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Sample records for coupled pacing improves

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

    SciTech Connect

    Dubey, M

    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.

  2. Bachmann's Bundle Pacing not Only Improves Interatrial Conduction but Also Reduces the Need for Ventricular Pacing.

    PubMed

    Sławuta, Agnieszka; Kliś, Magdalena; Skoczyński, Przemysław; Bańkowski, Tomasz; Moszczyńska-Stulin, Joanna; Gajek, Jacek

    2016-01-01

    Patients treated for sick sinus syndrome may have interatrial conduction disorder leading to atrial fibrillation. This study was aimed to assess the influence of the atrial pacing site on interatrial and atrioventricular conduction as well as the percentage of ventricular pacing in patients with sick sinus syndrome implanted with atrioventricular pacemaker. The study population: 96 patients (58 females, 38 males) aged 74.1 ± 11.8 years were divided in two groups: Group 1 (n = 44) with right atrial appendage pacing and group 2 (n = 52) with Bachmann's area pacing. We assessed the differences in atrioventricular conduction in sinus rhythm and atrial 60 and 90 bpm pacing, P-wave duration and percentage of ventricular pacing. No differences in baseline P-wave duration in sinus rhythm between the groups (102.4 ± 17 ms vs. 104.1 ± 26 ms, p = ns.) were noted. Atrial pacing 60 bpm resulted in longer P-wave in group 1 vs. group 2 (138.3 ± 21 vs. 106.1 ± 15 ms, p < 0.01). The differences between atrioventricular conduction time during sinus rhythm and atrial pacing at 60 and 90 bpm were significantly longer in patients with right atrial appendage vs. Bachmann's pacing (44.1 ± 17 vs. 9.2 ± 7 ms p < 0.01 and 69.2 ± 31 vs. 21.4 ± 12 ms p < 0.05, respectively). The percentage of ventricular pacing was higher in group 1 (21 vs. 4%, p < 0.01). Bachmann's bundle pacing decreases interatrial and atrioventricular conduction delay. Moreover, the frequency-dependent atrioventricular conduction lengthening is much less pronounced during Bachmann's bundle pacing. Right atrial appendage pacing in sick sinus syndrome patients promotes a higher percentage of ventricular pacing.

  3. Improved cardiac performance through pacing-induced diaphragmatic stimulation: a novel electrophysiological approach in heart failure management?

    PubMed

    Roos, Markus; Kobza, Richard; Jamshidi, Peiman; Bauer, Peter; Resink, Thérèse; Schlaepfer, Reinhard; Stulz, Peter; Zuber, Michel; Erne, Paul

    2009-02-01

    Pharmacological conditioning of the phrenic nerve can positively influence systolic performance, and diaphragm activation improves ventilatory function. Here we investigate whether pacing-induced diaphragmatic stimulation (PIDS) may improve left ventricular (LV) systolic function. We studied a total of 35 patients (4 females, mean age 67 +/- 9 years, ejection fraction 61 +/- 14%) within 7 days following open heart surgery. The haemodynamic impact of different PIDS and ventricular pacing configurations and coupling intervals was tested in 132 episodes. Success of PIDS was assessed using fluoroscopy and palpation. Left ventricular systolic performance was recorded using the electromechanical activation time (EMAT) obtained through acoustic cardiography. Eighteen subjects were tested in the catheter laboratory and 17 in the intensive care unit. For both groups, EMAT significantly improved when the diaphragm was stimulated 20 ms after the onset of ventricular pacing. In all instances, PIDS could be induced with or without causing patient symptoms, and LV systolic performance improvement was comparable in symptomatic and asymptomatic modes. No desensitization of the diaphragm was observed following PIDS delivery 4-6 and 24 h following open heart surgery. Pacing-induced diaphragmatic stimulation, if synchronized to the onset of ventricular contraction with a fixed, non-zero coupling delay, can improve LV systolic function reproducibly for at least 1 h without causing patient symptoms. The absence of diaphragm desensitization further underscores the potential of PIDS as a practical therapeutic approach in device-based heart failure management.

  4. Improvement in pump function with endocardial biventricular pacing increases with activation time at the left ventricular pacing site in failing canine hearts.

    PubMed

    Howard, Elliot J; Covell, James W; Mulligan, Lawrence J; McCulloch, Andrew D; Omens, Jeffrey H; Kerckhoffs, Roy C P

    2011-10-01

    Recently, attention has been focused on comparing left ventricular (LV) endocardial (ENDO) with epicardial (EPI) pacing for cardiac resynchronization therapy. However, the effects of ENDO and EPI lead placement at multiple sites have not been studied in failing hearts. We hypothesized that differences in the improvement of ventricular function due to ENDO vs. EPI pacing in dyssynchronous (DYSS) heart failure may depend on the position of the LV lead in relation to the original activation pattern. In six nonfailing and six failing dogs, electrical DYSS was created by atrioventricular sequential pacing of the right ventricular apex. ENDO was compared with EPI biventricular pacing at five LV sites. In failing hearts, increases in the maximum rate of LV pressure change (dP/dt; r = 0.64), ejection fraction (r = 0.49), and minimum dP/dt (r = 0.51), relative to DYSS, were positively correlated (P < 0.01) with activation time at the LV pacing site during ENDO but not EPI pacing. ENDO pacing at sites with longer activation delays led to greater improvements in hemodynamic parameters and was associated with an overall reduction in electrical DYSS compared with EPI pacing (P < 0.05). These findings were qualitatively similar for nonfailing hearts. Improvement in hemodynamic function increased with activation time at the LV pacing site during ENDO but not EPI pacing. At the anterolateral wall, end-systolic transmural function was greater with local ENDO compared with EPI pacing. ENDO pacing and intrinsic activation delay may have important implications for management of DYSS heart failure.

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

    PubMed

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

    1984-02-01

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

  6. Improvement of Right Ventricular Hemodynamics with Left Ventricular Endocardial Pacing during Cardiac Resynchronization Therapy

    PubMed Central

    HYDE, EOIN R.; BEHAR, JONATHAN M.; CROZIER, ANDREW; CLARIDGE, SIMON; JACKSON, TOM; SOHAL, MANAV; GILL, JASWINDER S.; O'NEILL, MARK D.; RAZAVI, REZA; RINALDI, CHRISTOPHER A.

    2016-01-01

    Background Cardiac resynchronization therapy (CRT) with biventricular epicardial (BV‐CS) or endocardial left ventricular (LV) stimulation (BV‐EN) improves LV hemodynamics. The effect of CRT on right ventricular function is less clear, particularly for BV‐EN. Our objective was to compare the simultaneous acute hemodynamic response (AHR) of the right and left ventricles (RV and LV) with BV‐CS and BV‐EN in order to determine the optimal mode of CRT delivery. Methods Nine patients with previously implanted CRT devices successfully underwent a temporary pacing study. Pressure wires measured the simultaneous AHR in both ventricles during different pacing protocols. Conventional epicardial CRT was delivered in LV‐only (LV‐CS) and BV‐CS configurations and compared with BV‐EN pacing in multiple locations using a roving decapolar catheter. Results Best BV‐EN (optimal AHR of all LV endocardial pacing sites) produced a significantly greater RV AHR compared with LV‐CS and BV‐CS pacing (P < 0.05). RV AHR had a significantly increased standard deviation compared to LV AHR (P < 0.05) with a weak correlation between RV and LV AHR (Spearman rs = −0.06). Compromised biventricular optimization, whereby RV AHR was increased at the expense of a smaller decrease in LV AHR, was achieved in 56% of cases, all with BV‐EN pacing. Conclusions BV‐EN pacing produces significant increases in both LV and RV AHR, above that achievable with conventional epicardial pacing. RV AHR cannot be used as a surrogate for optimizing LV AHR; however, compromised biventricular optimization is possible. The beneficial effect of endocardial LV pacing on RV function may have important clinical benefits beyond conventional CRT. PMID:27001004

  7. β3-Adrenergic receptor antagonist improves exercise performance in pacing-induced heart failure

    PubMed Central

    Masutani, Satoshi; Cheng, Heng-Jie; Morimoto, Atsushi; Hasegawa, Hiroshi; Han, Qing-Hua; Little, William C.

    2013-01-01

    In heart failure (HF), the impaired left ventricular (LV) arterial coupling and diastolic dysfunction present at rest are exacerbated during exercise. We have previously shown that in HF at rest stimulation of β3-adrenergic receptors by endogenous catecholamine depresses LV contraction and relaxation. β3-Adrenergic receptors are activated at higher concentrations of catecholamine. Thus exercise may cause increased stimulation of cardiac β3-adrenergic receptors and contribute to this abnormal response. We assessed the effect of L-748,337 (50 μg/kg iv), a selective β3-adrenergic receptor antagonist (β3-ANT), on LV dynamics during exercise in 12 chronically instrumented dogs with pacing-induced HF. Compared with HF at rest, exercise increased LV end-systolic pressure (PES), minimum LV pressure (LVPmin), and the time constant of LV relaxation (τ) with an upward shift of early diastolic portion of LV pressure-volume loop. LV contractility decreased and arterial elastance (EA) increased. LV arterial coupling (EES/EA) (0.40 vs. 0.51) was impaired. Compared with exercise in HF preparation, exercise after β3-ANT caused similar increases in heart rate and PES but significantly decreased τ (34.9 vs. 38.3 ms) and LVPmin with a downward shift of the early diastolic portion of LV pressure-volume loop and further augmented dV/dtmax. Both EES and EES/EA (0.68 vs. 0.40) were increased. LV mechanical efficiency improved from 0.39 to 0.53. In conclusion, after HF, β3-ANT improves LV diastolic filling; increases LV contractility, LV arterial coupling, and mechanical efficiency; and improves exercise performance. PMID:23873794

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

    PubMed

    Turnes, Tiago; Salvador, Amadeo Félix; Lisbôa, Felipe Domingos; de Aguiar, Rafael Alves; Cruz, Rogério Santos de Oliveira; Caputo, Fabrizio

    2014-01-01

    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.

  9. A Fast-Start Pacing Strategy Speeds Pulmonary Oxygen Uptake Kinetics and Improves Supramaximal Running Performance

    PubMed Central

    Turnes, Tiago; Salvador, Amadeo Félix; Lisbôa, Felipe Domingos; de Aguiar, Rafael Alves; Cruz, Rogério Santos de Oliveira; Caputo, Fabrizio

    2014-01-01

    The focus of the present study was to investigate the effects of a fast-start pacing strategy on running performance and pulmonary oxygen uptake () 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 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 response time is faster when a fast-start is adopted. PMID:25360744

  10. Shortening of atrioventricular delay at increased atrial paced heart rates improves diastolic filling and functional class in patients with biventricular pacing

    PubMed Central

    2012-01-01

    Background Use of rate adaptive atrioventricular (AV) delay remains controversial in patients with biventricular (Biv) pacing. We hypothesized that a shortened AV delay would provide optimal diastolic filling by allowing separation of early and late diastolic filling at increased heart rate (HR) in these patients. Methods 34 patients (75 ± 11 yrs, 24 M, LVEF 34 ± 12%) with Biv and atrial pacing had optimal AV delay determined at baseline HR by Doppler echocardiography. Atrial pacing rate was then increased in 10 bpm increments to a maximum of 90 bpm. At each atrial pacing HR, optimal AV delay was determined by changing AV delay until best E and A wave separation was seen on mitral inflow pulsed wave (PW) Doppler (defined as increased atrial duration from baseline or prior pacemaker setting with minimal atrial truncation). Left ventricular (LV) systolic ejection time and velocity time integral (VTI) at fixed and optimal AV delay was also tested in 13 patients. Rate adaptive AV delay was then programmed according to the optimal AV delay at the highest HR tested and patients were followed for 1 month to assess change in NYHA class and Quality of Life Score as assessed by Minnesota Living with Heart Failure Questionnaire. Results 81 AV delays were evaluated at different atrial pacing rates. Optimal AV delay decreased as atrial paced HR increased (201 ms at 60 bpm, 187 ms at 70 bpm, 146 ms at 80 bpm and 123 ms at 90 bpm (ANOVA F-statistic = 15, p = 0.0010). Diastolic filling time (P < 0.001 vs. fixed AV delay), mitral inflow VTI (p < 0.05 vs fixed AV delay) and systolic ejection time (p < 0.02 vs. fixed AV delay) improved by 14%, 5% and 4% respectively at optimal versus fixed AV delay at the same HR. NYHA improved from 2.6 ± 0.7 at baseline to 1.7 ± 0.8 (p < 0.01) 1 month post optimization. Physical component of Quality of Life Score improved from 32 ± 17 at baseline to 25 ± 12 (p < 0.05) at follow up. Conclusions Increased heart rate by atrial pacing in patients

  11. Characterization of excitation-contraction coupling in conscious dogs with pacing-induced heart failure.

    PubMed

    Neumann, T; Ravens, U; Heusch, G

    1998-02-01

    In isolated cardiac preparations of non-failing hearts from different species, including man, there is a positive force-frequency relation which is reversed into a negative relation in preparation from failing hearts. Whether or not such relations between ventricular function and heart rate hold true in the in situ heart is not clear at present. Mechanical restitution and postextrasystolic potentiation might serve as alternative measures of excitation-contraction coupling. Eleven dogs were instrumented with a left ventricular micromanometer, ultrasonic crystals for the measurement of regional wall thickness, two hydraulic occluders around the descending aorta and the inferior caval vein, and left atrial and ventricular pacing leads with a subcutaneous pacemaker. Left ventricular dP/dtmax, as an isovolumic phase index, and systolic wall thickening, as an ejection phase index, were plotted versus heart rate, and heart rate was increased by left atrial pacing from rest to 200 min-1 in increments of 25 min-1. In a subset of dogs, left ventricular filling was controlled and the frequency range expanded by the bradycardic agent UL-FS 49. Measurements were performed in the presence and absence of autonomic blockade (hexamethonium, atropine). Mechanical restitution and postextrasystolic potentiation were determined as normalized dP/dtmax and systolic wall thickening, respectively, of the extra- and postextrasystolic beat versus defined variations of the extrasystolic time interval (250-550 ms). Following control studies, heart failure was induced by rapid left ventricular pacing at 250 min-1 for 20 days +/- 6 (SD) and measurements repeated. Isolated left ventricular trabeculae from non-failing and failing hearts were studied during stimulation at 0.2-4 Hz. Only with filling control and in the absence of autonomic blockade, was there a slightly positive relation between dP/dtmax and heart rate in the control state. Otherwise, the relation of dP/dtmax to heart rate was flat

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

    ERIC Educational Resources Information Center

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

    2013-01-01

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

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

    PubMed Central

    2010-01-01

    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 < 0,05), and at best VV-interval to 5,4 ± 1,2 (p < 0,001). Simultaneous pacing achieved better TT distance compared with preoperative in 16 patients (76%). However, it was still higher after VV-optimization in 12 patients 57%. Corresponding figures for SMV were 3,0 ± 0,7, 3,5 ± 0,8 (p < 0,01), and 3,6 ± 0,8 (p < 0,001). Also dyssynchrony improved. 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. PMID:20384995

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

    PubMed

    Edner, Magnus; Ring, Margareta; Särev, Tooomas

    2010-04-12

    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. 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). The TT mean value preoperatively was 4.2 +/- 1.5 and increased at simultaneous pacing to 5.0 +/- 1.2 mm (p < 0.05), and at best VV-interval to 5.4 +/- 1.2 (p < 0.001). Simultaneous pacing achieved better TT distance compared with preoperative in 16 patients (76%). However, it was still higher after VV-optimization in 12 patients 57%. Corresponding figures for SMV were 3.0 +/- 0.7, 3.5 +/- 0.8 (p < 0,01), and 3.6 +/- 0.8 (p < 0.001). Also dyssynchrony improved. 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.

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

    PubMed Central

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

    2016-01-01

    Introduction Recent efforts to increase CRT response by multiSPOT pacing (MSP) from multiple bipols on the same left ventricular lead are still inconclusive. Aim The Left Ventricular (LV) MultiSPOTpacing for CRT (iSPOT) study compared the acute hemodynamic response of MSP pacing by using 3 electrodes on a quadripolar lead compared with conventional biventricular pacing (BiV). Methods Patients with left bundle branch block (LBBB) underwent an acute hemodynamic study to determine the %change in LV+dP/dtmax from baseline atrial pacing compared to the following configurations: BiV pacing with the LV lead in a one of lateral veins, while pacing from the distal, mid, or proximal electrode and all 3 electrodes together (i.e. MSP). All measurements were repeated 4 times at 5 different atrioventricular delays. We also measured QRS-width and individual Q-LV durations. Results Protocol was completed in 24 patients, all with LBBB (QRS width 171±20 ms) and 58% ischemic aetiology. The percentage change in LV+dP/dtmax for MSP pacing was 31.0±3.3% (Mean±SE), which was not significantly superior to any BiV pacing configuration: 28.9±3.2% (LV-distal), 28.3±2.7% (LV-mid), and 29.5±3.0% (LV-prox), respectively. Correlation between LV+dP/dtmax and either QRS-width or Q-LV ratio was poor. Conclusions In patients with LBBB MultiSPOT LV pacing demonstrated comparable improvement in contractility to best conventional BiV pacing. Optimization of atrioventricular delay is important for the best performance for both BiV and MultiSPOT pacing configurations. Trial Registration ClinicalTrials.gov NTC01883141 PMID:27124724

  16. Gpr176 is a Gz-linked orphan G-protein-coupled receptor that sets the pace of circadian behaviour

    PubMed Central

    Doi, Masao; Murai, Iori; Kunisue, Sumihiro; Setsu, Genzui; Uchio, Naohiro; Tanaka, Rina; Kobayashi, Sakurako; Shimatani, Hiroyuki; Hayashi, Hida; Chao, Hsu-Wen; Nakagawa, Yuuki; Takahashi, Yukari; Hotta, Yunhong; Yasunaga, Jun-ichirou; Matsuoka, Masao; Hastings, Michael H.; Kiyonari, Hiroshi; Okamura, Hitoshi

    2016-01-01

    G-protein-coupled receptors (GPCRs) participate in a broad range of physiological functions. A priority for fundamental and clinical research, therefore, is to decipher the function of over 140 remaining orphan GPCRs. The suprachiasmatic nucleus (SCN), the brain's circadian pacemaker, governs daily rhythms in behaviour and physiology. Here we launch the SCN orphan GPCR project to (i) search for murine orphan GPCRs with enriched expression in the SCN, (ii) generate mutant animals deficient in candidate GPCRs, and (iii) analyse the impact on circadian rhythms. We thereby identify Gpr176 as an SCN-enriched orphan GPCR that sets the pace of circadian behaviour. Gpr176 is expressed in a circadian manner by SCN neurons, and molecular characterization reveals that it represses cAMP signalling in an agonist-independent manner. Gpr176 acts independently of, and in parallel to, the Vipr2 GPCR, not through the canonical Gi, but via the unique G-protein subclass Gz. PMID:26882873

  17. Right ventricular free wall pacing improves cardiac pump function in severe pulmonary arterial hypertension: a computer simulation analysis.

    PubMed

    Lumens, Joost; Arts, Theo; Broers, Bernard; Boomars, Karin A; van Paassen, Pieter; Prinzen, Frits W; Delhaas, Tammo

    2009-12-01

    In pulmonary arterial hypertension (PAH), duration of myofiber shortening is prolonged in the right ventricular (RV) free wall (RVfw) compared with that in the interventricular septum and left ventricular free wall. This interventricular mechanical asynchrony eventually leads to right heart failure. We investigated by computer simulation whether, in PAH, early RVfw pacing may improve interventricular mechanical synchrony and, hence, cardiac pump function. A mathematical model of the human heart and circulation was used to simulate left ventricular and RV pump mechanics and myofiber mechanics. First, we simulated cardiovascular mechanics of a healthy adult at rest. Size and mass of heart and blood vessels were adapted so that mechanical tissue load was normalized. Second, compensated PAH was simulated by increasing mean pulmonary artery pressure to 32 mmHg while applying load adaptation. Third, decompensated PAH was simulated by increasing mean pulmonary artery pressure further to 79 mmHg without further adaptation. Finally, early RVfw pacing was simulated in severely decompensated PAH. Time courses of circumferential strain in the ventricular walls as simulated were similar to the ones measured in healthy subjects (uniform strain patterns) and in PAH patients (prolonged RVfw shortening). When simulating pacing in decompensated PAH, RV pump function was best upon 40-ms RVfw preexcitation, as evidenced by maximal decrease of RV end-diastolic volume, reduced RVfw myofiber work, and most homogeneous distribution of workload over the ventricular walls. Thus our simulations indicate that, in decompensated PAH, RVfw pacing may improve RV pump function and may homogenize workload over the ventricular walls.

  18. Importance of Gradients in Membrane Properties and Electrical Coupling in Sinoatrial Node Pacing

    PubMed Central

    Inada, Shin; Zhang, Henggui; Tellez, James O.; Shibata, Nitaro; Nakazawa, Kazuo; Kamiya, Kaichiro; Kodama, Itsuo; Mitsui, Kazuyuki; Dobrzynski, Halina; Boyett, Mark R.; Honjo, Haruo

    2014-01-01

    The sinoatrial node (SAN) is heterogeneous in terms of cell size, ion channels, current densities, connexins and electrical coupling. For example, Nav1.5 (responsible for INa) and Cx43 (responsible for electrical coupling) are absent from the centre of the SAN (normally the leading pacemaker site), but present in the periphery (at SAN-atrial muscle junction). To test whether the heterogeneity is important for the functioning of the SAN, one- and two-dimensional models of the SAN and surrounding atrial muscle were created. Normal functioning of the SAN (in terms of cycle length, position of leading pacemaker site, conduction times, activation and repolarization sequences and space constants) was observed when, from the centre to the periphery, (i) cell characteristics (cell size and ionic current densities) were changed in a gradient fashion from a central-type (lacking INa) to a peripheral-type (possessing INa) and (ii) coupling conductance was increased in a gradient fashion. We conclude that the heterogeneous nature of the node is important for its normal functioning. The presence of Nav1.5 and Cx43 in the periphery may be essential for the node to be able to drive the atrial muscle: Nav1.5 provides the necessary depolarizing current and Cx43 delivers it to the atrial muscle. PMID:24759974

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

    PubMed Central

    Kaladaridou, Anna; Bramos, Dimitrios; Skaltsiotes, Elias; Agrios, John; Pamboucas, Constantinos; Kottis, George; Antoniou, Anna; Papadopoulou, Elektra; Moulopoulos, Spyridon

    2014-01-01

    Aim. To assess the effect on left ventricular (LV) function of atrioventricular (AV) and ventricular pacing at the LV apical or lateral wall and to compare the normal torsional and deformation pattern of the intact LV myocardium with those created by the aforementioned LV pacing modes and sites. Methods. Experiments were conducted in pigs (n = 21) with normal LV function to investigate the acute hemodynamic effects of epicardial AV and ventricular LV pacing at the LV apical or lateral wall. Torsional and deformation indices of LV function were assessed using speckle tracking echocardiography. Results. AV pacing at the apex revealed a significant reduction in the radial strain of the base (P < 0.03), without affecting significantly the ejection fraction and the LV torsion or twist. In contrast, AV pacing at the lateral wall produced, in addition to the reduction of the radial strain of the base (P < 0.01), significant reduction of the circumferential and the radial strain of the apex (both P < 0.01) as well as of the ejection fraction (P < 0.002) and twist (P < 0.05). Conclusions. In pig hearts with intact myocardium, LV function is maintained at sinus rhythm level when AV pacing is performed at the LV apex. PMID:24660086

  20. Atrioventricular left ventricular apical pacing improves haemodynamic, rotational, and deformation variables in comparison to pacing at the lateral wall in intact myocardium: experimental study.

    PubMed

    Toumanidis, Savvas; Kaladaridou, Anna; Bramos, Dimitrios; Skaltsiotes, Elias; Agrios, John; Pamboucas, Constantinos; Kottis, George; Antoniou, Anna; Papadopoulou, Elektra; Moulopoulos, Spyridon

    2014-01-01

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

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

    ERIC Educational Resources Information Center

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

    2016-01-01

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

  2. Protein-Pacing from Food or Supplementation Improves Physical Performance in Overweight Men and Women: The PRISE 2 Study

    PubMed Central

    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.

    2016-01-01

    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. PMID:27187451

  3. Pacing-induced spatiotemporal dynamics can be exploited to improve reentry termination efficacy

    NASA Astrophysics Data System (ADS)

    Krogh-Madsen, Trine; Christini, David J.

    2009-08-01

    Some potentially fatal cardiac arrhythmias may be terminated by a series of premature stimuli. Monomorphic ventricular tachycardia, which may be modeled as an excitation wave traveling around in a ring, is one such arrhythmia. We investigated the mechanisms and requirements for termination of such reentry using an ionic cardiac ring model. Termination requires conduction block, which in turn is facilitated by spatial dispersion in repolarization and recovery time. When applying short series of two or three stimuli, we found that for conduction block to robustly occur, the magnitude of the spatial gradient in recovery time must exceed a critical value of 20 ms/cm. Importantly, the required spatial gradient can be induced in this homogeneous system by the dynamics of the stimulus-induced waves—we show analytically the necessary conditions. Finally, we introduce a type of pacing protocol, the “aggressive ramp,” which increases the termination efficacy by exploiting such pacing-induced heterogeneities. This technique, which is straightforward to implement, may therefore have important clinical implications.

  4. Pacing-induced spatiotemporal dynamics can be exploited to improve reentry termination efficacy.

    PubMed

    Krogh-Madsen, Trine; Christini, David J

    2009-08-01

    Some potentially fatal cardiac arrhythmias may be terminated by a series of premature stimuli. Monomorphic ventricular tachycardia, which may be modeled as an excitation wave traveling around in a ring, is one such arrhythmia. We investigated the mechanisms and requirements for termination of such reentry using an ionic cardiac ring model. Termination requires conduction block, which in turn is facilitated by spatial dispersion in repolarization and recovery time. When applying short series of two or three stimuli, we found that for conduction block to robustly occur, the magnitude of the spatial gradient in recovery time must exceed a critical value of 20 ms/cm. Importantly, the required spatial gradient can be induced in this homogeneous system by the dynamics of the stimulus-induced waves-we show analytically the necessary conditions. Finally, we introduce a type of pacing protocol, the "aggressive ramp," which increases the termination efficacy by exploiting such pacing-induced heterogeneities. This technique, which is straightforward to implement, may therefore have important clinical implications.

  5. Modulation of mitochondrial proteome and improved mitochondrial function by biventricular pacing of dyssynchronous failing hearts.

    PubMed

    Agnetti, Giulio; Kaludercic, Nina; Kane, Lesley A; Elliott, Steven T; Guo, Yurong; Chakir, Khalid; Samantapudi, Daya; Paolocci, Nazareno; Tomaselli, Gordon F; Kass, David A; Van Eyk, Jennifer E

    2010-02-01

    Cardiac resynchronization therapy (CRT) improves chamber mechanoenergetics and morbidity and mortality of patients manifesting heart failure with ventricular dyssynchrony; however, little is known about the molecular changes underlying CRT benefits. We hypothesized that mitochondria may play an important role because of their involvement in energy production. Mitochondria isolated from the left ventricle in a canine model of dyssynchronous or resynchronized (CRT) heart failure were analyzed by a classical, gel-based, proteomic approach. Two-dimensional gel electrophoresis revealed that 31 mitochondrial proteins where changed when controlling the false discovery rate at 30%. Key enzymes in anaplerotic pathways, such as pyruvate carboxylation and branched-chain amino acid oxidation, were increased. These concerted changes, along with others, suggested that CRT may increase the pool of Krebs cycle intermediates and fuel oxidative phosphorylation. Nearly 50% of observed changes pertained to subunits of the respiratory chain. ATP synthase-beta subunit of complex V was less degraded, and its phosphorylation modulated by CRT was associated with increased formation (2-fold, P=0.004) and specific activity (+20%, P=0.05) of the mature complex. The importance of these modifications was supported by coordinated changes in mitochondrial chaperones and proteases. CRT increased the mitochondrial respiratory control index with tightened coupling when isolated mitochondria were reexposed to substrates for both complex I (glutamate and malate) and complex II (succinate), an effect likely related to ATP synthase subunit modifications and complex quantity and activity. CRT potently affects both the mitochondrial proteome and the performance associated with improved cardiac function.

  6. Keeping Pace

    ERIC Educational Resources Information Center

    Henderson, Nancy

    2008-01-01

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

  7. Keeping Pace

    ERIC Educational Resources Information Center

    Henderson, Nancy

    2008-01-01

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

  8. Improving early relationships: a randomized, controlled trial of an age-paced parenting newsletter.

    PubMed

    Waterston, Tony; Welsh, Brenda; Keane, Brigid; Cook, Margaret; Hammal, Donna; Parker, Louise; McConachie, Helen

    2009-01-01

    Parenting is recognized as a key mediator in both health and educational outcomes. Much is known on the value of support and group work in benefiting parenting, but little is known on the effect of written information. A randomized, controlled trial was conducted to evaluate the effect of a parenting newsletter, sent monthly to the parents' home from birth to 1 year, on maternal well-being and parenting style. We tested the hypothesis that mothers receiving the newsletter would show less stress and better parenting characteristics than controls. Parents of first infants born in a North East England District General Hospital between February and October 2003 who consented to take part in the study were randomly allocated to either the intervention or control arm. Those in the intervention arm were sent 12 monthly issues of an age-paced parenting newsletter containing information on emotional development, parent-child interaction, and play. Both the intervention and control group received normal parenting support. Mothers in both groups completed the Well-being Index, Parenting Daily Hassles Scale, and the Adult-Adolescent Parenting Inventory at birth and at 1 year. One hundred eighty-five mothers were recruited, with 94 randomly assigned to the intervention group, and 91 controls. Allowing for differences at recruitment, there were significant differences between the groups at 1 year: the intervention mothers had lower frequency and intensity of perceived hassles and fewer inappropriate expectations of the infant on the Adult-Adolescent Parenting Inventory than the control mothers. A monthly parenting newsletter sent directly to the home in the first year of life seems to help parents to understand their infant better and feel less hassled. This intervention is low cost and can be applied to all parents, so it is nonstigmatizing.

  9. Improved fluid-structure coupling. [BWR

    SciTech Connect

    McMaster, W.H.; Gong, E.Y.; Landram, C.S.

    1981-01-01

    In the computer code PELE-IC, an incompressible Eulerian hydrodynamic algorithm was coupled to a Lagrangian finite element shell algorithm for the analysis of pressure suppression in boiling water reactors. This effort also required the development of a free surface algorithm capable of handling expanding gas bubbles. These algorithms have been improved to strengthen the coupling and to add the capability for following the more complex free surfaces resulting from steam condensation. These improvements have also permitted more economical 2D calculations and have made it feasible to develop a 3D version. A compressible option using the acoustic approximation has also been added, furthering the usefulness of the code. The coupling improvements were made in three areas which are identified as (1) preferential coupling, (2) merged cell coupling, and (3) free surface-structure coupling, and are described. These algorithms have been additionally implemented in a three dimensional version of the code called PELE3D. This version has a free surface capability to follow expanding and contracting bubbles and is coupled to a curved rigid surface.

  10. Improved Spline Coupling For Robotic Docking

    NASA Technical Reports Server (NTRS)

    Vranish, John M.

    1995-01-01

    Robotic docking mechanism like one described in "Self-Aligning Mechanical and Electrical Coupling" (GSC-13430) improved. Spline coupling redesigned to reduce stresses, enchancing performance and safety of mechanism. Does not involve significant increase in size. Convex spherical surfaces on spline driver mate with concave spherical surfaces on undersides on splines in receptacle. Spherical surfaces distribute load stresses better and tolerate misalignments better than flat and otherwise shaped surfaces.

  11. Improving Responsiveness to Intervention for English-Language Learners: A Comparison of Instructional Pace on Letter Naming Rates

    ERIC Educational Resources Information Center

    Gilbertson, Donna; Bluck, John

    2006-01-01

    An alternating treatments design was used to compare the effects of a 1-s and a 5-s paced intervention on rates of letter naming by English Language Learners (ELL). Participants were four kindergarten students performing below the average letter naming level and learning rate than other ELL classmates. The fast paced intervention consisted of a…

  12. PACE Status Update

    SciTech Connect

    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.

  13. The concept of triple wavefront fusion during biventricular pacing: Using the EGM to produce the best acute hemodynamic improvement in CRT.

    PubMed

    Ter Horst, Iris A H; Bogaard, Margot D; Tuinenburg, Anton E; Mast, Thomas P; de Boer, Teun P; Doevendans, Pieter A F M; Meine, Mathias

    2017-07-01

    Previous reports suggest that biventricular pacing (BiVp) fused with intrinsic conduction (BiVp-fusion, triple wavefront fusion) is associated with improved resynchronization compared to pure-BiVp in cardiac resynchronization therapy (CRT). This study aimed to assess the association between acute hemodynamic benefit of CRT and signs of BiVp-fusion by using a novel electrogram (EGM)-based method. In 17 patients undergoing CRT implantation, 28 combinations of atrioventricular (AV) and interventricular (VV) delays were applied while invasively measuring acute hemodynamic response based on maximum rate of left ventricular (LV) pressure rise (LV dP/dtmax ) to assess optimal BiVp settings. BiVp-fusion was noted if farfield signal (caused by first intrinsic ventricular depolarization) was seen prior to right ventricular (RV) pacing (RVp) artifact on integrated bipolar RV EGM, or QRS morphology changed compared to pure-BiVp (short AV-delay) as seen on electrocardiogram (ECG). Mean optimal RVp timing was at 98 ± 17% of intrinsic right atrial (RA)-RVfarfield (interval from right atrial pace or sense to RV farfield signal) interval, while preactivating the LV at 50 ± 11% of RA-RVsense (interval from right atrial pace or sense to RV sense interval) interval. BiVp-fusion was noted in 16 of 17 (94%) patients on ECG during optimal BiVp. Eight of these patients showed intrinsic farfield signal prior to RVp artifact on RV EGM. In the remaining eight, the RVp was paced just within the RA-RVfarfield interval with a mean of 25 ± 14 ms prior to the onset; therefore, the intrinsic farfield was masked. Optimal hemodynamic BiVp facilitates triple wavefront fusion, by pacing the RV around the onset of intrinsic farfield signal on RV EGM, while preactivating the LV. Aiming at BiVp-fusion could be a target for noninvasive EGM-based CRT device setting optimization. © 2017 Wiley Periodicals, Inc.

  14. Deception of ambient and body core temperature improves self paced cycling in hot, humid conditions.

    PubMed

    Castle, Paul C; Maxwell, Neil; Allchorn, Alan; Mauger, Alexis R; White, Danny K

    2012-01-01

    We used incorrect visual feedback of ambient and core temperature in the heat to test the hypothesis that deception would alleviate the decrement in cycling performance compared to a no deception trial. Seven males completed three 30 min cycling time trials in a randomised order on a Kingcycle ergometer. One time trial was in temperate, control conditions (CON: 21.8 ± 0.6°C; 43.3 ± 4.3%rh), the others in hot, humid conditions (HOT: 31.4 ± 0.3°C; 63.9 ± 4.5%rh). In one of the hot, humid conditions (31.6 ± 0.5°C; 65.4 ± 4.3%rh), participants were deceived (DEC) into thinking the ambient conditions were 26.0°C; 60.0%rh and their core temperature was 0.3°C lower than it really was. Compared to CON (16.63 ± 2.43 km) distance covered was lower in HOT (15.88 ± 2.75 km; P < 0.05), but DEC ameliorated this (16.74 ± 2.87 km; P < 0.05). Mean power output was greater in DEC (184.4 ± 60.4 W) than HOT (168.1 ± 54.1 W; P < 0.05) and no difference was observed between CON and DEC. Rectal temperature and iEMG of the vastus lateralis were not different, but RPE in the third minute was lower in DEC than HOT (P < 0.05). Deception improved performance in the heat by creating a lower RPE, evidence of a subtle mismatch between the subconscious expectation and conscious perception of the task demands.

  15. Polished Downhole Transducer Having Improved Signal Coupling

    DOEpatents

    Hall, David R.; Fox, Joe

    2006-03-28

    Apparatus and methods to improve signal coupling in downhole inductive transmission elements to reduce the dispersion of magnetic energy at the tool joints and to provide consistent impedance and contact between transmission elements located along the drill string. A transmission element for transmitting information between downhole tools is disclosed in one embodiment of the invention as including an annular core constructed of a magnetically conductive material. The annular core forms an open channel around its circumference and is configured to form a closed channel by mating with a corresponding annular core along an annular mating surface. The mating surface is polished to provide improved magnetic coupling with the corresponding annular core. An annular conductor is disposed within the open channel.

  16. Constant DI pacing suppresses cardiac alternans formation in numerical cable models

    NASA Astrophysics Data System (ADS)

    Zlochiver, S.; Johnson, C.; Tolkacheva, E. G.

    2017-09-01

    Cardiac repolarization alternans describe the sequential alternation of the action potential duration (APD) and can develop during rapid pacing. In the ventricles, such alternans may rapidly turn into life risking arrhythmias under conditions of spatial heterogeneity. Thus, suppression of alternans by artificial pacing protocols, or alternans control, has been the subject of numerous theoretical, numerical, and experimental studies. Yet, previous attempts that were inspired by chaos control theories were successful only for a short spatial extent (<2 cm) from the pacing electrode. Previously, we demonstrated in a single cell model that pacing with a constant diastolic interval (DI) can suppress the formation of alternans at high rates of activation. We attributed this effect to the elimination of feedback between the pacing cycle length and the last APD, effectively preventing restitution-dependent alternans from developing. Here, we extend this idea into cable models to study the extent by which constant DI pacing can control alternans during wave propagation conditions. Constant DI pacing was applied to ventricular cable models of up to 5 cm, using human kinetics. Our results show that constant DI pacing significantly shifts the onset of both cardiac alternans and conduction blocks to higher pacing rates in comparison to pacing with constant cycle length. We also demonstrate that constant DI pacing reduces the propensity of spatially discordant alternans, a precursor of wavebreaks. We finally found that the protective effect of constant DI pacing is stronger for increased electrotonic coupling along the fiber in the sense that the onset of alternans is further shifted to higher activation rates. Overall, these results support the potential clinical applicability of such type of pacing in improving protocols of implanted pacemakers, in order to reduce the risk of life-threatening arrhythmias. Future research should be conducted in order to experimentally validate

  17. Coupled improvement between thermoelectric and piezoelectric materials

    NASA Astrophysics Data System (ADS)

    Montgomery, David; Hewitt, Corey; Dun, Chaochao; Carroll, David

    A novel coupling effect in a thermoelectric and piezoelectric meta-structure is discussed. Thermo-piezoelectric generators (TPEGs) exhibit a synergistic effect that amplifies output voltage, and has been observed to increase piezoelectric voltages over 500% of initial values a time dependent thermoelectric/pyroelectric effect. The resulting improvement in voltage has been observed in carbon nanotubes as well as inorganics such as two-dimensional Bismuth Selenide platelets and Telluride nanorods thin-film thermoelectrics. TPEGs are built by integrating insulating layers of polyvinylidene fluoride (PVDF) piezoelectric films between flexible thin film p-type and n-type thermoelectrics. The physical phenomena arising in the interaction between thermoelectric and piezoelectrics is discussed and a model is presented to quantify the expected coupling voltage as a function of stress, thermal gradient, and different thermoelectric materials. TPEG are ideal to capture waste heat and vibrational energy while creating larger voltages and minimizing space when compared with similar thermoelectric or piezoelectric generators.

  18. Project for Program Improvement through the Utilization of Self-Paced Individualized Instruction Concepts Industrial Equipment Technology. Final Report.

    ERIC Educational Resources Information Center

    Crowley's Ridge Vocational Technical School, Forrest City, AR.

    The general objectives of an Arkansas technical school's self-paced individualized instruction program were designing, field testing, and disseminating an instructional management system with support materials that identify and justify the need for a program of instruction. Eight specific objectives have been developed to facilitate students'…

  19. Project for Program Improvement through the Utilization of Self-Paced Individualized Instruction Concepts Industrial Equipment Technology. Final Report.

    ERIC Educational Resources Information Center

    Crowley's Ridge Vocational Technical School, Forrest City, AR.

    The general objectives of an Arkansas technical school's self-paced individualized instruction program were designing, field testing, and disseminating an instructional management system with support materials that identify and justify the need for a program of instruction. Eight specific objectives have been developed to facilitate students'…

  20. Toward Improved Support for Loosely Coupled Large Scale Simulation Workflows

    SciTech Connect

    Boehm, Swen; Elwasif, Wael R; Naughton, III, Thomas J; Vallee, Geoffroy R

    2014-01-01

    High-performance computing (HPC) workloads are increasingly leveraging loosely coupled large scale simula- tions. Unfortunately, most large-scale HPC platforms, including Cray/ALPS environments, are designed for the execution of long-running jobs based on coarse-grained launch capabilities (e.g., one MPI rank per core on all allocated compute nodes). This assumption limits capability-class workload campaigns that require large numbers of discrete or loosely coupled simulations, and where time-to-solution is an untenable pacing issue. This paper describes the challenges related to the support of fine-grained launch capabilities that are necessary for the execution of loosely coupled large scale simulations on Cray/ALPS platforms. More precisely, we present the details of an enhanced runtime system to support this use case, and report on initial results from early testing on systems at Oak Ridge National Laboratory.

  1. Biventricular pacing in paced patients with normal hearts.

    PubMed

    Simantirakis, Emmanuel N; Arkolaki, Eva G; Chrysostomakis, Stavros I; Vardas, Panos E

    2009-11-01

    Right ventricular apical (RVA) stimulation, although beneficial in the treatment of symptomatic bradycardia, has proven detrimental in a substantial percentage of pacemaker recipients, leading to iatrogenic deterioration of left ventricular structure and function. Alternative right ventricular pacing sites appeared advantageous but their superiority has not been proven. Biventricular stimulation is effective in reducing ventricular dyssynchrony in subgroups of heart failure patients, improving their functional capacity, morbidity, and mortality. Therefore, it seems logical that this pacing strategy, by eliminating ventricular dyssynchrony, could play an important role in preventing the deleterious effects of chronic RVA stimulation in patients with normal hearts who undergo cardiac pacing for bradycardia indications. Preliminary investigations have yielded encouraging results, but further studies with harder endpoints such as quality of life, morbidity, and mortality are necessary to clarify the potentially advantageous effect of biventricular stimulation in paced patients with normal hearts.

  2. Selective pacing sites.

    PubMed

    Coppola, G; La Greca, C; Corrado, E; Ajello, L; Nogara, A; Ciaramitaro, G; Augugliaro, S; Novo, G; Novo, S; Assennato, P

    2015-04-01

    he right ventricular apex (RVA) has always been the most used pacing site, because it is easily accessible and provides a stable lead position with a low dislodgment rate. However, it is well-known that long-term right ventricular apical pacing may have deleterious effects on left ventricular function by inducing a iatrogenic left bundle branch block, which can have strong influences on the left ventricle hemodynamic performances. More specifically, RVA pacing causes abnormal contraction patterns and the consequent dyssynchrony may cause myocardial perfusion defects, histopathological alterations, left ventricular dilation and both systolic and diastolic left ventricular dysfunction. All these long-term changes could account for the higher morbidity and mortality rates observe in patients with chronic RVA pacing compared with atrial pacing. This observation led to the reassessment of traditional approaches and to the research of alternative pacing sites, in order to get to more physiological pattern of ventricular activation and to avoid deleterious effects. Then, attempts were made with: right ventricular outflow tract (RVOT) pacing, direct His bundle pacing (DHBP), parahisian pacing (PHP) and bifocal (RVA + RVOT) pacing. For example, RVOT pacing, especially in its septal portion, is superior to the RVA pacing and it would determine a contraction pattern very similar to the spontaneous one, not only because the septal portions are the first parts to became depolarized, but also for the proximity to the normal conduction system. RVOT is preferable in terms of safety too. DHBP is an attractive alternative to RVA pacing because it leads to a synchronous depolarization of myocardial cells and, therefore, to an efficient ventricular contraction. So it would be the best technique, however the procedure requires longer average implant times and dedicated instruments and it cannot be carried out in patients affected by His bundle pathologies; furthermore, due to the His

  3. Optimized temporary bi-ventricular pacing improves haemodynamic function after on-pump cardiac surgery in patients with severe left ventricular systolic dysfunction: a two-centre randomized control trial

    PubMed Central

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

    2012-01-01

    OBJECTIVES Optimized temporary bi-ventricular (BiV) pacing may benefit heart failure patients after on-pump cardiac surgery compared with conventional dual-chamber right ventricular (RV) pacing. An improvement in haemodynamic function with BiV pacing may reduce the duration of ‘Level 3’ intensive care. METHODS Thirty-eight patients in sinus rhythm, ejection fraction ≤35%, undergoing on-pump surgical revascularization, valve surgery or both were enrolled in this study. Before closing the sternum, temporary epicardial pacing wires were attached to the right atrium, RV outflow tract and basal posterolateral wall of the left ventricle. Patients were randomly assigned to postoperative BiV pacing with the optimization of the atrio- (AV) and inter-ventricular (VV) pacing intervals (Group 1) or conventional dual-chamber right AV pacing (Group 2). The primary end-point was the duration of ‘Level 3’ intensive care. Secondary end-points included cardiac output which was measured by thermodiluation at admission to the intensive care unit and at 6 and 18 h later, in five different pacing modes. RESULTS The duration of ‘Level 3’ care was similar between groups (40 ± 35 vs 54 ± 63 h; Group 1 vs 2; P = 0.43). Cardiac output was similar in all pacing modes at baseline. At 18 h, cardiac output with BiV pacing (5.8 l/min) was 7% higher than atrial inhibited (5.4 l/min) and 9% higher than dual-chamber RV pacing (5.3 l/min; P = 0.02 and 0.001, respectively). Optimization of the VV interval produced a further 4% increase in cardiac output compared with baseline settings (P = 0.005). CONCLUSIONS Postoperative haemodynamic function may be enhanced by temporary BiV pacing of high-risk patients after on-pump cardiac surgery. PMID:23138590

  4. Improved Coupling for UH-60 Performance Prediction

    NASA Technical Reports Server (NTRS)

    Romander, Ethan

    2012-01-01

    This presentation will have two parts to it. The first will consist of a review on force conservation in coupled stimulation. The second part will mainly be about the preliminary comparisons of measured/predicted blade motion. Furthermore, introduction to measurement technique and rigid body motion comparison will also be included in the presentation.

  5. Coupling device with improved thermal interface

    NASA Technical Reports Server (NTRS)

    Milam, Malcolm Bruce (Inventor)

    1992-01-01

    The primary object of the present invention is to provide a simple, reliable, and lightweight coupling that will also have an efficient thermal interface. A further object of the invention is to provide a coupling that is capable of blind mating with little or no insertion forces. Another object of the invention is to provide a coupling that acts as a thermal regulator to maintain a constant temperature on one side of the coupling. Another object of the invention is to increase the available surface area of a coupling thus providing a larger area for the conduction of heat across the thermal interface. Another object of the invention is to provide a fluidic coupling that has no fluid passing across the interface, thus reducing the likelihood of leaks and contamination. The foregoing objects are achieved by utilizing, as in the prior art, a hot area (at an elevated temperature as compared to a cold area) with a need to remove excess heat from the hot area to a cold area. In this device, the thermal interface will occur not on a planar horizontal surface, but along a non-planar vertical surface, which will reduce the reaction forces and increase the thermal conductivity of the device. One non-planar surface is a surface on a cold pin extending from the cold area and the other non-planar surface is a surface on a hot pin extending from the hot area. The cold pin is fixed and does not move while the hot pin is a flexible member and its movement towards the cold pin will bring the two non-planar surfaces together forming the thermal interface. The actuating member for the device is a shape-memory actuation wire which is attached through an aperture to the hot pin and through another aperture to an actuation wire retainer. By properly programming the actuation wire, heat from the hot area will cause the actuation wire to bend the hot wire. Heat from the hot area will cause the actuation wire to bend the hot pin towards the cold pin forming the coupling and the desired

  6. Improved media performance in optimally coupled exchange spring layer media

    NASA Astrophysics Data System (ADS)

    Berger, A.; Supper, N.; Ikeda, Y.; Lengsfield, B.; Moser, A.; Fullerton, E. E.

    2008-09-01

    We have studied the recording performance of perpendicular exchange spring layer (ESL)-media for hard disk drive recording. In particular, we investigated the role of interlayer coupling by varying the thickness of a nonmagnetic coupling layer (CL). We demonstrate that not only the media writeability is improved upon optimizing the CL thickness, but also that substantial recording performance improvements can be achieved due to improved media noise properties. The potential of these media structures for high areal density recording is demonstrated by performing areal density measurements, which showed a substantial improvement for optimally coupled ESL-media.

  7. Cardiac resynchronization therapy by multipoint pacing improves response of left ventricular mechanics and fluid dynamics: a three-dimensional and particle image velocimetry echo study.

    PubMed

    Siciliano, Mariachiara; Migliore, Federico; Badano, Luigi; Bertaglia, Emanuele; Pedrizzetti, Gianni; Cavedon, Stefano; Zorzi, Alessandro; Corrado, Domenico; Iliceto, Sabino; Muraru, Denisa

    2016-12-26

    To characterize the effect of multipoint pacing (MPP) compared to biventricular pacing (BiV) on left ventricle (LV) mechanics and intraventricular fluid dynamics by three-dimensional echocardiography (3DE) and echocardiographic particle imaging velocimetry (Echo-PIV). In 11 consecutive patients [8 men; median age 65 years (57-75)] receiving cardiac resynchronization therapy (CRT) with a quadripolar LV lead (Quartet,St.Jude Medical,Inc.), 3DE and Echo-PIV data were collected for each pacing configuration (CRT-OFF, BiV, and MPP) at follow-up after 6 months. 3DE data included LV volumes, LV ejection fraction (LVEF), strain, and systolic dyssynchrony index (SDI). Echo-PIV was used to evaluate the directional distribution of global blood flow momentum, ranging from zero, when flow force is predominantly along the base-apex direction, up to 90° when it becomes transversal. MPP resulted in significant reduction in end-diastolic and end-systolic volumes compared with both CRT-OFF (P = 0.02; P = 0.008, respectively) and BiV (P = 0.04; P = 0.03, respectively). LVEF and cardiac output were significant superior in MPP compared with CRT-OFF, but similar between MPP and BiV. Statistical significant differences when comparing global longitudinal and circumferential strain and SDI with MPP vs. CRT-OFF were observed (P = 0.008; P = 0.008; P = 0.01, respectively). There was also a trend towards improvement in strain between BiV and MPP that did not reach statistical significance. MPP reflected into a significant reduction of the deviation of global blood flow momentum compared with both CRT-OFF and BiV (P = 0.002) indicating a systematic increase of longitudinal alignment from the base-apex orientation of the haemodynamic forces. These preliminary results suggest that MPP resulted in significant improvement of LV mechanics and fluid dynamics compared with BiV. However, larger studies are needed to confirm this hypothesis. © Crown copyright 2016.

  8. Effect of Adaptive Paced Cardiolocomotor Synchronization During Running: A Preliminary Study

    PubMed Central

    Phillips, Bill; Jin, Yi

    2013-01-01

    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 performance

  9. Reversal of Pacing-Induced Cardiomyopathy by Normal QRS Axis Pacing

    PubMed Central

    Yang, Ji Hyun; Kim, Ju Youn; Kim, Sung-Hwan

    2016-01-01

    Right ventricular apical pacing has been a commonly used method for placement of permanent pacemaker, but it is known to be associated with ventricular dyssynchrony and may lead to heart failure. Septal pacing could be an alternative method to improve this complication but the results have been conflicting; hence, other strategies are needed. This case is about a patient with pacing-induced cardiomyopathy who showed much improvement after repositioning the leads to a site different from that of normally paced QRS axis. PMID:27275181

  10. Improving data transfer for model coupling

    NASA Astrophysics Data System (ADS)

    Zhang, C.; Liu, L.; Yang, G.; Li, R.; Wang, B.

    2015-10-01

    Data transfer, which means transferring data fields between two component models or rearranging data fields among processes of the same component model, is a fundamental operation of a coupler. Most of state-of-the-art coupler versions currently use an implementation based on the point-to-point (P2P) communication of the Message Passing Interface (MPI) (call such an implementation "P2P implementation" for short). In this paper, we reveal the drawbacks of the P2P implementation, including low communication bandwidth due to small message size, variable and big number of MPI messages, and jams during communication. To overcome these drawbacks, we propose a butterfly implementation for data transfer. Although the butterfly implementation can outperform the P2P implementation in many cases, it degrades the performance in some cases because the total message size transferred by the butterfly implementation is larger than that by the P2P implementation. To make the data transfer completely improved, we design and implement an adaptive data transfer library that combines the advantages of both butterfly implementation and P2P implementation. Performance evaluation shows that the adaptive data transfer library significantly improves the performance of data transfer in most cases and does not decrease the performance in any cases. Now the adaptive data transfer library is open to the public and has been imported into a coupler version C-Coupler1 for performance improvement of data transfer. We believe that it can also improve other coupler versions.

  11. Effect of biventricular pacing during a ventricular sensed event.

    PubMed

    Aktas, Mehmet Kemal; Jeevanantham, Vinodh; Sherazi, Saadia; Flynn, Dennis; Hall, Burr; Huang, David T; Rosero, Spencer; Daubert, James P; Shah, Abrar H

    2009-06-15

    Loss of biventricular (BiV) pacing occurs during ventricular sensed events such as frequent ventricular ectopy, nonsustained ventricular tachycardia, and intrinsic atrioventricular nodal conduction, such as in atrial fibrillation. Ventricular sense response (VSR) pacing, a novel cardiac resynchronization therapy pacing strategy, maintains BiV pacing during these sensed ventricular events. Patients who underwent echocardiographic optimization after BiV pacemaker implantation were enrolled, and aortic velocity-time integrals (VTIs) were recorded and compared during intrinsic conduction without pacing, optimized BiV pacing, and intrinsic conduction with VSR pacing alone. Thirty-two patients were enrolled (mean age 68 +/- 11 years, 78% men), with a mean baseline QRS duration of 164 +/- 24 ms and a mean left ventricular ejection fraction of 23 +/- 10%. The mean aortic VTI during intrinsic conduction with VSR pacing was 16.5 +/- 3.6 cm, compared with 15.3 +/- 3.4 cm during intrinsic conduction without pacing (p <0.001). The mean aortic VTI with optimized BiV pacing was 17.3 +/- 3.6 cm, significantly better (p <0.001) compared with intrinsic conduction without pacing. Improvements in aortic VTI were higher with optimized BiV pacing compared with VSR pacing alone (p = 0.02). In the subgroup of patients with left bundle branch block-type activation, the hemodynamic improvements realized with VSR pacing were similar to optimized BiV pacing. Mean aortic VTI improvements with VSR were similar in patients with ischemic and nonischemic cardiomyopathy. In conclusion, a cardiac resynchronization therapy algorithm that maintains BiV pacing during a ventricular sensed event appears to have an aortic VTI response that is significantly better compared with intrinsic conduction without pacing.

  12. Simulating PACE Global Ocean Radiances

    NASA Technical Reports Server (NTRS)

    Gregg, Watson W.; Rousseaux, Cecile S.

    2017-01-01

    The NASA PACE mission is a hyper-spectral radiometer planned for launch in the next decade. It is intended to provide new information on ocean biogeochemical constituents by parsing the details of high resolution spectral absorption and scattering. It is the first of its kind for global applications and as such, poses challenges for design and operation. To support pre-launch mission development and assess on-orbit capabilities, the NASA Global Modeling and Assimilation Office has developed a dynamic simulation of global water-leaving radiances, using an ocean model containing multiple ocean phytoplankton groups, particulate detritus, particulate inorganic carbon (PIC), and chromophoric dissolved organic carbon (CDOC) along with optical absorption and scattering processes at 1 nm spectral resolution. The purpose here is to assess the skill of the dynamic model and derived global radiances. Global bias, uncertainty, and correlation are derived using available modern satellite radiances at moderate spectral resolution. Total chlorophyll, PIC, and the absorption coefficient of CDOC (aCDOC), are simultaneously assimilated to improve the fidelity of the optical constituent fields. A 5-year simulation showed statistically significant (P < 0.05) comparisons of chlorophyll (r = 0.869), PIC (r = 0.868), and a CDOC (r =0.890) with satellite data. Additionally, diatoms (r = 0.890), cyanobacteria (r = 0.732), and coccolithophores (r = 0.716) were significantly correlated with in situ data. Global assimilated distributions of optical constituents were coupled with a radiative transfer model (Ocean-Atmosphere Spectral Irradiance Model, OASIM) to estimate normalized water-leaving radiances at 1 nm for the spectral range 250-800 nm. These unassimilated radiances were within 0.074 mW/sq cm/micron/sr of MODIS-Aqua radiances at 412, 443, 488, 531, 547, and 667 nm. This difference represented a bias of 10.4% (model low). A mean correlation of 0.706 (P < 0.05) was found with global

  13. 42 CFR 460.60 - PACE organizational structure.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... improvement program. (d) Organizational chart. (1) The PACE organization must have a current organizational chart showing officials in the PACE organization and relationships to any other organizational entities. (2) The chart for a corporate entity must indicate the PACE organization's relationship to the...

  14. 42 CFR 460.60 - PACE organizational structure.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... improvement program. (d) Organizational chart. (1) The PACE organization must have a current organizational chart showing officials in the PACE organization and relationships to any other organizational entities. (2) The chart for a corporate entity must indicate the PACE organization's relationship to the...

  15. Coupled Facility-Payload Vibration Modeling Improvements

    NASA Technical Reports Server (NTRS)

    Carnahan, Timothy M.; Kaiser, Michael A.

    2015-01-01

    A major phase of aerospace hardware verification is vibration testing. The standard approach for such testing is to use a shaker to induce loads into the payload. In preparation for vibration testing at National Aeronautics and Space Administration/Goddard Space Flight Center an analysis is performed to assess the responses of the payload. A new method of modeling the test is presented that takes into account dynamic interactions between the facility and the payload. This dynamic interaction has affected testing in the past, but been ignored or adjusted for during testing. By modeling the combined dynamics of the facility and test article (payload) it is possible to improve the prediction of hardware responses. Many aerospace test facilities work in similar way to those at NASA/Goddard Space Flight Center. Lessons learned here should be applicable to other test facilities with similar setups.

  16. Coupled Facility/Payload Vibration Modeling Improvements

    NASA Technical Reports Server (NTRS)

    Carnahan, Timothy M.; Kaiser, Michael

    2015-01-01

    A major phase of aerospace hardware verification is vibration testing. The standard approach for such testing is to use a shaker to induce loads into the payload. In preparation for vibration testing at NASA/GSFC there is an analysis to assess the responses of the payload. A new method of modeling the test is presented that takes into account dynamic interactions between the facility and the payload. This dynamic interaction has affected testing in the past, but been ignored or adjusted for during testing. By modeling the combination of the facility and test article (payload) it is possible to improve the prediction of hardware responses. Many aerospace test facilities work in similar way to those at NASA Goddard Space Flight Center. Lessons learned here should be applicable to other test facilities with similar setups.

  17. Improved multiple sequence alignments using coupled pattern mining.

    PubMed

    Hossain, K S M Tozammel; Patnaik, Debprakash; Laxman, Srivatsan; Jain, Prateek; Bailey-Kellogg, Chris; Ramakrishnan, Naren

    2013-01-01

    We present alignment refinement by mining coupled residues (ARMiCoRe), a novel approach to a classical bioinformatics problem, viz., multiple sequence alignment (MSA) of gene and protein sequences. Aligning multiple biological sequences is a key step in elucidating evolutionary relationships, annotating newly sequenced segments, and understanding the relationship between biological sequences and functions. Classical MSA algorithms are designed to primarily capture conservations in sequences whereas couplings, or correlated mutations, are well known as an additional important aspect of sequence evolution. (Two sequence positions are coupled when mutations in one are accompanied by compensatory mutations in another). As a result, better exposition of couplings is sometimes one of the reasons for hand-tweaking of MSAs by practitioners. ARMiCoRe introduces a distinctly pattern mining approach to improving MSAs: using frequent episode mining as a foundational basis, we define the notion of a coupled pattern and demonstrate how the discovery and tiling of coupled patterns using a max-flow approach can yield MSAs that are better than conservation-based alignments. Although we were motivated to improve MSAs for the sake of better exposing couplings, we demonstrate that our MSAs are also improvements in terms of traditional metrics of assessment. We demonstrate the effectiveness of ARMiCoRe on a large collection of data sets.

  18. Cardiac pacing in heart failure patients with left bundle branch block: impact of pacing site for optimizing left ventricular resynchronization.

    PubMed

    Pappone, C; Rosanio, S; Oreto, G; Tocchi, M; Gulletta, S; Salvati, A; Dicandia, C; Santinelli, V; Mazzone, P; Veglia, F; Ding, J; Sallusti, L; Spinelli, J; Vicedomini, G

    2000-07-01

    Acute left ventricular pacing has been associated with hemodynamic improvement in patients with congestive heart failure and wide QRS complex. We hypothesized that pacing two left ventricular sites simultaneously would produce faster activation and better systolic function than single-site pacing. We selected 14 heart failure patients (NYHA functional class III or IV) in normal sinus rhythm with left bundle branch block and QRS > 150 ms. An 8F dual micromanometer catheter was placed in the aorta for measuring +dP/dt (mmHg/s), aortic pulse pressure (mmHg), and end-diastolic pressure (mmHg). Pacing leads were positioned via coronary veins at the posterior base and lateral wall. Patients were acutely paced VDD at the posterior base, lateral wall, and both sites (dual-site) with 5 atrioventricular delays (from 8 ms to PR -30 ms). Pacing sequences were executed in randomized order using a custom external computer (FlexStim, Guidant CRM). Dual-site pacing increased peak +dP/dt significantly more than posterior base and lateral wall pacing. Dual-site and posterior base pacing raised aortic pulse pressure significantly more than lateral wall pacing. Dual-site pacing shortened QRS duration by 22 %, whereas posterior base and lateral wall pacing increased it by 2 and 12%, respectively (p = 0.006). In heart failure patients with left bundle branch block, dual-site pacing improves systolic function more than single-site stimulation. Improved ventricular activation synchrony, expressed by paced QRS narrowing, may account for the additional benefit of dual- vs single-site pacing in enhancing contractility. This novel approach deserves consideration for future heart failure pacing studies.

  19. Development and evaluation of the feasibility and effects on staff, patients, and families of a new tool, the Psychosocial Assessment and Communication Evaluation (PACE), to improve communication and palliative care in intensive care and during clinical uncertainty

    PubMed Central

    2013-01-01

    Background There are widespread concerns about communication and support for patients and families, especially when they face clinical uncertainty, a situation most marked in intensive care units (ICUs). Therefore, we aimed to develop and evaluate an interventional tool to improve communication and palliative care, using the ICU as an example of where this is difficult. Methods Our design was a phase I-II study following the Medical Research Council Guidance for the Development and Evaluation of Complex Interventions and the (Methods of Researching End-of-life Care (MORECare) statement. In two ICUs, with over 1900 admissions annually, phase I modeled a new intervention comprising implementation training and an assessment tool. We conducted a literature review, qualitative interviews, and focus groups with 40 staff and 13 family members. This resulted in the new tool, the Psychosocial Assessment and Communication Evaluation (PACE). Phase II evaluated the feasibility and effects of PACE, using observation, record audit, and surveys of staff and family members. Qualitative data were analyzed using the framework approach. The statistical tests used on quantitative data were t-tests (for normally distributed characteristics), the χ2 or Fisher’s exact test (for non-normally distributed characteristics) and the Mann–Whitney U-test (for experience assessments) to compare the characteristics and experience for cases with and without PACE recorded. Results PACE provides individualized assessments of all patients entering the ICU. It is completed within 24 to 48 hours of admission, and covers five aspects (key relationships, social details and needs, patient preferences, communication and information status, and other concerns), followed by recording of an ongoing communication evaluation. Implementation is supported by a training program with specialist palliative care. A post-implementation survey of 95 ICU staff found that 89% rated PACE assessment as very or

  20. Development and evaluation of the feasibility and effects on staff, patients, and families of a new tool, the Psychosocial Assessment and Communication Evaluation (PACE), to improve communication and palliative care in intensive care and during clinical uncertainty.

    PubMed

    Higginson, Irene J; Koffman, Jonathan; Hopkins, Philip; Prentice, Wendy; Burman, Rachel; Leonard, Sara; Rumble, Caroline; Noble, Jo; Dampier, Odette; Bernal, William; Hall, Sue; Morgan, Myfanwy; Shipman, Cathy

    2013-10-01

    There are widespread concerns about communication and support for patients and families, especially when they face clinical uncertainty, a situation most marked in intensive care units (ICUs). Therefore, we aimed to develop and evaluate an interventional tool to improve communication and palliative care, using the ICU as an example of where this is difficult. Our design was a phase I-II study following the Medical Research Council Guidance for the Development and Evaluation of Complex Interventions and the (Methods of Researching End-of-life Care (MORECare) statement. In two ICUs, with over 1900 admissions annually, phase I modeled a new intervention comprising implementation training and an assessment tool. We conducted a literature review, qualitative interviews, and focus groups with 40 staff and 13 family members. This resulted in the new tool, the Psychosocial Assessment and Communication Evaluation (PACE). Phase II evaluated the feasibility and effects of PACE, using observation, record audit, and surveys of staff and family members. Qualitative data were analyzed using the framework approach. The statistical tests used on quantitative data were t-tests (for normally distributed characteristics), the χ2 or Fisher's exact test (for non-normally distributed characteristics) and the Mann-Whitney U-test (for experience assessments) to compare the characteristics and experience for cases with and without PACE recorded. PACE provides individualized assessments of all patients entering the ICU. It is completed within 24 to 48 hours of admission, and covers five aspects (key relationships, social details and needs, patient preferences, communication and information status, and other concerns), followed by recording of an ongoing communication evaluation. Implementation is supported by a training program with specialist palliative care. A post-implementation survey of 95 ICU staff found that 89% rated PACE assessment as very or generally useful. Of 213 family members

  1. Burbank conducts PACE Session

    NASA Image and Video Library

    2011-12-01

    ISS030-E-007417 (1 Dec. 2011) --- In the International Space Station?s Destiny laboratory, NASA astronaut Dan Burbank, Expedition 30 commander, conducts a session with the Preliminary Advanced Colloids Experiment (PACE) at the Light Microscopy Module (LMM) in the Fluids Integrated Rack / Fluids Combustion Facility (FIR/FCF). PACE is designed to investigate the capability of conducting high magnification colloid experiments with the LMM for determining the minimum size particles which can be resolved with it.

  2. Burbank conducts PACE Session

    NASA Image and Video Library

    2011-12-01

    ISS030-E-007419 (1 Dec. 2011) --- In the International Space Station’s Destiny laboratory, NASA astronaut Dan Burbank, Expedition 30 commander, conducts a session with the Preliminary Advanced Colloids Experiment (PACE) at the Light Microscopy Module (LMM) in the Fluids Integrated Rack / Fluids Combustion Facility (FIR/FCF). PACE is designed to investigate the capability of conducting high magnification colloid experiments with the LMM for determining the minimum size particles which can be resolved with it.

  3. Burbank conducts PACE Session

    NASA Image and Video Library

    2011-12-01

    ISS030-E-007418 (1 Dec. 2011) --- In the International Space Station’s Destiny laboratory, NASA astronaut Dan Burbank, Expedition 30 commander, conducts a session with the Preliminary Advanced Colloids Experiment (PACE) at the Light Microscopy Module (LMM) in the Fluids Integrated Rack / Fluids Combustion Facility (FIR/FCF). PACE is designed to investigate the capability of conducting high magnification colloid experiments with the LMM for determining the minimum size particles which can be resolved with it.

  4. Biophysical Modelling to Simulate the Response to Multisite Left Ventricular Stimulation using a Quadripolar Pacing Lead

    PubMed Central

    Niederer, SA; Shetty, AK; Plank, G; Bostock, J; Razavi, R; Smith, NP; Rinaldi, CA

    2016-01-01

    Background Response to Cardiac Resynchronisation Therapy (CRT) is reduced in patients with postero-lateral scar. Multipolar pacing leads offer the ability to select desirable pacing sites and/or stimulate from multiple pacing sites concurrently using a single lead position. Despite this potential, the clinical evaluation and identification of metrics for optimisation of multisite CRT (MCRT) has not been performed. Methods The efficacy of MCRT via a quadripolar lead with two LV pacing sites in conjunction with RV pacing was compared with single site LV pacing using a coupled electro-mechanical biophysical model of the human heart with no, mild or severe scar in the LV postero-lateral wall. Result The maximum dP/dtmax improvement from baseline was 21%, 23%, 21% for standard CRT vs 22%, 24%, 25% for MCRT for no, mild and severe scar, respectively. In the presence of severe scar there was an incremental benefit of multisite vs standard CRT (25% vs 21%, 19% relative improvement). Minimizing total activation time (analogous to QRS duration) or minimizing the activation time of short axis slices of the heart did not correlate with CRT response. The peak electrical activation wave area in the LV corresponded with CRT response with an R2 value between 0.42-0.75. Conclusion Biophysical modelling predicts that in the presence of postero-lateral scar MCRT offers an improved response over conventional CRT. Maximising the activation wave area in the LV had the most consistent correlation with CRT response, independent of pacing protocol, scar size or lead location. PMID:22040178

  5. Pacing stress echocardiography

    PubMed Central

    Gligorova, Suzana; Agrusta, Marco

    2005-01-01

    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 values, biphasic with an

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

    PubMed

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

    2005-05-03

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

  7. Transferring PACE Assessments Upon Home Sale

    SciTech Connect

    National Renewable Energy Laboratory; 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 of this

  8. Repetitive optimizing left ventricular pacing configurations with quadripolar leads improves response to cardiac resynchronization therapy: A single-center randomized clinical trial.

    PubMed

    Gu, Min; Jin, Han; Hua, Wei; Fan, Xiao-Han; Ding, Li-Gang; Wang, Jing; Niu, Hong-Xia; Cai, Chi; Zhang, Shu

    2017-09-01

    This study aimed to investigate whether repetitive optimizing left ventricular pacing configurations (LVPCs) with quadripolar leads (QUAD) can improve response to cardiac resynchronization therapy (CRT). Fifty-two eligible patients were enrolled and 1:1 randomized to either the quadripolar LV leads (QUAD) group or the conventional bipolar leads (CONV) group. In the QUAD group, optimization of LVPC was performed for all patients before discharge and for nonresponders at 3 months follow-up. Clinical evaluations and transthoracic echocardiograms were performed before, 3, and 6 months after CRT implantation. At 3 months follow-up, 16 of 25 (64%) patients in the CONV group (1 patient was lost to follow-up) and 18 of 26 (69%) patients in the QUAD group were classified as responders. After optimizing the LVPCs in 3-month nonresponders in the QUAD group, 21 of 26 (80.8%) patients in the QUAD group were classified as responders at 6 months as compared with 17 of 25 (68%) patients in the CONV group. Left ventricular end-systolic volume (LVESV) reduction, left ventricular ejection fraction (LVEF) increase, and New York Heart Association (NYHA) functional class reduction at 6 months were significantly greater in the QUAD group than in the CONV group (LVESV: -26.9 ± 13.8 vs -17.2 ± 13.3%; P = .013; LVEF: +12.7 ± 8.0 vs +7.8 ± 6.3 percentage points; P = .017; NYHA: -1.27 ± 0.67 vs -0.72 ± 0.54 functional classes; P = .002). Compared with conventional bipolar leads, CRT using quadripolar leads with repetitive optimized LVPCs resulted in an additional increase in LVEF and reduction in LVESV and NYHA functional class at 6-month follow-up.

  9. History Teaching Project: A Project to Improve Productivity in Teaching at Carnegie-Mellon University through the Development of Self-Paced Instruction in Undergraduate History. Final Report.

    ERIC Educational Resources Information Center

    Beyer, Barry K.; And Others

    An experimental, undergraduate African-history course which used self-paced instructional techniques is described and evaluated in this project report. The project was initiated to assess the effectiveness of the Personalized System of Instruction (PSI) in undergraduate history instruction. Thirty-two students from Carnegie-Mellon University…

  10. Self-Paced Studies.

    ERIC Educational Resources Information Center

    Faust, Norma Jean

    1995-01-01

    Discusses the use of self-paced units. Development suggestions include determining the form of the units, including goals, responsibilities, and definitions of terms; keeping them short; including a variety of activities; and requiring that all lessons be completed at school. Contains sample units on climatology and meteorology, the sun, and…

  11. [Advances in cardiac pacing].

    PubMed

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

    2012-01-01

    This article contains a review of the current status of remote monitoring and follow-up involving cardiac pacing devices and of the latest developments in cardiac resynchronization therapy. In addition, the most important articles published in the last year are discussed. Copyright © 2012 Sociedad Española de Cardiología. Published by Elsevier Espana. All rights reserved.

  12. EuroPACE 2000.

    ERIC Educational Resources Information Center

    Van den Branden, Jef; Van der Perre, Georges

    1997-01-01

    Describes the Professional and Academic Channel for Europe (EuroPACE) 2000, a network of 44 traditional universities, 1 open university, and 15 partners in industry and society that supports telematics-based education and training. Looks at the network's organization, model of learning, and how it approaches virtual classrooms/campuses and…

  13. Self-Paced Studies.

    ERIC Educational Resources Information Center

    Faust, Norma Jean

    1995-01-01

    Discusses the use of self-paced units. Development suggestions include determining the form of the units, including goals, responsibilities, and definitions of terms; keeping them short; including a variety of activities; and requiring that all lessons be completed at school. Contains sample units on climatology and meteorology, the sun, and…

  14. Cardiac pacing and aviation.

    PubMed

    Toff, W D; Edhag, O K; Camm, A J

    1992-12-01

    Certain applicants with stable disturbances of rhythm or conduction requiring cardiac pacing, in whom no other disqualifying condition is present, may be considered fit for medical certification restricted to multi-crew operations. The reliability of modern pacing systems appears adequate to permit restricted certification even in pacemaker dependent subjects except for certain models of pacemakers and leads known to be at increased risk of failure. These are to be avoided. There is little evidence to suggest that newer devices are any more reliable than their predecessors. Single and dual chamber systems appear to have similar reliability up to 4 years, after which time significant attrition of dual chamber devices occurs, principally due to battery depletion. All devices require increased scrutiny as they approach their end of life as predicted from longevity data and pacing characteristics. Unipolar and bipolar leads are of similar reliability, apart from a number of specific bipolar polyurethane leads which have been identified. Atrial leads, particularly those without active fixation, are less secure than ventricular leads and applicants who are dependent on atrial sensing or pacing should be denied certification. Bipolar leads are to be preferred due to the lower risk of myopotential and exogenous EMI. Sensor-driven adaptive-rate pacing systems using active sensors may have reduced longevity and require close scrutiny. Activity-sensing devices using piezoelectric crystal sensors may be subject to significant rate rises in rotary wing aircraft. The impracticality of restricted certification in helicopters will, in any event, preclude certification. Such devices would best be avoided in hovercraft (air cushioned vehicle) pilots. Only minor rate rises are likely in fixed-wing aircraft which are unlikely to be of significance. Anti-tachycardia devices and implanted defibrillators are inconsistent with any form of certification to fly.

  15. Cardiac resynchronization as therapy for congestive cardiac failure in children dependent on chronic cardiac pacing.

    PubMed

    van Beek, Eugène; Backx, Ad; Singh, Sandeep

    2006-04-01

    Three patients with heart failure after chronic right ventricular apical pacing were treated with resynchronization. Biventricular pacing was used for two patients, and the other was treated with left univentricular pacing. In all patients, we observed a dramatic improvement of left ventricular dimension, function, and clinical state. We conclude that biventricular or left ventricular pacing is superior to right ventricular apical pacing in children who are pacemaker-dependent.

  16. Snare coupling of the pre-pectoral pacing lead delivery catheter to the femoral transseptal apparatus for endocardial cardiac resynchronization therapy : mid-term results.

    PubMed

    Patel, Mehul B; Worley, Seth J

    2013-04-01

    Limitations imposed by the coronary sinus venous anatomy triggered the transseptal approach for endocardial LV lead placement. The alignment of the interatrial septum (IAS) and its neighborhood anatomy does not favor transseptal puncture from the pre-pectoral area. Locating and advancing a pre-pectoral LV lead delivery catheter (PDC) through an opening created in the IAS via femoral transseptal puncture (FTP) is time consuming and technically difficult. We describe a method where the PDC is snare coupled to the femoral transseptal apparatus (FTA). When the FTA is advanced into the left atrium (LA) the coupled PDC follows. The catheter of a 25-mm loop snare kit is replaced with the PDC (SelectSite®). The snare loop is positioned in the right common iliac vein from the pre-pectoral access. The PDC is coupled to the FTA by advancing the transseptal apparatus through the open snare loop. After conventional FTP, the FTA is withdrawn back into the right atrium (RA) over an extra support wire positioned in the LA. The PDC with open snare loop is pulled over the FTA up to the RA. The PDC is advanced to close the snare loop on the extra support wire immediately distal to the tip of the dilator close to the puncture site. The PDC is deflected to align with the FTA. The snare coupled catheters are gently advanced across the IAS into the LA. The PDC is released from the FTA by advancing the snare and opening the loop; the snare is then removed from the PDC. The PDC is deflected and advanced into the left ventricle (LV). After positioning the 4.1 Fr lumen less LV lead, the PDC is sliced and removed. The PDC snare coupled to the FTA was advanced into the LA in all five patients, however, access was lost during catheter manipulation in the one right-sided case. Endocardial LV lead was successfully positioned in all five patients. Snare coupling the pre-pectoral SelectSite® catheter to the FTA is technically simple, reliable and a safe method for transseptal endocardial LV lead

  17. Comparison of the acute effects of right ventricular apical pacing and biventricular pacing in patients with heart failure.

    PubMed

    Kanzaki, Hideaki; Satomi, Kazuhiro; Noda, Takashi; Shimizu, Wataru; Kamakura, Shiro; Kitaura, Yasushi; Ishizaka, Nobukazu; Kitakaze, Masafumi

    2015-01-01

    Upgrading to biventricular (BiV) pacing benefits heart failure patients with right ventricular (RV) apical pacing. However, the impact of switching from RV apical pacing to BiV pacing on the left ventricular (LV) function accompanied by changes in the QRS duration remains unknown. We aimed to investigate the effects of BiV pacing in heart failure patients under RV apical pacing. In 37 patients with heart failure (LV ejection fraction: 22±9%), the maximum rate of LV pressure rise (LV dP/dtmax) and time constant of LV relaxation (tau) were determined in order to assess LV contractility and diastolic relaxation, respectively, under RV apical pacing and BiV pacing. Switching from RV pacing to BiV pacing, the QRS duration was shortened from 209±42 to 162±28 ms (p<0.001) and the LV dP/dtmax values were increased in all patients (+18.4±11.3%, p<0.001), whereas the LV tau values varied (-1.5±13.0%, p=0.723). Shortening of the QRS duration correlated with the increase in LV dP/dtmax (r=-0.689, p<0.001); however, it was not closely associated with the changes in LV tau. Switching from RV apical pacing to BiV pacing improves the LV contractile function in proportion to the degree of QRS shortening. BiV pacing is recommended in patients with systolic heart failure and a prolonged RV-paced QRS duration.

  18. Recurrent Coupling Improves Discrimination of Temporal Spike Patterns

    PubMed Central

    Yuan, Chun-Wei; Leibold, Christian

    2012-01-01

    Despite the ubiquitous presence of recurrent synaptic connections in sensory neuronal systems, their general functional purpose is not well understood. A recent conceptual advance has been achieved by theories of reservoir computing in which recurrent networks have been proposed to generate short-term memory as well as to improve neuronal representation of the sensory input for subsequent computations. Here, we present a numerical study on the distinct effects of inhibitory and excitatory recurrence in a canonical linear classification task. It is found that both types of coupling improve the ability to discriminate temporal spike patterns as compared to a purely feed-forward system, although in different ways. For a large class of inhibitory networks, the network’s performance is optimal as long as a fraction of roughly 50% of neurons per stimulus is active in the resulting population code. Thereby the contribution of inactive neurons to the neural code is found to be even more informative than that of the active neurons, generating an inherent robustness of classification performance against temporal jitter of the input spikes. Excitatory couplings are found to not only produce a short-term memory buffer but also to improve linear separability of the population patterns by evoking more irregular firing as compared to the purely inhibitory case. As the excitatory connectivity becomes more sparse, firing becomes more variable, and pattern separability improves. We argue that the proposed paradigm is particularly well-suited as a conceptual framework for processing of sensory information in the auditory pathway. PMID:22586392

  19. Improving relationships: mechanisms of change in couple therapy.

    PubMed

    Doss, Brian D; Thum, Yeow Meng; Sevier, Mia; Atkins, David C; Christensen, Andrew

    2005-08-01

    In a sample of 134 married couples randomly assigned to traditional or integrative behavioral couple therapy (TBCT vs. IBCT), a multivariate hierarchical growth curve analysis using latent variable regression revealed that measures of communication, behavior frequency, and emotional acceptance acted as mechanisms of change. TBCT led to greater changes in frequency of targeted behavior early in therapy, whereas IBCT led to greater changes in acceptance of targeted behavior both early and late in therapy. In addition, change in behavioral frequency was strongly related to improvements in satisfaction early in therapy; however, in the 2nd half of therapy, emotional acceptance was more strongly related to changes in satisfaction. Research and clinical implications are discussed. Copyright 2005 APA, all rights reserved.

  20. TCP Pacing Developed

    NASA Technical Reports Server (NTRS)

    Ivancic, William D.

    2002-01-01

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

  1. Acute hemodynamic effects of right ventricular pacing site and pacing mode in patients with congestive heart failure secondary to either ischemic or idiopathic dilated cardiomyopathy.

    PubMed

    Gold, M R; Brockman, R; Peters, R W; Olsovsky, M R; Shorofsky, S R

    2000-05-01

    The hemodynamic effects of pacing in patients with congestive heart failure (CHF) remain controversial. Early studies reported that pacing from the right ventricular (RV) apex improved acute hemodynamic parameters in patients with left ventricular systolic dysfunction, but these findings were not confirmed in subsequent controlled studies. More recently, it has been proposed that pacing from the RV side of the ventricular septum improves hemodynamic function compared with intrinsic conduction or apical pacing. Either dual-chamber or ventricular pacing have been evaluated, again with inconsistent findings. To assess the effects of pacing site and mode on acute hemodynamic function, we evaluated 21 subjects with CHF and intrinsic conduction disease. Hemodynamics were compared in AAI, VVI, and DDD modes with pacing from the RV apex or high septum. The pacing rate was constant in each patient and the order of testing was randomized. In the absence of ventricular pacing (AAI mode), the mean systemic arterial pressure was 85 +/- 11 mm Hg, the right atrial pressure was 11 +/- 4 mm Hg, the pulmonary capillary wedge pressure was 18 +/- 8 mm Hg and the cardiac index was 2.4 +/- 0.7 L/min/m(2). Compared with AAI pacing, there were no improvements in any hemodynamic parameter with DDD pacing from either RV site. Hemodynamic function worsened with VVI pacing from both RV sites. Subgroup analyses of patients with dilated cardiomyopathy, with prolonged PR interval, or with significant mitral regurgitation also failed to demonstrate an improvement with pacing. We conclude that pacing mode but not RV pacing site affects acute hemodynamic function. Pacing in the DDD mode prevents the deleterious effects of VVI pacing in this patient population.

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

    SciTech Connect

    Saha, Devashree

    2012-11-15

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

  3. Application Improvements of Slab-Coupled Optical Fiber Sensors

    NASA Astrophysics Data System (ADS)

    Chadderdon, Spencer Lee

    This dissertation explores techniques for improving slab-coupled optical fiber sensor (SCOS) technology for use in specific applications and sensing configurations. SCOS are advantageous for their small size and all-dielectric composition which permit non-intrusive measurement of electric fields within compact environments; however, their small size also limits their sensitivity. This work performs a thorough analysis of the factors contributing to the performance of SCOS and demonstrates methods which improve SCOS, while maintaining its small dimensions and high level of directional sensitivity. These improvements include increasing the sensitivity by 9x, improving the frequency response to include sub 300 kHz frequencies, and developing a method to tune the resonances. The analysis shows that the best material for the slab waveguide is an electro-optic polymer because of its low RF permittivity combined with high electro-optic coefficient. Additional improvements are based on changing the crystal orientation to a transverse configuration, which enhances the sensitivity due to a combined increase in the effective electro-optic coefficient and electric field penetration into the slab. The transverse SCOS configuration not only improves the overall sensitivity but increases the directional sensitivity of the SCOS. Lithium niobate and electro-optic polymer are both experimentally shown to exhibit minimal frequency dependent sensitivity making them suitable for broad frequency applications. Simultaneous interrogation of multiple SCOS with a single tunable laser is achieved by tuning the resonant wavelengths of KTP SCOS so their resonances overlap.

  4. Communication: Improved pair approximations in local coupled-cluster methods

    NASA Astrophysics Data System (ADS)

    Schwilk, Max; Usvyat, Denis; Werner, Hans-Joachim

    2015-03-01

    In local coupled cluster treatments the electron pairs can be classified according to the magnitude of their energy contributions or distances into strong, close, weak, and distant pairs. Different approximations are introduced for the latter three classes. In this communication, an improved simplified treatment of close and weak pairs is proposed, which is based on long-range cancellations of individually slowly decaying contributions in the amplitude equations. Benchmark calculations for correlation, reaction, and activation energies demonstrate that these approximations work extremely well, while pair approximations based on local second-order Møller-Plesset theory can lead to errors that are 1-2 orders of magnitude larger.

  5. Noninvasive external cardiac pacing for thallium-201 scintigraphy

    SciTech Connect

    Feldman, M.D.; Warren, S.E.; Gervino, E.V.; Aroesty, J.M.; Royal, H.D.; Parker, J.A.; Silverman, K.J.; Kolodny, G.M.; Zoll, P.M.; McKay, R.G.

    1988-01-01

    Improvements in noninvasive external cardiac pacing have led to a technique with reliable electrical capture and tolerable patient discomfort. To assess the use of this modality of pacing in combination with thallium scintigraphy as a noninvasive pacing stress test, we applied simultaneous noninvasive cardiac pacing, hemodynamic monitoring, and thallium-201 scintigraphy in 14 patients undergoing cardiac catheterization for chest pain syndromes. Two patients had normal coronary arteries, while the remaining 12 had significant coronary artery disease. Thallium scintigraphic responses to pacing were compared to routine exercise thallium stress testing in nine of these 14 patients. All patients were noninvasively paced to more than 85% of the age-predicted maximum heart rate. Twelve patients demonstrated reversible thallium defects, which corresponded in 11 cases to significant lesions seen on coronary angiography. Of nine patients who underwent both pacing and exercise thallium stress tests, comparable maximal rate-pressure products were achieved. Moreover, thallium imaging at peak pacing and during delayed views did not differ significantly from exercise thallium scintigraphy. A limiting factor associated with the technique was local patient discomfort, which occurred to some degree in all patients. We conclude that noninvasive external cardiac pacing together with thallium scintigraphy is capable of detecting significant coronary artery disease and may be comparable to routine exercise thallium stress testing. This new modality of stress testing could be useful in patients unable to undergo the exercise required for standard exercise tolerance testing, particularly if improvements in the technology can be found to reduce further the local discomfort.

  6. Improved measurement of ttZ couplings at the LHC

    SciTech Connect

    Baur, U.; Juste, A.; Rainwater, D.; Orr, L.H.; /Rochester U.

    2005-12-01

    We consider QCD t{bar t}Z production at the LHC with Z {yields} {bar {nu}}{nu} and all-hadronic t{bar t} decays, i.e. pp {yields} p{sub T}b{bar b}+4 jets, as a tool to measure ttZ couplings. This channel has a significantly larger cross section than those where the Z boson decays leptonically. However, t{bar t}, b{bar b} + 4 jet, t{bar t}j and t{bar t}jj production give rise to potentially large backgrounds. We show that these processes can be suppressed to an acceptable level with suitable cuts, and find that adding the p{sub T} b{bar b} + 4 jet channel to the final states used in previous ttZ couplings analyses will improve the sensitivity by 10-60%. We also discuss how the measurement of the ttZ couplings may constrain Little Higgs models.

  7. Biventricular Pacing (Cardiac Resynchronization Therapy)

    PubMed Central

    2005-01-01

    Executive Summary Issue In 2002, (before the establishment of the Ontario Health Technology Advisory Committee), the Medical Advisory Secretariat conducted a health technology policy assessment on biventricular (BiV) pacing, also called cardiac resynchronization therapy (CRT). The goal of treatment with BiV pacing is to improve cardiac output for people in heart failure (HF) with conduction defect on ECG (wide QRS interval) by synchronizing ventricular contraction. The Medical Advisory Secretariat concluded that there was evidence of short (6 months) and longer-term (12 months) effectiveness in terms of cardiac function and quality of life (QoL). More recently, a hospital submitted an application to the Ontario Health Technology Advisory Committee to review CRT, and the Medical Advisory Secretariat subsequently updated its health technology assessment. Background Chronic HF results from any structural or functional cardiac disorder that impairs the ability of the heart to act as a pump. It is estimated that 1% to 5% of the general population (all ages) in Europe have chronic HF. (1;2) About one-half of the patients with HF are women, and about 40% of men and 60% of women with this condition are aged older than 75 years. The incidence (i.e., the number of new cases in a specified period) of chronic HF is age dependent: from 1 to 5 per 1,000 people each year in the total population, to as high as 30 to 40 per 1,000 people each year in those aged 75 years and older. Hence, in an aging society, the prevalence (i.e., the number of people with a given disease or condition at any time) of HF is increasing, despite a reduction in cardiovascular mortality. A recent study revealed 28,702 patients were hospitalized for first-time HF in Ontario between April 1994 and March 1997. (3) Women comprised 51% of the cohort. Eighty-five percent were aged 65 years or older, and 58% were aged 75 years or older. Patients with chronic HF experience shortness of breath, a limited capacity

  8. Self-Paced Instruction: Hello, Education

    ERIC Educational Resources Information Center

    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. Self-Paced Instruction: Hello, Education

    ERIC Educational Resources Information Center

    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)

  10. Reader Comment: A Realistic Appraisal of First Efforts at Self-Paced Instruction

    ERIC Educational Resources Information Center

    Craver, W. Lionel, Jr.

    1974-01-01

    Examines a number of reasons for the apparent failure of self-paced instruction when it is first adopted by enthusiastic engineering instructors, and describes how and why the typical self-paced course improves during the second offering. (JR)

  11. Improved Subseasonal Prediction with Advanced Coupled Models including the 30km FIM-HYCOM Coupled Model

    NASA Astrophysics Data System (ADS)

    Benjamin, Stan; Sun, Shan; Grell, Georg; Green, Benjamin; Bleck, Rainer; Li, Haiqin

    2017-04-01

    Extreme events for subseasonal duration have been linked to multi-week processes related to onset, duration, and cessation of blocking events or, more generally, quasi-stationary waves. Results will be shown from different sets of 32-day prediction experiments (3200 runs each) over a 16-year period for earth system processes key for subseasonal prediction for different resolution, numerics, and physics using the FIM-HYCOM coupled model. The coupled atmosphere (FIM) and ocean (HYCOM) modeling system is a relatively new coupled atmosphere-ocean model developed for subseasonal to seasonal prediction (Green et al. 2017 Mon.Wea.Rev. accepted, Bleck et al 2015 Mon. Wea. Rev.). Both component models operate on a common icosahedral horizontal grid and use an adaptive hybrid vertical coordinate (sigma-isentropic in FIM and sigma-isopycnic in HYCOM). FIM-HYCOM has been used to conduct 16 years of subseasonal retrospective forecasts following the NOAA Subseasonal (SubX) NMME protocol (32-day forward integrations), run with 4 ensemble members per week. Results from this multi-year FIM-HYCOM hindcast include successful forecasts out to 14-20 days for stratospheric warming events (from archived 10 hPa fields), improved MJO predictability (Green et al. 2017) using the Grell-Freitas (2014, ACP) scale-aware cumulus scheme instead of the Simplified Arakawa-Schubert scheme, and little sensitivity to resolution for blocking frequency. Forecast skill of metrics from FIM-HYCOM including 500 hPa heights and MJO index is at least comparable to that of the operational Climate Forecast System (CFSv2) used by the National Centers for Environmental Prediction. Subseasonal skill is improved with a limited multi-model (FIM-HYCOM and CFSv2), consistent with previous seasonal multi-model ensemble results. Ongoing work will also be reported on for adding inline aerosol/chemistry treatment to the coupled FIM-HYCOM model and for advanced approaches to subgrid-scale clouds to address regional biases

  12. Improve power conversion efficiency of slab coupled optical waveguide lasers.

    PubMed

    Fan, Jiahua; Zhu, Lin; Dogan, Mehmet; Jacob, Jonah

    2014-07-28

    The slab coupled optical waveguide laser (SCOWL) is a promising candidate for high power, single mode emitter for a number of reasons, including its near diffraction limited optical quality, large modal size and near circular output pattern. Current SCOWL designs have limited electrical-optical power conversion efficiency (PCE) around 40%, which is lower than conventional RWG laser and broad area laser that are known to have much higher PCEs. To improve the SCOWL PCE, we theoretically optimize its structure by reducing Al content, increasing doping concentration and introducing a GRIN layer to prevent carrier leakage. Numerical simulations predict that an optimized SCOWL design has a maximum PCE of about 57% at room temperature.

  13. Improving the gate fidelity of capacitively coupled spin qubits

    NASA Astrophysics Data System (ADS)

    Wang, Xin; Barnes, Edwin

    2015-03-01

    Precise execution of quantum gates acting on two or multiple qubits is essential to quantum computation. For semiconductor spin qubits coupled via capacitive interaction, the best fidelity for a two-qubit gate demonstrated so far is around 70%, insufficient for fault-tolerant quantum computation. In this talk we present control protocols that may substantially improve the robustness of two-qubit gates against both nuclear noise and charge noise. Our pulse sequences incorporate simultaneous dynamical decoupling protocols and are simple enough for immediate experimental realization. Together with existing control protocols for single-qubit gates, our results constitute an important step toward scalable quantum computation using spin qubits. This work is done in collaboration with Sankar Das Sarma and supported by LPS-NSA-CMTC and IARPA-MQCO.

  14. Strong coherence between heart rate variability and intracardiac repolarization lability during biventricular pacing is associated with reverse electrical remodeling of the native conduction and improved outcome.

    PubMed

    Tereshchenko, Larisa G; Henrikson, Charles A; Berger, Ronald D

    2011-01-01

    Reverse electrical remodeling (RER) of the native conduction with cardiac resynchronization therapy (CRT) is associated with decreased mortality and antiarrhythmic effect of CRT. Still, mechanisms of RER are largely unknown. In this study, we explored repolarization lability during biventricular pacing. The width of native QRS was measured in lead II electrocardiogram before and at least 6 months after implantation of Cardiac Resynchronization Therapy Defibrillator (CRT-D) devices (Medtronic, Inc [Minneapolis, MN, USA] and Boston Scientific Corporate [Natick, MA, USA]) in 69 patients (mean age, 66.3 ± 13.9 years; 39 men [83%]) with either bundle-branch block (44 patients [64%]) or nonspecific intraventricular conduction delay (25 patients [36%]) and New York Heart Association class III and IV heart failure. Narrowing of the native QRS duration for at least 10 milliseconds was considered a marker of RER. Beat-to-beat QT variability and coherence was measured on surface electrocardiogram and intracardiac near-field electrogram during biventricular pacing. Reverse electrical remodeling was observed in 22 patients (32%) in whom coherence between heart rate variability and intracardiac repolarization lability was stronger (0.483 ± 0.243 vs 0.237 ± 0.146, P = .018) and normalized intracardiac QT variance was smaller (0.28 ± 0.0031 vs 0.46 ± 0.0048, P = .049), as compared with that in patients without RER. During a further 24 ± 13 months of follow-up, 21 patients (33%) died or experienced sustained ventricular tachycardia (VT)/ventricular fibrillation. Low intracardiac coherence (≤0.116) was associated with increased risk of death or sustained VT/VT (hazard ratio, 4.33; 95% confidence interval, 1.51-12.40; P = .006). Strong coherence between heart rate variability and intracardiac repolarization lability during biventricular pacing is associated with RER of the native conduction with CRT. Low coherence is associated with increased risk of VT

  15. Biventricular pacing: current trends and future strategies.

    PubMed

    Singh, Jagmeet P; Gras, Daniel

    2012-02-01

    The role of biventricular pacing is expanding beyond the New York Heart Association classes III and IV heart failure (HF) patient to include less symptomatic patients, earlier in the course of their disease process. This multisite pacing strategy has substantially altered the natural course of ventricular failure, exerting its physiological impact through favourable cardiac remodelling and improving the ejection fraction. This has in turn resulted in long-term clinical benefits such as improved quality of life and functional capacity with a concomitant reduction in hospitalization for HF and overall mortality. Despite the successes of cardiac resynchronization therapy (CRT) and the recent expansion of its role in the treatment of HF patients, there remain some inherent limitations to the technology and its delivery. A significant minority of patients continue to remain non-responsive to this pacing strategy. This review will highlight biventricular pacing in its present form, will elaborate on strategies to enhance response to CRT, and outline future trends and synergies towards maximizing the potential benefit of this therapeutic modality.

  16. Protein-Pacing and Multi-Component Exercise Training Improves Physical Performance Outcomes in Exercise-Trained Women: The PRISE 3 Study †

    PubMed Central

    Arciero, Paul J.; Ives, Stephen J.; Norton, Chelsea; Escudero, Daniela; Minicucci, Olivia; O’Brien, Gabe; Paul, Maia; Ormsbee, Michael J.; Miller, Vincent; Sheridan, Caitlin; He, Feng

    2016-01-01

    The beneficial cardiometabolic and body composition effects of combined protein-pacing (P; 5–6 meals/day at 2.0 g/kg BW/day) and multi-mode exercise (resistance, interval, stretching, endurance; RISE) training (PRISE) in obese adults has previously been established. The current study examines PRISE on physical performance (endurance, strength and power) outcomes in healthy, physically active women. Thirty exercise-trained women (>4 days exercise/week) were randomized to either PRISE (n = 15) or a control (CON, 5–6 meals/day at 1.0 g/kg BW/day; n = 15) for 12 weeks. Muscular strength (1-RM bench press, 1-RM BP) endurance (sit-ups, SUs; push-ups, PUs), power (bench throws, BTs), blood pressure (BP), augmentation index, (AIx), and abdominal fat mass were assessed at Weeks 0 (pre) and 13 (post). At baseline, no differences existed between groups. Following the 12-week intervention, PRISE had greater gains (p < 0.05) in SUs, PUs (6 ± 7 vs. 10 ± 7, 40%; 8 ± 13 vs. 14 ± 12, 43% ∆reps, respectively), BTs (11 ± 35 vs. 44 ± 34, 75% ∆watts), AIx (1 ± 9 vs. −5 ± 11, 120%), and DBP (−5 ± 9 vs. −11 ± 11, 55% ∆mmHg). These findings suggest that combined protein-pacing (P; 5–6 meals/day at 2.0 g/kg BW/day) diet and multi-component exercise (RISE) training (PRISE) enhances muscular endurance, strength, power, and cardiovascular health in exercise-trained, active women. PMID:27258301

  17. Improving Higgs coupling measurements through ZZ Fusion at the ILC

    SciTech Connect

    Han, Tao; Liu, Zhen; Qian, Zhuoni; Sayre, Joshua

    2015-06-17

    In this study, we evaluate the e-e+ → e-e+ + h process through the ZZ fusion channel at the International Linear Collider operating at 500 GeV and 1 TeV center-of-mass energies. We perform realistic simulations on the signal process and background processes. With judicious kinematic cuts, we find that the inclusive cross section can be measured to 2.9% after combining the 500 GeV at 500 fb-1 and 1 TeV at 1 ab-1 runs. A multivariate log-likelihood analysis further improves the precision of the cross section measurement to 2.3%. We discuss the overall improvement to model-independent Higgs width and coupling determinations and demonstrate the use of different channels in distinguishing new physics effects in Higgs physics. Our study demonstrates the importance of the ZZ fusion channel to Higgs precision physics, which has often been neglected in the literature.

  18. Improving Higgs coupling measurements through ZZ Fusion at the ILC

    DOE PAGES

    Han, Tao; Liu, Zhen; Qian, Zhuoni; ...

    2015-06-17

    In this study, we evaluate the e-e+ → e-e+ + h process through the ZZ fusion channel at the International Linear Collider operating at 500 GeV and 1 TeV center-of-mass energies. We perform realistic simulations on the signal process and background processes. With judicious kinematic cuts, we find that the inclusive cross section can be measured to 2.9% after combining the 500 GeV at 500 fb-1 and 1 TeV at 1 ab-1 runs. A multivariate log-likelihood analysis further improves the precision of the cross section measurement to 2.3%. We discuss the overall improvement to model-independent Higgs width and coupling determinations and demonstrate the usemore » of different channels in distinguishing new physics effects in Higgs physics. Our study demonstrates the importance of the ZZ fusion channel to Higgs precision physics, which has often been neglected in the literature.« less

  19. Public Assistance Comprehensive Education (PACE).

    ERIC Educational Resources Information Center

    Smith, Shirley

    The Public Assistance Comprehensive Education (PACE) Program at Bronx Community College provides programs and services to assist students on welfare to successfully overcome barriers they meet while becoming productive members of the workforce. Each semester, PACE will recruit 200 students from the COPE program and work intensively in addressing…

  20. [Percussion pacing of symptomatic bradycardia].

    PubMed

    Olesen, Mette Dam; Barnung, Steen Krøyer; Berlac, Peter Anthony

    2008-05-26

    Transvenous, transthoracic, and percussion pacing are well recognised treatments of bradycardia and asystole with residual p wave activity. We report two cases of severe bradycardia in which percussion pacing was applied and the procedure was found to be effective. This technique can be life-saving and it should be well-known by all doctors.

  1. Factors influencing pacing in triathlon

    PubMed Central

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

    2014-01-01

    Triathlon is a multisport event consisting of sequential swim, cycle, and run disciplines performed over a variety of distances. This complex and unique sport requires athletes to appropriately distribute their speed or energy expenditure (ie, pacing) within each discipline as well as over the entire event. As with most physical activity, the regulation of pacing in triathlon may be influenced by a multitude of intrinsic and extrinsic factors. The majority of current research focuses mainly on the Olympic distance, whilst much less literature is available on other triathlon distances such as the sprint, half-Ironman, and Ironman distances. Furthermore, little is understood regarding the specific physiological, environmental, and interdisciplinary effects on pacing. Therefore, this article discusses the pacing strategies observed in triathlon across different distances, and elucidates the possible factors influencing pacing within the three specific disciplines of a triathlon. PMID:25258562

  2. Factors influencing pacing in triathlon.

    PubMed

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

    2014-01-01

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

  3. Cooling performance improvements of a horizontal ground coupled heat pump

    SciTech Connect

    McGraw, B.A.; Baugh, R.N.; Johnson, W.S.; Griffith, W.

    1984-10-01

    Performance of the horizontal-coil ground-coupled heat pump system in TECH House I at the Tennessee Energy Conservation in Housing Facility is reported for the summers of 1983 and 1984. The overall coefficients of performance (COP) were 1.80 (1983 and 2.41 (1984) while the overall cooling seasonal performance factor (SPF) was 1.11 (1983) and 1.43 (1984) with the system located within the conditioned space. If the system had been outside the conditioned space, an SPF of 1.31 (1983) and 1.76 (1984) would have been realized. In both years, the systems were identical with the exception that prior to the 1984 cooling season, the ground coil was excavated and a new one of identical length was installed using sand as a backfill material. Although the 1984 SPF was 29% higher than that measured in 1983, the improvement cannot be totally attributed to the backfill material. During the summer of 1983, 30% more cooling degree days were incurred than in 1984. A decrease in runtime (as a result of lower ambient temperatures) would also increase the performance factor.

  4. Listening to music in the first, but not the last 1.5 km of a 5-km running trial alters pacing strategy and improves performance.

    PubMed

    Lima-Silva, A E; Silva-Cavalcante, M D; Pires, F O; Bertuzzi, R; Oliveira, R S F; Bishop, D

    2012-10-01

    We examined the effects of listening to music on attentional focus, rating of perceived exertion (RPE), pacing strategy and performance during a simulated 5-km running race. 15 participants performed 2 controlled trials to establish their best baseline time, followed by 2 counterbalanced experimental trials during which they listened to music during the first (M start) or the last (M finish) 1.5 km. The mean running velocity during the first 1.5 km was significantly higher in M start than in the fastest control condition (p<0.05), but there was no difference in velocity between conditions during the last 1.5 km (p>0.05). The faster first 1.5 m in M start was accompanied by a reduction in associative thoughts compared with the fastest control condition. There were no significant differences in RPE between conditions (p>0.05). These results suggest that listening to music at the beginning of a trial may draw the attentional focus away from internal sensations of fatigue to thoughts about the external environment. However, along with the reduction in associative thoughts and the increase in running velocity while listening to music, the RPE increased linearly and similarly under all conditions, suggesting that the change in velocity throughout the race may be to maintain the same rate of RPE increase.

  5. Four chamber pacing in dilated cardiomyopathy.

    PubMed

    Cazeau, S; Ritter, P; Bakdach, S; Lazarus, A; Limousin, M; Henao, L; Mundler, O; Daubert, J C; Mugica, J

    1994-11-01

    A 54-year-old man received a four chamber pacing system for severe congestive heart failure (NYHA functional Class IV). His ECG showed a left bundle branch block (200-msec QRS duration) with 200-msec PR interval, normal QRS axis, and 90-msec interatrial interval. An acute hemodynamic study with insertion of four temporary leads was performed prior to the implant, which demonstrated a significant increase in cardiac output and decrease of pulmonary capillary wedge pressure. A permanent pacemaker was implanted based on the encouraging results of the acute study. The right chamber leads were introduced by cephalic and subclavian approaches. The left atrium was paced with a coronary sinus lead, Medtronic SP 2188-58 model. An epicardial Medtronic 5071 lead was placed on the LV free wall. The four leads were connected to a standard bipolar DDD pacemaker, Chorus 6234. The two atrial leads were connected via a Y-connector to the atrial channel of the pacemaker with a bipolar pacing configuration. The two ventricular leads were connected in a similar fashion to the ventricular channel of the device. The right chamber leads were connected to the distal poles. The left chamber leads were connected to the proximal poles of the pacemaker. Six weeks later, the patient's clinical status improved markedly with a weight loss of 17 kg and disappearance of peripheral edema. His functional class was reduced to NYHA II. Four chamber pacing is technically feasible. In patients with evidence of interventricular dyssynchrony, this original pacing mode probably provides a mechanical activation sequence closer to the natural one.(ABSTRACT TRUNCATED AT 250 WORDS)

  6. Improving Relationships: Mechanisms of Change in Couple Therapy

    ERIC Educational Resources Information Center

    Doss, Brian D.; Thum, Yeow Meng; Sevier, Mia; Atkins, David C.; Christensen, Andrew

    2005-01-01

    In a sample of 134 married couples randomly assigned to traditional or integrative behavioral couple therapy (TBCT vs. IBCT), a multivariate hierarchical growth curve analysis using latent variable regression revealed that measures of communication, behavior frequency, and emotional acceptance acted as mechanisms of change. TBCT led to greater…

  7. Voluntary wheel running and pacing-induced dysfunction in hypertension.

    PubMed

    Kolwicz, Stephen C; MacDonnell, Scott M; Kendrick, Zebulon V; Houser, Steven R; Libonati, Joseph R

    2008-10-01

    We examined how voluntary wheel running in the female, spontaneously hypertensive rat (SHR) impacts myocardial tolerance to pacing stress and determined whether direct adenylyl cyclase agonism via forskolin infusion improved myocardial performance during pacing. Twenty-five 16-week-old female Wistar Kyoto (WKY, n = 8) and SHR (n = 17) were utilized. Animals within the SHR group were randomly assigned to a sedentary (SHR-SED, n = 8) or a voluntary wheel running (SHR-WHL, n = 9) group. The SHR-WHL had free access to a running wheel 24 h/day. Resting heart rates and blood pressures were collected immediately prior to sacrifice utilizing a tail cuff apparatus. Left ventricular (LV) function was measured in a Langendorff, isovolumic preparation during pacing stress (8.5 Hz) and during pacing stress + forskolin (5 micromol/L). SHR-WHL showed cardiac enlargement without alterations in heart rate, systolic blood pressure, or rate-pressure product. Pacing stress impaired inotropic and lusitropic performance to a similar extent in all groups (p < 0.05), while forskolin infusion improved LV function to a similar extent in all groups (p < 0.05). These data suggest that voluntary wheel running in SHR does not protect from pacing-induced myocardial dysfunction, and adenylyl cyclase agonism during pacing stress can functionally protect the heart. These data reiterate the importance of a competent myocardial beta-adrenergic signaling cascade.

  8. Slow Pace for Race to Top Spending

    ERIC Educational Resources Information Center

    McNeil, Michele

    2012-01-01

    Almost two years into the federal Race to the Top program, states are spending their shares of the $4 billion prize at a snail's pace--a reflection of the challenges the 12 winners face as they try to get ambitious education improvement plans off the ground. Through the end of March, the 11 states and the District of Columbia had spent just 14…

  9. Slow Pace for Race to Top Spending

    ERIC Educational Resources Information Center

    McNeil, Michele

    2012-01-01

    Almost two years into the federal Race to the Top program, states are spending their shares of the $4 billion prize at a snail's pace--a reflection of the challenges the 12 winners face as they try to get ambitious education improvement plans off the ground. Through the end of March, the 11 states and the District of Columbia had spent just 14…

  10. Improved detection and analysis of sensed and paced events in dual chamber pacemakers with extended memory function. A prospective multicenter trial in 626 patients.

    PubMed

    Sack, S; Mouton, E; Defaye, P; Dagres, N; Wolfhard, U; Wieneke, H; Herrmann, J; Oldenburg, O; Golles, A; Erbel, R

    2001-02-01

    This prospective study analyzed the incidence of atrial arrhythmias in a population of 626 patients in 173 medical centers of eleven European countries and Japan with indication for a dual chamber pacemaker system. The accuracy of the new Automatic Interpretation for Diagnosis Assistance (AIDA) program which is included in Chorus pacemakers was evaluated and the AIDA analysis was compared to and proven with Holter monitoring. Data stored in the pacemakers' memories for the first 24 hours (D1) were compared with simultaneously recorded 24-hour surface electrocardiograms, and data stored over the following 28 days (D28) were examined against reported intercurrent symptoms. At D1, atrial arrhythmias were detected by AIDA in 60 of 626 patients (12%), consisting of atrial fibrillation (n = 29), atrial flutter (n = 4), and miscellaneous arrhythmias (n = 17), and closely corroborated by Holter monitoring (sensitivity 93.7%, specificity 94.9%). At D28, 149 of 386 patients (49%) had had episodes of automatic mode switch prompted by atrial arrhythmias. Symptoms were reported by 81 patients (54%), 92 (62%) had no histories of atrial arrhythmias, and 57 patients (38%) were neither symptomatic nor had histories of atrial arrhythmias. An inverse relationship was found between the number of atrial paced events and the occurrence of atrial arrhythmias (p < 0.001). A history of atrial arrhythmias and older age were associated with a higher risk of atrial arrhythmias (p < 0.05). In contrast, gender, hypertension, concomitant heart disease, or type of atrial lead fixation system were not related with the occurrence of atrial arrhythmias. AIDA allowed to confirm, or disprove, the occurrence of atrial arrhythmias as a source of symptoms reported during long-term follow-up. It could also be used to examine the efficacy of antiarrhythmic therapy, and be of assistance when weighing the needs for anticoagulation in patients experiencing asymptomatic atrial arrhythmias.

  11. Improving the calculation of magnetic coupling constants in MRPT methods.

    PubMed

    Spivak, Mariano; Angeli, Celestino; Calzado, Carmen J; de Graaf, Coen

    2014-09-05

    The magnetic coupling in transition metal compounds with more than one unpaired electron per magnetic center has been studied with multiconfigurational perturbation theory. The usual shortcomings of these methodologies (severe underestimation of the magnetic coupling) have been overcome by describing the Slater determinants with a set of molecular orbitals that maximally resemble the natural orbitals of a high-level multiconfigurational reference configuration interaction calculation. These orbitals have significant delocalization tails onto the bridging ligands and largely increase the coupling strengths in the perturbative calculation. Copyright © 2014 Wiley Periodicals, Inc.

  12. Almanac 2013: cardiac arrhythmias and pacing.

    PubMed

    Liew, Reginald

    2013-10-01

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

  13. Optogenetic pacing in Drosophila melanogaster

    PubMed Central

    Alex, Aneesh; Li, Airong; Tanzi, Rudolph E.; Zhou, Chao

    2015-01-01

    Electrical stimulation is currently the gold standard for cardiac pacing. However, it is invasive and nonspecific for cardiac tissues. We recently developed a noninvasive cardiac pacing technique using optogenetic tools, which are widely used in neuroscience. Optogenetic pacing of the heart provides high spatial and temporal precisions, is specific for cardiac tissues, avoids artifacts associated with electrical stimulation, and therefore promises to be a powerful tool in basic cardiac research. We demonstrated optogenetic control of heart rhythm in a well-established model organism, Drosophila melanogaster. We developed transgenic flies expressing a light-gated cation channel, channelrhodopsin-2 (ChR2), specifically in their hearts and demonstrated successful optogenetic pacing of ChR2-expressing Drosophila at different developmental stages, including the larva, pupa, and adult stages. A high-speed and ultrahigh-resolution optical coherence microscopy imaging system that is capable of providing images at a rate of 130 frames/s with axial and transverse resolutions of 1.5 and 3.9 μm, respectively, was used to noninvasively monitor Drosophila cardiac function and its response to pacing stimulation. The development of a noninvasive integrated optical pacing and imaging system provides a novel platform for performing research studies in developmental cardiology. PMID:26601299

  14. On the effectiveness of self-paced learning.

    PubMed

    Tullis, Jonathan G; Benjamin, Aaron S

    2011-02-01

    Metacognitive monitoring and control must be accurate and efficient in order to allow self-guided learners to improve their performance. Yet few examples exist in which allowing learners to control learning produces higher levels of performance than restricting learners' control. Here we investigate the consequences of allowing learners to self-pace study of a list of words on later recognition, and show that learners with control of study-time allocation significantly outperformed subjects with no control, even when the total study time was equated between groups (Experiments 1 and 2). The self-pacing group also outperformed a group for which study time was automatically allocated as a function of normative item difficulty (Experiment 2). The advantage of self-pacing was apparent only in subjects who utilized a discrepancy reduction strategy-that is, who allocated more study time to normatively difficult items. Self-pacing can improve memory performance, but only when appropriate allocation strategies are used.

  15. Long-term Ventricular Pacing in Treatment of Sinoatrial Block

    PubMed Central

    Bayley, T. J.

    1971-01-01

    Six patients with symptoms due to sinoatrial block are described in whom no relief or improvement in block occurred when they were treated with isoprenaline or ephedrine. All six patients were treated by ventricular cardiac pacing with complete relief of symptoms. Despite the theoretical disadvantages of parasystole and loss of accrochage in treating these patients by ventricular pacing they have survived for periods of 18 months to over five years. PMID:5567769

  16. Aircraft Measurements for Understanding Air-Sea Coupling and Improving Coupled Model Predictions

    DTIC Science & Technology

    2013-09-30

    measured solar /IR irradiance profiles as input to, and validation of, the Navy’s coupled ocean/atmosphere model , COAMPS. FY13 effort focused on...coupling in different stages of the MJO. The objectives of the NRL project are to obtain vertical profiles of the solar and IR irradiance ...of the NRL solar and IR broadband radiometer irradiance data from the NOAA P-3 aircraft was completed. QC’ed datasets, with documentation, of the

  17. Diaphragm pacing: the state of the art

    PubMed Central

    Legras, Antoine; Arame, Alex; Pricopi, Ciprian; Boucherie, Jean-Claude; Badia, Alain; Panzini, Capucine Morelot

    2016-01-01

    Diaphragm pacing (DP) is an orphan surgical procedure that may be proposed in strictly selected ventilator-dependent patients to get an active diaphragm contraction. The goal is to wean from mechanical ventilation (MV) and restore permanent efficient breathing. The two validated indications, despite the lack of randomised control trials, concern patients with high-level spinal cord injuries (SCI) and central hypoventilation syndromes (CHS). To date, two different techniques exist. The first, intrathoracic diaphragm pacing (IT-DP), based on a radiofrequency method, in which the electrodes are directly placed around the phrenic nerve. The second, intraperitoneal diaphragm pacing (IP-DP) uses intradiaphragmatic electrodes implanted through laparoscopy. In both techniques, the phrenic nerves must be intact and diaphragm reconditioning is always required after implantation. No perioperative mortality has been reported and ventilator-weaning rate is about 72% to 96% in both techniques. Improvement of quality of life, by restoring a more physiological breathing, has been almost constant in patients that could be weaned. Failure or delay in recovery of effective diaphragm contractions could be due to irreversible amyotrophy or chest wall damage. Recent works have evaluated the interest of IP-DP in amyotrophic lateral sclerosis (ALS). After some short series were reported in the literature, the only multicentric randomized study including 74 ALS patients was prematurely stopped because of excessive mortality in paced patients. Then, another trial analysed the place of IP-DP in peripheral diaphragm dysfunction but, given the multiple biases, the published results cannot validate that indication. Reviewing all available literature as in our experience, shows that DP is an effective method to wean selected patients dependent on ventilator and improve their daily life. Other potential indications will have to be evaluated by randomised control trials. PMID:27195135

  18. Improving the well-being of couples facing cancer: a review of couples-based psychosocial interventions.

    PubMed

    Baik, Ok Mi; Adams, Kathryn Betts

    2011-04-01

    The purpose of this review article is to assess the available scientific evidence on the effects of couples-based psychosocial interventions for couples when one spouse faces cancer. For the present study, we conducted an extensive search of three electronic databases using a comprehensive search strategy. The literature search identified 14 studies evaluating couples intervention where one partner is facing cancer. Among them, eight studies concluded there was overall improvement for patients and eight studies reported overall improvement for partners, whereas an additional five studies showed partial improvement for patients and three demonstrated partial improvements for partners. Taken in the aggregate, these studies illustrated partial effectiveness--most had some positive results--but with clear limitations in terms of how many aspects of psychosocial well-being changed, lack of equal effectiveness for both patients and their partners, or limited maintenance of improvements over time, a common concern with brief psychosocial interventions. Although couples-based interventions may facilitate emotional support and dyadic coping, how these psychosocial interventions should be delivered, at what point in the illness and treatment they should be delivered, and how long they should continue remain as future challenges.

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

    ERIC Educational Resources Information Center

    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…

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

    ERIC Educational Resources Information Center

    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…

  1. MHD generator with improved network coupling electrodes to a load

    DOEpatents

    Rosa, Richard J.

    1977-01-01

    An MHD generator has a plurality of segmented electrodes extending longitudinally of a duct, whereby progressively increasing high DC voltages are derived from a set of cathode electrodes and progressively increasing low DC voltages are derived from a set of anode electrodes. First and second load terminals are respectively connected to the cathode and anode electrodes by separate coupling networks, each of which includes a number of SCR's and a number of diode rectifiers.

  2. Report: Progress Made, but Improvements Needed at CTS of Asheville Superfund Site in North Carolina to Advance Cleanup Pace and Reduce Potential Exposure

    EPA Pesticide Factsheets

    Report #16-P-0296, August 31, 2016. EPA Region 4 can accelerate the cleanup and completeness of work, and improve public communications, to better control human exposure to unsafe industrial contamination at the CTS site.

  3. School Improvement through Government Agencies: Loose or Tight Coupling?

    ERIC Educational Resources Information Center

    Bush, Tony

    2017-01-01

    In seeking to improve student outcomes, governments may choose to exercise direct control over schools, as in many centralised systems, or to provide frameworks for intermediate bodies to engage in improvement activities. One such body is the National College for School Leadership (NCSL), now the National College for Teaching and Leadership (NCTL)…

  4. Improvements in Representations of Cloud Microphysics for BBHRP and Models using Data Collected during M-PACE and TWP-ICE

    SciTech Connect

    Greg M. McFarquhar

    2010-02-22

    In our research we proposed to use data collected during the 2004 Mixed-Phase Arctic Cloud Experiment (MPACE) and the 2006 Tropical Warm Pool International Cloud Experiment (TWP-ICE) to improve retrievals of ice and mixed-phase clouds, to improve our understanding of how cloud and radiative processes affect cloud life cycles, and to develop and test methods for using ARM data more effectively in model. In particular, we proposed to: 1) use MPACE in-situ data to determine how liquid water fraction and cloud ice and liquid effective radius (r{sub ei} and r{sub ew}) vary with temperature, normalized cloud altitude and other variables for Arctic mixed-phase clouds, and to use these data to evaluate the performance of model parameterization schemes and remote sensing retrieval algorithms; 2) calculate rei and size/shape distributions using TWP-ICE in-situ data, investigate their dependence on cirrus type (oceanic or continental anvils or cirrus not directly traced to convection), and develop and test representations for MICROBASE; 3) conduct fundamental research enhancing our understanding of cloud/radiative interactions, concentrating on effects of small crystals and particle shapes and sizes on radiation; and 4) improve representations of microphysical processes for models (fall-out, effective density, mean scattering properties, rei and rew) and provide them to ARM PIs. In the course of our research, we made substantial progress on all four goals.

  5. Did recent world record marathon runners employ optimal pacing strategies?

    PubMed

    Angus, Simon D

    2014-01-01

    We apply statistical analysis of high frequency (1 km) split data for the most recent two world-record marathon runs: Run 1 (2:03:59, 28 September 2008) and Run 2 (2:03:38, 25 September 2011). Based on studies in the endurance cycling literature, we develop two principles to approximate 'optimal' pacing in the field marathon. By utilising GPS and weather data, we test, and then de-trend, for each athlete's field response to gradient and headwind on course, recovering standardised proxies for power-based pacing traces. The resultant traces were analysed to ascertain if either runner followed optimal pacing principles; and characterise any deviations from optimality. Whereas gradient was insignificant, headwind was a significant factor in running speed variability for both runners, with Runner 2 targeting the (optimal) parallel variation principle, whilst Runner 1 did not. After adjusting for these responses, neither runner followed the (optimal) 'even' power pacing principle, with Runner 2's macro-pacing strategy fitting a sinusoidal oscillator with exponentially expanding envelope whilst Runner 1 followed a U-shaped, quadratic form. The study suggests that: (a) better pacing strategy could provide elite marathon runners with an economical pathway to significant performance improvements at world-record level; and (b) the data and analysis herein is consistent with a complex-adaptive model of power regulation.

  6. Science Unit Plans. PACE '94.

    ERIC Educational Resources Information Center

    Schoon, Kenneth J., Ed.; Wiles, Clyde A., Ed.

    This booklet contains mathematics unit plans for Biology, Chemistry, and Physical Science developed by PACE (Promoting Academic Excellence In Mathematics, Science & Technology for Workers of the 21st Century). Each unit plan contains suggested timing, objectives, skills to be acquired, workplace relationships, learning activities with suggested…

  7. Pacing in Children's Television Programming.

    ERIC Educational Resources Information Center

    McCollum, James F., Jr.; Bryant, Jennings

    Following a content analysis, 85 children's programs were assigned a pacing index derived from the following criteria: (1) frequency of camera cuts; (2) frequency of related scene changes; (3) frequency of unrelated scene changes; (4) frequency of auditory changes; (5) percentage of active motion; (6) percentage of active talking; and (7)…

  8. Mathematics Unit Plans. PACE '94.

    ERIC Educational Resources Information Center

    Wiles, Clyde A., Ed.; Schoon, Kenneth J., Ed.

    This booklet contains mathematics unit plans for Algebra 1, Geometry, Math for Technology, Mathematical Problem Solving, and Pre-Algebra developed by PACE (Promoting Academic Excellence In Mathematics, Science & Technology for Workers of the 21st Century). Each unit plan contains suggested timing, objectives, skills to be acquired, workplace…

  9. Improved performance of AR-coated DFB lasers by the introduction of gain coupling

    SciTech Connect

    Morthier, G.; Vankwikelberge, P.; David, K.; Baets, R. )

    1990-03-01

    AR-coated DFB lasers with both gain- and index-coupled distributed feedback are studied numerically with respect to mode losses, mode suppression, and spatial hole burning. The mode losses and the spatial hole burning decrease with increasing gain coupling, while the mode suppression increases. It is shown that a large improvement in performance can already be obtained for small fractions of gain coupling.

  10. Improvement of uniformity in a weakly magnetized inductively coupled plasma

    NASA Astrophysics Data System (ADS)

    Lee, W. H.; Cheong, H. W.; Kim, J. W.; Whang, K. W.

    2015-12-01

    Magnetic fields are applied to inductively coupled plasma (ICP) to achieve high plasma densities using electromagnets. If the magnetic fields are set up such that the magnitude of magnetic flux density on the substrate decreases with both radial and axial distances from the substrate’s center (here after referred to as M-ICP-A), the plasma density increases by 237% compared with that for ICP although the non-uniformity of the plasma density for M-ICP-A (11.1%) is higher than that for ICP (10.9%). As the rate of decrease in the magnitude of magnetic flux density on the substrate increases both radially and axially, the non-uniformity in the plasma density increases further. The increase in the non-uniformity for M-ICP-A was confirmed to arise from the flute instability. To suppress the flute instability, we arranged the magnitude of magnetic flux density on the substrate to increase with increasing distance from the substrate center both radially and axially (here after referred to as M-ICP-V). In this configuration, plasma fluctuations were not observed, hence the plasma density non-uniformity was lowered to 8.1%, although the measured plasma density was higher than that for M-ICP-A. The oxide etch-rate non-uniformity in M-ICP-V (2.5%) was also lower than that for ICP (5.2%) or that for M-ICP-A (21.4%).

  11. Pacing in Distance Education: Something for Everyone?

    ERIC Educational Resources Information Center

    Shale, Doug G.

    1987-01-01

    Discusses the concept of pacing as it relates to distance education. Highlights include the relationship of pacing to academic standards, activity scheduling, student independence, student interaction, effective utilization of media, course materials, learning methods, student motivation, drop-out rate, and the cost effectiveness of pacing. (LRW)

  12. An Unconventional Route of Left Ventricular Pacing

    PubMed Central

    Sinha, Santosh Kumar; Varm, Chandra Mohan; Thakur, Ramesh; Krishna, Vinay; Goel, Amit; Kumar, Ashutosh; Jha, Mukesh Jitendra; Mishra, Vikas; Singh Syal, Karandeep

    2015-01-01

    We present a case of a rare complication of transvenous right ventricular pacing by temporary pacing wire causing iatrogenic interventricular septal perforation and left ventricular pacing in a 69-year-old man who was referred for recurrent syncope with sinus arrest. PMID:28197251

  13. Pacing in Distance Education: Something for Everyone?

    ERIC Educational Resources Information Center

    Shale, Doug G.

    1987-01-01

    Discusses the concept of pacing as it relates to distance education. Highlights include the relationship of pacing to academic standards, activity scheduling, student independence, student interaction, effective utilization of media, course materials, learning methods, student motivation, drop-out rate, and the cost effectiveness of pacing. (LRW)

  14. Finite element analysis of sucker rod couplings with guidelines for improving fatigue life

    SciTech Connect

    Hoffman, E.L.

    1997-09-01

    The response of a variety of sucker rod couplings to an applied axial load was simulated using axisymmetric finite element models. The calculations investigated three sucker rod sizes and various combinations of the slimhole, Spiralock, and Flexbar modifications to the coupling. In addition, the effect of various make-ups (assembly tightness) on the performance of coupling was investigated. An axial load was applied to the sucker rod ranging from {minus}5 ksi to 40 ksi, encompassing three load cycles identified on a modified Goodman diagram as acceptable for indefinite service life of the sucker rods. The simulations of the various coupling geometries and make-ups were evaluated with respect to how well they accomplish the two primary objectives of preloading threaded couplings: (1) to lock the threaded coupling together so that it will not loosen and eventually uncouple, and (2) to improve the fatigue resistance of the threaded connection by reducing the stress amplitude in the coupling when subjected to cyclic loading. Perhaps the most significant finding in this study was the characterization of the coupling parameters which affect two stress measures. The mean hydrostatic stress, which determines the permissible effective alternating stress, is a function of the coupling make-up. Whereas, the alternating effective stress is a function of the relative stiffnesses of the pin and box sections of the coupling and, as long as the coupling does not separate, is unaffected by the amount of circumferential displacement applied during make-up. The results of this study suggest approaches for improving the fatigue resistance of sucker rod couplings.

  15. Ischemic Stroke with Cardiac Pacemaker Implantation: Comparison of Physiological and Ventricular Pacing Modes.

    PubMed

    Kato, Yuji; Hayashi, Takeshi; Kato, Ritsushi; Tanahashi, Norio; Takao, Masaki

    2017-09-01

    The clinical characteristics of ischemic stroke in patients with a pacemaker (PM) are not well understood. Forty-six ischemic stroke patients with a PM were investigated retrospectively, and the impact of different pacing modes was compared. The patients were divided into a physiological pacing group (n = 22) and a ventricular pacing group (n = 24). The prevalence of atrial fibrillation (AF) was significantly higher in the ventricular pacing group (36% versus 75%; P = .008). The mean left atrial dimension was relatively large in the ventricular pacing group than in the physiological pacing group (44.5 ± 6.7 mm versus 39.1 ± 8.5 mm, respectively; P = .071). Twenty-four percent of the patients were receiving anticoagulants, whereas 41% of the patients were receiving antiplatelet drugs. Cardioembolism was the most common stroke subtype in both groups. Although there was no statistically significant difference, neurological severity on admission was higher in the ventricular pacing group than in the physiological pacing group (P = .061). Functional outcomes, excluding patients with transient ischemic attack or prior stroke, significantly declined in the ventricular pacing group compared with the physiological pacing group (P = .044). The avoidance of the ventricular pacing mode may result in improved clinical outcomes. In patients without persistent AF, it may be important to select physiological pacing instead of ventricular pacing to decrease potential stroke severity. Copyright © 2017 National Stroke Association. Published by Elsevier Inc. All rights reserved.

  16. Modeling Medicare Costs of PACE Populations

    PubMed Central

    Robinson, James; Karon, Sarita L.

    2000-01-01

    Historically, Medicare has paid PACE providers a monthly capitated rate equal to 95 percent of the site's county AAPCC multiplied by a PACE-specific frailty adjuster of 2.39. The Balanced Budget Act of 1997 makes PACE a permanent provider category and mandates that future Medicare payments be based upon the rate structure of the Medicare+Choice payment system, adjusted for the comparative frailty of PACE enrollees and other factors deemed to be appropriate by the Secretary of Health and Human Services. This study revisits the calculation of the PACE frailty adjuster and explores the effect of risk adjustment on that frailty adjuster. PMID:11481753

  17. 42 CFR 460.34 - Duration of PACE program agreement.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... (CONTINUED) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) PACE Program Agreement § 460.34 Duration of PACE program agreement. An agreement...

  18. 42 CFR 460.34 - Duration of PACE program agreement.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... (CONTINUED) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) PACE Program Agreement § 460.34 Duration of PACE program agreement. An agreement...

  19. 42 CFR 460.34 - Duration of PACE program agreement.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... (CONTINUED) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) PACE Program Agreement § 460.34 Duration of PACE program agreement. An agreement...

  20. 42 CFR 460.60 - PACE organizational structure.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... (CONTINUED) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) PACE Administrative Requirements § 460.60 PACE organizational structure. (a) A...

  1. 42 CFR 460.34 - Duration of PACE program agreement.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... (CONTINUED) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) PACE Program Agreement § 460.34 Duration of PACE program agreement. An agreement...

  2. 42 CFR 460.34 - Duration of PACE program agreement.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... (CONTINUED) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) PACE Program Agreement § 460.34 Duration of PACE program agreement. An agreement...

  3. Dual sensor VVIR mode pacing: is it worth it?

    PubMed

    Sulke, N; Tan, K; Kamalvand, K; Bostock, J; Bucknall, C

    1996-11-01

    Dual sensor ventricular demand rate responsive (VVIR mode) pacing was compared with single sensor rate responsive pacing to assess whether this new development should be more widely incorporated in modern pacemaker devices. A within patient randomized, double-blind crossover study involving ten patients, mean age 67.4 years (70% male), had Medtronic Legend Plus dual sensor VVIR pacemakers implanted for high grade AV block and chronic or persistent paroxysmal atrial fibrillation. Performance values were compared to 20 healthy control subjects of a similar age and gender. Patients were both subjectively and objectively assessed after 2 weeks of out-of-hospital activity in VVIR mode (minute ventilation sensing), VVIR mode (activity sensing), VVIR mode (dual sensor), and VVI mode (no rate response). All patients were assessed for subjective preference for, and objective improvement in, any pacing modality as assessed by standardized daily activity protocols and graded exercise treadmill testing. Subjective perception of exercise capacity and functional status was significantly lower in VVI mode (P < 0.05) compared to any of the VVIR modes, which did not differ. After completion of the study 70% of patients chose VVIR as their preferred mode, with 30% expressing no preference. Forty percent preferred activity sensor VVIR mode pacing, 30% preferred dual sensor VVIR mode pacing, and 70% found either dual sensor VVIR mode, minute ventilation sensor VVIR mode, or both modalities least acceptable. No patient found activity sensing VVIR mode least acceptable. Graded treadmill testing revealed significantly lower exercise tolerance during VVI mode pacing (P < 0.01) compared to the VVIR modalities, which did not differ. Overall, chronotropic response was best with dual sensor pacing during standardized daily activity protocols and during the standard car journey. The data from this study suggest that there is no marked clinical advantage obtained from the use of dual sensor

  4. Turbulence control with local pacing and its implication in cardiac defibrillation

    NASA Astrophysics Data System (ADS)

    Cao, Zhoujian; Li, Pengfei; Zhang, Hong; Xie, Fagen; Hu, Gang

    2007-03-01

    In this review article, we describe turbulence control in excitable systems by using a local periodic pacing method. The controllability conditions of turbulence suppression and the mechanisms underlying these conditions are analyzed. The local pacing method is applied to control Winfree turbulence (WT) and defect turbulence (DT) induced by spiral-wave breakup. It is shown that WT can always be suppressed by local pacing if the pacing amplitude and frequency are properly chosen. On the other hand, the pacing method can achieve suppression of DT induced by instabilities associated with the motions of spiral tips while failing to suppress DT induced by the instabilities of wave propagation far from tips. In the latter case, an auxiliary method of applying gradient field is suggested to improve the control effects. The implication of this local pacing method to realistic cardiac defibrillation is addressed.

  5. Optical pacing of the adult rabbit heart

    PubMed Central

    Jenkins, Michael W.; Wang, Y. T.; Doughman, Y. Q.; Watanabe, M.; Cheng, Y.; Rollins, A. M.

    2013-01-01

    Optical pacing has been demonstrated to be a viable alternative to electrical pacing in embryonic hearts. In this study, the feasibility of optically pacing an adult rabbit heart was explored. Hearts from adult New Zealand White rabbits (n = 9) were excised, cannulated and perfused on a modified Langendorff apparatus. Pulsed laser light (λ = 1851 nm) was directed to either the left or right atrium through a multimode optical fiber. An ECG signal from the left ventricle and a trigger pulse from the laser were recorded simultaneously to determine when capture was achieved. Successful optical pacing was demonstrated by obtaining pacing capture, stopping, then recapturing as well as by varying the pacing frequency. Stimulation thresholds measured at various pulse durations suggested that longer pulses (8 ms) had a lower energy capture threshold. To determine whether optical pacing caused damage, two hearts were perfused with 30 µM of propidium iodide and analyzed histologically. A small number of cells near the stimulation site had compromised cell membranes, which probably limited the time duration over which pacing was maintained. Here, short-term optical pacing (few minutes duration) is demonstrated in the adult rabbit heart for the first time. Future studies will be directed to optimize optical pacing parameters to decrease stimulation thresholds and may enable longer-term pacing. PMID:24049683

  6. Novel cable coupling technique for improved shallow distributed acoustic sensor VSPs

    NASA Astrophysics Data System (ADS)

    Munn, Jonathan D.; Coleman, Thomas I.; Parker, Beth L.; Mondanos, Michael J.; Chalari, Athena

    2017-03-01

    Vertical seismic profiles (VSPs) collected using fiber optic distributed acoustic sensors (DAS) are becoming increasingly common; yet, ensuring good cable coupling with the borehole wall remains a persistent challenge. Traditional cable deployment techniques used in the petroleum industry are either not possible or do not provide data of sufficient quality for shallow applications. Additionally, no direct field comparison of coupling techniques in the same borehole exists to determine the impacts of poor coupling on DAS VSP data quality. This paper addresses these issues by: (1) presenting a novel cable coupling solution using a removable and relatively inexpensive FLUTe™ flexible borehole liner; and (2) presenting field examples of DAS VSPs under different coupling conditions. The proposed coupling technique is analogous to a fully cemented deployment in that the cable is continuously coupled directly to the formation. Field experiments conducted to assess and validate the technique demonstrate a marked improvement in VSP data quality when the cable is coupled with a flexible borehole liner. Without the liner, seismic profiles are dominated by a high-amplitude cable wave and the p-wave arrival is not observed; however, with cable coupling provided by a borehole liner inflated using hydrostatic pressure, the cable wave is suppressed and clear p-wave arrivals are visible. Additional tests examining the influence of fiber optic cable structure on seismic responses demonstrate that tight buffered fibers are more sensitive to dynamic strain than loose tube fibers making them potentially better suited for certain DAS applications.

  7. Improvements to hydroxymethylated resorcinol coupling agent for durable bonding to wood

    Treesearch

    Alfred W. Christiansen; E. Arnold Okkonen

    2003-01-01

    Improving the exterior quality bonding of wood to epoxy adhesive resins is important for bonding glass-fiber-reinforced vinyl ester resin laminae to glulam structural members, as well as for repairing glulam members in exterior applications on site. The coupling agent for these applications, hydroxymethylated resorcinol (HMR), was recently improved by using a novolak...

  8. Cardiac Pacing - Is Telemonitoring Now Essential?

    PubMed

    Burri, Haran

    2013-11-01

    Modern pacemakers and implantable defibrillators are able to automatically perform tests executed manually during in-office visits; such as measurement of sensing and pacing thresholds. In addition, the devices also record a wealth of diagnostic data that are of clinical relevance. The advent of wireless technology in these devices allows automatic transmission of these data that can be consulted remotely by the physician. There is now solid evidence indicating that remote device follow-up can safely reduce the number of in-office visits, thereby improving convenience for patients and caregivers alike. Remote monitoring with automatic alerts for arrhythmias, heart failure and technical issues, has been shown to dramatically reduce delay to diagnosis of these events compared with standard follow-up; potentially improving patient safety and outcome. For these reasons, remote device management is becoming the standard of care.

  9. Improved modeling of photoluminescent and electroluminescent coupling in multijunction solar cells

    SciTech Connect

    Lan, Dongchen; Geisz, John F.; Steiner, Myles A.; Garcia, Ivan; Friedman, Daniel J.; Green, Martin A.

    2015-12-01

    The performance of tandem stacks of Group III-V multijunction solar cells continues to improve rapidly, both through improved performance of the individual cells in the stack and through increase in the number of stacked cells. As the radiative efficiency of these individual cells increases, radiative coupling between the stacked cells becomes an increasingly important factor not only in cell design, but also in accurate efficiency measurement and in determining performance of cells and systems under varying spectral conditions in the field. Past modeling has concentrated on electroluminescent coupling between the cells, although photoluminescent coupling is shown to be important for cells operating near their maximum power point voltage or below or when junction defect recombination is significant. Extension of earlier models is proposed to allow this non-negligible component of luminescent coupling to be included. The refined model is validated by measurement of the closely related external emission from both single and double junction cells.

  10. Tools and Trends in Self-Paced Language Instruction

    ERIC Educational Resources Information Center

    Godwin-Jones, Robert

    2007-01-01

    Ever since the PLATO system of the 1960's, CALL (computer assisted language learning) has had a major focus on providing self-paced, auto-correcting exercises for language learners to practice their skills and improve their knowledge of discrete areas of language learning. The computer has been recognized from the beginning as a patient and…

  11. Tools and Trends in Self-Paced Language Instruction

    ERIC Educational Resources Information Center

    Godwin-Jones, Robert

    2007-01-01

    Ever since the PLATO system of the 1960's, CALL (computer assisted language learning) has had a major focus on providing self-paced, auto-correcting exercises for language learners to practice their skills and improve their knowledge of discrete areas of language learning. The computer has been recognized from the beginning as a patient and…

  12. Keeping pace with Capitol Hill

    USGS Publications Warehouse

    Cooper, C.

    2007-01-01

    At the Capitol Hill, the legislative branch of the United States government, the work is always at pace. Working with Congress is a tough job yet, rewarding. The Congress worked hard together to serve the public interest but many big issues are one small part of what Congress does. However, many US news media do not report what the government does instead, the media report what the government argues about. The media reports the conflicts but story is always incomplete. In order for the people know what is happening to the government, contact the congressional representative to know the complete story.

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

    PubMed

    Deshmukh, Pramod M; Romanyshyn, Mary

    2004-06-01

    Direct His-bundle pacing (DHBP) produces rapid sequential multisite synchronous ventricular activation and, therefore, would be an ideal alternative to right ventricular apical (RVA) pacing. In 54 patients with cardiomyopathy, ejection fraction (EF) 0.23 +/- 0.11, persistent atrial fibrillation, and normal QRS < 120 ms. DHBP was attempted. This was successful in 39 patients. In seven patients, the effect of increasing heart rate on contractility (Treppe effect) was investigated. Twelve patients who also received a RVA lead underwent cardiopulmonary testing. After a mean follow-up of 42 months, 29 patients are still alive with EF improving from 0.23 +/- 0.11 to 0.33 +/- 0.15. Functional class improved from 3.5 to 2.2. DP/dt increased at each pacing site (P < 0.05) as the heart rate increased to 60, 100, and 120 beats/min. Rise in dP/dt by DHBP pacing at 120 beats/min was at least 170 +/- mmHg/s, greater than any other site in the ventricle (P < 0.05). Cardiopulmonary testing revealed longer exercise time (RVA 255 +/- 110 s) (His 280 +/- 104 s) (P < 0.05), higher O2 uptake (RVA 15 +/- 4 mL/kg per minute) (His 16 +/- 4 mL/kg minute) (P < 0.05), and later anaerobic threshold (RVA 126 +/- 71 s) (His 145 +/- 74 s) (P < 0.05) with DHBP compared to RVA pacing. Long-term DHBP is safe and effective in humans. DHBP is associated with a superior Treppe effect and increased cardiopulmonary reserve when compared to RVA pacing.

  14. COUPLING

    DOEpatents

    Frisch, E.; Johnson, C.G.

    1962-05-15

    A detachable coupling arrangement is described which provides for varying the length of the handle of a tool used in relatively narrow channels. The arrangement consists of mating the key and keyhole formations in the cooperating handle sections. (AEC)

  15. Comparison of DDD versus VVIR pacing modes in elderly patients with atrioventricular block.

    PubMed

    Kılıçaslan, Barış; Vatansever Ağca, Fahriye; Kılıçaslan, Esin Evren; Kınay, Ozan; Tigen, Kürşat; Cakır, Cayan; Nazlı, Cem; Ergene, Oktay

    2012-06-01

    Dual-chamber pacing is believed to have an advantage over single-chamber ventricular pacing. The aim of this study was to determine whether elderly patients who have implanted pacemakers for complete atrioventricular block gain significant benefits from dual-chamber (DDD) pacemakers compared with single chamber ventricular (VVIR) pacemakers. This study was designed as a randomized, two-period crossover study-each pacing mode was maintained for 1 month. Thirty patients (16 men, mean age 68.87 ± 6.89 years) with implanted DDD pacemakers were submitted to a standard protocol, which included an interview, pacemaker syndrome assessment, health related quality of life (HRQoL) questionnaires assessed by an SF-36 test, 6-minute walk test (6MWT), and transthoracic echocardiographic examinations. All of these parameters were obtained on both DDD and VVIR mode pacing. Paired data were compared. HRQoL scores were similar, and 6MWT results did not differ between the two groups. VVIR pacing elicited significant enlargement of the left atrium and impaired left ventricular diastolic functions as compared with DDD pacing. Two patients reported subclinical pacemaker syndrome, but this was not statistically significant. Our study revealed that in active elderly patients with complete heart block, DDD pacing and VVIR pacing yielded similar improvements in QoL and exercise performance. However, after a short follow-up period, we noted that VVIR pacing caused significant left atrial enlargement and impaired left ventricular diastolic functions.

  16. Pacing and Self-regulation: Important Skills for Talent Development in Endurance Sports.

    PubMed

    Elferink-Gemser, Marije T; Hettinga, Florentina J

    2017-07-01

    Pacing has been characterized as a multifaceted goal-directed process of decision making in which athletes need to decide how and when to invest their energy during the race, a process essential for optimal performance. Both physiological and psychological characteristics associated with adequate pacing and performance are known to develop with age. Consequently, the multifaceted skill of pacing might be under construction throughout adolescence, as well. Therefore, the authors propose that the complex skill of pacing is a potential important performance characteristic for talented youth athletes that needs to be developed throughout adolescence. To explore whether pacing is a marker for talent and how talented athletes develop this skill in middle-distance and endurance sports, they aim to bring together literature on pacing and literature on talent development and self-regulation of learning. Subsequently, by applying the cyclical process of self-regulation to pacing, they propose a practical model for the development of performance in endurance sports in youth athletes. Not only is self-regulation essential throughout the process of reaching the long-term goal of athletic excellence, but it also seems crucial for the development of pacing skills within a race and the development of a refined performance template based on previous experiences. Coaches and trainers are advised to incorporate pacing as a performance characteristic in their talent-development programs by stimulating their athletes to reflect, plan, monitor, and evaluate their races on a regular basis to build performance templates and, as such, improve their performance.

  17. Improving field enhancement of 2D hollow tapered waveguides via dielectric microcylinder coupling

    NASA Astrophysics Data System (ADS)

    Chen, Yongzhu; Xie, Xiangsheng; Li, Li; Chen, Gengyan; Guo, Lina; Lin, Xusheng

    2015-02-01

    We numerically study a novel scheme to improve the field enhancement of 2D hollow tapered waveguides (HTWs). A dielectric microcylinder is embedded into a metal-insulator-metal (MIM) HTW for resonant exciting gap surface plasmons (GSPs), which is different from the lowest propagating mode (TM0) excitation via the conventional fire-end coupling method. The physical mechanism of the field enhancement and the influence of critical parameters such as numerical aperture (NA) of the lens, permittivity of the microcylinder and the incident wavelength are discussed. The substantial improvement of the GSP excitation efficiency via dielectric microcylinder coupling shows potential in designing tapered MIM waveguides for nanofocusing and field enhancement.

  18. Adaptation of naturally paced saccades

    PubMed Central

    Blangero, Annabelle; Herman, James P.; Wallman, Josh; Harwood, Mark R.

    2014-01-01

    In the natural environment, humans make saccades almost continuously. In many eye movement experiments, however, observers are required to fixate for unnaturally long periods of time. The resulting long and monotonous experimental sessions can become especially problematic when collecting data in a clinical setting, where time can be scarce and subjects easily fatigued. With this in mind, we tested whether the well-studied motor learning process of saccade adaptation could be induced with a dramatically shortened intertrial interval. Observers made saccades to targets that stepped left or right either ∼250 ms or ∼1,600 ms after the saccade landed. In experiment I, we tested baseline saccade parameters to four different target amplitudes (5°, 10°, 15°, and 20°) in the two timing settings. In experiments II and III, we adapted 10° saccades via 2° intrasaccadic steps either backwards or forwards, respectively. Seven subjects performed eight separate adaptation sessions (2 intertrial timings × 2 adaptation direction × 2 session trial lengths). Adaptation proceeded remarkably similarly in both timing conditions across the multiple sessions. In the faster-paced sessions, robust adaptation was achieved in under 2 min, demonstrating the efficacy of our approach to streamlining saccade adaptation experiments. Although saccade amplitudes were similar between conditions, the faster-paced condition unexpectedly resulted in significantly higher peak velocities in all subjects. This surprising finding demonstrates that the stereotyped “main sequence” relationship between saccade amplitude and peak velocity is not as fixed as originally thought. PMID:24623511

  19. Thallium cardiac stressing by esophageal pacing

    SciTech Connect

    Allen, M.L.; Vacek, J.L.; Preston, D.F.; Robinson, R.G.; Feldkamp, M.J. )

    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.

  20. PACE: Proactively Secure Accumulo with Cryptographic Enforcement

    DTIC Science & Technology

    2017-05-27

    Microbenchmark Harness (JMH).2 We measured the performance of PACE’s encryption and signature functionality, both for reading and writing records...the run, including the time to setup PACE and to read or write the records. Instead of reporting on total time, we report on throughput—the number of...reads or writes per second. The purpose of this evaluation is to compare the performance of PACE-enabled versus non-PACE-enabled clients. Specifi

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

    NASA Astrophysics Data System (ADS)

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

    2016-05-01

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

  2. Couple Therapy with Veterans: Early Improvements and Predictors of Early Dropout.

    PubMed

    Fischer, Melanie S; Bhatia, Vickie; Baddeley, Jenna L; Al-Jabari, Rawya; Libet, Julian

    2017-07-28

    Family services within Veterans Affairs Medical Centers fulfill an important role in addressing relationship distress among Veterans, which is highly prevalent and comorbid with psychopathology. However, even for evidence-based couple therapies, effectiveness is weaker compared to controlled studies, maybe because many Veteran couples drop out early and do not reach the "active" treatment stage after the 3-4 session assessment. In order to improve outcomes, it is critical to identify couples at high risk for early dropout, and understand whether couples may benefit from the assessment as an intervention. The current study examined (a) demographics, treatment delivery mode, relationship satisfaction, and psychological symptoms as predictors of dropout during and immediately following the assessment phase, and (b) changes in relationship satisfaction during assessment. 174 couples completed questionnaires during routine intake procedures. The main analyses focused on 140 male Veterans and their female civilian partners; 36.43% dropped out during the assessment phase and 24.74% of the remaining couples immediately following the first treatment session. More severe depressive symptoms in non-Veteran partners were associated with dropout during assessment. Relationship satisfaction improved significantly during the assessment phase for couples who did not drop out, with larger gains for non-Veteran partners. No demographics or treatment delivery mode were associated with dropout. Although more research is needed on engaging couples at risk for early dropout and maximizing early benefits, the findings suggest that clinicians should attend to the civilian partner's and Veteran's depressive symptoms at intake and consider the assessment part of active treatment. © 2017 Family Process Institute.

  3. Coupling Advanced Modeling and Visualization to Improve High-Impact Tropical Weather Prediction

    NASA Technical Reports Server (NTRS)

    Shen, Bo-Wen; Tao, Wei-Kuo; Green, Bryan

    2009-01-01

    To meet the goals of extreme weather event warning, this approach couples a modeling and visualization system that integrates existing NASA technologies and improves the modeling system's parallel scalability to take advantage of petascale supercomputers. It also streamlines the data flow for fast processing and 3D visualizations, and develops visualization modules to fuse NASA satellite data.

  4. Improving Relationship Satisfaction--Qualitative Insights Derived from Individuals Currently within a Couple Relationship

    ERIC Educational Resources Information Center

    Coleman, Lester M.

    2011-01-01

    Given the prevalence of relationship breakdown, and the unequivocal association with poor outcomes, ways in which to improve relationship satisfaction are of great importance. Derived from in-depth interviews with 112 individuals in a couple relationship, this study aims to explore and understand different beliefs and perceived capabilities toward…

  5. Coupling Advanced Modeling and Visualization to Improve High-Impact Tropical Weather Prediction

    NASA Technical Reports Server (NTRS)

    Shen, Bo-Wen; Tao, Wei-Kuo; Green, Bryan

    2009-01-01

    To meet the goals of extreme weather event warning, this approach couples a modeling and visualization system that integrates existing NASA technologies and improves the modeling system's parallel scalability to take advantage of petascale supercomputers. It also streamlines the data flow for fast processing and 3D visualizations, and develops visualization modules to fuse NASA satellite data.

  6. Identification and reliability of pacing strategies in outrigger canoeing ergometry.

    PubMed

    Sealey, Rebecca M; Spinks, Warwick L; Leicht, Anthony S; Sinclair, Wade H

    2010-03-01

    This study examined the pacing strategies utilised; and the performance reproducibility during repeated outrigger canoeing ergometer time trials. Trained female outrigger canoeists (N=11) completed four 1000m outrigger canoe ergometer time trials. There was a significant 1.5% improvement in 1000m time in trial four compared to trial one. A fast start strategy was adopted in 36 of the 44 trials (82%) followed by a deceleration during the mid stages. As trials progressed there was an increased adoption of negative pacing (fast finish) between the last two splits, indicating a learning effect of pacing strategy across repeated trials. These results demonstrate that although some performance improvement was evident between the first and fourth time trials, the 1000m outrigger ergometer time trial is a reliable test that may be used as a tool to assist with crew selection and performance monitoring. Further, on account of the variation in pacing strategy noted in the fourth trial, the authors recommend utilising one familiarisation session and one test session when assessing performance such that learning or training adaptations resulting from multiple trials do not impact on results.

  7. A decade of nuclear pacing

    SciTech Connect

    Parsonnet, V.; Gilbert, L.; Zucker, I.R.; Werres, R.; Atherley, T.; Manhardt, M.; Cort, J.

    1984-01-01

    In April, 1973, a decade-long study was begun on nuclear-powered pacemakers. The first 15 of these were designed by the Numec Corporation under a contract from the United States Atomic Energy Commission. Altogether 151 units powered by the isotope plutonium 238 were implanted in 131 patients; the pacemakers of 4 different manufacturers were used. The last nuclear pacemaker was implanted in January, 1983. The actuarial survival at 10 years was 92%, meeting the original performance goal of the Commission of 90%. Ninety pulse generators are still in service today; 25 patients have died and 36 pulse generators have been replaced with non-nuclear units. The most common indication for replacement was an inappropriate pacing mode. This high reliability and superior performance suggest that continued use of a radioisotopic power source is justified, particularly if combined with the electronic circuits of today's dual-chambered, multiprogrammable, and multifunctional pacemakers.

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

    PubMed

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

    2015-08-26

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

  9. Self-Paced Training: Perceptions and Realities.

    ERIC Educational Resources Information Center

    Wulfeck, Wallace H., II; And Others

    Currently, there is concern about the quality of Navy training. This concern is best exemplified by the present debate over the adequacy of "self-pacing" in Navy training courses. This paper illuminates some perceptions surrounding self-pacing in Navy training, explores some realities of Navy training, and presents a recommendation about…

  10. Update in cardiac arrhythmias and pacing.

    PubMed

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

    2015-03-01

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

  11. Web Tools: Keeping Learners on Pace

    ERIC Educational Resources Information Center

    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…

  12. 42 CFR 460.186 - PACE premiums.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 4 2014-10-01 2014-10-01 false PACE premiums. 460.186 Section 460.186 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY...

  13. 42 CFR 460.186 - PACE premiums.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 4 2011-10-01 2011-10-01 false PACE premiums. 460.186 Section 460.186 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY...

  14. 42 CFR 460.186 - PACE premiums.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 4 2013-10-01 2013-10-01 false PACE premiums. 460.186 Section 460.186 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY...

  15. Web Tools: Keeping Learners on Pace

    ERIC Educational Resources Information Center

    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…

  16. Mechanical Coupling Error Suppression Technology for an Improved Decoupled Dual-Mass Micro-Gyroscope.

    PubMed

    Yang, Bo; Wang, Xingjun; Deng, Yunpeng; Hu, Di

    2016-04-08

    This paper presents technology for the suppression of the mechanical coupling errors for an improved decoupled dual-mass micro-gyroscope (DDMG). The improved micro-gyroscope structure decreases the moment arm of the drive decoupled torque, which benefits the suppression of the non-ideal decoupled error. Quadrature correction electrodes are added to eliminate the residual quadrature error. The structure principle and the quadrature error suppression means of the DDMG are described in detail. ANSYS software is used to simulate the micro-gyroscope structure to verify the mechanical coupling error suppression effect. Compared with the former structure, simulation results demonstrate that the rotational displacements of the sense frame in the improved structure are substantially suppressed in the drive mode. The improved DDMG structure chip is fabricated by the deep dry silicon on glass (DDSOG) process. The feedback control circuits with quadrature control loops are designed to suppress the residual mechanical coupling error. Finally, the system performance of the DDMG prototype is tested. Compared with the former DDMG, the quadrature error in the improved dual-mass micro-gyroscope is decreased 9.66-fold, and the offset error is decreased 6.36-fold. Compared with the open loop sense, the feedback control circuits with quadrature control loop decrease the bias drift by 20.59-fold and the scale factor non-linearity by 2.81-fold in the ±400°/s range.

  17. Mechanical Coupling Error Suppression Technology for an Improved Decoupled Dual-Mass Micro-Gyroscope

    PubMed Central

    Yang, Bo; Wang, Xingjun; Deng, Yunpeng; Hu, Di

    2016-01-01

    This paper presents technology for the suppression of the mechanical coupling errors for an improved decoupled dual-mass micro-gyroscope (DDMG). The improved micro-gyroscope structure decreases the moment arm of the drive decoupled torque, which benefits the suppression of the non-ideal decoupled error. Quadrature correction electrodes are added to eliminate the residual quadrature error. The structure principle and the quadrature error suppression means of the DDMG are described in detail. ANSYS software is used to simulate the micro-gyroscope structure to verify the mechanical coupling error suppression effect. Compared with the former structure, simulation results demonstrate that the rotational displacements of the sense frame in the improved structure are substantially suppressed in the drive mode. The improved DDMG structure chip is fabricated by the deep dry silicon on glass (DDSOG) process. The feedback control circuits with quadrature control loops are designed to suppress the residual mechanical coupling error. Finally, the system performance of the DDMG prototype is tested. Compared with the former DDMG, the quadrature error in the improved dual-mass micro-gyroscope is decreased 9.66-fold, and the offset error is decreased 6.36-fold. Compared with the open loop sense, the feedback control circuits with quadrature control loop decrease the bias drift by 20.59-fold and the scale factor non-linearity by 2.81-fold in the ±400°/s range. PMID:27070616

  18. How to Perform Permanent His Bundle Pacing: Tips and Tricks.

    PubMed

    Vijayaraman, Pugazhendhi; Dandamudi, Gopi

    2016-12-01

    Right ventricular pacing can cause ventricular dyssynchrony and result in reduced left ventricular systolic function and heart failure. Permanent His bundle pacing is a more physiologic form of pacing, but can be technically challenging. In this article, we describe our technique for permanent His bundle pacing including special considerations and limitations associated with His bundle pacing. © 2016 Wiley Periodicals, Inc.

  19. 42 CFR 460.60 - PACE organizational structure.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 4 2014-10-01 2014-10-01 false PACE organizational structure. 460.60 Section 460... ELDERLY (PACE) PACE Administrative Requirements § 460.60 PACE organizational structure. (a) A PACE... planning a change in organizational structure must notify CMS and the State administering agency, in...

  20. 42 CFR 460.60 - PACE organizational structure.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 4 2013-10-01 2013-10-01 false PACE organizational structure. 460.60 Section 460... ELDERLY (PACE) PACE Administrative Requirements § 460.60 PACE organizational structure. (a) A PACE... planning a change in organizational structure must notify CMS and the State administering agency, in...

  1. The effects of husbandry training on stereotypic pacing in captive African wild dogs (Lycaon pictus).

    PubMed

    Shyne, Amanda; Block, Martin

    2010-01-01

    To examine the effects of operant conditioning on stereotypic pacing in 3 female African wild dogs located at the Franklin Park Zoo in Boston, this study made recordings of pacing behavior immediately following individual sessions of husbandry training and 2 no-training conditions. The study found significant differences in the percentage of observations spent in stereotypic pacing behaviors for all 3 dogs among the 3 different conditions. The authors discuss the data in terms of the contribution of motivated tasks to the effects and the role of food deprivation in the expression of stereotypic pacing. The study suggests that even short periods of training may improve the African wild dogs' welfare by reducing stereotypic pacing following the conditioning sessions.

  2. Low-cost implementation of a self-paced treadmill by using a commercial depth sensor.

    PubMed

    Kim, Jonghyun; Gravunder, Andrew; Stanley, Christopher J; Park, Hyung-Soon

    2013-01-01

    A self-paced treadmill that can simulate overground walking has the potential to improve the effectiveness of treadmill training for gait rehabilitation. We have implemented a self-paced treadmill without the need for expensive equipment such as a motion capture system and an instrumented treadmill. For this, an inexpensive depth sensor, ASUS XtionTM, substitutes for the motion capture system, and a low-cost commercial treadmill is considered as the platform of the self-paced treadmill. The proposed self-paced treadmill is also convenient because the depth sensor does not require markers placed on user's body. Through pilot tests with two healthy subjects, it is quantitatively and qualitatively verified that the proposed self-paced treadmill achieves similar performance as one which utilizes a commercial motion capture system (VICON) as well as an instrumented treadmill.

  3. Elevated energy coupling and aerobic capacity improves exercise performance in endurance-trained elderly subjects.

    PubMed

    Conley, Kevin E; Jubrias, Sharon A; Cress, M Elaine; Esselman, Peter C

    2013-04-01

    Increased maximal oxygen uptake (V(O(2)max)), mitochondrial capacity and energy coupling efficiency are reported after endurance training (ET) in adult subjects. Here we test whether leg exercise performance (power output of the legs, P(max), at V(O(2)max)) reflects these improvements with ET in the elderly. Fifteen male and female subjects were endurance trained for a 6 month programme, with 13 subjects (69.5 ± 1.2 years old, range 65-80 years old; n = 7 males; n = 6 females) completing the study. This training significantly improved P(max) (Δ17%; P = 0.003), V(O(2)max) (Δ5.4%; P = 0.021) and the increment in oxygen uptake (V(O(2))) above resting (ΔV(O(2)m-r) = V(O(2)max) - V(O(2)rest; Δ9%; P < 0.02). In addition, evidence of improved energy coupling came from elevated leg power output per unit V(O(2))at the aerobic capacity [Δ(P(max)/ΔV(O(2)m-r)); P = 0.02] and during submaximal exercise in the ramp test as measured by delta efficiency (ΔP(ex)/ΔV(O(2)); P = 0.04). No change was found in blood lactate, muscle glycolysis or fibre type. The rise in P(max) paralleled the improvement in muscle oxidative phosphorylation capacity (ATP(max)) in these subjects. In addition, the greater exercise energy coupling [Δ(P(max)/ΔV(O(2)m-r)) and delta efficiency] was accompanied by increased mitochondrial energy coupling as measured by elevated ATP production per unit mitochondrial content in these subjects. These results suggest that leg exercise performance benefits from elevations in energy coupling and oxidative phosphorylation capacity at both the whole-body and muscle levels that accompany endurance training in the elderly.

  4. The evolution of pace in popular movies.

    PubMed

    Cutting, James E

    2016-01-01

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

  5. Earlier Right Ventricular Pacing in Cardiac Resynchronization Therapy for a Patient with Right Axis Deviation.

    PubMed

    Hattori, Yusuke; Ishibashi, Kohei; Noda, Takashi; Okamura, Hideo; Kanzaki, Hideaki; Anzai, Toshihisa; Yasuda, Satoshi; Kusano, Kengo

    2017-09-01

    We describe the case of a 37-year-old woman who presented with complete right bundle branch block and right axis deviation. She was admitted to our hospital due to severe heart failure and was dependent on inotropic agents. Cardiac resynchronization therapy was initiated but did not improve her condition. After the optimization of the pacing timing, we performed earlier right ventricular pacing, which led to an improvement of her heart failure. Earlier right ventricular pacing should be considered in patients with complete right bundle branch block and right axis deviation when cardiac resynchronization therapy is not effective.

  6. Pacing Adjustments Associated With Familiarization: Heat Versus Temperate Environments.

    PubMed

    Schmit, Cyril; Duffield, Rob; Hausswirth, Christophe; Coutts, Aaron J; Le Meur, Yann

    2016-10-01

    To describe the effect of the initial perceptual experience from heat familiarization on the pacing profile during a freepaced endurance time trial (TT) compared with temperate conditions. Two groups of well-trained triathletes performed two 20-km TTs in either hot (35°C and 50% relative humidity [RH], n = 12) or temperate (21°C and 50% RH, n = 22) conditions, after standardization of training for each group before both trials. To ensure no physiological acclimation differences between conditions, the TTs for both groups were separated by 11 ± 4 d. Performance improvement in the heat (11 ± 24 W) from the 1st to 2nd trial appeared comparable to that in temperate conditions (8 ± 14 W, P = .67). However, the specific alteration in pacing profile in the heat was markedly different than temperate conditions, with a change from "positive" to an "even" pacing strategy. Altered perceptions of heat during heat familiarization, rather than physiological acclimatization per se, may mediate initial changes in pacing and TT performance in the heat. These results highlight the need for athletes without time for sufficient heat acclimatization to familiarize themselves with hot conditions to reduce the uncertainty from behavior-based outcomes that may impede performance.

  7. Effects of Priming and Pacing Strategy on Oxygen-Uptake Kinetics and Cycling Performance.

    PubMed

    Bailey, Stephen J; Vanhatalo, Anni; Black, Matthew I; DiMenna, Fred J; Jones, Andrew M

    2016-05-01

    To assess whether combining prior "priming" exercise with an all-out pacing strategy is more effective at improving oxygen-uptake (VO2) kinetics and cycling performance than either intervention administered independently. Nine men completed target-work cycling performance trials using a self-paced or all-out pacing strategy with or without prior severe-intensity (70%Δ) priming exercise. Breath-by-breath pulmonary VO2 and cycling power output were measured during all trials. Compared with the self-paced unprimed control trial (22 ± 5 s), the VO2 mean response time (MRT) was shorter (VO2 kinetics were faster) with all-out pacing (17 ± 4 s) and priming (17 ± 3 s), with the lowest VO2 MRT observed when all-out pacing and priming were combined (15 ± 4 s) (P < .05). However, total O2 consumed and end-exercise VO2 were only higher than the control condition in the primed trials (P < .05). Similarly, cycling performance was improved compared with control (98 ± 11 s) in the self-paced primed (93 ± 8 s) and all-out primed (92 ± 8 s) trials (P < .05) but not the all-out unprimed trial (97 ± 5 s; P > .05). These findings suggest that combining an all-out start with severe-intensity priming exercise additively improves VO2 MRT but not total O2 consumption and cycling performance since these were improved by a similar magnitude in both primed trials relative to the self-paced unprimed control condition. Therefore, these results support the use of priming exercise as a precompetition intervention to improve oxidative metabolism and performance during short-duration high-intensity cycling exercise, independent of the pacing strategy adopted.

  8. Significance of pacing cycle lengths in manifest entrainment of orthodromic circus movement tachycardia by ventricular pacing.

    PubMed

    Zaman, L; Castellanos, A; Saoudi, N C; Stafford, W J; Trohman, R G; Interian, A; Myerburg, R J

    1987-06-01

    The physiology of entrainment of orthodromic circus movement tachycardia (CMT) was studied using ventricular pacing during 18 episodes of induced CMT in 7 patients with atrioventricular (AV) accessory pathways. The first paced impulse was delivered as late as possible in the tachycardia cycle (mean 88 +/- 5% of the spontaneous cycle length [CL]). Entrainment was demonstrated by the following criteria: 1:1 retrograde conduction via the accessory pathway; capture of atrial, ventricular and His bundle electrograms at the pacing rate; and resumption of tachycardia at its previous rate after cessation of pacing. The number of ventricular paced impulses ranged from 5 to 14 (mean 8 +/- 3), and entrainment occurred in 2 to 7 paced cycles (mean 4 +/- 2). Orthodromic activation of a major part of the reentry circuit (manifest entrainment) was demonstrated during 9 episodes by the occurrence of His bundle electrogram preceding the first CMT QRS at the time anticipated from the last paced beat. In the 9 other episodes, persistent retrograde His bundle activation and AV nodal penetration by each paced impulse caused a delay (mean 79 +/- 25 ms) in activation of the His bundle preceding the first CMT QRS after the last paced beat. The mean pacing CL achieving manifest entrainment was 92 +/- 3% of the tachycardia CL, compared with 84 +/- 3% for retrograde AV nodal penetration (p less than 0.01). In conclusion, manifest entrainment of orthodromic CMT can be demonstrated by ventricular pacing at very long CLs; shorter CLs may cause CMT termination due to retrograde AV nodal penetration.

  9. GPS/UWB/MEMS-IMU tightly coupled navigation with improved robust Kalman filter

    NASA Astrophysics Data System (ADS)

    Li, Zengke; Chang, Guobin; Gao, Jingxiang; Wang, Jian; Hernandez, Alberto

    2016-12-01

    The integration of Global Positioning System (GPS) with Inertial Navigation System (INS) has been very intensively developed and widely applied in multiple areas. To further enhance the reliability and availability of GPS/INS integrated navigation in GPS challenging environment, range observation through ultra-wideband (UWB) is introduced in GPS/INS tightly coupled navigation. An improved robust Kalman filter is proposed and used to resist the influence of gross error from UWB observation in GPS/UWB/IMU tightly coupled navigation. The variance of the squared Mahalanobis distance in moving window is calculated, which brings as new judgement factor for gross errors in order to decrease the rate of false outlier identification. A simulation analysis shows that the improved robust Kalman filter is able to correctly identify gross errors and the rate of false judgment as zero. In order to validate the new robust filter, a real experiment is conducted. The results indicate that the improved robust Kalman filter used in GPS/UWB/INS tightly coupled navigation is able to remove the harmful effect of gross error in UWB observation. It clearly illustrates that the improved robust Kalman filter is very effective, and all the simulated small and large gross errors added to UWB distance observation are successfully identified.

  10. 42 CFR 460.170 - Reinstatement in PACE.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... (CONTINUED) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) Participant Enrollment and Disenrollment § 460.170 Reinstatement in PACE. (a) A...

  11. 42 CFR 460.180 - Medicare payment to PACE organizations.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... SERVICES (CONTINUED) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) Payment § 460.180 Medicare payment to PACE organizations. (a) Principle...

  12. 42 CFR 460.170 - Reinstatement in PACE.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... (CONTINUED) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) Participant Enrollment and Disenrollment § 460.170 Reinstatement in PACE. (a) A...

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

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... SERVICES (CONTINUED) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) Participant Rights § 460.122 PACE organization's appeals process. For...

  14. 42 CFR 460.180 - Medicare payment to PACE organizations.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... SERVICES (CONTINUED) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) Payment § 460.180 Medicare payment to PACE organizations. (a) Principle...

  15. 42 CFR 460.122 - PACE organization's appeals process.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... SERVICES (CONTINUED) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) Participant Rights § 460.122 PACE organization's appeals process. For...

  16. 42 CFR 460.122 - PACE organization's appeals process.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... SERVICES (CONTINUED) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) Participant Rights § 460.122 PACE organization's appeals process. For...

  17. 42 CFR 460.170 - Reinstatement in PACE.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... (CONTINUED) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) Participant Enrollment and Disenrollment § 460.170 Reinstatement in PACE. (a) A...

  18. 42 CFR 460.170 - Reinstatement in PACE.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... (CONTINUED) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) Participant Enrollment and Disenrollment § 460.170 Reinstatement in PACE. (a) A...

  19. 42 CFR 460.180 - Medicare payment to PACE organizations.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... SERVICES (CONTINUED) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) Payment § 460.180 Medicare payment to PACE organizations. (a) Principle...

  20. Improved Helicopter Rotor Performance Prediction through Loose and Tight CFD/CSD Coupling

    NASA Astrophysics Data System (ADS)

    Ickes, Jacob C.

    Helicopters and other Vertical Take-Off or Landing (VTOL) vehicles exhibit an interesting combination of structural dynamic and aerodynamic phenomena which together drive the rotor performance. The combination of factors involved make simulating the rotor a challenging and multidisciplinary effort, and one which is still an active area of interest in the industry because of the money and time it could save during design. Modern tools allow the prediction of rotorcraft physics from first principles. Analysis of the rotor system with this level of accuracy provides the understanding necessary to improve its performance. There has historically been a divide between the comprehensive codes which perform aeroelastic rotor simulations using simplified aerodynamic models, and the very computationally intensive Navier-Stokes Computational Fluid Dynamics (CFD) solvers. As computer resources become more available, efforts have been made to replace the simplified aerodynamics of the comprehensive codes with the more accurate results from a CFD code. The objective of this work is to perform aeroelastic rotorcraft analysis using first-principles simulations for both fluids and structural predictions using tools available at the University of Toledo. Two separate codes are coupled together in both loose coupling (data exchange on a periodic interval) and tight coupling (data exchange each time step) schemes. To allow the coupling to be carried out in a reliable and efficient way, a Fluid-Structure Interaction code was developed which automatically performs primary functions of loose and tight coupling procedures. Flow phenomena such as transonics, dynamic stall, locally reversed flow on a blade, and Blade-Vortex Interaction (BVI) were simulated in this work. Results of the analysis show aerodynamic load improvement due to the inclusion of the CFD-based airloads in the structural dynamics analysis of the Computational Structural Dynamics (CSD) code. Improvements came in the form

  1. Sensor-triggered, rate-variable cardiac pacing. Current technologies and clinical implications.

    PubMed

    Benditt, D G; Milstein, S; Buetikofer, J; Gornick, C C; Mianulli, M; Fetter, J

    1987-11-01

    Conventional implantable dual-chamber cardiac pacemakers adjust heart rate and maintain normal atrial and ventricular contraction by tracking "native" atrial electrical activity and pacing the ventricles after a predetermined programmable atrioventricular delay. However, in patients with symptomatic bradyarrhythmias, optimal function of "atrial-tracking" devices may be limited by concomitant sinoatrial disease. Provision of chronotropic response during physical exertion or emotional stress may be achieved by using physiologic sensors to alter pacing rate independently of atrial activity. Additional systems using sensor technologies are being developed. Future pacing systems will have dual-chamber pacing capability and may use several sensors coupled synergistically in order to take advantage of particular strengths of each. Physiologic sensor technology may be of diagnostic value in both antitachycardia devices and implantable cardioverter and defibrillator systems.

  2. Life after PACE (Program of All-Inclusive Care for the Elderly): A retrospective/prospective, qualitative analysis of the impact of closing a nurse practitioner centered PACE site.

    PubMed

    Meunier, Miranda J; Brant, Jeannine M; Audet, Simmy; Dickerson, Dustin; Gransbery, Karen; Ciemins, Elizabeth L

    2016-11-01

    Caring for frail older adults is a significant healthcare concern as the frailest 10% of the population account for over 70% of healthcare expenditures. Research reveals the use of comprehensive models, such as Program of All-Inclusive Care for the Elderly (PACE), leads to improved functional outcomes for participants and cost savings through decreased utilization. This study examines how closing a PACE program impacts health outcomes of previously enrolled participants. Data were collected every 6 months for 2 years via phone surveys on 34 former participants enrolled in the program at the time of the closure. The survey included questions regarding satisfaction with care, activities of daily living (ADLs), instrumental ADLs (IADLs), emergency department (ED) visits, hospitalizations, and use of home health services. Deaths and nursing home placements were monitored. Outcomes were compared during and post-PACE. Higher numbers of ED visits, hospitalizations, and nursing home placements occurred post-PACE. PACE/post-PACE differences in ADL and IADL scores were not significant, nor were death rates. Higher satisfaction existed with PACE versus non-PACE care. Comprehensive care programs such as PACE are effective in reducing healthcare utilization, thus limiting costs. Further work is required to maintain, develop, and support comprehensive models similar to PACE. ©2016 American Association of Nurse Practitioners.

  3. The Pace of Cultural Evolution

    PubMed Central

    Perreault, Charles

    2012-01-01

    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. PMID:23024804

  4. The pace of cultural evolution.

    PubMed

    Perreault, Charles

    2012-01-01

    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.

  5. Carrier arraying with coupled phase-locked loops for tracking improvement

    NASA Technical Reports Server (NTRS)

    Divsalar, D.; Yuen, J. H.

    1982-01-01

    This paper considers a system that couples several phase-locked loops (PLL's) to improve carrier tracking performance. The system coherently combines the received carrier signals at geographically separated ground antennas to increase the total effective aperture. It automatically aligns the received carrier's phases to enhance received carrier signal-to-noise ratio. The tracking performance of this system is being assessed in terms of rms phase jitter.

  6. Improving MJO Prediction and Simulation Using AGCM Coupled Ocean Model with Refined Vertical Resolution

    NASA Astrophysics Data System (ADS)

    Tu, Chia-Ying; Tseng, Wan-Ling; Kuo, Pei-Hsuan; Lan, Yung-Yao; Tsuang, Ben-Jei; Hsu, Huang-Hsiung

    2017-04-01

    Precipitation in Taiwan area is significantly influenced by MJO (Madden-Julian Oscillation) in the boreal winter. This study is therefore conducted by toggling the MJO prediction and simulation with a unique model structure. The one-dimensional TKE (Turbulence Kinetic Energy) type ocean model SIT (Snow, Ice, Thermocline) with refined vertical resolution near surface is able to resolve cool skin, as well as diurnal warm layer. SIT can simulate accurate SST and hence give precise air-sea interaction. By coupling SIT with ECHAM5 (MPI-Meteorology), CAM5 (NCAR) and HiRAM (GFDL), the MJO simulations in 20-yrs climate integrations conducted by three SIT-coupled AGCMs are significant improved comparing to those driven by prescribed SST. The horizontal resolutions in ECHAM5, CAM5 and HiRAM are 2-deg., 1-deg and 0.5-deg., respectively. This suggests that the improvement of MJO simulation by coupling SIT is AGCM-resolution independent. This study further utilizes HiRAM coupled SIT to evaluate its MJO forecast skill. HiRAM has been recognized as one of the best model for seasonal forecasts of hurricane/typhoon activity (Zhao et al., 2009; Chen & Lin, 2011; 2013), but was not as successful in MJO forecast. The preliminary result of the HiRAM-SIT experiment during DYNAMO period shows improved success in MJO forecast. These improvements of MJO prediction and simulation in both hindcast experiments and climate integrations are mainly from better-simulated SST diurnal cycle and diurnal amplitude, which is contributed by the refined vertical resolution near ocean surface in SIT. Keywords: MJO Predictability, DYNAMO

  7. Ventricular pacing in single ventricles-A bad combination.

    PubMed

    Bulic, Anica; Zimmerman, Frank J; Ceresnak, Scott R; Shetty, Ira; Motonaga, Kara S; Freter, Anne; Trela, Anthony V; Hanisch, Deb; Russo, Lisa; Avasarala, Kishor; Dubin, Anne M

    2017-06-01

    Chronic ventricular pacing (VP) is associated with systolic dysfunction in a subset of pediatric patients with heart block and structurally normal hearts. The effect of chronic VP in congenital heart disease is less well understood, specifically in the single-ventricle (SV) population. To determine the longitudinal effect of VP in SV patients. SV patients with heart block and dual-chamber pacemakers requiring >50% VP were compared with nonpaced (controls) SV patients matched for age, sex, and SV morphology. Patients were excluded if a prepacing echocardiogram was not available. Echocardiogram and clinical parameters were compared at baseline (prepacing) and at last follow-up in the paced group, and in controls when they were at ages similar to those of their paced-group matches. Twenty-two paced and 53 control patients from 2 institutions were followed for similar durations (6.6±5 years vs 7.6±7.6 years; P = .59). There was no difference between groups regarding baseline ventricular function or the presence of moderate-to-severe atrioventricular valvar regurgitation (AVVR). Paced patients were more likely to develop moderate-to-severe systolic dysfunction (68% vs 15%; P < .01) and AVVR (55% vs 8%; P < .001) and require heart failure medications (65% vs 21%; P < .001). Chronic VP was also associated with a higher risk of transplantation or death (odds ratio, 4.9; 95% confidence interval, 1.05-22.7; P = .04). SV patients requiring chronic VP are at higher risk of developing moderate-to-severe ventricular dysfunction and AVVR with an increased risk of death or transplantation compared with controls. New strategies to either limit VP or improve synchronization in this vulnerable population is imperative. Copyright © 2017 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

  8. Improving couples' quality of life through a Web-based prostate cancer education intervention.

    PubMed

    Song, Lixin; Rini, Christine; Deal, Allison M; Nielsen, Matthew E; Chang, Hao; Kinneer, Patty; Teal, Randall; Johnson, David C; Dunn, Mary W; Mark, Barbara; Palmer, Mary H

    2015-03-01

    To evaluate the feasibility and acceptability of a newly developed web-based, couple-oriented intervention called Prostate Cancer Education and Resources for Couples (PERC). Quantitative, qualitative, mixed-methods approach. Oncology outpatient clinics at the University of North Carolina (UNC) Lineberger Comprehensive Cancer Center at UNC–Chapel Hill. 26 patients with localized prostate cancer (PCa) and their partners. Pre- and postpilot quantitative assessments and a postpilot qualitative interview were conducted. General and PCa-specific symptoms, quality of life, psychosocial factors, PERC’s ease of use, and web activities. Improvement was shown in some PCa-specific and general symptoms (small effect sizes for patients and small-to-medium effect sizes for partners), overall quality of life, and physical and social domains of quality of life for patients (small effect sizes). Web activity data indicated high PERC use. Qualitative and quantitative analyses indicated that participants found PERC easy to use and understand,as well as engaging, of high quality, and relevant. Overall, participants were satisfied with PERC and reported that PERC improved their knowledge about symptom management and communication as a couple. PERC was a feasible, acceptable method of reducing the side effects of PCa treatment–related symptoms and improving quality of life. PERC has the potential to reduce the negative impacts of symptoms and enhance quality of life for patients with localized PCa and their partners, particularly for those who live in rural areas and have limited access to post-treatment supportive care.

  9. Risk perception influences athletic pacing strategy.

    PubMed

    Micklewright, Dominic; Parry, David; Robinson, Tracy; Deacon, Greg; Renfree, Andrew; St Clair Gibson, Alan; Matthews, William J

    2015-05-01

    The objective of this study is to examine risk taking and risk perception associations with perceived exertion, pacing, and performance in athletes. Two experiments were conducted in which risk perception was assessed using the domain-specific risk taking (DOSPERT) scale in 20 novice cyclists (experiment 1) and 32 experienced ultramarathon runners (experiment 2). In experiment 1, participants predicted their pace and then performed a 5-km maximum effort cycling time trial on a calibrated Kingcycle mounted bicycle. Split times and perceived exertion were recorded every kilometer. In experiment 2, each participant predicted their split times before running a 100-km ultramarathon. Split times and perceived exertion were recorded at seven checkpoints. In both experiments, higher and lower risk perception groups were created using median split of DOSPERT scores. In experiment 1, pace during the first kilometer was faster among lower risk perceivers compared with higher risk perceivers (t(18) = 2.0, P = 0.03) and faster among higher risk takers compared with lower risk takers (t(18) = 2.2, P = 0.02). Actual pace was slower than predicted pace during the first kilometer in both the higher risk perceivers (t(9) = -4.2, P = 0.001) and lower risk perceivers (t(9) = -1.8, P = 0.049). In experiment 2, pace during the first 36 km was faster among lower risk perceivers compared with higher risk perceivers (t(16) = 2.0, P = 0.03). Irrespective of risk perception group, actual pace was slower than predicted pace during the first 18 km (t(16) = 8.9, P < 0.001) and from 18 to 36 km (t(16) = 4.0, P < 0.001). In both experiments, there was no difference in performance between higher and lower risk perception groups. Initial pace is associated with an individual's perception of risk, with low perceptions of risk being associated with a faster starting pace. Large differences between predicted and actual pace suggest that the performance template lacks accuracy, perhaps indicating

  10. Improvements and applications of COBRA-TF for stand-alone and coupled LWR safety analyses

    SciTech Connect

    Avramova, M.; Cuervo, D.

    2006-07-01

    The advanced thermal-hydraulic subchannel code COBRA-TF has been recently improved and applied for stand-alone and coupled LWR core calculations at the Pennsylvania State Univ. in cooperation with AREVA NP GmbH (Germany)) and the Technical Univ. of Madrid. To enable COBRA-TF for academic and industrial applications including safety margins evaluations and LWR core design analyses, the code programming, numerics, and basic models were revised and substantially improved. The code has undergone through an extensive validation, verification, and qualification program. (authors)

  11. Ventricular defibrillation combining DC electrical field and electrical pacing: an optical mapping study

    NASA Astrophysics Data System (ADS)

    Musunuri, Sai Shruthi; Tang, Liang; Joung, Boyoung; Berbari, Edward J.; Lin, Shien-Fong

    2009-02-01

    Although high voltage direct current (DC) shock is a standard technique to terminate ventricular fibrillation (VF), it can cause severe pain and tissue damage. The exact effect of the DC electric field, which can depolarize the heart during VF is still unknown. We hypothesized that low-energy DC field in combination with pacing (pacing+DC) could terminate VF by affecting the ventricular propagation pattern. In six Langendorff-perfused isolated rabbit hearts with the ablated sinoatrial (SA) node, the DC field was delivered to the left ventricle (cathode) and right ventricle (anode). We designed a timed protocol using LabVIEW programming that delivers pacing, DC and pacing+DC stimuli for two seconds time intervals each. The pacing pulse (with varying pacing cycle length: 300ms-30ms) was delivered to the apex. Transmembrane voltage was recorded with optical mapping technique for 16 seconds at a sampling rate of 2ms/frame. We crushed the sinoatrial node to reduce the heart rate. The baseline activation appeared to have endocardial origins with a mean escape ventricular rate of 60 +/- 5bpm at baseline. The DC field (30mA-60mA) alone increased the mean heart rate to 120+/-5bpm. Although DC alone terminated VF in a few cases, the rate of termination was very low (6.2%). However, when pacing+DC was applied, it was possible to terminate VF in 34 of 130 episodes in six rabbits. The rate of successful defibrillation of VF with pacing+DC was significantly higher than that with DC alone (20% vs 6.2%, p<0.01). Pacing alone never terminated the VF. In conclusion, DC field may affect the conduction velocity in normal condition. Pacing+DC intervention could lead to regularization of VF propagation and eventually to termination. Further improvement of this approach may offer a higher success rate of defibrillation with lower energy requirements.

  12. DDD versus VVIR pacing in patients, ages 70 and over, with complete heart block.

    PubMed

    Ouali, Sana; Neffeti, Elyes; Ghoul, Karima; Hammas, Sami; Kacem, Slim; Gribaa, Rim; Remedi, Fahmi; Boughzela, Essia

    2010-05-01

    Dual-chamber pacing is believed to have an advantage over single-chamber ventricular pacing. The aim of the study was to determine whether elderly patients with implanted pacemaker for complete atrioventricular block gain significant benefit from dual-chamber (DDD) compared with single-chamber ventricular demand (VVIR). The study was designed as a double-blind randomized two-period crossover study-each pacing mode was maintained for 3 months. Thirty patients (eight men, mean age 76.5 +/- 4.3 years) with implanted PM were submitted to a standard protocol, which included an interview, functional class assessment, quality of life (QoL) questionnaires, 6-minute walk test, and transthoracic echocardiographic examinations. QoL was measured by the SF-36. All these parameters were obtained on DDD mode pacing and VVIR mode pacing. Paired data were compared. QoL was significantly different between the two groups and showed the best values in DDD. Overall, no patient preferred VVIR mode, 18 preferred DDD mode, and 12 expressed no preference. No differences in mean walking distances were observed between patients with single-chamber and dual-chamber pacing. VVI pacing elicited marked decrease in left ventricle ejection fraction and significant enlargement of the left atrium. DDD pacing resulted in significant increase of the peak systolic velocities in lateral mitral annulus and septal mitral annulus. Early diastolic velocities on both sides of mitral annulus did not change. In active elderly patients with complete heart block, DDD pacing is associated with improved quality of life and systolic ventricular function compared with VVI pacing.

  13. Biventricular pacing in congestive heart failure: a boost toward finer living.

    PubMed

    Luck, Jerry C; Wolbrette, Deborah L; Boehmer, John P; Ulsh, Paula J; Silber, David; Naccarelli, Gerald V

    2002-01-01

    With 550,000 new cases each year, congestive heart failure is a major medical problem. Several medical therapies, including digoxin, angiotensin-converting enzyme inhibitors, and beta-blockers, have reduced the number of re-hospitalizations and slowed the progression of congestive heart failure. Angiotensin-converting enzyme inhibitors, some beta-blockers, and the combination of hydralazine with nitrates have improved survival. Despite these benefits, medical therapy frequently fails to improve quality of life. Biventricular pacing has been introduced to resynchronize mechanical and electrical asynchrony frequently observed in patients with heart failure. The most recent pacing trials show an improvement in quality of life and functional class. Long-term data are needed to determine the effect of biventricular pacing on survival. The acute hemodynamic studies suggest that resynchronization pacing therapy may predict a positive long-term benefit for many patients with congestive heart failure.

  14. Atrioventricular nodal ablation in atrial fibrillation: a meta-analysis of biventricular vs. right ventricular pacing mode.

    PubMed

    Chatterjee, Neal A; Upadhyay, Gaurav A; Ellenbogen, Kenneth A; Hayes, David L; Singh, Jagmeet P

    2012-06-01

    For patients with refractory atrial fibrillation (AF) undergoing atrioventricular nodal ablation (AVNA), initial single-chamber right ventricular (RV)-only pacing is standard. Given the deleterious effects of chronic RV-only pacing, the impact of an initial biventricular (BiV) pacing strategy post-ablation is of interest. We conducted a meta-analysis to determine the effect of BiV vs. RV-only pacing in patients undergoing AVNA for refractory atrial fibrillation. A search of multiple electronic databases identified 921 reports, which included four randomized controlled trials (n = 534). Mean New York Heart Association (NYHA) class was 2.3 and mean left ventricular ejection fraction (LVEF) was 44%. When compared with RV-only pacing, BiV pacing was not associated with reduced mortality [risk ratio 0.85, 95% confidence interval (CI) 0.40-1.82, P = 0.68]. In three studies comprised of patients with left ventricular systolic dysfunction (mean EF 41 ± 3%), BiV pacing demonstrated a non-significant reduction in cardiac mortality (risk ratio 0.59, 95% CI 0.25-1.39; P = 0.23). Compared with RV-only pacing, BiV pacing was associated with significant improvement in symptoms [Minnesota Living with Heart Failure Questionnaire (MLWHFQ) 2.72 points fewer, 95% CI 1.45-3.99] and increased LVEF (+2.6%, 95% CI 1.69-3.44), but no significant change in 6 min walk distance (6MWD) (5.02 ms more, 95% CI -1.56 to 11.59; P = 0.13). In patients with refractory AF undergoing AVNA, BiV pacing was not associated with significantly improved survival when compared with RV-only pacing. A modest, but significant improvement in structural and functional response to BiV pacing was observed.

  15. Skin to skin interactions. Does the infant massage improve the couple functioning?

    PubMed Central

    Gnazzo, Antonio; Guerriero, Viviana; Di Folco, Simona; Zavattini, Giulio C.; de Campora, Gaia

    2015-01-01

    Transition to parenthood is a critical stage of life due to several changes the couple has to handle. A large body of studies described how transition to parenthood can be linked to the onset of depressive symptoms, as well as the perception of a low social support, and an increased stress, representing a risk for the early mother–baby relationship. Infant massage (IM) emerged as a helpful tool to improve maternal skills in interacting with the baby, and leading toward a decreasing of post-partum symptoms. However, a growing body of literature highlights that men also may experience post-partum diseases, representing an additional risk for the development of the baby. To date, no study observed the impact of the IM on both partners. The aim of the current qualitative research is to observe the impact of the IM on a single couple of parents at childbirth. Pre (Time 1) and post-intervention (Time 3) procedure has been established to observe the changes occurring over the time in the couple. In particular, each member of the couple filled out the EPDS, the BDI-II, the MSPSS, and the PSI-SF both at Time 1 and at Time 3. The treatment (Time 2) was represented by the IM training, and lasted 4 weeks. Findings revealed a decrease in depressive symptoms in both partners, as well as an improvement of their perception of stress related to parental role. No changes has been detected with respect to the perception of social support. The IM seems to be a helpful approach to prevent the establishment of pathological conditions in new parents. Although no direct measures on the child were used, the current qualitative data seem to suggest that the IM may represent a valuable tool to prevent the onset of early negative outcomes of the baby. Further investigations and empirical data are needed to improve the knowledge in this field. PMID:26441813

  16. Sawtooth Pacing by Real-Time Auxiliary Power Control in a Tokamak Plasma

    SciTech Connect

    Goodman, T. P.; Felici, F.; Sauter, O.; Graves, J. P.

    2011-06-17

    In the standard scenario of tokamak plasma operation, sawtooth crashes are the main perturbations that can trigger performance-degrading, and potentially disruption-generating, neoclassical tearing modes. This Letter demonstrates sawtooth pacing by real-time control of the auxiliary power. It is shown that the sawtooth crash takes place in a reproducible manner shortly after the removal of that power, and this can be used to precisely prescribe, i.e., pace, the individual sawteeth. In combination with preemptive stabilization of the neoclassical tearing modes, sawtooth pacing provides a new sawtooth control paradigm for improved performance in burning plasmas.

  17. Conservation law for self-paced movements

    PubMed Central

    Huh, Dongsung; Sejnowski, Terrence J.

    2016-01-01

    Optimal control models of biological movements introduce external task factors to specify the pace of movements. Here, we present the dual to the principle of optimality based on a conserved quantity, called “drive,” that represents the influence of internal motivation level on movement pace. Optimal control and drive conservation provide equivalent descriptions for the regularities observed within individual movements. For regularities across movements, drive conservation predicts a previously unidentified scaling law between the overall size and speed of various self-paced hand movements in the absence of any external tasks, which we confirmed with psychophysical experiments. Drive can be interpreted as a high-level control variable that sets the overall pace of movements and may be represented in the brain as the tonic levels of neuromodulators that control the level of internal motivation, thus providing insights into how internal states affect biological motor control. PMID:27418602

  18. Determinants of Enrollment Among Applicants to PACE

    PubMed Central

    Irvin, Carol V.; Massey, Susan; Dorsey, Turahn

    1997-01-01

    During the 1970s and 1980s, a new approach to the integration of acute and long-term care(LTC) services was conceived and refined at On Lok, an organization in the Chinese community of San Francisco. Since then, On Lok and 10 Federal demonstration sites have tested this model which is today called the Program of All-inclusive Care for the Elderly (PACE). This program has gained considerable political support and as a result, the 1997 Balanced Budget Agreement establishes PACE as a permanent provider under Medicare. The Federal demonstration of PACE was designed as a voluntary program. By exploiting its voluntary enrollment design, this study analyzes the determinants of program participation within a group of screened applicants. Findings of this study support the theory that the capitated payment structure of PACE creates incentives for program staff to avoid costly individuals. However, home ownership and provider attachment also act as important and significant barriers to enrollment. PMID:10345402

  19. Pollution Abatement and Control Expenditures Survey (PACE)

    EPA Pesticide Factsheets

    The Pollution Abatement Costs and Expenditures (PACE) survey is the most comprehensive national source of pollution abatement costs and expenditures related to environmental protection for the manufacturing sector of the United States. The PACE survey collects facility-level data on pollution abatement capital expenditures and operating costs associated with compliance to local, state, and federal regulations and voluntary or market-driven pollution abatement activities.

  20. Update on arrhythmias and cardiac pacing 2013.

    PubMed

    Almendral, Jesús; Pombo, Marta; Martínez-Alday, Jesús; González-Rebollo, José M; Rodríguez-Font, Enrique; Martínez-Ferrer, José; Castellanos, Eduardo; García-Fernández, F Javier; Ruiz-Mateas, Francisco

    2014-04-01

    This report discusses a selection of the most relevant articles on cardiac arrhythmias and pacing published in 2013. The first section discusses arrhythmias, classified as regular paroxysmal supraventricular tachyarrhythmias, atrial fibrillation, and ventricular arrhythmias, together with their treatment by means of an implantable cardioverter defibrillator. The next section reviews cardiac pacing, subdivided into resynchronization therapy, remote monitoring of implantable devices, and pacemakers. The final section discusses syncope.

  1. Optogenetic pacing in Drosophila melanogaster (Conference Presentation)

    NASA Astrophysics Data System (ADS)

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

    2016-03-01

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

  2. Evaluation of an 18-couple module composed of improved performance SiGe unicouples

    SciTech Connect

    Kelly, C.E.; Klee, P.M.; Nakahara, J.F.; Hartman, R.F.

    1995-12-31

    Radioisotope Thermoelectric Generators (RTGs) have played a major role in providing spacecraft electrical power for interplanetary exploration. Silicon Germanium alloys are the thermoelectric material employed in RTGs. Over the past several years a number of investigations have reported improvements in the figure of merit of these alloys. These improvements are attractive to mission planners because they result in enhanced RTG specific power (watts/lb) and improved efficiency which leads to lower fuel costs. This paper describes the fabrication and testing of an 18-couple module device utilizing unicouples with improved SiGe alloys. The unicouples were fabricated using materials with over a 10% improvement in the 573 to 1,273 K integrated average figure-of-merit over Cassini materials. The p-type material was fabricated by the standard vacuum casting and hot pressing method while the n-type material containing GaP was fabricated by a new method of mechanical alloying and hot isostatic pressing. The unicouples were fabricated in a similar fashion to standard unicouples except that the thermoelectric materials were bonded to the SiMo hot shoe in two thermal cycles due to the disparity of the melting points. A sufficient quantity of unicouples was fabricated to assemble an 18-couple module to evaluate the thermoelectric performance of the improved SiGe materials. The module was brought up to operating temperature following the same heatup rate as previous modules. The module was stabilized at a hot shoe temperature of 1,308 K. Initial performance was compared to the established SiGe database and found to show no improvement thermally or electrically.

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

    NASA Astrophysics Data System (ADS)

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

    2006-02-01

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

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

    PubMed

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

    2010-02-01

    Gastric pacing has been investigated as a potential treatment for gastroparesis. New pacing protocols are required to improve symptom and motility outcomes; however, research progress has been constrained by a limited understanding of the effects of electrical stimulation on slow-wave activity. This study introduces high-resolution (HR) "entrainment mapping" for the analysis of gastric pacing and presents four demonstrations. Gastric pacing was initiated in a porcine model (typical amplitude 4 mA, pulse width 400 ms, period 17 s). Entrainment mapping was performed using flexible multielectrode arrays (paced propagation was found to be anisotropic (longitudinal 2.6 +/- 1.7 vs. circumferential 4.5 +/- 0.6 mm/s; P < 0.001). In the third demonstration, a dysrhythmic episode that occurred during pacing was mapped in HR, revealing an ectopic slow-wave focus and uncoupled propagations. In the fourth demonstration, differences were observed between paced and native slow-wave amplitudes (0.24 +/- 0.08 vs. 0.38 +/- 0.14 mV; P < 0.001), velocities (6.2 +/- 2.8 vs. 11.5 +/- 4.7 mm/s; P < 0.001), and activated areas (20.6 +/- 1.9 vs. 32.8 +/- 2.6 cm(2); P < 0.001). Entrainment mapping enables an accurate quantification of the effects of gastric pacing on slow-wave activity, offering an improved method to assess whether pacing protocols are likely to achieve physiologically and clinically useful outcomes.

  5. Improved algorithms and coupled neutron-photon transport for auto-importance sampling method

    NASA Astrophysics Data System (ADS)

    Wang, Xin; Li, Jun-Li; Wu, Zhen; Qiu, Rui; Li, Chun-Yan; Liang, Man-Chun; Zhang, Hui; Gang, Zhi; Xu, Hong

    2017-01-01

    The Auto-Importance Sampling (AIS) method is a Monte Carlo variance reduction technique proposed for deep penetration problems, which can significantly improve computational efficiency without pre-calculations for importance distribution. However, the AIS method is only validated with several simple examples, and cannot be used for coupled neutron-photon transport. This paper presents improved algorithms for the AIS method, including particle transport, fictitious particle creation and adjustment, fictitious surface geometry, random number allocation and calculation of the estimated relative error. These improvements allow the AIS method to be applied to complicated deep penetration problems with complex geometry and multiple materials. A Completely coupled Neutron-Photon Auto-Importance Sampling (CNP-AIS) method is proposed to solve the deep penetration problems of coupled neutron-photon transport using the improved algorithms. The NUREG/CR-6115 PWR benchmark was calculated by using the methods of CNP-AIS, geometry splitting with Russian roulette and analog Monte Carlo, respectively. The calculation results of CNP-AIS are in good agreement with those of geometry splitting with Russian roulette and the benchmark solutions. The computational efficiency of CNP-AIS for both neutron and photon is much better than that of geometry splitting with Russian roulette in most cases, and increased by several orders of magnitude compared with that of the analog Monte Carlo. Supported by the subject of National Science and Technology Major Project of China (2013ZX06002001-007, 2011ZX06004-007) and National Natural Science Foundation of China (11275110, 11375103)

  6. The Manipulation of Pace within Endurance Sport

    PubMed Central

    Skorski, Sabrina; Abbiss, Chris R.

    2017-01-01

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

  7. A study on improvement of discharge characteristic by using a transformer in a capacitively coupled plasma

    SciTech Connect

    Kim, Young-Cheol; Kim, Hyun-Jun; Lee, Hyo-Chang; Chung, Chin-Wook

    2015-12-15

    In a plasma discharge system, the power loss at powered line, matching network, and other transmission line can affect the discharge characteristics such as the power transfer efficiency, voltage and current at powered electrode, and plasma density. In this paper, we propose a method to reduce power loss by using a step down transformer mounted between the matching network and the powered electrode in a capacitively coupled argon plasma. This step down transformer decreases the power loss by reducing the current flowing through the matching network and transmission line. As a result, the power transfer efficiency was increased about 5%–10% by using a step down transformer. However, the plasma density was dramatically increased compared to no transformer. This can be understood by the increase in ohmic heating and the decrease in dc-self bias. By simply mounting a transformer, improvement of discharge efficiency can be achieved in capacitively coupled plasmas.

  8. Dye alignment in luminescent solar concentrators: I. Vertical alignment for improved waveguide coupling.

    PubMed

    Mulder, C L; Reusswig, P D; Velázquez, A M; Kim, H; Rotschild, C; Baldo, M A

    2010-04-26

    Luminescent solar concentrators (LSCs) use dye molecules embedded in a flat-plate waveguide to absorb solar radiation. Ideally, the dyes re-emit the absorbed light into waveguide modes that are coupled to solar cells. But some photons are always lost, re-emitted through the face of the LSC and coupled out of the waveguide. In this work, we improve the fundamental efficiency limit of an LSC by controlling the orientation of dye molecules using a liquid crystalline host. First, we present a theoretical model for the waveguide trapping efficiency as a function of dipole orientation. Next, we demonstrate an increase in the trapping efficiency from 66% for LSCs with no dye alignment to 81% for a LSC with vertical dye alignment. Finally, we show that the enhanced trapping efficiency is preserved for geometric gains up to 30, and demonstrate that an external diffuser can alleviate weak absorption in LSCs with vertically-aligned dyes.

  9. An Undergraduate Intern Program at PACES

    NASA Technical Reports Server (NTRS)

    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

  10. Improved precipitation extremes and climatology in a regional coupled model simulation over CORDEX south Asia domain

    NASA Astrophysics Data System (ADS)

    Kumar, P.; Sein, D.; Cabos, W.; Jacob, D.

    2014-12-01

    The South Asian continents are densely populated and their economy is largely dependent on agriculture which primarily depends on the summer monsoon (June-September). The region is highly vulnerable to climate variability and change. It has been well established that the SST anomalies in the Indian and the Pacific Ocean attributes to the monsoon interannual as well as intraseasonal variability. Most of the CMIP3 and CMIP5 climate models have difficulty in simulating the mean climate over South Asia. Regional Climate Models (RCMs) however simulate orographic induced precipitation better, but show limited ability to simulate mean precipitation over land and an overestimation over ocean more generally. These systematic differences between climate models and observation's may be related to poorly represented ocean dynamics and SST.For the first time a regional coupled atmosphere-ocean model is developed to study the monsoon climatology over the CORDEX South Asia domain. The REgional atmosphere MOdel REMO with 50km horizontal resolution is coupled via Oasis coupler to the Max Planck Institute for Meteorology global ocean - sea ice model MPIOM with increased resolution over the Indian Ocean (up to 20 km). Hereafter this coupled system will be called as ROM. For this study, four simulations for the period 1958-2001 are performed (i) REMO forced with ECMWF ERA40 reanalysis (ii) ROM forced with ECMWF ERA40 reanalysis (iii) REMO forced with MPI-ESM-LR CMIP5 historical simulation (iv) ROM forced with MPI-ESM-LR CMIP5 historical simulation. Differences in coupled and un-coupled RCM simulations are analyzed to investigate the effect of coupling on simulated climate, especially precipitation daily annual cycles and monthly spatial patterns. It has been observed that simulated feedback of ocean SST has positive influence on precipitation simulation of ROM both over land and ocean. The intensity of tropical cyclone is well simulated by the model ROM which improves the monsoon

  11. Catalytic partial oxidation coupled with membrane purification to improve resource and energy efficiency in syngas production.

    PubMed

    Iaquaniello, G; Salladini, A; Palo, E; Centi, G

    2015-02-01

    Catalytic partial oxidation coupled with membrane purification is a new process scheme to improve resource and energy efficiency in a well-established and large scale-process like syngas production. Experimentation in a semi industrial-scale unit (20 Nm(3)  h(-1) production) shows that a novel syngas production scheme based on a pre-reforming stage followed by a membrane for hydrogen separation, a catalytic partial oxidation step, and a further step of syngas purification by membrane allows the oxygen-to-carbon ratio to be decreased while maintaining levels of feed conversion. For a total feed conversion of 40 %, for example, the integrated novel architecture reduces oxygen consumption by over 50 %, with thus a corresponding improvement in resource efficiency and an improved energy efficiency and economics, these factors largely depending on the air separation stage used to produce pure oxygen.

  12. Cardiac optogenetic pacing in drosophila melanogaster using red-shifted opsins (Conference Presentation)

    NASA Astrophysics Data System (ADS)

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

    2017-02-01

    Electrical pacing is the current gold standard for investigation of mammalian cardiac electrical conduction systems as well as for treatment of certain cardiac pathologies. However, this method requires an invasive surgical procedure to implant the pacing electrodes. Recently, optogenetic pacing has been developed as an alternative, non-invasive method for heartbeat pacing in animals. It induces heartbeats by shining pulsed light on transgene-generated microbial opsins which in turn activate light gated ion channels in animal hearts. However, commonly used opsins, such as channelrhodopsin-2 (ChR2), require short light wavelength stimulation (475 nm), which is strongly absorbed and scattered by tissue. Here, we expressed recently engineered red-shifted opsins, ReaChR and CsChrimson, in the heart of a well-developed animal model, Drosophila melanogaster, for the first time. Optogenetic pacing was successfully conducted in both ReaChR and CsChrimson flies at their larval, pupal, and adult stages using 617 nm excitation light pulse, enabling a much deeper tissue penetration compared to blue stimulation light. A customized high speed and ultrahigh resolution OCM system was used to non-invasively monitor the heartbeat pacing in Drosophila. Compared to previous studies on optogenetic pacing of Drosophila, higher penetration depth of optogenetic excitation light was achieved in opaque late pupal flies. Lower stimulating power density is needed for excitation at each developmental stage of both groups, which improves the safety of this technique for heart rhythm studies.

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

    PubMed

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

    2012-01-01

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

  14. Biventricular pacing as bridge to rapid recovery in infancy.

    PubMed

    Dragulescu, Andreea; Bilska, Karolina; Van Doorn, Catharina; Goldman, Allan; Marek, Jan

    2010-09-01

    The authors present the unique case of an 8-month-old baby diagnosed with severe left ventricular failure of unknown etiology. Due to a lack of organ availability for this age, a mechanical assist device and assessment for cardiac transplantation were not offered. Subsequent comprehensive echocardiographic dyssynchrony assessment and the presence of left bundle branch block were suggestive of response to cardiac resynchronization therapy. Dual-chamber epicardial pacing was initiated, resulting in prompt marked clinical and echocardiographic improvement, which continued until complete normalization of cardiac function. The pacing system was safely turned off 6 months after its implantation. In conclusion, cardiac resynchronization therapy should be considered as a treatment option even in infancy, regardless of the etiology of disease and/or patient age. 2010 American Society of Echocardiography. Published by Mosby, Inc. All rights reserved.

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

    PubMed Central

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

    2011-01-01

    Children vary widely in the rate at which they acquire words—some start slow and speed up, others start fast and continue at a steady pace. Do early developmental variations of this sort help predict vocabulary skill just prior to kindergarten entry? This longitudinal study starts by examining important predictors (SES, parent input, child gesture) of vocabulary growth between 14 and 46 months (n=62), and then uses growth estimates to predict children's vocabulary at 54 months. Velocity and acceleration in vocabulary development at 30 months predicted later vocabulary, particularly for children from low socioeconomic backgrounds. Understanding the pace of early vocabulary growth thus improves our ability to predict school readiness, and may help identify children at risk for starting behind. PMID:22235920

  16. The benefits of biventricular pacing in heart failure patients with narrow QRS, NYHA class II and right ventricular pacing.

    PubMed

    Ng, Kenneth; Kedia, Navin; Martin, David; Tchou, Patrick; Natale, Andrea; Wilkoff, Bruce; Starling, Randall; Grimm, Richard A

    2007-02-01

    To identify subgroups of heart failure patients who might benefit from biventricular pacing. Cardiac resynchronization therapy (CRT) improves the quality of life, New York Heart Association (NYHA) functional class, and exercise capacity and decreases hospitalizations for heart failure for patients who have severe heart failure and a wide QRS. It is unclear if other populations of heart failure patients would benefit from CRT. One hundred forty-four consecutive heart failure patients who underwent CRT and completed 3 months of follow-up were reviewed. Demographic, echocardiographic, electrocardiographic, and clinical outcome data were analyzed to assess the relationship of functional class and QRS duration before device implantation to postimplant outcomes. There were 20, 88, and 36 patients in NYHA functional class II, III, and IV, respectively. Thirty-four patients had right ventricular pacing and another 29 patients had a QRS duration < or = 150 ms. Patients who were in NYHA functional class II at baseline had significant improvement in left ventricular ejection fraction and indices of left ventricular remodeling after CRT. Similar significant findings were seen in the subgroup with right ventricular pacing at baseline after CRT. However, in the subgroup with a narrow QRS duration, there were no significant changes in the indices of left ventricular remodeling or in the NYHA functional class and there was a significant increase in the QRS duration. For the study cohort as a whole, an improvement in NYHA functional class after CRT correlated with a significant decrease in adverse clinical outcomes. Heart failure patients who were in NYHA functional class II and those with right ventricular pacing appeared to benefit from CRT.

  17. Effect of atrial antitachycardia pacing treatments in patients with an atrial defibrillator: randomised study comparing subthreshold and nominal pacing outputs

    PubMed Central

    Mitchell, A R J; Spurrell, P A R; Cheatle, L; Sulke, N

    2002-01-01

    Objective: To assess the true efficacy of antitachycardia pacing on spontaneous persistent atrial fibrillation in patients with an implanted atrial defibrillator, by comparing the effects of nominal pacing treatment with subthreshold pacing treatment. Design: The effects of antitachycardia pacing and burst 50 Hz atrial pacing on spontaneous atrial arrhythmias were evaluated six months after implantation of a Medtronic Jewel AF® atrial defibrillator. Setting: Cardiology department in a district general hospital. Patients: 15 patients with persistent atrial fibrillation. Interventions: Patients were randomised to either “nominal” output pacing treatment or surface ECG and endocardial electrogram proven subthreshold “sham” pacing treatment for three months, and then crossed over to the alternative treatment for a further three months. Results: During the nominal output phase, 31 episodes of atrial fibrillation were treated with 53 bursts of 50 Hz pacing, 98 sequences of ramp atrial pacing, and 61 sequences of burst atrial pacing. Atrial fibrillation was not pace terminated during any episode. Thirty one episodes of atrial tachycardia were treated with 19 bursts of 50 Hz atrial pacing, 103 sequences of ramp atrial pacing, and 38 sequences of burst atrial pacing. Termination of atrial tachycardia was observed in 17 episodes. During the “sham” pacing period, no episodes were terminated by any pacing treatment. Conclusion: Atrial antitachycardia pacing treatments are ineffective at terminating persistent atrial fibrillation but may be useful in terminating episodes of atrial tachycardia or flutter, thus reducing the burden of arrhythmia. PMID:11997413

  18. High performance patch antenna using circular split ring resonators and thin wires employing electromagnetic coupling improvement

    NASA Astrophysics Data System (ADS)

    Abdelrehim, Adel A. A.; Ghafouri-Shiraz, H.

    2016-09-01

    In this paper, three dimensional periodic structure composed of circular split ring resonators and thin wires is used to improve the performance of a microstrip patch antenna. The three dimensional periodic structure is placed at the top of the patch within a specific separation distance to construct the proposed antenna. The radiated electromagnetic waves intensity of the proposed antenna is improved compared with the conventional patch antenna due to the electric and magnetic coupling enhancements. These enhancements occur between the patch and the periodic structure resonators and between the different resonator pairs of the periodic structure. As a result, the electric and the magnetic fields at the top of the patch are improved, the radiated electromagnetic beam size reduces which results in a highly focused beam and hence the antenna directivity and gain are improved, while the beam are is reduced. The proposed antenna has been designed and simulated using CST microwave studio at 10 GHz. An infinite two dimensional periodicity unit cell of circular split ring resonator and thin wire is designed to resonate at a 10 GHz and simulated in CST software, the scattering parameters are extracted, the results showed that the infinite periodicity two dimensional structure has a pass band frequency response of good transmission and reflection characteristics around 10 GHz. The infinite periodicity of the two dimensional periodic structure is then truncated and multi layers of such truncated structure is used to construct a three dimensional periodic structure. A parametric analysis has been performed on the proposed antenna incorporated with the three dimensional periodic structure. The impacts of the separation distance between the patch and three dimensional periodic structures and the size of the three dimensional periodic structure on the radiation and impedance matching parameters of the proposed antenna are studied. For experimental verification, the proposed

  19. Improving MJO Forecast Skill of AGCM by Coupling Ocean Model with Refined Vertical Resolution

    NASA Astrophysics Data System (ADS)

    Tu, C. Y.; Tseng, W. L.; Tsuang, B. J.; Hsu, H. H.

    2016-12-01

    Precipitation in Taiwan area is significantly influenced by MJO Madden-Julian Oscillation in the boreal winter (Hung et al., 2014). This study is therefore conducted by toggling the MJO forecast with a unique model structure. HiRAM High-Resolution Atmospheric Model developed by GFDL Geophysical Fluid Dynamics Laboratory has been recognized as one of the best model for seasonal forecasts of hurricane/typhoon activity (Zhao et al., 2009; Chen & Lin, 2011; 2013), but was not as successful in MJO forecast. The one-dimensional TKE (Turbulence Kinetic Energy ) type ocean model SIT Snow, Ice, Thermocline with fine vertical resolution near surface had demonstrated its skill in improving MJO eastward propagation when coupled with ECHAM5 (Tseng et al., 2015). This study utilizes HiRAM coupled SIT to evaluate its performance in MJO forecast. In the hindcast experiment water temperature at 10-m deep in SIT is nudged to GODAS (Global Ocean Data Assimilation System) data to avoid SST deviation induced by lack of advection in one-dimensional ocean model. The preliminary result of the HiRAM-SIT experiment during DYNAMO period shows improved success in MJO forecast. The improvement is mainly from better-simulated SST diurnal cycle and diurnal amplitude, which is contributed by the refined vertical resolution near ocean surface in SIT.

  20. Improved photocatalytic activity of nanocrystalline ZnO by coupling with CuO

    NASA Astrophysics Data System (ADS)

    Xu, Linhua; Zhou, Yang; Wu, Zijun; Zheng, Gaige; He, Jiaojiao; Zhou, Yanjing

    2017-07-01

    Although ZnO as a photocatalyst has attracted wide attention in the word in recent years, it is still a big challenge to develop low-cost, visible-light responsive ZnO based photocatalysts which can be used on a large scale. In this work, the CuO/ZnO nanocomposites have been synthesized by a facile one-step hydrothermal method and the influence of CuO contents on the photocatalytic properties of the nanocomposites has been investigated. The crystalline phase of the CuO/ZnO nanocomposites is determined by X-ray diffraction (XRD); the morphology and microstructures of the samples are analyzed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The photocatalytic performance of the samples is tested using methylene blue (MB)dyes as the simulated pollutant under irradiation of a Xe lamp. Compared with pure ZnO, the photocatalytic activity of the CuO/ZnO nanocomposites is largely improved, especially for the sample prepared by the precursor solution with the molar ratio of Zn2+: Cu2+=2:1. The improvement of the photocatalytic activity is attributed to two main factors: (1) the band coupling improves the separation efficiency of photogenerated electrons and holes; (2) the utilization efficiency for solar energy is enhanced in the CuO/ZnO coupling system.

  1. Improving Couples' Quality of Life Through a Web-Based Prostate Cancer Education Intervention

    PubMed Central

    Song, Lixin; Rini, Christine; Deal, Allison M.; Nielsen, Matthew E.; Chang, Hao; Kinneer, Patty; Teal, Randall; Johnson, David C.; Dunn, Mary W.; Mark, Barbara; Palmer, Mary H.

    2016-01-01

    Purpose/Objectives To evaluate the feasibility and acceptability of a newly developed web-based, couple-oriented intervention called Prostate Cancer Education and Resources for Couples (PERC). Design Quantitative, qualitative, mixed-methods approach. Setting Oncology outpatient clinics at the University of North Carolina (UNC) Lineberger Comprehensive Cancer Center at UNC–Chapel Hill. Sample 26 patients with localized prostate cancer (PCa) and their partners. Methods Pre- and postpilot quantitative assessments and a postpilot qualitative interview were conducted. Main Research Variables General and PCa-specific symptoms, quality of life, psychosocial factors, PERC's ease of use, and web activities. Findings Improvement was shown in some PCa-specific and general symptoms (small effect sizes for patients and small-to-medium effect sizes for partners), overall quality of life, and physical and social domains of quality of life for patients (small effect sizes). Web activity data indicated high PERC use. Qualitative and quantitative analyses indicated that participants found PERC easy to use and understand, as well as engaging, of high quality, and relevant. Overall, participants were satisfied with PERC and reported that PERC improved their knowledge about symptom management and communication as a couple. Conclusions PERC was a feasible, acceptable method of reducing the side effects of PCa treatment–related symptoms and improving quality of life. Implications for Nursing PERC has the potential to reduce the negative impacts of symptoms and enhance quality of life for patients with localized PCa and their partners, particularly for those who live in rural areas and have limited access to post-treatment supportive care. PMID:25806885

  2. Acute Resveratrol Consumption Improves Neurovascular Coupling Capacity in Adults with Type 2 Diabetes Mellitus.

    PubMed

    Wong, Rachel H X; Raederstorff, Daniel; Howe, Peter R C

    2016-07-12

    Poor cerebral perfusion may contribute to cognitive impairment in type 2 diabetes mellitus (T2DM). We conducted a randomized controlled trial to test the hypothesis that resveratrol can enhance cerebral vasodilator function and thereby alleviate the cognitive deficits in T2DM. We have already reported that acute resveratrol consumption improved cerebrovascular responsiveness (CVR) to hypercapnia. We now report the effects of resveratrol on neurovascular coupling capacity (CVR to cognitive stimuli), cognitive performance and correlations with plasma resveratrol concentrations. Thirty-six T2DM adults aged 40-80 years were randomized to consume single doses of resveratrol (0, 75, 150 and 300 mg) at weekly intervals. Transcranial Doppler ultrasound was used to monitor changes in blood flow velocity (BFV) during a cognitive test battery. The battery consisted of dual-tasking (finger tapping with both Trail Making task and Serial Subtraction 3 task) and a computerized multi-tasking test that required attending to four tasks simultaneously. CVR to cognitive tasks was calculated as the per cent increase in BFV from pre-test basal to peak mean blood flow velocity and also as the area under the curve for BFV. Compared to placebo, 75 mg resveratrol significantly improved neurovascular coupling capacity, which correlated with plasma total resveratrol levels. Enhanced performance on the multi-tasking test battery was also evident following 75 mg and 300 mg of resveratrol. a single 75 mg dose of resveratrol was able to improve neurovascular coupling and cognitive performance in T2DM. Evaluation of benefits of chronic resveratrol supplementation is now warranted.

  3. Left ventricular guidewire pacing for transcatheter aortic valve implantation.

    PubMed

    Guérios, Enio E; Wenaweser, Peter; Meier, Bernhard

    2013-12-01

    Previous reports prove the safety and efficacy of cardiac pacing employing a guidewire in the left ventricle as unipolar pacing electrode. We describe the use of left ventricular guidewire pacing as an alternative to conventional transvenous temporary right ventricular pacing in the context of transcatheter aortic valve implantation.

  4. A coupled phase-locked loops system for carrier tracking improvement

    NASA Technical Reports Server (NTRS)

    Divsalar, D.; Yuen, J. H.

    1982-01-01

    A system that couples several phase-locked loops to improve carrier tracking performance is considered. It coherently combines the received carrier signals at geographically separated ground antennas to increase the total effective aperture. The received carrier's phases are automatically aligned to enhance the received carrier signal-to-noise ratio. The system's tracking performance is assessed in terms of rms phase jitter. It is shown that the phase-locked loop in the first receiver, where the carrier arraying is performed, tracks the received carrier phase using the received carrier power from all receivers.

  5. Improved gauge actions on anisotropic lattices I. Study of fundamental parameters in the weak coupling limit

    NASA Astrophysics Data System (ADS)

    Sakai, S.; Saito, T.; Nakamura, A.

    2000-09-01

    On anisotropic lattices with the anisotropy ξ=a σ/a τ the following basic parameters are calculated by perturbative method: (1) the renormalization of the gauge coupling in spatial and temporal directions, g σ and g τ, (2) the Λ parameter, (3) the ratio of the renormalized and bare anisotropy η=ξ/ξ B and (4) the derivatives of the coupling constants with respect to ξ, ∂g σ-2/∂ξ and ∂g τ-2/∂ξ . We employ the improved gauge actions which consist of plaquette and six-link rectangular loops, c 0P(1×1) μν+c 1P(1×2) μν. This class of actions covers Symanzik, Iwasaki and DBW2 actions. The ratio η shows an impressive behavior as a function of c 1, i.e., η>1 for the standard Wilson and Symanzik actions, while η<1 for Iwasaki and DBW2 actions. This is confirmed non-perturbatively by numerical simulations in weak coupling regions. The derivatives ∂g -2τ/∂ξ and ∂g -2σ/∂ξ also change sign as -c 1 increases. For Iwasaki and DBW2 actions they become opposite sign to those for standard and Symanzik actions. However, their sum is independent of the type of actions due to Karsch's sum rule.

  6. Improved discretisation and linearisation of active tension in strongly coupled cardiac electro-mechanics simulations

    PubMed Central

    Sundnes, J.; Wall, S.; Osnes, H.; Thorvaldsen, T.; McCulloch, A.D.

    2013-01-01

    Mathematical models of cardiac electro-mechanics typically consist of three tightly coupled parts: systems of ordinary differential equations describing electro-chemical reactions and cross-bridge dynamics in the muscle cells, a system of partial differential equations modelling the propagation of the electrical activation through the tissue and a nonlinear elasticity problem describing the mechanical deformations of the heart muscle. The complexity of the mathematical model motivates numerical methods based on operator splitting, but simple explicit splitting schemes have been shown to give severe stability problems for realistic models of cardiac electro-mechanical coupling. The stability may be improved by adopting semi-implicit schemes, but these give rise to challenges in updating and linearising the active tension. In this paper we present an operator splitting framework for strongly coupled electro-mechanical simulations and discuss alternative strategies for updating and linearising the active stress component. Numerical experiments demonstrate considerable performance increases from an update method based on a generalised Rush–Larsen scheme and a consistent linearisation of active stress based on the first elasticity tensor. PMID:22800534

  7. Improved discretisation and linearisation of active tension in strongly coupled cardiac electro-mechanics simulations.

    PubMed

    Sundnes, J; Wall, S; Osnes, H; Thorvaldsen, T; McCulloch, A D

    2014-01-01

    Mathematical models of cardiac electro-mechanics typically consist of three tightly coupled parts: systems of ordinary differential equations describing electro-chemical reactions and cross-bridge dynamics in the muscle cells, a system of partial differential equations modelling the propagation of the electrical activation through the tissue and a nonlinear elasticity problem describing the mechanical deformations of the heart muscle. The complexity of the mathematical model motivates numerical methods based on operator splitting, but simple explicit splitting schemes have been shown to give severe stability problems for realistic models of cardiac electro-mechanical coupling. The stability may be improved by adopting semi-implicit schemes, but these give rise to challenges in updating and linearising the active tension. In this paper we present an operator splitting framework for strongly coupled electro-mechanical simulations and discuss alternative strategies for updating and linearising the active stress component. Numerical experiments demonstrate considerable performance increases from an update method based on a generalised Rush-Larsen scheme and a consistent linearisation of active stress based on the first elasticity tensor.

  8. Improved method of measuring pressure coupled response for composite solid propellants

    NASA Astrophysics Data System (ADS)

    Su, Wanxing; Wang, Ningfei; Li, Junwei; Zhao, Yandong; Yan, Mi

    2014-04-01

    Pressure coupled response is one of the main causes of combustion instability in the solid rocket motor. It is also a characteristic parameter for predicting the stability. The pressure coupled response function is usually measured by different methods to evaluate the performance of new propellant. Based on T-burner and "burning surface doubled and secondary attenuation", an improved method for measuring the pressure coupled response of composite propellant is introduced in this article. A computational fluid dynamics (CFD) study has also been conducted to validate the method and to understand the pressure oscillation phenomenon in T-burner. Three rounds of tests were carried out on the same batch of aluminized AP/HTPB composite solid propellant. The experimental results show that the sample propellant had a high response function under the conditions of high pressure (~11.5 MPa) and low frequency (~140 Hz). The numerically predicted oscillation frequency and amplitude are consistent with the experimental results. One practical solid rocket motor using this sample propellant was found to experience pressure oscillation at the end of burning. This confirms that the sample propellant is prone to combustion instability. Finally, acoustic pressure distribution and phase difference in T-burner were analyzed. Both the experimental and numerical results are found to be associated with similar acoustic pressure distribution. And the phase difference analysis showed that the pressure oscillations at the head end of the T-burner are 180° out of phase from those in the aft end of the T-burner.

  9. Triple-site pacing for cardiac resynchronization in permanent atrial fibrillation - Acute phase results from a prospective observational study.

    PubMed

    Marques, Pedro; Nobre Menezes, Miguel; Lima da Silva, Gustavo; Bernardes, Ana; Magalhães, Andreia; Cortez-Dias, Nuno; Carpinteiro, Luís; de Sousa, João; Pinto, Fausto J

    2016-06-01

    Multi-site pacing is emerging as a new method for improving response to cardiac resynchronization therapy (CRT), but has been little studied, especially in patients with atrial fibrillation. We aimed to assess the effects of triple-site (Tri-V) vs. biventricular (Bi-V) pacing on hemodynamics and QRS duration. This was a prospective observational study of patients with permanent atrial fibrillation and ejection fraction <40% undergoing CRT implantation (n=40). One right ventricular (RV) lead was implanted in the apex and another in the right ventricular outflow tract (RVOT) septal wall. A left ventricular (LV) lead was implanted in a conventional venous epicardial position. Cardiac output (using the FloTrac™ Vigileo™ system), mean QRS and ejection fraction were calculated. Mean cardiac output was 4.81±0.97 l/min with Tri-V, 4.68±0.94 l/min with RVOT septal and LV pacing, and 4.68±0.94 l/min with RV apical and LV pacing (p<0.001 for Tri-V vs. both BiV). Mean pre-implantation QRS was 170±25 ms, 123±18 ms with Tri-V, 141±25 ms with RVOT septal pacing and LV pacing and 145±19 with RV apical and LV pacing (p<0.001 for Tri-V vs. both BiV and pre-implantation). Mean ejection fraction was significantly higher with Tri-V (30±11%) vs. Bi-V pacing (28±12% with RVOT septal and LV pacing and 28±11 with RV apical and LV pacing) and pre-implantation (25±8%). Tri-V pacing produced higher cardiac output and shorter QRS duration than Bi-V pacing. This may have a significant impact on the future of CRT. Copyright © 2016 Sociedade Portuguesa de Cardiologia. Published by Elsevier España. All rights reserved.

  10. Suppressing arrhythmias in cardiac models using overdrive pacing and calcium channel blockers

    NASA Astrophysics Data System (ADS)

    Stamp, A. T.; Osipov, G. V.; Collins, J. J.

    2002-09-01

    Recent findings indicate that ventricular fibrillation might arise from spiral wave chaos. Our objective in this computational study was to investigate wave interactions in excitable media and to explore the feasibility of using overdrive pacing to suppress spiral wave chaos. This work is based on the finding that in excitable media, propagating waves with the highest excitation frequency eventually overtake all other waves. We analyzed the effects of low-amplitude, high-frequency pacing in one-dimensional and two-dimensional networks of coupled, excitable cells governed by the Luo-Rudy model. In the one-dimensional cardiac model, we found narrow high-frequency regions of 1:1 synchronization between the input stimulus and the system's response. The frequencies in this region were higher than the intrinsic spiral wave frequency of cardiac tissue. When we paced the two-dimensional cardiac model with frequencies from this region, we found that spiral wave chaos could, in some cases, be suppressed. When we coupled the overdrive pacing with calcium channel blockers, we found that spiral wave chaos could be suppressed in all cases. These findings suggest that low-amplitude, high-frequency overdrive pacing, in combination with calcium channel inhibitors (e.g., class II or class IV antiarrhythmic drugs), may be useful for eliminating fibrillation.

  11. Improved arterial-ventricular coupling in metabolic syndrome after exercise training: a pilot study.

    PubMed

    Fournier, Sara B; Donley, David A; Bonner, Daniel E; Devallance, Evan; Olfert, I Mark; Chantler, Paul D

    2015-01-01

    The metabolic syndrome (MetS) is associated with threefold increased risk of cardiovascular (CV) morbidity and mortality, which is partly due to a blunted CV reserve capacity, reflected by a reduced peak exercise left ventricular (LV) contractility and aerobic capacity and a blunted peak arterial-ventricular coupling. To date, no study has examined whether aerobic exercise training in MetS can reverse peak exercise CV dysfunction. Furthermore, examining how exercise training alters CV function in a group of individuals with MetS before the development of diabetes and/or overt CV disease can provide insights into whether some of the pathophysiological CV changes can be delayed/reversed, lowering their CV risk. The objective of this study was to examine the effects of 8 wk of aerobic exercise training in individuals with MetS on resting and peak exercise CV function. Twenty participants with MetS underwent either 8 wk of aerobic exercise training (MetS-ExT, n = 10) or remained sedentary (MetS-NonT, n = 10) during this period. Resting and peak exercise CV function was characterized using Doppler echocardiography and gas exchange. Exercise training did not alter resting LV diastolic or systolic function and arterial-ventricular coupling in MetS. In contrast, at peak exercise, an increase in LV contractility (40%, P < 0.01), cardiac output (28%, P < 0.05), and aerobic capacity (20%, P < 0.01), but a reduction in vascular resistance (30%, P < 0.05) and arterial-ventricular coupling (27%, P < 0.01), were noted in the MetS-ExT but not in the MetS-NonT group. Furthermore, an improvement in lifetime risk score was also noted in the MetS-ExT group. These findings have clinical importance because they provide insight that some of the pathophysiological changes associated with MetS can be improved and can lower the risk of CV disease.

  12. Coupled Integration of CSAC, MIMU, and GNSS for Improved PNT Performance.

    PubMed

    Ma, Lin; You, Zheng; Liu, Tianyi; Shi, Shuai

    2016-05-12

    Positioning, navigation, and timing (PNT) is a strategic key technology widely used in military and civilian applications. Global navigation satellite systems (GNSS) are the most important PNT techniques. However, the vulnerability of GNSS threatens PNT service quality, and integrations with other information are necessary. A chip scale atomic clock (CSAC) provides high-precision frequency and high-accuracy time information in a short time. A micro inertial measurement unit (MIMU) provides a strap-down inertial navigation system (SINS) with rich navigation information, better real-time feed, anti-jamming, and error accumulation. This study explores the coupled integration of CSAC, MIMU, and GNSS to enhance PNT performance. The architecture of coupled integration is designed and degraded when any subsystem fails. A mathematical model for a precise time aiding navigation filter is derived rigorously. The CSAC aids positioning by weighted linear optimization when the visible satellite number is four or larger. By contrast, CSAC converts the GNSS observations to range measurements by "clock coasting" when the visible satellite number is less than four, thereby constraining the error divergence of micro inertial navigation and improving the availability of GNSS signals and the positioning accuracy of the integration. Field vehicle experiments, both in open-sky area and in a harsh environment, show that the integration can improve the positioning probability and accuracy.

  13. Coupling NLDAS Model Output with MODIS Products for Improved Spatial Evapotranspiration Estimates

    NASA Astrophysics Data System (ADS)

    Kim, J.; Hogue, T.

    2008-12-01

    Given the growing concern over regional water supplies in much of the arid west, the quantification of water use by urban and agricultural landscapes is critically important. Water lost through evapotranspiration (ET) typically can not be recaptured or recycled, increasing the need for accurate accounting of ET in regional water management and planning. In this study, we investigate a method to better capture the spatial characteristics of ET by coupling operational North American Land Data Assimilation System (NLDAS) Noah Land Surface Model (LSM) outputs and a previously developed MODIS-based Potential Evapotranspiration (PET) product. The resultant product is higher resolution (1km) than the NLDAS model ET outputs (~12.5 km) and provides improved estimates within highly heterogeneous terrain and landscapes. We undertake this study in the Southern California region which provides an excellent case study for examining the developed product's ability to estimate vegetation dynamics over rapidly growing, and highly-irrigated, urban ecosystems. General trends in both products are similar; however the coupled MODIS-NLDAS ET product shows higher spatial variability, better capturing land surface heterogeneity than the NLDAS-based ET. Improved ET representation is especially obvious during the spring season, when precipitation is muted and evaporative flux is dominant. We also quantify seasonal landscape water demand over urban landscapes in several major counties (i.e. Los Angeles, San Diego and Riverside) using the MODIS-NLDAS ET model.

  14. Coupled Integration of CSAC, MIMU, and GNSS for Improved PNT Performance

    PubMed Central

    Ma, Lin; You, Zheng; Liu, Tianyi; Shi, Shuai

    2016-01-01

    Positioning, navigation, and timing (PNT) is a strategic key technology widely used in military and civilian applications. Global navigation satellite systems (GNSS) are the most important PNT techniques. However, the vulnerability of GNSS threatens PNT service quality, and integrations with other information are necessary. A chip scale atomic clock (CSAC) provides high-precision frequency and high-accuracy time information in a short time. A micro inertial measurement unit (MIMU) provides a strap-down inertial navigation system (SINS) with rich navigation information, better real-time feed, anti-jamming, and error accumulation. This study explores the coupled integration of CSAC, MIMU, and GNSS to enhance PNT performance. The architecture of coupled integration is designed and degraded when any subsystem fails. A mathematical model for a precise time aiding navigation filter is derived rigorously. The CSAC aids positioning by weighted linear optimization when the visible satellite number is four or larger. By contrast, CSAC converts the GNSS observations to range measurements by “clock coasting” when the visible satellite number is less than four, thereby constraining the error divergence of micro inertial navigation and improving the availability of GNSS signals and the positioning accuracy of the integration. Field vehicle experiments, both in open-sky area and in a harsh environment, show that the integration can improve the positioning probability and accuracy. PMID:27187399

  15. A Simulation Study of Paced TCP

    NASA Technical Reports Server (NTRS)

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

    2000-01-01

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

  16. The formation of bronchocutaneous fistulae due to retained epicardial pacing wires: A literature review

    PubMed Central

    Patris, Vasileios; Argiriou, Michalis; Salem, Agni-Leila; Giakoumidakis, Konstantinos; Baikoussis, Nikolaos G.; Charitos, Christos

    2016-01-01

    Temporary epicardial pacing wires during open-heart surgery are routinely used both for diagnostic and treatment purposes. In complicated cases where patients are unstable or the wires are difficult to remove, the pacing wires are cut at the skin level and allowed to retract by themselves. This procedure rarely causes complications. However, there have been cases reporting that retained pacing wires are linked to the formation of sterno-bronchial fistulae, which may present a while after the date of operation and are usually infected. This review aims to study the cases presenting sterno-bronchial fistulae due to retained epicardial pacing wires and to highlight the important factors associated with these. It is important to note these complications, as fistulae may cause a variety of problems to the patient if undiagnosed and left untreated. With the aid of scans such as fistulography, fistulae can be identified and treated and will improve the patients’ health dramatically. PMID:27716700

  17. Leadless pacing using induction technology: impact of pulse shape and geometric factors on pacing efficiency.

    PubMed

    Wieneke, Heinrich; Rickers, Sebastian; Velleuer, Jonathan; Bruck, Guido; Bai, Zijian; Kocks, Christian; Grandjean, Pierre-Andre; Lenihan, Tim; Jung, Peter; Erbel, Raimund; Prinzen, Frits W; Kisker, Erhard

    2013-03-01

    Leadless pacing can be done by transmitting energy by an alternating magnetic field from a subcutaneous transmitter unit (TU) to an endocardial receiver unit (RU). Safety and energy consumption are key issues that determine the clinical feasibility of this new technique. The aims of the study were (i) to evaluate the stimulation characteristics of the non-rectangular pacing pulses induced by the alternating magnetic field, (ii) to determine the extent and impact of RU movement caused by the beating heart, and (iii) to evaluate the influence of the relative position between TU and RU on pacing efficiency and energy consumption. In the first step pacing efficiency and energy consumption for predefined positions were determined by bench testing. Subsequently, in a goat at five different ventricular sites (three in the right ventricle, two in the left ventricle) pacing thresholds using non-rectangular induction pulses were compared with conventional pulses. Relative position, defined by parallel distance, radial distance, and angulation between TU and RU, were determined in vivo by X-ray and an inclination angle measurement system. Bench testing showed that by magnetic induction for every alignment between TU and RU appropriate pulses can be produced up to a distance of 100 mm. In the animal experiment pacing thresholds were similar for non-rectangular pulses as compared with conventional pulse shapes. In all five positions with distances between 62 and 102 mm effective pacing was obtained in vivo. Variations in distance, displacement and angle caused by the beating heart did not cause loss of capture. At pacing threshold energy consumptions between 0.28 and 5.36 mJ were measured. Major determinants of energy consumption were distance and pacing threshold. For any given RU position up to a distance of 100 mm reliable pacing using induction can be obtained. In anatomically crucial distances, up to 60 mm energy consumption is within a reasonable range.

  18. Pacing mode and long-term survival in elderly patients with congestive heart failure: 1980-1985.

    PubMed

    Brady, P A; Shen, W K; Neubauer, S A; Hammill, S C; Hodge, D O; Hayes, D L

    1997-11-01

    Dual-chamber pacing may improve short-term hemodynamics and functional class in some patients with congestive heart failure, even in the absence of conventional indications for pacemaker implantation. However, the impact of different pacing modes on survival of patients with congestive heart failure is controversial. In this retrospective study we analyzed survival data from 546 elderly patients, aged 70 years and older, who underwent implantation of a permanent dual-chamber (DDD, n = 62, DVI, n = 102) or single-chamber (VVI) pacemaker (n = 382) between 1980 and 1985. Survival was further analyzed according to the presence of absence of congestive heart failure, and pacemaker mode (DDD vs. DVI vs. VVI). Overall, dual-chamber pacing (DDD and DVI) was associated with a more favorable long-term outcome when compared with single-chamber ventricular pacing, although differences were only significant for DDD pacing (P = 0.002). When patients with and without preexisting congestive heart failure were analyzed separately, survival following dual-chamber pacing (DDD and DVI) was significantly better than survival following single-chamber pacing in patients without congestive heart failure (P = 0.03), but not in patients with preexisting heart failure (P = 0.139). When patients were analyzed according to the electrophysiological indication for pacemaker implantation, overall survival of patients with AV block (P = 0.0025) but not sinus node dysfunction (P = 0.346) was improved with dual-chamber pacing. This survival advantage in patients with AV block following dual-chamber pacing was lost in the presence of heart failure (P = 0.11). These findings suggest that dual-chamber pacing, in particular DDD pacing, improves the survival in elderly patients without preexisting congestive heart failure. In contrast to the short-term hemodynamic improvement observed in selected patients with congestive heart failure, dual-chamber pacing in elderly patients with congestive heart failure

  19. Optimal Implantation Depth and Adherence to Guidelines on Permanent Pacing to Improve the Results of Transcatheter Aortic Valve Replacement With the Medtronic CoreValve System: The CoreValve Prospective, International, Post-Market ADVANCE-II Study.

    PubMed

    Petronio, Anna S; Sinning, Jan-Malte; Van Mieghem, Nicolas; Zucchelli, Giulio; Nickenig, Georg; Bekeredjian, Raffi; Bosmans, Johan; Bedogni, Francesco; Branny, Marian; Stangl, Karl; Kovac, Jan; Schiltgen, Molly; Kraus, Stacia; de Jaegere, Peter

    2015-05-01

    The aim of the CoreValve prospective, international, post-market ADVANCE-II study was to define the rates of conduction disturbances and permanent pacemaker implantation (PPI) after transcatheter aortic valve replacement with the Medtronic CoreValve System (Minneapolis, Minnesota) using optimized implantation techniques and application of international guidelines on cardiac pacing. Conduction disturbances are a frequent complication of transcatheter aortic valve replacement. The rates of PPI in the published reports vary according to bioprosthesis type and the indications for PPI. The primary endpoint was the 30-day incidence of PPI with Class I/II indications when the Medtronic CoreValve System was implanted at an optimal depth (≤6 mm below the aortic annulus). The timing and resolution of all new-onset conduction disturbances were analyzed. A total of 194 patients were treated. The overall rate of PPI for Class I/II indications was 18.2%. An optimal depth was reached in 43.2% of patients, with a nonsignificantly lower incidence of PPI in patients with depths ≤6 mm, compared with those with deeper implants (13.3% vs. 21.1%; p = 0.14). In a paired analysis, new-onset left bundle branch block and first-degree atrioventricular block occurred in 45.4% and 39.0% of patients, respectively, and resolved spontaneously within 30 days in 43.2% and 73.9%, respectively. In patients with new PPI, the rate of intrinsic sinus rhythm increased from 25.9% at 7 days to 59.3% at 30 days (p = 0.004). Optimal Medtronic CoreValve System deployment and adherence to international guidelines on cardiac pacing are associated with a lower rate of new PPI after transcatheter aortic valve replacement, compared with results reported in previous studies. (CoreValve Advance-II Study: Prospective International Post-Market Study [ADVANCE II]; NCT01624870). Copyright © 2015 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  20. Fabrication of improved SiGe alloys for an 18-couple module test

    SciTech Connect

    Loughin, S.; Nakahara, J.F.; Centurioni, D.X.; Cook, B.A.; Harringa, J.L.

    1995-01-01

    N- and p-type Si{sub 0.78}Ge{sub 0.22} alloys were fabricated to determine if recently reported improvements in the figure-of-merit, Z, could be realized in devices. These will be tested in an 18-couple module to directly compare the performance of these materials with that of standard coarse-grain SiGe used in flight programs. We describe the synthesis by vacuum casting and hot pressing p-type SiGe and mechanical alloying and hot-isostatic pressing n-type SiGe. Improved materials and standard materials are characterized and compared. The integrated average figures-of-merit (573--1273 K) of the improved materials were Z{sub p} = 0.59 {times} 10{sup {minus}3} K{sup {minus}1} and Z{sub n} = 0.85 {times} 10{sup {minus}3} K{sup {minus}1} compared with Z{sub p} = 0.52 {times} l0{sup {minus}3} K{sup {minus}1} and Z{sub n} = 0.76 {times} 10{sup {minus}3} K{sup {minus}1} for the standard materials. We also report the power factors for improved and standard materials removed from fabricated devices to gain insight as to how subsequent processing impacts performance.

  1. Sequential biventricular pacing: evaluation of safety and efficacy.

    PubMed

    Mortensen, Peter T; Sogaard, Peter; Mansour, Hassan; Ponsonaille, Jean; Gras, Daniel; Lazarus, Arnaud; Reiser, Wolfgang; Alonso, Christine; Linde, Cecilia M; Lunati, Maurizio; Kramm, Berthold; Harrison, E Mark

    2004-03-01

    The study evaluated the clinical safety, performance, and efficacy of sequential biventricular pacing in the InSync III (Model 8042) biventricular stimulator in a multicenter, prospective 3-month study and assessed the proper functioning of features aiming at improving biventricular AV therapy delivery. The system was successfully implanted in 189 (95.9%) of 198 patients with symptomatic systolic heart failure and a prolonged QRS complex duration. Patients significantly improved their 6-minute hall walk distance (baseline 339 +/- 92 vs 3-month 422 +/- 127 meter, P < 0.001) and NYHA class (baseline 3.1 +/- 0.5 vs 3-month 1.9 +/- 0.7, P < 0.001). Echocardiographic optimization of sequential biventricular pacing showed an improvement in stroke volume compared to simultaneous stimulation (sequential 68 +/- 24 mL vs simultaneous 56 +/- 23 mL, P < 0.001) at baseline and at 3 months. In 88% (30/34) of the patients these improvements were seen within a small range of V-V delays of +/-20 ms and in 94% (32/34) within V-V delays of +/-40 ms. In contrast, programming beyond this range reduced stroke volume below that during simultaneous biventricular pacing. The device functioned as expected. LV lead dislodgement was observed in 12 patients and phrenic nerve stimulation required lead repositioning in 2 patients. Eight patients died during the study. Patient survival at 3 and 6 months was 97 +/- 2% and 94 +/- 2%, respectively. Cause of death was cardiac (n = 7), heart failure related (n = 3), arrhythmia related (n = 2), and unknown (n = 2). In conclusion, this sequential biventricular pacemaker was safe and efficacious.

  2. Recent improvements in the coupled TRAC-PF1/NEM methodology

    SciTech Connect

    Ivanov, K.N.; Baratta, A.J.

    1996-12-31

    The latest released version of the coupled three-dimensional thermal-hydraulic/kinetics TRAC-PF1/NEM code has reached the level of direct industry application. To complete the development of TRAC-PF1/NEM in a production mode version, further improvements have been implemented and tested. To enhance the accuracy of neutronic nodal predictions, assembly discontinuity factors (ADFs) have been utilized in the coupled TRAC-PF1/NEM methodology. The ADFs are obtained by the CASMO-3 single-assembly spectrum/depletion calculations, and they are treated in the TRAC-PF1/NEM cross-section table generation procedure as additional homogenization parameters. Since the radial component of uncertainty (introduced by not using discontinuity factor) is dominant, the ADFs are introduced in the nodal expansion method (NEM) algorithm for each of the four radial surfaces of the node. Choosing axial node boundaries to coincide with material discontinuities allows unity discontinuity factors to be used at the two axial node surfaces. The programs developed, which extract the cross-section information from the CASMO-3 output files, have been extended to read ADF information from CASMO card image files. Subsequently, the ADFs are assembled into the NEM cross-section tables.

  3. Improved computational performance of MFA using elementary metabolite units and flux coupling.

    PubMed

    Suthers, Patrick F; Chang, Young J; Maranas, Costas D

    2010-03-01

    Extending the scope of isotope mapping models becomes increasingly important in order to analyze strains and drive improved product yields as more complex pathways are engineered into strains and as secondary metabolites are used as starting points for new products. Here we present how the elementary metabolite unit (EMU) framework and flux coupling significantly decrease the computational burden of metabolic flux analysis (MFA) when applied to large-scale metabolic models. We applied these techniques to a previously published isotope mapping model of Escherichia coli accounting for 238 reactions. We find that the combined use of EMU and flux coupling analysis leads to a ten-fold decrease in the number of variables in comparison to the original isotope distribution vector (IDV) version of the model. In addition, using OptMeas the task of identifying additional measurement choices to fully specify the flows in the metabolic network required only 2% of the computation time of the one using IDVs. The observed computational savings reveal the rapid progress in performing MFA with increasingly larger isotope models with the ultimate goal of handling genome-scale models of metabolism.

  4. Fundamental and methodological investigations for the improvement of elemental analysis by inductively coupled plasma mass soectrometry

    SciTech Connect

    Ebert, Christopher Hysjulien

    2012-01-01

    This dissertation describes a variety of studies meant to improve the analytical performance of inductively coupled plasma mass spectrometry (ICP-MS) and laser ablation (LA) ICP-MS. The emission behavior of individual droplets and LA generated particles in an ICP is studied using a high-speed, high frame rate digital camera. Phenomena are observed during the ablation of silicate glass that would cause elemental fractionation during analysis by ICP-MS. Preliminary work for ICP torch developments specifically tailored for the improvement of LA sample introduction are presented. An abnormal scarcity of metal-argon polyatomic ions (MAr{sup +}) is observed during ICP-MS analysis. Evidence shows that MAr{sup +} ions are dissociated by collisions with background gas in a shockwave near the tip of the skimmer cone. Method development towards the improvement of LA-ICP-MS for environmental monitoring is described. A method is developed to trap small particles in a collodion matrix and analyze each particle individually by LA-ICP-MS.

  5. Technique for image fusion based on nonsubsampled shearlet transform and improved pulse-coupled neural network

    NASA Astrophysics Data System (ADS)

    Kong, Weiwei; Liu, Jianping

    2013-01-01

    A new technique for image fusion based on nonsubsampled shearlet transform (NSST) and improved pulse-coupled neural network (PCNN) is proposed. NSST, as a novel multiscale geometric analysis tool, can be optimally efficient in representing images and capturing the geometric features of multidimensional data. As a result, NSST is introduced into the area of image fusion to complete the decompositions of source images in any scale and any direction. Then the basic PCNN model is improved to be improved PCNN (IPCNN), which is more concise and more effective. IPCNN adopts the contrast of each pixel in images as the linking strength β, and the time matrix T of subimages can be obtained via the synchronous pulse-burst property. By using IPCNN, the fused subimages can be achieved. Finally, the final fused image can be obtained by using inverse NSST. The numerical experiments demonstrate that the new technique presented in this paper is competitive in the field of image fusion in terms of both fusion performance and computational efficiency.

  6. Improved mechanical properties of HDPE/nano-alumina composite through silane coupling agent

    NASA Astrophysics Data System (ADS)

    Akmil, N.; Luqman, C. A.; Ahmad, M.; Zaman, K.

    2012-11-01

    The effect of silane coupling agent to mechanical properties of HDPE/nano-alumina composite was investigated. Nano-alumina used in this study was produced by using sol-gel method. The shape and size of nano-alumina were determined by using TEM. Prior to the usage of nano alumina as a filler in the polymer matrix, (3-methacryloxypropyl) trimethoxysilane (MPS) was used to functionalize the nanoparticles due to its bifunctional nature: hydrolysable group (-Si(OCH3)3) and unsaturated carbon-carbon double bond. The XRD result shows diffraction spectrum of the synthesized nano-alumina. In order to improve the mechanical properties of the composite, nanoalumina was treated with (3-methacryloxypropyl) trimethoxysilane (MPS). A high tensile strength, is achieved at 4 wt% of MPS.

  7. Evaluation of Long Term Effect of RV Apical Pacing on Global LV Function by Echocardiography

    PubMed Central

    Tilkar, Mahendra; Jain, Siddhant; Mondal, Subrata; Sarkar, Piyabi; Modi, Nitin

    2016-01-01

    Introduction We very often face pacemaker implanted patients during follow-up with shortness of breath and effort intolerance inspite of normal clinical parameters. Aim The aim of our study is to evaluate the cause of effort intolerance and probable cause of sub-clinical Congestive Cardiac Failure (CCF) in a case of long term Right Ventricular (RV) apical pacing on global Left Ventricular (LV) function non- invasively by echocardiography. Materials and Methods We studied 54 patients (Male 42, Female 12) of complete heart block (CHB) with RV apical pacing (40 VVI and 14 DCP). Mean duration of pacing was 58+4 months. All patients underwent 24 hours Holter monitoring to determine the percentage of ventricular pacing beats. 2-D Echocardiography was done to assess the regional wall motion of abnormality and global LV ejection fraction by modified Simpson’s rule. These methods were coupled with the Doppler derived Myocardial Performance Index (MPI), tissue Doppler imaging, and mechanical regional dyssynchrony with 3-D Echocardiography. Data were analysed from 54 RV- apical paced patients and compared with age and body surface area of 60 controlled subjects (Male 46, Female 14). Results Evaluation of LV function in 54 patients demonstrated regional wall motion abnormality and Doppler study revealed both LV systolic and diastolic dysfunction compare with control subjects (regional wall motion abnormality 80±6% vs 30±3% with p-value<0.0001) which is proportional to the percentage of ventricular pacing beats (mean paced beat 78%). Global LVEF 50±4% vs 60±2% (p-valve <0.0001) and MPI 0.46 ±0.12 v/s 0.36±0.09 (p-value <0.0001). Conclusion RV–apical pacing induces iatrogenic electrical dyssynchrony which leads to remodeling of LV and produces mechanical dyssynchrony which is responsible for LV dysfunction. Alternate site of RV pacing and/or biventricular pacing should be done to maintain biventricular electrical synchrony which will preserve the LV function. PMID

  8. A Lever Coupling Mechanism in Dual-Mass Micro-Gyroscopes for Improving the Shock Resistance along the Driving Direction

    PubMed Central

    Gao, Yang; Li, Hongsheng; Huang, Libin; Sun, Hui

    2017-01-01

    This paper presents the design and application of a lever coupling mechanism to improve the shock resistance of a dual-mass silicon micro-gyroscope with drive mode coupled along the driving direction without sacrificing the mechanical sensitivity. Firstly, the mechanical sensitivity and the shock response of the micro-gyroscope are theoretically analyzed. In the mechanical design, a novel lever coupling mechanism is proposed to change the modal order and to improve the frequency separation. The micro-gyroscope with the lever coupling mechanism optimizes the drive mode order, increasing the in-phase mode frequency to be much larger than the anti-phase one. Shock analysis results show that the micro-gyroscope structure with the designed lever coupling mechanism can notably reduce the magnitudes of the shock response and cut down the stress produced in the shock process compared with the traditional elastic coupled one. Simulations reveal that the shock resistance along the drive direction is greatly increased. Consequently, the lever coupling mechanism can change the gyroscope’s modal order and improve the frequency separation by structurally offering a higher stiffness difference ratio. The shock resistance along the driving direction is tremendously enhanced without loss of the mechanical sensitivity. PMID:28468288

  9. A Lever Coupling Mechanism in Dual-Mass Micro-Gyroscopes for Improving the Shock Resistance along the Driving Direction.

    PubMed

    Gao, Yang; Li, Hongsheng; Huang, Libin; Sun, Hui

    2017-04-30

    This paper presents the design and application of a lever coupling mechanism to improve the shock resistance of a dual-mass silicon micro-gyroscope with drive mode coupled along the driving direction without sacrificing the mechanical sensitivity. Firstly, the mechanical sensitivity and the shock response of the micro-gyroscope are theoretically analyzed. In the mechanical design, a novel lever coupling mechanism is proposed to change the modal order and to improve the frequency separation. The micro-gyroscope with the lever coupling mechanism optimizes the drive mode order, increasing the in-phase mode frequency to be much larger than the anti-phase one. Shock analysis results show that the micro-gyroscope structure with the designed lever coupling mechanism can notably reduce the magnitudes of the shock response and cut down the stress produced in the shock process compared with the traditional elastic coupled one. Simulations reveal that the shock resistance along the drive direction is greatly increased. Consequently, the lever coupling mechanism can change the gyroscope's modal order and improve the frequency separation by structurally offering a higher stiffness difference ratio. The shock resistance along the driving direction is tremendously enhanced without loss of the mechanical sensitivity.

  10. Improved Arterial–Ventricular Coupling in Metabolic Syndrome after Exercise Training

    PubMed Central

    Fournier, Sara B.; Donley, David A.; Bonner, Daniel E.; DeVallance, Evan; Olfert, I. Mark; Chantler, Paul D.

    2014-01-01

    Purpose The metabolic syndrome (MetS) is associated with a three-fold increase risk of cardiovascular (CV) morbidity and mortality, which is in part, due to a blunted CV reserve capacity, reflected by a reduced peak exercise left ventricular contractility and aerobic capacity, and a blunted peak arterial-ventricular coupling. To date, no study has examined whether aerobic exercise training in MetS can reverse the peak exercise CV dysfunction. Further, examining how exercise training alters CV function in a group of individuals with MetS prior to the development of diabetes and/or overt CVD, can provide insights into whether some of the pathophysiological changes to the CV can be delayed/reversed, lowering their CV risk. The objective of this study was to examine the effects of 8 weeks of aerobic exercise training in individuals with MetS on resting and peak exercise CV function. Methods Twenty MetS underwent either 8 weeks of aerobic exercise training (MetS-ExT; n=10) or remained sedentary (MetS-NonT; n=10) during this time period. Resting and peak exercise CV function was characterized using Doppler echocardiography and gas exchange. Results Exercise training did not alter resting left ventricular diastolic or systolic function and arterial-ventricular coupling in MetS. In contrast, at peak exercise an increase in LV contractility (40%, p<0.01), cardiac output (28%, p<0.05) and aerobic capacity (20%, p<0.01), while a reduction in vascular resistance (30%, p<0.05) and arterial-ventricular coupling (27%, p<0.01), were noted in the MetS-ExT but not the MetS-NonT group. Further, an improvement in Lifetime Risk Score was also noted in the MetS-ExT group. Conclusions These findings have clinical importance as they provide insight that some of the pathophysiological changes associated with MetS can be improved and lower the risk of CVD. PMID:24870568

  11. PACE Yourself: A Handbook for ESL Tutors

    ERIC Educational Resources Information Center

    Dalle, Teresa S.; Young, Laurel L.

    2003-01-01

    "PACE Yourself" is for inexperienced or volunteer tutors of ESL. This handbook does not aim to make overnight experts of novices. Rather, the authors provide an easy-to-follow guide for people who want to tutor small groups of nonnative speakers of English but do not know how. Reproducible forms, appendixes of resources, terminology, ESL…

  12. Developmental Math, Flipped and Self-Paced

    ERIC Educational Resources Information Center

    Weng, Pangyen

    2015-01-01

    This article describes a developmental math course design that uses flipped instruction and self-paced learning. The design was created and taught at Metropolitan State University, where most students are returning adult students with little preparation in mathematics. The author argues that this design suits the students well: the learning…

  13. Suggested References. PACE I.D. Center.

    ERIC Educational Resources Information Center

    Bergson, Rita

    During the course of the PACE I.D. Center Project, 1966-1969, staff members recorded references that they felt contributed to the general knowledge of the prevention of learning and behavior problems. More specifically, those references that implied concern for the child in his total environment were considered most relevant. The references are…

  14. Setting the Pace: Experiments with Keller's PSI

    ERIC Educational Resources Information Center

    Purao, Sandeep; Sein, Maung; Nilsen, Hallgeir; Larsen, Even Åby

    2017-01-01

    The ideal of self-paced learning, which was introduced nearly 50 years ago by Keller in his Personalized System of Instruction (PSI), has not yet been widely adopted. In spite of its perceived promise of helping students to learn at the speed aligned to their individual backgrounds, motivation, and skills, PSI has been challenging to implement.…

  15. Self-Paced Physics, Course Materials.

    ERIC Educational Resources Information Center

    New York Inst. of Tech., Old Westbury.

    Samples of the Self-Paced Physics Course materials are presented in this collection for dissemination purposes. Descriptions are included of course objectives, characteristics, structures, and content. As a two-semester course of study for science and engineering sophomores, most topics are on a level comparable to that of classical physics by…

  16. Abnormalities in intracellular calcium regulation and contractile function in myocardium from dogs with pacing-induced heart failure

    NASA Technical Reports Server (NTRS)

    Perreault, C. L.; Shannon, R. P.; Komamura, K.; Vatner, S. F.; Morgan, J. P.

    1992-01-01

    24 d of rapid ventricular pacing induced dilated cardiomyopathy with both systolic and diastolic dysfunction in conscious, chronically instrumented dogs. We studied mechanical properties and intracellular calcium (Ca2+i) transients of trabeculae carneae isolated from 15 control dogs (n = 32) and 11 dogs with pacing-induced cardiac failure (n = 26). Muscles were stretched to maximum length at 30 degrees C and stimulated at 0.33 Hz; a subset (n = 17 control, n = 17 myopathic) was loaded with the [Ca2+]i indicator aequorin. Peak tension was depressed in the myopathic muscles, even in the presence of maximally effective (i.e., 16 mM) [Ca2+] in the perfusate. However, peak [Ca2+]i was similar (0.80 +/- 0.13 vs. 0.71 +/- 0.05 microM; [Ca2+]o = 2.5 mM), suggesting that a decrease in Cai2+ availability was not responsible for the decreased contractility. The time for decline from the peak of the Cai2+ transient was prolonged in the myopathic group, which correlated with prolongation of isometric contraction and relaxation. However, similar end-diastolic [Ca2+]i was achieved in both groups (0.29 +/- 0.05 vs. 0.31 +/- 0.02 microM), indicating that Cai2+ homeostasis can be maintained in myopathic hearts. The inotropic response of the myopathic muscles to milrinone was depressed compared with the controls. However, when cAMP production was stimulated by pretreatment with forskolin, the response of the myopathic muscles to milrinone was improved. Our findings provide direct evidence that abnormal [Ca2+]i handling is an important cause of contractile dysfunction in dogs with pacing-induced heart failure and suggest that deficient production of cAMP may be an important cause of these changes in excitation-contraction coupling.

  17. Abnormalities in intracellular calcium regulation and contractile function in myocardium from dogs with pacing-induced heart failure

    NASA Technical Reports Server (NTRS)

    Perreault, C. L.; Shannon, R. P.; Komamura, K.; Vatner, S. F.; Morgan, J. P.

    1992-01-01

    24 d of rapid ventricular pacing induced dilated cardiomyopathy with both systolic and diastolic dysfunction in conscious, chronically instrumented dogs. We studied mechanical properties and intracellular calcium (Ca2+i) transients of trabeculae carneae isolated from 15 control dogs (n = 32) and 11 dogs with pacing-induced cardiac failure (n = 26). Muscles were stretched to maximum length at 30 degrees C and stimulated at 0.33 Hz; a subset (n = 17 control, n = 17 myopathic) was loaded with the [Ca2+]i indicator aequorin. Peak tension was depressed in the myopathic muscles, even in the presence of maximally effective (i.e., 16 mM) [Ca2+] in the perfusate. However, peak [Ca2+]i was similar (0.80 +/- 0.13 vs. 0.71 +/- 0.05 microM; [Ca2+]o = 2.5 mM), suggesting that a decrease in Cai2+ availability was not responsible for the decreased contractility. The time for decline from the peak of the Cai2+ transient was prolonged in the myopathic group, which correlated with prolongation of isometric contraction and relaxation. However, similar end-diastolic [Ca2+]i was achieved in both groups (0.29 +/- 0.05 vs. 0.31 +/- 0.02 microM), indicating that Cai2+ homeostasis can be maintained in myopathic hearts. The inotropic response of the myopathic muscles to milrinone was depressed compared with the controls. However, when cAMP production was stimulated by pretreatment with forskolin, the response of the myopathic muscles to milrinone was improved. Our findings provide direct evidence that abnormal [Ca2+]i handling is an important cause of contractile dysfunction in dogs with pacing-induced heart failure and suggest that deficient production of cAMP may be an important cause of these changes in excitation-contraction coupling.

  18. Toward a More Efficient Implementation of Antifibrillation Pacing

    PubMed Central

    Wilson, Dan; Moehlis, Jeff

    2016-01-01

    We devise a methodology to determine an optimal pattern of inputs to synchronize firing patterns of cardiac cells which only requires the ability to measure action potential durations in individual cells. In numerical bidomain simulations, the resulting synchronizing inputs are shown to terminate spiral waves with a higher probability than comparable inputs that do not synchronize the cells as strongly. These results suggest that designing stimuli which promote synchronization in cardiac tissue could improve the success rate of defibrillation, and point towards novel strategies for optimizing antifibrillation pacing. PMID:27391010

  19. Pacemaker optimization in nonresponders to cardiac resynchronization therapy: left ventricular pacing as an available option.

    PubMed

    Gage, Ryan M; Burns, Kevin V; Vatterott, Daniel B; Kubo, Spencer H; Bank, Alan J

    2012-06-01

    Echocardiographic (ECHO)-guided pacemaker optimization (PMO) in cardiac resynchronization therapy (CRT) nonresponders acutely improves left ventricular (LV) function. However, the chronic results of LV pacing in this group are less understood. We retrospectively studied 28 CRT nonresponders optimized based on ECHO to LV pacing and compared them to 28 age- and gender-matched patients optimized to biventricular (BiV) pacing. ECHOs with tissue Doppler imaging assessed LV hemodynamics before, immediately after, and 29 ± 16 months after PMO. Also, 56 age- and gender-matched CRT responders were included for comparison of clinical outcomes. PMO resulted in acute improvements in longitudinal LV systolic function and several measures of dyssynchrony, with greater improvements in the LV paced group. Chronic improvements in ejection fraction (EF) (3.2 ± 7.7%), and left ventricle end-systolic volume (LVESV) (-11 ± 36 mL) and one dyssynchrony measure were seen in the combined group. Chronically, both LV and BiV paced patients improved some measures of systolic function and dyssynchrony although response varied between the groups. Survival at 3.5 years was similar (P = 0.973) between the PMO (58%) and nonoptimized groups (58%) but survival free of cardiovascular hospitalization was significantly (P = 0.037) better in the nonoptimized group. CRT nonresponders undergoing PMO to either LV or BiV pacing have acute improvements in longitudinal systolic function and some measures of dyssynchrony. Some benefits are sustained chronically, with improvements in EF, LVESV, and dyssynchrony. A strategy of ECHO-guided PMO results in survival for CRT nonresponders similar to that of CRT patients not referred for PMO. ©2012, The Authors. Journal compilation ©2012 Wiley Periodicals, Inc.

  20. [Performance optimization of property-improved biodiesel manufacturing process coupled with butanol extractive fermentation].

    PubMed

    Zhang, Longyun; Yang, Ying; Shi, Zhongping

    2008-11-01

    The products concentrations in traditional acetone-butanol (AB) fermentation are too low that large amount of energy has to be consumed in the distillation and product recovery process. Aiming at direct utilization of the fermentation products, in this study, optimization of property-improved biodiesel manufacturing process coupled with AB extractive fermentation was conducted, under the condition of using the biodiesel originated from waste cooking oil as the extractant and high concentrated corn flour medium. The effect of biodiesel/broth volume ratio, waste supernatant recycle ratio, and electronic carrier addition on the major process performance index was carefully investigated. Under the optimized condition, the biodiesel quality was improved with the cetane value increased from 51.4 to 54.4; "actual butanol yield" reached to a level of 18%, and waste supernatant recycle ratio exceeded 50%. In this way, elimination of energy-consuming product recovery process and realization of "energy-saving & waste minimization" industrial production target advocated by the state government, could be potentially expected.

  1. Design of a Water Coupling Bolus with Improved Flow Distribution for Multielement Superficial Hyperthermia Applicators

    PubMed Central

    Arunachalam, Kavitha; Maccarini, Paolo F; Schlorff, Jaime L.; Birkelund, Yngve; Jacobsen, Svein; Stauffer, Paul R.

    2009-01-01

    A water bolus used in superficial hyperthermia couples the electromagnetic (EM) or acoustic energy into the target tissue and cools the tissue surface to minimize thermal hotspots and patient discomfort during treatment. Parametric analyses of the fluid pressure inside the bolus computed using 3D fluid dynamics simulations are used in this study to determine a bolus design with improved flow and surface temperature distributions for large area superficial heat applicators. The simulation results are used in the design and fabrication of a 19×32 cm prototype bolus with dual input-dual output (DIDO) flow channels. Sequential thermal images of the bolus surface temperature recorded for a step change in the circulating water temperature are used to assess steady state flow and surface temperature distributions across the bolus. Modeling and measurement data indicate substantial improvement in bolus flow and surface temperature distributions when changing from the previous single input-single output (SISO) to DIDO configuration. Temperature variation across the bolus at steady state was measured to be less than 0.8°C for the DIDO bolus compared to 1.5°C for the SISO waterbolus. The new DIDO bolus configuration maintains a nearly uniform flow distribution and low variation in surface temperature over a large area typically treated in superficial hyperthermia. PMID:19848618

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

    PubMed

    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 < 0.0001). Implant complications occurred in 5 (6%) 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 < 0.0001), but remained stable during long-term follow-up in both groups. During 17.7 +/- 10.0 months of follow-up in the VDD group, only two VDD patients were reprogrammed to VVIR mode, compared to three 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.

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

    PubMed

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

    2003-12-01

    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% male) with symptomatic AV block who received a single pass bipolar VDD system to 80 patients (age 63 +/- 16 years, 70% male) 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 < 0.0001). Implant complications occurred in 5 (6%) 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 < 0.0001), but remained stable during long-term follow-up in both groups. During 17.7 +/- 10.0 months of follow-up in the VDD group, only 2 VDD patients were reprogrammed to VVIR mode, compared to 3 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.

  4. 42 CFR 460.50 - Termination of PACE program agreement.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... SERVICES (CONTINUED) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) Sanctions, Enforcement Actions, and Termination § 460.50 Termination of...

  5. 42 CFR 460.50 - Termination of PACE program agreement.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... SERVICES (CONTINUED) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) Sanctions, Enforcement Actions, and Termination § 460.50 Termination of...

  6. 42 CFR 460.50 - Termination of PACE program agreement.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... SERVICES (CONTINUED) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) Sanctions, Enforcement Actions, and Termination § 460.50 Termination of...

  7. 42 CFR 460.50 - Termination of PACE program agreement.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... SERVICES (CONTINUED) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) Sanctions, Enforcement Actions, and Termination § 460.50 Termination of...

  8. 42 CFR 460.50 - Termination of PACE program agreement.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... SERVICES (CONTINUED) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) Sanctions, Enforcement Actions, and Termination § 460.50 Termination of...

  9. Pacing, Pixels, and Paper: Flexibility in Learning Words from Flashcards

    ERIC Educational Resources Information Center

    Sage, Kara; Rausch, Joseph; Quirk, Abigail; Halladay, Lauren

    2016-01-01

    The present study focused on how self-control over pace might help learners successfully extract information from digital learning aids. Past research has indicated that too much control over pace can be overwhelming, but too little control over pace can be ineffective. Within the popular self-testing domain of flashcards, we sought to elucidate…

  10. Pacing, Pixels, and Paper: Flexibility in Learning Words from Flashcards

    ERIC Educational Resources Information Center

    Sage, Kara; Rausch, Joseph; Quirk, Abigail; Halladay, Lauren

    2016-01-01

    The present study focused on how self-control over pace might help learners successfully extract information from digital learning aids. Past research has indicated that too much control over pace can be overwhelming, but too little control over pace can be ineffective. Within the popular self-testing domain of flashcards, we sought to elucidate…

  11. 42 CFR 460.122 - PACE organization's appeals process.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 4 2010-10-01 2010-10-01 false PACE organization's appeals process. 460.122 Section 460.122 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN... FOR THE ELDERLY (PACE) Participant Rights § 460.122 PACE organization's appeals process. For purposes...

  12. Applying 20/20 Hindsight to Self-Pacing.

    ERIC Educational Resources Information Center

    Dunkleberger, Gary E.

    1980-01-01

    Discussed are several suggestions for the maintenance of a science self-paced classroom. Topics include the use of computers for student self-assessment, teachers and students roles in the self-paced classroom, and laboratory setup and packaging in the self-paced science laboratory. (Author/DS)

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

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... SERVICES (CONTINUED) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) Participant Rights § 460.122 PACE organization's appeals process. For purposes... which the participant believes that his or her life, health, or ability to regain or maintain maximum...

  14. Applying 20/20 Hindsight to Self-Pacing.

    ERIC Educational Resources Information Center

    Dunkleberger, Gary E.

    1980-01-01

    Discussed are several suggestions for the maintenance of a science self-paced classroom. Topics include the use of computers for student self-assessment, teachers and students roles in the self-paced classroom, and laboratory setup and packaging in the self-paced science laboratory. (Author/DS)

  15. Investigating the use of coupling agents to improve the interfacial properties between a resorbable phosphate glass and polylactic acid matrix.

    PubMed

    Hasan, Muhammad Sami; Ahmed, Ifty; Parsons, Andrew J; Rudd, Chris D; Walker, Gavin S; Scotchford, Colin A

    2013-09-01

    Eight different chemicals were investigated as potential candidate coupling agents for phosphate glass fibre reinforced polylactic acid composites. Evidence of reaction of the coupling agents with phosphate glass and their effect on surface wettability and glass degradation were studied along with their principle role of improving the interface between glass reinforcement and polymer matrix. It was found that, with an optimal amount of coupling agent on the surface of the glass/polymer, interfacial shear strength improved by a factor of 5. Evidence of covalent bonding between agent and glass was found for three of the coupling agents investigated, namely: 3-aminopropyltriethoxysilane; etidronic acid and hexamethylene diisocyanate. These three coupling agents also improved the interfacial shear strength and increased the hydrophobicity of the glass surface. It is expected that this would provide an improvement in the macroscopic properties of full-scale composites fabricated from the same materials which may also help to retain these properties for the desired length of time by retarding the breakdown of the fibre/matrix interface within these composites.

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

    PubMed

    Couture, Frédéric; Ly, Kévin; Levesque, Christine; Kwiatkowska, Anna; Ait-Mohand, Samia; Desjardins, Roxane; Guérin, Brigitte; Day, Robert

    2015-01-01

    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.

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

    PubMed Central

    Ly, Kévin; Levesque, Christine; Kwiatkowska, Anna; Ait-Mohand, Samia; Desjardins, Roxane; Guérin, Brigitte; Day, Robert

    2015-01-01

    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. PMID:26114115

  18. State of the art of leadless pacing

    PubMed Central

    Sperzel, Johannes; Burri, Haran; Gras, Daniel; Tjong, Fleur V.Y.; Knops, Reinoud E.; Hindricks, Gerhard; Steinwender, Clemens; Defaye, Pascal

    2015-01-01

    Despite undisputable benefits, conventional pacemaker therapy is associated with specific complications related to the subcutaneous device and the transvenous leads. Recently, two miniaturized leadless pacemakers, Nanostim™ (St. Jude Medical) and Micra™ (Medtronic), which can be completely implanted inside the right ventricle using steerable delivery systems, entered clinical application. The WiCS™-cardiac resynchronisation therapy (CRT) system (wireless cardiac stimulation for CRT, EBR Systems) delivers leadless left ventricular endocardial stimulation for cardiac resynchronization. In addition to obvious cosmetic benefits, leadless pacing systems may have the potential to overcome some complications of conventional pacing. However, acute and long-term complications still remains to be determined, as well as the feasibility of device explantation years after device placement. PMID:26024918

  19. Pre-Packaged Commercial PACE Financing Solutions

    SciTech Connect

    Wallander, Michael

    2015-11-02

    The objective of this project was to demonstrate a more streamlined method for facilitating commercial property assessed clean energy (PACE) retrofits. The Recipient aimed to prove that energy efficiency performance of simple, pre-packaged technologies (e.g., lighting and heating, ventilation and air conditioning (HVAC)) can be accurately estimated without the need for a detailed energy audit. A successful project would inspire consumer confidence in undertaking cost-effective retrofits.

  20. An improved coupling model for the lithosphere-atmosphere-ionosphere system

    NASA Astrophysics Data System (ADS)

    Kuo, C. L.; Lee, L. C.; Huba, J. D.

    2014-04-01

    In our previous model for the lithosphere-atmosphere-ionosphere coupling, the background magnetic field was assumed to be perpendicular to the horizontal plane. In the present paper, we improve the calculation of currents in the atmosphere by solving the current density J directly from the current continuity equation ∇ • J = 0. The currents in the atmosphere can be solved for any arbitrary angle of magnetic field, i.e., any magnetic latitude. In addition, a large ratio (~10) of Hall to Pedersen conductivities is used to generate a large Hall electric field. The effects of atmospheric currents and electric fields on the ionosphere with lithosphere current source located at magnetic latitudes of 7.5°, 15°, 22.5°, and 30° are obtained. For upward (downward) atmospheric currents flowing into the ionosphere, the simulation results show that the westward (eastward) electric fields dominate. At magnetic latitude of 7.5° or 15°, the upward (downward) current causes the increase (decrease) of total electron content (TEC) near the source region, while the upward (downward) current causes the decrease (increase) of TEC at magnetic latitude of 22.5°or 30°. The dynamo current density required to generate the same amount of TEC variation in the improved model is found to be smaller by a factor of 30 as compared to that obtained in our earlier paper. We also calculate the ionosphere dynamics with imposed zonal westward and eastward electric field based on SAMI3 code. It is found that the eastward (westward) electric field may trigger one (two) plasma bubble(s) in the nighttime ionosphere.

  1. The Precise Timing of Tachycardia Entrainment is Determined by the Post-Pacing Interval, the Tachycardia Cycle Length, and the Pacing Rate: Theoretical Insights and Practical Applications

    PubMed Central

    Kaiser, Daniel W.; Hsia, Henry H.; Dubin, Anne M.; Liem, L. Bing; Viswanathan, Mohan N.; Zei, Paul C.; Wang, Paul J.; Narayan, Sanjiv M.; Turakhia, Mintu P.

    2016-01-01

    BACKGROUND Previous observations have reported that the number of pacing stimuli required to entrain a tachycardia varies based on arrhythmia type and location, but a quantitative formulation of the number needed to entrain (NNE) that unifies these observations has not been characterized. OBJECTIVE We sought to investigate the relationship between the number of pacing stimulations (n), the tachycardia cycle length (TCL), the overdrive pacing cycle length (PCL), and the post-pacing interval (PPI) on the timing of tachycardia entrainment. METHODS First, we detailed a mathematically derivation unifying electrophysiological parameters with empirical confirmation in two patients undergoing catheter ablation of typical atrial flutter. Next, we validated our formula in 44 patients who underwent various catheter ablation procedures. For accuracy, we corrected for rate-related changes in conduction velocity. RESULTS We derived the equations, NNE=|(PPI-TCL)/(TCL-PCL)|+1 and [Advancement=(NNE-1)*(TCL-PCL)−(PPI-TCL)], which state that the NNE and the amount of tachycardia advancement on the first resetting stimulation are determined by regularly measured intracardiac parameters. In the retrospective cohort, the observed PPI-TCL highly correlated with the predicted PPI-TCL (r=0.97, p<0.001, mean difference 5.8 ms), calculated as: [(PPI-TCL)=(NNE-1)*(TCL-PCL)-Advancement]. CONCLUSIONS The number of pacing stimulations required to entrain a reentrant tachycardia is predictable at any PCL after correcting for cycle-length dependent changes in conduction velocity. This relationship unifies established empirically-derived diagnostic and mapping criteria for supraventricular and ventricular tachycardia. This relationship may help elucidate when anti-tachycardia pacing (ATP) episodes are ineffective or proarrhythmic and could potentially serve as a theoretical basis to customize ATP settings for improved safety and effectiveness. PMID:26611239

  2. An improved candidate reference method for serum potassium measurement by inductively coupled plasma-mass spectrometry.

    PubMed

    Zhang, Rui; Ma, Huaian; Li, Huiling; Xu, Jing; Zhang, Jianping; Zhang, Yang; Wang, Qingtao

    2013-05-01

    In 2002, the National Institute of Standards and Technology (NIST) established a reference method for serum potassium based on inductively coupled plasma-mass spectrometry (ICP-MS). The aim of this study was to develop an inexpensive and improved candidate reference method for accurate and precise determination of serum potassium. Serum samples were diluted with 1% HNO3 supplemented with (59)Cobalt as isotope internal standard, and potassium was measured by ICP-MS. The new method was evaluated with NIST standard reference materials (SRMs), according to the Clinical and Laboratory Standard Institute's evaluation protocols. At 4.300 and 4.678 mmol/l levels, the present method demonstrated analytical imprecision of 0.09% and 0.14%, and recoveries of 99.67% to 99.88%, respectively. The bias between the target values of SRMs were -0.02% to +0.28%, respectively. This method was linear between 0.0000 and 6.87 mmol/l (R(2)=1.000). The method had an uncertainty (U95%) of 0.76%. The proposed ICP-MS method to measure serum potassium is precise and accurate, with high sensitivity and specificity. It may be considered as a candidate reference method for the determination of serum potassium. Copyright © 2012 Elsevier B.V. All rights reserved.

  3. Prompt efficiency of energy harvesting by magnetic coupling of an improved bi-stable system

    NASA Astrophysics Data System (ADS)

    Li, Hai-Tao; Qin, Wei-Yang

    2016-11-01

    In order to improve the transform efficiency of bi-stable energy harvester (BEH), this paper proposes an advanced bi-stable energy harvester (ABEH), which is composed of two bi-stable beams coupling through their magnets. Theoretical analyzes and simulations for the ABEH are carried out. First, the mathematical model is established and its dynamical equations are derived. The formulas of magnetic force in two directions are given. The potential energy barrier of ABEH is reduced and the snap-through is liable to occur between potential wells. To demonstrate the ABEH’s advantage in harvesting energy, comparisons between the ABEH and the BEH are carried out for both harmonic and stochastic excitations. Our results reveal that the ABEH’s inter-well response can be elicited by a low-frequency excitation and the harvester can attain frequent jumping between potential wells at fairly weak random excitations. Thus, it can generate a higher output power. The present findings prove that the ABEH is preferable in harvesting energy and can be optimally designed such that it attains the best harvesting performance. Project supported by the National Natural Science Foundation of China (Grant No. 11172234) and the Scholarship from China Scholarship Council (Grant No. 201506290092).

  4. Fiber optic probe having fibers with endfaces formed for improved coupling efficiency and method using same

    DOEpatents

    O`Rourke, P.E.; Livingston, R.R.

    1995-03-28

    A fiber optic probe is disclosed for detecting scattered light, with transmitting and receiving fibers having slanted ends and bundled together to form a bevel within the tip of the probe. The probe comprises a housing with a transparent window across its tip for protecting the transmitting and receiving fibers held therein. The endfaces of the fibers are slanted, by cutting, polishing and the like, so that they lie in a plane that is not perpendicular to the longitudinal axis of the respective fiber. The fibers are held in the tip of the probe using an epoxy and oriented so that lines normal to the slanted endfaces are divergent with respect to one another. The epoxy, which is positioned substantially between the transmitting and receiving fibers, is tapered so that the transmitting fiber, the epoxy and the receiving fiber form a bevel of not more than 20 degrees. The angled fiber endfaces cause directing of the light cones toward each other, resulting in improved light coupling efficiency. A light absorber, such as carbon black, is contained in the epoxy to reduce crosstalk between the transmitting and receiving fibers. 3 figures.

  5. Improving sensitivity for microchip electrophoresis interfaced with inductively coupled plasma mass spectrometry using parallel multichannel separation.

    PubMed

    Cheng, Heyong; Liu, Jinhua; Xu, Zigang; Wang, Yuanchao; Ye, Meiying

    2016-08-26

    We reported sensitivity enhancement using multichannel parallel separation for microchip electrophoresis hyphenated with inductively coupled plasma mass spectrometry (MCE-ICP-MS) in this study. By using 2-20 array lanes for parallel separation, the sensitivity of the MCE-ICP-MS system was proportionally improved by 2-20 folds. No significantly adverse effect of parallel separation on column efficiency and resolution was observed. Rapid separation of Hg(2+) and methylmercuric (MeHg) ion within 36s under an electric field of 800Vcm(-1) was achieved in the 2-cm twenty-channels with a background electrolyte of 5mmolL(-1) borate buffer (pH 9.2). Detection limits of Hg(2+) and MeHg by the proposed system were decreased to 6.8-7.1ngL(-1). Good agreement between determined values and certified values of a certified reference fish was obtained with recoveries ranged between 94-98%. All results prove its advantages including high sensitivity, high efficiency and low operation cost, which are beneficial to routine analysis of metal speciation in environmental, biological and food fields. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Improved single-cell culture achieved using micromolding in capillaries technology coupled with poly (HEMA)

    PubMed Central

    Ye, Fang; Jiang, Jin; Chang, Honglong; Xie, Li; Deng, Jinjun; Ma, Zhibo; Yuan, Weizheng

    2015-01-01

    Cell studies at the single-cell level are becoming more and more critical for understanding the complex biological processes. Here, we present an optimization study investigating the positioning of single cells using micromolding in capillaries technology coupled with the cytophobic biomaterial poly (2-hydroxyethyl methacrylate) (poly (HEMA)). As a cytophobic biomaterial, poly (HEMA) was used to inhibit cells, whereas the glass was used as the substrate to provide a cell adhesive background. The poly (HEMA) chemical barrier was obtained using micromolding in capillaries, and the microchannel networks used for capillarity were easily achieved by reversibly bonding the polydimethylsiloxane mold and the glass. Finally, discrete cell adhesion regions were presented on the glass surface. This method is facile and low cost, and the reagents are commercially available. We validated the cytophobic abilities of the poly (HEMA), optimized the channel parameters for higher quality and more stable poly (HEMA) patterns by investigating the effects of changing the aspect ratio and the width of the microchannel on the poly (HEMA) grid pattern, and improved the single-cell occupancy by optimizing the dimensions of the cell adhesion regions. PMID:26339307

  7. Fiber optic probe having fibers with endfaces formed for improved coupling efficiency and method using same

    DOEpatents

    O'Rourke, Patrick E.; Livingston, Ronald R.

    1995-01-01

    A fiber optic probe for detecting scattered light, with transmitting and receiving fibers having slanted ends and bundled together to form a bevel within the tip of the probe. The probe comprises a housing with a transparent window across its tip for protecting the transmitting and receiving fibers held therein. The endfaces of the fibers are slanted, by cutting, polishing and the like, so that they lie in a plane that is not perpendicular to the longitudinal axis of the respective fiber. The fibers are held in the tip of the probe using an epoxy and oriented so that lines normal to the slanted endfaces are divergent with respect to one another. The epoxy, which is positioned substantially between the transmitting and receiving fibers, is tapered so that the transmitting fiber, the epoxy and the receiving fiber form a bevel of not more than 20 degrees. The angled fiber endfaces cause directing of the light cones toward each other, resulting in improved light coupling efficiency. A light absorber, such as carbon black, is contained in the epoxy to reduce crosstalk between the transmitting and receiving fibers.

  8. Coupled incremental precursor and co-factor supply improves 3-hydroxypropionic acid production in Saccharomyces cerevisiae.

    PubMed

    Chen, Yun; Bao, Jichen; Kim, Il-Kwon; Siewers, Verena; Nielsen, Jens

    2014-03-01

    3-Hydroxypropionic acid (3-HP) is an attractive platform chemical, which can be used to produce a variety of commodity chemicals, such as acrylic acid and acrylamide. For enabling a sustainable alternative to petrochemicals as the feedstock for these commercially important chemicals, fermentative production of 3-HP is widely investigated and is centered on bacterial systems in most cases. However, bacteria present certain drawbacks for large-scale organic acid production. In this study, we have evaluated the production of 3-HP in the budding yeast Saccharomyces cerevisiae through a route from malonyl-CoA, because this allows performing the fermentation at low pH thus making the overall process cheaper. We have further engineered the host strain by increasing availability of the precursor malonyl-CoA and by coupling the production with increased NADPH supply we were able to substantially improve 3-HP production by five-fold, up to a final titer of 463 mg l⁻¹. Our work thus led to a demonstration of 3-HP production in yeast via the malonyl-CoA pathway, and this opens for the use of yeast as a cell factory for production of bio-based 3-HP and derived acrylates in the future. Copyright © 2014 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

  9. Brains in Competition: Improved Cognitive Performance and Inter-Brain Coupling by Hyperscanning Paradigm with Functional Near-Infrared Spectroscopy.

    PubMed

    Balconi, Michela; Vanutelli, Maria E

    2017-01-01

    Hyperscanning brain paradigm was applied to competitive task for couples of subjects. Functional Near-Infrared Spectroscopy (fNIRS) and cognitive performance were considered to test inter-brain and cognitive strategy similarities between subjects (14 couples) during a joint-action. We supposed increased brain-to-brain coupling and improved cognitive outcomes due to joint-action and the competition. As supposed, the direct interaction between the subjects and the observed external feedback of their performance (an experimentally induced fictitious feedback) affected the cognitive performance with decreased Error Rates (ERs), and Response Times (RTs). In addition, fNIRS measure (oxyhemoglobin, O2Hb) revealed an increased brain activity in the prefrontal cortex (PFC) in post-feedback more than pre-feedback condition. Moreover, a higher inter-brain similarity was found for the couples during the task, with higher matched brain response in post-feedback condition than pre-feedback. Finally, a significant increased prefrontal brain lateralization effect was observed for the right hemisphere. Indeed the right PFC was more responsive with similar modalities within the couple during the post-feedback condition. The joined-task and competitive context was adduced to explain these cognitive performance improving, synergic brain responsiveness within the couples and lateralization effects (negative emotions).

  10. An Exploratory Study of Student-Paced versus Teacher-Paced Accommodations for Large-Scale Math Tests.

    ERIC Educational Resources Information Center

    Hollenbeck, Keith; Rozek-Tedesco, Marick A.; Tindal, Gerald; Glasgow, Aaron

    2000-01-01

    This study examined whether a teacher-paced video (TPV) accommodation or a student-paced computer (SPC) accommodation provided differential access for student with disabilities versus their general education peers on a large-scale math test. It found that although both pacing accommodations significantly influenced mean scores, the SPC…

  11. Optical stimulation enables paced electrophysiological studies in embryonic hearts

    PubMed Central

    Wang, Yves T.; Gu, Shi; Ma, Pei; Watanabe, Michiko; Rollins, Andrew M.; Jenkins, Michael W.

    2014-01-01

    Cardiac electrophysiology plays a critical role in the development and function of the heart. Studies of early embryonic electrical activity have lacked a viable point stimulation technique to pace in vitro samples. Here, optical pacing by high-precision infrared stimulation is used to pace excised embryonic hearts, allowing electrophysiological parameters to be quantified during pacing at varying rates with optical mapping. Combined optical pacing and optical mapping enables electrophysiological studies in embryos under more physiological conditions and at varying heart rates, allowing detection of abnormal conduction and comparisons between normal and pathological electrical activity during development in various models. PMID:24761284

  12. 42 CFR 460.90 - PACE benefits under Medicare and Medicaid.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... SERVICES (CONTINUED) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) PACE Services § 460.90 PACE benefits under Medicare and Medicaid. If a...

  13. 42 CFR 460.32 - Content and terms of PACE program agreement.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... SERVICES (CONTINUED) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) PACE Program Agreement § 460.32 Content and terms of PACE program agreement....

  14. 42 CFR 460.32 - Content and terms of PACE program agreement.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... SERVICES (CONTINUED) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) PACE Program Agreement § 460.32 Content and terms of PACE program agreement....

  15. 42 CFR 460.90 - PACE benefits under Medicare and Medicaid.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... SERVICES (CONTINUED) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) PACE Services § 460.90 PACE benefits under Medicare and Medicaid. If a...

  16. 42 CFR 460.90 - PACE benefits under Medicare and Medicaid.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... SERVICES (CONTINUED) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) PACE Services § 460.90 PACE benefits under Medicare and Medicaid. If a...

  17. 42 CFR 460.90 - PACE benefits under Medicare and Medicaid.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... SERVICES (CONTINUED) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) PACE Services § 460.90 PACE benefits under Medicare and Medicaid. If a...

  18. 42 CFR 460.32 - Content and terms of PACE program agreement.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... SERVICES (CONTINUED) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) PACE Program Agreement § 460.32 Content and terms of PACE program agreement....

  19. OSSE Assessment of Ocean Observing System Enhancements to Improve Coupled Tropical Cyclone Intensity Prediction

    NASA Astrophysics Data System (ADS)

    Halliwell, G. R., Jr.; Mehari, M. F.; Dong, J.; Kourafalou, V.; Atlas, R. M.; Kang, H.; Le Henaff, M.

    2016-02-01

    A new ocean OSSE system validated in the tropical/subtropical Atlantic Ocean is used to evaluate ocean observing strategies during the 2014 hurricane season with the goal of improving coupled tropical cyclone forecasts. Enhancements to the existing operational ocean observing system are evaluated prior to two storms, Edouard and Gonzalo, where ocean measurements were obtained during field experiments supported by the 2013 Disaster Relief Appropriation Act. For Gonzalo, a reference OSSE is performed to evaluate the impact of two ocean gliders deployed north and south of Puerto Rico and two Alamo profiling floats deployed in the same general region during most of the hurricane season. For Edouard, a reference OSSE is performed to evaluate impacts of the pre-storm ocean profile survey conducted by NOAA WP-3D aircraft. For both storms, additional OSSEs are then conducted to evaluate more extensive seasonal and pre-storm ocean observing strategies. These include (1) deploying a larger number of synthetic ocean gliders during the hurricane season, (2) deploying pre-storm synthetic thermistor chains or synthetic profiling floats along one or more "picket fence" lines that cross projected storm tracks, and (3) designing pre-storm airborne profiling surveys to have larger impacts than the actual pre-storm survey conducted for Edouard. Impacts are evaluated based on error reduction in ocean parameters important to SST cooling and hurricane intensity such as ocean heat content and the structure of the ocean eddy field. In all cases, ocean profiles that sample both temperature and salinity down to 1000m provide greater overall error reduction than shallower temperature profiles obtained from AXBTs and thermistor chains. Large spatial coverage with multiple instruments spanning a few degrees of longitude and latitude is necessary to sufficiently reduce ocean initialization errors over a region broad enough to significantly impact predicted surface enthalpy flux into the storm

  20. The effect of electronic repositioning on left ventricular pacing and phrenic nerve stimulation.

    PubMed

    Champagne, Jean; Healey, Jeffrey S; Krahn, Andrew D; Philippon, Francois; Gurevitz, Osnat; Swearingen, Anne; Glikson, Michael

    2011-03-01

    Cardiac resynchronization therapy (CRT) improves survival and reduces heart failure symptoms. However, phrenic nerve stimulation and high pacing thresholds are common problems that limit CRT effectiveness. Current technology allows reprogramming of left ventricular (LV) pacing vectors, permitting 'electronic repositioning' to overcome both phrenic nerve stimulation and high pacing output without the need for re-operation. Patients underwent prospective evaluation of a CRT system implantation with a bipolar LV. Optimal LV threshold and avoidance of phrenic nerve stimulation were determined at baseline and at 6 months. A subset of 48 patients underwent more detailed evaluation of pacing threshold and phrenic nerve stimulation at baseline and at 6 months. Between 2004 and 2007, 228 patients underwent CRT implantation (64 CRT pacemakers, 164 CRT defibrillators). At baseline, electronic reprogramming to determine an alternate configuration compared with standard LVtip to LVring found a ≥ 1.0 V reduction in pacing threshold in 80 patients (35%). Of the 17 patients who had an LVtip to LVring configuration and high pacing threshold (>5.0 V), 16 could be reduced by >1.0 V (94%) and 11 could be reduced by >2.0 V through electronic repositioning alone without repositioning the lead (65%). At implant, there were 48 patients with phrenic nerve stimulation at less than maximum pacing output (21%) using the standard LVtip to LVring configuration. In 37 cases (77%), there was at least one other configuration with no phrenic nerve stimulation, which prevented the need for lead revision. Electronic repositioning is an important tool in the management of CRT patients which may help to lower thresholds, avoid phrenic nerve stimulation, and prevent unnecessary re-operations for LV lead repositioning.

  1. Improving Predictability of Generalized Coupled Markov Chain Model through Bayesian Inference

    NASA Astrophysics Data System (ADS)

    Paudyal, P.; Jeong, J. A.; Park, E.

    2011-12-01

    In many actual fields, conditioning hard information is often, if not always, limited and the associating uncertainties in the predictions are prevailing. To limit the uncertainties arisen from the deficiency of the required information, additional correlated information, such as geophysical soft information, may be adopted. In this study, we modified the previously developed multidimensional generalized coupled Markov chain (GCMC) model (Park, 2010), which has been presented as a robust Markovian geostatistical model, by employing the principle of Bayesian inferences to integrate hard and soft information. In the modification, a prior of GCMC conditional probabilities on categorical variables based on adjacent hard information with a generic likelihood from probability distribution functions (PDFs) of soft information on given categories are jointly used to delineate the local posterior. By the process, a local soft information and adjacent hard information can be incorporated, and an improved posterior distribution can be yielded. The developed model is applied to the northern part of Jeju Island, Korea to test its improved predictability compared to the previous model without Bayesian updating. In the predictive simulations, the hard information is acquired at randomly selected 30 locations from the original geologic map composed of four different rock types. To prepare assumed geophysical information, a hypothetical PDF is assigned to each rock type at first. After the assignment, total 216 points are selected from an equally spaced grid imposed on the map and the corresponding geophysical properties are stochastically generated from the hypothetical PDFs. Finally, based on the generated values, a kriged map is built and used as input soft information for the modified model. With the hypothetical soft data, two types of multiple realizations using the model with and without Bayesian updating are developed. From the realizations based on each model, the

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

    PubMed

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

    2012-07-01

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

  3. Increased awareness about diabetes and its complications in a whole city: effectiveness of the "prevention, awareness, counselling and evaluation" [PACE] Diabetes Project [PACE-6].

    PubMed

    Somannavar, S; Lanthorn, H; Deepa, M; Pradeepa, R; Rema, M; Mohan, V

    2008-07-01

    To determine the effectiveness of a large scale multipronged diabetes awareness program provided through community involvement in Chennai. Mass awareness and free screening camps were conducted between 2004-2007 at various locations of Chennai as part of the Prevention, Awareness, Counselling and Evaluation [PACE] Diabetes Project. During a 3-year period, 774 diabetes awareness camps were conducted to reach the public directly. After the PACE project was completed, 3000 individuals, representative of Chennai, were surveyed in 2007 using a systematic stratified random sampling technique. The results were compared to a similar survey carried out, as part of the Chennai Urban Rural Epidemiology Study [CURES] in 2001-2002, which served as a measure of baseline diabetes awareness. Awareness of a condition called "diabetes" increased significantly from 75.5% in 2001-2002 (CURES) to 81% (p < 0.001) in 2007 (PACE). 74.1% of the citizens of Chennai are now aware that the prevalence of diabetes is increasing as compared to 60.2% earlier [p < 0.001]. Significantly more people felt that diabetes could be prevented (p < 0.001), and that a combination of diet and exercise were needed to do so (p < 0.001). Respondents reporting obesity, family history of diabetes, hypertension and mental stress as risk factors increased significantly after PACE (p < 0.001). More people were able to correctly identify the eyes (PACE 38.1% compared to CURES--16.1%, p < 0.001), kidney (PACE 42.3% compared to CURES 16.10%, p < 0.001), heart (PACE 4.6% compared to CURES 5.8%, p < 0.001) and feet (PACE 35.0% vs. CURES 21.9%, p < 0.001) as the main organs affected by diabetes. Through direct public education and mass media campaigns, awareness about diabetes and its complications can be improved even in a whole city. If similar efforts are implemented state-wise and nationally, prevention and control of non-communicable diseases, specifically diabetes and cardiovascular disease, is an achievable goal in

  4. A conceptual framework for coupling the biophysical and social dimensions of wildfire to improve fireshed planning and risk mitigation

    Treesearch

    Jeff Kline; Alan A. Ager; Paige Fischer

    2015-01-01

    The need for improved methods for managing wildfire risk is becoming apparent as uncharacteristically large wildfires in the western US and elsewhere exceed government capacities for their control and suppression. We propose a coupled biophysical-social framework to managing wildfire risk that relies on wildfire simulation to identify spatial patterns of wildfire risk...

  5. Dual chamber cardiac pacing in children: Single chamber pacing dual chamber sensing cardiac pacemaker or dual chamber pacing and sensing cardiac pacemaker?

    PubMed

    Bostan, Ozlem M; Celiker, Alpay; Karagöz, Tevfik; Ozer, Sema; Ozme, Sencan

    2002-12-01

    Dual chamber pacemakers (single chamber pacing dual chamber sensing cardiac pacemaker (VDD) and dual chamber pacing and sensing cardiac pacemaker (DDD)) are being used frequently in children and adolescents. The aim of this study was to verify the safety and performance of the VDD and DDD pacing systems, and to evaluate the differences between two pacing modes with regard to atrial sensing and tracking functions. In this study, we evaluated 14 patients with VDD pacing and 15 patients with DDD pacing between 1994 and 2000. In the patient group with VDD pacing, all had congenital or acquired atrioventricular (AV) block. In the patient group with DDD pacing, 11 had congenital or acquired AV block, three had sinus node dysfunction with AV conduction disturbance and one had idiopathic hypertrophic subaortic stenosis. Twenty-eight devices were implanted in the subpectoral area using the transvenous route. After implantation the atrial tracking capabilities of the pacing systems were analyzed by telemetry, Holter monitoring, and treadmill exercise testing. The mean age of patients in the VDD pacing group was younger. The percentage of congenital heart disease was higher in the DDD pacing group. There was no significant difference regarding fluoroscopy time during implantation and follow-up time between the two groups. During implantation, in the VDD pacing group the mean sensed atrial signal was 3.1 +/- 1.3 mV and this decreased to 1.37 +/- 0.68 mV (P < 0.05) during follow-up. This pattern was also observed in DDD group (3 +/- 2 mV vs 1.9 +/- 1.5 mV, P < 0.05). Although the P wave measurement at implantation did not differ between the two groups, it was significantly higher in the DDD pacing group at the last control. Three patients with VDD pacing were reprogrammed to VVI or single chamber pacing and sensing, rate adaptive cardiac pacemaker because of complete loss of AV synchrony. There was no atrial sensing problem in the DDD pacing group. During the follow-up, one

  6. Accurate gradient approximation for complex interface problems in 3D by an improved coupling interface method

    SciTech Connect

    Shu, Yu-Chen; Chern, I-Liang; Chang, Chien C.

    2014-10-15

    Most elliptic interface solvers become complicated for complex interface problems at those “exceptional points” where there are not enough neighboring interior points for high order interpolation. Such complication increases especially in three dimensions. Usually, the solvers are thus reduced to low order accuracy. In this paper, we classify these exceptional points and propose two recipes to maintain order of accuracy there, aiming at improving the previous coupling interface method [26]. Yet the idea is also applicable to other interface solvers. The main idea is to have at least first order approximations for second order derivatives at those exceptional points. Recipe 1 is to use the finite difference approximation for the second order derivatives at a nearby interior grid point, whenever this is possible. Recipe 2 is to flip domain signatures and introduce a ghost state so that a second-order method can be applied. This ghost state is a smooth extension of the solution at the exceptional point from the other side of the interface. The original state is recovered by a post-processing using nearby states and jump conditions. The choice of recipes is determined by a classification scheme of the exceptional points. The method renders the solution and its gradient uniformly second-order accurate in the entire computed domain. Numerical examples are provided to illustrate the second order accuracy of the presently proposed method in approximating the gradients of the original states for some complex interfaces which we had tested previous in two and three dimensions, and a real molecule ( (1D63)) which is double-helix shape and composed of hundreds of atoms.

  7. Efficacy of Precordial Percussion Pacing Assessed in a Cardiac Standstill Microminipig Model.

    PubMed

    Wada, Takeshi; Ohara, Hiroshi; Nakamura, Yuji; Cao, Xin; Izumi-Nakaseko, Hiroko; Ando, Kentaro; Honda, Mitsuru; Yoshihara, Katsunori; Nakazato, Yuji; Lurie, Keith G; Sugiyama, Atsushi

    2017-07-25

    Potential cardiovascular benefits of precordial percussion pacing (PPP) during cardiac standstill are unknown.Methods and Results:A cardiac standstill model in amicrominipigwas created by inducing complete atrioventricular block with a catheter ablation technique (n=7). Next, the efficacy of cardiopulmonary resuscitation by standard chest compressions (S-CPR), PPP and ventricular electrical pacing in this model were analyzed in series (n=4). To assess the mechanism of PPP, a non-selective, stretch-activated channel blocker, amiloride, was administered during PPP (n=3). Peak systolic and diastolic arterial pressures during S-CPR, PPP and ventricular electrical pacing were statistically similar. However, the duration of developed arterial pressure with PPP was comparable to that with ventricular electrical pacing, and significantly greater than that with S-CPR. Amiloride decreased the induction rate of ventricular electrical activity by PPP in a dose-related manner. Each animal survived without any neurological deficit at 24, 48 h and 1 week, even with up to 2 h of continuous PPP. In amicrominipigmodel of cardiac standstill, PPP can become a novel means to significantly improve physiological outcomes after cardiac standstill or symptomatic bradyarrhythmias in the absence of cardiac pacing. Activation of the non-selective stretch-activated channels may mediate some of the mechanophysiological effects of PPP. Further study of PPP by itself and together with S-CPR is warranted using cardiac arrest models of atrioventricular block and asystole.

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

    PubMed

    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.

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

    PubMed Central

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

    2014-01-01

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

  10. An improved coupling model for the lithosphere-atmosphere-ionosphere system (Invited)

    NASA Astrophysics Data System (ADS)

    Lee, L.; Kuo, C.; Huba, J. D.

    2013-12-01

    In order to explain the observed ionospheric TEC variations before strong earthquakes, we have developed a comprehensive model for the lithosphere-atmosphere-ionosphere (LAI) coupling [Kuo et al., 2011]. In our previous model, the dynamo current flows from the lithosphere, through the atmosphere, and into the ionosphere. The TEC variations in the ionosphere are numerically calculated based on NRL SAMI3 code. Nighttime plasma bubbles are generated for large earthquakes. However, the current in the atmosphere is obtained by first solving the electric field Ε from ▽(σΕ), where the conductivity tensor σ consists of Pedersen and Hall conductivity. The background magnetic field is assumed to be perpendicular to the horizontal plane. In the present paper, we improve the calculation of currents in the atmosphere by solving the current density J directly from the current continuity equation ▽J = 0. The currents in the atmosphere can be solved for any arbitrary angle of magnetic field, i.e., any magnetic latitude. The effects of atmospheric currents and electric fields on the ionosphere with lithosphere current source located at low magnetic altitude 15° and middle magnetic altitude 30° are obtained. For upward (downward) atmospheric currents flowing into the ionosphere, the simulation results show that the westward (eastward) electric fields dominate. At magnetic latitude 15°, the upward (downward) current causes the increase (decrease) of TEC, while the upward (downward) current causes the decrease (increase) of TEC at higher magnetic latitude 30°. The dynamo current density required to generate the same amount of TEC variation in the improved model is found to be smaller by a factor of 30 as compared to that obtained in our earlier paper. We also calculate the ionosphere dynamics with imposed zonal westward and eastward electric field based on SAMI3 code. In the nighttime ionosphere, it is found that the westward electric field may trigger two plasma bubbles

  11. Applications and Improvement of a Coupled, Global and Cloud-Resolving Modeling System

    NASA Technical Reports Server (NTRS)

    Tao, W.-K.; Chern, J.; Atlas, R.

    2005-01-01

    Recently Grabowski (2001) and Khairoutdinov and Randall (2001) have proposed the use of 2D CFWs as a "super parameterization" [or multi-scale modeling framework (MMF)] to represent cloud processes within atmospheric general circulation models (GCMs). In the MMF, a fine-resolution 2D CRM takes the place of the single-column parameterization used in conventional GCMs. A prototype Goddard MMF based on the 2D Goddard Cumulus Ensemble (GCE) model and the Goddard finite volume general circulation model (fvGCM) is now being developed. The prototype includes the fvGCM run at 2.50 x 20 horizontal resolution with 32 vertical layers from the surface to 1 mb and the 2D (x-z) GCE using 64 horizontal and 32 vertical grid points with 4 km horizontal resolution and a cyclic lateral boundary. The time step for the 2D GCE would be 15 seconds, and the fvGCM-GCE coupling frequency would be 30 minutes (i.e. the fvGCM physical time step). We have successfully developed an fvGCM-GCE coupler for this prototype. Because the vertical coordinate of the fvGCM (a terrain-following floating Lagrangian coordinate) is different from that of the GCE (a z coordinate), vertical interpolations between the two coordinates are needed in the coupler. In interpolating fields from the GCE to fvGCM, we use an existing fvGCM finite- volume piecewise parabolic mapping (PPM) algorithm, which conserves the mass, momentum, and total energy. A new finite-volume PPM algorithm, which conserves the mass, momentum and moist static energy in the z coordinate, is being developed for interpolating fields from the fvGCM to the GCE. In the meeting, we will discuss the major differences between the two MMFs (i.e., the CSU MMF and the Goddard MMF). We will also present performance and critical issues related to the MMFs. In addition, we will present multi-dimensional cloud datasets (i.e., a cloud data library) generated by the Goddard MMF that will be provided to the global modeling community to help improve the

  12. Applications and Improvement of a Coupled, Global and Cloud-Resolving Modeling System

    NASA Technical Reports Server (NTRS)

    Tao, W.-K.; Chern, J.; Atlas, R.

    2005-01-01

    Recently Grabowski (2001) and Khairoutdinov and Randall (2001) have proposed the use of 2D CFWs as a "super parameterization" [or multi-scale modeling framework (MMF)] to represent cloud processes within atmospheric general circulation models (GCMs). In the MMF, a fine-resolution 2D CRM takes the place of the single-column parameterization used in conventional GCMs. A prototype Goddard MMF based on the 2D Goddard Cumulus Ensemble (GCE) model and the Goddard finite volume general circulation model (fvGCM) is now being developed. The prototype includes the fvGCM run at 2.50 x 20 horizontal resolution with 32 vertical layers from the surface to 1 mb and the 2D (x-z) GCE using 64 horizontal and 32 vertical grid points with 4 km horizontal resolution and a cyclic lateral boundary. The time step for the 2D GCE would be 15 seconds, and the fvGCM-GCE coupling frequency would be 30 minutes (i.e. the fvGCM physical time step). We have successfully developed an fvGCM-GCE coupler for this prototype. Because the vertical coordinate of the fvGCM (a terrain-following floating Lagrangian coordinate) is different from that of the GCE (a z coordinate), vertical interpolations between the two coordinates are needed in the coupler. In interpolating fields from the GCE to fvGCM, we use an existing fvGCM finite- volume piecewise parabolic mapping (PPM) algorithm, which conserves the mass, momentum, and total energy. A new finite-volume PPM algorithm, which conserves the mass, momentum and moist static energy in the z coordinate, is being developed for interpolating fields from the fvGCM to the GCE. In the meeting, we will discuss the major differences between the two MMFs (i.e., the CSU MMF and the Goddard MMF). We will also present performance and critical issues related to the MMFs. In addition, we will present multi-dimensional cloud datasets (i.e., a cloud data library) generated by the Goddard MMF that will be provided to the global modeling community to help improve the

  13. Together - a couples' program to improve communication, coping, and financial management skills: development and initial pilot-testing.

    PubMed

    Falconier, Mariana K

    2015-04-01

    The accumulated knowledge about the negative impact of financial strain on couple's relationship functioning and the magnitude of the latest economic downturn have brought together the fields of financial counseling and couples' therapy. This article describes the development of a new interdisciplinary program that aims at helping couples under financial strain improve their financial management, communication, and dyadic coping skills. The article also reports the results from its initial pilot-testing with data collected from 18 financially distressed couples before and after participation in the program and 3 months later. Results from repeated measures ANOVAs suggest that the program may help reduce both partners' financial strain and the male negative communication and improve both partners' financial management skills and strategies to cope together with financial strain, and the male relationship satisfaction. These findings together with the high satisfaction reported by participants regarding the structure and content of the sessions and homework suggest that this program may be a promising approach to help couples experiencing financial strain. Gender differences, clinical implications, and possibilities for further research are also discussed.

  14. 'PACE-Gate': When clinical trial evidence meets open data access.

    PubMed

    Geraghty, Keith J

    2017-08-01

    Science is not always plain sailing and sometimes the voyage is across an angry sea. A recent clinical trial of treatments for chronic fatigue syndrome (the PACE trial) has whipped up a storm of controversy. Patients claim the lead authors overstated the effectiveness of cognitive behavioural therapy and graded exercise therapy by lowering the thresholds they used to determine improvement. In this extraordinary case, patients discovered that the treatments tested had much lower efficacy after an information tribunal ordered the release of data from the PACE trial to a patient who had requested access using a freedom of information request.

  15. Pacing failure due to microdislodgement of ventricular pacing lead detected by home monitoring technology.

    PubMed

    Loricchio, Maria Luisa; Castro, Antonio; Ciolli, Andrea; Sasdelli, Massimo; Ferraiuolo, Giuseppe

    2008-09-01

    A 68-year-old woman affected by sick sinus syndrome was implanted with a dual-chamber pacemaker provided by home monitoring technology. After discharge, an increase in ventricular threshold and a high variability of R wave measurements were detected early by the home monitoring system. Manual tests confirmed the presence of pacing and sensing failure and a normal ventricular impedance. The pacing lead integrity and a stable position of the lead tip in right ventricular apex were assessed by chest X-ray. A diagnosis of microdislodgement was made. After a second procedure for ventricular lead repositioning, no further malfunctions were detected.

  16. Influence of cinnamon and catnip on the stereotypical pacing of oncilla cats (Leopardus tigrinus) in captivity.

    PubMed

    Resende, Letícia de S; Pedretti Gomes, Karla C; Andriolo, Artur; Genaro, Gelson; Remy, Gabriella L; Almeida Ramos, Valdir de

    2011-01-01

    Nonhuman animals in captivity can experience environmental privation that results in their exhibiting abnormal behaviors. Environmental enrichment techniques can help improve their welfare. This study investigated the behavior of 8 zoo-housed oncilla cats (Leopardus tigrinus) in response to 2 odors (catnip and cinnamon) introduced individually into the animals' enclosures for 3 consecutive days. Proportion of scans spent engaging in stereotypical pacing were compared before, during, and after treatments. The addition of cinnamon reduced the proportion of pacing during and after enrichment (Wilcoxon: Z = 3.16, p < .001; Z = 3.16, p < .001, respectively), indicating a prolonged effect of the enrichment on the animals' behavior. Catnip appears to have elicited no significant difference in the stereotypic pacing before, during, or after the enrichment (Friedman: X(2) = 2.69; p = .260). The results highlight the potential use of cinnamon as a method of environmental enrichment for small captive-housed cats.

  17. Time To Teach, Time To Learn: Changing the Pace of School.

    ERIC Educational Resources Information Center

    Wood, Chip

    This book looks at how to improve education by refocusing time on relationships among teachers, parents, students, and good ideas. It draws attention to the inappropriate pace of teaching and learning which decreases the quality of education and quality of life for students and teachers. There are 10 chapters in three sections. Section 1,…

  18. Improved sphaleron decoupling condition and the Higgs coupling constants in the real singlet-extended standard model

    NASA Astrophysics Data System (ADS)

    Fuyuto, Kaori; Senaha, Eibun

    2014-07-01

    We improve the sphaleron decoupling condition in the real singlet-extended standard model (SM). The sphaleron energy is obtained using the finite-temperature one-loop effective potential with daisy resummation. For moderate values of the model parameters, the sphaleron decoupling condition is found to be vC/TC>(1.1-1.2), where TC denotes a critical temperature and vC is the corresponding vacuum expectation value of the doublet Higgs field at TC. We also investigate the deviation of the triple Higgs boson coupling from its standard model value in the region where the improved sphaleron decoupling condition is satisfied. As a result of the improvement, the deviation of the triple Higgs boson coupling gets more enhanced. In a typical case, if the Higgs couplings to the gauge bosons/fermions deviate from the SM values by about 3 (10)%, the deviation of the triple Higgs boson coupling can be as large as about 16 (50)%, which is about 4 (8)% larger than that based on the conventional criterion vC/TC>1.

  19. Distant electric coupling between nitrate reduction and sulphide oxidation investigated by an improved nitrate microscale biosensor

    NASA Astrophysics Data System (ADS)

    Marzocchi, U.; Revsbech, N. P.; Nielsen, L. P.; Risgaard-Petersen, N.

    2012-04-01

    Bacteria are apparently able to transmit electrons to other bacteria (Summers et al. 2010) or to electrodes (Malvankar et al. 2011) by some kind of nanowires (Reguera et al. 2005, Gorbi et al. 2006). Lately it has been shown that such transfer may occur over distances of centimetres in sediments, thereby coupling sulphide oxidation in deeper layers with oxygen reduction near the surface (Nielsen 2011). The finding of these long-distance electrical connections originated from analysis of O2, H2S, and pH profiles measured with microsensors. Nitrate is thermodynamically almost as good an electron acceptor as O2, and we therefore set up an experiment to investigate whether long-distance electron transfer also happens with NO3-. Aquaria were filled with sulphidic marine sediment from Aarhus Bay that was previously used to show long-distance electron transfer to O2. The aquaria were equipped with a lid so that they could be completely filled without a gas phase. Anoxic seawater with 300 μM NO3- was supplied at a constant rate resulting in a steady state concentration in the aquatic phase of 250 μM NO3-. The reservoir with the nitrate-containing water was kept anoxic by bubbling it with a N2/CO2 mixture and was kept at an elevated temperature. The water was cooled on the way to the aquaria to keep the water in the aquaria undersaturated with gasses, so that bubble formation by denitrification in the sediment could be minimised. Profiles of NO3-, H2S, and pH were measured as a function of time (2 months) applying commercial sensors for H2S and pH and an improved microscale NO3- biosensor developed in our laboratory. The penetration of NO3- in the sediment was 4-5 mm after 2 months, whereas sulphide only could be detected below 8-9 mm depth. The electron acceptor and electron donor were thus separated by 4-5 mm, indicating long distance electron transfer. A pH maximum of about 8.6 pH units at the NO3- reduction zone similar to a pH maximum observed in the O2 reduction

  20. Dynamic ventricular overdrive stimulation in atrial fibrillation: effects on ventricular rate irregularity, ventricular pacing, and fusion beats.

    PubMed

    Nölker, Georg; Gutleben, Klaus-Jürgen; Asbach, Stefan; Ritscher, Guido; Marschang, Harald; Sinha, Anil M; Boileau, Peter; Benser, Michael E; Hallier, Benoit; Hümmer, Alexander; Brachmann, Johannes

    2011-12-01

    In pacemaker patients with preserved atrio-ventricular (AV) conduction, atrial fibrillation (AF) can lead to symptomatic ventricular rate irregularity and loss of ventricular stimulation. We tested if dynamic ventricular overdrive (DVO) as a potentially pacemaker-integrated algorithm could improve both aspects. Different settings of DVO and ventricular-ventricular-inhibited-pacing (VVI) with different base rates were tested in two consecutive phases during electrophysiological studies for standard indications. Mean heart rate (HR), HR irregularity and percentage of ventricular pacing were evaluated. A fusion index (FI) indicative of the proportion of fusion beats was calculated for each stimulation protocol. Dynamic ventricular overdrive from the right ventricular apex was acutely applied in 38 patients (11 females, mean age 62.1 ± 11.5 years) with sustained AF and preserved AV conduction. Dynamic ventricular overdrive at LOW/MEDIUM setting increased the amount of ventricular pacing compared with VVI pacing at 60, 70, and 80 beats per minute (bpm; to 81/85% from 11, 25, and 47%, respectively; P < 0.05). It also resulted in a maximum decrease in interval differences (to 48 ± 18 ms from 149 ± 28, 117 ± 38, and 95 ± 46 ms, respectively; P < 0.05) and fusion (to 0.13 from 0.41, 0.42, and 0.36, respectively; P < 0.05) compared with VVI pacing at 60, 70, and 80 bpm. However, the application of DVO resulted in a significant increase in HR compared with intrinsic rhythm and VVI pacing at 80 bpm (to 97 bpm from 89 and 94 bpm, respectively; P < 0.05). Dynamic ventricular overdrive decreases HR irregularity and increases ventricular pacing rate compared with VVI pacing at fixed elevated base rates and spontaneous rhythm. Fusion index might help to refine information on pacing percentages provided by device counters.

  1. An improved surgical instrument without coupled motions that can be used in robotic-assisted minimally invasive surgery.

    PubMed

    Mei, Feng; Yili, Fu; Bo, Pan; Xudong, Zhao

    2012-08-01

    In order to enhance the dexterity of surgical instruments in robotic-assisted minimally invasive surgery, the robot is generally configured so as to have a wrist. However, this configuration has a problem in that there is a coupling of the motions of the wrist and the end-effector. In this paper an improved surgical instrument is proposed that eliminates the coupled motion using a compensation mechanism. The design concept behind the compensation mechanism can be applied to other types of surgical instruments. The performance of the proposed surgical instrument is validated by mechanical performance testing and animal experiments, which indicate that the problem of the coupled motion is successfully solved and the instrument is able to perform surgical tasks.

  2. Improved simulation of tropospheric ozone by a global-multi-regional two-way coupling model system

    NASA Astrophysics Data System (ADS)

    Yan, Y.; Lin, J.; Hu, L.; Chen, J.

    2016-12-01

    seasons. Additionally, the two-way coupled simulation also reduces the global tropospheric mean hydroxyl radical by 5% with improved estimates of methyl chloroform and methane lifetimes. Simulation improvements are more significant in the Northern Hemisphere, and are mainly driven by improved representation of spatial inhomogeneity in chemistry/emissions.

  3. Coupling of Helmholtz resonators to improve acoustic liners for turbofan engines at low frequency

    NASA Technical Reports Server (NTRS)

    Dean, L. W.

    1975-01-01

    An analytical and test program was conducted to evaluate means for increasing the effectiveness of low frequency sound absorbing liners for aircraft turbine engines. Three schemes for coupling low frequency absorber elements were considered. These schemes were analytically modeled and their impedance was predicted over a frequency range of 50 to 1,000 Hz. An optimum and two off-optimum designs of the most promising, a parallel coupled scheme, were fabricated and tested in a flow duct facility. Impedance measurements were in good agreement with predicted values and validated the procedure used to transform modeled parameters to hardware designs. Measurements of attenuation for panels of coupled resonators were consistent with predictions based on measured impedance. All coupled resonator panels tested showed an increase in peak attenuation of about 50% and an increase in attenuation bandwidth of one one-third octave band over that measured for an uncoupled panel. These attenuation characteristics equate to about 35% greater reduction in source perceived noise level (PNL), relative to the uncoupled panel, or a reduction in treatment length of about 24% for constant PNL reduction. The increased effectiveness of the coupled resonator concept for attenuation of low frequency broad spectrum noise is demonstrated.

  4. An atmosphere-wave regional coupled model: improving predictions of wave heights and surface winds in the southern North Sea

    NASA Astrophysics Data System (ADS)

    Wahle, Kathrin; Staneva, Joanna; Koch, Wolfgang; Fenoglio-Marc, Luciana; Ho-Hagemann, Ha T. M.; Stanev, Emil V.

    2017-04-01

    The coupling of models is a commonly used approach when addressing the complex interactions between different components of earth systems. We demonstrate that this approach can result in a reduction of errors in wave forecasting, especially in dynamically complicated coastal ocean areas, such as the southern part of the North Sea - the German Bight. Here, we study the effects of coupling of an atmospheric model (COSMO) and a wind wave model (WAM), which is enabled by implementing wave-induced drag in the atmospheric model. The numerical simulations use a regional North Sea coupled wave-atmosphere model as well as a nested-grid high-resolution German Bight wave model. Using one atmospheric and two wind wave models simultaneously allows for study of the individual and combined effects of two-way coupling and grid resolution. This approach proved to be particularly important under severe storm conditions as the German Bight is a very shallow and dynamically complex coastal area exposed to storm floods. The two-way coupling leads to a reduction of both surface wind speeds and simulated wave heights. In this study, the sensitivity of atmospheric parameters, such as wind speed and atmospheric pressure, to the wave-induced drag, in particular under storm conditions, and the impact of two-way coupling on the wave model performance, is quantified. Comparisons between data from in situ and satellite altimeter observations indicate that two-way coupling improves the simulation of wind and wave parameters of the model and justify its implementation for both operational and climate simulations.

  5. Use of external magnetic fields in hohlraum plasmas to improve laser-coupling

    SciTech Connect

    Montgomery, D. S.; Albright, B. J.; Barnak, D. H.; Chang, P. Y.; Davies, J. R.; Fiksel, G.; Froula, D. H.; Kline, J. L.; MacDonald, M. J.; Sefkow, A. B.; Yin, L.; Betti, R.

    2015-01-13

    Efficient coupling of laser energy into hohlraum targets is important for indirect drive ignition. Laser-plasma instabilities can reduce coupling, reduce symmetry, and cause preheat. We consider the effects of an external magnetic field on laser-energy coupling in hohlraum targets. Experiments were performed at the Omega Laser Facility using low-Z gas-filled hohlraum targets which were placed in a magnetic coil with Bz ≤ 7.5-T. We found that an external field Bz = 7.5-T aligned along the hohlraum axis results in up to a 50% increase in plasma temperature as measured by Thomson scattering. As a result, the experiments were modeled using the 2-D magnetohydrodynamics package in HYDRA and were found to be in good agreement.

  6. Use of external magnetic fields in hohlraum plasmas to improve laser-coupling

    SciTech Connect

    Montgomery, D. S. Albright, B. J.; Kline, J. L.; Yin, L.; Barnak, D. H.; Chang, P. Y.; Davies, J. R.; Fiksel, G.; Froula, D. H.; Betti, R.; MacDonald, M. J.; Sefkow, A. B.

    2015-01-15

    Efficient coupling of laser energy into hohlraum targets is important for indirect drive ignition. Laser-plasma instabilities can reduce coupling, reduce symmetry, and cause preheat. We consider the effects of an external magnetic field on laser-energy coupling in hohlraum targets. Experiments were performed at the Omega Laser Facility using low-Z gas-filled hohlraum targets which were placed in a magnetic coil with B{sub z} ≤ 7.5-T. We found that an external field B{sub z} = 7.5-T aligned along the hohlraum axis results in up to a 50% increase in plasma temperature as measured by Thomson scattering. The experiments were modeled using the 2-D magnetohydrodynamics package in HYDRA and were found to be in good agreement.

  7. Use of external magnetic fields in hohlraum plasmas to improve laser-coupling

    DOE PAGES

    Montgomery, D. S.; Albright, B. J.; Barnak, D. H.; ...

    2015-01-13

    Efficient coupling of laser energy into hohlraum targets is important for indirect drive ignition. Laser-plasma instabilities can reduce coupling, reduce symmetry, and cause preheat. We consider the effects of an external magnetic field on laser-energy coupling in hohlraum targets. Experiments were performed at the Omega Laser Facility using low-Z gas-filled hohlraum targets which were placed in a magnetic coil with Bz ≤ 7.5-T. We found that an external field Bz = 7.5-T aligned along the hohlraum axis results in up to a 50% increase in plasma temperature as measured by Thomson scattering. As a result, the experiments were modeled usingmore » the 2-D magnetohydrodynamics package in HYDRA and were found to be in good agreement.« less

  8. Improved extraction of hydrologic information from geophysical data through coupled hydrogeophysical inversion

    SciTech Connect

    Hinnell, A.C.; Ferre, T.P.A.; Vrugt, J.A.; Huisman, J.A.; Moysey, S.; Rings, J.; Kowalsky, M.B.

    2009-11-01

    There is increasing interest in the use of multiple measurement types, including indirect (geophysical) methods, to constrain hydrologic interpretations. To date, most examples integrating geophysical measurements in hydrology have followed a three-step, uncoupled inverse approach. This approach begins with independent geophysical inversion to infer the spatial and/or temporal distribution of a geophysical property (e.g. electrical conductivity). The geophysical property is then converted to a hydrologic property (e.g. water content) through a petrophysical relation. The inferred hydrologic property is then used either independently or together with direct hydrologic observations to constrain a hydrologic inversion. We present an alternative approach, coupled inversion, which relies on direct coupling of hydrologic models and geophysical models during inversion. We compare the abilities of coupled and uncoupled inversion using a synthetic example where surface-based electrical conductivity surveys are used to monitor one-dimensional infiltration and redistribution.

  9. Improvements to dry coupled ultrasound for wall thickness and weld inspection

    NASA Astrophysics Data System (ADS)

    Edwards, C.; Dixon, S.; Palmer, S. B.

    2000-05-01

    There are many ultrasonic applications where liquid couplants are undesirable. Automated scanning systems need complex couplant delivery and recovery systems in order to prevent either contamination or degradation to the test object. Soft materials such as rubbers can be used as a shoe to dry-couple the ultrasound from a piezoelectric transducer into the part but this can have relatively poor performance, particularly at high frequency where attenuation in the shoe material is large. The present paper describes results from a dual approach to tackle the problems associated with dry coupling. Various rubbers are examined for their ultrasonic properties and additional amplification is used to compensate for high frequency losses. As a result we have established that standard rubbers can be used as dry couplant materials for zero-degree longitudinal wave applications and it has even been possible to produce dry-coupled angled shear waves transducers suitable for flaw detection.

  10. DOA Estimation under Unknown Mutual Coupling and Multipath with Improved Effective Array Aperture

    PubMed Central

    Wang, Yuexian; Trinkle, Matthew; Ng, Brian W.-H.

    2015-01-01

    Subspace-based high-resolution direction of arrival (DOA) estimation significantly deteriorates under array manifold perturbation and rank deficiency of the covariance matrix due to mutual coupling and multipath propagation, respectively. In this correspondence, the unknown mutual coupling can be circumvented by the proposed method without any passive or active calibration process, and the DOA of the coherent signals can be accurately estimated accordingly. With a newly constructed matrix, the deficient rank can be restored, and the effective array aperture can be extended compared with conventional spatial smoothing. The proposed method achieves a good robustness and DOA estimation accuracy with unknown mutual coupling. The simulation results demonstrate the validity and efficiency of the proposed method. PMID:26670235

  11. Interatrial septum pacing decreases atrial dyssynchrony on strain rate imaging compared with right atrial appendage pacing.

    PubMed

    Yasuoka, Yoshinori; Abe, Haruhiko; Umekawa, Seiko; Katsuki, Keiko; Tanaka, Norio; Araki, Ryo; Imanaka, Takahiro; Matsutera, Ryo; Morisawa, Daisuke; Kitada, Hirokazu; Hattori, Susumu; Noda, Yoshiki; Adachi, Hidenori; Sasaki, Tatsuya; Miyatake, Kunio

    2011-03-01

    Interatrial septum pacing (IAS-P) decreases atrial conduction delay compared with right atrial appendage pacing (RAA-P). We evaluate the atrial contraction with strain rate of tissue Doppler imaging (TDI) during sinus activation or with IAS-P or RAA-P. Fifty-two patients with permanent pacemaker for sinus node disease were enrolled in the study. Twenty-three subjects were with IAS-P and 29 with RAA-P. The time from end-diastole to peak end-diastolic strain rate was measured and corrected with RR interval on electrocardiogram. It was defined as the time from end-diastole to peak end-diastolic strain rate (TSRc), and the balance between maximum and minimum TSRc at three sites (ΔTSRc) was compared during sinus activation and with pacing rhythm in each group. There were no significant differences observed in general characteristics and standard echocardiographic parameters except the duration of pacing P wave between the two groups. The duration was significantly shorter in the IAS-P group compared with the RAA-P group (95 ± 34 vs 138 ± 41; P = 0.001). TSRc was significantly different between sinus activation and pacing rhythm (36.3 ± 35.7 vs 61.6 ± 36.3; P = 0.003) in the RAA-P group, whereas no significant differences were observed in the IAS-P group (25.4 ± 12.1 vs 27.7 ± 14.7; NS). During the follow-up (mean 2.4 ± 0.7 years), the incidence of paroxysmal atrial fibrillation (AF) conversion to permanent AF was not significantly different between the two groups. IAS-P decreased the contraction delay on atrial TDI compared to RAA-P; however, it did not contribute to the reduction of AF incidence in the present study. ©2010, The Authors. Journal compilation ©2010 Wiley Periodicals, Inc.

  12. Positional Scanning Identifies the Molecular Determinants of a High Affinity Multi-Leucine Inhibitor for Furin and PACE4.

    PubMed

    Małuch, Izabela; Levesque, Christine; Kwiatkowska, Anna; Couture, Frédéric; Ly, Kévin; Desjardins, Roxane; Neugebauer, Witold A; Prahl, Adam; Day, Robert

    2017-03-24

    The proprotein convertase family of enzymes includes seven endoproteases with significant redundancy in their cleavage activity. We previously described the peptide Ac-LLLLRVK-Amba that displays potent inhibitory effects on both PACE4 and prostate cancer cell lines proliferation. Herein, the molecular determinants for PACE4 and furin inhibition were investigated by positional scanning using peptide libraries that substituted its leucine core with each natural amino acid. We determined that the incorporation of basic amino acids led to analogues with improved inhibitory potency toward both enzymes, whereas negatively charged residues significantly reduced it. All the remaining amino acids were in general well tolerated, with the exemption of the P6 position. However, not all of the potent PACE4 inhibitors displayed antiproliferative activity. The best analogues were obtained by the incorporation of the Ile residue at the P5 and P6 positions. These substitutions led to inhibitors with increased PACE4 selectivity and potent antiproliferative effects.

  13. Improved representations of coupled soil–canopy processes in the CABLE land surface model (Subversion revision 3432)

    DOE PAGES

    Haverd, Vanessa; Cuntz, Matthias; Nieradzik, Lars P.; ...

    2016-09-07

    CABLE is a global land surface model, which has been used extensively in offline and coupled simulations. While CABLE performs well in comparison with other land surface models, results are impacted by decoupling of transpiration and photosynthesis fluxes under drying soil conditions, often leading to implausibly high water use efficiencies. Here, we present a solution to this problem, ensuring that modelled transpiration is always consistent with modelled photosynthesis, while introducing a parsimonious single-parameter drought response function which is coupled to root water uptake. We further improve CABLE's simulation of coupled soil–canopy processes by introducing an alternative hydrology model with amore » physically accurate representation of coupled energy and water fluxes at the soil–air interface, including a more realistic formulation of transfer under atmospherically stable conditions within the canopy and in the presence of leaf litter. The effects of these model developments are assessed using data from 18 stations from the global eddy covariance FLUXNET database, selected to span a large climatic range. Here, marked improvements are demonstrated, with root mean squared errors for monthly latent heat fluxes and water use efficiencies being reduced by 40 %. Results highlight the important roles of deep soil moisture in mediating drought response and litter in dampening soil evaporation.« less

  14. Improved representations of coupled soil-canopy processes in the CABLE land surface model (Subversion revision 3432)

    NASA Astrophysics Data System (ADS)

    Haverd, Vanessa; Cuntz, Matthias; Nieradzik, Lars P.; Harman, Ian N.

    2016-09-01

    CABLE is a global land surface model, which has been used extensively in offline and coupled simulations. While CABLE performs well in comparison with other land surface models, results are impacted by decoupling of transpiration and photosynthesis fluxes under drying soil conditions, often leading to implausibly high water use efficiencies. Here, we present a solution to this problem, ensuring that modelled transpiration is always consistent with modelled photosynthesis, while introducing a parsimonious single-parameter drought response function which is coupled to root water uptake. We further improve CABLE's simulation of coupled soil-canopy processes by introducing an alternative hydrology model with a physically accurate representation of coupled energy and water fluxes at the soil-air interface, including a more realistic formulation of transfer under atmospherically stable conditions within the canopy and in the presence of leaf litter. The effects of these model developments are assessed using data from 18 stations from the global eddy covariance FLUXNET database, selected to span a large climatic range. Marked improvements are demonstrated, with root mean squared errors for monthly latent heat fluxes and water use efficiencies being reduced by 40 %. Results highlight the important roles of deep soil moisture in mediating drought response and litter in dampening soil evaporation.

  15. Improved representations of coupled soil–canopy processes in the CABLE land surface model (Subversion revision 3432)

    SciTech Connect

    Haverd, Vanessa; Cuntz, Matthias; Nieradzik, Lars P.; Harman, Ian N.

    2016-09-07

    CABLE is a global land surface model, which has been used extensively in offline and coupled simulations. While CABLE performs well in comparison with other land surface models, results are impacted by decoupling of transpiration and photosynthesis fluxes under drying soil conditions, often leading to implausibly high water use efficiencies. Here, we present a solution to this problem, ensuring that modelled transpiration is always consistent with modelled photosynthesis, while introducing a parsimonious single-parameter drought response function which is coupled to root water uptake. We further improve CABLE's simulation of coupled soil–canopy processes by introducing an alternative hydrology model with a physically accurate representation of coupled energy and water fluxes at the soil–air interface, including a more realistic formulation of transfer under atmospherically stable conditions within the canopy and in the presence of leaf litter. The effects of these model developments are assessed using data from 18 stations from the global eddy covariance FLUXNET database, selected to span a large climatic range. Here, marked improvements are demonstrated, with root mean squared errors for monthly latent heat fluxes and water use efficiencies being reduced by 40 %. Results highlight the important roles of deep soil moisture in mediating drought response and litter in dampening soil evaporation.

  16. Sex differences in pacing during ‘Ultraman Hawaii’

    PubMed Central

    Nikolaidis, Pantelis T.

    2016-01-01

    Background To date, little is known for pacing in ultra-endurance athletes competing in a non-stop event and in a multi-stage event, and especially, about pacing in a multi-stage event with different disciplines during the stages. Therefore, the aim of the present study was to examine the effect of age, sex and calendar year on triathlon performance and variation of performance by events (i.e., swimming, cycling 1, cycling 2 and running) in ‘Ultraman Hawaii’ held between 1983 and 2015. Methods Within each sex, participants were grouped in quartiles (i.e., Q1, Q2, Q3 and Q4) with Q1 being the fastest (i.e., lowest overall time) and Q4 the slowest (i.e., highest overall time). To compare performance among events (i.e., swimming, cycling 1, cycling 2 and running), race time in each event was converted in z score and this value was used for further analysis. Results A between-within subjects ANOVA showed a large sex × event (p = 0.015, η2 = 0.014) and a medium performance group × event interaction (p = 0.001, η2 = 0.012). No main effect of event on performance was observed (p = 0.174, η2 = 0.007). With regard to the sex × event interaction, three female performance groups (i.e., Q2, Q3 and Q4) increased race time from swimming to cycling 1, whereas only one male performance group (Q4) revealed a similar trend. From cycling 1 to cycling 2, the two slower female groups (Q3 and Q4) and the slowest male group (Q4) increased raced time. In women, the fastest group decreased (i.e., improved) race time from swimming to cycling 1 and thereafter, maintained performance, whereas in men, the fastest group decreased race time till cycling 2 and increased it in the running. Conclusion In summary, women pace differently than men during ‘Ultraman Hawaii’ where the fastest women decreased performance on day 1 and could then maintain on day 2 and 3, whereas the fastest men worsened performance on day 1 and 2 but improved on day 3. PMID:27703854

  17. Out-coupling membrane for large-size organic light-emitting panels with high efficiency and improved uniformity

    NASA Astrophysics Data System (ADS)

    Ding, Lei; Wang, Lu-Wei; Zhou, Lei; Zhang, Fang-hui

    2016-12-01

    An out-coupling membrane embedded with a scattering film of SiO2 spheres and polyethylene terephthalate (PET) plastic was successfully developed for 150 × 150 mm2 green OLEDs. Comparing with a reference OLED panel, an approximately 1-fold enhancement in the forward emission was obtained with an out-coupling membrane adhered to the surface of the external glass substrate of the panel. Moreover, it was verified that the emission color at different viewing angles can be stabilized without apparent spectral distortion. Particularly, the uniformity of the large-area OLEDs was greatly improved. Theoretical calculation clarified that the improved performance of the lighting panels is primarily attributed to the effect of particle scattering.

  18. The next step in cardiac pacing: the view from 1958.

    PubMed

    Jeffrey, K

    1992-06-01

    At a 1-day conference sponsored by the Rockefeller Institute in September 1958, physicians and engineers held a confused debate over future directions for the young field of cardiac pacing. Many of the existing impediments to long-term pacing for chronic illness received little attention; the participants focused instead on whether atrial synchrony would be a requirement for long-term pacing. The Rockefeller conference illustrates the observation that cardiac pacing has undergone several major redefinitions. This process is rarely a smooth one but involves uncertainty, intense debate, and explicit choice.

  19. Improving the sensitivity of J coupling measurements in solids with application to disordered materials

    SciTech Connect

    Guerry, Paul; Brown, Steven P.; Smith, Mark E.

    2016-05-15

    It has been shown previously that for magic angle spinning (MAS) solid state NMR the refocused INADEQUATE spin-echo (REINE) experiment can usefully quantify scalar (J) couplings in disordered solids. This paper focuses on the two z filter components in the original REINE pulse sequence, and investigates by means of a product operator analysis and fits to density matrix simulations the effects that their removal has on the sensitivity of the experiment and on the accuracy of the extracted J couplings. The first z filter proves unnecessary in all the cases investigated here and removing it increases the sensitivity of the experiment by a factor ∼1.1–2.0. Furthermore, for systems with broad isotropic chemical shift distributions (namely whose full widths at half maximum are greater than 30 times the mean J coupling strength), the second z filter can also be removed, thus allowing whole-echo acquisition and providing an additional √2 gain in sensitivity. Considering both random and systematic errors in the values obtained, J couplings determined by fitting the intensity modulations of REINE experiments carry an uncertainty of 0.2–1.0 Hz (∼1−10 %).

  20. Improving particle drag predictions in Euler-Lagrange simulations with two-way coupling

    NASA Astrophysics Data System (ADS)

    Ireland, Peter J.; Desjardins, Olivier

    2017-06-01

    Euler-Lagrange methods are popular approaches for simulating particle-laden flows. While such approaches have been rigorously verified in the dilute limit (where particles do not noticeably alter their carrier flow), much less verification has been attempted for cases where the coupling between the two phases leads to non-negligible modifications in the local fluid velocity. We review one of these techniques for coupled fluid-particle flows, the volume-filtered Euler-Lagrange method, and show that it (like many similar methods) provides erroneous predictions for the interphase drag force due to the presence of the particles. We show that these errors are tied to inaccuracies in the numerical implementation of the drag model for systems with two-way coupling. We therefore introduce a simple approach to correct the implementation of this drag model, and show that this corrected implementation provides accurate and grid-independent predictions of particle settling in two-way coupled flows at low particle Reynolds numbers. Finally, we study the effect of the corrected implementation on a more complicated, cluster-induced turbulence flow.

  1. Progress in using hydroxymethylated resorcinol coupling agent to improve bond durability to wood

    Treesearch

    Alfred W. Christiansen

    2001-01-01

    In the mid-1990s, researchers at the Forest Products Laboratory developed a coupling agent, hydroxymethylated resorcinol (HMR), that has the ability to enhance adhesive bonds between wood and nontraditional adhesives (Vick and others 1995, 1996). HMR is also effective in promoting durable bonding of phenol-resorcinol- formaldehyde (PRF) adhesives to CCA-treated...

  2. Differential Effects of Ventricular Pacing Sites of Contraction Synchrony and Global Cardiac Performance

    PubMed Central

    Alhammouri, Mohammed; Kim, Hyung Kook; Mokhtar, Yasser; Cannesson, Maxime; Tanabe, Masaki; Gorcsan, John; Schwartzman, David; Pinsky, Michael R.

    2011-01-01

    Background Quantification of left ventricular (LV) dyssynchrony allows for objective measures of resynchronization therapy (CRT) effectiveness. We tested the hypothesis that site of LV pacing, fusion beats and baseline contractility alter contraction synchrony as quantified by regional and global measures of LV performance. Methods and Results In 8 open-chested pentobarbital-anesthetized canine preparations we compared the effects of right atrial (RA), RA-high right ventricular (RV) free wall, as a model of left bundle branch block contraction pattern, RA-LV apex (LVa), RA-LV free wall (LVfw), and RA-RV-apical LV (CRTa) and RA-RV-free wall LV (CRTfw), as CRT. LV pressure-volume loops recorded using high-fidelity pressure and conductance catheters and echocardiographic angle-corrected color-coded strain imaging of mid-LV short axis views analyzed radial strain from six segments. To control for contractile state esmolol-induced beta blockage was studied, and in 5 dogs to control for RA and ventricular pacing fusion beat artifacts, repeat studies were done following AV node ablation. RA-RV pacing reduced stroke work (SW) (57±18 to 33±13* mmHg·mL,*p<0.05 vs RA pacing), decreased LV end-diastolic volume and induced marked radial dyssynchrony (maximal time difference between peak segmental strain) from 31±15 to 234±60* ms. Changes in radial dyssynchrony correlated significantly with changes in SW (r=−0.53, p<0.01). Dyssynchrony improved with both CRTa and CRTfw (69*±31 and 98*±63 ms, respectively) while SW only improved with CRTa (62±22* and 37±13 mmHg·mL, respectively * p<0.05 vs RV pacing). CRTa also tended to increased LV end-diastolic volume over RA-RV. Esmolol slowed HR from 118±10 to 108±10 beats/min* and tended to decrease contractility (end-systolic elastance (Ees) from 12.1±7.9 to 8.9±3.9 mmHg/ml, p=0.167) but did not alter the degree of RV-pacing induced dyssynchrony. AV ablation had no effect on the observed apical and free wall contraction

  3. Improved simulation of tropospheric ozone by a global-multi-regional two-way coupling model system

    NASA Astrophysics Data System (ADS)

    Yan, Yingying; Lin, Jintai; Chen, Jinxuan; Hu, Lu

    2016-02-01

    from 0.53 to 0.68, and it reduces the mean model bias from 10.8 to 6.7 ppb. Regionally, the coupled system reduces the bias by 4.6 ppb over Europe, 3.9 ppb over North America and 3.1 ppb over other regions. The two-way coupling brings O3 vertical profiles much closer to the HIPPO (for remote areas) and MOZAIC (for polluted regions) data, reducing the tropospheric (0-9 km) mean bias by 3-10 ppb at most MOZAIC sites and by 5.3 ppb for HIPPO profiles. The two-way coupled simulation also reduces the global tropospheric column ozone by 3.0 DU (9.5 %, annual mean), bringing them closer to the OMI data in all seasons. Additionally, the two-way coupled simulation also reduces the global tropospheric mean hydroxyl radical by 5 % with improved estimates of methyl chloroform and methane lifetimes. Simulation improvements are more significant in the Northern Hemisphere, and are mainly driven by improved representation of spatial inhomogeneity in chemistry/emissions. Within the nested domains, the two-way coupled simulation reduces surface ozone biases relative to typical GEOS-Chem one-way nested simulations, due to much improved LBCs. The bias reduction is 1-7 times the bias reduction from the global to the one-way nested simulation. Improving model representations of small-scale processes is important for understanding the global and regional tropospheric chemistry.

  4. Prevention awareness counselling and evaluation (PACE) diabetes project: a mega multi-pronged program for diabetes awareness and prevention in South India (PACE- 5).

    PubMed

    Somannavar, S; Lanthorn, H; Pradeepa, R; Narayanan, V; Rema, M; Mohan, V

    2008-06-01

    The Prevention Awareness Counselling Evaluation (PACE) Diabetes Project is a large scale community based project carried out to increase awareness of diabetes and its complications in Chennai city (population: 4.7 million) through 1) public education 2) media campaigns 3) general practitioner training 4) blood sugar screening and 5) community based "real life" prevention program Education took place in multiple forms and venues over the three-year period of the PACE project between 2004-2007. With the help of the community, awareness programs were conducted at residential sites, worksites, places of worship, public places and educational institutions through lectures, skits and street plays. Messages were also conveyed through popular local television and radio channels and print media. The General Practitioners (GPs) program included training in diabetes prevention, treatment and the advantages of early detection of complications. Free random capillary blood glucose testing was done for individuals who attended the awareness programs using glucose meter. Over a three-year period, we conducted 774 education sessions, 675 of which were coupled with opportunistic blood glucose screening. A total of 76,645 individuals underwent blood glucose screening. We also set up 176 "PACE Diabetes Education Counters" across Chennai, which were regularly replenished with educational materials. In addition, we trained 232 general practitioners in diabetology prevention, treatment and screening for complications. Multiple television and radio shows were given and messages about diabetes sent as Short Message Service (SMS) through mobile phones. Overall, we estimate that we reached diabetes prevention messages to nearly two million people in Chennai through the PACE Diabetes Project, making it one of the largest diabetes awareness and prevention programs ever conducted in India. Mass awareness and screening programs are feasible and, through community empowerment, can help in

  5. Improved MJO-simulation in ECHAM6.3 by coupling a Stochastic Multicloud Model to the convection scheme

    NASA Astrophysics Data System (ADS)

    Peters, Karsten; Crueger, Traute; Jakob, Christian; Möbis, Benjamin

    2017-03-01

    We implement a Stochastic Multicloud Model (SMCM) in an observation-informed configuration into the convection scheme of the state-of-the-art GCM ECHAM6.3. The SMCM configuration we use here has been tuned to represent observed tropical convection by associating the occurrence and strength of deep convection to midtropospheric vertical velocity and relative humidity. We show that compared to the ECHAM6.3 standard model, the SMCM-modified version shows improved capacity to simulate features of tropical intraseasonal variability, including MJO-like disturbances, without significantly distorting the mean model climate. This improvement goes in hand with ameliorated coupling of atmospheric convection to tropospheric moisture and spatiotemporal coherence of tropical convection compared to reanalysis and observations. We attribute these effects to (i) improved coupling of triggering and suppression of deep convective events to the model's large-scale environment and (ii) the observations-informed closure formulation which leads to an overall reduction of deep convective mass fluxes. Sensitivity tests show that while (ii) improves the convection-moisture relationship, it is (i) which improves the spatiotemporal coherence of tropical rainfall and is important for MJO simulation. Further, the simulated spatiotemporal coherence of tropical rainfall is an intrinsic property of the convection schemes themselves and not of their parameters. We stress that this study serves as a proof-of-concept and motivates further efforts towards building a novel convection parameterization with the SMCM as a central element.

  6. Relationship between left atrium catheter contact force and pacing threshold.

    PubMed

    Barrio-López, Teresa; Ortiz, Mercedes; Castellanos, Eduardo; Lázaro, Carla; Salas, Jefferson; Madero, Sergio; Almendral, Jesús

    2017-08-01

    The purpose of this study is to analyze the relationship between contact force (CF) and pacing threshold in left atrium (LA). Six to ten LA sites were studied in 28 consecutive patients with atrial fibrillation undergoing pulmonary vein isolation. Median CF, bipolar and unipolar electrogram voltage, impedance, and bipolar and unipolar thresholds for consistent constant capture and for consistent intermittent capture were measured at each site. Pacing threshold measurements were performed at 188 LA sites. Both unipolar and bipolar pacing thresholds correlated significantly with median CF; however, unipolar pacing threshold correlated better (unipolar: Pearson R -0.45; p < 0.001; Spearman Rho -0.62; p < 0.001, bipolar: Pearson R -0.39; p < 0.001; Spearman Rho -0.52; p < 0.001). Consistent constant capture threshold had better correlation with median CF than consistent intermittent capture threshold for both unipolar and bipolar pacing (Pearson R -0.45; p < 0.001 and Spearman Rho -0.62; p < 0.001 vs. Pearson R -0.35; p < 0.001; Spearman Rho -0.52; p < 0.001). The best pacing threshold cutoff point to detect a good CF (>10 g) was 3.25 mA for unipolar pacing with 69% specificity and 73% sensitivity. Both increased to 80% specificity and 74% sensitivity for sites with normal bipolar voltage and a pacing threshold cutoff value of 2.85 mA. Pacing thresholds correlate with CF in human not previously ablated LA. Since the combination of a normal bipolar voltage and a unipolar pacing threshold <2.85 mA provide reasonable parameters of validity, pacing threshold could be of interest as a surrogate for CF in LA.

  7. The role of pacing modality in determining long-term survival in the sick sinus syndrome.

    PubMed

    Sgarbossa, E B; Pinski, S L; Maloney, J D

    1993-09-01

    To determine whether the atrial-based pacing modalities ("physiologic pacing") improve survival when compared with single-chamber ventricular pacing in patients with the sick sinus syndrome. Retrospective, nonrandomized study. A tertiary care teaching hospital. A total of 507 patients with a mean age of 66 years who received an initial pacemaker for the sick sinus syndrome between January 1980 and December 1989. Pacing modes were ventricular (22%), atrial (4%), and dual-chamber (74%). Total and cardiovascular mortality rates. Mean follow-up was 66 months. Independent predictors of total mortality by the Cox proportional hazards model were 1) New York Heart Association functional class (hazard ratio = 1.67/class; 95% Cl, 1.31 to 2.11); 2) age (hazard ratio = 1.62/12-year increment; Cl, 1.28 to 2.05); 3) peripheral vascular disease (hazard ratio = 2.21; Cl, 1.42 to 3.42); 4) bundle branch block (hazard ratio = 2.04; Cl, 1.33 to 3.13); 5) coronary artery disease (hazard ratio = 1.66; Cl, 1.15 to 2.39); and 6) valvular heart disease (hazard ratio = 1.71; Cl, 1.08 to 2.69). The same variables were independent predictors of cardiovascular mortality, with cerebrovascular disease reaching borderline statistical significance (hazard ratio = 1.69; Cl, 1.00 to 2.86). Using univariate analysis, single-chamber ventricular pacing had more than 40% increased risk for both total and cardiovascular death, but the difference was of borderline statistical significance (total mortality: P = 0.053; hazard ratio = 1.43; Cl, 0.99 to 2.07; cardiovascular mortality: P = 0.15; hazard ratio = 1.41; Cl = 0.87 to 2.29). Because the role of the ventricular pacing mode as a long-term predictor of total and cardiovascular mortality remains inconclusive, a large, randomized study is necessary to confirm whether physiologic pacing provides a substantial reduction in mortality when compared with ventricular pacing.

  8. Improved validation of IDP ensembles by one-bond Cα-Hα scalar couplings.

    PubMed

    Gapsys, Vytautas; Narayanan, Raghavendran L; Xiang, ShengQi; de Groot, Bert L; Zweckstetter, Markus

    2015-11-01

    Intrinsically disordered proteins (IDPs) are best described by ensembles of conformations and a variety of approaches have been developed to determine IDP ensembles. Because of the large number of conformations, however, cross-validation of the determined ensembles by independent experimental data is crucial. The (1)JCαHα coupling constant is particularly suited for cross-validation, because it has a large magnitude and mostly depends on the often less accessible dihedral angle ψ. Here, we reinvestigated the connection between (1)JCαHα values and protein backbone dihedral angles. We show that accurate amino-acid specific random coil values of the (1)JCαHα coupling constant, in combination with a reparameterized empirical Karplus-type equation, allow for reliable cross-validation of molecular ensembles of IDPs.

  9. Sequential Atrioventricular Pacing in Patients With Hypertrophic Cardiomyopathy: An 18-year Experience.

    PubMed

    Jurado Román, Alfonso; Montero Cabezas, José M; Rubio Alonso, Belén; García Tejada, Julio; Hernández Hernández, Felipe; Albarrán González-Trevilla, Agustín; Velázquez Martín, María T; Coma Samartín, Raúl; Rodríguez García, Jesús; Tascón Pérez, Juan C

    2016-04-01

    Controversy persists regarding the role of sequential atrioventricular pacing in patients with obstructive hypertrophic cardiomyopathy and disabling symptoms. The aim of this study was to evaluate the effect of pacing on symptoms, dynamic gradient, and left ventricular function in patients with hypertrophic cardiomyopathy. From 1991 to 2009, dual-chamber pacemakers were implanted in 82 patients with obstructive hypertrophic cardiomyopathy and disabling symptoms despite optimal medical therapy. Sequential pacing was performed with a short atrioventricular delay. Clinical and echocardiographic parameters were measured before and immediately after implantation and after a long follow-up (median, 8.5 years [range, 1-18 years]). The New York Heart Association functional class was immediately reduced after pacemaker implantation in 95% of patients (P < .0001), and this improvement was maintained until the final follow-up in 89% (P = .016). The gradient was significantly reduced after implantation (94.5 ± 36.5 vs 46.4 ± 26.7mmHg; P < .0001) and at final follow-up (94.5 ± 36.5 vs 35.9 ± 24.0mmHg; P < .0001). Mitral regurgitation permanently improved in 52% of the patients (P < .0001). There were no differences in ventricular thickness or diameters, ejection fraction, or diastolic function. Sequential pacing in selected patients with obstructive hypertrophic cardiomyopathy improves functional class and reduces dynamic gradient and mitral regurgitation immediately after pacemaker implantation and at final follow-up. Prolonged ventricular pacing has no negative effects on systolic or diastolic function in these patients. Copyright © 2015 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

  10. G protein-coupled receptors: signalling and regulation by lipid agonists for improved glucose homoeostasis.

    PubMed

    Moran, Brian M; Flatt, Peter R; McKillop, Aine M

    2016-04-01

    G protein-coupled receptors (GPCRs) play a pivotal role in cell signalling, controlling many processes such as immunity, growth, cellular differentiation, neurological pathways and hormone secretions. Fatty acid agonists are increasingly recognised as having a key role in the regulation of glucose homoeostasis via stimulation of islet and gastrointestinal GPCRs. Downstream cell signalling results in modulation of the biosynthesis, secretion, proliferation and anti-apoptotic pathways of islet and enteroendocrine cells. GPR40 and GPR120 are activated by long-chain fatty acids (>C12) with both receptors coupling to the Gαq subunit that activates the Ca(2+)-dependent pathway. GPR41 and GPR43 are stimulated by short-chain fatty acids (C2-C5), and activation results in binding to Gαi that inhibits the adenylyl cyclase pathway attenuating cAMP production. In addition, GPR43 also couples to the Gαq subunit augmenting intracellular Ca(2+) and activating phospholipase C. GPR55 is specific for cannabinoid endogenous agonists (endocannabinoids) and non-cannabinoid fatty acids, which couples to Gα12/13 and Gαq proteins, leading to enhancing intracellular Ca(2+), extracellular signal-regulated kinase 1/2 (ERK) phosphorylation and Rho kinase. GPR119 is activated by fatty acid ethanolamides and binds to Gαs utilising the adenylate cyclase pathway, which is dependent upon protein kinase A. Current research indicates that GPCR therapies may be approved for clinical use in the near future. This review focuses on the recent advances in preclinical diabetes research in the signalling and regulation of GPCRs on islet and enteroendocrine cells involved in glucose homoeostasis.

  11. Improving the Mass-Limited Performance of Routine NMR Probes using Coupled Coils.

    PubMed

    Marsden, Brian; Lim, Victor; Taber, Bob; Zens, Albert

    2016-07-01

    We report a method to convert, on demand, a general use dual-broadband probe to a high performance mass-limited probe for both high band and low band nuclei. This technology uses magnetic coupling of inductors to achieve this capability. The method offers a cost effective way of increasing the performance of routine NMR probes without having to change probes or increase the overall foot print of the spectrometer.

  12. Improving the Mass-Limited Performance of Routine NMR Probes using Coupled Coils

    NASA Astrophysics Data System (ADS)

    Marsden, Brian; Lim, Victor; Taber, Bob; Zens, Albert

    2016-07-01

    We report a method to convert, on demand, a general use dual-broadband probe to a high performance mass-limited probe for both high band and low band nuclei. This technology uses magnetic coupling of inductors to achieve this capability. The method offers a cost effective way of increasing the performance of routine NMR probes without having to change probes or increase the overall foot print of the spectrometer.

  13. Ultra-wide bandwidth improvement of piezoelectric energy harvesters through electrical inductance coupling

    NASA Astrophysics Data System (ADS)

    Abdelmoula, H.; Abdelkefi, A.

    2015-11-01

    The design and analysis of innovative ultra-wide bandwidth piezoelectric energy harvesters are deeply investigated. An electrical inductance is considered in the harvester's circuit to be connected in series or parallel to a load resistance. A lumped-parameter model is used to model the electromechanical response of the harvester when subjected to harmonic excitations. A linear comprehensive analysis is performed to investigate the effects of an electrical inductance on the coupled frequencies and damping of the harvester. It is shown that including an electrical inductance connected in series or in parallel to an electrical load resistance can result in the appearance of a second coupled frequency of electrical type. The results show that the inclusion of an inductance may give the opportunity to tune one of the coupled frequencies of mechanical and electrical types to the available excitation frequency in the environment. Using the gradient method, an optimization analysis is then performed to determine the optimum values of the electrical inductance and load resistance that maximize the harvested power. It is demonstrated that, for each excitation frequency, there is a combination of optimum values of the electrical inductance and resistance in such a way an optimum constant value of the harvested power is found. Numerical analysis is then performed to show the importance of considering an additional inductance in the harvester's circuitry in order to design broadband energy harvesters. The results show that the presence of the second coupled frequency of electrical type due to the inductance gives the possibility to design optimal broadband inductive-resistive piezoelectric energy harvesters with minimum displacement due to shunt damping effect.

  14. Improving the physics of a coupled physical biogeochemical model of the North Atlantic through data assimilation: Impact on the ecosystem

    NASA Astrophysics Data System (ADS)

    Berline, Léo; Brankart, Jean-Michel; Brasseur, Pierre; Ourmières, Yann; Verron, Jacques

    2007-01-01

    Several studies on coupled physical-biogeochemical models have shown that major deficiencies in the biogeochemical fields arise from the deficiencies in the physical flow fields. This paper examines the improvement of the physics through data assimilation, and the subsequent impact on the ecosystem response in a coupled model of the North Atlantic. Sea surface temperature and sea surface height data are assimilated with a sequential method based on the SEEK filter adapted to the coupling needs. The model domain covers the Atlantic from 20°S to 70°N at eddy-permitting resolution. The biogeochemical model is a NPZD-DOM model based on the P3ZD formulation. The results of an annual assimilated simulation are compared with an annual free simulation. With assimilation, the representation of the mixed layer depth is significantly improved in mid latitudes, even though the mixed layer depth is generally overestimated compared to the observations. The representation of the mean and variance of the currents is also significantly improved. The nutrient input in the euphotic zone is used to assess the data assimilation impact on the ecosystem. Data assimilation results in a 50% reduction of the input due to vertical mixing in mid-latitudes, and in a four- to six-fold increase of the advective fluxes in mid-latitudes and subtropics. Averaged zonally, the net impact is a threefold increase for the subtropical gyre, and a moderate (20-30%) decrease at mid and high latitudes. Surface chlorophyll concentration increases along the subtropical gyre borders, but little changes are detected at mid and high latitudes. An increase of the primary production appears along the Gulf Stream path, but it represents only 12% on average for mid and high latitudes. In the subtropical gyre centre, primary production is augmented but stays underestimated (20% of observations). These experiments show the benefits of physical data assimilation in coupled physical-biogeochemical applications.

  15. Improvement of fog predictability in a coupled system of PAFOG and WRF

    NASA Astrophysics Data System (ADS)

    Kim, Wonheung; Yum, Seong Soo; Kim, Chang Ki

    2017-04-01

    Fog is difficult to predict because of the multi-scale nature of its formation mechanism: not only the synoptic conditions but also the local meteorological conditions crucially influence fog formation. Coarse vertical resolution and parameterization errors in fog prediction models are also critical reasons for low predictability. In this study, we use a coupled model system of a 3D mesoscale model (WRF) and a single column model with a fine vertical resolution (PAFOG, PArameterized FOG) to simulate fogs formed over the southern coastal region of the Korean Peninsula, where National Center for Intensive Observation of Severe Weather (NCIO) is located. NCIO is unique in that it has a 300 m meteorological tower built at the location to measure basic meteorological variables (temperature, dew point temperature and winds) at eleven different altitudes, and comprehensive atmospheric physics measurements are made with the various remote sensing instruments such as visibility meter, cloud radar, wind profiler, microwave radiometer, and ceilometer. These measurement data are used as input data to the model system and for evaluating the results. Particularly the data for initial and external forcings, which are tightly connected to the predictability of coupled model system, are derived from the tower measurement. This study aims at finding out the most important factors that influence fog predictability of the coupled system for NCIO. Nudging of meteorological tower data and soil moisture variability are found to be critically influencing fog predictability. Detailed results will be discussed at the conference.

  16. Studies on the coupling transformer to improve the performance of microwave ion source.

    PubMed

    Misra, Anuraag; Pandit, V S

    2014-06-01

    A 2.45 GHz microwave ion source has been developed and installed at the Variable Energy Cyclotron Centre to produce high intensity proton beam. It is operational and has already produced more than 12 mA of proton beam with just 350 W of microwave power. In order to optimize the coupling of microwave power to the plasma, a maximally flat matching transformer has been used. In this paper, we first describe an analytical method to design the matching transformer and then present the results of rigorous simulation performed using ANSYS HFSS code to understand the effect of different parameters on the transformed impedance and reflection and transmission coefficients. Based on the simulation results, we have chosen two different coupling transformers which are double ridged waveguides with ridge widths of 24 mm and 48 mm. We have fabricated these transformers and performed experiments to study the influence of these transformers on the coupling of microwave to plasma and extracted beam current from the ion source.

  17. Studies on the coupling transformer to improve the performance of microwave ion source

    SciTech Connect

    Misra, Anuraag E-mail: vspandit12@gmail.com Pandit, V. S. E-mail: vspandit12@gmail.com

    2014-06-15

    A 2.45 GHz microwave ion source has been developed and installed at the Variable Energy Cyclotron Centre to produce high intensity proton beam. It is operational and has already produced more than 12 mA of proton beam with just 350 W of microwave power. In order to optimize the coupling of microwave power to the plasma, a maximally flat matching transformer has been used. In this paper, we first describe an analytical method to design the matching transformer and then present the results of rigorous simulation performed using ANSYS HFSS code to understand the effect of different parameters on the transformed impedance and reflection and transmission coefficients. Based on the simulation results, we have chosen two different coupling transformers which are double ridged waveguides with ridge widths of 24 mm and 48 mm. We have fabricated these transformers and performed experiments to study the influence of these transformers on the coupling of microwave to plasma and extracted beam current from the ion source.

  18. The Use of Organic Coupling Agents to Improve the Durability of Steel/epoxy Joints in the Presence of Moisture.

    NASA Astrophysics Data System (ADS)

    Denicola, Anthony John, Jr.

    Despite the unique combination of properties epoxy resins possess, their versatility for structural bonding of metal substrates has not been fully utilized. The use of epoxy resins (and in general all adhesives) has been limited to non-load bearing or low load bearing applications. One of the primary reasons is the bond sensitivity of these resins to water or to high humidity. Recognizing this limitation, this study was undertaken with the goal of developing organic coupling agents which will chemically bond to the surface of steel via a chelate bond. B-diketone coupling agents were synthesized and tested. The coupling agents were applied from organic solution to the surface of a modified napkin ring torsion joint. The joints were bonded with epoxy resin adhesives and water immersed. The bond durability of the adhesive system was determined by subjecting the joints to a shear load. An ammonium citrate pretreatment was developed for use with the B-diketone agents. Optimization studies of the citrate pretreatment and coupling agent concentration were undertaken. The B-diketone coupling agents significantly improved the bond durability of low temperature cured epoxy systems. Polyfunctional mercaptoester coupling agents were also synthesized and evaluated. The effect of functionality, ring size, citrate pretreatment, and atmosphere on bond durability were examined. The mercaptoesters were found to be far superior to the B-diketones in improving bond durability. Low temperature and high temperature cured resins were examined. XPS analysis of 1018 steel treated with the mercaptoesters indicates the formation of polymeric coupling agent layers, approximately 100 (ANGSTROM) thick, on the steel surface. The results also indicate chelate bonding to the steel surface. A two step strength decay curve is observed for the mercaptoester treated systems, irrespective of the mercaptoester or the curing agent used. Plasticization of the mercaptoester layer at the early stages of

  19. Improved simulation of tropospheric ozone by a global-multi-regional two-way coupling model system

    NASA Astrophysics Data System (ADS)

    Yan, Y.-Y.; Lin, J.-T.; Chen, J.; Hu, L.

    2015-09-01

    Small-scale nonlinear chemical and physical processes over pollution source regions affect the global ozone (O3) chemistry, but these processes are not captured by current global chemical transport models (CTMs) and chemistry-climate models that are limited by coarse horizontal resolutions (100-500 km, typically 200 km). These models tend to contain large (and mostly positive) tropospheric O3 biases in the Northern Hemisphere. Here we use a recently built two-way coupling system of the GEOS-Chem CTM to simulate the global tropospheric O3 in 2009. The system couples the global model (at 2.5° long. × 2° lat.) and its three nested models (at 0.667° long. × 0.5° lat.) covering Asia, North America and Europe, respectively. Benefiting from the high resolution, the nested models better capture small-scale processes than the global model alone. In the coupling system, the nested models provide results to modify the global model simulation within respective nested domains while taking the lateral boundary conditions from the global model. Due to the "coupling" effects, the two-way system significantly improves the tropospheric O3 simulation upon the global model alone, as found by comparisons with a suite of ground (1420 sites from WDCGG, GMD, EMEP, and AQS), aircraft (HIPPO and MOZAIC), and satellite measurements (two OMI products). Compared to the global model alone, the two-way coupled simulation enhances the correlation in day-to-day variation of afternoon mean O3 with the ground measurements from 0.53 to 0.68, and it reduces the mean model bias from 10.8 to 6.7 ppb in annual average afternoon O3. Regionally, the coupled model reduces the bias by 4.6 ppb over Europe, 3.9 ppb over North America, and 3.1 ppb over other regions. The two-way coupling brings O3 vertical profiles much closer to the HIPPO (for remote areas) and MOZAIC (for polluted regions) data, reducing the tropospheric (0-9 km) mean bias by 3-10 ppb at most MOZAIC sites and by 5.3 ppb for HIPPO

  20. Biventricular pacing for successful weaning from extracorporal circulation in an infant with complex tetralogy of fallot.

    PubMed

    Abdel-Rahman, U; Kleine, P; Seitz, U; Moritz, A

    2002-01-01

    Biventricular pacing therapy is an innovative therapy for improving cardiac output in adult patients with severe heart failure. However, this technique is not yet used in infants with congenital heart disease. We present a six month old infant with tetralogy of fallot and atresia of the left pulmonary artery in which biventricular stimulation led to improved left ventricular function and successful weaning from extracorporeal circulation.

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

    NASA Astrophysics Data System (ADS)

    Bittihn, Philip; Luther, Gisela; Bodenschatz, Eberhard; Krinsky, Valentin; Parlitz, Ulrich; Luther, Stefan

    2008-10-01

    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.

  2. Diaphragm Pacing as a Rehabilitative Tool for Patients With Pompe Disease Who Are Ventilator-Dependent: Case Series

    PubMed Central

    Fuller, David D.; Martin, A. Daniel; Lottenberg, Lawrence; Islam, Saleem; Lawson, Lee Ann; Onders, Raymond P.; Byrne, Barry J.

    2016-01-01

    Background and Purpose Pompe disease is an inherited disorder notable for severe, progressive ventilatory compromise. Although ventilatory failure has been attributed to myofiber dysfunction secondary to diaphragmatic glycogen accumulation, neural involvement of the phrenic motor system is also a prominent feature. Direct diaphragm pacing supplements respiratory function in other disorders of the phrenic motor system. Accordingly, it is hypothesized that augmented neuromuscular activity via diaphragm pacing would promote weaning from mechanical ventilation in patients with Pompe disease who are unresponsive to conventional, muscle-directed treatments. Case Description Three patients with Pompe disease developed diaphragm paresis that resulted in chronic mechanical ventilation dependence. After preoperative inspiratory muscle strengthening exercises failed to improve function, fine-wire pacing electrodes were laparoscopically implanted into the diaphragm. Diaphragm conditioning was initiated the first postoperative week and consisted of gradual increases in stimulation parameters, lengthening of stimulation sessions, and ventilator weaning. Ventilation and intramuscular electromyographic activity were recorded periodically during conditioning to quantify diaphragm neuromuscular function. Outcomes During paced breathing without mechanical ventilation, tidal volumes increased, and 2 patients were weaned from daytime ventilator dependence within the first 3 months of pacing, which has been sustained over the long-term. A third patient reduced reliance on daytime ventilation, but weaning was delayed by malacia of the large airways. In all patients, pacing appeared to facilitate spontaneous phrenic motor unit activity during independent breathing without ventilator or pacer support. Discussion The findings are consistent with the view that diaphragm pacing has potential rehabilitative value to reduce reliance on mechanical ventilation in people with Pompe disease, but

  3. Diaphragm Pacing as a Rehabilitative Tool for Patients With Pompe Disease Who Are Ventilator-Dependent: Case Series.

    PubMed

    Smith, Barbara K; Fuller, David D; Martin, A Daniel; Lottenberg, Lawrence; Islam, Saleem; Lawson, Lee Ann; Onders, Raymond P; Byrne, Barry J

    2016-05-01

    Pompe disease is an inherited disorder notable for severe, progressive ventilatory compromise. Although ventilatory failure has been attributed to myofiber dysfunction secondary to diaphragmatic glycogen accumulation, neural involvement of the phrenic motor system is also a prominent feature. Direct diaphragm pacing supplements respiratory function in other disorders of the phrenic motor system. Accordingly, it is hypothesized that augmented neuromuscular activity via diaphragm pacing would promote weaning from mechanical ventilation in patients with Pompe disease who are unresponsive to conventional, muscle-directed treatments. Three patients with Pompe disease developed diaphragm paresis that resulted in chronic mechanical ventilation dependence. After preoperative inspiratory muscle strengthening exercises failed to improve function, fine-wire pacing electrodes were laparoscopically implanted into the diaphragm. Diaphragm conditioning was initiated the first postoperative week and consisted of gradual increases in stimulation parameters, lengthening of stimulation sessions, and ventilator weaning. Ventilation and intramuscular electromyographic activity were recorded periodically during conditioning to quantify diaphragm neuromuscular function. During paced breathing without mechanical ventilation, tidal volumes increased, and 2 patients were weaned from daytime ventilator dependence within the first 3 months of pacing, which has been sustained over the long-term. A third patient reduced reliance on daytime ventilation, but weaning was delayed by malacia of the large airways. In all patients, pacing appeared to facilitate spontaneous phrenic motor unit activity during independent breathing without ventilator or pacer support. The findings are consistent with the view that diaphragm pacing has potential rehabilitative value to reduce reliance on mechanical ventilation in people with Pompe disease, but further study is needed. Diaphragm pacing represents a

  4. Accelerating the "Pace" against Illiteracy: Parent and Child Education.

    ERIC Educational Resources Information Center

    Noe, Roger

    1989-01-01

    In 1980, Kentucky reported the nation's lowest percentage of adults, aged 25 and older, who had graduated from high school. Legislators were inundated with recommendations for reform. The result was the enactment of the Parent and Child Education (PACE) pilot program (1986). In the PACE program, parents without high school diplomas attend classes…

  5. Self-Paced Learning in Civil E.T.

    ERIC Educational Resources Information Center

    Sharples, Kent

    1977-01-01

    Briefly reports on the structure and evaluation of an individually-paced, two year civil engineering technology curriculum sponsored by a National Science Foundation grant. The written modules progress linearly with support media presentations. Students in the self-paced program generally outperformed lecture-based students on cognitive…

  6. Social Interaction in Self-Paced Distance Education

    ERIC Educational Resources Information Center

    Anderson, Terry; Upton, Lorne; Dron, Jon; Malone, Judi; Poelhuber, Bruno

    2015-01-01

    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…

  7. Achievement Monitoring of Individually Paced Instruction. Final Report.

    ERIC Educational Resources Information Center

    Pinsky, Paul D.

    A study was made to monitor achievement of individually paced instruction. The project concentrated on designing testing procedures in group paced instructional programs to provide information to student, teachers, parents and administrators which could be used in both a formative and summative evaluation. The three objectives of the project were:…

  8. Prediction of Procrastination in a Self-Pacing Instructional System.

    ERIC Educational Resources Information Center

    Ely, Donald D.; Hampton, John D.

    The objective of the study was to predict potential procrastinators in a self-pacing instructional system. Seventy-five entering college freshmen were randomly selected to participate in a large scale individually-paced program. Those students (25) who procrastinated were classified as "no-start-procrastinators" (NSP); the remainder (52) were…

  9. Is Self-Paced Instruction Really Worth It?

    ERIC Educational Resources Information Center

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

    1975-01-01

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

  10. Is Self-Paced Instruction Really Worth It?

    ERIC Educational Resources Information Center

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

    1975-01-01

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

  11. Torsion of the left ventricle during pacing with MRI tagging

    NASA Astrophysics Data System (ADS)

    Sorger, Jonathan M.; Wyman, Bradley T.; Faris, Owen P.; Hunter, William R.; McVeigh, Elliot R.

    2000-04-01

    In this study the effects of different pacing protocols on left ventricular (LV) torsion was evaluated over the full cardiac cycle. A systolic and diastolic series of Magnetic Resonance Imaging scans were combined and used to calculate the torsion of the LV. The asynchronous contraction resulting from ventricular pacing interferes with the temporal evolution of LV torsion. From these experiments we have shown that measuring torsion is an extremely sensitive indicator of the existence of ectopic excitation. The torsion of the left ventricle was investigated under three different protocols: (1) Right atrial pacing, (2) Right ventricular pacing and (3) Simultaneous pacing from the right ventricular apex and left ventricular base. The temporal evolution of torsion was determined from tagged magnetic resonance images and was evaluated over the full cardiac cycle. The peak twist Tmax for the RA paced heart was 11.09 (+/- 3.54) degrees compared to 6.06 (+/- 1.65) degrees and 6.09 (+/- 0.68) degrees for the RV and Bi-V paced hearts respectively. While biventricular pacing has been shown to increase the synchrony of contraction, it does not preserve the normal physiological twist patterns of the heart.

  12. An improvement in mass flux convective parameterizations and its impact on seasonal simulations using a coupled model

    NASA Astrophysics Data System (ADS)

    Elsayed Yousef, Ahmed; Ehsan, M. Azhar; Almazroui, Mansour; Assiri, Mazen E.; Al-Khalaf, Abdulrahman K.

    2017-02-01

    A new closure and a modified detrainment for the simplified Arakawa-Schubert (SAS) cumulus parameterization scheme are proposed. In the modified convective scheme which is named as King Abdulaziz University (KAU) scheme, the closure depends on both the buoyancy force and the environment mean relative humidity. A lateral entrainment rate varying with environment relative humidity is proposed and tends to suppress convection in a dry atmosphere. The detrainment rate also varies with environment relative humidity. The KAU scheme has been tested in a single column model (SCM) and implemented in a coupled global climate model (CGCM). Increased coupling between environment and clouds in the KAU scheme results in improved sensitivity of the depth and strength of convection to environmental humidity compared to the original SAS scheme. The new scheme improves precipitation simulation with better representations of moisture and temperature especially during suppressed convection periods. The KAU scheme implemented in the Seoul National University (SNU) CGCM shows improved precipitation over the tropics. The simulated precipitation pattern over the Arabian Peninsula and Northeast African region is also improved.

  13. An improvement in mass flux convective parameterizations and its impact on seasonal simulations using a coupled model

    NASA Astrophysics Data System (ADS)

    Elsayed Yousef, Ahmed; Ehsan, M. Azhar; Almazroui, Mansour; Assiri, Mazen E.; Al-Khalaf, Abdulrahman K.

    2015-11-01

    A new closure and a modified detrainment for the simplified Arakawa-Schubert (SAS) cumulus parameterization scheme are proposed. In the modified convective scheme which is named as King Abdulaziz University (KAU) scheme, the closure depends on both the buoyancy force and the environment mean relative humidity. A lateral entrainment rate varying with environment relative humidity is proposed and tends to suppress convection in a dry atmosphere. The detrainment rate also varies with environment relative humidity. The KAU scheme has been tested in a single column model (SCM) and implemented in a coupled global climate model (CGCM). Increased coupling between environment and clouds in the KAU scheme results in improved sensitivity of the depth and strength of convection to environmental humidity compared to the original SAS scheme. The new scheme improves precipitation simulation with better representations of moisture and temperature especially during suppressed convection periods. The KAU scheme implemented in the Seoul National University (SNU) CGCM shows improved precipitation over the tropics. The simulated precipitation pattern over the Arabian Peninsula and Northeast African region is also improved.

  14. Chemical coupling of thiolated chitosan to preformed liposomes improves mucoadhesive properties

    PubMed Central

    Gradauer, Kerstin; Vonach, Caroline; Leitinger, Gerd; Kolb, Dagmar; Fröhlich, Eleonore; Roblegg, Eva; Bernkop-Schnürch, Andreas; Prassl, Ruth

    2012-01-01

    Aim To develop mucoadhesive liposomes by anchoring the polymer chitosan-thioglycolic acid (chitosan-TGA) to the liposomal surface to target intestinal mucosal membranes. Methods Liposomes consisting of phosphatidylcholine (POPC) and a maleimide-functionalized lipid were incubated with chitosan-TGA, leading to the formation of a thioether bond between free SH-groups of the polymer and maleimide groups of the liposome. Uncoated and newly generated thiomer-coated liposomes were characterized according to their size, zeta potential, and morphology using photon correlation spectroscopy and transmission electron microscopy. The release behavior of calcitonin and the fluorophore/quencher-couple ANTS/DPX (8-aminonaphthalene-1,3,6-trisulfonic acid/p-xylene-bis- pyridinium bromide) from coated and uncoated liposomes, was investigated over 24 hours in simulated gastric and intestinal fluids. To test the mucoadhesive properties of thiomer-coated and uncoated liposomes in-vitro, we used freshly excised porcine small intestine. Results Liposomes showed a concentration-dependent increase in size – from approximately 167 nm for uncoated liposomes to 439 nm for the highest thiomer concentration used in this study. Likewise, their zeta potentials gradually increased from about −38 mV to +20 mV, clearly indicating an effective coupling of chitosan-TGA to the surface of liposomes. As a result of mucoadhesion tests, we found an almost two-fold increase in the mucoadhesion of coupled liposomes relative to uncoupled ones. With fluorescence microscopy, we saw a tight adherence of coated particles to the intestinal mucus. Conclusion Taken together, our current results indicate that thiomer-coated liposomes possess a high potential to be used as an oral drug-delivery system. PMID:22679365

  15. Is self-disclosure in couples coping with cancer associated with improvement in depressive symptoms?

    PubMed

    Hagedoorn, Mariët; Puterman, Eli; Sanderman, Robbert; Wiggers, Theo; Baas, Peter C; van Haastert, Michiel; DeLongis, Anita

    2011-11-01

    This study examined associations between the degree of self-disclosure and changes in depressive symptoms in couples coping with colorectal cancer. Sixty-four newly diagnosed patients and their partners completed a measure of depressive symptoms (Center of Epidemiologic Studies Depression Scale) 3 and 9 months postdiagnosis. Furthermore, approximately 2 months after the first assessment, they engaged in a cancer-related conversation in which the patient was asked to introduce a concern. Each partner's verbalizations of emotions, thoughts, and wishes (i.e., self-disclosures) were coded by independent observers. Patients who reported more depressive symptoms at baseline showed more self-disclosures. Mutual self-disclosure was not associated with lower levels of depressive symptoms in patients and partners as compared with one-sided self-disclosure or low disclosure in both patients and partners. It is important to note that decreases in depressive symptoms over time were least prominent in couples in which the partner disclosed a lot whereas the patient disclosed little. These results suggest that mere disclosure of emotions and thoughts to one's intimate partner is not beneficial in reducing distress. Partners' self-disclosure toward patients who disclose few emotions and concerns even appears to be harmful both for patients and partners, given that it reduces the decrease of depressive symptoms over time. If there is a mismatch in the need for self-disclosure within couples, partners with a strong need to talk about their emotions and concerns may be recommended to confide in someone else in their social network or to consult a health care professional. PsycINFO Database Record (c) 2011 APA, all rights reserved.

  16. Pacing and lapping movements among institutionalized patients with dementia.

    PubMed

    Nakaoka, Akiko; Suto, Shunji; Makimoto, Kiyoko; Yamakawa, Miyae; Shigenobu, Kazue; Tabushi, Kaoru

    2010-03-01

    Wandering is a complex behavior, and defining wandering has been challenging. The current study used the integrated circuit (IC) tag monitoring system to describe the distance moved per day and the spatial movements of patients with dementia. The study was conducted in a 60-bed semiacute dementia care unit in a general hospital in Japan over a 3-month period in 2006. The distance moved per day, the numbers of pacing and lapping movements, and the proportions of the distance moved that was paced or lapped were tabulated in 23 patients diagnosed with dementia. The distance moved per day and the numbers of pacing and lapping movements varied greatly within and among study participants. The median distance moved per day was inversely correlated with participants' age and Mini-Mental State Examination (MMSE) scores (adjusted r(2) = .34, P = .01). Consecutive lapping and pacing movements were rare patients with in Alzheimer's disease (AD), while 2 patients with frontotemporal dementia paced or lapped repeatedly.

  17. Coupling the biophysical and social dimensions of wildfire risk to improve wildfire mitigation planning

    Treesearch

    Alan A. Ager; Jeffrey D. Kline; A. Paige Fisher

    2015-01-01

    We describe recent advances in biophysical and social aspects of risk and their potential combined contribution to improve mitigation planning on fire-prone landscapes. The methods and tools provide an improved method for defining the spatial extent of wildfire risk to communities compared to current planning processes. They also propose an expanded role for social...

  18. Work-family enrichment among dual-earner couples: can work improve our family life?

    PubMed

    Dunn, Marianne G; O'Brien, Karen M

    2013-10-01

    The extent to which resources generated at work and positive affect were associated with enrichment in the family domain among 107 dual-earner couples was investigated. Grounded in work-family enrichment theory (Greenhaus & Powell, 2006), this study examined the indirect effect of workplace organizational support on family satisfaction through positive affect at work. Organizational support for work-family management was associated with positive affect at work for both women and men, and positive affect at work was related to family satisfaction for women. One interpersonal effect emerged: women's positive affect at work was associated with family satisfaction for men. Implications for theory, practice, research, and workplace policy are discussed.

  19. Improvement in mechanical properties of glass fiber fabric/PVC composites with chopped glass fibers and coupling agent

    NASA Astrophysics Data System (ADS)

    Lee, Jaewoong; Park, Su Bin; Lee, Joon Seok; Kim, Jong Won

    2017-07-01

    Glass fiber reinforced polyvinylchloride (PVC) composite is used widely because of its low price, chemical resistance, and dimensional stability, but most are short fiber reinforced PVC composites. Fabric reinforced composite have undulated regions, which is the only region without fiber, due to the characteristics of the weave construction, and it limits increasing the mechanical properties. Therefore, in this study, to increase the mechanical properties, the undulated regions of the glass fiber fabric/PVC composite were filled with a silane coupling agent treated chopped fiber. The physical properties, dynamic mechanical thermal properties, and mechanical properties of the prepared composite were observed. The critical fiber aspect ratio of the chopped fiber is different for each mechanical property. This shows that the fabric-reinforced composite of chopped fibers affect each of the mechanical properties differently. In addition, the silane coupling treatment increases the compatibility of the composite components, improving the mechanical properties.

  20. Resveratrol treatment rescues neurovascular coupling in aged mice: role of improved cerebromicrovascular endothelial function and downregulation of NADPH oxidase.

    PubMed

    Toth, Peter; Tarantini, Stefano; Tucsek, Zsuzsanna; Ashpole, Nicole M; Sosnowska, Danuta; Gautam, Tripti; Ballabh, Praveen; Koller, Akos; Sonntag, William E; Csiszar, Anna; Ungvari, Zoltan

    2014-02-01

    Moment-to-moment adjustment of cerebral blood flow (CBF) to neuronal activity via neurovascular coupling is essential for the maintenance of normal neuronal function. Increased oxidative stress that occurs with aging was shown to impair neurovascular coupling, which likely contributes to a significant age-related decline in higher cortical function, increasing the risk for vascular cognitive impairment. Resveratrol is a polyphenolic compound that exerts significant antiaging protective effects in large vessels, but its effects on the cerebromicrovasculature remain poorly defined. The present study was undertaken to investigate the capacity of resveratrol to improve neurovascular coupling in aging. In aged (24-mo-old) C57BL/6 mice N(ω)-nitro-l-arginine methyl ester-sensitive, nitric oxide-mediated CBF responses to whisker stimulation and to the endothelium-dependent dilator acethylcholine (ACh) were impaired compared with those in young (3-mo-old) mice. Treatment of aged mice with resveratrol rescued neurovascular coupling and ACh-induced responses, which was associated with downregulation of cortical expression of NADPH oxidase and decreased levels of biomarkers of oxidative/nitrative stress (3-nitrotyrosine, 8-isoprostanes). Resveratrol also attenuated age-related increases in reactive oxygen species (ROS) production in cultured cerebromicrovascular endothelial cells (DCF fluorescence, flow cytometry). In conclusion, treatment with resveratrol rescues cortical neurovascular coupling responses to increased neuronal activity in aged mice, likely by restoring cerebromicrovascular endothelial function via downregulation of NADPH oxidase-derived ROS production. Beneficial cerebromicrovascular effects of resveratrol may contribute to its protective effects on cognitive function in aging.

  1. Resveratrol treatment rescues neurovascular coupling in aged mice: role of improved cerebromicrovascular endothelial function and downregulation of NADPH oxidase

    PubMed Central

    Toth, Peter; Tarantini, Stefano; Tucsek, Zsuzsanna; Ashpole, Nicole M.; Sosnowska, Danuta; Gautam, Tripti; Ballabh, Praveen; Koller, Akos; Sonntag, William E.; Csiszar, Anna

    2013-01-01

    Moment-to-moment adjustment of cerebral blood flow (CBF) to neuronal activity via neurovascular coupling is essential for the maintenance of normal neuronal function. Increased oxidative stress that occurs with aging was shown to impair neurovascular coupling, which likely contributes to a significant age-related decline in higher cortical function, increasing the risk for vascular cognitive impairment. Resveratrol is a polyphenolic compound that exerts significant antiaging protective effects in large vessels, but its effects on the cerebromicrovasculature remain poorly defined. The present study was undertaken to investigate the capacity of resveratrol to improve neurovascular coupling in aging. In aged (24-mo-old) C57BL/6 mice Nω-nitro-l-arginine methyl ester-sensitive, nitric oxide-mediated CBF responses to whisker stimulation and to the endothelium-dependent dilator acethylcholine (ACh) were impaired compared with those in young (3-mo-old) mice. Treatment of aged mice with resveratrol rescued neurovascular coupling and ACh-induced responses, which was associated with downregulation of cortical expression of NADPH oxidase and decreased levels of biomarkers of oxidative/nitrative stress (3-nitrotyrosine, 8-isoprostanes). Resveratrol also attenuated age-related increases in reactive oxygen species (ROS) production in cultured cerebromicrovascular endothelial cells (DCF fluorescence, flow cytometry). In conclusion, treatment with resveratrol rescues cortical neurovascular coupling responses to increased neuronal activity in aged mice, likely by restoring cerebromicrovascular endothelial function via downregulation of NADPH oxidase-derived ROS production. Beneficial cerebromicrovascular effects of resveratrol may contribute to its protective effects on cognitive function in aging. PMID:24322615

  2. Atrial support pacing in heart failure: results from the multicenter PEGASUS CRT trial.

    PubMed

    Martin, David O; Day, John D; Lai, Peter Y; Murphy, Allan L; Nayak, Hemal M; Villareal, Rollo P; Weiner, Stanislav; Kraus, Stacia M; Stolen, Kira Q; Gold, Michael R

    2012-12-01

    Cardiac resynchronization therapy (CRT) efficacy trials to date used atrial-synchronous biventricular pacing wherein there is no or minimal atrial pacing. However, bradycardia and chronotropic incompetence are common in this patient population. This trial was designed to evaluate the effect of atrial support pacing among heart failure patients receiving a CRT defibrillator. PEGASUS CRT was a multicenter, 3-arm, randomized study. At 6 weeks, patients were randomized to DDD mode at a lower rate of 40 bpm (DDD-40; control arm), or one of the following 2 treatment arms: DDD-70, or DDDR-40. The primary endpoint was a clinical composite endpoint that included all-cause mortality, heart failure events, NYHA functional class, and patient global self-assessment. Subjects were classified as improved, unchanged, or worsened at 12 months. There were 1,433 patients randomized, of whom 66% were male, mean age was 67 ± 11 years, and mean left ventricular ejection fraction was 23 ± 7%. The average follow-up time was 10.5 ± 3.5 months and 1,309 patients contributed to the primary endpoint. No significant differences were observed in the composite endpoint between either of the 2 treatment arms compared to the control arm (P>0.05 for both comparisons). Additionally, there were no differences among the groups in mortality or heart failure events. In advanced heart failure patients treated with CRT, atrial support pacing did not improve clinical outcomes compared to atrial tracking. However, atrial pacing did not adversely affect mortality or heart failure events. © 2012 Wiley Periodicals, Inc.

  3. Surface plasmon coupling dynamics in InGaN/GaN quantum-well structures and radiative efficiency improvement.

    PubMed

    Fadil, Ahmed; Iida, Daisuke; Chen, Yuntian; Ma, Jun; Ou, Yiyu; Petersen, Paul Michael; Ou, Haiyan

    2014-09-22

    Surface plasmonics from metal nanoparticles have been demonstrated as an effective way of improving the performance of low-efficiency light emitters. However, reducing the inherent losses of the metal nanoparticles remains a challenge. Here we study the enhancement properties by Ag nanoparticles for InGaN/GaN quantum-well structures. By using a thin SiN dielectric layer between Ag and GaN we manage to modify and improve surface plasmon coupling effects, and we attribute this to the improved scattering of the nanoparticles at the quantum-well emission wavelength. The results are interpreted using numerical simulations, where absorption and scattering cross-sections are studied for different sized particles on GaN and GaN/SiN substrates.

  4. Surface plasmon coupling dynamics in InGaN/GaN quantum-well structures and radiative efficiency improvement

    PubMed Central

    Fadil, Ahmed; Iida, Daisuke; Chen, Yuntian; Ma, Jun; Ou, Yiyu; Petersen, Paul Michael; Ou, Haiyan

    2014-01-01

    Surface plasmonics from metal nanoparticles have been demonstrated as an effective way of improving the performance of low-efficiency light emitters. However, reducing the inherent losses of the metal nanoparticles remains a challenge. Here we study the enhancement properties by Ag nanoparticles for InGaN/GaN quantum-well structures. By using a thin SiN dielectric layer between Ag and GaN we manage to modify and improve surface plasmon coupling effects, and we attribute this to the improved scattering of the nanoparticles at the quantum-well emission wavelength. The results are interpreted using numerical simulations, where absorption and scattering cross-sections are studied for different sized particles on GaN and GaN/SiN substrates. PMID:25242090

  5. EPICARDIAL AND INTRAMURAL EXCITATION DURING VENTRICULAR PACING: EFFECT OF MYOCARDIAL STRUCTURE

    PubMed Central

    Taccardi, Bruno; Punske, Bonnie B.; Macchi, Emilio; MacLeod, Robert S.; Ershler, Philip R.

    2009-01-01

    Published studies show that ventricular pacing in canine hearts produces three distinct patterns of epicardial excitation: elliptical isochrones near an epicardial pacing site, with asymmetrical bulges; areas with high propagation velocity, up to 2 or 3 m/s and numerous breakthrough sites; lower velocity areas (< 1 m/s) where excitation moves across the epicardial projection of the septum. With increasing pacing depth the magnitude of epicardial potential maxima becomes asymmetrical. The electrophysiological mechanisms that generate the distinct patterns have not been fully elucidated. In this study we investigated those mechanisms experimentally. Under pentobarbital anesthesia epicardial and intramural excitation isochrone and potential maps have been recorded from 22 exposed or isolated dog hearts, by means of epicardial electrode arrays and transmural plunge electrodes. In 5 experiments, a ventricular cavity was perfused with diluted Lugol solution. Results The epicardial bulges result from electrotonic attraction from the helically shaped subepicardial portions of the wave front. The high velocity patterns and the associated multiple breakthroughs are due to involvement of the Purkinje network. The low velocity at the septum crossing is due to the missing Purkinje involvement in that area. The asymmetric magnitude of the epicardial potential maxima and the shift of the breakthrough sites provoked by deep stimulation are a consequence of the epi-endocardial obliqueness of the intramural fibers. These results improve our understanding of intramural and epicardial propagation during PVCs and paced beats. This can be useful for interpreting epicardial maps recorded at surgery or inversely computed from body surface ECGs. PMID:18263708

  6. Computer-Paced versus Experimenter-Paced Working Memory Span Tasks: Are They Equally Reliable and Valid?

    ERIC Educational Resources Information Center

    Bailey, Heather

    2012-01-01

    Working memory span tasks are popular measures, in part, because performance on these tasks predicts performance on other measures of cognitive ability. The traditional method of span-task administration is the experimenter-paced version, whose reliability and validity have been repeatedly demonstrated. However, computer-paced span tasks are…

  7. Understanding Air-Sea Coupling Processes and Coupled Model Predictions Using GOTEX Measurements and COAMPS/NCOM and Aircraft Measurements for Understanding Air-Sea Coupling and Improving Coupled Model Predictions

    DTIC Science & Technology

    2012-09-30

    part of the Dynamics of the Madden- Julian Oscillation (DYNAMO) and ONR Litterol Littoral Air-Sea Processes (LASP) DRI. The objectives of the GOTEX... McCreary et al.1989). These studies have hypothesized that a fully-coupled model study of the gap outflow would be beneficial. Observations from...REFERENCES McCreary , J. P., H. S. Lee, and D. B. Enfield, 1989: The response of the coastal ocean to strong offshore winds: With

  8. A New Model of Orbital Pacing for Pliocene Glaciations

    NASA Astrophysics Data System (ADS)

    Herbert, T.; Dowsett, H. J.; Caballero-Gill, R. P.

    2015-12-01

    The earth's climate system has gone through major changes over time that serve as natural experiments to test our understanding of linkages and feedbacks that may come into play if the Earth continues to warm, as expected from greenhouse gas forcing. Our project investigates patterns of climate change between the northern and southern hemispheres during the mid-Pliocene epoch (~3-4 Myr ago) when the overall climate state was warmer than today. Critically, evidence suggests that the amount of ice on Antarctica was similar to today, but that there was little or no permanent ice on land in the northern hemisphere. Most climate scientists have therefore supposed that orbitally-paced climate change would initiate in the region around the Antarctic, and be driven primarily by the 41,000 year obliquity cycle. Using distributed data sets on both sea surface temperature and the combination of deep sea temperature and global ice volume recorded by ð18O, we find a pervasive influence of eccentricity/precession on Pliocene paleoclimate that has been under-appreciated. We tentatively constrain the phase of the climate response by calibrating temperature patterns to the precessional "clock" of the Mediterranean sapropel sequence. Large Pliocene glacial events were paced by precession, and coincide with minimum northern hemisphere summer insolation. This mode is in many ways the opposite of the late Pleistocene, where climate positively follows the envelope of northern hemisphere precession. In the Pliocene case, glacial periods instead followed the lower envelope of precession and nodes of low precessional variance supported peak interglacial conditions. The observations can be explained by positing that during the warmer Pliocene, the high latitudes of the northern hemisphere could only support cryosphere expansion during times of minimal summer insolation. While the presence of ice-rafted debris in the North Atlantic and North Pacific unambiguously confirm a northern

  9. Inductively Coupling Plasma (ICP) Treatment of Propylene (PP) Surface and Adhesion Improvement

    NASA Astrophysics Data System (ADS)

    Liu, Yenchun; Fu, Yenpei

    2009-12-01

    Study on increasing the roughness of the polymer substrate surface to enhance the adhesion with the copper layer in an inductively coupling plasma (ICP) process was carried out. The microstructure of the polymer substrate surfaces, which were exposed to different kinds of plasma treatment, was identified by scanning electron microscopy(SEM) analysis, peel strength of the copper coating and water surface contact angle. The adhesion of the substrate was largely enhanced by plasma treatment and the copper deposited coating reached a value of 7.68 kgf/m in verifying the adhesion of the copper coating with polymer material. The quality of the line/space 50/50 μm produced in the laboratory was examined by the pressure cooker test and proved to meet the requirement.

  10. Education for Volunteer Teachers; A Report on the Project for the Advancement of Church Education (PACE) 1968-1970.

    ERIC Educational Resources Information Center

    Bowman, Locke E., Jr.; And Others

    The purpose of the Project for the Advancement of Church Education (PACE) was (1) to test the hypothesis that INSTROTEACH workshops improve the competence of volunteer teachers, (2) to test the hypothesis that Learning Laboratory training improves the competence of volunteer teachers, and (3) to conduct studies on the correlation between teacher…

  11. 42 CFR 460.24 - Limit on number of PACE program agreements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... SERVICES (CONTINUED) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) PACE Organization Application and Waiver Process § 460.24 Limit on number...

  12. 42 CFR 460.24 - Limit on number of PACE program agreements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... SERVICES (CONTINUED) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) PACE Organization Application and Waiver Process § 460.24 Limit on number...

  13. 42 CFR 460.24 - Limit on number of PACE program agreements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... SERVICES (CONTINUED) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) PACE Organization Application and Waiver Process § 460.24 Limit on number...

  14. 42 CFR 460.24 - Limit on number of PACE program agreements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... SERVICES (CONTINUED) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) PACE Organization Application and Waiver Process § 460.24 Limit on number...

  15. Coupling Protein Side-Chain and Backbone Flexibility Improves the Re-design of Protein-Ligand Specificity

    PubMed Central

    Ollikainen, Noah; de Jong, René M.; Kortemme, Tanja

    2015-01-01

    Interactions between small molecules and proteins play critical roles in regulating and facilitating diverse biological functions, yet our ability to accurately re-engineer the specificity of these interactions using computational approaches has been limited. One main difficulty, in addition to inaccuracies in energy functions, is the exquisite sensitivity of protein–ligand interactions to subtle conformational changes, coupled with the computational problem of sampling the large conformational search space of degrees of freedom of ligands, amino acid side chains, and the protein backbone. Here, we describe two benchmarks for evaluating the accuracy of computational approaches for re-engineering protein-ligand interactions: (i) prediction of enzyme specificity altering mutations and (ii) prediction of sequence tolerance in ligand binding sites. After finding that current state-of-the-art “fixed backbone” design methods perform poorly on these tests, we develop a new “coupled moves” design method in the program Rosetta that couples changes to protein sequence with alterations in both protein side-chain and protein backbone conformations, and allows for changes in ligand rigid-body and torsion degrees of freedom. We show significantly increased accuracy in both predicting ligand specificity altering mutations and binding site sequences. These methodological improvements should be useful for many applications of protein – ligand design. The approach also provides insights into the role of subtle conformational adjustments that enable functional changes not only in engineering applications but also in natural protein evolution. PMID:26397464

  16. Improvement in magnetic field immunity of externally-coupled transcutaneous energy transmission system for a totally implantable artificial heart.

    PubMed

    Yamamoto, Takahiko; Koshiji, Kohji; Homma, Akihiko; Tatsumi, Eisuke; Taenaka, Yoshiyuki

    2008-01-01

    Transcutaneous energy transmission (TET) that uses electromagnetic induction between the external and internal coils of a transformer is the most promising method to supply driving energy to a totally implantable artificial heart without invasion. Induction-heating (IH) cookers generate magnetic flux, and if a cooker is operated near a transcutaneous transformer, the magnetic flux generated will link with the external and internal coils of the transcutaneous transformer. This will affect the performance of the TET and the artificial heart system. Hence, it is necessary to improve the magnetic field immunity of the TET system. During operation of the system, if the transcutaneous transformer is in close proximity to an IH cooker, the electric power generated by the cooker and coupled to the transformer can drive the artificial heart system. To prevent this coupling, the external coil was shielded with a conductive shield that had a slit in it. This reduces the coupling between the transformer and the magnetic field generated by the induction cooker. However, the temperature of the shield increased due to heating by eddy currents. The temperature of the shield can be reduced by separating the IH cooker and the shield.

  17. Coupling Protein Side-Chain and Backbone Flexibility Improves the Re-design of Protein-Ligand Specificity.

    PubMed

    Ollikainen, Noah; de Jong, René M; Kortemme, Tanja

    2015-01-01

    Interactions between small molecules and proteins play critical roles in regulating and facilitating diverse biological functions, yet our ability to accurately re-engineer the specificity of these interactions using computational approaches has been limited. One main difficulty, in addition to inaccuracies in energy functions, is the exquisite sensitivity of protein-ligand interactions to subtle conformational changes, coupled with the computational problem of sampling the large conformational search space of degrees of freedom of ligands, amino acid side chains, and the protein backbone. Here, we describe two benchmarks for evaluating the accuracy of computational approaches for re-engineering protein-ligand interactions: (i) prediction of enzyme specificity altering mutations and (ii) prediction of sequence tolerance in ligand binding sites. After finding that current state-of-the-art "fixed backbone" design methods perform poorly on these tests, we develop a new "coupled moves" design method in the program Rosetta that couples changes to protein sequence with alterations in both protein side-chain and protein backbone conformations, and allows for changes in ligand rigid-body and torsion degrees of freedom. We show significantly increased accuracy in both predicting ligand specificity altering mutations and binding site sequences. These methodological improvements should be useful for many applications of protein-ligand design. The approach also provides insights into the role of subtle conformational adjustments that enable functional changes not only in engineering applications but also in natural protein evolution.

  18. Improving Air Quality (and weather) Predictions in Asia via Application of New Data Assimilation Techniques Applicable to Coupled Models

    NASA Astrophysics Data System (ADS)

    Carmichael, G. R.; Gao, M.; Wang, Z.; Saide, P. E.; Kim, J.; Song, C. H.; Cheng, Y.; Choi, M.

    2014-12-01

    Aerosol loading are high in large parts of Asia, with direct impacts on human health and on the Earth's weather and climate systems through their interactions with radiation and clouds. Their role is dependent on their distributions of size, number, phase and composition, which vary significantly in space and time. There remain large uncertainties in simulated aerosol distributions due to uncertainties in emission estimates and in chemical and physical processes associated with their formation and removal. These uncertainties lead to large uncertainties in weather and air quality predictions and in estimates of health and climate change impacts. Despite these uncertainties and challenges regional-scale coupled chemistry-meteorological models such as WRF-Chem have significant capabilities in predicting aerosol distributions and explaining aerosol-weather interactions. In this talk we explore the hypothesis that new advances in on-line, coupled atmospheric chemistry/meteorological models, and new emission inversion and data assimilation techniques applicable to such coupled models, can be applied in innovative ways using current and evolving observation systems to predictions of aerosol distributions at regional scales. We present results that show that the addition of geostationary data to other data sources, improves air quality predictions, and reduce uncertainties in health assessments and climate studies.

  19. Altering embryonic cardiac dynamics with optical pacing.

    PubMed

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

    2012-01-01

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

  20. Pushing the Pace of Tree Species Migration

    PubMed Central

    Lazarus, Eli D.; McGill, Brian J.

    2014-01-01

    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. PMID:25162663

  1. Interaction between spiral and paced waves in cardiac tissue.

    PubMed

    Agladze, Konstantin; Kay, Matthew W; Krinsky, Valentin; Sarvazyan, Narine

    2007-07-01

    For prevention of lethal arrhythmias, patients at risk receive implantable cardioverter-defibrillators, which use high-frequency antitachycardia pacing (ATP) to convert tachycardias to a normal rhythm. One of the suggested ATP mechanisms involves paced-induced drift of rotating waves followed by their collision with the boundary of excitable tissue. This study provides direct experimental evidence of this mechanism. In monolayers of neonatal rat cardiomyocytes in which rotating waves of activity were initiated by premature stimuli, we used the Ca(2+)-sensitive indicator fluo 4 to observe propagating wave patterns. The interaction of the spiral tip with a paced wave was then monitored at a high spatial resolution. In the course of the experiments, we observed spiral wave pinning to local heterogeneities within the myocyte layer. High-frequency pacing led, in a majority of cases, to successful termination of spiral activity. Our data show that 1) stable spiral waves in cardiac monolayers tend to be pinned to local heterogeneities or areas of altered conduction, 2) overdrive pacing can shift a rotating wave from its original site, and 3) the wave break, formed as a result of interaction between the spiral tip and a paced wave front, moves by a paced-induced drift mechanism to an area where it may become unstable or collide with a boundary. The data were complemented by numerical simulations, which was used to further analyze experimentally observed behavior.

  2. Interaction between spiral and paced waves in cardiac tissue

    PubMed Central

    Agladze, Konstantin; Kay, Matthew W.; Krinsky, Valentin; Sarvazyan, Narine

    2010-01-01

    For prevention of lethal arrhythmias, patients at risk receive implantable cardioverter-defibrillators, which use high-frequency antitachycardia pacing (ATP) to convert tachycardias to a normal rhythm. One of the suggested ATP mechanisms involves paced-induced drift of rotating waves followed by their collision with the boundary of excitable tissue. This study provides direct experimental evidence of this mechanism. In monolayers of neonatal rat cardiomyocytes in which rotating waves of activity were initiated by premature stimuli, we used the Ca2+-sensitive indicator fluo 4 to observe propagating wave patterns. The interaction of the spiral tip with a paced wave was then monitored at a high spatial resolution. In the course of the experiments, we observed spiral wave pinning to local heterogeneities within the myocyte layer. High-frequency pacing led, in a majority of cases, to successful termination of spiral activity. Our data show that 1) stable spiral waves in cardiac monolayers tend to be pinned to local heterogeneities or areas of altered conduction, 2) overdrive pacing can shift a rotating wave from its original site, and 3) the wave break, formed as a result of interaction between the spiral tip and a paced wave front, moves by a paced-induced drift mechanism to an area where it may become unstable or collide with a boundary. The data were complemented by numerical simulations, which was used to further analyze experimentally observed behavior. PMID:17384124

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

    PubMed

    Mond, Harry G

    2010-07-01

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

  4. Pacing: a concept analysis of the chronic pain intervention.

    PubMed

    Jamieson-Lega, Kathryn; Berry, Robyn; Brown, Cary A

    2013-01-01

    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. To conduct a formal concept analysis of the term 'pacing'. A standardized concept analysis process (including literature scoping to identify all uses of the concept, analysis to determine defining attributes of the concept and identification of model, borderline and contrary cases) was used to determine what the concept of pacing does and does not represent within the current evidence base. A conceptual model including the core attributes of action, time, balance, learning and self-management emerged. From these attributes, an evidence-based definition for pacing was composed and distributed to stakeholders for review. After consideration of stakeholder feedback, the emergent definition of pacing was finalized as follows: "Pacing is an active self-management strategy whereby individuals learn to balance time spent on activity and rest for the purpose of achieving increased function and participation in meaningful activities". The findings of the present concept analysis will help to standardize the use and definition of the term pacing across disciplines for the purposes of both pain management and research.

  5. Impact of pacing on systemic ventricular function in L-transposition of the great arteries.

    PubMed

    Hofferberth, Sophie C; Alexander, Mark E; Mah, Douglas Y; Bautista-Hernandez, Victor; del Nido, Pedro J; Fynn-Thompson, Francis

    2016-01-01

    To assess the impact of univentricular versus biventricular pacing (BiVP) on systemic ventricular function in patients with congenitally corrected transposition of the great arteries (ccTGA). We performed a retrospective review of all patients with a diagnosis of ccTGA who underwent pacemaker insertion. From 1993 to 2014, 53 patients were identified from the cardiology database and surgical records. Overall mortality was 7.5% (n = 4). One patient required transplantation and 3 late deaths occurred secondary to end-stage heart failure. Median follow-up was 3.7 years (range, 4 days to 22.5 years). Twenty-five (47%) underwent univentricular pacing only, of these, 8 (32%) developed significant systemic ventricular dysfunction. Twenty-eight (53%) received BiVP, 17 (26%) were upgraded from a dual-chamber system, 11 (21%) received primary BiVP. Fourteen (82%) of the 17 undergoing secondary BiVP demonstrated systemic ventricular dysfunction at the time of pacer upgrade, with 7 (50%) demonstrating improved systemic ventricular function after pacemaker upgrade. Overall, 42 (79%) patients underwent univentricular pacing, with 22 (52%) developing significant systemic ventricular dysfunction. In contrast, the 11 (21%) who received primary BiVP had preserved systemic ventricular function at latest follow-up. Late-onset systemic ventricular dysfunction is a major complication associated with the use of univentricular pacing in patients with ccTGA. All patients with ccTGA who develop heart block should undergo primary biventricular pacing, as this prevents late systemic ventricular dysfunction. Preemptive placement of BiVP leads at the time of anatomical repair or other permanent palliative procedure will facilitate subsequent BiVP should heart block develop. Copyright © 2016 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.

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

    NASA Astrophysics Data System (ADS)

    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.

  7. The Effect of Diuresis on the Paced QRS Complexes in Pacing-Dependent Patients with Heart Failure.

    PubMed

    Sheng, Fuqiang; Chen, Bin; He, Maorong; Zhang, Meilin; Shen, Guoying; Zhao, Xiaowei

    2016-03-01

    Augmentation of the amplitude of QRS complexes with diuretic therapy for patients with congestive heart failure has been well documented. However, the effect of diuresis on the paced QRS complexes in pacing-dependent patients with heart failure is scarce. To investigate the effect of diuresis on the paced QRS complexes in pacing-dependent patients with heart failure. Thrity-two consecutive pacing-dependent patients with heart failure were enrolled in this study. Before and after diuresis, the sums of paced QRS amplitude of leads I+II (ΣpQRSI+II ), six limb leads (ΣpQRS6L ), leads V1 -V3 (ΣpQRSV1-V3 ), leads V4 -V6 (ΣpQRSV4-V6 ), leads V1 -V6 (ΣpQRSV1-V6 ), and lead aVR (pQRSaVR ), paced QRS duration (pQRSd ), paced QT intervals (pQT) and the body weight of each patient were measured, then the % changes (Δ%) in paced electrocardiogram (ECG) variables and the Δ% in body weight were evaluated. Compared with before diuresis, paced ECG variables significantly increased and body weight significantly decreased after diuresis, Δ% in paced QRS amplitude(s) in all ECG variables (ΣpQRSI+II, ΣpQRS6L, ΣpQRSV1-V3 , ΣpQRSV4-V6 , ΣpQRSV1-V6 , and pQRSaVR ) correlated well with Δ% in body weight (r = 0.416, r = 0.849, r = 0.901, r = 0.371, r = 0.837, r = 0.619, and P = 0.018, P < 0.001, P < 0.001, P = 0.037, P < 0.001, P < 0.001), while there was no correlation between Δ% in pQRSd and pQT and Δ% in body weight. The changes in amplitude of paced QRS complexes may be useful for the monitoring of therapy of pacing-dependent patients with heart failure. © 2015 Wiley Periodicals, Inc.

  8. Coupling the Biophysical and Social Dimensions of Wildfire Risk to Improve Wildfire Mitigation Planning.

    PubMed

    Ager, Alan A; Kline, Jeffrey D; Fischer, A Paige

    2015-08-01

    We describe recent advances in biophysical and social aspects of risk and their potential combined contribution to improve mitigation planning on fire-prone landscapes. The methods and tools provide an improved method for defining the spatial extent of wildfire risk to communities compared to current planning processes. They also propose an expanded role for social science to improve understanding of community-wide risk perceptions and to predict property owners' capacities and willingness to mitigate risk by treating hazardous fuels and reducing the susceptibility of dwellings. In particular, we identify spatial scale mismatches in wildfire mitigation planning and their potential adverse impact on risk mitigation goals. Studies in other fire-prone regions suggest that these scale mismatches are widespread and contribute to continued wildfire dwelling losses. We discuss how risk perceptions and behavior contribute to scale mismatches and how they can be minimized through integrated analyses of landscape wildfire transmission and social factors that describe the potential for collaboration among landowners and land management agencies. These concepts are then used to outline an integrated socioecological planning framework to identify optimal strategies for local community risk mitigation and improve landscape-scale prioritization of fuel management investments by government entities.

  9. Coupled fluid and solid mechanics study for improved permeability estimation of fines' invaded porous materials

    NASA Astrophysics Data System (ADS)

    Mirabolghasemi, M.; Prodanovic, M.

    2012-12-01

    The problem of fine particle infiltration is seen in fields from subsurface transport, to drug delivery to industrial slurry flows. Sediment filtration and pathogen retention are well-known subsurface engineering problems that have been extensively studied through different macroscopic, microscopic and experimental modeling techniques Due to heterogeneity, standard constitutive relationships and models yield poor predictions for flow (e.g. permeability) and rock properties (e.g. elastic moduli) of the invaded (damaged) porous media. This severely reduces our ability to, for instance, predict retention, pressure build-up, newly formed flow pathways or porous medium mechanical behavior. We chose a coupled computational fluid dynamics (CFD) - discrete element modeling (DEM) approach to simulate the particulate flow through porous media represented by sphere packings. In order to minimize the uncertainty involved in estimating the flow properties of porous media on Darcy scale and address the dynamic nature of filtration process, this microscopic approach is adapted as a robust method that can incorporate particle interaction physics as well as the heterogeneity of the porous medium.. The coupled simulation was done in open-source packages which has both CFD (openFOAM) and DEM components (LIGGGHTS). We ran several sensitivity analyses over different parameters such as particle/grain size ratio, fluid viscosity, flow rate and sphere packing porosity in order to investigate their effects on the depth of invasion and damaged porous medium permeability. The response of the system to the variation of different parameters is reflected through different clogging mechanism; for instance, bridging is the dominant mechanism of pore-throat clogging when larger particles penetrate into the packing, whereas, in case of fine particles which are much smaller than porous medium grains (1/20 in diameter), this mechanism is not very effective due to the frequent formation and

  10. Testing a four-dimensional variational data assimilation method using an improved intermediate coupled model for ENSO analysis and prediction

    NASA Astrophysics Data System (ADS)

    Gao, Chuan; Wu, Xinrong; Zhang, Rong-Hua

    2016-07-01

    A four-dimensional variational (4D-Var) data assimilation method is implemented in an improved intermediate coupled model (ICM) of the tropical Pacific. A twin experiment is designed to evaluate the impact of the 4D-Var data assimilation algorithm on ENSO analysis and prediction based on the ICM. The model error is assumed to arise only from the parameter uncertainty. The "observation" of the SST anomaly, which is sampled from a "truth" model simulation that takes default parameter values and has Gaussian noise added, is directly assimilated into the assimilation model with its parameters set erroneously. Results show that 4D-Var effectively reduces the error of ENSO analysis and therefore improves the prediction skill of ENSO events compared with the non-assimilation case. These results provide a promising way for the ICM to achieve better real-time ENSO prediction.

  11. An Improved Direct Measurement of Leptonic Coupling Asymmetries with Polarized Z{sup 0}'s

    SciTech Connect

    Abe, Toshinori

    1999-08-03

    We report new direct measurements of the Z{sup 0}-lepton coupling asymmetry parameters A{sub e}, A{sub {mu}} and A{sub r}, with polarized Z{sup 0}'s collected by the SLD detector at the SLAC Linear Collider. The parameters are extracted from the measurement of the left-right-forward-backward asymmetries for each lepton species. The 1996, 1997 and 1998 SLD runs are included in this analysis and combined with published data from the 1993-95 runs. Preliminary results are A{sub e} = 0.1558 {+-} 0.0064, A{sub {mu}} = 0.137 {+-} 0.016 and A{sub {tau}} = 0.142 {+-} 0.016. If lepton universality is assumed, a combined asymmetry parameter A{sub l} = 0.1523 {+-} 0.0057 results. This translates into an effective weak mixing angle sin{sup 2} {theta}{sub W}{sup eff} = 0.23085 {+-} 0.00073 at the Z{sup 0} resonance.

  12. Improved dynamics and gravitational collapse of tachyon field coupled with a barotropic fluid

    NASA Astrophysics Data System (ADS)

    Marto, João; Tavakoli, Yaser; Moniz, Paulo Vargas

    2015-01-01

    We consider a spherically symmetric gravitational collapse of a tachyon field with an inverse square potential, which is coupled with a barotropic fluid. By employing an holonomy correction imported from loop quantum cosmology (LQC), we analyze the dynamics of the collapse within a semiclassical description. Using a dynamical system approach, we find that the stable fixed points given by the standard general relativistic setting turn into saddle points in the present context. This provides a new dynamics in contrast to the black hole and naked singularities solutions appearing in the classical model. Our results suggest that classical singularities can be avoided by quantum gravity effects and are replaced by a bounce. By a thorough numerical studies we show that, depending on the barotropic parameter γ, there exists a class of solutions corresponding to either a fluid or a tachyon dominated regimes. Furthermore, for the case γ 1, we find an interesting tracking behavior between the tachyon and the fluid leading to a dust-like collapse. In addition, we show that, there exists a threshold scale which determines when an outward energy flux emerges, as a nonsingular black hole is forming, at the corresponding collapse final stages.

  13. Improvements in G protein-coupled receptor purification yield light stable rhodopsin crystals.

    PubMed

    Salom, David; Le Trong, Isolde; Pohl, Ehmke; Ballesteros, Juan A; Stenkamp, Ronald E; Palczewski, Krzysztof; Lodowski, David T

    2006-12-01

    G protein-coupled receptors (GPCRs) represent the largest family of transmembrane signaling proteins and are the target of approximately half of all therapeutic agents. Agonist ligands bind their cognate GPCRs stabilizing the active conformation that is competent to bind G proteins, thus initiating a cascade of intracellular signaling events leading to modification of the cell activity. Despite their biomedical importance, the only known GPCR crystal structures are those of inactive rhodopsin forms. In order to understand how GPCRs are able to transduce extracellular signals across the plasma membrane, it is critical to determine the structure of these receptors in their ligand-bound, active state. Here, we report a novel combination of purification procedures that allowed the crystallization of rhodopsin in two new crystal forms and can be applicable to the purification and crystallization of other membrane proteins. Importantly, these new crystals are stable upon photoactivation and the preliminary X-ray diffraction analysis of both photoactivated and ground state rhodopsin crystals are also reported.

  14. Improved UV response of ZnO nanotubes by resonant coupling of anchored plasmonic silver nanoparticles

    NASA Astrophysics Data System (ADS)

    Biswas, Pranab; Cho, Seong Rae; Kim, Jong-Woo; Baek, Sung-Doo; Myoung, Jae-Min

    2017-06-01

    In this study, plasmonic silver (Ag) nanoparticle-(NP) anchored ZnO nanorods (NRs) and nanotube-(NT) based UV photodetectors are demonstrated. Here, Ag NPs are synthesized and anchored by using a room-temperature photochemical method by exposing the precursor solution in UV radiation. In order to achieve a stronger surface plasmon resonance (SPR) and minimum agglomeration, the photochemical method is optimized with a precursor concentration of 5 mmol, a UV intensity of 0.4 mW · cm-2, and an exposure time of 30 min. An asymmetry around 380 nm in the absorption spectra of the NP solution indicates the presence of plasmonic resonance in that region. Upon anchoring the Ag NPs, ZnO NRs show enhanced band edge emission (380-400 nm) and the emission is further significantly increased in Ag NP-anchored ZnO NTs. The on/off ratio and photoresponse properties of the UV photodetectors are enhanced significantly after anchoring Ag NPs on the ZnO nanostructures. It is believed that the near-field coupling of SPR causes an optical enhancement of ZnO, whereas the bridging effect and hot-electron transfer to the conduction band of ZnO by plasmonic Ag NPs, anchored in close proximity, gives rise to a faster response of the photodetectors.

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

    NASA Astrophysics Data System (ADS)

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

    2016-11-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2017-01-01

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

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

    PubMed Central

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

    2016-01-01

    Currently, no non-invasive cardiac pacing device acceptable for prolonged use in conscious patients exists. High Intensity Focused Ultrasound (HIFU) can be used to perform remote pacing using reversibility of electromechanical coupling of cardiomyocytes. Here we described an extracorporeal cardiac stimulation device and study its efficacy and safety. We conducted experiments ex vivo and in vivo in a large animal model (pig) to evaluate clinical potential of such a technique. The stimulation threshold was determined in 10 different ex vivo hearts and different clinically relevant electrical effects such as consecutive stimulations of different heart chambers with a single ultrasonic probe, continuous pacing or the inducibility of ventricular tachycardia were shown. Using ultrasonic contrast agent, consistent cardiac stimulation was achievable in vivo for up to 1 hour sessions in 4 different animals. No damage was observed in inversion-recovery MR sequences performed in vivo in the 4 animals. Histological analysis revealed no differences between stimulated and control regions, for all ex vivo and in vivo cases. PMID:27827415

  18. Antitachycardia pacing programming in implantable cardioverter defibrillator: A systematic review.

    PubMed

    De Maria, Elia; Giacopelli, Daniele; Borghi, Ambra; Modonesi, Letizia; Cappelli, Stefano

    2017-05-26

    Implantable cardioverter defibrillator (ICD) programming involves several parameters. In recent years antitachycardia pacing (ATP) has gained an increasing importance in the treatment of ventricular arrhythmias, whether slow or fast. It reduces the number of unnecessary and inappropriate shocks and improves both patient's quality of life and device longevity. There is no clear indication regarding the type of ATP to be used, except for the treatment of fast ventricular tachycardias (188 bpm-250 bpm) where it has been shown a greater efficacy and safety of burst compared to ramp; 8 impulses in each sequence of ATP appears to be the best programming option in this setting. Beyond ATP use, excellent clinical results were obtained with programming standardization following these principles: extended detection time in ventricular fibrillation (VF) zone; supraventricular discrimination criteria up to 200 bpm; first shock in VF zone at the maximum energy in order to reduce the risk of multiple shocks. The MADIT-RIT trial and some observational registries have also recently demonstrated that programming with a widespread use of ATP, higher cut-off rates or delayed intervention reduces the number of inappropriate and unnecessary therapies and improves the survival of patients during mid-term follow-up.

  19. Improved Dyson series expansion for steady-state quantum transport beyond the weak coupling limit: divergences and resolution.

    PubMed

    Thingna, Juzar; Zhou, Hangbo; Wang, Jian-Sheng

    2014-11-21

    We present a general theory to calculate the steady-state heat and electronic currents for nonlinear systems using a perturbative expansion in the system-bath coupling. We explicitly demonstrate that using the truncated Dyson-series leads to divergences in the steady-state limit, thus making it impossible to be used for actual applications. In order to resolve the divergences, we propose a unique choice of initial condition for the reduced density matrix, which removes the divergences at each order. Our approach not only allows us to use the truncated Dyson-series, with a reasonable choice of initial condition, but also gives the expected result that the steady-state solutions should be independent of initial preparations. Using our improved Dyson series we evaluate the heat and electronic currents up to fourth-order in system-bath coupling, a considerable improvement over the standard quantum master equation techniques. We then numerically corroborate our theory for archetypal settings of linear systems using the exact nonequilibrium Green's function approach. Finally, to demonstrate the advantage of our approach, we deal with the nonlinear spin-boson model to evaluate heat current up to fourth-order and find signatures of cotunnelling process.

  20. Improved Dyson series expansion for steady-state quantum transport beyond the weak coupling limit: Divergences and resolution

    SciTech Connect

    Thingna, Juzar; Zhou, Hangbo; Wang, Jian-Sheng

    2014-11-21

    We present a general theory to calculate the steady-state heat and electronic currents for nonlinear systems using a perturbative expansion in the system-bath coupling. We explicitly demonstrate that using the truncated Dyson-series leads to divergences in the steady-state limit, thus making it impossible to be used for actual applications. In order to resolve the divergences, we propose a unique choice of initial condition for the reduced density matrix, which removes the divergences at each order. Our approach not only allows us to use the truncated Dyson-series, with a reasonable choice of initial condition, but also gives the expected result that the steady-state solutions should be independent of initial preparations. Using our improved Dyson series we evaluate the heat and electronic currents up to fourth-order in system-bath coupling, a considerable improvement over the standard quantum master equation techniques. We then numerically corroborate our theory for archetypal settings of linear systems using the exact nonequilibrium Green's function approach. Finally, to demonstrate the advantage of our approach, we deal with the nonlinear spin-boson model to evaluate heat current up to fourth-order and find signatures of cotunnelling process.

  1. Direct left ventricular endocardial pacing: an alternative when traditional resynchronization via coronary sinus is not feasible or effective.

    PubMed

    Moriña-Vázquez, Pablo; Roa-Garrido, Jessica; Fernández-Gómez, Juan M; Venegas-Gamero, José; Pichardo, Rafael B; Carranza, Manuel H

    2013-06-01

    Biventricular pacing through the coronary sinus (CS) is effective for the treatment of patients with heart failure and left bundle-branch block. However, this approach is not always feasible. Although surgical epicardial lead implantation is an alternative, the technique may be deleterious in some patients. Thus, direct left ventricular (LV) endocardial pacing under local anesthesia may be an option. We describe our technique and analyze the results of direct LV endocardial pacing. Fourteen patients with failed resynchronization via CS (April 2006-September 2011) were selected. Using a femoral approach, we performed transseptal puncture and LV mapping, then fixed the active lead where the longest electrical delay was observed; the generator was placed in the anterior thigh. For resynchronization, eight patients with a device previously implanted through the upper veins received a single-chamber generator that was set to the VVT mode to sense the subclavian pacing spike. Six patients received a complete femoral resynchronization system with either a defibrillator or pacemaker. Patients were followed for 6-54 months. The LV lead was successfully implanted in all cases. Two patients experienced excessive bleeding and two died during follow-up. All except one improved at least one New York Heart Association class and experienced improved left ventricle ejection fraction. One patient with recurrent episodes of ventricular fibrillation was asymptomatic. Direct LV endocardial pacing is safe and may be a less risky, more efficient alternative than surgical epicardial lead implantation for resynchronization via CS. ©2013, The Authors. Journal compilation ©2013 Wiley Periodicals, Inc.

  2. Thermal reliability and performance improvement of close-coupled catalytic converter

    SciTech Connect

    Hijikata, Toshihiko; Kurachi, Hiroshi; Katsube, Fumio; Honacker, H. van

    1996-09-01

    This paper proposes a high temperature catalytic converter design using a ceramic substrate and intumescent matting. It also describes the improvement of converter performance using an advanced thin wall ceramic substrate. Due to future tightening of emission regulations and improvement of fuel economy, higher exhaust gas temperatures are suggested. Therefore, reduction of thermal reliability of an intumescent mat will be a concern because the catalytic converter will be exposed to high temperatures. For this reason, a new design converter has been developed using a dual cone structure for both the inlet and outlet cones. This minimizes heat conduction through the cone and decreases the temperature affecting the mat area. This design converter, without the use of a heat-shield, reduces the converter surface temperature to 441 C despite a catalyst bed temperature of 1,050 C. The long term durability of the converter is demonstrated by the hot vibration test. Since the new design converter does not need a heat-shield, the catalyst diameter can be enlarged by the width of the air gap used in the current design converter. By using an advanced thin wall ceramic substrate, such as 0.11 mm/620 kcpsm (4 mil/400 cpsi), it is possible to improve emission performance and pressure drop compared with the conventional 0.16 mm/620 kcpsm (6 mil/400 cpsi) ceramic substrate.

  3. G protein–coupled receptor 21 deletion improves insulin sensitivity in diet-induced obese mice

    PubMed Central

    Osborn, Olivia; Oh, Da Young; McNelis, Joanne; Sanchez-Alavez, Manuel; Talukdar, Saswata; Lu, Min; Li, PingPing; Thiede, Lucinda; Morinaga, Hidetaka; Kim, Jane J.; Heinrichsdorff, Jan; Nalbandian, Sarah; Ofrecio, Jachelle M.; Scadeng, Miriam; Schenk, Simon; Hadcock, John; Bartfai, Tamas; Olefsky, Jerrold M.

    2012-01-01

    Obesity-induced inflammation is a key component of systemic insulin resistance, which is a hallmark of type 2 diabetes. A major driver of this inflammation/insulin resistance syndrome is the accumulation of proinflammatory macrophages in adipose tissue and liver. We found that the orphan GPCR Gpr21 was highly expressed in the hypothalamus and macrophages of mice and that whole-body KO of this receptor led to a robust improvement in glucose tolerance and systemic insulin sensitivity and a modest lean phenotype. The improvement in insulin sensitivity in the high-fat diet–fed (HFD-fed) Gpr21 KO mouse was traced to a marked reduction in tissue inflammation caused by decreased chemotaxis of Gpr21 KO macrophages into adipose tissue and liver. Furthermore, mice lacking macrophage expression of Gpr21 were protected from HFD-induced inflammation and displayed improved insulin sensitivity. Results of in vitro chemotaxis studies in human monocytes suggested that the defect in chemotaxis observed ex vivo and in vivo in mice is also translatable to humans. Cumulatively, our data indicate that GPR21 has a critical function in coordinating macrophage proinflammatory activity in the context of obesity-induced insulin resistance. PMID:22653059

  4. Using a Coupled Lake Model with WRF to Improve High-Resolution Regional Climate Simulations

    NASA Astrophysics Data System (ADS)

    Mallard, M.; Bullock, R.; Nolte, C. G.; Alapaty, K.; Otte, T.; Gula, J.

    2012-12-01

    Lakes can play a significant role in regional climate by modifying air masses through fluxes of heat and moisture and by modulating inland extremes in temperature. Representing these effects becomes more important as regional climate modeling efforts employ finer grid spacing in order to simulate smaller scales. The Weather Research and Forecasting (WRF) model does not simulate lakes explicitly. Instead, lake points are treated as ocean points, with sea surface temperatures (SSTs) interpolated from the nearest neighboring ocean point in the driving coarse-scale fields. This can result in substantial errors for inland lakes such as the Great Lakes. Although prescribed lake surface temperatures (LSTs) can be used for retrospective modeling applications, this may not be desirable for applications involving downscaling future climate scenarios from a global climate model (GCM). In such downscaling simulations, lakes that impact the regional climate in the area of interest may not be resolved by the coarser global input fields. Explicitly simulating the LST would allow WRF to better represent interannual variability in regions significantly affected by lakes, and the influence of such variability on temperature and precipitation patterns. Therefore, coupling a lake model to WRF may lead to more reliable assessments of the impacts of extreme events on human health and the environment. We employ a version of WRF coupled to the Freshwater Lake model, FLake (Gula and Peltier 2012). FLake is a 1D bulk lake model which provides updated LSTs and ice coverage throughout the integration. This two-layer model uses a temperature-depth profile which includes a homogeneous mixed layer at the surface and a thermocline below. The shape of the thermocline is assumed, based on past theoretical and observational studies. Therefore, additional variables required for FLake to run are minimal, and it does not require tuning for individual lakes. These characteristics are advantageous for a

  5. Improved Methodical Approach for Quantitative BRET Analysis of G Protein Coupled Receptor Dimerization

    PubMed Central

    Szalai, Bence; Hoffmann, Péter; Prokop, Susanne; Erdélyi, László; Várnai, Péter; Hunyady, László

    2014-01-01

    G Protein Coupled Receptors (GPCR) can form dimers or higher ordered oligomers, the process of which can remarkably influence the physiological and pharmacological function of these receptors. Quantitative Bioluminescence Resonance Energy Transfer (qBRET) measurements are the gold standards to prove the direct physical interaction between the protomers of presumed GPCR dimers. For the correct interpretation of these experiments, the expression of the energy donor Renilla luciferase labeled receptor has to be maintained constant, which is hard to achieve in expression systems. To analyze the effects of non-constant donor expression on qBRET curves, we performed Monte Carlo simulations. Our results show that the decrease of donor expression can lead to saturation qBRET curves even if the interaction between donor and acceptor labeled receptors is non-specific leading to false interpretation of the dimerization state. We suggest here a new approach to the analysis of qBRET data, when the BRET ratio is plotted as a function of the acceptor labeled receptor expression at various donor receptor expression levels. With this method, we were able to distinguish between dimerization and non-specific interaction when the results of classical qBRET experiments were ambiguous. The simulation results were confirmed experimentally using rapamycin inducible heterodimerization system. We used this new method to investigate the dimerization of various GPCRs, and our data have confirmed the homodimerization of V2 vasopressin and CaSR calcium sensing receptors, whereas our data argue against the heterodimerization of these receptors with other studied GPCRs, including type I and II angiotensin, β2 adrenergic and CB1 cannabinoid receptors. PMID:25329164

  6. Fast Paced, Low Cost Projects at MSFC

    NASA Technical Reports Server (NTRS)

    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

  7. Testing cloud microphysics parameterizations in NCAR CAM5 with ISDAC and M-PACE observations

    SciTech Connect

    Liu X.; Lin W.; Xie, S.; Boyle, J.; Klein, S. A.; Shi, X.; Wang, Z.; Ghan, S. J.; Earle, M.; Liu, P. S. K.; Zelenyuk, A.

    2011-12-24

    Arctic clouds simulated by the National Center for Atmospheric Research (NCAR) Community Atmospheric Model version 5 (CAM5) are evaluated with observations from the U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Indirect and Semi-Direct Aerosol Campaign (ISDAC) and Mixed-Phase Arctic Cloud Experiment (M-PACE), which were conducted at its North Slope of Alaska site in April 2008 and October 2004, respectively. Model forecasts for the Arctic spring and fall seasons performed under the Cloud-Associated Parameterizations Testbed framework generally reproduce the spatial distributions of cloud fraction for single-layer boundary-layer mixed-phase stratocumulus and multilayer or deep frontal clouds. However, for low-level stratocumulus, the model significantly underestimates the observed cloud liquid water content in both seasons. As a result, CAM5 significantly underestimates the surface downward longwave radiative fluxes by 20-40 W m{sup -2}. Introducing a new ice nucleation parameterization slightly improves the model performance for low-level mixed-phase clouds by increasing cloud liquid water content through the reduction of the conversion rate from cloud liquid to ice by the Wegener-Bergeron-Findeisen process. The CAM5 single-column model testing shows that changing the instantaneous freezing temperature of rain to form snow from -5 C to -40 C causes a large increase in modeled cloud liquid water content through the slowing down of cloud liquid and rain-related processes (e.g., autoconversion of cloud liquid to rain). The underestimation of aerosol concentrations in CAM5 in the Arctic also plays an important role in the low bias of cloud liquid water in the single-layer mixed-phase clouds. In addition, numerical issues related to the coupling of model physics and time stepping in CAM5 are responsible for the model biases and will be explored in future studies.

  8. A Unified Air-Sea Interface for Fully Coupled Atmosphere-Wave-Ocean Models for Improving Intensity Prediction of Tropical Cyclones

    DTIC Science & Technology

    2012-09-30

    A Unified Air-Sea Interface for Fully Coupled Atmosphere-Wave-Ocean Models for Improving Intensity Prediction of Tropical Cyclones Annual Progress...interaction and its impact on rapid intensity changes in tropical cyclones (TCs), and to develop a physically based and computationally efficient...Coupled Atmosphere-Wave-Ocean Models for Improving Intensity Prediction of Tropical Cyclones 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT

  9. Advanced Micro Grid Energy Management Coupled with Integrated Volt/VAR Control for Improved Energy Efficiency, Energy Security, and Power Quality at DoD Installations

    DTIC Science & Technology

    2016-10-28

    EW-201147) Advanced Micro-Grid Energy Management Coupled with Integrated Volt/VAR Control for Improved Energy Efficiency, Energy Security, and...12-C-0002 5b. GRANT NUMBER Advanced Micro-Grid Energy Management Coupled with Integrated Volt/VAR Control for Improved Energy Efficiency, Energy ...AGENCY NAME(S) AND ADDRESS(ES) 10. SPONSOR/MONITOR’S ACRONYM(S) ESTCP ESTCP Energy & Water Program 11. SPONSOR/MONITOR’S REPORT 4800 Mark Center Drive

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

    PubMed

    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

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

    PubMed Central

    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. AV delay optimization and management of DDD paced patients with dilated cardiomyopathy.

    PubMed

    Guardigli, G; Ansani, L; Percoco, G F; Toselli, T; Spisani, P; Braggion, G; Antonioli, G E

    1994-11-01

    Ten DDD paced patients, suffering from dilated cardiomyopathy in the NYHA functional classes III or IV were studied by means of Doppler echocardiography at different programmed values of atrioventricular (AV) delay (200, 150, 120, 100, and 80 msec). The following variables were evaluated: LV diameter, ejection fraction, mitral and aortic flow velocity integrals, and stroke volume. During VDD pacing, a resting AV delay associated with the best diastolic filling and systolic function was identified and programmed individually. Shortening of the AV delay to about 100 msec was associated with a gradual and progressive improvement. Further decrease caused an impairment of systolic function. The patients were clinically and hemodynamically reevaluated after 2 months of follow-up. A reduction of NYHA class and an improvement of LV function were consistently found. The reported data suggest that programming of an optimal AV delay may improve myocardial function in DDD paced patients with congestive heart failure. This result may be the consequence of an optimization of left ventricular filling and a better use of the Frank-Starling law.

  13. Improved light olefin yield from methyl bromide coupling over modified SAPO-34 molecular sieves.

    PubMed

    Zhang, Aihua; Sun, Shouli; Komon, Zachary J A; Osterwalder, Neil; Gadewar, Sagar; Stoimenov, Peter; Auerbach, Daniel J; Stucky, Galen D; McFarland, Eric W

    2011-02-21

    As an alternative to the partial oxidation of methane to synthesis gas followed by methanol synthesis and the subsequent generation of olefins, we have studied the production of light olefins (ethylene and propylene) from the reaction of methyl bromide over various modified microporous silico-aluminophosphate molecular-sieve catalysts with an emphasis on SAPO-34. Some comparisons of methyl halides and methanol as reaction intermediates in their conversion to olefins are presented. Increasing the ratio of Si/Al and incorporation of Co into the catalyst framework improved the methyl bromide yield of light olefins over that obtained using standard SAPO-34.

  14. Optimization of Printed Antennas Using Genetic Algorithm Coupled with Improved Cavity Model

    NASA Astrophysics Data System (ADS)

    Sathi, Vahid; Ehteshami, Nasrin; Ghobadi, C.

    2012-06-01

    An accurate electromagnetic optimization tool for designing rectangular and circular microstrip antennas is proposed. This optimization method is based on the improved cavity model analysis in conjunction with the well-known genetic algorithm, which is employed to optimize the dimensions and feed point location of rectangular and circular microstrip antennas. Results obtained by this technique agree quite well with the measured data and the data obtained by the FEM based software HFSS by ANSOFT. This technique can be fruitfully used in microwave CAD applications.

  15. Left ventricular dysfunction is related to the presence and extent of a septal flash in patients with right ventricular pacing.

    PubMed

    Sarvari, Sebastian Imre; Sitges, Marta; Sanz, Maria; Tolosana Viu, Jose Maria; Edvardsen, Thor; Stokke, Thomas Muri; Mont, Lluis; Bijnens, Bart

    2017-02-01

    Septal flash (SF), a marker of left ventricular (LV) dyssynchrony in the presence of a left bundle branch block (LBBB), has been shown to predict improved ventricular function and outcome when corrected with cardiac resynchronization therapy. We hypothesized that a SF is present in patients receiving right ventricular (RV) pacing and its presence and extent could predict the development of LV dysfunction and remodelling. Seventy-four consecutive patients receiving conventional RV pacing (>6 months, >85% paced) were studied with two-dimensional (2D) echocardiography. Indications for pacing were sinus-node dysfunction and atrioventricular conduction disorders. The presence of a SF was determined on stepwise advanced 2D echocardiographic views and confirmed using greyscale M-mode. Septal flash excursion was quantified by the amplitude of the early inward motion, measured from QRS onset to maximal inward motion. Fifty-seven (of 74; 77%) patients receiving RV pacing had a detectable SF. Patients with a SF had lower LV ejection fraction (EF) (52 ± 10 vs. 60 ± 4%, P < 0.001) and greater indexed end-systolic volume (33 ± 16 vs. 23 ± 5 mL/m2, P < 0.001). Receiver operating characteristic analysis demonstrated that a SF of 3.5 mm was the optimal cut-off value (area under the curve = 0.95) to identify reduced LV function (EF < 50%) with a sensitivity of 91% and a specificity of 90%. A SF was present in a majority of patients receiving conventional RV pacing and its magnitude was related to LV dysfunction and adverse remodelling. Given the similarities observed in LBBB and pacemaker-induced dyssynchrony, SF magnitude might be a predictor for the development of LV dysfunction and adverse remodelling in patients receiving conventional RV pacing.

  16. Critical role of inhomogeneities in pacing termination of cardiac reentry

    NASA Astrophysics Data System (ADS)

    Sinha, Sitabhra; Stein, Kenneth M.; Christini, David J.

    2002-09-01

    Reentry around nonconducting ventricular scar tissue, a cause of lethal arrhythmias, is typically treated by rapid electrical stimulation from an implantable cardioverter defibrillator. However, the dynamical mechanisms of termination (success and failure) are poorly understood. To elucidate such mechanisms, we study the dynamics of pacing in one- and two-dimensional models of anatomical reentry. In a crucial realistic difference from previous studies of such systems, we have placed the pacing site away from the reentry circuit. Our model-independent results suggest that with such off-circuit pacing, the existence of inhomogeneity in the reentry circuit is essential for successful termination of tachycardia under certain conditions. Considering the critical role of such inhomogeneities may lead to more effective pacing algorithms.

  17. Critical role of inhomogeneities in pacing termination of cardiac reentry.

    PubMed

    Sinha, Sitabhra; Stein, Kenneth M.; Christini, David J.

    2002-09-01

    Reentry around nonconducting ventricular scar tissue, a cause of lethal arrhythmias, is typically treated by rapid electrical stimulation from an implantable cardioverter defibrillator. However, the dynamical mechanisms of termination (success and failure) are poorly understood. To elucidate such mechanisms, we study the dynamics of pacing in one- and two-dimensional models of anatomical reentry. In a crucial realistic difference from previous studies of such systems, we have placed the pacing site away from the reentry circuit. Our model-independent results suggest that with such off-circuit pacing, the existence of inhomogeneity in the reentry circuit is essential for successful termination of tachycardia under certain conditions. Considering the critical role of such inhomogeneities may lead to more effective pacing algorithms. (c) 2002 American Institute of Physics.

  18. A Flexible Self-Paced Course in Process Control.

    ERIC Educational Resources Information Center

    King, Franklin G.

    1979-01-01

    Describes an undergraduate chemical engineering course which has been taught by a self-paced instructional method at Howard University, Washington, D.C. The instructional method, course description, and students' grades are also discussed. (HM)

  19. Using Individualized Self-Paced Instruction When Teaching Elementary Accounting.

    ERIC Educational Resources Information Center

    Carr, Glenna D.; Echord, Barbara S.

    1981-01-01

    A study was conducted to see if junior college and high school students do as well in learning elementary accounting through an individualized self-paced approach as through the traditional teacher-led method. (CT)

  20. 42 CFR 460.180 - Medicare payment to PACE organizations.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... SERVICES (CONTINUED) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) PROGRAMS OF ALL-INCLUSIVE CARE... risk adjustment model. (5) CMS may adjust the monthly capitation amount to take into account...

  1. The PACES Summer Science Trek: A Pre-College Science

    NASA Technical Reports Server (NTRS)

    Smith, Michelle B.

    1997-01-01

    The University of Texas at El Paso (UTEP) received five-year funding to form the Pan American Center for Earth and Environmental Studies (PACES) in July 1995. PACES has as its goals to conduct research contributing to NASA's Mission to Planet Earth and to develop skilled scientists and engineers. PACES seeks to gain a more comprehensive understanding of geological, ecological and environmental processes and changes taking place in the southwestern United States and northern Mexico region. The PACES center has collaborative ties with two NASA field center (Goddard Space Flight Center and Ames Research Center) and the Jet Propulsion Laboratory. The original proposal contained no provision for outreach programs. However, at a meeting in the fall of 1995, Dan Goldin, NASA Administrator, issued the challenge that in order to accomplish NASA's goals to educate more of the citizenry in science and engineering, the Centers should take a broader perspective aimed at younger children.

  2. A Self-Paced Laboratory Section in Physiological Psychology.

    ERIC Educational Resources Information Center

    Jacobs, Keith W.

    1980-01-01

    Describes a one semester-hour self-paced laboratory section accompanying a physiological psychology course. Points out five disadvantages and three advantages, including more time and advance planning needed, active involvement of students, and increased learning and retention. (CK)

  3. The Efficacy of Self-Paced Study in Multitrial Learning

    ERIC Educational Resources Information Center

    de Jonge, Mario; Tabbers, Huib K.; Pecher, Diane; Jang, Yoonhee; Zeelenberg, René

    2015-01-01

    In 2 experiments we investigated the efficacy of self-paced study in multitrial learning. In Experiment 1, native speakers of English studied lists of Dutch-English word pairs under 1 of 4 imposed fixed presentation rate conditions (24 × 1 s, 12 × 2 s, 6 × 4 s, or 3 × 8 s) and a self-paced study condition. Total study time per list was equated for…

  4. The Efficacy of Self-Paced Study in Multitrial Learning

    ERIC Educational Resources Information Center

    de Jonge, Mario; Tabbers, Huib K.; Pecher, Diane; Jang, Yoonhee; Zeelenberg, René

    2015-01-01

    In 2 experiments we investigated the efficacy of self-paced study in multitrial learning. In Experiment 1, native speakers of English studied lists of Dutch-English word pairs under 1 of 4 imposed fixed presentation rate conditions (24 × 1 s, 12 × 2 s, 6 × 4 s, or 3 × 8 s) and a self-paced study condition. Total study time per list was equated for…

  5. Nanocellulose-based Translucent Diffuser for Optoelectronic Device Applications with Dramatic Improvement of Light Coupling.

    PubMed

    Wu, Wei; Tassi, Nancy G; Zhu, Hongli; Fang, Zhiqiang; Hu, Liangbing

    2015-12-09

    Nanocellulose is a biogenerated and biorenewable organic material. Using a process based on 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO)/NaClO/NaBr system, a highly translucent and light-diffusive film consisting of many layers of nanocellulose fibers and wood pulp microfibers was made. The film demonstrates a combination of large optical transmittance of ∼90% and tunable diffuse transmission of up to ∼78% across the visible and near-infrared spectra. The detailed characterizations of the film indicate the combination of high optical transmittance and haze is due to the film's large packing density and microstructured surface. The superior optical properties make the film a translucent light diffuser and applicable for improving the efficiencies of optoelectronic devices such as thin-film silicon solar cells and organic light-emitting devices.

  6. Haemodynamic consequences of targeted single- and dual-site right ventricular pacing in adults with congenital heart disease undergoing surgical pulmonary valve replacement.

    PubMed

    Plymen, Carla M; Finlay, Malcolm; Tsang, Victor; O'leary, Justin; Picaut, Nathalie; Cullen, Shay; Walker, Fiona; Deanfield, John E; Hsia, T Y; Bolger, Aidan P; Lambiase, Pier D

    2015-02-01

    The purpose of this study was to create an epicardial electroanatomic map of the right ventricle (RV) and then apply post-operative-targeted single- and dual-site RV temporary pacing with measurement of haemodynamic parameters. Cardiac resynchronization therapy is an established treatment for symptomatic left ventricular (LV) dysfunction. In congenital heart disease, RV dysfunction is a common cause of morbidity-little is known regarding the potential benefits of CRT in this setting. Sixteen adults (age = 32 ± 8 years; 6 M, 10 F) with right bundle branch block (RBBB) and repaired tetralogy of Fallot (n = 8) or corrected congenital pulmonary stenosis (n = 8) undergoing surgical pulmonary valve replacement (PVR) for pulmonary regurgitation underwent epicardial RV mapping and haemodynamic assessment of random pacing configurations including the site of latest RV activation. The pre-operative pulmonary regurgitant fraction was 49 ± 10%; mean LV end-diastolic volume (EDV) 85 ± 19 mL/min/m(2) and RVEDV 183 ± 89 mL/min/m(2) on cardiac magnetic resonance imaging. The mean pre-operative QRS duration is 136 ± 26 ms. The commonest site of latest activation was the RV free wall and DDD pacing here alone or combined with RV apical pacing resulted in significant increases in cardiac output (CO) vs. AAI pacing (P < 0.01 all measures). DDDRV alternative site pacing significantly improved CO by 16% vs. AAI (P = 0.018), and 8.5% vs. DDDRV apical pacing (P = 0.02). Single-site RV pacing targeted to the region of latest activation in patients with RBBB undergoing PVR induces acute improvements in haemodynamics and supports the concept of 'RV CRT'. Targeted pacing in such patients has therapeutic potential both post-operatively and in the long term. © The Author 2014. Published by Oxford University Press on behalf of the European Society of Cardiology.

  7. Mutual coupling of hydrologic and hydrodynamic models - a viable approach for improved large-scale inundation estimates?

    NASA Astrophysics Data System (ADS)

    Hoch, Jannis; Winsemius, Hessel; van Beek, Ludovicus; Haag, Arjen; Bierkens, Marc

    2016-04-01

    Due to their increasing occurrence rate and associated economic costs, fluvial floods are large-scale and cross-border phenomena that need to be well understood. Sound information about temporal and spatial variations of flood hazard is essential for adequate flood risk management and climate change adaption measures. While progress has been made in assessments of flood hazard and risk on the global scale, studies to date have made compromises between spatial resolution on the one hand and local detail that influences their temporal characteristics (rate of rise, duration) on the other. Moreover, global models cannot realistically model flood wave propagation due to a lack of detail in channel and floodplain geometry, and the representation of hydrologic processes influencing the surface water balance such as open water evaporation from inundated water and re-infiltration of water in river banks. To overcome these restrictions and to obtain a better understanding of flood propagation including its spatio-temporal variations at the large scale, yet at a sufficiently high resolution, the present study aims to develop a large-scale modeling tool by coupling the global hydrologic model PCR-GLOBWB and the recently developed hydrodynamic model DELFT3D-FM. The first computes surface water volumes which are routed by the latter, solving the full Saint-Venant equations. With DELFT3D FM being capable of representing the model domain as a flexible mesh, model accuracy is only improved at relevant locations (river and adjacent floodplain) and the computation time is not unnecessarily increased. This efficiency is very advantageous for large-scale modelling approaches. The model domain is thereby schematized by 2D floodplains, being derived from global data sets (HydroSHEDS and G3WBM, respectively). Since a previous study with 1way-coupling showed good model performance (J.M. Hoch et al., in prep.), this approach was extended to 2way-coupling to fully represent evaporation

  8. Feasibility of Leadless Cardiac Pacing Using Injectable Magnetic Microparticles

    PubMed Central

    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

  9. Impedance to transesophageal atrial pacing: significance regarding power sources.

    PubMed

    Kerr, C R; Chung, D C; Wickham, G; Jameson, M; Vorderbrugge, S

    1989-06-01

    Transesophageal stimulation is an expeditious method of atrial pacing. Using pulse widths of 10 msec results in reduction of current requirement to values that are usually less than 15 mA. An unknown variable in transesophageal atrial pacing has been impedance. In this study, we investigated the impedance to transesophageal atrial pacing in ten patients using a stimulator with a 63 V power source capable of delivering constant current to 20 mA against an impedance of 2,000 ohms. A bipolar electrode was used to deliver stimuli with a current of 15 mA. Voltage across a known resistance and current were measured on an oscilloscope and the impedance was calculated. Pacing thresholds were also performed and ranged from 6.2 to 16.5 mA (mean 9.4 +/- 2.9 mA, SD). Impedance varied between 720 and 2,670 ohms (mean 1,750 +/- 540 ohms). The stimulator used to measure impedance in man and two other commercially available stimulators were bench tested against known resistances of 500 to 2,000 ohms. The other stimulators with power sources of 12.5 and 15 V had attenuation of the delivered current at resistances of between 1,000 and 2,000 ohms. Thus, this study has demonstrated that transesophageal atrial pacing incurs impedances two to five times greater than incurred with intracardiac pacing leads. Therefore stimulators with high power sources are required to deliver the programmed current against these impedances.

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

    SciTech Connect

    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.

  11. Improving the Understanding and Model Representation of Processes that Couple Shallow Clouds, Aerosols, and Land-Ecosystems

    NASA Astrophysics Data System (ADS)

    Fast, J. D.; Berg, L. K.; Schmid, B.; Alexander, M. L. L.; Bell, D.; D'Ambro, E.; Hubbe, J. M.; Liu, J.; Mei, F.; Pekour, M. S.; Pinterich, T.; Schobesberger, S.; Shilling, J.; Springston, S. R.; Thornton, J. A.; Tomlinson, J. M.; Wang, J.; Zelenyuk, A.

    2016-12-01

    Cumulus convection is an important component in the atmospheric radiation budget and hydrologic cycle over the southern Great Plains and over many regions of the world, particularly during the summertime growing season when intense turbulence induced by surface radiation couples the land surface to clouds. Current convective cloud parameterizations, however, contain uncertainties resulting from insufficient coincident data that couples cloud macrophysical and microphysical properties to inhomogeneity in surface layer, boundary layer, and aerosol properties. We describe the measurement strategy and preliminary findings from the recent Holistic Interactions of Shallow Clouds, Aerosols, and Land-Ecosystems (HI-SCALE) campaign conducted in May and September of 2016 in the vicinity of the DOE's Atmospheric Radiation Measurement (ARM) Southern Great Plains (SGP) site located in Oklahoma. The goal of the HI-SCALE campaign is to provide a detailed set of aircraft and surface measurements needed to obtain a more complete understanding and improved parameterizations of the lifecycle of shallow clouds. The sampling is done in two periods, one in the spring and the other in the late summer to take advantage of variations in the "greenness" for various types of vegetation, new particle formation, anthropogenic enhancement of biogenic secondary organic aerosol (SOA), and other aerosol properties. The aircraft measurements will be coupled with extensive routine ARM SGP measurements as well as Large Eddy Simulation (LES), cloud resolving, and cloud-system resolving models. Through these integrated analyses and modeling studies, the affects of inhomogeneity in land use, vegetation, soil moisture, convective eddies, and aerosol properties on the evolution of shallow clouds will be determined, including the feedbacks of cloud radiative effects.

  12. Application synergies between the NASA Pre- Aerosol Cloud and ocean Ecosystem (PACE) and Hyperspectral Infrared Imager (HyspIRI) missions

    NASA Astrophysics Data System (ADS)

    Lee, C. M.; Omar, A. H.; Hook, S. J.; Tzortziou, M.; Luvall, J. C.; Turner, W. W.

    2016-02-01

    Observations from the Pre-Aerosol Cloud and ocean Ecosystem (PACE) and Hyperspectral InfraRed Imager (HyspIRI) satellite missions are highly complementary and have the potential to significantly advance understanding of various science and applications challenges in the ocean sciences and water quality communities. Scheduled for launch in the 2022 timeframe, PACE is designed to make climate-quality global measurements essential for understanding ocean biology, biogeochemistry and ecology, and determining the role of the ocean in global biogeochemical cycling and ocean ecology, and how it affects and is affected by climate change. PACE will provide high signal-to-noise, hyperspectral observations over an extended spectral range (UV to SWIR) and will have global coverage every 1-2 days, at approximately 1 km spatial resolution; furthermore, PACE is currently designed to include a polarimeter, which will vastly improve atmospheric correction algorithms over water bodies. The PACE mission will enable advances in applications across a range of areas, including oceans, climate, water resources, ecological forecasting, disasters, human health and air quality. HyspIRI, with contiguous measurements in VSWIR, and multispectral measurements in TIR, will be able to provide detailed spectral observations and higher spatial resolution (30 to 60-m) over aquatic systems, but at a temporal resolution that is approximately 5-16 days. HyspIRI would enable improved, detailed studies of aquatic ecosystems, including benthic communities, algal blooms, coral reefs, and wetland species distribution as well as studies of water quality indicators or pollutants such as oil spills, suspended sediment, and colored dissolved organic matter. Together, PACE and HyspIRI will be able to address numerous applications and science priorities, including improving and extending climate data records, and studies of inland, coastal and ocean environments.

  13. Diaphragm Pacing without Tracheostomy in Congenital Central Hypoventilation Syndrome Patients.

    PubMed

    Diep, Bonnie; Wang, Annie; Kun, Sheila; McComb, J Gordon; Shaul, Donald B; Shin, Cathy E; Keens, Thomas G; Perez, Iris A

    2015-01-01

    Congenital central hypoventilation syndrome (CCHS) is a rare disorder affecting central control of breathing. Thus, patients require lifelong assisted ventilation. Diaphragm pacing (DP) may permit decannulation in those who are ventilator dependent only during sleep. The purpose of this study is to determine if patients with CCHS can be successfully ventilated by DP without tracheostomy. We reviewed the records of 18 CCHS patients (mean age 19.5 ± 10.1 years; 44% female) who were ventilated by DP only during sleep. Prior to diaphragm pacer implantation surgery, 14 CCHS patients had been using home portable positive pressure ventilation (PPV) via tracheostomy, 1 had been on PPV via endotracheal tube, and 3 had been using noninvasive PPV (NPPV). Of the patients with tracheostomy prior to DP (n = 15), 11 (73%) were decannulated and ventilated successfully by DP without tracheostomy. Of all the patients reviewed (n = 18), 13 (72%) were successfully ventilated by DP without tracheostomy. Obesity prevented successful DP without tracheostomy in 1 patient, and upper airway obstruction prevented success in another patient. Snoring and/or obstructive apneas were present in some patients, but they were improved by diaphragm pacer changes, adenotonsillectomy, and/or use of nasal steroids. DP without tracheostomy can be successfully achieved in patients with CCHS. Snoring and obstructive apneas, when present, can be managed by diaphragm pacer changes and medical therapies. Obesity can pose a challenge to successful DP. © 2015 S. Karger AG, Basel.

  14. The Pace of Perceivable Extreme Climate Change

    NASA Astrophysics Data System (ADS)

    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.

  15. Memory effects, transient growth, and wave breakup in a model of paced atrium

    NASA Astrophysics Data System (ADS)

    Garzón, Alejandro; Grigoriev, Roman O.

    2017-09-01

    The mechanisms underlying cardiac fibrillation have been investigated for over a century, but we are still finding surprising results that change our view of this phenomenon. The present study focuses on the transition from normal rhythm to spiral wave chaos associated with a gradual increase in the pacing rate. While some of our findings are consistent with existing experimental, numerical, and theoretical studies of this problem, one result appears to contradict the accepted picture. Specifically we show that, in a two-dimensional model of paced homogeneous atrial tissue, transition from discordant alternans to conduction block, wave breakup, reentry, and spiral wave chaos is associated with the transient growth of finite amplitude disturbances rather than a conventional instability. It is mathematically very similar to subcritical, or bypass, transition from laminar fluid flow to turbulence, which allows many of the tools developed in the context of fluid turbulence to be used for improving our understanding of cardiac arrhythmias.

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

    PubMed Central

    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. Design, synthesis, and structure-activity relationship studies of a potent PACE4 inhibitor.

    PubMed

    Kwiatkowska, Anna; Couture, Frédéric; Levesque, Christine; Ly, Kévin; Desjardins, Roxane; Beauchemin, Sophie; Prahl, Adam; Lammek, Bernard; Neugebauer, Witold; Dory, Yves L; Day, Robert

    2014-01-09

    PACE4 plays an important role in the progression of prostate cancer and is an attractive target for the development of novel inhibitor-based tumor therapies. We previously reported the design and synthesis of a novel, potent, and relatively selective PACE4 inhibitor known as a Multi-Leu (ML) peptide. In the present work, we examined the ML peptide through detailed structure-activity relationship studies. A variety of ML-peptide analogues modified at the P8-P5 positions with leucine isomers (Nle, DLeu, and DNle) or substituted at the P1 position with arginine mimetics were tested for their inhibitory activity, specificity, stability, and antiproliferative effect. By incorporating d isomers at the P8 position or a decarboxylated arginine mimetic, we obtained analogues with an improved stability profile and excellent antiproliferative properties. The DLeu or DNle residue also has improved specificity toward PACE4, whereas specificity was reduced for a peptide modified with the arginine mimetic, such as 4-amidinobenzylamide.

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

    PubMed

    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.

  19. Ecosystem function in waste stabilisation ponds: Improving water quality through a better understanding of biophysical coupling

    NASA Astrophysics Data System (ADS)

    Ghadouani, Anas; Reichwaldt, Elke S.; Coggins, Liah X.; Ivey, Gregory N.; Ghisalberti, Marco; Zhou, Wenxu; Laurion, Isabelle; Chua, Andrew

    2014-05-01

    Wastewater stabilisation ponds (WSPs) are highly productive systems designed to treat wastewater using only natural biological and chemical processes. Phytoplankton, microbial communities and hydraulics play important roles for ecosystem functionality of these pond systems. Although WSPs have been used for many decades, they are still considered as 'black box' systems as very little is known about the fundamental ecological processes which occur within them. However, a better understanding of how these highly productive ecosystems function is particularly important for hydrological processes, as treated wastewater is commonly discharged into streams, rivers, and oceans, and subject to strict water quality guidelines. WSPs are known to operate at different levels of efficiency, and treatment efficiency of WSPs is dependent on physical (flow characteristics and sludge accumulation and distribution) and biological (microbial and phytoplankton communities) characteristics. Thus, it is important to gain a better understanding of the role and influence of pond hydraulics and vital microbial communities on pond performance and WSP functional stability. The main aim of this study is to investigate the processes leading to differences in treatment performance of WSPs. This study uses a novel and innovative approach to understand these factors by combining flow cytometry and metabolomics to investigate various biochemical characteristics, including the metabolite composition and microbial community within WSPs. The results of these analyses will then be combined with results from the characterisation of pond hydrodynamics and hydraulic performance, which will be performed using advanced hydrodynamic modelling and advanced sludge profiling technology. By understanding how hydrodynamic and biological processes influence each other and ecosystem function and stability in WSPs, we will be able to propose ways to improve the quality of the treatment using natural processes, with

  20. Coupling xylitol dehydrogenase with NADH oxidase improves l-xylulose production in Escherichia coli culture.

    PubMed

    Han, Qi; Eiteman, Mark A

    2017-11-01

    Escherichia coli expressing NAD-dependent xylitol-4-dehydrogenase (XDH) from Pantoea ananatis and growing on glucose or glycerol converts xylitol to the rare sugar l-xylulose. Although blocking potential l-xylulose consumption (l-xylulosekinase, lyxK) or co-expression of the glycerol facilitator (glpF) did not significantly affect l-xylulose formation, co-expressing XDH with water-forming NADH oxidase (NOX) from Streptococcus pneumoniae increased l-xylulose formation in shake flasks when glycerol was the carbon source. Controlled batch processes at the 1L scale demonstrated that the final equilibrium l-xylulose/xylitol ratio was correlated to the intracellular NAD(+)/NADH ratio, with 69% conversion of xylitol to l-xylulose and a yield of 0.88g l-xylulose/g xylitol consumed attained for MG1655/pZE12-xdh/pCS27-nox growing on glycerol. NADH oxidase was less effective at improving l-xylulose formation in the bioreactor than in shake flasks, likely as a result of an intrinsic maximum NAD(+)/NADH and l-xylulose/xylitol equilibrium ratio being attained. Intermittently feeding carbon source was ineffective at increasing the final l-xylulose concentration because introduction of carbon source was accompanied by a reduction in NAD(+)/NADH ratio. A batch process using 12g/L glycerol and 22g/L xylitol generated over 14g/L l-xylulose after 80h, corresponding to 65% conversion and a yield of 0.89g l-xylulose/g xylitol consumed. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. Improved transmission performance resulting from the reduced chirp of a semiconductor laser coupled to an external high-Q resonator

    SciTech Connect

    Cartledge, J.C. )

    1990-05-01

    The coupling of a Fabry--Perot laser to an external high-{ital Q} resonator, whose resonance frequencies are not altered by changes in the carrier density, yields a dynamic single-longitudinal-mode laser with a significantly reduced transient frequency chirp. The improvement in the receiver sensitivity due to the reduced chirp is examined for NRZ and RZ intensity modulation, direct detection systems operating in the 1.55-{mu}m wavelength region with conventional single-mode optical fiber. The methodology involves a solving modified rate equations numerically for the optical power and phase of the external resonator laser in response to an injected current waveform, modeling the signal transmission properties of single-mode optical fibers by convolution and modulus squared operations, and using a truncated pulse train approximation to evaluate the probability of error in the presence of intersymbol interference, shot noise, APD multiplication noise, and preamplifier circuit noise.

  2. Closely Coupled Multi-Mode Radiators: A New Concept for Improving the Performance of Electrically Small Antennas

    DTIC Science & Technology

    2012-04-01

    experimentally verify the effect of asymmetry on improving the omni-directionality. Asymmetric coupled loop antenna on  PEC ground. P1 LL CC P2 Ls Zo Zh Zh ( f...phase shifter in (a).(Here, Zo = 50 Ω, Zh = 115 Ω, Ls = 50 mm, L = 23 nH, and C = 3.3 pF.) Fig. 4. Simulated and measured VSWR of the antenna combined...antenna in Fig. 1 obtained by feeding its two ports using the ideal feed network shown in the inset. P1 LL CC P2 Ls Ls Zo Zh Zh (a) (b) 0.5 1.0 1.5

  3. Possible acute and chronic synergistic effect of dual chamber pacing and disopyramide in obstructive hypertrophic cardiomyopathy: a case report.

    PubMed

    Haruki, Shintaro; Minami, Yuichiro; Kajimoto, Katsuya; Yashiro, Bun; Suzuki, Tsuyoshi; Kawana, Masatoshi; Hagiwara, Nobuhisa

    2010-01-01

    It remains unclear whether the combination of dual-chamber (DDD) pacing and disopyramide can achieve prolonged left ventricular outflow tract (LVOT) gradient reduction and symptom relief in patients with obstructive hypertrophic cardiomyopathy (HCM). In an HCM patient with a severe LVOT gradient, the combination of DDD pacing and disopyramide achieved marked improvement of gradient in the catheter laboratory and also after medium-term follow-up. The patient's severe dyspnoea was alleviated during the follow-up period. This combination might enable physicians to treat and manage elderly symptomatic obstructive HCM patients with a severe LVOT gradient more effectively and less invasively.

  4. Instructor-paced vs. self-paced skiing modes in older recreational alpine skiers.

    PubMed

    Scheiber, Peter; Seifert, John G; Müller, Erich

    2011-04-01

    Parallel ski steering (PSS), carving in long radii (CLR), and individual technique (IT) skiing modes are mainly used throughout instructor-guided skiing of older recreational skiers. The aims of this study were (a) to determine differences in the physiologic response of older skiers to PSS, CLR, and IT skiing modes, (b) to quantify correlations between rate of perceived exertion (RPE) and the physiologic response, and (c) to analyze the relationship between aerobic capacity, skiing skills, and the blood lactate (LA) response during instructor-guided skiing. Twenty recreational skiers (61.1 ± 5.6 years) performed instructor-paced (PSS and CLR) and self-paced (IT) skiing modes. Heart rate (HR), LA, mean arterial blood pressure (MAP), and RPE were determined during skiing. Skiers skiing skills were judged by expert ski instructors. The aerobic capacity was tested by a physical work capacity test (PWC130) test. Heart rate was lower for PSS (106 ± 15 b · min(-1)), compared to CLR (118 ± 16 b · min(-1)) and IT (120 ± 15 b · min(-1)) skiing modes, both p < 0.001. Lactate levels were 1.45 ± 0.50 mmol · L(-1) for PSS, 1.67 ± 0.61 mmol · L(-1) for CLR, and 2.00 ± 0.74 mmol · L(-1) for IT skiing modes, all p < 0.004. Individual reductions in LA concentrations from 3.9 to 2.6 mmol · L were found, for IT and PSS skiing modes, respectively. No significant correlations were determined between any physiologic variable and RPE. Weak correlations were found between LA and PWC130 results (R2 < 0.114) and between LA and skiing skills (R2 < 0.132). In conclusion, significant reductions in the physiologic response were determined for PSS and CLR, compared with IT skiing modes. Instructor-paced skiing modes may minimize the risk of premature fatigue of skiers with high physiological responses. Those skiers may not perceive their disproportionate higher stress compared with skiers on the low end.

  5. Improved Measurement Performance of Inorganic Elements in Coal by Laser-Induced Breakdown Spectroscopy Coupled with Internal Standardization

    NASA Astrophysics Data System (ADS)

    Yao, Shunchun; Xu, Jialong; Bai, Kaijie; Lu, Jidong

    2015-11-01

    Laser-induced breakdown spectroscopy was employed to determine the inorganic elements in coal. To improve the measurement's accuracy and precision, a new internal standardization scheme, which we named changed internal standardization, was compared with the traditional internal standardization and no internal standardization for the analysis of inorganic elements. The new internal standardization scheme used the atomic line of carbon at 247.86 nm and the molecular band of CN at 388.34 nm and C2 at 516.32 nm to normalize the lines of inorganic elements that were distributed in the same spectral channel. The performance of the utilization of the new internal standardization scheme was evaluated using a set of coal samples, including twenty calibration samples and five validation samples. The results show that the coefficients of determination R2 and the slope of calibration models coupled with changed internal standardization are better than that of the calibration models coupled with fixed internal standardization and no internal standardization. Moreover, the measurement accuracy and reproducibility of changed internal standardization for the analysis of five validation samples also yielded further improvement. The results that we obtained suggest that changed internal standardization could compensate for the matrix effects, as well as the influence of the difference in the spectral response of the light collection system. supported by Open Research Fund of State Key Laboratory of Pulsed Power Laser Technology of China (No. SKL2013KF03), National Natural Science Foundation of China (Nos. 51206055, 51476061), the Fundamental Research Funds for the Central Universities of China (No. 2014ZZ0014), the New Star of Pearl River on Science and Technology of Guangzhou, China (No. 2014J2200054), the Key Laboratory of Efficient and Clean Energy Utilization of Guangdong Higher Education Institutes of China (No. KLB10004) and Guangdong Province Key Laboratory of Efficient and

  6. 42 CFR 460.90 - PACE benefits under Medicare and Medicaid.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 4 2012-10-01 2012-10-01 false PACE benefits under Medicare and Medicaid. 460.90 Section 460.90 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN... FOR THE ELDERLY (PACE) PACE Services § 460.90 PACE benefits under Medicare and Medicaid. If a Medicare...

  7. Rapid Recovery in Sub-Optimal Readers in Wales through a Self-Paced Computer-Based Reading Programme

    ERIC Educational Resources Information Center

    Reed, Phil; Hughes, Antony; Phillips, Gordon

    2013-01-01

    Basic literacy skills underlie much future adult functioning, and are targeted in children through a variety of means. Children with identified special needs in reading were exposed to a self-paced computer-based reading programme that focused on improving phonetic ability. Exposure was limited to three, 40-minute sessions a week, for 10 weeks.…

  8. Rapid Recovery in Sub-Optimal Readers in Wales through a Self-Paced Computer-Based Reading Programme

    ERIC Educational Resources Information Center

    Reed, Phil; Hughes, Antony; Phillips, Gordon

    2013-01-01

    Basic literacy skills underlie much future adult functioning, and are targeted in children through a variety of means. Children with identified special needs in reading were exposed to a self-paced computer-based reading programme that focused on improving phonetic ability. Exposure was limited to three, 40-minute sessions a week, for 10 weeks.…

  9. Improved Modeling of Land-Atmosphere Interactions using a Coupled Version of WRF with the Land Information System

    NASA Technical Reports Server (NTRS)

    Case, Jonathan L.; LaCasse, Katherine M.; Santanello, Joseph A., Jr.; Lapenta, William M.; Petars-Lidard, Christa D.

    2007-01-01

    The exchange of energy and moisture between the Earth's surface and the atmospheric boundary layer plays a critical role in many hydrometeorological processes. Accurate and high-resolution representations of surface properties such as sea-surface temperature (SST), vegetation, soil temperature and moisture content, and ground fluxes are necessary to better understand the Earth-atmosphere interactions and improve numerical predictions of weather and climate phenomena. The NASA/NWS Short-term Prediction Research and Transition (SPORT) Center is currently investigating the potential benefits of assimilating high-resolution datasets derived from the NASA moderate resolution imaging spectroradiometer (MODIS) instruments using the Weather Research and Forecasting (WRF) model and the Goddard Space Flight Center Land Information System (LIS). The LIS is a software framework that integrates satellite and ground-based observational and modeled data along with multiple land surface models (LSMs) and advanced computing tools to accurately characterize land surface states and fluxes. The LIS can be run uncoupled to provide a high-resolution land surface initial condition, and can also be run in a coupled mode with WRF to integrate surface and soil quantities using any of the LSMs available in LIS. The LIS also includes the ability to optimize the initialization of surface and soil variables by tuning the spin-up time period and atmospheric forcing parameters, which cannot be done in the standard WRF. Among the datasets available from MODIS, a leaf-area index field and composite SST analysis are used to improve the lower boundary and initial conditions to the LIS/WRF coupled model over both land and water. Experiments will be conducted to measure the potential benefits from using the coupled LIS/WRF model over the Florida peninsula during May 2004. This month experienced relatively benign weather conditions, which will allow the experiments to focus on the local and mesoscale

  10. Improved Modeling of Land-Atmosphere Interactions using a Coupled Version of WRF with the Land Information System

    NASA Technical Reports Server (NTRS)

    Case, Jonathan L.; LaCasse, Katherine M.; Santanello, Joseph A., Jr.; Lapenta, William M.; Petars-Lidard, Christa D.

    2007-01-01

    The exchange of energy and moisture between the Earth's surface and the atmospheric boundary layer plays a critical role in many hydrometeorological processes. Accurate and high-resolution representations of surface properties such as sea-surface temperature (SST), vegetation, soil temperature and moisture content, and ground fluxes are necessary to better understand the Earth-atmosphere interactions and improve numerical predictions of weather and climate phenomena. The NASA/NWS Short-term Prediction Research and Transition (SPORT) Center is currently investigating the potential benefits of assimilating high-resolution datasets derived from the NASA moderate resolution imaging spectroradiometer (MODIS) instruments using the Weather Research and Forecasting (WRF) model and the Goddard Space Flight Center Land Information System (LIS). The LIS is a software framework that integrates satellite and ground-based observational and modeled data along with multiple land surface models (LSMs) and advanced computing tools to accurately characterize land surface states and fluxes. The LIS can be run uncoupled to provide a high-resolution land surface initial condition, and can also be run in a coupled mode with WRF to integrate surface and soil quantities using any of the LSMs available in LIS. The LIS also includes the ability to optimize the initialization of surface and soil variables by tuning the spin-up time period and atmospheric forcing parameters, which cannot be done in the standard WRF. Among the datasets available from MODIS, a leaf-area index field and composite SST analysis are used to improve the lower boundary and initial conditions to the LIS/WRF coupled model over both land and water. Experiments will be conducted to measure the potential benefits from using the coupled LIS/WRF model over the Florida peninsula during May 2004. This month experienced relatively benign weather conditions, which will allow the experiments to focus on the local and mesoscale

  11. Cardiac Resynchronization Therapy With Wireless Left Ventricular Endocardial Pacing: The SELECT-LV Study.

    PubMed

    Reddy, Vivek Y; Miller, Marc A; Neuzil, Petr; Søgaard, Peter; Butter, Christian; Seifert, Martin; Delnoy, Peter Paul; van Erven, Lieselot; Schalji, Martin; Boersma, Lucas V A; Riahi, Sam

    2017-05-02

    A total of 30% to 40% of patients with congestive heart failure eligible for cardiac resynchronization therapy (CRT) either do not respond to conventional CRT or remain untreated due to an inability or impediment to coronary sinus (CS) lead implantation. The WiSE-CRT system (EBR Systems, Sunnyvale, California) was developed to address this at-risk patient population by performing biventricular pacing via a wireless left ventricular (LV) endocardial pacing electrode. The SELECT-LV (Safety and Performance of Electrodes implanted in the Left Ventricle) study is a prospective multicenter non-randomized trial assessing the safety and performance of the WiSE-CRT system. A total of 35 patients indicated for CRT who had "failed" conventional CRT underwent implantation of an LV endocardial pacing electrode and a subcutaneous pulse generator. System performance, clinical efficacy, and safety events were assessed out to 6 months post-implant. The procedure was successful in 97.1% (n = 34) of attempted implants. The most common indications for endocardial LV pacing were difficult CS anatomy (n =12), failure to respond to conventional CRT (n = 10), and a high CS pacing threshold or phrenic nerve capture (n = 5). The primary performance endpoint, biventricular pacing on the 12-lead electrocardiogram at 1 month, was achieved in 33 of 34 patients. A total of 28 patients (84.8%) had improvement in the clinical composite score at 6 months, and 21 (66%) demonstrated a positive echocardiographic CRT response (≥5% absolute increase in LV ejection fraction). There were no pericardial effusions, but serious procedure/device-related events occurred in 3 patients (8.6%) within 24 h, and 8 patients (22.9%) between 24 h and 1 month. The SELECT-LV study demonstrates the clinical feasibility for the WiSE-CRT system, and provided clinical benefits to a majority of patients within an otherwise "failed" CRT population. (Safety and Performance of Electrodes Implanted in the Left Ventricle

  12. Previous experience influences pacing during 20 km time trial cycling.

    PubMed

    Micklewright, D; Papadopoulou, E; Swart, J; Noakes, T

    2010-10-01

    To investigate how experience and feedback influence pacing and performance during time trial cycling. Twenty-nine cyclists performed three 20 km cycling time trials using a Computrainer. The first two time trials (TT1 and TT2) were performed (1) without any performance feedback (n = 10), (2) with accurate performance feedback (n = 10) or (3) with false feedback showing the speed to be 5% greater than the actual speed (n = 9). All participants received full feedback during the third time trial (TT3), and their performance and pacing data were compared against TT2. Completion time, average power and average speed did not change among the false feedback group, but their pacing strategy did change as indicated by a lower average cadence, 89.2 (SD 5.2) vs 96.4 (6.8) rpm, p<0.05, and higher power during the first 5 km (SMD = 39, 36, 36, 27 and 27 W for 1-5 km respectively). Pacing changed among the blind feedback group indicated by a faster completion time, 35.9 (3.1) vs 36.8 (4.4) min, p<0.05, and power increases during the final 5 km (SMD = 14, 13, 18, 23 and 53 W for 16-20 km respectively). No performance or pacing changes were observed among the accurate feedback group. Pacing is influenced by an interaction between feedback and previous experience. Conscious cognitive processes that lead to ratings of perceived exertion and pacing appear to be influenced by previous experience.

  13. The revised NASPE/BPEG generic code for antibradycardia, adaptive-rate, and multisite pacing. North American Society of Pacing and Electrophysiology/British Pacing and Electrophysiology Group.

    PubMed

    Bernstein, Alan D; Daubert, Jean-Claude; Fletcher, Ross D; Hayes, David L; Lüderitz, Berndt; Reynolds, Dwight W; Schoenfeld, Mark H; Sutton, Richard

    2002-02-01

    In light of evolving pacemaker technology and increasing interest in multisite pacing, the Committee on the Development of Position Statements (CDPS) of the North American Society of Pacing and Electrophysiology (NASPE) created an ad hoc Pacemaker Mode Code Task Force in April 2001 under the chairmanship of David L. Hayes, MD, for the purpose of bringing the NASPE/British Pacing and Electrophysiology Group (BPEG) Generic Pacemaker Code (NBG Code) up to date. The task force, whose members are the authors of this article, designed a revised NBG Code in which three major issues were taken into account. First, it was recognized that all modern pacemakerpulse generators are capable of extensive bidirectional communication with an external programming device, making them "communicating" pulse generators as defined by the current (1987) NBG Code. Second, it was decided that a means of providing basic information regarding the location of multisite pacing would be a useful ingredient of the NBG Code. Third, in view of the extensive antibradycardia pacing capabilities common in modern implantable cardioverter defibrillators and the availability of the NASPE/BPEG Defibrillator Code (NBD Code), it was considered unnecessary for the NBG Code to address the presence or absence of antitachycardia features. The resulting updated version of the NBG Code as described herein was endorsed by the BPEG on September 20, 2001 and adopted by the NASPE Board of Trustees on October 18, 2001. The structure of the revised NBG Code differs from that of the previous version in two respects alone: Position IV specifies only the presence or absence of rate modulation, and Position V specifies only the location or absence of multisite pacing (i.e., biatrial or biventricular pacing with at least two stimulation sites in each case) more than one stimulation site in any single cardiac chamber, or any combination of these. The revised NBG Code is deliberately configured to avoid confusion with earlier

  14. Cardiac pacing strategies and post-implantation risk of atrial fibrillation and heart failure events in sinus node dysfunction patients: a collaborative analysis of over 6000 patients.

    PubMed

    Chen, Shaojie; Wang, Zhenglong; Kiuchi, Marcio Galindo; Andrea, Bruno Rustum; Krucoff, Mitchell W; Liu, Shaowen; Pürerfellner, Helmut

    2016-08-01

    Pacing-modes selection in sinus-node-dysfunction (SND) patients continues to be a subject of debate. Atrial fibrillation (AF) and cardiac dysfunction remain significant problems following cardiac-pacing therapy. Prevention of these complications is of clinical relevance. We performed a collaborative pooled-analysis of randomized trials (RCT) to evaluate the effect of currently available pacing strategies on the risk of post-implantation AF and heart failure events (HF) in SND patients. The primary endpoint was a composite AF and HF events. Ten RCTs (n = 6639, male 57 %, median follow-up 2.5 years) were included. The pooled-analysis was stratified into two subsets [single chamber atrial pacing (AAI) vs. dual chamber pacing (DDD), and minimal ventricular pacing (MinVP) vs. DDD]. No significant difference was observed in the AAI vs. DDD subset regarding the primary outcome (P = 0.83). Notably, the mean percentage of ventricular-pacing in the MinVP group was 6.5 vs. 77.4 % in the DDD group (P < 0.05), and MinVP was associated with a substantially reduced risk of composite AF and HF (OR 0.66, P = 0.007) in patients receiving pacemaker as primary treatment. However, in the long-term paced patients scheduled for device replacement, there was no significant difference in the rate of primary endpoint between MinVP vs. DDD groups (P > 0.05). These results support MinVP over conventional DDD for SND patients who received pacemaker as primary treatment in improving the clinical outcome. For patients who already had chronic ventricular-pacing and impaired cardiac function, a device update to MinVP algorithm may exert no favorable effect on the cardiac performance.

  15. Improving homology modeling of G-protein coupled receptors through multiple-template derived conserved inter-residue interactions

    PubMed Central

    Chaudhari, Rajan; Heim, Andrew J.

    2017-01-01

    Evidenced by the three-rounds of G-protein coupled receptors (GPCR) Dock competitions, improving homology modeling methods of helical transmembrane proteins including the GPCRs, based on templates of low sequence identity, remains an eminent challenge. Current approaches addressing this challenge adopt the philosophy of “modeling first, refinement next”. In the present work, we developed an alternative modeling approach through the novel application of available multiple templates. First, conserved inter-residue interactions are derived from each additional template through conservation analysis of each template-target pairwise alignment. Then, these interactions are converted into distance restraints and incorporated in the homology modeling process. This approach was applied to modeling of the human β2 adrenergic receptor using the bovin rhodopsin and the human protease-activated receptor 1 as templates and improved model quality was demonstrated compared to the homology model generated by standard single-template and multiple-template methods. This method of “refined restraints first, modeling next”, provides a fast and complementary way to the current modeling approaches. It allows rational identification and implementation of additional conserved distance restraints extracted from multiple templates and/or experimental data, and has the potential to be applicable to modeling of all helical transmembrane proteins. PMID:25503850

  16. Improving homology modeling of G-protein coupled receptors through multiple-template derived conserved inter-residue interactions

    NASA Astrophysics Data System (ADS)

    Chaudhari, Rajan; Heim, Andrew J.; Li, Zhijun

    2015-05-01

    Evidenced by the three-rounds of G-protein coupled receptors (GPCR) Dock competitions, improving homology modeling methods of helical transmembrane proteins including the GPCRs, based on templates of low sequence identity, remains an eminent challenge. Current approaches addressing this challenge adopt the philosophy of "modeling first, refinement next". In the present work, we developed an alternative modeling approach through the novel application of available multiple templates. First, conserved inter-residue interactions are derived from each additional template through conservation analysis of each template-target pairwise alignment. Then, these interactions are converted into distance restraints and incorporated in the homology modeling process. This approach was applied to modeling of the human β2 adrenergic receptor using the bovin rhodopsin and the human protease-activated receptor 1 as templates and improved model quality was demonstrated compared to the homology model generated by standard single-template and multiple-template methods. This method of "refined restraints first, modeling next", provides a fast and complementary way to the current modeling approaches. It allows rational identification and implementation of additional conserved distance restraints extracted from multiple templates and/or experimental data, and has the potential to be applicable to modeling of all helical transmembrane proteins.

  17. Improving homology modeling of G-protein coupled receptors through multiple-template derived conserved inter-residue interactions.

    PubMed

    Chaudhari, Rajan; Heim, Andrew J; Li, Zhijun

    2015-05-01

    Evidenced by the three-rounds of G-protein coupled receptors (GPCR) Dock competitions, improving homology modeling methods of helical transmembrane proteins including the GPCRs, based on templates of low sequence identity, remains an eminent challenge. Current approaches addressing this challenge adopt the philosophy of "modeling first, refinement next". In the present work, we developed an alternative modeling approach through the novel application of available multiple templates. First, conserved inter-residue interactions are derived from each additional template through conservation analysis of each template-target pairwise alignment. Then, these interactions are converted into distance restraints and incorporated in the homology modeling process. This approach was applied to modeling of the human β2 adrenergic receptor using the bovin rhodopsin and the human protease-activated receptor 1 as templates and improved model quality was demonstrated compared to the homology model generated by standard single-template and multiple-template methods. This method of "refined restraints first, modeling next", provides a fast and complementary way to the current modeling approaches. It allows rational identification and implementation of additional conserved distance restraints extracted from multiple templates and/or experimental data, and has the potential to be applicable to modeling of all helical transmembrane proteins.

  18. Design of a water coupling bolus with improved flow distribution for multi-element superficial hyperthermia applicators.

    PubMed

    Arunachalam, Kavitha; Maccarini, Paolo F; Schlorff, Jaime L; Birkelund, Yngve; Jacobsen, Svein; Stauffer, Paul R

    2009-11-01

    A water bolus used in superficial hyperthermia couples the electromagnetic (EM) or acoustic energy into the target tissue and cools the tissue surface to minimise thermal hotspots and patient discomfort during treatment. Parametric analyses of the fluid pressure inside the bolus computed using 3D fluid dynamics simulations are used in this study to determine a bolus design with improved flow and surface temperature distributions for large area superficial heat applicators. The simulation results are used in the design and fabrication of a 19 x 32 cm prototype bolus with dual input-dual output (DIDO) flow channels. Sequential thermal images of the bolus surface temperature recorded for a step change in the circulating water temperature are used to assess steady state flow and surface temperature distributions across the bolus. Modelling and measurement data indicate substantial improvement in bolus flow and surface temperature distributions when changing from the previous single input-single output (SISO) to DIDO configuration. Temperature variation across the bolus at steady state was measured to be less than 0.8 degrees C for the DIDO bolus compared to 1.5 degrees C for the SISO water bolus. The new DIDO bolus configuration maintains a nearly uniform flow distribution and low variation in surface temperature over a large area typically treated in superficial hyperthermia.

  19. Interindividual comparison of different sensor principles for rate adaptive pacing.

    PubMed

    Malinowski, K

    1998-11-01

    In recent years a multitude of rate adaptive sensor systems based on different sensor signals have been developed to adapt the pacing rate to the physical load of the patient. In contrast to those systems the closed loop stimulation (CLS) represents a new concept, which regards the pacemaker as part of the cardiocirculatory system. The pacemaker converts the regulating information of the circulatory center into a heart rate. This study compares the closed loop stimulation and the different sensor systems that evaluate external parameters for rate adaptive pacing with a control group. To this end, 27 patients and 15 patients with a healthy sinus node (control group) were subjected to physical and mental stress tests. The recorded results were analyzed with regard to the maximum rates reached during stress. The results show that none of the studied sensor-controlled systems was able to determine an adequate pacing rate under all of the various load states. The dual sensor systems experience problems in balancing the input of the two sensor signals when calculating the pacing rate. The evaluation of a single external parameter, such as the acceleration of the upper body with the accelerometer, also failed to provide an adequate pacing rate in many stress situations. In contrast to all sensor systems, CLS achieved a heart rate in agreement with those of the reference group in all physical and mental stress situations.

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

    NASA Technical Reports Server (NTRS)

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

    1997-01-01

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