WorldWideScience

Sample records for biventricular pacing devices

  1. Hemodynamic aspects of biventricular pacing in heart failure

    OpenAIRE

    Ståhlberg, Marcus

    2010-01-01

    Background and aims Biventricular pacing or cardiac resynchronization therapy (CRT) is an established treatment option for selected heart failure (HF) patients. We aimed at evaluating acute and longer-term hemodynamic effects of different pacemaker programmings in CRT patients. For the latter purpose, 10 CRT patients also received an implantable hemodynamic monitor (IHM), allowing for long-term hemodynamic monitoring during ambulatory periods. Study I The hemodynamic ...

  2. 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.

  3. Comparison of permanent left ventricular and biventricular pacing in patients with heart failure and chronic atrial fibrillation: prospective haemodynamic study

    OpenAIRE

    Garrigue, S; Bordachar, P.; Reuter, S.; Jaïs, P.; Kobeissi, A; Gaggini, G; Haïssaguerre, M; Clementy, J

    2002-01-01

    Objective: To compare clinical and haemodynamic variables between left ventricular and biventricular pacing in patients with severe heart failure; and to analyse haemodynamic changes during daily life and maximum exercise during chronic left ventricular and biventricular pacing.

  4. 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.

  5. Biventricular stimulation to prevent cardiac desynchronization: rationale, design, and endpoints of the 'Biventricular Pacing for Atrioventricular Block to Prevent Cardiac Desynchronization (BioPace)' study.

    Science.gov (United States)

    Funck, Reinhard C; Blanc, Jean-Jacques; Mueller, Hans-Helge; Schade-Brittinger, Carmen; Bailleul, Christophe; Maisch, Bernhard

    2006-08-01

    Despite the deleterious effects of cardiac dyssynchrony and the positive effects of cardiac resynchronization therapy, patients with high-degree atrioventricular block continue to receive desynchronizing right ventricular (RV) pacing systems. Although it is unclear whether the negative effects of RV pacing and left bundle branch block (LBBB) are comparable, and whether they depend on the presence and the degree of structural heart disease, one may hypothesize that RV pacing may have similar effects to LBBB. In the BioPace trial, the long-term effects of RV pacing vs. biventricular pacing will be prospectively compared in 1200 pacemaker patients with high likelihood of mostly paced ventricular events, regardless of whether in sinus rhythm or in atrial fibrillation (AF). After echocardiographic examination of left ventricular (LV) function, patients will be randomly assigned to the implantation of an RV vs. a biventricular pacing system and followed for up to 5 years. Primary study endpoints are survival, quality of life (QoL), and the distance covered in a 6-min hall walk (6-MHW) at 24 months after implantation. Secondary endpoints are QoL and the 6-MHW result at 12 months after implantation, hospitalization rate, LV dimensions, LV ejection fraction, and the development of chronic AF and other adverse events. PMID:16864616

  6. 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...... ventricular end-systolic volumes (LVESV) at 1 year. Cox models were used to assess the influence of ectopic beats on the outcomes of heart failure (HF) or death, ventricular tachyarrhythmias (VTAs), and death. RESULTS: In the pre-implantation Holter recording, ectopic beats accounted for a mean 3.2 ± 5...... biventricular pacing (Holter monitoring of patients selected for CRT for optimal outcome. (MADIT-CRT: Multicenter Automatic Defibrillator Implantation With Cardiac Resynchronization...

  7. 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.

  8. Acute contractile recovery extent during biventricular pacing is not associated with follow-up in patients undergoing resynchronization

    OpenAIRE

    Federica DeVecchi; Emanuela Facchini; Anna Degiovanni; Chiara Sartori; Chiara Cavallino; Matteo Santagostino; Virginia Di Ruocco; Andrea Magnani; Eraldo Occhetta; Paolo Nicola Marino

    2016-01-01

    Background: It has been reported that contractility, as assessed using dobutamine infusion, is independently associated with reverse remodeling after CRT. Controversy, however, exists about the capacity of this approach to predict a long-term clinical response. This study's purpose was to assess whether long-term CRT clinical effects can be predicted according to acute inotropic response induced by biventricular stimulation (CRT on), as compared with AAI–VVI right stimulation pacing mode (CRT...

  9. 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.

  10. 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.

  11. 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 paci...... in the right ventricular outflow tract demonstrated a 63% increase in cardiac output. After change to biventricular DDD pacing, left ventricular systolic function and diastolic dimensions normalised....

  12. 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.

  13. Biventricular Finite Element Modeling of the Acorn CorCap Cardiac Support Device on a Failing Heart

    OpenAIRE

    Wenk, JF; L. Ge; Zhang, Z; Mojsejenko, D; Potter, DD; Tseng, EE; Guccione, JM; Ratcliffe, MB

    2013-01-01

    Background: The Acorn CorCap Cardiac Support Device (CSD; Acorn Cardiovascular Inc, St. Paul, MN) is a woven polyester jacket that is placed around the heart and designed to reverse the progressive remodeling associated with dilated cardiomyopathy. However, the effects of the Acorn CSD on myofiber stress and ventricular function remain unknown. We tested the hypothesis that the Acorn CSD reduces end-diastolic (ED) myofiber stress. Methods: A previously described weakly coupled biventricular f...

  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. MRI with cardiac pacing devices – Safety in clinical practice

    International Nuclear Information System (INIS)

    Objectives: The aim of this study was to introduce a single centre “real life” experience of performing MRI examinations in clinical practice on patients with cardiac pacemaker systems. Additionally, we aimed to evaluate the safety of using a dedicated safety protocol for these patients. Materials and methods: We used a 1.5 T MRI scanner to conduct 68 MRI scans of different body regions in patients with pacing systems. Of the cardiac devices, 32% were MR-conditional, whereas the remaining 68% were MR-unsafe. We recorded the functional parameters of the devices prior, immediately after, and approximately one month after the MRI scanning, and compared the device parameters to the baseline values. Results: All MRI examinations were completed safely, and each device could be interrogated normally following the MRI. We observed no changes in the programmed parameters of the devices. For most of the participants, the distributions of the immediate and one-month changes in the device parameters were within 20% of the baseline values, although some changes approached clinically important thresholds. Furthermore, we observed no differences in the variable changes between MR-conditional and MR-unsafe pacing systems, or between scans of the thorax area and other scanned areas. Conclusion: MRI in patients with MR-conditional pacing systems and selected MR-unsafe systems could be performed safely under strict conditions in this study

  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. 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

  19. Atrioventricular Junction Ablation in Atrial Fibrillation: Choosing The Right Patient and Pacing Device

    Directory of Open Access Journals (Sweden)

    Finn Akerstr�m; Mois�s Rodr�guez-Ma�ero; Marta Pach�n; Alberto Puchol; X. Alberte Fern�ndez-L�pez; Luis Mart�nez-Sande; Miguel Valderr�bano MD; Miguel A. Arias.

    2015-08-01

    Full Text Available Atrial fibrillation (AF is the most common cardiac arrhythmia and despite advancements in rhythm control through direct catheter ablation, maintaining sinus rhythm is currently not possible in a large proportion of AF patients. Furthermore, in some instances pharmacological rate control may be insufficient, resulting in a highly symptomatic patient at risk of developing tachycardia-induced cardiomyopathy and heart failure (HF. Catheter ablation of the atrioventricular junction (AVJ with subsequent permanent pacemaker implantation provides definite rate control and represents an attractive therapeutic option when pharmacological rate control is not achieved. In those with reduced ventricular function, cardiac resynchronization therapy (CRT should be considered over right ventricular apical (RVA pacing in order to avoid the deleterious effects associated with a high amount of chronic RVA pacing. Another group of patients that may also benefit from AVJ ablation are HF patients with concomitant AF receiving CRT. In this patient cohort AVJ ablation ensures near 100% biventricular pacing, thus allowing optimization of the therapeutic effects of CRT.

  20. 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.

  1. 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.

  2. 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

  3. 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.

  4. Cardiac pacing device therapy for atrial dysrhythmias: how does it work?

    Science.gov (United States)

    Irwin, Marleen E

    2004-01-01

    Atrial fibrillation (AF) is the most common dysrhythmia in North America. Paroxysmal or persistent AF affects an estimated 2.8 million individuals, causes significant morbidity, and is associated with 1 billion dollars in healthcare costs each year in the United States. An aging population, the prevalence of hypertension, and the emergence of heart failure as the final common pathway of heart disease finds us in an age where the incidence of AF is ever increasing and the management challenges are indeed an expanding clinical problem. Although guidelines for selection of the appropriate pacing mode have been published, device therapy for the control of AF and paroxysmal AF is an emerging clinical management strategy. In 2001 The American College of Cardiology (ACC)/American Heart Association (AHA) published a document to revise the 1998 guidelines for device therapy, and even now these guidelines require elucidation and inclusion for the use of cardiac pacing device therapy for the control of atrial dysrhythmia. Choosing a complex system, in particular for the patient with persistent and symptomatic atrial dysrhythmia, is a most intricate challenge for the healthcare professional and the healthcare system. Rate dependent effects on refractoriness, reduction of ectopy, remodeling of the substrate, and prevention of pauses have been described as the potential mechanisms responsible for the rhythmic control effect attributed to atrial pacing. However, while permanent cardiac pacing is required for patients with symptomatic bradycardia with atrioventricular block and AF, the concept of pacing for the primary prevention of AF is novel. Pacing algorithms, single site, biatrial, and dual-site atrial pacing and site-specific pacing have all been studied as substrate modulators to prevent recurrent atrial dysrhythmia.A dilemma exists surrounding the primary approach for the control of symptomatic AF with rapid ventricular response. The question remains: should it be to

  5. 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

  6. 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

  7. HeartWare HVAD for Biventricular Support in Children and Adolescents: The Stanford Experience.

    Science.gov (United States)

    Stein, Mary Lyn; Yeh, Justin; Reinhartz, Olaf; Rosenthal, David N; Kaufman, Beth D; Almond, Chris S; Hollander, Seth A; Maeda, Katsuhide

    2016-01-01

    Despite increasing use of mechanical circulatory support in children, experience with biventricular device implantation remains limited. We describe our experience using the HeartWare HVAD to provide biventricular support to three patients and compare these patients with five patients supported with HeartWare left ventricular assist device (LVAD). At the end of the study period, all three biventricular assist device (BiVAD) patients had been transplanted and were alive. LVAD patients were out of bed and ambulating a median of 10.5 days postimplantation. The BiVAD patients were out of bed a median of 31 days postimplantation. Pediatric patients with both left ventricular and biventricular heart failure can be successfully bridged to transplantation with the HeartWare HVAD. Rapid improvement in functional status following HVAD implantation for isolated left ventricular support is seen. Patients supported with BiVAD also demonstrate functional recovery, albeit more modestly. In the absence of infection, systemic inflammatory response raises concern for inadequate support. PMID:26919182

  8. 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.

  9. 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. 

  10. Qualitative and Quantitative Assessment of Metal Artifacts Arising from Implantable Cardiac Pacing Devices in Oncological PET/CT Studies : A Phantom Study

    NARCIS (Netherlands)

    Ay, Mohammad R.; Mehranian, Abolfazl; Abdoli, Mehrsima; Ghafarian, Pardis; Zaidi, Habib

    2011-01-01

    Purpose: We evaluate the magnitude of metallic artifacts caused by various implantable cardiac pacing devices (without leads) on both attenuation maps (mu-maps) and positron emission tomography (PET) images using experimental phantom studies. We also assess the efficacy of a metal artifact reduction

  11. 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.

  12. 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. PMID:26869940

  13. 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.

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

    Directory of Open Access Journals (Sweden)

    Russell Stuart J

    2012-02-01

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

  15. 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

  16. 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.

  17. 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.

  18. 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. PMID:25387600

  19. 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.

  20. 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.

  1. [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.

  2. 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...

  3. Left ventricular pacing vector selection by novel echo-particle imaging velocimetry analysis for optimization of quadripolar cardiac resynchronization device: a case report

    OpenAIRE

    Martiniello, Alfonso/A. Roberto/R.; Pedrizzetti, Gianni/G.; Bianchi, Valter/V.; Tonti, Giovanni/G.; D’Onofrio, Antonio/A.; Caso, Pio/P.

    2016-01-01

    Background The availability of pacing configurations offered by quadripolar left ventricular leads could improve patients’ response to cardiac resynchronization therapy; however, the selection of an optimal setting remains a challenge. Echo-particle imaging velocimetry has shown that regional anomalies of synchrony/synergy of the left ventricle are related to the alteration, reduction, or suppression of the physiological intracavitary pressure gradients. These observations are also supported ...

  4. The Post-Myocardial Infarction Pacing Remodeling Prevention Therapy (PRomPT) Trial

    DEFF Research Database (Denmark)

    Chung, Eugene S; Fischer, Trent M; Kueffer, Fred;

    2015-01-01

    BACKGROUND: Despite considerable improvements in the medical management of patients with myocardial infarction (MI), patients with large MI still have substantial risk of developing heart failure. In the early post-MI setting, implantable cardioverter defibrillators have reduced arrhythmic deaths...... but have no impact on overall mortality. Therefore, additional interventions are required to further reduce the overall morbidity and mortality of patients with large MI. METHODS: The Pacing Remodeling Prevention Therapy (PRomPT) trial is designed to study the effects of peri-infarct pacing in preventing...... adverse post-MI remodeling. Up to 120 subjects with peak creatine phosphokinase >3,000 U/L (or troponin T >10 μg/L) at time of MI will be randomized to either dual-site or single-site biventricular pacing with the left ventricular lead implanted in a peri-infarct region or to a nonimplanted control group...

  5. 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)

  6. Pacemaker Prevention Therapy in Drug-refractory Paroxysmal Atrial Fibrillation: Reliability of Diagnostics and Effectiveness of Prevention Pacing Therapy in Vitatron™ Selection® Device

    OpenAIRE

    2006-01-01

    Introduction. Atrial fibrillation (AF), the most common and rising disorder of cardiac rhythm, is quite difficult to control and/or to treat. Non pharmacological therapies for AF may involve the use of dedicated pacing algorithms to detect and prevent atrial arrhythmia that could be a trigger for AF onset. Selection 900E/AF2.0 Vitatron DDDRP pacemaker (1) keeps an atrial arrhythmia diary thus providing detailed onset reports of arrhythmias of interest, (2) provides us data about the number of...

  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. 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

  9. 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.

  10. 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

  11. Could Harmonic Scalpel (Ultracision®) be considered the best device in surgical treatment of vulvar cancer of patients with implanted pace-maker? Proposal and rationale

    Science.gov (United States)

    Gizzo, Salvatore; Andrisani, Alessandra; Ancona, Emanuele; Quaranta, Michela; Vitagliano, Amerigo; Noventa, Marco; Nardelli, Giovanni Battista; Ambrosini, Guido

    2015-01-01

    Vulvar cancer (VC) represents about 4% of gynecologic malignancies, its incidence increases with age and peak incidence is found between 70-79 years. In cases of locally advanced disease surgery is often required and radical vulvectomy, with or without mono-bilateral inguino-femoral lymphadenectomy, is standard management. Various devices have been implemented in gynecological surgery in an attempt to minimize or avoid frequent intra/postoperative complications linked to energy use, unfortunately the majority of these devices require monopolar or bipolar energy. Ultracision® represents a unique surgical device capable of performing both cutting and coagulation at different intensities without use of electric energy. The use of Ultracision® in the radical treatment of VC has advantages both in terms of intraoperative and postoperative complications responsible for the reduction of surgical time and blood loss, complete tissue removal according to oncological criteria, diminished desensitization of peripheral areas and reduction of wound complications. These advantages have been widely demonstrated and contribute to making Ultracision® a cost-effective option in the routine treatment of patients affected by vulvar cancer especially when considering its safety in cardiopathic patients with implanted pacemaker. If the impressive results achieved in radical vulvar surgery will be confirmed, scalpel use could be proposed as routine for surgery of the routinely in surgical approach of vulvar and perineal area, in both benign and malignant disease. PMID:26309660

  12. 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.

  13. Outcome of biventricular repair in infants with multiple left heart obstructive lesions.

    Science.gov (United States)

    Cavigelli-Brunner, Anna; Bauersfeld, Urs; Prêtre, René; Kretschmar, Oliver; Oxenius, Angela; Valsangiacomo Buechel, Emanuela R

    2012-04-01

    The decision to perform biventricular repair for infants with multiple obstructive or hypoplastic left heart lesions (LHL) and borderline left ventricle (LV) may be controversial. This study sought to assess the mortality and morbidity of patients with LHL after biventricular repair and to determine the growth of the left-sided cardiac structures. Retrospective analysis of 39 consecutive infants with LHL who underwent biventricular repair was performed. The median age at surgery was 7 days (range 1-225 days), and the median follow-up period was 34 months (range 1-177 months). Between diagnosis and the end of the follow-up period, the size of the aortic annulus (z-score -4.1 ± 2.8 vs. -0.1 ± 2.7) and the LV (LV end-diastolic diameter z-score -1.7 ± 2.8 vs. 0.21 ± 1.7) normalized. During the follow-up period, 23 patients required 39 reinterventions (62%) consisting of redo surgery for 21 patients (57%) and catheter-guided reinterventions for 8 patients (22%). At the end of the follow-up period, 25 of 34 patients were doing subjectively well; 10 children (29%) received cardiac medication; 12 (35%) presented with failure to thrive (weight ≤ P3) and 5 (15%) with pulmonary hypertension. The overall mortality rate was 13%. Biventricular repair for patients with multiple LHL results in sufficient growth of the left-sided cardiac structures. Nevertheless, residual or newly developing obstructive lesions and pulmonary hypertension are frequent, causing significant morbidity that requires reintervention. PMID:22159427

  14. Costs and Outcomes in the Care of Bi-ventricular Support as a Bridge to Cardiac Transplant.

    Science.gov (United States)

    Swartz, Michael F; Angona, Ron; Smith, Karen; Kraenzlin, Franca; Stypula, Christine M; Joshi, Devang; Tchantchaleishvili, Vakhtang; Hicks, George L; Massey, H Todd

    2016-01-01

    Bi-ventricular (Bi-V) mechanical circulatory support is commonly used as a bridge to cardiac transplant. However, the optimal strategy is unknown. We examined the outcomes, as well as the costs in the use of Bi-V support as a bridge to cardiac transplant. From 2001 to 2014, three different Bi-V support strategies were utilized: 1) Para-corporeal ventricular assist device (PVAD-2001-2006), 2) Heartmate II left ventricular assist device in conjunction with a temporary CentriMag right ventricular assist device (HMII + CMAG-2006-2012), and the total artificial heart (TAH-2012-2014). Total costs were derived from the hospitalization at implant, and postimplant costs defined as equipment and re-hospitalizations before transplantation. Sixty-five (34 PVADs, 20 HMII + CMAG, and 11 TAHs) devices were used as a bridge for transplant. There were no differences in implant variables including age, INTERMACS score, or implant length of stay. Although the wait list mortality was not different between groups (PVAD-32%, HMII + CMAG-45%, TAH-54%; p = 0.3), the percentage of patients transplanted were highest in the PVAD group: (PVAD-55.8%, HMII + CMAG-30.0%, TAH-18.2%; p = 0.01). Total costs were not significantly different between groups (PVAD-$306,166 ± 247,839, HMII + CMAG-$278,958 ± 135,324, TAH-$321,387 ± 21,2477; p = 0.5). Despite variations in therapy, outcomes and costs for patients requiring Bi-V support as a bridge to cardiac transplant have remained constant. PMID:27258229

  15. 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.

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

    OpenAIRE

    Edmar Atik; Patrícia O. Marques; Rogério A. Miranda; Vitor C. Guerra; Lucília Santana Faria; Marcelo Jatene

    2009-01-01

    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...

  17. Atrial Fibrillation and Pacing Algorithms

    OpenAIRE

    Terranova, Paolo; Severgnini, Barbara; Valli, Paolo; Dell'Orto, Simonetta; Greco, Enrico Maria

    2006-01-01

    Pacing prevention algorithms have been introduced in order to maximize the benefits of atrial pacing in atrial fibrillation prevention. It has been demonstrated that algorithms actually keep overdrive atrial pacing, reduce atrial premature contractions, and prevent short-long atrial cycle phenomenon, with good patient tolerance. However, clinical studies showed inconsistent benefits on clinical endpoints such as atrial fibrillation burden. Factors which may be responsible for neutral results ...

  18. 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.

  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. Historical highlights in cardiac pacing.

    Science.gov (United States)

    Geddes, L A

    1990-01-01

    The benchmarks in cardiac pacing are identified, beginning with F. Steiner (1871), who rhythmically stimulated the chloroform-arrested hearts of 3 horses, 1 donkey, 10 dogs, 14 cats, and 8 rabbits. The chloroform-arrested heart in human subjects was paced by T. Greene in the following year (1872) in the UK. In 1882, H. Ziemssen in Germany applied cardiac pacing to a 42-year old woman who had a large defect in the anterior left chest wall subsequent to resection of an enchondroma. Intentional cardiac pacing did not occur until 1932, when A.A. Hyman in the US demonstrated that cardiac pacing could be clinically practical. Hyman made a batteryless pacemaker for delivery in induction shock stimuli (60-120/min) to the atria. His pacemaker was powered by a hand-wound, spring-driven generator which provided 6 min of pacemaking without rewinding. Closed-chest ventricular pacing was introduced in the US in 1952 by P.M. Zoll et al. Zoll (1956) also introduced closed-chest ventricular defibrillation. W.L. Weirich et al. (1958) demonstrated that direct-heart stimulation in closed-chest patients could be achieved with slender wire electrodes. S. Furman and J.B. Schwedel (1959) developed a monopolar catheter electrode for ventricular pacing in man. In the same year, W. Greatbatch and W.M. Chardack developed the implantable pacemaker. PMID:18238328

  1. 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.

  2. 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.

  3. 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.

  4. 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

  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. 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…

  7. 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.

  8. The PACE evaluation: initial findings.

    Science.gov (United States)

    Branch, L G; Coulam, R F; Zimmerman, Y A

    1995-06-01

    As of mid-1994 there were nine replications of the On Lok model operating under dual capitation payments as sites in the Program of All-inclusive Care for the Elderly (PACE). A tenth site had begun operating under capitation, but was unable to remain viable. The present descriptive study documents the growth and development of the first seven of these sites, all that had been operating under capitation during 1992. Comparisons among these sites and with On Lok are presented in the areas of organizational structure, client characteristics, approaches to case management, service delivery options, and financing. There is considerable variability in the implementation of the PACE model. Combined Medicare and Medicaid capitation monthly payments range from $2,147 to $5,973. These seven PACE sites (excluding On Lok) served a total of 888 current clients at the end of 1992, after a cumulative 136 months of experience under capitation. The very slow enrollment rates may imply that the target clients are less enthusiastic about this model than are its architects. The client selection process may suggest niche-marketing or skimming, but not the full representation of the nursing home population in their states. Given both the slow enrollment and the niche-marketing (the benevolent term) or skimming (the pejorative term) that has occurred, caution about the long-term viability of the PACE model may be warranted. PMID:7622088

  9. 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

  10. 42 CFR 460.186 - PACE premiums.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 4 2010-10-01 2010-10-01 false PACE premiums. 460.186 Section 460.186 Public...) Payment § 460.186 PACE premiums. The amount that a PACE organization can charge a participant as a monthly premium depends on the participant's eligibility under Medicare and Medicaid, as follows: (a)...

  11. 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.

  12. In-vivo motion analysis of bi-ventricular hearts from tagged MR images

    Science.gov (United States)

    Park, Kyoungju; Axel, Leon; Metaxas, Dimitris N.

    2005-04-01

    We conduct experiments to look at the in-vivo cardiac motion during systole, to visualize heart contraction, and to examine the clinical usefulness. Our model-based technique incorporates subject-specific modeling, motion analysis and the extraction of clinically relevant parameters within one framework. Previous bi-ventricular model based method could only handle up to the mid-ventricles and have a few test-subjects. Our parameterized model includes the LV, RV and up to the basal area for full ventricular motion study. Finite element methods capture cardiac motion by tracking the material points from tagged Magnetic Resonance (MR) images. A number of experiments from ten subjects are evaluated and analyzed. We tested subject several times and compared the resulting parameters to ensure the reproducibility and deviations. The resulting parameters can be used to describe the cardiac motion of normal subjects. The patterns of normal subjects were derived from experiments. While significant shape and motion variations were apparent in normal subjects, the quantitative analysis show typical patterns. Generally, the basal area moves downwards and the apical area contracts towards the cavity. The principal strain analysis describes the directions and magnitudes of maximum shortening, and maximum thickening.

  13. 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.

  14. Thallium cardiac stressing by esophageal pacing

    Energy Technology Data Exchange (ETDEWEB)

    Allen, M.L.; Vacek, J.L.; Preston, D.F.; Robinson, R.G.; Feldkamp, M.J. (Univ. of Kansas Medical Center, Kansas City (USA))

    1989-09-01

    Forty-three patients were examined with the transesophageal pacing method of cardiac stressing and thallium imaging. Transesophageal cardiac pacing, using a pill electrode or a permanent pacemaker lead, is a safe alternative for patients who are physically unable to exercise. Prior studies suggest that transvenous right atrial pacing with thallium injection is equivalent to physical exercise thallium studies in the detection of coronary artery disease. The esophageal pacing bipolar electrode similarly increases heart rate without the necessity of transvenous pacing or fluoroscopy and without the adverse side effects often seen when using pharmacologic stressing agents (i.e., dipyridamole). The results compare well with cardiac catheterization, echocardiographic, and electrocardiographic results. Cardiac paced stress testing requires no sedation, is performed on an out-patient basis, and causes little if any discomfort for the patient.

  15. Low atrial septum pacing in pacemaker patients

    OpenAIRE

    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 treatment in the prevention of the arrhythmia related complications. These treatment modalities when available in pacemaker systems could come at a relative low cost as the indication for pacemaker imp...

  16. Real time three-dimensional transesophageal echocardiography guided coronary sinus cannulation during CARILLON mitral annuloplasty device therapy for a patient with chronic severe mitral regurgitation.

    Science.gov (United States)

    Mahmoud, Hani M; Al-Ghamdi, Mohammed A; Ghabashi, Abdullah E

    2015-01-01

    The coronary sinus (CS) has become a clinically important structure especially through its role in providing access for different cardiac procedures such as arrhythmia ablation, biventricular pacing and recently, percutaneous valvular interventions. Fluoroscopy with or without two-dimensional transesophageal echocardiography is the widely used method for guidance. A 78-year-old female patient undergoing percutaneous CARILLON mitral annuloplasty device therapy for chronic severe symptomatic mitral regurgitation. After insertion of the CS catheter through the right internal jugular vein, multiple trials for CS cannulation guided by fluoroscopy and two-dimensional transesophageal echocardiography were unsuccessful. So, real time three-dimensional zoom mode was used. Then, the volume was rotated to have the anatomically oriented enface view of the interatrial septum from the right atrial perspective. The CS ostium was identified adjacent to the eustachian valve. Then the catheter was reintroduced through the superior vena cava into the right atrium then easily navigated to cannulate the CS ostium. The position was confirmed by the fluoroscopically known course of the CS plus the pattern of the invasive pressure wave form. CS cannulation is not always feasible using fluoroscopy and/or two-dimensional Echocardiography guidance. Real time three-dimensional transesophageal echocardiography can be used to guide CS cannulation as it provides an anatomically oriented and informative enface view of the CS ostium. It can help reducing fluoroscopic radiation time. PMID:25231878

  17. 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.

  18. Web Tools: Keeping Learners on Pace

    Science.gov (United States)

    Kosloski, Mickey

    2016-01-01

    One of the greatest challenges in teaching technology and engineering is pacing. Some students grasp new technological concepts quickly, while others need repetition and may struggle to keep pace. This poses an obstacle for the technology and engineering teacher, and is particularly true when teaching students to build a website. However, there…

  19. 42 CFR 460.60 - PACE organizational structure.

    Science.gov (United States)

    2010-10-01

    ... 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 PACE organization must be, or be a distinct part of, one of the following: (1) An entity of city, county, State,...

  20. The pace of cultural evolution.

    Directory of Open Access Journals (Sweden)

    Charles Perreault

    Full Text Available Today, humans inhabit most of the world's terrestrial habitats. This observation has been explained by the fact that we possess a secondary inheritance mechanism, culture, in addition to a genetic system. Because it is assumed that cultural evolution occurs faster than biological evolution, humans can adapt to new ecosystems more rapidly than other animals. This assumption, however, has never been tested empirically. Here, I compare rates of change in human technologies to rates of change in animal morphologies. I find that rates of cultural evolution are inversely correlated with the time interval over which they are measured, which is similar to what is known for biological rates. This correlation explains why the pace of cultural evolution appears faster when measured over recent time periods, where time intervals are often shorter. Controlling for the correlation between rates and time intervals, I show that (1 cultural evolution is faster than biological evolution; (2 this effect holds true even when the generation time of species is controlled for; and (3 culture allows us to evolve over short time scales, which are normally accessible only to short-lived species, while at the same time allowing for us to enjoy the benefits of having a long life history.

  1. 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.

  2. 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

  3. 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...

  4. 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.

  5. 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.

  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. No incremental benefit of multisite atrial pacing compared with right atrial pacing in patients with drug refractory paroxysmal atrial fibrillation

    OpenAIRE

    Levy, T; Walker, S; Rex, S; Rochelle, J; Paul, V.

    2001-01-01

    OBJECTIVE—To evaluate the incremental antifibrillatory effect of multisite atrial pacing compared with right atrial pacing in patients with drug refractory paroxysmal atrial fibrillation paced for arrhythmia prevention alone.
METHODS—In 20 of these patients (mean (SD) age 64 (8) years; 14 female, six male), a single blinded randomised crossover study was performed to investigate the incremental benefit of one month of multisite atrial pacing compared with one month of right atrial pacing. Out...

  8. 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)

  9. 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.

  10. 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...

  11. Visual aided pacing in respiratory maneuvers

    International Nuclear Information System (INIS)

    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

  12. 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.

  13. 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.

  14. Gait Alterations During Constant Pace Treadmill Racewalking.

    Science.gov (United States)

    Hanley, Brian

    2015-08-01

    Racewalking is an Olympic event requiring great endurance, and racewalkers often use treadmills in training because of the benefits of having a flat unchanging surface where pace judgment can be learned and because inclement weather can be avoided. The effects of fatigue associated with racewalking on a treadmill have not been studied and could be informative with regard to the maintenance of legal technique. The aim of this study was to measure key gait variables during a physically demanding treadmill racewalk. Fourteen international racewalkers completed 10 km on an instrumented treadmill at a pace equivalent to 103% of their recent best time. Spatiotemporal and ground reaction force data were recorded at 4 distances. High-speed videography data were simultaneously recorded to analyze changes in knee angle between the early and late stages. Increases in step length and corresponding decreases in cadence were found, although the small changes were not considered meaningful. There was also a small increase in flight time and a small decrease in push-off force. There were no other significant changes for any other variables (including knee angles). The increase in flight time might be important given that racewalkers are not permitted a visible loss of contact and suggests that fatiguing sessions on a treadmill can lead to the adoption of nonlegal technique. However, this disadvantage of treadmill training can be negated if the coach scrutinizes athletes throughout the session, and overall the consistent technique used is of benefit with regard to learning correct form and pacing ability. PMID:25647657

  15. 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...

  16. Arrhythmia management after device removal.

    Science.gov (United States)

    Nishii, Nobuhiro

    2016-08-01

    Arrhythmic management is needed after removal of cardiac implantable electronic devices (CIEDs). Patients completely dependent on CIEDs need temporary device back-up until new CIEDs are implanted. Various methods are available for device back-up, and the appropriate management varies among patients. The duration from CIED removal to implantation of a new CIED also differs among patients. Temporary pacing is needed for patients with bradycardia, a wearable cardioverter defibrillator (WCD) or catheter ablation is needed for patients with tachyarrhythmia, and sequential pacing is needed for patients dependent on cardiac resynchronization therapy. The present review focuses on arrhythmic management after CIED removal. PMID:27588151

  17. Optimized multisite ventricular pacing in postoperative single-ventricle patients.

    Science.gov (United States)

    Havalad, Vinod; Cabreriza, Santos E; Cheung, Eva W; Aponte-Patel, Linda; Wang, Alice; Cheng, Bin; Wang, Daniel Y; Silver, Eric; Bacha, Emile A; Spotnitz, Henry M

    2014-10-01

    Ventricular dyssynchrony is associated with morbidity and mortality after palliation of a single ventricle. The authors hypothesized that resynchronization with optimized temporary multisite pacing postoperatively would be safe, feasible, and effective. Pacing was assessed in the intensive care unit within the first 24 h after surgery. Two unipolar atrial pacing leads and four bipolar ventricular pacing leads were placed at standardized sites intraoperatively. Pacing was optimized to maximize mean arterial pressure. The protocol tested 11 combinations of the 4 different ventricular lead sites, 6 atrioventricular delays (50-150 ms), and 14 intraventricular delays. Optimal pacing settings were thus determined and ultimately compared in four configurations: bipolar, unipolar, single-site atrioventricular pacing, and intrinsic rhythm. Each patient was his or her own control, and all pacing comparisons were implemented in random sequence. Single-ventricle palliation was performed for 17 children ages 0-21 years. Pacing increased mean arterial pressure (MAP) versus intrinsic rhythm, with the following configurations: bipolar multisite pacing increased MAP by 2.2 % (67.7 ± 2.4 to 69.2 ± 2.4 mmHg; p = 0.013) and unipolar multisite pacing increased MAP by 2.8 % (67.7 ± 2.4 to 69.6 ± 2.7 mmHg; p = 0.002). Atrioventricular single-site pacing increased MAP by 2.1 % (67.7 ± 2.4 to 69.1 ± 2.5 mmHg: p = 0.02, insignificant difference under Bonferroni correction). The echocardiographic fractional area change in nine patients increased significantly only with unipolar pacing (32 ± 3.1 to 36 ± 4.2 %; p = 0.02). No study-related adverse events occurred. Multisite pacing optimization is safe and feasible in the early postoperative period after single-ventricle palliation, with improvements in mean arterial pressure and fractional area shortening. Further study to evaluate clinical benefits is required. PMID:24827078

  18. Medical staff radiation exposure in electrophysiology procedures: First results during biventricular ICD implantation

    International Nuclear Information System (INIS)

    Cardiac resynchronization therapy (CRT) requires a very long fluoroscopy time due to the need to monitor the placement of the device and electrodes inside the patient’s body at every step of the procedure. Aim of this study was to analyse staff X-ray exposure during the intervention, measuring Hp(10) values with electronic dosimeters worn by medical staff. The scattered X-ray field was characterized using a spectrometric CdTe (cadmium-telluride) detector to define the radiation field impinging on the operator and thereby identify the correct dosimeter position for accurate measurement (i.e., above or under the shielding apron). In particular, knowledge of the X-ray spectrum yields information on photon flux and the energy distribution of the X-rays. Dosimetric data were then recorded in a series of 20 consecutive patients, obtaining a first set of Hp(10) data that can be used to estimate the risk for the electrophysiologist performing this procedure.

  19. Induction of atrial fibrillation with rapid high voltage ventricular pacing for ventricular fibrillation conversion testing

    OpenAIRE

    Schuchert, A; Kuhl, M; Ruppel, R; Meinertz, T

    2000-01-01

    OBJECTIVE—To assess whether rapid high voltage ventricular pacing can also induce atrial fibrillation, and whether the induction of atrial fibrillation during ventricular fibrillation conversion testing is related to the patient's heart disease.
DESIGN—Prospective study of 50 patients who received the dual chamber implantable cardioverter-defibrillator (ICD) Ventak AV II DR (Guidant) as a first implant. This device can record atrial activity even during a ventricular fibrillation episode and ...

  20. 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.

  1. 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.

  2. Far field pacing supersedes anti-tachycardia pacing in a generic model of excitable media

    Energy Technology Data Exchange (ETDEWEB)

    Bittihn, Philip; Parlitz, Ulrich [Drittes Physikalisches Institut, Goettingen University, Friedrich-Hund-Platz 1, 37077 Goettingen (Germany); Luther, Gisela; Bodenschatz, Eberhard; Krinsky, Valentin; Luther, Stefan [Max Planck Institute for Dynamics and Self-Organization, Bunsenstrasse 10, 37073 Goettingen (Germany)], E-mail: bittihn@physik3.gwdg.de

    2008-10-15

    Removing anchored spirals from obstacles is an important step in terminating cardiac arrhythmia. Conventional anti-tachycardia pacing (ATP) has this ability, but only under very restrictive conditions. In a generic model of excitable media, we demonstrate that for unpinning spiral waves from obstacles this profound limitation of ATP can be overcome by far field pacing (FFP). More specifically, an argument is presented for why FFP includes and thus can only extend the capabilities of ATP in the configurations considered. By numerical simulations, we show that in the model there exists a parameter region in which unpinning is possible by FFP but not by ATP. The relevance of this result regarding clinical applications is discussed.

  3. 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.

  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......-pharmacological rheumatology care. Methods: An international, multidisciplinary expert panel comprising 60 clinicians and/or healthcare providers experienced with activity pacing across 12 different countries participated in a Delphi survey. Over four Delphi rounds, the panellists identified and ranked the most important...... for future research on activity pacing were formulated and prioritized. Results: Of the 60 panelists, nearly two third (63%) completed all four Delphi rounds. The panel prioritized 9 goals, 11 behaviours, 9 strategies to change behaviour and 10 contextual factors of activity pacing. These items were...

  5. An Undergraduate Intern Program at PACES

    Science.gov (United States)

    Starks, Scott A.

    1997-01-01

    The University of Texas at El Paso (UTEP) established the Pan American Center for Earth and Environmental Studies (PACES) in 1995 to conduct basic and applied research that contributes to NASA's Mission to Planet Earth. Specifically, PACES provides a repository of remote sensing and other information that supports investigations into an improved understanding of geological, ecological and environmental processes occurring in the southwestern United States and Northern Mexico. Approximately 85% of UTEP's students come from El Paso County, a fast growing urban region representative of many large cities in the Southwest that have, or will soon have, a majority of their population composed of groups currently underrepresented in the scientific and technical workforce. UTEP's student population has an ethnic distribution (63% Hispanic, 32% Anglo, 3% African American, 1.5 % Asian American, and less than 1% Native American) that closely matches the demographics of the region it serves. Thus, UTEP has a mission to serve a multicultural population where minority students comprise the majority. Most Hispanic students at UTEP are primarily of Mexican origin. A large number are first or second-generation U.S. citizens. Characteristics that unite Hispanic students, in particular those of Mexican-origin, are a strong sense of family loyalty and a belief that all family members are responsible for contributing to the economic stability and well-being of the family. Most of their families are larger in number than the national average, and a variety of generations live together or share considerable resources. Thus, many young people feel an obligation and a desire to go to work at a young age and to continue working while in college, thereby assisting their parents and other family members. Older siblings understand that they have responsibilities to do household chores, to aid their younger siblings economically, and to assist elderly family members. This "work ethic" within the

  6. 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 ...

  7. A bi-ventricular cardiac atlas built from 1000+ high resolution MR images of healthy subjects and an analysis of shape and motion.

    Science.gov (United States)

    Bai, Wenjia; Shi, Wenzhe; de Marvao, Antonio; Dawes, Timothy J W; O'Regan, Declan P; Cook, Stuart A; Rueckert, Daniel

    2015-12-01

    Atlases encode valuable anatomical and functional information from a population. In this work, a bi-ventricular cardiac atlas was built from a unique data set, which consists of high resolution cardiac MR images of 1000+ normal subjects. Based on the atlas, statistical methods were used to study the variation of cardiac shapes and the distribution of cardiac motion across the spatio-temporal domain. We have shown how statistical parametric mapping (SPM) can be combined with a general linear model to study the impact of gender and age on regional myocardial wall thickness. Finally, we have also investigated the influence of the population size on atlas construction and atlas-based analysis. The high resolution atlas, the statistical models and the SPM method will benefit more studies on cardiac anatomy and function analysis in the future.

  8. Diaphragm pacing failure secondary to deteriorated chest wall mechanics: When a good diaphragm does not suffice to take a good breath in

    Directory of Open Access Journals (Sweden)

    Lila Layachi

    2015-01-01

    Full Text Available Diaphragm pacing allows certain quadriplegic patients to be weaned from mechanical ventilation. Pacing failure can result from device dysfunction, neurotransmission failure, or degraded lung mechanics (such as atelectasis. We report two cases where progressive pacing failure was attributed to deteriorated chest wall mechanics. The first patient suffered from cervical spinal cord injury at age 45, was implanted with a phrenic stimulator (intrathoracic, successfully weaned from ventilation, and permanently paced for 7 years. Pacing effectiveness then slowly declined, finally attributed to rib cage stiffening due to ankylosing spondylitis. The second patient became quadriplegic after meningitis at age 15, was implanted with a phrenic stimulator (intradiaphragmatic and weaned. After a year hypoventilation developed without obvious cause. In relationship with complex endocrine disorders, the patient had gained 31 kg. Pacing failure was attributed to excessive mechanical inspiratory load. Rib cage mechanics abnormalities should be listed among causes of diaphragm pacing failure and it should be kept in mind that a “good diaphragm” is not sufficient to produce a “good inspiration”.

  9. Diaphragm pacing failure secondary to deteriorated chest wall mechanics: When a good diaphragm does not suffice to take a good breath in.

    Science.gov (United States)

    Layachi, Lila; Georges, Marjolaine; Gonzalez-Bermejo, Jésus; Brun, Anne-Laure; Similowski, Thomas; Morélot-Panzini, Capucine

    2015-01-01

    Diaphragm pacing allows certain quadriplegic patients to be weaned from mechanical ventilation. Pacing failure can result from device dysfunction, neurotransmission failure, or degraded lung mechanics (such as atelectasis). We report two cases where progressive pacing failure was attributed to deteriorated chest wall mechanics. The first patient suffered from cervical spinal cord injury at age 45, was implanted with a phrenic stimulator (intrathoracic), successfully weaned from ventilation, and permanently paced for 7 years. Pacing effectiveness then slowly declined, finally attributed to rib cage stiffening due to ankylosing spondylitis. The second patient became quadriplegic after meningitis at age 15, was implanted with a phrenic stimulator (intradiaphragmatic) and weaned. After a year hypoventilation developed without obvious cause. In relationship with complex endocrine disorders, the patient had gained 31 kg. Pacing failure was attributed to excessive mechanical inspiratory load. Rib cage mechanics abnormalities should be listed among causes of diaphragm pacing failure and it should be kept in mind that a "good diaphragm" is not sufficient to produce a "good inspiration". PMID:26236593

  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. Development of Pacing, Electrophysiology and Defibrillation in India

    OpenAIRE

    Nair, Mohan; Francis, Johnson; Venugopal, K

    2002-01-01

    History of cardiac pacing in India dates back to late 1960s. Kar1 reported that cardiac pacing was introduced in India in 1966. Basu2 while discussing on cardiac pacemaking in Calcutta, mentions that the first pacing was performed in April 1967 at the Institute of Post Graduate Medical Education and Research (IPGME&R). Bhatia et al3 started pacemaker implantation at AIIMS, New Delhi in 1968. Their first patient was a doctor from Assam and the pulse generator was supplied by Medtronic Inc. Th...

  12. 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.

  13. 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

  14. Factors explaining voluntary participation in PACE-Vaquita

    OpenAIRE

    Sara Avila

    2011-01-01

    Vaquita marina, a small species of porpoise endemic to the Northern Gulf of California in Mexico, is the world’s most endangered cetacean species. With the purpose of preserving vaquita, the Mexican government launched PACE-Vaquita in 2008. This voluntary program offers an innovative schedule of compensations: as in a payment for conservation program, PACE-Vaquita compensates for temporary reductions in fishing reductions in fishing effort; as in a program to accelerate technology adoption,PA...

  15. Determination of myocardial energetic output for cardiac rhythm pacing

    OpenAIRE

    Heřman, Dalibor; Převorovská, Světlana; Maršík, František

    2007-01-01

    This research is aimed to the determination of the changes in the cardiac energetic output for three different modes of cardiac rhythm pacing. The clinical investigation of thirteen patients with the permanent dual-chamber pacemaker implantation was carried out. The patients were taken to echocardiography examination conducted by way of three pacing modes (AAI, VVI and DDD). The myocardial energetic parameters—the stroke work index (SWI) and the myocardial oxygen consumption (MVO2) are not di...

  16. Feasibility of Leadless Cardiac Pacing Using Injectable Magnetic Microparticles.

    Science.gov (United States)

    Rotenberg, Menahem Y; Gabay, Hovav; Etzion, Yoram; Cohen, Smadar

    2016-01-01

    A noninvasive, effective approach for immediate and painless heart pacing would have invaluable implications in several clinical scenarios. Here we present a novel strategy that utilizes the well-known mechano-electric feedback of the heart to evoke cardiac pacing, while relying on magnetic microparticles as leadless mechanical stimulators. We demonstrate that after localizing intravenously-injected magnetic microparticles in the right ventricular cavity using an external electromagnet, the application of magnetic pulses generates mechanical stimulation that provokes ventricular overdrive pacing in the rat heart. This temporary pacing consistently managed to revert drug-induced bradycardia, but could only last up to several seconds in the rat model, most likely due to escape of the particles between the applied pulses using our current experimental setting. In a pig model with open chest, MEF-based pacing was induced by banging magnetic particles and has lasted for a longer time. Due to overheating of the electromagnet, we intentionally terminated the experiments after 2 min. Our results demonstrate for the first time the feasibility of external leadless temporary pacing, using injectable magnetic microparticles that are manipulated by an external electromagnet. This new approach can have important utilities in clinical settings in which immediate and painless control of cardiac rhythm is required. PMID:27091192

  17. PACE and the Federal Housing Finance Agency (FHFA)

    Energy Technology Data Exchange (ETDEWEB)

    Zimring, Mark; Fuller, Merrian

    2010-03-17

    The FHFA regulates Fannie Mae, Freddie Mac, and the 12 Federal Home Loan Banks (the government-sponsored enterprises - GSEs). On June 18, 2009, James B. Lockhart III, then Director of FHFA, released a letter expressing concern about the negative impact of energy loan tax assessment programs (ELTAPs) - also known as Property Assessed Clean Energy (PACE) programs - on both the housing finance system and homeowner program participants. Subsequently, a number of PACE proponents responded to the concerns laid out in the FHFA letter. In early Fall 2009, word circulated that FHFA was planning to follow its June letter with guidance to other agencies, possibly including Fannie Mae and Freddie Mac, discouraging them from buying loans on properties subject to PACE-type assessment liens. This triggered a second round of stakeholder letters, several of which were addressed to President Obama. On October 18, 2009, the White House, in what some believe was an attempt to obviate the need for FHFA guidance, released a Policy Framework for PACE Financing Programs that outlined best practices guidance for homeowner and lender protection. As of February 2010, FHFA and the GSEs have agreed to monitor PACE programs and work with stakeholders and the Administration to consider additional guidance beyond the Policy Framework and to collect more information on PACE program efficacy and risks. A summary of the communications timeline and highlights of the communications are provided.

  18. 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.

  19. Ross-Konno and Endocardial Fibroelastosis Resection After Hybrid Stage I Palliation in Infancy: Successful Staged Left-Ventricular Rehabilitation and Conversion to Biventricular Circulation After Fetal Diagnosis of Aortic Stenosis

    OpenAIRE

    Moon-Grady, Anita J.; Moore, Phillip; Azakie, Anthony

    2010-01-01

    We report a patient who presented during fetal life with severe aortic stenosis, left-ventricular dysfunction, and endocardial fibroelastosis (evolving hypoplastic left heart syndrome). Management involved in utero and postnatal balloon aortic valvuloplasty for partial relief of obstruction and early postnatal hybrid stage I palliation until recovery of left-ventricular systolic function had occurred. The infant subsequently had successful conversion to a biventricular circulation by combinin...

  20. 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

  1. Biomechanically and electromyographically assessed load on the spine in self-paced and force-paced lifting work.

    Science.gov (United States)

    Leskinen, T P; Stålhammar, H R; Rautanen, M T; Troup, J D

    1992-01-01

    The purpose of this study was to measure dose of spinal load when different pacing methods were applied to lifting work and to develop methodology for such measurements. The compressive load on the spine computed by a dynamic biomechanical model and the electromyographic activity of back muscles were used for describing the spinal load. Five men and five women worked in a laboratory on two days lifting a box up and down for 30 min on both days, on one day force-paced (4 lifts/min), and on the other self-paced in random order. The weight of the box was rated by the subjects to be acceptable for the work done. The lift rate of our female subjects was higher and that of the male subjects lower in self-paced than in force-paced work. There were no significant differences in peak lumbosacral compressions nor in the amplitude distributions of electromyography between the two pacing methods. The biomechanically-calculated compressive forces on the spine were lower (about 2.7 kN for the men and 2.3 kN for women) than the biomechanical recommendations for safe lifting, but the EMG activity showed quite high peaks so that for 1% of work time the activity was on women above 60% and on men above 40% of the activity during maximum isometric voluntary test contraction. PMID:1633794

  2. 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.

  3. 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.

  4. Surgical Considerations and Challenges for Bilateral Continuous-Flow Durable Device Implantation.

    Science.gov (United States)

    Maltais, Simon; Womack, Sara; Davis, Mary E; Danter, Matthew R; Kushwaha, Sudhir S; Stulak, John M; Haglund, Nicholas

    2016-01-01

    The concept of biventricular support with durable centrifugal pumps is evolving, and the surgical strategy and best practice guidelines for implantation of right-sided devices are still unknown. We present optimal strategy for bilateral HeartWare continuous-flow ventricular assist device (HVAD) implantation in a series of four patients. Patients were implanted with the HVAD pumps simultaneously or sequentially. This report offers a perspective on surgical considerations such as right ventricular positioning, implications related to potential risks of obstruction from the tricuspid apparatus, the role if any of downsizing the outflow anastomosis, and considerations for speed adjustments. In this series, one patient died on support and three patients experienced pump thrombosis requiring device revision. All other patients survived until orthotopic heart transplantation, although one of these patients died from perioperative complications, 2 days posttransplantation. Surgical management of patients with medically refractory biventricular heart failure remains challenging and associated with a high incidence of pump thrombosis. Best practice guidelines from experts' consensus are still needed to address this challenging population. PMID:26479465

  5. 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.

  6. Pacing accuracy during an incremental step test in adolescent swimmers

    Directory of Open Access Journals (Sweden)

    Scruton A

    2015-08-01

    Full Text Available Adrian Scruton, James Baker, Justin Roberts, Itay Basevitch, Viviane Merzbach, Dan Gordon Sport and Exercise Sciences Research Group, Anglia Ruskin University, Cambridge, UK Abstract: To assess pacing accuracy in a group of adolescent swimmers during an incremental step test. Fifteen well-trained swimmers (age 15±1.5 years; height 170.2±8.8 cm; mass 60.2±6.6 kg, completed two 7×200 m tests, separated by ~72 hours. They swam to a predetermined incrementally increasing pace per step and were instructed to swim at even pace. Upon completion of each step, rating of perceived exertion, heart rate and blood lactate were recorded. Significant differences observed for both trials between actual and predicted swim time (P<0.05. Significant differences also observed between the first and second 100 m of each step in trial 1 for step 1 (P=0.001, effect size [ES] =0.54, step 2 (P=0.0001, ES =0.57, step 4 (P=0.0001, ES =0.53, step 5 (P=0.005, ES =0.65, step 6 (P=0.0001, ES =0.50, and step 7 (P=0.0001, ES =0.70. Similar responses witnessed for trial 2 (P<0.05. Findings suggest that the finite anaerobic capacity was engaged sooner than would normally be anticipated, as a function of an inability to regulate pace. This is proposed to be a consequence of the volume of exposure to the biological and psychological sensations and cognitive developmental status. Given the apparent error in pacing judgment exhibited in this population group, caution should be applied when adopting such tests to monitor training responses with adolescent athletes, and alternate means of modulating pace be investigated. Keywords: effort regulation, children, exercise testing, perception

  7. International piping benchmarks: Use of simplified code PACE 2

    International Nuclear Information System (INIS)

    This report compares the results obtained using the code PACE 2 with the International Working Group on Fast Reactors (IWGFR) International Piping Benchmark solutions. PACE 2 is designed to analyse systems of pipework using a simplified method which is economical of computer time and hence inexpensive. This low cost is not achieved without some loss of accuracy in the solution, but for most parts of a system this inaccuracy is acceptable and those sections of particular importance may be reanalysed using more precise methods in order to produce a satisfactory analysis of the complete system at reasonable cost. (author)

  8. Investigating possible ethnicity and sex bias in clinical examiners: an analysis of data from the MRCP(UK) PACES and nPACES examinations

    OpenAIRE

    McManus, I C; Elder, A T; DACRE, J

    2013-01-01

    Background Bias of clinical examiners against some types of candidate, based on characteristics such as sex or ethnicity, would represent a threat to the validity of an examination, since sex or ethnicity are ‘construct-irrelevant’ characteristics. In this paper we report a novel method for assessing sex and ethnic bias in over 2000 examiners who had taken part in the PACES and nPACES (new PACES) examinations of the MRCP(UK). Method PACES and nPACES are clinical skills examinations that have ...

  9. The effects of fluid ingestion on free-paced intermittent-sprint performance and pacing strategies in the heat.

    Science.gov (United States)

    Skein, Melissa; Duffield, Rob

    2010-02-01

    The purpose of this study was to examine the effects of fluid ingestion on pacing strategies and performance during intermittent-sprint exercise in the heat. Nine male rugby players performed a habituation session and 2 x 50-min intermittent-sprint protocols at a temperature of 31 degrees C, either with or without fluid. Participants were informed of a third session (not performed) to ensure that they remained blind to all respective conditions. The protocol consisted of a 15-m sprint every minute separated by self-paced bouts of hard running, jogging, and walking for the remainder of the minute. Sprint time, distance covered during self-paced exercise, and vertical jump height before and after exercise were recorded. Heart rate, core temperature, nude mass, capillary blood haematocrit, pH, lactate concentration, perceptual ratings of perceived exertion, thermal stress, and thirst were also recorded. Sprint times (fluid vs. no-fluid: 2.82 +/- 0.11 vs. 2.82 +/- 0.14) and distance covered during self-paced exercise (fluid vs. no-fluid: 4168 +/- 419 vs. 3981 +/- 263 m) were not different between conditions (P = 0.10-0.98) but were progressively reduced to a greater extent in the no-fluid trial (7 +/- 13%) (d = 0.56-0.58). There were no differences (P = 0.22-1.00; d = stress did not differ between conditions (P = 0.34-0.91; d < or =0.20-0.48). Rating of thirst after exercise was lower in the fluid trial (P = 0.02; d = 0.62-0.73). The present results suggest that fluid availability did not improve intermittent-sprint performance, however did affect pacing strategies with a greater reduction in distance covered of self-paced exercise during the no-fluid trial. PMID:20077276

  10. Computer assisted optimisation on non-pharmacological treatment of congestive heart failure and supraventricular arrhythmia

    OpenAIRE

    Reumann, Matthias

    2007-01-01

    Heart Failure is the most common cardiac disease worldwide; supraventricular arrhythmia the most common cardiac arrhythmia. The understanding of these diseases advances treatment options. Ablation therapy and atrial antitachycardial pacing are non-pharmacological options in the treatment of atrial fibrillation. Cardiac resynchronization therapy with biventricular pacing devices has been shown successful in patients with severe heart failure. However, an optimization or even individual therapy...

  11. 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.

  12. "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.)

  13. 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

  14. '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

  15. 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.

  16. Self-Paced Physics, Segments 24-27.

    Science.gov (United States)

    New York Inst. of Tech., Old Westbury.

    Four study segments of the Self-Paced Physics Course materials are presented in this fifth problems and solutions book used as a part of student course work. The subject matter is related to work in electric fields, potential differences, parallel plates, electric potential energies, potential gradients, capacitances, and capacitor circuits.…

  17. Self-Paced Physics, Segments 28-31.

    Science.gov (United States)

    New York Inst. of Tech., Old Westbury.

    Four study segments of the Self-Paced Physics Course materials are presented in this sixth problems and solutions book used as a part of student course work. The subject matter is related to electric currents, current densities, resistances, Ohm's law, voltages, Joule heating, electromotive forces, single loop circuits, series and parallel…

  18. 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...

  19. 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

  20. MFTF-B PACE tests and final cost report

    International Nuclear Information System (INIS)

    The Mirror Fusion Test Facility (MFTF-B) construction project was successfully completed in February 1986, with the conclusion of the Plant and Capital Equipment (PACE) Tests. This series of tests, starting in September 1985 and running through February 1986, demonstrated the overall machine capabilities and special facilities accomplishments for the Mirror Fusion Test Facility Project

  1. A method for permanent transvenous left ventricular pacing.

    Science.gov (United States)

    Blanc, J J; Benditt, D G; Gilard, M; Etienne, Y; Mansourati, J; Lurie, K G

    1998-11-01

    LV-based pacing has recently been reported to be of benefit in patients with severe cardiac failure and left bundle branch block. LV permanent pacing has been reported using epicardial leads but the surgical mortality is excessive. A transvenous approach is now favored. In this regard, cannulation of the coronary sinus and of one of its tributaries using only the permanent electrode is feasible but technically challenging. We describe a "long guiding sheath" method using catheterization, and a long radiopaque and peelable sheath. Once the coronary sinus is cannulated with the electrophysiological catheter, the long sheath is advanced to the mid-part of the coronary sinus. The permanent pacing electrode is then placed through the sheath and into a tributary of the coronary sinus. This method has been attempted in 10 patients and was successful in 8, with an average lead insertion time of 21 +/- 5.5 minutes and an average fluoroscopic time of 11 +/- 5.5 minutes. In conclusion, although transvenous left ventricular pacing remains a challenge, the "long guiding sheath" approach appears to facilitate this procedure with both a high success rate and an acceptable procedure time. PMID:9826852

  2. 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。

  3. What Pace Is Best? Assessing Adults' Learning from Slideshows and Video

    Science.gov (United States)

    Sage, Kara

    2014-01-01

    When acquiring information from a 2D platform, self-control and/or optimal pacing may help reduce cognitive load and enhance learning outcomes. In the present research, adults viewed novel action sequences via one of four learning media: (1) self-paced slideshows, where viewers advanced through slides at their own pace by clicking a mouse, (2)…

  4. 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…

  5. "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…

  6. The Pace and Shape of Senescence in Angiosperms

    DEFF Research Database (Denmark)

    Baudisch, Annette; Salguero-Gómez, Roberto; Jones, Owen;

    2013-01-01

    (‘senescence’), decreases (‘negative senescence’) or remains constant over age (‘negligible senescence’). 3. We extract mortality trajectories from ComPADRe III, a data base that contains demographic information for several hundred plant species. We apply age-from-stage matrix decomposition methods to obtain...... age-specific trajectories from 290 angiosperm species of various growth forms distributed globally. From these trajectories, we survey pace and shape values and investigate how growth form and ecoregion influence these two aspects of mortality using a Bayesian regression analysis that accounts...... analysis that accounts for phylogenetic history and in the distinction between metrics of pace and shape as two separate aspects of mortality. We believe that our approach could prove useful in future comparative studies of mortality patterns....

  7. Optimal pacing strategy for a race of two competing cyclists

    OpenAIRE

    Dahmen, Thorsten; Saupe, Dietmar

    2014-01-01

    For optimal pacing strategies in the case of two or more competing or cooperating cyclists only few approaches take slipstreaming into account. However, by incorporating the slipstream effect in the model of a race of two runners on a flat course , it has been shown, how the trailing runner can position himself at striking distance behind the other and when he should start the final sprint. (Pitcher, 2009: Optimal strategies for a two - runner model of middle - distance running. SIAM Journal ...

  8. Recognition of ventricular fibrillation concomitant with pacing artifacts

    OpenAIRE

    Zysko, Dorota; Smereka, Jacek; CHÊCIÑSKI, IGOR; WRÓBLEWSKI, PAWE£; TERPI£OWSKI, £UKASZ; JACEK, GAJEK; WALDEMAR, GOZDZIK; KUMAR AGRAWAL, ANIL

    2013-01-01

    Introduction. In pre-hospital settings recognition of underlying rhythm in patients with ventricular stimulation can be difficult especially when a 3-lead electrocardiogram (ECG) is analyzed. This fact is particularly important in patients with life-threatening cardiac dysrhythmias. The pacing spikes in the ECG of a patient with cardiac arrest due to ventricular fibrillation may be misdiagnosed as QRS complexes. Aim of the study. The aim of this study was to assess emergency medical care stud...

  9. 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.

  10. 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

  11. Determination of myocardial energetic output for cardiac rhythm pacing.

    Science.gov (United States)

    Herman, Dalibor; Prevorovská, Svetlana; Marsík, Frantisek

    2007-12-01

    This research is aimed to the determination of the changes in the cardiac energetic output for three different modes of cardiac rhythm pacing. The clinical investigation of thirteen patients with the permanent dual-chamber pacemaker implantation was carried out. The patients were taken to echocardiography examination conducted by way of three pacing modes (AAI, VVI and DDD). The myocardial energetic parameters-the stroke work index (SWI) and the myocardial oxygen consumption (MVO2) are not directly measurable, however, their values can be determined using the numerical model of the human cardiovascular system. The 24-segment hemodynamical model (pulsating type) of the human cardiovascular system was used for the numerical simulation of the changes of myocardial workload for cardiac rhythm pacing. The model was fitted by well-measurable parameters for each patient. The calculated parameters were compared using the two-tailed Student's test. The differences of SWI and MVO2 between the modes AAI and VVI and the modes DDD and VVI are statistically significant (P0.05). PMID:18080208

  12. Are Electronic Cardiac Devices Still Evolving?

    Science.gov (United States)

    Mabo, P.

    2014-01-01

    Summary Objectives The goal of this paper is to review some important issues occurring during the past year in Implantable devices. Methods First cardiac implantable device was proposed to maintain an adequate heart rate, either because the heart’s natural pacemaker is not fast enough, or there is a block in the heart’s electrical conduction system. During the last forty years, pacemakers have evolved considerably and become programmable and allow to configure specific patient optimum pacing modes. Various technological aspects (electrodes, connectors, algorithms diagnosis, therapies, …) have been progressed and cardiac implants address several clinical applications: management of arrhythmias, cardioversion / defibrillation and cardiac resynchronization therapy. Results Observed progress was the miniaturization of device, increased longevity, coupled with efficient pacing functions, multisite pacing modes, leadless pacing and also a better recognition of supraventricular or ventricular tachycardia’s in order to deliver appropriate therapy. Subcutaneous implant, new modes of stimulation (leadless implant or ultrasound lead), quadripolar lead and new sensor or new algorithm for the hemodynamic management are introduced and briefly described. Each times, the main result occurring during the two past years are underlined and repositioned from the history, remaining limitations are also addressed. Conclusion Some important technological improvements were described. Nevertheless, news trends for the future are also considered in a specific session such as the remote follow-up of the patient or the treatment of heart failure by neuromodulation. PMID:25123732

  13. 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.

  14. 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

  15. 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.

  16. Pacing the right ventricular outflow tract septum: time to embrace the future.

    Science.gov (United States)

    Hillock, Richard J; Mond, Harry G

    2012-01-01

    Transvenous pacing has revolutionized the management of patients with potentially life-threatening bradycardias and at its most basic level ensures rate support to maintain cardiac output. However, we have known for at least a decade that pacing from the right ventricle (RV) apex can induce left ventricle (LV) dysfunction, atrial fibrillation, heart failure, and maybe an increased mortality. Although pacemaker manufacturers have developed successful pacing algorithms designed to minimize unnecessary ventricular pacing, it cannot be avoided in a substantial proportion of pacemaker-dependent patients. Just as there is undoubted evidence that RV apical pacing is injurious, there is emerging evidence that pacing from the RV septum is associated with a shorter duration of activation, improved haemodynamics, and less LV remodelling. The move from traditional RV apical pacing to RV septal pacing requires a change in mindset for many practitioners. The anatomical landmarks and electrocardiograph features of RV septal pacing are well described and easily recognized. While active fixation is required to place the lead on the septum, shaped stylets are now available to assist the implanter. In addition, concerns about the stability and longevity of steroid-eluting active fixation leads have proven to be unfounded. We therefore encourage all implanters to adopt RV septal pacing to minimize the potential of harm to their patients. PMID:21846639

  17. 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.

  18. 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. PMID:16245675

  19. 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.

  20. The influence of collective behaviour on pacing in endurance competitions

    Directory of Open Access Journals (Sweden)

    Andrew eRenfree

    2015-12-01

    Full Text Available A number of theoretical models have been proposed to explain pacing strategies in individual competitive endurance events. These have typically related to internal regulatory processes informing the making of decisions relating to muscular work rate. Despite a substantial body of research investigating the influence of collective group dynamics on individual behaviours in various animal species, this issue has not been comprehensively studied in individual athletic events. This is surprising given that athletes directly compete in close proximity to one another, and that collective behaviour has also been observed in other human environments. Whilst reasons for adopting collective behaviour are not fully understood, it is thought to result from individual agents following simple local rules resulting in seemingly complex large systems acting to confer some biological advantage to the collective as a whole. Although such collective behaviours may generally be beneficial, endurance events are complicated by the fact that increasing levels of physiological disruption as activity progresses may compromise the ability of individuals to continue to interact with other group members. This could result in early fatigue and relative underperformance due to suboptimal utilisation of physiological resources by some athletes. Alternatively, engagement with a collective behaviour may benefit all due to a reduction in the complexity of decisions to be made and a subsequent reduction in cognitive loading and mental fatigue. This paper seeks evidence for collective behaviour in previously published analyses of pacing behaviour and proposes mechanisms through which it could potentially be either beneficial, or detrimental to individual performance.

  1. 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.

  2. 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.

  3. Two unsung heroes of closed-chest cardiac pacing: Green and McWilliam.

    Science.gov (United States)

    Geddes, L A

    1994-07-01

    In the latter half of the last century, cardiorespiratory arrest was not uncommon due to the anesthetic used (chloroform). Animal studies showed that the heart could be paced. One physician (Green) resuscitated 5 of 7 cardiac arrest patients with single stimuli applied to body surface electrodes. Another (McWilliam) issued a proposal for adoption of closed-chest pacing and provided information on the procedure. The following historical footnote describes these pioneering events in the history of cardiac pacing. PMID:7937239

  4. 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.

  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. Biventricular MR volumetric analysis and MR flow quantification in the ascending aorta and pulmonary trunk for quantification of valvular regurgitation; Biventrikulaere MR-Volumetrie und MR-Flussmessungen in Aorta ascendens und Truncus pulmonalis zur Quantifizierung von Klappeninsuffizienzen

    Energy Technology Data Exchange (ETDEWEB)

    Rominger, M.B. [Marburg Univ. (Germany). Abt. Strahlendiagnostik; Kluge, A.; Bachmann, G.F. [Diagnostische Radiologie, Kerckhoff-Klinik GmbH, Bad Nauheim (Germany)

    2004-03-01

    Purpose: To test the value of biventricular volumetric analysis and the combination of biventricular volumetric analysis with flow quantification in the ascending aorta (Ao) and pulmonary trunk (Pu) for quantification of regurgitation volume and cardiac function in valvular regurgitation (VR) according to location and presence of single or multivalvular disease. Materials and Methods: In 106 patients, the stroke volumes were assessed by measuring the biventricular volumes and the forward-stroke volumes in the great and small circulation by measuring the flow in the Ao and Pu. Valve regurgitation volumes and quotients were calculated for single and multivalvular disease and correlated with semiquantitative 2D-echocardiography (grade I-IV). For the assessment of the cardiac function in VR, the volumetric parameters of ejection fraction and end-diastolic (EDV) and end-systolic (ESV) volumes were determined. Results: The detection rate was 49% for left ventricular (LV) VR and 42% for right ventricular (RV) VR. Low LV VR and RV VR usually could not be detected quantitatively, with the detection rate improving with echocardiographically higher insufficiency grades. Quantitative MRI could detect a higher grade solitary aortic valve insufficiency ({>=}2) in 11 of 12 patients and higher grade mitral valve insufficiency in 4 of 10 patients. A significant increase in RV and LV ventricular EDV and ESV was seen more often with increased MR regurgitation volumes. Aortic stenosis did not interfere with flow measurements in the Ao. Conclusions: Biventricular volumetry combined with flow measurements in Ao and Pu is a robust, applicable and simple method to assess higher grade regurgitation volumes and the cardiac function in single and multivalvular regurgitation at different locations. It is an important application for the diagnosis of VR by MRI. [German] Ziel: Untersuchung der Wertigkeit der biventrikulaeren Volumetrie und der Kombination von biventrikulaerer Volumetrie und

  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. 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...... change (geographic shifts of isotherms over time) and the shift in seasonal timing of temperatures. Both measures are higher in the ocean than on land at some latitudes, despite slower ocean warming. These indices give a complex mosaic of predicted range shifts and phenology changes that deviate from...... simple poleward migration and earlier springs or later falls. They also emphasize potential conservation concerns, because areas of high marine biodiversity often have greater velocities of climate change and seasonal shifts....

  9. 1974 Arizona P.A.C.E. participation.

    Science.gov (United States)

    Zabezensky, F

    1976-12-01

    Members of the Arizona State Society for Medical Technology were contacted to ascertain their knowledge of the P.A.C.E. program as well as to obtain release of the transcripts for those who participated during 1974. Observations regarding reported credits were noted. The Analysis of Variance test with Scheffe comparison was utilized to determine if any characteristic accounted for the difference in total continuing education hours reported. It was concluded that residence location, marital status, sex, age, degree level, length of membership in ASMT, years experience, employment extent, place of employment, and number of beds at place of employment had no significant effect on the total hours reported. A significant difference in total hours reported was noted for those individuals who reported either CEU or college credits. A significant difference was also noted in the total hours reported with respect to job description. PMID:998653

  10. Seasonal Pacing - Match Importance Affects Activity in Professional Soccer

    Science.gov (United States)

    Link, Daniel; de Lorenzo, Michael F.

    2016-01-01

    This research explores the influence of match importance on player activity in professional soccer. Therefore, we used an observational approach and analyzed 1,211 matches of German Bundesliga and 2nd Bundesliga. The importance measurement employed is based on post season consequences of teams involved in a match. This means, if a match result could potentially influence the final rank, and this rank would lead to different consequences for a team, such as qualification for Champions League opposed to qualification for Europe League, then this match is classified as important; otherwise not. Activity was quantified by TOTAL DISTANCE COVERED, SPRINTS, FAST RUNS, DUELS, FOULS and ATTEMPTS. Running parameters were recorded using a semi-automatic optical tracking system, while technical variables were collected by professional data loggers. Based on our importance classification, low important matches occurred at the beginning of round 29. A two-way ANOVA indicates significantly increased FAST RUNS (+4%, d = 0.3), DUELS (+16%, d = 1.0) and FOULS (+36%, d = 1.2) in important matches compared to low important ones. For FAST RUNS and FOULS, this effect only exists in Bundesliga. A comparison of the two leagues show that TOTAL DISTANCE COVERED (+3%, d = 0.9), SPRINTS (+25%, d = 1.4) and FAST RUNS (+15%, d = 1.4) are higher compared to 2nd Bundesliga, whilst FOULS is less in Bundesliga (-7%, d = 0.3). No difference in player activity was found between matches at the beginning of a season (round 1–6) and at the end of a season (round 29–34). We conclude that match importance influences player activity in German professional soccer. The most reasonable explanation is a conscious or unconscious pacing strategy, motivated by preserving abilities or preventing injury. Since this tendency mainly exists in Bundesliga, this may suggest that more skilled players show a higher awareness for the need of pacing. PMID:27281051

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

    Science.gov (United States)

    Munoz, Iker; Seiler, Stephen; Alcocer, Alberto; Carr, Natasha; Esteve-Lanao, Jonathan

    2015-01-01

    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. PMID:26448854

  12. 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.

  13. Seasonal Pacing - Match Importance Affects Activity in Professional Soccer.

    Science.gov (United States)

    Link, Daniel; de Lorenzo, Michael F

    2016-01-01

    This research explores the influence of match importance on player activity in professional soccer. Therefore, we used an observational approach and analyzed 1,211 matches of German Bundesliga and 2nd Bundesliga. The importance measurement employed is based on post season consequences of teams involved in a match. This means, if a match result could potentially influence the final rank, and this rank would lead to different consequences for a team, such as qualification for Champions League opposed to qualification for Europe League, then this match is classified as important; otherwise not. Activity was quantified by TOTAL DISTANCE COVERED, SPRINTS, FAST RUNS, DUELS, FOULS and ATTEMPTS. Running parameters were recorded using a semi-automatic optical tracking system, while technical variables were collected by professional data loggers. Based on our importance classification, low important matches occurred at the beginning of round 29. A two-way ANOVA indicates significantly increased FAST RUNS (+4%, d = 0.3), DUELS (+16%, d = 1.0) and FOULS (+36%, d = 1.2) in important matches compared to low important ones. For FAST RUNS and FOULS, this effect only exists in Bundesliga. A comparison of the two leagues show that TOTAL DISTANCE COVERED (+3%, d = 0.9), SPRINTS (+25%, d = 1.4) and FAST RUNS (+15%, d = 1.4) are higher compared to 2nd Bundesliga, whilst FOULS is less in Bundesliga (-7%, d = 0.3). No difference in player activity was found between matches at the beginning of a season (round 1-6) and at the end of a season (round 29-34). We conclude that match importance influences player activity in German professional soccer. The most reasonable explanation is a conscious or unconscious pacing strategy, motivated by preserving abilities or preventing injury. Since this tendency mainly exists in Bundesliga, this may suggest that more skilled players show a higher awareness for the need of pacing. PMID:27281051

  14. 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.

  15. 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

  16. 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

  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. Mechanical circulatory assist devices: a primer for critical care and emergency physicians.

    Science.gov (United States)

    Sen, Ayan; Larson, Joel S; Kashani, Kianoush B; Libricz, Stacy L; Patel, Bhavesh M; Guru, Pramod K; Alwardt, Cory M; Pajaro, Octavio; Farmer, J Christopher

    2016-01-01

    Mechanical circulatory assist devices are now commonly used in the treatment of severe heart failure as bridges to cardiac transplant, as destination therapy for patients who are not transplant candidates, and as bridges to recovery and "decision-making". These devices, which can be used to support the left or right ventricles or both, restore circulation to the tissues, thereby improving organ function. Left ventricular assist devices (LVADs) are the most common support devices. To care for patients with these devices, health care providers in emergency departments (EDs) and intensive care units (ICUs) need to understand the physiology of the devices, the vocabulary of mechanical support, the types of complications patients may have, diagnostic techniques, and decision-making regarding treatment. Patients with LVADs who come to the ED or are admitted to the ICU usually have nonspecific clinical symptoms, most commonly shortness of breath, hypotension, anemia, chest pain, syncope, hemoptysis, gastrointestinal bleeding, jaundice, fever, oliguria and hematuria, altered mental status, headache, seizure, and back pain. Other patients are seen for cardiac arrest, psychiatric issues, sequelae of noncardiac surgery, and trauma. Although most patients have LVADs, some may have biventricular support devices or total artificial hearts. Involving a team of cardiac surgeons, perfusion experts, and heart-failure physicians, as well as ED and ICU physicians and nurses, is critical for managing treatment for these patients and for successful outcomes. This review is designed for critical care providers who may be the first to see these patients in the ED or ICU. PMID:27342573

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. Observation of blood B-type natriuretic peptide level changes in different periods and different cardiac pacing modes

    Institute of Scientific and Technical Information of China (English)

    WANG Ru-xing; LI Xiao-rong; JIANG Wen-ping; LIU Zhi-hua; YANG Xiang-jun; XIAO Chun-hui; SHAO Li-zheng; ZHU Jian-qiu

    2005-01-01

    @@ In recent years, the indications of cardiac pacing have extended continuously with the rapid development of pacing technique. Pacemaker treatment has not only limited in arrhythmias of bradycardia and the number of pacemaker treatment has increased year by year.

  7. [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.

  8. 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 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.

  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. Ventilation patterns mimicking COPD in patients with diaphragmatic pacing for Ondine's curse

    International Nuclear Information System (INIS)

    Ventilation was studied with 133Xe in 18 patients with central hypoventilation (Ondine's Curse) in whom diaphragmatic pacers were implanted. Three distinct patterns emerged: Type I, improvement in ventilation on the paced side (11 of 18 patients); Type II, improvement on both the paced and unpaced side (4 of 18); and Type III, no improvement (3 of 18). With the pacer off, many of these patients have patterns that mimic chronic obstructive pulmonary disease and that revert to normal with pacing. This retention, clearly reversible, cannot reflect permanent airways or airspace disease

  11. Assessment of Ventricular Dissynchrony in Right Ventricular Single Chamber Pacing using Echocardiografic Parameters

    Directory of Open Access Journals (Sweden)

    Vita I

    2014-04-01

    Full Text Available Background: Right ventricular apical pacing has been used since the early years of pace-makers, despite the fact that it determined nonphysiological ventricular depolarization. As medical technologies developed, septal lead implantation became feasible, in order to outrun the above mentioned inconveniences. The question whether the apical or septal lead position is better still gives rise to a lot of controversies. Different echocardiographic parameters are currently used to assess the impact of specific sites of stimulation on ventricular function. The aim of the study was to determine which of the followed synchronicity parameters varied significantly during apical stimulation, compared to septal stimulation in patients requiring single chamber pacing.

  12. 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.

  13. 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.

  14. 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...

  15. 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

  16. 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

  17. The effect of shared temporal cognitions and Pacing styles on intragroup conflict in portuguese healthcare teams

    OpenAIRE

    Queimado, Alexandra Coelho de Meireles de Oliveira

    2015-01-01

    Master in Human Resources Management This study aimed to evaluate the impact of two specific dimensions of time-related matters (shared temporal cognitions and pacing styles), as a cognitive contextual factor, on different types of team conflict. We hypothesized that the relationship between shared temporal cognitions and the different types of conflict is moderated by pacing styles. A total of 30 teams (245 individuals) participated in this study. All teams were part of different Portugue...

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

    OpenAIRE

    Peckel, Mathieu; Pozzo, Thierry; Bigand, Emmanuel

    2014-01-01

    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 th...

  19. PACE - A test bed for the dynamics and control of flexible multibody systems

    Science.gov (United States)

    Kwak, M. K.; Schlaegel, W. T.; Das, A.

    1993-04-01

    The Phillips Laboratory at Edwards AFB has constructed a test bed for the validation and comparison of modeling and control theories for the dynamics and control of flexible multibody systems. This project is called the Planar Articulating Controls Experiment (PACE). This paper presents the experimental apparatus for PACE and the equations of motion are derived by using the Hamilton principle and the assumed mode method. Control techniques for the slewing control and vibration suppression are also discussed.

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

    OpenAIRE

    Mathieu ePeckel; Thierry ePozzo; Emmanuel eBigand

    2014-01-01

    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 th...

  1. Study of Access and Quality of Care in For-Profit PACE

    OpenAIRE

    David Jones; Nancy Duda; Bob Schmitz; Sandi Nelson; Chelsea Swete; Alex Bryce; Jared Coopersmith; Karen CyBulski

    2013-01-01

    This report summarizes a study to address quality of and access to care for participants of for-profit Programs of All-Inclusive Care for the Elderly (PACE) organizations. The PACE model allows people who otherwise need a nursing home-level of care to remain in the community by providing health care and related support services, such as social supports, meals and chore services, and transportation.

  2. 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

  3. 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. PMID:26959957

  4. 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.

  5. Colony pace: a life-history trait affecting social insect epidemiology.

    Science.gov (United States)

    Buechel, Séverine Denise; Schmid-Hempel, Paul

    2016-01-13

    Among colonies of social insects, the worker turnover rate (colony 'pace') typically shows considerable variation. This has epidemiological consequences for parasites, because in 'fast-paced' colonies, with short-lived workers, the time of parasite residence in a given host will be reduced, and further transmission may thus get less likely. Here, we test this idea and ask whether pace is a life-history strategy against infectious parasites. We infected bumblebees (Bombus terrestris) with the infectious gut parasite Crithidia bombi, and experimentally manipulated birth and death rates to mimic slow and fast pace. We found that fewer workers and, importantly, fewer last-generation workers that are responsible for rearing sexuals were infected in colonies with faster pace. This translates into increased fitness in fast-paced colonies, as daughter queens exposed to fewer infected workers in the nest are less likely to become infected themselves, and have a higher chance of founding their own colonies in the next year. High worker turnover rate can thus act as a strategy of defence against a spreading infection in social insect colonies. PMID:26763696

  6. Single trial prediction of self-paced reaching directions from EEG signals

    Directory of Open Access Journals (Sweden)

    Eileen Yi Lee Lew

    2014-08-01

    Full Text Available Early detection of movement intention could possibly minimize the delays in the activation of neuroprosthetic devices. As yet, single trial analysis using non-invasive approaches for understanding such movement preparation remains a challenging task. We studied the feasibility of predicting movement directions in self-paced upper limb center-out reaching tasks, i.e., spontaneous movements executed without an external cue that can better reflect natural motor behavior in humans. We reported results of non-invasive electroencephalography (EEG recorded from mild stroke patients and able-bodied participants. Previous studies have shown that low frequency EEG oscillations are modulated by the intent to move and therefore, can be decoded prior to the movement execution. Motivated by these results, we investigated whether slow cortical potentials (SCPs preceding movement onset can be used to classify reaching directions and evaluated the performance using 5-fold cross-validation. For able-bodied subjects, we obtained an average decoding accuracy of 76% (chance level of 25% at 62.5ms before onset using the amplitude of on-going SCPs with above chance level performances between 875ms to 437.5ms prior to onset. The decoding accuracy for the stroke patients was on average 47% with their paretic arms. Comparison of the decoding accuracy across different frequency ranges (i.e., SCPs, delta, theta, alpha and gamma yielded the best accuracy using SCPs filtered between 0.1 to 1 Hz. Across all the subjects, including stroke subjects, the best selected features were obtained mostly from the fronto-parietal regions, hence consistent with previous neurophysiological studies on arm reaching tasks. In summary, we concluded that SCPs allow the possibility of single trial decoding of reaching directions at least 312.5ms before onset of reach.

  7. 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.

  8. 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.

  9. Concentration device

    DEFF Research Database (Denmark)

    2013-01-01

    A concentration device (2) for filter filtration concentration of particles (4) from a volume of a fluid (6). The concentration device (2) comprises a filter (8) configured to filter particles (4) of a predefined size in the volume of the fluid (6). The concentration device (2) comprises...

  10. 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

  11. 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.

  12. Exercise performance in young patients with complete atrioventricular block: the relevance of synchronous atrioventricular pacing.

    Science.gov (United States)

    Gonzalez Corcia, M Cecilia; Remy, Lorraine Saint; Marchandise, Sebastien; Moniotte, Stephane

    2016-08-01

    At present, there are many pacing strategies for young patients with complete atrioventricular block. The most frequent policy is to attempt placing a dual-chamber system when possible; however, there is a group of patients that is functioning with a non-synchronous ventricular pacing, raising the question of the ideal timing to upgrade their systems. We investigated the exercise performance of a group of children and young adults with complete atrioventricular block and dual-chamber pacemakers in both single- and dual-chamber pacing modalities. A total of 15 patients performed maximal exercise stress testing after programming the VVIR or DDD modes with 2 hours of interval in a double-blind study protocol. Compared with VVIR pacing, DDD pacing resulted in increase in the peak VO2, longer test duration, major increase in the heart rate achieved during peak exercise, decreased systemic non-invasive arterial blood pressure measured at maximal exercise, higher maximal workload, prolongation of the anaerobic threshold timing, and better self-rated performance perception in all the patients. Synchronous atrioventricular pacing contributes to an increase in both the exercise performance and the performance perception in 100% of the patients. This difference contributes to create a sense of "fitness" with repercussions in the overall health, self-esteem, and life quality, as well as encourages youngster to practice sports. Our experience tends to favour upgrading patients' systems to dual-chamber systems before reaching the adolescent years, even if the centre policy is to prolong as long as possible the epicardial site in order to avoid long years of right ventricular pacing. PMID:26796814

  13. 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.

  14. 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.

  15. Influence of filling on left ventricular diastolic pressure-volume curve during pacing ischemia in dogs.

    Science.gov (United States)

    Shintani, H; Glantz, S A

    1994-04-01

    The reversible upward shift of the diastolic pressure-volume curve that occurs during pacing-induced ischemia has not been fully explained by increases in passive chamber stiffness or reductions in relaxation rate. We measured the fully relaxed pressure-volume relation defined by both filling and nonfilling beats and the isovolumic relaxation time constant in nonfilling beats before and during demand ischemia using our in situ left ventricular volume clamping technique in 10 dogs. Pacing-induced ischemia shifted the diastolic pressure-volume curves in filling beats upward compared with the end-diastolic pressure-volume relation of the normally perfused heart. In contrast, the end-diastolic points for nonfilling beats during pacing-induced ischemia fell on the fully relaxed pressure-volume relation defined by the normally perfused heart. Left ventricular filling per se was necessary for the upward shift of the diastolic pressure-volume curve observed during pacing-induced ischemia. We speculate that active force developed during diastole induced by stretch activation or, perhaps, length-dependent changes in calcium sensitivity of the myofilaments in the ischemic myocardium due to stretch of the myocardium during rapid diastolic filling may contribute to the upward shift of the diastolic pressure-volume curve observed during pacing-induced ischemia. PMID:8184915

  16. Aliskiren protecting atrial structural remodeling from rapid atrial pacing in a canine model.

    Science.gov (United States)

    Zhao, Zhiqiang; Chen, Yan; Li, Weimin; Wang, Xinghua; Li, Jian; Yang, Wansong; Cheng, Lijun; Liu, Tong; Liu, Enzhao; Li, Guangping

    2016-08-01

    Atrial fibrillation (AF) contributing to the increasing mortality risk is the most common disease in clinical practice. Owing to the side effects and relative inefficacy of current antiarrhythmic drugs, some research focuses on renin-angiotensin-aldosterone system (RAS) for finding out the new treatment of AF. The purpose of this study is to confirm whether aliskiren as a proximal inhibitor of renin, which completely inhibits RAS, has beneficial effects on atrial structural remodeling in AF. In this study, rapid atrial pacing was induced at 500 beats per minute for 2 weeks in a canine model. A different dose of aliskiren was given orally for 2 weeks before rapid atrial pacing. HE staining and Masson's staining were used for analysis of myocardial fibrosis. TGF-β1, signal pathways, and pro-inflammatory cytokines were shown for the mechanism of structural remodeling after the treatment of aliskiren. Serious atrial fibrosis was induced by rapid atrial pacing, followed by the elevated TGF-β1, upregulated MEK and ERK1/2, and increased inflammatory factors. Aliskiren could apparently improve myocardial fibrosis by reducing the expression of TGF-β1, inhibiting MEK and ERK1/2 signal pathways, and decreasing IL-18 and TLR4 in both serum and atrial tissue. In conclusion, aliskiren could prevent atrial structural remodeling from rapid atrial pacing for 2 weeks. Aliskiren may play a potential beneficial role in the treatment of AF induced by rapid atrial pacing. PMID:27118660

  17. 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. PMID:25647691

  18. 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.

  19. Microfluidic Device

    Science.gov (United States)

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

    2016-01-01

    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.

  20. The effects of presentation pace and modality on learning a multimedia science lesson

    Science.gov (United States)

    Chung, Wen-Hung

    Working memory is a system that consists of multiple components. The visuospatial sketchpad is the main entrance for visual and spatial information, whereas acoustic and verbal information is processed in the phonological loop. The central executive works as a coordinator of information from these two subsystems. Numerous studies have shown that working memory has a very limited capacity. Based on these characteristics of working memory, theories such as cognitive load theory and the cognitive theory of multimedia learning provide multimedia design principles. One of these principles is that when verbal information accompanying pictures is presented in audio mode instead of visually, learning can be more effective than if both text and pictures are presented visually. This is called the modality effect. However, some studies have found that the modality effect does not occur in some situations. In most experiments examining the modality effect, the multimedia is presented as system-paced. If learners are able to repeat listening as many times as they need, the superiority of spoken text over visual text seems lessened. One aim of this study was to examine the modality effect in a learner-controlled condition. This study also used the one-word-at-a-time technique to investigate whether the modality effect would still occur if both reading and listening rates were equal. There were 182 college students recruited for this study. Participants were randomly assigned to seven groups: a self-paced listening group, a self-paced reading group, a self text-block reading group, a general-paced listening group, a general-paced reading group, a fast-paced listening group, and a fast-paced reading group. The experimental material was a cardiovascular multimedia module. A three-by-two between-subjects design was used to test the main effect. Results showed that modality effect was still present but not between the self-paced listening group and the self text-block reading group

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

    OpenAIRE

    Nadia Baiesi; Gianluca Gabrielli; Elda Guerra; Rossella Ropa

    2014-01-01

    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 in...

  2. Dual-Chamber Pacing for Cardiac Arrhythmias: Controversies in Cloning the Conduction System

    OpenAIRE

    Parsonnet, Victor; Bernstein, Alan D.; Norman, John C.

    1984-01-01

    From the outset, the art and science of cardiac pacing has been beset with a variety of problems. With the passage of time and concentrated effort in the interrelated sciences, many have been solved. We no longer are concerned with premature battery failure or leaking pulse-generator capsules, but now focus on an entirely new set of issues that beg for resolution. Foremost among these is the true role of dual-chamber pacing in the treatment of slow and fast cardiac arrhythmias of a multitude ...

  3. 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.

  4. 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

  5. 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. __________________________________________________

  6. 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

  7. 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…

  8. Respiratory muscle pacing with chronically implanted intramuscular Permaloc electrodes: A feasibility study

    Directory of Open Access Journals (Sweden)

    James S. Walter, PhD

    2011-02-01

    Full Text Available We tested the feasibility of stimulating upper-intercostal and abdominal muscles plus the diaphragm by using chronically implanted intramuscular electrodes. During two survival surgeries with six dogs, intramuscular electrodes were implanted bilaterally in the three respiratory muscles. Standard stimulation of the diaphragm was conducted. The dorsolateral and ventrolateral abdominal wall areas were stimulated with a 25 mA current. The second to fourth intercostal spaces were stimulated to elicit the largest tidal volume associated with the least coactivation of the serratus and latissimus muscles. Lone diaphragm and upper-intercostal muscle pacing produced inhaled tidal volumes (mean +/- standard error of the mean of 293 +/- 36 mL and 59 +/- 17 mL, respectively. Lone abdominal muscle pacing produced an exhaled volume of 55 +/- 17 mL. Combined pacing of diaphragm and intercostal muscles increased the inhaled volume to 389 +/- 39 mL. The addition of abdominal pacing following the combined stimulation of diaphragm and intercostals increased the exhaled volume to 472 +/- 54 mL. During autopsy, dislodgement of the electrodes overlying the ribs was a concern and probably resulted from loose animal jackets. Chronic intramuscular Permaloc electrodes can be implanted in several respiratory muscles and increase tidal volumes more than diaphragm stimulation alone.

  9. Language switch costs in sentence comprehension depend on language dominance: Evidence from self-paced reading

    NARCIS (Netherlands)

    Bultena, S.S.; Dijkstra, A.F.J.; Hell, J.G. van

    2015-01-01

    This study investigated two prominent issues in the comprehension of language switches. First, how does language switching direction affect switch costs in sentence context? Second, are switch costs modulated by L2 proficiency and cross-linguistic activation? We conducted a self-paced reading task i

  10. Modeling Pacing Behavior and Test Speededness Using Latent Growth Curve Models

    Science.gov (United States)

    Kahraman, Nilufer; Cuddy, Monica M.; Clauser, Brian E.

    2013-01-01

    This research explores the usefulness of latent growth curve modeling in the study of pacing behavior and test speededness. Examinee response times from a high-stakes, computerized examination, collected before and after the examination was subjected to a timing change, were analyzed using a series of latent growth curve models to detect…

  11. 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.

  12. 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

  13. 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

  14. 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.

  15. 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

  16. 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.

  17. 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...

  18. The Effects of TV Program Pacing on the Behavior of Preschool Children

    Science.gov (United States)

    Anderson, Daniel R.; And Others

    1977-01-01

    Assertions that television (Sesame Street in particular) produces hyperactivity, impulsivity, disorganized behavior, and shortened attention spans in pre-school children were investigated. No evidence was found that rapid television pacing has an immediate negative impact on behavior of preschool children. (Author/STS)

  19. 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.

  20. Managing after-work stress: paced breathing while watching video content (abstract)

    NARCIS (Netherlands)

    Tijs, T.J.W.; Weda, J.; Weffers-Albu, M.A.; Hoogenstraaten, W.

    2011-01-01

    Objectives. After a hard day’s work, we need to recover from work stress. Two frequently reported activities to relieve stress are television (TV) watching and paced breathing exercises. We investigated the potential of combining these techniques. Method. Two explorativeexperiments were conducted.

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

    DEFF Research Database (Denmark)

    Nielsen, R.O.; Nohr, Ellen Aagaard; Rasmussen, Sten;

    2013-01-01

    Many researchers acknowledge the importance of "training errors" as the main cause of running-related injuries. The purpose of this clinical commentary is to present a theoretical framework for the assumption that some running-related injuries among rear-foot strikers develop due to rapidly...... changing running volume, while others develop due to rapidly changing running pace....

  2. Cross-sectional Association between Walking Pace and Sleep-disordered Breathing.

    Science.gov (United States)

    Suri, S V; Batterham, A M; Ells, L; Danjoux, G; Atkinson, G

    2015-10-01

    Sleep-disordered breathing is an important comorbidity for several diseases, including stroke. Initial screening tools comprise simple yes/no questions about known risk factors for sleep-disordered breathing, e.g., obesity, sex. But walking speed has not been investigated in this context. We examined the cross-sectional association between walking pace and sleep-disordered breathing in the population-level Multi-Ethnic Study of Atherosclerosis. A sample of 2912 men and 3213 women (46-87 years) reported perceived walking pace outside their homes. A walking pacesleep apnoea (3.5%), self-reported apnoeas (8.4%), loud snoring (20.5%), daytime tiredness (22.2%) and slow-walking pace (26.9%). The 95% CI risk differences (multivariable-adjusted) for slow vs. faster walking pace were; sleep apnoea (0.4-2.5%), self-reported apnoeas (0.1-3.8%), loud snoring (1.2-8.3%), and daytime tiredness (3.0-7.8%). Risk differences were similar between sexes. The multivariable-adjusted risk ratio indicated that slower walkers had 1.5 (95% CI: 1.0 to 2.1) times the risk of sleep apnoea vs. faster walkers. In conclusion, a slower walking speed was associated with a greater prevalence of sleep-disordered breathing, independently from other common screening factors. Therefore, a simple walking speed question may help consolidate screening for this disorder. PMID:26090878

  3. 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...

  4. Managing the Finances. PACE Revised. Level 2. Unit 16. Research & Development Series No. 240BB16.

    Science.gov (United States)

    Ashmore, M. Catherine; Pritz, Sandra G.

    This unit on managing the finances of a small business, the 16th in a series of 18 modules, is on the second level of the revised PACE (Program for Acquiring Competence in Entrepreneurship) comprehensive curriculum. Geared to advanced secondary and beginning postsecondary or adult students, the modules provide an opportunity to learn about and try…

  5. A Procedure to Establish Self-Pacing Behaviors in Academically Deficient First Year Students.

    Science.gov (United States)

    Opdahl, Chris A.

    Research investigating the performance of students enrolled in courses taught by a Personalized System of Instruction (PSI) has tended to support the claim that PSI is a superior teaching method. The present research study isolated the self-pacing aspect of PSI courses and attempted to teach 13 academically deficient first year college students…

  6. Team Performance and Risk-Adjusted Health Outcomes in the Program of All-Inclusive Care for the Elderly (PACE)

    Science.gov (United States)

    Mukamel, Dana B.; Temkin-Greener, Helena; Delavan, Rachel; Peterson, Derick R.; Gross, Diane; Kunitz, Stephen; Williams, T. Franklin

    2006-01-01

    Purpose: The Program of All-Inclusive Care for the Elderly (PACE) is a community-based program providing primary, acute, and long-term care to frail elderly individuals. A central component of the PACE model is the interdisciplinary care team, which includes both professionals and non-professionals. The purpose of this study was to examine the…

  7. Remote Sensing Ocean Color Observations from NASA's PACE Mission: Applications and Societal Benefits

    Science.gov (United States)

    Tzortziou, M.; Omar, A. H.; Turner, W.

    2014-12-01

    The PACE (Pre- Aerosol, Clouds and ocean Ecosystems) mission is a strategic Climate Continuity mission, included in NASA's 2010 plan: "Responding to the Challenge of Climate and Environmental Change: NASA's Plan for a Climate-Centric Architecture for Earth Observations and Applications from Space". On a polar orbit, PACE will make climate-quality global measurements that are essential for understanding ocean biology, biogeochemistry and ecology, and determining how the ocean's role in global biogeochemical cycling and ocean ecology both affects and is affected by climate change. With advanced global remote sensing capabilities that include high spectral-resolution imaging, extended spectral coverage to the UV and SWIR, improved spatial resolution in inland, estuarine and coastal waters, enhanced atmospheric correction and higher signal-to-noise, PACE is expected to provide high quality observations that, over the long-term, will contribute to an extended time series of records on inland, coastal, and ocean ecosystems—all of which have substantial value beyond basic science and research. The combination of climate-quality, global atmospheric and oceanic observations provided by the PACE mission will provide a unique capability to help understand changes that affect our ecosystem services, implement science-based management strategies of coastal, marine and inland aquatic resources, and support assessments, policy analyses, and design approaches to plan adaptation and responses to impacts of climate change. Here we discuss the PACE applications program, the new capabilities afforded by this future satellite mission, and how they could potentially advance applications across a range of areas, including Oceans, Climate, Water Resources, Ecological Forecasting, Disasters, Human Health and Air Quality.

  8. 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.

  9. A Case Exemplar for National Policy Leadership: Expanding Program of All-Inclusive Care for the Elderly (PACE).

    Science.gov (United States)

    Cortes, Tara A; Sullivan-Marx, Eileen M

    2016-03-01

    In November 2015, President Obama signed the Program of All-Inclusive Care for the Elderly (PACE) Innovation Act, which expands a proven model of care to serve high-cost and high-need populations. Specifically, the law provides the Centers for Medicare & Medicaid Services with the authority to waive Medicaid requirements that could not be waived without additional statutory authority. Those requirements include the age of the beneficiary to be served and nursing home eligibility as a condition for PACE enrollment. The law also allows providers and other entities who are not current PACE providers the opportunity to become PACE providers and serve a predominately dually eligible population that has high needs and high cost through a coordinated, integrated model. The current article describes the impact of nursing on the legislation and policy that has shaped the evolution of the PACE program for more than 40 years. [Journal of Gerontological Nursing, 42(3), 9-14.]. PMID:26934968

  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. 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

  13. 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

  14. 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.

  15. Stratification devices

    DEFF Research Database (Denmark)

    Andersen, Elsa; Furbo, Simon

    2008-01-01

    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...

  16. Brief time-based activity pacing instruction as a singular behavioral intervention was not effective in participants with symptomatic osteoarthritis.

    Science.gov (United States)

    Murphy, Susan L; Kratz, Anna L; Kidwell, Kelley; Lyden, Angela K; Geisser, Michael E; Williams, David A

    2016-07-01

    Osteoarthritis (OA) of the lower extremities is a prevalent cause of disability in which symptoms interfere with mobility and activity participation. Behavioral self-management for OA symptomatology is commonly recommended; but these interventions are underutilized, unstandardized in application, and at times, unavailable in the context of clinical care. For people with chronic pain, rehabilitation professionals may select to apply activity pacing instruction as one behavioral strategy to manage symptoms. Activity pacing is widely used in combination with other pharmacological and behavioral interventions but has not been studied as a singular behavioral intervention for people with OA. The purpose of this study was to evaluate the effectiveness of an occupational therapist-delivered, time-based activity pacing program for treatment of pain, fatigue, and physical function in people with symptomatic knee or hip OA. A 3-arm randomized controlled trial was conducted in which 193 people were randomized into tailored activity pacing, general activity pacing, or usual care arms. Assessments were done at 10 weeks and 6 months after baseline. Using linear mixed models, Western Ontario and McMaster Universities Osteoarthritis Index pain scores changed over time, decreasing the most in the general and usual care groups; only the usual care group had decreased pain over 6 months. The tailored and general activity pacing groups reported higher frequency of pacing behaviors than the usual care group at 10 weeks, but pacing was not sustained at 6 months. This trial does not support the use of time-based pacing as a singular behavioral strategy for people with knee or hip OA. PMID:26963847

  17. 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.

  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. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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 sex-based differences in tactics adopted and design training programmes accordingly. PMID:26736042

  5. BET 2: Diagnosing acute myocardial infarction in the presence of ventricular pacing: can Sgarbossa criteria help?

    Science.gov (United States)

    Jothieswaran, Arunan; Body, Richard

    2016-09-01

    The Sgarbossa criteria can be used to identify patients who have acute myocardial infarction (AMI) in the presence of left bundle branch block, which obscures the usual changes associated with ST elevation myocardial infarction. Patients with ventricular paced rhythm have ECG changes with similar morphology to left bundle branch block. A short-cut systematic review was carried out to establish whether the Sgarbossa criteria can accurately diagnose AMI in the presence of ventricular paced rhythm. Three studies were directly relevant to the question. The author, date and country of publication, patient group studied, study type, relevant outcomes, results and study weaknesses of these papers are tabulated. The clinical bottom line is that. PMID:27539980

  6. DiPALS: Diaphragm Pacing in patients with Amyotrophic Lateral Sclerosis - a randomised controlled trial.

    Science.gov (United States)

    McDermott, Christopher J; Bradburn, Mike J; Maguire, Chin; Cooper, Cindy L; Baird, Wendy O; Baxter, Susan K; Cohen, Judith; Cantrill, Hannah; Dixon, Simon; Ackroyd, Roger; Baudouin, Simon; Bentley, Andrew; Berrisford, Richard; Bianchi, Stephen; Bourke, Stephen C; Darlison, Roy; Ealing, John; Elliott, Mark; Fitzgerald, Patrick; Galloway, Simon; Hamdalla, Hisham; Hanemann, C Oliver; Hughes, Philip; Imam, Ibrahim; Karat, Dayalan; Leek, Roger; Maynard, Nick; Orrell, Richard W; Sarela, Abeezar; Stradling, John; Talbot, Kevin; Taylor, Lyn; Turner, Martin; Simonds, Anita K; Williams, Tim; Wedzicha, Wisia; Young, Carolyn; Shaw, Pamela J

    2016-01-01

    BACKGROUND Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease resulting in death, usually from respiratory failure, within 2-3 years of symptom onset. Non-invasive ventilation (NIV) is a treatment that when given to patients in respiratory failure leads to improved survival and quality of life. Diaphragm pacing (DP), using the NeuRx/4(®) diaphragm pacing system (DPS)™ (Synapse Biomedical, Oberlin, OH, USA), is a new technique that may offer additional or alternative benefits to patients with ALS who are in respiratory failure. OBJECTIVE The Diaphragm Pacing in patients with Amyotrophic Lateral Sclerosis (DiPALS) trial evaluated the effect of DP on survival over the study duration in patients with ALS with respiratory failure. DESIGN The DiPALS trial was a multicentre, parallel-group, open-label, randomised controlled trial incorporating health economic analyses and a qualitative longitudinal substudy. PARTICIPANTS Eligible participants had a diagnosis of ALS (ALS laboratory-supported probable, clinically probable or clinically definite according to the World Federation of Neurology revised El Escorial criteria), had been stabilised on riluzole for 30 days, were aged ≥ 18 years and were in respiratory failure. We planned to recruit 108 patients from seven UK-based specialist ALS or respiratory centres. Allocation was performed using 1 : 1 non-deterministic minimisation. INTERVENTIONS Participants were randomised to either standard care (NIV alone) or standard care (NIV) plus DP using the NeuRX/4 DPS. MAIN OUTCOME MEASURES The primary outcome was overall survival, defined as the time from randomisation to death from any cause. Secondary outcomes were patient quality of life [assessed by European Quality of Life-5 Dimensions, three levels (EQ-5D-3L), Short Form questionnaire-36 items and Sleep Apnoea Quality of Life Index questionnaire]; carer quality of life (EQ-5D-3L and Caregiver Burden Inventory); cost-utility analysis and health

  7. PACE: Pattern Accurate Computationally Efficient Bootstrapping for Timely Discovery of Cyber-Security Concepts

    OpenAIRE

    McNeil, Nikki; Bridges, Robert A.; Iannacone, Michael D.; Czejdo, Bogdan; Perez, Nicolas; Goodall, John R.

    2013-01-01

    Public disclosure of important security information, such as knowledge of vulnerabilities or exploits, often occurs in blogs, tweets, mailing lists, and other online sources months before proper classification into structured databases. In order to facilitate timely discovery of such knowledge, we propose a novel semi-supervised learning algorithm, PACE, for identifying and classifying relevant entities in text sources. The main contribution of this paper is an enhancement of the traditional ...

  8. Managing after-work stress: paced breathing while watching video content (abstract)

    OpenAIRE

    Tijs, T.J.W.; Weda, J.; Weffers-Albu, M.A.; Hoogenstraaten, W.

    2011-01-01

    Objectives. After a hard day’s work, we need to recover from work stress. Two frequently reported activities to relieve stress are television (TV) watching and paced breathing exercises. We investigated the potential of combining these techniques. Method. Two explorativeexperiments were conducted. In both experiments, stress was measured through physiological monitoring (heart rate, blood pressure, skinconductance, peripheral temperature, and respiration) and the Stress Arousal Checklist [3]....

  9. 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...

  10. Explaining the Slow Pace of Energy Technological Innovation: Why Market Conditions Matter

    OpenAIRE

    Jin, Wei; Zhang, ZhongXiang

    2014-01-01

    As a useful complement to numerous innovation policy studies from a normative perspective, this paper provides a positive framework to analyze the basic economic mechanism of energy technological innovation and explains its slow pace of technological progress. We find that the capital-intensiveness of energy technology is an inhibiting factor to catalyze market size effect and slows innovations and diffusions of energy technology in the market. We also show that the substantial homogeneity of...

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

    Science.gov (United States)

    Peckel, Mathieu; Pozzo, Thierry; Bigand, Emmanuel

    2014-01-01

    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 20 s before a 2 s 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 the 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 motoric

  12. 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

  13. RETARDATION OF PACE OF LIFE AND RESOURCES TRANSFORMATION – SOME IMPLICATIONS OF CITIZENS

    OpenAIRE

    Joanna Kostecka

    2014-01-01

    The article attempts to explain the term retardation of pace of life and transforming natural resources, highlights the complexity of the concept and presents proposals for action for its dissemination. Retardation of resources transformation is an important tool for the implementation of the new approach on those environmental resources and services that are left. Environmental education that supports the implementation of retardation should use active methods of education and should be inte...

  14. Hemodynamic Surveillance of Ventricular Pacing Effectiveness with the Transvalvular Impedance Sensor

    OpenAIRE

    Valeria Calvi; Giovanni Pizzimenti; Marco Lisi; Giuseppe Doria; Ludovico Vasquez; Francesco Lisi; Salvatore Felis; Donatella Tempio; Alfredo Virgilio; Alberto Barbetta; Franco Di Gregorio

    2014-01-01

    The Transvalvular Impedance (TVI) is derived between atrial and ventricular pacing electrodes. A sharp TVI increase in systole is an ejection marker, allowing the hemodynamic surveillance of ventricular stimulation effectiveness in pacemaker patients. At routine follow-up checks, the ventricular threshold test was managed by the stimulator with the supervision of a physician, who monitored the surface ECG. When the energy scan resulted in capture loss, the TVI system must detect the failure a...

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

    OpenAIRE

    Ray Antonelli; Viera, Anthony J.

    2015-01-01

    Introduction 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. Methods 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 + ...

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

    Science.gov (United States)

    Buhmann, Jeska; Desmet, Frank; Moens, Bart; Van Dyck, Edith; Leman, Marc

    2016-01-01

    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. PMID:27167064

  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. Migration of a retained temporary epicardial pacing wire into an abdominal aortic aneurysm.

    Science.gov (United States)

    Mukaihara, Kosuke; Yotsumoto, Goichi; Matsumoto, Kazuhisa; Imoto, Yutaka

    2015-07-01

    A 69-year old male was referred to our hospital for the treatment of coronary artery disease. Preoperative computed tomography (CT) revealed an abdominal aortic aneurysm (AAA) and a giant tumour of the left kidney. He underwent off-pump coronary artery bypass grafting (OPCAB) prior to aneurysmectomy and nephrectomy. Temporary epicardial pacing wires (TEPWs) were placed on the right atrium and right ventricle. The bipolar ventricular wire was removed and the unipolar atrial wire was cut flush with the skin surface on postoperative day 5. CT 7 days after the OPCAB procedure revealed a retained TEPW sutured to the right atrial wall. One month later, the patient underwent a repair of the AAA and left nephrectomy. We found that a TEPW had migrated inside the AAA intraoperatively. The retained TEPW was thus no longer observed on postoperative CT. Migration of the atrial pacing wire through the aortic lumen was suspected, although the detailed mechanism is unknown. This is the first reported case of a migrated temporary pacing wire into the aorta under noninfectious conditions. PMID:25173602

  19. The distribution of pace adopted by cyclists during a cross-country mountain bike World Championships.

    Science.gov (United States)

    Abbiss, Chris R; Ross, Megan L R; Garvican, Laura A; Ross, Neil; Pottgiesser, Torben; Gregory, John; Martin, David T

    2013-01-01

    The purpose of this study was to examine the distribution of pace self-selected by cyclists of varying ability, biological age and sex performing in a mountain bike World Championship event. Data were collected on cyclists performing in the Elite Male (ELITEmale; n = 75), Elite Female (ELITEfemale; n = 50), Under 23 Male (U23male; n = 62), Under 23 Female (U23female; n = 34), Junior Male (JNRmale; n = 71) and Junior Female (JNRfemale; n = 30) categories of the 2009 UCI Cross-Country Mountain Bike World Championships. Split times were recorded for the top, middle and bottom 20% of all finishers of each category. Timing splits were positioned to separate the course into technical and non-technical, uphill, downhill and rolling/flat sections. Compared with bottom performers, top performers in all male categories (ELITEmale, U23male, JNRmale) maintained a more even pace over the event as evidenced by a significantly lower standard deviation and range in average lap speed. Top performers, males, and ELITEmale athletes spent a lower percentage of overall race time on technical uphill sections of the course, compared with middle and bottom placed finishers, females, and JNRmale athletes, respectively. Better male performers adopt a more even distribution of pace throughout cross-country mountain events. Performance of lower placed finishers, females and JNRmale athletes may be improved by enhancing technical uphill cycling ability. PMID:23521618

  20. The influence of performance level, age and gender on pacing strategy during a 100-km ultramarathon.

    Science.gov (United States)

    Renfree, Andrew; Crivoi do Carmo, Everton; Martin, Louise

    2016-01-01

    The aim of this study is to analyse the influence of performance level, age and gender on pacing during a 100-km ultramarathon. Results of a 100-km race incorporating the World Masters Championships were used to identify differences in relative speeds in each 10-km segment between participants finishing in the first, second, third and fourth quartiles of overall positions (Groups 1, 2, 3 and 4, respectively). Similar analyses were performed between the top and bottom 50% of finishers in each age category, as well as within male and female categories. Pacing varied between athletes achieving different absolute performance levels. Group 1 ran at significantly lower relative speeds than all other groups in the first three 10-km segments (all P bottom' competitors in the early stages, but higher relative speeds in the later stages. Females showed lower relative starting speeds and higher finishing speeds than males. 'Top' and 'bottom' finishing males displayed differing strategies, but this was not the case within females. Although pacing remained consistent across age categories, it differed with level of performance within each, possibly suggesting strategies are anchored on direct competitors. Strategy differs between genders and differs depending on performance level achieved in males but not females. PMID:26034882

  1. The distribution of pace adopted by cyclists during a cross-country mountain bike World Championships.

    Science.gov (United States)

    Abbiss, Chris R; Ross, Megan L R; Garvican, Laura A; Ross, Neil; Pottgiesser, Torben; Gregory, John; Martin, David T

    2013-01-01

    The purpose of this study was to examine the distribution of pace self-selected by cyclists of varying ability, biological age and sex performing in a mountain bike World Championship event. Data were collected on cyclists performing in the Elite Male (ELITEmale; n = 75), Elite Female (ELITEfemale; n = 50), Under 23 Male (U23male; n = 62), Under 23 Female (U23female; n = 34), Junior Male (JNRmale; n = 71) and Junior Female (JNRfemale; n = 30) categories of the 2009 UCI Cross-Country Mountain Bike World Championships. Split times were recorded for the top, middle and bottom 20% of all finishers of each category. Timing splits were positioned to separate the course into technical and non-technical, uphill, downhill and rolling/flat sections. Compared with bottom performers, top performers in all male categories (ELITEmale, U23male, JNRmale) maintained a more even pace over the event as evidenced by a significantly lower standard deviation and range in average lap speed. Top performers, males, and ELITEmale athletes spent a lower percentage of overall race time on technical uphill sections of the course, compared with middle and bottom placed finishers, females, and JNRmale athletes, respectively. Better male performers adopt a more even distribution of pace throughout cross-country mountain events. Performance of lower placed finishers, females and JNRmale athletes may be improved by enhancing technical uphill cycling ability.

  2. Diaphragm pacing in infants and children. A life-table analysis of implanted components.

    Science.gov (United States)

    Weese-Mayer, D E; Morrow, A S; Brouillette, R T; Ilbawi, M N; Hunt, C E

    1989-04-01

    Since 1976, we have implanted bilateral phrenic nerve electrodes for diaphragm pacing in 33 infants and children. This population includes 23 patients with congenital central hypoventilation syndrome (CHS), two with late onset CHS and hypothalamic dysfunction, three with hypoventilation associated with Chiari II malformation and myelomeningocele, and five with quadriplegia. Our experience, totalling 192 system-years and 96 patient-years of pacing, has enabled us to document the nature and frequency of problems related to the implanted components of the Avery Laboratories (S-232-1) pacemaker system when used in a pediatric population. By life table analysis, the mean time to need for replacement of any implanted component was 56.3 months. A total of 26 failures requiring component replacement occurred and were classified into four types: (1) receiver failure (15 cases), (2) electrode wire or wire insulation breakage (six cases), (3) infection requiring diaphragm pacer system removal (three cases), and (4) mechanical nerve injury (two cases). We conclude that the present diaphragm pacing system is effective but not without risk of biomedical component failure. The present system might be substantially improved by (1) a modified receiver design with a hermetic seal to prevent fluid penetration, (2) stronger, better insulated electrode wires, and (3) modifications of surgical technique and electrode type to prevent phrenic nerve damage. PMID:2784647

  3. Efficacy of paced breathing for insomnia: enhances vagal activity and improves sleep quality.

    Science.gov (United States)

    Tsai, H J; Kuo, Terry B J; Lee, Guo-She; Yang, Cheryl C H

    2015-03-01

    Fourteen self-reported insomniacs (SRI) and 14 good sleepers (GS) had their cardiac neuronal activity assessed by heart rate variability (HRV) under controlled respiration at a slow frequency rate of 0.1 Hz, and a forced rate of 0.2 Hz during daytime rest. Nighttime sleep was measured by polysomnography. The SRI showed depressed high frequency power of HRV compared to the GS. An increased total power of HRV was observed among the SRI during slow, paced breathing compared with spontaneous breathing and 0.2 Hz. Sleep onset latency, number of awakenings, and awakening time during sleep were decreased and sleep efficiency was increased if SRI practiced slow, paced breathing exercises for 20 min before going to sleep. Our results indicate that there is autonomic dysfunction among insomniacs, especially in relation to vagal activity; however, this decreased vagal activity can be facilitated by practicing slow, paced breathing, thereby improving sleep quality. PMID:25234581

  4. A positron emission tomography study of self-paced finger movements at different frequencies

    International Nuclear Information System (INIS)

    Regional cerebral blood flow was measured in six right-handed volunteers using positron emission tomography during tasks involving repetitive self-paced finger tapping at five different frequencies. The contralateral primary sensorimotor cortex, the pre-supplementary motor area and the cingulate motor area showed significant activation during self-paced finger tapping tasks, compared with the resting state. A positive correlation between the regional cerebral blood flow and the movement frequency was found only in the primary sensorimotor cortex. In the pre-supplementary motor area and the cingulate motor area, however, activity increased when the subject employed movement frequencies faster or slower than his own pace. The same tendency was noted with respect to the relative variability of the inter-tapping interval.The results therefore indicate that the activity of the pre-supplementary motor area and the cingulate motor area may well be related to the increased difficulty in motor control rather than to the execution of the movement itself. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

  5. "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.

  6. 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

  7. Keeping Pace

    Science.gov (United States)

    Scully, Maura King

    2012-01-01

    So many communications channels, so little time and, usually, so few resources is the situation today's communicators face. Educational institutions, places steeped in history and tradition, "have been slow to react." But while the communications channels have changed, the fundamentals of communication haven't. Maintaining perspective about…

  8. 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

  9. 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

  10. 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.

  11. The size and structure of arm movement variability decreased with work pace in a standardised repetitive precision task.

    Science.gov (United States)

    Srinivasan, Divya; Samani, Afshin; Mathiassen, Svend Erik; Madeleine, Pascal

    2015-01-01

    Increased movement variability has been suggested to reduce the risk of developing musculoskeletal disorders caused by repetitive work. This study investigated the effects of work pace on arm movement variability in a standardised repetitive pipetting task performed by 35 healthy women. During pipetting at slow and fast paces differing by 15%, movements of arm, hand and pipette were tracked in 3D, and used to derive shoulder and elbow joint angles. The size of cycle-to-cycle motor variability was quantified using standard deviations of several kinematics properties, while the structure of variability was quantified using indices of sample entropy and recurrence quantification analysis. When pace increased, both the size and structure of motor variability in the shoulder and elbow decreased. These results suggest that motor variability drops when repetitive movements are performed at increased paces, which may in the long run lead to undesirable outcomes such as muscle fatigue or overuse. PMID:25216404

  12. 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.

  13. 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.

  14. High frequency pacing of edge localized modes by injection of lithium granules in DIII-D H-mode discharges

    Science.gov (United States)

    Bortolon, A.; Maingi, R.; Mansfield, D. K.; Nagy, A.; Roquemore, A. L.; Baylor, L. R.; Commaux, N.; Jackson, G. L.; Gilson, E. P.; Lunsford, R.; Parks, P. B.; Chrystal, C.; Grierson, B. A.; Groebner, R.; Haskey, S. R.; Makowski, M. J.; Lasnier, C. J.; Nazikian, R.; Osborne, T.; Shiraki, D.; Van Zeeland, M. A.

    2016-05-01

    A newly installed Lithium Granule Injector (LGI) was used to pace edge localized modes (ELM) in DIII-D. ELM pacing efficiency was studied injecting lithium granules of nominal diameter 0.3–0.9 mm, speed of 50–120 m s‑1 and average injection rates up to 100 Hz for 0.9 mm granules and up to 700 Hz for 0.3 mm granules. The efficiency of ELM triggering was found to depend strongly on size of the injected granules, with triggering efficiency close to 100% obtained with 0.9 mm diameter granules, lower with smaller sizes, and weakly depending on granule velocity. Robust ELM pacing was demonstrated in ITER-like plasmas for the entire shot length, at ELM frequencies 3–5 times larger than the ‘natural’ ELM frequency observed in reference discharges. Within the range of ELM frequencies obtained, the peak ELM heat flux at the outer strike point was reduced with increasing pacing frequency. The peak heat flux reduction at the inner strike point appears to saturate at high pacing frequency. Lithium was found in the plasma core, with a concurrent reduction of metallic impurities and carbon. Overall, high frequency ELM pacing using the lithium granule injection appears to be compatible with both H-mode energy confinement and attractive H-mode pedestal characteristics, but further assessment is needed to determine whether the projected heat flux reduction required for ITER can be met.

  15. 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.

  16. Thermonuclear device

    International Nuclear Information System (INIS)

    Purpose: To absorb fabrication errors in radial toroidal coils and a spacer and completely fill the gap between them by the provision of an expansion device between the coils and the supporting spacer by injecting fillers of a predetermined composition. Constitution: An expansion device comprising an expansion plate, packings inserted into grooves formed in the outer circumference of the expansion plate and a recessed pressure receiving plate is inserted between the wall surface of radial toroidal coils and a spacer for maintaining the gap between the toroidal coils. Then, filler comprising polyester resin and glass beads incorporated therein is injected from an injection aperture of the recessed pressure receiving plate having an exhaust aperture at the upper part. The filler is solidified and enables the fabrication error in the coils and the spacer to be absorbed. Since the gap between the coils and the spacer is completely filled, the tumbling force of the coils can surely be transmitted by way of the spacer to upper and lower racks. (Moriyama, K.)

  17. 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.

  18. PLASMA DEVICE

    Science.gov (United States)

    Baker, W.R.

    1961-08-22

    A device is described for establishing and maintaining a high-energy, rotational plasma for use as a fast discharge capacitor. A disc-shaped, current- conducting plasma is formed in an axinl magnetic field and a crossed electric field, thereby creating rotational kinetic enengy in the plasma. Such energy stored in the rotation of the plasma disc is substantial and is convertible tc electrical energy by generator action in an output line electrically coupled to the plasma volume. Means are then provided for discharging the electrical energy into an external circuit coupled to the output line to produce a very large pulse having an extremely rapid rise time in the waveform thereof. (AE C)

  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. PMID:22409173

  20. Implementation of Optimal Pacing Scheme in Xinjiang's Oil and Gas Pipeline Leak Monitoring Network

    Directory of Open Access Journals (Sweden)

    Peng Zhou

    2011-01-01

    Full Text Available Flow against Xingjian’s oil and gas pipeline leakage and the pipe network sudden burst pipe to pipeline leakage flow for the application objects, Optimal pacing scheme is designed in pipeline leak monitoring. Based on the property of Markov chain for network data, a new estimator with particle filter is proposed for congestion control in this paper. In the context of a reconfigurable transport protocol framework, we propose a QoS aware Transport Protocol (QSTP, specifically designed to operate over QoS (Quality of Service enabled networks with bandwidth guarantee. The proposed scheme can adaptively adjust the network rate in real -time, so that it can efficiently avoid the traffic congestion. It proposes a Link Layer Adaptive Pacing (LLAP scheme that adaptively controls the offered load into the network. The algorithms actively probe the underlay network and compute virtual multicast trees by dynamically selecting the least loaded available paths on the overlay network. The low computational complexity of the proposed algorithms leads to time and resource saving, as shown through extensive experiments. The Simulation results show that Network congestion avoidance strategy with optimal pacing scheme can efficiently improve the bandwidth utilization, Transmission Control Protocol (TCP friendliness and reduce the packet drop rate in Pipeline Flux Leak Monitoring networks. Flood flow identified by the National Centre for testing: discussion group first proposed the use of particle filters to solve the new model can estimate the network congestion control problem. The results are sound, stable performance, efficiency 29%. Adaptive algorithm using the model proposed optimization scheme, to achieve accurate positioning of the leak, 0.05% measurement accuracy, positioning accuracy is improved 32%, more than 17% of the nodes in a more reliable routing path, reliable routing path of increase of 40%.

  1. 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.

  2. 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

  3. Prevention of Atrioventricular Block During Radiofrequency Ablation by Pace Mapping of Koch’s Triangle

    Directory of Open Access Journals (Sweden)

    Hossein Vakili

    2008-08-01

    Full Text Available Background: Complete atrioventricular block (AV block is a serious complication of slow pathway ablation therapy in the treatment of atrioventricular nodal re-entrant tachycardia (AVNRT. The present study was aimed at determining whether the electroanatomical pace mapping of Koch’s triangle could significantly improve the safety, efficiency, and efficacy of selective slow pathway ablation in the treatment of AVNRT. Methods: A total number of 124 patients were selected to be studied consecutively for radiofrequency (RF ablation therapy in the treatment of AVNRT. The subjects were divided into two groups: one, designated Group 1, to serve as the control group, and the other, designated Group 2, to serve as the study group. Conventional fluoroscopic slow pathway ablation was performed on the Group 1 subjects (n=66, with the Group 2 subjects receiving slow pathway ablation therapy guided by pace mapping of Koch’s triangle. The slow pathway ablation in Group 2 (n=58 was performed with regard to the pace mapping data obtained on the basis of the St-H interval in the anteroseptal (AS, midseptal (MS, and posteroseptal (PS regions of Koch’s triangle. The anterograde fast pathway (AFP location was determined based on the shortest St-H interval obtained by stimulating the anteroseptal (AS, midseptal (MS, and posteroseptal (PS aspects of Koch’s triangle. Results: In the Group 2 subjects, AFP location was AS in 50 (86.2% of the cases, MS in 7 (12% of the cases, and PS in 1 case (1.7%. One patient with posteroseptal AFP was administered retrograde fast pathway ablation therapy. One patient in the control group (Group 1, representing 1.5% of the group, developed persistent AV block in the course of the treatment, but none of the subjects in the study group (Group 2 developed any complications. Conclusion: It was concluded that an atypical fast pathway location is conducive to the development of atrioventricular block in the ablation therapy in AVNRT

  4. Nechui’s Aesthetic Code: Repetition, Pacing, and Non-Purposeful Narration

    OpenAIRE

    Tarnawsky, Maxim

    2014-01-01

    Traditional and modernist comments on the mechanics of Nechui’s prose style are largely critical, focusing on what are assumed to be errors or infelicities in writing. This article examines these presumed errors and proceeds to focus on three central quali­ties of Nechui’s writing: repetition, pacing, and the absence of purposeful construction. The intention here is not to make judgments about the strengths and weaknesses of his writing but rather to point out its essential features. Two cent...

  5. Lunar exosphere observed by MAP-PACE onboard SELENE(KAGUYA)

    Science.gov (United States)

    Yokota, Shoichiro; Saito, Yoshifumi; Tanaka, Takaaki; Asamura, Kazushi; Nishino, Masaki N.; Tsunakawa, Hideo

    The Moon has no global intrinsic magnetic field and only has a very thin atmosphere called surface-bounded exosphere. The lunar exosphere has been observed by ground-based technique on many occasions since its discovery. The alkali components such as Na or K have especially been observed to understand the generation process and the transport mechanisms. One of the loss processes of the exospheric particles is photoionization and ion-pickup process. The ionized exospheric particles are transported by the surrounding electric field. Therefore, ion measurements made from lunar orbit is another way to study the lunar exosphere as well as in-teractions between the solar wind and the planetary surface. Japanese lunar orbiter SELENE (KAGUYA), which was launched on September 14, 2007, has the in-situ plasma analyzers named MAP-PACE (MAgnetic field and Plasma experiment -Plasma energy Angle and Com-position Experiment) in order to investigate the plasma environment at 100km altitude around the Moon. PACE consists of two sensors for low energy electron measurements and two sensors for low energy ion measurements. One of the ion spectrometer, MAP-PACE IMA, which has a mass analyzer detected low-energy ions from the Moon at an altitude of 100 km. IMA has identified ion species of He+, C+, O+, Na+, K+ and Ar+. The measurements of ions from the Moon enable us to continuously monitor the lunar exosphere. The 1.5-year observation of SELENE(KAGUYA) shows that the ions from the Moon have been detected both when the Moon is exposed to the solar wind and when it is in the Earth's lobe region. The observation suggests that the solar wind is not the dominant source mechanism for the lunar exospheres. Moreover, the MAP-PACE observation shows the dependence on the solar zenith angle and the dawn-dusk asymmetry of the lunar exosphere. We report the features of the lunar exospheres obtained by the SELENE(KAGUYA) observation and discuss the source mechanism of the lunar exosphere.

  6. 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

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. Deaf Readers’ Response to Syntactic Complexity: Evidence from Self-Paced Reading

    Science.gov (United States)

    Traxler, Matthew J.; Corina, David P.; Morford, Jill P.; Hafer, Sarah; Hoversten, Liv J.

    2013-01-01

    This study was designed to determine the feasibility of using self-paced reading methods to study deaf readers and to assess how deaf readers respond to two syntactic manipulations. Three groups of participants read the test sentences: deaf readers, hearing monolingual English readers, and hearing bilingual readers whose second language was English. In Experiment 1, participants read sentences containing subject relative or object relative clauses. The test sentences contained semantic information that influences on-line processing outcomes (Traxler et al., 2002; 2005). All of the participant groups had greater difficulty processing sentences containing object relative clauses. This difficulty was reduced when helpful semantic cues were present. In Experiment 2, participants read active voice and passive voice sentences. The sentences were processed similarly by all three groups. Comprehension accuracy was higher in hearing readers than in deaf readers. Within deaf readers, native signers read the sentences faster and comprehended them to a higher degree than did non-native signers. These results indicate that self-paced reading is a useful method for studying sentence interpretation among deaf readers. PMID:23868696

  12. 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

    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...... cycles vs. 64±14 bursts/100 cardiac cycles, pDDD-60 to 16.7±6 mL/min/kg during DDD-80, and p-NT-proBNP remained unchanged. The QoL score indicated that DDD-60 was better tolerated. CONCLUSION: In CRT patients with non...

  13. 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.

  14. 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.

  15. The Australian history of cardiac pacing: memories from a bygone era.

    Science.gov (United States)

    Mond, Harry G; Wickham, Geoffrey G; Sloman, J Graeme

    2012-06-01

    Although Dr Albert Hyman in New York is believed to have built the first cardiac pacemaker in 1932, he acknowledges Dr Mark Lidwell in Sydney, Australia as having not only built a pacemaker, but also successfully used it to resuscitate a newborn infant in or before 1929. Fully implantable pacemakers, however, were not possible until 1958, following the development of the silicon transistor. Within three years of that first implant, a pulse generator attached to epicardial leads was implanted at the Royal Melbourne Hospital. About the same time, an engineer in Sydney with intermittent complete heart block who had received epicardial leads and an external pulse generator proposed a simple sensing circuit, leading to the design of the first demand pacing system. By the mid 1960s, physicians were inserting transvenous leads in the right ventricle attached to pulse generators implanted in the anterior abdominal wall. In 1963, an Australian pacemaker company, Telectronics, was founded in Sydney. This innovative company-designed many of the features of transvenous leads and pulse generators we take for granted today. Australia also played a leading role in the design or early evaluation of the lithium power source, lead fixation, steroid elution, automatic anti-tachycardia pacing algorithms and the minute ventilation rate adaptive sensor. This manuscript describes the challenges and frustrations of those pioneers: physicians, surgeons and biomedical engineers. PMID:22033147

  16. Cardiovascular strain impairs prolonged self-paced exercise in the heat.

    Science.gov (United States)

    Périard, Julien D; Cramer, Matthew N; Chapman, Phillip G; Caillaud, Corinne; Thompson, Martin W

    2011-02-01

    It has been proposed that self-paced exercise in the heat is regulated by an anticipatory reduction in work rate based on the rate of heat storage. However, performance may be impaired by the development of hyperthermia and concomitant rise in cardiovascular strain increasing relative exercise intensity. This study evaluated the influence of thermal strain on cardiovascular function and power output during self-paced exercise in the heat. Eight endurance-trained cyclists performed a 40 km simulated time trial in hot (35°C) and thermoneutral conditions (20°C), while power output, mean arterial pressure, heart rate, oxygen uptake and cardiac output were measured. Time trial duration was 64.3 ± 2.8 min (242.1 W) in the hot condition and 59.8 ± 2.6 min (279.4 W) in the thermoneutral condition (P heat was depressed from 20 min onwards compared with exercise in the thermoneutral condition (P temperature reached 39.8 ± 0.3 (hot) and 38.9 ± 0.2°C (thermoneutral; P skin temperature was ~7.5°C higher in the heat, and skin blood flow was significantly elevated (P stroke volume, cardiac output and mean arterial pressure were significantly depressed compared with the thermoneutral condition (P heat. PMID:20851861

  17. 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.

  18. Hemodynamic Surveillance of Ventricular Pacing Effectiveness with the Transvalvular Impedance Sensor

    Directory of Open Access Journals (Sweden)

    Valeria Calvi

    2014-01-01

    Full Text Available The Transvalvular Impedance (TVI is derived between atrial and ventricular pacing electrodes. A sharp TVI increase in systole is an ejection marker, allowing the hemodynamic surveillance of ventricular stimulation effectiveness in pacemaker patients. At routine follow-up checks, the ventricular threshold test was managed by the stimulator with the supervision of a physician, who monitored the surface ECG. When the energy scan resulted in capture loss, the TVI system must detect the failure and increase the output voltage. A TVI signal suitable to this purpose was present in 85% of the tested patients. A total of 230 capture failures, induced in 115 patients in both supine and sitting upright positions, were all promptly recognized by real-time TVI analysis (100% sensitivity. The procedure was never interrupted by the physician, as the automatic energy regulation ensured full patient’s safety. The pulse energy was then set at 4 times the threshold to test the alarm specificity during daily activity (sitting, standing up, and walking. The median prevalence of false alarms was 0.336%. The study shows that TVI-based ejection assessment is a valuable approach to the verification of pacing reliability and the autoregulation of ventricular stimulation energy.

  19. Hemodynamic Surveillance of Ventricular Pacing Effectiveness with the Transvalvular Impedance Sensor.

    Science.gov (United States)

    Calvi, Valeria; Pizzimenti, Giovanni; Lisi, Marco; Doria, Giuseppe; Vasquez, Ludovico; Lisi, Francesco; Felis, Salvatore; Tempio, Donatella; Virgilio, Alfredo; Barbetta, Alberto; Di Gregorio, Franco

    2014-01-01

    The Transvalvular Impedance (TVI) is derived between atrial and ventricular pacing electrodes. A sharp TVI increase in systole is an ejection marker, allowing the hemodynamic surveillance of ventricular stimulation effectiveness in pacemaker patients. At routine follow-up checks, the ventricular threshold test was managed by the stimulator with the supervision of a physician, who monitored the surface ECG. When the energy scan resulted in capture loss, the TVI system must detect the failure and increase the output voltage. A TVI signal suitable to this purpose was present in 85% of the tested patients. A total of 230 capture failures, induced in 115 patients in both supine and sitting upright positions, were all promptly recognized by real-time TVI analysis (100% sensitivity). The procedure was never interrupted by the physician, as the automatic energy regulation ensured full patient's safety. The pulse energy was then set at 4 times the threshold to test the alarm specificity during daily activity (sitting, standing up, and walking). The median prevalence of false alarms was 0.336%. The study shows that TVI-based ejection assessment is a valuable approach to the verification of pacing reliability and the autoregulation of ventricular stimulation energy. PMID:26556408

  20. Observation of ions from the Moon by MAP-PACE IMA onboard SELENE(KAGUYA)

    Science.gov (United States)

    Yokota, Shoichiro; Saito, Yoshifumi; Tanaka, Takaaki; Asamura, Kazushi; Nishino, Masaki; Tsunakawa, Hideo

    2010-05-01

    The Moon has no global intrinsic magnetic field and only has a very thin atmosphere. Ion measurements made from lunar orbit give us the information regarding interactions between the solar wind and the planetary surface. The ion mass spectrometry also provides the surface composition and the source and loss mechanisms of planetary tenuous atmospheres. An ion energy mass spectrometer MAP-PACE IMA onboard a lunar orbiter SELENE(KAGUYA) has detected low-energy ions from the Moon at an altitude of 100 km. IMA has identified ion species of He+, C+, O+, Na+, K+ and Ar+. The measurements of ions from the Moon enable us to continuously monitor the lunar exospheres. The 1.5-year observation of SELENE(KAGUYA) shows that the ions from the Moon have been detected both when the Moon is exposed to the solar wind and when it is in the Earth's lobe region. The observation suggests that the solar wind is not the dominant source mechanism for the lunar exospheres. Moreover, the MAP-PACE IMA shows the dependence on the solar zenith angle and the dawn-dusk asymmetry. We report the features of the lunar exospheres obtained by the SELENE(KAGUYA) observation and discuss the source mechanism of the lunar exospheres.

  1. 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.

  2. Human radiation studies: Remembering the early years. Oral history of physiologist Nello Pace, Ph.D., August 16, 1994

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-06-01

    Dr. Nello Pace was interviewed by representatives of the US DOE Office of Human Radiation Experiments (OHRE). Dr. Pace was selected fro the interview because of the positions he held with the US Navy, at the University of California, Berkeley, and as Director of the White Mountain Research Station near Bishop, California. Following a brief biographical sketch, Dr. Pace related his remembrances concerning tritium injections experiments in animals and humans during World War II, the development of Medical Physics Degree Programs at UC Berkeley, conducting the first radiation survey at Nagasaki after the bomb, and the establishment of a research laboratory at White Mountain. He also offers reflections on Shields Warren and comments on the public`s attitudes towards radiation both then and now.

  3. Human radiation studies: Remembering the early years. Oral history of physiologist Nello Pace, Ph.D., August 16, 1994

    International Nuclear Information System (INIS)

    Dr. Nello Pace was interviewed by representatives of the US DOE Office of Human Radiation Experiments (OHRE). Dr. Pace was selected fro the interview because of the positions he held with the US Navy, at the University of California, Berkeley, and as Director of the White Mountain Research Station near Bishop, California. Following a brief biographical sketch, Dr. Pace related his remembrances concerning tritium injections experiments in animals and humans during World War II, the development of Medical Physics Degree Programs at UC Berkeley, conducting the first radiation survey at Nagasaki after the bomb, and the establishment of a research laboratory at White Mountain. He also offers reflections on Shields Warren and comments on the public's attitudes towards radiation both then and now

  4. 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.

  5. 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.

  6. 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.

  7. Comparison of the Event-Related Desynchronization during Self-Paced Movement and when playing a Nintendo Wii Game

    OpenAIRE

    Nikola Šobajić; Andrej Savić

    2011-01-01

    We compared pre-movement event-related desynchronization (ERD) of μ rhythm over the primary motor cortex using surface electrodes in a group of five healthy subjects during self-paced wrist movement and the wrist movement when playing a Nintendo Wii. We present a method that uses ERD to detect the onset of movement in single-trial electroencephalographic (EEG) data. This algorithm produced a mean detection accuracy of 83% for the self-paced movement and 75% for the Wii-included sessions, with...

  8. 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.

  9. Large-scale ocean circulation-cloud interactions reduce the pace of transient climate change

    Science.gov (United States)

    Trossman, D. S.; Palter, J. B.; Merlis, T. M.; Huang, Y.; Xia, Y.

    2016-04-01

    Changes to the large-scale oceanic circulation are thought to slow the pace of transient climate change due, in part, to their influence on radiative feedbacks. Here we evaluate the interactions between CO2-forced perturbations to the large-scale ocean circulation and the radiative cloud feedback in a climate model. Both the change of the ocean circulation and the radiative cloud feedback strongly influence the magnitude and spatial pattern of surface and ocean warming. Changes in the ocean circulation reduce the amount of transient global warming caused by the radiative cloud feedback by helping to maintain low cloud coverage in the face of global warming. The radiative cloud feedback is key in affecting atmospheric meridional heat transport changes and is the dominant radiative feedback mechanism that responds to ocean circulation change. Uncertainty in the simulated ocean circulation changes due to CO2 forcing may contribute a large share of the spread in the radiative cloud feedback among climate models.

  10. 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. PMID:26989775

  11. 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.

  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. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. Is Rhythm Control with Pulmonary Vein Isolation Superior to Rate Control with AV Nodal Ablation in Patients with Heart Failure?

    Directory of Open Access Journals (Sweden)

    Dhanunjaya Lakkireddy MD, FACC

    2008-12-01

    Full Text Available Pulmonary-vein isolation is increasingly being used to treat atrial fibrillation in patients with heart failure. Is Pulmonary vein isolation better than AV nodal ablation with bi-ventricular pacing in patients with heart failure?

  20. 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

  1. 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

  2. Infrared criminalistic devices

    Science.gov (United States)

    Gibin, Igor S.; Savkov, E. V.; Popov, Pavel G.

    1996-12-01

    We are presenting the devices of near-IR spectral range in this report. The devices may be used in criminalistics, in bank business, in restoration works, etc. the action principle of these devices is describing briefly.

  3. Intrauterine devices (IUD)

    Science.gov (United States)

    ... medlineplus.gov/ency/article/007635.htm Intrauterine devices (IUD) To use the sharing features on this page, please enable JavaScript. An intrauterine device (IUD) is a small plastic T-shaped device used ...

  4. 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 ...

  5. 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

  6. Predictors of right ventricular failure after left ventricular assist device implantation.

    Science.gov (United States)

    Koprivanac, Marijan; Kelava, Marta; Sirić, Franjo; Cruz, Vincent B; Moazami, Nader; Mihaljević, Tomislav

    2014-12-01

    Number of left ventricular assist device (LVAD) implantations increases every year, particularly LVADs for destination therapy (DT). Right ventricular failure (RVF) has been recognized as a serious complication of LVAD implantation. Reported incidence of RVF after LVAD ranges from 6% to 44%, varying mostly due to differences in RVF definition, different types of LVADs, and differences in patient populations included in studies. RVF complicating LVAD implantation is associated with worse postoperative mortality and morbidity including worse end-organ function, longer hospital length of stay, and lower success of bridge to transplant (BTT) therapy. Importance of RVF and its predictors in a setting of LVAD implantation has been recognized early, as evidenced by abundant number of attempts to identify independent risk factors and develop RVF predictor scores with a common purpose to improve patient selection and outcomes by recognizing potential need for biventricular assist device (BiVAD) at the time of LVAD implantation. The aim of this article is to review and summarize current body of knowledge on risk factors and prediction scores of RVF after LVAD implantation. Despite abundance of studies and proposed risk scores for RVF following LVAD, certain common limitations make their implementation and clinical usefulness questionable. Regardless, value of these studies lies in providing information on potential key predictors for RVF that can be taken into account in clinical decision making. Further investigation of current predictors and existing scores as well as new studies involving larger patient populations and more sophisticated statistical prediction models are necessary. Additionally, a short description of our empirical institutional approach to management of RVF following LVAD implantation is provided. PMID:25559829

  7. 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...

  8. Effect of warm-up and precooling on pacing during a 15-km cycling time trial in the heat

    NARCIS (Netherlands)

    Levels, K.; Teunissen, L.P.J.; Haan, de A.; Koning, de J.J.; Os, van B.; Daanen, H.A.M.

    2013-01-01

    PURPOSE:The best way to apply precooling for endurance exercise in the heat is still unclear. Therefore, we analyzed the effect of different preparation regimes on pacing during a 15-km cycling time trial in the heat.METHODS:Ten male subjects completed four 15-km time trials (30°C), preceded by diff

  9. 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.

  10. 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.

  11. 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 be...

  12. 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.

  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. 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-

  15. 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…

  16. 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...

  17. 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...

  18. 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…

  19. 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…

  20. Pacing and decision making in sport and exercise : The roles of perception and action in the regulation of exercise intensity

    NARCIS (Netherlands)

    Smits, Benjamin L. M.; Pepping, Gert-Jan; Hettinga, Florentina J.

    2014-01-01

    In pursuit of optimal performance, athletes and physical exercisers alike have to make decisions about how and when to invest their energy. The process of pacing has been associated with the goal-directed regulation of exercise intensity across an exercise bout. The current review explores divergent

  1. The role of the entry-and-stretch phase at the different paces of race in front crawl swimming.

    Science.gov (United States)

    Samson, Mathias; Monnet, Tony; Bernard, Anthony; Lacouture, Patrick; David, Laurent

    2015-01-01

    The aim of this study was to determine the role played by the entry-and-stretch phase in the coordination of swimming, at the different paces of race. Three national level swimmers (two men and one woman) were recorded, in lateral and bottom views, in three swimming paces: sprint (50 m and 100 m), middle-distance (200 m and 400 m) and long-distance (800 m and 1500 m). Anatomical landmark positions were obtained by manual digitalisation of the videos. Computational fluid dynamics and experimental studies (with a strain gauge balance and particle image velocimetry method) were used to measure and to calculate the external forces applied to the hand and to the forearm and to visualise the flow around the profile. Entry-and-stretch is the phase which varies the most according to the swimming pace. This phase can be decomposed into two sub-phases: one, the extension forward coordinated with the insweep of the opposite arm, and another one, the rotation downward coordinated with the upsweep. Results show that, at the three paces, this phase is not propulsive and could contribute essentially to maintain the horizontal balance of the body. PMID:25654468

  2. Comparison of longevity, paging, and sensing characteristics of steroid-eluting epicardial versus conventional endocardial pacing leads in children

    NARCIS (Netherlands)

    Beaufort-Krol, GCM; Mulder, H; Nagelkerke, D; Waterbolk, TW; Bink-Boelkens, MTE

    1999-01-01

    Objective: Because of either cardiac anatomy or small size, pacing in children often occurs by means of epicardial leads. The disadvantage of epicardial leads is the shorter longevity of these leads compared with endocardial leads. During short-term follow-up, improved stimulation thresholds were fo

  3. 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…

  4. Atrial fibrillation in rats induced by rapid transesophageal atrial pacing during brief episodes of asphyxia: A new in vivo model

    DEFF Research Database (Denmark)

    Haugan, K.; Lam, Henrik Rye; Knudsen, C. B.;

    2004-01-01

    Non-pharmacological in vivo models of atrial fibrillation (AF) have been developed in large animals only. We aimed to develop and characterize a new small animal non-pharmacological in vivo model of AF. AF was induced by transesophageal atrial burst pacing during 35 seconds periods of asphyxia...

  5. Reclaiming Students' Voices: Fourth Graders' Discussion of the Great Migration in a Climate of Paced Curriculum

    Science.gov (United States)

    Hill, K. Dara

    2013-01-01

    In this study, a researcher investigated how teachers can negotiate their practice to engage high-needs students whose life experiences are not reflected in the curriculum, without compromising administrative demands for standardized curriculum and pacing. A fourth-grade teacher in a high-achieving, high-poverty urban primary school in Detroit…

  6. 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...

  7. 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

  8. Pacing strategy in male elite and age group 100 km ultra-marathoners

    Directory of Open Access Journals (Sweden)

    Knechtle B

    2015-03-01

    Full Text Available Beat Knechtle,1,2 Thomas Rosemann,1 Matthias A Zingg,1 Michael Stiefel,1 Christoph A Rüst11Institute of Primary Care, University of Zurich, Zurich, 2Gesundheitszentrum St Gallen, St Gallen, SwitzerlandAbstract: Pacing strategy has been investigated in elite 100 km and elite 161 km (100 mile ultra-marathoners, but not in age group ultra-marathoners. This study investigated changes in running speed over segments in male elite and age group 100 km ultra-marathoners with the assumption that running speed would decrease over segments with increasing age of the athlete. Running speed during segments in male elite and age group finishers for 5-year age groups (ie, 18–24 to 65–69 years in the 100 km Lauf Biel in Switzerland was investigated during the 2000–2009 period. Average running speed over segment time station (TS TS1–TS2 (56.1 km was compared with running speed Start–TS1 (38 km and Start–TS3 (76.7 km and running speed TS2–TS3 was compared with running speed Start–Finish. For the top ten athletes in each edition, running speed decreased from 2000 to 2009 for TS1–TS2 and TS2–TS3 (P<0.0001 but not in TS3–Finish (P>0.05. During TS1–TS2, athletes were running at 98.0%±2.1% of the running speed of Start–TS1. In TS2–TS3, they were running at 94.6%±3.4% of the running speed of TS1–TS2. In TS3–Finish, they were running at 95.5%±3.8% of running speed in TS2–TS3. For age group athletes, running speed decreased in TS1–TS2 and TS2–TS3. In TS3–Finish, running speed remained unchanged with the exception of the age group 40–44 years for which running speed increased. Running speed showed the largest decrease in the age group 18–24 years. To summarize, the top ten athletes in each edition maintained their running speed in the last segment (TS3–Finish although running speed decreased over the first two segments (TS1–TS2 and TS2–TS3. The best pacers were athletes in the age group 40–44 years, who were able to

  9. 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

  10. 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.

  11. 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

  12. Implantable CMOS Biomedical Devices

    Directory of Open Access Journals (Sweden)

    Toshihiko Noda

    2009-11-01

    Full Text Available The results of recent research on our implantable CMOS biomedical devices are reviewed. Topics include retinal prosthesis devices and deep-brain implantation devices for small animals. Fundamental device structures and characteristics as well as in vivo experiments are presented.

  13. Hip supporting device

    DEFF Research Database (Denmark)

    2011-01-01

    The present invention relates to a device for limiting movements in one or more anatomical joints, such as a device for limiting movement in the human hip joint after hip replacement surgery. This is provided by a device for limiting movement in the human hip joint, said device comprising: at least...

  14. 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. PMID:26867696

  15. 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.

  16. A Near-Optimal Scheme for TCP ACK Pacing to Maintain Throughput in Wireless Networks

    CERN Document Server

    Bhutani, Gitanjali

    2009-01-01

    The advent of fourth generation technologies in wireless networks and the rapid growth of 3G have heralded an era that will require researchers to find reliable and easily implement-able solutions to the problem of poor TCP performance in the wireless environment. Since a large part of the Internet is TCP-based, solving this problem will be instrumental in determining if the move from wired to wireless will be seamless or not. This paper proposes a scheme that uses the base station's ability to predict the time at which the link may be going down and to estimate the period for which the mobile would be unreachable due to conditions like fading. By using cross-layer and ACK pacing algorithms, the base station prevents the fixed host from timing out while waiting for ACKs from the mobile. This in turn prevents TCP on the fixed host from bringing down the throughput drastically due to temporary network conditions, caused by mobility or the unreliability of wireless links. Experimental results indicate a reasonab...

  17. 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

  18. 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...

  19. 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.

  20. 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.

  1. 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.

  2. Diaphragmatic pacing stimulation in spinal cord injury: anesthetic and perioperative management

    Directory of Open Access Journals (Sweden)

    Miguel L. Tedde

    2012-11-01

    Full Text Available OBJECTIVE: The standard therapy for patients with high-level spinal cord injury is long-term mechanical ventilation through a tracheostomy. However, in some cases, this approach results in death or disability. The aim of this study is to highlight the anesthetics and perioperative aspects of patients undergoing insertion of a diaphragmatic pacemaker. METHODS: Five patients with quadriplegia following high cervical traumatic spinal cord injury and ventilator-dependent chronic respiratory failure were implanted with a laparoscopic diaphragmatic pacemaker after preoperative assessments of their phrenic nerve function and diaphragm contractility through transcutaneous nerve stimulation. ClinicalTrials.gov: NCT01385384. RESULTS: The diaphragmatic pacemaker placement was successful in all of the patients. Two patients presented with capnothorax during the perioperative period, which resolved without consequences. After six months, three patients achieved continuous use of the diaphragm pacing system, and one patient could be removed from mechanical ventilation for more than 4 hours per day. CONCLUSIONS: The implantation of a diaphragmatic phrenic system is a new and safe technique with potential to improve the quality of life of patients who are dependent on mechanical ventilation because of spinal cord injuries. Appropriate indication and adequate perioperative care are fundamental to achieving better results.

  3. 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. PMID:26132703

  4. 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.

  5. 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.

  6. Mechanisms underlying syntactic comprehension deficits in vascular aphasia: new evidence from self-paced listening.

    Science.gov (United States)

    Caplan, David; Michaud, Jennifer; Hufford, Rebecca

    2015-01-01

    Sixty-one people with aphasia (pwa) and 41 matched controls were tested for the ability to understand sentences that required the ability to process particular syntactic elements and assign particular syntactic structures. Participants paced themselves word-by-word through 20 examples of 11 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. The results were consistent with several models of syntactic comprehension deficits in pwa: resource reduction, slowed lexical and/or syntactic processing, abnormal susceptibility to interference from thematic roles generated non-syntactically. They suggest that a previously unidentified disturbance limiting the duration of parsing and interpretation may lead to these deficits, and that this mechanism may lead to structure-specific deficits in pwa. The results thus point to more than one mechanism underlying syntactic comprehension disorders both across and within pwa. PMID:26165856

  7. Performance on paced serial addition tasks indicates an associative network for calculation.

    Science.gov (United States)

    Hiscock, M; Caroselli, J S; Kimball, L E; Panwar, N

    2001-06-01

    Although paced serial addition (PSA) tasks are considered to be tests of general information-processing capacity, recent work suggests that performance on such tasks is influenced by arithmetic-specific variables. We designed two visual PSA experiments to determine whether the performance of normal adults would support predictions derived from the cognitive psychology of calculation. Experiment 1 showed that mixing familiar (Arabic numeral) and less familiar (Roman numeral) stimulus formats reduced scores below the averaged scores for pure Arabic and Roman lists. The Roman-Arabic order of addends was more difficult than the Arabic-Roman order. Experiment 2, which involved only Arabic numerals as addends, showed that performance could be impaired by constraining the trial-to-trial variability of sums. The results of both experiments confirm the importance of arithmetic-specific variables in PSA and provide support for an associative network model of calculation. In addition, the findings implicate interference from extraneous addends and responses as the performance-limiting factor. PMID:11404809

  8. 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.

  9. 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

  10. 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

  11. 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

  12. 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.

  13. Sixteen failures in a single model of bipolar polyurethane-insulated ventricular pacing lead: a 44-month experience.

    Science.gov (United States)

    Hanson, J S

    1984-05-01

    During a 44-month period, 105 Medtronic model 6972-58 polyurethane-insulated, bipolar ventricular pacing leads were implanted, of which 16 failed clinically at a mean of 20.5 months post-implant. Pacing dysfunction presented as either intermittent or complete loss of sensing and/or capture and, rarely, oversensing . Thirteen of the 16 patients were asymptomatic, and problems were detected in 11 instances during routine telephonic surveillance. At the time of lead replacement, low or widely fluctuating lead resistance values and high current drain were uniformly observed. The single lead capable of total extraction revealed rupture of both internal and external insulation. A brief summary of the currently much-discussed "polyurethane controversy" is presented, and the issue of patient management is discussed. PMID:6204292

  14. Adjunctive anti-tachycardia pacing therapy for patients with acute myocardial infarction during emergency percutaneous coronary intervention

    Institute of Scientific and Technical Information of China (English)

    HAN Ya-ling; LIANG Ming; JING Quan-min; WANG Shou-li; WANG Zu-lu; CHEN Xing-hua

    2005-01-01

    @@ It was reported that more than 95% arrhythmias complicated with acute myocardial infarction (AMI) occurred within the first 24 hours of AMI onset, and emergency percutaneous coronary intervention (PCI) has been worldwide applied to realize reperfusion.1 But how to deal with tachyarrhythmia induced by ischemia and reperfusion around emergency PCI procedure, has become one of the focus during peri-PCI stage. It has been reported that anti-tachycardia pacing (ATP) termination of post AMI tachyarrhythmia by implantation of cardioverter-defibrillator (ICD) or other model of pacemaker had ideal result.2,3 But the studies on the effect of ATP therapy for tachyarrhythmia during emergency PCI procedure were rarely reported. In this study, the effect and the safety of ATP therapy for 115 patients with tachyarrhythmia during emergency PCI procedure by implantation of temporary pacing catheter were reported.

  15. Comparison of the Event-Related Desynchronization during Self-Paced Movement and when playing a Nintendo Wii Game

    Directory of Open Access Journals (Sweden)

    Nikola Šobajić

    2011-06-01

    Full Text Available We compared pre-movement event-related desynchronization (ERD of μ rhythm over the primary motor cortex using surface electrodes in a group of five healthy subjects during self-paced wrist movement and the wrist movement when playing a Nintendo Wii. We present a method that uses ERD to detect the onset of movement in single-trial electroencephalographic (EEG data. This algorithm produced a mean detection accuracy of 83% for the self-paced movement and 75% for the Wii-included sessions, without requiring subject training. This technique can be employed in an EEG-based brain–computer interface due to its high recognition rate and simplicity in computation.

  16. 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

  17. Engaging nursing homes (NHs) in the PACE study:comparing recruitment in observational and intervention research designs

    OpenAIRE

    Collingridge Moore, Danielle

    2016-01-01

    Background: NH residents are often excluded from epidemiological studies, demonstrating a need for representative, internationally comparable research in this area. Data on palliative care provided by NHs is reported to the Care Quality Commission in England, but the quality of care is often locally determined. Aims: To review the challenges encountered in engaging and recruiting NHs across England to the European Commission funded PACE research project; a two part study comprising of a retro...

  18. Therapeutic efficacy of digital music gastric electrical pacing for refractory functional dyspepsia concomitant with non-erosive reflux disease

    OpenAIRE

    Ya-mei RAN; Lin, Ling; Yu-qin HE; Chen, Qiang; Ji, Lei; Xiu-qiong LANG; Huang, Zhi-yong; YANG, MIN

    2015-01-01

    Objective To study the clinical efficacy of digital music gastric electrical pacing for refractory functional dyspepsia concomitant with non-erosive reflux disease, and its effects on mental health and life-quality of the patients. Methods According to the Rome Ⅲ criteria and Montreal consensus in diagnosis of gastroesophageal reflux disease, 50 patients with concomitant refractory functional dyspepsia and non-erosive reflux disease were recruited. The clinical efficacy of digital music gastr...

  19. Properties of PACE-I HgCdTe Detectors in Space - the NICMOS Warm-up Monitoring Program

    OpenAIRE

    Boeker, T.

    2000-01-01

    We summarize the results of a monitoring program which was executed following the cryogen exhaustion of the Near Infrared Camera and Multi-Object Spectrometer (NICMOS) onboard the Hubble Space Telescope. During the subsequent warm-up, detector parameters such as detective quantum efficiency, dark current, bias offsets, and saturation levels have been measured over the temperature range 62K to about 100K. The measurements provide a unique database of the characteristics of PACE-I HgCdTe detect...

  20. 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

  1. Effects of musical tempo on physiological, affective, and perceptual variables and performance of self-selected walking pace.

    Science.gov (United States)

    Almeida, Flávia Angélica Martins; Nunes, Renan Felipe Hartmann; Ferreira, Sandro Dos Santos; Krinski, Kleverton; Elsangedy, Hassan Mohamed; Buzzachera, Cosme Franklin; Alves, Ragami Chaves; Gregorio da Silva, Sergio

    2015-06-01

    [Purpose] This study investigated the effects of musical tempo on physiological, affective, and perceptual responses as well as the performance of self-selected walking pace. [Subjects] The study included 28 adult women between 29 and 51 years old. [Methods] The subjects were divided into three groups: no musical stimulation group (control), and 90 and 140 beats per minute musical tempo groups. Each subject underwent three experimental sessions: involved familiarization with the equipment, an incremental test to exhaustion, and a 30-min walk on a treadmill at a self-selected pace, respectively. During the self-selected walking session, physiological, perceptual, and affective variables were evaluated, and walking performance was evaluated at the end. [Results] There were no significant differences in physiological variables or affective response among groups. However, there were significant differences in perceptual response and walking performance among groups. [Conclusion] Fast music (140 beats per minute) promotes a higher rating of perceived exertion and greater performance in self-selected walking pace without significantly altering physiological variables or affective response. PMID:26180303

  2. 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。

  3. PACE – the first placebo controlled trial of paracetamol for acute low back pain: statistical analysis plan

    Science.gov (United States)

    2013-01-01

    Background Paracetamol (acetaminophen) is recommended in most clinical practice guidelines as the first choice of treatment for low back pain, however there is limited evidence to support this recommendation. The PACE trial is the first placebo controlled trial of paracetamol for acute low back pain. This article describes the statistical analysis plan. Results PACE is a randomized double dummy placebo controlled trial that investigates and compares the effect of paracetamol taken in two regimens for the treatment of low back pain. The protocol has been published. The analysis plan was completed blind to study group and finalized prior to initiation of analyses. All data collected as part of the trial were reviewed, without stratification by group, and classified by baseline characteristics, process of care and trial outcomes. Trial outcomes were classified as primary and secondary outcomes. Appropriate descriptive statistics and statistical testing of between-group differences, where relevant, have been planned and described. Conclusions A standard analysis plan was developed for the results of the PACE study. This plan comprehensively describes the data captured and pre-determined statistical tests of relevant outcome measures. The plan demonstrates transparent and verifiable use of the data collected. This a priori plan will be followed to ensure rigorous standards of data analysis are strictly adhered to. Trial registration Australia and New Zealand Clinical Trials Registry ACTRN12609000966291 PMID:23937999

  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. Keeping Pace with Your Eating: Visual Feedback Affects Eating Rate in Humans.

    Directory of Open Access Journals (Sweden)

    Laura L Wilkinson

    Full Text Available Deliberately eating at a slower pace promotes satiation and eating quickly has been associated with a higher body mass index. Therefore, understanding factors that affect eating rate should be given high priority. Eating rate is affected by the physical/textural properties of a food, by motivational state, and by portion size and palatability. This study explored the prospect that eating rate is also influenced by a hitherto unexplored cognitive process that uses ongoing perceptual estimates of the volume of food remaining in a container to adjust intake during a meal. A 2 (amount seen; 300 ml or 500 ml x 2 (amount eaten; 300 ml or 500 ml between-subjects design was employed (10 participants in each condition. In two 'congruent' conditions, the same amount was seen at the outset and then subsequently consumed (300 ml or 500 ml. To dissociate visual feedback of portion size and actual amount consumed, food was covertly added or removed from a bowl using a peristaltic pump. This created two additional 'incongruent' conditions, in which 300 ml was seen but 500 ml was eaten or vice versa. We repeated these conditions using a savoury soup and a sweet dessert. Eating rate (ml per second was assessed during lunch. After lunch we assessed fullness over a 60-minute period. In the congruent conditions, eating rate was unaffected by the actual volume of food that was consumed (300 ml or 500 ml. By contrast, we observed a marked difference across the incongruent conditions. Specifically, participants who saw 300 ml but actually consumed 500 ml ate at a faster rate than participants who saw 500 ml but actually consumed 300 ml. Participants were unaware that their portion size had been manipulated. Nevertheless, when it disappeared faster or slower than anticipated they adjusted their rate of eating accordingly. This suggests that the control of eating rate involves visual feedback and is not a simple reflexive response to orosensory stimulation.

  8. Keeping Pace with Your Eating: Visual Feedback Affects Eating Rate in Humans.

    Science.gov (United States)

    Wilkinson, Laura L; Ferriday, Danielle; Bosworth, Matthew L; Godinot, Nicolas; Martin, Nathalie; Rogers, Peter J; Brunstrom, Jeffrey M

    2016-01-01

    Deliberately eating at a slower pace promotes satiation and eating quickly has been associated with a higher body mass index. Therefore, understanding factors that affect eating rate should be given high priority. Eating rate is affected by the physical/textural properties of a food, by motivational state, and by portion size and palatability. This study explored the prospect that eating rate is also influenced by a hitherto unexplored cognitive process that uses ongoing perceptual estimates of the volume of food remaining in a container to adjust intake during a meal. A 2 (amount seen; 300 ml or 500 ml) x 2 (amount eaten; 300 ml or 500 ml) between-subjects design was employed (10 participants in each condition). In two 'congruent' conditions, the same amount was seen at the outset and then subsequently consumed (300 ml or 500 ml). To dissociate visual feedback of portion size and actual amount consumed, food was covertly added or removed from a bowl using a peristaltic pump. This created two additional 'incongruent' conditions, in which 300 ml was seen but 500 ml was eaten or vice versa. We repeated these conditions using a savoury soup and a sweet dessert. Eating rate (ml per second) was assessed during lunch. After lunch we assessed fullness over a 60-minute period. In the congruent conditions, eating rate was unaffected by the actual volume of food that was consumed (300 ml or 500 ml). By contrast, we observed a marked difference across the incongruent conditions. Specifically, participants who saw 300 ml but actually consumed 500 ml ate at a faster rate than participants who saw 500 ml but actually consumed 300 ml. Participants were unaware that their portion size had been manipulated. Nevertheless, when it disappeared faster or slower than anticipated they adjusted their rate of eating accordingly. This suggests that the control of eating rate involves visual feedback and is not a simple reflexive response to orosensory stimulation. PMID:26828922

  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. 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

  11. 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.

  12. 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.

  13. Alerts and Notices (Devices)

    Science.gov (United States)

    ... powered, Hand-held Lasers Used for Pointing or Entertainment 12/16/10 Medical Device Safety Archive The ... About FDA Contact FDA Browse by Product Area Product Areas back Food Drugs Medical Devices Radiation-Emitting ...

  14. Development of Medical Devices

    OpenAIRE

    Limaye, Dnyanesh

    2016-01-01

    The medical devices sector helps save lives by providing innovative health care solutions regarding diagnosis, prevention, monitoring, treatment, and alleviation. Medical devices are classified into 1 of 3 categories in the order of increasing risk: Class I, Class II, and Class III.1 Medical devices are distinguished from drugs for regulatory purposes based on mechanism of action. Unlike drugs, medical devices operate via physical or mechanical means and are not dependent on metabolism to acc...

  15. Smart devices are different

    DEFF Research Database (Denmark)

    Stisen, Allan; Blunck, Henrik; Bhattacharya, Sourav;

    2015-01-01

    research results. This is due to variations in training and test device hardware and their operating system characteristics among others. In this paper, we systematically investigate sensor-, device- and workload-specific heterogeneities using 36 smartphones and smartwatches, consisting of 13 different...... device models from four manufacturers. Furthermore, we conduct experiments with nine users and investigate popular feature representation and classification techniques in HAR research. Our results indicate that on-device sensor and sensor handling heterogeneities impair HAR performances significantly...

  16. 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

  17. 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.

  18. Photovoltaic device and method

    Science.gov (United States)

    Cleereman, Robert J; Lesniak, Michael J; Keenihan, James R; Langmaid, Joe A; Gaston, Ryan; Eurich, Gerald K; Boven, Michelle L

    2015-01-27

    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.

  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. 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

  1. 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

  2. Thermography of electronic devices

    Directory of Open Access Journals (Sweden)

    Panfilova S. P.

    2007-12-01

    Full Text Available 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 of the thermographic method for checking the electronic devices is provided. The main features of software used in thermography and its significance are described.

  3. 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)....

  4. 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.

  5. 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.

  6. Radiation emitting devices regulations

    International Nuclear Information System (INIS)

    The Radiation Emitting Devices Regulations are the regulations referred to in the Radiation Emitting Devices Act and relate to the operation of devices. They include standards of design and construction, standards of functioning, warning symbol specifications in addition to information relating to the seizure and detention of machines failing to comply with the regulations. The radiation emitting devices consist of the following: television receivers, extra-oral dental x-ray equipment, microwave ovens, baggage inspection x-ray devices, demonstration--type gas discharge devices, photofluorographic x-ray equipment, laser scanners, demonstration lasers, low energy electron microscopes, high intensity mercury vapour discharge lamps, sunlamps, diagnostic x-ray equipment, ultrasound therapy devices, x-ray diffraction equipment, cabinet x-ray equipment and therapeutic x-ray equipment

  7. Effect of renal sympathetic denervation on atrial substrate remodeling in ambulatory canines with prolonged atrial pacing.

    Directory of Open Access Journals (Sweden)

    Xule Wang

    Full Text Available We have previously demonstrated that catheter-based renal sympathetic denervation (RSD could suppress atrial fibrillation (AF in canines with short-time rapid right atrial pacing (RAP. However, the role of renal denervation on atrial remodeling is unclear. The aim of the present study was to explore the long-term effect of RSD on the atrial remodeling during prolonged RAP. Twenty mongrel dogs were implanted with a high-frequency cardiac pacemaker with a transvenous lead inserted into the right atrial appendage. The dogs were divided into three groups: a sham-operated group (n = 6, the chronic RAP (CRAP group (n = 7, and the CRAP+RSD group (n = 7. In the CRAP+RSD group, a pacemaker was implanted 6 weeks after RSD was performed bilaterally for recovery. RAP was maintained for 5 weeks in CRAP group and CRAP+RSD group. The plasma levels of Angiotensin II and aldosterone were significantly increased in CRAP group compared with sham-operated group, but the increasing trend was inhibited in CRAP+RSD group compared with CRAP group (P<0.05. Similarly, RSD suppressed the increasing trend that prolonged RAP produced in the left atrial levels of ANP, TNF-α and IL-6. Compared with the sham-operated group, the CRAP group had significantly increased levels of caspase-3, bax and Cx40 whereas the level of Bcl-2 decreased (P<0.05. RSD markedly reduced the upregulation of caspase-3, bax and Cx40 and the downregulation of Bcl-2 expression compared with the CRAP group (P<0.05. Picric acid-sirius red staining study suggested that RSD could markedly alleviate the lesion degree of cardic fibrosis induced by CRAP (P<0.05. Immunohistochemistry results showed that the densities of TH- and GAP43- positive nerves were significantly elevated in the CRAP group compared with the sham-operated group, while RSD operation signicantly inhibited the these changes produced by CRAP. These findings suggest that renal denervation could suppress the atrial remodeling after

  8. Smart portable rehabilitation devices

    Directory of Open Access Journals (Sweden)

    Leahey Matt

    2005-07-01

    Full Text Available Abstract Background The majority of current portable orthotic devices and rehabilitative braces provide stability, apply precise pressure, or help maintain alignment of the joints with out the capability for real time monitoring of the patient's motions and forces and without the ability for real time adjustments of the applied forces and motions. Improved technology has allowed for advancements where these devices can be designed to apply a form of tension to resist motion of the joint. These devices induce quicker recovery and are more effective at restoring proper biomechanics and improving muscle function. However, their shortcoming is in their inability to be adjusted in real-time, which is the most ideal form of a device for rehabilitation. This introduces a second class of devices beyond passive orthotics. It is comprised of "active" or powered devices, and although more complicated in design, they are definitely the most versatile. An active or powered orthotic, usually employs some type of actuator(s. Methods In this paper we present several new advancements in the area of smart rehabilitation devices that have been developed by the Northeastern University Robotics and Mechatronics Laboratory. They are all compact, wearable and portable devices and boast re-programmable, real time computer controlled functions as the central theme behind their operation. The sensory information and computer control of the three described devices make for highly efficient and versatile systems that represent a whole new breed in wearable rehabilitation devices. Their applications range from active-assistive rehabilitation to resistance exercise and even have applications in gait training. The three devices described are: a transportable continuous passive motion elbow device, a wearable electro-rheological fluid based knee resistance device, and a wearable electrical stimulation and biofeedback knee device. Results Laboratory tests of the devices

  9. Activity pacing for osteoarthritis symptom management: study design and methodology of a randomized trial testing a tailored clinical approach using accelerometers for veterans and non-veterans

    Directory of Open Access Journals (Sweden)

    Geisser Michael E

    2011-08-01

    Full Text Available Abstract Background Osteoarthritis (OA is a prevalent chronic disease and a leading cause of disability in adults. For people with knee and hip OA, symptoms (e.g., pain and fatigue can interfere with mobility and physical activity. Whereas symptom management is a cornerstone of treatment for knee and hip OA, limited evidence exists for behavioral interventions delivered by rehabilitation professionals within the context of clinical care that address how symptoms affect participation in daily activities. Activity pacing, a strategy in which people learn to preplan rest breaks to avoid symptom exacerbations, has been effective as part of multi-component interventions, but hasn't been tested as a stand-alone intervention in OA or as a tailored treatment using accelerometers. In a pilot study, we found that participants who underwent a tailored activity pacing intervention had reduced fatigue interference with daily activities. We are now conducting a full-scale trial. Methods/Design This paper provides a description of our methods and rationale for a trial that evaluates a tailored activity pacing intervention led by occupational therapists for adults with knee and hip OA. The intervention uses a wrist accelerometer worn during the baseline home monitoring period to glean recent symptom and physical activity patterns and to tailor activity pacing instruction based on how symptoms relate to physical activity. At 10 weeks and 6 months post baseline, we will examine the effectiveness of a tailored activity pacing intervention on fatigue, pain, and physical function compared to general activity pacing and usual care groups. We will also evaluate the effect of tailored activity pacing on physical activity (PA. Discussion Managing OA symptoms during daily life activity performance can be challenging to people with knee and hip OA, yet few clinical interventions address this issue. The activity pacing intervention tested in this trial is designed to help

  10. 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.

  11. Therapeutic efficacy of digital music gastric electrical pacing for refractory functional dyspepsia concomitant with non-erosive reflux disease

    Directory of Open Access Journals (Sweden)

    Ya-mei RAN

    2015-04-01

    Full Text Available Objective To study the clinical efficacy of digital music gastric electrical pacing for refractory functional dyspepsia concomitant with non-erosive reflux disease, and its effects on mental health and life-quality of the patients. Methods According to the Rome Ⅲ criteria and Montreal consensus in diagnosis of gastroesophageal reflux disease, 50 patients with concomitant refractory functional dyspepsia and non-erosive reflux disease were recruited. The clinical efficacy of digital music gastric electrical pacing were evaluated using the score of clinical symptoms before treatment and 15 days after treatment, and the mental health and life-quality of patients were assessed using symptom checklist 90. Results Main symptoms, including upper abdominal pain, abdominal fullness, early satiety, belching, hiccup, nausea, heartburn, acid reflux (daytime, nocturnal acid reflux, loss of appetite and sleep, were significantly improved 15 days after treatment compared with those of pre-treatment, and there were statistically significant differences (all P<0.005. The significant response rate/response rate (efficacy rate were 59.0%/100.0%, 59.3%/96.3%, 47.0%/94.1%, 61.3%/96.8 %, 86.7%/100.0%, 80.0%/100.0%, 64.3%/92.9%, 73.7%/89.5%, 64.3%/85.7%, 90.0%/90.0%, 36.7%/93.3% respectively. After treatment for 15 days, the overall response rate of symptom relief was 94.4% in patients and the overall significant response rate was 65.7%. The symptom scores of somatization, obsessive-compulsiveness, depression, and anxiety were significantly improved, and the differences were statistically significant (all P<0.01. Conclusion The clinical efficacy of digital music gastric electrical pacing is significant for refractory functional dyspepsia concomitant with nonerosive reflux disease, and it is expected to be a new option for the treatment of this disease complex. DOI: 10.11855/j.issn.0577-7402.2015.03.08

  12. 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)

  13. 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.

  14. Mechanical CPR devices

    OpenAIRE

    Halperin, Henry; Carver, David J.

    2010-01-01

    It is recognized that the quality of cardiopulmonary resuscitation (CPR) is an important predictor of outcome from cardiac arrest. Mechanical chest-compression devices provide an alternative to manual CPR. Physiological and animal data suggest that mechanical chest-compression devices are more effective than manual CPR. Consequently, there has been much interest in the development of new techniques and devices to improve the efficacy of CPR. This review will consider the evidence ...

  15. Optical fibre nanowire devices

    OpenAIRE

    Xu, Fei

    2008-01-01

    The Optical Fibre Nanowire (OFN) is a potential building block in future micro- and nano-photonic device since it offers a number of unique optical and mechanical properties. In this thesis, the background and fundamental features of nanowires are introduced; the theory, design and demonstration of novel nanowire devices are discussed. At first, a short adiabatic taper tip is manufactured, and it is used as optical tweezers for trapping 1?m microspheres. Then, the most important devic...

  16. Sensor sentinel computing device

    Energy Technology Data Exchange (ETDEWEB)

    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.

  17. Effect of atrial preference pacing on reducing long-term burden of atrial fibrillation:a clinical study

    International Nuclear Information System (INIS)

    Objective: To evaluate the clinical effect of atrial preference pacing (APP) on the prevention of paroxysmal atrial fibrillation. Methods: Based on the type of implanted pacemaker, 46 patients with sick sinus syndrome and paroxysmal atrial fibrillation were divided into two groups. Dual-chamber pacemaker equipped with APP function was implanted in patients of group APP (n=21), while conventional dual-chamber pacemaker was implanted in patients of control group (n=25). The patients were followed up for six months, the maximum P wave duration (Pmax), the P wave dispersion (Pd), the structure of heart chambers, the data of automatic mode switch (AMS) and the total burden of atrial fibrillation were estimated,and the results were statistically analyzed and compared between two groups. Results: The basic clinical characteristics of two groups were comparable. After six months pacing, the difference in Pmax between two groups was of no significance (115.0 ± 10.1 ms vs 122.0 ± 11.0 ms, P > 0.05), while the increase of Pd in control group was more obvious than that in group APP (32.7 ± 4.2 ms vs 20.1 ± 5.3 ms, P 0.05), and also no remarkable difference in the left ventricular end-diastolic volume (LVEDV), left ventricular end-systolic volume (LVESV) and left ventricular ejection fraction (LVEF) could be found (P > 0.05). Moreover, no significant difference existed between two groups (P > 0.05). After six months pacing,in group APP the frequencies of AMS decreased more sharply (145 ± 37 times vs 327 ± 13 times, P < 0.05), the duration of AMS shortened more apparently (73 ± 15 hours vs 139 ± 28 hours, P < 0.05) and the total burden of atrial fibrillation was alleviated more obviously (13 ± 5% vs 28 ± 6%, P < 0.05) when compared to those in control group. Conclusion: Atrial preference pacing can coordinate the anisotropy of double atrial depolarization, reduce the frequencies of long-term paroxysmal atrial fibrillation, shorten the duration of atrial fibrillation

  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 partial pressure of CO2 (PETCO2 ; P pressure and oxygen uptake were lower from 50% of work completed onward in HOT compared with COOL (P pressure. PMID:25943664

  19. Thermal and Cardiovascular Strain Mitigate the Potential Benefit of Carbohydrate Mouth Rinse During Self-Paced Exercise in the Heat

    OpenAIRE

    Cramer, Matthew N; Thompson, Martin W.; PÉRIARD, JULIEN D.

    2015-01-01

    Purpose: To determine whether a carbohydrate mouth rinse can alter self-paced exercise performance independently of a high degree of thermal and cardiovascular strain. Methods: Eight endurance-trained males performed two 40-km cycling time trials in 35°C, 60% RH while swilling a 20-ml bolus of 6.5% maltodextrin (CHO) or a color- and taste-matched placebo (PLA) every 5 km. Heart rate, power output, rectal temperature (Tre), and mean skin temperature (Tsk) were recorded continuously; cardiac...

  20. Thermal and cardiovascular strain mitigate the potential benefit of carbohydrate mouth rinse during self-paced exercise in the heat

    OpenAIRE

    Matthew eCramer; Martin eThompson; Julien ePériard

    2015-01-01

    Purpose: To determine whether a carbohydrate mouth rinse can alter self-paced exercise performance independently of a high degree of thermal and cardiovascular strain.Methods: Eight endurance-trained males performed two 40-km cycling time trials in 35°C, 60% RH while swilling a 20-ml bolus of 6.5% maltodextrin (CHO) or a colour- and taste-matched placebo (PLA) every 5 km. Heart rate, power output, rectal temperature (Tre), and mean skin temperature (Tsk) were recorded continuously; cardiac ou...

  1. 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...

  2. New Medical Device Evaluation.

    Science.gov (United States)

    Ikeda, Koji

    2016-01-01

    In this presentation, as a member of the Harmonization by Doing (HBD) project, I discuss the significance of regulatory science in global medical device development and our experience in the international collaboration process for medical devices. In Japan, most innovative medical therapeutic devices were previously developed and exported by foreign-based companies. Due to this device lag, Japanese had minimal opportunities for receiving treatment with innovative medical devices. To address this issue, the Japanese government has actively accepted foreign clinical trial results and promoted global clinical trials in projects such as HBD. HBD is a project with stakeholders from academia, regulatory authorities, and industry in the US and Japan to promote global clinical trials and reduce device lags. When the project started, medical device clinical trials were not actively conducted in Japan at not just hospitals but also at medical device companies. We started to identify issues under the concept of HBD. After 10 years, we have now become key members in global clinical trials and able to obtain approvals without delay. Recently, HBD has started promoting international convergence. Physicians and regulatory authorities play central roles in compiling guidelines for the clinical evaluation of medical device development, which will be a more active field in the near future. The guidelines compiled will be confirmed with members of academia and regulatory authorities in the United Sates. PMID:27040333

  3. 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...

  4. Cataphoric Devices in Spoken Discourse

    OpenAIRE

    Gernsbacher, Morton Ann; Jescheniak, Jörg D.

    1995-01-01

    We propose that speakers mark key words with cataphoric devices. Cataphoric devices are counterparts to anaphoric devices: Just as anaphoric devices enable backward reference, cataphoric devices enable forward reference. And just as anaphoric devices mark concepts that have been mentioned before, cataphoric devices mark concepts that are likely to be mentioned again. We investigated two cataphoric devices: spoken stress and the indefinite this. Our experiments demonstrated three ways that con...

  5. 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

  6. Vaginal mechanical contraceptive devices.

    OpenAIRE

    Smith, M.; Barwin, B. N.

    1983-01-01

    The alleged adverse effects of oral contraceptives and intrauterine devices have led to increased consumer and physician demand for vaginal contraceptive devices. The efficacy and the advantages and disadvantages of vaginal sponges, cervical caps and diaphragms are discussed and compared in this article.

  7. Microfabricated particle focusing device

    Energy Technology Data Exchange (ETDEWEB)

    Ravula, Surendra K.; Arrington, Christian L.; Sigman, Jennifer K.; Branch, Darren W.; Brener, Igal; Clem, Paul G.; James, Conrad D.; Hill, Martyn; Boltryk, Rosemary June

    2013-04-23

    A microfabricated particle focusing device comprises an acoustic portion to preconcentrate particles over large spatial dimensions into particle streams and a dielectrophoretic portion for finer particle focusing into single-file columns. The device can be used for high throughput assays for which it is necessary to isolate and investigate small bundles of particles and single particles.

  8. Unconventional Quantum Computing Devices

    OpenAIRE

    Lloyd, Seth

    2000-01-01

    This paper investigates a variety of unconventional quantum computation devices, including fermionic quantum computers and computers that exploit nonlinear quantum mechanics. It is shown that unconventional quantum computing devices can in principle compute some quantities more rapidly than `conventional' quantum computers.

  9. Digital communication device

    DEFF Research Database (Denmark)

    2005-01-01

    The invention concerns a digital communication device like a hearing aid or a headset. The hearing aid or headset has a power supply, a signal processing device, means for receiving a wireless signal and a receiver or loudspeaker, which produces an audio signal based on a modulated pulsed signal...

  10. Metallic spintronic devices

    CERN Document Server

    Wang, Xiaobin

    2014-01-01

    Metallic Spintronic Devices provides a balanced view of the present state of the art of metallic spintronic devices, addressing both mainstream and emerging applications from magnetic tunneling junction sensors and spin torque oscillators to spin torque memory and logic. Featuring contributions from well-known and respected industrial and academic experts, this cutting-edge work not only presents the latest research and developments but also: Describes spintronic applications in current and future magnetic recording devicesDiscusses spin-transfer torque magnetoresistive random-access memory (STT-MRAM) device architectures and modelingExplores prospects of STT-MRAM scaling, such as detailed multilevel cell structure analysisInvestigates spintronic device write and read optimization in light of spintronic memristive effectsConsiders spintronic research directions based on yttrium iron garnet thin films, including spin pumping, magnetic proximity, spin hall, and spin Seebeck effectsProposes unique solutions for ...

  11. 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...

  12. Positioning devices for patients

    International Nuclear Information System (INIS)

    It has been suggested that it is very important to position patients reproducibly at different stages of radiotherapy treatment planning and treatment, or similar procedures. Devices have been described for positioning a patient's upper and lower thorax. This invention provides reproducible positioning for a female patient's breasts, for example in planning treatment of and treating breast tumours. The patient is placed prone, using for example an upper thorax device. A support device is placed central to and beneath her breasts to partially displace them outwards. The device may be triangular in section with one apex contacting the chest wall at the sternum. Restraining straps may be provided to hold the breasts against the support device. Means may be provided to take a healthy breast from the path of radiation through the tumour. (author)

  13. 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.

  14. Fluidic nanotubes and devices

    Science.gov (United States)

    Yang, Peidong; He, Rongrui; Goldberger, Joshua; Fan, Rong; Wu, Yiying; Li, Deyu; Majumdar, Arun

    2008-04-08

    Fluidic nanotube devices are described in which a hydrophilic, non-carbon nanotube, has its ends fluidly coupled to reservoirs. Source and drain contacts are connected to opposing ends of the nanotube, or within each reservoir near the opening of the nanotube. The passage of molecular species can be sensed by measuring current flow (source-drain, ionic, or combination). The tube interior can be functionalized by joining binding molecules so that different molecular species can be sensed by detecting current changes. The nanotube may be a semiconductor, wherein a tubular transistor is formed. A gate electrode can be attached between source and drain to control current flow and ionic flow. By way of example an electrophoretic array embodiment is described, integrating MEMs switches. A variety of applications are described, such as: nanopores, nanocapillary devices, nanoelectrophoretic, DNA sequence detectors, immunosensors, thermoelectric devices, photonic devices, nanoscale fluidic bioseparators, imaging devices, and so forth.

  15. Chromosomal assignment of the genes for proprotein convertases PC4, PC5, and PACE 4 in mouse and human

    Energy Technology Data Exchange (ETDEWEB)

    Mbikay, M.; Seidah, N.G.; Chretien, M. [Univ. of Montreal, Quebec (Canada)] [and others

    1995-03-01

    The genes for three subtilisin/kexin-like proprotein convertases, PC4, PC5, and PACE4, were mapped in the mouse by RFLP analysis of a DNA panel from a (C57BL/6JEi x SPRET/Ei) F{sub 1} x SPRET/Ei backcross. The chromosomal locations of the human homologs were determined by Southern blot analysis of a DNA panel from human-rodent somatic cell hybrids, most of which contained a single human chromosome each. The gene for PC4 (Pcsk4 locus) mapped to mouse chromosome 10, close to the Adn (adipsin, a serine protease) locus and near the Amh (anti-Mullerian hormone) locus; in a human, the gene was localized to chromosome 19. The gene for PC5 (Pcsk5 locus) mapped to mouse chromosome 19 close to the Lpc1 (lipoacortin-1) locus and, in human, was localized to chromosome 9. The gene for PACE4 (Pcsk6 locus) mapped to mouse chromosome 7, at a distance of 13 cM from the Pcsk3 locus, which specifies furin, another member of this family of enzymes previoulsy mapped to this chromosome. This is in concordance with the known close proximity of these two loci in the homologous region on human chromosome 15q25-qter. Pcsk3 and Pcsk6 mapped to a region of mouse chromosome 7 that has been associated cytogenetically with postnatal lethality in maternal disomy, suggesting that these genes might be candidates for imprinting. 43 refs., 3 figs., 2 tabs.

  16. Comparison of objective methods to classify the pattern of respiratory sinus arrhythmia during mechanical ventilation and paced spontaneous breathing

    International Nuclear Information System (INIS)

    Respiratory sinus arrhythmia (RSA) is a fluctuation of heart period that occurs during a respiratory cycle. It has been suggested that inspiratory heart period acceleration and expiratory deceleration during spontaneous ventilation (henceforth named positive RSA) improve the efficiency of gas exchange compared to the absence or the inversion of such a pattern (negative RSA). During mechanical ventilation (MV), for which maximizing the efficiency of gas exchange is of critical importance, the pattern of RSA is still the object of debate. In order to gain a better insight into this matter, we compared five different methods of RSA classification using the data of five mechanically ventilated piglets. The comparison was repeated using the data of 15 volunteers undergoing a protocol of paced spontaneous breathing, which is expected to result in a positive RSA pattern. The results showed that the agreement between the employed methods is limited, suggesting that the lack of a consensus about the RSA pattern during MV is, at least in part, of methodological origin. However, independently of the method used, the pattern of RSA within the respiratory cycle was not consistent among the subjects and conditions of MV considered. Also, the outcomes showed that even during paced spontaneous breathing a negative RSA pattern might be present, when a low respiratory frequency is imposed

  17. 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.

  18. 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.

  19. 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.

  20. 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

  1. 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.

  2. 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. PMID:26854943

  3. Paced-mating increases the number of adult new born cells in the internal cellular (granular layer of the accessory olfactory bulb.

    Directory of Open Access Journals (Sweden)

    Rebeca Corona

    Full Text Available The continuous production and addition of new neurons during life in the olfactory bulb is well accepted and has been extensively studied in rodents. This process could allow the animals to adapt to a changing environment. Olfactory neurogenesis begins in the subventricular zone where stem cells proliferate and give rise to young undifferentiated neuroblasts that migrate along the rostral migratory stream to the olfactory bulb (OB. Olfaction is crucial for the expression of sexual behavior in rodents. In female rats, the ability to control the rate of sexual interactions (pacing has important physiological and behavioral consequences. In the present experiment we evaluated if pacing behavior modifies the rate of new cells that reach the main and accessory olfactory bulb. The BrdU marker was injected before and after different behavioral tests which included: females placed in a mating cage (control, females allowed to pace the sexual interaction, females that mated but were not able to control the rate of the sexual interaction and females exposed to a sexually active male. Subjects were sacrificed fifteen days after the behavioral test. We observed a significant increase in the density of BrdU positive cells in the internal cellular layer of the accessory olfactory bulb when females paced the sexual interaction in comparison to the other 3 groups. No differences in the cell density in the main olfactory bulb were found. These results suggest that pacing behavior promotes an increase in density of the new cells in the accessory olfactory bulb.

  4. OPTOGENETICS: A NOVEL APPROACH IN PACING HAERT TISSUE AND ENGENDER PROPAGATING CARDIAC IMPULSES

    Directory of Open Access Journals (Sweden)

    Pasam Naga Abhinay

    2012-04-01

    Full Text Available The cardiac pacemaker controls the rhythmicity of heart contractions and these can be substituted by battery-operated devices as last resource. Optogenetics involves insertion of light-sensitive proteins into human embryonic stem cell to encode DNA making mammalian tissues light-sensitive. The first discovered protein of this type is Channelrhodopsin2 (ChR2, which is widely used in neuroscience. The limitation of electrical stimulation of heart, a standard technique can be overcome by using ChR2.The various methods involved in optogenetics and energy needs were discussed in this section. Initially, optogenetics is confined only to neuronal system, later on extended to heart and other organs. This method involves precise localized stimulation and constant prolonged depolarization of cardiomyocytes and cardiac tissue resulting in alterations of pacemaking, Ca2+ homeostasis, electrical coupling and arrhythmogenic spontaneous extra beats.

  5. Nanoelectronic device applications handbook

    CERN Document Server

    Morris, James E

    2013-01-01

    Nanoelectronic Device Applications Handbook gives a comprehensive snapshot of the state of the art in nanodevices for nanoelectronics applications. Combining breadth and depth, the book includes 68 chapters on topics that range from nano-scaled complementary metal-oxide-semiconductor (CMOS) devices through recent developments in nano capacitors and AlGaAs/GaAs devices. The contributors are world-renowned experts from academia and industry from around the globe. The handbook explores current research into potentially disruptive technologies for a post-CMOS world.These include: Nanoscale advance

  6. Electronic devices and circuits

    CERN Document Server

    Pridham, Gordon John

    1972-01-01

    Electronic Devices and Circuits, Volume 3 provides a comprehensive account on electronic devices and circuits and includes introductory network theory and physics. The physics of semiconductor devices is described, along with field effect transistors, small-signal equivalent circuits of bipolar transistors, and integrated circuits. Linear and non-linear circuits as well as logic circuits are also considered. This volume is comprised of 12 chapters and begins with an analysis of the use of Laplace transforms for analysis of filter networks, followed by a discussion on the physical properties of

  7. Output hardcopy devices

    CERN Document Server

    Durbeck, Robert

    1988-01-01

    Output Hardcopy Devices provides a technical summary of computer output hardcopy devices such as plotters, computer output printers, and CRT generated hardcopy. Important related technical areas such as papers, ribbons and inks, color techniques, controllers, and character fonts are also covered. Emphasis is on techniques primarily associated with printing, as well as the plotting capabilities of printing devices that can be effectively used for computer graphics in addition to their various printing functions. Comprised of 19 chapters, this volume begins with an introduction to vector and ras

  8. Radiations from display devices

    International Nuclear Information System (INIS)

    45 display devices have been analyzed for X-ray emmission and for electrostatic - and low-frequency magnetic fields. 3 have been further analyzed for UV and visible light emmission. No emmissions above established risk levels have been found. For low-frequency magnetic fields very little is known of risks, so the levels have been compared with other commonly used devices. The measured levels correspond roughly to that which occur in the use of an electrical egg-beater, or a small hand electrical drill. Data are presented for the tested devices.(author)

  9. Compound semiconductor device physics

    CERN Document Server

    Tiwari, Sandip

    2013-01-01

    This book provides one of the most rigorous treatments of compound semiconductor device physics yet published. A complete understanding of modern devices requires a working knowledge of low-dimensional physics, the use of statistical methods, and the use of one-, two-, and three-dimensional analytical and numerical analysis techniques. With its systematic and detailed**discussion of these topics, this book is ideal for both the researcher and the student. Although the emphasis of this text is on compound semiconductor devices, many of the principles discussed will also be useful to those inter

  10. Emission rate measuring device

    Science.gov (United States)

    Luckat, S.

    1980-09-01

    The development and application of an emission rate measuring device for gaseous components is explored. The device contains absorption fluid from a supply container that moistens a cylindrical paper sleeve. A newer model is provided with a direct current motor requiring less electricity than an older model. The hose pump is modified to avoid changing it and the filter sleeve is fastened more securely to the distributor head. Application of the measuring devices is discussed, particularly at the Cologne Cathedral, where damage to the stone is observed.

  11. Physics of photonic devices

    CERN Document Server

    Chuang, Shun Lien

    2009-01-01

    The most up-to-date book available on the physics of photonic devices This new edition of Physics of Photonic Devices incorporates significant advancements in the field of photonics that have occurred since publication of the first edition (Physics of Optoelectronic Devices). New topics covered include a brief history of the invention of semiconductor lasers, the Lorentz dipole method and metal plasmas, matrix optics, surface plasma waveguides, optical ring resonators, integrated electroabsorption modulator-lasers, and solar cells. It also introduces exciting new fields of research such as:

  12. Powering biomedical devices

    CERN Document Server

    Romero, Edwar

    2013-01-01

    From exoskeletons to neural implants, biomedical devices are no less than life-changing. Compact and constant power sources are necessary to keep these devices running efficiently. Edwar Romero's Powering Biomedical Devices reviews the background, current technologies, and possible future developments of these power sources, examining not only the types of biomedical power sources available (macro, mini, MEMS, and nano), but also what they power (such as prostheses, insulin pumps, and muscular and neural stimulators), and how they work (covering batteries, biofluids, kinetic and ther

  13. Promoting continence in nursing homes in four European countries: the use of PACES as a mechanism for improving the uptake of evidence-based recommendations

    Science.gov (United States)

    Harvey, Gill; Kitson, Alison; Munn, Zachary

    2012-01-01

    Background Multi-faceted approaches are generally recognised as the most effective way to support the implementation of evidence into practice. Audit and feedback often constitute one element of a multi-faceted implementation package, alongside other strategies, such as interactive education and facilitated support mechanisms. This paper describes a multi-faceted implementation strategy that used the Joanna Briggs Institute Practical Application of Clinical Evidence System (PACES) as an online audit tool to support facilitators working to introduce evidence-based continence recommendations in nursing homes in four different European countries. Aims/objectives The paper describes the experience of using PACES with an international group of nursing home facilitators. In particular, the objectives of the paper are: to describe the process of introducing PACES to internal facilitators in eight nursing homes; to discuss the progress made during a 12-month period of collecting and analysing audit data using PACES; to summarise the collective experience of using PACES, including reflections on its strengths and limitations. Methods Descriptive data were collected during the 12-month period of working with PACES in the eight nursing home sites. These data included digital and written notes taken at an initial 3-day introductory programme, at monthly teleconferences held between the external and internal facilitators and at a final 2-day meeting. Qualitative analysis of the data was undertaken on an ongoing basis throughout the implementation period, which enabled formative evaluation of PACES. A final summative evaluation of the experience of using PACES was undertaken as part of the closing project meeting in June 2011. Results The nursing home facilitators took longer than anticipated to introduce PACES and it was only after 9–10 months that they became confident and comfortable using the system. This was due to a combination of factors, including a lack of audit

  14. Microreactor Array Device

    Science.gov (United States)

    Wiktor, Peter; Brunner, Al; Kahn, Peter; Qiu, Ji; Magee, Mitch; Bian, Xiaofang; Karthikeyan, Kailash; Labaer, Joshua

    2015-03-01

    We report a device to fill an array of small chemical reaction chambers (microreactors) with reagent and then seal them using pressurized viscous liquid acting through a flexible membrane. The device enables multiple, independent chemical reactions involving free floating intermediate molecules without interference from neighboring reactions or external environments. The device is validated by protein expressed in situ directly from DNA in a microarray of ~10,000 spots with no diffusion during three hours incubation. Using the device to probe for an autoantibody cancer biomarker in blood serum sample gave five times higher signal to background ratio compared to standard protein microarray expressed on a flat microscope slide. Physical design principles to effectively fill the array of microreactors with reagent and experimental results of alternate methods for sealing the microreactors are presented.

  15. Advanced underwater lift device

    Science.gov (United States)

    Flanagan, David T.; Hopkins, Robert C.

    1993-01-01

    Flexible underwater lift devices ('lift bags') are used in underwater operations to provide buoyancy to submerged objects. Commercially available designs are heavy, bulky, and awkward to handle, and thus are limited in size and useful lifting capacity. An underwater lift device having less than 20 percent of the bulk and less than 10 percent of the weight of commercially available models was developed. The design features a dual membrane envelope, a nearly homogeneous envelope membrane stress distribution, and a minimum surface-to-volume ratio. A proof-of-concept model of 50 kg capacity was built and tested. Originally designed to provide buoyancy to mock-ups submerged in NASA's weightlessness simulators, the device may have application to water-landed spacecraft which must deploy flotation upon impact, and where launch weight and volume penalties are significant. The device may also be useful for the automated recovery of ocean floor probes or in marine salvage applications.

  16. Dielectrophoretically tunable optofluidic devices

    Science.gov (United States)

    Xu, Su; Ren, Hongwen; Wu, Shin-Tson

    2013-12-01

    Tunable optofluidic devices exhibit some unique characteristics that are not achievable in conventional solid-state photonic devices. They provide exciting opportunities for emerging applications in imaging, information processing, sensing, optical communication, lab-on-a-chip and biomedical engineering. A dielectrophoresis effect is an important physical mechanism to realize tunable optofluidic devices. Via balancing the voltage-induced dielectric force and interfacial tension, the liquid interface can be dynamically manipulated and the optical output reconfigured or adaptively tuned in real time. Dielectrophoretically tunable optofluidic devices offer several attractive features, such as rapid prototyping, miniaturization, easy integration and low power consumption. In this review paper, we first explain the underlying operation principles and then review some recent progress in this field, covering the topics of adaptive lens, beam steering, iris, grating, optical switch/attenuator and single pixel display. Finally, the future perspectives are discussed.

  17. Thermoelectric materials and devices

    Science.gov (United States)

    Park, Yeonjoon (Inventor); Choi, Sang H. (Inventor); King, Glen C. (Inventor); Elliott, James R. (Inventor); Talcott, Noel A. (Inventor)

    2011-01-01

    New thermoelectric materials comprise highly [111]-oriented twinned group IV alloys on the basal plane of trigonal substrates, which exhibit a high thermoelectric figure of merit and good material performance, and devices made with these materials.

  18. Geometry and Cloaking Devices

    Science.gov (United States)

    Ochiai, T.; Nacher, J. C.

    2011-09-01

    Recently, the application of geometry and conformal mappings to artificial materials (metamaterials) has attracted the attention in various research communities. These materials, characterized by a unique man-made structure, have unusual optical properties, which materials found in nature do not exhibit. By applying the geometry and conformal mappings theory to metamaterial science, it may be possible to realize so-called "Harry Potter cloaking device". Although such a device is still in the science fiction realm, several works have shown that by using such metamaterials it may be possible to control the direction of the electromagnetic field at will. We could then make an object hidden inside of a cloaking device. Here, we will explain how to design invisibility device using differential geometry and conformal mappings.

  19. Authenticated sensor interface device

    Energy Technology Data Exchange (ETDEWEB)

    Coleman, Jody Rustyn; Poland, Richard W.

    2016-10-18

    A system and method for the secure storage and transmission of data is provided. A data aggregate device can be configured to receive secure data from a data source, such as a sensor, and encrypt the secure data using a suitable encryption technique, such as a shared private key technique, a public key encryption technique, a Diffie-Hellman key exchange technique, or other suitable encryption technique. The encrypted secure data can be provided from the data aggregate device to different remote devices over a plurality of segregated or isolated data paths. Each of the isolated data paths can include an optoisolator that is configured to provide one-way transmission of the encrypted secure data from the data aggregate device over the isolated data path. External data can be received through a secure data filter which, by validating the external data, allows for key exchange and other various adjustments from an external source.

  20. Halo traction device.

    Science.gov (United States)

    Manthey, D E

    1994-08-01

    A thorough understanding of the underlying diseases and of the halo pin traction device will allow for appropriate treatment of complications. Consultation or referral to the neurosurgeon is advised to prevent serious sequelae. The following points should be remembered: 1. Pins should only be tightened during the first 24-hour period after application. 2. Pin infection is treated by local wound care in most cases. 3. CT scan cannot completely exclude the presence of an abscess secondary to artifact, but MRI may be compatible with the newer devices. 4. Pin penetration of the inner table of the skull requires admission. 5. Any suspected loss of alignment or reduction of the cervical spine requires C-spine immobilization. 5. Nasotracheal or fiberoptic intubation or emergent cricothyroidotomy should be used if orotracheal intubation proves difficult due to the device. 7. The anterior portion of the vest is removable for cardiopulmonary resuscitation without compromising the stability of the device. PMID:8062799

  1. MDR (Medical Device Reporting)

    Data.gov (United States)

    U.S. Department of Health & Human Services — This database allows you to search the CDRH's database information on medical devices which may have malfunctioned or caused a death or serious injury during the...

  2. Resources: Handheld Computing Devices

    OpenAIRE

    Denson, Cameron

    2008-01-01

    The article features a valuable resource to aid teachers in their effort to satisfy the need to implement modern instructional technology and their students' need to access green technology. It states that handheld computing devices are currently being widely used in many classrooms and technology savvy educators can manifest to the benefits of these data-collection systems. It believes that handheld units can offer students with an all-inclusive technological device that caters to all learners.

  3. Nanoplasmonics advanced device applications

    CERN Document Server

    Chon, James W M

    2013-01-01

    Focusing on control and manipulation of plasmons at nanometer dimensions, nanoplasmonics combines the strength of electronics and photonics, and is predicted to replace existing integrated circuits and photonic devices. It is one of the fastest growing fields of science, with applications in telecommunication, consumer electronics, data storage, medical diagnostics, and energy.Nanoplasmonics: Advanced Device Applications provides a scientific and technological background of a particular nanoplasmonic application and outlines the progress and challenges of the application. It reviews the latest

  4. Inverted organic photosensitive device

    Energy Technology Data Exchange (ETDEWEB)

    Forrest, Stephen R.; Tong, Xiaoran; Lee, Jun Yeob; Cho, Yong Joo

    2015-09-08

    There is disclosed a method for preparing the surface of a metal substrate. The present disclosure also relates to an organic photovoltaic device including a metal substrate made by such method. Also disclosed herein is an inverted photosensitive device including a stainless steel foil reflective electrode, an organic donor-acceptor heterojunction over the reflective electrode, and a transparent electrode over the donor-acceptor heterojunction.

  5. Holographic liquid crystal devices

    OpenAIRE

    Pavani, Kotakonda, (Thesis)

    2009-01-01

    Liquid crystals have become natural candidates for use in electro-optic devices for their ability to change the orientation of the director with the application of an electric field, and exhibiting large range of refractive index. The aim of the work presented in this thesis is to fabricate liquid crystal optoelectronic devices such as electrically switchable liquid crystal diffraction gratings and polarization rotators by exploiting the holographic surface relief effect in photopolymer and b...

  6. Projection and registration device

    OpenAIRE

    Verlinden, J.C.

    2009-01-01

    A projection and recording device, provided with a processing and control unit, a memory for recording images and other data, an input/output interface, a controllable camera, a touch screen for the input and display of data and images, a position determining system for determining the position of at least one object in relation to the projection and recording device, with images recorded by the camera being storable in the memory and displayable on the touch screen, and a projector for proje...

  7. Electronic security device

    International Nuclear Information System (INIS)

    The present invention relates to a security device having a control box containing an electronic system and a communications loop over which the system transmits a signal. The device is constructed so that the communications loop can extend from the control box across the boundary of a portal such as a door into a sealed enclosure into which access is restricted whereby the loop must be damaged or moved in order for an entry to be made into the enclosure. The device is adapted for detecting unauthorized entries into such enclosures such as rooms or containers and for recording the time at which such entries occur for later reference. Additionally, the device detects attempts to tamper or interfere with the operation of the device itself and records the time at which such events take place. In the preferred embodiment, the security device includes a microprocessor-based electronic system and a detection module capable of registering changes in the voltage and phase of the signal transmitted over the loop. 11 figs

  8. Synthetic nanoscale motion devices

    Energy Technology Data Exchange (ETDEWEB)

    Lyshevski, M.A. [Microsystems and Nanotechnologies, Webster, NY (United States); Lyshevski, S.E. [Rochester Inst. of Technology, Rochester, NY (United States). Dept. of Electrical Engineering

    2007-07-01

    This study examined biomolecular axial and radial topology rotational machines, as well as translational motion devices made from proteins. In particular, it documented the integrated topological, structural and analytic design of synthetic nanoscale motion devices in an effort to promote high performance and meet specifications. Control, analysis and design problems were solved for electromagnetic motion devices. A systematic synthesis resulted in a radial topology permanent-magnetic device with noncontact electrostatic bearings for use in microrobotics. Such nanoscale motion devices can be made from carbon nanotubes using molecular nanotechnology and surface chemistry. Structures, magnets and windings were formed by depositing polymers and organic/inorganic molecules on the noncontact electrostatic bearings. The electromagnetic torque was studied to analyze the electromagnetics and nonuniform field. The electromagnetic torque was varied in order to control the phase voltages applied to the windings. The closed-loop systems were designed for stability, controllability and optimal performance. The proposed machines can be used as nanoscale generators to convert mechanical energy into electrical energy. The permanent-magnet synthetic motion devices may have practical use in nano- and micro robots, assemblers and propulsors. Practical control laws were derived from electromagnetic and electromechanical analyses. 5 refs., 3 figs.

  9. 生物起搏在细胞移植中的作用%Effect of biological pacing on cell transplantation

    Institute of Scientific and Technical Information of China (English)

    罗时珂; 李萍

    2009-01-01

    近年来随着分子生物学、细胞移植及基因工程的快速发展,生物起搏成为治疗缓慢心律失常的新方向,生物起搏器的研究主要经历了3个阶段:①细胞治疗:将具有多向分化能力的胚胎干细胞或骨髓间充质干细胞植入心脏分化成起搏样细胞后发挥起搏功能.②基因转移:将窦房结细胞中的起搏基因通过载体转入心脏,使普通心肌细胞转化成自律细胞从而产生自主兴奋.③基因细胞治疗:将起搏基因转染干细胞后注入心脏,两者共同增强心肌生物起搏功能.尽管目前生物起搏器在大量动物实验中取得成功,但应用于临床仍面临许多问题,随着窦房结细胞起搏机制进一步阐明,心脏生物起搏器必将造福人类.%Recently years,with the rapid development of molecular biology,cell transplantation and genetic engineering,biological pacing has become the new direction of treatment for bradyarrhythmia.The researches on biological pacing mainly experience three stages:①Cell therapy:Embryonic stem cells or mesenchymal stem cells,who have the ability of multi-direction differentiation,can be differentiate into generate pacemaker cells to play pacing function after implanted into heart.②Gene transfer:The pacing genes in sinus node cells are delivered to heart by using of vectors,which make ordinary cardiomyocytes convert into automatic cells to generate spontaneous impulse.③Gene therapy:Stem cells are as platforms to carry pacemaker genes to heart and co-working to enhance myocardial pacing function.So far,biological pacing is successful in a lot of animal experiments,but it also face to many problems in clinical application.Along with further clarification on pacing mechanism of sinus code cells,biological pacing will benefit mankind.

  10. Properties of PACE-I HgCdTe Detectors in Space - the NICMOS Warm-up Monitoring Program

    CERN Document Server

    Böker, T

    2000-01-01

    We summarize the results of a monitoring program which was executed following the cryogen exhaustion of the NearInfrared Camera and MultiObject Spectrometer (NICMOS) onboard the Hubble Space Telescope. During the subsequent warm-up, detector parameters such as detective quantum efficiency, dark current, bias offsets, and saturation levels have been measured over the temperature range 62 K to about 100 K. The measurements provide a unique database of the characteristics of PACE-I HgCdTe detector arrays in the space environment. A surprising result of the analysis is the fact that all three NICMOS detectors showed an enhanced dark current in the temperature range between 77 K and 85 K. We discuss possible explanations for this unexpected behavior.

  11. Patient Activation through Counseling and Exercise – Acute Leukemia (PACE-AL) – a randomized controlled trial

    DEFF Research Database (Denmark)

    Jarden, Mary; Møller, Tom; Kjeldsen, Lars;

    2013-01-01

    , strength exercises using hand weights and relaxation exercise. Individual health counseling sessions include a self directed home walk program with a step counter. The primary endpoint is functional performance/exercise capacity (6 minute walk distance). The secondary endpoints are submaximal VO2 max test...... and supervised counseling and exercise program.Methods/design: This paper presents the study protocol: Patient Activation through Counseling and Exercise -- Acute Leukemia (PACE-AL) trial, a two center, randomized controlled trial of 70 patients with acute leukemia (35 patients/study arm) following induction...... chemotherapy in the outpatient setting. Eligible patients will be randomized to usual care or to the 12 week exercise and counseling program. The intervention includes 3 hours + 30 minutes per week of supervised and structured aerobic training (moderate to high intensity 70 - 80%) on an ergometer cycle...

  12. Pace:pienen jalanjäljen koti spontaanin kaupunkikehittämisen välineenä

    OpenAIRE

    Säilynoja, A. (Anu)

    2016-01-01

    Anu Säilynojan diplomityön, Pace -pienen jalanjäljen koti spontaanin kaupunkikehittämisen välineenä, tarkoitus on etsiä globaalien ympäristö-, ja sosiaalisten ongelmien aiheuttamaan tilanteeseen sopeutuvaa ja monistettavaa asumisen tapaa, konseptia, joka mahdollistaisi ihmisarvoisen elämän ja kodin useammalle; sallisi kaupunkien väestönkasvun kestävällä tavalla samalla pienentäen asukkaidensa ekologista jalanjälkeä. Diplomityössä selvitetään kestämättömään tilanteeseen johtaneita syitä ja spo...

  13. Alternative Devices for Taking Insulin

    Science.gov (United States)

    ... KB). Alternate Language URL Alternative Devices for Taking Insulin Page Content On this page: What alternative devices ... the skin. [ Top ] What alternative devices for taking insulin are available? Insulin pens provide a convenient, easy- ...

  14. Cataphoric devices in spoken discourse.

    Science.gov (United States)

    Gernsbacher, M A; Jescheniak, J D

    1995-08-01

    We propose that speakers mark key words with cataphoric devices. Cataphoric devices are counterparts to anaphoric devices: Just as anaphoric devices enable backward reference, cataphoric devices enable forward reference. And just as anaphoric devices mark concepts that have been mentioned before, cataphoric devices mark concepts that are likely to be mentioned again. We investigated two cataphoric devices: spoken stress and the indefinite this. Our experiments demonstrated three ways that concepts marked by cataphoric devices gain a privileged status in listeners' mental representations: Cataphoric devices enhance the activation of the concepts that they mark; cataphoric devices suppress the activation of previously mentioned concepts; and cataphoric devices protect the concepts that they mark from being suppressed by subsequently mentioned concepts. PMID:7641525

  15. How James Kept the Pace?; A Look into the Organic Unity of Daisy Miller

    Directory of Open Access Journals (Sweden)

    Sina Movaghati

    2015-12-01

    Full Text Available Many Critics believe that Henry James has set the definitive standards of modern fiction writing. Undoubtedly his groundbreaking article “The Art of fiction,” which published for the first time in 1884, has a major contribution in developing the theories of fiction writing. The term Organic Unity has derived from a major Formalist Critic, Cleanth Brooks. Both James and Brooks believed that a critic should approach a text as an organic whole. So, in this article we try to pinpoint the ideas which James and Brooks claimed in their essays and see how these ideas conform to one of James’ well-known stories, Daisy Miller. We want to observe that how James develops and shapes his story around the central theme. Furthermore, we want to investigate that are there any literary devices embedded in the text of the story which help James to deliver his fiction with artistry?Keywords: James, Cleanth Brooks, Organic Unity, The Art of Fiction, Daisy Miller

  16. The pace of past climate change vs. potential bird distributions and land use in the United States.

    Science.gov (United States)

    Bateman, Brooke L; Pidgeon, Anna M; Radeloff, Volker C; VanDerWal, Jeremy; Thogmartin, Wayne E; Vavrus, Stephen J; Heglund, Patricia J

    2016-03-01

    Climate change may drastically alter patterns of species distributions and richness, but predicting future species patterns in occurrence is challenging. Significant shifts in distributions have already been observed, and understanding these recent changes can improve our understanding of potential future changes. We assessed how past climate change affected potential breeding distributions for landbird species in the conterminous United States. We quantified the bioclimatic velocity of potential breeding distributions, that is, the pace and direction of change for each species' suitable climate space over the past 60 years. We found that potential breeding distributions for landbirds have shifted substantially with an average velocity of 1.27 km yr(-1) , about double the pace of prior distribution shift estimates across terrestrial systems globally (0.61 km yr(-1) ). The direction of shifts was not uniform. The majority of species' distributions shifted west, northwest, and north. Multidirectional shifts suggest that changes in climate conditions beyond mean temperature were influencing distributional changes. Indeed, precipitation variables that were proxies for extreme conditions were important variables across all models. There were winners and losers in terms of the area of distributions; many species experienced contractions along west and east distribution edges, and expansions along northern distribution edges. Changes were also reflected in the potential species richness, with some regions potentially gaining species (Midwest, East) and other areas potentially losing species (Southwest). However, the degree to which changes in potential breeding distributions are manifested in actual species richness depends on landcover. Areas that have become increasingly suitable for breeding birds due to changing climate are often those attractive to humans for agriculture and development. This suggests that many areas might have supported more breeding bird

  17. The pace of past climate change vs. potential bird distributions and land use in the United States.

    Science.gov (United States)

    Bateman, Brooke L; Pidgeon, Anna M; Radeloff, Volker C; VanDerWal, Jeremy; Thogmartin, Wayne E; Vavrus, Stephen J; Heglund, Patricia J

    2016-03-01

    Climate change may drastically alter patterns of species distributions and richness, but predicting future species patterns in occurrence is challenging. Significant shifts in distributions have already been observed, and understanding these recent changes can improve our understanding of potential future changes. We assessed how past climate change affected potential breeding distributions for landbird species in the conterminous United States. We quantified the bioclimatic velocity of potential breeding distributions, that is, the pace and direction of change for each species' suitable climate space over the past 60 years. We found that potential breeding distributions for landbirds have shifted substantially with an average velocity of 1.27 km yr(-1) , about double the pace of prior distribution shift estimates across terrestrial systems globally (0.61 km yr(-1) ). The direction of shifts was not uniform. The majority of species' distributions shifted west, northwest, and north. Multidirectional shifts suggest that changes in climate conditions beyond mean temperature were influencing distributional changes. Indeed, precipitation variables that were proxies for extreme conditions were important variables across all models. There were winners and losers in terms of the area of distributions; many species experienced contractions along west and east distribution edges, and expansions along northern distribution edges. Changes were also reflected in the potential species richness, with some regions potentially gaining species (Midwest, East) and other areas potentially losing species (Southwest). However, the degree to which changes in potential breeding distributions are manifested in actual species richness depends on landcover. Areas that have become increasingly suitable for breeding birds due to changing climate are often those attractive to humans for agriculture and development. This suggests that many areas might have supported more breeding bird

  18. The effect of age and microstructural white matter integrity on lap time variation and fast-paced walking speed.

    Science.gov (United States)

    Tian, Qu; Ferrucci, Luigi; Resnick, Susan M; Simonsick, Eleanor M; Shardell, Michelle D; Landman, Bennett A; Venkatraman, Vijay K; Gonzalez, Christopher E; Studenski, Stephanie A

    2016-09-01

    Macrostructural white matter damage (WMD) is associated with less uniform and slower walking in older adults. The effect of age and subclinical microstructural WM degeneration (a potentially earlier phase of WM ischemic damage) on walking patterns and speed is less clear. This study examines the effect of age on the associations of regional microstructural WM integrity with walking variability and speed, independent of macrostructural WMD. This study involved 493 participants (n = 51 young; n = 209 young-old; n = 233 old-old) from the Baltimore Longitudinal Study of Aging. All completed a 400-meter walk test and underwent a concurrent brain MRI with diffusion tensor imaging. Microstructural WM integrity was measured as fractional anisotropy (FA). Walking variability was measured as trend-adjusted variation in time over ten 40-meter laps (lap time variation, LTV). Fast-paced walking speed was assessed as mean lap time (MLT). Multiple linear regression models of FA predicting LTV and MLT were adjusted for age, sex, height, weight, and WM hyperintensities. Independent of WM hyperintensities, lower FA in the body of the corpus callosum was associated with higher LTV and longer MLT only in the young-old. Lower FA in superior longitudinal, inferior fronto-occipital, and uncinate fasciculi, the anterior limb of the internal capsule, and the anterior corona radiate was associated with longer MLT only in the young-old. While macrostructural WMD is known to predict more variable and slower walking in older adults, microstructural WM disruption is independently associated with more variable and slower fast-paced walking only in the young-old. Disrupted regional WM integrity may be a subclinical contributor to abnormal walking at an earlier phase of aging. PMID:26399234

  19. The pace of past climate change vs. potential bird distributions and land use in the United States

    Science.gov (United States)

    Bateman, Brooke L.; Pidgeon, Anna M.; Radeloff, Volker C.; VanDerWal, Jeremy; Thogmartin, Wayne E.; Vavrus, Stephen J.; Heglund, Patricia J.

    2016-01-01

    Climate change may drastically alter patterns of species distributions and richness, but predicting future species patterns in occurrence is challenging. Significant shifts in distributions have already been observed, and understanding these recent changes can improve our understanding of potential future changes. We assessed how past climate change affected potential breeding distributions for landbird species in the conterminous United States. We quantified the bioclimatic velocity of potential breeding distributions, that is, the pace and direction of change for each species’ suitable climate space over the past 60 years. We found that potential breeding distributions for landbirds have shifted substantially with an average velocity of 1.27 km yr−1, about double the pace of prior distribution shift estimates across terrestrial systems globally (0.61 km yr−1). The direction of shifts was not uniform. The majority of species’ distributions shifted west, northwest, and north. Multidirectional shifts suggest that changes in climate conditions beyond mean temperature were influencing distributional changes. Indeed, precipitation variables that were proxies for extreme conditions were important variables across all models. There were winners and losers in terms of the area of distributions; many species experienced contractions along west and east distribution edges, and expansions along northern distribution edges. Changes were also reflected in the potential species richness, with some regions potentially gaining species (Midwest, East) and other areas potentially losing species (Southwest). However, the degree to which changes in potential breeding distributions are manifested in actual species richness depends on landcover. Areas that have become increasingly suitable for breeding birds due to changing climate are often those attractive to humans for agriculture and development. This suggests that many areas might have supported more breeding bird

  20. Human activities and climate variability drive fast-paced change across the world's estuarine-coastal ecosystems

    Science.gov (United States)

    Cloern, James E.; Abreu, Paulo C.; Carstensen, Jacob; Chauvaud, Laurent; Elmgren, Ragnar; Grall, Jacques; Greening, Holly; Johansson, John O.R.; Kahru, Mati; Sherwood, Edward T.; Xu, Jie; Yin, Kedong

    2016-01-01

    Time series of environmental measurements are essential for detecting, measuring and understanding changes in the Earth system and its biological communities. Observational series have accumulated over the past 2–5 decades from measurements across the world's estuaries, bays, lagoons, inland seas and shelf waters influenced by runoff. We synthesize information contained in these time series to develop a global view of changes occurring in marine systems influenced by connectivity to land. Our review is organized around four themes: (i) human activities as drivers of change; (ii) variability of the climate system as a driver of change; (iii) successes, disappointments and challenges of managing change at the sea-land interface; and (iv) discoveries made from observations over time. Multidecadal time series reveal that many of the world's estuarine–coastal ecosystems are in a continuing state of change, and the pace of change is faster than we could have imagined a decade ago. Some have been transformed into novel ecosystems with habitats, biogeochemistry and biological communities outside the natural range of variability. Change takes many forms including linear and nonlinear trends, abrupt state changes and oscillations. The challenge of managing change is daunting in the coastal zone where diverse human pressures are concentrated and intersect with different responses to climate variability over land and over ocean basins. The pace of change in estuarine–coastal ecosystems will likely accelerate as the human population and economies continue to grow and as global climate change accelerates. Wise stewardship of the resources upon which we depend is critically dependent upon a continuing flow of information from observations to measure, understand and anticipate future changes along the world's coastlines.