recovery, swimmers should therefore be advised to undertake a swimming-based recovery rather than a land-based recovery.

  8. [Effects of temporary dual-chamber cardiac pacing in refractory cardiac failure].

    Science.gov (United States)

    Scanu, P; Lecluse, E; Michel, L; Bureau, G; Saloux, E; Cleron, S; Valette, B; Grollier, G; Potier, J C; Foucault, J P

    1996-12-01

    The authors studied 18 patients (15 men, 3 women) with an average age of 67 +/- 8 years with refractory cardiac failure. In order to determine the potential of pacing to raise cardiac output in severe cardiac failure. The average ejection fraction was 26 +/- 6.5%. All patients were in sinus rhythm:resting cardiac output was 3.35 l/min. Two temporary pacing catheters were positioned in the right atrium and at the apex of the right ventricle for dual-chamber mode pacing triggered by the spontaneous P waves. Changes in cardiac output were measured by Doppler echocardiography at different values of atrioventricular delay. Patients were considered to be responders if their cardiac outputs rose by 15%. In 7 patients meeting this criterion, the average increase in cardiac output was 27% (2.99 +/- 0.7 to 3.81 +/- 0.86 l/mn; p < 0.01); all had dilated cardiomyopathies with left bundle branch block and the optimal AV delay was 103 +/- 21 ms (80-140 ms); the duration of diastolic filling increased from 212 +/- 98 to 292 +/- 116 ms (p = 0.02). In the non-responding group (11 patients with an increase of cardiac output of only 3.6 +/- 0.09 to 3.9 +/- 0.92 l/mn; p < 0.01), the underlying disease process was mainly ischaemic. Two predictive factors of efficacy of dual-chamber pacing were identified: a short ventricular filling period (29 +/- 8% of the RR interval in the responders vs 44 +/- 9% in the non-responders; p < 0.01) and the presence of 1st degree atrioventricular block. Dual-chamber pacing could be a valuable method of increasing resting cardiac outputs in a selected group of patients with severe, refractory, cardiac failure.

  9. Ferroelectric devices

    CERN Document Server

    Uchino, Kenji

    2009-01-01

    Updating its bestselling predecessor, Ferroelectric Devices, Second Edition assesses the last decade of developments-and setbacks-in the commercialization of ferroelectricity. Field pioneer and esteemed author Uchino provides insight into why this relatively nascent and interdisciplinary process has failed so far without a systematic accumulation of fundamental knowledge regarding materials and device development.Filling the informational void, this collection of information reviews state-of-the-art research and development trends reflecting nano and optical technologies, environmental regulat

  10. Introduction to the Special Section on Biomedical Devices for Personal Health Applications

    Institute of Scientific and Technical Information of China (English)

    I-Ming CHEN

    2011-01-01

    @@ This Special Section of Frontiers of Mechanical Engineering (FME) is dedicated to the topic of Biomedical Devices for Personal Health Applications.To reflect the fast pace of development in this area of research, a number of special sessions were firstly organized in the 2010 IEEE International Conference on Robotics, Automation, and Mechatronics (RAM 2010) from 28 to 30 June 2010 in Singapore.

  11. The Fast-Paced iPad Revolution: Can Educators Stay up to Date and Relevant about These Ubiquitous Devices?

    Science.gov (United States)

    Peluso, Deanna C. C.

    2012-01-01

    Stepping into a modern day classroom, one will find that it is filled with a ubiquitous array of multimodal and digital resources, yet a majority of these revolutionary resources are likely not school issued, rather they were brought by the young people themselves. Digital mediums for communication, expression and multimodally engaging in one's…

  12. Do immunological, endocrine and metabolic traits fall on a single Pace-of-Life axis? Covariation and constraints among physiological systems

    NARCIS (Netherlands)

    Versteegh, M. A.; Schwabl, I.; Jaquier, S.; Tieleman, B. I.

    2012-01-01

    Variation in demographic and physiological attributes of life history is thought to fall on one single axis, a phenomenon termed the Pace-of-Life. A slow Pace-of-Life is characterized by low annual reproduction, long life span and low metabolic rate, a fast Pace-of-Life by the opposite characteristi

  13. Towards Development of a 3-State Self-Paced Brain-Computer Interface

    Directory of Open Access Journals (Sweden)

    Ali Bashashati

    2007-01-01

    the presence of a right- or a left-hand movement and the second classifies the detected movement as a right or a left one. In an offline analysis of the EEG data collected from four able-bodied individuals, the 3-state brain-computer interface shows a comparable performance with a 2-state system and significant performance improvement if used as a 2-state BCI, that is, in detecting the presence of a right- or a left-hand movement (regardless of the type of movement. It has an average true positive rate of 37.5% and 42.8% (at false positives rate of 1% in detecting right- and left-hand extensions, respectively, in the context of a 3-state self-paced BCI and average detection rate of 58.1% (at false positive rate of 1% in the context of a 2-state self-paced BCI.

  14. Trame di Pace. Simboli, carte, azioni di un’utopia possibile. 1945-2003

    Directory of Open Access Journals (Sweden)

    Nadia Baiesi

    2014-06-01

    Full Text Available La mostra racconta la storia degli uomini e delle donne che hanno ragionato di pace non più come di una nobile speranza, ma come dell’unica chance di salvezza per l’umanità. La scansione cronologica, per decenni, parte dal 1945 e arriva al 2003 con la diffusione della bandiera arcobaleno in occasione della campagna «Pace da tutti i balconi», nata per scongiurare il secondo conflitto in Iraq. Al centro della mostra un percorso sui simboli che sono stati inventati, ripresi, risignificati in diversi contesti, movimenti radicali del pacifismo antimilitarista e nonviolento e movimenti contro singole guerre. Accompagnano i materiali iconografici (bandiere e manifesti originali, opere d’arte del maestro Anastasi, due percorsi documentari con immagini d’epoca, locandine, testi di decreti, opuscoli, volantini, articoli di quotidiani e riviste.

  15. Self-Paced E-Training in E-Learning for University Teaching Staff

    Directory of Open Access Journals (Sweden)

    Norah Ahmed Al-Malki

    2015-03-01

    Full Text Available The shift towards adopting e-training methods and practices in the workplace to equip staff with soft and hard skills have become an essential component of training in many Higher Education institutions. The aim of this paper is to advocate such a shift in Saudi universities through presenting the preliminary outcomes of a short-scale pilot study conducted by the Deanship of E-learning and Distance Education (DELDE during August 2014. Basically, the paper introduces the results of a first run of a self-paced e-training program focusing on introducing topics related to e-learning development and instruction. The paper 1 explores the pedagogical motivation for adopting the self-paced learning model, 2 outlines the elements of the developed course, and 3 discusses the results of the first run of the e-training program.

  16. Interventricular cardiac resynchronization with right ventricular apical pacing in a patient with Ebstein's defect.

    Science.gov (United States)

    Maffe, Stefano; Perucca, Antonello; Paffoni, Paola; Signorotti, Fabiana; Pardo, Nicolò Franchetti; Dellavesa, Pierfranco; Parravicini, Umberto; Zenone, Franco; Paino, Anna Maria; Bielli, Massimo; Carola, Federico; Zanetta, Marco

    2008-06-01

    We present the case of a patient with Ebstein's defect surgically corrected, and a complete right bundle branch block (RBBB) documented on echocardiogram. After an episode of near syncope due to a high-grade atrioventricular (AV) block, the patient was assisted with a bicameral DDDR pacemaker implanted with traditional right ventricular apical pacing. After the DDDR, and after stimulation with an AV delay of 180 ms, a narrow QRS complex was observed. Meanwhile, the typical left bundle branch block morphology of the right ventricular pacing and the native RBBB morphology were missing. The QRS complex narrowing persisted, even with physical activity and also with the heart rate progression. An echocardiographic study confirmed an improvement of the cardiac resynchronization parameters with this programmed stimulation.

  17. Permanent pacing system malfunction due to hidden adjacent fractures of atrial and ventricular leads.

    Science.gov (United States)

    Wang, L; Davis, M J

    1997-03-01

    Periods of failure of ventricular pacing and atrial sensing were discovered on Holter recording in a 10-year-old boy 4 years after the implantation of a dual-chamber pacemaker with endocardial bipolar leads brought out through the right atrial wall. The old generator was explanted and the old leads tested. There was considerable atrial oversensing of an electrical artefact. The pacing threshold of ventricular lead was 1.8 V compared with 0.3 V 6 days post implantation. Post-operative lateral chest X-ray disclosed fractures of both atrial and ventricular leads at the approximate site of exit from the right atriotomy. Review of the preoperative lateral film showed that the fractures had been hidden by an ECG electrode.

  18. IN VIVO CHARACTERIZATION OF ATTACHMENT SAFETY BETWEEN CARDIAC PACING LEAD AND CANINE HEART MUSCLE

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    In vivo experiments of screwing the electrode of canine hearts and assigning external excitation on the lead-myocardium interface was carried out to evaluate the lead/myocardium adherence safety. The electrode is specially designed to host a measurement unit of strain gauges.We obtained the lead/heart interactions data from 12 dogs under natural heart beating and beating with external excitations. The data recorded from the acute phase and the chronic phase of pulling out pacing leads were compared with each other. The electrode/heart interaction is caused by the heart beat and influenced by the lung breath. This process induced tolerable damage to the lead or myocardium. The interaction decreases as the frequency of external excitations increases. The lead is more likely to be detached from myocardium under higher excitation frequency. At the same implanting sites, safer pacing lead/myocardium attachment can be realized in the chronic tests than in the acute tests.

  19. Interaction Equivalency in Self-Paced Online Learning Environments: An Exploration of Learner Preferences

    Directory of Open Access Journals (Sweden)

    Jason F. Rhode

    2009-02-01

    Full Text Available This mixed methods study explored the dynamics of interaction within a self-paced online learning environment. It used rich media and a mix of traditional and emerging asynchronous computer-mediated communication tools to determine what forms of interaction learners in a self-paced online course value most and what impact they perceive interaction to have on their overall learning experience. This study demonstrated that depending on the specific circumstance, not all forms of interaction may be either equally valued by learners or effective. Participants differentiated among the various learning interactions available and indicated that informal interactions were as important as formal interactions in determining the quality of the online learning experience. Participants also reported the activity of blogging as being equally valued and in some ways superior to instructor-directed asynchronous discussion via the discussion board in a learning management system.

  20. Pellet Fueling, ELM pacing, and Disruption Mitigation Technology Development for ITER

    Energy Technology Data Exchange (ETDEWEB)

    Baylor, Larry R [ORNL; Combs, Stephen Kirk [ORNL; Foust, Charles R [ORNL; Jernigan, Thomas C [ORNL; Meitner, S. J. [Oak Ridge National Laboratory (ORNL); Parks, P. B. [General Atomics; Caughman, John B [ORNL; Maruyama, S. [ITER International Team, Garching, Germany; Qualls, A L [ORNL; Rasmussen, David A [ORNL; ThomasJr., C. E. [Third Dimension Technologies, LLC, Knoxville, TN

    2009-01-01

    Plasma fueling with pellet injection, pacing of edge localized modes (ELMs) by small frequent pellets, and disruption mitigation with gas jets or injected pellets are some of the most important technological capabilities needed for successful operation of ITER. Tools are being developed at Oak Ridge National Laboratory that can be employed on ITER to provide the necessary core pellet fueling and the mitigation of ELMs and disruptions. Here we present progress on the development of the technology to provide reliable high throughput inner wall pellet fueling, pellet ELM pacing with high frequency small pellets, and disruption mitigation with gas jets and pellets. Examples of how these tools can be employed on ITER are discussed.

  1. Leave-one-out prediction error of systolic arterial pressure time series under paced breathing

    CERN Document Server

    Ancona, N; Marinazzo, D; Nitti, L; Pellicoro, M; Pinna, G D; Stramaglia, S

    2004-01-01

    In this paper we show that different physiological states and pathological conditions may be characterized in terms of predictability of time series signals from the underlying biological system. In particular we consider systolic arterial pressure time series from healthy subjects and Chronic Heart Failure patients, undergoing paced respiration. We model time series by the regularized least squares approach and quantify predictability by the leave-one-out error. We find that the entrainment mechanism connected to paced breath, that renders the arterial blood pressure signal more regular, thus more predictable, is less effective in patients, and this effect correlates with the seriousness of the heart failure. The leave-one-out error separates controls from patients and, when all orders of nonlinearity are taken into account, alive patients from patients for which cardiac death occurred.

  2. Pacing, packing and sex-based differences in Olympic and IAAF World Championship marathons.

    Science.gov (United States)

    Hanley, Brian

    2016-09-01

    The aim of this study was to describe pacing profiles and packing behaviours of athletes in Olympic and World Championship marathons. Finishing and split times were collated for 673 men and 549 women across nine competitions. The mean speeds for each intermediate 5 km and end 2.2 km segments were calculated. Medallists of both sexes maintained even-paced running from 10 km onwards whereas slower finishers dropped off the lead pack at approximately half-distance. Athletes who ran with the same opponents throughout slowed the least in the second half (P medal positions. Marathon runners are advised to identify rivals with similar abilities and ambitions to run alongside provided they start conservatively. Coaches should note important sex-based differences in tactics adopted and design training programmes accordingly.

  3. Electrochemical device

    Science.gov (United States)

    Grimes, Patrick G.; Einstein, Harry; Bellows, Richard J.

    1988-01-12

    A tunnel protected electrochemical device features channels fluidically communicating between manifold, tunnels and cells. The channels are designed to provide the most efficient use of auxiliary power. The channels have a greater hydraulic pressure drop and electrical resistance than the manifold. This will provide a design with the optimum auxiliary energy requirements.

  4. Assistive Devices

    Science.gov (United States)

    ... a number of assistive devices. These are tools, products or types of equipment that help you perform tasks and activities. They may help you move around, see, communicate, eat, or get dressed. Some are high-tech tools, such as computers. Others are much simpler, ...

  5. Printing Device

    NARCIS (Netherlands)

    Berg, van den M.J.; Markies, P.R.; Zuilhof, H.

    2014-01-01

    An ink jetprinting device includes a pressure chamber formed by a plurality of wall segments, a first aperture extending through a wall segment and communicating with an ink jet orifice and a second aperture extending through a wall segment and communicating with an ink supply duct. The pressure cha

  6. Detection device

    Science.gov (United States)

    Smith, J.E.

    1981-02-27

    The present invention is directed to a detection device comprising: (1) an entrance chamber; (2) a central chamber; and (3) an exit chamber. The central chamber includes an ionizing gas, anode, and means for connecting the anode with an external power supply and pulse counter.

  7. Separating device

    NARCIS (Netherlands)

    De Jong, T.P.R.

    2001-01-01

    A sorting device (1) suitable for sorting wire from a waste stream, comprising a body (2) that moves when in use, and provided with spikes or similar projections. The body is embodied as a rotatable roll (2), which oscillates axially during its rotation. The roll is coupled to an oscillation engine

  8. Effect of Environmental and Feedback Interventions on Pacing Profiles in Cycling: A Meta-Analysis

    Science.gov (United States)

    Davies, Michael J.; Clark, Bradley; Welvaert, Marijke; Skorski, Sabrina; Garvican-Lewis, Laura A.; Saunders, Philo; Thompson, Kevin G.

    2016-01-01

    In search of their optimal performance athletes will alter their pacing strategy according to intrinsic and extrinsic physiological, psychological and environmental factors. However, the effect of some of these variables on pacing and exercise performance remains somewhat unclear. Therefore, the aim of this meta-analysis was to provide an overview as to how manipulation of different extrinsic factors affects pacing strategy and exercise performance. Only self-paced exercise studies that provided control and intervention group(s), reported trial variance for power output, disclosed the type of feedback received or withheld, and where time-trial power output data could be segmented into start, middle and end sections; were included in the meta-analysis. Studies with similar themes were grouped together to determine the mean difference (MD) with 95% confidence intervals (CIs) between control and intervention trials for: hypoxia, hyperoxia, heat-stress, pre-cooling, and various forms of feedback. A total of 26 studies with cycling as the exercise modality were included in the meta-analysis. Of these, four studies manipulated oxygen availability, eleven manipulated heat-stress, four implemented pre-cooling interventions and seven studies manipulated various forms of feedback. Mean power output (MPO) was significantly reduced in the middle and end sections (p 0.05). Negative feedback improved overall trial MPO and MPO in the middle section of trials (p 0.05). The available data suggests exercise regulation in hypoxia and heat-stress is delayed in the start section of trials, before significant reductions in MPO occur in the middle and end of the trial. Additionally, negative feedback involving performance deception may afford an upward shift in MPO in the middle section of the trial improving overall performance. Finally, performance improvements can be retained when participants are informed of the deception. PMID:27994554

  9. Basal metabolism in tropical birds: Latitude, altitude, and the 'pace of life'

    OpenAIRE

    Londoño, GA; Chappell, MA; Castañeda, MDR; Jankowski, JE; Robinson, SK

    2015-01-01

    © 2014 The Authors. Life history varies across latitudes, with the 'pace of life' being 'slower' in tropical regions. Because life history is coupled to energy metabolism via allocation tradeoffs and links between performance capacity and energy use, low metabolic intensity is expected in tropical animals. Low metabolism has been reported for lowland tropical birds, but it is unclear if this is due to 'slow' life history or to a warm, stable environment. We measured basal metabolic rates (BMR...

  10. Effects of Long-term Right Ventricular Apical Pacing on Left Ventricular Remodeling and Cardiac Function

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Objective: To investigate the impacts of long-term right ventricular apical pacing on the ventricular remodeling and cardiac functions of patients with high-grade and third-degree atrioventricular blockage with normal heart structures and cardiac functions. In addition, we provide many evidences for choosing an optimal electrode implantation site.Methods: Study participants included patients who were admitted for pacemaker replacements and revisited for examinations of implanted pacemakers at outpatient. Pa...

  11. The impact of the perception of rhythmic music on oscillatory self-paced movements

    Directory of Open Access Journals (Sweden)

    Mathieu ePeckel

    2014-09-01

    Full Text Available Inspired by theories of perception-action coupling and embodied music cognition, we investigated how rhythmic music perception impacts self-paced oscillatory movements. In a pilot study, we examined the kinematic parameters of self-paced oscillatory movements, walking and finger tapping using optical motion capture. In accordance with biomechanical constraints accounts of motion, we found that movements followed a hierarchical organization depending on the proximal/distal characteristic of the limb used. Based on these findings, we were interested in knowing how and when the perception of rhythmic music could resonate with the motor system in the context of these constrained oscillatory movements. In order to test this, we conducted an experiment where participants performed four different effector-specific movements (lower leg, whole arm and forearm oscillation and finger tapping while rhythmic music was playing in the background. Musical stimuli consisted of computer-generated MIDI musical pieces with a 4/4 metrical structure. The musical tempo of each song increased from 60 BPM to 120 BPM by 6 BPM increments. A specific tempo was maintained for 20s before a 2s transition to the higher tempo. The task of the participant was to maintain a comfortable pace for the four movements (self-paced while not paying attention to the music. No instruction on whether to synchronize with the music was given. Results showed that participants were distinctively influenced by the background music depending on the movement used with the tapping task being consistently the most influenced. Furthermore, eight strategies put in place by participants to cope with task were unveiled. Despite not instructed to do so, participants also occasionally synchronized with music. Results are discussed in terms of the link between perception and action (i.e. motor/perceptual resonance. In general, our results give support to the notion that rhythmic music is processed in a

  12. Pacing Profiles in Competitive Track Races: Regulation of Exercise Intensity Is Related to Cognitive Ability

    Science.gov (United States)

    Van Biesen, Debbie; Hettinga, Florentina J.; McCulloch, Katina; Vanlandewijck, Yves

    2016-01-01

    Pacing has been defined as the goal-directed regulation of exercise intensity over an exercise bout, in which athletes need to decide how and when to invest their energy. The purpose of this study was to explore if the regulation of exercise intensity during competitive track races is different between runners with and without intellectual impairment, which is characterized by significant limitations in intellectual functioning (IQ ≤ 75) and adaptive behavioral deficits, diagnosed before the age of 18. The samples included elite runners with intellectual impairment (N = 36) and a comparison group of world class runners without impairment (N = 39), of which 47 were 400 m runners (all male) and 28 were 1500 m-runners (15 male and 13 female). Pacing was analyzed by means of 100 m split times (for 400 m races) and 200 m split times (for 1500 m races). Based on the split times, the average velocity was calculated for four segments of the races. Velocity fluctuations were defined as the differences in velocity between consecutive race segments. A mixed model ANOVA revealed significant differences in pacing profiles between runners with and without intellectual impairment (p 100 m (7.2 ± 0.1 m/s), slowly decelerated in the second race segment (−0.6 ± 0.1 m/s), and finished with an end sprint (+0.9 ± 0.1 m/s); the 1500 m runners with intellectual impairment started slower (6.1 ± 0.3 m/s), accelerated in the second segment (+0.2 ± 0.7 m/s), and then slowly decreased until the finish (F = 6.8, p < 0.05). Our findings support the hypothesis that runners with intellectual impairment have difficulties to efficiently self-regulate their exercise intensity. Their limited cognitive resources may constrain the successful integration of appropriate pacing strategies during competitive races. PMID:28066258

  13. Turismo di guerra, turismo di pace: sguardi incrociati su Italia e Francia

    OpenAIRE

    Elisa Tizzoni

    2015-01-01

    L’articolo offre alcune riflessioni sul rapporto del turismo con i concetti di guerra e pace in occasione dei due conflitti mondiali, analizzando in chiave comparata il contesto francese e quello italiano. Dopo una sintetica introduzione circa le principali ripercussioni dei conflitti contemporanei sul turismo e sui caratteri che esso può assumere in contesti di guerra, l’attenzione viene rivolta al fenomeno del cosiddetto “turismo di guerra”, sviluppatosi nella fase finale e negli anni immed...

  14. Compatibility of temporary pacemaker myocardial pacing leads with magnetic resonance imaging: an ex vivo tissue study.

    Science.gov (United States)

    Pfeil, Alexander; Drobnik, Stefanie; Rzanny, Reinhard; Aboud, Anas; Böttcher, Joachim; Schmidt, Peter; Ortmann, Christian; Mall, Gita; Hekmat, Khosro; Brehm, Bernhard; Reichenbach, Juergen; Mayer, Thomas E; Wolf, Gunter; Hansch, Andreas

    2012-02-01

    The presence of temporary myocardial pacing leads is considered a safety contraindication for magnetic resonance imaging (MRI). The aim of this ex vivo tissue study was to measure the heating effects at the tip of the leads using proton magnetic resonance spectroscopy ((1)HMRS) thermometry. The tissue effects were verified by histological analyses. Pig hearts with implanted temporary pacemaker myocardial pacing leads were examined by whole-body MRI at 1.5 Tesla. The tests were performed either by a sequence with high specific absorption rate (SAR) or by standard clinical sequences with lower SAR. Temperature changes were detected via (1)HMRS thermometry, by monitoring the frequency difference between water protons and the reference signals of N-methyl protons of creatine/phosphocreatine (Cr/PCr) and trimethylamine (TMA). Histology was performed using several staining techniques. Standard low-SAR and high-SAR sequences did not cause significant temperature increases in the myocardial tissue surrounding the implanted leads. There were no histopathological signs of thermal damage around the tips of the leads in any of the hearts or in a control implanted heart not subjected to MRI. The present data suggest that temporary pacemaker myocardial pacing leads may be compatible with MR scanning at 1.5 Tesla. However, further in vivo studies and carefully monitored patient studies are needed before final safety recommendations can be made.

  15. Obliquity-paced climate change recorded in Antarctic debris-covered glaciers

    Science.gov (United States)

    Mackay, Sean L.; Marchant, David R.

    2017-01-01

    The degree to which debris-covered glaciers record past environmental conditions is debated. Here we describe a novel palaeoclimate archive derived from the surface morphology and internal debris within cold-based debris-covered glaciers in Antarctica. Results show that subtle changes in mass balance impart major changes in the concentration of englacial debris and corresponding surface topography, and that over the past ∼220 ka, at least, the changes are related to obliquity-paced solar radiation, manifest as variations in total summer energy. Our findings emphasize solar radiation as a significant driver of mass balance changes in high-latitude mountain systems, and demonstrate that debris-covered glaciers are among the most sensitive recorders of obliquity-paced climate variability in interior Antarctica, in contrast to most other Antarctic archives that favour eccentricity-paced forcing over the same time period. Furthermore, our results open the possibility that similar-appearing debris-covered glaciers on Mars may likewise hold clues to environmental change. PMID:28186094

  16. Continued obliquity pacing of East Asian summer precipitation after the mid-Pleistocene transition

    Science.gov (United States)

    Li, Tao; Liu, Fei; Abels, Hemmo A.; You, Chen-Feng; Zhang, Zeke; Chen, Jun; Ji, Junfeng; Li, Laifeng; Li, Le; Liu, Hou-Chun; Ren, Chao; Xia, Renyuan; Zhao, Liang; Zhang, Wenfang; Li, Gaojun

    2017-01-01

    Records from natural archives show that the strength of the East Asian summer monsoon (EASM) strongly depends on the orbital configuration of the Earth. However, the dominant orbital cycles driving EASM have been found to be spatially different. Speleothem stable oxygen isotopic records from southern China, which are believed to reflect large-scale changes in the Asian monsoon system, are dominated by climatic precession cycles. Further north, on the Chinese Loess Plateau (CLP), loess-and-paleosol sequences, which are argued to be controlled by monsoon intensity, are in pace with global ice volume changes dominated by obliquity, and after the mid-Pleistocene transition by 100-kyr cycles. To understand these critical discrepancies, here we apply a novel proxy based on the trace metal compositions of pedogenic carbonate in the eolian deposits on the CLP to reconstruct summer precipitation over the last 1.5 million years. Our reconstructions show that summer precipitation on the CLP is dominantly forced by obliquity not in pace with the ice-volume-imprinted loess-paleosol sequences before and after the mid-Pleistocene transition or with the precession-paced speleothem oxygen isotopic records. Coupled with climate model results, we suggest that the obliquity-driven variations of summer precipitation may originate from the gradient of boreal insolation that modulates the thermal contrast between the Asian continent and surrounding oceans.

  17. Spontaneous Velocity Effect of Musical Expression on Self-Paced Walking.

    Directory of Open Access Journals (Sweden)

    Jeska Buhmann

    Full Text Available The expressive features of music can influence the velocity of walking. So far, studies used instructed (and intended synchronization. But is this velocity effect still present with non-instructed (spontaneous synchronization? To figure that out, participants were instructed to walk in their own comfort tempo on an indoor track, first in silence and then with tempo-matched music. We compared velocities of silence and music conditions. The results show that some music has an activating influence, increasing velocity and motivation, while other music has a relaxing influence, decreasing velocity and motivation. The influence of musical expression on the velocity of self-paced walking can be predicted with a regression model using only three sonic features explaining 56% of the variance. Phase-coherence between footfall and beat did not contribute to the velocity effect, due to its implied fixed pacing. The findings suggest that the velocity effect depends on vigor entrainment that influences both stride length and pacing. Our findings are relevant for preventing injuries, for gait improvement in walking rehabilitation, and for improving performance in sports activities.

  18. Evidence for a Border-Collision Bifurcation in Paced Cardiac Tissue

    Science.gov (United States)

    Berger, Carolyn

    2005-11-01

    Bifurcations in the electrical response of cardiac tissue can destabilize spatial-temporal waves of electrical activity in the heart, leading to tachycardia or even fibrillation. Therefore, it is important to characterize the types of bifurcations occurring in cardiac tissue. Our goal is to classify the bifurcation that occurs in cardiac cells when a change in pacing rate induces a transition from 1:1 to 2:2 phase-locked behavior. Current mathematical models predict that the bifurcation mediating the transition is a supercritical pitchfork type. For such a bifurcation, small random noise is predicted to be amplified by greater amounts as the bifurcation is approached (Weisenfeld). However, our experimental observations of paced bullfrog myocardium driven by small beat-to-beat alternations in the pacing rate (rather than driven by noise) displays de-amplification as the bifurcation is approached. To explain this surprising result, we hypothesize that the transition to 2:2 behavior is mediated by border-collision bifurcation, which is predicted to show little noise amplification. Wiesenfeld, K. Phys. Rev. A 32, 1744 (1985).

  19. The effects of joint torque, pace and work:rest ratio on powered hand tool operations.

    Science.gov (United States)

    Lin, Jia-Hua; McGorry, Raymond W; Maikala, Rammohan V

    2012-01-01

    Repetitive use of hand-held power tools is associated with work-related upper extremity musculoskeletal disorders. Using a pneumatic nutrunner, 21 men completed twelve 360 repetitive fastener-driving sessions on three joints (hard, soft and control) at slow and fast pace, and two different work:rest patterns. Handgrip force and perceived exertions were collected throughout each session. For the control joint, the mean grip force exerted was 39.6% of maximum voluntary exertion (MVE) whereas during hard and soft joint sessions it was 48.9% MVE and 56.9% MVE, respectively. Throughout each session, the grip force decreased, more while operating soft and hard joints as compared with the control joint (regression slope: -0.022 and -0.023, compared with -0.007 N/drive, respectively), suggesting considerable upper extremity muscular effort by participants during torque buildup. Fast work pace resulted in higher average grip forces by participants but a greater decrease in the force as the session progressed. Providing rest breaks reduced perceived exertions. The findings gain additional knowledge for assembly task design to possibly reduce the hand/arm injury risks for the operator. Practitioner Summary: Powered hand tools are widely used in assembly and manufacturing industries. However, the nature of their repetitive use on human operator biomechanical and perceptual responses is not fully understood. This study examined work-related risk factors such as joint torque, pace and work:rest ratios on powered hand tool performance.

  20. Making time for soil: Technoscientific futurity and the pace of care.

    Science.gov (United States)

    de la Bellacasa, Maria Puig

    2015-10-01

    The dominant drive for understanding soil has been to pace its fertility with human demand. Today, warnings about soil's exhaustion and endangered ecology raise concerns marked by fears of gloomy environmental futures, prompting scientists and soil practitioners urgently to develop better ways of taking care of soils. Yet the pace required by ecological soil care could be at odds with the predominant temporal orientation of technoscientific intervention, which is driven by an inherently progressivist, productionist and restless mode of futurity. Through a conceptual and historical approach to the soil sciences and other domains of soil knowledge, this article looks for soil ontologies and relations to soil care that are obscured by the predominant timescape. Contemporary discussions of the future of the soil sciences expose tensions between 'progress as usual'--by intensifying productivity--and the need to protect the pace of soil renewal. The intimate relation of soil science with productionism is being interrogated, as ecology attempts to engage with soil as a living community rather than a receptacle for crops. In this context, and beyond science, the 'foodweb' model of soil ecology has become a figure of alternative human-soil relations that involve environmental practitioners in the soil community. Reading these ways of making time for soil as a form of 'care time' helps to reveal a diversity of more-than-human interdependent temporalities, disrupting the anthropocentric appeal of predominant timescales of technoscientific futurity and their reductive notion of innovation.

  1. Obliquity-paced climate change recorded in Antarctic debris-covered glaciers.

    Science.gov (United States)

    Mackay, Sean L; Marchant, David R

    2017-02-10

    The degree to which debris-covered glaciers record past environmental conditions is debated. Here we describe a novel palaeoclimate archive derived from the surface morphology and internal debris within cold-based debris-covered glaciers in Antarctica. Results show that subtle changes in mass balance impart major changes in the concentration of englacial debris and corresponding surface topography, and that over the past ∼220 ka, at least, the changes are related to obliquity-paced solar radiation, manifest as variations in total summer energy. Our findings emphasize solar radiation as a significant driver of mass balance changes in high-latitude mountain systems, and demonstrate that debris-covered glaciers are among the most sensitive recorders of obliquity-paced climate variability in interior Antarctica, in contrast to most other Antarctic archives that favour eccentricity-paced forcing over the same time period. Furthermore, our results open the possibility that similar-appearing debris-covered glaciers on Mars may likewise hold clues to environmental change.

  2. Gradual Pace

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    China pledges to promote steady development of its financial sector and prevent possible risks pointed out by the IMF The People’s Bank of China,the central bank,recently responded to a report-Financial Sector Assessment for China-jointly issued by the International Monetary Fund(IMF) and the

  3. Running Pace Decrease during a Marathon Is Positively Related to Blood Markers of Muscle Damage

    Science.gov (United States)

    Del Coso, Juan; Fernández, David; Abián-Vicen, Javier; Salinero, Juan José; González-Millán, Cristina; Areces, Francisco; Ruiz, Diana; Gallo, César; Calleja-González, Julio; Pérez-González, Benito

    2013-01-01

    Background Completing a marathon is one of the most challenging sports activities, yet the source of running fatigue during this event is not completely understood. The aim of this investigation was to determine the cause(s) of running fatigue during a marathon in warm weather. Methodology/Principal Findings We recruited 40 amateur runners (34 men and 6 women) for the study. Before the race, body core temperature, body mass, leg muscle power output during a countermovement jump, and blood samples were obtained. During the marathon (27 °C; 27% relative humidity) running fatigue was measured as the pace reduction from the first 5-km to the end of the race. Within 3 min after the marathon, the same pre-exercise variables were obtained. Results Marathoners reduced their running pace from 3.5 ± 0.4 m/s after 5-km to 2.9 ± 0.6 m/s at the end of the race (P 15% pace reduction) had elevated post-race myoglobin (1318 ± 1411 v 623 ± 391 µg L−1; P<0.05), lactate dehydrogenase (687 ± 151 v 583 ± 117 U L−1; P<0.05), and creatine kinase (564 ± 469 v 363 ± 158 U L−1; P = 0.07) in comparison with marathoners that preserved their running pace reasonably well throughout the race. However, they did not differ in their body mass change (−3.1 ± 1.0 v −3.0 ± 1.0%; P = 0.60) or post-race body temperature (38.7 ± 0.7 v 38.9 ± 0.9 °C; P = 0.35). Conclusions/Significance Running pace decline during a marathon was positively related with muscle breakdown blood markers. To elucidate if muscle damage during a marathon is related to mechanistic or metabolic factors requires further investigation. PMID:23460881

  4. Effects of Reduced Strength on Self-Selected Pacing for Long-Duration Activities

    Science.gov (United States)

    Buxton, Roxanne E.; Ryder, Jeffrey W.; English, Kirk E.; Guined, Jamie R.; Ploutz-Snyder, Lori L.

    2015-01-01

    Strength and aerobic capacity are predictors of astronaut performance for extravehicular activities (EVA) during exploration missions. It is expected that astronauts will self-select a pace below their ventilatory threshold (VT). PURPOSE: To determine the percentage of VT that subjects self-select for prolonged occupational tasks. METHODS: Maximal aerobic capacity and a variety of lower-body strength and power variables were assessed in 17 subjects who climbed 480 rungs on a ladder ergometer and then completed 10 km on a treadmill as quickly as possible using a self-selected pace. The tasks were performed on 4 days, with a weighted suit providing 0% (suit fabric only), 40%, 60%, and 80% of additional bodyweight (BW), thereby altering the strength to BW ratio. Oxygen consumption and heart rate were continuously measured. Repeated measures ANOVA and post-hoc comparisons were performed on the percent of VT values under each suited condition. RESULTS: Subjects consistently self-paced at or below VT for both tasks and the pace was related to suit weight. At the midpoint for the ladder climb the 80% BW condition elicited the lowest metabolic cost (-19+/-14% below VT), significantly different than the 0% BW (-3+/-16%, P=0.002) and the 40% BW conditions (-5+/-22%, P=0.023). The 60% BW condition (-13+/-19%) was different than the 40% BW condition (P=0.034). Upon completion of the ladder task there were no differences among the conditions (0%BW: 3+/-18%; 40%BW: 3+/-21%; 60%BW: - 8+/-25%; 80%BW: -10+/-18%). All subjects failed to complete 5km at 80%BW. At the midpoint of the treadmill test the three remaining conditions were all significantly different (0%BW: -20+/-15%; 40%BW: - 33+/-15%; 60%BW: -41+/-19%). Upon completion of the treadmill test the 60% BW condition (-38+/-12%) was significantly different than the 40% BW (-28+/-15%, P=0.024). CONCLUSIONS: Decreasing relative strength results in progressive and disproportionate decreases (relative to VT) in self-selected pacing

  5. Running pace decrease during a marathon is positively related to blood markers of muscle damage.

    Directory of Open Access Journals (Sweden)

    Juan Del Coso

    Full Text Available BACKGROUND: Completing a marathon is one of the most challenging sports activities, yet the source of running fatigue during this event is not completely understood. The aim of this investigation was to determine the cause(s of running fatigue during a marathon in warm weather. METHODOLOGY/PRINCIPAL FINDINGS: We recruited 40 amateur runners (34 men and 6 women for the study. Before the race, body core temperature, body mass, leg muscle power output during a countermovement jump, and blood samples were obtained. During the marathon (27 °C; 27% relative humidity running fatigue was measured as the pace reduction from the first 5-km to the end of the race. Within 3 min after the marathon, the same pre-exercise variables were obtained. RESULTS: Marathoners reduced their running pace from 3.5 ± 0.4 m/s after 5-km to 2.9 ± 0.6 m/s at the end of the race (P 15% pace reduction had elevated post-race myoglobin (1318 ± 1411 v 623 ± 391 µg L(-1; P<0.05, lactate dehydrogenase (687 ± 151 v 583 ± 117 U L(-1; P<0.05, and creatine kinase (564 ± 469 v 363 ± 158 U L(-1; P = 0.07 in comparison with marathoners that preserved their running pace reasonably well throughout the race. However, they did not differ in their body mass change (-3.1 ± 1.0 v -3.0 ± 1.0%; P = 0.60 or post-race body temperature (38.7 ± 0.7 v 38.9 ± 0.9 °C; P = 0.35. CONCLUSIONS/SIGNIFICANCE: Running pace decline during a marathon was positively related with muscle breakdown blood markers. To elucidate if muscle damage during a marathon is related to mechanistic or metabolic factors requires further investigation.

  6. "Distinvar" device

    CERN Multimedia

    1965-01-01

    The alignment of one of the accelerator magnets being checked by the AR Division survey group. A "distinvar" device, invented by the group, using calibrated invar wires stretched between the fixed survey pillar (on the left) and a fixed point on the magnet. In two days it is thus possible to measure the alignment of the 100 magnets with an accuracy better than 1/10.

  7. Magnetohydrodynamic device

    Energy Technology Data Exchange (ETDEWEB)

    Gorlin, S.M.; Ljubimov, G.A.; Bitjurin, V.A.; Kovbasjuk, V.I.; Maximenko, V.I.; Medin, S.A.; Barshak, A.E.

    1979-12-25

    A magnetohydrodynamic device having a duct for a conducting gas to flow at an angle with the direction of the magnetic field induction vector is described. The duct is situated in the magnetic system and is provided with a plurality of electrodes adapted to interact electrically with the gas, whereas the cross-sectional shape of the duct working space is bounded by a closed contour formed by a curve inscribed into a rectangle. 1 claim.

  8. Cortical field potentials preceding self-paced forelimb movements and influences of cerebellectomy upon them in rats.

    Science.gov (United States)

    Ohishi, Hiroko; Ichikawa, Jun; Matsuzaki, Ryuichi; Kyuhou, Shin ichi; Matsuura-Nakao, Kazuko; Seki, Tomomi; Gemba, Hisae

    2003-11-27

    Seven rats were well trained to move lever to the left by right forelimb at self-pace (self-paced forelimb movements). Cortical field potentials associated with self-paced forelimb movements were recorded by electrodes implanted chronically on the surface and at a 2.0 mm depth in the forelimb motor cortex on the left side. A surface-negative, depth-positive potential starting about 1.0 s prior to the movement was recorded in the rostral part of the forelimb motor cortex. Further we found that the premovement potential was eliminated by the cerebellar hemispherectomy on the right side. This suggests the participation of the cerebellar hemisphere in preparing the activity of the motor cortex before self-paced forelimb movements in rats, by cerebello-thalamo-cortical projections.

  9. PACE4-Based Molecular Targeting of Prostate Cancer Using an Engineered 64Cu-Radiolabeled Peptide Inhibitor

    Directory of Open Access Journals (Sweden)

    Frédéric Couture

    2014-08-01

    Full Text Available The potential of PACE4 as a pharmacological target in prostate cancer has been demonstrated as this proprotein convertase is strongly overexpressed in human prostate cancer tissues and its inhibition, using molecular or pharmacological approaches, results in reduced cell proliferation and tumor progression in mouse tumor xenograft models. We developed a PACE4 high-affinity peptide inhibitor, namely, the multi-leucine (ML, and sought to determine whether this peptide could be exploited for the targeting of prostate cancer for diagnostic or molecular imaging purposes. We conjugated a bifunctional chelator 1,4,7-triazacyclononane-1,4,7- triacetic acid (NOTA to the ML peptide for copper-64 (64Cu labeling and positron emission tomography (PET– based prostate cancer detection. Enzyme kinetic assays against recombinant PACE4 showed that the NOTA-modified ML peptide displays identical inhibitory properties compared to the unmodified peptide. In vivo biodistribution of the 64Cu/NOTA-ML peptide evaluated in athymic nude mice bearing xenografts of two human prostate carcinoma cell lines showed a rapid and high uptake in PACE4-expressing LNCaP tumor at an early time point and in PACE4-rich organs. Co-injection of unlabeled peptide confirmed that tumor uptake was target-specific. PACE4-negative tumors displayed no tracer uptake 15 minutes after injection, while the kidneys, demonstrated high uptake due to rapid renal clearance of the peptide. The present study supports the feasibility of using a 64Cu/NOTA-ML peptide for PACE4-targeted prostate cancer detection and PACE4 status determination by PET imaging but also provides evidence that ML inhibitor–based drugs would readily reach tumor sites under in vivo conditions for pharmacological intervention or targeted radiation therapy.

  10. Electrooptical devices

    Science.gov (United States)

    Hurwitz, C. E.

    1980-03-01

    This report covers work carried out with support of the Department of the Air Force during the period 1 October 1979 through 31 March 1980. A part of this support was provided by the Rome Air Development Center. CW operation at temperatures up to 55 C has been achieved for GaInAsP/InP double-heterostructure (DH) lasers emitting at 1.5 micrometers, which were grown without a GaInAsP buffer layer. These devices are of interest for use as sources in fiber-optics communications systems, since the lowest transmission loss reported for fused-silica optical fibers occurs at 1.55 micrometers. Surface passivation techniques developed for InP and GaInAsP avalanche photodiodes have resulted in reductions of dark current as large as four orders of magnitude, to values as low as .0000016 A/sq cm at 0.9 V(b) where V(b) is the breakdown voltage. Devices consisting entirely of InP have been passivated with plasma-deposited Si3N4, and those with a GaInAsP layer but with the p-n junction in InP have been passivated with polyimide. Neither of these techniques successfully reduces dark currents in devices with the p-n junction in the GaInAsP, but a film of photoresist sprayed with SF6 as the propellant has given excellent results. The electrical characteristics in InP ion implanted with Sn, Ge, Si, and C have been investigated. All of these column IV elements yielded n-type conductivity and Sn, Ge, and Si showed high electrical activation; however, implanted C was found to have a net electrical activation of only about 5 percent.

  11. Implementation study of an analog spiking neural network for assisting cardiac delay prediction in a cardiac resynchronization therapy device.

    Science.gov (United States)

    Sun, Qing; Schwartz, François; Michel, Jacques; Herve, Yannick; Dalmolin, Renzo

    2011-06-01

    In this paper, we aim at developing an analog spiking neural network (SNN) for reinforcing the performance of conventional cardiac resynchronization therapy (CRT) devices (also called biventricular pacemakers). Targeting an alternative analog solution in 0.13- μm CMOS technology, this paper proposes an approach to improve cardiac delay predictions in every cardiac period in order to assist the CRT device to provide real-time optimal heartbeats. The primary analog SNN architecture is proposed and its implementation is studied to fulfill the requirement of very low energy consumption. By using the Hebbian learning and reinforcement learning algorithms, the intended adaptive CRT device works with different functional modes. The simulations of both learning algorithms have been carried out, and they were shown to demonstrate the global functionalities. To improve the realism of the system, we introduce various heart behavior models (with constant/variable heart rates) that allow pathologic simulations with/without noise on the signals of the input sensors. The simulations of the global system (pacemaker models coupled with heart models) have been investigated and used to validate the analog spiking neural network implementation.

  12. Scalable devices

    KAUST Repository

    Krüger, Jens J.

    2014-01-01

    In computer science in general and in particular the field of high performance computing and supercomputing the term scalable plays an important role. It indicates that a piece of hardware, a concept, an algorithm, or an entire system scales with the size of the problem, i.e., it can not only be used in a very specific setting but it\\'s applicable for a wide range of problems. From small scenarios to possibly very large settings. In this spirit, there exist a number of fixed areas of research on scalability. There are works on scalable algorithms, scalable architectures but what are scalable devices? In the context of this chapter, we are interested in a whole range of display devices, ranging from small scale hardware such as tablet computers, pads, smart-phones etc. up to large tiled display walls. What interests us mostly is not so much the hardware setup but mostly the visualization algorithms behind these display systems that scale from your average smart phone up to the largest gigapixel display walls.

  13. Influence of gender on pacing adopted by elite triathletes during a competition.

    Science.gov (United States)

    Le Meur, Yann; Hausswirth, Christophe; Dorel, Sylvain; Bignet, Frank; Brisswalter, Jeanick; Bernard, Thierry

    2009-07-01

    The aim of this study was to compare the pacing strategies adopted by women and men during a World Cup ITU triathlon. Twelve elite triathletes (6 females, 6 males) competed in a World Cup Olympic distance competition where speed and heart rate (HR) were measured in the three events. The power output (PO) was recorded in cycling to determine the time spent in five intensity zones ([0-10% VT1]; [10% VT1-VT1]; [VT1-VT2]; [VT2-MAP] and > or =MAP) [ventilatory threshold (VT); maximal aerobic power (MAP)]. Swimming and running speeds decreased similarly for both genders (P < 0.05) and HR values were similar through the whole race (92 +/- 2 and 92 +/- 3% of maximal HR for women and men, respectively). The distribution of time spent in the five zones during the cycling leg was the same for both genders. The men's speed and PO decreased after the first bike lap (P < 0.05) and the women spent relatively more time above MAP in the hilly sections (45 +/- 4 vs. 32 +/- 4%). The men's running speed decreased significantly over the whole circuit, whereas the women slowed only over the uphill and downhill sections (P < 0.05). This study indicates that both female and male elite triathletes adopted similar positive pacing strategies during swimming and running legs. Men pushed the pace harder during the swim-to-cycle transition contrary to the women and female triathletes were more affected by changes in slope during the cycling and running phases.

  14. Matrine Inhibits Pacing Induced Atrial Fibrillation by Modulating IKM3 and ICa-L

    Directory of Open Access Journals (Sweden)

    Yuhong Zhou, Wei Xu, Ruyi Han, Jiaying Zhou, Zhenwei Pan, Huo Rong, Junnan Li, Changqing Xu, Guofen Qiao, Yanjie Lu

    2012-01-01

    Full Text Available Aim: To elucidate the protective effects of Matrine on atrial fibrillation (AF induced by electric pacing in mice and underlying molecular and ion channel mechanisms.Methods: AF was introduced by electric pacing in mice and the incidence and duration of AF were evaluated. Functional expression of M3 receptor (M3-R and Cav1.2 were explored by western and Real-time PCR, action potential (AP and the density of (IKM3 L-type calcium channel (ICa-L were both recorded using whole-cell patch in isolated atrial cardiomyocytes.Results: In control group, incidence and duration of AF induced by electric pacing were 50 ± 17% and 3.68 ± 1.84 s, respectively; after application of carbachol 50 µg/kg both incidence and duration of AF were significantly increased to 86 ± 24% and 65.2 ± 29.0 s. Compared with control group, pretreatment of Matrine for 15 days significantly reduced AF incidence and duration in dose-dependent manner. Atrial membrane-protein expression of M3-R was decreased and membrane Cav1.2 expression was up-regulated. In single Matrine-treated atrial cardiomyocyte the density of IKM3 was significantly decreased by 39% as well compared with control group, P Ca-L density of atrium was increased by 40%.Conclusion: These data demonstrated at the first time that the anti-AF effects of Matrine may due, at least in part, to down-regulation of IKM3 density and M3-R expression and up-regulation of ICa-L density and α1C/Cav1.2 expression.

  15. Uncovering the dynamics of cardiac systems using stochastic pacing and frequency domain analyses.

    Science.gov (United States)

    Lemay, Mathieu; de Lange, Enno; Kucera, Jan P

    2012-01-01

    Alternans of cardiac action potential duration (APD) is a well-known arrhythmogenic mechanism which results from dynamical instabilities. The propensity to alternans is classically investigated by examining APD restitution and by deriving APD restitution slopes as predictive markers. However, experiments have shown that such markers are not always accurate for the prediction of alternans. Using a mathematical ventricular cell model known to exhibit unstable dynamics of both membrane potential and Ca²⁺ cycling, we demonstrate that an accurate marker can be obtained by pacing at cycle lengths (CLs) varying randomly around a basic CL (BCL) and by evaluating the transfer function between the time series of CLs and APDs using an autoregressive-moving-average (ARMA) model. The first pole of this transfer function corresponds to the eigenvalue (λ(alt)) of the dominant eigenmode of the cardiac system, which predicts that alternans occurs when λ(alt) ≤ -1. For different BCLs, control values of λ(alt) were obtained using eigenmode analysis and compared to the first pole of the transfer function estimated using ARMA model fitting in simulations of random pacing protocols. In all versions of the cell model, this pole provided an accurate estimation of λ(alt). Furthermore, during slow ramp decreases of BCL or simulated drug application, this approach predicted the onset of alternans by extrapolating the time course of the estimated λ(alt). In conclusion, stochastic pacing and ARMA model identification represents a novel approach to predict alternans without making any assumptions about its ionic mechanisms. It should therefore be applicable experimentally for any type of myocardial cell.

  16. Uncovering the dynamics of cardiac systems using stochastic pacing and frequency domain analyses.

    Directory of Open Access Journals (Sweden)

    Mathieu Lemay

    Full Text Available Alternans of cardiac action potential duration (APD is a well-known arrhythmogenic mechanism which results from dynamical instabilities. The propensity to alternans is classically investigated by examining APD restitution and by deriving APD restitution slopes as predictive markers. However, experiments have shown that such markers are not always accurate for the prediction of alternans. Using a mathematical ventricular cell model known to exhibit unstable dynamics of both membrane potential and Ca²⁺ cycling, we demonstrate that an accurate marker can be obtained by pacing at cycle lengths (CLs varying randomly around a basic CL (BCL and by evaluating the transfer function between the time series of CLs and APDs using an autoregressive-moving-average (ARMA model. The first pole of this transfer function corresponds to the eigenvalue (λ(alt of the dominant eigenmode of the cardiac system, which predicts that alternans occurs when λ(alt ≤ -1. For different BCLs, control values of λ(alt were obtained using eigenmode analysis and compared to the first pole of the transfer function estimated using ARMA model fitting in simulations of random pacing protocols. In all versions of the cell model, this pole provided an accurate estimation of λ(alt. Furthermore, during slow ramp decreases of BCL or simulated drug application, this approach predicted the onset of alternans by extrapolating the time course of the estimated λ(alt. In conclusion, stochastic pacing and ARMA model identification represents a novel approach to predict alternans without making any assumptions about its ionic mechanisms. It should therefore be applicable experimentally for any type of myocardial cell.

  17. Investigating the pace of temperature change and its implications over the twenty-first century

    Science.gov (United States)

    Chavaillaz, Y.; Joussaume, S.; Braconnot, P.; Vautard, R.

    2015-12-01

    In most studies, climate change is approached by focusing on the evolution between a fixed current baseline and the future, emphasizing stronger warming as we move further from the current climate. Under climate conditions that are continuously evolving, human systems might have to constantly adapt to a changing target. We propose here an alternative approach, and consider indicators of the pace of temperature change and its effects on temperature distributions estimated from projections of an ensemble of 18 General Circulation Models. The pace is represented by a rate defined by the difference between two subsequent 20-year periods. Under the strongest emission pathway (RCP 8.5), the warming rate strongly increases over the twenty-first century, with a maximum reached before 2080. Whilst northern high-latitudes witness the highest temperature rise, all other latitudes highlight at least a doubling in the warming rate compared to the current period. The spatial extent of significant shifts in annual temperature distributions between two subsequent 20-year periods is projected to be at least four times larger than in the current period. They are mainly located in tropical areas, such as West Africa and South-East Asia. The fraction of the world population exposed to these shifts grows from 8% to 60% from around 2060 onwards, i.e. reaching 6 billions people. In contrast, low mitigation measures (RCP 6.0) are sufficient to keep the warming rate similar to current values. Under the medium mitigation pathway (RCP 4.5), population exposure to significant shifts drops to negligible values by the end of the century. Strong mitigation measures (RCP 2.6) are the only option that generates a global return to historical conditions regarding our indicators. Considering the pace of change can bring an alternative way to interact with climate impacts and adaptation communities.

  18. Contribution of ultraviolet and shortwave infrared observations to atmospheric correction of PACE ocean-color imagery

    Science.gov (United States)

    Frouin, Robert J.; Gross-Colzy, Lydwine S.

    2016-05-01

    The Pre-Aerosol, Cloud, and ocean Ecosystem (PACE) mission will carry into space a spectrometer measuring at 5 nm resolution in the ultraviolet (UV) to near infrared (NIR) and at lower resolution in spectral bands in the NIR and shortwave infrared (SWIR). These observations have great potential for improving estimates of marine reflectance in the post-EOS era. In view of this, we evaluate, using simulations with a coupled radiation transfer code, the gain in marine reflectance accuracy expected by including observations in the UV and SWIR compared with just using observations in the visible to NIR. The study is performed for the PACE threshold aggregate bands with respect to the standard set of bands used to generate ocean color products. The top-of-atmosphere (TOA) signal measured by the PACE spectrometer is simulated for a variety of realistic atmospheric and oceanic conditions. The TOA reflectance and the marine reflectance of the simulated ensemble are decomposed into principal components, and the components of the TOA reflectance sensitive to the ocean signal identified. Inverse models are constructed to retrieve the principal components of the marine reflectance, allowing a reconstruction, therefore an estimation of the marine reflectance. Theoretical performance is quantified as a function of angular geometry, aerosol properties, and water type, showing a significant improvement in retrieval accuracy when using the extended spectral range. On average over all the situations considered (including sun glint), the RMS error is reduced from 0.0037 to 0.0024 at 412 nm, from 0.0013 to 0.0007 at 665 nm, and from 0.0010 to 0.0004 at 865 nm (Case 2 waters are better handled). The performance is degraded at large zenith angles and aerosol optical thickness, is better at scattering angles around 120-130 degrees, and exhibits little dependence on aerosol single scattering albedo and aerosol scale height.

  19. Practical microwave electron devices

    CERN Document Server

    Meurant, Gerard

    2013-01-01

    Practical Microwave Electron Devices provides an understanding of microwave electron devices and their applications. All areas of microwave electron devices are covered. These include microwave solid-state devices, including popular microwave transistors and both passive and active diodes; quantum electron devices; thermionic devices (including relativistic thermionic devices); and ferrimagnetic electron devices. The design of each of these devices is discussed as well as their applications, including oscillation, amplification, switching, modulation, demodulation, and parametric interactions.

  20. Effect of nifekalant on acute electrical remodelling in rapid atrial pacing canine model

    Institute of Scientific and Technical Information of China (English)

    TANG Min; ZHANG Shu; SUN Qi; HUA Wei; HUANG Cong-xin

    2006-01-01

    Background Nifekalant may prevent atrial fibrillation (AF) and possibly be useful in treatment of atrial tachyarrhythmia in patients with severe heart failure. This study investigated the electophysiologic effect of nifekalant on the acute atrial remodeling in rapid atrial pacing (RAP) model of canine.Methods Twelve mongrel dogs subjected to rapid stimulation (400 beats/min) at left atrial appendage (LAA)for 24 hours, were randomized into the control group (rapid pacing only, n=6) and the nifekalant group (intravenous nifekalant therapy immediately after RAP, n=6). Atrial electrophysiological parameters were measured in right atrium, coronary sinus, LAA, posterior wall of left atrium (PWLA) and left superior pulmonary vein (LSPV), before and after the RAP.Results In the control group, the effective refractory periods (ERP) were shortened greatly at all sites, paced dogs had substantially shorter ERPs in the high right atrium, LAA, and LSPV, but fewer changes in the PWLA,the coefficient variation of ERP (COV ERP) was increased significantly. After rapid atrial stimulation, the inducibility of AF increased significantly [induction number: pre-RAP vs post-RAP, 1.00± 0.89 vs 8.17 ± 2.79,P<0.01; duration of AF: pre-RAP vs post-RAP, (450.34± 362.59) ms vs (9975.77 ±4376.99) ms, P<0.01]. In the nifekalant group, although the ERPs were prolonged at all sites compared with those in pre-RAP state, only the value at LSPV differed significantly from that in pre-RAP state [pre-RAP vs post-RAP, (102.50±5.24) ms vs (132.51 ±5.20) ms, P<0.01]; the COV ERP did not change statistically in this group. The inducibility of AF slightly increased but insignificantly after pacing [induction number: pre-RAP vs post-RAP, 0.83 ±0.75 vs 1.67±0.82, P=0.19; duration of AF: pre-RAP vs post-RAP, (378.67±317.88) ms vs (1124.08±1109.77) ms,P=0.06]. Conduction time values did not alter significantly in either of the two groups after RAP.Conclusions In canine RAP model, nifekalant

  1. Basal metabolism in tropical birds: latitude, altitude, and the ‘pace of life’

    OpenAIRE

    Londoño, Gustavo Adolfo

    2016-01-01

    Life history varies across latitudes, with the ‘pace of life’ being ‘slower’ in tropical regions. Because life history is coupled to energy metabolism via allocation tradeoffs and links between performance capacity and energy use, low metabolic intensity is expected in tropical animals. Low metabolism has been reported for lowland tropical birds, but it is unclear if this is due to ‘slow’ life history or to a warm, stable environment. We measured basal metabolic rates (BMR) of 253 bird spe...

  2. Pacing and time allocation at the micro- and meso-level within the class hour: Why pacing is important, how to study it, and what it implies for individual lesson planning

    Directory of Open Access Journals (Sweden)

    Joshua Goldsmith

    2009-11-01

    Full Text Available The topic of pacing at the level of the individual class hour has received relatively little coverage in research literature. In order to provide a research-based take on the issue, the current work surveys the existing literature, develops terminology and draws a key distinction between macro-, meso-, and micro-levels of pacing, sequencing, grading, and transitioning. In order to focus on one of pacing’s constituent sub-topics—the allocation of classroom time—this article presents a case study of a first semester college-level introductory German class at a top-tier American university. The data come from two hours of class, one each from the beginning and end of the semester, in an attempt to discover not only how pacing affects teaching synchronically but also how it might change diachronically. Utterances and gestures were transcribed in order to segment the class into activities and sub-activities, and a model for using verbal and gestural cues to perform this kind of segmentation is proposed. The paper also discusses how the teacher allocates time to different kinds of activities, considering pacing strategies that help keep students focused and “on plan” and how these pacing strategies can allow for more time and activities spent on communicative, pair-based work. It is argued that because of the case study teacher’s focus on pacing and use of various strategies to pace the class, not only researchers but also teachers might be able to generalize the micro- and meso-pacing model described in this study to the pacing of individual lessons in their own classrooms.-------------------------------------------------------------------- L’anàlisi detallada del pacing en una hora de classe és un aspecte poc tractat en la literatura científica. Per garantir una perspectiva basada en resultats empírics, aquest estudi es proposa fer un repàs a la literatura ja publicada sobre el tema, desenvolupar-ne la terminologia i distingir

  3. Technical aspects of lead implantation for left ventricle pacing through the coronary sinus, using anatomic radiology and intracavitary electrography in the cardiac resynchronization therapy

    OpenAIRE

    Fernando Sérgio Oliva de Souza; Domingo Marcolino Braile; Reinaldo Wilson Vieira; Salomon Ordinola Rojas; Nicola Luciano Mortati; Alexandre Caputo Rabelo; Sérgio Almeida de Oliveira

    2005-01-01

    OBJETIVO: Apresentar a experiência de 157 implantes utilizando uma técnica simplificada para cateterização do seio coronariano, baseada no eletrograma intracavitário e anatomia radiológica, demonstrando o porcentual de sucesso e tempo total de utilização de radioscopia. MÉTODO: De outubro de 2001 a fevereiro de 2005, foram realizados 157 implantes de marcapasso biventricular em pacientes previamente selecionados, utilizando-se anatomia radiológica e observação de eletrograma intracavitário, d...

  4. Electrophoresis device

    Science.gov (United States)

    Rhodes, P. H.; Snyder, R. S. (Inventor)

    1982-01-01

    A device for separating cellular particles of a sample substance into fractionated streams of different cellular species includes a casing having a distribution chamber, a separation chamber, and a collection chamber. The electrode chambers are separated from the separation chamber interior by means of passages such that flow variations and membrane variations around the slotted portion of the electrode chamber do not enduce flow perturbations into the laminar buffer curtain flowing in the separation chamber. The cellular particles of the sample are separated under the influence of the electrical field and the separation chamber into streams of different cellular species. The streams of separated cells enter a partition array in the collection chamber where they are fractionated and collected.

  5. Stratification devices

    DEFF Research Database (Denmark)

    Andersen, Elsa; Furbo, Simon

    2008-01-01

    heating system. High temperatures in the top of the storage tank established by the energy from the solar collector reduce the use of auxiliary energy. Low temperatures in the bottom of the storage tank improve the operation conditions for the solar collector. Using thermal stratified heat storages...... results in longer operation periods and improved utilization of the solar collector. Thermal stratification can be achieved, for example by using inlet stratification devices at all inlets to the storage tank. This paper presents how thermal stratification is established and utilized by means of inlet......Thermal stratification in the storage tank is extremely important in order to achieve high thermal performance of a solar heating system. High temperatures in the top of the storage tank and low temperatures in the bottom of the storage tank lead to the best operation conditions for any solar...

  6. Learning from feedback training data at a self-paced brain-computer interface

    Science.gov (United States)

    Zhang, Haihong; Liyanage, Sidath Ravindra; Wang, Chuanchu; Guan, Cuntai

    2011-08-01

    Inherent changes that appear in brain signals when transferring from calibration to feedback sessions are a challenging but critical issue in brain-computer interface (BCI) applications. While previous studies have mostly focused on the adaptation of classifiers, in this paper we study the feasibility and the importance of the adaptation of feature extraction in a self-paced BCI paradigm. First, we conduct calibration and feedback training on able-bodied naïve subjects using a new self-paced motor imagery BCI including the idle state. The online results suggest that the feature space constructed from calibration data may become ineffective during feedback sessions. Hence, we propose a new supervised method that learns from a feedback session to construct a more appropriate feature space, on the basis of the maximum mutual information principle between feedback signal, target signal and EEG. Specifically, we formulate the learning objective as maximizing a kernel-based mutual information estimate with respect to the spatial-spectral filtering parameters. We then derive a gradient-based optimization algorithm for the learning task. An experimental study is conducted using offline simulation. The results show that the proposed method is able to construct effective feature spaces to capture the discriminative information in feedback training data and, consequently, the prediction error can be significantly reduced using the new features.

  7. VARIABILITY OF COORDINATION PARAMETERS AT 400-M FRONT CRAWL SWIMMING PACE

    Directory of Open Access Journals (Sweden)

    Christophe Schnitzler

    2009-06-01

    Full Text Available This study examined the variability of physiological, perceptual, stroke and coordination parameters in both genders during several swim trials at the 400-m pace speed. Twelve national level competitors (6 men, 6 women swam 400-m at maximal speed. They then swam three additional trials (100, 200 and 300-m at the pace (speed of the previous 400-m. Three cameras were used to determine stroke cycle [speed (V, stroke length (SL, stroke rate (SR] and coordination [index of coordination (IdC, stroke phases] parameters. Physiological [heart rate (HR and lactate [La-] and perceptual [subjective workload (TWL] parameters were assessed after each swim trial. Inter-trial data indicated that HR, [La-] and TWL increased significantly with the distance swum (p 0.05. Thus, despite changes in both physiological and perceptual responses consecutive to increasing fatigue, coordination parameters remained stable during an all-out 400-m freestyle swim. The examination of these parameters based on short-distance trials appears then to be valid, which offers interesting perspectives for swim testing.

  8. Characterizing Spatial Dynamics of Bifurcation to Alternans in Isolated Whole Rabbit Hearts Based on Alternate Pacing

    Directory of Open Access Journals (Sweden)

    Kanchan Kulkarni

    2015-01-01

    Full Text Available Sudden cardiac death instigated by ventricular fibrillation (VF is the largest cause of natural death in the USA. Alternans, a beat-to-beat alternation in the action potential duration, has been implicated as being proarrhythmic. The onset of alternans is mediated via a bifurcation, which may occur through either a smooth or a border-collision mechanism. The objective of this study was to characterize the mechanism of bifurcation to alternans based on experiments in isolated whole rabbit hearts. High resolution optical mapping was performed and the electrical activity was recorded from the left ventricle (LV epicardial surface of the heart. Each heart was paced using an “alternate pacing protocol,” where the basic cycle length (BCL was alternatively perturbed by ±δ. Local onset of alternans in the heart, BCLstart, was measured in the absence of perturbations (δ=0 and was defined as the BCL at which 10% of LV exhibited alternans. The influences of perturbation size were investigated at two BCLs: one prior to BCLstart (BCLprior=BCLstart+20 ms and one preceding BCLprior (BCLfar=BCLstart+40 ms. Our results demonstrate significant spatial correlation of the region exhibiting alternans with smooth bifurcation characteristics, indicating that transition to alternans in isolated rabbit hearts occurs predominantly through smooth bifurcation.

  9. Continuous renal replacement therapy. Keeping pace with changes in technology and technique.

    Science.gov (United States)

    Baldwin, Ian

    2002-01-01

    The rapidly changing nature of new technologies and techniques in acute health care means it can be difficult keeping pace. Most facilities, large or small, are usually in continuous evaluation of a new technology. Published reviews and professional group guidelines can assist the process of change for continuous renal replacement therapy (CRRT) technologies and techniques. The current techniques and technologies are a mixed application of old and new technologies providing a combination of convective and diffusive solute clearance methods. There are a variety of anticoagulation approaches. New, purpose-built CRRT machines offer many advantages over old technology but their costs can be prohibitive and users do not always meet them with rapid behavioral change. Reading journal publications and texts, scientific meetings, education and training, Internet web site review/participation, quality improvement activities and an accurate local data base are the keys to keeping pace with changes and identifying whether a benefit can be anticipated and demonstrated. Possible changes for the future of techniques and technologies may be in the areas of modified approaches to continuous therapy with tailored approaches for specific patient care settings. Improved membrane characteristics for wider indications and the bio-artificial kidney are emerging along with blood pump and circuit design improvements, with new machine/operator interfaces.

  10. Usefulness of Hemodynamic Sensors for Physiologic Cardiac Pacing in Heart Failure Patients

    Directory of Open Access Journals (Sweden)

    Eraldo Occhetta

    2011-01-01

    Full Text Available The rate adaptive sensors applied to cardiac pacing should respond as promptly as the normal sinus node with an highly specific and sensitive detection of the need of increasing heart rate. Sensors operating alone may not provide optimal heart responsiveness: central venous pH sensing, variations in the oxygen content of mixed venous blood, QT interval, breathing rate and pulmonary minute ventilation monitored by thoracic impedance variations, activity sensors. Using sensors that have different attributes but that work in a complementary manners offers distinct advantages. However, complicated sensors interactions may occur. Hemodynamic sensors detect changes in the hemodynamic performances of the heart, which partially depends on the autonomic nervous system-induced inotropic regulation of myocardial fibers. Specific hemodynamic sensors have been designed to measure different expression of the cardiac contraction strength: Peak Endocardial Acceleration (PEA, Closed Loop Stimulation (CLS and TransValvular Impedance (TVI, guided by intraventricular impedance variations. Rate-responsive pacing is just one of the potential applications of hemodynamic sensors in implantable pacemakers. Other issues discussed in the paper include: hemodynamic monitoring for the optimal programmation and follow up of patients with cardiac resynchronization therapy; hemodynamic deterioration impact of tachyarrhythmias; hemodynamic upper rate limit control; monitoring and prevention of vasovagal malignant syncopes.

  11. Investigation on Walking and Pacing Stability of German Shepherd Dog for Different Locomotion Speeds

    Institute of Scientific and Technical Information of China (English)

    Weijun Tian; Qian Cong; Carlo Menon

    2011-01-01

    The motion of three German Shepherd Dogs on a treadmill was recorded using a three-dimensional motion capture system.The locomotion speed of the dog was respectively set at 4 km·h-1, 5.5 km·h-1, 7 km·h-1 and 8.5 km·h-1 By processing the acquired data, the joint trajectories of the dogs' hind limbs were computed and a time series analysis was conducted. Joint angle-angle diagrams were obtained and the Lyapunov exponents were computed. Results show that the stability decreased when speed increased, which can be attributed to the decrease in the stance phase respect to the swing phase when speed is increased. Results also show that the dogs changed gait during the tests, namely walking in the range of 4 km·h-1 to 7 km·h-1 and pacing at 8.5 km·h-1. A significant drop in stability was observed from walking to pacing.

  12. Utilizing solid impurity granules for ELM pacing in NSTX-U

    Science.gov (United States)

    Lunsford, Robert; Roquemore, L.; Jaworski, M. A.; Kaita, R.; Maingi, R.; NSTX-U Team

    2015-11-01

    Periodic edge localized modes (ELMs) rapidly transport stored energy from the edge plasma to the divertor. These events result in abrupt heating of the plasma facing components (PFCs) which reduces their effective lifetime as well as generating a strong impurity influx. If the frequency of these ELMs can be increased through controlled triggering, also known as pacing, then the inverse relationship between the peak heat flux and the frequency of the ELMs can be utilized to prevent material damage that could result from otherwise unmitigated ELMs. At NSTX, the ability of small (300 - 1000 micron) impurity granules to trigger and pace these ELMs is being explored. In these experiments, ELMs are triggered by seeding a density perturbation within the edge-pedestal region through low speed injection and ablation of impurity granules, thus generating a localized instability. Granules are dropped from a reservoir and transit a vertical flight tube at which point a rotating impeller imparts horizontal momentum into the falling granules. This drives them into the edge of the discharge at speeds ranging from 50-150 m/s and average injection frequencies of up to 200 Hz depending upon the settings of the injector. Results from the initial laboratory injection tests of lithium, boron carbide (B4C) and vitreous carbon granules and their subsequent implementation in NSTX-U experiments will be discussed. Work supported by DOE Contract No. DE-AC02-09CH11466.

  13. Constitutive innate immunity is a component of the pace-of-life syndrome in tropical birds.

    Science.gov (United States)

    Irene Tieleman, B; Williams, Joseph B; Ricklefs, Robert E; Klasing, Kirk C

    2005-08-22

    We studied the relationship between one component of immune function and basal metabolic rate (BMR), an indicator of the 'pace-of-life syndrome', among 12 tropical bird species and among individuals of the tropical house wren (Troglodytes aedon), to gain insights into functional connections between life history and physiology. To assess constitutive innate immunity we introduced a new technique in the field of ecological and evolutionary immunology that quantifies the bactericidal activity of whole blood. This in vitro assay utilises a single blood sample to provide a functional, integrated measure of constitutive innate immunity. We found that the bactericidal activity of whole blood varied considerably among species and among individuals within a species. This variation was not correlated with body mass or whole-organism BMR. However, among species, bacteria killing activity was negatively correlated with mass-adjusted BMR, suggesting that species with a slower pace-of-life have evolved a more robust constitutive innate immune capability. Among individuals of a single species, the house wren, bacteria killing activity was positively correlated with mass-adjusted BMR, pointing to physiological differences in individual quality on which natural selection potentially could act.

  14. The Integration and Functional Evaluation of Rabbit Pacing Cells Transplanted into the Left Ventricular Free Wall

    Directory of Open Access Journals (Sweden)

    Zhihui Zhang, Zhiyuan Song, Jun Cheng, Yaoming Nong, Lu Wei, Changhai Zhang

    2012-01-01

    Full Text Available To evaluate the feasibility of cell transplantation to treat bradyarrhythmia, we analyzed the in vivo integration and pacing function after transplantation of mHCN4-modified rabbit bone marrow mesenchymal stem cells (MSCs into the rabbit left ventricle free wall epicardium. In our investigation, we injected MSCs transduced with or without mHCN4 into the rabbit left ventricle free wall epicardium. Chemical ablation of the sinoatrial node was performed and bilateral vagus nerves were sequentially stimulated to observe premature left ventricular contraction or left ventricular rhythm. We found that the mHCN4-transduced MSC group had a significantly higher ventricular rate and a shorter QRS duration than that of the control and EGFP group. Furthermore, the mHCN4-transduced MSCs, but not the control cells, gradually adapted long-spindle morphology and became indistinguishable from adjacent ventricle myocytes. The modified MSCs showed pacing function approximately 1 week after transplantation and persisted at least 4 weeks after transplantation. In conclusion, a bradyarrhythmia model can be successfully established by chemical ablation of the sinoatrial node and sequential bilateral vagus nerve stimulation. The mHCN4-modified rabbit MSCs displayed evident dynamic morphology changes after being transplanted into rabbit left ventricle free wall epicardium. Our studies may provide a promising strategy of using modified stem cell transplantation to treat bradyarrhythmia.

  15. The Self-Paced Graz Brain-Computer Interface: Methods and Applications

    Directory of Open Access Journals (Sweden)

    Reinhold Scherer

    2007-01-01

    Full Text Available We present the self-paced 3-class Graz brain-computer interface (BCI which is based on the detection of sensorimotor electroencephalogram (EEG rhythms induced by motor imagery. Self-paced operation means that the BCI is able to determine whether the ongoing brain activity is intended as control signal (intentional control or not (non-control state. The presented system is able to automatically reduce electrooculogram (EOG artifacts, to detect electromyographic (EMG activity, and uses only three bipolar EEG channels. Two applications are presented: the freeSpace virtual environment (VE and the Brainloop interface. The freeSpace is a computer-game-like application where subjects have to navigate through the environment and collect coins by autonomously selecting navigation commands. Three subjects participated in these feedback experiments and each learned to navigate through the VE and collect coins. Two out of the three succeeded in collecting all three coins. The Brainloop interface provides an interface between the Graz-BCI and Google Earth.

  16. A Combination of Pre- and Postprocessing Techniques to Enhance Self-Paced BCIs

    Directory of Open Access Journals (Sweden)

    Raheleh Mohammadi

    2012-01-01

    Full Text Available Mental task onset detection from the continuous electroencephalogram (EEG in real time is a critical issue in self-paced brain computer interface (BCI design. The paper shows that self-paced BCI performance can be significantly improved by combining a range of simple techniques including (1 constant-Q filters with varying bandwidth size depending on the center frequency, instead of constant bandwidth filters for frequency decomposition of the EEG signal in the 6 to 36 Hz band; (2 subject-specific postprocessing parameter optimization consisting of dwell time and threshold, and (3 debiasing before postprocessing by readjusting the classification output based on the current and previous brain states, to reduce the number of false detections. This debiasing block is shown to be optimal when activated only in special cases which are predetermined during the training phase. Analysis of the data recorded from seven subjects executing foot movement shows a statistically significant 10% ( average improvement in true positive rate (TPR and a 1% reduction in false positive rate (FPR detections compared with previous work on the same data.

  17. Metabolic rate covaries with fitness and the pace of the life history in the field.

    Science.gov (United States)

    Pettersen, Amanda K; White, Craig R; Marshall, Dustin J

    2016-05-25

    Metabolic rate reflects the 'pace of life' in every organism. Metabolic rate is related to an organism's capacity for essential maintenance, growth and reproduction-all of which interact to affect fitness. Although thousands of measurements of metabolic rate have been made, the microevolutionary forces that shape metabolic rate remain poorly resolved. The relationship between metabolic rate and components of fitness are often inconsistent, possibly because these fitness components incompletely map to actual fitness and often negatively covary with each other. Here we measure metabolic rate across ontogeny and monitor its effects on actual fitness (lifetime reproductive output) for a marine bryozoan in the field. We also measure key components of fitness throughout the entire life history including growth rate, longevity and age at the onset of reproduction. We found that correlational selection favours individuals with higher metabolic rates in one stage and lower metabolic rates in the other-individuals with similar metabolic rates in each developmental stage displayed the lowest fitness. Furthermore, individuals with the lowest metabolic rates lived for longer and reproduced more, but they also grew more slowly and took longer to reproduce initially. That metabolic rate is related to the pace of the life history in nature has long been suggested by macroevolutionary patterns but this study reveals the microevolutionary processes that probably generated these patterns.

  18. Kinematics of the forefoot in the horizontal plane during progressive pace barefoot racewalking on a treadmill after aerobic exercise load.

    Science.gov (United States)

    Wang, Hongzhao; Huo, Ming; An, Xiangde; Li, Yong; Onoda, Ko; Li, Desheng; Huang, Qiuchen; Chen, De; Yin, Lu; Maruyama, Hitoshi

    2016-01-01

    [Purpose] The aim of this study was to measure the changes in forefoot maximum medial/lateral rotation in the horizontal plane during progressive pace barefoot racewalking on a treadmill after a physically demanding aerobic exercise load (a fatigue protocol). [Subjects] Eleven junior racewalking men participated in this study. [Methods] To identify changes in forefoot maximum medial/lateral rotation in the horizontal plane after physically demanding aerobic exercise load, an 8 ch wireless Motion Recorder (MVP-RF8-BC) was utilized. [Results] Forefoot maximum medial/lateral rotation in the horizontal plane was significantly associated with increased paces during progressive pace treadmill racewalking. Significant increases in forefoot maximum medial/lateral rotation were observed during progressive pace barefoot racewalking on the instrumented treadmill at 8 km/h and 10 km/h after a physically demanding aerobic exercise load. [Conclusion] The findings of this study indicated that forefoot maximum medial/lateral rotation increased during progressive pace barefoot racewalking in the fatigue state after a physically demanding aerobic exercise load, which implies that the kinematic features of the forefoot are changed in the fatigue state.

  19. A 'slow pace of life' in Australian old-endemic passerine birds is not accompanied by low basal metabolic rates.

    Science.gov (United States)

    Bech, Claus; Chappell, Mark A; Astheimer, Lee B; Londoño, Gustavo A; Buttemer, William A

    2016-05-01

    Life history theory suggests that species experiencing high extrinsic mortality rates allocate more resources toward reproduction relative to self-maintenance and reach maturity earlier ('fast pace of life') than those having greater life expectancy and reproducing at a lower rate ('slow pace of life'). Among birds, many studies have shown that tropical species have a slower pace of life than temperate-breeding species. The pace of life has been hypothesized to affect metabolism and, as predicted, tropical birds have lower basal metabolic rates (BMR) than temperate-breeding birds. However, many temperate-breeding Australian passerines belong to lineages that evolved in Australia and share 'slow' life-history traits that are typical of tropical birds. We obtained BMR from 30 of these 'old-endemics' and ten sympatric species of more recently arrived passerine lineages (derived from Afro-Asian origins or introduced by Europeans) with 'faster' life histories. The BMR of 'slow' temperate-breeding old-endemics was indistinguishable from that of new-arrivals and was not lower than the BMR of 'fast' temperate-breeding non-Australian passerines. Old-endemics had substantially smaller clutches and longer maximal life spans in the wild than new arrivals, but neither clutch size nor maximum life span was correlated with BMR. Our results suggest that low BMR in tropical birds is not functionally linked to their 'slow pace of life' and instead may be a consequence of differences in annual thermal conditions experienced by tropical versus temperate species.

  20. Heart failure in patients with sick sinus syndrome treated with single lead atrial or dual-chamber pacing

    DEFF Research Database (Denmark)

    Riahi, Sam; Nielsen, Jens Cosedis; Hjortshøj, Søren;

    2012-01-01

    pacing (%VP) and pacing site in the ventricle.METHODS AND RESULTS: We analysed data from 1415 patients randomized to AAIR (n = 707) or DDDR pacing (n = 708). Ventricular pacing leads were recorded as located in either an apical or a non-apical position. The %VP and HF hospitalizations were recorded......, 170 of the 707 (26%) patients developed HF vs. 169 of the 708 (26%) patients in the DDDR group, hazard rate ratio (HR) 1.00, 95% confidence interval (CI) 0.79-1.22, P = 0.87. In DDDR patients, 146 of the 512 patients (29%) with ventricular leads in an apical position developed HF vs. 28 of the 161...... patients (17%) with the leads in a non-apical position, HR 0.67, CI 0.45-1.00, P = 0.05. After adjustments this difference was non-significant. The incidence of HF was not associated with %VP (P = 0.57).CONCLUSION: In patients with SSS, HF was not associated with pacing mode, %VP, or ventricular lead...

  1. Device Characterisation of Short Channel Devices and its Impact on CMOS Circuit Design

    Directory of Open Access Journals (Sweden)

    Kiran Agarwal Gupta

    2012-10-01

    Full Text Available Semiconductor technology has reached an end in the manufacture of conventional Metal Oxide semiconductor Field Effect Transistor (MOSFET. The continuous scaling of semiconductor devices has kept pace with Moore’s law and transistors below 1µm are grouped under deep sub-micron (DSM technology node. But this trend seem to end beyond deep sub micron levels due to main design constraints such as short channel effects (SCE , and variations in process design parameters leading to high leakage currents. Silicon material processes technology has undergone a change in process material and technology beyond 180nm node. For DSM technology nodes leakage current dominates the devices. Circuit designing using MOSFETs at deep sub micron levels, needs a careful study of the behaviour of short channel devices for the parameter variations such as threshold voltage, channel length leading to high leakage currents and poor performance of devices. In this paper we have presented the behaviour of NMOS metal oxide semiconductor field effect transistor (MOSFETs for 90nm technology node in detail and finally compared with 180nm and 45nm nodes. The simulations have been carried out using libraries from TSMC foundry and the device has been simulated using Virtuoso Cadence Spectre Simulator version 6.1.5 with HSPICE.

  2. Device Characterisation of Short Channel Devices and its Impact on CMOS Circuit Design

    Directory of Open Access Journals (Sweden)

    Kiran Agarwal Gupta

    2012-11-01

    Full Text Available Semiconductor technology has reached an end in the manufacture of conventional Metal Oxide semiconductor Field Effect Transistor (MOSFET. The continuous scaling of semiconductor devices has kept pace with Moore’s law and transistors below 1µm are grouped under deep sub-micron (DSM technology node. But this trend seem to end beyond deep sub micron levels due to main design constraints such as short channel effects (SCE , and variations in process design parameters leading to high leakage currents. Silicon material processes technology has undergone a change in process material and technology beyond 180nm node. For DSM technology nodes leakage current dominates the devices. Circuit designing using MOSFETs at deep sub micron levels, needs a careful study of the behaviour of short channel devices for the parameter variations such as threshold voltage, channel length leading to highleakage currents and poor performance of devices. In this paper we have presented the behaviour of NMOS metal oxide semiconductor field effect transistor (MOSFETs for 90nm technology node in detail and finally compared with 180nm and 45nm nodes. The simulations have been carried out using libraries fromTSMC foundry and the device has been simulated using Virtuoso Cadence Spectre Simulator version 6.1.5 with HSPICE.

  3. Laser device

    Science.gov (United States)

    Scott, Jill R.; Tremblay, Paul L.

    2007-07-10

    A laser device includes a target position, an optical component separated a distance J from the target position, and a laser energy source separated a distance H from the optical component, distance H being greater than distance J. A laser source manipulation mechanism exhibits a mechanical resolution of positioning the laser source. The mechanical resolution is less than a spatial resolution of laser energy at the target position as directed through the optical component. A vertical and a lateral index that intersect at an origin can be defined for the optical component. The manipulation mechanism can auto align laser aim through the origin during laser source motion. The laser source manipulation mechanism can include a mechanical index. The mechanical index can include a pivot point for laser source lateral motion and a reference point for laser source vertical motion. The target position can be located within an adverse environment including at least one of a high magnetic field, a vacuum system, a high pressure system, and a hazardous zone. The laser source and an electro-mechanical part of the manipulation mechanism can be located outside the adverse environment. The manipulation mechanism can include a Peaucellier linkage.

  4. Microfluidics and Lab-on-a-Chip Devices

    DEFF Research Database (Denmark)

    Castillo, Jaime

    2015-01-01

    The rapid advances in microfabrication and nanofabrication in combination with the synthesis and discovery of new materials have propelled the drive to develop new technological devices such as smartphones, personal and tablet computers. These devices have changed the way humankind interacts...... communicate what is happening around us. Following the advances of all these communication devices as well as those in microfabrication and nanofabrication and the emergence of new materials, technologies such as lab-on-a-chip (LOC) and micro total analysis systems (microTAS) were also boosted, albeit...... at a slower pace. LOC and microTAS applications have principally been utilized in the biomedical, food and environmental fields. But lately they have also found their place in the synthesis of new chemical compounds and the fabrication of nanostructures. It has become obvious that the LOC and micro...

  5. Environmental effects on the behavior of zoo-housed lions and tigers, with a case study of the effects of a visual barrier on pacing.

    Science.gov (United States)

    Bashaw, Meredith J; Kelling, Angela S; Bloomsmith, Mollie A; Maple, Terry L

    2007-01-01

    Tigers and lions in the wild are nocturnal nonhuman animals who may hunt and mate opportunistically during daylight hours. In captivity, they spend most time on exhibit sleeping or pacing. To better understand their activity budget, this study examined the daily behavior patterns of 2 Sumatran tigers and 3 African lions in different housings. The proportion of scans the large felids spent engaged in stereotypic pacing varied by time of day and environment. The tigers spent different amounts of time pacing when housed in different exhibits; the lions paced more in off-exhibit housing than when on exhibit. These differences suggest changes to the cats' immediate housing environment may decrease pacing but provide little insight into altering specifics. Carnivores' pacing relates to their inability to control sensory access to social partners. Both environments with increased pacing contained chain-link fencing. allowing uncontrolled sensory contact. Where the tigers paced, the study placed a visual barrier between one female and keepers' or conspecifics' cues. This did not significantly decrease pacing. However, the study suggests considering sensory access and environmental variables when designing environments for captive carnivores.

  6. Implantation of Lumenless Pacing Leads at the Inter-atrial Septum and Right Ventricular Outflow Tract with Deflectable Catheter-sheath

    Institute of Scientific and Technical Information of China (English)

    Rong BAI; Ruth KAM; Chi Keong CHING; Li Fern HSU; Wee Siong TEO

    2008-01-01

    Current permanent fight ventricular and fight atrial endocardial pacing leads are implanted utilizing a central lumen stylet. Right ventricular apex pacing initiates an abnormal asyno chronous electrical activation pattern, which results in asynchronous ventricular contraction and re-laxation. When pacing from right atrial appendage, the conduction time between two atria will be prolonged, which results in heterogeneity for both depolarization and repolarization. Six patients with Class Ⅰ indication for permanent pacing were implanted with either single chamber or dual chamber pacemaker. The SelectSecure 3830 4-French (Fr) lumenless lead and the SelectSite C304 8.5-Fr steerable catheter-sheath (Medtronic Inc., USA) were used. Pre-selected pacing sites included inter-atrial septum and right ventricular outflow tract, which were defined by ECG and fluoroscopic criteria. All the implanting procedures were successful without complication. Testing results (mean atrial pacing threshold: 0.87 V; mean P wave amplitude: 2.28 mV; mean ventricular pacing threshold:0.53V; mean R wave amplitude: 8.75 mV) were satisfactory. It is concluded that implantation of a 4-Fr lumenless pacing lead by using a streerable catheter-sheath to achieve inter-atrial septum or right ventricular outflow tract pacing is safe and feasible.

  7. Immune investment is explained by sexual selection and pace-of-life, but not longevity in parrots (Psittaciformes.

    Directory of Open Access Journals (Sweden)

    Darryl B Edwards

    Full Text Available Investment in current reproduction should come at the expense of traits promoting future reproduction, such as immunity and longevity. To date, comparative studies of pace-of-life traits have provided some support for this, with slower paced species having greater immune function. Another means of investment in current reproduction is through secondary sexual characters (SSC. Investment in SSC's is considered costly, both in terms of immunity and longevity, with greater costs being borne by species with more elaborate traits. Yet within species, females prefer more ornate males and those males are typically immunologically superior. Because of this, predictions about the relationship between immunity and SSC's across species are not clear. If traits are costly, brighter species should have reduced immune function, but the opposite is true if SSC's arise from selection for more immunocompetent individuals. My approach was to investigate immune investment in relation to SSC's, pace-of-life and longevity while considering potentially confounding ecological factors. To do so I assessed leukocyte counts from in a novel group, the Psittaciformes. Investment in SSC's best explained investment in immunity: species with brighter plumage had higher leukocyte counts and those with a greater degree of sexual dichromatism had fewer. Ecological variables and pace-of-life models tended to be poor predictors of immune investment. However, shorter incubation periods were associated with lower leukocyte counts supporting the notion that species with a fast pace-of-life invest less in immunity. These results suggest that investment in reproduction in terms of fast pace-of-life and sexual dichromatism results in reduced immunity; however, investment in plumage colour per se does not impose a cost on immunity across species.

  8. Immune investment is explained by sexual selection and pace-of-life, but not longevity in parrots (Psittaciformes).

    Science.gov (United States)

    Edwards, Darryl B

    2012-01-01

    Investment in current reproduction should come at the expense of traits promoting future reproduction, such as immunity and longevity. To date, comparative studies of pace-of-life traits have provided some support for this, with slower paced species having greater immune function. Another means of investment in current reproduction is through secondary sexual characters (SSC). Investment in SSC's is considered costly, both in terms of immunity and longevity, with greater costs being borne by species with more elaborate traits. Yet within species, females prefer more ornate males and those males are typically immunologically superior. Because of this, predictions about the relationship between immunity and SSC's across species are not clear. If traits are costly, brighter species should have reduced immune function, but the opposite is true if SSC's arise from selection for more immunocompetent individuals. My approach was to investigate immune investment in relation to SSC's, pace-of-life and longevity while considering potentially confounding ecological factors. To do so I assessed leukocyte counts from in a novel group, the Psittaciformes. Investment in SSC's best explained investment in immunity: species with brighter plumage had higher leukocyte counts and those with a greater degree of sexual dichromatism had fewer. Ecological variables and pace-of-life models tended to be poor predictors of immune investment. However, shorter incubation periods were associated with lower leukocyte counts supporting the notion that species with a fast pace-of-life invest less in immunity. These results suggest that investment in reproduction in terms of fast pace-of-life and sexual dichromatism results in reduced immunity; however, investment in plumage colour per se does not impose a cost on immunity across species.

  9. Medical devices: US medical device regulation.

    Science.gov (United States)

    Jarow, Jonathan P; Baxley, John H

    2015-03-01

    Medical devices are regulated by the US Food and Drug Administration (FDA) within the Center for Devices and Radiological Health. Center for Devices and Radiological Health is responsible for protecting and promoting the public health by ensuring the safety, effectiveness, and quality of medical devices, ensuring the safety of radiation-emitting products, fostering innovation, and providing the public with accurate, science-based information about the products we oversee, throughout the total product life cycle. The FDA was granted the authority to regulate the manufacturing and marketing of medical devices in 1976. It does not regulate the practice of medicine. Devices are classified based on complexity and level of risk, and "pre-1976" devices were allowed to remain on the market after being classified without FDA review. Post-1976 devices of lower complexity and risk that are substantially equivalent to a marketed "predicate" device may be cleared through the 510(k) premarket notification process. Clinical data are typically not needed for 510(k) clearance. In contrast, higher-risk devices typically require premarket approval. Premarket approval applications must contain data demonstrating reasonable assurance of safety and efficacy, and this information typically includes clinical data. For novel devices that are not high risk, the de novo process allows FDA to simultaneously review and classify new devices. Devices that are not legally marketed are permitted to be used for clinical investigation purposes in the United States under the Investigational Device Exemptions regulation.

  10. [Despite medication, overdrive pacing is required to stabilize the electrical storm associated with acute coronary syndrome: a case report].

    Science.gov (United States)

    Umeda, Masanobu; Morimoto, Atsushi; Yokoyama, Kaori; Tateishi, Emi; Makino, Kanako; Yamamoto, Kazuo; Nakagawa, Yoko; Fukuhara, Shinya; Takase, Eiji

    2007-10-01

    A 75-year-old female complained of severe chest pain and was emergently admitted to our hospital because of anterior acute myocardial infarction. Emergent coronary angiography was performed and revealed occlusion in segment 7, so a stent was implanted. Lidocaine, carvedilol, amiodarone, magnesium, and nifekalant were administered successively because non-sustained ventricular tachycardia (NSVT) frequently appeared like an electrical storm. After nifekalant administration, QTc was significantly prolonged and torsades de pointes was induced. Overdrive pacing was performed and finally the NSVT was completely controlled. If fatal arrhythmias such as NSVT show resistance to medication, overdrive pacing should be considered to stabilize the arrhythmia associated with acute coronary syndrome.

  11. 长时间滚压泵辅助循环管理体会%The management experience of long duration roller pump ventricular assist device

    Institute of Scientific and Technical Information of China (English)

    王中; 王试福; 王大勇

    2011-01-01

    目的 总结本院51例心脏术后心脏和/或肺功能不全滚压泵长时间辅助循环(VAD)管理经验.方法 51例心脏术后患者因心脏和/或肺功能不全而难以脱离体外循环,采用滚压泵进行长时间心肺功能辅助,根据患者心肺功能状态分别采用全心辅助和单纯左心辅助两种辅助方式,辅助期间尽可能提供满意的灌注流量,重视各种脏器保护,注意维持内环境稳定,妥善调节前后负荷之间的关系.结果 全心辅助43例(其中单纯呼吸功能不全13例,全心功能不全27例,呼吸功能不全合并左心功能不全3例),单纯左心辅助8例.VAD时间360~1020(679±29)min,辅助后脱机或在IABP辅助下脱机并存活至出ICU 23例,辅助后不能脱机17例,辅助后脱机或在IABP辅助下脱机但术后10 d内死于ICU 11例.结论 心脏术后因心肺功能不全而难以脱离体外循环时应积极对衰竭器官进行辅助.选择适当辅助方式,精心进行流量调控,妥善进行前、后负荷管理,维持稳定内环境状态,可提高辅助成功率.%OBJECTIVE To summarize the management experience of long duration roller pump ventricular assist device ( VAD ) for left heart assistance in 51 post cardiac surgery patients with heart and/or lung dysfunction. METHODS Ventricular assist devices of roller pump were used for 51 patients who couldn't wean off ECC because of heart and/or lung dysfunction. According to patients' heart and lung condition, biventricular assist advice and left ventricular assist device were used respectively. During assistance,satisfactoryperfusion blood flow was provided and much attention was paid to the conservation of major organs. Body internal environment was maintained in normal status. The relationship between preload and afterload of the heart was adjusted adequately. RESULTS Biventricular assist device was used in 43 cases ( pure respiratory insufficiency 13 cases, biventricular dysfuntion 27 cases, respiratory

  12. Entrepreneurial Call for Strategic Agility in Fast-Paced Business Environment

    Directory of Open Access Journals (Sweden)

    Arslan Ayub

    2014-06-01

    Full Text Available The 21st century came with blending of threats and opportunities of deep-rooted obstructions of fast-paced business environment. Research on strategic management has consequently increased and grabbed the attention of both academicians and strategic policy makers. The current study is therefore directed to analyze the multifaceted influence of entrepreneurial orientation on strategic agility and organizational performance. The study uses exploratory approach; primary data is collected from 323 professional working in private sectors in twin cities of Islamabad and Rawalpindi, Pakistan. The study found significantly positive relationship between entrepreneurial orientation and strategic agility, entrepreneurial orientation and organizational performance, and strategic agility and organizational performance. The study discusses important implications regarding entrepreneurs‘ deployment of entrepreneurial orientation and strategic agility for enhancing organizational performance.

  13. Rapid ventricular pacing for a basilar artery pseudoaneurysm in a pediatric patient: case report.

    Science.gov (United States)

    Nimjee, Shahid M; Smith, Tony P; Kanter, Ronald J; Ames, Warwick; Machovec, Kelly A; Grant, Gerald A; Zomorodi, Ali R

    2015-06-01

    Large cerebral aneurysms of the basilar apex are difficult to treat. Recently, endovascular treatment has mitigated much of the morbidity associated with treating these lesions. However, the morphology of aneurysms of the vertebrobasilar system can preclude endovascular treatment. Rapid ventricular pacing (RVP) facilitates open surgical treatment of cerebral aneurysms. It can assist in reducing the pressure of the neck of the aneurysm, allowing safe application of a clip. The authors present a case of a pediatric patient who developed a basilar artery pseudoaneurysm that required surgery. Given the large size of the aneurysm, RVP was performed, allowing the surgeons to dissect the dome of the aneurysm from the surrounding tissue and pontine perforating branches away from the lesion to safely clip the lesion. The patient had an uneventful recovery. To the authors' knowledge, this represents the first known case of RVP to aid in basilar artery clip occlusion in a pediatric patient.

  14. Rising to the challenge: accelerated pace of discovery transforms marine virology.

    Science.gov (United States)

    Brum, Jennifer R; Sullivan, Matthew B

    2015-03-01

    Marine viruses have important roles in microbial mortality, gene transfer, metabolic reprogramming and biogeochemical cycling. In this Review, we discuss recent technological advances in marine virology including the use of near-quantitative, reproducible metagenomics for large-scale investigation of viral communities and the emergence of gene-based viral ecology. We also describe the reprogramming of microbially driven processes by viral metabolic genes, the identification of novel viruses using cultivation-dependent and cultivation-independent tools, and the potential for modelling studies to provide a framework for studying virus-host interactions. These transformative advances have set a rapid pace in exploring and predicting how marine viruses manipulate and respond to their environment.

  15. The pace of plant community change is accelerating in remnant prairies.

    Science.gov (United States)

    Alstad, Amy O; Damschen, Ellen I; Givnish, Thomas J; Harrington, John A; Leach, Mark K; Rogers, David A; Waller, Donald M

    2016-02-01

    Patterns of biodiversity are changing rapidly. "Legacy studies" use historical data to document changes between past and present communities, revealing long-term trends that can often be linked to particular drivers of ecological change. However, a single pair of historical samples cannot ascertain whether rates of change are consistent or whether the impact and identity of drivers have shifted. Using data from a second resurvey of 47 Wisconsin prairie remnants, we show that the pace of community change has increased with shifts in the strength of particular drivers. Annual rates of local colonization and extinction accelerated by 129 and 214%, respectively, between 1950 and 1987 and between 1987 and 2012. Two anthropogenic drivers-patch area and fire history-increased in importance between these periods. As the strength and number of anthropogenic forces increase, rates of biodiversity change are likely to accelerate in other ecosystems as well.

  16. Social Class, Gender and the Pace of Academic Life: What Kind of Solution is Slow?

    Directory of Open Access Journals (Sweden)

    Heather Mendick

    2014-09-01

    Full Text Available My starting point for this article is the increasing pace of academic life. As the other articles in this special section evidence, the Slow movement, which seeks to challenge our contemporary obsession with speed, is being taken up by many in order to intervene into "fast academia". However, in this article, I suggest we should pause and question what kind of a solution this offers to the current crisis of speed. Working auto/biographically and using examples drawn from popular culture, I argue that Slow is both classed and gendered, re/producing wider patterns of inclusion and exclusion. Specifically, I suggest that Slow naturalises a particular relationship to self which requires not just stability of employment but an individualist way of being, constituting selves that calculate and invest in them-selves for the future. URN: http://nbn-resolving.de/urn:nbn:de:0114-fqs140374

  17. Do changes in the pace of events affect one-off judgments of duration?

    Directory of Open Access Journals (Sweden)

    Hannah M Darlow

    Full Text Available Five experiments examined whether changes in the pace of external events influence people's judgments of duration. In Experiments 1a-1c, participants heard pieces of music whose tempo accelerated, decelerated, or remained constant. In Experiment 2, participants completed a visuo-motor task in which the rate of stimulus presentation accelerated, decelerated, or remained constant. In Experiment 3, participants completed a reading task in which facts appeared on-screen at accelerating, decelerating, or constant rates. In all experiments, the physical duration of the to-be-judged interval was the same across conditions. We found no significant effects of temporal structure on duration judgments in any of the experiments, either when participants knew that a time estimate would be required (prospective judgments or when they did not (retrospective judgments. These results provide a starting point for the investigation of how temporal structure affects one-off judgments of duration like those typically made in natural settings.

  18. Functional remodeling of Ca2+-activated Cl- channel in pacing induced canine failing heart

    Institute of Scientific and Technical Information of China (English)

    Ning Li; Kejuan Ma; Siyong Teng; Jonathan C.Makielski; Jielin Pu

    2008-01-01

    Objective To determine whether Ca2+ activated Cl- current(Icl(Ca)) contributes to the functional remodeling of the failing heart.Methods Whole cell patch-clamp recording technique was employed to record the Icl(Ca) in cardiac myocytes enzymatically isolatedfrom rapidly pacing induced canine failing hearts at room temperature and compared that of the normal hearts (Nor).Results Thecurrent density of DIDS(200M)sensitive Icl(Ca) induced by intracellular Ca2+ release trigged by L-type Ca2+ current(Ica,L)wassignificantly decreased in heart failare(HE)cells compared to Nor cells.At membrane voltage of 20mV,the Icl(Ca) density was 3.02±0.54 pA/pF in Nor(n=6)vs.1.31±0.25 pA/pF in HF(n=8)cells,(P<0.01),while the averaged Ica,L density did not show differencebetween two groups.The time constant of current decay of Icl(Ca) was similar in both types of cells.On the other hand,in intra cellularCa2+ clamped mode,where the[Ca2+];was maintained at 100nmol/L,Icl(Ca) density be increased significantly in HF cells when themembrane voltage at+30mV or higher.Conclusions Our results suggest that Icl(Ca) density was decreased in pacing induced failingheart but the channel function be enhanced.Impaired Ca2+ handing in HF cells rather than reduced,Icl(Ca) channel function itself may havecaused this abnormality.The Icl(Ca) density reduction might contribute to the prolongation of action potential in failing heart.The Icl(Ca)channel function up-rugulation is likely to cause cardiac arrhythmia by inducing a delayed after depolarization,when Ca2+ overloadoccurred in diastolic failing heart cells.

  19. Dehydration: cause of fatigue or sign of pacing in elite soccer?

    Science.gov (United States)

    Edwards, Andrew M; Noakes, Timothy D

    2009-01-01

    Numerous studies have suggested that dehydration is a causal factor to fatigue across a range of sports such as soccer; however, empirical evidence is equivocal on this point. It is also possible that exercise-induced moderate dehydration is purely an outcome of significant metabolic activity during a game. The diverse yet sustained physical activities in soccer undoubtedly threaten homeostasis, but research suggests that under most environmental conditions, match-play fluid loss is minimal ( approximately 1-2% loss of body mass), metabolite accumulation remains fairly constant, and core temperatures do not reach levels considered sufficiently critical to require the immediate cessation of exercise. A complex (central) metabolic control system which ensures that no one (peripheral) physiological system is maximally utilized may explain the diversity of research findings concerning the impact of individual factors such as dehydration on elite soccer performance. In consideration of the existing literature, we propose a new interpretative pacing model to explain the self-regulation of elite soccer performance and, in which, players behaviourally modulate efforts according to a subconscious strategy. This strategy is based on both pre-match (intrinsic and extrinsic factors) and dynamic considerations during the game (such as skin temperature, thirst, accumulation of metabolites in the muscles, plasma osmolality and substrate availability), which enables players to avoid total failure of any single peripheral physiological system either prematurely or at the conclusion of a match. In summary, we suggest that dehydration is only an outcome of complex physiological control (operating a pacing plan) and no single metabolic factor is causal of fatigue in elite soccer.

  20. PACE Continuous Innovation Indicators-a novel tool to measure progress in cancer treatments.

    Science.gov (United States)

    Paddock, Silvia; Brum, Lauren; Sorrow, Kathleen; Thomas, Samuel; Spence, Susan; Maulbecker-Armstrong, Catharina; Goodman, Clifford; Peake, Michael; McVie, Gordon; Geipel, Gary; Li, Rose

    2015-01-01

    Concerns about rising health care costs and the often incremental nature of improvements in health outcomes continue to fuel intense debates about 'progress' and 'value' in cancer research. In times of tightening fiscal constraints, it is increasingly important for patients and their representatives to define what constitutes 'value' to them. It is clear that diverse stakeholders have different priorities. Harmonisation of values may be neither possible nor desirable. Stakeholders lack tools to visualise or otherwise express these differences and to track progress in cancer treatments based on variable sets of values. The Patient Access to Cancer care Excellence (PACE) Continuous Innovation Indicators are novel, scientifically rigorous progress trackers that employ a three-step process to quantify progress in cancer treatments: 1) mine the literature to determine the strength of the evidence supporting each treatment; 2) allow users to weight the analysis according to their priorities and values; and 3) calculate Evidence Scores (E-Scores), a novel measure to track progress, based on the strength of the evidence weighted by the assigned value. We herein introduce a novel, flexible value model, show how the values from the model can be used to weight the evidence from the scientific literature to obtain E-Scores, and illustrate how assigning different values to new treatments influences the E-Scores. The Indicators allow users to learn how differing values lead to differing assessments of progress in cancer research and to check whether current incentives for innovation are aligned with their value model. By comparing E-Scores generated by this tool, users are able to visualise the relative pace of innovation across areas of cancer research and how stepwise innovation can contribute to substantial progress against cancer over time. Learning from experience and mapping current unmet needs will help to support a broad audience of stakeholders in their efforts to

  1. The People with Arthritis Can Exercise (PACE Program: A Qualitative Evaluation of Participant Satisfaction

    Directory of Open Access Journals (Sweden)

    Leigh F. Callahan, PhD

    2005-07-01

    Full Text Available Introduction Developed by the Arthritis Foundation, People with Arthritis Can Exercise is a community-based exercise program for individuals with arthritis. This qualitative study was designed to assess participant satisfaction with the program and examine motivators and barriers to attending program classes. Methods We conducted an 8-week randomized controlled trial of People with Arthritis Can Exercise among 347 participants residing in 18 urban and rural communities across North Carolina. Semistructured telephone interviews were conducted with 51 of the participants. Participants were asked about their overall satisfaction with the program. Motivating factors and barriers to attending the classes, including content, instructor, location, and schedule, were examined. Results Of the 51 participants interviewed, 96% were female, with an average age in years of 67 (range, 32–90 years. Participants reported deriving considerable social support from exercising in a group with others who have arthritis. They identified two main factors that motivated them to continue participating in the exercise class: ability to work at their own pace during the class and confidence that they could do different kinds of exercise safely. Participants also reported that the instructor played a vital role in sustaining their motivation to exercise. Among the participants, noncompleters of the program reported arthritis-related illness or insufficient physical challenge as key barriers to class participation. Conclusion This study suggests that a group exercise program for older adults with arthritis promotes a sense of social support and increases self-efficacy for exercise by allowing participants to work at their own pace.

  2. Orbitally paced phosphogenesis in Mediterranean shallow marine carbonates during the middle Miocene Monterey event

    Science.gov (United States)

    Auer, Gerald; Hauzenberger, Christoph A.; Reuter, Markus; Piller, Werner E.

    2016-04-01

    During the Oligo-Miocene, major phases of phosphogenesis occurred in the Earth's oceans. However, most phosphate deposits represent condensed or allochthonous hemipelagic deposits, formed by complex physical and chemical enrichment processes, limiting their applicability for the study regarding the temporal pacing of Miocene phosphogenesis. The Oligo-Miocene Decontra section located on the Maiella Platform (central Apennines, Italy) is a widely continuous carbonate succession deposited in a mostly middle to outer neritic setting. Of particular interest are the well-winnowed grain to packstones of the middle Miocene Bryozoan Limestone, where occurrences of authigenic phosphate grains coincide with the prominent carbon isotope excursion of the Monterey event. This unique setting allows the analysis of orbital forcing on phosphogenesis, within a bio, chemo, and cyclostratigraphically constrained age-model. LA-ICP-MS analyses revealed a significant enrichment of uranium in the studied authigenic phosphates compared to the surrounding carbonates, allowing natural gamma-radiation (GR) to be used as a qualitative proxy for autochthonous phosphate content. Time series analyses indicate a strong 405 kyr eccentricity forcing of GR in the Bryozoan Limestone. These results link maxima in the GR record and thus phosphate content to orbitally paced increases in the burial of organic carbon, particularly during the carbon isotope maxima of the Monterey event. Thus, phosphogenesis during the middle Miocene in the Mediterranean was controlled by the 405 kyr eccentricity and its influence on large-scale paleoproductivity patterns. Rare earth element data were used as a tool to reconstruct the formation conditions of the investigated phosphates, indicating generally oxic formation conditions, which are consistent with microbially mediated phosphogenesis.

  3. Increases in myocardial workload induced by rapid atrial pacing trigger alterations in global metabolism.

    Directory of Open Access Journals (Sweden)

    Aslan T Turer

    Full Text Available To determine whether increases in cardiac work lead to alterations in the plasma metabolome and whether such changes arise from the heart or peripheral organs.There is growing evidence that the heart influences systemic metabolism through endocrine effects and affecting pathways involved in energy homeostasis.Nineteen patients referred for cardiac catheterization were enrolled. Peripheral and selective coronary sinus (CS blood sampling was performed at serial timepoints following the initiation of pacing, and metabolite profiling was performed by liquid chromatography-mass spectrometry (LC-MS.Pacing-stress resulted in a 225% increase in the median rate·pressure product from baseline. Increased myocardial work induced significant changes in the peripheral concentration of 43 of 125 metabolites assayed, including large changes in purine [adenosine (+99%, p = 0.006, ADP (+42%, p = 0.01, AMP (+79%, p = 0.004, GDP (+69%, p = 0.003, GMP (+58%, p = 0.01, IMP (+50%, p = 0.03, xanthine (+61%, p = 0.0006], and several bile acid metabolites. The CS changes in metabolites qualitatively mirrored those in the peripheral blood in both timing and magnitude, suggesting the heart was not the major source of the metabolite release.Isolated increases in myocardial work can induce changes in the plasma metabolome, but these changes do not appear to be directly cardiac in origin. A number of these dynamic metabolites have known signaling functions. Our study provides additional evidence to a growing body of literature on metabolic 'cross-talk' between the heart and other organs.

  4. BK channels regulate sinoatrial node firing rate and cardiac pacing in vivo.

    Science.gov (United States)

    Lai, Michael H; Wu, Yuejin; Gao, Zhan; Anderson, Mark E; Dalziel, Julie E; Meredith, Andrea L

    2014-11-01

    Large-conductance Ca(2+)- and voltage-activated K(+) (BK) channels play prominent roles in shaping muscle and neuronal excitability. In the cardiovascular system, BK channels promote vascular relaxation and protect against ischemic injury. Recently, inhibition of BK channels has been shown to lower heart rate in intact rodents and isolated hearts, suggesting a novel role in heart function. However, the underlying mechanism is unclear. In the present study, we recorded ECGs from mice injected with paxilline (PAX), a membrane-permeable BK channel antagonist, and examined changes in cardiac conduction. ECGs revealed a 19 ± 4% PAX-induced reduction in heart rate in wild-type but not BK channel knockout (Kcnma1(-/-)) mice. The heart rate decrease was associated with slowed cardiac pacing due to elongation of the sinus interval. Action potential firing recorded from isolated sinoatrial node cells (SANCs) was reduced by 55 ± 15% and 28 ± 9% by application of PAX (3 μM) and iberiotoxin (230 nM), respectively. Furthermore, baseline firing rates from Kcnma1(-/-) SANCs were 33% lower than wild-type SANCs. The slowed firing upon BK current inhibition or genetic deletion was due to lengthening of the diastolic depolarization phase of the SANC action potential. Finally, BK channel immunoreactivity and PAX-sensitive currents were identified in SANCs with HCN4 expression and pacemaker current, respectively, and BK channels cloned from SANCs recapitulated similar activation as the PAX-sensitive current. Together, these data localize BK channels to SANCs and demonstrate that loss of BK current decreases SANC automaticity, consistent with slowed sinus pacing after PAX injection in vivo. Furthermore, these findings suggest BK channels are potential therapeutic targets for disorders of heart rate.

  5. Integrating mobile technology with routine dietetic practice: the case of myPace for weight management.

    Science.gov (United States)

    Harricharan, Michelle; Gemen, Raymond; Celemín, Laura Fernández; Fletcher, David; de Looy, Anne E; Wills, Josephine; Barnett, Julie

    2015-05-01

    The field of Mobile health (mHealth), which includes mobile phone applications (apps), is growing rapidly and has the potential to transform healthcare by increasing its quality and efficiency. The present paper focuses particularly on mobile technology for body weight management, including mobile phone apps for weight loss and the available evidence on their effectiveness. Translation of behaviour change theory into weight management strategies, including integration in mobile technology is also discussed. Moreover, the paper presents and discusses the myPace platform as a case in point. There is little clinical evidence on the effectiveness of currently available mobile phone apps in enabling behaviour change and improving health-related outcomes, including sustained body weight loss. Moreover, it is unclear to what extent these apps have been developed in collaboration with health professionals, such as dietitians, and the extent to which apps draw on and operationalise behaviour change techniques has not been explored. Furthermore, presently weight management apps are not built for use as part of dietetic practice, or indeed healthcare more widely, where face-to-face engagement is fundamental for instituting the building blocks for sustained lifestyle change. myPace is an innovative mobile technology for weight management meant to be embedded into and to enhance dietetic practice. Developed out of systematic, iterative stages of engagement with dietitians and consumers, it is uniquely designed to complement and support the trusted health practitioner-patient relationship. Future mHealth technology would benefit if engagement with health professionals and/or targeted patient groups, and behaviour change theory stood as the basis for technology development. Particularly, integrating technology into routine health care practice, rather than replacing one with the other, could be the way forward.

  6. GaN and ZnO-based materials and devices

    CERN Document Server

    2012-01-01

    The AlInGaN and ZnO materials systems have proven to be one of the scientifically and technologically important areas of development over the past 15 years, with applications in UV/visible optoelectronics and in high-power/high-frequency microwave devices. The pace of advances in these areas has been remarkable and the wide band gap community relies on books like the one we are proposing to provide a review and summary of recent progress.

  7. Aspectos técnicos do implante de eletrodo para estimulação ventricular esquerda através do seio coronariano, com a utilização de anatomia radiológica e eletrograma intracavitário, na terapia de ressincronização cardíaca Technical aspects of lead implantation for left ventricle pacing through the coronary sinus, using anatomic radiology and intracavitary electrography in the cardiac resynchronization therapy

    Directory of Open Access Journals (Sweden)

    Fernando Sérgio Oliva de Souza

    2005-09-01

    Full Text Available OBJETIVO: Apresentar a experiência de 157 implantes utilizando uma técnica simplificada para cateterização do seio coronariano, baseada no eletrograma intracavitário e anatomia radiológica, demonstrando o porcentual de sucesso e tempo total de utilização de radioscopia. MÉTODO: De outubro de 2001 a fevereiro de 2005, foram realizados 157 implantes de marcapasso biventricular em pacientes previamente selecionados, utilizando-se anatomia radiológica e observação de eletrograma intracavitário, demonstrando a taxa de sucesso, complicações e tempo total de utilização de radioscopia. RESULTADOS: O implante do sistema, utilizando-se a estimulação do ventrículo esquerdo via seio coronariano, não foi possível em onze procedimentos. Em 20 pacientes foram observadas dificuldades na canulação do óstio coronário e em 39 pacientes observou-se dificuldade de progressão do eletrodo através do seio coronário. O tempo médio de utilização de radioscopia foi 18,27 ± 15,46 min. CONCLUSÃO: A técnica de implante, proposta pelo autor, utilizando o eletrograma intracavitário e anatomia radiológica, demonstrou ser segura e eficaz para canulação do óstio do seio coronário, necessitando de reduzidos tempos de radioscopia.OBJECTIVE: To present the experience of 157 implantations using a simplified technique for coronary sinus catheterization, based on the atrial component of the intracavitary electrogram and radiological anatomy, showing the success rate and total time of radioscopy use. METHOD: From October 2001 to February 2005, 157 biventricular pacemaker implantations were performed in previously selected patients, using radiological anatomy and observation of the intracavitary electrogram, focusing on the atrial component. Here we show the success rate, complications and total time of radioscopy use. RESULTS: The implantation of the system employing left ventricular pacing via the coronary sinus was not possible in 11 patients

  8. A comparative study of right ventricular outflow tract pacing and right ventricular apical pacing in children%儿童右室流出道起搏与右室心尖起搏的对比研究

    Institute of Scientific and Technical Information of China (English)

    陈晶; 曾国洪; 曾少颖; 王树水

    2014-01-01

    目的:回顾性对比研究儿童行VVI起搏治疗的右室流出道起搏与右室心尖部起搏对近期心功能、QRS波时限及起搏参数的影响。方法:回顾2006年7月至2013年11月,在我科行VVI起搏治疗的38例患儿病例资料,根据术中记录螺旋电极植入的部位分为右室流出道组(n=22)和右室心尖部组(n=16)。记录术前和术后的心脏彩超心功能指标及QRS波时限,术中与术后起搏参数指标进行比较。结果:右室流出道组与右室心尖组在术前及术后心功能指标、术中及术后的起搏阈值差值、导线阻抗差值、R波幅度差值差异无统计学意义。右室流出道起搏组与右室心尖起搏组术后QRS波时限增宽,差异有统计学意义。术前与术后的QRS波时限差值[(134.95±12.86)ms vs(147.44±22.35)ms,t=1.35,P=0.01],差异有统计学意义。结论:儿童右室流出道起搏安全可行,两者起搏术后QRS波时限增宽,但右室心尖起搏组QRS波时限增宽更明显。%Objective To compare the impacts of right ventricular outflow tract pacing and right ventricular apical pacing on short-term cardiac function, QRS duration and pacing parameters in children undergoing VVI pacemaker therapy. Methods The clinical data of 38 children undergoing VVI pacemaker treatment in our department from July 2006 to November 2013 were retrospectively reviewed and analyzed to make grouping: 22 with right ventricular outflow tract pacing based on the operational records were assigned in one group and 16 with right ventricular apical pacing as the other group. The two groups were compared in terms of cardiac function indexes , QRS complex width and intra- and post- operative parameters of the implanted pacemakers. Results There were no significant differences between the two groups in pre-and post-operative cardiac function indexes , intra- and post-operative difference in pacing thresholds

  9. Fast self paced listening times in syntactic comprehension is aphasia -- implications for deficits

    Directory of Open Access Journals (Sweden)

    Jennifer Michaud

    2015-04-01

    Full Text Available Sixty one people with aphasia (pwa and forty one matched controls were tested for the ability to understand sentences that required the ability to assign particular syntactic structures. Participants paced themselves word-by-word through twenty examples of eleven spoken sentence types and indicated which of two pictures corresponded to the meaning of each sentence. Sentences were developed in pairs such that comprehension of the experimental version of a pair required an aspect of syntactic processing not required in the corresponding baseline sentence. The need for the syntactic operations required only in the experimental version was triggered at a “critical word” in the experimental sentence. Listening times for critical words in experimental sentences were compared to those for corresponding words in the corresponding baseline sentences. We adjusted self paced listening times for word duration by subtracting word durations from tag-to-tag self paced listening times to correct for word duration, yielding what we have previously called “corrected listening times.” Corrected listening times above ceiling (10,000 msec for sentence-final words and 5,000 msec for all other words were discarded. For controls, this led to 0.2% of data being discarded and for PWAs 2.2% were discarded. Corrected listening times that were more than 3 standard deviations above or below the mean for that sentence type for each subject were adjusted either down to the upper limit or up to the lower limit of the 3SD range (not discarded. For accurate sentences, 1.7% of the control data were adjusted and 1.8% of the aphasic data were adjusted. For inaccurate sentences, 10% of the corrected listening times were adjusted for controls and 3.3% for aphasics. Our interest is in incremental parsing and interpretation. The measure we used of this process was the residual of a regression of corrected self paced listening times for critical words in experimental sentences

  10. High-Rate Pacing Reduces Variability of Repolarization and Prevents Repolarization-Dependent Arrhythmias in Dogs With Chronic AV Block

    DEFF Research Database (Denmark)

    Oosterhoff, Peter; Thomsen, Morten Bækgaard; Maas, Joep N;

    2010-01-01

    rates (60–65 bpm vs 100–110 bpm) in 7 dogs with chronic atrioventricular block, while recording right and left ventricular (LV) monophasic action potential (MAP) and LV electrogram (EGM). Simulations showed a sampling frequency of 500 Hz is sufficient to capture relevant STV values. High-rate pacing...

  11. Examining the Effectiveness of a Semi-Self-Paced Flipped Learning Format in a College General Chemistry Sequence

    Science.gov (United States)

    Hibbard, Lisa; Sung, Shannon; Wells, Breche´

    2016-01-01

    Flipped learning has come to the forefront in education. It maximizes learning by moving content delivery online, where learning can be self-paced, allowing for class time to focus on student-centered active learning. This five-year cross-sectional study assessed student performance in a college general chemistry for majors sequence taught by a…

  12. At Their Own Pace: Interim Findings from an Evaluation of a Computer-Assisted, Modular Approach to Developmental Math

    Science.gov (United States)

    Gardenhire, Alissa; Diamond, John; Headlam, Camielle; Weiss, Michael J.

    2016-01-01

    Community colleges nationwide are looking for solutions to help students complete developmental (remedial) math--a known barrier to graduation. Some are offering computer-assisted, modular developmental math courses that allow students to earn credits incrementally and move through the curriculum at their own pace. One of these modularized…

  13. Self-Paced Tutorial Courses for Mineral Science - Metallurgy Departments. Final Progress Report (July 1975-August 1980).

    Science.gov (United States)

    Twidwell, L. G.

    Four courses in extractive metallurgy (Pyrometallurgy, Hydrometallurgy, Electrometallurgy; and Physical Chemistry of Iron and Steel) were prepared in a modular, self-paced format. Development of the course materials included: (1) preparation of course outlines by unit coordinators and advisory committees; (2) approval of course outlines (included…

  14. Understanding the Nature of Small Business. PACE Revised. Level 3. Unit 1. Research & Development Series No. 240CB1.

    Science.gov (United States)

    Ashmore, M. Catherine; Pritz, Sandra G.

    This individualized, competency-based unit on understanding the nature of small business, the first of 18 modules, is on the third level of the revised Program for Acquiring Competence in Entrepreneurship (PACE). Intended for the advanced secondary and postsecondary levels and for adults wanting training or retraining, this unit, together with the…

  15. An integrated optical coherence microscopy imaging and optical stimulation system for optogenetic pacing in Drosophila melanogaster (Conference Presentation)

    Science.gov (United States)

    Alex, Aneesh; Li, Airong; Men, Jing; Jerwick, Jason; Tanzi, Rudolph E.; Zhou, Chao

    2016-03-01

    Electrical stimulation is the clinical standard for cardiac pacing. Although highly effective in controlling cardiac rhythm, the invasive nature, non-specificity to cardiac tissues and possible tissue damage limits its applications. Optogenetic pacing of the heart is a promising alternative, which is non-invasive and more specific, has high spatial and temporal precision, and avoids the shortcomings in electrical stimulation. Drosophila melanogaster, which is a powerful model organism with orthologs of nearly 75% of human disease genes, has not been studied for optogenetic pacing in the heart. Here, we developed a non-invasive integrated optical pacing and optical coherence microscopy (OCM) imaging system to control the heart rhythm of Drosophila at different developmental stages using light. The OCM system is capable of providing high imaging speed (130 frames/s) and ultrahigh imaging resolutions (1.5 μm and 3.9 μm for axial and transverse resolutions, respectively). A light-sensitive pacemaker was developed in Drosophila by specifically expressing the light-gated cation channel, channelrhodopsin-2 (ChR2) in transgenic Drosophila heart. We achieved non-invasive and specific optical control of the Drosophila heart rhythm throughout the fly's life cycle (larva, pupa, and adult) by stimulating the heart with 475 nm pulsed laser light. Heart response to stimulation pulses was monitored non-invasively with OCM. This integrated non-invasive optogenetic control and in vivo imaging technique provides a novel platform for performing research studies in developmental cardiology.

  16. The influence of right ventricular apical pacing on left atrial volume in patients with normal left ventricular function

    Directory of Open Access Journals (Sweden)

    AR Moaref1

    2008-03-01

    Full Text Available Background: Right ventricular apical (RVA pacing has been reported to induce several deleterious effects particularly in the presence of structural heart disease but can also involve patients with normal left ventricular (LV function. Left atrial (LA enlargement is one of these effects, but the majority of studies have measured LA dimension rather than volume.Objective: The present prospective study was designed to assess the effect of RVA pacing on LA volume in patients with normal LV function.Patients and Methods: The study comprised 41 consecutive patients with LV ejection fraction ≥ 45% and LV end diastolic dimension ≤ 56 mm who underwent single-or dual- chamber pacemaker implantation in RVA and followed for LA volume measurement and pacemaker analysis at least during the ensuing 4.2 months. Results: In all, 21 patients were excluded from the study due to five spontaneous wide QRS complex (≥120msec, one recent acute coronary syndrome,one significant valvular heart disease, three pacing frequency <90%, eight death or losing follow up in three cases. In remaining 20 patients, LA volume ragned from 21 to 54 mm3 with mean of 37.3±9.7 mm3 prior to pacemaker implantation that increased to 31 to 103 mm3 (54.3±17.0 during follow-up (P<0.001.Conclusion: RVA pacing might lead to an increase in LA volume even in patients with normal LV function.

  17. Major League Baseball pace-of-play rules and their influence on predicted muscle fatigue during simulated baseball games.

    Science.gov (United States)

    Sonne, Michael W L; Keir, Peter J

    2016-11-01

    Major League Baseball (MLB) has proposed rule changes to speed up baseball games. Reducing the time between pitches may impair recovery from fatigue. Fatigue is a known precursor to injury and may jeopardise joint stability. This study examined how fatigue accumulated during baseball games and how different pace of play initiatives may influence fatigue. Pitcher data were retrieved from a public database. A predictive model of muscle fatigue estimated muscle fatigue in 8 arm muscles. A self-selected pace (22.7 s), 12 s pace (Rule 8.04 from the MLB) and a 20 s rest (a pitch clock examined in the 2014 Arizona Fall League (AFL)) were examined. Significantly more muscle fatigue existed in both the AFL and Rule 8.04 conditions, when compared to the self-selected pace condition (5.01 ± 1.73%, 3.95 ± 1.20% and 3.70 ± 1.10% MVC force lost, respectively). Elevated levels of muscle fatigue are predicted in the flexor-pronator mass, which is responsible for providing elbow stability. Reduced effectiveness of the flexor-pronator mass may reduce the active contributions to joint rotational stiffness, increasing strain on the ulnar collateral ligament (UCL) and possibly increasing injury risk.

  18. Creatine kinase and creatine kinase subunit-B in coronary sinus blood in pacing-induced angina pectoris

    DEFF Research Database (Denmark)

    Bagger, J P; Ingerslev, J; Heinsvig, E M

    1982-01-01

    In nine out of 10 patients with angiographic documented coronary artery disease, pacing-induced angina pectoris provoked myocardial production of lactate, whereas no significant release of either creatine kinase or creatine kinase subunit-B to coronary sinus and peripheral venous blood could...

  19. Pseudo-postpacing interval of diastolic potential after entrainment pacing of remote bystander pathway in reentrant ventricular tachycardia.

    Science.gov (United States)

    Kaneko, Yoshiaki; Nakajima, Tadashi; Irie, Tadanobu; Igawa, Osamu; Iijima, Takafumi; Ota, Masaki; Tamura, Mio; Iizuka, Takashi; Tamura, Shuntaro; Saito, Akihiro; Kurabayashi, Masahiko

    2014-09-01

    After entrainment pacing, the postpacing interval of a diastolic potential may be misinterpreted if the distal tip of the ablation catheter captures a remote bystander pathway adjacent to the critical isthmus of a complex reentrant circuit in a structurally diseased heart. We discuss this possible pitfall of entrainment mapping of reentrant ventricular tachycardia, observed after a healed myocardial infarction.

  20. Pseudo-postpacing interval of diastolic potential after entrainment pacing of remote bystander pathway in reentrant ventricular tachycardia

    OpenAIRE

    Kaneko, Yoshiaki; Nakajima, Tadashi; Irie, Tadanobu; Igawa, Osamu; Iijima, Takafumi; Ota, Masaki; Tamura, Mio; Iizuka, Takashi; Tamura, Shuntaro; Saito, Akihiro; Kurabayashi, Masahiko

    2013-01-01

    After entrainment pacing, the postpacing interval of a diastolic potential may be misinterpreted if the distal tip of the ablation catheter captures a remote bystander pathway adjacent to the critical isthmus of a complex reentrant circuit in a structurally diseased heart. We discuss this possible pitfall of entrainment mapping of reentrant ventricular tachycardia, observed after a healed myocardial infarction.

  1. The influence of sex, age, and race experience on pacing profiles during the 90 km Vasaloppet ski race.

    Science.gov (United States)

    Carlsson, Magnus; Assarsson, Hannes; Carlsson, Tomas

    2016-01-01

    The purpose of this study was to investigate pacing-profile differences during the 90 km Vasaloppet ski race related to the categories of sex, age, and race experience. Skiing times from eight sections (S1 to S8) were analyzed. For each of the three categories, 400 pairs of skiers were matched to have a finish time within 60 seconds, the same start group, and an assignment to the same group for the other two categories. Paired-samples Student's t-tests were used to investigate sectional pacing-profile differences between the subgroups. Results showed that males skied faster in S2 (P=0.0042), S3 (P=0.0049), S4 (P=0.010), and S1-S4 (PS7 (PS8 (P=0.0088), and S5-S8 (PS3 (P=0.0029), and for the other sections, there were no differences. Experienced subjects (≥4 Vasaloppet ski race completions) skied faster in S1 (PS1-S4 (P=0.0054); inexperienced skiers (S8 (P=0.0063). In conclusion, females had a more even pacing profile than that of males with the same finish time, start group, age, and race experience. No clear age-related pacing-profile difference was identified for the matched subgroups. Moreover, experienced skiers skied faster in the first half whereas inexperienced skiers had higher skiing speeds during the second half of the race.

  2. Peri-infarct zone pacing to prevent adverse left ventricular remodelling in patients with large myocardial infarction

    DEFF Research Database (Denmark)

    Stone, Gregg W; Chung, Eugene S; Stancak, Branislav;

    2016-01-01

    AIMS: We sought to determine whether peri-infarct pacing prevents left ventricular (LV) remodelling and improves functional and clinical outcomes in patients with large first myocardial infarction (MI). METHODS AND RESULTS: A total of 126 patients at 27 international sites within 10 days of onset...

  3. Comparing E-Learning Tools' Success: The Case of Instructor-Student Interactive vs. Self-Paced Tools

    Science.gov (United States)

    Hsieh, Po-An J.; Cho, Vincent

    2011-01-01

    e-Learning tools have profoundly transformed modern pedagogical approaches. Vendors provide different types of systems, such as self-paced (SP) and instructor-student interactive (ISI) e-Learning tools. Although both types of tools represent promising solutions to facilitate the learning process, it is important to theoretically identify a…

  4. Testing Age-Paced Parenting Newsletters up to Age 3: Greater Impact on First-Time Parents

    Science.gov (United States)

    Ostergren, Carol S.; Riley, David A.

    2012-01-01

    An age-paced newsletter for parents of toddlers was evaluated. Mothers reported the newsletters were as useful as information from doctors or nurses and more useful than other sources of information. We hypothesized and found that first-time mothers reported the newsletters more useful than experienced mothers--reading more of the newsletters and…

  5. How Adults Learn from Self-Paced, Technology-Based Corporate Training: New Focus for Learners, New Focus for Designers

    Science.gov (United States)

    Dobrovolny, Jackie

    2006-01-01

    "How" do adults learn from self-paced, technology-based corporate training, which they select based on its relevance to their current employment responsibilities? Specifically, "how" do adults use the following learning strategies: prior experience, reflection, metacognition, conversations, generative learning strategies, and authentic…

  6. The challenge of engaging all students via self-paced interactive e-learning tutorials for introductory physics

    CERN Document Server

    DeVore, Seth; Singh, Chandralekha

    2016-01-01

    As research-based self-paced e-learning tools become increasingly available, a critical issue educators encounter is implementing strategies to ensure that all students engage with them as intended. Here, we discuss the effectiveness of research-based e-learning tutorials as self-paced learning tools in large enrollment brick and mortar introductory physics courses. These interactive tutorials were developed via research in physics education and were found to be effective for a diverse group of introductory physics students in one-on-one implementation. Instructors encouraged the use of these self-paced tools in a self-paced learning environment by telling students that they would be helpful for solving the assigned homework problems and that the underlying physics principles in the tutorial problems would be similar to those in the in-class quizzes (which we call paired problems). We find that many students, who struggled in the courses in which these adaptive e-learning tutorials were assigned as a self-stu...

  7. Characterization and comparison of polysaccharides from Lycium barbarum in China using saccharide mapping based on PACE and HPTLC.

    Science.gov (United States)

    Wu, Ding-Tao; Cheong, Kit-Leong; Deng, Yong; Lin, Peng-Cheng; Wei, Feng; Lv, Xiao-Jie; Long, Ze-Rong; Zhao, Jing; Ma, Shuang-Cheng; Li, Shao-Ping

    2015-12-10

    Water-soluble polysaccharides from 51 batches of fruits of L. barbarum (wolfberry) in China were investigated and compared using saccharide mapping, partial acid hydrolysis, single and composite enzymatic digestion, followed by polysaccharide analysis by using carbohydrate gel electrophoresis (PACE) analysis and high performance thin layer chromatography (HPTLC) analysis, respectively. Results showed that multiple PACE and HPTLC fingerprints of partial acid and enzymatic hydrolysates of polysaccharides from L. barbarum in China were similar, respectively. In addition, results indicated that β-1,3-glucosidic, α-1,4-galactosiduronic and α-1,5-arabinosidic linkages existed in polysaccharides from L. barbarum collected in China, and the similarity of polysaccharides in L. barbarum collected from different regions of China was pretty high, which are helpful for the improvement of the performance of polysaccharides from L. barbarum in functional/health foods area. Furthermore, polysaccharides from Panax notoginseng, Angelica sinensis, and Astragalus membranaceus var. mongholicus were successfully distinguished from those of L. barbarum based on their PACE fingerprints. These results were beneficial to improve the quality control of polysaccharides from L. barabrum and their products, which suggested that saccharide mapping based on PACE and HPTLC analysis could be a routine approach for quality control of polysaccharides.

  8. 77 FR 60732 - PACE Select Advisors Trust and UBS Global Asset Management (Americas) Inc.; Notice of Application

    Science.gov (United States)

    2012-10-04

    ... COMMISSION PACE Select Advisors Trust and UBS Global Asset Management (Americas) Inc.; Notice of Application... Global Asset Management (Americas) Inc. (the ``Adviser'') (collectively, ``Applicants''). Filing Dates... Global Asset Management (Americas) Inc., 1285 Avenue of the Americas, New York, NY 10019-6028....

  9. Observation of functional remodeling of Ca2+-activated Cl- channel in pacing-induced canine failing heart

    Institute of Scientific and Technical Information of China (English)

    浦介麟

    2006-01-01

    Objective To study whether Ca2+-activated Cl-current (Ito2) contributes to the functional remodeling of the failing heart. Methods The cardiac myocytes were isolated enzymatically from rapidly pacing-induced failing canine hearts (HF) at room temperature. Patch-Clamp whole cell recording technique was employed to record the Ito2.The Cl- transport blocker 4,4’-diisothiocyanos-

  10. Effect of Low-level Vagus Nerve Stimulation on Cardiac Remodeling in a Rapid Atrial Pacing-induced Canine Model of Atrial Fibrillation.

    Science.gov (United States)

    Lu, Yanmei; Sun, Juan; Zhou, Xianhui; Zhang, Ling; Ma, Mei; Tang, Baopeng

    2016-03-01

    The aim of this study was to establish a rapid atrial pacing-induced canine model of atrial fibrillation in studying the effects of low-level vagus nerve stimulation (LLVNS) on atrial fibrillation and the underlying mechanisms for those effects. Adult beagle dogs were randomly assigned to 3 groups: a sham operation group (sham group), a fast left atrial appendage 12-hour pacing group (pacing group), and a 12-hour pacing + LLVNS group (LLVNS group). All dogs underwent tests for their left and right atrial effective refractory period at various time points, after which they were killed, and samples of atrial and anterior right ganglionated plexi tissue were removed and microscopically examined. As pacing times increased, the mean effective refractory period in the pacing group became significantly shortened. The pacing group and the LLVNS group did show significant differences (P nerve growth factor and neurturin (NRTN) in the sham group and the LLVNS group were lower than those in the pacing group (nerve growth factor in 3 groups were (36.35 ± 6.18) × 1000, (86.35 ± 5.63) × 1000, and (40.50 ± 7.24) × 1000 μm²/mm², P nerves.

  11. Impact of right-ventricular apical pacing on the optimal left-ventricular lead positions measured by phase analysis of SPECT myocardial perfusion imaging

    Energy Technology Data Exchange (ETDEWEB)

    Hung, Guang-Uei [Chang Bing Show Chwan Memorial Hospital, Changhua (China); China Medical University, Department of Biomedical Imaging and Radiological Science, Taichung (China); Huang, Jin-Long [Taichung Veterans General Hospital, Cardiovascular Center, Taichung (China); School of Medicine, National Yang-Ming University, Institute of Clinical Medicine, and Cardiovascular Research Institute, Department of Medicine, Taipei (China); Chung-Shan Medical University, Department of Medicine, School of Medicine, Taichung (China); Lin, Wan-Yu; Tsai, Shih-Chung [Taichung Veterans General Hospital, Department of Nuclear Medicine, Taichung (China); Wang, Kuo-Yang [Taichung Veterans General Hospital, Cardiovascular Center, Taichung (China); Chung-Shan Medical University, Department of Medicine, School of Medicine, Taichung (China); Chen, Shih-Ann [School of Medicine, National Yang-Ming University, Institute of Clinical Medicine, and Cardiovascular Research Institute, Department of Medicine, Taipei (China); Taipei Veterans General Hospital, Division of Cardiology, Department of Medicine, Taipei (China); Lloyd, Michael S.; Chen, Ji [Emory University, Department of Radiology and Imaging Sciences, Atlanta, GA (United States)

    2014-06-15

    The use of SPECT phase analysis to optimize left-ventricular (LV) lead positions for cardiac resynchronization therapy (CRT) was performed at baseline, but CRT works as simultaneous right ventricular (RV) and LV pacing. The aim of this study was to assess the impact of RV apical (RVA) pacing on optimal LV lead positions measured by SPECT phase analysis. This study prospectively enrolled 46 patients. Two SPECT myocardial perfusion scans were acquired under sinus rhythm with complete left bundle branch block and RVA pacing, respectively, following a single injection of {sup 99m}Tc-sestamibi. LV dyssynchrony parameters and optimal LV lead positions were measured by the phase analysis technique and then compared between the two scans. The LV dyssynchrony parameters were significantly larger with RVA pacing than with sinus rhythm (p ∝0.01). In 39 of the 46 patients, the optimal LV lead positions were the same between RVA pacing and sinus rhythm (kappa = 0.861). In 6 of the remaining 7 patients, the optimal LV lead positions were along the same radial direction, but RVA pacing shifted the optimal LV lead positions toward the base. The optimal LV lead positions measured by SPECT phase analysis were consistent, no matter whether the SPECT images were acquired under sinus rhythm or RVA pacing. In some patients, RVA pacing shifted the optimal LV lead positions toward the base. This study supports the use of baseline SPECT myocardial perfusion imaging to optimize LV lead positions to increase CRT efficacy. (orig.)

  12. Redistribution of myocardial perfusion during permanent dual chamber pacing in symptomatic non-obstructive hypertrophic cardiomyopathy : A quantitative positron emission tomography study

    NARCIS (Netherlands)

    Posma, JL; Blanksma, PK; vanderWall, EE

    1996-01-01

    Dual chamber pacing causes significant symptomatic improvement in many patients with hypertrophic cardiomyopathy. The mechanism behind this beneficial response is not fully understood. Positron emission tomography showed a redistribution of myocardial flow during pacing in a patient with non-obstruc

  13. Medical Device Safety

    Science.gov (United States)

    A medical device is any product used to diagnose, cure, or treat a condition, or to prevent disease. They ... may need one in a hospital. To use medical devices safely Know how your device works. Keep ...

  14. Implantable electronic medical devices

    CERN Document Server

    Fitzpatrick, Dennis

    2014-01-01

    Implantable Electronic Medical Devices provides a thorough review of the application of implantable devices, illustrating the techniques currently being used together with overviews of the latest commercially available medical devices. This book provides an overview of the design of medical devices and is a reference on existing medical devices. The book groups devices with similar functionality into distinct chapters, looking at the latest design ideas and techniques in each area, including retinal implants, glucose biosensors, cochlear implants, pacemakers, electrical stimulation t

  15. The specialized role of the RN in the Program of All-inclusive Care for the Elderly (PACE) interdisciplinary care team.

    Science.gov (United States)

    Madden, Karen A; Waldo, Mary; Cleeter, Deborah

    2014-01-01

    There is an increasing volume of literature supporting the Program of All-inclusive Care for the Elderly (PACE) as an innovative model of health care delivery for frail seniors. Registered Nurses (RN) hold an essential position among the PACE interdisciplinary teams (IDT) which serve as the foundational practice approach to patient care. There are currently 97 PACE programs in 31 states. Federal and respective state laws provide comprehensive specifications for IDT composition, minimum qualification of team members and services provided. The role of the RN is not fully defined beyond the requirement of periodic assessments. The intent of this study was to explore and describe the role of the nurse in PACE and to compare nursing care delivery models. Focused interviews and survey results show great variation in nursing roles as well as some common themes among nursing leaders for the vision of PACE nurses.

  16. Ultraefficient Themoelectric Devices Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Thermoelectric (TE) devices already found a wide range of commercial, military and aerospace applications. However, at present commercially available TE devices...

  17. Infrared-based blink-detecting glasses for facial pacing: toward a bionic blink.

    Science.gov (United States)

    Frigerio, Alice; Hadlock, Tessa A; Murray, Elizabeth H; Heaton, James T

    2014-01-01

    IMPORTANCE Facial paralysis remains one of the most challenging conditions to effectively manage, often causing life-altering deficits in both function and appearance. Facial rehabilitation via pacing and robotic technology has great yet unmet potential. A critical first step toward reanimating symmetrical facial movement in cases of unilateral paralysis is the detection of healthy movement to use as a trigger for stimulated movement. OBJECTIVE To test a blink detection system that can be attached to standard eyeglasses and used as part of a closed-loop facial pacing system. DESIGN, SETTING, AND PARTICIPANTS Standard safety glasses were equipped with an infrared (IR) emitter-detector unit, oriented horizontally across the palpebral fissure, creating a monitored IR beam that became interrupted when the eyelids closed, and were tested in 24 healthy volunteers from a tertiary care facial nerve center community. MAIN OUTCOMES AND MEASURES Video-quantified blinking was compared with both IR sensor signal magnitude and rate of change in healthy participants with their gaze in repose, while they shifted their gaze from central to far-peripheral positions, and during the production of particular facial expressions. RESULTS Blink detection based on signal magnitude achieved 100% sensitivity in forward gaze but generated false detections on downward gaze. Calculations of peak rate of signal change (first derivative) typically distinguished blinks from gaze-related eyelid movements. During forward gaze, 87% of detected blink events were true positives, 11% were false positives, and 2% were false negatives. Of the 11% false positives, 6% were associated with partial eyelid closures. During gaze changes, false blink detection occurred 6% of the time during lateral eye movements, 10% of the time during upward movements, 47% of the time during downward movements, and 6% of the time for movements from an upward or downward gaze back to the primary gaze. Facial expressions

  18. Automatic artefact removal in a self-paced hybrid brain- computer interface system

    Directory of Open Access Journals (Sweden)

    Yong Xinyi

    2012-07-01

    Full Text Available Abstract Background A novel artefact removal algorithm is proposed for a self-paced hybrid brain-computer interface (BCI system. This hybrid system combines a self-paced BCI with an eye-tracker to operate a virtual keyboard. To select a letter, the user must gaze at the target for at least a specific period of time (dwell time and then activate the BCI by performing a mental task. Unfortunately, electroencephalogram (EEG signals are often contaminated with artefacts. Artefacts change the quality of EEG signals and subsequently degrade the BCI’s performance. Methods To remove artefacts in EEG signals, the proposed algorithm uses the stationary wavelet transform combined with a new adaptive thresholding mechanism. To evaluate the performance of the proposed algorithm and other artefact handling/removal methods, semi-simulated EEG signals (i.e., real EEG signals mixed with simulated artefacts and real EEG signals obtained from seven participants are used. For real EEG signals, the hybrid BCI system’s performance is evaluated in an online-like manner, i.e., using the continuous data from the last session as in a real-time environment. Results With semi-simulated EEG signals, we show that the proposed algorithm achieves lower signal distortion in both time and frequency domains. With real EEG signals, we demonstrate that for dwell time of 0.0s, the number of false-positives/minute is 2 and the true positive rate (TPR achieved by the proposed algorithm is 44.7%, which is more than 15.0% higher compared to other state-of-the-art artefact handling methods. As dwell time increases to 1.0s, the TPR increases to 73.1%. Conclusions The proposed artefact removal algorithm greatly improves the BCI’s performance. It also has the following advantages: a it does not require additional electrooculogram/electromyogram channels, long data segments or a large number of EEG channels, b it allows real-time processing, and c it reduces signal distortion.

  19. Clinical applications of magnets on cardiac rhythm management devices.

    Science.gov (United States)

    Jacob, Sony; Panaich, Sidakpal S; Maheshwari, Rahul; Haddad, John W; Padanilam, Benzy J; John, Sinoj K

    2011-09-01

    The growing indications for permanent pacemaker and implantable cardioverter defibrillator (ICD) implantation have increased the number of patients with these cardiac rhythm management devices (CRMDs). Cardiac rhythm management devices occasionally perform inappropriately in response to electromagnetic interference (e.g. surgical electrocautery) or lead noise over-sensing (e.g. lead fracture). Temporary reprogramming of the CRMDs using device programmers can prevent these untoward device responses. However, these programmers are device manufacturer specific and require technically qualified personnel to operate. This could cause delayed patient care and increased use of resources in certain clinical situations. Alternatively, clinical magnets, when appropriately positioned over the device site, can change the pacing to an asynchronous mode in pacemakers and suspend tachycardia therapies in ICDs. Although readily available, clinical magnets have not been widely used for this purpose, perhaps due to the unfamiliarity with the variable responses of CRMDs to magnet application. This article provides a comprehensive overview of the current literature on the mechanism of action and the specific responses of various CRMDs to clinical magnets.

  20. Monitoring of Vital Signs with Flexible and Wearable Medical Devices.

    Science.gov (United States)

    Khan, Yasser; Ostfeld, Aminy E; Lochner, Claire M; Pierre, Adrien; Arias, Ana C

    2016-06-01

    Advances in wireless technologies, low-power electronics, the internet of things, and in the domain of connected health are driving innovations in wearable medical devices at a tremendous pace. Wearable sensor systems composed of flexible and stretchable materials have the potential to better interface to the human skin, whereas silicon-based electronics are extremely efficient in sensor data processing and transmission. Therefore, flexible and stretchable sensors combined with low-power silicon-based electronics are a viable and efficient approach for medical monitoring. Flexible medical devices designed for monitoring human vital signs, such as body temperature, heart rate, respiration rate, blood pressure, pulse oxygenation, and blood glucose have applications in both fitness monitoring and medical diagnostics. As a review of the latest development in flexible and wearable human vitals sensors, the essential components required for vitals sensors are outlined and discussed here, including the reported sensor systems, sensing mechanisms, sensor fabrication, power, and data processing requirements.

  1. Scientific Computing Using Consumer Video-Gaming Hardware Devices

    CERN Document Server

    Volkema, Glenn

    2016-01-01

    Commodity video-gaming hardware (consoles, graphics cards, tablets, etc.) performance has been advancing at a rapid pace owing to strong consumer demand and stiff market competition. Gaming hardware devices are currently amongst the most powerful and cost-effective computational technologies available in quantity. In this article, we evaluate a sample of current generation video-gaming hardware devices for scientific computing and compare their performance with specialized supercomputing general purpose graphics processing units (GPGPUs). We use the OpenCL SHOC benchmark suite, which is a measure of the performance of compute hardware on various different scientific application kernels, and also a popular public distributed computing application, Einstein@Home in the field of gravitational physics for the purposes of this evaluation.

  2. Digital devices: big challenge in color management

    Science.gov (United States)

    Vauderwange, Oliver; Curticapean, Dan; Dreβler, Paul; Wozniak, Peter

    2014-09-01

    The paper will present how the students learn to find technical solutions in color management by using adequate digital devices and recognize the specific upcoming tasks in this area. Several issues, problems and their solutions will be discussed. The scientific background offer specific didactical solutions in this area of optics. Color management is the major item of this paper. Color management is a crucial responsibility for media engineers and designers. Print, screen and mobile applications must independently display the same colors. Predictability and consistency in the color representation are the aims of a color management system. This is only possible in a standardized and audited production workflow. Nowadays digital media have a fast-paced development process. An increasing number of different digital devices with different display sizes and display technologies are a great challenge for every color management system. The authors will present their experience in the field of color management. The design and development of a suitable learning environment with the required infrastructure is in the focus. The combination of theoretical and practical lectures creates a deeper understanding in the area of the digital color representation.

  3. Bantu expansion shows that habitat alters the route and pace of human dispersals.

    Science.gov (United States)

    Grollemund, Rebecca; Branford, Simon; Bostoen, Koen; Meade, Andrew; Venditti, Chris; Pagel, Mark

    2015-10-27

    Unlike most other biological species, humans can use cultural innovations to occupy a range of environments, raising the intriguing question of whether human migrations move relatively independently of habitat or show preferences for familiar ones. The Bantu expansion that swept out of West Central Africa beginning ∼5,000 y ago is one of the most influential cultural events of its kind, eventually spreading over a vast geographical area a new way of life in which farming played an increasingly important role. We use a new dated phylogeny of ∼400 Bantu languages to show that migrating Bantu-speaking populations did not expand from their ancestral homeland in a "random walk" but, rather, followed emerging savannah corridors, with rainforest habitats repeatedly imposing temporal barriers to movement. When populations did move from savannah into rainforest, rates of migration were slowed, delaying the occupation of the rainforest by on average 300 y, compared with similar migratory movements exclusively within savannah or within rainforest by established rainforest populations. Despite unmatched abilities to produce innovations culturally, unfamiliar habitats significantly alter the route and pace of human dispersals.

  4. Analysis of a Student-Centered, Self-Paced Pedagogy Style for Teaching Information Systems Courses

    Directory of Open Access Journals (Sweden)

    Sharon Paranto

    2006-12-01

    Full Text Available The entry-level skills for students enrolling in a college-level information systems course can vary widely. This paper analyzes the impact of a "student-centered" pedagogy model, in which students use a self-paced approach for learning the material in an introductory information systems course, with pre-assigned dates for lectures and for assignment/exam deadlines. This new paradigm was implemented in several sections of an introductory information systems course over a two-semester time span. Under the new model, tutorial-style textbooks were used to help students master the material, all other materials were available online, and all exams were given using a hands-on, task-oriented online testing package, which included a multiple-choice/true-false component to test student understanding of the conceptual portion of the course. An anonymous student survey was used to gain student perceptions of the level of learning that took place under the new paradigm, as well as to measure student satisfaction with the course design, and a pre-/post-test was used to provide a measure of student learning.

  5. Potentiation and Electrical Stimulus Frequency During Self-Paced Exercise and Recovery

    Directory of Open Access Journals (Sweden)

    Froyd Christian

    2014-10-01

    Full Text Available The aim of this study was to investigate the effect of potentiation on stimulation-induced muscle function during and after an intense bout of self-paced dynamic exercise. Ten active subjects performed a time trial involving repetitive concentric extension-flexion of the right knee using a Biodex dynamometer. Electrical stimulation before and after a 5 s maximal isometric voluntary contraction was performed before the start of the time trial and immediately (< 5 s after each 20% of the time trial as well as 1, 2, 4 and 8 min after time trial termination. Potentiation was observed before the time trial and as early as 1-2 min after the time trial, but no potentiation was detected during or immediately after the time trial for neither single or paired stimuli. At termination of the time trial, “potentiated” peak torque was significantly more reduced than “unpotentiated" peak torque for single stimulus (-65 ± 10% and -42 ± 18%, respectively and paired stimuli at 100 Hz (-51 ± 10% and -33 ± 15%, respectively. Faster recovery for “potentiated” compared to “unpotentiated” peak torque indicate that potentiate peak torque measurements or delay the post-exercise measurements more than a few seconds, will underestimate peripheral fatigue. In conclusion, the potentiation after maximal contraction disappears during intense exercise. Whether the muscle is already potentiated during intense contraction or fatiguing mechanisms inhibits potentiation remains to be clarified

  6. Changes in the timing of hay cutting in Germany do not keep pace with climate warming.

    Science.gov (United States)

    Bock, Anna; Sparks, Tim H; Estrella, Nicole; Menzel, Annette

    2013-10-01

    A unique long-term phenological data set of over 110 000 records of 1st cutting dates for haymaking across Germany, spanning the years 1951-2011 was examined. In addition, we analyzed a long-term data set in the beginning of flowering of meadow foxtail (Alopecurus pratensis) covering the last 20 years. We tested whether hay-cutting dates (based on a human decision when to cut) showed trends, temperature relationships and spatial distribution similar to the development of this grassland species, and if these trends could be related to climate change. The timing of 1st hay cut was strongly influenced (P cutting, with the majority of German federal states having significant (P cutting) were likely to be responsible for the regional differences, while the general increase in AES appears to have confounded the overall trend in hay cutting in the last 20 years. Trends over time and responses to temperature were small relative to those associated with the phenology of meadow foxtail. The advance in phenology of this species is greater than the advance in hay cutting, implying that hay cutting may not be keeping pace with a changing climate, which may have a positive effect on grassland ecology.

  7. Mapping the neural systems that mediate the Paced Auditory Serial Addition Task (PASAT).

    Science.gov (United States)

    Lockwood, Alan H; Linn, Richard T; Szymanski, Herman; Coad, Mary Lou; Wack, David S

    2004-01-01

    The paced auditory serial addition task (PASAT), in which subjects hear a number-string and add the two most-recently heard numbers, is a neuropsychological test sensitive to cerebral dysfunction. We mapped the brain regions activated by the PASAT using positron emission tomography (PET) and 15O-water to measure cerebral blood flow. We parsed the PASAT by mapping sites activated by immediate repetition of numbers and by repetition of the prior number after the presentation of the next number in the series. The PASAT activated dispersed non-contiguous foci in the superior temporal gyri, bifrontal and biparietal sites, the anterior cingulate and bilateral cerebellar sites. These sites are consistent with the elements of the task that include auditory perception and processing, speech production, working memory, and attention. Sites mediating addition were not identified. The extent of the sites activated during the performance of the PASAT accounts for the sensitivity of this test and justifies its use in a variety of seemingly disparate conditions.

  8. Optimal Pacing for Running 400 m and 800 m Track Races

    CERN Document Server

    Reardon, James C

    2012-01-01

    Physicists seeking to understand complex biological systems often find it rewarding to create simple "toy models" that reproduce system behavior. Here a toy model is used to understand a puzzling phenomenon from the sport of track and field. Races are almost always won, and records set, in 400 m and 800 m running events by people who run the first half of the race faster than the second half, which is not true of shorter races, nor of longer. There is general agreement that performance in the 400 m and 800 m is limited somehow by the amount of anaerobic metabolism that can be tolerated in the working muscles in the legs. A toy model of anaerobic metabolism is presented, from which an optimal pacing strategy is analytically calculated via the Euler-Lagrange equation. This optimal strategy is then modified to account for the fact that the runner starts the race from rest; this modification is shown to result in the best possible outcome by use of an elementary variational technique that supplements what is foun...

  9. Exogenous midkine administration prevents cardiac remodeling in pacing-induced congestive heart failure of rabbits.

    Science.gov (United States)

    Harada, Masahide; Hojo, Mayumi; Kamiya, Kaichiro; Kadomatsu, Kenji; Murohara, Toyoaki; Kodama, Itsuo; Horiba, Mitsuru

    2016-01-01

    Midkine (MK), a heparin-binding growth factor, has been shown to prevent cardiac remodeling after ischemic injury through its anti-apoptotic effect. Cell apoptosis is central to the pathophysiology of cardiac remodeling in congestive heart failure (CHF) of ischemic as well as non-ischemic origin. We hypothesized that MK exerts the anti-apoptotic cardioprotective effect in CHF of non-ischemic etiology. MK protein or vehicle (normal saline) was subcutaneously administered in tachycardia-induced CHF rabbits (right ventricular pacing, 350 beats/min, 4 weeks). The vehicle-treated rabbits (n = 19, control) demonstrated severe CHF and high mortality rate, whereas MK (n = 16) demonstrated a well-compensated state and a lower mortality rate. In echocardiography, left ventricular (LV) end-diastolic dimension decreased in MK versus control, whereas LV systolic function increased. In histological analysis (picrosirius red staining), MK decreased collagen deposition area compared with control. TUNEL staining showed that MK prevented cell apoptosis and minimized myocyte loss in the CHF rabbit ventricle, associated with activation of PI3-K/Akt signaling, producing a parallel decrease of Bax/Bcl-2 ratio. MK prevented progression of cardiac remodeling in the CHF rabbit, likely by activation of anti-apoptotic signaling. Exogenous MK application might be a novel therapeutic strategy for CHF due to non-ischemic origin.

  10. Distractor Effect of Auditory Rhythms on Self-Paced Tapping in Chimpanzees and Humans.

    Directory of Open Access Journals (Sweden)

    Yuko Hattori

    Full Text Available Humans tend to spontaneously align their movements in response to visual (e.g., swinging pendulum and auditory rhythms (e.g., hearing music while walking. Particularly in the case of the response to auditory rhythms, neuroscientific research has indicated that motor resources are also recruited while perceiving an auditory rhythm (or regular pulse, suggesting a tight link between the auditory and motor systems in the human brain. However, the evolutionary origin of spontaneous responses to auditory rhythms is unclear. Here, we report that chimpanzees and humans show a similar distractor effect in perceiving isochronous rhythms during rhythmic movement. We used isochronous auditory rhythms as distractor stimuli during self-paced alternate tapping of two keys of an electronic keyboard by humans and chimpanzees. When the tempo was similar to their spontaneous motor tempo, tapping onset was influenced by intermittent entrainment to auditory rhythms. Although this effect itself is not an advanced rhythmic ability such as dancing or singing, our results suggest that, to some extent, the biological foundation for spontaneous responses to auditory rhythms was already deeply rooted in the common ancestor of chimpanzees and humans, 6 million years ago. This also suggests the possibility of a common attentional mechanism, as proposed by the dynamic attending theory, underlying the effect of perceiving external rhythms on motor movement.

  11. Distractor Effect of Auditory Rhythms on Self-Paced Tapping in Chimpanzees and Humans.

    Science.gov (United States)

    Hattori, Yuko; Tomonaga, Masaki; Matsuzawa, Tetsuro

    2015-01-01

    Humans tend to spontaneously align their movements in response to visual (e.g., swinging pendulum) and auditory rhythms (e.g., hearing music while walking). Particularly in the case of the response to auditory rhythms, neuroscientific research has indicated that motor resources are also recruited while perceiving an auditory rhythm (or regular pulse), suggesting a tight link between the auditory and motor systems in the human brain. However, the evolutionary origin of spontaneous responses to auditory rhythms is unclear. Here, we report that chimpanzees and humans show a similar distractor effect in perceiving isochronous rhythms during rhythmic movement. We used isochronous auditory rhythms as distractor stimuli during self-paced alternate tapping of two keys of an electronic keyboard by humans and chimpanzees. When the tempo was similar to their spontaneous motor tempo, tapping onset was influenced by intermittent entrainment to auditory rhythms. Although this effect itself is not an advanced rhythmic ability such as dancing or singing, our results suggest that, to some extent, the biological foundation for spontaneous responses to auditory rhythms was already deeply rooted in the common ancestor of chimpanzees and humans, 6 million years ago. This also suggests the possibility of a common attentional mechanism, as proposed by the dynamic attending theory, underlying the effect of perceiving external rhythms on motor movement.

  12. Small organ size contributes to the slow pace of life in tropical birds.

    Science.gov (United States)

    Wiersma, Popko; Nowak, Brittany; Williams, Joseph B

    2012-05-15

    Attributes of an animal's life history, such as reproductive rate or longevity, typically fall along a 'slow-fast' continuum. Animals at the fast end of this continuum, such as temperate birds, are thought to experience high rates of mortality and invest more resources in reproduction, whereas animals at the slow end, such as tropical birds, live longer, have fewer offspring and invest more resources in self-maintenance. We have previously shown that tropical birds, compared with temperate species, have a reduced basal (BMR) and peak metabolic rate (PMR), patterns consistent with a slow pace of life. Here, we elucidate a fundamental linkage between the smaller mass of central organs of tropical species and their reduced BMR, and between their smaller flight muscles and reduced PMR. Analyses of up to 408 species from the literature showed that the heart, flight muscles, liver, pancreas and kidneys were smaller in tropical species. Direct measurements on 49 species showed smaller heart, lungs, flight muscles, liver, kidneys, ovaries and testes in tropical species, as well as lower feather mass. In combination, our results indicate that the benign tropical environment imposes a relaxed selection pressure on high levels of sustained metabolic performance, permitting species to reduce the mass of organs that are energetically costly to maintain. Brain, gizzard and intestine were exceptions, even though energy turnover of brain and intestine are high. Feather mass was 37% lower in tropical species compared with similar-sized temperate birds, supporting the idea that temperate birds require more insulation for thermoregulation.

  13. Divertor load footprint of ELMs in pellet triggering and pacing experiments at JET

    Energy Technology Data Exchange (ETDEWEB)

    Frigione, D., E-mail: domenico.frigione@frascati.enea.it [Unità Tecnica Fusione, ENEA C.R. Frascati, via E. Fermi 45, 00044 Frascati (Roma) (Italy); Garzotti, L. [CCFE, Culham Science Centre, OX14 3DB (United Kingdom); Lennholm, M. [EFDA CSU, Culham Science Centre, OX14 3DB (United Kingdom); Alper, B. [CCFE, Culham Science Centre, OX14 3DB (United Kingdom); Artaserse, G. [Unità Tecnica Fusione, ENEA C.R. Frascati, via E. Fermi 45, 00044 Frascati (Roma) (Italy); Bennett, P. [CCFE, Culham Science Centre, OX14 3DB (United Kingdom); Giovannozzi, E. [Unità Tecnica Fusione, ENEA C.R. Frascati, via E. Fermi 45, 00044 Frascati (Roma) (Italy); Eich, T. [Max Planck Institute for Plasma Physics, Garching (Germany); Kocsis, G. [WIGNER RCP RMI, POB 49, 1525 Budapest (Hungary); Lang, P.T. [Max Planck Institute for Plasma Physics, Garching (Germany); Maddaluno, G. [Unità Tecnica Fusione, ENEA C.R. Frascati, via E. Fermi 45, 00044 Frascati (Roma) (Italy); Mooney, R. [CCFE, Culham Science Centre, OX14 3DB (United Kingdom); Rack, M. [Institut für Energieforschung – Plasmaphysik, Forschungszentrum Jülich, 52425 Jülich (Germany); Sips, G. [EFDA CSU, Culham Science Centre, OX14 3DB (United Kingdom); Tvalashvili, G. [CCFE, Culham Science Centre, OX14 3DB (United Kingdom); Viola, B. [Unità Tecnica Fusione, ENEA C.R. Frascati, via E. Fermi 45, 00044 Frascati (Roma) (Italy); Wilkes, D. [CCFE, Culham Science Centre, OX14 3DB (United Kingdom)

    2015-08-15

    An investigation of pellet pacing and triggering of Edge Localized Modes (ELMs) was carried out in the frame of ELM mitigation studies aimed at reducing their damaging effects on the plasma-facing components (PFCs). The divertor power load footprint of triggered ELMs was compared with gas puffing controlled ELMs. Small pellets, corresponding to a few per cent of the target plasma particle inventory, were used to minimize the fueling effect and the total particle throughput. There is no evidence that pellets can reduce the divertor power load with respect to gas fueling when operating at the same ELM frequency. The line average density and the energy confinement time remained constant when the gas was progressively substituted by pellets. The launch from the Vertical High Field Side (VHFS) confirmed to be more efficient in ELM triggering than from the Low Field Side (LFS) while the power load footprint remained the same both in time evolution and in spatial distribution when changing the injection geometry.

  14. Time-domain analysis for extracting fast-paced pupil responses

    Science.gov (United States)

    Zénon, Alexandre

    2017-01-01

    The eye pupil reacts to cognitive processes, but its analysis is challenging when luminance varies or when stimulation is fast-paced. Current approaches relying on deconvolution techniques do not account for the strong low-frequency spontaneous changes in pupil size or the large interindividual variability in the shape of the responses. Here a system identification framework is proposed in which the pupil responses to different parameters are extracted by means of an autoregressive model with exogenous inputs. In an example application of this technique, pupil size was shown to respond to the luminance and arousal scores of affective pictures presented in rapid succession. This result was significant in each subject (N = 5), but the pupil response varied between individuals both in amplitude and latency, highlighting the need for determining impulse responses subjectwise. The same method was also used to account for pupil size variations caused by respiration, illustrating the possibility to model the relation between pupil size and other continuous signals. In conclusion, this new framework for the analysis of pupil size data allows us to dissociate the response of the eye pupil from intermingled sources of influence and can be used to study the relation between pupil size and other physiological signals. PMID:28134323

  15. Positive Pacing Strategies Are Utilized by Elite Male and Female Para-cyclists in Short Time Trials in the Velodrome

    Science.gov (United States)

    Wright, Rachel L.

    2016-01-01

    In para-cycling, competitors are classed based on functional impairment resulting in cyclists with neurological and locomotor impairments competing against each other. In Paralympic competition, classes are combined by using a factoring adjustment to race times to produce the overall medallists. Pacing in short-duration track cycling events is proposed to utilize an “all-out” strategy in able-bodied competition. However, pacing in para-cycling may vary depending on the level of impairment. Analysis of the pacing strategies employed by different classification groups may offer scope for optimal performance; therefore, this study investigated the pacing strategy adopted during the 1-km time trial (TT) and 500-m TT in elite C1 to C3 para-cyclists and able-bodied cyclists. Total times and intermediate split times (125-m intervals; measured to 0.001 s) were obtained from the C1-C3 men's 1-km TT (n = 28) and women's 500-m TT (n = 9) from the 2012 Paralympic Games and the men's 1-km TT (n = 19) and women's 500-m TT (n = 12) from the 2013 UCI World Track Championships from publically available video. Split times were expressed as actual time, factored time (for the para-cyclists) and as a percentage of total time. A two-way analysis of variance was used to investigate differences in split times between the different classifications and the able-bodied cyclists in the men's 1-km TT and between the para-cyclists and able-bodied cyclists in the women's 500-m TT. The importance of position at the first split was investigated with Kendall's Tau-b correlation. The first 125-m split time was the slowest for all cyclists, representing the acceleration phase from a standing start. C2 cyclists were slowest at this 125-m split, probably due to a combination of remaining seated in this acceleration phase and a high proportion of cyclists in this group being trans-femoral amputees. Not all cyclists used aero-bars, preferring to use drop, flat or bullhorn handlebars. Split times

  16. Positive pacing strategies are utilised by elite male and female para-cyclists in short time trials in the velodrome

    Directory of Open Access Journals (Sweden)

    Rachel Lindsey Wright

    2016-01-01

    Full Text Available In para-cycling, competitors are classed based on functional impairment resulting in cyclists with neurological and locomotor impairments competing against each other. In Paralympic competition, classes are combined by using a factoring adjustment to race times to produce the overall medallists. Pacing in short-duration track cycling events is proposed to utilise an all-out strategy in able-bodied competition. However, pacing in para-cycling may vary depending on the level of impairment. Analysis of the pacing strategies employed by different classification groups may offer scope for optimal performance; therefore, this study investigated the pacing strategy adopted during the 1-km time trial (TT and 500-m TT in elite C1 to C3 para-cyclists and able-bodied cyclists. Total times and intermediate split times (125-m intervals; measured to 0.001s were obtained from the C1-C3 men’s 1-km TT (n=28 and women’s 500-m TT (n=9 from the 2012 Paralympic Games and the men’s 1-km TT (n=19 and women’s 500-m TT (n=12 from the 2013 UCI World Track Championships from publically available video. Split times were expressed as actual time, factored time (for the para-cyclists and as a percentage of total time. A two-way analysis of variance was used to investigate differences in split times between the different classifications and the able-bodied cyclists in the men’s 1-km TT and between the para-cyclists and able-bodied cyclists in the women’s 500-m TT. The importance of position at the first split was investigated with Kendall’s Tau-b correlation. The first 125-m split time was the slowest for all cyclists, representing the acceleration phase from a standing start. C2 cyclists were slowest at this 125-m split, probably due to a combination of remaining seated in this acceleration phase and a high proportion of cyclists in this group being trans-femoral amputees. Not all cyclists used aero-bars, preferring to use drop, flat or bullhorn handlebars

  17. INDICACIONES DE ESTIMULACIÓN ELÉCTRICA TRANSITORIA, COMPLICACIONES Y NECESIDAD DE ESTIMULACIÓN CARDÍACA PERMANENTE / Use of temporary cardiac pacing, its complications and need for permanent cardiac pacing

    Directory of Open Access Journals (Sweden)

    Humberto Ramos González

    2013-07-01

    Full Text Available Resumen: Introducción: La estimulación cardíaca temporal está indicada en diversas situaciones de extrema urgencia, en pacientes con bradiarritmias graves y bloqueos aurículo-ventriculares de II o III grados.Su indicación siempre se considera ante la presencia de síntomas como: compromiso hemodinámico importante, que no responde a los medicamentos, y poca tolerancia el ritmo lento. Objetivo: Describir las principales indicaciones de estimulación eléctrica transitoria que pueden llevar a la estimulación eléctrica permanente, así como las complicaciones que se presentan al utilizarla. Método: Se realizó un estudio descriptivo donde se estudiaron 266 pacientes de 281 ingresados en el Hospital "Arnaldo Milián Castro", a los cuales se les implantó un marcapasos transitorio. Se describen las indicaciones y complicaciones del procedimiento. Resultados: Se observó un mayor número de indicaciones de estimulación eléctrica transitoria cuando aumenta la edad de la población en estudio, 45,86 % para los mayores de 80 años. El sexo femenino predominó (156 pacientes, con una relación mujer-hombre de 1,56:1. La causa degenerativa (42,1 % fue la mayor indicación de estimulación eléctrica permanente. La punción de vasos no deseados fue la complicación más frecuente (7,1 %. Conclusiones: La indicación de estimulación eléctrica transitoria es más frecuente en los mayores de 80 años, principalmente por causa degenerativa, que finalmente lleva a la estimulación eléctrica permanente. El porcentaje de complicaciones no se muestra elevado cuando se tiene en cuenta que este procedimiento no se realizó bajo visión fluoroscópica. / Abstract: Introduction: Temporary cardiac pacing is used in various extreme emergency situations, in patients with severe bradyarrhythmias and second and third degree atrioventricular block. Its use is always considered when there are symptoms such as a significant hemodynamic compromise, not responding

  18. Match intensity and pacing strategies in rugby league: an examination of whole-game and interchanged players, and winning and losing teams.

    Science.gov (United States)

    Black, Georgia M; Gabbett, Tim J

    2014-06-01

    There is currently limited information on whether pacing occurs during rugby league match play. In addition, to date no research has investigated whether pacing strategies differ between winning and losing teams. This study investigated the pacing strategies of whole-game and interchanged rugby league players. Furthermore, we investigated the pacing strategies of winning and losing teams. Fifty-two rugby league players, from a sample of 11 teams competing in a semi-elite competition, underwent global positioning system analysis. Performances were divided into match quartiles for whole-game and interchanged players. Total distance, including low- and high-speed distances, and repeated high-intensity effort bouts were recorded. The total distance and low-speed distance covered across all quartiles of the match, but specifically quartiles 1 and 8, were greater for interchanged players than whole-game players. The match outcome differentially affected the pacing strategies of whole-game and interchanged players. Whole-game players from winning teams set a higher pacing strategy than whole-game players from losing teams (effect size [ES] = 1.03 ± 0.77, 96%, very likely), whereas interchanged players from losing teams demonstrated a greater "end-spurt" than interchanged players from winning teams (ES = 0.60 ± 0.52, 96%, very likely). The pacing strategies of interchanged players were higher than whole-game players, irrespective of playing position. The results of this study suggest that pacing strategies differ between interchanged and whole-game rugby league players. Furthermore, our results demonstrate a different pacing strategy between winning and losing teams. These findings suggest that physical preparation for rugby league matches, and recovery from these matches, should be individualized for whole-game and interchanged players. Finally, performing physically intense training on a regular basis is likely to develop the physical and mental qualities required to

  19. Ubiquitous Health Management System with Watch-Type Monitoring Device for Dementia Patients

    Directory of Open Access Journals (Sweden)

    Dongmin Shin

    2014-01-01

    Full Text Available For patients who have a senile mental disorder such as dementia, the quantity of exercise and amount of sunlight are an important clue for doses and treatment. Therefore, monitoring daily health information is necessary for patients’ safety and health. A portable and wearable sensor device and server configuration for monitoring data are needed to provide these services for patients. A watch-type device (smart watch that patients wear and a server system are developed in this paper. The smart watch developed includes a GPS, accelerometer, and illumination sensor, and can obtain real time health information by measuring the position of patients, quantity of exercise, and amount of sunlight. The server system includes the sensor data analysis algorithm and web server used by the doctor and protector to monitor the sensor data acquired from the smart watch. The proposed data analysis algorithm acquires the exercise information and detects the step count in patients’ motion acquired from the acceleration sensor and verifies the three cases of fast pace, slow pace, and walking pace, showing 96% of the experimental results. If developed and the u-Healthcare System for dementia patients is applied, higher quality medical services can be provided to patients.

  20. IMPLEMENTATION OF BIOFEEDBACK IN A CLOSED LOOP OF HEART RATE VARIABILITY AND PACED BREATHING IN PATIENTS WITH ARTERIAL HYPERTENSION

    OpenAIRE

    Kulik, O.; Schmidt, O; BELAL S. A. S.; Rank, I.

    2014-01-01

    The effectiveness of biofeedback in a closed loop of heart rate variability (HRV) and paced breathing in patients with arterial hypertension was studied. 61 subjects with arterial hypertension (31 females and 30 males, mean age 56.8 ± 6.2 years) were examined. In accordance with the objective of the study all subjects were divided into 2 groups: 1 biofeedback group (34 subjects) and 2 the comparison group (27 subjects). 5 biofeedback sessions were performed in biofeedback group. In the compar...

  1. The influence of sex, age, and race experience on pacing profiles during the 90 km Vasaloppet ski race

    Science.gov (United States)

    Carlsson, Magnus; Assarsson, Hannes; Carlsson, Tomas

    2016-01-01

    The purpose of this study was to investigate pacing-profile differences during the 90 km Vasaloppet ski race related to the categories of sex, age, and race experience. Skiing times from eight sections (S1 to S8) were analyzed. For each of the three categories, 400 pairs of skiers were matched to have a finish time within 60 seconds, the same start group, and an assignment to the same group for the other two categories. Paired-samples Student’s t-tests were used to investigate sectional pacing-profile differences between the subgroups. Results showed that males skied faster in S2 (P=0.0042), S3 (P=0.0049), S4 (P=0.010), and S1–S4 (Pskied faster in S6 (Pskied faster than young subjects (19 to 39 years) in S3 (P=0.0029), and for the other sections, there were no differences. Experienced subjects (≥4 Vasaloppet ski race completions) skied faster in S1 (Pski race completions) had a shorter mean skiing time in S5–S8 (P=0.0063). In conclusion, females had a more even pacing profile than that of males with the same finish time, start group, age, and race experience. No clear age-related pacing-profile difference was identified for the matched subgroups. Moreover, experienced skiers skied faster in the first half whereas inexperienced skiers had higher skiing speeds during the second half of the race. PMID:26937207

  2. The effect of atrial preference pacing on atrial fibrillation electrophysiological substrate in Myotonic Dystrophy type 1 population

    OpenAIRE

    Russo, Vincenzo; NIGRO, GERARDO; DI MEO, FEDERICA; PAPA, ANDREA ANTONIO; CIOPPA, NADIA DELLA; PROIETTI, RICCARDO; Russo, Maria Giovanna; Calabrò, Raffaele; Politano, Luisa

    2014-01-01

    P-wave dispersion is a non invasive indicator of intra-atrial conduction heterogeneity producing substrate for reentry, which is a pathophysiological mechanism of atrial fibrillation. The relationship between P-wave dispersion (PD) and atrial fibrillation (AF) in Myotonic dystrophy type 1 (DM1) patients is still unclear. Atrial Preference Pacing (APP) is an efficient algorithm to prevent paroxysmal AF in patients implanted with dual-chamber pacemaker. Aim of our study was to evaluate the poss...

  3. 生理性起搏的研究进展%Advances in Study of Physiological Pacing

    Institute of Scientific and Technical Information of China (English)

    李林; 李兴德

    2014-01-01

    Cur ently ,Cardiac pacemaker is the preferred treatment of sinus node dysfunction , high degree atrioventricular block and other slow ar hythmia disease , and the clinical indications has been extended to refractory congestive heart failure , ventricular fibril ation , carotid sinus hypersensitivity induced syncope and other non-pacing and conduction system diseases . However, mimicking the physiological pacing maximum has been the main direction of electric physiologists to research , we do the fol owing review on the research progress of physiological pacing.%心脏起搏器是目前治疗窦房结功能障碍、高度房室传导阻滞等缓慢型心律失常的首选治疗方案,且临床适应症已经扩展到顽固性充血性心力衰竭、心室颤动、颈动脉窦过敏所致晕厥等非起搏及传导系统疾病的治疗。然而最大程度的模仿生理性起搏,一直是起搏电生理学家们所研究的主要方向,现就生理性起搏的研究进展做如下综述。

  4. Using self-paced, `flipped' teaching to promote deep learning in an Earth Sciences programming course

    Science.gov (United States)

    Kalnins, L. M.

    2015-12-01

    Over the last year we implemented a complete restructuring of a second year Matlab-based course on numerical modelling of Earth processes, with changes aimed at 1) strengthening students' independence as programmers, 2) addressing student concerns about support in developing coding skills, and 3) improving key modelling skills such as choosing boundary conditions. To address this, we designed a mastery-based approach where students progress through a series of small programming projects at their own pace. As part of this, all lectures are `flipped' into short videos, allowing all contact hours to be spent on programming. The projects themselves are structured based on a `bottlenecks to learning' approach, explicitly separating out the steps of learning new commands and code structures, creating a conceptual and mathematical model of the problem, and development of more generic programmings skills such as debugging before asking the students to combine all of the above to build a numerical model of an Earth Sciences problem. Compared with the previous, traditionally taught cohort, student questionnaires show a strong improvement in overall satisfaction. Free text responses show a focus on learning for understanding, and that students particularly valued the encouragement to slow down and work towards understanding when they encountered a difficult topic, rather than being pressured by a set timetable to move on. Quantitatively, exam performance improved on key conceptual questions, such as boundary conditions and discretisation, and overall achievement also rose, with 25% of students achieving an `A+' standard of work. Many of the final projects also demonstrated programming and modelling skills that had not been directly taught, ranging from use of new commands to extension of techniques taught in 1D to the 2D case: strong confirmation of the independent skills we aimed to foster with this new approach.

  5. Timing is everything: ecological vs. evolutionary pacing of Triassic-Jurassic carbon cycle disruptions

    Science.gov (United States)

    Whiteside, J. H.; Olsen, P. E.; Eglinton, T. I.

    2007-12-01

    Eruption of Earth's largest flood basalt, the Central Atlantic Magmatic Province (CAMP) has been proposed as the trigger for a major carbon cycle disruption at the Triassic-Jurassic mass extinction interval at ~201 Ma. Inferred from negative excursions in the carbon isotopic composition (δ13C) of carbonate and organic matter, this perturbation has been linked to massive dissociation of isotopically light, methane-rich gas hydrates caused by volcanogenic CO2-induced global warming. However, both the sequence and duration of the CAMP eruptions relative to the carbon cycle perturbation remain circumstantial and indirect, because the data have been from stratigraphic sections far from the flood basalts and without accumulation rate constraints. Here we use a record of atmospheric (δ13C) from specific molecules (nC25 - nC32 n-alkanes) diagnostic of terrestrial plant leaf waxes from astronomically-paced cyclical lacustrine strata in which CAMP flood basalts are interbedded to directly examine the relationship between the (δ13C) excursions and their durations. We show that the flood basalts postdate the abrupt start of a ~400 ky negative excursion coincident with the initiation of the mass extinction event, but predate a protracted 1.5 m.y. negative excursion. Based on a modified BLAG carbon cycle model, the timing and long durations of our (δ13C) excursions are incompatible with CAMP-triggered gas hydrate release. Instead, we suggest that the (δ13C) pattern is more consistent with a catastrophically-triggered functional reorganization of the biosphere, part of which involved the ascent of dinosaurs to ecological dominance, playing out over evolutionary time.

  6. Self-paced brain-computer interface control of ambulation in a virtual reality environment

    Science.gov (United States)

    Wang, Po T.; King, Christine E.; Chui, Luis A.; Do, An H.; Nenadic, Zoran

    2012-10-01

    Objective. Spinal cord injury (SCI) often leaves affected individuals unable to ambulate. Electroencephalogram (EEG) based brain-computer interface (BCI) controlled lower extremity prostheses may restore intuitive and able-body-like ambulation after SCI. To test its feasibility, the authors developed and tested a novel EEG-based, data-driven BCI system for intuitive and self-paced control of the ambulation of an avatar within a virtual reality environment (VRE). Approach. Eight able-bodied subjects and one with SCI underwent the following 10-min training session: subjects alternated between idling and walking kinaesthetic motor imageries (KMI) while their EEG were recorded and analysed to generate subject-specific decoding models. Subjects then performed a goal-oriented online task, repeated over five sessions, in which they utilized the KMI to control the linear ambulation of an avatar and make ten sequential stops at designated points within the VRE. Main results. The average offline training performance across subjects was 77.2±11.0%, ranging from 64.3% (p = 0.001 76) to 94.5% (p = 6.26×10-23), with chance performance being 50%. The average online performance was 8.5±1.1 (out of 10) successful stops and 303±53 s completion time (perfect = 211 s). All subjects achieved performances significantly different than those of random walk (p ambulation after only 10 minutes training. The ability to achieve such BCI control with minimal training indicates that the implementation of future BCI-lower extremity prosthesis systems may be feasible.

  7. Muscle-Type Specific Autophosphorylation of CaMKII Isoforms after Paced Contractions

    Science.gov (United States)

    Eilers, Wouter; Gevers, Wouter; van Overbeek, Daniëlle; de Haan, Arnold; Jaspers, Richard T.; Hilbers, Peter A.; van Riel, Natal; Flück, Martin

    2014-01-01

    We explored to what extent isoforms of the regulator of excitation-contraction and excitation-transcription coupling, calcium/calmodulin protein kinase II (CaMKII) contribute to the specificity of myocellular calcium sensing between muscle types and whether concentration transients in its autophosphorylation can be simulated. CaMKII autophosphorylation at Thr287 was assessed in three muscle compartments of the rat after slow or fast motor unit-type stimulation and was compared against a computational model (CaMuZclE) coupling myocellular calcium dynamics with CaMKII Thr287 phosphorylation. Qualitative differences existed between fast- (gastrocnemius medialis) and slow-type muscle (soleus) for the expression pattern of CaMKII isoforms. Phospho-Thr287 content of δA CaMKII, associated with nuclear functions, demonstrated a transient and compartment-specific increase after excitation, which contrasted to the delayed autophosphorylation of the sarcoplasmic reticulum-associated βM CaMKII. In soleus muscle, excitation-induced δA CaMKII autophosphorylation demonstrated frequency dependence (P = 0.02). In the glycolytic compartment of gastrocnemius medialis, CaMKII autophosphorylation after excitation was blunted. In silico assessment emphasized the importance of mitochondrial calcium buffer capacity for excitation-induced CaMKII autophosphorylation but did not predict its isoform specificity. The findings expose that CaMKII autophosphorylation with paced contractions is regulated in an isoform and muscle type-specific fashion and highlight properties emerging for phenotype-specific regulation of CaMKII. PMID:25054156

  8. Muscle-Type Specific Autophosphorylation of CaMKII Isoforms after Paced Contractions

    Directory of Open Access Journals (Sweden)

    Wouter Eilers

    2014-01-01

    Full Text Available We explored to what extent isoforms of the regulator of excitation-contraction and excitation-transcription coupling, calcium/calmodulin protein kinase II (CaMKII contribute to the specificity of myocellular calcium sensing between muscle types and whether concentration transients in its autophosphorylation can be simulated. CaMKII autophosphorylation at Thr287 was assessed in three muscle compartments of the rat after slow or fast motor unit-type stimulation and was compared against a computational model (CaMuZclE coupling myocellular calcium dynamics with CaMKII Thr287 phosphorylation. Qualitative differences existed between fast- (gastrocnemius medialis and slow-type muscle (soleus for the expression pattern of CaMKII isoforms. Phospho-Thr287 content of δA CaMKII, associated with nuclear functions, demonstrated a transient and compartment-specific increase after excitation, which contrasted to the delayed autophosphorylation of the sarcoplasmic reticulum-associated βM CaMKII. In soleus muscle, excitation-induced δA CaMKII autophosphorylation demonstrated frequency dependence (P = 0.02. In the glycolytic compartment of gastrocnemius medialis, CaMKII autophosphorylation after excitation was blunted. In silico assessment emphasized the importance of mitochondrial calcium buffer capacity for excitation-induced CaMKII autophosphorylation but did not predict its isoform specificity. The findings expose that CaMKII autophosphorylation with paced contractions is regulated in an isoform and muscle type-specific fashion and highlight properties emerging for phenotype-specific regulation of CaMKII.

  9. Automated Electrophysiology Makes the Pace for Cardiac Ion Channel Safety Screening

    Directory of Open Access Journals (Sweden)

    Clemens eMoeller

    2011-11-01

    Full Text Available The field of automated patch-clamp electrophysiology has emerged from the tension between the pharmaceutical industry’s need for high-throughput compound screening versus its need to be conservative due to regulatory requirements. On the one hand, hERG channel screening was increasingly requested for new chemical entities, as the correlation between blockade of the ion channel coded by hERG and Torsades de Pointes cardiac arrhythmia gained increasing attention. On the other hand, manual patch-clamping, typically quoted as the gold-standard for understanding ion channel function and modulation, was far too slow (and, consequently, too expensive for keeping pace with the numbers of compounds submitted for hERG channel investigations from pharmaceutical R&D departments. In consequence it became more common for some pharmaceutical companies to outsource safety pharmacological investigations, with a focus on hERG channel interactions. This outsourcing has allowed those pharmaceutical companies to build up operational flexibility and greater independence from internal resources, and allowed them to obtain access to the latest technological developments that emerged in automated patch-clamp electrophysiology – much of which arose in specialized biotech companies. Assays for nearly all major cardiac ion channels are now available by automated patch-clamping using heterologous expression systems, and recently, automated action potential recordings from stem-cell derived cardiomyocytes have been demonstrated. Today, most of the large pharmaceutical companies have acquired automated electrophysiology robots and have established various automated cardiac ion channel safety screening assays on these, in addition to outsourcing parts of their needs for safety screening.

  10. Rhetorical Devices in English Advertisements

    Institute of Scientific and Technical Information of China (English)

    陈芃

    2011-01-01

    In order to achieve persuasive and convincing effects,rhetorical devices are frequently applied in English advertisements.The paper classifies rhetorical devices into four basic categories: phonetic devices,lexical devices,syntactic devices and figures of

  11. Probucol attenuates atrial autonomic remodeling in a canine model of atrial fibrillation produced by prolonged atrial pacing

    Institute of Scientific and Technical Information of China (English)

    GONG Yong-tai; LI Wei-min; LI Yue; YANG Shu-sen; SHENG Li; YANG Ning; SHAN Hong-bo; XUE Hong-jie; LIU Wei; YANG Bao-feng; DONG De-li; LI Bao-xin

    2009-01-01

    Background We hypothesize that increased atrial oxidative stress and inflammation may play an important role in atrial nerve sprouting and heterogeneous sympathetic hyperinnervation during atrial fibrillation (AF). To test the hypothesis, we examined whether the antioxidant and anti-inflammatory treatment with probucol attenuates atrial autonomic remodeling in a canine model of AF produced by prolonged rapid right atrial pacing. Methods Twenty-one dogs were divided into a sham-operated group, a control group and a probucol group. Dogs in the control group and probucol group underwent right atrial pacing at 400 beats per minute for 6 weeks, and those in the probucol group received probucol 1 week before rapid atrial pacing until pacing stopped. After 6-week rapid atrial pacing, general properties including left atrial structure and function, atrial hemodynamics and the inducibility and duration of AF were measured in all the groups. Atrial oxidative stress markers and serum C-reactive protein (CRP) concentration were estimated. The degree of nerve sprouting and sympathetic innervation at the right atrial anterior wall (RAAW) and the left atrial anterior wall (LAAW) were quantified by immunohistochemistry, atdal norepinephrine contents were also detected. Atrial beta-nerve growth factor (beta-NGF) mRNA and protein expression at the RAAW and LAAW were assessed by real-time quantitative RT-PCR and Western blotting respectively. Results Atrial tachypacing induced significant nerve sprouting and heterogeneous sympathetic hyperinnervation, and the magnitude of nerve sprouting and hyperinnervation was higher in the RAAW than in the LAAW. Atrial beta-NGF mRNA and protein levels were significantly increased at the RAAW and LAAW, and the upregulation of beta-NGF expression was greater at the RAAW than at the LAAW in the control group. The beta-NGF protein level was positively correlated with the density of sympathetic nerves in all groups. Probucol decreased the increase of

  12. The influence of sex, age, and race experience on pacing profiles during the 90 km Vasaloppet ski race

    Directory of Open Access Journals (Sweden)

    Carlsson M

    2016-02-01

    Full Text Available Magnus Carlsson,1,2 Hannes Assarsson,1 Tomas Carlsson1,2 1School of Education, Health and Social Studies, Dalarna University, 2Dala Sports Academy, Falun, Sweden Abstract: The purpose of this study was to investigate pacing-profile differences during the 90 km Vasaloppet ski race related to the categories of sex, age, and race experience. Skiing times from eight sections (S1 to S8 were analyzed. For each of the three categories, 400 pairs of skiers were matched to have a finish time within 60 seconds, the same start group, and an assignment to the same group for the other two categories. Paired-samples Student’s t-tests were used to investigate sectional pacing-profile differences between the subgroups. Results showed that males skied faster in S2 (P=0.0042, S3 (P=0.0049, S4 (P=0.010, and S1–S4 (P<0.001, whereas females skied faster in S6 (P<0.001, S7 (P<0.001, S8 (P=0.0088, and S5–S8 (P<0.001. For the age category, old subjects (40 to 59 years skied faster than young subjects (19 to 39 years in S3 (P=0.0029, and for the other sections, there were no differences. Experienced subjects (≥4 Vasaloppet ski race completions skied faster in S1 (P<0.001 and S1–S4 (P=0.0054; inexperienced skiers (<4 Vasaloppet ski race completions had a shorter mean skiing time in S5–S8 (P=0.0063. In conclusion, females had a more even pacing profile than that of males with the same finish time, start group, age, and race experience. No clear age-related pacing-profile difference was identified for the matched subgroups. Moreover, experienced skiers skied faster in the first half whereas inexperienced skiers had higher skiing speeds during the second half of the race. Keywords: pacing strategy, cross-country skiing, endurance performance, sex difference

  13. Implantable Medical Devices

    Science.gov (United States)

    ... Artery Disease Venous Thromboembolism Aortic Aneurysm More Implantable Medical Devices Updated:Sep 16,2016 For Rhythm Control ... a Heart Attack Introduction Medications Surgical Procedures Implantable Medical Devices • Life After a Heart Attack • Heart Attack ...

  14. Radial left ventricular dyssynchrony by speckle tracking in apical versus non apical right ventricular pacing- evidence of dyssynchrony on medium term follow up

    Directory of Open Access Journals (Sweden)

    Dinesh Choudhary

    2016-03-01

    Conclusion: Pacing in non apical location (RV mid septum or low RVOT is associated with less dyssynchrony by specific measures like 2D radial strain and correlates with better ventricular function in long term.

  15. Fixed and self-paced treadmill walking for able-bodied and transtibial amputees in a multi-terrain virtual environment.

    Science.gov (United States)

    Sinitski, Emily H; Lemaire, Edward D; Baddour, Natalie; Besemann, Markus; Dudek, Nancy L; Hebert, Jacqueline S

    2015-02-01

    A self-paced treadmill automatically adjusts speed in real-time to match the user's walking speed, potentially enabling more natural gait than fixed-speed treadmills. This research examined walking speed changes for able-bodied and transtibial amputee populations on a self-paced treadmill in a multi-terrain virtual environment and examined gait differences between fixed and self-paced treadmill speed conditions. Twelve able-bodied (AB) individuals and 12 individuals with unilateral transtibial amputation (TT) walked in a park-like virtual environment with level, slopes, and simulated uneven terrain scenarios. Temporal-spatial and range-of-motion parameters were analyzed. Within the self-paced condition, all participants significantly varied walking speed (pmultiple movement scenarios in order to elicit more natural gait across various terrain. Fixed-speed treadmills may induce gait compensations to maintain the fixed speed.

  16. Thermography of electronic devices

    OpenAIRE

    Panfilova S. P.; Vlasov A. I.; Gridnev V. N.; Chervinsky A. S.

    2007-01-01

    The possibility of application of thermography to diagnose the electronic devices is analyzed in the article. Typical faults of electronic devices which can be found by means of thermography are given. Advantages of noncontact thermal inspection in comparison with the contact one are described. Some features of thermography of electronic devices are considered. Thermography apparatus is viewed and some pieces of advice about choosing it for electronic devices diagnosis are given. An example o...

  17. Heterostructures and quantum devices

    CERN Document Server

    Einspruch, Norman G

    1994-01-01

    Heterostructure and quantum-mechanical devices promise significant improvement in the performance of electronic and optoelectronic integrated circuits (ICs). Though these devices are the subject of a vigorous research effort, the current literature is often either highly technical or narrowly focused. This book presents heterostructure and quantum devices to the nonspecialist, especially electrical engineers working with high-performance semiconductor devices. It focuses on a broad base of technical applications using semiconductor physics theory to develop the next generation of electrical en

  18. Device-less interaction

    NARCIS (Netherlands)

    Monaci, G.; Triki, M.; Sarroukh, B.E.

    2009-01-01

    This document describes the results of a technology survey for device-less interaction. The Device-less Interaction project (2007-307) aims at providing interaction options for future home appliances without resorting to a remote control or any other dedicated control device. The target home applia

  19. Organic photosensitive devices

    Science.gov (United States)

    Rand, Barry P; Forrest, Stephen R

    2013-11-26

    The present invention generally relates to organic photosensitive optoelectronic devices. More specifically, it is directed to organic photosensitive optoelectronic devices having a photoactive organic region containing encapsulated nanoparticles that exhibit plasmon resonances. An enhancement of the incident optical field is achieved via surface plasmon polariton resonances. This enhancement increases the absorption of incident light, leading to a more efficient device.

  20. Photovoltaic device and method

    Science.gov (United States)

    Cleereman, Robert; Lesniak, Michael J.; Keenihan, James R.; Langmaid, Joe A.; Gaston, Ryan; Eurich, Gerald K.; Boven, Michelle L.

    2015-11-24

    The present invention is premised upon an improved photovoltaic device ("PVD") and method of use, more particularly to an improved photovoltaic device with an integral locator and electrical terminal mechanism for transferring current to or from the improved photovoltaic device and the use as a system.

  1. Cycling in the Absence of Task-Related Feedback : Effects on Pacing and Performance

    NARCIS (Netherlands)

    Smits, Benjamin L. M.; Polman, Remco C. J.; Otten, Bert; Pepping, Gert-Jan; Hettinga, Florentina J.

    2016-01-01

    Introduction: To achieve personal goals in exercise task completion, exercisers have to regulate, distribute, and manage their effort. In endurance sports, it has become very commonplace for athletes to consult task -related feedback on external devices to do so. The aim of the present study was to

  2. Any Time, Any Place, Any Pace-Really? Examining Mobile Learning in a Virtual School Environment

    Science.gov (United States)

    Barbour, Michael K.; Grzebyk, Tamme Quinn; Eye, John

    2014-01-01

    Over the past decade, the number of K-12 students engaged in online learning has increased from between 40,000 and 50,000 to more than two million. Students have also gained increased access to mobile devices throughout recent years, and educators have actively looked for ways to capitalize on this trend. A case study of students enrolled in an…

  3. The Program of All-Inclusive Care for the Elderly (PACE): an innovative long-term care model in the United States.

    Science.gov (United States)

    Mui, A C

    2001-01-01

    This article examines the long-term care service system in the United States, its problems, and an improved long-term care model. Problematic quality of care in institutional settings and fragmentation of service coordination in community-based settings are two major issues in the traditional long-term care system. The Program of All-Inclusive Care for the Elderly (PACE) has been emerging since the 1970s to address these issues, particularly because most frail elders prefer community-based to institutional care. The Balanced Budget Act of 1997 made PACE a permanent provider type under Medicare and granted states the option of paying a capitation rate for PACE services under Medicaid. The PACE model is a managed long-term care system that provides frail elders alternatives to nursing home life. The PACE program's primary goals are to maximize each frail elderly participant's autonomy and continued community residence, and to provide quality care at a lower cost than Medicare, Medicaid, and private-pay participants, who pay in the traditional fee-for-service system. In exchange for Medicare and Medicaid fixed monthly payments for each participating frail elder, PACE service systems provide a continuum of long-term care services, including hospital and nursing home care, and bear full financial risk. Integration of acute and long-term care services in the PACE model allows care of frail elders with multiple problems by a single service organization that can provide a full range of services. PACE's range of services and organizational features are discussed.

  4. Pace bowlers in cricket with history of lumbar stress fracture have increased risk of lower limb muscle strains, particularly calf strains

    OpenAIRE

    John Orchard; Patrick Farhart; Alex Kountouris; et al.

    2010-01-01

    John Orchard1, Patrick Farhart2, Alex Kountouris3, Trefor James3, Marc Portus31School of Public Health, University of Sydney, Australia; 2Punjab Kings XI team, Indian Premier League, India; 3Cricket Australia, Melbourne, AustraliaObjective: To assess whether a history of lumbar stress fracture in pace bowlers in cricket is a risk factor for lower limb muscle strains.Methods: This was a prospective cohort risk factor study, conducted using injury data from contracted first class pace bowlers i...

  5. Yes, I Am Ready Now: Differential Effects of Paced versus Unpaced Mating on Anxiety and Central Oxytocin Release in Female Rats

    OpenAIRE

    2011-01-01

    Sexual activity and partner intimacy results in several positive consequences in the context of stress-coping, both in males and females, such as reduced state anxiety in male rats after successful mating. However, in female rats, mating is a rewarding experience only when the estrous female is able to control sexual interactions, i.e., under paced-mating conditions. Here, we demonstrate that sex-steroid priming required for female mating is anxiolytic; subsequent sexual activity under paced ...

  6. Reliability of lower leg proximal end and forefoot kinematics during different paces of barefoot racewalking on a treadmill using a motion recorder (MVP-RF8-BC).

    Science.gov (United States)

    Wang, Hongzhao; Huo, Ming; An, Xiangde; Li, Yong; Onoda, Ko; Li, Desheng; Huang, Qiuchen; Maruyama, Hitoshi

    2016-04-01

    [Purpose] This study was performed to investigate the changes in lower leg proximal end and forefoot kinematics, and reliability of measurement during different paces of barefoot racewalking on treadmill. [Subjects] Eleven junior racewalking men participated in this study. [Methods] To identify changes in lower leg proximal end and forefoot kinematics, during different paces of barefoot racewalking on a treadmill, a wireless motion recorder (MVP-RF8-BC) was used. Interclass correlation coefficients (ICC 1, 2) were used to estimate reliability. [Results] There were significant differences in the lower leg proximal end and forefoot maximum medial/lateral rotations at a pace of 9 km/h compared with those at a pace of 5 km/h pace. The intra-examiner reliability estimates ranged from 0.82 and 0.89 to 0.87 and 0.93 for lower leg proximal end inversion/eversion rotation and medial/lateral rotation, and from 0.92 and 0.84 to 0.93 and 0.91 for forefoot inversion/eversion rotation and medial/lateral rotation. [Conclusion] We conclude that the lower leg proximal end and forefoot kinematics of barefoot racewalking on a treadmill are influenced by different paces and that assessment of lower leg proximal end and forefoot kinematics by means of the wireless motion recorder (MVP-RF8-BC) is adequately reliable. This information may be useful for determining exercise prescriptions.

  7. Four Weeks of Inspiratory Muscle Training Improves Self-Paced Walking Performance in Overweight and Obese Adults: A Randomised Controlled Trial

    Directory of Open Access Journals (Sweden)

    A. M. Edwards

    2012-01-01

    Full Text Available Objective. To examine whether a programme of inspiratory muscle training (IMT improves accumulative distance of self-paced walking in overweight and obese adults. Methods. A total of 15 overweight and obese adults were randomized into experimental (EXP: =8 and placebo (PLA: =7 groups. Lung function, inspiratory muscle performance, 6-minute walking test, and predicted ̇VO2 max were assessed prior to and following the 4-week IMT intervention. Both groups performed 30 inspiratory breaths, twice daily using a proprietary inspiratory resistance device set to 55% of baseline maximal effort (EXP, or performing the same inspiratory training procedure at the minimum resistive setting (PLA. Results. Lung function was unchanged in both groups after-training; however inspiratory muscle strength was significantly improved in EXP (19±25.2 cm H2O gain; <0.01 but did not significantly change in PLA. Additionally, the posttraining distance covered in the 6-minute walking test was significantly extended for EXP (62.5±37.7 m gain; <0.01, but not for PLA. A positive association was observed between the change (% of performance gain in the 6-minute walking test and body mass index (=0.736; <0.05 for EXP. Conclusion. The present study suggests that IMT provides a practical, minimally intrusive intervention to significantly augment both inspiratory muscle performance and walking distance covered by overweight and obese adults in a clinically relevant 6-minute walk test. This indicates that IMT may provide a useful priming (preparatory strategy prior to entry in a physical training programme for overweight and obese adults.

  8. FLUIDICS DEVICE FOR ASSAY

    DEFF Research Database (Denmark)

    2007-01-01

    The present invention relates to a device for use in performing assays on standard laboratory solid supports whereon chemical entities are attached. The invention furthermore relates to the use of such a device and a kit comprising such a device. The device according to the present invention is a......, when operatively connected, one or more chambers (21) comprising the chemical entities (41), the inlet(s) (5) and outlet(s) (6) and chambers (21) being in fluid connection. The device further comprise means for providing differing chemical conditions in each chamber (21)....

  9. Solid state devices

    Science.gov (United States)

    1991-01-01

    The Solid State Device research program is directed toward developing innovative devices for space remote and in-situ sensing, and for data processing. Innovative devices can result from the standard structures in innovative materials such as low and high temperature superconductors, strained layer superlattices, or diamond films. Innovative devices can also result from innovative structures achieved using electron tunneling or nanolithography in standard materials. A final step is to use both innovative structures and innovative materials. A new area of emphasis is the miniaturization of sensors and instruments molded by using the techniques of electronic device fabrication to micromachine silicon into micromechanical and electromechanical sensors and actuators.

  10. Unitary lens semiconductor device

    Science.gov (United States)

    Lear, Kevin L.

    1997-01-01

    A unitary lens semiconductor device and method. The unitary lens semiconductor device is provided with at least one semiconductor layer having a composition varying in the growth direction for unitarily forming one or more lenses in the semiconductor layer. Unitary lens semiconductor devices may be formed as light-processing devices such as microlenses, and as light-active devices such as light-emitting diodes, photodetectors, resonant-cavity light-emitting diodes, vertical-cavity surface-emitting lasers, and resonant cavity photodetectors.

  11. Optical plasma microelectronic devices

    CERN Document Server

    Forati, Ebrahim; Dill, Thyler; Sievenpiper, Dan

    2015-01-01

    The semiconductor channel in conventional microelectronic devices was successfully replaced with an optically triggered gas plasma channel. The combination of DC and laser-induced gas ionizations controls the conductivity of the channel, enabling us to realize different electronic devices such as transistors, switches, modulators, etc. A special micro-scale metasurface was used to enhance the laser-gas interaction, as well as combining it with DC ionization properly. Optical plasma devices benefit form the advantages of plasma/vacuum electronic devices while preserving most of the integrablity of semiconductor based devices.

  12. Functional linkages for the pace of life, life-history, and environment in birds.

    Science.gov (United States)

    Williams, Joseph B; Miller, Richard A; Harper, James M; Wiersma, Popko

    2010-11-01

    For vertebrates, body mass underlies much of the variation in metabolism, but among animals of the same body mass, metabolism varies six-fold. Understanding how natural selection can influence variation in metabolism remains a central focus of Physiological Ecologists. Life-history theory postulates that many physiological traits, such as metabolism, may be understood in terms of key maturational and reproductive characteristics over an organism's life-span. Although it is widely acknowledged that physiological processes serve as a foundation for life-history trade-offs, the physiological mechanisms that underlie the diversification of life-histories remain elusive. Data show that tropical birds have a reduced basal metabolism (BMR), field metabolic rate, and peak metabolic rate compared with temperate counterparts, results consistent with the idea that a low mortality, and therefore increased longevity, and low productivity is associated with low mass-specific metabolic rate. Mass-adjusted BMR of tropical and temperate birds was associated with survival rate, in accordance with the view that animals with a slow pace of life tend to have increased life spans. To understand the mechanisms responsible for a reduced rate of metabolism in tropical birds compared with temperate species, we summarized an unpublished study, based on data from the literature, on organ masses for both groups. Tropical birds had smaller hearts, kidneys, livers, and pectoral muscles than did temperate species of the same body size, but they had a relatively larger skeletal mass. Direct measurements of organ masses for tropical and temperate birds showed that the heart, kidneys, and lungs were significantly smaller in tropical birds, although sample sizes were small. Also from an ongoing study, we summarized results to date on connections between whole-organism metabolism in tropical and temperate birds and attributes of their dermal fibroblasts grown in cell culture. Cells derived from

  13. Experience with the Sarns centrifugal pump as a ventricular assist device.

    Science.gov (United States)

    Joyce, L D; Kiser, J C; Eales, F; King, R M; Toninato, C J; Hansen, J

    1990-01-01

    The authors used the Sarns centrifugal pump (Sarns 3M, Ann Arbor, MI) as a ventricular assist device (VAD) in 30 patients between May 1985 and February 1990. Sixteen patients were unweanable from cardiopulmonary bypass at the time of surgery; nine were patients who developed cardiogenic shock postoperatively in the intensive care unit. One was a donor organ failure; one had a failed PTCA; and one an acute myocardial infarction with cardiogenic shock preoperatively. Two patients were bridged to cardiac transplantation. Of the 28 nontransplant candidates, 20 (71.4%) were weaned successfully, 14 (50%) were discharged from the hospital, and 13 (46%) are alive from 1 to 46 months postoperatively (mean, 21.1 months). Three patients received right ventricular support alone; all three were weaned, and two (66.7%) were discharged. Ten patients received left ventricular assistance alone. Six (60%) were weaned, and four (40%) were discharged. Two patients received left ventricular support initially but were taken back for right VAD insertion because of right-sided heart failure; one (50%) is alive. Fifteen patients received biventricular support. Eleven (77.3%) were weaned, and eight (53.3%) were discharged. Patient ages ranged from 19 to 73 years, with a mean age for men of 59 years and 50.5 years for women. There were no thromboembolic events. Various clinical parameters were evaluated to determine effect on weanability and survival. These results show survival equivalent to any other VAD at this time. The centrifugal pump is a convenient and effective means of maintaining ventricular support in individuals who are believed to have salvageable myocardium.

  14. The influence of restoration of spontaneous circulation in temporary different pacing sites%不同的起搏部位对复苏后自主循环恢复的影响

    Institute of Scientific and Technical Information of China (English)

    王合金; 潘莹; 谢江霞

    2014-01-01

    different pacing sites in hemodynamic and cardiovascular events after restoration of spontaneous circulation.Methods A total of 76 patients with-in hospital cardiac arrest occurred from November 2010 to January 2014 were confirmed by electrionic device monitoring or electrocardiogram and they received cardiopulmonary resuscitation,and their ages were over 18 years.Patients with end-stage of various disease,malignancy and cardiac arrest due to incurable diseases or debility of physical conditions were excluded.The 76 patients were divided into two groups according to pacing site checked by X-ray fluoroscopy in emergency rescue unit:right ventriclular outflow trace pacing group [n =36,male 26 cases,female 10 cases,age (57.31 ± 16.65) years] and right ventricular apex pacing group [n =40,22 male cases and 18 female cases,age (60.43 ± 15.48) years].All patients' QRS duration were measured by ECG after pacemaker implantition and left ventricular ejection fraction (LVEF),left ventricular short axis reduced rate (FS),heart rate (HR),cardiac index (CI) were tested by bedside echocardiography and non-invasive hemodynamic monitoring was used during the early to middle stage.All the hemodynamic variables and the cardiac events were observed after spontaneous circulation recovery.All the data were analyzed by SPSS version 13.0 statistical software.Results There were no significant differences in age,gender,the primary disease,the time from cardiac arrest to spontaneous circulation restoration and dosage of epinephrine (P > 0.05).In comparison with right ventricular apex pacing group,LVEF,FS,HR,CI were higher in right ventriclular outflow trace pacing group [(0.46 ± 0.04)% vs.(0.44 ±0.05)%,(0.34±0.05) vs.(0.32±0.04),(0.04±0.46) L/minvs.(3.47±0.46) L/min,(0.46±0.29) L/ (min · m2) vs.(2.46 ±0.26) L/ (min · m2),P < 0.05] and right ventriclular outflow trace pacing group had shorter QRS duration than right ventriclular apex pacing group [(128.25 ± 6.06) ms vs.(151.93

  15. Reliability of transesophageal pacing in the assessment of sinus node function in patients with sick sinus syndrome.

    Science.gov (United States)

    Alboni, P; Paparella, N; Cappato, R; Pedroni, P; Candini, G C; Antonioli, G E

    1989-02-01

    The purpose of this study was to find out whether transesophageal pacing could be utilized for assessment of sinus node function in patients with sick sinus syndrome (SSS). In 17 patients with SSS (study group) we compared the results of sinus node tests obtained both in the basal state and after pharmacological autonomic blockade by endocavitary stimulation and, 24 hours later, by transesophageal pacing. In another group of 17 patients with SSS (control group), we compared the results obtained by two endocavitary studies. In "study group", sinus cycle length (SCL) and corrected sinus node recovery time (CSRT) did not show significant differences between the two studies both in the basal state and after autonomic blockade, whereas sinoatrial conduction time (SACT) was more prolonged during esophageal pacing (P less than 0.01). In "control group", sinus node measures did not show significant differences between the two studies. In the "study group," the following coefficients of correlation were obtained in the basal state; SCL, r = 0.65, CSRT, r = 0.57, SACT, r = 0.52 and after autonomic blockade: SCL, r = 0.95, CSRT, r = 0.62 and SACT, r = 0.53. In the basal state, the correlation for SCL and CSRT between the two studies was lower in the "study group" than in the "control group" (P less than 0.05), whereas after autonomic blockade the correlation for sinus node measures did not show significant differences between the two groups of patients. These data suggest that transesophageal study influences the autonomic tone regulating the sinus node; however, it is not responsible for important variations in sinus node measures.(ABSTRACT TRUNCATED AT 250 WORDS)

  16. Cloud Retrieval Information Content Studies with the Pre-Aerosol, Cloud and ocean Ecosystem (PACE) Ocean Color Imager (OCI)

    Science.gov (United States)

    Coddington, Odele; Platnick, Steven; Pilewskie, Peter; Schmidt, Sebastian

    2016-04-01

    The NASA Pre-Aerosol, Cloud and ocean Ecosystem (PACE) Science Definition Team (SDT) report released in 2012 defined imager stability requirements for the Ocean Color Instrument (OCI) at the sub-percent level. While the instrument suite and measurement requirements are currently being determined, the PACE SDT report provided details on imager options and spectral specifications. The options for a threshold instrument included a hyperspectral imager from 350-800 nm, two near-infrared (NIR) channels, and three short wave infrared (SWIR) channels at 1240, 1640, and 2130 nm. Other instrument options include a variation of the threshold instrument with 3 additional spectral channels at 940, 1378, and 2250 nm and the inclusion of a spectral polarimeter. In this work, we present cloud retrieval information content studies of optical thickness, droplet effective radius, and thermodynamic phase to quantify the potential for continuing the low cloud climate data record established by the MOderate Resolution and Imaging Spectroradiometer (MODIS) and Visible Infrared Imaging Radiometer Suite (VIIRS) missions with the PACE OCI instrument (i.e., non-polarized cloud reflectances and in the absence of midwave and longwave infrared channels). The information content analysis is performed using the GEneralized Nonlinear Retrieval Analysis (GENRA) methodology and the Collection 6 simulated cloud reflectance data for the common MODIS/VIIRS algorithm (MODAWG) for Cloud Mask, Cloud-Top, and Optical Properties. We show that using both channels near 2 microns improves the probability of cloud phase discrimination with shortwave-only cloud reflectance retrievals. Ongoing work will extend the information content analysis, currently performed for dark ocean surfaces, to different land surface types.

  17. Long-term outcome in patients receiving permanent pacemaker implantation for atrioventricular block: Comparison of VDD and DDD pacing.

    Science.gov (United States)

    Liao, Jo-Nan; Chao, Tze-Fan; Tuan, Ta-Chuan; Kong, Chi-Woon; Chen, Shih-Ann

    2016-08-01

    A permanent pacemaker (PPM) with dual chamber pacing (DDD) offers atrioventricular synchronization for patients with atrioventricular block (AVB). Single lead atrial synchronous ventricular pacing mode (VDD) is an alternative, but there are concerns about its efficacy and risk of atrial undersensing. Whether VDD can be a good alternative in patients with AVB remains unknown. The aim of the present study was to compare the long-term risk of mortality of VDD with DDD pacing.A total of 207 patients undergoing PPM implantations for AVB with VDD mode were enrolled from 2000 to 2013. Another 828 age- and sex-matched patients undergoing DDD implantations during the same period of time were selected as the control group in a 1 to 4 ratio. The study endpoint was mortality.A total of 1035 patients (64.3% male) were followed up for 46.5 ± 43.2 months. The mean ages were 75.0 years for VDD, and 74.9 years for DDD. The Kaplan-Meier survival analysis showed no significant difference in long-term survival between the VDD and DDD groups (log-rank P = 0.313). After adjustment for baseline characteristics, the VDD and DDD groups had a similar long-term prognosis with an adjusted hazard ratio of 0.875 (P = 0.445). Further analyses for the risk of cardiovascular and noncardiovascular deaths also showed no significant differences between the 2 groups.The long-term prognosis of VDD mode is comparable to that of DDD mode. Single lead VDD can be considered as an alternative choice in patients with AVB without sinus nodal dysfunction.

  18. Heat stress exacerbates the reduction in middle cerebral artery blood velocity during prolonged self-paced exercise.

    Science.gov (United States)

    Périard, J D; Racinais, S

    2015-06-01

    This study examined the influence of hyperthermia on middle cerebral artery mean blood velocity (MCA Vmean). Eleven cyclists undertook a 750 kJ self-paced time trial in HOT (35 °C) and COOL (20 °C) conditions. Exercise time was longer in HOT (56 min) compared with COOL (49 min; P heat appears to have exacerbated the reduction in MCA Vmean, in part via increases in peripheral blood flow and a decrease in arterial blood pressure.

  19. The effect of atrial preference pacing on atrial fibrillation electrophysiological substrate in Myotonic Dystrophy type 1 population.

    Science.gov (United States)

    Russo, Vincenzo; Nigro, Gerardo; DI Meo, Federica; Papa, Andrea Antonio; Cioppa, Nadia Della; Proietti, Riccardo; Russo, Maria Giovanna; Calabrò, Raffaele; Politano, Luisa

    2014-12-01

    P-wave dispersion is a non invasive indicator of intra-atrial conduction heterogeneity producing substrate for reentry, which is a pathophysiological mechanism of atrial fibrillation. The relationship between P-wave dispersion (PD) and atrial fibrillation (AF) in Myotonic dystrophy type 1 (DM1) patients is still unclear. Atrial Preference Pacing (APP) is an efficient algorithm to prevent paroxysmal AF in patients implanted with dual-chamber pacemaker. Aim of our study was to evaluate the possible correlation between atrial preference pacing algorithm, P-wave dispersion and AF burden in DM1 patients with normal cardiac function underwent permanent dual-chamber pacemaker implantation. We enrolled 50 patients with DM1 (age 50.3 ± 7.3; 11 F) underwent dual-chamber pacemaker implantation for various degree of atrioventricula block. The study population was randomized following 1 months stabilization period to APP algorithm features programmed OFF or ON. Patients were assessed every 3 months for the first year, and every 6 months thereafter up to 3 years. At each follow-up visit, we counted: the number of premature atrial beats, the number and the mean duration of AF episodes, AF burden and the percentage of atrial and ventricular pacing. APP ON Group showed lower number of AF episodes (117 ± 25 vs. 143 ± 37; p = 0.03) and AF burden (3059 ± 275 vs. 9010 ± 630 min; p < 0.04) than APP OFF Group. Atrial premature beats count (44903 ± 30689 vs. 13720 ± 7717 beats; p = 0.005) and Pwave dispersion values (42,1 ± 11 ms vs. 29,1 ± 4,2 ms, p = 0,003) were decreased in APP ON Group. We found a significant positive correlation between PD and AF burden (R = 0,8, p = 0.007). Atrial preference pacing algorithm, decreasing the number of atrial premature beats and the P-wave dispersion, reduces the onset and perpetuator factors of AF episodes and decreases the AF burden in DM1 patients underwent dual chamber pacemaker implantation for various degree of atrioventricular blocks

  20. Stretchable Organic Semiconductor Devices.

    Science.gov (United States)

    Qian, Yan; Zhang, Xinwen; Xie, Linghai; Qi, Dianpeng; Chandran, Bevita K; Chen, Xiaodong; Huang, Wei

    2016-11-01

    Stretchable electronics are essential for the development of intensely packed collapsible and portable electronics, wearable electronics, epidermal and bioimplanted electronics, 3D surface compliable devices, bionics, prosthesis, and robotics. However, most stretchable devices are currently based on inorganic electronics, whose high cost of fabrication and limited processing area make it difficult to produce inexpensive, large-area devices. Therefore, organic stretchable electronics are highly attractive due to many advantages over their inorganic counterparts, such as their light weight, flexibility, low cost and large-area solution-processing, the reproducible semiconductor resources, and the easy tuning of their properties via molecular tailoring. Among them, stretchable organic semiconductor devices have become a hot and fast-growing research field, in which great advances have been made in recent years. These fantastic advances are summarized here, focusing on stretchable organic field-effect transistors, light-emitting devices, solar cells, and memory devices.

  1. Sensor sentinel computing device

    Science.gov (United States)

    Damico, Joseph P.

    2016-08-02

    Technologies pertaining to authenticating data output by sensors in an industrial environment are described herein. A sensor sentinel computing device receives time-series data from a sensor by way of a wireline connection. The sensor sentinel computing device generates a validation signal that is a function of the time-series signal. The sensor sentinel computing device then transmits the validation signal to a programmable logic controller in the industrial environment.

  2. Controlling Smart Devices

    OpenAIRE

    Milanič, Matjaž

    2016-01-01

    Smart devices make our lives easier. However, by delegating more and more tasks to smart devices our wellbeing becomes dependent on their correct functioning. This creates a need for monitoring home devices in a similar way as businesses already do. The thesis describes the steps required for building a monitoring system suited for smart home monitoring, from the initial design to the final implementation of the solution. The goal was to create a user friendly monitoring system, designed as m...

  3. Uterine involution in colombian fine pace mares, measured by ultrasonography and endometrial cytology

    Directory of Open Access Journals (Sweden)

    Germán Ramírez

    2006-06-01

    Full Text Available Today, there still exists a controversial issue, as to the high incidence of early embryonic death in mares, mated on the first post partum oestrus. The purpose of this study was first, to determine the post partum period of uterine involution in fine pace Colombian mares using endometrial cytology and ultra sonograph. Secondly, to determine the relation between the neutrophil percentages found in cytology and the echogenicity of accumulated intrauterine fluid during the first 30 post partum days. Twenty (n=20 mares were examined beginning on the 6th post partum day and on alternate days, up to the 30th day. All subjects were grazing Kikuyo grass (Pennisetum clandestinum at la Sabana de Bogotá, 2.600 meters over sea level, 4 º north latitude and with an average temperature of 13 º C. From the 3rd postpartum day, all 20 mares were exposed to 2 healthy stallions, to establish their heat behaviour. Ten of them, following complete randomization, were inseminated on the first postpartum heat, while the others were inseminated on the second post partum heat. Genital examination was carried out by a technician, who did not know the reproductive history of any of the experimental mares. Examinations included rectal palpation, ultra sonograph (Pie Medical 480, linear array, 5 MHz, vaginal swabs and endometrial cytology. Uterine dimension was recorded by rectal palpation and ultra sonograph, it was included the uterine horn dimensions (tip, middle, and corporo-cornual junction of previously gravid and non gravid uterus. Intrauterine fluid detection was performed by the use of an echogenicity scale. Ovaric structures were recorded (preovulatory follicles and ovulation. Pregnancy diagnosis was performed on day 15 post ovulation and then confirmed on day 40. Endometrial cytology samples were taken from uterus after the perineal area was disinfected using non covered isopos with a Pollanski speculum. Smears specimens were fixed with metil alcohol for 15

  4. Establishment Registration & Device Listing

    Data.gov (United States)

    U.S. Department of Health & Human Services — This searchable database contains establishments (engaged in the manufacture, preparation, propagation, compounding, assembly, or processing of medical devices...

  5. Virtual Training Devices Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — The Virtual Training Devices (VTD) Laboratory at the Life Cycle Software Engineering Center, Picatinny Arsenal, provides a software testing and support environment...

  6. The neural bases of the constructive nature of autobiographical memories studied with a self-paced fMRI design

    Energy Technology Data Exchange (ETDEWEB)

    Botzung, A.; Denkova, E.; Ciuciu, P.; Scheiber, C.; Manning, L. [CNRS, Strasbourg (France)

    2008-07-01

    In Conway and Pleydell-Pearce's model (2000), autobiographical memories are viewed as transitory mental representations, more often generated in an effort-full way. An important claim of the model concerns the dynamic process that evolves over time, from the left prefrontal areas to posterior regions, to retrieve specific memories. The present work aims at investigating, using fMRI, the temporal distribution of effort-full autobiographical memory construction. In addition, a self-paced design was implemented to elucidate the question of the timing window required to evoke recollections. The results showed a large pattern of brain regions, which included the two major poles of activation predicted by Conway and Pleydell-Pearce's model. Likewise, we were able to detect the earlier implication of the left dorso-lateral prefrontal cortex, by comparison with posterior structures, which seemed to confirm its involvement in the effort-full retrieval process. Finally, the self-paced procedure allowed us to refine the timing window necessary to construct past events. (authors)

  7. Physiological pace of life: the link between constitutive immunity, developmental period, and metabolic rate in European birds.

    Science.gov (United States)

    Pap, Péter László; Vágási, Csongor István; Vincze, Orsolya; Osváth, Gergely; Veres-Szászka, Judit; Czirják, Gábor Árpád

    2015-01-01

    Constitutive innate immunity is the first lined of defence against infections, but the causes determining its variability among species are poorly understood. The pace of life hypothesis predicts that species with a fast speed of life, characterized by high energy turnover and short developmental time, invest relatively little in defence in favour of growth and early reproduction, whereas 'slow-living' species are predicted to invest more resources into costly defence. We conducted phylogenetic comparative analysis on 105 European bird species and determined that the number of leukocytes, and the levels of natural antibodies (NAbs) and complement, measured on adult birds, increased or tended to positively correlate with the length of incubation period. However, we found that the length of incubation and fledging periods have opposite effects on immune defence (i.e. immune parameters show a negative association with the length of fledging period). Our results suggest that the contrasting effects of the incubation and fledging periods are related to the timing of the development of immune cells and of NAbs and complement, which largely mature during the embryonic phase of development. In support of this hypothesis, we found that species with a long relative incubation period [i.e. whose total pre-fledging developmental time (incubation plus fledging) consists largely of the incubation period] invested more in constitutive innate immunity. Finally, in support of the pace of life hypothesis, for a subsample of 63 species, we found that the basal metabolic rate significantly or tended to negatively correlate with immune measures.

  8. Protein-Pacing from Food or Supplementation Improves Physical Performance in Overweight Men and Women: The PRISE 2 Study.

    Science.gov (United States)

    Arciero, Paul J; Edmonds, Rohan C; Bunsawat, Kanokwan; Gentile, Christopher L; Ketcham, Caitlin; Darin, Christopher; Renna, Mariale; Zheng, Qian; Zhang, Jun Zhu; Ormsbee, Michael J

    2016-05-11

    We recently reported that protein-pacing (P; six meals/day @ 1.4 g/kg body weight (BW), three of which included whey protein (WP) supplementation) combined with a multi-mode fitness program consisting of resistance, interval sprint, stretching, and endurance exercise training (RISE) improves body composition in overweight individuals. The purpose of this study was to extend these findings and determine whether protein-pacing with only food protein (FP) is comparable to WP supplementation during RISE training on physical performance outcomes in overweight/obese individuals. Thirty weight-matched volunteers were prescribed RISE training and a P diet derived from either whey protein supplementation (WP, n = 15) or food protein sources (FP, n = 15) for 16 weeks. Twenty-one participants completed the intervention (WP, n = 9; FP, n = 12). Measures of body composition and physical performance were significantly improved in both groups (p < 0.05), with no effect of protein source. Likewise, markers of cardiometabolic disease risk (e.g., LDL (low-density lipoprotein) cholesterol, glucose, insulin, adiponectin, systolic blood pressure) were significantly improved (p < 0.05) to a similar extent in both groups. These results demonstrate that both whey protein and food protein sources combined with multimodal RISE training are equally effective at improving physical performance and cardiometabolic health in obese individuals.

  9. Protein-Pacing from Food or Supplementation Improves Physical Performance in Overweight Men and Women: The PRISE 2 Study

    Directory of Open Access Journals (Sweden)

    Paul J. Arciero

    2016-05-01

    Full Text Available We recently reported that protein-pacing (P; six meals/day @ 1.4 g/kg body weight (BW, three of which included whey protein (WP supplementation combined with a multi-mode fitness program consisting of resistance, interval sprint, stretching, and endurance exercise training (RISE improves body composition in overweight individuals. The purpose of this study was to extend these findings and determine whether protein-pacing with only food protein (FP is comparable to WP supplementation during RISE training on physical performance outcomes in overweight/obese individuals. Thirty weight-matched volunteers were prescribed RISE training and a P diet derived from either whey protein supplementation (WP, n = 15 or food protein sources (FP, n = 15 for 16 weeks. Twenty-one participants completed the intervention (WP, n = 9; FP, n = 12. Measures of body composition and physical performance were significantly improved in both groups (p < 0.05, with no effect of protein source. Likewise, markers of cardiometabolic disease risk (e.g., LDL (low-density lipoprotein cholesterol, glucose, insulin, adiponectin, systolic blood pressure were significantly improved (p < 0.05 to a similar extent in both groups. These results demonstrate that both whey protein and food protein sources combined with multimodal RISE training are equally effective at improving physical performance and cardiometabolic health in obese individuals.

  10. Permanent His-bundle pacing clinical application%永久希氏束起搏临床应用

    Institute of Scientific and Technical Information of China (English)

    吴高俊; 苏蓝; 方丹红; 黄伟剑

    2012-01-01

    Objective To explore the safety and feasibility of permanent His-bundle pacing (HBP).Methods Seventeen patients[ ( 11 male,mean age(67.8±9.6)years)with a standard pacemaker(PM) indication or systolic heart failure who have frequent dependence on right ventricular pacing were enrolled between February,2011 and November,2011.A system consisting of a steerable catheter and a4.1 F screw-in lead were used for permanent HBP.Results After initial failure of HBP in the first 7 cases,HBP was successful in 9 patients.The total success rate was 52.9% (9/17),but the success rate increased to 90% in the later practice.In permanent HBP pacing,the acute pacing threshold was( 1.2±0.7 )V at pulse duration of O.4msec,and the sensed potentials were (3.5± 1.4) mV.The pacing threshold was ( 1.7 ± 1.3 ) V,and sensed potentials were (3.4±3.3) mV during 5 ~ 14 months follow-up,which were not significantly different compared with the measurements at implantation( P>0.05 ).The QRS width was( 104.4±23.5 ) ms at implantation and( 108.9±23.7 ) ms at the follow-up,which were similar to the native QRS width( 107.8±27.7)ms.Among them,QRS width was reduced from 150 ms and 200 ms to 120、160 ms in two patients with systolic heart failure( one patient had depended on right ventricular pacing for half a year).In the two patients,cardiac function was improved (from NYHA Class Ⅲ to Class Ⅰ and Ⅱ ) after HBP.No major complications were observed.Conclusion Permanent HBP is feasible and safe,may be a better choice for the patients with systolic heart failure who require permanent PM with anticipated frequent ventricular pacing or who have frequent dependence on right ventricular pacing.%目的 探讨永久希氏束起搏(HBP)的安全性和可行性.方法 对17例有常规心脏起搏适应证或长期依赖右心室起搏伴收缩性心力衰竭的患者,采用4.1F螺旋导线进行永久HBP,门诊随访3~l2个月.结果 成功HBP 9例(52.9%),急性期和慢性期

  11. Application of decision-making theory to the regulation of muscular work rate during self-paced competitive endurance activity.

    Science.gov (United States)

    Renfree, Andrew; Martin, Louise; Micklewright, Dominic; St Clair Gibson, Alan

    2014-02-01

    Successful participation in competitive endurance activities requires continual regulation of muscular work rate in order to maximise physiological performance capacities, meaning that individuals must make numerous decisions with regards to the muscular work rate selected at any point in time. Decisions relating to the setting of appropriate goals and the overall strategic approach to be utilised are made prior to the commencement of an event, whereas tactical decisions are made during the event itself. This review examines current theories of decision-making in an attempt to explain the manner in which regulation of muscular work is achieved during athletic activity. We describe rational and heuristic theories, and relate these to current models of regulatory processes during self-paced exercise in an attempt to explain observations made in both laboratory and competitive environments. Additionally, we use rational and heuristic theories in an attempt to explain the influence of the presence of direct competitors on the quality of the decisions made during these activities. We hypothesise that although both rational and heuristic models can plausibly explain many observed behaviours in competitive endurance activities, the complexity of the environment in which such activities occur would imply that effective rational decision-making is unlikely. However, at present, many proposed models of the regulatory process share similarities with rational models. We suggest enhanced understanding of the decision-making process during self-paced activities is crucial in order to improve the ability to understand regulation of performance and performance outcomes during athletic activity.

  12. 右心室不同位点起搏对QRS时限的影响%Effect of different right ventricular pacing sites on QRS complex duration

    Institute of Scientific and Technical Information of China (English)

    任晓庆; 唐闽; 方丕华; 王方正; 张澍

    2013-01-01

    Objective To investigate the effect of right ventricular different pacing site on QRS complex width,and provide a reference for lead location.Methods Two hundred and sixteen patients[mean age,(69± 13) years] scheduled for a permanent pacemaker implantation,which met the class Ⅰ or Ⅱ a pacemaker installed indications,were enrolled for the study.Pacing and electrocardiography recording were underwent at right ventricular apex,right ventricular inflow tract (RVIT),mid septum,high septum and right ventricular outflow tract (RVOT),respectively.Then the duration and morphology of QRS complex paced in different right ventricular locations were analysed and compared.Results QRS durations at all different right ventricular pacing sites were significantly lengthened compared with baseline electrocardiography (P<0.001).QRS duration with right ventricular apex pacing was most broad (168± 16)ms,QRS duration with RVIT pacing was (166± 15) ms,and QRS duration with RVOT pacing was (165± 15)ins.There was no significant difference in QRS duration with apex,RVIT and RVOT (P> 0.05).QRS duration at septum pacing was significantly narrower (P<0.001),QRS morphology and electrical axis was normal compared with other right ventricular pacing sites.QRS duration with mid-septum pacing was most narrow (139±19) ms,and shorter than that with high septum (153± 14) ms.Conclusions QRS duration at mid-septum pacing was most narrow,QRS morphology and electrical axis was normal compared with any other right ventricular pacing sites.Mid-septum may be the best choice for right ventricular pacing site.%目的 观察右心室不同起搏位点的QRS时限,为临床导线放置提供参考依据.方法 选择216例符合Ⅰ类或Ⅱa类起搏器植入适应证的患者,在放置心室导线过程中,分别在右心室心尖部、流入道、中位间隔部、高位间隔部和流出道等不同位点起搏右心室,记录起搏时的体表心电图,比较不同位点QRS

  13. Association between RR interval and high-frequency heart rate variability acquired during short-term, resting recordings with free and paced breathing.

    Science.gov (United States)

    Sandercock, Gavin; Gladwell, Valerie; Dawson, Samantha; Nunan, David; Brodie, David; Beneke, Ralph

    2008-07-01

    High-frequency (HF) oscillations in RR interval from 0.15-0.40 Hz are widely accepted as a measure of cardiac vagal outflow but the HF/RR relationship appears complex, particularly with longer RR intervals. The aim of this study was to evaluate the HF/RR interval relationship during free and paced breathing. HF power and mean RR interval length were recorded in 150 men and 120 women (mean age 34.5 +/- 11.4) during 5 min of supine rest with either free or paced (12 cycles min(-1)) breathing. Linear and quadratic models were used to assess the relationship between RR interval and the natural logarithm of HF power (lnHF). The RR interval length at which there was no further increase in lnHF was determined as the deflection point. ANCOVA was used to determine differences in the linear regression slopes for lnHF/RR with paced or free breathing. With free breathing (n = 131), the adjusted R(2) was similar between linear (15.3%) and quadratic (17.5%) fits and saturation of lnHF occurred within the recorded RR interval range (1326 ms). With paced breathing (n = 139), adjusted R(2) values were again similar between linear (22.4%) and quadratic (23.2%) fits. The deflection point was outside the range of recorded RR intervals at 1458 ms. ANCOVA showed a significant difference in the slope of the lnHF/RR regression lines between free and paced breathing. The lnHF/RR relationship is weaker when derived from between-subject recordings than from repeated within-subject samples. lnHF/RR showed evidence of saturation at approximately 45 bpm with free breathing. With paced breathing, a deflection in lnHF was found outside the recorded RR interval range ( approximately 41 bpm). Paced breathing creates a stronger lnHF/RR relationship. The slope of the lnHF/RR regression line with paced breathing is significantly different from that observed with free breathing. It appears that lnHF is a valid index of vagal outflow, except in subjects with very low heart rates. Paced breathing data

  14. Freestyle race pacing strategies (400 m) of elite able-bodied swimmers and swimmers with disability at major international championships.

    Science.gov (United States)

    Taylor, Joseph B; Santi, Giampaolo; Mellalieu, Stephen D

    2016-10-01

    Freestyle race pacing strategies (400 m) were compared between elite able-bodied swimmers and those with minimal physical (International Paralympic Committee S10 classification) and visual disabilities (International Paralympic Committee S13 classification). Data comprised 50-m lap splits and overall race times from 1176 400-m freestyle swims from World Championships, European Championships and Olympic/Paralympic Games between 2006 and 2012. Five pacing strategies were identified across groups (even, fast start, negative, parabolic and parabolic fast start), with negative and even strategies the most commonly adopted. The negative pacing strategy produced the fastest race times for all groups except for female S13 swimmers where an even strategy was most effective. Able-bodied groups swam faster than their S10 and S13 counterparts, with no differences between S10 and S13 groups. The results suggest adoption of multiple pacing strategies across groups, and even where impairments are considered minimal they are still associated with performance detriments in comparison to their able-bodied counterparts. The findings have implications for the planning and implementation of training related to pacing strategies to ensure optimal swimmer preparation for competition. Analogous performance levels in S10 and S13 swimmers also suggest a case for integrated competition of these classifications in 400-m freestyle swimming.

  15. Comparison of Long-Term Effect of Dual-Chamber Pacing and Alcohol Septal Ablation in Patients with Hypertrophic Obstructive Cardiomyopathy

    Directory of Open Access Journals (Sweden)

    Jan Krejci

    2013-01-01

    Full Text Available Introduction. Nonpharmacological treatment of patients with hypertrophic obstructive cardiomyopathy (HOCM comprises surgical myectomy (SME, alcohol septal ablation (ASA, and dual-chamber (DDD pacing. The aim of the study was to compare the long-term effect of DDD pacing and ASA in symptomatic HOCM patients. Patients and Methods. We evaluated retrospective data from three cardiocenters; there were 24 patients treated with DDD pacing included and 52 treated with ASA followed for 101 ± 49 and 87 ± 23 months, respectively. Results. In the group treated with DDD pacing, the left ventricle outflow tract gradient (LVOTG decreased from 82 ± 44 mmHg to 21 ± 21 mmHg, and NYHA class improved from 2.7 ± 0.5 to 2.1 ± 0.6 (both P<0.001. In the ASA-treated group, a decline in LVOTG from 73 ± 38 mmHg to 24 ± 26 mmHg and reduction in NYHA class from 2.8 ± 0.5 to 1.7 ± 0.8 were observed (both P<0.001. The LVOTG change was similar in both groups (P=0.264, and symptoms were more affected by ASA (P=0.001. Conclusion. ASA and DDD pacing were similarly effective in reducing LVOTG. The symptoms improvement was more expressed in patients treated with ASA.

  16. Smart devices are different

    DEFF Research Database (Denmark)

    Stisen, Allan; Blunck, Henrik; Bhattacharya, Sourav

    2015-01-01

    The widespread presence of motion sensors on users' personal mobile devices has spawned a growing research interest in human activity recognition (HAR). However, when deployed at a large-scale, e.g., on multiple devices, the performance of a HAR system is often significantly lower than in reporte...

  17. Inverted organic photosensitive devices

    Energy Technology Data Exchange (ETDEWEB)

    Forrest, Stephen R.; Bailey-Salzman, Rhonda F.

    2016-12-06

    The present disclosure relates to organic photosensitive optoelectronic devices grown in an inverted manner. An inverted organic photosensitive optoelectronic device of the present disclosure comprises a reflective electrode, an organic donor-acceptor heterojunction over the reflective electrode, and a transparent electrode on top of the donor-acceptor heterojunction.

  18. Planar electrochemical device assembly

    Science.gov (United States)

    Jacobson, Craig P.; Visco, Steven J.; De Jonghe, Lutgard C.

    2007-06-19

    A pre-fabricated electrochemical device having a dense electrolyte disposed between an anode and a cathode preferably deposited as thin films is bonded to a porous electrically conductive support. A second porous electrically conductive support may be bonded to a counter electrode of the electrochemical device. Multiple electrochemical devices may be bonded in parallel to a single porous support, such as a perforated sheet to provide a planar array. Planar arrays may be arranged in a stacked interconnected array. A method of making a supported electrochemical device is disclosed wherein the method includes a step of bonding a pre-fabricated electrochemical device layer to an existing porous metal or porous metal alloy layer.

  19. Compound semiconductor device modelling

    CERN Document Server

    Miles, Robert

    1993-01-01

    Compound semiconductor devices form the foundation of solid-state microwave and optoelectronic technologies used in many modern communication systems. In common with their low frequency counterparts, these devices are often represented using equivalent circuit models, but it is often necessary to resort to physical models in order to gain insight into the detailed operation of compound semiconductor devices. Many of the earliest physical models were indeed developed to understand the 'unusual' phenomena which occur at high frequencies. Such was the case with the Gunn and IMPATI diodes, which led to an increased interest in using numerical simulation methods. Contemporary devices often have feature sizes so small that they no longer operate within the familiar traditional framework, and hot electron or even quantum­ mechanical models are required. The need for accurate and efficient models suitable for computer aided design has increased with the demand for a wider range of integrated devices for operation at...

  20. Device for cutting protrusions

    Science.gov (United States)

    Bzorgi, Fariborz M.

    2011-07-05

    An apparatus for clipping a protrusion of material is provided. The protrusion may, for example, be a bolt head, a nut, a rivet, a weld bead, or a temporary assembly alignment tab protruding from a substrate surface of assembled components. The apparatus typically includes a cleaver having a cleaving edge and a cutting blade having a cutting edge. Generally, a mounting structure configured to confine the cleaver and the cutting blade and permit a range of relative movement between the cleaving edge and the cutting edge is provided. Also typically included is a power device coupled to the cutting blade. The power device is configured to move the cutting edge toward the cleaving edge. In some embodiments the power device is activated by a momentary switch. A retraction device is also generally provided, where the retraction device is configured to move the cutting edge away from the cleaving edge.