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  1. 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.

  2. 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

  3. 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.

  4. 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.

  5. Regional Framework for Self Paced Learning Modules. South Fraser Health Region.

    ERIC Educational Resources Information Center

    Blenkinsopp, John

    The purpose of this manual is to provide a guide for developing consistent, effective self-directed learning modules for the Surrey Memorial Hospital staff, physicians, and volunteers in the South Fraser Region. Eleven sections include: (1) "Philosophy for Self Paced Learning"; "What's Exciting?"; "What's the…

  6. 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.

  7. Mapping of regional myocardial strain and work during ventricular pacing: experimental study using magnetic resonance imaging tagging.

    PubMed

    Prinzen, F W; Hunter, W C; Wyman, B T; McVeigh, E R

    1999-05-01

    The purpose of this study was to determine the spatial distribution of myocardial function (myofiber shortening and work) within the left ventricular (LV) wall during ventricular pacing. Asynchronous electrical activation, as induced by ventricular pacing, causes various abnormalities in LV function, perfusion and structure. These derangements may be caused by abnormalities in regional contraction patterns. However, insight into these patterns during pacing is as yet limited. In seven anesthetized dogs, high spatial and temporal resolution magnetic resonance-tagged images were acquired in three orthogonal planes. Three-dimensional deformation data and LV cavity pressure and volume were used to determine midwall circumferential strain and external and total mechanical work at 192 sites around the left ventricle. During ventricular pacing, systolic fiber strain and external work were approximately zero in regions near the pacing site, and gradually increased to more than twice the normal value in the most remote regions. Total mechanical work, normalized to the value during right atrial pacing, was 38 +/- 13% (right ventricular apex [RVapex] pacing) and 61 +/- 23% (left ventricular base [LVbase] pacing) close to the pacing site, and 125 +/- 48% and 171 +/- 60% in remote regions, respectively (p < 0.05 between RVapex and LVbase pacing). The number of regions with reduced work was significantly larger during RVapex than during LVbase pacing. This was associated with a reduction of global LV pump function during RVapex pacing. Ventricular pacing causes a threefold difference in myofiber work within the LV wall. This difference appears large enough to regard local myocardial function as an important determinant for abnormalities in perfusion, metabolism, structure and pump function during asynchronous electrical activation. Pacing at sites that cause more synchronous activation may limit the occurrence of such derangements.

  8. 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

  9. 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.

  10. 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

  11. Changes in Left Ventricular Global and Regional Longitudinal Strain During Right Ventricular Pacing

    PubMed Central

    Algazzar, Alaa Solaiman; Katta, Azza Ali; Ahmed, Khaled Sayed; Elkenany, Nasima Mohamed; Ibrahim, Maher Abdelaleem

    2016-01-01

    Background Our study aimed to demonstrate the short-term impacts of right ventricular apical pacing (RVAP) and right ventricular septal pacing (RVSP) on left ventricular (LV) regional longitudinal strain (RLS) and global longitudinal strain (GLS) in patients with preserved ejection fraction (EF). LV strain and functions may be altered by RVAP. RVSP might be a better alternative. The detrimental effect of right ventricular (RV) pacing may be mediated by regional LV impairment. Methods Sixty-two patients indicated for permanent pacemaker implantation and preserved LV systolic function were included. Dual chamber pacemakers were implanted in all patients. Patients were divided into two groups according to RV lead position: group A (RVAP, n = 32) and group B (RVSP, n = 30). Patients were examined at baseline and after 6 months of implantation for LV systolic functions, global and regional strain by echocardiography and 2D speckle tracking echocardiography. Results Paced QRS duration was significantly shorter in group B compared to group A patients (P = 0.02). Regarding ventricular strain, there was no statistically significant difference between both groups at baseline measurements in comparisons of GLS, relative apical longitudinal strain (rALS) and RLS (P > 0.05). In contrast, there was statistically significant difference between both groups in results of GLS (P = 0.01) at 6 months. In addition, RLSs in septal, apical and rALS were affected after 6 months with P values of 0.02, 0.03 and 0.03, respectively. Conclusion RVAP appears to worsen GLS more than RVSP, and the resultant decrease in apical strain is most correlated region to decrease in GLS. PMID:28197264

  12. 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

  13. "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…

  14. 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

  15. 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.

  16. 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.

  17. 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

  18. 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

  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

    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.

  20. 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…

  1. Pacing-Induced Regional Differences in Adenosine Receptors mRNA Expression in a Swine Model of Dilated Cardiomyopathy

    PubMed Central

    Del Ry, Silvia; Cabiati, Manuela; Lionetti, Vincenzo; Aquaro, Giovanni D.; Martino, Alessandro; Mattii, Letizia; Morales, Maria-Aurora

    2012-01-01

    The adenosinergic system is essential in the mediation of intrinsic protection and myocardial resistance to insult; it may be considered a cardioprotective molecule and adenosine receptors (ARs) represent potential therapeutic targets in the setting of heart failure (HF). The aim of the study was to test whether differences exist between mRNA expression of ARs in the anterior left ventricle (LV) wall (pacing site: PS) compared to the infero septal wall (opposite region: OS) in an experimental model of dilated cardiomyopathy. Cardiac tissue was collected from LV PS and OS of adult male minipigs with pacing-induced HF (n = 10) and from a control group (C, n = 4). ARs and TNF–α mRNA expression was measured by Real Time-PCR and the results were normalized with the three most stably expressed genes (GAPDH, HPRT1, TBP). Immunohistochemistry analysis was also performed. After 3 weeks of pacing higher levels of expression for each analyzed AR were observed in PS except for A1R (A1R: C = 0.6±0.2, PS = 0.1±0.04, OS = 0.04±0.01, p<0.0001 C vs. PS and OS respectively; A2AR: C = 1.04±0.59, PS = 2.62±0.79, OS = 2.99±0.79; A2BR: C = 1.2±0.1, PS = 5.59±2.3, OS = 1.59±0.46; A3R: C = 0.76±0.18, PS = 8.40±3.38, OS = 4.40±0.83). Significant contractile impairment and myocardial hypoperfusion were observed at PS after three weeks of pacing as compared to OS. TNF-α mRNA expression resulted similar in PS (6.3±2.4) and in OS (5.9±2.7) although higher than in control group (3.4±1.5). ARs expression was mainly detected in cardiomyocytes. This study provided new information on ARs local changes in the setting of LV dysfunction and on the role of these receptors in relation to pacing-induced abnormalities of myocardial perfusion and contraction. These results suggest a possible therapeutic role of adenosine in patients with HF and dyssynchronous LV contraction. PMID:23071699

  2. Regional variations in action potential alternans in isolated murine Scn5a (+/-) hearts during dynamic pacing.

    PubMed

    Matthews, G D K; Martin, C A; Grace, A A; Zhang, Y; Huang, C L-H

    2010-10-01

    clinical observations suggest that alternans in action potential (AP) characteristics presages breakdown of normal ordered cardiac electrical activity culminating in ventricular arrhythmogenesis. We compared such temporal nonuniformities in monophasic action potential (MAP) waveforms in left (LV) and right ventricular (RV) epicardia and endocardia of Langendorff-perfused murine wild-type (WT), and Scn5a(+/-) hearts modelling Brugada syndrome (BrS) for the first time. a dynamic pacing protocol imposed successively incremented steady pacing rates between 5.5 and 33 Hz. A signal analysis algorithm detected sequences of >10 beats showing alternans. Results were compared before and following the introduction of flecainide (10 microm) and quinidine (5 microm) known to exert pro- and anti-arrhythmic effects in BrS. sustained and transient amplitude and duration alternans were both frequently followed by ventricular ectopic beats and ventricular tachycardia or fibrillation. Diastolic intervals (DIs) that coincided with onsets of transient (tr) or sustained (ss) alternans in MAP duration (DI*) and amplitude (DI') were determined. Kruskal-Wallis tests followed by Bonferroni-corrected Mann-Whitney U-tests were applied to these DI results sorted by recording site, pharmacological conditions or experimental populations. WT hearts showed no significant heterogeneities in any DI. Untreated Scn5a (+/-) hearts showed earlier onsets of transient but not sustained duration alternans in LV endocardium compared with RV endocardium or LV epicardium. Flecainide administration caused earlier onsets of both transient and sustained duration alternans selectively in the RV epicardium in the Scn5a (+/-) hearts. these findings in a genetic model thus implicate RV epicardial changes in the arrhythmogenicity produced by flecainide challenge in previously asymptomatic clinical BrS.

  3. 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

  4. 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.

  5. 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.

  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. Regional myocardial blood flow and coronary vascular reserve in unanesthetized ponies during pacing-induced ventricular tachycardia

    SciTech Connect

    Parks, C.; Manohar, M.; Lundeen, G.

    1983-08-01

    To examine the effects of tachycardia on coronary circulation, transmural distribution of myocardial blood flow (MBF, 15-micron diameter radionuclide-labeled microspheres) was studied in six healthy adult ponies at rest (heart rate . 60 +/- 7 beats . min-1), during ventricular pacing at 150 and 200 beats . min-1, as well as with ventricular pacing at 250 beats . min-1 before and during maximal coronary vasodilatation (iv adenosine infusion; 4 mumole . kg-1 . min-1). Mean aortic pressure and cardiac output were unchanged from control values with ventricular pacing. Whereas ventricular pacing at 150 and 200 beats . min-1 resulted in a progressive uniform increase in transmural MBF and well-maintained endo:epi perfusion ratio, pacing at 250 beats . min-1 did not result in a further increase in MBF compared to pacing at 200 beats . min-1 and the left ventricular (LV) subendocardial:subepicardial (endo:epi) perfusion ratio was significantly less than 1.00 (0.87 +/- 0.05). Blood flow to the LV papillary muscles and subendocardium was significantly less than that recorded at 200 beats . min-1. The LV endo:epi perfusion ratio with ventricular pacing at 250 beats . min-1 during adenosine infusion resulted in a decrease in mean aortic pressure (63% of control value) and a marked further reduction in blood flow to the LV papillary muscles as well as the LV subendocardium, while MBF increased dramatically in the LV subepicardium compared to values observed during ventricular pacing at 250 beats . min-1 alone. These data demonstrate that coronary vasomotion functions to maintain LV subendocardial blood flow in the pony myocardium at a heart rate of 200 beats . min-1, while at 250 beats . min-1 exhaustion of coronary vasodilator reserve in the deeper layers limits further increase in MBF.

  10. Orbitally-paced variations of water availability in the SE Asian Monsoon region following the Miocene Climate Transition

    NASA Astrophysics Data System (ADS)

    Heitmann, Emma O.; Ji, Shunchuan; Nie, Junsheng; Breecker, Daniel O.

    2017-09-01

    Middle Miocene Earth had several boundary conditions similar to those predicted for future Earth including similar atmospheric pCO2 and substantial Antarctic ice cover but no northern hemisphere ice sheets. We describe a 12 m outcrop of the terrestrial Yanwan Section in the Tianshui Basin, Gansu, China, following the Miocene Climate Transition (13.9-13.7 Ma). It consists of ∼25 cm thick CaCO3-cemented horizons that overprint siltstones every ∼1 m. We suggest that stacked soils developed in siltstones under a seasonal climate with a fluctuating water table, evidenced by roots, clay films, mottling, presence of CaCO3 nodules, and stacked carbonate nodule δ13 C and δ18 O profiles that mimic modern soils. We suggest that the CaCO3-cemented horizons are capillary-fringe carbonates that formed in an arid climate with a steady water table and high potential evapotranspiration rates (PET), evidenced by sharp upper and basal contacts, micrite, sparite, and root-pore cements. The CaCO3 of the cemented horizons and the carbonate nodules have similar mean δ18 O and δ13 C values but the cements have significantly smaller variance in δ13 C and δ18 O values and a different δ18 O versus δ13 C slope, supporting the conclusion that these carbonates are from different populations. The magneto-stratigraphic age model indicates obliquity pacing of the arid conditions required to form the CaCO3-cemented horizons suggesting an orbital control on water availability. We suggest two possible drivers for the obliquity pacing of arid conditions: 1) variability in the cross-equatorial pressure gradient that controls summer monsoon (ASM) strength and is influenced by obliquity-paced variations of Antarctic ice volume and 2) variability in Western Pacific Ocean-East Asian continent pressure gradient controlled by the 25-45°N meridional insolation gradient. We also suggest that variations in aridity were influenced by variations in PET and sensible heating of the regional land

  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. 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

  14. 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.

  15. Does regional anaesthesia improve outcome?

    PubMed

    Hopkins, P M

    2015-12-01

    This review examines the recent evidence of an impact of regional anaesthesia on important clinical outcomes. Evidence was obtained from a variety of studies, with increasing numbers of analyses of large databases being prominent. The benefits and limitations of these approaches are considered in order to provide a context for interpretation of the data they generate. There should be little argument that correctly performed and appropriately used regional anaesthetic techniques can provide the most effective postoperative analgesia for the duration of the block, but the majority of studies suggest that this does not translate into improved longer-term surgical outcomes. The evidence for reduced incidence of major complications when regional anaesthesia is compared with, or added to, general anaesthesia is mixed. There appears to be a small effect in reducing blood loss during major joint arthroplasty. Some, but not all, studies demonstrate a reduced incidence of respiratory and infective complications with regional anaesthesia, but the effect on cardiovascular complications is variable. There are even some data consistent with a hypothesis that general anaesthesia may be protective against postoperative cognitive dysfunction. In conclusion, there is probably no generally applicable benefit in long-term outcomes with regional anaesthesia. More likely is an interaction between patient factors, the surgical procedure, and the relative capability of the anaesthetist to manage different types of anaesthesia. © The Author 2015. Published by Oxford University Press on behalf of the British Journal of Anaesthesia. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  16. 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.

  17. 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.

  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. Different regions of latest electrical activation during left bundle-branch block and right ventricular pacing in cardiac resynchronization therapy patients determined by coronary venous electro-anatomic mapping.

    PubMed

    Mafi Rad, Masih; Blaauw, Yuri; Dinh, Trang; Pison, Laurent; Crijns, Harry J; Prinzen, Frits W; Vernooy, Kevin

    2014-11-01

    Current targeted left ventricular (LV) lead placement strategy is directed at the latest activated region during intrinsic activation. However, cardiac resynchronization therapy (CRT) is most commonly applied by simultaneous LV and right ventricular (RV) pacing without contribution from intrinsic conduction. Therefore, targeting the LV lead to the latest activated region during RV pacing might be more appropriate. We investigated the difference in LV electrical activation sequence between left bundle-branch block (LBBB) and RV apex (RVA) pacing using coronary venous electro-anatomic mapping (EAM). Twenty consecutive CRT candidates with LBBB underwent intra-procedural coronary venous EAM during intrinsic activation and RVA pacing using EnSite NavX. Left ventricular lead placement was aimed at the latest activated region during LBBB according to current recommendations. In all patients, LBBB was associated with a circumferential LV activation pattern, whereas RVA pacing resulted in activation from the apex of the heart to the base. In 10 of 20 patients, RVA pacing shifted the latest activated region relative to LBBB. In 18 of 20 patients, the LV lead was successfully positioned in the latest activated region during LBBB. For the whole study population, LV lead electrical delay, expressed as percentage of QRS duration, was significantly shorter during RVA pacing than during LBBB (72 ± 13 vs. 82 ± 5%, P = 0.035). Right ventricular apex pacing alters LV electrical activation pattern in CRT patients with LBBB, and shifts the latest activated region in a significant proportion of these patients. These findings warrant reconsideration of the current practice of LV lead targeting for CRT. © 2014 The Authors. European Journal of Heart Failure © 2014 European Society of Cardiology.

  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. Comparison of Protein-Pacing Alone or With Yoga/Stretching and Resistance Training on Glycemia, Total and Regional Body Composition, and Aerobic Fitness in Overweight Women.

    PubMed

    Ruby, Maxwell; Repka, Chris P; Arciero, Paul J

    2016-07-01

    Yoga/Stretching (YS) and functional resistance (FR) training are popular exercise routines. A protein-pacing (PP) diet is a common dietary regimen. Thus, we assessed the effectiveness of a PP diet alone and in combination with either YS or FR to improve body composition and cardiometabolic health. Twenty-seven overweight women (age = 43.2 ± 4.6 years) were randomized into 3 groups: yoga (YS, n = 8) or resistance (FR, n = 10) training (3 days/week) in conjunction with PP diet (50% carbohydrate, 25% protein, and 25% fat) or PP diet-only (PP, n = 9) throughout 12-week study. PP maintained preexisting levels of physical activity. Body weight (BW), total (BF) and abdominal (ABF) body fat, waist circumference (WC), plasma biomarkers, and aerobic fitness (VO2) were measured at baseline and 12 weeks. WC and total cholesterol improved in all groups, whereas glycemia tended to improve (P = .06) in S. BF, ABF, and VO2 increased significantly in YS and FR (P < .05). Feelings of vigor increased in YS and tension decreased in FR (P < .05). YS training tended to decrease blood glucose compared with FR and PP and is equally effective at enhancing body composition, and aerobic fitness in overweight women providing a strong rationale for further research on YS training.

  5. 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.

  6. 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

  7. 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.

  8. 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...

  9. 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...

  10. 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.

  11. 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

  12. 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

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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

  19. 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.

  20. 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…

  1. 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…

  2. [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.

  3. 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…

  4. 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…

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. Sectoral approaches to improve regional carbon budgets

    SciTech Connect

    Smith, Pete; Nabuurs, Gert-Jan; Marland, Gregg

    2008-06-01

    Humans utilise about 40% of the earth s net primary production (NPP) but the products of this NPP are often managed by different sectors, with timber and forest products managed by the forestry sector and food and fibre products from croplands and grasslands managed by the agricultural sector. Other significant anthropogenic impacts on the global carbon cycle include human utilization of fossil fuels and impacts on less intensively managed systems such as peatlands, wetlands and permafrost. A great deal of knowledge, expertise and data is available within each sector. We describe the contribution of sectoral carbon budgets to our understanding of the global carbon cycle. Whilst many sectors exhibit similarities for carbon budgeting, some key differences arise due to differences in goods and services provided, ecology, management practices used, landmanagement personnel responsible, policies affecting land management, data types and availability, and the drivers of change. We review the methods and data sources available for assessing sectoral carbon budgets, and describe some of key data limitations and uncertainties for each sector in different regions of the world. We identify the main gaps in our knowledge/data, show that coverage is better for the developed world for most sectors, and suggest how sectoral carbon budgets could be improved in the future. Research priorities include the development of shared protocols through site networks, a move to full carbon accounting within sectors, and the assessment of full greenhouse gas budgets.

  11. 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.

  12. Does regional anaesthesia really improve outcome?

    PubMed

    Kettner, S C; Willschke, H; Marhofer, P

    2011-12-01

    In recent decades, a number of studies have attempted to determine whether regional anaesthesia offers convincing benefits over general anaesthesia. However, today we interpret meta-analyses more carefully, and it remains unclear whether regional anaesthesia reduces mortality. However, regional anaesthesia offers superior analgesia over opioid-based analgesia, and a significant reduction in postoperative pain is still a worthwhile outcome. Recent developments in technical aspects of regional anaesthesia have the potential to provide significant advantages for many patients in all age groups. Moreover, studies focusing on specific outcomes have shown benefits for regional anaesthesia used for surgery and postoperative analgesia.

  13. 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.

  14. 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

  15. 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)

  16. 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)

  17. Improving image segmentation by learning region affinities

    SciTech Connect

    Prasad, Lakshman; Yang, Xingwei; Latecki, Longin J

    2010-11-03

    We utilize the context information of other regions in hierarchical image segmentation to learn new regions affinities. It is well known that a single choice of quantization of an image space is highly unlikely to be a common optimal quantization level for all categories. Each level of quantization has its own benefits. Therefore, we utilize the hierarchical information among different quantizations as well as spatial proximity of their regions. The proposed affinity learning takes into account higher order relations among image regions, both local and long range relations, making it robust to instabilities and errors of the original, pairwise region affinities. Once the learnt affinities are obtained, we use a standard image segmentation algorithm to get the final segmentation. Moreover, the learnt affinities can be naturally unutilized in interactive segmentation. Experimental results on Berkeley Segmentation Dataset and MSRC Object Recognition Dataset are comparable and in some aspects better than the state-of-art methods.

  18. 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)

  19. Improving Regional Air Quality with Wind Energy

    SciTech Connect

    Not Available

    2005-05-01

    This model documentation is designed to assist State and local governments in pursuing wind energy purchases as a control measure under regional air quality plans. It is intended to support efforts to draft State Implementation Plans (SIPs), including wind energy purchases, to ensure compliance with the standard for ground-level ozone established under the Clean Air Act.

  20. Improving Education in the Arabian Gulf Region.

    ERIC Educational Resources Information Center

    Rasheed, Mohammed A.; Hengst, Herbert R.

    1983-01-01

    Educational development in the seven Arab states of the Gulf region has been stimulated by the Arab Bureau of Education for the Gulf States (ABEGS), established in 1976. ABEGS has focused on obtaining information on education programs from member states, educating Arabs about their own culture, and establishing a multinational university. (LC)

  1. Health Information System Simulation. Curriculum Improvement Project. Region II.

    ERIC Educational Resources Information Center

    Anderson, Beth H.; Lacobie, Kevin

    This volume is one of three in a self-paced computer literacy course that gives allied health students a firm base of knowledge concerning computer usage in the hospital environment. It also develops skill in several applications software packages. This volume contains five self-paced modules that allow students to interact with a health…

  2. 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

  3. 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.

  4. 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

  5. Improving watershed management practices in humid regions

    USDA-ARS?s Scientific Manuscript database

    Understanding the basic hydrology and erosion is vital for effective management and utilization of water resources and soil conservation planning. To improve the understanding we used watershed studies on three continents. The results show that in well vegetated (sub) humid and temperate watersheds ...

  6. 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…

  7. [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.

  8. 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

  9. 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.

  10. 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

  11. Improving Regional Groundwater Models with Transmissivity Observations

    NASA Astrophysics Data System (ADS)

    Halford, K. J.

    2013-12-01

    Hydraulic-conductivity estimates in groundwater-flow models typically are constrained by a range for each hydrogeologic unit. These often-times wide ranges are derived from interpretations of many aquifer tests binned by hydrogeologic unit. Uncertainty is added to these ranges where hydraulic-conductivity estimates derived from aquifer tests use contributing thicknesses that differ from simulated thicknesses in a numerical model. Transmissivity observations from individual aquifer tests constrain model calibration better than hydraulic-conductivity ranges assigned to hydrogeologic units because simulated transmissivity and aquifer-test results are compared directly. Transmissivity comparisons require that simulated thicknesses and hydraulic conductivities for the volume investigated by the aquifer test be extracted from a model and integrated into a simulated transmissivity. Transmissivity observations have been ignored primarily because sampling simulated transmissivities is mechanically painful from complex models. A suite of programs called T-COMP has been developed to sample simulated transmissivities easily from regional MODFLOW models. Transmissivities of model cells are sampled where drawdown exceeds a user-defined threshold. Sampled transmissivities of model cells are averaged within a layer and summed between layers. This computationally intensive process occurs in separate programs that are executed prior to model calibration. Simulated transmissivities can be sampled quickly during calibration because nodes and their fractional contributions have been defined.

  12. 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.

  13. 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.

  14. 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)

  15. 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.

  16. 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…

  17. 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…

  18. 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.

  19. 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.

  20. 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

  1. 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

  2. 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

  3. 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.

  4. Biophysical Modeling to Determine the Optimization of Left Ventricular Pacing Site and AV/VV Delays in the Acute and Chronic Phase of Cardiac Resynchronization Therapy

    PubMed Central

    LEE, ANGELA W. C.; CROZIER, ANDREW; HYDE, EOIN R.; LAMATA, PABLO; TRUONG, MICHAEL; SOHAL, MANAV; JACKSON, THOMAS; BEHAR, JONATHAN M.; CLARIDGE, SIMON; SHETTY, ANOOP; SAMMUT, EVA; PLANK, GERNOT; RINALDI, CHRISTOPHER ALDO

    2017-01-01

    Device Optimization for Acute and Chronic CRT Background Cardiac anatomy and function adapt in response to chronic cardiac resynchronization therapy (CRT). The effects of these changes on the optimal left ventricle (LV) lead location and timing delay settings have yet to be fully explored. Objective To predict the effects of chronic CRT on the optimal LV lead location and device timing settings over time. Methods Biophysical computational cardiac models were generated for 3 patients, immediately post‐implant (ACUTE) and after at least 6 months of CRT (CHRONIC). Optimal LV pacing area and device settings were predicted by pacing the ACUTE and CHRONIC models across the LV epicardium (49 sites each) with a range of 9 pacing settings and simulating the acute hemodynamic response (AHR) of the heart. Results There were statistically significant differences between the distribution of the AHR in the ACUTE and CHRONIC models (P < 0.0005 in all cases). The site delivering the maximal AHR shifted location between the ACUTE and CHRONIC models but provided a negligible improvement (<2%). The majority of the acute optimal LV pacing regions (76–100%) and device settings (76–91%) remained optimal chronically. Conclusion Optimization of the LV pacing location and device settings were important at the time of implant, with a reduced benefit over time, where the majority of the acute optimal LV pacing region and device settings remained optimal with chronic CRT. PMID:27885749

  5. Biophysical Modeling to Determine the Optimization of Left Ventricular Pacing Site and AV/VV Delays in the Acute and Chronic Phase of Cardiac Resynchronization Therapy.

    PubMed

    Lee, Angela W C; Crozier, Andrew; Hyde, Eoin R; Lamata, Pablo; Truong, Michael; Sohal, Manav; Jackson, Thomas; Behar, Jonathan M; Claridge, Simon; Shetty, Anoop; Sammut, Eva; Plank, Gernot; Rinaldi, Christopher Aldo; Niederer, Steven

    2017-02-01

    Cardiac anatomy and function adapt in response to chronic cardiac resynchronization therapy (CRT). The effects of these changes on the optimal left ventricle (LV) lead location and timing delay settings have yet to be fully explored. To predict the effects of chronic CRT on the optimal LV lead location and device timing settings over time. Biophysical computational cardiac models were generated for 3 patients, immediately post-implant (ACUTE) and after at least 6 months of CRT (CHRONIC). Optimal LV pacing area and device settings were predicted by pacing the ACUTE and CHRONIC models across the LV epicardium (49 sites each) with a range of 9 pacing settings and simulating the acute hemodynamic response (AHR) of the heart. There were statistically significant differences between the distribution of the AHR in the ACUTE and CHRONIC models (P < 0.0005 in all cases). The site delivering the maximal AHR shifted location between the ACUTE and CHRONIC models but provided a negligible improvement (<2%). The majority of the acute optimal LV pacing regions (76-100%) and device settings (76-91%) remained optimal chronically. Optimization of the LV pacing location and device settings were important at the time of implant, with a reduced benefit over time, where the majority of the acute optimal LV pacing region and device settings remained optimal with chronic CRT. © 2016 Wiley Periodicals, Inc.

  6. Satellite Sounder Data Assimilation for Improving Alaska Region Weather Forecast

    NASA Technical Reports Server (NTRS)

    Zhu, Jiang; Stevens, E.; Zavodsky, B. T.; Zhang, X.; Heinrichs, T.; Broderson, D.

    2014-01-01

    Data assimilation has been demonstrated very useful in improving both global and regional numerical weather prediction. Alaska has very coarser surface observation sites. On the other hand, it gets much more satellite overpass than lower 48 states. How to utilize satellite data to improve numerical prediction is one of hot topics among weather forecast community in Alaska. The Geographic Information Network of Alaska (GINA) at University of Alaska is conducting study on satellite data assimilation for WRF model. AIRS/CRIS sounder profile data are used to assimilate the initial condition for the customized regional WRF model (GINA-WRF model). Normalized standard deviation, RMSE, and correlation statistic analysis methods are applied to analyze one case of 48 hours forecasts and one month of 24-hour forecasts in order to evaluate the improvement of regional numerical model from Data assimilation. The final goal of the research is to provide improved real-time short-time forecast for Alaska regions.

  7. 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

  8. 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

  9. 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.

  10. 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…

  11. 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…

  12. Trust regions in Kriging-based optimization with expected improvement

    NASA Astrophysics Data System (ADS)

    Regis, Rommel G.

    2016-06-01

    The Kriging-based Efficient Global Optimization (EGO) method works well on many expensive black-box optimization problems. However, it does not seem to perform well on problems with steep and narrow global minimum basins and on high-dimensional problems. This article develops a new Kriging-based optimization method called TRIKE (Trust Region Implementation in Kriging-based optimization with Expected improvement) that implements a trust-region-like approach where each iterate is obtained by maximizing an Expected Improvement (EI) function within some trust region. This trust region is adjusted depending on the ratio of the actual improvement to the EI. This article also develops the Kriging-based CYCLONE (CYClic Local search in OptimizatioN using Expected improvement) method that uses a cyclic pattern to determine the search regions where the EI is maximized. TRIKE and CYCLONE are compared with EGO on 28 test problems with up to 32 dimensions and on a 36-dimensional groundwater bioremediation application in appendices supplied as an online supplement available at http://dx.doi.org/10.1080/0305215X.2015.1082350. The results show that both algorithms yield substantial improvements over EGO and they are competitive with a radial basis function method.

  13. Regional Travel-Time Predictions, Uncertainty and Location Improvement

    SciTech Connect

    Flanagan, M; Myers, S

    2004-07-15

    We investigate our ability to improve regional travel-time prediction and seismic event location using an a priori three-dimensional (3D) velocity model of Western Eurasia and North Africa (WENA 1.0). Three principal results are presented. First, the 3D WENA 1.0 velocity model improves travel-time prediction over the IASPI91 model, as measured by variance reduction, for regional phases recorded at 22 stations throughout the modeled region, including aseismic areas. Second, a distance-dependent uncertainty model is developed and tested for the WENA 1.0 model. Third, relocation using WENA 1.0 and the associated uncertainty model provides an end-to-end validation test. Model validation is based on a comparison of approximately 10,000 Pg, Pn, and P travel-time predictions and empirical observations from ground truth (GT) events. Ray coverage for the validation dataset provides representative, regional-distances sampling across Eurasia and North Africa. The WENA 1.0 model markedly improves travel-time predictions for most stations with an average variance reduction of 14% for all ray paths. We find that improvement is station dependent, with some stations benefiting greatly from WENA predictions (25% at OBN, and 16% at BKR), some stations showing moderate improvement (12% at ARU, and 17% at NIL), and some stations benefiting only slightly (7% at AAE, and 8% at TOL). We further test WENA 1.0 by relocating five calibration events. Again, relocation of these events is dependent on ray paths that evenly sample WENA 1.0 and therefore provide an unbiased assessment of location performance. These results highlight the importance of accurate GT datasets in assessing regional travel-time models and demonstrate that an a priori 3D model can markedly improve our ability to locate small magnitude events in a regional monitoring context.

  14. 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.

  15. 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.

  16. 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…

  17. 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)…

  18. 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…

  19. Improving and Communicating Workforce Skills: A Regional Initiative

    ERIC Educational Resources Information Center

    Baird, Dee

    2011-01-01

    The demand for improved workplace skills in the U.S. is rapidly rising, and U.S. industries, employees, and educational systems are struggling to respond. This paper describes the Skills Advantage program, an effort led by employers and facilitated by Kirkwood Community College to address regional employment needs. This work-ready certificate…

  20. Influence of pacing site characteristics on response to cardiac resynchronization therapy.

    PubMed

    Wong, Jorge A; Yee, Raymond; Stirrat, John; Scholl, David; Krahn, Andrew D; Gula, Lorne J; Skanes, Allan C; Leong-Sit, Peter; Klein, George J; McCarty, David; Fine, Nowell; Goela, Aashish; Islam, Ali; Thompson, Terry; Drangova, Maria; White, James A

    2013-07-01

    Transmural scar occupying left ventricular (LV) pacing regions has been associated with reduced response to cardiac resynchronization therapy (CRT). However, spatial influences of lead tip delivery relative to scar at both pacing sites remain poorly explored. This study evaluated scar distribution relative to LV and right ventricular (RV) lead tip placement through coregistration of late gadolinium enhancement MRI and cardiac computed tomographic (CT) findings. Influences on CRT response were assessed by serial echocardiography. Sixty patients receiving CRT underwent preimplant late gadolinium enhancement MRI, postimplant cardiac CT, and serial echocardiography. Blinded segmental evaluations of mechanical delay, percentage scar burden, and lead tip location were performed. Response to CRT was defined as a reduction in LV end-systolic volume ≥15% at 6 months. The mean age and LV ejection fraction were 64±9 years and 25±7%, respectively. Mean scar volume was higher among CRT nonresponders for both the LV (23±23% versus 8±14% [P=0.01]) and RV pacing regions (40±32% versus 24±30% [P=0.04]). Significant pacing region scar was identified in 13% of LV pacing regions and 37% of RV pacing regions. Absence of scar in both regions was associated with an 81% response rate compared with 55%, 25%, and 0%, respectively, when the RV, LV, or both pacing regions contained scar. LV pacing region dyssynchrony was not predictive of response. Myocardial scar occupying the LV pacing region is associated with nonresponse to CRT. Scar occupying the RV pacing region is encountered at higher frequency and seems to provide a more intermediate influence on CRT response.

  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. Hospital-Based Coalition to Improve Regional Surge Capacity

    PubMed Central

    Terndrup, Thomas E.; Leaming, James M.; Adams, R. Jerry; Adoff, Spencer

    2012-01-01

    Introduction Surge capacity for optimization of access to hospital beds is a limiting factor in response to catastrophic events. Medical facilities, communication tools, manpower, and resource reserves exist to respond to these events. However, these factors may not be optimally functioning to generate an effective and efficient surge response. The objective was to improve the function of these factors. Methods Regional healthcare facilities and supporting local emergency response agencies developed a coalition (the Healthcare Facilities Partnership of South Central Pennsylvania; HCFP-SCPA) to increase regional surge capacity and emergency preparedness for healthcare facilities. The coalition focused on 6 objectives: (1) increase awareness of capabilities and assets, (2) develop and pilot test advanced planning and exercising of plans in the region, (3) augment written medical mutual aid agreements, (4) develop and strengthen partnership relationships, (5) ensure National Incident Management System compliance, and (6) develop and test a plan for effective utilization of volunteer healthcare professionals. Results In comparison to baseline measurements, the coalition improved existing areas covered under all 6 objectives documented during a 24-month evaluation period. Enhanced communications between the hospital coalition, and real-time exercises, were used to provide evidence of improved preparedness for putative mass casualty incidents. Conclusion The HCFP-SCPA successfully increased preparedness and surge capacity through a partnership of regional healthcare facilities and emergency response agencies. PMID:23316266

  3. Characterization and comparison of polysaccharides from Lycium barbarum in China using saccharide mapping based on PACE and HPTLC.

    PubMed

    Wu, Ding-Tao; Cheong, Kit-Leong; Deng, Yong; Lin, Peng-Cheng; Wei, Feng; Lv, Xiao-Jie; Long, Ze-Rong; Zhao, Jing; Ma, Shuang-Cheng; Li, Shao-Ping

    2015-12-10

    Water-soluble polysaccharides from 51 batches of fruits of L. barbarum (wolfberry) in China were investigated and compared using saccharide mapping, partial acid hydrolysis, single and composite enzymatic digestion, followed by polysaccharide analysis by using carbohydrate gel electrophoresis (PACE) analysis and high performance thin layer chromatography (HPTLC) analysis, respectively. Results showed that multiple PACE and HPTLC fingerprints of partial acid and enzymatic hydrolysates of polysaccharides from L. barbarum in China were similar, respectively. In addition, results indicated that β-1,3-glucosidic, α-1,4-galactosiduronic and α-1,5-arabinosidic linkages existed in polysaccharides from L. barbarum collected in China, and the similarity of polysaccharides in L. barbarum collected from different regions of China was pretty high, which are helpful for the improvement of the performance of polysaccharides from L. barbarum in functional/health foods area. Furthermore, polysaccharides from Panax notoginseng, Angelica sinensis, and Astragalus membranaceus var. mongholicus were successfully distinguished from those of L. barbarum based on their PACE fingerprints. These results were beneficial to improve the quality control of polysaccharides from L. barabrum and their products, which suggested that saccharide mapping based on PACE and HPTLC analysis could be a routine approach for quality control of polysaccharides.

  4. 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)

  5. 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

  6. 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)

  7. Improved regional ventricular function after successful surgical revascularization

    SciTech Connect

    Brundage, B.H.; Massie, B.M.; Botvinick, E.H.

    1984-04-01

    Left ventricular segments with reversible asynergy at rest demonstrate reversible myocardial perfusion defects on exercise thallium-201 scintigrams. To determine if improved perfusion eliminates asynergy at rest, 23 patients with angina (stable in 21, unstable in 2) were studied before and after coronary artery bypass surgery. All patients underwent exercise myocardial perfusion scintigraphy, contrast ventriculography and coronary arteriography before and after surgery. Selective graft angiography was performed during the postoperative catheterization to determine graft patency. Segmental ventricular function was quantitated by a regional fraction method. The scintigrams were divided into five regions and compared with the corresponding regions of the ventriculogram. Seventy-one of a possible 142 ventricular segments exhibited exercise-induced perfusion deficits. Preoperative regional ejection fraction was normal in 42 of these segments and abnormal in 29. Postoperatively, in 19 of the abnormal segments, function improved or normalized. All these segments had improved perfusion during exercise after surgery and were supplied by a patent bypass graft. Nine of the 10 segments in which abnormal wall motion persisted postoperatively continued to have exercise-induced perfusion deficits, and 9 of the 10 segments were supplied by an occluded or stenotic graft or one with poor run off. Of the 42 segments with normal wall motion preoperatively, 30 had improved perfusion after surgery and 35 maintained normal function. This study indicates that asynergy at rest is permanently reversed after coronary bypass surgery if improved myocardial perfusion can be documented. These findings are consistent with but do not prove the concept that reversible rest asynergy may reflect chronic ischemia or a prolonged effect from previous ischemic episodes.

  8. Large N: a strategy for improving regional sport performance.

    PubMed

    Cornett, Andrew C; Stager, Joel M

    2015-07-01

    It has been hypothesized that large differences in maximal performance can arise between various geopolitical regions solely on the basis of differing numbers of participants in the target activity. While there is evidence in support of this hypothesis for a measure of intellectual performance, the same relationship has not been examined for a measure of physical performance. To determine whether the number of participants is a predictor of the best athletic performance in a region. The 2005-2010 USA Swimming Age Group Detail reports were used to determine the number of competitive swimmers participating in each age group for the 59 local swimming communities in the United States. The USA Swimming performance database provided 50-yd-freestyle times in each community for boys and girls for each age (6-19 y). Simple linear regression was used to examine the relationship between the outcome variable (fastest time) and the predictor variable (log of the number of swimmers) for each combination of age, sex, and calendar year. The log of the number of swimmers in a region was a significant predictor of the best performance in that region for all 168 combinations of age, sex, and calendar year (P<.05) and explained, on average, 41%, and as much as 62%, of the variance in the fastest time. These findings have important implications for the development of regional sport strategic policy. Increasing the number of participants in the target activity appears a viable strategy for improving regional performance.

  9. Algorithmic improvements to an exact region-filling technique

    NASA Astrophysics Data System (ADS)

    Elias Fabris, Antonio; Ramos Batista, Valério

    2015-09-01

    We present many algorithmic improvements in our early region filling technique, which in a previous publication was already proved to be correct for all connected digital pictures. Ours is an integer-only method that also finds all interior points of any given digital picture by displaying and storing them in a locating matrix. Our filling/locating program is applicable both in computer graphics and image processing.

  10. Probabilistic region growing method for improving magnetic resonance image segmentation

    NASA Astrophysics Data System (ADS)

    Zanaty, E. A.; Asaad, Ayman

    2013-12-01

    In this paper, we propose a new region growing algorithm called 'probabilistic region growing (PRG)' which could improve the magnetic resonance image (MRI) segmentation. The proposed approach includes a threshold based on estimating the probability of pixel intensities of a given image. This threshold uses a homogeneity criterion which is obtained automatically from characteristics of the regions. The homogeneity criterion will be calculated for each pixel as well as the probability of pixel value. The proposed PRG algorithm selects the pixels sequentially in a random walk starting at the seed point, and the homogeneity criterion is updated continuously. The proposed PRG algorithm is applied to the challenging applications: grey matter/white matter segmentation in MRI data sets. The experimental results compared with other segmentation techniques show that the proposed PRG method produces more accurate and stable results.

  11. 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.

  12. 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

  13. 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

  14. 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...

  15. 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...

  16. 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...

  17. 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...

  18. 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...

  19. 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...

  20. The Student Experience of PACE at Macquarie University: Understanding Motivations for Learning

    ERIC Educational Resources Information Center

    McLachlan, Kath; Rawlings-Sanaei, Felicity; Mason, Colina; Haski-Levanthal, Debbie; Nabeel, Hussein

    2017-01-01

    Professional and Community Engagement (PACE) at Macquarie University offers undergraduate students experiential learning opportunities with local, regional and international partners. Through PACE, students work on mutually beneficial projects that both meet the partner's organizational goals and enable students to strengthen graduate capabilities…

  1. 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

  2. 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.

  3. 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

  4. 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.

  5. Improving regional universal newborn hearing screening programmes in Italy.

    PubMed

    Molini, E; Cristi, M C; Lapenna, R; Calzolaro, L; Muzzi, E; Ciciriello, E; Della Volpe, A; Orzan, E; Ricci, G

    2016-02-01

    The Universal Newborn Hearing Screening (UNHS) programme aims at achieving early detection of hearing impairment. Subsequent diagnosis and intervention should follow promptly. Within the framework of the Ministry of Health project CCM 2013 "Preventing Communication Disorders: a Regional Program for early Identification, Intervention and Care of Hearing Impaired Children", the limitations and strengths of current UNHS programs in Italy have been analysed by a group of professionals working in tertiary centres involved in regional UNHS programmes, using SWOT analysis and a subsequent TOWS matrix. Coverage and lost-to-follow up rates are issues related to UNHS programmes. Recommendations to improve the effectiveness of the UNHS programme have been identified. The need for homogeneous policies, high-quality information and dissemination of knowledge for operators and families of hearing-impaired children emerged from the discussion. © Copyright by Società Italiana di Otorinolaringologia e Chirurgia Cervico-Facciale.

  6. 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…

  7. 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…

  8. 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.

  9. Improvements on foF1 estimation at polar regions

    NASA Astrophysics Data System (ADS)

    Sabbagh, Dario; Scotto, Carlo; Sgrigna, Vittorio

    2016-04-01

    The analysis of a sample of polar ionograms reveals that the DuCharme and Petrie empirical formula often fails in the foF1 estimation at polar regions. A study of the discrepancies between modeled and observed foF1 values is presented, using a data set of Antarctic ionograms from different stations. Such discrepancies have been quantitatively evaluated. Based on this study a correction to the DuCharme and Petrie formula is proposed. This correction is performed to be implemented in an improved version of Autoscala software for a particular ionospheric station, in the frame of AUSPICIO (Automatic Interpretation of Polar Ionograms and Cooperative Ionospheric Observations) project.

  10. 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.

  11. Quality assurance and improvement: the Pediatric Regional Anesthesia Network.

    PubMed

    Polaner, David M; Martin, Lynn D

    2012-01-01

    Quality assurance and improvement (QA/QI) is a critical activity in medicine. The use of large-scale collaborative databases is increasingly essential to obtain enough reports with which to establish standards of practice and define the incidence of complications and risk/benefit ratios for rare events. Such projects can enhance local QA/QI endeavors by enabling institutions to obtain benchmark data against which to compare their performance and can be used for prospective analyses of inter-institutional differences to determine 'best practice'. The pediatric regional anesthesia network (PRAN) is such a project. The first data cohort is currently being analyzed and offers insight into how such data can be used to detect trends in adverse events and improve care.

  12. 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.

  13. 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.

  14. Satellite Sounder Data Assimilation for Improving Alaska Region Weather Forecast

    NASA Technical Reports Server (NTRS)

    Zhu, Jiang; Stevens, E.; Zhang, X.; Zavodsky, B. T.; Heinrichs, T.; Broderson, D.

    2014-01-01

    A case study and monthly statistical analysis using sounder data assimilation to improve the Alaska regional weather forecast model are presented. Weather forecast in Alaska faces challenges as well as opportunities. Alaska has a large land with multiple types of topography and coastal area. Weather forecast models must be finely tuned in order to accurately predict weather in Alaska. Being in the high-latitudes provides Alaska greater coverage of polar orbiting satellites for integration into forecasting models than the lower 48. Forecasting marine low stratus clouds is critical to the Alaska aviation and oil industry and is the current focus of the case study. NASA AIRS/CrIS sounder profiles data are used to do data assimilation for the Alaska regional weather forecast model to improve Arctic marine stratus clouds forecast. Choosing physical options for the WRF model is discussed. Preprocess of AIRS/CrIS sounder data for data assimilation is described. Local observation data, satellite data, and global data assimilation data are used to verify and/or evaluate the forecast results by the MET tools Model Evaluation Tools (MET).

  15. 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

  16. 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.

  17. Improving sea level simulation in Mediterranean regional climate models

    NASA Astrophysics Data System (ADS)

    Adloff, Fanny; Jordà, Gabriel; Somot, Samuel; Sevault, Florence; Arsouze, Thomas; Meyssignac, Benoit; Li, Laurent; Planton, Serge

    2017-08-01

    For now, the question about future sea level change in the Mediterranean remains a challenge. Previous climate modelling attempts to estimate future sea level change in the Mediterranean did not meet a consensus. The low resolution of CMIP-type models prevents an accurate representation of important small scales processes acting over the Mediterranean region. For this reason among others, the use of high resolution regional ocean modelling has been recommended in literature to address the question of ongoing and future Mediterranean sea level change in response to climate change or greenhouse gases emissions. Also, it has been shown that east Atlantic sea level variability is the dominant driver of the Mediterranean variability at interannual and interdecadal scales. However, up to now, long-term regional simulations of the Mediterranean Sea do not integrate the full sea level information from the Atlantic, which is a substantial shortcoming when analysing Mediterranean sea level response. In the present study we analyse different approaches followed by state-of-the-art regional climate models to simulate Mediterranean sea level variability. Additionally we present a new simulation which incorporates improved information of Atlantic sea level forcing at the lateral boundary. We evaluate the skills of the different simulations in the frame of long-term hindcast simulations spanning from 1980 to 2012 analysing sea level variability from seasonal to multidecadal scales. Results from the new simulation show a substantial improvement in the modelled Mediterranean sea level signal. This confirms that Mediterranean mean sea level is strongly influenced by the Atlantic conditions, and thus suggests that the quality of the information in the lateral boundary conditions (LBCs) is crucial for the good modelling of Mediterranean sea level. We also found that the regional differences inside the basin, that are induced by circulation changes, are model-dependent and thus not

  18. 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

  19. 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.

  20. 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.

  1. Regional collaborative quality improvement for trauma reduces complications and costs.

    PubMed

    Hemmila, Mark R; Cain-Nielsen, Anne H; Wahl, Wendy L; Vander Kolk, Wayne E; Jakubus, Jill L; Mikhail, Judy N; Birkmeyer, Nancy J

    2015-01-01

    Although evidence suggests that quality improvement to reduce complications for trauma patients should decrease costs, studies have not addressed this question directly. In Michigan, trauma centers and a private payer have created a regional collaborative quality initiative (CQI). This CQI program began as a pilot in 2008 and expanded to a formal statewide program in 2010. We examined the relationship between outcomes and expenditures for trauma patients treated in collaborative participant and nonparticipant hospitals. Payer claims and collaborative registry data were analyzed for 30-day episode payments and serious complications in patients admitted with trauma diagnoses. Patients were categorized as treated in hospitals that had different CQI status: (1) never participated (Never-CQI); (2) collaborative participant, but patient treated before CQI initiation (Pre-CQI); or (3) active collaborative participant (Post-CQI). DRG International Classification of Diseases--9th Rev. codes were crosswalked to Abbreviated Injury Scale (AIS) 2005 codes. Episode payment data were risk adjusted (age, sex, comorbidities, type/severity of injury, and year of treatment), and price was standardized. Outcome data were risk adjusted. A serious complication consisted of one or more of the following occurrences: acute lung injury/adult respiratory distress syndrome, acute kidney injury, cardiac arrest with cardiopulmonary resuscitation, decubitus ulcer, deep vein thrombosis, enterocutaneous fistula, extremity compartment syndrome, mortality, myocardial infarction, pneumonia, pulmonary embolism, severe sepsis, stroke/cerebral vascular accident, unplanned intubation, or unplanned return to operating room. The risk-adjusted rate of serious complications declined from 14.9% to 9.1% (p < 0.001) in participating hospitals (Post-CQI, n = 26). Average episode payments decreased by $2,720 (from $36,043 to $33,323, p = 0.08) among patients treated in Post-CQI centers, whereas patients treated

  2. An Improved Approach of Mesh Segmentation to Extract Feature Regions

    PubMed Central

    Gu, Minghui; Duan, Liming; Wang, Maolin; Bai, Yang; Shao, Hui; Wang, Haoyu; Liu, Fenglin

    2015-01-01

    The objective of this paper is to extract concave and convex feature regions via segmenting surface mesh of a mechanical part whose surface geometry exhibits drastic variations and concave-convex features are equally important when modeling. Referring to the original approach based on the minima rule (MR) in cognitive science, we have created a revised minima rule (RMR) and presented an improved approach based on RMR in the paper. Using the logarithmic function in terms of the minimum curvatures that are normalized by the expectation and the standard deviation on the vertices of the mesh, we determined the solution formulas for the feature vertices according to RMR. Because only a small range of the threshold parameters was selected from in the determined formulas, an iterative process was implemented to realize the automatic selection of thresholds. Finally according to the obtained feature vertices, the feature edges and facets were obtained by growing neighbors. The improved approach overcomes the inherent inadequacies of the original approach for our objective in the paper, realizes full automation without setting parameters, and obtains better results compared with the latest conventional approaches. We demonstrated the feasibility and superiority of our approach by performing certain experimental comparisons. PMID:26436657

  3. 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.

  4. 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…

  5. 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.

  6. 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…

  7. 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...

  8. 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...

  9. 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...

  10. 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…

  11. 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.

  12. 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...

  13. 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...

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. Improvement of snowpack simulations in a regional climate model

    SciTech Connect

    Jin, J.; Miller, N.L.

    2011-01-10

    To improve simulations of regional-scale snow processes and related cold-season hydroclimate, the Community Land Model version 3 (CLM3), developed by the National Center for Atmospheric Research (NCAR), was coupled with the Pennsylvania State University/NCAR fifth-generation Mesoscale Model (MM5). CLM3 physically describes the mass and heat transfer within the snowpack using five snow layers that include liquid water and solid ice. The coupled MM5–CLM3 model performance was evaluated for the snowmelt season in the Columbia River Basin in the Pacific Northwestern United States using gridded temperature and precipitation observations, along with station observations. The results from MM5–CLM3 show a significant improvement in the SWE simulation, which has been underestimated in the original version of MM5 coupled with the Noah land-surface model. One important cause for the underestimated SWE in Noah is its unrealistic land-surface structure configuration where vegetation, snow and the topsoil layer are blended when snow is present. This study demonstrates the importance of the sheltering effects of the forest canopy on snow surface energy budgets, which is included in CLM3. Such effects are further seen in the simulations of surface air temperature and precipitation in regional weather and climate models such as MM5. In addition, the snow-season surface albedo overestimated by MM5–Noah is now more accurately predicted by MM5–CLM3 using a more realistic albedo algorithm that intensifies the solar radiation absorption on the land surface, reducing the strong near-surface cold bias in MM5–Noah. The cold bias is further alleviated due to a slower snowmelt rate in MM5–CLM3 during the early snowmelt stage, which is closer to observations than the comparable components of MM5–Noah. In addition, the over-predicted precipitation in the Pacific Northwest as shown in MM5–Noah is significantly decreased in MM5 CLM3 due to the lower evaporation resulting from the

  20. 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.

  1. Scanning linear estimation: improvements over region of interest (ROI) methods.

    PubMed

    Kupinski, Meredith K; Clarkson, Eric W; Barrett, Harrison H

    2013-03-07

    In tomographic medical imaging, a signal activity is typically estimated by summing voxels from a reconstructed image. We introduce an alternative estimation scheme that operates on the raw projection data and offers a substantial improvement, as measured by the ensemble mean-square error (EMSE), when compared to using voxel values from a maximum-likelihood expectation-maximization (MLEM) reconstruction. The scanning-linear (SL) estimator operates on the raw projection data and is derived as a special case of maximum-likelihood estimation with a series of approximations to make the calculation tractable. The approximated likelihood accounts for background randomness, measurement noise and variability in the parameters to be estimated. When signal size and location are known, the SL estimate of signal activity is unbiased, i.e. the average estimate equals the true value. By contrast, unpredictable bias arising from the null functions of the imaging system affect standard algorithms that operate on reconstructed data. The SL method is demonstrated for two different tasks: (1) simultaneously estimating a signal's size, location and activity; (2) for a fixed signal size and location, estimating activity. Noisy projection data are realistically simulated using measured calibration data from the multi-module multi-resolution small-animal SPECT imaging system. For both tasks, the same set of images is reconstructed using the MLEM algorithm (80 iterations), and the average and maximum values within the region of interest (ROI) are calculated for comparison. This comparison shows dramatic improvements in EMSE for the SL estimates. To show that the bias in ROI estimates affects not only absolute values but also relative differences, such as those used to monitor the response to therapy, the activity estimation task is repeated for three different signal sizes.

  2. 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...

  3. 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...

  4. 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...

  5. 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...

  6. 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...

  7. 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...

  8. 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...

  9. 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...

  10. 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...

  11. 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...

  12. 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.

  13. 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

  14. 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.

  15. 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.

  16. 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

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. Lunar plasma measurement by MAP-PACE onboard KAGUYA (SELENE)

    NASA Astrophysics Data System (ADS)

    Saito, Yoshifumi

    Low energy charged particles around the Moon were vigorously observed by Moon orbiting satellites and plasma instrumentation placed on the lunar surface in 1960s and 1970s. Though there were some satellites that explored the Moon afterwards, most of them were dedicated to the global mapping of the lunar surface. KAGUYA(SELENE) is a Japanese lunar orbiter that studies the origin and evolution of the Moon by means of global mapping of element abundances, mineralogical composition, and surface geographical mapping from 100km altitude. KAGUYA was successfully launched on 14 September 2007 by HIIA launch vehicle from Tanegashima Space Center in Japan. KAGUYA was inserted into a circular lunar polar orbit of 100km altitude and started continuous observation in mid-December 2007. One of the fourteen science instruments MAP-PACE (MAgnetic field and Plasma experiment - Plasma energy Angle and Composition Experiment) was developed for the comprehensive three-dimensional plasma measurement around the Moon. MAP-PACE consists of 4 sensors: ESA (Electron Spectrum Analyzer)-S1, ESA-S2, IMA (Ion Mass Analyzer), and IEA (Ion Energy Analyzer). ESA-S1 and S2 measure the distribution function of low energy electrons below 15keV. IMA and IEA measure the distribution function of low energy ions below 28keV/q. IMA has an ability to discriminate the ion mass with high mass resolution. PACE sensors have been measuring solar wind, plasmas in the wake region of the Moon and plasmas in the Earth's magnetosphere. ESA sensors have discovered electron heating over magnetic anomalies on the lunar surface. ESA sensors have also observed electrons accelerated from the lunar surface in the wake region. PACE ion sensors have discovered new features of low energy ions around the Moon. IMA has discovered the existence of alkali ions that are originated from the lunar surface or lunar atmosphere and are picked up by the solar wind. IEA and IMA sensors discovered solar wind reflection by the Moon. PACE

  2. 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

  3. 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.

  4. 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

  5. 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

  6. 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.

  7. Assessment of a Regional Transportation Education Alliance To Improve Mobility.

    ERIC Educational Resources Information Center

    Kuhn, Beverly T.

    This report examines issues related to transportation education, with the objective of developing and packaging transportation-related materials for use in college and university transportation education programs. The study was conducted by the Southwest Region University Transportation Center (SWUTC) region, but it is expected that the results…

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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

  14. 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.

  15. 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.

  16. 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.

  17. 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

  18. 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.

  19. 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

  20. 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.

  1. 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.

  2. Report: Region 6 Needs to Improve Oversight Practices

    EPA Pesticide Factsheets

    Report #10-P-0100, April 14, 2010. Region 6’s documentation of its oversight was not sufficient to determine whether CANM’s allegations had merit or whether NMED’s actions and decisions with regard to the MWL monitoring wells were technically sound.

  3. The relationship between complex fractionated electrograms and atrial low-voltage zones during atrial fibrillation and paced rhythm.

    PubMed

    Teh, Andrew W; Kistler, Peter M; Lee, Geoffrey; Medi, Caroline; Heck, Patrick M; Spence, Steven J; Sparks, Paul B; Morton, Joseph B; Sanders, Prashanthan; Kalman, Jonathan M

    2011-12-01

    Mapping of atrial fibrillation (AF) involves identification of low-voltage regions associated with complex fractionated electrograms (CFE) which theoretically represent abnormal substrate and targets for ablation. Whether low-voltage CFE areas also identify abnormal substrate during paced rhythm is unknown. Twelve patients with persistent AF undergoing ablation of AF had high-density three-dimensional electroanatomic maps created during AF and paced rhythm (24 maps) and the mean voltage during AF and paced rhythm was compared for eight segments of the left atrium (LA). The following were correlated during AF and paced rhythm: regional mean voltage; %low voltage (defined as <0.5 mV); and extent of CFE. In addition, the relationship between the extent of CFE in AF: (i) %low voltage and (ii) conduction during paced rhythm were determined. Mean voltage was lower during AF than paced rhythm for all regions and globally (0.7 ± 0.2 mV vs. 2.1 ± 0.6 mV, P < 0.001). The regional and overall %low voltage of the LA was greater during AF than paced rhythm (53 ± 19% vs. 9 ± 2%, P < 0.001). There was no correlation between mean voltage or %low voltage during AF and paced rhythm. Complex fractionated electrograms were prevalent throughout all regions during AF, but did not correlate with %low voltage, fractionation, or slowed conduction during paced rhythm. Areas of CFE and low voltage recorded during AF frequently demonstrate normal atrial myocardial characteristics (normal conduction, electrograms, and voltage) during sinus rhythm. Therefore, AF CFE sites do not necessarily identify regions of an abnormal atrial substrate. However, this does not exclude the possibility that CFE might identify a focal driver or source occurring in a region of normal atrial myocardium.

  4. 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.

  5. The Improved E-Region Wind Interferometer, ERWIN-2

    NASA Astrophysics Data System (ADS)

    Brown, Stephen; Kristoffersen, Samuel; Sargoytchev, Stoyan; Solheim, Brian; Ward, William E.

    The E-region wind interferometer, ERWIN, which operated at Resolute Bay for close to 10 years has been renovated for operation at the Polar Environment Atmospheric Research Laboratory at Eureka, Canada. ERWIN was a field widened Michelson interfetometer which measured winds in the E-region using Doppler shifts in hydroxyl, oxygen green line and O2 airglow emssions using a photomultiplier tube. The new implementation of this instrument, incoporates the interferometer from the old instrument but otherwise is completely reconfigured. Changes include incorporation of imaging capabilities using a CCD detector (instead of a photo-multiplier tube), and an optical system which allows simultaneous (instead of sequential) viewing in four directions and zenith. In this configuration, the instrument operates by seqentially viewing the same three emissions as the previous instrument. This presentation provides details of the new configuration, the observation and calibration process, the data analysis approach and some initial results.

  6. 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

  7. 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.

  8. Effect of left ventricular pacing mode and site on hemodynamic, torsional and strain indices.

    PubMed

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

    Several reports have indicated that left ventricular (LV) lead placement at an optimal pacing site is an important determinant of short- and long-term outcome. This study investigated the effect of pacing mode (atrioventricular [AV] or ventricular) and site (LV apical or lateral) outside the ischemic region on the LV hemodynamic, torsional and strain indices in the ischemic myocardium. Experiments were conducted in anesthetized open-chest pigs (n = 15) 30 min after LAD ligation to investigate the hemodynamic effects of temporary epicardial AV and ventricular LV pacing at the LV apical (outside the ischemic region) or lateral wall. LV hemodynamic data were recorded (ejection fraction, stroke volume, dP/dtmax, systolic pressure, cardiac output and e/e΄ ratio) and torsional (twist, rotation), as well as deformation (radial and circumferential strain), indices of LV function were assessed using two-dimensional speckle tracking imaging. The LV function was highly dependent on the pacing mode and site. LV dP/dtmax, systolic pressure and twist decreased significantly during LV pacing in comparison to sinus rhythm (p = 0.004, p<0.001, p = 0.002, respectively). Torsion in sinus rhythm decreased significantly during AV-pacing at the lateral wall (0.11±0.04°/mm vs. 0.06±0.02°/mm, p = 0.005) but did not change significantly during AV-pacing at the apex (0.07±0.05°/mm). LV pacing at the apical or lateral wall, in the ischemic myocardium, leads to a suboptimal response in comparison to sinus rhythm. LV pacing at the apex outside the ischemic area exhibits a better response than pacing at the lateral wall, possibly because pacing from this site leads to a more physiological propagation of electrical conduction. Copyright © 2016 Hellenic Cardiological Society. Published by Elsevier B.V. All rights reserved.

  9. 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

  10. 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

  11. 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.

  12. Improving a regional model using reduced complexity and parameter estimation

    USGS Publications Warehouse

    Kelson, Victor A.; Hunt, Randall J.; Haitjema, Henk M.

    2002-01-01

    The availability of powerful desktop computers and graphical user interfaces for ground water flow models makes possible the construction of ever more complex models. A proposed copper-zinc sulfide mine in northern Wisconsin offers a unique case in which the same hydrologic system has been modeled using a variety of techniques covering a wide range of sophistication and complexity. Early in the permitting process, simple numerical models were used to evaluate the necessary amount of water to be pumped from the mine, reductions in streamflow, and the drawdowns in the regional aquifer. More complex models have subsequently been used in an attempt to refine the predictions. Even after so much modeling effort, questions regarding the accuracy and reliability of the predictions remain. We have performed a new analysis of the proposed mine using the two-dimensional analytic element code GFLOW coupled with the nonlinear parameter estimation code UCODE. The new model is parsimonious, containing fewer than 10 parameters, and covers a region several times larger in areal extent than any of the previous models. The model demonstrates the suitability of analytic element codes for use with parameter estimation codes. The simplified model results are similar to the more complex models; predicted mine inflows and UCODE-derived 95% confidence intervals are consistent with the previous predictions. More important, the large areal extent of the model allowed us to examine hydrological features not included in the previous models, resulting in new insights about the effects that far-field boundary conditions can have on near-field model calibration and parameterization. In this case, the addition of surface water runoff into a lake in the headwaters of a stream while holding recharge constant moved a regional ground watershed divide and resulted in some of the added water being captured by the adjoining basin. Finally, a simple analytical solution was used to clarify the GFLOW model

  13. Improving SLCF Science in the Himalayan Region: ICIMOD's Atmosphere Initiative

    NASA Astrophysics Data System (ADS)

    Panday, A. K.; Pradhan, B. B.; Surapipith, V.

    2013-12-01

    What fraction of the black carbon arriving on Yala Glacier in Langtang, Nepal, is from cooking fires in the houses in the valley below? What fraction is from elsewhere in rural Nepal? What fraction is from industrial and transport sources in Kathmandu? What fraction is from northern India and beyond? What fraction is from the high altitude forest fires that take place during March or April? Effectively mitigating the impacts of black carbon and other short-lived climate forcers requires detailed understanding not just of emissions and impacts, but also of the atmospheric transport pathways that connect the two. In mountainous areas of the Hindu-Kush Himalaya detailed quantitative knowledge about emissions, atmospheric processes, and impacts is still largely missing. The International Centre for Integrated Mountain Development (ICIMOD) is an intergovernmental organization covering Afghanistan, Pakistan, India, Nepal, China, Bhutan, Bangladesh, and Myanmar. ICIMOD's recently established Atmosphere Initiative not only assesses mitigation options and contributes to policy and capacity building in the region, but also works actively to promote collaboration among researchers in the region, while building up an in-house team whose research will address key questions about SLCF. In Spring 2013 ICIMOD's Atmosphere Initiative, in collaboration with the Institute for Advanced Sustainability Studies (IASS) in Potsdam, Germany, carried out the largest field campaign to date in Nepal, hosting instruments belonging to dozens of institutions around the world, at nine field site within and upwind of the Kathmandu Valley, Nepal. The dataset that has been collected gives unprecedented insights into the emissions and atmospheric processes taking place downwind of and within the largest urban agglomeration in the Himalaya region. Meanwhile, in collaboration with national partner institutions, ICIMOD is in the process of setting up one atmospheric observatory each in Bhutan and in

  14. PACES Participation in Educational Outreach Programs at the University of Texas at El Paso

    NASA Technical Reports Server (NTRS)

    Dodge, Rebecca L.

    1997-01-01

    The University of Texas at El Paso (UTEP) is involved in several initiatives to improve science education within the El Paso area public schools. These include outreach efforts into the K- 12 classrooms; training programs for in-service teachers; and the introduction of a strong science core curricula within the College of Education. The Pan American Center for Earth and Environmental Studies (PACES), a NASA-funded University Research Center, will leverage off the goals of these existing initiatives to provide curriculum support materials at all levels. We will use currently available Mission to Planet Earth (MTPE) materials as well as new materials developed specifically for this region, in an effort to introduce the Earth System Science perspective into these programs. In addition, we are developing curriculum support materials and classes within the Geology and Computer Departments, to provide education in the area of remote sensing and GIS applications at the undergraduate and graduate levels.

  15. A regional programme to improve skin cancer management.

    PubMed

    McGeoch, Graham R; Sycamore, Mark J; Shand, Brett I; Simcock, Jeremy W

    2015-12-01

    In 2008, public specialist and general practice services in Canterbury were unable to manage demand for skin cancer treatment. Local clinicians decided the solution was to develop a see-and-treat skin excision clinic staffed by plastic surgeons and general practitioners (GPs), and the introduction of subsidised excisions in general practice. This paper describes the collaboration between clinicians, managers and funders and the results and quality management measures of these initiatives. There is an increasing incidence of skin cancer. GPs in Canterbury were unable to meet increasing demand for skin cancer treatment because some lacked confidence and competence in skin cancer management. There was no public funding for primary care management of skin cancer, driving patients to fully funded secondary care services. Secondary care services were at capacity, with no coordinated programme across primary and secondary care. The programme has resulted in a greater number of skin cancers being treated by the public health system, a reduction in waiting times for treatment, and fewer minor skin lesions being referred to secondary care. Quality measures have been achieved and are improving steadily. Development of the programme has improved working relationships between primary and secondary care clinicians. The strategy was to facilitate the working relationship between primary and secondary care and increase the capacity for skin lesion excisions in both sectors. Skin cancer management can be improved by a coordinated approach between primary and secondary care.

  16. 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.

  17. Regionalization of services improves access to emergency vascular surgical care.

    PubMed

    Roche-Nagle, G; Bachynski, K; Nathens, A B; Angoulvant, D; Rubin, B B

    2013-04-01

    Management of vascular surgical emergencies requires rapid access to a vascular surgeon and hospital with the infrastructure necessary to manage vascular emergencies. The purpose of this study was to assess the impact of regionalization of vascular surgery services in Toronto to University Health Network (UHN) and St Michael's Hospital (SMH) on the ability of CritiCall Ontario to transfer patients with life- and limb-threatening vascular emergencies for definitive care. A retrospective review of the CritiCall Ontario database was used to assess the outcome of all calls to CritiCall regarding patients with vascular disease from April 2003 to March 2010. The number of patients with vascular emergencies referred via CritiCall and accepted in transfer by the vascular centers at UHN or SMH increased 500% between 1 April 2003-31 December 2005 and 1 January 2006-31 March 2010. Together, the vascular centers at UHN and SMH accepted 94.8% of the 1002 vascular surgery patients referred via CritiCall from other hospitals between 1 January 2006 and 31 March 2010, and 72% of these patients originated in hospitals outside of the Toronto Central Local Health Integration Network. Across Ontario, the number of physicians contacted before a patient was accepted in transfer fell from 2.9 ± 0.4 before to 1.7 ± 0.3 after the vascular centers opened. In conclusion, the vascular surgery centers at UHN and SMH have become provincial resources that enable the efficient transfer of patients with vascular surgical emergencies from across Ontario. Regionalization of services is a viable model to increase access to emergent care.

  18. Transcriptional regulation of subtilisin-like proprotein convertase PACE4 by E2F: possible role of E2F-mediated upregulation of PACE4 in tumor progression.

    PubMed

    Yuasa, Keizo; Suzue, Kaori; Nagahama, Masami; Matsuda, Yoshiko; Tsuji, Akihiko

    2007-11-01

    PACE4, a member of the subtilisin-like proprotein convertase (SPC) family, is expressed at high levels in certain tumor cells and plays a role in metastatic progression through activation of matrix metalloproteinases. The mechanism leading to overexpression of PACE4 in tumor cells remains unclear. In this study, we show that the E2F1 transcription factor, which is implicated in carcinoma invasiveness, upregulates the expression of PACE4. HT1080 (highly tumorigenic and invasive) cells expressed much higher levels of PACE4 and E2F family (E2F1 and E2F2) transcripts than IMR90 (normal fibroblast) cells. Expression levels of other SPCs (furin and PC6) remained unchanged in these cells. Promoter analysis indicated that two E2F consensus binding sites (-117/-110 and -86/-79) in the 5'-flanking region of the human PACE4 gene function as positive regulatory elements. Mutation of these sites abolished PACE4 promoter response to E2F1 as well as binding of E2F1 in electrophoretic mobility-shift assays. Other E2F members, E2F2 and E2F3, also activated PACE4 expression, as in the case of E2F1. These results indicate a novel mechanism for E2F family-mediated promotion of carcinoma invasiveness through PACE4.

  19. Improved Bayesian Infrasonic Source Localization for regional infrasound

    SciTech Connect

    Blom, Philip S.; Marcillo, Omar; Arrowsmith, Stephen J.

    2015-10-20

    The Bayesian Infrasonic Source Localization (BISL) methodology is examined and simplified providing a generalized method of estimating the source location and time for an infrasonic event and the mathematical framework is used therein. The likelihood function describing an infrasonic detection used in BISL has been redefined to include the von Mises distribution developed in directional statistics and propagation-based, physically derived celerity-range and azimuth deviation models. Frameworks for constructing propagation-based celerity-range and azimuth deviation statistics are presented to demonstrate how stochastic propagation modelling methods can be used to improve the precision and accuracy of the posterior probability density function describing the source localization. Infrasonic signals recorded at a number of arrays in the western United States produced by rocket motor detonations at the Utah Test and Training Range are used to demonstrate the application of the new mathematical framework and to quantify the improvement obtained by using the stochastic propagation modelling methods. Moreover, using propagation-based priors, the spatial and temporal confidence bounds of the source decreased by more than 40 per cent in all cases and by as much as 80 per cent in one case. Further, the accuracy of the estimates remained high, keeping the ground truth within the 99 per cent confidence bounds for all cases.

  20. Improved Bayesian Infrasonic Source Localization for regional infrasound

    DOE PAGES

    Blom, Philip S.; Marcillo, Omar; Arrowsmith, Stephen J.

    2015-10-20

    The Bayesian Infrasonic Source Localization (BISL) methodology is examined and simplified providing a generalized method of estimating the source location and time for an infrasonic event and the mathematical framework is used therein. The likelihood function describing an infrasonic detection used in BISL has been redefined to include the von Mises distribution developed in directional statistics and propagation-based, physically derived celerity-range and azimuth deviation models. Frameworks for constructing propagation-based celerity-range and azimuth deviation statistics are presented to demonstrate how stochastic propagation modelling methods can be used to improve the precision and accuracy of the posterior probability density function describing themore » source localization. Infrasonic signals recorded at a number of arrays in the western United States produced by rocket motor detonations at the Utah Test and Training Range are used to demonstrate the application of the new mathematical framework and to quantify the improvement obtained by using the stochastic propagation modelling methods. Moreover, using propagation-based priors, the spatial and temporal confidence bounds of the source decreased by more than 40 per cent in all cases and by as much as 80 per cent in one case. Further, the accuracy of the estimates remained high, keeping the ground truth within the 99 per cent confidence bounds for all cases.« less

  1. Scanning Linear Estimation: Improvements over Region of Interest (ROI) Methods

    PubMed Central

    Kupinski, Meredith K.; Clarkson, Eric W.; Barrett, Harrison H.

    2013-01-01

    In tomographic medical imaging, signal activity is typically estimated by summing voxels from a reconstructed image. We introduce an alternative estimation scheme that operates on the raw projection data and offers a substantial improvement, as measured by the ensemble mean-square error (EMSE), when compared to using voxel values from a maximum-likelihood expectation-maximization (MLEM) reconstruction. The scanning-linear (SL) estimator operates on the raw projection data and is derived as a special case of maximum-likelihood (ML) estimation with a series of approximations to make the calculation tractable. The approximated likelihood accounts for background randomness, measurement noise, and variability in the parameters to be estimated. When signal size and location are known, the SL estimate of signal activity is an unbiased estimator, i.e., the average estimate equals the true value. By contrast, standard algorithms that operate on reconstructed data are subject to unpredictable bias arising from the null functions of the imaging system. The SL method is demonstrated for two different tasks: 1) simultaneously estimating a signal's size, location, and activity; 2) for a fixed signal size and location, estimating activity. Noisy projection data are realistically simulated using measured calibration data from the multi-module multi-resolution (M3R) small-animal SPECT imaging system. For both tasks the same set of images is reconstructed using the MLEM algorithm (80 iterations), and the average and the maximum value within the ROI are calculated for comparison. This comparison shows dramatic improvements in EMSE for the SL estimates. To show that the bias in ROI estimates affects not only absolute values but also relative differences, such as those used to monitor response to therapy, the activity estimation task is repeated for three different signal sizes. PMID:23384998

  2. 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.

  3. Short Period Surface Wave Dispersion Across the Mediterranean Region: Improvements Using Regional Seismic Networks

    DTIC Science & Technology

    2007-09-01

    Italy, the North Sea Basin, the Silesian Basin in northern Germany and Poland, the Tyrrhenian and Adriatic Basins surrounding Italy, and the...Turkey and Northern Anatolian Fault (ANF) experiments in Turkey, as well as other temporary deployments such as the Mid- Sea Experiment and the...goal is to improve data coverage in the Mediterranean Sea , North Africa, and parts of the Middle East.We plan to continue to improve the data set in

  4. 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…

  5. 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…

  6. 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…

  7. 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.…

  8. 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…

  9. Improved construction materials for polar regions using microcellular thermoplastic foams

    NASA Technical Reports Server (NTRS)

    Cunningham, Daniel J.

    1994-01-01

    Microcellular polymer foams (MCF) are thermoplastic foams with very small cell diameters, less than 10 microns, and very large cell densities, 10(exp 9) to 10(exp 15) cells per cubic centimeter of unfoamed material. The concept of foaming polymers with microcellular voids was conceived to reduce the amount of material used for mass-produced items without compromising the mechanical properties. The reasoning behind this concept was that if voids smaller than the critical flaw size pre-existing in polymers were introduced into the matrix, they would not affect the overall strength of the product. MCF polycarbonate (PC), polystyrene (PS), and polyvinyl chloride (PVC) were examined to determine the effects of the microstructure towards the mechanical properties of the materials at room and arctic temperatures. Batch process parameters were discovered for these materials and foamed samples of three densities were produced for each material. To quantify the toughness and strength of these polymers, the tensile yield strength, tensile toughness, and impact resistance were measured at room and arctic temperatures. The feasibility of MCF polymers has been demonstrated by the consistent and repeatable MCF microstructures formed, but the improvements in the mechanical properties were not conclusive. Therefore the usefulness of the MCF polymers to replace other materials in arctic environments is questionable.

  10. 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.

  11. 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

  12. 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

  13. 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.

  14. 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.

  15. 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.

  16. 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...

  17. 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...

  18. 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...

  19. 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...

  20. 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...

  1. Southern Regional Action Plan To Improve the Quality of Early Care and Education. Southern Regional Task Force on Child Care.

    ERIC Educational Resources Information Center

    Southern Inst. on Children and Families, Columbia, SC.

    This booklet presents the action plan developed by the Southern Regional Task Force on Child Care for improving the quality of early care and education (ECE) in southern states. Also included in the booklet are tables that represent data collected from 16 participating states and the District of Columbia on state child care quality standards and…

  2. 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.

  3. Bi-Regional Educational Improvement Forum (Atlanta, Georgia, November 19-20, 1979).

    ERIC Educational Resources Information Center

    Appalachia Educational Lab., Charleston, WV.

    The Bi-Regional Educational Improvement Forum in Atlanta, Georgia (November 1979) considered three areas of school improvement, including State Department of Education (SEA) delivery systems and the use of technology to improve schooling. The three forum articles concerned with delivery systems treat the transformation of policies emanating from…

  4. 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…

  5. 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…

  6. 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...

  7. 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)

  8. 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...

  9. 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)

  10. 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.

  11. 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

  12. 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

  13. 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.

  14. 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

  15. 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…

  16. Report: Agency-Wide Application of Region 7 NPDES Program Process Improvements Could Increase EPA Efficiency

    EPA Pesticide Factsheets

    Report #11-P-0315, July 6, 2011. Although Region 7 NPDES Kaizen event participants continued to follow up on the commitments and action items identified, no single authority was responsible for tracking the process improvement outcomes.

  17. 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

  18. 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...

  19. 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....

  20. 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....

  1. 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...

  2. 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...

  3. 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...

  4. 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....

  5. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2006-03-01

    Low-energy defibrillation is very desirable in cardiac rhythm management. We previously reported that ventricular fibrillation (VF) can be synchronized with a novel synchronized pacing technique (SyncP) using low-energy pacing pulses. This study sought to create a line of block during VF using SyncP. SyncP was performed in six isolated rabbit hearts during VF using optical recording to control the delivery of pacing pulses in real time. Four pacing electrodes with interelectrode distances of 5 mm were configured in a line along and across the myocardial fiber direction. The electrodes were controlled independently (independent mode) or fired together (simultaneous mode). Significant wavefront synchronization was observed along the electrode line as indicated by a decrease in variance. With the independent SyncP protocol, the decrease in the variance was 19.3 and 13.7% (P<0.001) for the along-, and across-fiber configurations, respectively. With the simultaneous SyncP protocol, the variance was reduced by 24.2 and 10.7% (P<0.001) in the along- and across-fiber configurations. The effect of synchronization dropped off with distance from the line of pacing. We conclude that SyncP can effectively create a line of functional block that isolates regions of VF propagation. Further optimization of this technique may prove useful for low-energy ventricular defibrillation.

  7. Independent component analysis applied to self-paced functional MR imaging paradigms.

    PubMed

    Moritz, Chad H; Carew, John D; McMillan, Alan B; Meyerand, M Elizabeth

    2005-03-01

    Self-paced functional MR imaging (fMRI) paradigms, in which the task timing is determined by the subject's performance, can offer several advantages over commonly applied paradigms with predetermined stimulus timing. Independent component analysis (ICA) does not require specification of a timed response function, and could be an advantageous method of deriving results from fMRI data sets with varying response timings and durations. In this study normal volunteers (N = 10) each performed two self-paced fMRI motor and arithmetic paradigms. Individual data sets were analyzed with the Infomax spatial ICA algorithm. Conventional regression analysis was performed for comparison purposes. Spatial ICA effectively produced task-related components from each of the self-paced data sets, even in a few cases where regression analysis yielded non-specific functional maps. For the motor paradigm, these components consistently mapped to primary motor areas. ICA of the arithmetic paradigm yielded multiple task-related components that variably mapped to regions of parietal and frontal lobes. Regression analysis generally yielded similar spatial maps. The multiple task-related ICA components that were sometimes produced from each self-paced data set can be challenging to identify and evaluate for significance. These preliminary results indicate that ICA is useful as an exploratory and complementary method to conventional regression analysis for fMRI of self-paced paradigms.

  8. 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

  9. Characteristics of Midwest Region School Districts Identified for Improvement. Summary. Issues & Answers. REL 2012-No. 121

    ERIC Educational Resources Information Center

    van der Ploeg, Arie; Wan, Yinmei; Garcia, Alicia N.; Wraight, Sara; Burke, Matthew; Norbury, Heather; Gerdeman, R. Dean

    2012-01-01

    This report presents statistical profiles for the Midwest Region states of school districts designated as "in improvement" for school year 2009/10 under accountability provisions of the No Child Left Behind Act of 2001 and compares the prevalence and characteristics of these districts and those of districts not in improvement. It also…

  10. 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

  11. 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.

  12. 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.

  13. 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

  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. 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.

  19. Microcomputer Applications for Health Care Professionals. Volume I. Curriculum Improvement Project. Region II.

    ERIC Educational Resources Information Center

    Bruce, Lucy

    This volume is one of three in a self-paced computer literacy course that gives allied health students a firm base of knowledge concerning computer usage in the hospital environment. It also develops skill in several applications software packages. Volume I contains materials for a three-hour course. A student course syllabus provides this…

  20. Microcomputer Applications for Health Care Professionals. Volume II. Curriculum Improvement Project. Region II.

    ERIC Educational Resources Information Center

    Bruce, Lucy

    This volume is one of three in a self-paced computer literacy course that gives allied health students a firm base of knowledge concerning computer usage in the hospital environment. It also develops skill in several applications software packages. Volume II contains materials for three one-hour courses on word processing applications, spreadsheet…

  1. The West African Health Organization's experience in improving the health research environment in the ECOWAS region.

    PubMed

    Aidam, Jude; Sombié, Issiaka

    2016-04-20

    The West African Health Organization (WAHO) implemented a research development program in West Africa during 2009-2013 using the Knowledge for Better Health Research Capacity Development Framework, developed by Pang et al. (Bull World Health Organ 81(11):815-820, 2003), on strategies used to improve the research environment. The framework has the following components: stewardship, financing, sustainable resourcing and research utilization. This paper describes how WAHO implemented this research development program in the West African region to help improve the research environment and lessons learnt. This is a retrospective review of the regional research development program using a triangulation of activity reports, an independent evaluation and the authors' experiences with stakeholders. This program was designed to address gaps along the components of the framework and to improve partnership. The activities, results and challenges are summarised for each component of the framework. The independent evaluation was conducted using over 180 semi-structured interviews of key stakeholders in the West African region and activity reports. WAHO and major stakeholders validated these findings during a regional meeting. All 15 ECOWAS countries benefited from this regional research development program. WAHO provided technical and financial support to eight countries to develop their policies, priorities and plans for research development to improve their research governance. WAHO, along with other technical and financial partners, organised many capacity-strengthening trainings in health systems research methodology, resource mobilization, ethical oversight and on HRWeb, a research information management platform. WAHO helped launch a regional network of health research institutions to improve collaboration between regional participating institutions. Further, WAHO developed strategic research partnerships and mobilised additional funding to support the program. The program

  2. Coronary hemodynamics and myocardial metabolism during and after pacing stress in normal humans.

    PubMed

    Camici, P; Marraccini, P; Marzilli, M; Lorenzoni, R; Buzzigoli, G; Puntoni, R; Boni, C; Bellina, C R; Klassen, G A; L'Abbate, A

    1989-09-01

    We investigated coronary hemodynamics, myocardial utilization of circulating substrates (by coronary sinus catheterization), and overall use of oxidative fuels (by regional indirect calorimetry) in healthy adults during incremental atrial pacing (up to 159 +/- 9 beats/min), and during 25 min of recovery. Great cardiac vein flow (thermodilution) increased from 52 +/- 9 to 115 +/- 15 ml/min (P less than 0.001) with pacing; myocardial O2 uptake (301 +/- 53 to 593 +/- 71 mumol/min, P less than 0.001) and CO2 production (225 +/- 37 to 518 +/- 66 mumol/min, P less than 0.005) paralleled the pacing-induced rise in rate-pressure product (9.4 +/- 0.9 to 21.1 +/- 1.1 mmHg.beat. min-1.10(-3), P less than 0.001). During recovery, all the above variables returned to base line within 5 min, but myocardial O2 extraction remained depressed (67 +/- 2 vs. 71 +/- 3%, P less than 0.05). Circulating glucose uptake rose linearly with pacing (P less than 0.05) and remained above base line throughout recovery. By contrast, free fatty acid (FFA) uptake (10 mumol/min) did not increase with pacing and fell during recovery (P less than 0.01). Calorimetry, however, showed that net lipid oxidation exceeded FFA uptake throughout the study, whereas net carbohydrate oxidation was small at base line, rose significantly at maximal pacing (62% of myocardial energy output), and remained above base line during recovery (32% of energy output). In the basal state as well as during recovery, myocardial uptake of glucose equivalents (lactate plus glucose plus pyruvate) was in excess of carbohydrate oxidation, indicating nonoxidative disposal of these substrates.(ABSTRACT TRUNCATED AT 250 WORDS)

  3. 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.

  4. 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.

  5. 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

  6. Pro-region engineering for improved yeast display and secretion of brain derived neurotrophic factor.

    PubMed

    Burns, Michael L; Malott, Thomas M; Metcalf, Kevin J; Puguh, Arthya; Chan, Jonah R; Shusta, Eric V

    2016-03-01

    Brain derived neurotrophic factor (BDNF) is a promising therapeutic candidate for a variety of neurological diseases. However, it is difficult to produce as a recombinant protein. In its native mammalian context, BDNF is first produced as a pro-protein with subsequent proteolytic removal of the pro-region to yield mature BDNF protein. Therefore, in an attempt to improve yeast as a host for heterologous BDNF production, the BDNF pro-region was first evaluated for its effects on BDNF surface display and secretion. Addition of the wild-type pro-region to yeast BDNF production constructs improved BDNF folding both as a surface-displayed and secreted protein in terms of binding its natural receptors TrkB and p75, but titers remained low. Looking to further enhance the chaperone-like functions provided by the pro-region, two rounds of directed evolution were performed, yielding mutated pro-regions that further improved the display and secretion properties of BDNF. Subsequent optimization of the protease recognition site was used to control whether the produced protein was in pro- or mature BDNF forms. Taken together, we have demonstrated an effective strategy for improving BDNF compatibility with yeast protein engineering and secretion platforms. Copyright © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Improving integrated waste management at the regional level: the case of Lombardia.

    PubMed

    Rigamonti, Lucia; Falbo, Alida; Grosso, Mario

    2013-09-01

    The article summarises the main results of the 'Gestione Rifiuti in Lombardia: Analisi del ciclo di vita' (Waste management in Lombardia region: Life cycle assessment; GERLA) project. Life cycle assessment (LCA) has been selected by Regione Lombardia as a strategic decision support tool in the drafting of its new waste management programme. The goal was to use the life cycle thinking approach to assess the current regional situation and thus to give useful strategic indications for the future waste management. The first phase of the study consisted of the LCA of the current management of municipal waste in the Lombardia region (reference year: 2009). The interpretation of such results has allowed the definition of four possible waste management scenarios for the year 2020, with the final goal being to improve the environmental performance of the regional system. The results showed that the current integrated waste management of Lombardia region is already characterised by good energy and environmental performances. However, there is still room for further improvement: actions based, on the one hand, on a further increase in recycling rates and, on the other hand, on a series of technological modifications, especially in food waste and residual waste management, can be undertaken to improve the overall system.

  8. Augmentation of Indian Regional Navigation Satellite System to Improve Dilution of Precision

    NASA Astrophysics Data System (ADS)

    Sarma, Achanta D.; Sultana, Quddusa; Srinivas, Vemuri Satya

    The Indian Regional Navigation Satellite System (IRNSS) is an autonomous and independent navigational system being developed by India. IRNSS will provide position, navigation and timing services for national applications. To improve accuracy, it can be augmented using GPS and pseudolites (pseudo-satellites). In this paper, the effect on DOP (Dilution of Precision) due to augmentation of the proposed constellation of IRNSS with pseudolites is investigated. GDOP is reduced to 163 (max) due to augmentation of IRNSS with two airport pseudolites (APLs). Due to augmentation of IRNSS with GPS, GDOP is reduced to 265 (max). The regional effect on DOP due to IRNSS is also investigated at different locations in the Indian region.

  9. 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.

  10. Day surgery regional anesthesia in children: safety and improving outcomes, do they make a difference?

    PubMed

    Deer, Jeremy D; Sawardekar, Amod; Suresh, Santhanam

    2016-12-01

    The objective of this review is to provide an overview of recent developments in pediatric regional anesthesia and elucidate outcomes as it relates to patient safety and overall satisfaction. Since the inception of the Pediatric Regional Anesthesia Network database, the acquisition of data has enabled the pediatric anesthesiologist to extrapolate results and translate them into useful outcomes. Despite the growing trend to provide regional anesthesia in the pediatric population, there continues to be a paucity of available research studies to evaluate outcomes of various regional nerve blocks. This review serves as a conduit to explore the most recent data available, in each regional anesthetic technique, as it relates to outcomes such as analgesia, patient safety and satisfaction. Despite the limited number of randomized controlled trials evaluating the safety of individual regional anesthetic techniques, the growing body of data, such as presented in the Pediatric Regional Anesthesia Network database, suggests a high degree of safety in performing various regional anesthetic modalities. Modern medicine should continue to embrace the use of regional anesthesia, particularly in the ambulatory setting, to reduce perioperative pain and improve patient outcomes.

  11. Improving Smallholder Farmer Biosecurity in the Mekong Region Through Change Management.

    PubMed

    Young, J R; Evans-Kocinski, S; Bush, R D; Windsor, P A

    2015-10-01

    Transboundary animal diseases including foot-and-mouth disease and haemorrhagic septicaemia remain a major constraint for improving smallholder large ruminant productivity in the Mekong region, producing negative impacts on rural livelihoods and compromising efforts to reduce poverty and food insecurity. The traditional husbandry practices of smallholders largely exclude preventive health measures, increasing risks of disease transmission. Although significant efforts have been made to understand the social aspects of change development in agricultural production, attention to improving the adoption of biosecurity has been limited. This study reviews smallholder biosecurity risk factors identified in the peer-reviewed literature and from field research observations conducted in Cambodia and Laos during 2006-2013, considering these in the context of a change management perspective aimed at improving adoption of biosecurity measures. Motivation for change, resistance to change, knowledge management, cultural dimensions, systems theory and leadership are discussed. Due to geographical, physical and resource variability, the implementation of biosecurity interventions suitable for smallholders is not a 'one size fits all'. Smallholders should be educated in biosecurity principles and empowered to make personal decisions rather than adopt prescribed pre-defined interventions. Biosecurity interventions should be aligned with smallholder farmer motivations, preferably offering clear short-term risk management benefits that elicit interest from smallholders. Linking biosecurity and disease control with improved livestock productivity provides opportunities for sustainable improvements in livelihoods. Participatory research and extension that improves farmer knowledge and practices offers a pathway to elicit sustainable broad-scale social change. However, examples of successes need to be communicated both at the 'evidence-based level' to influence regional policy

  12. Improvement of regional myocardial blood flow and function and reduction of infarct size with ivabradine: protection beyond heart rate reduction.

    PubMed

    Heusch, Gerd; Skyschally, Andreas; Gres, Petra; van Caster, Patrick; Schilawa, Dustin; Schulz, Rainer

    2008-09-01

    Effects of the bradycardic agent ivabradine on regional blood flow, contractile function, and infarct size were studied in a pig model of myocardial ischaemia/reperfusion. Heart rate reduction by beta-blockade is associated with negative inotropism and unmasked alpha-adrenergic coronary vasoconstriction. Ivabradine is the only available bradycardic agent for clinical use. Anaesthetized pigs were subjected to 90 min controlled left anterior descending coronary artery hypoperfusion and 120 min reperfusion. Regional blood flow was measured with microspheres, regional function with sonomicrometry, and infarct size with triphenyl tetrazolium chloride staining. Pigs received placebo or ivabradine (0.6 mg/kg i.v.) before or during ischaemia or before reperfusion, respectively. Pre-treatment with ivabradine reduced infarct size from 35 +/- 4 (SEM) to 19 +/- 4% of area at risk (AAR). Ivabradine 15-20 min after the onset of ischaemia increased regional myocardial blood flow from 2.12 +/- 0.31 to 3.55 +/- 0.56 microL/beat/g and systolic wall thickening from 6.7 +/- 1.0 to 16.3 +/- 3.0%; infarct size was reduced from 12 +/- 4 to 2 +/- 1% of AAR. Ivabradine 5 min before reperfusion still reduced infarct size from 36 +/- 4 to 21 +/- 5% of AAR. The benefit of ivabradine on flow and function was eliminated by atrial pacing, but part of the reduction of infarct size by ivabradine was not. Ivabradine's protection goes beyond heart rate reduction.

  13. Improved Phase Characterization of Far-Regional Body Wave Arrivals in Central Asia

    DTIC Science & Technology

    2009-09-30

    contains triplicated arrivals from upper-mantle discontinuities that, when properly identified, can improve seismic monitoring functions. However...templates are further analyzed in a non-linear fashion by comparing them with the synthetic seismograms, looking for quantitative explanations for... seismic monitoring functions. However, far-regional seismograms are typically under-utilized because along-path heterogeneity and phase interactions

  14. U.S. Forest Service Region 1 Lake Chemistry, NADP, and IMPROVE air quality data analysis

    Treesearch

    Jill Grenon; Mark Story

    2009-01-01

    This report was developed to address the need for comprehensive analysis of U.S. Forest Service (USFS) Region 1 air quality monitoring data. The monitoring data includes Phase 3 (long-term data) lakes, National Atmospheric Deposition Program (NADP), and Interagency Monitoring of Protected Visual Environments (IMPROVE). Annual and seasonal data for the periods of record...

  15. Adjusting the Stems Regional Forest Growth Model to Improve Local Predictions

    Treesearch

    W. Brad Smith

    1983-01-01

    A simple procedure using double sampling is described for adjusting growth in the STEMS regional forest growth model to compensate for subregional variations. Predictive accuracy of the STEMS model (a distance-independent, individual tree growth model for Lake States forests) was improved by using this procedure

  16. SERVE Regional Forum on School Improvement, Proceedings (Tampa, Florida, October 6-9, 1996).

    ERIC Educational Resources Information Center

    Chapman, Stephen

    The first SERVE Regional Forum on School Improvement brought together 300 educators from Alabama, Florida, Georgia, Mississippi, North Carolina, and South Carolina. These proceedings include: introductory information on SERVE, an introduction to the forum, the forum agenda, comments from participants, summaries of the keynote presentations, and…

  17. 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.

  18. 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.

  19. 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.

  20. Demonstrating Improvements from a NWP-based Satellite Precipitation Adjustment Technique in Tropical Mountainous Regions

    NASA Astrophysics Data System (ADS)

    Zhang, X.; Anagnostou, E. N.

    2016-12-01

    This research contributes to the improvement of high resolution satellite applications in tropical regions with mountainous topography. Such mountainous regions are usually covered by sparse networks of in-situ observations while quantitative precipitation estimation from satellite sensors exhibits strong underestimation of heavy orographically enhanced storm events. To address this issue, our research applies a satellite error correction technique based solely on high-resolution numerical weather predictions (NWP). Our previous work has demonstrated the accuracy of this method in two mid-latitude mountainous regions (Zhang et al. 2013*1, Zhang et al. 2016*2), while the current research focuses on a comprehensive evaluation in three topical mountainous regions: Colombia, Peru and Taiwan. In addition, two different satellite precipitation products, NOAA Climate Prediction Center morphing technique (CMORPH) and Precipitation Estimation from Remotely Sensed Information using Artificial Neural Networks-Cloud Classification System (PERSIANN-CCS), are considered. The study includes a large number of heavy precipitation events (68 events over the three regions) in the period 2004 to 2012. The NWP-based adjustments of the two satellite products are contrasted to their corresponding gauge-adjusted post-processing products. Preliminary results show that the NWP-based adjusted CMORPH product is consistently improved relative to both original and gauge-adjusted precipitation products for all regions and storms examined. The improvement of PERSIANN-CCS product is less significant and less consistent relative to the CMORPH performance improvements from the NWP-based adjustment. *1Zhang, Xinxuan, Emmanouil N. Anagnostou, Maria Frediani, Stavros Solomos, and George Kallos. "Using NWP simulations in satellite rainfall estimation of heavy precipitation events over mountainous areas." Journal of Hydrometeorology 14, no. 6 (2013): 1844-1858.*2 Zhang, Xinxuan, Emmanouil N. Anagnostou

  1. 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.

  2. Utility of High-Output His Pacing during Difficult AV Node Ablation. An Underutilized Strategy.

    PubMed

    Kanjwal, Khalil; Grubb, Blair P

    2016-06-01

    Atrioventricular (AV) node ablation is a commonly performed procedure for patients with chronic drug refractory atrial fibrillation (AF) with episodes of rapid ventricular response. We report on a 72-year-old man who had difficulty managing chronic drug refractory AFs with frequent hospitalizations for rapid ventricular rate. The patient was taken to the electrophysiology laboratory for AV node ablation. Extensive mapping and localization techniques of the compact AV node and ablation in the region were unsuccessful. Subsequently, high-output His bundle pacing using 20 mA at 2 ms of output energy was performed in an attempt to localize the His bundle in areas where high-output pacing resulted in a narrower QRS complex. Further ablations in the areas where pacing produced a narrower QRS complex resulted in complete heart block. This case highlights the importance of using this simple pacing maneuver to achieve complete heart block in patients in whom standard strategies to localize and ablate the compact AV node are unsuccessful.

  3. The pace of vocabulary growth during preschool predicts cortical structure at school age.

    PubMed

    Asaridou, Salomi S; Demir-Lira, Özlem Ece; Goldin-Meadow, Susan; Small, Steven L

    2017-04-01

    Children vary greatly in their vocabulary development during preschool years. Importantly, the pace of this early vocabulary growth predicts vocabulary size at school entrance. Despite its importance for later academic success, not much is known about the relation between individual differences in early vocabulary development and later brain structure and function. Here we examined the association between vocabulary growth in children, as estimated from longitudinal measurements from 14 to 58 months, and individual differences in brain structure measured in 3rd and 4th grade (8-10 years old). Our results show that the pace of vocabulary growth uniquely predicts cortical thickness in the left supramarginal gyrus. Probabilistic tractography revealed that this region is directly connected to the inferior frontal gyrus (pars opercularis) and the ventral premotor cortex, via what is most probably the superior longitudinal fasciculus III. Our findings demonstrate, for the first time, the relation between the pace of vocabulary learning in children and a specific change in the structure of the cerebral cortex, specifically, cortical thickness in the left supramarginal gyrus. They also highlight the fact that differences in the pace of vocabulary growth are associated with the dorsal language stream, which is thought to support speech perception and articulation. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. 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

  5. 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

  6. 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…

  7. 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…

  8. 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…

  9. 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:…

  10. 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…

  11. 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)

  12. 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)

  13. 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.

  14. Current State of Economic Returns from Education in China's Ethnic Regions and Explorations into Ways of Improvement

    ERIC Educational Resources Information Center

    Lijun, Zhang; Fei, Wang

    2010-01-01

    Economic development and social progress in China's ethnic minority regions depend on improvements in population attributes brought about by education. Developing education in China's ethnic regions is a project of fundamental significance for realizing sustainable economic and social development in the ethnic regions. Improving the economic…

  15. Improving GHG inventories by regional information exchange: a report from Asia

    PubMed Central

    Umemiya, Chisa

    2006-01-01

    Background The Parties to the United Nations Framework Convention on Climate Change (UNFCCC) are required to develop and report a national inventory of greenhouse gases not controlled by the Montreal Protocol. In the Asia region, "Workshops on Greenhouse Gas Inventories in Asia (WGIA)" have been organised annually since 2003 under the support of the government of Japan. WGIAs promote information exchange in the region to support countries' efforts to improve the quality of greenhouse gas inventories. This paper reports the major outcomes of the WGIAs and discusses the key aspects of information exchange in the region for the improvement of inventories. Results The major outcomes of WGIAs intended to help countries improve GHG inventories, can be summarised as follows: (1) identification of common issues and possible solutions by sector, (2) reporting country inventory practices, and (3) verification of the UNFCCC reporting requirements. Conclusion The workshops provided the opportunity for countries to share common issues and constraints pertinent to GHG inventories and to exchange information regarding possible solutions for those issues based on their own experience. The relevance of information exchange is determined due to emission sources, emitting mechanisms from sources, and technologies used. Information exchange about emission sources that are unique to Asia, like those of the agriculture sector, contributes significantly to the accumulation of knowledge at the regional and global levels. Enabling countries to verify their national circumstances with the reporting requirements under UNFCCC is also an essential part of the WGIA information exchange activities. PMID:16930465

  16. Improving GHG inventories by regional information exchange: a report from Asia.

    PubMed

    Umemiya, Chisa

    2006-08-23

    The Parties to the United Nations Framework Convention on Climate Change (UNFCCC) are required to develop and report a national inventory of greenhouse gases not controlled by the Montreal Protocol. In the Asia region, "Workshops on Greenhouse Gas Inventories in Asia (WGIA)" have been organised annually since 2003 under the support of the government of Japan. WGIAs promote information exchange in the region to support countries' efforts to improve the quality of greenhouse gas inventories. This paper reports the major outcomes of the WGIAs and discusses the key aspects of information exchange in the region for the improvement of inventories. The major outcomes of WGIAs intended to help countries improve GHG inventories, can be summarised as follows: (1) identification of common issues and possible solutions by sector, (2) reporting country inventory practices, and (3) verification of the UNFCCC reporting requirements. The workshops provided the opportunity for countries to share common issues and constraints pertinent to GHG inventories and to exchange information regarding possible solutions for those issues based on their own experience. The relevance of information exchange is determined due to emission sources, emitting mechanisms from sources, and technologies used. Information exchange about emission sources that are unique to Asia, like those of the agriculture sector, contributes significantly to the accumulation of knowledge at the regional and global levels. Enabling countries to verify their national circumstances with the reporting requirements under UNFCCC is also an essential part of the WGIA information exchange activities.

  17. 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.

  18. 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.

  19. Improving Ramsey spectroscopy in the extreme-ultraviolet region with a random-sampling approach

    SciTech Connect

    Eramo, R.; Bellini, M.; Corsi, C.; Liontos, I.; Cavalieri, S.

    2011-04-15

    Ramsey-like techniques, based on the coherent excitation of a sample by delayed and phase-correlated pulses, are promising tools for high-precision spectroscopic tests of QED in the extreme-ultraviolet (xuv) spectral region, but currently suffer experimental limitations related to long acquisition times and critical stability issues. Here we propose a random subsampling approach to Ramsey spectroscopy that, by allowing experimentalists to reach a given spectral resolution goal in a fraction of the usual acquisition time, leads to substantial improvements in high-resolution spectroscopy and may open the way to a widespread application of Ramsey-like techniques to precision measurements in the xuv spectral region.

  20. 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

  1. Reshaping Rural Schools in the Northwest Region: Lessons from Federal School Improvement Grant Implementation. REL 2016-107

    ERIC Educational Resources Information Center

    Scott, Caitlin; Ostler, Nora

    2016-01-01

    The five states in the Regional Educational Laboratory (REL) Northwest Region have many rural schools that have been designated as in need of improvement. And all five states had rural schools in the first cohort of federal School Improvement Grant (SIG) recipients. To address school improvement, the majority of those schools implemented the…

  2. Parent Involvement Activities in School Improvement Plans in the Northwest Region. Summary. Issues & Answers. REL 2008-No. 064

    ERIC Educational Resources Information Center

    Speth, Timothy; Saifer, Steffen; Forehand, Gregory

    2008-01-01

    This document presents a summary of the larger report, "Parent Involvement Activities in School Improvement Plans in the Northwest Region." Although the No Child Left Behind Act of 2001 (NCLB) spells out parent involvement requirements for schools in need of improvement, the majority of the Northwest Region school improvement plans…

  3. 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…

  4. Combined networked switching output feedback control with ?-region stability for performance improvement

    NASA Astrophysics Data System (ADS)

    Nikolakopoulos, George; Dritsas, Leonidas; Delshad, Saleh S.

    2014-06-01

    In this article, a combined networked switching output feedback control scheme, with a ?-region stability performance improvement module is presented. The network induced time delays, that are considered to be time varying and integer multiples of the sampling period, are being embedded in the system model, by state augmentation. The resulting model of the overall networked closed-loop system is switching, with the current measured round-trip time delay acting as the switching rule. Based on this modelling approach, a Linear Matrix Inequality (LMI) tuned switching output feedback controller is designed. The proposed approach establishes robustness against time delays and is able to guarantee the overall stability of the switching closed-loop system. Integrated in the controlled synthesis phase, an LMI tuned performance improvement module is being introduced, based on ?-region stability. Multiple simulation results are being presented that prove the efficacy of the proposed scheme.

  5. Improvement of Global and Regional Mean Sea Level Trends Derived from all Altimetry Missions.

    NASA Astrophysics Data System (ADS)

    Ablain, Michael; Benveniste, Jérôme; Faugere, Yannice; Larnicol, Gilles; Cazenave, Anny; Johannessen, Johnny A.; Stammer, Detlef; Timms, Gary

    2012-07-01

    The global mean sea level (GMSL) has been calculated on a continual basis since January 1993 using data from satellite altimetry missions. The global mean sea level (MSL) deduced from TOPEX/Poseidon, Jason-1 and Jason-2 is increasing with a global trend of 3.2 mm from 1993 to 2010 applying the post glacial rebound (MSL Aviso website http://www.jason.oceanobs.com/msl). Besides, the regional sea level trends bring out an inhomogeneous repartition of the ocean elevation with local MSL slopes ranging from +/- 8 mm/year. A study published in 2009 [Ablain et al., 2009] has shown that the global MSL trend uncertainty was estimated at +/-0.6 mm/year with a confidence interval of 90%. The main sources of errors at global and regional scales are due to the orbit calculation and the wet troposphere correction. But others sea-level components have also a significant impact on the long-term stability of MSL as for instance the stability of instrumental parameters and the atmospheric corrections. Thanks to recent studies performed in Sea Level Essential Climate Variable Project in the frame of the Climate Change Initiative, an ESA Programme, in addition to activities performed within the SALP/CNES, strong improvements have been provided for the estimation of the global and regional MSL trends. In this paper, we propose to describe them; they concern the orbit calculation thanks to new gravity fields, the atmospheric corrections thanks to ERA-interim reanalyses, the wet troposphere corrections thanks to the stability improvement, and also empirical corrections allowing us to link regional time series together better. These improvements are described at global and regional scale for all the altimetry missions.

  6. Regional Seismic Travel-Time Prediction, Uncertainty, and Location Improvement in Western Eurasia

    NASA Astrophysics Data System (ADS)

    Flanagan, M. P.; Myers, S. C.

    2004-12-01

    We investigate our ability to improve regional travel-time prediction and seismic event location using an a priori, three-dimensional velocity model of Western Eurasia and North Africa: WENA1.0 [Pasyanos et al., 2004]. Our objective is to improve the accuracy of seismic location estimates and calculate representative location uncertainty estimates. As we focus on the geographic region of Western Eurasia, the Middle East, and North Africa, we develop, test, and validate 3D model-based travel-time prediction models for 30 stations in the study region. Three principal results are presented. First, the 3D WENA1.0 velocity model improves travel-time prediction over the iasp91 model, as measured by variance reduction, for regional Pg, Pn, and P phases recorded at the 30 stations. Second, a distance-dependent uncertainty model is developed and tested for the WENA1.0 model. Third, an end-to-end validation test based on 500 event relocations demonstrates improved location performance over the 1-dimensional iasp91 model. Validation of the 3D model is based on a comparison of approximately 11,000 Pg, Pn, and P travel-time predictions and empirical observations from ground truth (GT) events. Ray coverage for the validation dataset is chosen to provide representative, regional-distance sampling across Eurasia and North Africa. The WENA1.0 model markedly improves travel-time predictions for most stations with an average variance reduction of 25% for all ray paths. We find that improvement is station dependent, with some stations benefiting greatly from WENA1.0 predictions (52% at APA, 33% at BKR, and 32% at NIL), some stations showing moderate improvement (12% at KEV, 14% at BOM, and 12% at TAM), some benefiting only slightly (6% at MOX, and 4% at SVE), and some are degraded (-6% at MLR and -18% at QUE). We further test WENA1.0 by comparing location accuracy with results obtained using the iasp91 model. Again, relocation of these events is dependent on ray paths that evenly

  7. 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…

  8. An Improved Anchor Shot Detection Method Using Fitness of Face Location and Dissimilarity of Icon Region

    NASA Astrophysics Data System (ADS)

    Keum, Ji-Soo; Lee, Hyon-Soo; Hagiwara, Masafumi

    In this letter, we propose an improved anchor shot detection (ASD) method in order to effectively retrieve anchor shots from news video. The face location and dissimilarity of icon region are used to reduce false alarms in the proposed method. According to the results of the experiment on several types of news video, the proposed method obtained high anchor detection results compared with previous methods.

  9. Pittsburgh Regional Healthcare Initiative puts new spin on improving healthcare quality.

    PubMed

    2002-11-01

    For nearly 4 years, the Pittsburgh Regional Healthcare Initiative (PRHI) has been working to improve the way healthcare is delivered in southwestern Pennsylvania by combining the voices and resources of hospitals, providers, the business community, insurers, health plans, and federal agencies. As one example of borrowing from business, the PRHI has created a new learning and management system, called Perfecting Patient Care, which is based on the Toyota Production System model and is now being used successfully in hospitals.

  10. 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...

  11. 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...

  12. 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...

  13. 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...

  14. Improving Regional Forecast by Assimilating Atmospheric InfraRed Sounder (AIRS) Profiles into WRF Model

    NASA Technical Reports Server (NTRS)

    Chou, Shih-Hung; Zavodsky, Brad; Jedlovec, Gary J.

    2009-01-01

    In data sparse regions, remotely-sensed observations can be used to improve analyses and produce improved forecasts. One such source comes from the Atmospheric InfraRed Sounder (AIRS), which together with the Advanced Microwave Sounding Unit (AMSU), represents one of the most advanced space-based atmospheric sounding systems. The purpose of this paper is to describe a procedure to optimally assimilate high resolution AIRS profile data into a regional configuration of the Advanced Research WRF (ARW) version 2.2 using WRF-Var. The paper focuses on development of background error covariances for the regional domain and background type, and an optimal methodology for ingesting AIRS temperature and moisture profiles as separate overland and overwater retrievals with different error characteristics. The AIRS thermodynamic profiles are derived from the version 5.0 Earth Observing System (EOS) science team retrieval algorithm and contain information about the quality of each temperature layer. The quality indicators were used to select the highest quality temperature and moisture data for each profile location and pressure level. The analyses were then used to conduct a month-long series of regional forecasts over the continental U.S. The long-term impacts of AIRS profiles on forecast were assessed against verifying NAM analyses and stage IV precipitation data.

  15. A 'regionalized' approach based on climate zones for improved Interpolation of global precipitation δ18O

    NASA Astrophysics Data System (ADS)

    Terzer, S.; Araguas, L.; Aggarwal, P. K.

    2012-12-01

    Spatial interpolation of point-based precipitation isotope measurements is a common task required to generate 'isoscapes' which are used for various applications in hydrology, climatology, ecology and forensics. While various prediction methods have been explored (employing interpolation and/or multiple regression), one of their basic objectives is to identify a globally suitable parameterization. On the other hand, regional models have been developed to improve interpolation on a limited spatial extent. We have developed a new approach based on climate zones to 'regionalize' regression parameters, building a global prediction model based on a set of regionally adjusted multiple regression/interpolation procedures. A climate zone boundary fuzzification technique was used to smooth out climate zone transitions. Evaluation of the new model in comparison with a globally fitted one shows that the regionalized model has a lower model uncertainty at similar confidence intervals. The resulting global interpolation thus provides an improved and reliable map of precipitation isotopes with significant differences in predicted values in most parts of the world.

  16. Improving Renal Cell Carcinoma Classification by Automatic Region of Interest Selection

    PubMed Central

    Chaudry, Qaiser; Raza, S. Hussain; Sharma, Yachna; Young, Andrew N.; Wang, May D.

    2016-01-01

    In this paper, we present an improved automated system for classification of pathological image data of renal cell carcinoma. The task of analyzing tissue biopsies, generally performed manually by expert pathologists, is extremely challenging due to the variability in the tissue morphology, the preparation of tissue specimen, and the image acquisition process. Due to the complexity of this task and heterogeneity of patient tissue, this process suffers from inter-observer and intra-observer variability. In continuation of our previous work, which proposed a knowledge-based automated system, we observe that real life clinical biopsy images which contain necrotic regions and glands significantly degrade the classification process. Following the pathologist’s technique of focusing on selected region of interest (ROI), we propose a simple ROI selection process which automatically rejects the glands and necrotic regions thereby improving the classification accuracy. We were able to improve the classification accuracy from 90% to 95% on a significantly heterogeneous image data set using our technique.

  17. 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

  18. 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.

  19. 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.

  20. 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

  1. 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.

  2. DDD(R)-pacing, but not AAI(R)-pacing induces left ventricular desynchronization in patients with sick sinus syndrome: tissue-Doppler and 3D echocardiographic evaluation in a randomized controlled comparison.

    PubMed

    Albertsen, Andi Eie; Nielsen, Jens Cosedis; Poulsen, Steen Hvitfeldt; Mortensen, Peter Thomas; Pedersen, Anders Kirstein; Hansen, Peter Steen; Jensen, Henrik Kjaerulf; Egeblad, Henrik

    2008-02-01

    Increasing evidence from randomized trials and experimental studies indicates that right ventricular (RV) pacing may induce congestive heart failure. We studied regional left ventricular (LV) dyssynchrony and global LV function in 50 consecutive patients with sick sinus syndrome (SSS) randomized to either atrial pacing [AAI(R)] or dual chamber RV-pacing [DDD(R)]. Fifty consecutive patients were randomized to AAI(R) or DDD(R)-pacing. Tissue-Doppler imaging was used to quantify LV dyssynchrony in terms of number of segments with delayed longitudinal contraction (DLC). Left ventricular ejection fraction (LVEF) was measured using three-dimensional echocardiography. Dyssynchrony was more pronounced in the DDD(R)-group than in the AAI(R)-group at the 12 months follow-up (P < 0.05). This reflected a significant increase of dyssynchrony in the DDD(R)-group from baseline to the 12 months follow-up (1.3 +/- 1 to 2.1 +/- 1 segments displaying DLC per patient), P < 0.05. No change was observed in the AAI(R)-group (1.6 +/- 2 to 1.3 +/- 2 segments displaying DLC per patient, NS). No difference in LVEF, NYHA or NT-proBNP was observed between AAI(R)- and DDD(R)-mode after 12 months of pacing although LVEF decreased significantly in the DDD(R)-group from baseline (63.1 +/- 8%) to the 12 months follow-up (59.3 +/- 8%, P < 0.05), while LVEF remained unchanged in the AAI(R)-group (61.5 +/- 11% at baseline vs. 62.3 +/- 7% after 12 months, NS. In patients with SSS, DDD(R)-pacing but not AAI(R)-pacing induces significant LV desynchronization and reduction of LVEF.

  3. Using an international clinical registry of regional anesthesia to identify targets for quality improvement.

    PubMed

    Sites, Brian D; Barrington, Michael J; Davis, Matthew

    2014-01-01

    Despite the widespread use of regional anesthesia, limited information on clinical performance exists. Institutions, therefore, have little knowledge of how they are performing in regard to both safety and effectiveness. In this study, we demonstrate how a medical institution (or physician/physician group) may use data from a multicenter clinical registry of regional anesthesia to inform quality improvement strategies. We analyzed data from the International Registry of Regional Anesthesia that includes prospective data on peripheral regional anesthesia procedures from 19 centers located around the world. Using data from the clinical registry, we present summary statistics of the overall safety and effectiveness of regional anesthesia. Furthermore, we demonstrate, using a variety of performance measures, how these data can be used by hospitals to identify areas for quality improvement. To do so, we compare the performance of 1 member institution (a US medical center in New Hampshire) to that of the other 18 member institutions of the clinical registry. The clinical registry contained information on 23,271 blocks that were performed between June 1, 2011, and May 1, 2014, on 16,725 patients. The overall success rate was 96.7%, immediate complication rate was 2.2%, and the all-cause 60-day rate of neurological sequelae was 8.3 (95% confidence interval, 7.2- 9.7) per 10,000. Registry-wide major hospital events included 7 wrong-site blocks, 3 seizures, 1 complete heart block, 1 retroperitoneal hematoma, and 3 pneumothoraces. For our reference medical center, we identified areas meriting quality improvement. Specifically, after accounting for differences in the age, sex, and health status of patient populations, the reference medical center appeared to rely more heavily on opioids for postprocedure management, had higher patient pain scores, and experienced delayed discharge when compared with other member institutions. To our knowledge, this is the first large

  4. Using an International Clinical Registry of Regional Anesthesia to Identify Targets for Quality Improvement

    PubMed Central

    Sites, Brian D.; Barrington, Michael J.; Davis, Matthew

    2014-01-01

    Background Despite the widespread use of regional anesthesia, limited information on clinical performance exists. Institutions, therefore, have little knowledge of how they are performing in regards to both safety and effectiveness. In this study, we demonstrate how a medical institution (or physician/physician group) may use data from a multi-center clinical registry of regional anesthesia to inform quality improvement strategies. Methods We analyzed data from the International Registry of Regional Anesthesia that includes prospective data on peripheral regional anesthesia procedures from 19 centers located around the world. Using data from the clinical registry, we present summary statistics of the overall safety and effectiveness of regional anesthesia. Furthermore, we demonstrate, using a variety of performance measures, how these data can be used by hospitals to identify areas for quality improvement. To do so, we compare the performance of one member institution (a United States medical center in New Hampshire) to that of the other 18 member institutions of the clinical registry. Results The clinical registry contained information on 23,271 blocks that were performed between June 1, 2011, and May 1, 2014, on 16,725 patients. The overall success rate was 96.7%, immediate complication rate was 2.2%, and the all-cause 60-day rate of neurological sequelae was 8.3 (95% CI, 7.2–9.7) per 10,000. Registry wide major hospital events included 7 wrong site blocks, 3 seizures, 1 complete heart block, 1 retroperitoneal hematoma, and 3 pneumothoraces. For our reference medical center, we identified areas meriting quality improvement. Specifically, after accounting for differences in the age, sex, and health status of patient populations, the reference medical center appeared to rely more heavily on opioids for post procedure management, had higher patient pain scores, and experienced delayed discharge when compared with other member institutions. Conclusions To our

  5. The World Health Organization African region laboratory accreditation process: improving the quality of laboratory systems in the African region.

    PubMed

    Gershy-Damet, Guy-Michel; Rotz, Philip; Cross, David; Belabbes, El Hadj; Cham, Fatim; Ndihokubwayo, Jean-Bosco; Fine, Glen; Zeh, Clement; Njukeng, Patrick A; Mboup, Souleymane; Sesse, Daniel E; Messele, Tsehaynesh; Birx, Deborah L; Nkengasong, John N

    2010-09-01

    Few developing countries have established laboratory quality standards that are affordable and easy to implement and monitor. To address this challenge, the World Health Organization Regional Office for Africa (WHO AFRO) established a stepwise approach, using a 0- to 5-star scale, to the recognition of evolving fulfillment of the ISO 15189 standard rather than pass-fail grading. Laboratories that fail to achieve an assessment score of at least 55% will not be awarded a star ranking. Laboratories that achieve 95% or more will receive a 5-star rating. This stepwise approach acknowledges to laboratories where they stand, supports them with a series of evaluations to use to demonstrate improvement, and recognizes and rewards their progress. WHO AFRO's accreditation process is not intended to replace established ISO 15189 accreditation schemes, but rather to provide an interim pathway to the realization of international laboratory standards. Laboratories that demonstrate outstanding performance in the WHO-AFRO process will be strongly encouraged to enroll in an established ISO 15189 accreditation scheme. We believe that the WHO-AFRO approach for laboratory accreditation is affordable, sustainable, effective, and scalable.

  6. 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.

  7. Optimization of regional navigation satellite constellation by improved NSGA-II algorithm

    NASA Astrophysics Data System (ADS)

    Chang, Hui; Hu, Xiulin; Zhang, Yunyu; Zeng, Yujiang; Wang, Ying

    2009-12-01

    In this paper, the non-dominated sorting genetic algorithm II (NSGA-II) based on the concept of Pareto optimal is improved. A new algorithm with lower O(MNlogN) computational complexity to construct non-dominated set replaces the NSGA-II original fast non-dominated sorting algorithm with O(MN2) com-putational complexity. The new algorithm improves operating efficiency of NSGA-II significantly. Based on the combination of the improved NSGA-II algorithm and regional navigation satellite constellation design, a new idea to design regional navigation satellite constellation is proposed in this paper. The new idea is implemented by Satellite Tool Kits (STK) and Matlab: the improved NSGA-II algorithm is implemented by Matlab and the calculation of the objective function values is implemented by STK. STK/Connect interface is used to integrate STK and Matlab into one simulation. Simulation results show that new idea has some advantages over the traditional methods, being more efficient, more flexible and more comprehensive.

  8. 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.

  9. 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.

  10. 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.

  11. The impact of SLMTA in improving laboratory quality systems in the Caribbean Region

    PubMed Central

    Guevara, Giselle; Gordon, Floris; Irving, Yvette; Whyms, Ismae; Parris, Keith; Beckles, Songee; Maruta, Talkmore; Ndlovu, Nqobile; Albalak, Rachel; Alemnji, George

    2016-01-01

    Background Past efforts to improve laboratory quality systems and to achieve accreditation for better patient care in the Caribbean Region have been slow. Objective To describe the impact of the Strengthening of Laboratory Management Toward Accreditation (SLMTA) training programme and mentorship amongst five clinical laboratories in the Caribbean after 18 months. Method Five national reference laboratories from four countries participated in the SLMTA programme that incorporated classroom teaching and implementation of improvement projects. Mentors were assigned to the laboratories to guide trainees on their improvement projects and to assist in the development of Quality Management Systems (QMS). Audits were conducted at baseline, six months, exit (at 12 months) and post-SLMTA (at 18 months) using the Stepwise Laboratory Quality Improvement Process Towards Accreditation (SLIPTA) checklist to measure changes in implementation of the QMS during the period. At the end of each audit, a comprehensive implementation plan was developed in order to address gaps. Results Baseline audit scores ranged from 19% to 52%, corresponding to 0 stars on the SLIPTA five-star scale. After 18 months, one laboratory reached four stars, two reached three stars and two reached two stars. There was a corresponding decrease in nonconformities and development of over 100 management and technical standard operating procedures in each of the five laboratories. Conclusion The tremendous improvement in these five Caribbean laboratories shows that SLMTA coupled with mentorship is an effective, user-friendly, flexible and customisable approach to the implementation of laboratory QMS. It is recommended that other laboratories in the region consider using the SLMTA training programme as they engage in quality systems improvement and preparation for accreditation. PMID:27066396

  12. Semirational Directed Evolution of Loop Regions in Aspergillus japonicus β-Fructofuranosidase for Improved Fructooligosaccharide Production

    PubMed Central

    Trollope, K. M.; Görgens, J. F.

    2015-01-01

    The Aspergillus japonicus β-fructofuranosidase catalyzes the industrially important biotransformation of sucrose to fructooligosaccharides. Operating at high substrate loading and temperatures between 50 and 60°C, the enzyme activity is negatively influenced by glucose product inhibition and thermal instability. To address these limitations, the solvent-exposed loop regions of the β-fructofuranosidase were engineered using a combined crystal structure- and evolutionary-guided approach. This semirational approach yielded a functionally enriched first-round library of 36 single-amino-acid-substitution variants with 58% retaining activity, and of these, 71% displayed improved activities compared to the parent. The substitutions yielding the five most improved variants subsequently were exhaustively combined and evaluated. A four-substitution combination variant was identified as the most improved and reduced the time to completion of an efficient industrial-like reaction by 22%. Characterization of the top five combination variants by isothermal denaturation assays indicated that these variants displayed improved thermostability, with the most thermostable variant displaying a 5.7°C increased melting temperature. The variants displayed uniquely altered, concentration-dependent substrate and product binding as determined by differential scanning fluorimetry. The altered catalytic activity was evidenced by increased specific activities of all five variants, with the most improved variant doubling that of the parent. Variant homology modeling and computational analyses were used to rationalize the effects of amino acid changes lacking direct interaction with substrates. Data indicated that targeting substitutions to loop regions resulted in improved enzyme thermostability, specific activity, and relief from product inhibition. PMID:26253664

  13. weather@home 2: validation of an improved global-regional climate modelling system

    NASA Astrophysics Data System (ADS)

    Guillod, Benoit P.; Jones, Richard G.; Bowery, Andy; Haustein, Karsten; Massey, Neil R.; Mitchell, Daniel M.; Otto, Friederike E. L.; Sparrow, Sarah N.; Uhe, Peter; Wallom, David C. H.; Wilson, Simon; Allen, Myles R.

    2017-05-01

    Extreme weather events can have large impacts on society and, in many regions, are expected to change in frequency and intensity with climate change. Owing to the relatively short observational record, climate models are useful tools as they allow for generation of a larger sample of extreme events, to attribute recent events to anthropogenic climate change, and to project changes in such events into the future. The modelling system known as weather@home, consisting of a global climate model (GCM) with a nested regional climate model (RCM) and driven by sea surface temperatures, allows one to generate a very large ensemble with the help of volunteer distributed computing. This is a key tool to understanding many aspects of extreme events. Here, a new version of the weather@home system (weather@home 2) with a higher-resolution RCM over Europe is documented and a broad validation of the climate is performed. The new model includes a more recent land-surface scheme in both GCM and RCM, where subgrid-scale land-surface heterogeneity is newly represented using tiles, and an increase in RCM resolution from 50 to 25 km. The GCM performs similarly to the previous version, with some improvements in the representation of mean climate. The European RCM temperature biases are overall reduced, in particular the warm bias over eastern Europe, but large biases remain. Precipitation is improved over the Alps in summer, with mixed changes in other regions and seasons. The model is shown to represent the main classes of regional extreme events reasonably well and shows a good sensitivity to its drivers. In particular, given the improvements in this version of the weather@home system, it is likely that more reliable statements can be made with regards to impact statements, especially at more localized scales.

  14. Optimizing paced ventricular function in patients with and without repaired congenital heart disease by contractility-guided lead implant.

    PubMed

    Karpawich, Peter P; Singh, Harinder; Zelin, Kathleen

    2015-01-01

    This study evaluates the concept of optimizing ventricular pacing in regard to functional cardiac response. Lead implant based on physiologic variables of contractility at various sites was performed in patients with and without congenital heart disease (CHD). Since right ventricular apical pacing may adversely alter contractility and myocellular function, septal and outflow tract pacing have been advocated. However, there are few studies in the young and essentially none in those with CHD. A total of 113 consecutive patients with and without repaired CHD, aged two to 51 (median 16), some with preexisting epicardial pacemakers, underwent transvenous pacemaker implant using standard sensing/pacing indices plus measurements of pressures, QRS, and contractility responses at each of five predefined potential ventricular implant sites: apex, inflow-, low-, mid-, and infundibular/outflow-septal with each patient serving as his/her own control. Implant was at the site of best contractility with active-fixation, low-threshold steroid-eluting leads. Measured contractility indices varied up to 31% (mean 12%) between sites per patient. Septal regions (mid-, inflow-, and low-) were associated with the most optimal and right ventricular epicardial showed the worst contractility (P < 0.05) responses. Apex was optimal in some CHD patients. Threshold and sensing were comparable up to 11 years (mean 7) postimplant regardless of septal site. There is no single "sweet spot" for optimal ventricular pacing, and the best implant sites are patient and CHD variable. Current lead designs ensure chronic stability/performance regardless of site. Proactive contractility-guided pacing implant can optimize chronic paced ventricular function. ©2014 Wiley Periodicals, Inc.

  15. 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.

  16. 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.

  17. Improvement of global and regional mean sea level derived from satellite altimetry multi missions

    NASA Astrophysics Data System (ADS)

    Ablain, M.; Faugere, Y.; Larnicol, G.; Picot, N.; Cazenave, A.; Benveniste, J.

    2012-04-01

    With the satellite altimetry missions, the global mean sea level (GMSL) has been calculated on a continual basis since January 1993. 'Verification' phases, during which the satellites follow each other in close succession (Topex/Poseidon--Jason-1, then Jason-1--Jason-2), help to link up these different missions by precisely determining any bias between them. Envisat, ERS-1 and ERS-2 are also used, after being adjusted on these reference missions, in order to compute Mean Sea Level at high latitudes (higher than 66°N and S), and also to improve spatial resolution by combining all these missions together. The global mean sea level (MSL) deduced from TOPEX/Poseidon, Jason-1 and Jason-2 provide a global rate of 3.2 mm from 1993 to 2010 applying the post glacial rebound (MSL aviso website http://www.jason.oceanobs.com/msl). Besides, the regional sea level trends bring out an inhomogeneous repartition of the ocean elevation with local MSL slopes ranging from + 8 mm/yr to - 8 mm/year. A study published in 2009 [Ablain et al., 2009] has shown that the global MSL trend unceratainty was estimated at +/-0.6 mm/year with a confidence interval of 90%. The main sources of errors at global and regional scales are due to the orbit calculation and the wet troposphere correction. But others sea-level components have also a significant impact on the long-term stability of MSL as for instance the stability of instrumental parameters and the atmospheric corrections. Thanks to recent studies performed in the frame of the SALP project (supported by CNES) and Sea-level Climate Change Initiative project (supported by ESA), strong improvements have been provided for the estimation of the global and regional MSL trends. In this paper, we propose to describe them; they concern the orbit calculation thanks to new gravity fields, the atmospheric corrections thanks to ERA-interim reanalyses, the wet troposphere corrections thanks to the stability improvement, and also empirical corrections

  18. Quantifying 10 years of Improvements in Earthquake and Tsunami Monitoring in the Caribbean and Adjacent Regions

    NASA Astrophysics Data System (ADS)

    von Hillebrandt-Andrade, C.; Huerfano Moreno, V. A.; McNamara, D. E.; Saurel, J. M.

    2014-12-01

    The magnitude-9.3 Sumatra-Andaman Islands earthquake of December 26, 2004, increased global awareness to the destructive hazard of earthquakes and tsunamis. Post event assessments of global coastline vulnerability highlighted the Caribbean as a region of high hazard and risk and that it was poorly monitored. Nearly 100 tsunamis have been reported for the Caribbean region and Adjacent Regions in the past 500 years and continue to pose a threat for its nations, coastal areas along the Gulf of Mexico, and the Atlantic seaboard of North and South America. Significant efforts to improve monitoring capabilities have been undertaken since this time including an expansion of the United States Geological Survey (USGS) Global Seismographic Network (GSN) (McNamara et al., 2006) and establishment of the United Nations Educational, Scientific and Cultural Organization (UNESCO) Intergovernmental Coordination Group (ICG) for the Tsunami and other Coastal Hazards Warning System for the Caribbean and Adjacent Regions (CARIBE EWS). The minimum performance standards it recommended for initial earthquake locations include: 1) Earthquake detection within 1 minute, 2) Minimum magnitude threshold = M4.5, and 3) Initial hypocenter error of <30 km. In this study, we assess current compliance with performance standards and model improvements in earthquake and tsunami monitoring capabilities in the Caribbean region since the first meeting of the UNESCO ICG-Caribe EWS in 2006. The three measures of network capability modeled in this study are: 1) minimum Mw detection threshold; 2) P-wave detection time of an automatic processing system and; 3) theoretical earthquake location uncertainty. By modeling three measures of seismic network capability, we can optimize the distribution of ICG-Caribe EWS seismic stations and select an international network that will be contributed from existing real-time broadband national networks in the region. Sea level monitoring improvements both offshore and

  19. Wiener filtering improves quantification of regional myocardial perfusion with thallium-201 SPECT

    SciTech Connect

    Links, J.M.; Jeremy, R.W.; Dyer, S.M.; Frank, T.L.; Becker, L.C. )

    1990-07-01

    Quantitation of myocardial perfusion with thallium-201 (201Tl) SPECT is limited by finite resolution and image noise. This study examined whether Wiener filtering could improve quantitation of the severity of myocardial perfusion deficits. In 19 anesthetized dogs, adjustable stenoses were placed on the left anterior descending (LAD, n = 12) or circumflex (LCx, n = 7) arteries. Thallium-201 SPECT images were acquired during maximal coronary vasodilation with dipyridamole, and simultaneous measurements of myocardial blood flow were made with microspheres. The relationship between SPECT and microsphere flow deficits in the LAD region was significantly better (p less than 0.05) with Wiener filtering (Y = 0.90X + 0.03, r = 0.78) than with conventional Hanning filtering (Y = 0.66X + 0.34, r = 0.61). Similarly, in the LCx region the relationship between SPECT and microsphere perfusion deficits was better (p less than 0.01) with the Wiener filter (Y = 0.91X + 0.07, r = 0.66) than with the Hanning filter (Y = 0.36X + 0.50, r = 0.40). Wiener filtering improves quantitation of the severity of regional myocardial perfusion deficits, allowing better assessment of the functional significance of coronary artery stenoses.

  20. 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

  1. 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.

  2. Quantifying 10 years of improved earthquake-monitoring performance in the Caribbean region

    USGS Publications Warehouse

    McNamara, Daniel E.; Hillebrandt-Andrade, Christa; Saurel, Jean-Marie; Huerfano-Moreno, V.; Lynch, Lloyd

    2015-01-01

    Over 75 tsunamis have been documented in the Caribbean and adjacent regions during the past 500 years. Since 1500, at least 4484 people are reported to have perished in these killer waves. Hundreds of thousands are currently threatened along the Caribbean coastlines. Were a great tsunamigenic earthquake to occur in the Caribbean region today, the effects would potentially be catastrophic due to an increasingly vulnerable region that has seen significant population increases in the past 40–50 years and currently hosts an estimated 500,000 daily beach visitors from North America and Europe, a majority of whom are not likely aware of tsunami and earthquake hazards. Following the magnitude 9.1 Sumatra–Andaman Islands earthquake of 26 December 2004, the United Nations Educational, Scientific and Cultural Organization (UNESCO) Intergovernmental Coordination Group (ICG) for the Tsunami and other Coastal Hazards Early Warning System for the Caribbean and Adjacent Regions (CARIBE‐EWS) was established and developed minimum performance standards for the detection and analysis of earthquakes. In this study, we model earthquake‐magnitude detection threshold and P‐wave detection time and demonstrate that the requirements established by the UNESCO ICG CARIBE‐EWS are met with 100% of the network operating. We demonstrate that earthquake‐monitoring performance in the Caribbean Sea region has improved significantly in the past decade as the number of real‐time seismic stations available to the National Oceanic and Atmospheric Administration tsunami warning centers have increased. We also identify weaknesses in the current international network and provide guidance for selecting the optimal distribution of seismic stations contributed from existing real‐time broadband national networks in the region.

  3. Improvement of downscaled rainfall and temperature across generations over the Western Himalayan region of India

    NASA Astrophysics Data System (ADS)

    Das, L.; Dutta, M.; Akhter, J.; Meher, J. K.

    2016-12-01

    It is a challenging task to create station level (local scale) climate change information over the mountainous locations of Western Himalayan Region (WHR) in India because of limited data availability and poor data quality. In the present study, missing values of station data were handled through Multiple Imputation Chained Equation (MICE) technique. Finally 22 numbers of rain gauge and 16 number of temperature station data having continuous record during 1901­2005 and 1969­2009 period respectively were considered as reference stations for developing downscaled rainfall and temperature time series from five commonly available GCMs in the IPCC's different generation assessment reports namely 2nd, 3rd, 4th and 5th hereafter known as SAR, TAR, AR4 and AR5 respectively. Downscaled models were developed using the combined data from the ERA-interim reanalysis and GCMs historical runs (in spite of forcing were not identical in different generation) as predictor and station level rainfall and temperature as predictands. Station level downscaled rainfall and temperature time series were constructed for five GCMs available in each generation. Regional averaged downscaled time series comprising of all stations was prepared for each model and generation and the downscaled results were compared with observed time series. Finally an Overall Model Improvement Index (OMII) was developed using the downscaling results, which was used to investigate the model improvement across generations as well as the improvement of downscaling results obtained from the Empirical Statistical Downscaling (ESD) methods. In case of temperature, models have improved from SAR to AR5 over the study area. In all most all the GCMs TAR is showing worst performance over the WHR by considering the different statistical indices used in this study. In case of precipitation, no model has shown gradual improvement from SAR to AR5 both for interpolated and downscaled values.

  4. Improving Remotely-sensed Precipitation Estimates Over Mountainous Regions For Use In Hydrological Models

    NASA Astrophysics Data System (ADS)

    Yucel, I.; Akcelik, M.; Kuligowski, R. J.

    2014-12-01

    In support of the National Oceanic and Atmospheric Administration (NOAA) National Weather Service's (NWS) flash flood warning and heavy precipitation forecast efforts, the NOAA National Environmental Satellite Data and Information Service (NESDIS) Center for Satellite Applications and Research (STAR) has been providing satellite based precipitation estimates operationally since 1978. Two of the satellite based rainfall algorithms are the Hydro-Estimator (HE) and the Self-Calibrating Multivariate Precipitation Retrieval (SCaMPR). However, unlike the HE algorithm the SCaMPR does not currently make any adjustments for the effects of complex topography on rainfall. This study investigates the potential for improving the SCaMPR algorithm by incorporating an orographic correction and humidity correction based calibration of the SCaMPR against rain gauge transects in northwestern Mexico to identify correctable biases related to elevation, slope, wind direction and humidity. Elevation-dependent bias structure of the SCaMPR algorithm suggest that the rainfall algorithm underestimates precipitation in case of upward atmospheric movements and overestimates rainfall in case of downward atmospheric movements along with mountainous terrain. A regionally dependent empirical elevation-based bias correction technique may help improve the quality of satellite-derived precipitation products. As well as orography, effect of atmospheric indices over precipitation estimates is analyzed. The findings suggest that continued improvement to the developed orographic correction scheme is warranted in order to advance quantitative precipitation estimation in complex terrain regions for use in weather forecasting and hydrologic applications.

  5. Improved BOLD detection in the medial temporal region using parallel imaging and voxel volume reduction.

    PubMed

    Bellgowan, Patrick S F; Bandettini, Peter A; van Gelderen, Peter; Martin, Alex; Bodurka, Jerzy

    2006-02-15

    Using gradient-echo EPI, signal dropout due to macroscopic off resonance effects can prevent blood-oxygenation-level-dependent (BOLD) signal change detection. The anterior medial temporal lobe (MTL) is located near these susceptibility gradients and therefore shows considerable signal dropout with GE-EPI. Reducing the volume of the image voxel reduces susceptibility-related signal dropout. However, this is accompanied by a prohibitive reduction in signal-to-noise ratio (SNR). To compensate for SNR loss with smaller voxels, we used a multi-channel MRI receiver with an array of receive-only 16-element surface coils at 3 T. We demonstrate that the reduction of susceptibility artifacts, through use of high resolution images, coupled with the gains in image SNR from the array coil improves the temporal signal-to-noise ratio (TSNR) and enhances the contrast-to-noise ratio (CNR). Furthermore, a comparison of 2 mm with 4-mm-thick axial images both with the same in-plane resolution showed that thinner slices enhanced TSNR and CNR throughout the ventral-medial regions of the temporal lobes, with the greatest improvement in the most anterior regions of the MTL. Further improvements were seen when adjacent 2 mm slices were combined to match overall voxel volume. These results demonstrate that BOLD investigation of anterior MTL function can be enhanced by decreasing voxel size but only in combination with the SNR gained by using the 16-channel head coil system.

  6. 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.

  7. Improving aerosol interaction with clouds and precipitation in a regional chemical weather modeling system

    NASA Astrophysics Data System (ADS)

    Zhou, C.; Zhang, X.; Gong, S.

    2015-12-01

    A comprehensive aerosol-cloud-precipitation interaction (ACI) scheme has been developed under CMA chemical weather modeling system GRAPES/CUACE. Calculated by a sectional aerosol activation scheme based on the information of size and mass from CUACE and the thermal-dynamic and humid states from the weather model GRAPES at each time step, the cloud condensation nuclei (CCN) is fed online interactively into a two-moment cloud scheme (WDM6) and a convective parameterization to drive the cloud physics and precipitation formation processes. The modeling system has been applied to study the ACI for January 2013 when several persistent haze-fog events and eight precipitation events occurred. The results show that interactive aerosols with the WDM6 in GRAPES/CUACE obviously increase the total cloud water, liquid water content and cloud droplet number concentrations while decrease the mean diameter of cloud droplets with varying magnitudes of the changes in each case and region. These interactive micro-physical properties of clouds improve the calculation of their collection growth rates in some regions and hence the precipitation rate and distributions in the model, showing 24% to 48% enhancements of TS scoring for 6-h precipitation in almost all regions. The interactive aerosols with the WDM6 also reduce the regional mean bias of temperature by 3 °C during certain precipitation events, but the monthly means bias is only reduced by about 0.3°C.

  8. Improving aerosol interaction with clouds and precipitation in a regional chemical weather modeling system

    NASA Astrophysics Data System (ADS)

    Zhou, C.; Zhang, X.; Gong, S.; Wang, Y.; Xue, M.

    2015-06-01

    A comprehensive aerosol-cloud-precipitation interaction (ACI) scheme has been developed under CMA chemical weather modeling system GRAPES/CUACE. Calculated by a sectional aerosol activation scheme based on the information of size and mass from CUACE and the thermal-dynamic and humid states from the weather model GRAPES at each time step, the cloud condensation nuclei (CCN) is fed online interactively into a two-moment cloud scheme (WDM6) and a convective parameterization to drive the cloud physics and precipitation formation processes. The modeling system has been applied to study the ACI for January 2013 when several persistent haze-fog events and eight precipitation events occurred. The results show that interactive aerosols with the WDM6 in GRAPES/CUACE obviously increase the total cloud water, liquid water content and cloud droplet number concentrations while decrease the mean diameter of cloud droplets with varying magnitudes of the changes in each case and region. These interactive micro-physical properties of clouds improve the calculation of their collection growth rates in some regions and hence the precipitation rate and distributions in the model, showing 24 to 48% enhancements of TS scoring for 6 h precipitation in almost all regions. The interactive aerosols with the WDM6 also reduce the regional mean bias of temperature by 3 °C during certain precipitation events, but the monthly means bias is only reduced by about 0.3 °C.

  9. Improving Snow Measurement Technology to Better Parameterise Cold Regions Hydrometeorology Models

    NASA Astrophysics Data System (ADS)

    Pomeroy, J.; Debeer, C.; Ellis, C.; Essery, R.; Helgason, W.; Kinar, N.; Link, T.; MacDonald, J.

    2008-12-01

    Marmot Creek Research Basin, in the Rocky Mountains of Alberta, Canada constitutes a long term cold regions hydrometeorological observatory with over 45 years of intensive observations in alpine and forested zones. Recently, novel combinations of measurement technology to snow have been deployed in Marmot Creek to advance the understanding of snow processes and to improve hydrometeorological models of streamflow and atmospheric variables. One advance has been the development and application of portable acoustic reflectometry to measure the density and structure of seasonal snowpacks using an audible sound wave. This has permitted the non-invasive measurement of snow water equivalent for both stationary and snow survey applications. Another advance has been the use of oblique time-lapse digital photography which is corrected for elevation and view angle from a LiDAR DEM to produce daily orthogonal snow covered area images of the alpine zone. These images are used to calculate snowcovered area and to develop and test improved snowcover melt and depletion algorithms. Deployment of 3-axis ultrasonic anemometers and fast hygrometers with collection of 10 Hz data and full correction for non-stationarity, axis rotation and other effects has shown that horizontal turbulence is often advected into mountain clearings and causes failure of traditional bulk transfer calculations of latent and sensible heat. For forest snow a hanging, weighed spruce tree and hanging, weighed sub-canopy troughs are used to capture intercepted snow load and unloaded snow fluxes respectively. These quantities provide the information needed to test detailed models of the snow interception and unloading processes. To quantify variations in sub-canopy energy for snowmelt, infrared imaging radiometers and narrow beam radiometers are used to measure thermal radiation exitance from needles, stems and trunks in forests of varying structure. These measurements are being used to develop improved models of

  10. 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.

  11. 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.

  12. 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)

  13. 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)

  14. 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...

  15. 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)

  16. Development and Implementation of Quality Rating and Improvement Systems in Midwest Region States. REL 2016-143

    ERIC Educational Resources Information Center

    Faria, Ann-Marie; Greenberg, Ariela; Hawkinson, Laura; Metzger, Ivan

    2016-01-01

    This report describes common and unique approaches that Regional Educational Laboratory (REL) Midwest Region states have adopted in developing and implementing their quality rating and improvement systems (QRISs). A QRIS is a method for assessing, improving, and communicating the quality of early childhood education and care providers. The study…

  17. TEMPORARY PACE MAKERS IMPLANTATION: DO WE NEED FLUOROSCOPY?

    PubMed

    Shah, Bakhtawar; Awan, Zahid Aslam

    2015-01-01

    Temporary pace maker (TPM implantation is done mostly in emergency with assistance of fluoroscopy. Fluoroscopy has various constrains which may delay the procedure at different occasion. We are going to share our experience in TPM implantation without fluoroscopy from internal jugular vein. The case series study was conducted in Hayatabad Medical complex Peshawar from January 2011 to November 2011. Internal jugular vein was cannulated with 6 French sheaths in the supra-clavicular region with modified Seldinger technique. TPM wire connected to the TPM device and advanced in the sheath to the right ventricle. Position was confirmed from captured beat on monitor. There was no need of repositioning and lead remains stable. Total 122 TPM leads were implanted in the study period. All patients were implanted from internal jugular vein. There were 71 male and 51 female patients. Among these patients 55 were in hemodynamically unstable state. The average time of implantation was less than 10 minutes. There was failure in one case. So the overall success rate was 99.180%. TPM implantation from the internal jugular vein even without fluoroscopy is safe, less time consuming and convenient.

  18. 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

  19. Improving the coordination of patients' medication management: a regional Finnish development project.

    PubMed

    Kivekäs, Eija; Luukkonen, Irmeli; Mykkänen, Juha; Saranto, Kaija

    2014-01-01

    In this paper, we present an overview of activities and results from a regional development project in Finland. The aim in this project was to analyze how healthcare providers produce and receive information on a patient's medication, and to identify opportunities to improve the quality, effectiveness, availability and collaboration of social and healthcare services in relation to medication information. The project focused on the most important points in patients' medication management such as home care and care transitions. In a regional development project, data was gathered by interviews and a multi professional workshop. The study revealed that medication information reached only some professionals and lay caregivers despite electronic patient record (EPR) systems and tools. Differences in work processes related to medication reconciliation and information management were discussed in the group meeting and were regarded as a considerable risk for patient safety.

  20. Regional representativeness assessment and improvement of eddy flux observations in China.

    PubMed

    He, Honglin; Zhang, Liyun; Gao, Yangzi; Ren, Xiaoli; Zhang, Li; Yu, Guirui; Wang, Shaoqiang

    2015-01-01

    Both the amounts of data describing the site-scale carbon flux at a high temporal and spatial resolution collected in China and the number of eddy covariance flux towers have been increasing during the last decade. To correctly upscale these fluxes to the regional and global level, the representativeness of the current network of flux towers must be known. The present study quantifies the representativeness of the flux network for the regional carbon exchange. This analysis combined the total solar radiation, air temperature, vapor pressure and the enhanced vegetation index to indicate the environmental characteristics of each 1-km pixel cell and flux tower. Next, the Euclidean distance from each pixel to the tower was calculated to determine the representativeness of the existing flux towers. To improve the regional representativeness, additional tower locations were pinpointed by identifying and clustering the underrepresented areas. The existing network of flux towers performed well in representing the environmental conditions of the middle and the northeastern portions of China. The well-represented areas covered 60.9% of the total areas. The towers in croplands and grasslands represented the vegetation types well, but the wetlands and barelands were poorly represented. The representativeness of the flux network increased with the addition of nine towers located in forests, grasslands, wetlands and barelands. The representativeness of 27.5% of the land areas improved. In addition, the well-represented areas were enlarged by 15.2%. Substantial gains in representation were achieved by adding new towers on the Tibet Plateau. The representativeness of the northwest and southwest was improved less significantly, suggesting that more towers are required to capture certain ecosystem behaviors. Copyright © 2014 Elsevier B.V. All rights reserved.

  1. 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…

  2. 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…

  3. 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

  4. 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.

  5. 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.

  6. Improved line parameters for ozone bands in the 10-microm spectral region.

    PubMed

    Flaud, J M; Camy-Peyret, C; Rinsland, C P; Devi, V M; Smith, M A; Goldman, A

    1990-09-01

    A complete update of spectroscopic line parameters for the 10-microm bands of ozone is reported. The listing contains calculated positions, intensities, lower state energies, and air- and self-broadened halfwidths of more than 53,000 lines. The results have been generated using improved spectroscopic parameters obtained in a number of recent high resolution laboratory studies. A total of eighteen bands of (16)O(3) (sixteen hot bands plus the nu(1) and nu(3) fundamentals) are included along with the nu(1) and nu(3) fundamentals of both (16)O(16)O(18)O and (16)O(18)O(16)O. As shown by comparisons of line-by-line simulations with 0.003-cm(-1) resolution balloon-borne stratospheric solar spectra, the new parameters greatly improve the accuracy of atmospheric calculations in the 10-microm region, especially for the isotopic (16)O(16)O(18)O and (16)O(18)O(16)O lines.

  7. Improved line parameters for ozone bands in the 10-micron spectral region

    NASA Technical Reports Server (NTRS)

    Flaud, Jean-Marie; Camy-Peyret, Claude; Rinsland, Curtis P.; Smith, Mary Ann H.; Devi, Malathy V.

    1990-01-01

    A complete update of spectroscopic line parameters for the 10-micron bands of ozone is reported. The listing contains calculated positions, intensities, lower state energies, and air- and self-broadened halfwidths of more than 53,000 lines. The results have been generated using improved spectroscopic parameters obtained in a number of recent high resolution laboratory studies. A total of eighteen bands of (O-16)3 (sixteen hot bands plus the nu(1) and nu(3) fundamentals) are included along with the nu(1) and nu(3) fundamentals of both (O-16)(O-16)(O-18) and (O-16)(O-18)(O-16). As shown by comparisons of line-by-line simulations with 0.003/cm resolution balloon-borne stratospheric solar spectra, the new parameters greatly improve the accuracy of atmospheric calculations in the 10-micron region, especially for the isotopic (O-16)(O-16)(O-18) and (O-16)(O-18)(O-16) lines.

  8. Improved saliency toolbox/Itti model for region of interest extraction

    NASA Astrophysics Data System (ADS)

    He, Dong-Jian; Liu, Shang-Wang; Liang, Xin-Hong; Cai, Cheng

    2011-09-01

    The saliency toolbox (STB)/Itti model is an outstanding computational selective visual attention model. In this paper, we propose an improved STB/Itti model to overcome the drawback of STB/Itti--its output ``saliency map'' is not large enough for region of interest (ROI) extraction. First, we employ a simplified pulse coupled neural network (PCNN) with a special input image, and more importantly, the PCNN does not require iterations. Subsequently, the PCNN takes the place of the winner-take-all network in STB/Itti. Experimental results show that the improved STB/Itti model works well for ROI extraction, with the mean area under the curve value of 0.8306 and robustness against noise and geometric attacks. The proposed model can greatly enhance the performances of both STB/Itti and PCNN model in image processing.

  9. 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.

  10. Regional Body-Wave Corrections and Surface-Wave Tomography Models to Improve Discrimination

    SciTech Connect

    Walter, W R; Pasyanos, M E; Rodgers, A J; Meyeda, K M; Sicherman, A

    2003-07-18

    Our identification research for the past several years has focused on the problem of correctly discriminating small-magnitude explosions from a background of earthquakes, mining tremors, and other events. Small magnitudes lead to an emphasis on regional waveforms. The goal is to reduce the variance within the population of each type of event, while increasing the separation between the explosions and the other event types. We address this problem for both broad categories of seismic waves, body waves, and surface waves. First, we map out the effects of propagation and source size in advance so that they can be accounted for and removed from observed events. This can dramatically reduce the population variance. Second, we try to optimize the measurement process to improve the separation between population types. For body waves we focus on the identification power of the short-period regional phases Pn, Pg, Sn and Lg, and coda that can often be detected down to very small magnitudes. It is now well established that particular ratios of these phases, such as 6- to 8-Hz Pn/Lg, can effectively discriminate between closely located explosions and earthquakes. To extend this discrimination power over broad areas, we developed a revised Magnitude and Distance Amplitude Correction (MDAC2) procedure (Walter and Taylor, 2002). This joint source and path model fits the observed spectra and removes magnitude and distance trends from the data. It allows for the possibility of variable apparent stress scaling in earthquakes, an unresolved issue that is the subject of investigation under separate funding. The MDACZ procedure makes use of the extremely stable coda estimates of Mw for source magnitude and can also use independent Q tomography to help reduce trade-offs in fitting spectra. We can then apply the kriging operation to the MDAC2 residuals to provide full 2-D path corrections by phase and frequency band. These corrections allow the exploration of all possible ratios and

  11. Limb Correction of Infrared Imagery in Cloudy Regions for the Improved Interpretation of RGB Composites

    NASA Technical Reports Server (NTRS)

    Elmer, Nicholas J.; Berndt, Emily; Jedlovec, Gary J.

    2016-01-01

    Red-Green-Blue (RGB) composites (EUMETSAT User Services 2009) combine information from several channels into a single composite image. RGB composites contain the same information as the original channels, but presents the information in a more efficient manner. However, RGB composites derived from infrared imagery of both polar-orbiting and geostationary sensors are adversely affected by the limb effect, which interferes with the qualitative interpretation of RGB composites at large viewing zenith angles. The limb effect, or limb-cooling, is a result of an increase in optical path length of the absorbing atmosphere as viewing zenith angle increases (Goldberg et al. 2001; Joyce et al. 2001; Liu and Weng 2007). As a result, greater atmospheric absorption occurs at the limb, causing the sensor to observe anomalously cooler brightness temperatures. Figure 1 illustrates this effect. In general, limb-cooling results in a 4-11 K decrease in measured brightness temperature (Liu and Weng 2007) depending on the infrared band. For example, water vapor and ozone absorption channels display much larger limb-cooling than infrared window channels. Consequently, RGB composites created from infrared imagery not corrected for limb effects can only be reliably interpreted close to nadir, which reduces the spatial coverage of the available imagery. Elmer (2015) developed a reliable, operational limb correction technique for clear regions. However, many RGB composites are intended to be used and interpreted in cloudy regions, so a limb correction methodology valid for both clear and cloudy regions is needed. This paper presents a limb correction technique valid for both clear and cloudy regions, which is described in Section 2. Section 3 presents several RGB case studies demonstrating the improved functionality of limb-corrected RGBs in both clear and cloudy regions, and Section 4 summarizes and presents the key conclusions of this work.

  12. Beta-blockade improves adjacent regional sympathetic innervation during postinfarction remodeling.

    PubMed

    Kramer, C M; Nicol, P D; Rogers, W J; Seibel, P S; Park, C S; Reichek, N

    1999-10-01

    The effect of beta-blockade on left ventricular (LV) remodeling, when added to angiotensin-converting enzyme inhibition (ACEI) after anterior myocardial infarction (MI), is incompletely understood. On day 2 after coronary ligation-induced anteroapical infarction, 17 sheep were randomized to ramipril (ACEI, n = 8) or ramipril and metoprolol (ACEI-beta, n = 9). Magnetic resonance imaging was performed before and 8 wk after MI to measure changes in LV end-diastolic, end-systolic, and stroke volume indexes, LV mass index, ejection fraction (EF), and regional percent intramyocardial circumferential shortening. (123)I-labeled m-iodobenzylguanidine (MIBG) and fluorescent microspheres before and after adenosine were infused before death at 8 wk post-MI for quantitation of sympathetic innervation, blood flow, and blood flow reserve in adjacent and remote noninfarcted regions. Infarct size, regional blood flow, blood flow reserve, and the increase in LV mass and LV end-diastolic and end-systolic volume indexes were similar between groups. However, EF fell less over the 8-wk study period in the ACEI-beta group (-13 +/- 11 vs. -22 +/- 4% in ACEI, P < 0.05). The ratio of adjacent to remote region (123)I-MIBG uptake was greater in ACEI-beta animals than in the ACEI group (0.93 +/- 0.06 vs. 0.86 +/- 0.07, P < 0.04). When added to ACE inhibition after transmural anteroapical MI, beta-blockade improves EF and adjacent regional sympathetic innervation but does not alter LV size.

  13. Improving aerosol interaction with clouds and precipitation in a regional chemical weather modeling system

    NASA Astrophysics Data System (ADS)

    Zhou, C.; Zhang, X.; Gong, S.; Wang, Y.; Xue, M.

    2016-01-01

    A comprehensive aerosol-cloud-precipitation interaction (ACI) scheme has been developed under a China Meteorological Administration (CMA) chemical weather modeling system, GRAPES/CUACE (Global/Regional Assimilation and PrEdiction System, CMA Unified Atmospheric Chemistry Environment). Calculated by a sectional aerosol activation scheme based on the information of size and mass from CUACE and the thermal-dynamic and humid states from the weather model GRAPES at each time step, the cloud condensation nuclei (CCN) are interactively fed online into a two-moment cloud scheme (WRF Double-Moment 6-class scheme - WDM6) and a convective parameterization to drive cloud physics and precipitation formation processes. The modeling system has been applied to study the ACI for January 2013 when several persistent haze-fog events and eight precipitation events occurred.

    The results show that aerosols that interact with the WDM6 in GRAPES/CUACE obviously increase the total cloud water, liquid water content, and cloud droplet number concentrations, while decreasing the mean diameters of cloud droplets with varying magnitudes of the changes in each case and region. These interactive microphysical properties of clouds improve the calculation of their collection growth rates in some regions and hence the precipitation rate and distributions in the model, showing 24 to 48 % enhancements of threat score for 6 h precipitation in almost all regions. The aerosols that interact with the WDM6 also reduce the regional mean bias of temperature by 3 °C during certain precipitation events, but the monthly means bias is only reduced by about 0.3 °C.

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

    PubMed

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

    2016-03-01

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

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

    USGS Publications Warehouse

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

    2016-01-01

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

  16. Personal hand gel for improved hand hygiene compliance on the regional anesthesia team.

    PubMed

    Parks, Colby L; Schroeder, Kristopher M; Galgon, Richard E

    2015-12-01

    Hand hygiene reduces healthcare-associated infections, and several recent publications have examined hand hygiene in the perioperative period. Our institution's policy is to perform hand hygiene before and after patient contact. However, observation suggests poor compliance. This is a retrospective review of a quality improvement database showing the effect of personal gel dispensers on perioperative hand hygiene compliance on a regional anesthesia team. Healthcare providers assigned to the Acute Pain Service were observed for compliance with hand hygiene policy during a quality improvement initiative. Provider type and compliance were prospectively recorded in a database. Team members were then given a personal gel dispensing device and again observed for compliance. We have retrospectively reviewed this database to determine the effects of this intervention. Of the 307 encounters observed, 146 were prior to implementing personal gel dispensers. Compliance was 34%. Pre- and post-patient contact compliances were 23 and 43%, respectively. For 161 encounters after individual gel dispensers were provided, compliance was 63%. Pre- and post-patient contact compliances were 53 and 72%, respectively. Improvement in overall compliance from 34 to 63% was significant. On the Acute Pain Service, compliance with hand hygiene policy improves when individual sanitation gel dispensing devices are worn on the person.

  17. 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.

  18. 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.

  19. 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

  20. 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.

  1. 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.

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

    PubMed

    Lomax, Mitch

    2012-10-01

    The purpose of the present study was to assess the impact of 3 recovery protocols on blood lactate clearance after maximal intensity swimming. Thirty-three regional standard swimmers were tested throughout the course a year and were required to complete a race-paced 200-m swim in their main stroke or individual medley. After the race-paced swim, swimmers were assigned a self-paced continuous steady rate swim of 20 minutes (self-prescribed); a 20-minute coach-administered modified warm-up consisting of various swimming modes, intensities, and rest intervals (coach prescribed); or a 20-minute land-based recovery consisting of light-intensity walking, skipping, and stretching (land based). Blood lactate concentration was measured from the fingertip before and after the race-paced swim and after the recovery activity. The concentration of blood lactate was higher (p < 0.01) after race-paced swimming (range of 10.5-11.0 mmol·L(-1)) compared with baseline (range 1.3-1.4 mmol·L(-1)). However, there were no differences (p > 0.05) between the groups (recovery protocols) at these time points. Conversely, differences were observed between groups after the recovery activities (p < 0.01). Specifically, blood lactate concentration was higher after the land-based activity (3.7 ± 1.8 mmol·L(-1)) than either the self-prescribed (2.0 ± 1.2 mmol·L(-1)) or coach-prescribed (1.8 ± 0.9 mmol·L(-1)) swimming protocols. The results of the present study suggest that it does not matter whether a self-paced continuous steady rate swimming velocity or a swimming recovery consisting of various strokes, intensities, and rest intervals is adopted as a recovery activity. As both swimming recoveries removed more blood lactate than the land-based recovery, swimmers should therefore be advised to undertake a swimming-based recovery rather than a land-based recovery.

  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. New Local, National and Regional Cereal Price Indices for Improved Identification of Food Insecurity

    NASA Technical Reports Server (NTRS)

    Brown, Molly E.; Tondel, Fabien; Thorne, Jennifer A.; Essam, Timothy; Mann, Bristol F.; Stabler, Blake; Eilerts, Gary

    2011-01-01

    Large price increases over a short time period can be indicative of a deteriorating food security situation. Food price indices developed by the United Nations Food and Agriculture Organization (FAO) are used to monitor food price trends at a global level, but largely reflect supply and demand conditions in export markets. However, reporting by the United States Agency for International Development (USAID)'s Famine Early Warning Systems Network (FEWS NET) indicates that staple cereal prices in many markets of the developing world, especially in surplus-producing areas, often have a delayed and variable response to international export market price trends. Here we present new price indices compiled for improved food security monitoring and assessment, and specifically for monitoring conditions of food access across diverse food insecure regions. We found that cereal price indices constructed using market prices within a food insecure region showed significant differences from the international cereals price, and had a variable price dispersion across markets within each marketshed. Using satellite-derived remote sensing information that estimates local production and the FAO Cereals Index as predictors, we were able to forecast movements of the local or national price indices in the remote, arid and semi-arid countries of the 38 countries examined. This work supports the need for improved decision-making about targeted aid and humanitarian relief, by providing earlier early warning of food security crises.

  6. Level Set Based Hippocampus Segmentation in MR Images with Improved Initialization Using Region Growing

    PubMed Central

    Zhou, Zhaozhong; Ding, Xiaokang; Deng, Xiaolei; Zou, Ling; Li, Bailin

    2017-01-01

    The hippocampus has been known as one of the most important structures referred to as Alzheimer's disease and other neurological disorders. However, segmentation of the hippocampus from MR images is still a challenging task due to its small size, complex shape, low contrast, and discontinuous boundaries. For the accurate and efficient detection of the hippocampus, a new image segmentation method based on adaptive region growing and level set algorithm is proposed. Firstly, adaptive region growing and morphological operations are performed in the target regions and its output is used for the initial contour of level set evolution method. Then, an improved edge-based level set method utilizing global Gaussian distributions with different means and variances is developed to implement the accurate segmentation. Finally, gradient descent method is adopted to get the minimization of the energy equation. As proved by experiment results, the proposed method can ideally extract the contours of the hippocampus that are very close to manual segmentation drawn by specialists. PMID:28191031

  7. Towards improving the representation of polar regions in global reanalyses at the NASA GMAO

    NASA Astrophysics Data System (ADS)

    Cullather, R. I.; Zhao, B.; Nowicki, S.; Bosilovich, M. G.; Suarez, M.; Putman, W.; Shuman, C. A.

    2015-12-01

    Atmospheric reanalyses have been employed in a wide variety of studies investigating processes in the changing Arctic and Antarctic. However reanalyses underperform in polar regions due in part to limitations in the background model, which are associated with spatial resolution and with inadequate representations of physical processes. Some chronic issues include the use of incorrect topography over ice sheets, persistent temperature biases, and discontinuities in time series due to abrupt changes to the observing system. These limitations provoke caution in the use of global reanalyses in polar regions, but also call into question their general applicability to evolving polar climate topics. For example, the assessment of conditions over Greenland and Antarctica in the most recent IPCC report relied heavily on limited area models rather than global reanalyses. The performance of contemporary reanalyses over the north and south polar caps are reviewed with emphasis on differences in atmospheric energy and moisture budgets. In particular, the recently released MERRA-2 reanalysis is critically assessed. Significant changes that are relevant to polar regions in MERRA-2 over the previous MERRA version include an improved representation of glaciated land surfaces and sea ice albedo. Ongoing work to address issues of increased spatial resolution and the introduction of more complex physical processes related to surface hydrology over polar ice sheets will be described.

  8. Analysis of Stakeholder's Behaviours for an Improved Management of an Agricultural Coastal Region in Oman

    NASA Astrophysics Data System (ADS)

    Khatri, Ayisha Al; Jens, Grundmann; der Weth Rüdiger, van; Niels, Schütze

    2015-04-01

    Al Batinah coastal area is the main agricultural region in Oman. Agriculture is concentrated in Al Batinah, because of more fertile soils and easier access to water in the form of groundwater compared to other administrative areas in the country. The region now is facing a problem as a result of over abstraction of fresh groundwater for irrigation from the main aquifer along the coast. This enforces the inflow of sea water into the coastal aquifer and causes salinization of the groundwater. As a consequence the groundwater becomes no longer suitable for irrigation which impacts the social and economical situation of farmers as well as the environment. Therefore, the existing situation generates conflicts between different stakeholders regarding water availability, sustainable aquifer management, and profitable agricultural production in Al Batinah region. Several management measures to maintain the groundwater aquifer in the region, were implemented by the government. However, these solutions showed only limited successes for the existing problem. The aim of this study now is to evaluate the implementation potential of several management interventions and their combinations by analysing opinions and responses of all relevant stakeholders in the region. This is done in order to identify potential conflicts among stakeholders to a participatory process within the frame of an integrated water resources management and to support decision makers in taking more informed decisions. Questionnaires were designed for collecting data from different groups of stakeholders e.g. water professionals, farmers from the study area and decision makers of different organizations and ministries. These data were analysed statistically for each group separately as well as regarding relations amongst groups by using the SPSS (Statistical Package for Social Science) software package. Results show, that the need to improve the situation is supported by all groups. However, significant

  9. Improving mb:Ms discrimination using phase matched filters derived from regional group velocity tomography

    SciTech Connect

    Ford, S R; Hazler, S; Pasyanos, M E; Walter, W R

    1999-07-23

    This study reports on the ongoing investigation of surface wave group velocity dispersion across the Middle East and North Africa. Using broadband data gathered from various sources, we have measured group velocity using a multiple narrow-band filter method. To date, we have examined over 13,500 seismograms and made quality measurements for about 6500 Rayleigh and 3500 Love wave paths. A conjugate gradient method is used to perform the group velocity tomography at several periods. There is excellent agreement between short period structure and large known sedimentary features. Longer period structure is sensitive to crustal thickness, particularly the contrast between continental and oceanic regions and thicker crusts found beneath erogenic zones. We also find slow upper mantle velocities along rift systems. Correlation between the inversion results and known major tectonic features gives us confidence in our surface wave group velocities. Accurate group velocity maps can be used to construct phase matched filters. The filters can improve weak surface waves by compressing the dispersed signal. We are particularly interested in using the filters to calculate regionally determined M{sub s} measurements, which we hope can be used to extend the threshold of m{sub b}:M{sub s} discriminants to lower magnitude levels. A preliminary analysis of surface wave data processed using phase matched filters indicates a significant improvement in increasing the signal-to-noise ratio and improving magnitude estimates. Where signal-to-noise is very poor, phase matched filtering can still be useful in lowering the upper bound on M{sub s} measurements. We propose a series of tests in order to analyze the utility of phase matched filters. Goals of the study include determining at what distance and magnitude ranges we can expect to see improvement using the filters and the overall effect of the filters on discrimination capability. We also propose to look at seismic velocity models of

  10. Improved sequence-based prediction of disordered regions with multilayer fusion of multiple information sources

    PubMed Central

    Mizianty, Marcin J.; Stach, Wojciech; Chen, Ke; Kedarisetti, Kanaka Durga; Disfani, Fatemeh Miri; Kurgan, Lukasz

    2010-01-01

    Motivation: Intrinsically disordered proteins play a crucial role in numerous regulatory processes. Their abundance and ubiquity combined with a relatively low quantity of their annotations motivate research toward the development of computational models that predict disordered regions from protein sequences. Although the prediction quality of these methods continues to rise, novel and improved predictors are urgently needed. Results: We propose a novel method, named MFDp (Multilayered Fusion-based Disorder predictor), that aims to improve over the current disorder predictors. MFDp is as an ensemble of 3 Support Vector Machines specialized for the prediction of short, long and generic disordered regions. It combines three complementary disorder predictors, sequence, sequence profiles, predicted secondary structure, solvent accessibility, backbone dihedral torsion angles, residue flexibility and B-factors. Our method utilizes a custom-designed set of features that are based on raw predictions and aggregated raw values and recognizes various types of disorder. The MFDp is compared at the residue level on two datasets against eight recent disorder predictors and top-performing methods from the most recent CASP8 experiment. In spite of using training chains with ≤25% similarity to the test sequences, our method consistently and significantly outperforms the other methods based on the MCC index. The MFDp outperforms modern disorder predictors for the binary disorder assignment and provides competitive real-valued predictions. The MFDp's outputs are also shown to outperform the other methods in the identification of proteins with long disordered regions. Availability: http://biomine.ece.ualberta.ca/MFDp.html Supplementary information: Supplementary data are available at Bioinformatics online. Contact: lkurgan@ece.ualberta.ca PMID:20823312

  11. 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...

  12. 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.…

  13. 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.…

  14. Indicators of improved water access in the context of schistosomiasis transmission in rural Eastern Region, Ghana.

    PubMed

    Kulinkina, Alexandra V; Kosinski, Karen C; Plummer, Jeanine D; Durant, John L; Bosompem, Kwabena M; Adjei, Michael N; Griffiths, Jeffrey K; Gute, David M; Naumova, Elena N

    2017-02-01

    Populations with poor access to water, sanitation and hygiene (WASH) infrastructure are disproportionately affected by the neglected tropical diseases (NTDs). As a result, WASH has gained increasing prominence in integrated control and elimination of NTDs, including schistosomiasis. In order to identify underserved populations, relevant measures of access to WASH infrastructure at sub-national or local levels are needed. We conducted a field survey of all public water sources in 74 rural communities in the Eastern Region of Ghana and computed indicators of water access using two methods: one based on the design capacity and another on the spatial distribution of water sources. The spatial method was applied to improved and surface water sources. According to the spatial method, improved water sources in the study area were well-distributed within communities with 95% (CI95%: 91, 98) of the population having access within 500m when all, and 87% (CI95%: 81, 93) when only functional water sources were considered. According to the design capacity-based method, indicator values were lower: 63% (CI95%: 57, 69) for all and 49% (CI95%: 43, 55) for only functional sources. Surface water access was substantial with 62% (CI95%: 54, 71) of the population located within 500m of a perennial surface water source. A negative relationship was observed between functional improved water access and surface water access within 300m. In this context, perceived water quality of the improved sources was also important, with a 17% increase in surface water access in towns with one reported water quality problem as compared to towns with no problems. Our study offers a potential methodology to use water point mapping data to identify communities in need of improved water access to achieve schistosomiasis risk reduction.

  15. NASA Earth Science Research Results for Improved Regional Crop Yield Prediction

    NASA Astrophysics Data System (ADS)

    Mali, P.; O'Hara, C. G.; Shrestha, B.; Sinclair, T. R.; G de Goncalves, L. G.; Salado Navarro, L. R.

    2007-12-01

    spatial and temporal resolution remote sensing datasets; improved time-series meteorological inputs required for crop growth models; and regional prediction capability through geo-processing-based yield modeling.

  16. 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

  17. Regional analgesia for improvement of long-term functional outcome after elective large joint replacement

    PubMed Central

    Atchabahian, Arthur; Schwartz, Gary; Hall, Charles B; Lajam, Claudette M; Andreae, Michael H

    2015-01-01

    Background Regional analgesia is more effective than conventional analgesia for controlling pain and may facilitate rehabilitation after large joint replacement in the short term. It remains unclear if regional anaesthesia improves functional outcomes after joint replacement beyond three months after surgery. Objectives To assess the effects of regional anaesthesia and analgesia on long-term functional outcomes 3, 6 and 12 months after elective major joint (knee, shoulder and hip) replacement surgery. Search methods We performed an electronic search of several databases (CENTRAL, MEDLINE, EMBASE, CINAHL), and handsearched reference lists and conference abstracts. We updated our search in June 2015. Selection criteria We included randomized controlled trials (RCTs) comparing regional analgesia versus conventional analgesia in patients undergoing total shoulder, hip or knee replacement. We included studies that reported a functional outcome with a follow-up of at least three months after surgery. Data collection and analysis We used standard methodological procedures expected by Cochrane. We contacted study authors for additional information. Main results We included six studies with 350 participants followed for at least three months. All of these studies enrolled participants undergoing total knee replacement. Studies were at least partially blinded. Three studies had a high risk of performance bias and one a high risk of attrition bias, but the risk of bias was otherwise unclear or low. Only one study assessed joint function using a global score. Due to heterogeneity in outcome and reporting, we could only pool three out of six RCTs, with range of motion assessed at three months after surgery used as a surrogate for joint function. All studies had a high risk of detection bias. Using the random-effects model, there was no statistically significant difference between the experimental and control groups (mean difference 3.99 degrees, 95% confidence interval (CI)

  18. 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.

  19. Improving Loop Modeling of the Antibody Complementarity-Determining Region 3 Using Knowledge-Based Restraints

    PubMed Central

    Finn, Jessica A.; Koehler Leman, Julia; Cisneros, Alberto; Crowe, James E.; Meiler, Jens

    2016-01-01

    Structural restrictions are present even in the most sequence diverse portions of antibodies, the complementary determining region (CDR) loops. Previous studies identified robust rules that define canonical structures for five of the six CDR loops, however the heavy chain CDR 3 (HCDR3) defies standard classification attempts. The HCDR3 loop can be subdivided into two domains referred to as the “torso” and the “head” domains and two major families of canonical torso structures have been identified; the more prevalent “bulged” and less frequent “non-bulged” torsos. In the present study, we found that Rosetta loop modeling of 28 benchmark bulged HCDR3 loops is improved with knowledge-based structural restraints developed from available antibody crystal structures in the PDB. These restraints restrict the sampling space Rosetta searches in the torso domain, limiting the φ and ψ angles of these residues to conformations that have been experimentally observed. The application of these restraints in Rosetta result in more native-like structure sampling and improved score-based differentiation of native-like HCDR3 models, significantly improving our ability to model antibody HCDR3 loops. PMID:27182833

  20. 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

  1. 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.

  2. Improving Regional and National Weather Operations with New Lightning Mapping Technologies

    NASA Astrophysics Data System (ADS)

    Macgorman, D. R.

    2003-12-01

    , sparse-lightning holes in the updraft cores of supercell storms, cores of large lightning density resembling the reflectivity cores of cells, and the maturation of the stratiform precipitation region of mesoscale convective systems, which produce much of the rainfall and flooding in the central United States. However, it is relatively difficult for weather forecasters to incorporate much information from lightning data into their forecasts when using only raw, real-time lightning locations. More research is needed to help extract or summarize information from the lightning data and present it in a form easier for forecasters to digest. Another area in which lightning data can contribute is data assimilation into numerical weather models to improve their forecasts. Research has demonstrated that lightning data can be assimilated into forecast models in much the same way as radar data are, but lightning data could readily be available over large regions of the globe where obtaining radar data is not feasible. Besides improving the initialization of the model by improving the location and extent of storms when the model begins its forecast cycle, a process that itself still can be improved, lightning data could be used in variational schemes to diagnose and compensate for errors often present in the atmosphere at the beginning of a model's forecast cycle. Otherwise, these errors in the model atmosphere often cause the forecast to return close to the state it would have had in 6-12 h without even simple data assimilation.

  3. 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.

  4. Theory of the development of alternans in the heart during controlled diastolic interval pacing

    NASA Astrophysics Data System (ADS)

    Otani, Niels F.

    2017-09-01

    The beat-to-beat alternation in action potential durations (APDs) in the heart, called APD alternans, has been linked to the development of serious cardiac rhythm disorders, including ventricular tachycardia and fibrillation. The length of the period between action potentials, called the diastolic interval (DI), is a key dynamical variable in the standard theory of alternans development. Thus, methods that control the DI may be useful in preventing dangerous cardiac rhythms. In this study, we examine the dynamics of alternans during controlled-DI pacing using a series of single-cell and one-dimensional (1D) fiber models of alternans dynamics. We find that a model that combines a so-called memory model with a calcium cycling model can reasonably explain two key experimental results: the possibility of alternans during constant-DI pacing and the phase lag of APDs behind DIs during sinusoidal-DI pacing. We also find that these results can be replicated by incorporating the memory model into an amplitude equation description of a 1D fiber. The 1D fiber result is potentially concerning because it seems to suggest that constant-DI control of alternans can only be effective over only a limited region in space.

  5. 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

  6. 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

  7. Improving smallholder cattle reproductive efficiency in Cambodia to address expanding regional beef demand.

    PubMed

    Olmo, L; Ashley, K; Young, J R; Suon, S; Thomson, P C; Windsor, P A; Bush, R D

    2017-01-01

    This study aimed to identify factors associated with cattle reproductive output in rural smallholder farms in Cambodia in order to determine the main causes of reproductive failure and design efficient interventions for improvement. The majority of the nation's beef is produced on smallholder farms where productivity is constrained by poor animal reproductivity reflected in the recent livestock population decline of approximately 13 % from 2009 to 2013. Farmers (n = 240) from 16 villages from five provinces were surveyed in mid-2015 to determine their baseline knowledge, attitude and practices (KAP) associated with cattle reproduction. In addition, 16 case studies from three of these provinces were conducted to provide a more detailed assessment of current cattle reproductive husbandry practices. In order to assess the reproductive impact of previously implemented interventions, an endpoint KAP survey and longitudinal health and husbandry study from three Cambodian provinces conducted between 2008 and 2013 were also analysed. Three multivariable prediction models (two KAP and one longitudinal) identified the following significant factors associated with the reproductive outcomes 'number of calves born' or probability that cows 'gave birth': target feeding (P = 0.074), growing vegetables (P = 0.005), attitudes towards cattle vaccination (P = 0.010), improving bull selection (P = 0.032), local breed use (P = 0.005), number of joining attempts (P < 0.001), discontinuation of animal draught practices (P = 0.003) and retention of breeding animals (P < 0.001). The identification of significant factors and interventions in this study has led to intervention recommendations that can potentially improve reproductive efficiency, combat the declining cattle population and improve smallholder capacity to supply to expanding regional meat demand in South-East Asia and China.

  8. Heterogeneity in Trauma Registry Data Quality: Implications for Regional and National Performance Improvement in Trauma.

    PubMed

    Dente, Christopher J; Ashley, Dennis W; Dunne, James R; Henderson, Vernon; Ferdinand, Colville; Renz, Barry; Massoud, Romeo; Adamski, John; Hawke, Thomas; Gravlee, Mark; Cascone, John; Paynter, Steven; Medeiros, Regina; Atkins, Elizabeth; Nicholas, Jeffrey M

    2016-03-01

    Led by the American College of Surgeons Trauma Quality Improvement Program, performance improvement efforts have expanded to regional and national levels. The American College of Surgeons Trauma Quality Improvement Program recommends 5 audit filters to identify records with erroneous data, and the Georgia Committee on Trauma instituted standardized audit filter analysis in all Level I and II trauma centers in the state. Audit filter reports were performed from July 2013 to September 2014. Records were reviewed to determine whether there was erroneous data abstraction. Percent yield was defined as number of errors divided by number of charts captured. Twelve centers submitted complete datasets. During 15 months, 21,115 patient records were subjected to analysis. Audit filter captured 2,901 (14%) records and review yielded 549 (2.5%) records with erroneous data. Audit filter 1 had the highest number of records identified and audit filter 3 had the highest percent yield. Individual center error rates ranged from 0.4% to 5.2%. When comparing quarters 1 and 2 with quarters 4 and 5, there were 7 of 12 centers with substantial decreases in error rates. The most common missed complications were pneumonia, urinary tract infection, and acute renal failure. The most common missed comorbidities were hypertension, diabetes, and substance abuse. In Georgia, the prevalence of erroneous data in trauma registries varies among centers, leading to heterogeneity in data quality, and suggests that targeted educational opportunities exist at the institutional level. Standardized audit filter assessment improved data quality in the majority of participating centers. Copyright © 2016 American College of Surgeons. Published by Elsevier Inc. All rights reserved.

  9. Improved quantification for local regions of interest in preclinical PET imaging

    NASA Astrophysics Data System (ADS)

    Cal-González, J.; Moore, S. C.; Park, M.-A.; Herraiz, J. L.; Vaquero, J. J.; Desco, M.; Udias, J. M.

    2015-09-01

    In Positron Emission Tomography, there are several causes of quantitative inaccuracy, such as partial volume or spillover effects. The impact of these effects is greater when using radionuclides that have a large positron range, e.g. 68Ga and 124I, which have been increasingly used in the clinic. We have implemented and evaluated a local projection algorithm (LPA), originally evaluated for SPECT, to compensate for both partial-volume and spillover effects in PET. This method is based on the use of a high-resolution CT or MR image, co-registered with a PET image, which permits a high-resolution segmentation of a few tissues within a volume of interest (VOI) centered on a region within which tissue-activity values need to be estimated. The additional boundary information is used to obtain improved activity estimates for each tissue within the VOI, by solving a simple inversion problem. We implemented this algorithm for the preclinical Argus PET/CT scanner and assessed its performance using the radionuclides 18F, 68Ga and 124I. We also evaluated and compared the results obtained when it was applied during the iterative reconstruction, as well as after the reconstruction as a postprocessing procedure. In addition, we studied how LPA can help to reduce the ‘spillover contamination’, which causes inaccurate quantification of lesions in the immediate neighborhood of large, ‘hot’ sources. Quantification was significantly improved by using LPA, which provided more accurate ratios of lesion-to-background activity concentration for hot and cold regions. For 18F, the contrast was improved from 3.0 to 4.0 in hot lesions (when the true ratio was 4.0) and from 0.16 to 0.06 in cold lesions (true ratio  =  0.0), when using the LPA postprocessing. Furthermore, activity values estimated within the VOI using LPA during reconstruction were slightly more accurate than those obtained by post-processing, while also visually improving the image contrast and uniformity

  10. Improved quantification for local regions of interest in preclinical PET imaging

    PubMed Central

    Cal-González, J.; Moore, S. C.; Park, M.-A.; Herraiz, J. L.; Vaquero, J. J.; Desco, M.; Udias, J. M.

    2015-01-01

    In Positron Emission Tomography, there are several causes of quantitative inaccuracy, such as partial volume or spillover effects. The impact of these effects is greater when using radionuclides that have a large positron range, e.g., 68Ga and 124I, which have been increasingly used in the clinic. We have implemented and evaluated a local projection algorithm (LPA), originally evaluated for SPECT, to compensate for both partial-volume and spillover effects in PET. This method is based on the use of a high-resolution CT or MR image, co-registered with a PET image, which permits a high-resolution segmentation of a few tissues within a volume of interest (VOI) centered on a region within which tissue-activity values need to be estimated. The additional boundary information is used to obtain improved activity estimates for each tissue within the VOI, by solving a simple inversion problem. We implemented this algorithm for the preclinical Argus PET/CT scanner and assessed its performance using the radionuclides 18F, 68Ga and 124I. We also evaluated and compared the results obtained when it was applied during the iterative reconstruction, as well as after the reconstruction as a postprocessing procedure. In addition, we studied how LPA can help to reduce the “spillover contamination”, which causes inaccurate quantification of lesions in the immediate neighborhood of large, “hot” sources. Quantification was significantly improved by using LPA, which provided more accurate ratios of lesion-to-background activity concentration for hot and cold regions. For 18F, the contrast was improved from 3.0 to 4.0 in hot lesions (when the true ratio was 4.0) and from 0.16 to 0.06 in cold lesions (true ratio = 0.0), when using the LPA postprocessing. Furthermore, activity values estimated within the VOI using LPA during reconstruction were slightly more accurate than those obtained by post-processing, while also visually improving the image contrast and uniformity within the VOI

  11. 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.

  12. 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.

  13. 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.

  14. The hemodynamic and metabolic response to pacing after aortocoronary bypass.

    PubMed

    Hilton, J D; Weisel, R D; Baird, R J; Goldman, B S; Jablonsky, G; Pym, J; Scully, H E; Ivanov, J; Mickle, D A; Feiglin, D H; Morch, J E; McLaughlin, P R

    1981-08-01

    Long-term follow-up of aortocoronary bypass has shown good preservation of ventricular function. However, myocardial reserve in the immediate postoperative period may not be optimal. Nineteen patients who underwent elective aortocoronary bypass protected with cold potassium cardioplegia were studied in the early postoperative period at rest and during the stress of atrial and ventricular pacing. Performance was assessed by hemodynamic, metabolic and nuclear angiographic measurements. In the first 2--6 hours after aortic cross clamping, myocardial performance was preserved at rest and there was no evidence of ischemic metabolism. Atrial pacing at a rate of 119 beats/min caused a significant increase in cardiac index (p less than 0.01) without deterioration in hemodynamics, ejection fraction or metabolic status. At the same rate, ventricular pacing did not change the cardiac index and there was a decrease in hemodynamic function. Ejection fraction decreased from 56% to 44% (p less than 0.05) without a change in end-diastolic volume. Lactate, pyruvate and beta hydroxybutyrate extractions were changed to net production. Ventricular performance was preserved at rest immediately after aortocoronary bypass done with multidose cold potassium cardioplegia, with adequate reserve to meet the stress of atrial but not ventricular pacing. We conclude that the therapeutic implications of the type of pacing selected in the immediate postoperative period may be important.

  15. [Analysis of fusion waves created with temporal pacing].

    PubMed

    Ueda, M; Shigemi, K; Hayashi, K; Kakihara, K; Nakajima, Y; Fukushima, H; Tanaka, Y

    1998-08-01

    Fifty-five beats of fusion waves were recorded continuously with an audio digital tape and the tape was re-played for analysis. A 45-year-old male (56 kg, 175 cm) with cervical spondylosis was scheduled to undergo laminoplasty of the cervical vertebral (C2-C6). A temporal ventricular (VVI mode) pacing lead was inserted from the right cubital vein to the right ventricular apex for preventing bradycardia while manipulating the medulla. The height of the R wave decreased gradually and the depth of S wave increased in the earlier period of fusion beats and it was reversed later. The narrow QRS width indicated that the electrode was placed near the cardiac conducting system. The gradually increasing intervals between P waves activated the pacing, and the P wave intervals recovered inhibiting the pacing. During the recovery phase, some beats were still activated by pacing instead of depressing the rate below the original rate. These beats suggest the importance of considering the atrial-ventricular conducting time. Arterial pressure fluctuated only slightly during the 'fusion beats, suggesting that despite the abnormality in the cardiac conduction system due to pacing, contraction of the ventricular muscles was only slightly affected in this case.

  16. An improved model of high-latitude f-region scintillation (WBMOD version 13)

    NASA Astrophysics Data System (ADS)

    Secan, James A.; Bussey, Robert M.

    1994-08-01

    Many modern military systems used for communications, command and control, navigation, and surveillance depend on reliable and relatively noise-free transmission of radiowave signals through the earth's ionosphere. Small-scale irregularities in the ionospheric density can cause severe distortion, known as radiowave scintillation, of both the amplitude and phase of these signals. The WBMOD computer program can he used to estimate these effects on a wide range of systems. The objective of this study is to investigate improvements to the WBMOD model based on extensive data sets covering both the equatorial and high-latitude regimes. This report summarizes the work completed during the third year of this project, which includes completion of the new model for the high-latitude (auroral and polar cap) region of the WBMOD model.

  17. Learning from 8 years of regional cyanobacteria observation in Brittany in view of sanitary survey improvement.

    PubMed

    Pitois, Frédéric; Thomas, Olivier; Thoraval, Isabelle; Baurès, Estelle

    2014-01-01

    Cyanobacteria and cyanotoxins have been more and more studied during the last decades with regard to environment and health issues. More recently the consequences of climate change reinforced the need for research in view of a better management of cyanobacteria blooms. In this context the exploitation of the water quality survey of 26 recreational lakes in Brittany (north western France) between 2004 and 2011 is reported in this paper in order to encompass spatial and interannual patterns of cyanobacteria development at a regional scale. Starting from weekly data principally acquired during summertime, the links between cyanobacteria cell densities, toxin occurrences and interannual meteorological factors can give insights on the potential evolution of cyanobacterial crisis in the future. This study is part of a project aiming at a better understanding of potentially toxic cyanobacteria crisis occurrences in recreational waters, in order to improve predictive monitoring routines.

  18. Engineering a regulatory region of jadomycin gene cluster to improve jadomycin B production in Streptomyces venezuelae.

    PubMed

    Zheng, Jian-Ting; Wang, Sheng-Lan; Yang, Ke-Qian

    2007-09-01

    Streptomyces venezuelae ISP5230 produces a group of jadomycin congeners with cytotoxic activities. To improve jadomycin fermentation process, a genetic engineering strategy was designed to replace a 3.4-kb regulatory region of jad gene cluster that contains four regulatory genes (3' end 272 bp of jadW2, jadW3, jadR2, and jadR1) and the native promoter upstream of jadJ (P(J)) with the ermEp* promoter sequence so that ermEp* drives the expression of the jadomycin biosynthetic genes from jadJ in the engineered strain. As expected, the mutant strain produced jadomycin B without ethanol treatment, and the yield increased to about twofold that of the stressed wild-type. These results indicated that manipulation of the regulation of a biosynthetic gene cluster is an effective strategy to increase product yield.

  19. [Drug release of coated dental implant neck region to improve tissue integration].

    PubMed

    Wolf, Jens; Sternberg, Katrin; Behrend, Detlef; Schmitz, Klaus-Peter; von Schwanewede, Heinrich

    2009-08-01

    In order to improve tissue integration, the neck region of dental implants was coated with the biodegradable polymer poly (L-lactide) incorporating tetracycline, ibuprofen and the combination of both drugs using a solvent dip-coating process. Metallographic analysis, light microscopy and electron microscopy were used to detect the thickness range and the surface characteristics of the coatings. Cytotoxicity was evaluated using the tetrazolium colorimetric method with the fibroblast cell line L929. The in vitro drug release was measured in isotonic sodium chloride solution by UV spectroscopy. To explore if drug release is concentration-dependent, the total amount of drug was varied in the coating (20% wt, 30% wt and 40% wt). The results showed a continuous release of the embedded drugs in relevant dosage over a period of 6 months. In contrast to high tetracycline concentrations, high ibuprofen concentrations resulted in a decreased metabolic activity of the L929 fibroblasts.

  20. Electrocardiographic identification of prior myocardial infarction during right ventricular pacing--effect of septal versus apical pacing.

    PubMed

    Tzeis, Stylianos; Andrikopoulos, George; Asbach, Stefan; Semmler, Verena; Lennerz, Carsten; Solzbach, Ulrich; Vrazic, Hrvoje; Kloppe, Axel; Klein, Norbert; Pastromas, Sokratis; Biermann, Jürgen; Kolb, Christof

    2014-12-20

    Electrocardiographic (ECG) identification of prior myocardial infarction (MI) during right ventricular (RV) pacing is of clinical importance. Proposed ECG criteria have been evaluated only during apical pacing. We evaluated the effect of pacing site on the predictive performance of ECG signs of prior MI. The present study is a secondary analysis of a prospective, multicenter study which randomized recipients of an implantable cardioverter defibrillator to an apical versus septal RV lead positioning. ECGs of patients with or without prior MI were analyzed for the presence of the following criteria: Cabrera sign, Chapman sign, QR pattern in leads I, aVL, V5 or V6, QR in inferior leads and notching in the descending slope of the QRS complex in inferior leads. The MI group included 89 patients (55.1% apically paced), while 99 patients had no prior MI (50.5% apically paced). In the total population, the Cabrera sign presented the highest specificity (97%) and diagnostic accuracy (62.2%), with a sensitivity of 23.6%. The Cabrera sign was the only significant predictor of a prior MI [OR=9.9, (95%CI:2.8-34.5), p<0.001], among all ECG markers. Pacing site did not significantly influence the sensitivity and specificity of the Cabrera sign for detection of prior MI. In our study, the Cabrera sign was the only ECG marker that predicted the presence of prior MI during ventricular paced rhythm. Septal RV lead positioning did not affect the predictive performance of the Cabrera sign. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  1. Sputter-deposited TiN electrode coatings for superior sensing and pacing performance.

    PubMed

    Schaldach, M; Hubmann, M; Weikl, A; Hardt, R

    1990-12-01

    The sensing and pacing performance of pacemaker electrodes is characterized by the electrochemical properties of the electrode/tissue interface affecting tissue reactions and the kinetics of the ionic exchange. The usually smooth metallic electrode surface results in a high pass filter characteristic. To better match the electrode's filter characteristic to the spectral content of the depolarization signal, various combinations of electrode shape, material and surface structure have been researched. The electrode with sputter-deposited TiN coating presented in this report has been designed to meet the demand for low acute as well as chronic thresholds and superior sensing performance not only with respect to spontaneous activity but also regarding the detection of the evoked response. The clinical results obtained with this electrode prove the excellent pacing and sensing properties resulting from minimized polarization losses and optimized filtering of the signal to be detected, respectively. The acute and chronic clinical advantages over previous concepts are attributed mainly to the biocompatibility of the material used and the microcrystalline surface structure achieved by the coating process. The design concept of the new electrode is presented together with the clinical results obtained. While the advancements in microelectronics and battery technology have certainly formed the basis for the development of pulse generators featuring an ever increasing versatility of functions at the same or even smaller pacemaker dimensions, from a point of view of pacing system performance the development of improved electrode concepts as the one presented must be regarded as equally indispensable.

  2. Hydrological modelling improvements required in basins in the Hindukush-Karakoram-Himalayas region

    NASA Astrophysics Data System (ADS)

    Khan, Asif; Richards, Keith S.; McRobie, Allan; Booij, Martijn

    2016-04-01

    Millions of people rely on river water originating from basins in the Hindukush-Karakoram-Himalayas (HKH), where snow- and ice-melt are significant flow components. One such basin is the Upper Indus Basin (UIB), where snow- and ice-melt can contribute more than 80% of total flow. Containing some of the world's largest alpine glaciers, this basin may be highly susceptible to global warming and climate change, and reliable predictions of future water availability are vital for resource planning for downstream food and energy needs in a changing climate, but depend on significantly improved hydrological modelling. However, a critical assessment of available hydro-climatic data and hydrological modelling in the HKH region has identified five major failings in many published hydro-climatic studies, even those appearing in reputable international journals. The main weaknesses of these studies are: i) incorrect basin areas; ii) under-estimated precipitation; iii) incorrectly-defined glacier boundaries; iv) under-estimated snow-cover data; and v) use of biased melt factors for snow and ice during the summer months. This paper illustrates these limitations, which have either resulted in modelled flows being under-estimates of measured flows, leading to an implied severe water scarcity; or have led to the use of unrealistically high degree-day factors and over-estimates of glacier melt contributions, implying unrealistic melt rates. These effects vary amongst sub-basins. Forecasts obtained from these models cannot be used reliably in policy making or water resource development, and need revision. Detailed critical analysis and improvement of existing hydrological modelling may be equally necessary in other mountain regions across the world.

  3. Improving Shade Modelling in a Regional River Temperature Model Using Fine-Scale LIDAR Data

    NASA Astrophysics Data System (ADS)

    Hannah, D. M.; Loicq, P.; Moatar, F.; Beaufort, A.; Melin, E.; Jullian, Y.

    2015-12-01

    Air temperature is often considered as a proxy of the stream temperature to model the distribution areas of aquatic species water temperature is not available at a regional scale. To simulate the water temperature at a regional scale (105 km²), a physically-based model using the equilibrium temperature concept and including upstream-downstream propagation of the thermal signal was developed and applied to the entire Loire basin (Beaufort et al., submitted). This model, called T-NET (Temperature-NETwork) is based on a hydrographical network topology. Computations are made hourly on 52,000 reaches which average 1.7 km long in the Loire drainage basin. The model gives a median Root Mean Square Error of 1.8°C at hourly time step on the basis of 128 water temperature stations (2008-2012). In that version of the model, tree shadings is modelled by a constant factor proportional to the vegetation cover on 10 meters sides the river reaches. According to sensitivity analysis, improving the shade representation would enhance T-NET accuracy, especially for the maximum daily temperatures, which are currently not very well modelized. This study evaluates the most efficient way (accuracy/computing time) to improve the shade model thanks to 1-m resolution LIDAR data available on tributary of the LoireRiver (317 km long and an area of 8280 km²). Two methods are tested and compared: the first one is a spatially explicit computation of the cast shadow for every LIDAR pixel. The second is based on averaged vegetation cover characteristics of buffers and reaches of variable size. Validation of the water temperature model is made against 4 temperature sensors well spread along the stream, as well as two airborne thermal infrared imageries acquired in summer 2014 and winter 2015 over a 80 km reach. The poster will present the optimal length- and crosswise scale to characterize the vegetation from LIDAR data.

  4. Brain regions essential for improved lexical access in an aged aphasic patient: a case report.

    PubMed

    Meinzer, Marcus; Flaisch, Tobias; Obleser, Jonas; Assadollahi, Ramin; Djundja, Daniela; Barthel, Gabriela; Rockstroh, Brigitte

    2006-08-17

    The relationship between functional recovery after brain injury and concomitant neuroplastic changes is emphasized in recent research. In the present study we aimed to delineate brain regions essential for language performance in aphasia using functional magnetic resonance imaging and acquisition in a temporal sparse sampling procedure, which allows monitoring of overt verbal responses during scanning. An 80-year old patient with chronic aphasia (2 years post-onset) was investigated before and after intensive language training using an overt picture naming task. Differential brain activation in the right inferior frontal gyrus for correct word retrieval and errors was found. Improved language performance following therapy was mirrored by increased fronto-thalamic activation while stability in more general measures of attention/concentration and working memory was assured. Three healthy age-matched control subjects did not show behavioral changes or increased activation when tested repeatedly within the same 2-week time interval. The results bear significance in that the changes in brain activation reported can unequivocally be attributed to the short-term training program and a language domain-specific plasticity process. Moreover, it further challenges the claim of a limited recovery potential in chronic aphasia, even at very old age. Delineation of brain regions essential for performance on a single case basis might have major implications for treatment using transcranial magnetic stimulation.

  5. Improving intranasal delivery of neurological nanomedicine to the olfactory region using magnetophoretic guidance of microsphere carriers.

    PubMed

    Xi, Jinxiang; Zhang, Ze; Si, Xiuhua A

    2015-01-01

    Although direct nose-to-brain drug delivery has multiple advantages, its application is limited by the extremely low delivery efficiency (<1%) to the olfactory region where drugs can enter the brain. It is crucial to developing new methods that can deliver drug particles more effectively to the olfactory region. We introduced a delivery method that used magnetophoresis to improve olfactory delivery efficiency. The performance of the proposed method was assessed numerically in an image-based human nose model. Influences of the magnet layout, magnet strength, drug-release position, and particle diameter on the olfactory dosage were examined. Results showed that particle diameter was a critical factor in controlling the motion of nasally inhaled ferromagnetic drug particles. The optimal particle size was found to be approximately 15 μm for effective magnetophoretic guidance while avoiding loss of particles to the walls in the anterior nose. Olfactory delivery efficiency was shown to be sensitive to the position and strength of magnets and the release position of drug particles. The results of this study showed that clinically significant olfactory doses (up to 45%) were feasible using the optimal combination of magnet layout, selective drug release, and microsphere-carrier diameter. A 64-fold-higher delivery of dosage was predicted in the magnetized nose compared to the control case, which did not have a magnetic field. However, the sensitivity of olfactory dosage to operating conditions and the unstable nature of magnetophoresis make controlled guidance of nasally inhaled aerosols still highly challenging.

  6. An improved permanent magnet quadrupole design with larger good field region for high intensity proton linacs

    NASA Astrophysics Data System (ADS)

    Mathew, Jose V.; Rao, S. V. L. S.; Krishnagopal, S.; Singh, P.

    2013-11-01

    The Low Energy High Intensity Proton Accelerator (LEHIPA), being developed at the Bhabha Atomic Research Centre (BARC) will produce a 20 MeV, 30 mA, continuous wave (CW) proton beam. At these low velocities, space-charge forces dominate, and could lead to larger beam sizes and beam halos. Hence in the design of the focusing lattice of the LEHIPA drift tube linac (DTL) using permanent magnet quadrupoles (PMQs), a larger good field region is preferred. Here we study, using the two dimensional (2D) and three dimensional (3D) simulation codes PANDIRA and RADIA, four different types of cylindrical PMQ designs: 16-segment trapezoidal Halbach configuration, bullet-nosed geometry and 8- and 16-segment rectangular geometries. The trapezoidal Halbach geometry is used in a variety of accelerators since it provides very high field gradients in small bores, while the bullet-nosed geometry, which is a combination of the trapezoidal and rectangular designs, is used in some DTLs. This study shows that a larger good field region is possible in the 16-segment rectangular design as compared to the Halbach and bullet-nosed designs, making it more attractive for high-intensity proton linacs. An improvement in good-field region by ˜16% over the Halbach design is obtained in the optimized 16-segment rectangular design, although the field gradient is lower by ˜20%. Tolerance studies show that the rectangular segment PMQ design is substantially less sensitive to the easy axis orientation errors and hence will be a better choice for DTLs.

  7. Using helium-oxygen to improve regional deposition of inhaled particles: mechanical principles.

    PubMed

    Katz, I; Pichelin, M; Montesantos, S; Majoral, C; Martin, A; Conway, J; Fleming, J; Venegas, J; Greenblatt, E; Caillibotte, G

    2014-04-01

    Helium-oxygen has been used for decades as a respiratory therapy conjointly with aerosols. It has also been shown under some conditions to be a means to provide more peripheral, deeper, particle deposition for inhalation therapies. Furthermore, we can also consider deposition along parallel paths that are quite different, especially in a heterogeneous pathological lung. It is in this context that it is hypothesized that helium-oxygen can improve regional deposition, leading to more homogeneous deposition by increasing deposition in ventilation-deficient lung regions. Analytical models of inertial impaction, sedimentation, and diffusion are examined to illustrate the importance of gas property values on deposition distribution through both fluid mechanics- and particle mechanics-based mechanisms. Also considered are in vitro results from a bench model for a heterogeneously obstructed lung. In vivo results from three-dimensional (3D) imaging techniques provide visual examples of changes in particle deposition patterns in asthmatics that are further analyzed using computational fluid dynamics (CFD). Based on analytical modeling, it is shown that deeper particle deposition is expected when breathing helium-oxygen, as compared with breathing air. A bench model has shown that more homogeneous ventilation distribution is possible breathing helium-oxygen in the presence of heterogeneous obstructions representative of central airway obstructions. 3D imaging of asthmatics has confirmed that aerosol delivery with a helium-oxygen carrier gas results in deeper and more homogeneous deposition distributions. CFD results are consistent with the in vivo imaging and suggest that the mechanics of gas particle interaction are the source of the differences seen in deposition patterns. However, intersubject variability in response to breathing helium-oxygen is expected, and an example of a nonresponder is shown where regional deposition is not significantly changed.

  8. The Deep South Clouds & Aerosols project: Improving the modelling of clouds in the Southern Ocean region

    NASA Astrophysics Data System (ADS)

    Morgenstern, Olaf; McDonald, Adrian; Harvey, Mike; Davies, Roger; Katurji, Marwan; Varma, Vidya; Williams, Jonny

    2016-04-01

    Southern-Hemisphere climate projections are subject to persistent climate model biases affecting the large majority of contemporary climate models, which degrade the reliability of these projections, particularly at the regional scale. Southern-Hemisphere specific problems include the fact that satellite-based observations comparisons with model output indicate that cloud occurrence above the Southern Ocean is substantially underestimated, with consequences for the radiation balance, sea surface temperatures, sea ice, and the position of storm tracks. The Southern-Ocean and Antarctic region is generally characterized by an acute paucity of surface-based and airborne observations, further complicating the situation. In recognition of this and other Southern-Hemisphere specific problems with climate modelling, the New Zealand Government has launched the Deep South National Science Challenge, whose purpose is to develop a new Earth System Model which reduces these very large radiative forcing problems associated with erroneous clouds. The plan is to conduct a campaign of targeted observations in the Southern Ocean region, leveraging off international measurement campaigns in this area, and using these and existing measurements of cloud and aerosol properties to improve the representation of clouds in the nascent New Zealand Earth System Model. Observations and model development will target aerosol physics and chemistry, particularly sulphate, sea salt, and non-sulphate organic aerosol, its interactions with clouds, and cloud microphysics. The hypothesis is that the cloud schemes in most GCMs are trained on Northern-Hemisphere data characterized by substantial anthropogenic or terrestrial aerosol-related influences which are almost completely absent in the Deep South.

  9. Pacing strategy during the initial phase of the run in triathlon: influence on overall performance.

    PubMed

    Hausswirth, Christophe; Le Meur, Yann; Bieuzen, Francois; Brisswalter, Jeanick; Bernard, Thierry

    2010-04-01

    The aim of the present study was to determine the best pacing strategy to adopt during the initial phase of a short distance triathlon run for highly trained triathletes. Ten highly trained male triathletes completed an incremental running test to determine maximal oxygen uptake, a 10-km control run at free pace and three individual time-trial triathlons (1.5-km swimming, 40-km cycling, 10-km running) in a randomised order. Swimming and cycling speeds were imposed as identical to the first triathlon performed and the first run kilometre was done alternatively 5% faster (Tri-Run(+5%)), 5% slower (Tri-Run(-5%)) and 10% slower (Tri-Run(-10%)) than the control run (C-Run). The subjects were instructed to finish the 9 remaining kilometres as quickly as possible at a free self-pace. Tri-Run(-5%) resulted in a significantly faster overall 10-km performance than Tri-Run(+5%) and Tri-Run(-10%) (p < 0.05) but no significant difference was observed with C-Run (p > 0.05) (2,028 +/- 78 s vs. 2,000 +/- 72 s, 2,178 +/- 121 s and 2,087 +/- 88 s, for Tri-Run(-5%), C-Run, Tri-Run(+5%) and Tri-Run(-10%), respectively). Tri-Run(+5%) strategy elicited higher values for oxygen uptake, ventilation, heart rate and blood lactate at the end of the first kilometre than the three other conditions. After 5 and 9.5 km, these values were higher for Tri-Run(-5%) (p < 0.05). The present results showed that the running speed achieved during the cycle-to-run transition is crucial for the improvement of the running phase as a whole. Triathletes would benefit to automate a pace 5% slower than their 10-km control running speed as both 5% faster and 10% slower running speeds over the first kilometre involved weaker overall performances.

  10. Toward Improved Land Surface Initialization in Support of Regional WRF Forecasts at the Kenya Meteorological Department

    NASA Technical Reports Server (NTRS)

    Case. Jonathan; Mungai, John; Sakwa, Vincent; Kabuchanga, Eric; Zavodsky, Bradley T.; Limaye, Ashutosh S.

    2014-01-01

    Flooding and drought are two key forecasting challenges for the Kenya Meteorological Department (KMD). Atmospheric processes leading to excessive precipitation and/or prolonged drought can be quite sensitive to the state of the land surface, which interacts with the boundary layer of the atmosphere providing a source of heat and moisture. The development and evolution of precipitation systems are affected by heat and moisture fluxes from the land surface within weakly-sheared environments, such as in the tropics and sub-tropics. These heat and moisture fluxes during the day can be strongly influenced by land cover, vegetation, and soil moisture content. Therefore, it is important to represent the land surface state as accurately as possible in numerical weather prediction models. Enhanced regional modeling capabilities have the potential to improve forecast guidance in support of daily operations and high-end events over east Africa. KMD currently runs a configuration of the Weather Research and Forecasting (WRF) model in real time to support its daily forecasting operations, invoking the Nonhydrostatic Mesoscale Model (NMM) dynamical core. They make use of the National Oceanic and Atmospheric Administration / National Weather Service Science and Training Resource Center's Environmental Modeling System (EMS) to manage and produce the WRF-NMM model runs on a 7-km regional grid over eastern Africa. Two organizations at the National Aeronautics and Space Administration Marshall Space Flight Center in Huntsville, AL, SERVIR and the Short-term Prediction Research and Transition (SPoRT) Center, have established a working partnership with KMD for enhancing its regional modeling capabilities. To accomplish this goal, SPoRT and SERVIR will provide experimental land surface initialization datasets and model verification capabilities to KMD. To produce a land-surface initialization more consistent with the resolution of the KMD-WRF runs, the NASA Land Information System (LIS

  11. Translating the potential of hydrological forecasts into improved decision making in African regions

    NASA Astrophysics Data System (ADS)

    Sheffield, J.; He, X.; Wanders, N.; Wood, E. F.; Ali, A.; Olang, L.; Estes, L. D.; Caylor, K. K.; Evans, T. P.

    2015-12-01

    Hydrological forecasts at local scale and seasonal time scales have the potential to inform decision-making by individuals and institutions to improve management of water resources and enhance food security. Much progress has been made in recent years in understanding climate variability and its predictability over African regions. However, there remain many challenges in translating large-scale evaluations and forecasts into locally relevant information. This is hampered by lack of on the ground data of hydrological and agricultural states, and the generally low skill of climate forecasts at time scales beyond one or two weeks. Additionally, the uptake of forecasts is not prevalent because of lack of capacity, and institutional and cultural barriers to using new and uncertain information. New technologies for monitoring and forecasting relevant hydrological variables, and novel approaches to understanding how this information may be used within decision making processes, have the potential to make substantial progress in addressing these challenges. We present a quasi-operational drought and flood monitoring and forecasting system and its use in understanding the potential of hydrological forecasts for improved decision-making. The system monitors in near real-time the terrestrial water cycle for the African continent based on remote sensing data and land surface hydrological modeling. The monitoring forms initial conditions for hydrological forecasts at short time scale, aimed at flood forecasting, and seasonal scale aimed at drought and crop yield forecasts. The flood forecasts are driven by precipitation and temperature forecasts from the Global Forecast System (GFS). The drought forecasts are driven by climate forecasts from the North American Multi-Model Ensemble (NMME). The seasonal forecast skill is modest and seasonally/regionally dependent with part of the skill coming from persistence in initial land surface conditions. We discuss the use of the system

  12. Improving the understanding and diagnosis of Earth system changes in cold regions

    NASA Astrophysics Data System (ADS)

    Lettenmaier, D. P.

    2015-12-01

    I review key hydrological state variables and fluxes relevant to cold regions, specifically snow, permafrost and seasonally frozen soils, lakes, and wetlands, and comment on the ability of current models to represent the associated processes, and the quality of the data sets upon which model development and diagnosis efforts rest. Although snow processes are relatively well represented in current generation land surface models, at least at large scales for deep mountain snowpacks, the representation of high latitude snow processes remain complicated by the role of snow redistribution, and of sublimation during the shoulder (especially spring) season. Most credible land surface models now include representations of permafrost, some of which perform well when forced with local climate data; however their performance over large areas is limited by spatial variability of key processes, including soil thermal characteristics. Likewise, many land surface models now represent the hydrology and energetics of lakes, which cover a substantial portion of the landscape in many high latitude environs. However, accurate representation of lakes requires knowledge of certain characteristics of their bathymetry and hydrological connectivity, information which is not always available. Likewise, the representation of wetlands in models, although improved in many cases, is limited by topography (and the role of microtopography, even at large scales). Nonetheless, increased attention to high latitude hydrological processes has demonstrably improved the fidelity of land surface representations over the last decade or so.

  13. Enhancing Dissemination, Implementation, and Improvement Science in CTSAs through Regional Partnerships

    PubMed Central

    Brown, Arleen F.; Vassar, Stefanie D.; Sankaré, Ibrahima C.; Martinez, Arturo B.; Kubicek, Katrina; Kuo, Tony; Mahajan, Anish; Gould, Michael; Mittman, Brian S.

    2015-01-01

    Abstract Background and Importance Challenges in healthcare policy and practice have stimulated interest in dissemination and implementation science. The Institute of Medicine Committee on the Clinical Translational Science Award (CTSA) program recommended expanding the CTSA program's investment and activity in this domain. Guidance is needed to facilitate successful growth of DII science infrastructure, activity and impacts. Objectives Several CTSAs in Southern California collaborated to identify and respond to local challenges and opportunities to expand dissemination, implementation and improvement research by strengthening capacity and relationships between DII researchers and community, health system, and population health partners. Main outcomes Planning and outreach by the Southern California CTSAs increased awareness and interest in DII research and generated recommendations for growth. Recommendations include: increasing strong partnerships with healthcare and population health systems to guide policy research agendas and collaborative DII science; promoting multi‐sector partnerships that involve researchers and delivery systems throughout DII processes; bringing together multiple disciplines; and addressing national and international barriers as well as opportunities in DII science. Implications CTSAs through regional collaboration can increase their contributions to improved community health via skill‐building, partnership development and enhanced outreach to local healthcare and public health agencies and delivery systems. PMID:26602191

  14. Improved confinement region without large magnetohydrodynamic activity in TPE-RX reversed-field pinch plasma

    NASA Astrophysics Data System (ADS)

    Yambe, Kiyoyuki; Hirano, Yoichi; Sakakita, Hajime; Koguchi, Haruhisa

    2014-11-01

    We found that spontaneous improved confinement was brought about depending on the operating region in the Toroidal Pinch Experiment-Reversed eXperiment (TPE-RX) reversed-field pinch plasma [Y. Yagi et al., Fusion Eng. Des. 45, 421 (1999)]. Gradual decay of the toroidal magnetic field at plasma surface Btw reversal makes it possible to realize a prolonged discharge, and the poloidal beta value and energy confinement time increase in the latter half of the discharge, where reversal and pinch parameters become shallow and low, respectively. In the latter half of the discharge, the plasma current and volume-averaged toroidal magnetic field increase again, the electron density slowly decays, the electron temperature and soft X-ray radiation intensity increase, and the magnetic fluctuations are markedly reduced. In this period of improved confinement, the value of (-Btw)/Bpw, where Bpw is the poloidal magnetic field at the plasma surface, stays almost constant, which indicates that the dynamo action occurs without large magnetohydrodynamic activities.

  15. Improved confinement region without large magnetohydrodynamic activity in TPE-RX reversed-field pinch plasma

    SciTech Connect

    Yambe, Kiyoyuki; Hirano, Yoichi; Sakakita, Hajime; Koguchi, Haruhisa

    2014-11-15

    We found that spontaneous improved confinement was brought about depending on the operating region in the Toroidal Pinch Experiment-Reversed eXperiment (TPE-RX) reversed-field pinch plasma [Y. Yagi et al., Fusion Eng. Des. 45, 421 (1999)]. Gradual decay of the toroidal magnetic field at plasma surface B{sub tw} reversal makes it possible to realize a prolonged discharge, and the poloidal beta value and energy confinement time increase in the latter half of the discharge, where reversal and pinch parameters become shallow and low, respectively. In the latter half of the discharge, the plasma current and volume-averaged toroidal magnetic field 〈B{sub t}〉 increase again, the electron density slowly decays, the electron temperature and soft X-ray radiation intensity increase, and the magnetic fluctuations are markedly reduced. In this period of improved confinement, the value of (〈B{sub t}〉-B{sub tw})/B{sub pw}, where B{sub pw} is the poloidal magnetic field at the plasma surface, stays almost constant, which indicates that the dynamo action occurs without large magnetohydrodynamic activities.

  16. White noise improves learning by modulating activity in dopaminergic midbrain regions and right superior temporal sulcus.

    PubMed

    Rausch, Vanessa H; Bauch, Eva M; Bunzeck, Nico

    2014-07-01

    In neural systems, information processing can be facilitated by adding an optimal level of white noise. Although this phenomenon, the so-called stochastic resonance, has traditionally been linked with perception, recent evidence indicates that white noise may also exert positive effects on cognitive functions, such as learning and memory. The underlying neural mechanisms, however, remain unclear. Here, on the basis of recent theories, we tested the hypothesis that auditory white noise, when presented during the encoding of scene images, enhances subsequent recognition memory performance and modulates activity within the dopaminergic midbrain (i.e., substantia nigra/ventral tegmental area, SN/VTA). Indeed, in a behavioral experiment, we can show in healthy humans that auditory white noise-but not control sounds, such as a sinus tone-slightly improves recognition memory. In an fMRI experiment, white noise selectively enhances stimulus-driven phasic activity in the SN/VTA and auditory cortex. Moreover, it induces stronger connectivity between SN/VTA and right STS, which, in addition, exhibited a positive correlation with subsequent memory improvement by white noise. Our results suggest that the beneficial effects of auditory white noise on learning depend on dopaminergic neuromodulation and enhanced connectivity between midbrain regions and the STS-a key player in attention modulation. Moreover, they indicate that white noise could be particularly useful to facilitate learning in conditions where changes of the mesolimbic system are causally related to memory deficits including healthy and pathological aging.

  17. The OPTI-MIND study: a prospective, observational study of pacemaker patients according to pacing modality and primary indications.

    PubMed

    Biffi, Mauro; Melissano, Donato; Rossi, Paolo; Kaliska, Gabriela; Havliĉek, Aleš; Pelargonio, Gemma; Romero, Rafael; Guastaferro, Ciro; Menichelli, Maurizio; Vireca, Elisa; Frisoni, Jessica; Boriani, Giuseppe; Malacky, Tibor

    2014-05-01

    The OPTI-MIND study aims to collect 2-year clinical outcomes of pacemaker patients in real-world clinical practice, overall and according to patient characteristics and pacemaker settings. The present analysis of the OPTI-MIND study describes the programmed device settings after discharge from the pacemaker implant. The objective was to determine whether these settings fit recent guidelines for device-programmed physiological pacing based on the preservation of atrioventricular synchrony, avoiding unnecessary pacing, ensuring rate increase during exercise or preventing neurally mediated symptoms. A total of 1740 patients were enroled at 68 centres worldwide. Baseline patient characteristics and device programming settings are available in 1674 of 1740 patients (96%). Guidelines to ensure physiological pacing were followed in 41% of patients: in patients with sinus node disease (SND), and without atrioventricular block (AVB), device programming could have led to unnecessary right ventricular pacing in 38% of patients. In SND patients with chronotropic incompetence, assisted rate increase during exercise was not programmed in 42% of patients. In 11% of patients with AVB, atrioventricular (AV) synchrony was not pursued; the main drivers being advanced age and history of atrial fibrillation. Patients with both SND and AVB were generally programmed physiologically (87%). The present analysis showed that frequent deviations occurred when comparing the device settings at discharge from the pacemaker implant in clinical practice to the available guidelines on pacing mode selection. Analysis of 2-year outcomes in the OPTI-MIND study will provide an insight into whether specific physiological settings could improve the quality of pacing with a positive effect on patient outcome.

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

    PubMed

    Nussinovitch, Udi; Gepstein, Lior

    2015-07-01

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

  19. Enhancement of the double flexible pace search threshold determination for change vector analysis

    NASA Astrophysics Data System (ADS)

    Azzouzi, S. A.; Vidal, A.; Bentounes, H. A.

    2015-04-01

    Remote sensing is one of the most reliable ways to monitor land use and land cover change of large areas. On the other hand, satellite images from different agencies are becoming accessible due to the new user dissemination policies. For that reason, interpretation of remotely sensed data in a spatiotemporal context is becoming a valuable research topic. In the present day, a map of change has a great significant for scientific purposes or planning and management applications. However, it is difficult to extract useful visual information from the large collection of available satellite images. For that reason, automatic or semi-automatic exploration is needed. One of the key stages in the change detection methods is threshold selection. This threshold determination problem has been addressed by several recent techniques based on Change Vector Analysis (CVA). Thus, this work provides a simple semi-automatic procedure that defines the change/no change condition and a comparative study will be involved together with the previous existing method called Double Flexible Pace Search (DFPS). This study uses Landsat Thematic Mapper scenes acquired on different dates in an Algerian region. First, some training data sets containing all possible classes of change are required and their respective supervised posterior probability maps for each scene are obtained. The selected supervised classifier is based on the Maximum Likelihood method. Then four training sets (two sets from each date) are chosen from their corresponding probability maps based on their spatial location in the original images. The optimal average will be obtained as an average of the thresholds obtained at every set. This work verifies that the proposed approach is effective on the selected area, providing improved change map results.

  20. An improved earthquake catalogue in the Marmara Sea region, Turkey, using massive template matching

    NASA Astrophysics Data System (ADS)

    Matrullo, Emanuela; Lengliné, Olivier; Schmittbuhl, Jean; Karabulut, Hayrullah; Bouchon, Michel

    2016-04-01

    After the 1999 Izmit earthquake, the Main Marmara Fault (MMF) represents a 150 km unruptured segment of the North Anatolian Fault located below the Marmara Sea. One of the principal issue for seismic hazard assessment in the region is to know if the MMF is totally or partially locked and where the nucleation of the major forthcoming event is going to take place. The area is actually one of the best-instrumented fault systems in Europe. Since year 2007, various seismic networks both broadband, short period and OBS stations were deployed in order to monitor continuously the seismicity along the MMF and the related fault systems. A recent analysis of the seismicity recorded during the 2007-2012 period has provided new insights on the recent evolution of this important regional seismic gap. This analysis was based on events detected with STA/LTA procedure and manually picked P and S wave arrivals times (Schmittbuhl et al., 2015). In order to extend the level of details and to fully take advantage of the dense seismic network we improved the seismic catalog using an automatic earthquake detection technique based on a template matching approach. This approach uses known earthquake seismic signals in order to detect newer events similar to the tested one from waveform cross-correlation. To set-up the methodology and verify the accuracy and the robustness of the results, we initially focused in the eastern part of the Marmara Sea (Cinarcik basin) and compared new detection with those manually identified. Through the massive analysis of cross-correlation based on the template scanning of the continuous recordings, we construct a refined catalog of earthquakes for the Marmara Sea in 2007-2014 period. Our improved earthquake catalog will provide an effective tool to improve the catalog completeness, to monitor and study the fine details of the time-space distribution of events, to characterize the repeating earthquake source processes and to understand the mechanical state of

  1. Application of Suomi-NPP Green Vegetation Fraction and NUCAPS for Improving Regional Numerical Weather Prediction

    NASA Technical Reports Server (NTRS)

    Case, Jonathan L.; Berndt, Emily B.; Srikishen, Jayanthi; Zavodsky, Bradley T.

    2014-01-01

    The NASA SPoRT Center is working to incorporate Suomi-NPP products into its research and transition activities to improve regional numerical weather prediction (NWP). Specifically, SPoRT seeks to utilize two data products from NOAA/NESDIS: (1) daily global VIIRS green vegetation fraction (GVF), and (2) NOAA Unique CrIS and ATMS Processing System (NUCAPS) temperature and moisture retrieved profiles. The goal of (1) is to improve the representation of vegetation in the Noah land surface model (LSM) over existing climatological GVF datasets in order to improve the land-atmosphere energy exchanges in NWP models and produce better temperature, moisture, and precipitation forecasts. The goal of (2) is to assimilate NUCAPS retrieved profiles into the Gridpoint Statistical Interpolation (GSI) data assimilation system to assess the impact on a summer pre-frontal convection case. Most regional NWP applications make use of a monthly GVF climatology for use in the Noah LSM within the Weather Research and Forecasting (WRF) model. The GVF partitions incoming energy into direct surface heating/evaporation over bare soil versus evapotranspiration processes over vegetated surfaces. Misrepresentations of the fractional coverage of vegetation during anomalous weather/climate regimes (e.g., early/late bloom or freeze; drought) can lead to poor NWP model results when land-atmosphere feedback is important. SPoRT has been producing a daily MODIS GVF product based on the University of Wisconsin Direct Broadcast swaths of Normalized Difference Vegetation Index (NDVI). While positive impacts have been demonstrated in the WRF model for some cases, the reflectances composing these NDVI do not correct for atmospheric aerosols nor satellite view angle, resulting in temporal noisiness at certain locations (especially heavy vegetation). The method behind the NESDIS VIIRS GVF is expected to alleviate the issues seen in the MODIS GVF real-time product, thereby offering a higher-quality dataset for

  2. Drought, Fire and Insects in Western US Forests: Observations to Improve Regional Land System Modeling

    NASA Astrophysics Data System (ADS)

    Law, B. E.; Yang, Z.; Berner, L. T.; Hicke, J. A.; Buotte, P.; Hudiburg, T. W.

    2015-12-01

    Drought, fire and insects are major disturbances in the western US, and conditions are expected to get warmer and drier in the future. We combine multi-scale observations and modeling with CLM4.5 to examine the effects of these disturbances on forests in the western US. We modified the Community Land Model, CLM4.5, to improve simulated drought-related mortality in forests, and prediction of insect outbreaks under future climate conditions. We examined differences in plant traits that represent species variation in sensitivity to drought, and redefined plant groupings in PFTs. Plant traits, including sapwood area: leaf area ratio and stemwood density were strongly correlated with water availability during the ecohydrologic year. Our database of co-located observations of traits for 30 tree species was used to produce parameterization of the model by species groupings according to similar traits. Burn area predicted by the new fire model in CLM4.5 compares well with recent years of GFED data, but has a positive bias compared with Landsat-based MTBS. Biomass mortality over recent decades increased, and was captured well by the model in general, but missed mortality trends of some species. Comparisons with AmeriFlux data showed that the model with dynamic tree mortality only (no species trait improvements) overestimated GPP in dry years compared with flux data at semi-arid sites, and underestimated GPP at more mesic sites that experience dry summers. Simulations with both dynamic tree mortality and species trait parameters improved estimates of GPP by 17-22%; differences between predicted and observed NEE were larger. Future projections show higher productivity from increased atmospheric CO2 and warming that somewhat offsets drought and fire effects over the next few decades. Challenges include representation of hydraulic failure in models, and availability of species trait and carbon/water process data in disturbance- and drought-impacted regions.

  3. Different horse's paces during hippotherapy on spatio-temporal parameters of gait in children with bilateral spastic cerebral palsy: A feasibility study.

    PubMed

    Antunes, Fabiane Nunes; Pinho, Alexandre Severo do; Kleiner, Ana Francisca Rozin; Salazar, Ana Paula; Eltz, Giovana Duarte; de Oliveira Junior, Alcyr Alves; Cechetti, Fernanda; Galli, Manuela; Pagnussat, Aline Souza

    2016-12-01

    Hippotherapy is often carried out for the rehabilitation of children with Cerebral Palsy (CP), with the horse riding at a walking pace. This study aimed to explore the immediate effects of a hippotherapy protocol using a walk-trot pace on spatio-temporal gait parameters and muscle tone in children with Bilateral Spastic CP (BS-CP). Ten children diagnosed with BS-CP and 10 healthy aged-matched children (reference group) took part in this study. The children with BS-CP underwent two sessions of hippotherapy for one week of washout between them. Two protocols (lasting 30min) were applied on separate days: Protocol 1: the horse's pace was a walking pace; and Protocol 2: the horse's pace was a walk-trot pace. Children from the reference group were not subjected to treatment. A wireless inertial measurement unit measured gait spatio-temporal parameters before and after each session. The Modified Ashworth Scale was applied for muscle tone measurement of hip adductors. The participants underwent the gait assessment on a path with surface irregularities (ecological context). The comparisons between BS-CP and the reference group found differences in all spatio-temporal parameters, except for gait velocity. Within-group analysis of children with BS-CP showed that the swing phase did not change after the walk pace and after the walk-trot pace. The percentage of rolling phase and double support improved after the walk-trot. The spasticity of the hip adductors was significantly reduced as an immediate result of both protocols, but this decrease was more evident after the walk-trot. The walk-trot protocol is feasible and is able to induce an immediate effect that improves the gait spatio-temporal parameters and the hip adductors spasticity. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Teachers' Perceptions of the Educational Platform--Is There a Connection between School Improvement and Regional Educational Development?

    ERIC Educational Resources Information Center

    Boström, Lena; Dalin, Rolf

    2016-01-01

    This research examined teachers' attitudes in a school development project, The best regional educational system in the world which focuses on regional development and school improvement. The project was performed in counties in Mid Sweden, which have a lower educational level and school achievements and a competence escape compare with other…

  5. Acarbose improves glycemic control and reduces body weight: Subanalysis data of South Asia region.

    PubMed

    Kalra, S; Sahay, R K; Schnell, O; Sheu, W H H; Grzeszczak, W; Watada, H; Soegondo, S; Yamamoto, N; Weng, J; Rathod, R

    2013-10-01

    Alpha-glucosidase inhibitors (AGIs) are widely used especially in Asian countries as a treatment option for type 2 diabetes patients with high postprandial glycaemia. However, data from South Asia region is very limited. In order to examine the effect of AGI in real-life setting, 10 PMS/NIS from all over the world from the launch of acarbose to date were pooled in one database and exploratory analysis was performed for glycemic parameters and weight. In total 62,905 patients were pooled from 21 countries and regions. Mean follow up (± SD) was 12.2 ± 4.8 weeks (range 0.1-108.9). From South Asia region (India and Pakistan), 8,738 Asian patients were enrolled. Mean PPG decreased from 240.0 and 261.1 mg/dl at baseline by 70.26 ± 65.10 and 82.96 ± 56.59 mg/dl at the last visit in total and South Asian populations, respectively (n = 53,883; n = 7,991, P < 0.0001 for both). Mean FPG decreased from 171.6 and 176.5 mg/dl at baseline by 38.48 ± 47.83 and 49.59 ± 41.41 mg/dl at the last visit in total and South Asian populations, respectively (n = 56,672; n = 7,837, P < 0.0001 for both). Mean HbA1c decreased from 8.4 and 8.4% at baseline by 1.11 ± 1.31% and 0.91 ± 0.93% at the last visit in total and South Asian populations, respectively (n = 38,843; n = 2,343, P < 0.0001 for both). Mean relative reduction of body weight (BW) was 1.40 ± 3.28% and 1.10 ± 3.39% at the last visit for mean baseline BW 73.6 and 74.2 kg in total and South Asian populations, respectively (n = 54,760; n = 7,718, P < 0.0001 for both). Consistent with RCT meta-analyses, post-hoc analysis of real-life data showed acarbose treatment improved glycaemic control and reduced the BW. Acarbose treatment in real life setting showed significant reductions in all glycemic parameters and BW in Asian patients from South Asia region.

  6. Pacing during an ultramarathon running event in hilly terrain

    PubMed Central

    Cole-Hunter, Tom; Wiegand, Aaron N.; Solomon, Colin

    2016-01-01

    Purpose The dynamics of speed selection as a function of distance, or pacing, are used in recreational, competitive, and scientific research situations as an indirect measure of the psycho-physiological status of an individual. The purpose of this study was to determine pacing on level, uphill and downhill sections of participants in a long (>80 km) ultramarathon performed on trails in hilly terrain. Methods Fifteen ultramarathon runners competed in a  173 km event (five finished at  103 km) carrying a Global-Positioning System (GPS) device. Using the GPS data, we determined the speed, relative to average total speed, in level (LEV), uphill (UH) and downhill (DH) gradient categories as a function of total distance, as well as the correlation between overall performance and speed variability, speed loss, and total time stopped. Results There were no significant differences in normality, variances or means in the relative speed in 173-km and 103-km participants. Relative speed decreased in LEV, UH and DH. The main component of speed loss occurred between 5% and 50% of the event distance in LEV, and between 5% and 95% in UH and DH. There were no significant correlations between overall performance and speed loss, the variability of speed, or total time stopped. Conclusions Positive pacing was observed at all gradients, with the main component of speed loss occurring earlier (mixed pacing) in LEV compared to UH and DH. A speed reserve (increased speed in the last section) was observed in LEV and UH. The decrease in speed and variability of speed were more important in LEV and DH than in UH. The absence of a significant correlation between overall performance and descriptors of pacing is novel and indicates that pacing in ultramarathons in trails and hilly terrain differs to other types of running events. PMID:27812406

  7. Paced effort and all-out 30-second power tests.

    PubMed

    MacIntosh, B R; MacEachern, P

    1997-11-01

    The purpose of this study was to determine whether mean power output in 30 seconds was greater in a paced effort test or an all-out effort under optimal loading conditions. Nine male athletes volunteered to participate. All testing was done on a Monark cycle ergometer with continuous measurement of velocity and resistance. Power output was calculated (Resistance x Velocity) and corrected for acceleration of the flywheel. For each subject, optimal resistance for peak power output was determined with 5 brief (7-second) tests. Subsequently, 3 all-out 30-second tests using 80, 90 and 100% of this estimated optimal resistance, then 3 paced effort 30-second tests were completed on separate days. Pacing was accomplished with velocity feedback at 80, 100 or 120% of optimal velocity calculated from the all-out tests. Subjects were encouraged to try to exceed the target velocity if possible during the final 10 seconds of the paced effort test. The best all-out test (772 +/- 35 W) was not different (paired t test, p = 0.31) from the best paced effort test (787 +/- 27 W). Furthermore, there was no significant difference between mean power output in the all-out tests at 90% (736 +/- 28 W) and 100% (766 +/- 36 W) of estimated optimal resistance for peak power output (1.16 +/- 0.05 N x kg[-1]), but mean power at 80% of the estimated optimal resistance was lower (722 +/- 31 W; ANOVA for repeated measures, p < 0.05). In conclusion, a paced effort test does not permit greater mean power output over 30 seconds than an all-out test, and there is considerable latitude in apparent optimal resistance for mean power output in a 30-second test.

  8. Effect of age and performance on pacing of marathon runners.

    PubMed

    Nikolaidis, Pantelis Theodoros; Knechtle, Beat

    2017-01-01

    Pacing strategies in marathon runners have previously been examined, especially with regard to age and performance level separately. However, less information about the age × performance interaction on pacing in age-group runners exists. The aim of the present study was to examine whether runners with similar race time and at different age differ for pacing. Data (women, n=117,595; men, n=180,487) from the "New York City Marathon" between 2006 and 2016 were analyzed. A between-within subjects analysis of variance showed a large main effect of split on race speed (p<0.001, η(2)=0.538) with the fastest speed in the 5-10 km split and the slowest in the 35-40 km. A small sex × split interaction on race speed was found (p<0.001, η(2)=0.035) with men showing larger increase in speed at 5 km and women at 25 km and 40 km (end spurt). An age-group × performance group interaction on Δspeed was shown for both sexes at 5 km, 10 km, 15 km, 20 km, 25 km, 30 km, 35 km, and 40 km (p<0.001, 0.001≤η(2)≤0.004), where athletes in older age-groups presented a relatively more even pace compared with athletes in younger age-groups, a trend that was more remarkable in the relatively slow performance groups. So far, the present study is the first one to observe an age × performance interaction on pacing; ie, older runners pace differently (smaller changes) than younger runners with similar race time. These findings are of great practical interest for coaches working with marathon runners of different age, but similar race time.

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

    PubMed

    Scruton, Adrian; Baker, James; Roberts, Justin; Basevitch, Itay; Merzbach, Viviane; Gordon, Dan

    2015-01-01

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

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

    PubMed Central

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

    2016-01-01

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

  11. The risk of atrial fibrillation during right ventricular pacing.

    PubMed

    Pastore, Gianni; Zanon, Francesco; Baracca, Enrico; Aggio, Silvio; Corbucci, Giorgio; Boaretto, Graziano; Roncon, Loris; Noventa, Franco; Barold, S Serge

    2016-03-01

    Right ventricular pacing adversely affects left atrial (LA) structure and function that may trigger atrial fibrillation (AF). This study compares the occurrence of persistent/permanent AF during long-term Hisian area (HA), right ventricular septal (RVS), and right ventricular apex (RVA) pacing in patients with complete/advanced atrioventricular block (AVB). We collected retrospective data from 477 consecutive patients who underwent pacemaker implantation for complete/advanced AVB. Ventricular pacing leads were located in the HA, RVS, and RVA in 148, 140, and 189 patients, respectively. The occurrence of persistent/permanent AF was observed in 114 (23.9%) patients (follow-up 58.5 ± 26.5 months). Hisian area groups presented a lower rate of AF occurrence (16.9%) compared with RVS and RVA groups (25.7 and 28.0%, respectively), P = 0.049. Cox's proportional hazard model was used to estimate HR. The risk of persistent/permanent AF was significantly lower in the patients paced from HA compared with those paced from RVA, HR = 0.28 (95% CI 0.16-0.48, P = 0.0001). The RVS and RVA pacing groups showed a similar AF risk: HR 1.04 (95% CI 0.66-1.64, P = 0.856). Other independent predictors of persistent/permanent AF occurrence included previous (before device implantation) paroxysmal AF (HR = 4.08; 95% CI 3.15-7.31, P = 0.0001), LA diameter, and age, whereas baseline bundle-branch block was associated with a lower risk of AF occurrence (HR = 0.56; 95% CI 0.35-0.81, P = 0.003). HA pacing compared with RVA or RVS pacing seems to be associated with a lower risk of persistent/permanent AF occurrence. The risk of persistent/permanent AF was similar in the RVA vs. RVS groups. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.

  12. Emergent precordial percussion revisited--pacing the heart in asystole.

    PubMed

    Monteleone, Peter P; Alibertis, Kostas; Brady, William J

    2011-06-01

    Precordial percussion is a technique by which a manual force is applied repeatedly to the chest of a patient experiencing an unstable bradycardic or asystolic rhythm. The force is used not to defibrillate the myocardium as is the case with the "precordial thump" in pulseless ventricular tachycardia/ventricular fibrillation but rather to initiate a current through the myocardium in the form of an essentially mechanically paced beat. In this review, we discuss the physiology and utility of precordial percussion, or precordial thump, in the emergency setting as a very temporary bridge to more effective and permanent pacing techniques. Copyright © 2011 Elsevier Inc. All rights reserved.

  13. Permanent pacemaker malfunction: diagnostic aspects of temporary pacing.

    PubMed Central

    Berman, N D

    1980-01-01

    A temporary pacing electrode can function as a diagnostic as well as a therapeutic tool. This is illustrated in two patients whose permanent pacemakers unexpectedly failed. In the first patient a demand pacemaker was inhibited by a magnet rather than converting to the asynchronous mode. In the second the pacemaker appeared to be producing low-voltage potentials not detectable on the surface electrocardiogram. The presence of a temporary pacing electrode can be useful for defining the cause of pacemaker failure and the nature of any associated arrhythmias. Images FIG. 1 FIG. 3 PMID:7260759

  14. The expression of proprotein convertase PACE4 is highly regulated by Hash-2 in placenta: possible role of placenta-specific basic helix-loop-helix transcription factor, human achaete-scute homologue-2.

    PubMed

    Koide, Shizuyo; Yoshida, Ichiro; Tsuji, Akihiko; Matsuda, Yoshiko

    2003-09-01

    PACE4 is a member of the mammalian subtilisin-like proprotein convertase (SPC) family, which contribute to the activation of transforming growth factor (TGF) beta family proteins. We previously reported that PACE4 is highly expressed in syncytiotrophoblasts of human placenta [Tsuji et al. (2003) BIOCHIM: Biophys. Acta 1645, 95-104]. In this study, the regulatory mechanism for PACE4 expression in placenta was analyzed using a human placental choriocarcinoma cell line, BeWo cells. Promoter analysis indicated that an E-box cluster (E4-E9) in the 5'-flanking region of the PACE4 gene acts as a negative regulatory element. The binding of human achaete-scute homologue 2 (Hash-2) to the E-box cluster was shown by gel mobility-shift assay. The overexpression of Hash-2 caused a marked decrease in PACE4 gene expression. When BeWo cells were grown under low oxygen (2%) conditions, the expression of Hash-2 decreased, while that of PACE4 increased. In both cases, other SPCs, such as furin, PC5/6, and PC7/8, were not affected. Further, PACE4 expression was found to be developmentally regulated in rat placenta. By in situ hybridization, Mash-2 (mammalian achaete-scute homologue 2) mRNA was found to be expressed in the spongiotrophoblast layer where PACE4 was not expressed. In contrast, the PACE4 mRNA was expressed mainly in the labyrinthine layer where Mash-2 was not detected. These results suggest that PACE4 expression is down-regulated by Hash-2/Mash-2 in both human and rat placenta and that many bioactive proteins might be regulated by PACE4 activity.

  15. [Anesthesic management of thoracic aortic stent graft deployment using rapid ventricular pacing].

    PubMed

    Yamagishi, Akio; Kunisawa, Takayuki; Katsumi, Norifumi; Nagashima, Michio; Takahata, Osamu; Iwasaki, Hiroshi

    2008-08-01

    Controlled hypotension is useful for accurate deployment of an aortic endograft. We describe the use of rapid ventricular pacing during thoracic aortic stent graft deployment. Anesthesia was induced and maintained with intravenous propofol and remifentanil. A pulmonary artery catheter with pacing function was introduced, and rapid ventricular pacing was started before stent graft deployment. Pacing mode was VVI and pacing rate was 120-160 beats min(-1). Aortic pressure and flow decreased immediately and were maintained at low levels during surgical manipulation. After stopping rapid ventricular pacing, heart rate and aortic pressure recovered immediately. Rapid ventricular pacing was performed 4 times, and there were no complications such as entailed arrhythmia. With rapid ventricular pacing maneuver, which is thought to cause a rapid change in cardiac output, continuous cardiac output measurement can be a useful monitor. This procedure has advantages over pharmacologic or other methods of aortic pressure reduction. Rapid ventricular pacing is safe and effective during stent graft positioning and deployment.

  16. Assessing the Effects of Dust Loading of Snow on Regional Hydroclimatology Using an Improved Regional Climate Model

    NASA Astrophysics Data System (ADS)

    Oaida, C. M.; Xue, Y.; Painter, T.; Flanner, M. G.; De Sales, F.

    2012-12-01

    Radiative processes play an important role on both global and regional scales. This study focuses on their effects over snow-covered surfaces due to dust loading. Studies have shown that dust emissions from the Colorado Plateau have increased 5-7 fold in the last century and a half due to grazing and agricultural practices, which decreases snow albedo and enhances solar radiation absorption. In an offline study, Painter et al. (2007) have shown that snow cover was shortened by 18 to 35 days due to dust radiative forcing in snow in the San Juan Mountains, Colorado, USA. Our present study will quantitatively assess dust's influence on radiative forcing and runoff timing in mountain snow packs using a physically comprehensive regional climate model. For this study, we employ NCAR's WRF ARW model, which is coupled with a land surface model, Simplified Simple Biosphere version 3 (SSiB3). We have modified the original WRF-SSiB3 framework to include a snow-radiative transfer model, Snow, Ice, and Aerosol Radiative (SNICAR) model. SNICAR considers the effects of snow grain size and aerosol on snow albedo evolution. Snow grain size and growth is important in snow albedo feedbacks, especially when aerosols in snow are considered, because larger snow grains decrease snow albedo, and in the presence of dust, grain growth rates increase, decreasing snow reflectance even further than if the snow was pure. In the original WRF-SSiB3, albedo was empirically adjusted during snow melt. Implementing SNICAR allows us to have a more physically based process to represent changes in albedo due to snow metamorphism as well as those due to impurities in snow, which makes the regional climate model capable of realistically simulating radiative forcing on snow covered areas with aerosol loading. The model was further modified to account for the presence of aerosols in snow in terms of the distribution of these impurities as well as their scavenging by melt water throughout the snow layers We

  17. Parent Involvement Activities in School Improvement Plans in the Northwest Region. Issues & Answers. REL 2008-No. 064

    ERIC Educational Resources Information Center

    Speth, Timothy; Saifer, Steffen; Forehand, Gregory

    2008-01-01

    Although the No Child Left Behind Act of 2001 (NCLB) spells out parent involvement requirements for schools in need of improvement, the majority of the Northwest Region school improvement plans reviewed failed to include such provisions. Reported findings include: (1) Despite a wide range of parent involvement practices discussed in legislation…

  18. [Medication administration practices in elderly residential facilities in Ile de France Region in 2014: findings and room for improvement].

    PubMed

    de Saunière, Anne; Bonneau, Laetitia; Donio, Valérie; Godinot, Valérie; Flouzat, Jean-Philippe; Bensasson, Géraldine; Code, Christelle; Galay, Guillaume; Pige, Dominique

    2016-11-25

    The institutions expressed great interest in medication administration systems and tools designed to monitor all stages of medication administration. A dozen simple and pragmatic improvement actions were identified and listed in the Ile-de-France Regional Health Agency action plan to improve medication administration management of in EHPAD..

  19. Improvements to Optical Track Association with the Direct Bayesian Admissible Region Method

    NASA Astrophysics Data System (ADS)

    Fujimoto, K.; Scheeres, D. J.; Herzog, J.; Schildknecht, T.

    2013-09-01

    The direct Bayesian admissible region approach proposed by Fujimoto and Scheeres is an a priori state free measurement association and initial orbit determination (IOD) technique. Given a short-arc series of optical measurements, or a tracklet, a compact region in the range / range-rate space is defined based on a set of physical constraints such that all likely and relevant orbits are contained within it. The admissible region (AR) is a uniform probability density function (pdf) whose support is this compact region. Multiple ARs may be propagated to a common epoch and an a posteriori pdf directly computed based on Bayes' rule. When the direct Bayesian approach was initially applied to tracklets from a survey of geostationary (GEO) objects taken at the Zimmerwald Observatory of the Astronomical Institute of the University of Bern, two difficulties arose. The first were false associations due to the ambiguity in the number of revolutions made between observations. The second were missed associations due to the nominal assumption that the observation errors were small enough to be ignored. Consequently, a "hybrid"method was implemented, where the direct Bayesian results were passed to a least squares batch filter. Although the second difficulty was well addressed with this new method, not all multi-rev solutions were removed, casting light on the fundamental limits of conducting tracklet association based solely on astrometrical and dynamical information. Furthermore, it was noted that the direct Bayesian approach would allow one to reevaluate future observational strategies in order to minimize false positive / negative association solutions. It addressed the association of tracklets in a much more probabilistically straightforward way than other IOD techniques, and thus any changes to the current strategy would directly affect the a posteriori pdf in the state space without the need to assume an observation geometry, dynamical system, or the type of errors

  20. A synthetic luciferin improves in vivo bioluminescence imaging of gene expression in cardiovascular brain regions.

    PubMed

    Simonyan, Hayk; Hurr, Chansol; Young, Colin N

    2016-10-01

    Bioluminescence imaging is an effective tool for in vivo investigation of molecular processes. We have demonstrated the applicability of bioluminescence imaging to spatiotemporally monitor gene expression in cardioregulatory brain nuclei during the development of cardiovascular disease, via incorporation of firefly luciferase into living animals, combined with exogenous d-luciferin substrate administration. Nevertheless, d-luciferin uptake into the brain tissue is low, which decreases the sensitivity of bioluminescence detection, particularly when considering small changes in gene expression in tiny central areas. Here, we tested the hypothesis that a synthetic luciferin, cyclic alkylaminoluciferin (CycLuc1), would be superior to d-luciferin for in vivo bioluminescence imaging in cardiovascular brain regions. Male C57B1/6 mice underwent targeted delivery of an adenovirus encoding the luciferase gene downstream of the CMV promoter to the subfornical organ (SFO) or paraventricular nucleus of hypothalamus (PVN), two crucial cardioregulatory neural regions. While bioluminescent signals could be obtained following d-luciferin injection (150 mg/kg), CycLuc1 administration resulted in a three- to fourfold greater bioluminescent emission from the SFO and PVN, at 10- to 20-fold lower substrate concentrations (7.5-15 mg/kg). This CycLuc1-mediated enhancement in bioluminescent emission was evident early following substrate administration (i.e., 6-10 min) and persisted for up to 1 h. When the exposure time was reduced from 60 s to 1,500 ms, minimal signal in the PVN was detectable with d-luciferin, whereas bioluminescent images could be reliably captured with CycLuc1. These findings demonstrate that bioluminescent imaging with the synthetic luciferin CycLuc1 provides an improved physiological genomics tool to investigate molecular events in discrete cardioregulatory brain nuclei.