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Sample records for coupled pacing improves

  1. [Analysis of cardiorespiratory coupling in athletes and non-athletes at paced rate of breathing].

    PubMed

    Trubachev, V V; Gorbunov, A V; Trubacheva, V S; Nemtseva, M S; Ogorodnikova, M S

    2015-02-01

    The aims of the work were the study of cardiorespiratory coupling by method of paced breathing and the analysis of heart rate variability in men. Heart rhythm of 14 athletes and 12 non-athletes, 21 ± 1.4 years old, was registered in 3 minute sessions during spontaneous and paced breathing 14, 10, 9, 8, 7, 6, 5, 4 times/minute. The subjects were following breathing rate from a display. Initial heart rate being more slow in athletes (p < 0.05) was retained during episodes of controlled breathing. The power of FFT spectra peaks of RR-intervals was growing quasilinearly during reduction of breathing rate, reaching its peak value at 5-4 breaths/minute in athletes. More pronounced modulations of RR intervals were observed in HF spectral band (p < 0.05) of athletes breathing 14-10 times/minute compared to non-athletes. The power of LF band of the spectrum in athletes breathing 8-4 times/minute was 2 times higher: variability of RR-intervals "shrinked" accordingly to paced breathing rate. The dominant role in slow oscillations of heart rate manifested by paced respirations with involvement of vagus baroreflex afferentations of lungs and chest is hypothesized to be the consequence of breathing under attentional control.

  2. 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

  3. "Value" of improved treadmill exercise capacity: lessons from a study of rate responsive pacing

    PubMed Central

    Staniforth, A; Andrews, R; Harrison, M; Perry, A; Cowley, A

    1998-01-01

    Objectives—To compare the value of a series of cardiovascular measurements in patients with symptomatic disease receiving an effective treatment (rate responsive pacing).
Patients—12 pacemaker dependent patients with VVIR units.
Interventions—Single blind crossover between VVI and VVIR.
Outcome measures—Exercise capacity was assessed by treadmill tests (modified Bruce protocol and a fixed workload protocol) with respiratory gas analysis. Self paced corridor walk tests were also undertaken. Quality of life (QOL) was assessed by questionnaire. Daily activity was measured in the patients' homes using shoe and belt pedometers.
Results—Treadmill tests and QOL questionnaires correctly identified the clinical benefit associated with VVIR. The modified Bruce protocol was superior to the fixed workload protocol as it was better tailored to the fairly well preserved exercise capacity of the patients. Symptom scores, but not walking times, were improved with VVIR during corridor walk tests. VVIR did not improve daily activity measured using either the belt or shoe pedometers.
Conclusions—VVIR pacing improved some but not all measures of exercise capacity. This finding illustrates the difficulty of selecting an instrument to measure symptomatic improvement in clinical research; and raises the question, what is the best way of measuring exercise capacity?

 Keywords: rate responsive pacing;  exercise capacity;  quality of life PMID:9875118

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

    PubMed Central

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

    2004-01-01

    Objectives: To assess whether patients with congestive heart failure (CHF) and a normal QRS duration can benefit from left ventricular (VDD-LV) pacing. Design: Cardiac resynchronisation is reserved for patients with a broad QRS duration on the premise that systolic resynchronisation is the mechanism of benefit, yet improvement from pacing correlates poorly with QRS duration. In CHF patients with a broad QRS duration, those with a high resting pulmonary capillary wedge pressure (PCWP) > 15 mm Hg benefit. In this acute haemodynamic VDD-LV pacing study, patients with CHF with a normal QRS duration were divided into two groups—patients with a resting PCWP > 15 mm Hg and patients with a resting PCWP < 15 mm Hg—to determine whether benefit is predicted by a high resting PCWP. Patients: 20 patients with CHF, New York Heart Association functional class IIb–IV, all with a normal QRS duration (⩽ 120 ms). Interventions: Temporary pacing wires were positioned to enable VDD-LV pacing and a pulmonary artery catheter was inserted for measurement of PCWP, right atrial pressure, and cardiac output. Results: In patients with a PCWP > 15 mm Hg (n  =  10), cardiac output increased from 3.9 (1.5) to 4.5 (1.65) l/min (p < 0.01), despite a fall in PCWP from 24.7 (7.1) to 21.0 (6.2) mm Hg (p < 0.001). In patients with a PCWP < 15 mm Hg there was no change in PCWP or cardiac output. Combined data showed that PCWP decreased from 17.0 (9.1) to 15.3 (7.7) mm Hg during VDD-LV pacing (p < 0.014) and cardiac output increased non-significantly from 4.7 (1.5) to 4.9 (1.5) (p  =  0.125). Conclusions: Patients with CHF with a normal QRS duration and PCWP > 15 mm Hg derive acute haemodynamic benefit from VDD-LV pacing. PMID:15084543

  5. "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 to integrate content mastery…

  6. "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…

  7. Improving estimation of cardiac vagal tone during spontaneous breathing using a paced breathing calibration.

    PubMed

    Wilhelm, Frank H; Grossman, Paul; Coyle, Michael A

    2004-01-01

    Respiratory sinus arrhythmia (RSA) is a commonly employed non-invasive measure of cardiac vagal control. It has been demonstrated that respiratory parameters such as tidal volume and respiratory frequency can change RSA without altering tonic vagal activity. Thus, within-individual comparisons of cardiac vagal control across different behavioral tasks might benefit from an adjustment for respiratory confounds. We tested an adjustment method using transfer function analysis and paced breathing at 3 different respiratory frequencies as the basis for regressing out respiratory related RSA changes in a task where breathing was not controlled. Electrocardiogram and calibrated respiration were recorded with the LifeShirt system from 15 young adult participants. Time series of RR intervals and lung volume change were computed and the respiration-to-RR-interval transfer-function magnitude (RSA-TF, in ms/liter) estimated. Mean (SD) of RSA-TF was 142 (68) at 9 breaths/min, 78 (52) at 13.5 breaths/min, 57 (43) at 18 breaths/min, and 121 (56) during baseline, with a respiratory frequency of 12.5 (3.8) breaths/min. At baseline, measured and predicted RSA-TF values (mean 94 +/- 82) differed significantly and correlated only moderately (r = 0.67). Factors contributing to a less than perfect correlation included slightly elevated subjective anxiety levels and hyperventilation during paced breathing, both of which may have affected cardiac vagal tone. This study demonstrates a novel procedure for computing a respiratory unrelated RSA index. Results provide some support for the utility of this adjustment method for improving the estimation of cardiac vagal tone from RSA, but also indicate that the paced breathing procedure may need to be further refined.

  8. Self-pacing increases critical power and improves performance during severe-intensity exercise.

    PubMed

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

    2015-07-01

    The parameters of the power-duration relationship for severe-intensity exercise (i.e., the critical power (CP) and the curvature constant (W')) are related to the kinetics of pulmonary O2 uptake, which may be altered by pacing strategy. We tested the hypothesis that the CP would be higher when derived from a series of self-paced time-trials (TT) than when derived from the conventional series of constant work-rate (CWR) exercise tests. Ten male subjects (age, 21.5 ± 1.9 years; mass, 75.2 ± 11.5 kg) completed 3-4 CWR and 3-4 TT prediction trial protocols on a cycle ergometer for the determination of the CP and W'. The CP derived from the TT protocol (265 ± 44 W) was greater (P < 0.05) than the CP derived from the CWR protocol (250 ± 47 W), while the W' was not different between protocols (TT: 18.1 ± 5.7 kJ, CWR: 20.6 ± 7.4 kJ, P > 0.05). The mean response time of pulmonary O2 uptake was shorter during the TTs than the CWR trials (TT: 34 ± 16, CWR: 39 ± 19 s, P < 0.05). The CP was correlated with the total O2 consumed in the first 60 s across both protocols (r = 0.88, P < 0.05, n = 20). These results suggest that in comparison with the conventional CWR exercise protocol, a self-selected pacing strategy enhances CP and improves severe-intensity exercise performance. The greater CP during TT compared with CWR exercise has important implications for performance prediction, suggesting that TT completion times may be overestimated by CP and W' parameters derived from CWR protocols.

  9. 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

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

    PubMed Central

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

    2016-01-01

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

  11. Recent developments in cardiac pacing.

    PubMed

    Rodak, D J

    1995-10-01

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

  12. 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.

  13. 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…

  14. Centennial-scale climate change from decadally-paced explosive volcanism: a coupled sea ice-ocean mechanism

    NASA Astrophysics Data System (ADS)

    Zhong, Y.; Miller, G. H.; Otto-Bliesner, B. L.; Holland, M. M.; Bailey, D. A.; Schneider, D. P.; Geirsdottir, A.

    2011-12-01

    Northern Hemisphere summer cooling through the Holocene is largely driven by the steady decrease in summer insolation tied to the precession of the equinoxes. However, centennial-scale climate departures, such as the Little Ice Age, must be caused by other forcings, most likely explosive volcanism and changes in solar irradiance. Stratospheric volcanic aerosols have the stronger forcing, but their short residence time likely precludes a lasting climate impact from a single eruption. Decadally paced explosive volcanism may produce a greater climate impact because the long response time of ocean surface waters allows for a cumulative decrease in sea-surface temperatures that exceeds that of any single eruption. Here we use a global climate model to evaluate the potential long-term climate impacts from four decadally paced large tropical eruptions. Direct forcing results in a rapid expansion of Arctic Ocean sea ice that persists throughout the eruption period. The expanded sea ice increases the flux of sea ice exported to the northern North Atlantic long enough that it reduces the convective warming of surface waters in the subpolar North Atlantic. In two of our four simulations the cooler surface waters being advected into the Arctic Ocean reduced the rate of basal sea-ice melt in the Atlantic sector of the Arctic Ocean, allowing sea ice to remain in an expanded state for > 100 model years after volcanic aerosols were removed from the stratosphere. In these simulations the coupled sea ice-ocean mechanism maintains the strong positive feedbacks of an expanded Arctic Ocean sea ice cover, allowing the initial cooling related to the direct effect of volcanic aerosols to be perpetuated, potentially resulting in a centennial-scale or longer change of state in Arctic climate. The fact that the sea ice-ocean mechanism was not established in two of our four simulations suggests that a long-term sea ice response to volcanic forcing is sensitive to the stability of the seawater

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

    PubMed

    Arciero, Paul J; Edmonds, Rohan C; Bunsawat, Kanokwan; Gentile, Christopher L; Ketcham, Caitlin; Darin, Christopher; Renna, Mariale; Zheng, Qian; Zhang, Jun Zhu; Ormsbee, Michael J

    2016-05-11

    We recently reported that protein-pacing (P; six meals/day @ 1.4 g/kg body weight (BW), three of which included whey protein (WP) supplementation) combined with a multi-mode fitness program consisting of resistance, interval sprint, stretching, and endurance exercise training (RISE) improves body composition in overweight individuals. The purpose of this study was to extend these findings and determine whether protein-pacing with only food protein (FP) is comparable to WP supplementation during RISE training on physical performance outcomes in overweight/obese individuals. Thirty weight-matched volunteers were prescribed RISE training and a P diet derived from either whey protein supplementation (WP, n = 15) or food protein sources (FP, n = 15) for 16 weeks. Twenty-one participants completed the intervention (WP, n = 9; FP, n = 12). Measures of body composition and physical performance were significantly improved in both groups (p < 0.05), with no effect of protein source. Likewise, markers of cardiometabolic disease risk (e.g., LDL (low-density lipoprotein) cholesterol, glucose, insulin, adiponectin, systolic blood pressure) were significantly improved (p < 0.05) to a similar extent in both groups. These results demonstrate that both whey protein and food protein sources combined with multimodal RISE training are equally effective at improving physical performance and cardiometabolic health in obese individuals.

  16. 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

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

    PubMed

    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

  18. 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.

  19. PACE EH post project assessment of quality of life changes in a Florida community related to infrastructure improvements.

    PubMed

    Harduar-Morano, Laurel; Price, Julianne R; Parker, Daniel; Blackmore, Carina

    2008-06-01

    The Indian River county health department, environmental health division (IRCHD EH) in Florida implemented the Protocol for Assessing Community Excellence in Environmental Health (PACE EH) in the low-income community of West Wabasso, Florida. Over two and a half years, IRCHD EH worked with the community and various governmental agencies to bring much-needed improvements to the area. At the end of the two and a half years, a survey was conducted to discover if the residents' quality of life had increased due to the community's improvements. The survey results yielded high satisfaction rates among residents. The general response was that their feelings of safety and overall well-being attributed to infrastructure improvements in their community had increased significantly. An unforeseen benefit realized by all parties involved was a renewed trust in government. The majority of surveyed residents (91%) felt that governmental agencies were better able to respond to their issues. PMID:18561568

  20. 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…

  1. 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…

  2. Improved fluid-structure coupling. [BWR

    SciTech Connect

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

    1981-01-01

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

  3. 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.

  4. 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.

  5. Pacing Without Wires: Leadless Cardiac Pacing

    PubMed Central

    Bernard, Michael L.

    2016-01-01

    Background: Worldwide, more than 700,000 pacemakers are implanted annually with more than 250,000 implanted in the United States. Since the first fully transvenous pacemaker implantations in the early 1960s, great technologic advances have been made in pacing systems. However, the combination of subcutaneous pulse generators and transvenous pacing leads has remained constant for more than 50 years. Leadless pacing systems offer an alternative to traditional pacing systems by eliminating the need for permanent transvenous leads while providing therapy for patients with bradyarrhythmias. Methods: We discuss the 2 leadless cardiac pacemakers (LCPs), the Nanostim Leadless Pacemaker and Micra Transcatheter Pacing System, and the 1 ultrasound-powered device, the WiCS-LV, that have been studied in humans. Currently LCPs are restricted to single-chamber pacing, specifically, ventricular pacing. Dual-chamber pacing and multichamber pacing with leadless systems have yet to be studied. Results: LCPs represent the greatest advancement in bradycardia therapy since the first transvenous pacemaker implantation more than 50 years ago. Conclusion: Initial studies of both the Nanostim and Micra LCPs show favorable efficacy and safety results compared to transvenous pacemakers. Pending US Food and Drug Administration approval, these devices will transform our ability to provide pacing for patients with bradyarrhythmias. Future developments may allow for completely leadless single-chamber and multichamber pacing, ushering in an era of pacing without wires.

  6. Pacing Without Wires: Leadless Cardiac Pacing

    PubMed Central

    Bernard, Michael L.

    2016-01-01

    Background: Worldwide, more than 700,000 pacemakers are implanted annually with more than 250,000 implanted in the United States. Since the first fully transvenous pacemaker implantations in the early 1960s, great technologic advances have been made in pacing systems. However, the combination of subcutaneous pulse generators and transvenous pacing leads has remained constant for more than 50 years. Leadless pacing systems offer an alternative to traditional pacing systems by eliminating the need for permanent transvenous leads while providing therapy for patients with bradyarrhythmias. Methods: We discuss the 2 leadless cardiac pacemakers (LCPs), the Nanostim Leadless Pacemaker and Micra Transcatheter Pacing System, and the 1 ultrasound-powered device, the WiCS-LV, that have been studied in humans. Currently LCPs are restricted to single-chamber pacing, specifically, ventricular pacing. Dual-chamber pacing and multichamber pacing with leadless systems have yet to be studied. Results: LCPs represent the greatest advancement in bradycardia therapy since the first transvenous pacemaker implantation more than 50 years ago. Conclusion: Initial studies of both the Nanostim and Micra LCPs show favorable efficacy and safety results compared to transvenous pacemakers. Pending US Food and Drug Administration approval, these devices will transform our ability to provide pacing for patients with bradyarrhythmias. Future developments may allow for completely leadless single-chamber and multichamber pacing, ushering in an era of pacing without wires. PMID:27660571

  7. 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'…

  8. Polished Downhole Transducer Having Improved Signal Coupling

    DOEpatents

    Hall, David R.; Fox, Joe

    2006-03-28

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

  9. Coupled improvement between thermoelectric and piezoelectric materials

    NASA Astrophysics Data System (ADS)

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

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

  10. Sensors for rate responsive pacing

    PubMed Central

    Dell'Orto, Simonetta; Valli, Paolo; Greco, Enrico Maria

    2004-01-01

    Advances in pacemaker technology in the 1980s have generated a wide variety of complex multiprogrammable pacemakers and pacing modes. The aim of the present review is to address the different rate responsive pacing modalities presently available in respect to physiological situations and pathological conditions. Rate adaptive pacing has been shown to improve exercise capacity in patients with chronotropic incompetence. A number of activity and metabolic sensors have been proposed and used for rate control. However, all sensors used to optimize pacing rate metabolic demands show typical limitations. To overcome these weaknesses the use of two sensors has been proposed. Indeed an unspecific but fast reacting sensor is combined with a more specific but slower metabolic one. Clinical studies have demonstrated that this methodology is suitable to reproduce normal sinus behavior during different types and loads of exercise. Sensor combinations require adequate sensor blending and cross checking possibly controlled by automatic algorithms for sensors optimization and simplicity of programming. Assessment and possibly deactivation of some automatic functions should be also possible to maximize benefits from the dual sensor system in particular conditions. This is of special relevance in patient whose myocardial contractility is limited such as in subjects with implantable defibrillators and biventricular pacemakers. The concept of closed loop pacing, implementing a negative feedback relating pacing rate and the control signal, will provide new opportunities to optimize dual-sensors system and deserves further investigation. The integration of rate adaptive pacing into defibrillators is the natural consequence of technical evolution. PMID:16943981

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

    SciTech Connect

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

    2014-01-01

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

  12. Experience with an ICD incorporating biventricular pacing.

    PubMed

    Kühlkamp, V; Dörnberger, V; Rüb, N; Eigenberger, B; Kettering, K; Bosch, R; Mewis, C

    2003-04-01

    Biventricular pacing for cardiac resynchronization is a promising therapy for symptomatic improvement in selected patients with underlying severe congestive heart failure. ICD treatment has been shown to prolong life in patients with life threatening ventricular tachyarrhythmias, but it does not improve quality of life. This review discusses current experience with ICD's incorporating biventricular pacing.

  13. Temporary internal pacing.

    PubMed

    Ortiz Díaz-Miguel, R; Gómez Grande, M L

    2014-12-01

    Technology and insertion techniques for cardiac temporary internal pacing have experienced a remarkable development over the last few years. Despite this fact, the procedure continues to have potentially fatal associated complications. Temporary internal pacing is indicated for the treatment of bradyarrhythmias or tachyarrhythmias refractory to conventional treatment, or arrhythmias causing cardiovascular or clinical instability of the patient. On the other hand, the indications of temporary cardiac pacing are far less well defined than those of permanent pacing. Since the decision of implementing temporary pacing is complex and delicate, it should always be carefully considered, and over-indication should be avoided. We must base these decisions on robust knowledge of the arrhythmias that may benefit from temporary internal pacing, and should also acquire the habit of considering external temporary pacing among other less aggressive treatments, and to make the best use of new technologies such as echocardiography that add accuracy to the procedure. PMID:24786750

  14. Atrial overexpression of angiotensin-converting enzyme 2 improves the canine rapid atrial pacing-induced structural and electrical remodeling. Fan, ACE2 improves atrial substrate remodeling.

    PubMed

    Fan, Jinqi; Zou, Lili; Cui, Kun; Woo, Kamsang; Du, Huaan; Chen, Shaojie; Ling, Zhiyu; Zhang, Quanjun; Zhang, Bo; Lan, Xianbin; Su, Li; Zrenner, Bernhard; Yin, Yuehui

    2015-01-01

    The purpose of this study was to investigate whether atrial overexpression of angiotensin-converting enzyme 2 (ACE2) by homogeneous transmural atrial gene transfer can reverse atrial remodeling and its mechanisms in a canine atrial-pacing model. Twenty-eight mongrel dogs were randomly divided into four groups: Sham-operated, AF-control, gene therapy with adenovirus-enhanced green fluorescent protein (Ad-EGFP) and gene therapy with Ad-ACE2 (Ad-ACE2) (n = 7 per subgroup). AF was induced in all dogs except the Sham-operated group by rapid atrial pacing at 450 beats/min for 2 weeks. Ad-EGFP and Ad-ACE2 group then received epicardial gene painting. Three weeks after gene transfer, all animals except the Sham group underwent rapid atrial pacing for another 3 weeks and then invasive electrophysiological, histological and molecular studies. The Ad-ACE2 group showed an increased ACE2 and Angiotensin-(1-7) expression, and decreased Angiotensin II expression in comparison with Ad-EGFP and AF-control group. ACE2 overexpression attenuated rapid atrial pacing-induced increase in activated extracellular signal-regulated kinases and mitogen-activated protein kinases (MAPKs) levels, and decrease in MAPK phosphatase 1(MKP-1) level, resulting in attenuation of atrial fibrosis collagen protein markers and transforming growth factor-β1. Additionally, ACE2 overexpression also modulated the tachypacing-induced up-regulation of connexin 40, down-regulation of connexin 43 and Kv4.2, and significantly decreased the inducibility and duration of AF. ACE2 overexpression could shift the renin-angiotensin system balance towards the protective axis, attenuate cardiac fibrosis remodeling associated with up-regulation of MKP-1 and reduction of MAPKs activities, modulate tachypacing-induced ion channels and connexin remodeling, and subsequently reduce the inducibility and duration of AF.

  15. Effect of adaptive paced cardiolocomotor synchronization during running: a preliminary study.

    PubMed

    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 and

  16. Self-Paced Fortran.

    ERIC Educational Resources Information Center

    Burnett, James

    1979-01-01

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

  17. Improving data transfer for model coupling

    NASA Astrophysics Data System (ADS)

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

    2015-10-01

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

  18. Improving entanglement of two atoms in strong coupling regime

    NASA Astrophysics Data System (ADS)

    Liu, Hui; Yang, Qing; Yang, Ming; Cao, Zhuoliang

    2016-03-01

    We consider a model of two identical atoms coupled to a single-mode cavity. When in atom-field strong coupling regime, the entanglement of the two atoms with spontaneous emission should be investigated beyond rotating-wave approximation (RWA). In order to improve the entanglement of the two atoms, some typical feedback based on quantum-jump are attempted to impose on the atoms. The result of numerical simulations shows that an appropriate feedback control can improve the entanglement.

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

    PubMed Central

    2013-01-01

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

  20. Coupled Facility/Payload Vibration Modeling Improvements

    NASA Technical Reports Server (NTRS)

    Carnahan, Timothy M.; Kaiser, Michael

    2015-01-01

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

  1. Coupled Facility-Payload Vibration Modeling Improvements

    NASA Technical Reports Server (NTRS)

    Carnahan, Timothy M.; Kaiser, Michael A.

    2015-01-01

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

  2. Physiological cardiac pacing: Current status.

    PubMed

    Das, Asit; Kahali, Dhiman

    2016-01-01

    Adverse hemodynamics of right ventricular (RV) pacing is a well-known fact. It was believed to be the result of atrio-ventricular (AV) dyssynchrony and sequential pacing of the atrium and ventricle may solve these problems. However, despite maintenance of AV synchrony, the dual chamber pacemakers in different trials have failed to show its superiority over single chamber RV apical pacing in terms of death, progression of heart failure, and atrial fibrillation (AF). As a consequence, investigators searched for alternate pacing sites with a more physiological activation pattern and better hemodynamics. Direct His bundle pacing and Para-Hisian pacing are the most physiological ventricular pacing sites. But, this is technically difficult. Ventricular septal pacing compared to apical pacing results in a shorter electrical activation delay and consequently less mechanical dyssynchrony. But, the study results are heterogeneous. Selective site atria pacing (atrial septal) is useful for patients with atrial conduction disorders in prevention of AF. PMID:27543481

  3. 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

  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. PMID:1493823

  6. 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.

  7. 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.

  8. Visualizing Improved Spin Coupling in Large Magnetic Molecules

    NASA Astrophysics Data System (ADS)

    Donner, Judith; Broschinski, Jan-Philipp; Feldscher, Bastian; Glaser, Thorsten; Khajetoorians, Alexander Ako; Wegner, Daniel

    In an attempt to combine a high spin ground state and a large magnetic anisotropy in one molecule, triplesalen-based complexes are promising building blocks for a new generation of single molecule magnets (SMMs). The spin coupling in these molecules is based on the spin polarization effect, which requires a delocalized aromatic π-system in the central carbon ring of the complex. Unfortunately, chemical analysis indicates that this ring can change its configuration to [6]radialene, therefore causing a loss of aromaticity and weakening the magnetic coupling. We have employed a combination of scanning tunneling microscopy (STM) and spectroscopy (STS) to investigate single Cu3-triplesalen and Cu3-triplesalalen molecules, the latter being designed to show an enhanced intramolecular spin coupling. The large molecules were deposited in situ using the unconventional techniques pulse injection and rapid heating. A thorough structural and spectroscopic analysis allows us to discuss the electronic properties of the two complexes, with a special focus on the state of the central carbon ring. We find that even small changes in the ligand structure have a drastic influence on the intramolecular spin coupling, which opens the way for an improved rational design of future SMMs.

  9. Self-Paced Instruction: Hello, Education

    ERIC Educational Resources Information Center

    Leuba, Richard J.; Flammer, Gordon H.

    1975-01-01

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

  10. Application Improvements of Slab-Coupled Optical Fiber Sensors

    NASA Astrophysics Data System (ADS)

    Chadderdon, Spencer Lee

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

  11. Securing Contactless Chips with PACE

    NASA Astrophysics Data System (ADS)

    Kügler, Dennis

    PACE (Password Authenticated Connection Establishment) is a cryptographic protocol that was developed to provide a secure knowledge-based authentication mechanism for contactless chips. The problems that are inherent to (but not limited to) contactless chips are described and PACE as a solution based on cryptographic tools is sketched. Finally, it is shown how to use PACE together with traditional short PINs of 4-6 digits as access control mechanism for contactless chips withstanding denial-of-service attacks.

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

    SciTech Connect

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

    2015-03-28

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

  13. Improved measurement of ttZ couplings at the LHC

    SciTech Connect

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

    2005-12-01

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

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

    PubMed

    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

  15. 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

  16. 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

  17. 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.

  18. Improving the gate fidelity of capacitively coupled spin qubits

    NASA Astrophysics Data System (ADS)

    Wang, Xin; Barnes, Edwin

    2015-03-01

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

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

    SciTech Connect

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

    2015-06-17

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

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

    DOE PAGESBeta

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

    2015-06-17

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

  1. 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)

  2. 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…

  3. 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.

  4. 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

  5. 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

  6. Obstacles to activity pacing: assessment, relationship to activity and functioning.

    PubMed

    Cane, Douglas; McCarthy, Mary; Mazmanian, Dwight

    2016-07-01

    Activity pacing is frequently included among the strategies provided to individuals with chronic pain to manage pain and improve functioning. Individuals with chronic pain may, however, limit their use of activity pacing because they perceive significant obstacles to its use. This study describes the development of a measure to assess obstacles to activity pacing and examines the relationship of this measure to activity patterns and functioning. A sample of 637 individuals with chronic pain completed items describing potential obstacles to activity pacing as part of their pretreatment assessment. Item analyses were used to construct a 14-item measure of obstacles to activity pacing. A subset of these individuals completed the measure again after completion of a group treatment program. The resulting measure demonstrated excellent internal consistency and was minimally affected by social desirability. Correlations with measures of activity and psychosocial functioning provided initial construct validity for the measure. Sex differences were found with women initially identifying more obstacles to activity pacing. Fewer obstacles were identified by both men and women after treatment, and these changes were related to modest changes in activity patterns and functioning. The present results identify a number of obstacles that may limit the use of activity pacing by individuals with chronic pain. Treatment may result in a decrease in the number of obstacles identified, and this change is related to changes in the individual's activity pattern and psychosocial functioning. PMID:26963845

  7. Improving Relationships: Mechanisms of Change in Couple Therapy

    ERIC Educational Resources Information Center

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

    2005-01-01

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

  8. 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…

  9. 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.

  10. 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…

  11. The PACE evaluation: initial findings.

    PubMed

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

    1995-06-01

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

  12. 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…

  13. The PACE evaluation: initial findings.

    PubMed

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

    1995-06-01

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

  14. Right ventricular apex pacing: is it obsolete?

    PubMed

    Sanaa, Islem; Franceschi, Frédéric; Prevot, Sébastien; Bastard, Emilie; Deharo, Jean-Claude

    2009-02-01

    Clinical trials in patients with pacemakers for sinus node dysfunction or atrioventricular block have highlighted the fact that desynchronization of ventricular contraction induced by right ventricular apical pacing is associated with long-term morbidity and mortality. These clinical data confirm pathophysiological results indicating that right ventricular apical pacing causes abnormal ventricular contraction, reduces pump function and leads to myocardial hypertrophy and ultrastructural abnormalities. In this manuscript, we discuss the clinical evidence for the adverse and beneficial effects of various right ventricular pacing sites, left ventricular pacing sites and biventricular pacing. We also propose a decisional algorithm for pacing modalities, based on atrioventricular conduction, left ventricular function and expected lifespan. PMID:19303581

  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. MHD generator with improved network coupling electrodes to a load

    DOEpatents

    Rosa, Richard J.

    1977-01-01

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

  17. Entanglement of Coupled Optomechanical Systems Improved by Optical Parametric Amplifiers

    NASA Astrophysics Data System (ADS)

    Pan, Guixia; Xiao, Ruijie; Zhou, Ling

    2016-08-01

    A scheme to generate the stationary entanglement of two distant coupled optical cavities placed optical parametric amplifiers is proposed. We study how the optical parametric amplifiers can affect the entanglement behaviors of the movable mirrors and the cavity fields. With the existence of optical parametric amplifiers, we show that larger stationary entanglement of optical and mechanical modes can be obtained and the entanglement increases with the increasing parametric gain. Especially, the degree of entanglement between the two cavity fields is more pronouncedly enhanced. Moreover, for a fixed parametric gain, the entanglement of distant cavity optomechanical systems increases as the input laser power is increased.

  18. Self-Paced Instruction: A Review

    ERIC Educational Resources Information Center

    Allison, Elisabeth

    1975-01-01

    Discussed the benefits and costs of self-paced instruction (SPI) based on brief summaries of experiences in teaching introductory economics at seven universities. Provided also is a six-step pattern for setting up a self-paced course. The author concludes that the evidence on the educational benefits of self-paced instruction is at present…

  19. 42 CFR 460.186 - PACE premiums.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

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

  20. Stability of disability among PACE enrollees: financial and programmatic implications.

    PubMed

    Mukamel, D B; Temkin-Greener, H; Clark, M L

    1998-01-01

    This article examines the experience of the first 11 Program of All-inclusive Care for the Elderly (PACE) programs. It investigates changes in functional status of participants in relation to length of enrollment in the program and individual risk characteristics. Our findings indicate that mature programs experience stable disability mix over time, supporting the rationale for the current PACE payment method. However, significant differences exist between programs, suggesting that payment rates could be more program specific. Analysis of the effect of patient characteristics at admission on the likelihood of improvement in functional status identified areas for quality improvement. The implications of this study have increasing importance in light of the expected expansion of PACE to approximately 100 sites by the year 2000.

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

    NASA Astrophysics Data System (ADS)

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

    2015-12-01

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

  2. 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...

  3. 42 CFR 460.60 - PACE organizational structure.

    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 Administrative Requirements § 460.60 PACE organizational structure. (a) A...

  4. 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...

  5. 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...

  6. 42 CFR 460.60 - PACE organizational structure.

    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 Administrative Requirements § 460.60 PACE organizational structure. (a) A...

  7. 42 CFR 460.60 - PACE organizational structure.

    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 Administrative Requirements § 460.60 PACE organizational structure. (a) A...

  8. 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...

  9. 42 CFR 460.60 - PACE organizational structure.

    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 Administrative Requirements § 460.60 PACE organizational structure. (a) A...

  10. 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...

  11. 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...

  12. Improved Fiber-Optic-Coupled Pressure And Vibration Sensors

    NASA Technical Reports Server (NTRS)

    Zuckerwar, Allan J.; Cuomo, Frank W.

    1994-01-01

    Improved fiber-optic coupler enables use of single optical fiber to carry light to and from sensor head. Eliminates problem of alignment of multiple fibers in sensor head and simplifies calibration by making performance both more predictable and more stable. Sensitivities increased, sizes reduced. Provides increased margin for design of compact sensor heads not required to contain amplifier circuits and withstand high operating temperatures.

  13. 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.

  14. 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…

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

    SciTech Connect

    Hoffman, E.L.

    1997-09-01

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

  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. Innovative pacing: Recent advances, emerging technologies, and future directions in cardiac pacing.

    PubMed

    Austin, Christopher; Kusumoto, Fred

    2016-07-01

    The field of cardiovascular medicine is rapidly evolving as advancements in technology and engineering provide clinicians new and exciting ways to care for an aging population. Cardiac pacing, in particular, has seen a series of game-changing technologies emerge in the past several years spurred by low-power electronics, high density batteries, improved catheter delivery systems and innovative software design. We look at several of these emerging pacemaker technologies, discussing the rationale, current state and future directions of these pioneering developments in electrophysiology. PMID:27017442

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

    PubMed

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

    2008-11-01

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

  19. Improvement of bias stability for a micromachined gyroscope based on dynamic electrical balancing of coupling stiffness

    NASA Astrophysics Data System (ADS)

    Su, Jianbin; Xiao, Dingbang; Wu, Xuezhong; Hou, Zhanqiang; Chen, Zhihua

    2013-07-01

    We present a dynamic electrical balancing of coupling stiffness for improving the bias stability of micromachined gyroscopes, which embeds the coupling stiffness in a closed-loop system to make the micromachined gyroscope possess more robust bias stability by suppressing the variation of coupling stiffness. The effect of the dynamic electrical balancing control is theoretically analyzed and implemented using a silicon micromachined gyroscope as an example case. It has been experimentally shown that, comparing with open loop detection, the proposed method increased the stability of the amplitude of the mechanical quadrature signal by 38 times, and therefore improved the bias stability by 5.2 times from 89 to 17 deg/h, and the temperature stability of scale factor by 2.7 times from 622 to 231 ppm/°C. Experimental results effectively indicated the theoretical model of dynamic electrical balancing of coupling stiffness.

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

    PubMed

    Skein, Melissa; Duffield, Rob

    2010-02-01

    The purpose of this study was to examine the effects of fluid ingestion on pacing strategies and performance during intermittent-sprint exercise in the heat. Nine male rugby players performed a habituation session and 2 x 50-min intermittent-sprint protocols at a temperature of 31 degrees C, either with or without fluid. Participants were informed of a third session (not performed) to ensure that they remained blind to all respective conditions. The protocol consisted of a 15-m sprint every minute separated by self-paced bouts of hard running, jogging, and walking for the remainder of the minute. Sprint time, distance covered during self-paced exercise, and vertical jump height before and after exercise were recorded. Heart rate, core temperature, nude mass, capillary blood haematocrit, pH, lactate concentration, perceptual ratings of perceived exertion, thermal stress, and thirst were also recorded. Sprint times (fluid vs. no-fluid: 2.82 +/- 0.11 vs. 2.82 +/- 0.14) and distance covered during self-paced exercise (fluid vs. no-fluid: 4168 +/- 419 vs. 3981 +/- 263 m) were not different between conditions (P = 0.10-0.98) but were progressively reduced to a greater extent in the no-fluid trial (7 +/- 13%) (d = 0.56-0.58). There were no differences (P = 0.22-1.00; d = <0.20-0.84) between conditions in any physiological measures. Perceptual ratings of perceived exertion and thermal stress did not differ between conditions (P = 0.34-0.91; d < or =0.20-0.48). Rating of thirst after exercise was lower in the fluid trial (P = 0.02; d = 0.62-0.73). The present results suggest that fluid availability did not improve intermittent-sprint performance, however did affect pacing strategies with a greater reduction in distance covered of self-paced exercise during the no-fluid trial. PMID:20077276

  2. Consistency of Students' Pace in Online Learning

    ERIC Educational Resources Information Center

    Hershkovitz, Arnon; Nachmias, Rafi

    2009-01-01

    The purpose of this study is to investigate the consistency of students' behavior regarding their pace of actions over sessions within an online course. Pace in a session is defined as the number of logged actions divided by session length (in minutes). Log files of 6,112 students were collected, and datasets were constructed for examining pace…

  3. 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…

  4. 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.

  5. Passive Active Conservation Evaluator. PACE programmer's manual

    NASA Astrophysics Data System (ADS)

    1981-11-01

    The program features, programming conventions, and algorithms of the PACE comuter program are described. This manual is intended to aid programmers in installing and modifying the program. Written descriptions of program routines, a listing of the program and is data base, a section on programming conventions, an explanation of the algorithms within the program, and advice on installation of PACE are included.

  6. 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...

  7. 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...

  8. 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...

  9. Endocardial pacing: the wave of the future?

    PubMed

    Bordachar, Pierre; Ploux, Sylvain; Lumens, Joost

    2012-10-01

    Cardiac resynchronization therapy (CRT) is a proven treatment for heart failure and requires the implantation of a left ventricular (LV) lead, usually placed in a tributary of the coronary sinus. Encouraged by the fact that approximately 30 % of the patients receiving CRT do not benefit from this therapy, LV endocardial pacing has been proposed as an alternative to traditional LV transvenous epicardial pacing. Endocardial LV pacing has a number of potential advantages over conventional LV epicardial pacing, including a more physiological endocardial-to-epicardial transmural activation sequence, a faster ventricular activation, a larger choice of stimulation sites and a potential superior hemodynamic performance. On the other hand, cardiologists will have to deal with new implant techniques' (transseptal), higher risk of thromboembolic events, and challenging extraction procedures of infected material. The future of endocardial stimulation will depend on the results of randomized studies adequately powered to assess the feasibility, the safety and the effectiveness of this new pacing strategy.

  10. Clinical Outcome After Permanent Pacemaker Implantation in Patients With a High Percentage of Ventricular Pacing.

    PubMed

    Sakatani, Tomohiko; Sakamoto, Akira; Kawamura, Kohei; Tanigaki, Toru; Tsubakimoto, Yoshinori; Isodono, Koji; Kimura, Shinzo; Matsuo, Akiko; Inoue, Keiji; Kitamura, Makoto; Fujita, Hiroshi

    2015-01-01

    Previous reports have suggested that right ventricular apical pacing may lead to cardiac dysfunction. Septal pacing is thought to be superior to apical pacing in the prevention of cardiac dyssynchrony, however, there have been no reports on the contribution of septal pacing to improving clinical outcome.We retrospectively evaluated factors associated with cardiac events in patients with right ventricular pacing.The study population consisted of 256 consecutive patients newly implanted with permanent pacemakers and followed-up for 29 ± 18 months. Cardiac events, consisting of cardiac death or heart failure requiring hospitalization, occurred in 22 patients. Kaplan-Meier curves revealed that patients with a high percentage of ventricular pacing (> 90%, n = 101, group H) had a higher incidence of cardiac events than patients with a low percentage of ventricular pacing (< 10%, n = 83, group L) (P = 0.002). In group H, multivariate analysis showed that age (HR: 1.174, 95%CI: 1.066-1.291, P = 0.001), ejection fraction (EF) (HR: 0.898, 95%CI: 0.836-0.964, P = 0.003), QRS duration during cardiac pacing (HR: 1.059, 95%CI: 1.017-1.103, P = 0.006), and existing basal cardiac diseases (HR: 13.080, 95%CI: 2.463-69.479, P = 0.003) were significant predictors of cardiac events, although pacing site had no significant association with prognosis (P = 0.56).Higher age, lower EF, longer QRS duration during cardiac pacing, and existing basal cardiac diseases are associated with poor prognosis in patients with a high percentage of ventricular pacing. PMID:26549389

  11. 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.

  12. 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

  13. Program of all-inclusive care (PACE): past, present, and future.

    PubMed

    Hirth, Victor; Baskins, Judith; Dever-Bumba, Maureen

    2009-03-01

    From modest beginnings in 1973 to over 60 programs nationwide, the PACE concept has proven the value of integrated, interdisciplinary-based care for frail older adults. The evolution of PACE and its regulatory and reimbursement model have changed over time, but the principals of care have remained unchanged. Nationally PACE programs are dealing with some of the same challenges they had 30 years ago and yet PACE programs continue to expand and provide care to an ever wider distribution of populations. The looming issue of ever-growing health care expenditures represents another opportunity for PACE to demonstrate its value while providing a level of quality beyond what could normally be provided by typical Medicare and Medicaid payments for similar conditions and patient characteristics. The future for PACE includes a number of possibilities including flexibility in financing and reimbursement, design changes to work with community-based physicians, potential eligibility adjustments, and growth of rural PACE. The PACE model has clearly demonstrated that in a debilitated, frail population in whom health care expenses would be expect to be high, a combination of team care, managed health care services, and care coordination can lead to both improved health outcomes and reduced expenses over time.

  14. COUPLING

    DOEpatents

    Frisch, E.; Johnson, C.G.

    1962-05-15

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

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

    NASA Technical Reports Server (NTRS)

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

    2009-01-01

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

  16. 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...

  17. 42 CFR 460.170 - Reinstatement in PACE.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

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

  18. 42 CFR 460.122 - 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...

  19. 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...

  20. 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...

  1. 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...

  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, 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...

  4. 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...

  5. 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...

  6. Improved Hydrological Predictions by the Coupling of Land-Surface-Atmosphere Processes

    NASA Astrophysics Data System (ADS)

    Larsen, M. A.; Refsgaard, J.; Jensen, K. H.; Christensen, J. H.; Butts, M. B.; Drews, M.

    2012-12-01

    The study is a part of the Danish HYACINTS project (www.hyacints.dk). A part of the study involves the development of a fully dynamic coupling between the HIRHAM regional climate model (Danish Meteorological Institute) and the MIKE SHE hydrological model (DHI / Geological Survey of Denmark and Greenland). A main expectation of the coupled setup is improved hydrological predictions. As climate models generally include only a simplistic hydrological description, the improvements are expected as a result of higher detail and resolution in soil water and water table depths as generated in the hydrological model component. Equally, the hydrological model may benefit from the horizontal redistribution of sensible energy made possible through the climate model. In the preparation of the coupling, the optimal setup of the climate model component is assessed among eight simulations with varying domain sizes and resolutions. Similarly the hydrological model is parameterized by upscaling from autocalibration results performed against field measurements at distinct surfaces within the catchment. The coupled climate model domain is covering an area of 4000x2800 km in 11 km resolution over northern Europe forced by ERA-Interim reanalysis data at the boundaries. The coupled hydrological model catchment is located at the approximate climate model domain center in the Western part of Denmark covering an area of 2500 km2. The effect of the coupling is tested using a 1 year period by running the model in two versions; a fully coupled setup and a traditional passive one-way setup using HIRHAM output as MIKE SHE input. Validation variables include evapotranspiration, sensible heat flux and soil moisture.

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

    PubMed

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

    2016-04-08

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

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

    PubMed

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

    2016-01-01

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

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

    PubMed Central

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

    2016-01-01

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

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

    PubMed

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

    2013-04-01

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

  11. Conservation law for self-paced movements.

    PubMed

    Huh, Dongsung; Sejnowski, Terrence J

    2016-08-01

    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.

  12. Conservation law for self-paced movements.

    PubMed

    Huh, Dongsung; Sejnowski, Terrence J

    2016-08-01

    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

  13. 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.

  14. 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. PMID:24774592

  15. 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.

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

    SciTech Connect

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

    2011-06-17

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

  17. 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

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

    NASA Astrophysics Data System (ADS)

    Ickes, Jacob C.

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

  19. 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. PMID:19926815

  20. Temporary leadless pacing in a patient with severe device infection.

    PubMed

    Kypta, Alexander; Blessberger, Hermann; Lichtenauer, Michael; Steinwender, Clemens

    2016-05-17

    A 64-year-old patient underwent implantation of a transcatheter pacing systems (TPS) for severe lead endocarditis. The patient experienced fever after a dental procedure. On the transoesophageal echocardiogram (TEE), vegetations were attached to the leads. Because the patient was pacemaker dependent, a temporary pacing lead had to be placed. After removal, however, he did not improve. A second TEE showed new vegetations. Ventricular fibrillation occurred spontaneously; so isoprenalin had to be stopped and a new lead was implanted. Vegetations appeared soon after the new temporary lead was placed. We used a TPS as a bridging device, followed by implantation of a resynchronisation system, and explantation of the TPS. After the Micra TPS was implanted, the patient recovered noticeably. All inflammation parameters were negative and an additional (18)F-fluorodeoxyglucose-positron emission tomography/CT imaging also proved to be negative. So a CRT-D device was then implanted, and the TCP was removed.

  1. Temporary leadless pacing in a patient with severe device infection.

    PubMed

    Kypta, Alexander; Blessberger, Hermann; Lichtenauer, Michael; Steinwender, Clemens

    2016-01-01

    A 64-year-old patient underwent implantation of a transcatheter pacing systems (TPS) for severe lead endocarditis. The patient experienced fever after a dental procedure. On the transoesophageal echocardiogram (TEE), vegetations were attached to the leads. Because the patient was pacemaker dependent, a temporary pacing lead had to be placed. After removal, however, he did not improve. A second TEE showed new vegetations. Ventricular fibrillation occurred spontaneously; so isoprenalin had to be stopped and a new lead was implanted. Vegetations appeared soon after the new temporary lead was placed. We used a TPS as a bridging device, followed by implantation of a resynchronisation system, and explantation of the TPS. After the Micra TPS was implanted, the patient recovered noticeably. All inflammation parameters were negative and an additional (18)F-fluorodeoxyglucose-positron emission tomography/CT imaging also proved to be negative. So a CRT-D device was then implanted, and the TCP was removed. PMID:27190123

  2. 42 CFR 460.122 - PACE organization's appeals process.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... team denies a request for services or payment, the PACE organization must give a participant written... 42 Public Health 4 2010-10-01 2010-10-01 false PACE organization's appeals process. 460.122... FOR THE ELDERLY (PACE) Participant Rights § 460.122 PACE organization's appeals process. For...

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

    PubMed

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

    2013-12-01

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

  4. Neurophysiological determinants of theoretical concepts and mechanisms involved in pacing.

    PubMed

    Roelands, Bart; de Koning, Jos; Foster, Carl; Hettinga, Floor; Meeusen, Romain

    2013-05-01

    improve performance. The distribution of the power output reveals that after dopamine reuptake inhibition, subjects are able to maintain a higher power output compared with placebo. Manipulations of serotonin and, especially, noradrenaline, have the opposite effect and force subjects to decrease power output early in the time trial. Interestingly, after manipulation of brain serotonin, subjects are often unable to perform an end sprint, indicating an absence of a reserve capacity or motivation to increase power output. Taken together, it appears that many factors, such as ambient conditions and manipulation of brain neurotransmitters, have the potential to influence power output during exercise, and might thus be involved as regulatory mechanisms in the complex skill of pacing.

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

    PubMed Central

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

    2015-01-01

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

  6. 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.

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

    SciTech Connect

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

    2015-12-15

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

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

    PubMed

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

    2015-02-01

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

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

    PubMed

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

    2015-02-01

    Catalytic partial oxidation coupled with membrane purification is a new process scheme to improve resource and energy efficiency in a well-established and large scale-process like syngas production. Experimentation in a semi industrial-scale unit (20 Nm(3)  h(-1) production) shows that a novel syngas production scheme based on a pre-reforming stage followed by a membrane for hydrogen separation, a catalytic partial oxidation step, and a further step of syngas purification by membrane allows the oxygen-to-carbon ratio to be decreased while maintaining levels of feed conversion. For a total feed conversion of 40 %, for example, the integrated novel architecture reduces oxygen consumption by over 50 %, with thus a corresponding improvement in resource efficiency and an improved energy efficiency and economics, these factors largely depending on the air separation stage used to produce pure oxygen. PMID:25571881

  10. Permanent cardiac pacing in Malaysia. An update.

    PubMed

    Saw, H S; Chong, K T; Singham, A M

    1981-10-01

    Updated data on permanent cardiac pacing in Malaysia is presented. Over the past 3 1/2 years (1976-1980), 75 patients underwent insertion of pacemakers giving an annual incidence of about 20 cases as compared with a total of 21 cases in the previous 8 years (1968-1977). Many of the features reported in an earlier paper in 1977 viz mode of presentation, age and sex distribution and indications for pacing remain unchanged. Over this period only 4 patients required lead replacement. Since concentrating mainly on the use of epicardial leads implanted via a subxiphoid approach, complications have been remarkably low. The problem of availability of pacemakers has been averted. Cost remains a major consideration when recommending one pacemaker in preference over another. The details concerning clinical features, indications for pacing, complications and other problems encountered in the management of these patients are discussed.

  11. 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

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

    NASA Astrophysics Data System (ADS)

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

    2016-09-01

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

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

    PubMed Central

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

    2016-01-01

    Background: Poor cerebral perfusion may contribute to cognitive impairment in type 2 diabetes mellitus (T2DM). We conducted a randomized controlled trial to test the hypothesis that resveratrol can enhance cerebral vasodilator function and thereby alleviate the cognitive deficits in T2DM. We have already reported that acute resveratrol consumption improved cerebrovascular responsiveness (CVR) to hypercapnia. We now report the effects of resveratrol on neurovascular coupling capacity (CVR to cognitive stimuli), cognitive performance and correlations with plasma resveratrol concentrations. Methods: Thirty-six T2DM adults aged 40–80 years were randomized to consume single doses of resveratrol (0, 75, 150 and 300 mg) at weekly intervals. Transcranial Doppler ultrasound was used to monitor changes in blood flow velocity (BFV) during a cognitive test battery. The battery consisted of dual-tasking (finger tapping with both Trail Making task and Serial Subtraction 3 task) and a computerized multi-tasking test that required attending to four tasks simultaneously. CVR to cognitive tasks was calculated as the per cent increase in BFV from pre-test basal to peak mean blood flow velocity and also as the area under the curve for BFV. Results: Compared to placebo, 75 mg resveratrol significantly improved neurovascular coupling capacity, which correlated with plasma total resveratrol levels. Enhanced performance on the multi-tasking test battery was also evident following 75 mg and 300 mg of resveratrol. Conclusion: a single 75 mg dose of resveratrol was able to improve neurovascular coupling and cognitive performance in T2DM. Evaluation of benefits of chronic resveratrol supplementation is now warranted. PMID:27420093

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

    NASA Astrophysics Data System (ADS)

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

    2014-04-01

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

  15. An Integrated Preprofessional Individually Paced Instruction Curriculum.

    ERIC Educational Resources Information Center

    McCollom, Kenneth A.; Kurtz, Edwin B.

    The individually-paced instruction program carried out by the engineering faculty at Oklahoma State University is described in this article to illustrate its goals, principles, characteristics, developments, and present status. The instructional model is discussed in connection with behavioral objectives, criteria for performance, and student…

  16. 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…

  17. Self-Paced Graphics with Track Options.

    ERIC Educational Resources Information Center

    Hilliard, Garland K.

    An engineering graphics course offered at North Carolina State University for freshman engineering students is described. The course is divided into 14 units and the students are allowed to proceed at their own pace. The first 11 units comprise the required core; the remaining 3 units may be chosen from other areas such as computer graphics,…

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

    PubMed

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

    2016-01-01

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

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

    PubMed

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

    2016-05-12

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

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

    PubMed Central

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

    2016-01-01

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

  1. The potential and reality of permanent his bundle pacing.

    PubMed

    Barba-Pichardo, Rafael; Moriña-Vázquez, Pablo; Venegas-Gamero, José; Frutos-López, Manuel; Moreno-Lozano, Valle; Herrera-Carranza, Manuel

    2008-10-01

    Right ventricular apex pacing can have deleterious effects. Our aims were to investigate how many patients referred for permanent pacing were suitable candidates for permanent His bundle pacing, and to determine the proportion in whom such pacing was successful. All cases of suprahisian block and most cases of infrahisian block (71.4%) were corrected by temporary His bundle pacing. However, permanent His bundle pacing was achieved in only 55% of cases in which it was attempted, and in only 35.4% of all possible cases. PMID:18817687

  2. 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

  3. 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

  4. Interfacial coupling between immiscible polymers: Flow accelerates reaction and improves adhesion

    NASA Astrophysics Data System (ADS)

    Song, Jie

    As the workhorses of the plastics industry, polyolefins are consumed in the largest volume of all types of polymers. Despite their wide use, polyolefins suffer from poor adhesion and compatibility with other polar polymers due to their intrinsic low polarity and lack of functional groups. The first goal of this study is to enhance interfacial adhesion between polyolefins with other polymers through coupling reaction of functional polymers. We have used functional polyethylenes with maleic anhydride, hydroxyl, primary and secondary amino groups grafted through reactive extrusion. Functional polyolefins dramatically improved the performance of polyolefins, including adhesion, compatibility, hardness and scratch resistance, and greatly expand their applications. The second goal is to understand the factors affecting adhesion. We systematically investigated two categories of parameters. One is molecular: the type and incorporation level of functional groups. The other is processing condition: die design in extruders, reaction time and temperature. The interfacial adhesion was measured with the asymmetric dual cantilever beam test and T-peel test. The extent of reaction was quantified through measuring anchored copolymers via X-ray photoelectron spectroscopy. A quantitative correlation between adhesion and coupling reaction was developed. A coextruded bilayer system with coupling reaction at interfaces was created to clarify processing effects on the kinetics of coupling reactions. For the reaction between maleic anhydride modified polyethylene and nylon 6, the reaction rate during coextrusion through a fishtail die with compressive/extensional flow was strikingly almost two orders of magnitude larger than that through a constant thickness die without compressive flow. The latter reaction rate was close to that of quiescent lamination. We attribute the reaction acceleration through the fishtail die to the large deformation rate under the compressive/extensional flow

  5. 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.

  6. 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.

  7. Single chamber atrial pacing: an underused and cost-effective pacing modality in sinus node disease

    PubMed Central

    Clarke, K; Connelly, D; Charles, R

    1998-01-01

    Objective—To determine the safety and cost effectiveness of single chamber atrial pacing in patients with sinus node disease.
Design—Retrospective follow up study.
Setting—Tertiary referral centre.
Patients—81 patients with single chamber atrial pacemakers implanted between 1992 and 1996.
Main outcome measures—The development of high grade atrioventricular block resulting in a further pacemaker procedure. The cost savings of changing our current pacing practice to conform with British Pacing and Electrophysiology Group guidelines.
Results—During the follow up period, four patients (5.8%) required a further procedure to upgrade their atrial pacemaker to a dual chamber system owing to the development of high grade atrioventricular block. In 1995 and 1996, 343 pacemakers were implanted in patients with sinus node disease; 19 (5.5%) received single chamber atrial pacemakers and 271 (79%) dual chamber pacemakers. If the current pacing practice was changed so that all patients received single chamber atrial pacemakers, with revision for symptomatic atrioventricular block, savings in excess of £206 000 would have been made in the two year period.
Conclusions—Atrial pacing in patients with sinus node disease is underused. The need for patients to undergo further procedures owing to the development of atrioventricular block is small and significant cost savings could be made by changing pacemaker practice.

 Keywords: sinus node disease;  atrial pacing;  cost effectiveness PMID:9875119

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

    NASA Technical Reports Server (NTRS)

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

    1992-01-01

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

  9. The Problem of Pacing a Student Learning at Home.

    ERIC Educational Resources Information Center

    Yule, Ronald M.

    1985-01-01

    The problem of pacing distance learning students is discussed together with suggested pacing methods: insertion of questions in text of study guides; short-term, regular assignments; tutorial letters; audiocassette and videotape usage; and computer assisted instruction. (MBR)

  10. 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...

  11. 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...

  12. 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...

  13. 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...

  14. 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...

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

    SciTech Connect

    Ebert, Christopher Hysjulien

    2012-01-01

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

  16. PACE (Revised). Resource Guide. Research & Development Series No. 240D.

    ERIC Educational Resources Information Center

    Ashmore, M. Catherine; Pritz, Sandra G.

    This resource guide contains information on the Program for Acquiring Competence in Entrepreneurship (PACE) materials, a glossary, and listings of sources of information. Introductory materials include a description of PACE, information on use of PACE materials, and objectives of the 18 units for all three levels at which they are developed. An…

  17. 77 FR 3958 - Mortgage Assets Affected by PACE Programs

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-26

    ... assets affected by Property Assessed Clean Energy (``PACE'') programs and Notice of Intent (``NOI'') to... property assessed clean energy (PACE) programs.'' In response to and compliance with the California... property assessed clean energy (PACE) programs.'' The California District Court further ordered that ``...

  18. 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)

  19. 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…

  20. The Efficacy of PACE in the Remediation of Naming Deficits.

    ERIC Educational Resources Information Center

    Li, Edith Chin; And Others

    1988-01-01

    The study compared PACE (Promoting Aphasics' Communicative Effectiveness) and traditional stimulation therapy in the remediation of naming deficits in a 66-year-old conduction aphasic. In PACE, client and clinician engage in natural interaction sequences using multiple channels, including gestures, to communicate. PACE resulted in greater gains in…

  1. His bundle pacing: Initial experience and lessons learned.

    PubMed

    Deshmukh, Amrish; Deshmukh, Pramod

    2016-01-01

    Direct His bundle pacing provides the most physiologic means of artificial pacing of the ventricles with a preserved His-Purkinje system and may play a role in patients with a diseased intrinsic conduction system. We describe our initial motivations and experience with permanent direct His bundle pacing and important lessons learned since that time. PMID:27591359

  2. 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

  3. Visual aided pacing in respiratory maneuvers

    NASA Astrophysics Data System (ADS)

    Rambaudi, L. R.; Rossi, E.; Mántaras, M. C.; Perrone, M. S.; Siri, L. Nicola

    2007-11-01

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

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

    PubMed Central

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

    2014-01-01

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

  5. Gait Alterations During Constant Pace Treadmill Racewalking.

    PubMed

    Hanley, Brian

    2015-08-01

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

  6. 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…

  7. 42 CFR 460.32 - Content and terms 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) PACE Program Agreement § 460.32 Content and terms of PACE program agreement....

  8. 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...

  9. 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....

  10. 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....

  11. 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...

  12. 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....

  13. 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...

  14. 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...

  15. Comparison of effectiveness of right ventricular septal pacing versus right ventricular apical pacing.

    PubMed

    Cano, Oscar; Osca, Joaquín; Sancho-Tello, María-José; Sánchez, Juan M; Ortiz, Víctor; Castro, José E; Salvador, Antonio; Olagüe, José

    2010-05-15

    Chronic right ventricular apical pacing (RVAP) has been associated with negative hemodynamic and clinical effects. The aim of the present study was to compare RVAP with right ventricular septal pacing (RVSP) in terms of echocardiographic features and clinical outcomes. A total of 93 patients without structural heart disease and with an indication for a permanent pacemaker were randomly assigned to receive a screw-in lead either in the RV apex (n = 46) or in the RV mid-septum (n = 47). The patients were divided into 3 subgroups according to the percentage of ventricular pacing: control group (n = 21, percentage of ventricular pacing < or =10%), RVAP group (n = 28), or RVSP group (n = 32; both latter groups had a percentage of ventricular pacing >10%). The RVAP group had more intraventricular dyssynchrony and a trend toward a worse left ventricular ejection fraction compared to the RVSP and control groups at 12 months of follow-up (maximal delay to peak systolic velocity between any of the 6 left ventricular basal segments was 57.8 +/- 38.2, 35.5 +/- 20.6, and 36.5 +/- 17.8 ms for RVAP, RVSP, and control group, respectively; p = 0.006; mean left ventricular ejection fraction 62.9 +/- 7.9%, 66.5 +/- 7.2%, and 66.6 +/- 7.2%, respectively, p = 0.14). Up to 48.1% of the RVAP patients showed significant intraventricular dyssynchrony compared to 19.4% of the RVSP patients and 23.8% of the controls (p = 0.04). However, no overt clinical benefits from RVSP were found. In conclusion, RVAP was associated with increased dyssynchrony compared to the RVSP and control patients. RVSP could represent an alternative pacing site in selected patients to reduce the harmful effects of traditional RVAP. PMID:20451689

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

    PubMed

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

    2013-09-01

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

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

    PubMed

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

    2013-09-01

    Eight different chemicals were investigated as potential candidate coupling agents for phosphate glass fibre reinforced polylactic acid composites. Evidence of reaction of the coupling agents with phosphate glass and their effect on surface wettability and glass degradation were studied along with their principle role of improving the interface between glass reinforcement and polymer matrix. It was found that, with an optimal amount of coupling agent on the surface of the glass/polymer, interfacial shear strength improved by a factor of 5. Evidence of covalent bonding between agent and glass was found for three of the coupling agents investigated, namely: 3-aminopropyltriethoxysilane; etidronic acid and hexamethylene diisocyanate. These three coupling agents also improved the interfacial shear strength and increased the hydrophobicity of the glass surface. It is expected that this would provide an improvement in the macroscopic properties of full-scale composites fabricated from the same materials which may also help to retain these properties for the desired length of time by retarding the breakdown of the fibre/matrix interface within these composites. PMID:22781920

  18. 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.

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

    PubMed

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

    2014-04-01

    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 optimal 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 modeling 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

  20. Maine PACE Program Final Technical Report

    SciTech Connect

    Fischer, Dana; Adamson, Joy M

    2015-01-30

    The ARRA EECBG BetterBuilding helped augment the existing Home Energy Savings Programs (HESP) and incentives with financing through a subordinate lien PACE and HUD PowerSaver programs. The program was designed to document innovative techniques to dramatically increase the number of homes participating in weatherization programs in participating towns. Maine will support new energy efficiency retrofit pilots throughout the state, designed to motivate a large number of homeowners to invest in comprehensive home energy efficiency upgrades to bring real solutions to market.

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

    DOEpatents

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

    1995-01-01

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

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

    PubMed

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

    2016-08-26

    We reported sensitivity enhancement using multichannel parallel separation for microchip electrophoresis hyphenated with inductively coupled plasma mass spectrometry (MCE-ICP-MS) in this study. By using 2-20 array lanes for parallel separation, the sensitivity of the MCE-ICP-MS system was proportionally improved by 2-20 folds. No significantly adverse effect of parallel separation on column efficiency and resolution was observed. Rapid separation of Hg(2+) and methylmercuric (MeHg) ion within 36s under an electric field of 800Vcm(-1) was achieved in the 2-cm twenty-channels with a background electrolyte of 5mmolL(-1) borate buffer (pH 9.2). Detection limits of Hg(2+) and MeHg by the proposed system were decreased to 6.8-7.1ngL(-1). Good agreement between determined values and certified values of a certified reference fish was obtained with recoveries ranged between 94-98%. All results prove its advantages including high sensitivity, high efficiency and low operation cost, which are beneficial to routine analysis of metal speciation in environmental, biological and food fields. PMID:27488720

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

    DOEpatents

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

    1995-03-28

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

  4. 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.

  5. 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. PMID:22044295

  6. Classification of similar but differently paced activities in the KTH dataset

    NASA Astrophysics Data System (ADS)

    Sengupta, Shreeya; Wang, Hui; Ojha, Piyush; Blackburn, William

    2015-02-01

    The KTH video dataset [1] contains three activities - walking, jogging and running - which are very similar but are carried out at a different natural pace. We show that explicit inclusion of a feature which may be interpreted as a measure of the overall state of motion in a frame improves a classifier's ability to discriminate between these activities.

  7. Suppression of electrical storm by biventricular pacing in a patient with idiopathic dilated cardiomyopathy and ventricular tachycardia.

    PubMed

    Tanabe, Yasutaka; Chinushi, Masaomi; Washizuka, Takashi; Minagawa, Shirou; Furushima, Hiroshi; Watanabe, Hiroshi; Hosaka, Yukio; Komura, Satoru; Aizawa, Yoshifusa

    2003-01-01

    This study presents a patient with idiopathic dilated cardiomyopathy who had suffered from multiple ICD shocks. Amiodarone and a beta-blocker failed to suppress ventricular tachycardia. His ECG showed a very wide QRS complex with an intraventricular conduction delay, so biventricular (BV) pacing was attempted. The BV pacing successfully prevented the multiple ICD shocks accompanied with an improvement in left ventricular systolic function and physical activity.

  8. Use of balloon flotation pacing catheters for prophylactic temporary pacing during diagnostic and therapeutic catheterization procedures.

    PubMed

    Harvey, J R; Wyman, R M; McKay, R G; Baim, D S

    1988-11-01

    The use of prophylactic temporary pacemakers during diagnostic catheterization, coronary angioplasty and percutaneous balloon valvuloplasty was investigated retrospectively over an 18-month period. Balloon flotation temporary pacemaker leads were placed in 193 (12%) of 1,609 patients undergoing diagnostic catheterization, 641 (65%) of 993 patients undergoing coronary angioplasty and 199 (100%) of 199 patients undergoing aortic or mitral valvuloplasty. There were no perforations or significant arrhythmic complications related to pacemaker placement in these 1,033 cases, and pacing was initiated promptly when required by withdrawal of the catheter tip into the right ventricle. Significant bradycardia or new conduction defects developed in 17 patients (1%) during diagnostic catheterization, 10 patients (1%) during angioplasty and 20 patients (10%) during valvuloplasty, but were severe enough to require initiation of temporary pacing in only 1 (0.06%), 4 (0.4%) and 5 (2.5%) patients, respectively. No patient undergoing diagnostic catheterization or angioplasty (but 5 patients undergoing valvuloplasty) required immediate pacing support to treat a life-threatening bradycardia. The total cost of prophylactic pacemakers was $103,300, with a cost per actual use of $19,300 for diagnostic cases, $16,025 for angioplasty and $3,980 for balloon valvuloplasty. These data suggest that prophylactic temporary pacing is not indicated during either diagnostic catheterization or coronary angioplasty, but should be used routinely during balloon valvuloplasty.

  9. Can Regional Ocean-Atmosphere Coupled Model Improve the Simulation of the Interannual Variability of Western North Pacific Summer Monsoon?

    NASA Astrophysics Data System (ADS)

    Zou, L.; Zhou, T.

    2012-12-01

    With the motivation to improve the simulation of interannual variability of western North Pacific summer monsoon (WNPSM), a flexible regional ocean-atmosphere-land system coupled model (FROALS) was developed through the OASIS3.0 coupler. The regionally coupled model is composed of a regional climate model RegCM3 as its atmospheric component, a global climate ocean model (LICOM) as its oceanic component. Impacts of local air-sea interaction on the simulation of interannual variability of WNPSM are investigated by performing regionally ocean-atmosphere coupled and uncoupled simulations, with focus on the El Niño decaying summer. Compared to uncoupled simulation, the regionally coupled simulation exhibits improvements in both the climatology and interannual variability of rainfall over WNP. In El Niño decaying summer, the WNP saw an anomalous anticyclone, less rainfall and enhanced subsidence, which led to an increase in downward shortwave radiation flux, and thereby a warmer SST anomalies. Thus the ocean appears as a slave to atmospheric forcing. But in the uncoupled simulation, the atmosphere is a slave to oceanic SST forcing, the warmer SST anomalies located over east of the Philippines unrealistically produce excessive rainfall. In the regionally coupled run, the un-realistic positive rainfall anomalies and the associated atmospheric circulations over east of the Philippines are significantly improved, highlighting the importance of air-sea coupling in the simulation of interannual variability of WNPSM. One limitation of the model is that the anomalous anticyclone over WNP is weaker than the observation in both the regionally coupled and uncoupled simulations. This is resulted from the weaker simulated climatological summer rainfall intensity over the monsoon trough.

  10. 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

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

    SciTech Connect

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

    2014-10-15

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

  12. A review of multisite pacing to achieve cardiac resynchronization therapy.

    PubMed

    Rinaldi, Christopher Aldo; Burri, Haran; Thibault, Bernard; Curnis, Antonio; Rao, Archana; Gras, Daniel; Sperzel, Johannes; Singh, Jagmeet P; Biffi, Mauro; Bordachar, Pierre; Leclercq, Christophe

    2015-01-01

    Non-response to cardiac resynchronization therapy remains a significant problem in up to 30% of patients. Multisite stimulation has emerged as a way of potentially overcoming non-response. This may be achieved by the use of multiple leads placed within the coronary sinus and its tributaries (dual-vein pacing) or more recently by the use of multipolar (quadripolar) left ventricular pacing leads which can deliver pacing stimuli at multiple sites within the same vein. This review covers the role of multisite pacing including the interaction with the underlying pathophysiology, the current and planned studies, and the potential pitfalls of this technology. PMID:25214507

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

    PubMed

    Falconier, Mariana K

    2015-04-01

    The accumulated knowledge about the negative impact of financial strain on couple's relationship functioning and the magnitude of the latest economic downturn have brought together the fields of financial counseling and couples' therapy. This article describes the development of a new interdisciplinary program that aims at helping couples under financial strain improve their financial management, communication, and dyadic coping skills. The article also reports the results from its initial pilot-testing with data collected from 18 financially distressed couples before and after participation in the program and 3 months later. Results from repeated measures ANOVAs suggest that the program may help reduce both partners' financial strain and the male negative communication and improve both partners' financial management skills and strategies to cope together with financial strain, and the male relationship satisfaction. These findings together with the high satisfaction reported by participants regarding the structure and content of the sessions and homework suggest that this program may be a promising approach to help couples experiencing financial strain. Gender differences, clinical implications, and possibilities for further research are also discussed. PMID:24910157

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

    NASA Astrophysics Data System (ADS)

    Fuyuto, Kaori; Senaha, Eibun

    2014-07-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2012-04-01

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

  16. Improvement of efficient coupling and optical resonances by using taper-waveguides coupled to cascade of UV210 polymer micro-resonators

    NASA Astrophysics Data System (ADS)

    Castro-Beltran, R.; Huby, N.; Loas, G.; Lhermite, H.; Pluchon, D.; Bêche, B.

    2014-12-01

    In this paper, we report the overall design, fabrication and optical characterization of single and multiple resonant micro-structures patterned on UV210 polymer and shaped by using deep-UV lithography procedures. Various families of ring and racetrack forms are investigated with different geometrical dimensions linked to the micro-resonators and the specific taper-waveguides and gaps allowing the optimized coupling. Well defined photonic structures families in the sub-micrometer range obtained by this deep UV-light process are clearly confirmed through scanning electron microscopy. In order to evaluate and quantify the efficiency of the sub-micrometer coupling, the recirculation of the light and the quality of the optical resonance aspects, a global study including top view intensity imaging, spectral measurements and fast Fourier transform analysis is performed for all these devices based on single and multiple family resonators. The experimental TE-mode resonance transmissions reveal a complete agreement with the period of the theoretically expected resonances. A maximum value of the quality factor Q = 3.5  ×  103 at 1035 nm with a 3.2 times higher resonance contrast is assessed for cascade of triple micro-resonators with respect to photonic devices based on only one micro-resonator. In addition, UV210 circuits made of specific tapers coupling to cascade loops act directly on the improvement of the evanescent coupling and resonances in terms of quality factor and extinction rate by selecting the optical mode resonance successively and more precisely. All these designs have low cost technological reproducible steps, and the devices and protocol measurements are markedly suitable for mass fabrication and metrology applications.

  17. 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.

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

    NASA Technical Reports Server (NTRS)

    Dean, L. W.

    1975-01-01

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

  19. A Self-Pacing Program in Algebra, Volume 2.

    ERIC Educational Resources Information Center

    Baltimore County Public Schools, Towson, MD.

    This self-pacing program is the result of a cooperative curriculum development project between The Maryland Department of Education and The Baltimore County Schools. Included is a teachers guide for the use of the materials. The philosophy of this approach is that of individualization of instruction wherein the student moves at a pace commensurate…

  20. PACE: has it changed the chronic care paradigm?

    PubMed

    Lynch, Marty; Hernandez, Mauro; Estes, Carroll

    2008-01-01

    The Program of All-inclusive Care for the Elderly (PACE) grew out of a small community organization in San Francisco and has been replicated by non-profit organizations in a number of other communities across the country. The authors review the successes of PACE as reported in the literature and discuss reasons for its limited growth as well as its significant influence on state and federal long term care policy. They argue that PACE has significantly changed how we think of long term care through its pioneering work fully integrating medical and long term care. PACE has also provided an influential model for breaking down the funding silos that characterize the medical and long term care services arena. State Medicaid agencies and Medicare have learned from PACE. Health plans and private long term insurers may also still learn from PACE. However, the fact that only a little more than 10,000 elders have enrolled in PACE nationwide prevents the authors from finding that PACE has brought about significant structural change in a long term care industry dominated by for-profit nursing homes.

  1. Postpericardiotomy syndrome following temporary and permanent transvenous pacing

    PubMed Central

    Bajaj, B.; Evans, K.; Thomas, P.

    1999-01-01

    The postpericardiotomy syndrome may occur as a complication of temporary and permanent pacing. Physicians involved in procedures which may be complicated by this condition therefore need to be aware of its diagnosis and management.


Keywords: postpericardiotomy syndrome; cardiac pacing PMID:10435173

  2. 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…

  3. 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:…

  4. 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)

  5. 42 CFR 460.122 - PACE organization's appeals process.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... writing. (e) Services furnished during appeals process. During the appeals process, the PACE organization... Section 460.122 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...

  6. Rural Policy Development: An NRHA and PACE Association Collaborative Model

    ERIC Educational Resources Information Center

    Fitzgerald, Peter; Morgan, Alan; Morris, Tom

    2004-01-01

    The Program of All-Inclusive Care for the Elderly (PACE) offers a unique model of comprehensive care for frail, elderly people. To date, all of the PACE programs have been located in urban areas. Rural advocates and policymakers, however, believe the program may hold great promise for use in rural areas, which have higher percentages of elderly…

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

    SciTech Connect

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

    2015-01-13

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

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

    SciTech Connect

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

    2015-01-15

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

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

    SciTech Connect

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

    2009-11-01

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

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

    DOE PAGESBeta

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

    2015-01-13

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

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

    PubMed Central

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

    2015-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2016-09-01

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

  13. Understanding and improving acoustic to seismic coupling as it pertains to Sandia's helicopter detector

    SciTech Connect

    Elliott, G.; Fogler, R.J.

    1985-03-18

    This report covers results to date of an ongoing study undertaken in mid 1984 for the purpose of understanding the basic physics of the acoustic-to-seismic coupling phenomenon involved in the operation of a helicopter detector under development at Sandia National Laboratories. This study has been recently expanded to include assistance from the US Army Waterways Experiment Station and the University of Mississippi. A series of tests were conducted near Albuquerque, New Mexico USA, for the purpose of investigating the coupling phenomenon using an impulsive noise source and two different helicopters. Results of these tests including the evaluation of a new microphone windscreen design are reported.

  14. Improving the sensitivity of J coupling measurements in solids with application to disordered materials

    NASA Astrophysics Data System (ADS)

    Guerry, Paul; Brown, Steven P.; Smith, Mark E.

    2016-05-01

    It has been shown previously that for magic angle spinning (MAS) solid state NMR the refocused INADEQUATE spin-echo (REINE) experiment can usefully quantify scalar (J) couplings in disordered solids. This paper focuses on the two z filter components in the original REINE pulse sequence, and investigates by means of a product operator analysis and fits to density matrix simulations the effects that their removal has on the sensitivity of the experiment and on the accuracy of the extracted J couplings. The first z filter proves unnecessary in all the cases investigated here and removing it increases the sensitivity of the experiment by a factor ˜1.1-2.0. Furthermore, for systems with broad isotropic chemical shift distributions (namely whose full widths at half maximum are greater than 30 times the mean J coupling strength), the second z filter can also be removed, thus allowing whole-echo acquisition and providing an additional √2 gain in sensitivity. Considering both random and systematic errors in the values obtained, J couplings determined by fitting the intensity modulations of REINE experiments carry an uncertainty of 0.2-1.0 Hz (˜1-10 %).

  15. Application of Phase Smoothing Pseudo Range PPP/INS Tightly Coupled Technique in Improving the Results of Low Precision MEMS

    NASA Astrophysics Data System (ADS)

    Luo, X.

    2015-12-01

    In land surveying and engineering surveying, we need to obtain high precision navigation results. However, due to the inertial device costs less than a introduction, commonly used low precision inertial navigation equipment with tightly coupled GPS / INS integrated to get high precision navigation results. Many studies have improved the accuracy of error by using the UKF and CKF filtering algorithm, but it is still using the traditional pseudo code directly, the improvement effect is not obvious, and the disturbance is large. In this study, the PPP /INSmodel is improved by using the carrier phase smoothing pseudo range algorithm. Experimental results show that based on phase smoothing pseudo range PPP/INS tight coupled method, the position precision and the velocity precision for of the measured data of higher accuracy of MEMS and GPS receiver can get to a decimeter level and centimeter level. This coupling method has higher accuracy, stronger anti disturbance and Have a better convergence than the traditional C/A code. Based on different phase smoothing epoch number combination the accuracy and smoothing effect is also different, the larger smooth epoch number is, the better treatment effect it has and The higher precision it has. For high precision measurement, the equipment cost is saved. It has a practical significance meaning in the measurement of outdoor ground.

  16. 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…

  17. 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

  18. Mid-Term Results of Dual-Chamber Pacing in Children with Hypertrophic Obstructive Cardiomyopathy.

    PubMed

    Alday, Luis E.; Bruno, Eva; Moreyra, Eduardo; Amuchastegui, Luis M.; Juaneda, Ernesto; Maisuls, Hector

    1998-04-01

    BACKGROUND: Permanent dual-chambered pacing (DDD) is an alternative to surgical treatment in patients with severe hypertrophic obstructive cardiomyopathy (HOCM) who do not have a satisfactory response to medical treatment. METHODS: Five children with severe HOCM still symptomatic despite medical treatment underwent permanent DDD pacing and were followed for 21 +/- 9.7 months. RESULTS: All patients improved their functional class. Doppler echocardiographic studies showed an early reduction of the left ventricular outflow tract gradient from 66 +/- 40 to 40 +/- 20 mmHg (P < 0.05) and to 30 +/- 11 mmHg (P < 0.05 and NS for comparison with the baseline and the early post-DDD pacing gradients, respectively) at mid-term follow-up. There was no evidence of left ventricular systolic dysfunction, and the results of left ventricular filling studies ruled out deleterious effects on diastolic function. Doppler echocardiography played a key role in the initial and subsequent assessment of these patients. CONCLUSIONS: Permanent DDD pacing is a reasonable alternative to surgery in children with HOCM who are still symptomatic despite medical therapy.

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

    NASA Astrophysics Data System (ADS)

    Yan, Yingying; Lin, Jintai; Chen, Jinxuan; Hu, Lu

    2016-02-01

    from 0.53 to 0.68, and it reduces the mean model bias from 10.8 to 6.7 ppb. Regionally, the coupled system reduces the bias by 4.6 ppb over Europe, 3.9 ppb over North America and 3.1 ppb over other regions. The two-way coupling brings O3 vertical profiles much closer to the HIPPO (for remote areas) and MOZAIC (for polluted regions) data, reducing the tropospheric (0-9 km) mean bias by 3-10 ppb at most MOZAIC sites and by 5.3 ppb for HIPPO profiles. The two-way coupled simulation also reduces the global tropospheric column ozone by 3.0 DU (9.5 %, annual mean), bringing them closer to the OMI data in all seasons. Additionally, the two-way coupled simulation also reduces the global tropospheric mean hydroxyl radical by 5 % with improved estimates of methyl chloroform and methane lifetimes. Simulation improvements are more significant in the Northern Hemisphere, and are mainly driven by improved representation of spatial inhomogeneity in chemistry/emissions. Within the nested domains, the two-way coupled simulation reduces surface ozone biases relative to typical GEOS-Chem one-way nested simulations, due to much improved LBCs. The bias reduction is 1-7 times the bias reduction from the global to the one-way nested simulation. Improving model representations of small-scale processes is important for understanding the global and regional tropospheric chemistry.

  20. Regulation of Pacing Strategy during Athletic Competition

    PubMed Central

    de Koning, Jos J.; Foster, Carl; Bakkum, Arjan; Kloppenburg, Sil; Thiel, Christian; Joseph, Trent; Cohen, Jacob; Porcari, John P.

    2011-01-01

    Background Athletic competition has been a source of interest to the scientific community for many years, as a surrogate of the limits of human ambulatory ability. One of the remarkable things about athletic competition is the observation that some athletes suddenly reduce their pace in the mid-portion of the race and drop back from their competitors. Alternatively, other athletes will perform great accelerations in mid-race (surges) or during the closing stages of the race (the endspurt). This observation fits well with recent evidence that muscular power output is regulated in an anticipatory way, designed to prevent unreasonably large homeostatic disturbances. Principal Findings Here we demonstrate that a simple index, the product of the momentary Rating of Perceived Exertion (RPE) and the fraction of race distance remaining, the Hazard Score, defines the likelihood that athletes will change their velocity during simulated competitions; and may effectively represent the language used to allow anticipatory regulation of muscle power output. Conclusions These data support the concept that the muscular power output during high intensity exercise performance is actively regulated in an anticipatory manner that accounts for both the momentary sensations the athlete is experiencing as well as the relative amount of a competition to be completed. PMID:21283744

  1. 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

  2. Improving the Mass-Limited Performance of Routine NMR Probes using Coupled Coils

    NASA Astrophysics Data System (ADS)

    Marsden, Brian; Lim, Victor; Taber, Bob; Zens, Albert

    2016-07-01

    We report a method to convert, on demand, a general use dual-broadband probe to a high performance mass-limited probe for both high band and low band nuclei. This technology uses magnetic coupling of inductors to achieve this capability. The method offers a cost effective way of increasing the performance of routine NMR probes without having to change probes or increase the overall foot print of the spectrometer.

  3. Ultra-wide bandwidth improvement of piezoelectric energy harvesters through electrical inductance coupling

    NASA Astrophysics Data System (ADS)

    Abdelmoula, H.; Abdelkefi, A.

    2015-11-01

    The design and analysis of innovative ultra-wide bandwidth piezoelectric energy harvesters are deeply investigated. An electrical inductance is considered in the harvester's circuit to be connected in series or parallel to a load resistance. A lumped-parameter model is used to model the electromechanical response of the harvester when subjected to harmonic excitations. A linear comprehensive analysis is performed to investigate the effects of an electrical inductance on the coupled frequencies and damping of the harvester. It is shown that including an electrical inductance connected in series or in parallel to an electrical load resistance can result in the appearance of a second coupled frequency of electrical type. The results show that the inclusion of an inductance may give the opportunity to tune one of the coupled frequencies of mechanical and electrical types to the available excitation frequency in the environment. Using the gradient method, an optimization analysis is then performed to determine the optimum values of the electrical inductance and load resistance that maximize the harvested power. It is demonstrated that, for each excitation frequency, there is a combination of optimum values of the electrical inductance and resistance in such a way an optimum constant value of the harvested power is found. Numerical analysis is then performed to show the importance of considering an additional inductance in the harvester's circuitry in order to design broadband energy harvesters. The results show that the presence of the second coupled frequency of electrical type due to the inductance gives the possibility to design optimal broadband inductive-resistive piezoelectric energy harvesters with minimum displacement due to shunt damping effect.

  4. G protein-coupled receptors: signalling and regulation by lipid agonists for improved glucose homoeostasis.

    PubMed

    Moran, Brian M; Flatt, Peter R; McKillop, Aine M

    2016-04-01

    G protein-coupled receptors (GPCRs) play a pivotal role in cell signalling, controlling many processes such as immunity, growth, cellular differentiation, neurological pathways and hormone secretions. Fatty acid agonists are increasingly recognised as having a key role in the regulation of glucose homoeostasis via stimulation of islet and gastrointestinal GPCRs. Downstream cell signalling results in modulation of the biosynthesis, secretion, proliferation and anti-apoptotic pathways of islet and enteroendocrine cells. GPR40 and GPR120 are activated by long-chain fatty acids (>C12) with both receptors coupling to the Gαq subunit that activates the Ca(2+)-dependent pathway. GPR41 and GPR43 are stimulated by short-chain fatty acids (C2-C5), and activation results in binding to Gαi that inhibits the adenylyl cyclase pathway attenuating cAMP production. In addition, GPR43 also couples to the Gαq subunit augmenting intracellular Ca(2+) and activating phospholipase C. GPR55 is specific for cannabinoid endogenous agonists (endocannabinoids) and non-cannabinoid fatty acids, which couples to Gα12/13 and Gαq proteins, leading to enhancing intracellular Ca(2+), extracellular signal-regulated kinase 1/2 (ERK) phosphorylation and Rho kinase. GPR119 is activated by fatty acid ethanolamides and binds to Gαs utilising the adenylate cyclase pathway, which is dependent upon protein kinase A. Current research indicates that GPCR therapies may be approved for clinical use in the near future. This review focuses on the recent advances in preclinical diabetes research in the signalling and regulation of GPCRs on islet and enteroendocrine cells involved in glucose homoeostasis.

  5. Studies on the coupling transformer to improve the performance of microwave ion source

    NASA Astrophysics Data System (ADS)

    Misra, Anuraag; Pandit, V. S.

    2014-06-01

    A 2.45 GHz microwave ion source has been developed and installed at the Variable Energy Cyclotron Centre to produce high intensity proton beam. It is operational and has already produced more than 12 mA of proton beam with just 350 W of microwave power. In order to optimize the coupling of microwave power to the plasma, a maximally flat matching transformer has been used. In this paper, we first describe an analytical method to design the matching transformer and then present the results of rigorous simulation performed using ANSYS HFSS code to understand the effect of different parameters on the transformed impedance and reflection and transmission coefficients. Based on the simulation results, we have chosen two different coupling transformers which are double ridged waveguides with ridge widths of 24 mm and 48 mm. We have fabricated these transformers and performed experiments to study the influence of these transformers on the coupling of microwave to plasma and extracted beam current from the ion source.

  6. Studies on the coupling transformer to improve the performance of microwave ion source

    SciTech Connect

    Misra, Anuraag E-mail: vspandit12@gmail.com Pandit, V. S. E-mail: vspandit12@gmail.com

    2014-06-15

    A 2.45 GHz microwave ion source has been developed and installed at the Variable Energy Cyclotron Centre to produce high intensity proton beam. It is operational and has already produced more than 12 mA of proton beam with just 350 W of microwave power. In order to optimize the coupling of microwave power to the plasma, a maximally flat matching transformer has been used. In this paper, we first describe an analytical method to design the matching transformer and then present the results of rigorous simulation performed using ANSYS HFSS code to understand the effect of different parameters on the transformed impedance and reflection and transmission coefficients. Based on the simulation results, we have chosen two different coupling transformers which are double ridged waveguides with ridge widths of 24 mm and 48 mm. We have fabricated these transformers and performed experiments to study the influence of these transformers on the coupling of microwave to plasma and extracted beam current from the ion source.

  7. Improved Diabatic Model for Vibronic Coupling in the Ground Electronic State of NO_3

    NASA Astrophysics Data System (ADS)

    Stanton, J. F.

    2011-06-01

    While model Hamiltonian approaches have provided considerable qualitative understanding regarding the nature of vibronic coupling and, especially, its effect on the electronic spectra of the nitrate radical, the parametrizations heretofore applied have been rather simplistic. As a result, while patterns of energy levels and appearance of ``forbidden" spectral features are satisfactorily reproduced, the absolute position of the levels has not been calculated accurately enough to allow meaningful comparisons with those based on experimental assignments. In recent years, the machinery has been developed and applied to rather routinely make quite accurate calculations of level positions in strongly coupled systems (to, say, 20 Cm-1 per quantum of excitation). Such calculations, which have been carried out for systems such as BNB, the formyloxyl radical (HCO_2) and low-lying excited electronic states of propadienylidene (H_2C=C=C:), have now been completed for NO_3. The spectra obtained from the corresponding model Hamiltonian, which explicitly treat the coupling between the ground {tilde X}^2A_2' and {tilde B}^2E' electronic states, and use a fairly elaborate parametrization of the corresponding diabatic surfaces, are presented and discussed.

  8. Processing radio PSAs: production pacing, arousing content, and age.

    PubMed

    Lang, Annie; Schwartz, Nancy; Lee, Seungjo; Angelini, James

    2007-09-01

    This experiment uses the limited capacity model of mediated message processing (LC3MP) to investigate the effects of production pacing and arousing content in radio public service announcements (PSAs) on the emotional and cognitive responses of college-age and tween (9-12-year-olds) participants. The LC3MP predicts that both arousing content and production pacing should increase emotional arousal, physiological arousal, cognitive effort, and encoding up to the point of cognitive overload after which cognitive effort and encoding should decrease. Results showed that, as expected, arousing content did increase emotional arousal and cognitive effort for both tweens and college students, though the effect was larger for college students. For production pacing, however, the results were less clear cut. First, it was found that for radio PSAs pacing increased arousal for calm messages only. Further, the effects of production pacing on cognitive effort were larger for tweens and were experienced primarily during the first 25 seconds of the message, while college students were less affected by production pacing, and those effects appeared in the last 25 seconds of the messages. Finally, none of the messages in this experiment resulted in cognitive overload - thus both production pacing and arousing content increased memory for both groups of participants.

  9. 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...

  10. 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...

  11. 42 CFR 460.24 - Limit on number of PACE program agreements.

    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 Organization Application and Waiver Process § 460.24 Limit on number...

  12. 42 CFR 460.24 - Limit on number of PACE program agreements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... SERVICES (CONTINUED) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) PACE Organization Application and Waiver Process § 460.24 Limit on number...

  13. 42 CFR 460.24 - Limit on number of PACE program agreements.

    Code of Federal Regulations, 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. An improvement in mass flux convective parameterizations and its impact on seasonal simulations using a coupled model

    NASA Astrophysics Data System (ADS)

    Elsayed Yousef, Ahmed; Ehsan, M. Azhar; Almazroui, Mansour; Assiri, Mazen E.; Al-Khalaf, Abdulrahman K.

    2015-11-01

    A new closure and a modified detrainment for the simplified Arakawa-Schubert (SAS) cumulus parameterization scheme are proposed. In the modified convective scheme which is named as King Abdulaziz University (KAU) scheme, the closure depends on both the buoyancy force and the environment mean relative humidity. A lateral entrainment rate varying with environment relative humidity is proposed and tends to suppress convection in a dry atmosphere. The detrainment rate also varies with environment relative humidity. The KAU scheme has been tested in a single column model (SCM) and implemented in a coupled global climate model (CGCM). Increased coupling between environment and clouds in the KAU scheme results in improved sensitivity of the depth and strength of convection to environmental humidity compared to the original SAS scheme. The new scheme improves precipitation simulation with better representations of moisture and temperature especially during suppressed convection periods. The KAU scheme implemented in the Seoul National University (SNU) CGCM shows improved precipitation over the tropics. The simulated precipitation pattern over the Arabian Peninsula and Northeast African region is also improved.

  15. 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.

  16. An improved three-dimensional coupled fluid structure model for Coriolis flowmeters

    NASA Astrophysics Data System (ADS)

    Mole, N.; Bobovnik, G.; Kutin, J.; Štok, B.; Bajsić, I.

    2008-05-01

    The paper presents a coupled numerical model built to simulate the operation of Coriolis flowmeters, which exploit the alteration of the vibration mode shape of the measuring tube for the mass flow rate measurement. The explained measuring effect is a consequence of the interaction between the motion of the tube, vibrating at its natural frequency, and the fluid flow in it. The numerical model is realized by coupling of a finite volume (FV) code for fluid flow analysis with a finite element (FE) code for structural analysis using the conventional staggered solution procedure, with added inner iterations to achieve strong coupling. The simulation algorithm is divided into two steps. A free vibration of the measuring tube considered in the first step is complemented in the second step, after the numerical free vibration response is properly stabilized, with the harmonic excitation force actuating the measuring tube at its resonant frequency of several hundreds of Hertz to resemble the operation of actual Coriolis flowmeters. Different scenarios using zero-order or three-point fluid load predictor and soft application of the fluid load in the initial stages of the simulation are compared to yield a simulation strategy, which will minimize the time needed to obtain the stabilized steady-state response of the vibrating measuring tube. The proposed simulation procedure was applied on a straight-tube Coriolis flowmeter and used for the estimation of the velocity profile effect. The results exhibit sufficient stability (low scatter) to be used for the estimation of sensitivity variations of order of magnitude around tenths of a percent.

  17. 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

  18. Work-family enrichment among dual-earner couples: can work improve our family life?

    PubMed

    Dunn, Marianne G; O'Brien, Karen M

    2013-10-01

    The extent to which resources generated at work and positive affect were associated with enrichment in the family domain among 107 dual-earner couples was investigated. Grounded in work-family enrichment theory (Greenhaus & Powell, 2006), this study examined the indirect effect of workplace organizational support on family satisfaction through positive affect at work. Organizational support for work-family management was associated with positive affect at work for both women and men, and positive affect at work was related to family satisfaction for women. One interpersonal effect emerged: women's positive affect at work was associated with family satisfaction for men. Implications for theory, practice, research, and workplace policy are discussed.

  19. Using Magnetic Coupling to Improve the (1)H/(2)H Double Tuned Circuit.

    PubMed

    Taber, Bob; Zens, Albert

    2015-10-01

    We report in this paper an analysis of double-tuned (1)H/(2)H circuits that are capacitively or inductively matched to 50 Ω ports. In this analysis we use a novel new parameter called the circuit fill factor (CFF). It provides a means of characterizing the performance degradation associated with additional inductors in the circuit in addition to circuit losses. This parameter allows for quick and insightful analysis of multiple tuned circuits for efficiency. It is also shown that magnetically coupled double-tuned circuits are less prone to unwanted spurious resonances due to their general symmetry which eliminates multiple ground paths in the circuit.

  20. Coupling of drug containing liposomes to microbubbles improves ultrasound triggered drug delivery in mice.

    PubMed

    Cool, Steven K; Geers, Bart; Roels, Stefan; Stremersch, Stephan; Vanderperren, Katrien; Saunders, Jimmy H; De Smedt, Stefaan C; Demeester, Joseph; Sanders, Niek N

    2013-12-28

    Local extravasation and triggered drug delivery by use of ultrasound and microbubbles is a promising strategy to target drugs to their sites of action. In the past we have developed drug loaded microbubbles by coupling drug containing liposomes to the surface of microbubbles. Until now the advantages of this drug loading strategy have only been demonstrated in vitro. Therefore, in this paper, microbubbles with indocyanine green (ICG) containing liposomes at their surface or a mixture of ICG-liposomes and microbubbles was injected intravenously in mice. Immediately after injection the left hind leg was exposed to 1 MHz ultrasound and the ICG deposition was monitored 1, 4 and 7 days post-treatment by in vivo fluorescence imaging. In mice that received the ICG-liposome loaded microbubbles the local ICG deposition was, at each time point, about 2-fold higher than in mice that received ICG-liposomes mixed with microbubbles. We also showed that the perforations in the blood vessels allow the passage of ICG-liposomes up to 5h after microbubble and ultrasound treatment. An increase in tissue temperature to 41°C was observed in all ultrasound treated mice. However, ultrasound tissue heating was excluded to cause the local ICG deposition. We concluded that coupling of drug containing liposomes to microbubbles may increase ultrasound mediated drug delivery in vivo.

  1. The PACES Summer Science Trek: A Pre-College Science

    NASA Technical Reports Server (NTRS)

    Smith, Michelle B.

    1997-01-01

    The University of Texas at El Paso (UTEP) received five-year funding to form the Pan American Center for Earth and Environmental Studies (PACES) in July 1995. PACES has as its goals to conduct research contributing to NASA's Mission to Planet Earth and to develop skilled scientists and engineers. PACES seeks to gain a more comprehensive understanding of geological, ecological and environmental processes and changes taking place in the southwestern United States and northern Mexico region. The PACES center has collaborative ties with two NASA field center (Goddard Space Flight Center and Ames Research Center) and the Jet Propulsion Laboratory. The original proposal contained no provision for outreach programs. However, at a meeting in the fall of 1995, Dan Goldin, NASA Administrator, issued the challenge that in order to accomplish NASA's goals to educate more of the citizenry in science and engineering, the Centers should take a broader perspective aimed at younger children.

  2. 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.

  3. Testing cloud microphysics parameterizations in NCAR CAM5 with ISDAC and M-PACE observations

    SciTech Connect

    Liu X.; Lin W.; Xie, S.; Boyle, J.; Klein, S. A.; Shi, X.; Wang, Z.; Ghan, S. J.; Earle, M.; Liu, P. S. K.; Zelenyuk, A.

    2011-12-24

    Arctic clouds simulated by the National Center for Atmospheric Research (NCAR) Community Atmospheric Model version 5 (CAM5) are evaluated with observations from the U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Indirect and Semi-Direct Aerosol Campaign (ISDAC) and Mixed-Phase Arctic Cloud Experiment (M-PACE), which were conducted at its North Slope of Alaska site in April 2008 and October 2004, respectively. Model forecasts for the Arctic spring and fall seasons performed under the Cloud-Associated Parameterizations Testbed framework generally reproduce the spatial distributions of cloud fraction for single-layer boundary-layer mixed-phase stratocumulus and multilayer or deep frontal clouds. However, for low-level stratocumulus, the model significantly underestimates the observed cloud liquid water content in both seasons. As a result, CAM5 significantly underestimates the surface downward longwave radiative fluxes by 20-40 W m{sup -2}. Introducing a new ice nucleation parameterization slightly improves the model performance for low-level mixed-phase clouds by increasing cloud liquid water content through the reduction of the conversion rate from cloud liquid to ice by the Wegener-Bergeron-Findeisen process. The CAM5 single-column model testing shows that changing the instantaneous freezing temperature of rain to form snow from -5 C to -40 C causes a large increase in modeled cloud liquid water content through the slowing down of cloud liquid and rain-related processes (e.g., autoconversion of cloud liquid to rain). The underestimation of aerosol concentrations in CAM5 in the Arctic also plays an important role in the low bias of cloud liquid water in the single-layer mixed-phase clouds. In addition, numerical issues related to the coupling of model physics and time stepping in CAM5 are responsible for the model biases and will be explored in future studies.

  4. Inductively Coupling Plasma (ICP) Treatment of Propylene (PP) Surface and Adhesion Improvement

    NASA Astrophysics Data System (ADS)

    Liu, Yenchun; Fu, Yenpei

    2009-12-01

    Study on increasing the roughness of the polymer substrate surface to enhance the adhesion with the copper layer in an inductively coupling plasma (ICP) process was carried out. The microstructure of the polymer substrate surfaces, which were exposed to different kinds of plasma treatment, was identified by scanning electron microscopy(SEM) analysis, peel strength of the copper coating and water surface contact angle. The adhesion of the substrate was largely enhanced by plasma treatment and the copper deposited coating reached a value of 7.68 kgf/m in verifying the adhesion of the copper coating with polymer material. The quality of the line/space 50/50 μm produced in the laboratory was examined by the pressure cooker test and proved to meet the requirement.

  5. 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…

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

    PubMed Central

    Peckel, Mathieu; Pozzo, Thierry; Bigand, Emmanuel

    2014-01-01

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

  7. Improvements for operational baseband tune and coupling measurements and feedback at RHIC

    SciTech Connect

    Wilinski, M.; Dawson, C.; Degen, C.; Marusic, A.; Mernick, K.; Minty, M.; Russo, T.

    2010-05-02

    Throughout RHIC Run-9 (polarized protons) and Run-10 (gold), numerous modifications to the Baseband Tune (BBQ) system were made. Hardware and software improvements resulted in improved resolution and control, allowing the system to overcome challenges from competing 60Hz mains harmonics, other spectral content, and other beam issues. Test points from the Analog Front End (AFE) were added and connected to diagnostics that allow us to view signals, such as frequency spectra on a Sr785 dynamic signal analyser (DSA), in real time. Also, additional data can now be logged using a National Instruments DAQ (NI-DAQ). Development time using tune feedback to obtain full-energy beams at RHIC has been significantly reduced from many ramps over a few weeks, to just a few ramps over several hours. For many years BBQ was an expert-only system, but the many improvements allowed BBQ to finally be handed over to the Operations Staff for routine control.

  8. 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.

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

    PubMed

    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

  10. 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

  11. 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.

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

    PubMed Central

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

    2015-01-01

    Background: The peaking period for endurance competition is characterized for a relative increase of the intensity of training, after a longer period of training relatively dominated by lower intensity and higher volume Objectives: The present study was designed to compare physiological and 10 km performance effects of high intensity training (HIT) versus race pace interval training (RP) during peaking for competition in well-trained runners. Patients and Methods: 13 athletes took part in the study, they were divided into two groups: HIT and RP. HIT performed short intervals at ~105% of the maximal aerobic velocity (MAV), while RP trained longer intervals at a speed of ~90% of the MAV (a speed approximating 10 km race pace). After 12 weeks of baseline training, the athletes trained for 6 weeks under one of the two peaking regimes. Subjects performed 10 km prior to and after the intervention period. The total load of training was matched between groups during the treatment phase. Subjects completed a graded treadmill running test until volitional exhaustion prior to each 10 km race. MAV was determined as the minimal velocity eliciting maximal oxygen consumption (VO2max). Results: Both groups significantly improved their 10 km time (35 minutes 29 seconds ± 1 minutes 41 seconds vs 34 minutes 53 seconds ± 1 minutes 55 seconds, P < 0.01 for HIT; 35 minutes 27 seconds ± 1 minutes 40 seconds vs 34 minutes 53 seconds ± 1 minutes 18 seconds P < 0.01 for RP). VO2max increased after HIT (69 ± 3.6 vs 71.5 ± 4.2 ml.Kg-1.min-1, P < 0.05); while it didn’t for RP (68.4 ± 6 vs 69.8 ± 3 ml.Kg-1.min-1, p>0.05). In contrast, running economy decreased significantly after HIT (210 ± 6 ml.Kg-1.km-1 vs 218 ± 9, P < 0.05). Conclusions: A 6 week period of training at either 105% of MAV or 90% of MAV yielded similar performance gains in a 10km race performed at ~90% MAV. Therefore, the physiological impact of HIT training seems to be positive for VO2max but negative for running

  13. Improvement in magnetic field immunity of externally-coupled transcutaneous energy transmission system for a totally implantable artificial heart.

    PubMed

    Yamamoto, Takahiko; Koshiji, Kohji; Homma, Akihiko; Tatsumi, Eisuke; Taenaka, Yoshiyuki

    2008-01-01

    Transcutaneous energy transmission (TET) that uses electromagnetic induction between the external and internal coils of a transformer is the most promising method to supply driving energy to a totally implantable artificial heart without invasion. Induction-heating (IH) cookers generate magnetic flux, and if a cooker is operated near a transcutaneous transformer, the magnetic flux generated will link with the external and internal coils of the transcutaneous transformer. This will affect the performance of the TET and the artificial heart system. Hence, it is necessary to improve the magnetic field immunity of the TET system. During operation of the system, if the transcutaneous transformer is in close proximity to an IH cooker, the electric power generated by the cooker and coupled to the transformer can drive the artificial heart system. To prevent this coupling, the external coil was shielded with a conductive shield that had a slit in it. This reduces the coupling between the transformer and the magnetic field generated by the induction cooker. However, the temperature of the shield increased due to heating by eddy currents. The temperature of the shield can be reduced by separating the IH cooker and the shield.

  14. Coupling Protein Side-Chain and Backbone Flexibility Improves the Re-design of Protein-Ligand Specificity

    PubMed Central

    Ollikainen, Noah; de Jong, René M.; Kortemme, Tanja

    2015-01-01

    Interactions between small molecules and proteins play critical roles in regulating and facilitating diverse biological functions, yet our ability to accurately re-engineer the specificity of these interactions using computational approaches has been limited. One main difficulty, in addition to inaccuracies in energy functions, is the exquisite sensitivity of protein–ligand interactions to subtle conformational changes, coupled with the computational problem of sampling the large conformational search space of degrees of freedom of ligands, amino acid side chains, and the protein backbone. Here, we describe two benchmarks for evaluating the accuracy of computational approaches for re-engineering protein-ligand interactions: (i) prediction of enzyme specificity altering mutations and (ii) prediction of sequence tolerance in ligand binding sites. After finding that current state-of-the-art “fixed backbone” design methods perform poorly on these tests, we develop a new “coupled moves” design method in the program Rosetta that couples changes to protein sequence with alterations in both protein side-chain and protein backbone conformations, and allows for changes in ligand rigid-body and torsion degrees of freedom. We show significantly increased accuracy in both predicting ligand specificity altering mutations and binding site sequences. These methodological improvements should be useful for many applications of protein – ligand design. The approach also provides insights into the role of subtle conformational adjustments that enable functional changes not only in engineering applications but also in natural protein evolution. PMID:26397464

  15. Coupling the Biophysical and Social Dimensions of Wildfire Risk to Improve Wildfire Mitigation Planning.

    PubMed

    Ager, Alan A; Kline, Jeffrey D; Fischer, A Paige

    2015-08-01

    We describe recent advances in biophysical and social aspects of risk and their potential combined contribution to improve mitigation planning on fire-prone landscapes. The methods and tools provide an improved method for defining the spatial extent of wildfire risk to communities compared to current planning processes. They also propose an expanded role for social science to improve understanding of community-wide risk perceptions and to predict property owners' capacities and willingness to mitigate risk by treating hazardous fuels and reducing the susceptibility of dwellings. In particular, we identify spatial scale mismatches in wildfire mitigation planning and their potential adverse impact on risk mitigation goals. Studies in other fire-prone regions suggest that these scale mismatches are widespread and contribute to continued wildfire dwelling losses. We discuss how risk perceptions and behavior contribute to scale mismatches and how they can be minimized through integrated analyses of landscape wildfire transmission and social factors that describe the potential for collaboration among landowners and land management agencies. These concepts are then used to outline an integrated socioecological planning framework to identify optimal strategies for local community risk mitigation and improve landscape-scale prioritization of fuel management investments by government entities.

  16. Testing a four-dimensional variational data assimilation method using an improved intermediate coupled model for ENSO analysis and prediction

    NASA Astrophysics Data System (ADS)

    Gao, Chuan; Wu, Xinrong; Zhang, Rong-Hua

    2016-07-01

    A four-dimensional variational (4D-Var) data assimilation method is implemented in an improved intermediate coupled model (ICM) of the tropical Pacific. A twin experiment is designed to evaluate the impact of the 4D-Var data assimilation algorithm on ENSO analysis and prediction based on the ICM. The model error is assumed to arise only from the parameter uncertainty. The "observation" of the SST anomaly, which is sampled from a "truth" model simulation that takes default parameter values and has Gaussian noise added, is directly assimilated into the assimilation model with its parameters set erroneously. Results show that 4D-Var effectively reduces the error of ENSO analysis and therefore improves the prediction skill of ENSO events compared with the non-assimilation case. These results provide a promising way for the ICM to achieve better real-time ENSO prediction.

  17. Aluminum nanoparticles for plasmon-improved coupling of light into silicon.

    PubMed

    Villesen, T F; Uhrenfeldt, Christian; Johansen, B; Hansen, J Lundsgaard; Ulriksen, H U; Larsen, Arne Nylandsted

    2012-03-01

    This paper investigates the improved photo-current response obtained by depositing Al nanoparticles on top of a Si diode. Well defined Al nanodiscs with a diameter and height of 100 nm are produced on the surface of a Si diode using electron-beam lithography, and the change in photo-current generation is characterized. A blue shift of the photo-current response is demonstrated, substantially improving the relation between gains and losses compared to what is typically observed in similar schemes using Ag nanoparticles. Enhanced photo-current response is observed in diodes with Al particles on the surface at all wavelengths larger than ≈465 nm, thereby minimizing the losses in the blue range usually reported with Ag nanoparticles on the surface. PMID:22293458

  18. Improved photoelectric conversion efficiency from titanium oxide-coupled tin oxide nanoparticles formed in flame

    NASA Astrophysics Data System (ADS)

    Gu, Feng; Huang, Wenjuan; Wang, Shufen; Cheng, Xing; Hu, Yanjie; Li, Chunzhong

    2014-12-01

    The charge losses as a result of recombination to redox electrolyte and dye cation make tin oxide (SnO2)-based dye-sensitized solar cells (DSSCs) particularly inferior when compared with its titanium oxide (TiO2) counterpart. In this article, TiO2 nanocrystal is sealed in SnO2 by a modified flame spray pyrolysis (FSP) approach and the recombination losses to dye cation of SnO2 photoanode are effectively suppressed due to the negatively shifted Fermi level with the formation of bandedge-engineered core/shell structure. The fabricated TiO2@SnO2 (TSN)-device shows an open circuit voltage of 0.59 V and an efficiency of 3.82%, significantly better than those of the TiO2-, and SnO2-DSSCs devices. After surface modification, the conversion efficiency could be further improved to 7.87% while the open circuit voltage reaches 0.70 V. The higher efficiency of the TSN-based device is attributed to the enhanced electron injection arising from decreased interfacial charge recombination losses and improved electron transport. This strategy renders a new concept for further improvement of photovoltaic performance by engineering the dynamics of electron transport and recombination in DSSCs.

  19. Improved Dyson series expansion for steady-state quantum transport beyond the weak coupling limit: Divergences and resolution

    SciTech Connect

    Thingna, Juzar; Zhou, Hangbo; Wang, Jian-Sheng

    2014-11-21

    We present a general theory to calculate the steady-state heat and electronic currents for nonlinear systems using a perturbative expansion in the system-bath coupling. We explicitly demonstrate that using the truncated Dyson-series leads to divergences in the steady-state limit, thus making it impossible to be used for actual applications. In order to resolve the divergences, we propose a unique choice of initial condition for the reduced density matrix, which removes the divergences at each order. Our approach not only allows us to use the truncated Dyson-series, with a reasonable choice of initial condition, but also gives the expected result that the steady-state solutions should be independent of initial preparations. Using our improved Dyson series we evaluate the heat and electronic currents up to fourth-order in system-bath coupling, a considerable improvement over the standard quantum master equation techniques. We then numerically corroborate our theory for archetypal settings of linear systems using the exact nonequilibrium Green's function approach. Finally, to demonstrate the advantage of our approach, we deal with the nonlinear spin-boson model to evaluate heat current up to fourth-order and find signatures of cotunnelling process.

  20. Improved Dyson series expansion for steady-state quantum transport beyond the weak coupling limit: divergences and resolution.

    PubMed

    Thingna, Juzar; Zhou, Hangbo; Wang, Jian-Sheng

    2014-11-21

    We present a general theory to calculate the steady-state heat and electronic currents for nonlinear systems using a perturbative expansion in the system-bath coupling. We explicitly demonstrate that using the truncated Dyson-series leads to divergences in the steady-state limit, thus making it impossible to be used for actual applications. In order to resolve the divergences, we propose a unique choice of initial condition for the reduced density matrix, which removes the divergences at each order. Our approach not only allows us to use the truncated Dyson-series, with a reasonable choice of initial condition, but also gives the expected result that the steady-state solutions should be independent of initial preparations. Using our improved Dyson series we evaluate the heat and electronic currents up to fourth-order in system-bath coupling, a considerable improvement over the standard quantum master equation techniques. We then numerically corroborate our theory for archetypal settings of linear systems using the exact nonequilibrium Green's function approach. Finally, to demonstrate the advantage of our approach, we deal with the nonlinear spin-boson model to evaluate heat current up to fourth-order and find signatures of cotunnelling process. PMID:25416868

  1. 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

  2. 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. PMID:27167064

  3. Using a Coupled Lake Model with WRF to Improve High-Resolution Regional Climate Simulations

    NASA Astrophysics Data System (ADS)

    Mallard, M.; Bullock, R.; Nolte, C. G.; Alapaty, K.; Otte, T.; Gula, J.

    2012-12-01

    Lakes can play a significant role in regional climate by modifying air masses through fluxes of heat and moisture and by modulating inland extremes in temperature. Representing these effects becomes more important as regional climate modeling efforts employ finer grid spacing in order to simulate smaller scales. The Weather Research and Forecasting (WRF) model does not simulate lakes explicitly. Instead, lake points are treated as ocean points, with sea surface temperatures (SSTs) interpolated from the nearest neighboring ocean point in the driving coarse-scale fields. This can result in substantial errors for inland lakes such as the Great Lakes. Although prescribed lake surface temperatures (LSTs) can be used for retrospective modeling applications, this may not be desirable for applications involving downscaling future climate scenarios from a global climate model (GCM). In such downscaling simulations, lakes that impact the regional climate in the area of interest may not be resolved by the coarser global input fields. Explicitly simulating the LST would allow WRF to better represent interannual variability in regions significantly affected by lakes, and the influence of such variability on temperature and precipitation patterns. Therefore, coupling a lake model to WRF may lead to more reliable assessments of the impacts of extreme events on human health and the environment. We employ a version of WRF coupled to the Freshwater Lake model, FLake (Gula and Peltier 2012). FLake is a 1D bulk lake model which provides updated LSTs and ice coverage throughout the integration. This two-layer model uses a temperature-depth profile which includes a homogeneous mixed layer at the surface and a thermocline below. The shape of the thermocline is assumed, based on past theoretical and observational studies. Therefore, additional variables required for FLake to run are minimal, and it does not require tuning for individual lakes. These characteristics are advantageous for a

  4. The planning, implementation and publication of a complex intervention trial for chronic fatigue syndrome: the PACE trial

    PubMed Central

    White, Peter D.; Chalder, Trudie; Sharpe, Michael

    2015-01-01

    The PACE trial was a four-arm trial of specialist medical care, compared with specialist medical care with a supplementary therapy: adaptive pacing therapy, cognitive–behavioural therapy or graded exercise therapy, for patients with chronic fatigue syndrome. The trial found that both cognitive–behavioural and graded exercise therapies were more effective than either of the other two treatments in reducing fatigue and improving physical disability. This paper describes the design, conduct and main results of the trial, along with a description of the challenges that had to be overcome in order to produce clear answers to the clinically important questions the trial posed. PMID:26191420

  5. Comparison of ventilation and voice outcomes between unilateral laryngeal pacing and unilateral cordotomy for the treatment of bilateral vocal fold paralysis

    PubMed Central

    Li, Yike; Pearce, Elizabeth C.; Mainthia, Rajshri; Athavale, Sanjay M.; Dang, Jennifer; Ashmead, Daniel H; Garrett, C. Gaelyn; Rousseau, Bernard; Billante, Cheryl R.; Zealear, David L.

    2013-01-01

    Background/Aims Rehabilitation of the bilaterally paralyzed human larynx remains a complex clinical problem. Conventional treatment generally involves surgical enlargement of the compromised airway, but often with resultant dysphonia and risk of aspiration. In this retrospective study, we compared one such treatment, posterior cordotomy, against unilateral laryngeal pacing: reanimation of vocal fold opening by functional electrical stimulation of the posterior cricoarytenoid muscle. Methods Post-operative peak inspiratory flow (PIF) values and overall voice grade ratings were compared between the two surgical groups, and pre and post-operative PIF were compared within the pacing group. Results There were five patients in the unilateral pacing group and 12 patients in the unilateral cordotomy group. Within the pacing group, post-operative PIF values were significantly improved from pre-operative PIF values (p=0.04) without significant effect on voice (grade) (p=0.62). Within the pacing group, the mean post-operative PIF value was significantly higher than that in the cordotomy group (p=0.05). Also, the mean post-operative overall voice grade values in the pacing group were significantly lower (better) than that of cordotomy group (p=0.03). Conclusion Unilateral pacing appears to be an effective and superior treatment to posterior cordotomy with respect to post-operative ventilation and voice outcome measures. PMID:23736349

  6. A self-tuning effect of membership functions in a fuzzy-logic-based cardiac pacing system.

    PubMed

    Sugiura, T; Sugiura, N; Kazui, T; Harada, Y

    1998-01-01

    This paper describes a self-tuning method of membership functions in a fuzzy-logic-based cardiac pacing system and validates its feasibility in a double sensor system which has minute ventilation and oxygen saturation level as its guides for the rate regulation. Though the agreement between the pacing rates (fuzzy rates) calculated with three linguistic variables for each parameter and the target rates were not satisfactory, it was improved significantly by tuning the membership functions. Almost the same evaluated values with those obtained by using six linguistic variables for each parameter were obtained. Time required for the self-tuning process was about 40 s (386CPU, 20 MHz) which was fast enough for the system. The smaller number of linguistic labels results in a smaller number of rules, which is beneficial in implantable cardiac pacemakers with limited memory capacity. A fuzzy-logic-based cardiac pacing system is promising for the realization of custom-made cardiac pacemakers.

  7. A Multiscale Tridomain Model for Simulating Bioelectric Gastric Pacing

    PubMed Central

    Sathar, Shameer; Trew, Mark L.; O’Grady, Greg

    2015-01-01

    Goal Gastric motility disorders have been associated with abnormal slow wave electrical activity (‘gastric dysrhythmias’). Gastric pacing is a potential therapy for gastric dysrhythmias, however, new pacing protocols are required that can effectively modulate motility patterns, while being power efficient. This study presents a novel comprehensive 3D multi-scale modeling framework of the human stomach, including anisotropic conduction, capable of evaluating pacing strategies. Methods A high resolution anatomically realistic mesh was generated from CT images taken from a human stomach. Principal conduction axes were calculated and embedded within this model based on a modified Laplace-Dirichlet rule based algorithm. A continuum based tridomain formulation was implemented and evaluated for performance, and used to model the slow wave propagation, which takes into account the two main cell types present in gastric musculature. Model parameters were found by matching predicted normal slow-wave activity to experimental observation and data. These simulation parameters were applied while modeling an external pacing event to entrain slow wave patterns. Results The proposed formulation was found to be 2 times more efficient than a previous formulation for a normal slow wave simulation. Convergence analysis showed that a mesh resolution of ≈ 0.4 –0.5mm is required for an accurate solution process. Conclusion The effect of different pacing frequencies on entrainment demonstrated that the pacing protocols are limited by the frequency of the native propagation and the refractory period of the cellular activity. Significance The model is expected to become an important tool in studying pacing protocols for both efficiency and effectiveness. PMID:26080372

  8. Digestion of high rate activated sludge coupled to biochar formation for soil improvement in the tropics.

    PubMed

    Nansubuga, Irene; Banadda, Noble; Ronsse, Frederik; Verstraete, Willy; Rabaey, Korneel

    2015-09-15

    High rate activated sludge (HRAS) is well-biodegradable sludge enabling energy neutrality of wastewater treatment plants via anaerobic digestion. However, even through successful digestion a notable residue still remains. Here we investigated whether this residue can be converted to biochar, for its use as a fertilizer or as a solid fuel, and assessed its characteristics and overall process efficiency. In a first phase, HRAS was anaerobicaly digested under mesophilic conditions at a sludge retention time of 20 days. HRAS digested well (57.9 ± 6.2% VS degradation) producing on average 0.23 ± 0.04 L CH4 per gram VS fed. The digestate particulates were partially air-dried to mimic conditions used in developing countries, and subsequently converted to biochar by fixed-bed slow pyrolysis at a residence time of 15 min and at highest heating temperatures (HHT) of 300 °C, 400 °C and 600 °C. Subsequently, the produced chars were characterized by proximate analysis, CHN-elemental analysis, pH in solution and bomb calorimetry for higher heating value. The yield and volatile matter decreased with increasing HHT while ash content and fixed carbon increased with increasing HHT. The produced biochar showed properties optimal towards soil amendment when produced at a temperature of 600 °C with values of 5.91 wt%, 23.75 wt%, 70.35% on dry basis (db) and 0.44 for volatile matter, fixed carbon, ash content and H/C ratio, respectively. With regard to its use for energy purposes, the biochar represented a lower calorific value than the dried HRAS digestate likely due to high ash content. Based on these findings, it can be concluded that anaerobic digestion of HRAS and its subsequent biochar formation at HHT of 600 °C represents an attractive route for sludge management in tropic settings like in Uganda, coupling carbon capture to energy generation, carbon sequestration and nutrient recovery. PMID:26072019

  9. Digestion of high rate activated sludge coupled to biochar formation for soil improvement in the tropics.

    PubMed

    Nansubuga, Irene; Banadda, Noble; Ronsse, Frederik; Verstraete, Willy; Rabaey, Korneel

    2015-09-15

    High rate activated sludge (HRAS) is well-biodegradable sludge enabling energy neutrality of wastewater treatment plants via anaerobic digestion. However, even through successful digestion a notable residue still remains. Here we investigated whether this residue can be converted to biochar, for its use as a fertilizer or as a solid fuel, and assessed its characteristics and overall process efficiency. In a first phase, HRAS was anaerobicaly digested under mesophilic conditions at a sludge retention time of 20 days. HRAS digested well (57.9 ± 6.2% VS degradation) producing on average 0.23 ± 0.04 L CH4 per gram VS fed. The digestate particulates were partially air-dried to mimic conditions used in developing countries, and subsequently converted to biochar by fixed-bed slow pyrolysis at a residence time of 15 min and at highest heating temperatures (HHT) of 300 °C, 400 °C and 600 °C. Subsequently, the produced chars were characterized by proximate analysis, CHN-elemental analysis, pH in solution and bomb calorimetry for higher heating value. The yield and volatile matter decreased with increasing HHT while ash content and fixed carbon increased with increasing HHT. The produced biochar showed properties optimal towards soil amendment when produced at a temperature of 600 °C with values of 5.91 wt%, 23.75 wt%, 70.35% on dry basis (db) and 0.44 for volatile matter, fixed carbon, ash content and H/C ratio, respectively. With regard to its use for energy purposes, the biochar represented a lower calorific value than the dried HRAS digestate likely due to high ash content. Based on these findings, it can be concluded that anaerobic digestion of HRAS and its subsequent biochar formation at HHT of 600 °C represents an attractive route for sludge management in tropic settings like in Uganda, coupling carbon capture to energy generation, carbon sequestration and nutrient recovery.

  10. Nanocellulose-based Translucent Diffuser for Optoelectronic Device Applications with Dramatic Improvement of Light Coupling.

    PubMed

    Wu, Wei; Tassi, Nancy G; Zhu, Hongli; Fang, Zhiqiang; Hu, Liangbing

    2015-12-01

    Nanocellulose is a biogenerated and biorenewable organic material. Using a process based on 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO)/NaClO/NaBr system, a highly translucent and light-diffusive film consisting of many layers of nanocellulose fibers and wood pulp microfibers was made. The film demonstrates a combination of large optical transmittance of ∼90% and tunable diffuse transmission of up to ∼78% across the visible and near-infrared spectra. The detailed characterizations of the film indicate the combination of high optical transmittance and haze is due to the film's large packing density and microstructured surface. The superior optical properties make the film a translucent light diffuser and applicable for improving the efficiencies of optoelectronic devices such as thin-film silicon solar cells and organic light-emitting devices. PMID:26572592

  11. Pacing impedance variability in tined steroid eluting leads.

    PubMed

    Danilovic, D; Ohm, O J

    1998-07-01

    The aim of the study was to investigate pacing impedance (PI) behavior in ambulatory patients. Eighteen atrial and 18 ventricular tined steroid eluting leads with 1.2-mm2 and 5.6-mm2 electrodes were implanted in 20 patients. At 9-27 months after implantation PI was measured automatically by means of additional algorithms downloaded via telemetry links into implanted Thera pulse generators. PI was determined based on the voltage drop on the output capacitor during the 5 V-1 ms pacing impulse, at the programmable sampling rates from 1 second to 30 minutes. The study examined in particular: (1) PI trends and variations associated with different breathing patterns, body postures, provocative maneuvers, bike exercise, and during 24 hours; (2) impact of pacing rate and AV-delay on PI; (3) correlation between PI variability and pacing threshold, lead configuration, absolute PI value, age, gender, disease, and cardiac chamber. The most important findings were: (1) large PI variations of up to 450 omega were observed in properly functioning leads, (2) PI variability exhibited a weak negative correlation with pacing thresholds as if electrode positional stability was not a major factor underlying PI variations, (3) unipolar and bipolar PI variations were equivalent to each other (correlation factor = 0.93) implying that PI was mostly dependent on the circumstances around the lead tip.

  12. The formal pace of Sesame Street over 26 years.

    PubMed

    Koolstra, Cees M; van Zanten, Juliette; Lucassen, Nicole; Ishaak, Nazreen

    2004-08-01

    Television producers often use a high rate in the succession of visual and auditory features in their programs to attract the attention of viewers. In this study an attempt was made to measure the formal pace of television programs by scoring the rates of an extensive set of formal visual and auditory characteristics. Sesame Street was chosen as a focal point because this educational program--with its high pace--is very successful in its competition with the majority of commercial programs from which children can choose to watch at home. The analyzed material consisted of 49 Dutch episodes of Sesame Street broadcast between 1977 and 2003. The formal pace characteristics of separate program items from Sesame Street could be reliably established. Factor analysis indicated that clear pace factors were (a) "editing," consisting of a frequent use of different types of shots (total shots, medium shots, and close-ups) combined with a large number of cuts and (b) speech rate. Over a period of 26 years, the pace of editing increased: the mean number of cuts increased from about 4 to 8 per minute. The mean speech rate decreased from 175 to 139 words per minute.

  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. Pacing impedance variability in tined steroid eluting leads.

    PubMed

    Danilovic, D; Ohm, O J

    1998-07-01

    The aim of the study was to investigate pacing impedance (PI) behavior in ambulatory patients. Eighteen atrial and 18 ventricular tined steroid eluting leads with 1.2-mm2 and 5.6-mm2 electrodes were implanted in 20 patients. At 9-27 months after implantation PI was measured automatically by means of additional algorithms downloaded via telemetry links into implanted Thera pulse generators. PI was determined based on the voltage drop on the output capacitor during the 5 V-1 ms pacing impulse, at the programmable sampling rates from 1 second to 30 minutes. The study examined in particular: (1) PI trends and variations associated with different breathing patterns, body postures, provocative maneuvers, bike exercise, and during 24 hours; (2) impact of pacing rate and AV-delay on PI; (3) correlation between PI variability and pacing threshold, lead configuration, absolute PI value, age, gender, disease, and cardiac chamber. The most important findings were: (1) large PI variations of up to 450 omega were observed in properly functioning leads, (2) PI variability exhibited a weak negative correlation with pacing thresholds as if electrode positional stability was not a major factor underlying PI variations, (3) unipolar and bipolar PI variations were equivalent to each other (correlation factor = 0.93) implying that PI was mostly dependent on the circumstances around the lead tip. PMID:9670178

  15. Mutual coupling of hydrologic and hydrodynamic models - a viable approach for improved large-scale inundation estimates?

    NASA Astrophysics Data System (ADS)

    Hoch, Jannis; Winsemius, Hessel; van Beek, Ludovicus; Haag, Arjen; Bierkens, Marc

    2016-04-01

    Due to their increasing occurrence rate and associated economic costs, fluvial floods are large-scale and cross-border phenomena that need to be well understood. Sound information about temporal and spatial variations of flood hazard is essential for adequate flood risk management and climate change adaption measures. While progress has been made in assessments of flood hazard and risk on the global scale, studies to date have made compromises between spatial resolution on the one hand and local detail that influences their temporal characteristics (rate of rise, duration) on the other. Moreover, global models cannot realistically model flood wave propagation due to a lack of detail in channel and floodplain geometry, and the representation of hydrologic processes influencing the surface water balance such as open water evaporation from inundated water and re-infiltration of water in river banks. To overcome these restrictions and to obtain a better understanding of flood propagation including its spatio-temporal variations at the large scale, yet at a sufficiently high resolution, the present study aims to develop a large-scale modeling tool by coupling the global hydrologic model PCR-GLOBWB and the recently developed hydrodynamic model DELFT3D-FM. The first computes surface water volumes which are routed by the latter, solving the full Saint-Venant equations. With DELFT3D FM being capable of representing the model domain as a flexible mesh, model accuracy is only improved at relevant locations (river and adjacent floodplain) and the computation time is not unnecessarily increased. This efficiency is very advantageous for large-scale modelling approaches. The model domain is thereby schematized by 2D floodplains, being derived from global data sets (HydroSHEDS and G3WBM, respectively). Since a previous study with 1way-coupling showed good model performance (J.M. Hoch et al., in prep.), this approach was extended to 2way-coupling to fully represent evaporation

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

    PubMed

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

    2013-01-01

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

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

    PubMed

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

    2013-01-01

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

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

    PubMed

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

    1989-04-01

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

  19. Ecosystem function in waste stabilisation ponds: Improving water quality through a better understanding of biophysical coupling

    NASA Astrophysics Data System (ADS)

    Ghadouani, Anas; Reichwaldt, Elke S.; Coggins, Liah X.; Ivey, Gregory N.; Ghisalberti, Marco; Zhou, Wenxu; Laurion, Isabelle; Chua, Andrew

    2014-05-01

    Wastewater stabilisation ponds (WSPs) are highly productive systems designed to treat wastewater using only natural biological and chemical processes. Phytoplankton, microbial communities and hydraulics play important roles for ecosystem functionality of these pond systems. Although WSPs have been used for many decades, they are still considered as 'black box' systems as very little is known about the fundamental ecological processes which occur within them. However, a better understanding of how these highly productive ecosystems function is particularly important for hydrological processes, as treated wastewater is commonly discharged into streams, rivers, and oceans, and subject to strict water quality guidelines. WSPs are known to operate at different levels of efficiency, and treatment efficiency of WSPs is dependent on physical (flow characteristics and sludge accumulation and distribution) and biological (microbial and phytoplankton communities) characteristics. Thus, it is important to gain a better understanding of the role and influence of pond hydraulics and vital microbial communities on pond performance and WSP functional stability. The main aim of this study is to investigate the processes leading to differences in treatment performance of WSPs. This study uses a novel and innovative approach to understand these factors by combining flow cytometry and metabolomics to investigate various biochemical characteristics, including the metabolite composition and microbial community within WSPs. The results of these analyses will then be combined with results from the characterisation of pond hydrodynamics and hydraulic performance, which will be performed using advanced hydrodynamic modelling and advanced sludge profiling technology. By understanding how hydrodynamic and biological processes influence each other and ecosystem function and stability in WSPs, we will be able to propose ways to improve the quality of the treatment using natural processes, with

  20. Tropical pacing of Antarctic sea ice increase

    NASA Astrophysics Data System (ADS)

    Schneider, D. P.

    2015-12-01

    One reason why coupled climate model simulations generally do not reproduce the observed increase in Antarctic sea ice extent may be that their internally generated climate variability does not sync with the observed phases of phenomena like the Pacific Decadal Oscillation (PDO) and ENSO. For example, it is unlikely for a free-running coupled model simulation to capture the shift of the PDO from its positive to negative phase during 1998, and the subsequent ~15 year duration of the negative PDO phase. In previously presented work based on atmospheric models forced by observed tropical SSTs and stratospheric ozone, we demonstrated that tropical variability is key to explaining the wind trends over the Southern Ocean during the past ~35 years, particularly in the Ross, Amundsen and Bellingshausen Seas, the regions of the largest trends in sea ice extent and ice season duration. Here, we extend this idea to coupled model simulations with the Community Earth System Model (CESM) in which the evolution of SST anomalies in the central and eastern tropical Pacific is constrained to match the observations. This ensemble of 10 "tropical pacemaker" simulations shows a more realistic evolution of Antarctic sea ice anomalies than does its unconstrained counterpart, the CESM Large Ensemble (both sets of runs include stratospheric ozone depletion and other time-dependent radiative forcings). In particular, the pacemaker runs show that increased sea ice in the eastern Ross Sea is associated with a deeper Amundsen Sea Low (ASL) and stronger westerlies over the south Pacific. These circulation patterns in turn are linked with the negative phase of the PDO, characterized by negative SST anomalies in the central and eastern Pacific. The timing of tropical decadal variability with respect to ozone depletion further suggests a strong role for tropical variability in the recent acceleration of the Antarctic sea ice trend, as ozone depletion stabilized by late 1990s, prior to the most

  1. Soil-water coupling finite element analysis on seismic enhancement effect of group-pile foundation with ground improvement

    NASA Astrophysics Data System (ADS)

    Zhang, F.; Jin, Y.; Bao, X.; Kondo, Y.; Nakamura, K.

    2010-06-01

    In this paper, soil-water coupling finite element analyses on a real-scale field test of 9-pile foundation subjected to horizontal cyclic loading is conducted at first using a program named as DBLEAVES (Ye, 2007). In the analysis, nonlinear behaviors of ground and piles are described by cyclic mobility model (Zhang et al, 2007) and axial force dependent model (AFD model) proposed by Zhang and Kimura (2002) which can take into consideration of axial-force dependency in the nonlinear moment-curvature relations. After the applicability of the proposed numerical method is verified by comparing the numerical results with the field test results, numerical experiments on seismic enhancement effect of group-pile foundation with ground improvement are conducted both in static loading and dynamic loading. In finding out the optimum pattern of ground improvement around existing pile foundation, three influential factors are considered in the numerical experiments, that is, the size, the location and the shape of ground-improvement zone around the pile group.

  2. Improved transmission performance resulting from the reduced chirp of a semiconductor laser coupled to an external high-Q resonator

    SciTech Connect

    Cartledge, J.C. )

    1990-05-01

    The coupling of a Fabry--Perot laser to an external high-{ital Q} resonator, whose resonance frequencies are not altered by changes in the carrier density, yields a dynamic single-longitudinal-mode laser with a significantly reduced transient frequency chirp. The improvement in the receiver sensitivity due to the reduced chirp is examined for NRZ and RZ intensity modulation, direct detection systems operating in the 1.55-{mu}m wavelength region with conventional single-mode optical fiber. The methodology involves a solving modified rate equations numerically for the optical power and phase of the external resonator laser in response to an injected current waveform, modeling the signal transmission properties of single-mode optical fibers by convolution and modulus squared operations, and using a truncated pulse train approximation to evaluate the probability of error in the presence of intersymbol interference, shot noise, APD multiplication noise, and preamplifier circuit noise.

  3. 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.

  4. Improved Measurement Performance of Inorganic Elements in Coal by Laser-Induced Breakdown Spectroscopy Coupled with Internal Standardization

    NASA Astrophysics Data System (ADS)

    Yao, Shunchun; Xu, Jialong; Bai, Kaijie; Lu, Jidong

    2015-11-01

    Laser-induced breakdown spectroscopy was employed to determine the inorganic elements in coal. To improve the measurement's accuracy and precision, a new internal standardization scheme, which we named changed internal standardization, was compared with the traditional internal standardization and no internal standardization for the analysis of inorganic elements. The new internal standardization scheme used the atomic line of carbon at 247.86 nm and the molecular band of CN at 388.34 nm and C2 at 516.32 nm to normalize the lines of inorganic elements that were distributed in the same spectral channel. The performance of the utilization of the new internal standardization scheme was evaluated using a set of coal samples, including twenty calibration samples and five validation samples. The results show that the coefficients of determination R2 and the slope of calibration models coupled with changed internal standardization are better than that of the calibration models coupled with fixed internal standardization and no internal standardization. Moreover, the measurement accuracy and reproducibility of changed internal standardization for the analysis of five validation samples also yielded further improvement. The results that we obtained suggest that changed internal standardization could compensate for the matrix effects, as well as the influence of the difference in the spectral response of the light collection system. supported by Open Research Fund of State Key Laboratory of Pulsed Power Laser Technology of China (No. SKL2013KF03), National Natural Science Foundation of China (Nos. 51206055, 51476061), the Fundamental Research Funds for the Central Universities of China (No. 2014ZZ0014), the New Star of Pearl River on Science and Technology of Guangzhou, China (No. 2014J2200054), the Key Laboratory of Efficient and Clean Energy Utilization of Guangdong Higher Education Institutes of China (No. KLB10004) and Guangdong Province Key Laboratory of Efficient and

  5. 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.

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

    PubMed Central

    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. PMID:26346728

  7. 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

  8. Improved Modeling of Land-Atmosphere Interactions using a Coupled Version of WRF with the Land Information System

    NASA Technical Reports Server (NTRS)

    Case, Jonathan L.; LaCasse, Katherine M.; Santanello, Joseph A., Jr.; Lapenta, William M.; Petars-Lidard, Christa D.

    2007-01-01

    The exchange of energy and moisture between the Earth's surface and the atmospheric boundary layer plays a critical role in many hydrometeorological processes. Accurate and high-resolution representations of surface properties such as sea-surface temperature (SST), vegetation, soil temperature and moisture content, and ground fluxes are necessary to better understand the Earth-atmosphere interactions and improve numerical predictions of weather and climate phenomena. The NASA/NWS Short-term Prediction Research and Transition (SPORT) Center is currently investigating the potential benefits of assimilating high-resolution datasets derived from the NASA moderate resolution imaging spectroradiometer (MODIS) instruments using the Weather Research and Forecasting (WRF) model and the Goddard Space Flight Center Land Information System (LIS). The LIS is a software framework that integrates satellite and ground-based observational and modeled data along with multiple land surface models (LSMs) and advanced computing tools to accurately characterize land surface states and fluxes. The LIS can be run uncoupled to provide a high-resolution land surface initial condition, and can also be run in a coupled mode with WRF to integrate surface and soil quantities using any of the LSMs available in LIS. The LIS also includes the ability to optimize the initialization of surface and soil variables by tuning the spin-up time period and atmospheric forcing parameters, which cannot be done in the standard WRF. Among the datasets available from MODIS, a leaf-area index field and composite SST analysis are used to improve the lower boundary and initial conditions to the LIS/WRF coupled model over both land and water. Experiments will be conducted to measure the potential benefits from using the coupled LIS/WRF model over the Florida peninsula during May 2004. This month experienced relatively benign weather conditions, which will allow the experiments to focus on the local and mesoscale

  9. Self-paced BCI using multiple SWT-based classifiers.

    PubMed

    Faradji, Farhad; Ward, Rabab K; Birch, Gary E

    2008-01-01

    The presence of false activations inhibits the use of existing self-paced BCIs in real life applications. We present a new design method for a self-paced BCI that yielded 0% false activations using the data of two subjects. This system obtains templates/shapes of the movement related finger flexion patterns. To obtain the templates, the intentional control data are decomposed into 5 levels using the stationary wavelet transform. Then, ensemble averaging is done. These templates are used to train 5 radial basis function neural networks. This is followed by a majority voting classifier.

  10. Centrifugal dryers keep pace with the market

    SciTech Connect

    Fiscor, S.

    2008-03-15

    New plant design and upgrades create a shift in dewatering strategies. The article describes recent developments. Three major manufacturers supply centrifugal dryers - TEMA, Centrifugal & Mechanical Industries (CMI) and Ludowici. CMI introduced a line of vertical centrifugal dryers. TEMA improved the techniques by developing a horizontal vibratory centrifuge (HVC) which simplified maintenance. 3 figs., 1 photo.

  11. Improving homology modeling of G-protein coupled receptors through multiple-template derived conserved inter-residue interactions.

    PubMed

    Chaudhari, Rajan; Heim, Andrew J; Li, Zhijun

    2015-05-01

    Evidenced by the three-rounds of G-protein coupled receptors (GPCR) Dock competitions, improving homology modeling methods of helical transmembrane proteins including the GPCRs, based on templates of low sequence identity, remains an eminent challenge. Current approaches addressing this challenge adopt the philosophy of "modeling first, refinement next". In the present work, we developed an alternative modeling approach through the novel application of available multiple templates. First, conserved inter-residue interactions are derived from each additional template through conservation analysis of each template-target pairwise alignment. Then, these interactions are converted into distance restraints and incorporated in the homology modeling process. This approach was applied to modeling of the human β2 adrenergic receptor using the bovin rhodopsin and the human protease-activated receptor 1 as templates and improved model quality was demonstrated compared to the homology model generated by standard single-template and multiple-template methods. This method of "refined restraints first, modeling next", provides a fast and complementary way to the current modeling approaches. It allows rational identification and implementation of additional conserved distance restraints extracted from multiple templates and/or experimental data, and has the potential to be applicable to modeling of all helical transmembrane proteins.

  12. A generic selection system for improved expression and thermostability of G protein-coupled receptors by directed evolution

    PubMed Central

    Klenk, Christoph; Ehrenmann, Janosch; Schütz, Marco; Plückthun, Andreas

    2016-01-01

    Structural and biophysical studies as well as drug screening approaches on G protein-coupled receptors (GPCRs) have been largely hampered by the poor biophysical properties and low expression yields of this largest class of integral membrane proteins. Thermostabilisation of GPCRs by introduction of stabilising mutations has been a key factor to overcome these limitations. However, labelled ligands with sufficient affinity, which are required for selective binding to the correctly folded receptor, are often not available. Here we describe a novel procedure to improve receptor expression and stability in a generic way, independent of specific ligands, by means of directed evolution in E. coli. We have engineered a homogenous fluorescent reporter assay that only detects receptors which are correctly integrated into the inner cell membrane and, thus, discriminates functional from non-functional receptor species. When we combined this method with a directed evolution procedure we obtained highly expressing mutants of the neurotensin receptor 1 with greatly improved thermostability. By this procedure receptors with poor expression and/or low stability, for which no ligands or only ones with poor binding properties are available, can now be generated in quantities allowing detailed structural and biophysical analysis. PMID:26887595

  13. Improving the spatial resolution of soft X-ray detection using an Electron-Multiplying Charge-Coupled Device

    NASA Astrophysics Data System (ADS)

    Soman, M. R.; Hall, D. J.; Tutt, J. H.; Murray, N. J.; Holland, A. D.; Schmitt, T.; Raabe, J.; Schmitt, B.

    2013-01-01

    The Super Advanced X-ray Emission Spectrometer (SAXES) is an instrument at the Swiss Light Source designed for Resonant Inelastic X-ray Scattering with an energy resolution (E/ΔE) better than 12000 at 930 eV. Improvements to the instrument have been predicted that could allow the energy resolution to be improved by a factor of two. To achieve this, the spatial resolution of the detector (currently a Charge-Coupled Device, CCD) over which the energy spectrum is dispersed would have to be improved to better than 5 μm. X-ray photons with energies between a few hundred to a few thousand electron volts primarily interact within the field-free region of back-illuminated CCDs, where each photon forms an electron cloud that diffuses isotropically before reaching the depleted region close to the electrodes. Each photon's electron cloud is likely to be detected as an event with signal split across multiple pixels. Analysing these split events using centroiding techniques allows the photon's interaction position to be determined to a sub-pixel level. PolLux is a soft X-ray microspectroscopy endstation at the Swiss Light Source that can focus 200 eV to 1200 eV X-rays to a spot size of approximately 20 nm. Previous studies using data taken with a linear scan across the centre of a pixel in 3 μm steps predicted an improved resolution by applying centroiding techniques and using an Electron-Multiplying CCD (EM-CCD). In this study, a full 2D map of the centroiding accuracy in the pixel is presented, formed by rastering in two dimensions across the image plane in single micron steps. The improved spatial resolution from centroiding events in the EM-CCD in all areas of the pixel over the standard CCD is attributed to the improved signal to noise ratio provided by the multiplication register even at high pixel readout speeds (tens of MHz).

  14. Evaluation and Application of a Rigorously Validated Ocean OSSE System to Improve Ocean Model Initialization for Coupled Hurricane Prediction

    NASA Astrophysics Data System (ADS)

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

    2015-12-01

    A new fraternal-twin OSSE system has been configured over an extended North Atlantic Ocean domain to evaluate ocean observing strategies with respect to improving coupled hurricane forecasts. It is the first ocean OSSE system to employ all rigorous validation and calibration methods developed for atmospheric OSSE systems. It is based on two different configurations of the Hybrid Coordinate Ocean Model (HYCOM). Model configurations used for the unconstrained Nature Run (NR) and data-assimilative Forecast Model (FM), including lower horizontal and vertical resolution for the FM, produce the substantially different physics and truncation errors required of a credible OSSE system. Evaluation of the NR demonstrates sufficient realism in terms of mean climatology and of statistical properties of eddy and current variability to represent the "true" ocean. System evaluation is performed by comparing OSSE's to Observing System Experiments (OSEs) that are identical except for assimilating actual observations. Based on RMS error increases, the OSSE system tends to overestimate impacts by <10% on average and thus requires only small calibration. The system is then applied to evaluate ocean observing strategies during the 2014 hurricane season. Example results are presented that evaluate different strategies for conducting airborne ocean profile surveys prior to Hurricane Edouard. The impact of the actual pre-storm survey performed prior to Edouard is evaluated against alternate survey strategies. Results demonstrate the importance of surveying as large a region as possible with ocean profiles separated by < 100 km. Modest additional advantages are achieved by profiling both temperature and salinity with CTDs compared to temperature profiles alone from XBTs. The HYCOM-HWRF coupled hurricane prediction model can now be initialized with analyses produced by the OSSE system. The impact of airborne survey design on actual hurricane forecasts will also be discussed.

  15. Improve the Strength of PLA/HA Composite Through the Use of Surface Initiated Polymerization and Phosphonic Acid Coupling Agent

    PubMed Central

    Wang, Tongxin; Chow, Laurence C.; Frukhtbeyn, Stanislav A.; Ting, Andy Hai; Dong, Quanxiao; Yang, Mingshu; Mitchell, James W.

    2011-01-01

    Bioresorbable composite made from degradable polymers, e.g., polylactide (PLA), and bioactive calcium phosphates, e.g., hydroxyapatite (HA), are clinically desirable for bone fixation, repair and tissue engineering because they do not need to be removed by surgery after the bone heals. However, preparation of PLA/HA composite from non-modified HA usually results in mechanical strength reductions due to a weak interface between PLA and HA. In this study, a calcium-phosphate/phosphonate hybrid shell was developed to introduce a greater amount of reactive hydroxyl groups onto the HA particles. Then, PLA was successfully grafted on HA by surface-initiated polymerization through the non-ionic surface hydroxyl groups. Thermogravimetric analysis indiated that the amount of grafted PLA on HA can be up to 7 %, which is about 50 % greater than that from the literature. PLA grafted HA shows significantly different pH dependent ζ-potential and particle size profiles from those of uncoated HA. By combining the phosphonic acid coupling agent and surface initiated polymerization, PLA could directly link to HA through covalent bond so that the interfacial interaction in the PLA/HA composite can be significantly improved. The diametral tensile strength of PLA/HA composite prepared from PLA-grafted HA was found to be over twice that of the composite prepared from the non-modified HA. Moreover, the tensile strength of the improved composite was 23 % higher than that of PLA alone. By varying additional variables, this approach has the potential to produce bioresorbable composites with improved mechanical properties that are in the range of natural bones, and can have wide applications for bone fixation and repair in load-bearing areas. PMID:22399838

  16. The Print and Computer Enlargement System--PACE. Final Report.

    ERIC Educational Resources Information Center

    Morford, Ronald A.

    The Print and Computer Enlargement (PACE) System is being designed as a portable computerized reading and writing system that enables a low-vision person to read regular print and then create and edit text using large-print computerized output. The design goal was to develop a system that: weighed no more than 12 pounds so it could be easily…

  17. 42 CFR 460.180 - Medicare payment to PACE organizations.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

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

  18. Curriculum Designs for Tech Prep Clusters. PACE '94.

    ERIC Educational Resources Information Center

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

    This booklet contains descriptions of various Tech Prep programs developed by PACE (Promoting Academic Excellence In Mathematics, Science & Technology for Workers of the 21st Century). Each entry includes general program descriptions, curriculum outlines, and course descriptions. The clusters and their specialty areas described in the booklet are:…

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

    ERIC Educational Resources Information Center

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

    2013-01-01

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

  20. Self-Paced Physics, Segments 37-40.

    ERIC Educational Resources Information Center

    New York Inst. of Tech., Old Westbury.

    Four study segments of the Self-Paced Physics Course materials are presented in this eighth problems and solutions book used as a part of course assignments. The content is related to magnetic induction, Faraday's law, induced currents, Lenz's law, induced electromotive forces, time-varying magnetic fields, self-inductance, inductors,…

  1. Mixed microprocessor-random logic approach for innovative pacing systems.

    PubMed

    Gaggini, G; Garberoglio, B; Silvestri, L

    1992-11-01

    Modern pacing systems are becoming more and more sophisticated. Conversion of the information supplied by a sensor into suitable parameters for a rate controlling algorithm and the management of complex timing are common tasks for an integrated circuit (IC) in cardiac pacing. An effective solution consists of using a microprocessor to implement algorithms and pacing modes in a flexible way. The key point of using the same hardware resources for different tasks on a time sharing basis allows the design of a less complex IC when compared to a random logic structure with the same performances. The major design problems in a full microprocessor solution are its relatively low operating speed due to the low frequency clock necessary for low current drain, and the sequential structure of the machine itself. This can lead to unacceptable timing inaccuracy in all situations requiring the management of complex decision trees. In order to take full benefit from the advantages of a microprocessor structure without these drawbacks, a mixed microprocessor-random logic approach has been investigated. This architecture uses a microprocessor core to perform all high level nonreal-time operations (setup of the pacing cycle, data reduction and processing, data integrity checks) while a set of random logic peripherals is used for all critical timing aspects.

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

    DOEpatents

    Chen, Dong; Heidelberger, Phillip; Vranas, Pavlos

    2013-08-13

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

  3. Microcomputers in Education: A Self-Paced Orientation.

    ERIC Educational Resources Information Center

    Carey, Doris; Carey, Regan

    Designed to serve as a self-paced computer course for education students with no experience using microcomputers, this manual contains instructions for operating an Apple IIe microcomputer, its introductory software, and Bank Street Writer, using the DOS 3.3 System Master. The lessons, which contain illustrations and sample screens, include…

  4. ET-1 levels in cardioischemic patients undergoing atrial pacing.

    PubMed

    Parlapiano, C; Borgia, M C; Tonnarini, G; Alessandri, N; Campana, E; Quaglione, R; Ciccaglioni, A; Giancaspro, G; Pantone, P; Giovanniello, T; Califano, F

    2001-01-01

    Atrial pacing (AP) procedure was carried out in 11 cardioischemic patients to reproduce tachycardia-induced myocardial ischemia. Six control subjects underwent the same procedure until the maximum pacing rate was reached. During the procedure, endothelin-1 (ET-1) and plasma lactate levels were measured in the coronary sinus and in the aortic root. In all the patients, atrial pacing provoked electrocardiographic signs and metabolic evidence of myocardial ischemia and a significant decrease (p<0.001) in left ventricular ejection fraction. At AP-induced ischemia, coronary sinus (17.31 +/- 4.20 pg/mL) and arterial (9.60 +/- 3.31 pg/mL) ET-1 plasma levels were significantly different (p<0.001) in the patients. On the contrary, at maximum pacing rate, no significant difference (p=0.186) emerged between coronary sinus (9.72 +/- 1.09 pg/mL) and arterial (8.95 +/- 0.75 pg/mL) plasma ET-1 levels in the control group. These results suggest that, in cardioischemic patients, tachycardia can induce the coronary endothelium to release significant amounts of ET-1. PMID:11563817

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

    ERIC Educational Resources Information Center

    New York Inst. of Tech., Old Westbury.

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

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

    ERIC Educational Resources Information Center

    New York Inst. of Tech., Old Westbury.

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

  7. Self-Paced Physics, Segments 19-23.

    ERIC Educational Resources Information Center

    New York Inst. of Tech., Old Westbury.

    Five study segments of the Self-Paced Physics Course materials are presented in this fourth problems and solutions book used as a part of student course work. The subject matter is related to electric charges, insulators, Coulomb's law, electric fields, lines of force, solid angles, conductors, motion of charged particles, dipoles, electric flux,…

  8. The Pace of Vocabulary Growth Helps Predict Later Vocabulary Skill

    ERIC Educational Resources Information Center

    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],…

  9. Library Skills for Teachers: A Self-Paced Workbook.

    ERIC Educational Resources Information Center

    Mech, Terrence

    Designed to introduce education students to the basic library resources in the field, this self-paced workbook assumes a basic knowledge of the library and its resources. Each section in the eight-chapter workbook discusses a particular type of reference material and sample entries are provided when appropriate. Eleven assignments (two multiple…

  10. Evaluation of Self-Paced Instructional Materials in Pharmaceutics

    ERIC Educational Resources Information Center

    Ayres, James W.; And Others

    1977-01-01

    The instructional effectiveness of two different presentation methods (lecture and self-paced or modularized) was examined using two groups of pharmacy students. Little or no difference was found in this study of junior and senior students at Oregon State University. (LBH)

  11. A method for permanent transvenous left ventricular pacing.

    PubMed

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

    1998-11-01

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

  12. PACES: A Model of Student Well-Being

    ERIC Educational Resources Information Center

    Nelson, Mark D.; Tarabochia, Dawn W.; Koltz, Rebecca L.

    2015-01-01

    School counselors design, deliver, and evaluate comprehensive, developmental school counseling programs that are focused on enhancing student development and success. A model of student well-being, known as PACES, is defined and described that consists of five distinct and interactive domains: physical, affective, cognitive, economic, and social.…

  13. Self-Paced Physics, Segments 11-14.

    ERIC Educational Resources Information Center

    New York Inst. of Tech., Old Westbury.

    Four segments of the Self-Paced Physics Course materials are presented in this problems and solutions book for use as the third part of student course work. The subject-matter topics are related to impulses, inelastic and elastic collisions, two-dimensional collision problems, universal constant of gravitation, gravitational acceleration and…

  14. Kentucky's Parent and Child Education (PACE) Program. Innovations.

    ERIC Educational Resources Information Center

    Devlin, Kevin M.

    A lack of education is a major cause of poverty among many Kentucky citizens. In 1986, Kentucky's dropout rate was the second highest of the 50 states. That same year, Kentucky established the Parent and Child Education (PACE) Program in an effort to combat the problems of insufficient education and poverty that tend to be perpetuated from…

  15. Differential Response to Question Pacing in Learning from Prose.

    ERIC Educational Resources Information Center

    Koran, Mary Lou; Koran, John J., Jr.

    In an experiment designed to explore the interaction of individual differences with question pacing in learning from written materials, 93 college students were administered aptitude tests representing verbal and memory abilities and then randomly assigned to treatments in which questions were placed after every one or four pages or were omitted…

  16. PACE Model Gives Advertising Campaign-Centered Curriculum (Commentary).

    ERIC Educational Resources Information Center

    Thayer, Frank

    1990-01-01

    Describes PACE (Portfolio, Assignments, Content, and Evaluation), an advertising curriculum model in which students work on real advertising campaigns. Explains that students form account groups which locate products needing promotional assistance. Identifies the goals of the curriculum to be competent writing and practical understanding of…

  17. PACE Center: A Mobile Career Information and Exploration Center.

    ERIC Educational Resources Information Center

    Bingham County Career Education, Blackfoot, ID.

    An innovative component of the Federally-sponsored Bingham County career education project is the Programed Activities for Career Exploration (PACE) Center, a mobile unit offering programed student activities to assist individual students in career planning. The mobile center visits each high school in the county; the sophomore year is selected as…

  18. Self-Paced Physics, Segments 32-36.

    ERIC Educational Resources Information Center

    New York Inst. of Tech., Old Westbury.

    Five study segments of the Self-Paced Physics Course materials are presented in this seventh problems and solutions book used as a part of student course work. The content is related to magnetic fields, magnetic moments, forces on charged particles in magnetic fields, electron volts, cyclotron, electronic charge to mass ratio, current-carrying…

  19. Basic Library Skills: A Self-Paced Workbook.

    ERIC Educational Resources Information Center

    Tierney, Judith

    This self-paced workbook is designed to introduce college students to the resources and facilities of the library and to providing the knowledge and skills necessary to do basic library research. Two introductory chapters include a library-specific tour with floor plans (the D. Leonard Corgan Library, Wilkes-Barre, Pennsylvania) and information…

  20. Self-Pacing Online Technology Approach: The Preservice Teacher Course.

    ERIC Educational Resources Information Center

    Sanders, Jay

    This paper describes an online technology course at Middle Tennessee State University that meets the needs of many preservice teachers and models techniques that can be applied in their K-12 classrooms. The first section describes the self-pacing online technology approach, including the following components of the online model: World Wide…

  1. Pacing strategies during a cycling time trial with simulated headwinds and tailwinds.

    PubMed

    Atkinson, G; Brunskill, A

    2000-10-01

    increased significantly during the first 8.05 km of the V condition when power outputs were 5% higher than in condition C. Heart rate showed no main effect of pacing strategy (p = 0.80) and the interaction between strategy and race split did not reach statistical significance (p = 0.07). These results suggest that in a 16.1 km time trial with equal 8.05 km headwind and tailwind sections, riders habitually set off too fast in the first few kilometres and will benefit (10 s improvement) from a constant pacing strategy and, to a slightly greater degree (12 s improvement), from a variable (5% +/- mean) pacing strategy in line with the variations in wind direction during the race. Riders should choose a constant power when external conditions are constant, but when there are hilly or variable wind sections in the race, a variable power strategy should be planned. This strategy would be best monitored with 'power-measuring devices' rather than heart rate or subjective feelings as the sensitivity of these variables to small but meaningful changes in power during a race is low. PMID:11083127

  2. Pacing strategies during a cycling time trial with simulated headwinds and tailwinds.

    PubMed

    Atkinson, G; Brunskill, A

    2000-10-01

    increased significantly during the first 8.05 km of the V condition when power outputs were 5% higher than in condition C. Heart rate showed no main effect of pacing strategy (p = 0.80) and the interaction between strategy and race split did not reach statistical significance (p = 0.07). These results suggest that in a 16.1 km time trial with equal 8.05 km headwind and tailwind sections, riders habitually set off too fast in the first few kilometres and will benefit (10 s improvement) from a constant pacing strategy and, to a slightly greater degree (12 s improvement), from a variable (5% +/- mean) pacing strategy in line with the variations in wind direction during the race. Riders should choose a constant power when external conditions are constant, but when there are hilly or variable wind sections in the race, a variable power strategy should be planned. This strategy would be best monitored with 'power-measuring devices' rather than heart rate or subjective feelings as the sensitivity of these variables to small but meaningful changes in power during a race is low.

  3. Advances in Atmospheric Correction for NASA's PACE mission

    NASA Astrophysics Data System (ADS)

    Remer, L. A.; Franz, B. A.; Boss, E.

    2015-12-01

    The PACE (Pre- Aerosol, Clouds and ocean Ecosystem) 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, ecology, aerosol and cloud properties. These measurements will be used to help determine how the ocean and atmosphere are influencing and being influenced by a changing climate. At the heart of the PACE mission is a broad spectrum moderate resolution (~1 km nadir) radiometer, called the Ocean Color Instrument (OCI). OCI will provide high spectral resolution (5 nm) from the UV to NIR (350 - 800 nm), with additional spectral bands in the NIR and SWIR to support atmospheric correction, and aerosol and cloud science. Never before has a U.S. space borne instrument measured across such a broad spectral range at such a fine spectral and spatial resolutions on a global scale. The added capability of OCI presents unique new opportunities for oceanic and atmospheric retrievals, but also new challenges, especially for atmospheric correction. These challenges are being met in a variety of creative ways. In addition to OCI, PACE may include a multi-spectral, multi-angle polarimeter that will enhance aerosol and cloud characterization, aid significantly in atmospheric correction for oceanic retrievals, and may offer new insight into characterization of oceanic hydrosols. With these advanced global remote sensing capabilities PACE is expected to: (1) Provide high quality observations for both basic science research, as well as applications; and (2) Extend the current time-series of climate quality data to enable detection of long-term trends.

  4. Effects of surface treatment with coupling agents of PVDF-HFP fibers on the improvement of the adhesion characteristics on PDMS

    NASA Astrophysics Data System (ADS)

    Kwon, O. M.; See, S. J.; Kim, S. S.; Hwang, H. Y.

    2014-12-01

    Surface treatment of polyvinylidene fluoride-co-hexafluoropropylene (PVDF-HFP) fibers was conducted with coupling agents such as epoxy silane, amino silane, and titanate to improve the adhesion characteristics of PVDF-HFP fibers and polydimethylsiloxane (PDMS). The adhesion strength was largest when 4 wt% amino silane was used for surface treatment, showing a 250% improvement compared to the untreated case. Surface roughening and shrinking of the PVDF-HFP fibers were observed after surface treatment, but no chemical bonding occurred between the PVDF-HFP fibers and the coupling agents. It was thus concluded that the improvement of the adhesion characteristics of the PVDF-HFP fibers and PDMS was caused by the physical bonding between them due to the surface treatment with coupling agents. In addition, for the surface roughening mechanism, amino silane infiltration into the PVDF-HFP fibers during the surface treatment, followed by extraction during the drying process, was suggested.

  5. [Successful treatment of diaphragm pacing-induced obstructive sleep apnea syndrome with nasal CPAP].

    PubMed

    Moue, Y; Kamio, K; Tanigaki, T; Hayashi, Y; Kuwahira, I; Takasaki, Y; Ohta, Y; Yamabayashi, H

    1993-08-01

    We report a 71-year-old female patient with primary alveolar hypoventilation syndrome who received diaphragm pacing (DP) and developed obstructive sleep apnea syndrome (OSAS). Application of nCPAP markedly improved her nocturnal hypoxemia. The monitored polygrams before and after the application strongly suggested that the main mechanism of OSAS was an imbalance of activity between upper airway dilator muscles and pump muscles. Moreover, paradoxical movement of the rib cage is not necessarily due to upper airway obstruction. Monitoring of tidal volume and arterial oxygen saturation is essential for the diagnosis of DP-induced OSAS.

  6. 42 CFR 460.132 - Quality assessment and performance improvement plan.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... AND HUMAN SERVICES (CONTINUED) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) Quality Assessment and Performance Improvement § 460.132...

  7. 42 CFR 460.136 - Internal quality assessment and performance improvement activities.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ..., DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) Quality Assessment and Performance Improvement §...

  8. 42 CFR 460.132 - Quality assessment and performance improvement plan.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... AND HUMAN SERVICES (CONTINUED) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) Quality Assessment and Performance Improvement § 460.132...

  9. 42 CFR 460.136 - Internal quality assessment and performance improvement activities.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ..., DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) Quality Assessment and Performance Improvement §...

  10. 42 CFR 460.136 - Internal quality assessment and performance improvement activities.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ..., DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) Quality Assessment and Performance Improvement §...

  11. 42 CFR 460.132 - Quality assessment and performance improvement plan.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... AND HUMAN SERVICES (CONTINUED) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) Quality Assessment and Performance Improvement § 460.132...

  12. 42 CFR 460.132 - Quality assessment and performance improvement plan.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... AND HUMAN SERVICES (CONTINUED) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) Quality Assessment and Performance Improvement § 460.132...

  13. 42 CFR 460.136 - Internal quality assessment and performance improvement activities.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... performance improvement activities. (1) A PACE organization must ensure that all interdisciplinary team... performance improvement requirements. A PACE organization must do the following: (1) Use a set of outcome... coordinator. A PACE organization must designate an individual to coordinate and oversee implementation...

  14. PACE IV: The Developmental Physical Education Curriculum from Theory to Practice (PACE = Positive Approaches to Children's Education).

    ERIC Educational Resources Information Center

    Indiana Univ., Bloomington. Dept. of Kinesiology.

    The purpose of PACE is to bring together individuals who have been responsible for new, innovative, and exciting developmental physical education programs. The following summaries are included: "Literacy in the Gym" (Tami Benham); "Activity Ideas for Fundamental Movement Skill Development" (Thomas H. Green); "Creative Movement Activities: A…

  15. Improving Ground Motion Simulation Capabilities for Underground Explosion Monitoring: Coupling Hydrodynamic-To Solvers and Studies of Emplacement Conditions

    NASA Astrophysics Data System (ADS)

    Xu, H.; Rodgers, A.; Lomov, I.; Petersson, A.; Sjogreen, B.; Vorobiev, O.; Chipman, V.

    2011-12-01

    We report research being performed to improve underground nuclear explosion (UNE) monitoring by developing capabilities for hydrodynamic modeling of ground motions. This effort involves work along two thrusts: 1) we are coupling hydrodynamic (non-linear shock) and seismic (linear anelastic) wave propagation codes; and 2) we are investigating the effect of source emplacement conditions on ground motions in the near field due to nonlinearity and comparing with the empirical models. For both thrusts we are modeling explosion motions using GEODYN, a fully three-dimensional Eulerian hydrodynamic code developed at LLNL. This code incorporates many important features for modeling shock waves in geologic materials, including non-linear response (e.g. porosity, tensile failure, yielding), topography, gravity, 3D material heterogeneities and adaptive mesh refinement. The calculation accuracy is well validated with the analytical solutions to the Lamb's problem and to the finite dilatational volume source at depth in a linear elastic medium. In order to propagate full waveform solutions from hydrodynamic simulations to distances where seismic measurements are made we are coupling GEODYN to WPP (LLNL's anelastic finite difference code for seismic wave simulation). Complex motions computed by GEODYN for explosions are recorded on a dense grid spanning the ranges where motions become linear (elastic). These wavefield records are processed and embedded into the WPP domain where they are introduced as a boundary driving source and continue to propagate as elastic waves at much lower numerical cost than with nonlinear GEODYN. The coupling scheme is validated by comparing the analytical, direct GEODYN solutions and WPP solutions to the finite dilatational volume source at depth in a linear elastic medium, and also by comparing the direct GEODYN solutions and WPP solutions to a complex 1kt chemical explosion in nonlinear granite at stations beyond the elastic radius. The excellent

  16. Coupling Gd-DTPA with a bispecific, recombinant protein anti-EGFR-iRGD complex improves tumor targeting in MRI

    PubMed Central

    XIN, XIAOYAN; SHA, HUIZI; SHEN, JINGTAO; ZHANG, BING; ZHU, BIN; LIU, BAORUI

    2016-01-01

    Recombinant anti-epidermal growth factor receptor-internalizing arginine-glycine-aspartic acid (anti-EGFR single-domain antibody fused with iRGD peptide) protein efficiently targets the EGFR extracellular domain and integrin αvβ/β5, and shows a high penetration into cells. Thus, this protein may improve penetration of conjugated drugs into the deep zone of gastric cancer multicellular 3D spheroids. In the present study, a novel tumor-targeting contrast agent for magnetic resonance imaging (MRI) was developed, by coupling gadolinium-diethylene triamine pentaacetate (Gd-DTPA) with the bispecific recombinant anti-EGFR-iRGD protein. The anti-EGFR-iRGD protein was extracted from Escherichia coli and Gd was loaded onto the recombinant protein by chelation using DTPA anhydride. Single-targeting agent anti-EGFR-DTPA-Gd, which served as the control, was also prepared. The results of the present study showed that anti-EGFR-iRGD-DTPA-Gd exhibited no significant cyto toxicity to human gastric carcinoma cells (BGC-823) under the experimental conditions used. Compared with a conventional contrast agent (Magnevist), anti-EGFR-iRGD-DTPA-Gd showed higher T1 relaxivity (10.157/mM/sec at 3T) and better tumor-targeting ability. In addition, the signal intensity and the area under curve for the enhanced signal time in tumor, in vivo, were stronger than Gd-DTPA alone or the anti-EGFR-Gd control. Thus, Gd-labelled anti-EGFR-iRGD has potential as a tumor-targeting contrast agent for improved MRI. PMID:27035336

  17. Environmental Coupling Modulates the Attractors of Rhythmic Coordination

    ERIC Educational Resources Information Center

    Kudo, Kazutoshi; Park, Hyeonsaeng; Kay, Bruce A.; Turvey, M. T.

    2006-01-01

    A simple instance of coupling behavior to the environment is oscillating the hands in pace with metronome beats. This environmental coupling can be weaker (1 beat per cycle) or stronger (2 beats per cycle). The authors examined whether strength of environmental coupling enhanced the stability of in-phase bimanual coordination. Detuning by…

  18. Coupling the NASA-CASA ecosystem model with a hydrologic routing algorithm for improved water management in Yosemite National Park

    NASA Astrophysics Data System (ADS)

    Teaby, A.; Johnson, E. R.; Griffin, M.; Carrillo, C.; Kannan, T.; Shupe, J. W.; Schmidt, C.

    2013-12-01

    Historic trends reveal extreme precipitation variability within the Yosemite National Park (YNP) geographic region. While California obtains greater than half of its annual water supply from the Sierra Nevada, snowpack, precipitation, and runoff can fluctuate between less than 50% and greater than 200% of climatological averages. Advances in hydrological modeling are crucial to improving water-use efficiency at the local, state, and national levels. The NASA Carnegie Ames Stanford Approach (CASA) is a global simulation model that combines multi-year satellite, climate, and other land surface databases to estimate biosphere-atmosphere exchange of energy, water, and trace gases from plants and soils. By coupling CASA with a Hydrological Routing Algorithm known as HYDRA, it is possible to calculate current water availability and observe hydrological trends within YNP. Satellite-derived inputs such as surface evapotranspiration, temperature, precipitation, land cover, and elevation were included to create a valuable decision support tool for YNP's water resource managers. These results will be of enhanced importance given current efforts to restore 81 miles of the Merced River within the park's boundary. Validations of model results were conducted using in situ stream gage measurements. The model accurately simulated observed streamflow values, achieving a relatively strong Nash-Sutcliffe model efficiency coefficient. This geospatial assessment provides a standardized method which may be repeated in both national and international water-stressed regions.

  19. Improving carbohydrate production of Chlorella sorokiniana NIES-2168 through semi-continuous process coupled with mixotrophic cultivation.

    PubMed

    Wang, Yue; Chiu, Sheng-Yi; Ho, Shih-Hsin; Liu, Zhuo; Hasunuma, Tomohisa; Chang, Ting-Ting; Chang, Kuan-Fu; Chang, Jo-Shu; Ren, Nan-Qi; Kondo, Akihiko

    2016-08-01

    Biofuels from microalgae is now a hot issue of great potential. However, achieving high starch productivity with photoautotrophic microalgae is still challenging. A feasible approach to enhance the growth and target product of microalgae is to conduct mixotrophic cultivation. The appropriate acetate addition combined with CO2 supply as dual carbon sources (i.e., mixotrophic cultivation) could enhance the cell growth of some microalgae species, but the effect of acetate-mediated mixotrophic culture mode on carbohydrate accumulation in microalgae remains unclear. Moreover, there is still lack of the information concerning how to increase the productivity of carbohydrates from microalgae under acetate-amended mixotrophic cultivation and how to optimize the engineering strategies to achieve the goal. This study was undertaken to develop an optimal acetate-contained mixotrophic cultivation system coupled with effective operation strategies to markedly improve the carbohydrate productivity of Chlorella sorokiniana NIES-2168. The optimal carbohydrate productivity of 695 mg/L/d was obtained, which is the highest value ever reported. The monosaccharide in the accumulated carbohydrates is mainly glucose (i.e., 85-90%), which is very suitable for bio-alcohols fermentation. Hence, by applying the optimal process developed in this study, C. sorokiniana NIES-2168 has a high potential to serve as a feedstock for subsequent biofuels conversion. PMID:27312599

  20. Winds, Mountains, and Wildland Fire: Improved Understanding of Coupled Atmosphere-Topography-Fire Interactions Through Large-Eddy Simulation

    NASA Astrophysics Data System (ADS)

    Munoz-Esparza, D.; Sauer, J.; Linn, R.

    2015-12-01

    Anomalous and unexpected fire behavior in complex terrain continues to result in substantial loss of property and extremely dangerous conditions for firefighting field personnel. We briefly discuss proposed hypotheses of fire interactions with atmospheric flows over complex terrain that can lead to poorly-understood and potentially catastrophic scenarios. Then, our recent results of numerical investigations via large-eddy simulation of coupled atmosphere-topography-fire phenomenology with the Los Alamos National Laboratory, HiGrad-Firetec model are presented as an example of the potential for increased understanding of these complex processes. This investigation focuses on the influence of downslope surface wind enhancement through stably stratified flow over an isolated hill, and the resulting dramatic changes in fire behavior including spread rate, and intensity. Implications with respect to counter-intuitive fire behavior and extreme fire events are discussed. This work demonstrates a tremendous opportunity to immediately create safer and more effective policy for field personnel through improved predictability of atmospheric conditions over complex terrain

  1. Fabrication of Silicon Backshorts with Improved Out-of-Band Rejection for Waveguide-Coupled Superconducting Detectors

    NASA Technical Reports Server (NTRS)

    Crowe, Erik J.; Bennett, Charles L.; Chuss, David T.; Denis, Kevin L.; Eimer, Joseph; Lourie, Nathan; Marriage, Tobias; Moseley, Samuel H.; Rostem, Karwan; Stevenson, Thomas R.; Towner, Deborah; U-yen, Kongpop; Wollack, Edward J.

    2012-01-01

    The Cosmology Large Angular Scale Surveyor (CLASS) is a ground-based instrument that will measure the polarization of the cosmic microqave background to search for gravitational waves form a posited epoch of inflation early in the universe's history. This measurement will require integration of superconducting transition-edge sensors with microwave waveguide inputs with good conrol of systematic errors, such as unwanted coupling to stray signals at frequencies outside of a precisely defined microwave band. To address these needs we will present work on the fabrication of silicon quarter-wave backshorts for the CLASS 40GHz focal plane. The 40GHz backshort consists of three degeneratively doped silicon wafers. Two spacer wafers are micromachined with through wafer vins to provide a 2.0mm long square waveguide. The third wafer acts as the backshort cap. The three wafers are bonded at the wafer level by Au-Au thermal compression bonding then aligned and flip chip bonded to the CLASS detector at the chip level. The micromachining techniques used have been optimized to create high aspect ratio waveguides, silicon pillars, and relief trenches with the goal of providing improved out of band signal rejection. We will discuss the fabrication of integrated CLASS superconducting detectors with silicon quarter wave backshorts and present current measurement results.

  2. A self-paced oral feeding system that enhances preterm infants’ oral feeding skills

    PubMed Central

    Lau, C; Fucile, S; Schanler, RJ

    2014-01-01

    Aim Very low birth weight (VLBW) infants have difficulty transitioning to independent oral feeding, be they breast- or bottle-feeding. We developed a ‘self-paced’ feeding system that eliminates the natural presence of the positive hydrostatic pressure and internal vacuum build-up within a bottle during feeding. Such system enhanced these infants’ oral feeding performance as monitored by overall transfer (OT; % ml taken/ml prescribed), rate of transfer (RT; ml/min over an entire feeding). This study hypothesizes that the improvements observed in these infants resulted from their ability to use more mature oral feeding skills (OFS). Methods ‘Feeders and growers’ born between 26–29 weeks gestation were assigned to a control or experimental group fed with a standard or self-paced bottle, respectively. They were monitored when taking 1–2 and 6–8 oral feedings/day. OFS was monitored using our recently published non-invasive assessment scale that identifies 4 maturity levels based on infants’ RT and proficiency (PRO; % ml taken during the first 5 min of a feeding/total ml prescribed) during bottle feeding. Results Infants oral feeding outcomes, i.e., OT, RT, PRO, and OFS maturity levels were enhanced in infants fed with the self-paced vs. standard bottle (p ≤ 0.007). Conclusion The improved oral feeding performance of VLBW infants correlated with enhanced OFS. This study is a first to recognize that VLBW infants’ true OFS are more mature than recognized. We speculate that the physical properties inherent to standard bottles that are eliminated with the self-paced system interfere with the display of their true oral feeding potential thereby hindering their overall oral feeding performance. PMID:25999776

  3. Effects of pacing magnitudes and forms on bistability width in a modeled ventricular tissue

    NASA Astrophysics Data System (ADS)

    Huang, Xiaodong; Liu, Xuemei; Zheng, Lixian; Mi, Yuanyuan; Qian, Yu

    2013-07-01

    Bistability in periodically paced cardiac tissue is relevant to cardiac arrhythmias and its control. In the present paper, one-dimensional tissue of the phase I Luo-Rudy model is numerically investigated. The effects of various parameters of pacing signals on bistability width are studied. The following conclusions are obtained: (i) Pacing can be classified into two types: pulsatile and sinusoidal types. Pulsatile pacing reduces bistability width as its magnitude is increased. Sinusoidal pacing increases the width as its amplitude is increased. (ii) In a pacing period the hyperpolarizing part plays a more important role than the depolarizing part. Variations of the hyperpolarizing ratio in a period evidently change the width of bistability and its variation tendency. (iii) A dynamical mechanism is proposed to qualitatively explain the phenomena, which reveals the reason for the different effects of pulsatile and sinusoidal pacing on bistability. The methods for changing bistability width by external pacing may help control arrhythmias in cardiology.

  4. 42 CFR 460.150 - Eligibility to enroll in a PACE program.

    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) Participant Enrollment and Disenrollment § 460.150 Eligibility to enroll in...

  5. 42 CFR 460.150 - Eligibility to enroll in a PACE program.

    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 Enrollment and Disenrollment § 460.150 Eligibility to enroll in...

  6. 42 CFR 460.150 - Eligibility to enroll in a PACE program.

    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 Enrollment and Disenrollment § 460.150 Eligibility to enroll in...

  7. 42 CFR 460.150 - Eligibility to enroll in a PACE program.

    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 Enrollment and Disenrollment § 460.150 Eligibility to enroll in...

  8. A Study of Instructional Methods Used in Fast-Paced Classes

    ERIC Educational Resources Information Center

    Lee, Seon-Young; Olszewski-Kubilius, Paula

    2006-01-01

    This study involved 15 secondary-level teachers who taught fast-paced classes at a university based summer program and similar regularly paced classes in their local schools in order to examine how teachers differentiate or modify instructional methods and content selections for fast-paced classes. Interviews were conducted with the teachers…

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

    ERIC Educational Resources Information Center

    Izmirli, Serkan; Kurt, Adile Askim

    2016-01-01

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

  10. Society for the Teaching of Psychology and the University of Wisconsin-Milwaukee: U-Pace

    ERIC Educational Resources Information Center

    EDUCAUSE, 2014

    2014-01-01

    The Society for the Teaching of Psychology and the University of Wisconsin-Milwaukee (UWM) partnered to disseminate U-Pace, a technology-enabled instructional model that promotes student success through deeper learning. UWM developed U-Pace in 2006 for an Introduction to Psychology course and, over time, evidence indicates that U-Pace not only…

  11. Unintended Outcomes of University-Community Partnerships: Building Organizational Capacity with PACE International Partners

    ERIC Educational Resources Information Center

    Lloyd, Kate; Clark, Lindie; Hammersley, Laura; Baker, Michaela; Rawlings-Sanaei, Felicity; D'ath, Emily

    2015-01-01

    Professional and Community Engagement (PACE) at Macquarie University provides experiential opportunities for students and staff to contribute to more just, inclusive and sustainable societies by engaging in activities with partner organizations. PACE International offers a range of opportunities with partners overseas. Underpinning PACE is a…

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

    ERIC Educational Resources Information Center

    Sage, Kara

    2014-01-01

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

  13. Changes in Mood in New Enrollees at a Program of All-Inclusive Care for the Elderly (PACE)

    PubMed Central

    Seaton, Stephanie M.; Sutcliffe, Siobhan; Austin, Shane

    2015-01-01

    OBJECTIVES To examine changes in mood after 9 months of enrollment in a Program of All- Inclusive Care for the Elderly (PACE). DESIGN Cohort Study SETTING Alexian Brothers PACE–St. Louis, Missouri PARTICIPANTS Newly enrolled patients aged 55 or older, living in the PACE service area, eligible for nursing home care, and able to live safely in the community with continuous care for at least 9 months (n=182). MAIN OUTCOME MEASURES Geriatric Depression Scale (GDS)-15 score at the pre- admission evaluation (PAE) and the 9 month evaluation (9ME). RESULTS Of the 182 patients evaluated, 27% (n=49) met the definition of depression as defined by the GDS-15 score of ≥6 at the PAE. At the 9ME, only 11% of patients met the depression criteria (p<0.001). Of the patients who met the criteria for depression at the PAE, 80% of patients (n=39) no longer met this criteria at the 9ME (p=0.029). Similar findings were observed by age, sex, and race. Greater improvement was observed among those who were depressed at the PAE; the depressed cohort improved by 5.0 points (p<0.001) on the GDS-15 scale from the PAE to the 9ME, whereas the non-depressed cohort improved by 0.6 points (p=0.003). CONCLUSION The use of PACE as an alternative intervention may be a good option to improve mood in older adults. PMID:26260643

  14. Optimal pacing for running 400- and 800-m track races

    NASA Astrophysics Data System (ADS)

    Reardon, James

    2013-06-01

    We present a toy model of anaerobic glycolysis that utilizes appropriate physiological and mathematical consideration while remaining useful to the athlete. The toy model produces an optimal pacing strategy for 400-m and 800-m races that is analytically calculated via the Euler-Lagrange equation. The calculation of the optimum v(t) is presented in detail, with an emphasis on intuitive arguments in order to serve as a bridge between the basic techniques presented in undergraduate physics textbooks and the more advanced techniques of control theory. Observed pacing strategies in 400-m and 800-m world-record races are found to be well-fit by the toy model, which allows us to draw a new physiological interpretation for the advantages of common weight-training practices.

  15. Factors affecting the regulation of pacing: current perspectives

    PubMed Central

    Mauger, Alexis R

    2014-01-01

    During prolonged dynamic and rhythmic exercise, muscular pain and discomfort arises as a result of an increased concentration of deleterious metabolites. Sensed by peripheral nociceptors and transmitted via afferent feedback to the brain, this provides important information regarding the physiological state of the muscle. These sensations ultimately contribute to what is termed “exercise-induced pain”. Despite being well recognized by athletes and coaches, and suggested to be integral to exercise performance, this construct has largely escaped attention in experimental work. This perspective article highlights the current understanding of pacing in endurance performance, and the causes of exercise-induced pain. A new perspective is described, which proposes how exercise-induced pain may be a contributing factor in helping individuals to regulate their work rate during exercise and thus provides an important construct in pacing. PMID:25228823

  16. Simple circuit for pacing hearts of experimental animals.

    PubMed

    Freeman, G L; Colston, J T

    1992-06-01

    In this paper we describe a simple pacing circuit which can be used to drive the heart over a wide range of rates. The circuit is an astable multivibrator, based on an LM555 integrated circuit. It is powered by a 9-V battery and is small enough for use in rabbits. The circuit is easily constructed and inexpensive, making it attractive for numerous applications in cardiovascular research.

  17. 640 X 480 Pace HgCdTe FPA

    NASA Astrophysics Data System (ADS)

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

    1992-12-01

    A hybrid HgCdTe 640 X 480 infrared (IR) focal plane array (FPA) that meets the sensitivity, resolution, and field-of-view requirements of high-performance medium wavelength infrared (MWIR) imaging systems has been developed. The key technology making this large, high sensitivity device producible is the epitaxial growth of HgCdTe on a CdTe-buffered, sapphire substrate (referred to as PACE, for Producible Alternative to CdTe for Epitaxy; PACE-I refers to sapphire). The device offers TV resolution with excellent sensitivity at temperatures below 120 K. Mean NE(Delta) T as low as 13 mK has been achieved at operating temperatures < 130 K, which is about an order of magnitude better than has been achieved with PtSi 640 X 480 FPAs. In addition, the latter require cooling to PACE-I FPA D* at 78 K and background of 1014 photons/cm2-sec is BLIP-limited at 1 X 1012 cm-Hz1/2/W for the typical mean quantum efficiency of 60 - 70%. Imagery having excellent quality has been obtained using simple two-point nonuniformity compensation.

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

    PubMed

    Zhao, Xiaopeng; Schaeffer, David G

    2007-11-01

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

  19. Intracytoplasmic morphologically selected sperm injection results in improved clinical outcomes in couples with previous ICSI failures or male factor infertility: a meta-analysis.

    PubMed

    Setti, Amanda S; Braga, Daniela P A F; Figueira, Rita C S; Iaconelli, Assumpto; Borges, Edson

    2014-12-01

    The objective of this study was to perform the first meta-analysis to compare conventional intracytoplasmic sperm injection (ICSI) outcomes and intracytoplasmic morphologically selected sperm injection (IMSI) outcomes in couples with previous ICSI failures (IF) or male factor infertility (MF). A systematic review was performed by searching Medline database to identify articles reporting on the comparison between ICSI and IMSI outcomes in couples with IF or MF. The main outcome measures were the implantation, pregnancy and miscarriage rates. Thirteen studies fulfilled our predetermined criteria. The overall results of meta-analysis for implantation (OR: 2.88; CI: 2.13-3.89), pregnancy (OR: 2.07; CI: 1.22-3.50) and miscarriage rates (OR: 0.31; CI: 0.14-0.67) were in favor of IMSI in couples with IF. Additionally, the overall result of meta-analysis for implantation (OR: 1.56; CI: 1.11-2.18) and pregnancy rate (OR: 1.61; CI: 1.17-2.23) were in favor of IMSI in couples with MF. IMSI increases the odds of implantation by 50% and pregnancy by 60% in couples with MF. In light of improved clinical outcomes, we recommend promoting the IMSI method in couples with MF. Moreover, IMSI results in a 3-fold increase in implantation rate, a 2-fold increase in pregnancy rate and a 70% decrease in miscarriage rate as compared to ICSI in couples with IF, however, as no randomized evidence exists, randomized studies are needed to confirm the IMSI benefits in couples with IF. PMID:25461360

  20. Intracytoplasmic morphologically selected sperm injection results in improved clinical outcomes in couples with previous ICSI failures or male factor infertility: a meta-analysis.

    PubMed

    Setti, Amanda S; Braga, Daniela P A F; Figueira, Rita C S; Iaconelli, Assumpto; Borges, Edson

    2014-12-01

    The objective of this study was to perform the first meta-analysis to compare conventional intracytoplasmic sperm injection (ICSI) outcomes and intracytoplasmic morphologically selected sperm injection (IMSI) outcomes in couples with previous ICSI failures (IF) or male factor infertility (MF). A systematic review was performed by searching Medline database to identify articles reporting on the comparison between ICSI and IMSI outcomes in couples with IF or MF. The main outcome measures were the implantation, pregnancy and miscarriage rates. Thirteen studies fulfilled our predetermined criteria. The overall results of meta-analysis for implantation (OR: 2.88; CI: 2.13-3.89), pregnancy (OR: 2.07; CI: 1.22-3.50) and miscarriage rates (OR: 0.31; CI: 0.14-0.67) were in favor of IMSI in couples with IF. Additionally, the overall result of meta-analysis for implantation (OR: 1.56; CI: 1.11-2.18) and pregnancy rate (OR: 1.61; CI: 1.17-2.23) were in favor of IMSI in couples with MF. IMSI increases the odds of implantation by 50% and pregnancy by 60% in couples with MF. In light of improved clinical outcomes, we recommend promoting the IMSI method in couples with MF. Moreover, IMSI results in a 3-fold increase in implantation rate, a 2-fold increase in pregnancy rate and a 70% decrease in miscarriage rate as compared to ICSI in couples with IF, however, as no randomized evidence exists, randomized studies are needed to confirm the IMSI benefits in couples with IF.

  1. Impact of improved wave dissipation parameterisations on wave-current interactions in a coupled wave-ocean model

    NASA Astrophysics Data System (ADS)

    Hanafin, J. A.; Ardhuin, F.; Roland, A.; Leckler, F.; Rascle, N.

    2012-12-01

    The WAVEWATCH-III model is used operationally as part of the PREVIMER coastal forecast system. A global version of the model provides boundary conditions for a series of stand-alone high-resolution regional sub-domains, on unstructured grids, which are coupled with the regional ocean model MARS. New developments in the WW3 model include a combination of dissipation parameterisations (Ardhuin et al 2010). An anisotropic breaking-induced wind wave dissipation has been based on the local saturation spectrum, with a higher dissipation rate in the mean wave direction, designed to fit observed directional spreading. Additionally, a cumulative dissipation rate inspired by Babanin and Young (2005) but directly estimated from breaking wave probabilities dramatically enhances the dissipation at frequencies greater than 3 times the peak frequency. Regarding swell, a non-linear dissipation based on SAR-derived dissipation rates across the Pacific (Ardhuin et al., 2009) has been introduced. Validation of this model (Rascle and Ardhuin 2012, submitted) using a global hindcast from 1994-2010 shows improvements in significant wave height compared to an altimeter database, with values <10% in general. Regarding extreme events, Hanafin et al (2012) showed that the prediction of the timing of arrival, peak period and spectral distribution of very long swell generated by hurricane-level winds in the North Atlantic compared very well to coastal buoy observations. One of the aims of such improvements is to assist users by providing better geophysical parameters as output. Improvements noted in the mean squared slope compared to buoys, for example, implies a larger amount of energy is available to near-surface Langmuir turbulence. A recent study using the WW3 wave model and the MARS ocean model (Ardhuin et al, in press, JPO 2012) focused on near-shore wave interaction with strong currents. At small scales, rapid steepening of wave slopes by opposing currents induces enhanced breaking as

  2. Novel Insights into Structure-Activity Relationships of N-Terminally Modified PACE4 Inhibitors.

    PubMed

    Kwiatkowska, Anna; Couture, Frédéric; Levesque, Christine; Ly, Kévin; Beauchemin, Sophie; Desjardins, Roxane; Neugebauer, Witold; Dory, Yves L; Day, Robert

    2016-02-01

    PACE4 plays important roles in prostate cancer cell proliferation. The inhibition of this enzyme has been shown to slow prostate cancer progression and is emerging as a promising therapeutic strategy. In previous work, we developed a highly potent and selective PACE4 inhibitor, the multi-Leu (ML) peptide, an octapeptide with the sequence Ac-LLLLRVKR-NH2 . Here, with the objective of developing a useful compound for in vivo administration, we investigate the effect of N-terminal modifications. The inhibitory activity, toxicity, stability, and cell penetration properties of the resulting analogues were studied and compared to the unmodified inhibitor. Our results show that the incorporation of a polyethylene glycol (PEG) moiety leads to a loss of antiproliferative activity, whereas the attachment of a lipid chain preserves or improves it. However, the lipidated peptides are significantly more toxic when compared with their unmodified counterparts. Therefore, the best results were achieved not by the N-terminal extension but by the protection of both ends with the d-Leu residue and 4-amidinobenzylamide, which yielded the most stable inhibitor, with an excellent activity and toxicity profile. PMID:26751825

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

    PubMed

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

    2006-08-01

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

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

    PubMed

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

    2005-01-01

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

  5. Improving the Out-Coupling of a Metal-Metal Terahertz Frequency Quantum Cascade Laser Through Integration of a Hybrid Mode Section into the Waveguide

    NASA Astrophysics Data System (ADS)

    Fobbe, Tobias; Nong, Hanond; Schott, Rüdiger; Pal, Shovon; Markmann, Sergej; Hekmat, Negar; Zhu, Jingxuan; Han, Yingjun; Li, Lianhe; Dean, Paul; Linfield, Edmund H.; Davies, A. Giles; Wieck, Andreas D.; Jukam, Nathan

    2016-05-01

    A hybrid mode section is integrated into the end of the metal-metal waveguide of a terahertz (THz) frequency quantum cascade laser (QCL) by removing sub-wavelength portions of the top metal layer. This allows a hybrid mode to penetrate into the air, which reduces the effective index of the mode and improves the out-coupling performance at the facet. The transmission of the hybrid section is further increased by ensuring its length fulfills the criterion for constructive interference. These simple modifications to a 2.5-THz metal-metal QCL waveguide result in a significant increase in the output emission power. In addition, simulations show that further improvements in out-coupling efficiency can be achieved for lower frequencies with effective refractive indices close to the geometric mean of the indices of the metal-metal waveguide and air.

  6. Higher sympathetic nerve activity during ventricular (VVI) than during dual-chamber (DDD) pacing

    NASA Technical Reports Server (NTRS)

    Taylor, J. A.; Morillo, C. A.; Eckberg, D. L.; Ellenbogen, K. A.

    1996-01-01

    OBJECTIVES: We determined the short-term effects of single-chamber ventricular pacing and dual-chamber atrioventricular (AV) pacing on directly measured sympathetic nerve activity. BACKGROUND: Dual-chamber AV cardiac pacing results in greater cardiac output and lower systemic vascular resistance than does single-chamber ventricular pacing. However, it is unclear whether these hemodynamic advantages result in less sympathetic nervous system outflow. METHODS: In 13 patients with a dual-chamber pacemaker, we recorded the electrocardiogram, noninvasive arterial pressure (Finapres), respiration and muscle sympathetic nerve activity (microneurography) during 3 min of underlying basal heart rate and 3 min of ventricular and AV pacing at rates of 60 and 100 beats/min. RESULTS: Arterial pressure was lowest and muscle sympathetic nerve activity was highest at the underlying basal heart rate. Arterial pressure increased with cardiac pacing and was greater with AV than with ventricular pacing (change in mean blood pressure +/- SE: 10 +/- 3 vs. 2 +/- 2 mm Hg at 60 beats/min; 21 +/- 5 vs. 14 +/- 2 mm Hg at 100 beats/min; p < 0.05). Sympathetic nerve activity decreased with cardiac pacing and the decline was greater with AV than with ventricular pacing (60 beats/min -40 +/- 11% vs. -17 +/- 7%; 100 beats/min -60 +/- 9% vs. -48 +/- 10%; p < 0.05). Although most patients showed a strong inverse relation between arterial pressure and muscle sympathetic nerve activity, three patients with severe left ventricular dysfunction (ejection fraction < or = 30%) showed no relation between arterial pressure and sympathetic activity. CONCLUSIONS: Short-term AV pacing results in lower sympathetic nerve activity and higher arterial pressure than does ventricular pacing, indicating that cardiac pacing mode may influence sympathetic outflow simply through arterial baroreflex mechanisms. We speculate that the greater incidence of adverse outcomes in patients treated with single-chamber ventricular

  7. INDIVIDUAL DIFFERENCES IN LEARNING FROM SELF-PACED PROGRAMED INSTRUCTION, REPORT 1--STUDIES IN TELEVISED INSTRUCTION, INDIVIDUALIZING GROUP INSTRUCTION.

    ERIC Educational Resources Information Center

    GROPPER, GEORGE L.; KRESS, GERARD C., JR.

    SELF-PACED INSTRUCTION, DETERMINANTS OF A SELF-ADOPTED PACE, AND THE EFFECTS OF THE PACE ADOPTED ON BEHAVIOR WERE STUDIED. THIS REPRESENTED THE FIRST IN A SERIES OF THREE STUDIES, CONCERNING THE RELATIONSHIP BETWEEN PACING MODE AND BEHAVIOR. (REFER TO ACCESSION NUMBERS ED 003 200, ED 003 201, AND ED 003 202 FOR ADDITIONAL INFORMATION ON THIS…

  8. Phenytoin free fraction determination: comparison of an improved direct serum injection high-performance liquid chromatographic method to ultrafiltration coupled with fluorescence polarization immunoassay.

    PubMed

    Gurley, B J; Marx, M; Olsen, K

    1995-08-18

    Recent developments in restricted-access media (RAM) liquid chromatography make the simultaneous determination of total and free phenytoin concentrations possible by direct injection of drug-containing serum samples. A comparison of phenytoin free fraction determination by ultrafiltration coupled with fluorescence polarization immunoassay (TDX) to an improved direct injection RAM-HPLC method is presented. Our improved method differs from those previously reported with regard to column type, mobile-phase composition, and column temperature. Replicate samples analyzed by each method yielded similar values for serum phenytoin free fraction. PMID:8548029

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

    PubMed

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

    2016-07-01

    Long-term right ventricular apical pacing (RVAP) is reportedly associated with heart failure (HF) development. However, the predictors of pacing-induced HF (PHF) remained unclear. We retrospectively enrolled 234 patients without structural heart disease who underwent a permanent pacemaker implantation with RVAP between 1982 and 2004. RVAP-induced HF was defined as left ventricular ejection fraction decrease >5 % with HF symptom without other HF development etiology. The QRS duration of a paced beat (pQRSd) and myocardial scar score were analyzed from each patient's 12-lead ECG. During a mean 15.6 years (range 3.3-30.0 years), 48 patients (20.5 %) patients developed RVAP-induced HF. The PHF group patients had a longer pQRSd (192.4 ± 13.5 vs. 175.7 ± 14.7 ms in non-PHF patients, p < 0.001) and a higher myocardial scar score (5.2 ± 1.9 vs. 2.7 ± 1.9, respectively p < 0.001). In multivariate Cox regression analysis, old age at implantation [Hazard ratio (HR) 1.62, 95 % confidential interval (CI) 1.22-2.16, p = 0.001], a longer pQRSd (HR 1.54, 95 % CI 1.15-2.05, p = 0.003), a higher myocardial scar score (HR 1.23, 95 % CI 1.03-1.49, p = 0.037), and a higher percentage of ventricular pacing (HR 1.31, 95 % CI 1.01-1.49, p = 0.010) were independent predictors of PHF. Based on the results of the receiver-operating characteristic (ROC) curve, the pQRSd cutoff was 185 ms (AUC 0.79, sensitivity 66.7 %, specificity 76.3 %) and myocardial scar score cutoff value was 4 (AUC 0.81, sensitivity 81.3 %, specificity 66.1 %). The pQRSd was positively correlated with scar score (r = 0.70, p < 0.001). pQRSd ≥185 ms and/or myocardial scar score ≥4 might be independent long-term prognostic markers of PHF.

  10. The pace of East African monsoon evolution during the Holocene

    NASA Astrophysics Data System (ADS)

    Weldeab, Syee; Menke, Valerie; Schmiedl, Gerhard

    2014-03-01

    African monsoon precipitation experienced a dramatic change in the course of the Holocene. The pace with which the African monsoon shifted from a strong early to middle to a weak late Holocene is critical for our understanding of climate dynamics, hydroclimate-vegetation interaction, and shifts of prehistoric human settlements, yet it is controversially debated. On the basis of planktonic foraminiferal Ba/Ca time series from the eastern Mediterranean Sea, here we present a proxy record of Nile River runoff that provides a spatially integrated measure of changes in East African monsoon (EAM) precipitation. The runoff record indicates a markedly gradual middle to late Holocene EAM transition that lasted over 3500 years. The timing and pace of runoff change parallels those of insolation and vegetation changes over the Nile basin, indicating orbitally forced variation of insolation as the main EAM forcing and the absence of a nonlinear precipitation-vegetation feedback. A tight correspondence between a threshold level of Nile River runoff and the timing of occupation/abandonment of settlements suggests that along with climate changes in the eastern Sahara, the level of Nile River and intensity of summer floods were likely critical for the habitability of the Nile Valley (Egypt).

  11. The Transfer Functions of Cardiac Tissue during Stochastic Pacing

    PubMed Central

    de Lange, Enno; Kucera, Jan P.

    2009-01-01

    Abstract The restitution properties of cardiac action potential duration (APD) and conduction velocity (CV) are important factors in arrhythmogenesis. They determine alternans, wavebreak, and the patterns of reentrant arrhythmias. We developed a novel approach to characterize restitution using transfer functions. Transfer functions relate an input and an output quantity in terms of gain and phase shift in the complex frequency domain. We derived an analytical expression for the transfer function of interbeat intervals (IBIs) during conduction from one site (input) to another site downstream (output). Transfer functions can be efficiently obtained using a stochastic pacing protocol. Using simulations of conduction and extracellular mapping of strands of neonatal rat ventricular myocytes, we show that transfer functions permit the quantification of APD and CV restitution slopes when it is difficult to measure APD directly. We find that the normally positive CV restitution slope attenuates IBI variations. In contrast, a negative CV restitution slope (induced by decreasing extracellular [K+]) amplifies IBI variations with a maximum at the frequency of alternans. Hence, it potentiates alternans and renders conduction unstable, even in the absence of APD restitution. Thus, stochastic pacing and transfer function analysis represent a powerful strategy to evaluate restitution and the stability of conduction. PMID:19134481

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

    PubMed

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

    2005-10-01

    Supporting parents in the first three years of a child's life has the potential to produce successful outcomes. Present government initiatives such as Sure Start focus on this age group. An American educational intervention, in the style of a monthly newsletter, was adapted for use in the UK for parents of young children. Topics were presented in an easy-to-read format and focused on infant emotional development, parent interaction and play. Newsletters, called Baby Express were posted at monthly intervals to the family home providing age-paced information which could meet the specific needs of parents at that stage of their child's life. The aim of the study was to determine the applicability of the newsletter to UK parents and evaluate their satisfaction. Sixty home-based interviews were conducted and 95 per cent of mothers reported reading all or part of the newsletter. Changes in parenting style were spontaneously reported by 28 per cent of mothers. This study found that an aged-paced parenting newsletter was an acceptable and useful method of supporting parents in the early months of a child's life and promotes positive changes in parenting behaviour. PMID:16245675

  13. The Mixed-Phase Arctic Cloud Experiment (M-PACE)

    NASA Technical Reports Server (NTRS)

    Verlinde, J.; Harrington, J. Y.; McFarquhar, G. M.; Yannuzzi, V. T.; Avramov, A.; Greenberg, S.; Johnson, N.; Zhang, G.; Poellot, M. R.; Mather, J. H.; Turner, D. D.; Eloranta, E. W.; Zak, B. D.; Prenni, A. J.; Daniel, J. S.; Kok, G. L.; Tobin, D. C.; Holz, R.; Sassen, K.; Spangenberg, D.; Minnis, P.; Tooman, T. P.; Ivey, M. D.; Richardson, S. J.; Bahramann, C. P.

    2007-01-01

    The Mixed-Phase Arctic Cloud Experiment (M-PACE) was conducted September 27 through October 22, 2004 on the North Slope of Alaska. The primary objective was to collect a data set suitable to study interactions between microphysics, dynamics and radiative transfer in mixed-phase Arctic clouds. Observations taken during the 1997/1998 Surface Heat and Energy Budget of the Arctic (SHEBA) experiment revealed that Arctic clouds frequently consist of one (or more) liquid layers precipitating ice. M-PACE sought to investigate the physical processes of these clouds utilizing two aircraft (an in situ aircraft to characterize the microphysical properties of the clouds and a remote sensing aircraft to constraint the upwelling radiation) over the Department of Energy s Atmospheric Radiation Measurement (ARM) Climate Research Facility (ACRF) on the North Slope of Alaska. The measurements successfully documented the microphysical structure of Arctic mixed-phase clouds, with multiple in situ profiles collected in both single-layer and multi-layer clouds over two ground-based remote sensing sites. Liquid was found in clouds with temperatures down to -30 C, the coldest cloud top temperature below -40 C sampled by the aircraft. Remote sensing instruments suggest that ice was present in low concentrations, mostly concentrated in precipitation shafts, although there are indications of light ice precipitation present below the optically thick single-layer clouds. The prevalence of liquid down to these low temperatures could potentially be explained by the relatively low measured ice nuclei concentrations.

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

    PubMed

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

    2005-10-01

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

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

    PubMed

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

    2016-06-01

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

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

    PubMed Central

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

    2016-01-01

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

  17. Effects of spironolactone towards rabbit atrial remodeling with rapid pacing.

    PubMed

    Wang, Lian-Fa; Gu, Lei; Huang, Meng-Xun; Zhou, Wen-Bing; Li, Hua; Zhang, Bang-Zhu

    2016-01-01

    This study aimed to observe the effects of spironolactone towards the rabbit atrial remodeling with rapid atrial pacing (RAP). 30 rabbits were randomly divided into control group, RAP group and spironolactone group, with 10 rabbits in each group. RAP was performed at the speed of 800 beats/min for 8 h, atrial effective refractory period (AERP) was determined before and at the 1(st), 2(nd), 4(th), 6(th) and 8(th) of the pacing, the expressions of atrial muscular calcium channel α1C subunit and β1 subunit mRNA were performed the RT-PCR detection, and ultrastructural changes of atrial myocytes were observed. AERP of RAP group shortened, with poor frequency adaptability; the expressions of calcium channel α1C subunit and β1 subunit mRNA decreased 22% and 26%, respectively, when compared with the control group; ultrastructure of atrial myocytes changed significantly. AERP of spironotlactone group shortened less that RAP group, and the frequency adaptability was maintained, the decreased expressions of calcium channel α1C subunit and β1 subunit mRNA significantly reduced. RAP could cause atrial remodeling, while spironolactone could inhibit RAP-induced atrial remodeling. PMID:26826809

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

    DOEpatents

    Blocksome, Michael A.

    2011-09-13

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

  19. Spatial discordance and phase reversals during alternate pacing in discrete-time kinematic and cardiomyocyte ionic models

    NASA Astrophysics Data System (ADS)

    Weinberg, Seth H.

    2015-10-01

    Alternans, a beat-to-beat alternation in the cardiac action potential duration (APD), is a dynamical instability linked with the initiation of arrhythmias and sudden cardiac death, and arises via a period-doubling bifurcation when myocytes are stimulated at fast rates. In this study, we analyze the stability of a propagating electrical wave in a one-dimensional cardiac myocyte model in response to an arrhythmogenic rhythm known as alternate pacing. Using a discrete-time kinematic model and complex frequency (Z) domain analysis, we derive analytical expressions to predict phase reversals and spatial discordance in the interbeat interval (IBI) and APD, which, importantly, cannot be predicted with a model that neglects the influence of cell coupling on repolarization. We identify key dimensionless parameters that determine the transition from spatial concordance to discordance. Finally, we show that the theoretical predictions agree closely with numerical simulations of an ionic myocyte model, over a wide range of parameters, including variable IBI, altered ionic current gating, and reduced cell coupling. We demonstrate a novel approach to predict instability in cardiac tissue during alternate pacing and further illustrate how this approach can be generalized to more detail models of myocyte dynamics.

  20. Understanding the relation between urbanization and the eco-environment in China's Yangtze River Delta using an improved EKC model and coupling analysis.

    PubMed

    Zhao, Yabo; Wang, Shaojian; Zhou, Chunshan

    2016-11-15

    Better understanding the relationship between urbanization (U) and the eco-environment (E) is necessary to coordinate the development of them. Using a comprehensive index system for U and E with statistic data, and an improved environmental Kuznets curve (EKC) model and dynamic coordination coupling degree (CCD) model, this study addressed the relationship between U and E in the Yangtze River Delta (YRD) in the period 1980-2013. The main conclusions were as follows: (1) Economic urbanization and eco-environment endowment were the highest weighted factors in the U and E system respectively, and thus constitute the key factors. (2) Differentiated inverted-U curves were shown to exist in the relation between U and E across the cities studied, thereby confirming the improved EKC hypothesis. We further found economically developed areas to have higher urbanization levels than less developed areas at the point at which the curve inflects, less developed areas have higher eco-environmental pressure at inflection. Before the appearance of the inflection point, a striking positive correlation was observed between eco-environmental pressure and the urbanization level, while a negative correlation was found to follow it. (3) A dynamic coordination coupling relation was found to exist between U and E, which conforms to an S-shaped curve. The coordination coupling process in the YRD has gradually moved from a "low-grade symbiosis" stage into a "break-in development" stage, but the pattern of coordination belonging to the eco-environment part of the relation was found to always show some lag. The dynamic CCD model showed a difference in the spatial distribution of CCD, presenting higher values in the periphery of the region, and lower values in the center during the study period. The improved EKC and coupling analysis detailed in this study may help Chinese decision makers to formulate sustainable measures to balance urbanization development and eco-environment protection.

  1. Understanding the relation between urbanization and the eco-environment in China's Yangtze River Delta using an improved EKC model and coupling analysis.

    PubMed

    Zhao, Yabo; Wang, Shaojian; Zhou, Chunshan

    2016-11-15

    Better understanding the relationship between urbanization (U) and the eco-environment (E) is necessary to coordinate the development of them. Using a comprehensive index system for U and E with statistic data, and an improved environmental Kuznets curve (EKC) model and dynamic coordination coupling degree (CCD) model, this study addressed the relationship between U and E in the Yangtze River Delta (YRD) in the period 1980-2013. The main conclusions were as follows: (1) Economic urbanization and eco-environment endowment were the highest weighted factors in the U and E system respectively, and thus constitute the key factors. (2) Differentiated inverted-U curves were shown to exist in the relation between U and E across the cities studied, thereby confirming the improved EKC hypothesis. We further found economically developed areas to have higher urbanization levels than less developed areas at the point at which the curve inflects, less developed areas have higher eco-environmental pressure at inflection. Before the appearance of the inflection point, a striking positive correlation was observed between eco-environmental pressure and the urbanization level, while a negative correlation was found to follow it. (3) A dynamic coordination coupling relation was found to exist between U and E, which conforms to an S-shaped curve. The coordination coupling process in the YRD has gradually moved from a "low-grade symbiosis" stage into a "break-in development" stage, but the pattern of coordination belonging to the eco-environment part of the relation was found to always show some lag. The dynamic CCD model showed a difference in the spatial distribution of CCD, presenting higher values in the periphery of the region, and lower values in the center during the study period. The improved EKC and coupling analysis detailed in this study may help Chinese decision makers to formulate sustainable measures to balance urbanization development and eco-environment protection. PMID

  2. New horizons in schizophrenia treatment: autophagy protection is coupled with behavioral improvements in a mouse model of schizophrenia

    PubMed Central

    Merenlender-Wagner, Avia; Shemer, Zeev; Touloumi, Olga; Lagoudaki, Roza; Giladi, Eliezer; Andrieux, Annie; Grigoriadis, Nikolaos C; Gozes, Illana

    2015-01-01

    Autophagy plays a key role in the pathophysiology of schizophrenia as manifested by a 40% decrease in BECN1/Beclin 1 mRNA in postmortem hippocampal tissues relative to controls. This decrease was coupled with the deregulation of the essential ADNP (activity-dependent neuroprotector homeobox), a binding partner of MAP1LC3B/LC3B (microtubule-associated protein 1 light chain 3 β) another major constituent of autophagy. The drug candidate NAP (davunetide), a peptide fragment from ADNP, enhanced the ADNP-LC3B interaction. Parallel genetic studies have linked allelic variation in the gene encoding MAP6/STOP (microtubule-associated protein 6) to schizophrenia, along with altered MAP6/STOP protein expression in the schizophrenic brain and schizophrenic-like behaviors in Map6-deficient mice. In this study, for the first time, we reveal significant decreases in hippocampal Becn1 mRNA and reversal by NAP but not by the antipsychotic clozapine (CLZ) in Map6-deficient (Map6+/−) mice. Normalization of Becn1 expression by NAP was coupled with behavioral protection against hyperlocomotion and cognitive deficits measured in the object recognition test. CLZ reduced hyperlocomotion below control levels and did not significantly affect object recognition. The combination of CLZ and NAP resulted in normalized outcome behaviors. Phase II clinical studies have shown NAP-dependent augmentation of functional activities of daily living coupled with brain protection. The current studies provide a new mechanistic pathway and a novel avenue for drug development. PMID:25484074

  3. Improving the photocatalytic activity and anti-photocorrosion of semiconductor ZnO by coupling with versatile carbon.

    PubMed

    Han, Chuang; Yang, Min-Quan; Weng, Bo; Xu, Yi-Jun

    2014-08-28

    Coupling ZnO with carbon materials using a suitable integration method to form ZnO-carbon composites has been established as a promising strategy to ameliorate the photocatalytic performance of semiconductor ZnO. In this perspective article, we describe the recent advances and current status of enhancing the photocatalytic activity and anti-photocorrosion of semiconductor ZnO by coupling with versatile carbon materials, e.g., C60, carbon nanotube, graphene and other carbon materials. The primary roles of carbon materials in boosting the photoactivity and photostability of ZnO have been outlined and illustrated with some selected typical examples. In particular, the three main kinds of mechanisms with regard to anti-photocorrosion of ZnO by coupling with carbon have been demonstrated. Finally, we give a concise perspective on this important research area and specifically propose further research opportunities in optimizing the photocatalytic performance of ZnO-carbon composites and widening the scope of their potential photocatalytic applications.

  4. 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.

  5. An improved quasi-diabatic representation of the 1, 2, 3(1)A coupled adiabatic potential energy surfaces of phenol in the full 33 internal coordinates.

    PubMed

    Zhu, Xiaolei; Malbon, Christopher L; Yarkony, David R

    2016-03-28

    In a recent work we constructed a quasi-diabatic representation, H(d), of the 1, 2, 3(1)A adiabatic states of phenol from high level multireference single and double excitation configuration interaction electronic structure data, energies, energy gradients, and derivative couplings. That H(d) accurately describes surface minima, saddle points, and also regions of strong nonadiabatic interactions, reproducing the locus of conical intersection seams and the coordinate dependence of the derivative couplings. The present work determines the accuracy of H(d) for describing phenol photodissociation. Additionally, we demonstrate that a modest energetic shift of two diabats yields a quantifiably more accurate H(d) compared with experimental energetics. The analysis shows that in favorable circumstances it is possible to use single point energies obtained from the most reliable electronic structure methods available, including methods for which the energy gradients and derivative couplings are not available, to improve the quality of a global representation of several coupled potential energy surfaces. Our data suggest an alternative interpretation of kinetic energy release measurements near λphot ∼ 248 nm.

  6. An improved quasi-diabatic representation of the 1, 2, 31A coupled adiabatic potential energy surfaces of phenol in the full 33 internal coordinates

    NASA Astrophysics Data System (ADS)

    Zhu, Xiaolei; Malbon, Christopher L.; Yarkony, David R.

    2016-03-01

    In a recent work we constructed a quasi-diabatic representation, Hd, of the 1, 2, 31A adiabatic states of phenol from high level multireference single and double excitation configuration interaction electronic structure data, energies, energy gradients, and derivative couplings. That Hd accurately describes surface minima, saddle points, and also regions of strong nonadiabatic interactions, reproducing the locus of conical intersection seams and the coordinate dependence of the derivative couplings. The present work determines the accuracy of Hd for describing phenol photodissociation. Additionally, we demonstrate that a modest energetic shift of two diabats yields a quantifiably more accurate Hd compared with experimental energetics. The analysis shows that in favorable circumstances it is possible to use single point energies obtained from the most reliable electronic structure methods available, including methods for which the energy gradients and derivative couplings are not available, to improve the quality of a global representation of several coupled potential energy surfaces. Our data suggest an alternative interpretation of kinetic energy release measurements near λphot ˜ 248 nm.

  7. Rate-related accelerating (autodecremental) atrial pacing for reversion of paroxysmal supraventricular tachycardia.

    PubMed

    Nathan, A; Hellestrand, K; Ward, D; Spurrell, R; Camm, J

    1982-01-01

    Twenty consecutive patients with paroxysmal intra A-V nodal or atrio-ventricular tachycardia had a new tachycardia reversion pacing modality evaluated during routine electrophysiological study. The pacing was controlled by a micropressor interfaced with a stimulator connected to a right atrial pacing electrode. On detection of tachycardia the first pacing cycle interval is equal to the tachycardia cycle length minus a decrement value D. Each subsequent pacing cycle is further reduced by the same value of D, thus accelerating the pacing burst until a plateau of 100 beats/min faster than tachycardia (with an absolute lower limit of 275 beats/min) is reached. Seven different values of D (2, 4, 8, 16, 24, 34, 50 msec) were assessed in combination with three different durations of pacing P (500, 5000 msec). With P:500, only 2/20 tachycardias were terminated, but with P:1000, 16/20 were terminated. With P:5000 all were terminated and the combination successful in all patients was P:5000 and D:16. No unwanted arrhythmias were induced. In contrast, competitive constant rate overdrive atrial pacing accomplished tachycardia termination in all cases, but in four instances resulted in atrial flutter or fibrillation. Autodecremental pacing, which tends to avoid stimulation in the vulnerable period, allowed safe and successful termination of all tachycardias evaluated in this study. PMID:7069321

  8. Pacing in Olympic track races: competitive tactics versus best performance strategy.

    PubMed

    Thiel, Christian; Foster, Carl; Banzer, Winfried; De Koning, Jos

    2012-01-01

    The purpose of this study was to describe pacing strategies in the 800 to 10,000-m Olympic finals. We asked 1) if Olympic finals differed from World Records, 2) how variable the pace was, 3) whether runners faced catastrophic events, and 4) for the winning strategy. Publically available data from the Beijing 2008 Olympic Games gathered by four transponder antennae under the 400-m track were analysed to extract descriptors of pacing strategies. Individual pacing patterns of 133 finalists were visualised using speed by distance plots. Six of eight plots differed from the patterns reported for World Records. The coefficient of running speed variation was 3.6-11.4%. In the long distance finals, runners varied their pace every 100 m by a mean 1.6-2.7%. Runners who were 'dropped' from the field achieved a stable running speed and displayed an endspurt. Top contenders used variable pacing strategies to separate themselves from the field. All races were decided during the final lap. Olympic track finalists employ pacing strategies which are different from World Record patterns. The observed micro- and macro-variations of pace may have implications for training programmes. Dropping off the pace of the leading group is an active step, and the result of interactive psychophysiological decision making.

  9. Spine-shaped gold protrusions improve the adherence and electrical coupling of neurons with the surface of micro-electronic devices

    PubMed Central

    Hai, Aviad; Dormann, Ada; Shappir, Joseph; Yitzchaik, Shlomo; Bartic, Carmen; Borghs, Gustaaf; Langedijk, J. P. M.; Spira, Micha E.

    2009-01-01

    Interfacing neurons with micro- and nano-electronic devices has been a subject of intense study over the last decade. One of the major problems in assembling efficient neuro-electronic hybrid systems is the weak electrical coupling between the components. This is mainly attributed to the fundamental property of living cells to form and maintain an extracellular cleft between the plasma membrane and any substrate to which they adhere. This cleft shunts the current generated by propagating action potentials and thus reduces the signal-to-noise ratio. Reducing the cleft thickness, and thereby increasing the seal resistance formed between the neurons and the sensing surface, is thus a challenge and could improve the electrical coupling coefficient. Using electron microscopic analysis and field potential recordings, we examined here the use of gold micro-structures that mimic dendritic spines in their shape and dimensions to improve the adhesion and electrical coupling between neurons and micro-electronic devices. We found that neurons cultured on a gold-spine matrix, functionalized by a cysteine-terminated peptide with a number of RGD repeats, readily engulf the spines, forming tight apposition. The recorded field potentials of cultured Aplysia neurons are significantly larger using gold-spine electrodes in comparison with flat electrodes. PMID:19474080

  10. Spine-shaped gold protrusions improve the adherence and electrical coupling of neurons with the surface of micro-electronic devices.

    PubMed

    Hai, Aviad; Dormann, Ada; Shappir, Joseph; Yitzchaik, Shlomo; Bartic, Carmen; Borghs, Gustaaf; Langedijk, J P M; Spira, Micha E

    2009-12-01

    Interfacing neurons with micro- and nano-electronic devices has been a subject of intense study over the last decade. One of the major problems in assembling efficient neuro-electronic hybrid systems is the weak electrical coupling between the components. This is mainly attributed to the fundamental property of living cells to form and maintain an extracellular cleft between the plasma membrane and any substrate to which they adhere. This cleft shunts the current generated by propagating action potentials and thus reduces the signal-to-noise ratio. Reducing the cleft thickness, and thereby increasing the seal resistance formed between the neurons and the sensing surface, is thus a challenge and could improve the electrical coupling coefficient. Using electron microscopic analysis and field potential recordings, we examined here the use of gold micro-structures that mimic dendritic spines in their shape and dimensions to improve the adhesion and electrical coupling between neurons and micro-electronic devices. We found that neurons cultured on a gold-spine matrix, functionalized by a cysteine-terminated peptide with a number of RGD repeats, readily engulf the spines, forming tight apposition. The recorded field potentials of cultured Aplysia neurons are significantly larger using gold-spine electrodes in comparison with flat electrodes.

  11. Pacing and Defibrillators in Complex Congenital Heart Disease

    PubMed Central

    Chubb, Henry; O’Neill, Mark; Rosenthal, Eric

    2016-01-01

    Device therapy in the complex congenital heart disease (CHD) population is a challenging field. There is a myriad of devices available, but none designed specifically for the CHD patient group, and a scarcity of prospective studies to guide best practice. Baseline cardiac anatomy, prior surgical and interventional procedures, existing tachyarrhythmias and the requirement for future intervention all play a substantial role in decision making. For both pacing systems and implantable cardioverter defibrillators, numerous factors impact on the merits of system location (endovascular versus non-endovascular), lead positioning, device selection and device programming. For those with Fontan circulation and following the atrial switch procedure there are also very specific considerations regarding access and potential complications. This review discusses the published guidelines, device indications and the best available evidence for guidance of device implantation in the complex CHD population. PMID:27403295

  12. Coastal oceanography sets the pace of rocky intertidal community dynamics.

    PubMed

    Menge, B A; Lubchenco, J; Bracken, M E S; Chan, F; Foley, M M; Freidenburg, T L; Gaines, S D; Hudson, G; Krenz, C; Leslie, H; Menge, D N L; Russell, R; Webster, M S

    2003-10-14

    The structure of ecological communities reflects a tension among forces that alter populations. Marine ecologists previously emphasized control by locally operating forces (predation, competition, and disturbance), but newer studies suggest that inputs from large-scale oceanographically modulated subsidies (nutrients, particulates, and propagules) can strongly influence community structure and dynamics. On New Zealand rocky shores, the magnitude of such subsidies differs profoundly between contrasting oceanographic regimes. Community structure, and particularly the pace of community dynamics, differ dramatically between intermittent upwelling regimes compared with relatively persistent down-welling regimes. We suggest that subsidy rates are a key determinant of the intensity of species interactions, and thus of structure in marine systems, and perhaps also nonmarine communities.

  13. Listeners lengthen phrase boundaries in self-paced music.

    PubMed

    Kragness, Haley E; Trainor, Laurel J

    2016-10-01

    Previous work has shown that musicians tend to slow down as they approach phrase boundaries (). In the present experiments, we used a paradigm from the action perception literature, the dwell time paradigm (Hard, Recchia, & Tversky, 2011), to investigate whether participants engage in phrase boundary lengthening when self-pacing through musical sequences. When participants used a key press to produce each successive chord of Bach chorales, they dwelled longer on boundary chords than nonboundary chords in both the original chorales and atonal manipulations of the chorales. When a novel musical sequence was composed that controlled for metrical and melodic contour cues to boundaries, the dwell time difference between boundaries and nonboundaries was greater in the tonal condition than in the atonal condition. Furthermore, similar results were found for a group of nonmusicians, suggesting that phrase-final lengthening in musical production is not dependent on musical training and can be evoked by harmonic cues. (PsycINFO Database Record PMID:27379872

  14. Self-paced freshman physics laboratory and student assessment

    NASA Astrophysics Data System (ADS)

    Patterson, J. R.; Prescott, J. R.

    1980-02-01

    Laboratory work is included as an essential part of any physics course because it teaches the student aspects of physics that are distinct from lecture material and that can be learned in no other way. For the same reason it presents its own problems in assessment, particularly in large first-year university classes. For the last five years we have been putting into practice a form of self-paced laboratory experience and assessment. The laboratory is design oriented. The grade for the course is determined by the aggregation of point values for a variable number of experiments completed in a fixed period of time to a satisfactory standard. The marks feature a degree of discrimination comparable to written theory examinations. Within the limits imposed by class size, the student has a fair degree of freedom of choice.

  15. Nuclear magnetic resonance imaging in patients with cardiac pacing devices.

    PubMed

    Buendía, Francisco; Sánchez-Gómez, Juan M; Sancho-Tello, María J; Olagüe, José; Osca, Joaquín; Cano, Oscar; Arnau, Miguel A; Igual, Begoña

    2010-06-01

    Currently, nuclear magnetic resonance imaging is contraindicated in patients with a pacemaker or implantable cardioverter-defibrillator. This study was carried out because the potential risks in this situation need to be clearly defined. This prospective study evaluated clinical and electrical parameters before and after magnetic resonance imaging was performed in 33 patients (five with implantable cardioverter-defibrillators and 28 with pacemakers). In these patients, magnetic resonance imaging was considered clinically essential. There were no clinical complications. There was a temporary communication failure in two cases, sensing errors during imaging in two cases, and a safety signal was generated in one pacemaker at the maximum magnetic resonance frequency and output level. There were no technical restrictions on imaging nor were there any permanent changes in the performance of the cardiac pacing device. PMID:20515632

  16. Listeners lengthen phrase boundaries in self-paced music.

    PubMed

    Kragness, Haley E; Trainor, Laurel J

    2016-10-01

    Previous work has shown that musicians tend to slow down as they approach phrase boundaries (). In the present experiments, we used a paradigm from the action perception literature, the dwell time paradigm (Hard, Recchia, & Tversky, 2011), to investigate whether participants engage in phrase boundary lengthening when self-pacing through musical sequences. When participants used a key press to produce each successive chord of Bach chorales, they dwelled longer on boundary chords than nonboundary chords in both the original chorales and atonal manipulations of the chorales. When a novel musical sequence was composed that controlled for metrical and melodic contour cues to boundaries, the dwell time difference between boundaries and nonboundaries was greater in the tonal condition than in the atonal condition. Furthermore, similar results were found for a group of nonmusicians, suggesting that phrase-final lengthening in musical production is not dependent on musical training and can be evoked by harmonic cues. (PsycINFO Database Record

  17. Improved Measurement of 3J(H αi, N i+1 ) Coupling Constants in H 2O Dissolved Proteins

    NASA Astrophysics Data System (ADS)

    Löhr, Frank; Schmidt, Jürgen M.; Maurer, Steffen; Rüterjans, Heinz

    2001-11-01

    A modification to the recently proposed α/β-HN(CO)CA-J TROSY pulse sequence (P. Permi et al., J. Magn. Reson.146, 255-259 (2000)) makes it possible to determine 3J(Hαi, Ni+1) coupling constants from a single E.COSY-type cross-peak pattern rather than from two 1Hα spin-state-edited subspectra. Advantages are increased 15N resolution, critical to extracting accurate 1Hα-15N coupling constants, and minimized differential relaxation due to nested 13Cα and 15N evolution periods. Application of the improved pulse sequence to Desulfovibrio vulgaris flavodoxin results in 3J(Hαi, Ni+1) values being systematically larger than those obtained with the original scheme. Parametrization of the coupling dependence on the protein backbone torsion angle ψ yields the Karplus relation 3J(Hαi, Ni+1)=-1.00 cos2(ψ-120°)+0.65 cos(ψ-120°)-0.15 Hz, with a residual root-mean-square difference of 0.13 Hz between measured and back-calculated coupling constants. The curve compares with data derived from ubiquitin (A. C. Wang and A. Bax, J. Am. Chem. Soc.117, 1810-1813 (1995)), although spanning a slightly larger range of J values in flavodoxin. The orientation of the Ala39/Ser40 peptide link, forming a type-II β-turn in flavodoxin, is twisted against X-ray-derived torsions by approximately 10° in the NMR structure as evident from the analysis of φ- and ψ-related 3J coupling constants. The remaining deviation of some experimental values from the prediction is likely to be due to strong hydrogen bonding, substituent effects, or the additional dependence on the adjacent torsions φ.

  18. Ab Initio and Improved Empirical Potentials for the Calculation of the Anharmonic Vibrational States and Intramolecular Mode Coupling of N-Methylacetamide

    NASA Technical Reports Server (NTRS)

    Gregurick, Susan K.; Chaban, Galina M.; Gerber, R. Benny; Kwak, Dochou (Technical Monitor)

    2001-01-01

    The second-order Moller-Plesset ab initio electronic structure method is used to compute points for the anharmonic mode-coupled potential energy surface of N-methylacetamide (NMA) in the trans(sub ct) configuration, including all degrees of freedom. The vibrational states and the spectroscopy are directly computed from this potential surface using the Correlation Corrected Vibrational Self-Consistent Field (CC-VSCF) method. The results are compared with CC-VSCF calculations using both the standard and improved empirical Amber-like force fields and available low temperature experimental matrix data. Analysis of our calculated spectroscopic results show that: (1) The excellent agreement between the ab initio CC-VSCF calculated frequencies and the experimental data suggest that the computed anharmonic potentials for N-methylacetamide are of a very high quality; (2) For most transitions, the vibrational frequencies obtained from the ab initio CC-VSCF method are superior to those obtained using the empirical CC-VSCF methods, when compared with experimental data. However, the improved empirical force field yields better agreement with the experimental frequencies as compared with a standard AMBER-type force field; (3) The empirical force field in particular overestimates anharmonic couplings for the amide-2 mode, the methyl asymmetric bending modes, the out-of-plane methyl bending modes, and the methyl distortions; (4) Disagreement between the ab initio and empirical anharmonic couplings is greater than the disagreement between the frequencies, and thus the anharmonic part of the empirical potential seems to be less accurate than the harmonic contribution;and (5) Both the empirical and ab initio CC-VSCF calculations predict a negligible anharmonic coupling between the amide-1 and other internal modes. The implication of this is that the intramolecular energy flow between the amide-1 and the other internal modes may be smaller than anticipated. These results may have

  19. The Influence of Collective Behavior on Pacing in Endurance Competitions.

    PubMed

    Renfree, Andrew; Crivoi do Carmo, Everton; Martin, Louise; Peters, Derek M

    2015-01-01

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

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

    PubMed Central

    Link, Daniel; de Lorenzo, Michael F.

    2016-01-01

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

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

    PubMed

    Link, Daniel; de Lorenzo, Michael F

    2016-01-01

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

  2. The Influence of Collective Behavior on Pacing in Endurance Competitions

    PubMed Central

    Renfree, Andrew; Crivoi do Carmo, Everton; Martin, Louise; Peters, Derek M.

    2015-01-01

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

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

    PubMed

    Link, Daniel; de Lorenzo, Michael F

    2016-01-01

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

  4. A two-dimensional coupled flow-mass transport model based on an improved unstructured finite volume algorithm.

    PubMed

    Zhou, Jianzhong; Song, Lixiang; Kursan, Suncana; Liu, Yi

    2015-05-01

    A two-dimensional coupled water quality model is developed for modeling the flow-mass transport in shallow water. To simulate shallow flows on complex topography with wetting and drying, an unstructured grid, well-balanced, finite volume algorithm is proposed for numerical resolution of a modified formulation of two-dimensional shallow water equations. The slope-limited linear reconstruction method is used to achieve second-order accuracy in space. The algorithm adopts a HLLC-based integrated solver to compute the flow and mass transport fluxes simultaneously, and uses Hancock's predictor-corrector scheme for efficient time stepping as well as second-order temporal accuracy. The continuity and momentum equations are updated in both wet and dry cells. A new hybrid method, which can preserve the well-balanced property of the algorithm for simulations involving flooding and recession, is proposed for bed slope terms approximation. The effectiveness and robustness of the proposed algorithm are validated by the reasonable good agreement between numerical and reference results of several benchmark test cases. Results show that the proposed coupled flow-mass transport model can simulate complex flows and mass transport in shallow water.

  5. A two-dimensional coupled flow-mass transport model based on an improved unstructured finite volume algorithm.

    PubMed

    Zhou, Jianzhong; Song, Lixiang; Kursan, Suncana; Liu, Yi

    2015-05-01

    A two-dimensional coupled water quality model is developed for modeling the flow-mass transport in shallow water. To simulate shallow flows on complex topography with wetting and drying, an unstructured grid, well-balanced, finite volume algorithm is proposed for numerical resolution of a modified formulation of two-dimensional shallow water equations. The slope-limited linear reconstruction method is used to achieve second-order accuracy in space. The algorithm adopts a HLLC-based integrated solver to compute the flow and mass transport fluxes simultaneously, and uses Hancock's predictor-corrector scheme for efficient time stepping as well as second-order temporal accuracy. The continuity and momentum equations are updated in both wet and dry cells. A new hybrid method, which can preserve the well-balanced property of the algorithm for simulations involving flooding and recession, is proposed for bed slope terms approximation. The effectiveness and robustness of the proposed algorithm are validated by the reasonable good agreement between numerical and reference results of several benchmark test cases. Results show that the proposed coupled flow-mass transport model can simulate complex flows and mass transport in shallow water. PMID:25686488

  6. Improved feedback control of wall stabilized kink modes with different plasma-wall couplings and mode rotation

    NASA Astrophysics Data System (ADS)

    Peng, Q.; Levesque, J. P.; Stoafer, C. C.; Bialek, J.; Byrne, P.; Hughes, P. E.; Mauel, M. E.; Navratil, G. A.; Rhodes, D. J.

    2016-04-01

    A new algorithm for feedback control of rotating, wall-stabilized kink modes in the High Beta Tokamak-Extended Pulse (HBT-EP) device maintains an accurate phase shift between the perturbation and the measured rotating mode through current control, with control power emphasizing fast rotation and phase jumps over fast amplitude changes. In HBT-EP, wall-stabilized kink modes become unstable above the ideal wall stability limit, and feedback suppression is aimed at delaying the onset of discharge disruption through reduction of the kink mode amplitude. Performance of the new feedback algorithm is tested under different experimental conditions, including variation of the plasma-wall coupling, insertion of a ferritic wall, changing mode rotation frequency over the range of 4-8 kHz using an internal biased electrode, and adjusting the feedback phase-angle to accelerate, amplify, or suppress the mode. We find the previously reported excitation of the slowly rotating mode at high feedback gain in HBT-EP is mitigated by the current control scheme. We also find good agreement between the observed and predicted changes to the mode rotation frequency and amplitude. When ferritic material is introduced, or the plasma-wall coupling becomes weaker as the walls are retracted from plasma, the feedback gain needs to be increased to achieve the same level of suppression. When mode rotation is slowed by a biased electrode, the feedback system still achieves mode suppression, and demonstrates wide bandwidth effectiveness.

  7. Head-to-head running race simulation alters pacing strategy, performance, and mood state.

    PubMed

    Tomazini, Fabiano; Pasqua, Leonardo A; Damasceno, Mayara V; Silva-Cavalcante, Marcos D; de Oliveira, Fernando R; Lima-Silva, Adriano E; Bertuzzi, Rômulo

    2015-10-01

    The objective of this study was to analyze the influence of the presence and absence of competitors on pacing, overall running performance, and mood state during a self-paced 3-km run. Nine recreational runners participated in this study. They performed the following tests: a) an incremental test to exhaustion to measure the respiratory compensation point (RCP), maximal oxygen uptake, and peak treadmill speed; b) a submaximal speed constant test to measure running economy; and c) two 3-km running time trials performed collectively (COL, head-to-head competition) or individually (IND, performed alone) to establish pacing and running performance. The COL condition was formed of a group of four runners or five runners. Runners were grouped by matched performance times and to retain head-to-head characteristics.A mood state profile questionnaire was completed before and after the 3-km running time trial. The overall performance was better in the COL than in the IND (11.75 ± 0.05 min vs. 12.25 ± 0.06 min, respectively; p = 0.04). The running speeds during the first 500 m were significantly greater in COL (16.8 ± 2.16 km·h−1) than in IND (15.3 ± 2.45 km·h−1) (p = 0.03).The gain in running speed from IND to COL during the first 400 m (i.e. running speed in COL less running speed in IND) was significantly correlated with the RCP (r = 0.88; p = 0.05). The vigor score significantly decreased from pre- to post-running in COL (p=0.05), but not in IND (p=0.20). Additionally, the post running vigor was significantly higher in IND compared to COL (p = 0.03).These findings suggested that the presence of competitors induces a fast start, which results in an improved overall performance and reduced post-exercise vigor scores, compared to an individual run.

  8. Head-to-head running race simulation alters pacing strategy, performance, and mood state.

    PubMed

    Tomazini, Fabiano; Pasqua, Leonardo A; Damasceno, Mayara V; Silva-Cavalcante, Marcos D; de Oliveira, Fernando R; Lima-Silva, Adriano E; Bertuzzi, Rômulo

    2015-10-01

    The objective of this study was to analyze the influence of the presence and absence of competitors on pacing, overall running performance, and mood state during a self-paced 3-km run. Nine recreational runners participated in this study. They performed the following tests: a) an incremental test to exhaustion to measure the respiratory compensation point (RCP), maximal oxygen uptake, and peak treadmill speed; b) a submaximal speed constant test to measure running economy; and c) two 3-km running time trials performed collectively (COL, head-to-head competition) or individually (IND, performed alone) to establish pacing and running performance. The COL condition was formed of a group of four runners or five runners. Runners were grouped by matched performance times and to retain head-to-head characteristics.A mood state profile questionnaire was completed before and after the 3-km running time trial. The overall performance was better in the COL than in the IND (11.75 ± 0.05 min vs. 12.25 ± 0.06 min, respectively; p = 0.04). The running speeds during the first 500 m were significantly greater in COL (16.8 ± 2.16 km·h−1) than in IND (15.3 ± 2.45 km·h−1) (p = 0.03).The gain in running speed from IND to COL during the first 400 m (i.e. running speed in COL less running speed in IND) was significantly correlated with the RCP (r = 0.88; p = 0.05). The vigor score significantly decreased from pre- to post-running in COL (p=0.05), but not in IND (p=0.20). Additionally, the post running vigor was significantly higher in IND compared to COL (p = 0.03).These findings suggested that the presence of competitors induces a fast start, which results in an improved overall performance and reduced post-exercise vigor scores, compared to an individual run. PMID:26013576

  9. A role for PACE4 in the proteolytic activation of anthrax toxin protective antigen.

    PubMed Central

    Gordon, V M; Rehemtulla, A; Leppla, S H

    1997-01-01

    Several bacterial protein toxins require activation by eukaryotic proteases. Previous studies have shown that anthrax toxin protective antigen (PA), Pseudomonas exotoxin A (PE), and diphtheria toxin (DT) are cleaved by furin C-terminal to the sequences RKKR, RQPR, and RVRR, respectively. Because furin-deficient cells retain some sensitivity to PA and DT, it is evident that other cellular proteases can activate these toxins. Whereas furin has been shown to require arginine residues at positions -1 and -4 for substrate recognition, another protease with an activity which could substitute for furin in toxin activation, the furin-related protease PACE4, requires basic residues in the -1, -2, and -4 positions of the substrate sequence. To examine the relative roles of furin and PACE4 in toxin activation, we used furin-deficient CHO cells (FD11 cells) transfected with either the furin (FD11/furin cells) or PACE4 (FD11/PACE4 cells) gene. Mutant PA proteins containing the cleavage sequence RAAR or KR were cytotoxic toward cells expressing only PACE4. In vitro cleavage data demonstrated that PACE4 can recognize RAAR and, to a much lesser extent, KR and RR. When extracts from PACE4-transfected cells were used as a source of proteases, PACE4 had minimal activity, indicating that it had been partially inactivated or did not remain associated with the cell membranes. Cleavage of iodinated PA containing the sequence RKKR or RAAR was detected on the surface of all cell types tested, but cleavage of a dibasic sequence was detected only intracellularly and only in cells that expressed furin or PACE4. The data provide evidence that PACE4 is present at the exterior of cells, that it plays a role in the proteolytic activation of anthrax toxin PA, and that PACE4 can activate substrates at the sequence RAAR or KR. PMID:9234799

  10. Improved SERS sensitivity on plasmon-free TiO₂ photonic microarray by enhancing light-matter coupling.

    PubMed

    Qi, Dianyu; Lu, Liujia; Wang, Lingzhi; Zhang, Jinlong

    2014-07-16

    Highly sensitive surface-enhanced Raman scattering (SERS) detection was achieved on plasmon-free TiO2 photonic artificial microarray, which can be quickly recovered under simulated solar light irradiation and repeatedly used. The sensitive detection performance is attributed to the enhanced matter-light interaction through repeated and multiple light scattering in photonic microarray. Moreover, the SERS sensitivity is unprecedentedly found to be dependent on the different light-coupling performance of microarray with various photonic band gaps, where microarray with band gap center near to laser wavelength shows a lower SERS signal due to depressed light propagation, while those with band gap edges near to laser wavelength show higher sensitivity due to slow light effect.

  11. Improvements on high-precision measurement of bromine isotope ratios by multicollector inductively coupled plasma mass spectrometry.

    PubMed

    Wei, Hai-Zhen; Jiang, Shao-Yong; Zhu, Zhi-Yong; Yang, Tao; Yang, Jing-Hong; Yan, Xiong; Wu, He-Pin; Yang, Tang-Li

    2015-10-01

    A new, feasible procedure for high-precision bromine isotope analysis using multicollector inductively coupled plasma mass spectrometry (MC-ICP-MS) is described. With a combination of HR mass resolution mode and accurate optimization of the Zoom Optics parameters (Focus Quad: -1.30; Zoom Quad: 0.00), the challenging problem of the isobaric interferences ((40)Ar(38)ArH(+) and (40)Ar(40)ArH(+)) in the measurement of bromine isotopes ((79)Br(+), (81)Br(+)) has been effectively solved. The external reproducibility of the measured (81)Br/(79)Br ratios in the selected standard reference materials ranged from ±0.03‰ to ±0.14‰, which is superior to or equivalent to the best results from previous contributions. The effect of counter cations on the Br(+) signal intensity and the instrumental-induced mass bias was evaluated as the loss of HBr aerosol in nebulizer and potential diffusive isotope fractionations.

  12. The Potential of Soft Soil Improvement Through a Coupled Technique Between Electro Kinetic and Alkaline Activation of Soft Soil

    NASA Astrophysics Data System (ADS)

    Ahmed, G. E.; Ismail, H. B.; Huat, B. K.; Afshin, A.; Azhar, A. T. S.

    2016-07-01

    Soil stabilization techniques have been in development for decades with different rates of success. Alkaline activation of soft soil is one of those techniques that has proved to deliver some of the best shear strength values with minor drawbacks in comparison with conventional soil stabilization methods. However, environmental considerations have not been taken into account, as major mineral glassy phase activators are poisoning alkaline solutions, such as sodium-, potassium-hydroxide, and sodium-, potassium-silicate, which poses serious hazards to man and environment. This paper addresses the ways of discarding the involvement of the aforementioned alkaline solutions in soft soil stabilization by investigating the potential of a coupled electro kinetic alkaline activation technique for soft soil strengthening, through which the provision of alkaline pH is governed by electro kinetic potential. Uncertainties in regard to the dissolution of aluminosilicate as well as the dominance of acidic front are challenges that need to be overcome.

  13. Improving sensitivity in microchip electrophoresis coupled to ESI-MS/MS on the example of a cardiac drug mixture.

    PubMed

    Schwarzkopf, Fabian; Scholl, Tobias; Ohla, Stefan; Belder, Detlev

    2014-07-01

    A comprehensive study for a sensitivity optimization in MCE with mass spectrometric detection is presented. As a text mixture, we chose a mixture of the cardiac drugs propranolol, bisoprolol, lidocaine, procaine and studied the effect of different chip layouts and experimental parameters with the aim of achieving both high sensitivity in MS detection and adequate chip electrophoretic separation. An important aspect was a comparison of microfluidic layouts containing various sheath-flow channels with that avoiding sheath-flow junctions on-chip. We utilized glass chips with monolithically integrated nanospray emitter tips coupled dead volume-free to an IT mass spectrometer running in fragmentation mode (MS(n) ). With this setup, detection limits down to 0.6 ng/mL for the model compound propranolol were achieved.

  14. Improvement of Mitochondria Extract from Saccharomyces cerevisiae Characterization in Shotgun Proteomics Using Sheathless Capillary Electrophoresis Coupled to Tandem Mass Spectrometry.

    PubMed

    Ibrahim, Marianne; Gahoual, Rabah; Enkler, Ludovic; Becker, Hubert Dominique; Chicher, Johana; Hammann, Philippe; François, Yannis-Nicolas; Kuhn, Lauriane; Leize-Wagner, Emmanuelle

    2016-04-01

    In this work, we describe the characterization of a quantity-limited sample (100 ng) of yeast mitochondria by shotgun bottom-up proteomics. Sample characterization was carried out by sheathless capillary electrophoresis, equipped with a high sensitivity porous tip and coupled to tandem mass spectrometry (CESI-MS-MS) and concomitantly with a state-of-art nano flow liquid chromatography coupled to a similar mass spectrometry (MS) system (nanoLC-MS-MS). With single injections, both nanoLC-MS-MS and CESI-MS-MS 60 min-long separation experiments allowed us to identify 271 proteins (976 unique peptides) and 300 proteins (1,765 unique peptides) respectively, demonstrating a significant specificity and complementarity in identification depending on the physicochemical separation employed. Such complementary, maximizing the number of analytes detected, presents a powerful tool to deepen a biological sample's proteomic characterization. A comprehensive study of the specificity provided by each separating technique was also performed using the different properties of the identified peptides: molecular weight, mass-to-charge ratio (m/z), isoelectric point (pI), sequence coverage or MS-MS spectral quality enabled to determine the contribution of each separation. For example, CESI-MS-MS enables to identify larger peptides and eases the detection of those having extreme pI without impairing spectral quality. The addition of peptides, and therefore proteins identified by both techniques allowed us to increase significantly the sequence coverages and then the confidence of characterization. In this study, we also demonstrated that the two yeast enolase isoenzymes were both characterized in the CESI-MS-MS data set. The observation of discriminant proteotypic peptides is facilitated when a high number of precursors with high-quality MS-MS spectra are generated. PMID:26860395

  15. Improvement of Mitochondria Extract from Saccharomyces cerevisiae Characterization in Shotgun Proteomics Using Sheathless Capillary Electrophoresis Coupled to Tandem Mass Spectrometry.

    PubMed

    Ibrahim, Marianne; Gahoual, Rabah; Enkler, Ludovic; Becker, Hubert Dominique; Chicher, Johana; Hammann, Philippe; François, Yannis-Nicolas; Kuhn, Lauriane; Leize-Wagner, Emmanuelle

    2016-04-01

    In this work, we describe the characterization of a quantity-limited sample (100 ng) of yeast mitochondria by shotgun bottom-up proteomics. Sample characterization was carried out by sheathless capillary electrophoresis, equipped with a high sensitivity porous tip and coupled to tandem mass spectrometry (CESI-MS-MS) and concomitantly with a state-of-art nano flow liquid chromatography coupled to a similar mass spectrometry (MS) system (nanoLC-MS-MS). With single injections, both nanoLC-MS-MS and CESI-MS-MS 60 min-long separation experiments allowed us to identify 271 proteins (976 unique peptides) and 300 proteins (1,765 unique peptides) respectively, demonstrating a significant specificity and complementarity in identification depending on the physicochemical separation employed. Such complementary, maximizing the number of analytes detected, presents a powerful tool to deepen a biological sample's proteomic characterization. A comprehensive study of the specificity provided by each separating technique was also performed using the different properties of the identified peptides: molecular weight, mass-to-charge ratio (m/z), isoelectric point (pI), sequence coverage or MS-MS spectral quality enabled to determine the contribution of each separation. For example, CESI-MS-MS enables to identify larger peptides and eases the detection of those having extreme pI without impairing spectral quality. The addition of peptides, and therefore proteins identified by both techniques allowed us to increase significantly the sequence coverages and then the confidence of characterization. In this study, we also demonstrated that the two yeast enolase isoenzymes were both characterized in the CESI-MS-MS data set. The observation of discriminant proteotypic peptides is facilitated when a high number of precursors with high-quality MS-MS spectra are generated.

  16. Improved energy coupling into the gain region of the Ni-like Pd transient collisional x-ray laser

    SciTech Connect

    Smith, R; Dunn, J; Filevich, J; Moon, S; Nilsen, J; Keenan, R; Shlyaptsev, V; Rocca, J; Hunter, J; Shepherd, R; Booth, R; Marconi, M

    2004-10-05

    We present within this paper a series of experiments, which yield new observations to further our understanding of the transient collisional x-ray laser medium. We use the recently developed technique of picosecond x-ray laser interferometry to probe the plasma conditions in which the x-ray laser is generated and propagates. This yields two dimensional electron density maps of the plasma taken at different times relative to the peak of the 600ps plasma-forming beam. In another experimental campaign, the output of the x-ray laser plasma column is imaged with a spherical multilayer mirror onto a CCD camera to give a two-dimensional intensity map of the x-ray laser output. Near-field imaging gives insights into refraction, output intensity and spatial mode structure. Combining these images with the density maps gives an indication of the electron density at which the x-ray laser is being emitted at (yielding insights into the effect of density gradients on beam propagation). Experimental observations coupled with simulations predict that most effective coupling of laser pump energy occurs when the duration of the main heating pulse is comparable to the gain lifetime ({approx}10ps for Ni-like schemes). This can increase the output intensity by more than an order of magnitude relative to the case were the same pumping energy is delivered within a shorter heating pulse duration (< 3ps). We have also conducted an experiment in which the output of the x-ray laser was imaged onto the entrance slit of a high temporal resolution streak camera. This effectively takes a one-dimensional slice of the x-ray laser spatial profile and sweeps it in time. Under some conditions we observe rapid movement of the x-ray laser ({approx} 3 {micro}m/ps) towards the target surface.

  17. Low-Sodium DASH Diet Improves Diastolic Function and Ventricular-Arterial Coupling in Hypertensive Heart Failure with Preserved Ejection Fraction

    PubMed Central

    Hummel, Scott L.; Seymour, E. Mitchell; Brook, Robert D.; Sheth, Samar S.; Ghosh, Erina; Zhu, Simeng; Weder, Alan B.; Kovács, Sándor J.; Kolias, Theodore J.

    2014-01-01

    Background Heart failure with preserved ejection fraction (HFPEF) involves failure of cardiovascular reserve in multiple domains. In HFPEF animal models, dietary sodium restriction improves ventricular and vascular stiffness and function. We hypothesized that the sodium-restricted Dietary Approaches to Stop Hypertension diet (DASH/SRD) would improve left ventricular diastolic function, arterial elastance, and ventricular-arterial (V-A) coupling in hypertensive HFPEF. Methods and Results Thirteen patients with treated hypertension and compensated HFPEF consumed the DASH/SRD (target sodium 50 mmol/2100 kcal) for 21 days. We measured baseline and post-DASH/SRD brachial and central BP (via radial arterial tonometry), and cardiovascular function with echocardiographic measures (all previously invasively validated). Diastolic function was quantified via the Parametrized Diastolic Filling formalism, which yields relaxation/viscoelastic (c) and passive/stiffness (k) constants through analysis of Doppler mitral inflow velocity (E-wave) contours. Effective arterial elastance (Ea) end-systolic elastance (Ees), and V-A coupling (defined as the ratio Ees:Ea) were determined using previously published techniques. Wilcoxon matched-pairs tests were used for pre-post comparisons. The DASH/SRD reduced clinic and 24-hour brachial systolic pressure (155±35 to 138±30 and 130±16 to 123±18 mmHg, both p=.02) and central end-systolic pressure trended lower (116±18 to 111±16 mmHg, p=.12). In conjunction, diastolic function improved (c, 24.3±5.3 to 22.7±8.1 s−1;p=.03; k, 252±115 to 170±37 s−1;p=.03), Ea decreased (2.0±0.4 to 1.7±0.4 mmHg/ml;p=.007), and V-A coupling improved (Ees:Ea, 1.5±0.3 to 1.7±0.4;p=.04). Conclusions In hypertensive HFPEF patients, the sodium-restricted DASH diet was associated with favorable changes in ventricular diastolic function, arterial elastance, and V-A coupling. PMID:23985432

  18. Short-coupled variant of Torsade de Pointes as a cause of electrical storm and aborted sudden cardiac death: insights into mechanism and treatment.

    PubMed

    Chiladakis, John A; Spiroulias, Georgios; Koutsogiannis, Nikolaos; Zagli, Fani; Alexopoulos, Dimritrios

    2008-01-01

    This case report describes a 50-year-old woman with normal repolarization duration who survived multiple electrical storms and cardiac arrest related to recurrent short-coupled torsade de pointes (TdP). Overdrive ventricular pacing could not prevent malignant TdP, but exposed a pause-related TdP initiation pattern. Isoproterenol and atrial pacing completely suppressed TdP, suggesting that ventricular pacing may entail vulnerability to this condition.

  19. Integrating mobile technology with routine dietetic practice: the case of myPace for weight management.

    PubMed

    Harricharan, Michelle; Gemen, Raymond; Celemín, Laura Fernández; Fletcher, David; de Looy, Anne E; Wills, Josephine; Barnett, Julie

    2015-05-01

    The field of Mobile health (mHealth), which includes mobile phone applications (apps), is growing rapidly and has the potential to transform healthcare by increasing its quality and efficiency. The present paper focuses particularly on mobile technology for body weight management, including mobile phone apps for weight loss and the available evidence on their effectiveness. Translation of behaviour change theory into weight management strategies, including integration in mobile technology is also discussed. Moreover, the paper presents and discusses the myPace platform as a case in point. There is little clinical evidence on the effectiveness of currently available mobile phone apps in enabling behaviour change and improving health-related outcomes, including sustained body weight loss. Moreover, it is unclear to what extent these apps have been developed in collaboration with health professionals, such as dietitians, and the extent to which apps draw on and operationalise behaviour change techniques has not been explored. Furthermore, presently weight management apps are not built for use as part of dietetic practice, or indeed healthcare more widely, where face-to-face engagement is fundamental for instituting the building blocks for sustained lifestyle change. myPace is an innovative mobile technology for weight management meant to be embedded into and to enhance dietetic practice. Developed out of systematic, iterative stages of engagement with dietitians and consumers, it is uniquely designed to complement and support the trusted health practitioner-patient relationship. Future mHealth technology would benefit if engagement with health professionals and/or targeted patient groups, and behaviour change theory stood as the basis for technology development. Particularly, integrating technology into routine health care practice, rather than replacing one with the other, could be the way forward.

  20. PACE Continuous Innovation Indicators—a novel tool to measure progress in cancer treatments

    PubMed Central

    Paddock, Silvia; Brum, Lauren; Sorrow, Kathleen; Thomas, Samuel; Spence, Susan; Maulbecker-Armstrong, Catharina; Goodman, Clifford; Peake, Michael; McVie, Gordon; Geipel, Gary; Li, Rose

    2015-01-01

    Concerns about rising health care costs and the often incremental nature of improvements in health outcomes continue to fuel intense debates about ‘progress’ and ‘value’ in cancer research. In times of tightening fiscal constraints, it is increasingly important for patients and their representatives to define what constitutes ’value’ to them. It is clear that diverse stakeholders have different priorities. Harmonisation of values may be neither possible nor desirable. Stakeholders lack tools to visualise or otherwise express these differences and to track progress in cancer treatments based on variable sets of values. The Patient Access to Cancer care Excellence (PACE) Continuous Innovation Indicators are novel, scientifically rigorous progress trackers that employ a three-step process to quantify progress in cancer treatments: 1) mine the literature to determine the strength of the evidence supporting each treatment; 2) allow users to weight the analysis according to their priorities and values; and 3) calculate Evidence Scores (E-Scores), a novel measure to track progress, based on the strength of the evidence weighted by the assigned value. We herein introduce a novel, flexible value model, show how the values from the model can be used to weight the evidence from the scientific literature to obtain E-Scores, and illustrate how assigning different values to new treatments influences the E-Scores. The Indicators allow users to learn how differing values lead to differing assessments of progress in cancer research and to check whether current incentives for innovation are aligned with their value model. By comparing E-Scores generated by this tool, users are able to visualise the relative pace of innovation across areas of cancer research and how stepwise innovation can contribute to substantial progress against cancer over time. Learning from experience and mapping current unmet needs will help to support a broad audience of stakeholders in their

  1. PACE Continuous Innovation Indicators-a novel tool to measure progress in cancer treatments.

    PubMed

    Paddock, Silvia; Brum, Lauren; Sorrow, Kathleen; Thomas, Samuel; Spence, Susan; Maulbecker-Armstrong, Catharina; Goodman, Clifford; Peake, Michael; McVie, Gordon; Geipel, Gary; Li, Rose

    2015-01-01

    Concerns about rising health care costs and the often incremental nature of improvements in health outcomes continue to fuel intense debates about 'progress' and 'value' in cancer research. In times of tightening fiscal constraints, it is increasingly important for patients and their representatives to define what constitutes 'value' to them. It is clear that diverse stakeholders have different priorities. Harmonisation of values may be neither possible nor desirable. Stakeholders lack tools to visualise or otherwise express these differences and to track progress in cancer treatments based on variable sets of values. The Patient Access to Cancer care Excellence (PACE) Continuous Innovation Indicators are novel, scientifically rigorous progress trackers that employ a three-step process to quantify progress in cancer treatments: 1) mine the literature to determine the strength of the evidence supporting each treatment; 2) allow users to weight the analysis according to their priorities and values; and 3) calculate Evidence Scores (E-Scores), a novel measure to track progress, based on the strength of the evidence weighted by the assigned value. We herein introduce a novel, flexible value model, show how the values from the model can be used to weight the evidence from the scientific literature to obtain E-Scores, and illustrate how assigning different values to new treatments influences the E-Scores. The Indicators allow users to learn how differing values lead to differing assessments of progress in cancer research and to check whether current incentives for innovation are aligned with their value model. By comparing E-Scores generated by this tool, users are able to visualise the relative pace of innovation across areas of cancer research and how stepwise innovation can contribute to substantial progress against cancer over time. Learning from experience and mapping current unmet needs will help to support a broad audience of stakeholders in their efforts to

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

    ERIC Educational Resources Information Center

    Lefstein, Adam; Snell, Julia

    2013-01-01

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

  3. Locating the Business. PACE Revised. Level 1. Unit 7. Research & Development Series No. 240AB7.

    ERIC Educational Resources Information Center

    Ashmore, M. Catherine; Pritz, Sandra G.

    This lesson on locating a business, the seventh in a series of 18 units, is part of the first level of a comprehensive entrepreneurship curriculum entitled: A Program for Acquiring Competence in Entrepreneurship (PACE). (Designed for use with secondary students, the first level of PACE introduces students to the concepts involved in…

  4. Effects of Pacing and Cognitive Style across Dynamic and Non-Dynamic Representations

    ERIC Educational Resources Information Center

    Hoffler, Tim N.; Schwartz, Ruth N.

    2011-01-01

    The effects of self-pacing versus system-pacing were examined in different versions of a computer-based learning environment (static pictures/animations). The role of cognitive style was also considered. While the variables investigated did not have a direct impact on either learning outcome or cognitive load, significant interaction effects were…

  5. PACE: A test bed for the dynamics and control of flexible multibody systems

    NASA Technical Reports Server (NTRS)

    Kwak, Moon K.; Smith, Monty J.; Das, Alok

    1993-01-01

    The Phillips Laboratory at Edwards AFB has constructed a test bed for the validation and comparison of modeling and control theories for the dynamics and control of flexible multibody systems. This project is called the Planar Articulating Controls Experiment (PACE). This paper presents the experimental apparatus for PACE and the problem formulation. An in-depth analysis on DC motor dynamics was also performed.

  6. Keeping Pace with K-12 Online & Blended Learning: An Annual Review of Policy and Practice, 2013

    ERIC Educational Resources Information Center

    Watson, John; Murin, Amy; Vashaw, Lauren; Gemin, Butch; Rapp, Chris

    2013-01-01

    This is the 10th annual "Keeping Pace" report. "Keeping Pace" has several goals: (1) add to the body of knowledge about online education policy and practice, and make recommendations for advances; (2) serve as a reference source for information about programs and policies across the country, both for policymakers and…

  7. Web 2.0 and Social Media Connecting Learners in Self-Paced Study: Practitioners' Perspectives

    ERIC Educational Resources Information Center

    Thiessen, Janice

    2016-01-01

    Distance learners determine the time and place for their studies--those engaged in self-paced study may also choose the rate at which they proceed through their courses. However, it is difficult to incorporate purposeful learner-learner interaction into self-paced study. A multiple-case study included three open universities with in-house design…

  8. Which Students Benefit from Self-Paced Mastery Instruction and Why.

    ERIC Educational Resources Information Center

    Stinard, Thomas A.; Dolphin, Warren D.

    1981-01-01

    The determinants of achievement were compared under conventional and self-paced mastery examination schedules in an anatomy/physiology course. General scholastic ability did not interact with method, but prior preparation in science did. Students with less science preparation showed greater achievement under self-paced mastery testing than their…

  9. Self-Pacing in a Personalized Psychology Course: Letting Students Set the Deadlines.

    ERIC Educational Resources Information Center

    Roberts, M. Susan; And Others

    1988-01-01

    Describes two studies which evaluated procedures supplemental to instructor-set and student-set deadlines in a self-paced psychology course. One procedure required students to report their progress on quizzes, while the other required them to meet all deadlines. Concludes that both measures reduced procrastination through increased pacing rates…

  10. Financing the Business. PACE Revised. Level 1. Unit 8. Research & Development Series No. 240AB8.

    ERIC Educational Resources Information Center

    Ashmore, M. Catherine; Pritz, Sandra G.

    This lesson on financing a business, the eighth in a series of 18 units, is part of the first level of a comprehensive entrepreneurship curriculum entitled: A Program for Acquiring Competence in Entrepreneurship (PACE). (Designed for use with secondary students, the first level of PACE introduces students to the concepts involved in…

  11. Managing the Finances. PACE Revised. Level 1. Unit 16. Research & Development Series No. 240AB16.

    ERIC Educational Resources Information Center

    Ashmore, M. Catherine; Pritz, Sandra G.

    This lesson on competent financial management, the 16th in a series of 18 units, is part of the first level of a comprehensive entrepreneurship curriculum entitled: A Program for Acquiring Competence in Entrepreneurship (PACE). (Designed for use with secondary students, the first level of PACE introduces students to the concepts involved in…

  12. EVALUATION OF AN INDIVIDUALLY PACED COURSE FOR AIRBORNE RADIO CODE OPERATORS. FINAL REPORT.

    ERIC Educational Resources Information Center

    BALDWIN, ROBERT O.; JOHNSON, KIRK A.

    IN THIS STUDY COMPARISONS WERE MADE BETWEEN AN INDIVIDUALLY PACED VERSION OF THE AIRBORNE RADIO CODE OPERATOR (ARCO) COURSE AND TWO VERSIONS OF THE COURSE IN WHICH THE STUDENTS PROGRESSED AT A FIXED PACE. THE ARCO COURSE IS A CLASS C SCHOOL IN WHICH THE STUDENT LEARNS TO SEND AND RECEIVE MILITARY MESSAGES USING THE INTERNATIONAL MORSE CODE. THE…

  13. patGPCR: A Multitemplate Approach for Improving 3D Structure Prediction of Transmembrane Helices of G-Protein-Coupled Receptors

    PubMed Central

    Wu, Hongjie; Lü, Qiang; Quan, Lijun; Qian, Peide; Xia, Xiaoyan

    2013-01-01

    The structures of the seven transmembrane helices of G-protein-coupled receptors are critically involved in many aspects of these receptors, such as receptor stability, ligand docking, and molecular function. Most of the previous multitemplate approaches have built a “super” template with very little merging of aligned fragments from different templates. Here, we present a parallelized multitemplate approach, patGPCR, to predict the 3D structures of transmembrane helices of G-protein-coupled receptors. patGPCR, which employs a bundle-packing related energy function that extends on the RosettaMem energy, parallelizes eight pipelines for transmembrane helix refinement and exchanges the optimized helix structures from multiple templates. We have investigated the performance of patGPCR on a test set containing eight determined G-protein-coupled receptors. The results indicate that patGPCR improves the TM RMSD of the predicted models by 33.64% on average against a single-template method. Compared with other homology approaches, the best models for five of the eight targets built by patGPCR had a lower TM RMSD than that obtained from SWISS-MODEL; patGPCR also showed lower average TM RMSD than single-template and multiple-template MODELLER. PMID:23554839

  14. Improved theoretical approximation for the ion drag force in collisionless plasma with strong ion-grain coupling

    SciTech Connect

    Khrapak, S. A.; Nosenko, V.; Morfill, G. E.; Merlino, R.

    2009-04-15

    We point out a deficiency in our previous analytic calculation of the ion drag force for conditions of the experiment by Nosenko et al. [Phys. Plasmas 14, 103702 (2007)]. An inaccurate approximation is corrected and the ion drag force is recalculated. The improved model yields better overall agreement with the experimental results as compared to the original calculation.

  15. Coupling landscape water storage and supplemental irrigation to increase productivity and improve environmental stewardship in the US Midwest

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Agriculture must expand production for a growing population while simultaneously reducing its environmental impacts. These goals need not be in tension with one another. Here we outline a vision for improving both the productivity and environmental performance of agriculture in the US Corn Belt. Mea...

  16. Improvements in Fabrication of 3D SU-8 Prisms for Low-Coupling-Loss Interconnections Between Fibers and Waveguides

    NASA Astrophysics Data System (ADS)

    Nguyen, Minh-Hang; Chu, Thi-Xuan; Nguyen, Long; Nguyen, Hai-Binh; Lee, Chun-Wei; Tseng, Fan-Gang; Chen, Te-Chang; Lee, Ming-Chang

    2016-07-01

    Fabrication of three-dimensional (3D) SU-8 (an epoxy-based negative photoresist from MicroChem) prisms as low-loss couplers for interconnection between optical components, particularly optical fibers and silicon-on-isolator waveguides (SOI WGs), which have mismatched mode sizes, has been investigated. With an interfacial structure formed by a 3D SU-8 prism partly overlaying an SOI WG end with a portion of buried oxide (BOX) removed under the interface, low-loss coupling is ensured and the transmission efficiency can reach 70%. To fabricate these 3D SU-8 prisms, a simple method with two photolithography steps was used for SU-8 hinges and CYTOP (an amorphous fluoropolymer from AGC Chemicals) prism windows, with mild soft and hard bakes, to define the prism profiles with diluted SU-8 filled in the CYTOP prism windows. A buffered oxide etchant is used to remove BOX parts under the interfaces. Some of the fabricated structures were tested, demonstrating the contribution of overlaying SU-8 prisms to the transmission efficiency of optical interconnections between fibers and SOI WGs.

  17. Improvements in Fabrication of 3D SU-8 Prisms for Low-Coupling-Loss Interconnections Between Fibers and Waveguides

    NASA Astrophysics Data System (ADS)

    Nguyen, Minh-Hang; Chu, Thi-Xuan; Nguyen, Long; Nguyen, Hai-Binh; Lee, Chun-Wei; Tseng, Fan-Gang; Chen, Te-Chang; Lee, Ming-Chang

    2016-11-01

    Fabrication of three-dimensional (3D) SU-8 (an epoxy-based negative photoresist from MicroChem) prisms as low-loss couplers for interconnection between optical components, particularly optical fibers and silicon-on-isolator waveguides (SOI WGs), which have mismatched mode sizes, has been investigated. With an interfacial structure formed by a 3D SU-8 prism partly overlaying an SOI WG end with a portion of buried oxide (BOX) removed under the interface, low-loss coupling is ensured and the transmission efficiency can reach 70%. To fabricate these 3D SU-8 prisms, a simple method with two photolithography steps was used for SU-8 hinges and CYTOP (an amorphous fluoropolymer from AGC Chemicals) prism windows, with mild soft and hard bakes, to define the prism profiles with diluted SU-8 filled in the CYTOP prism windows. A buffered oxide etchant is used to remove BOX parts under the interfaces. Some of the fabricated structures were tested, demonstrating the contribution of overlaying SU-8 prisms to the transmission efficiency of optical interconnections between fibers and SOI WGs.

  18. Validation of determination of plasma metabolites derived from thyme bioactive compounds by improved liquid chromatography coupled to tandem mass spectrometry.

    PubMed

    Rubió, Laura; Serra, Aida; Macià, Alba; Borràs, Xenia; Romero, Maria-Paz; Motilva, Maria-José

    2012-09-15

    In the present study, a selective and sensitive method, based on microelution solid-phase extraction (μSPE) plate and ultra-performance liquid chromatography coupled to tandem mass spectrometry (UPLC-MS/MS) was validated and applied to determine the plasma metabolites of the bioactive compounds of thyme. For validation process, standards of the more representative components of the phenolic and monoterpene fractions of thyme were spiked in plasma samples and then the quality parameters of the method were studied. Extraction recoveries (%R) of the studied compounds were higher than 75%, and the matrix effect (%ME) was lower than 18%. The LODs ranged from 1 to 65 μg/L, except for the thymol sulfate metabolite, which was 240 μg/L. This method was then applied for the analysis of rat plasma obtained at different times, from 0 to 6h, after an acute intake of thyme extract (5 g/kg body weight). Different thyme metabolites were identified and were mainly derived from rosmarinic acid (coumaric acid sulfate, caffeic acid sulfate, ferulic acid sulfate, hydroxyphenylpropionic acid sulfate, dihydroxyphenylpropionic acid sulfate and hydroxybenzoic acid) and thymol (thymol sulfate and thymol glucuronide). The most abundant thyme metabolites generated were hydroxyphenylpropionic acid sulfate and thymol sulfate, their respective concentrations in plasma being 446 and 8464 μM 1h after the intake of the thyme extract.

  19. Validation of determination of plasma metabolites derived from thyme bioactive compounds by improved liquid chromatography coupled to tandem mass spectrometry.

    PubMed

    Rubió, Laura; Serra, Aida; Macià, Alba; Borràs, Xenia; Romero, Maria-Paz; Motilva, Maria-José

    2012-09-15

    In the present study, a selective and sensitive method, based on microelution solid-phase extraction (μSPE) plate and ultra-performance liquid chromatography coupled to tandem mass spectrometry (UPLC-MS/MS) was validated and applied to determine the plasma metabolites of the bioactive compounds of thyme. For validation process, standards of the more representative components of the phenolic and monoterpene fractions of thyme were spiked in plasma samples and then the quality parameters of the method were studied. Extraction recoveries (%R) of the studied compounds were higher than 75%, and the matrix effect (%ME) was lower than 18%. The LODs ranged from 1 to 65 μg/L, except for the thymol sulfate metabolite, which was 240 μg/L. This method was then applied for the analysis of rat plasma obtained at different times, from 0 to 6h, after an acute intake of thyme extract (5 g/kg body weight). Different thyme metabolites were identified and were mainly derived from rosmarinic acid (coumaric acid sulfate, caffeic acid sulfate, ferulic acid sulfate, hydroxyphenylpropionic acid sulfate, dihydroxyphenylpropionic acid sulfate and hydroxybenzoic acid) and thymol (thymol sulfate and thymol glucuronide). The most abundant thyme metabolites generated were hydroxyphenylpropionic acid sulfate and thymol sulfate, their respective concentrations in plasma being 446 and 8464 μM 1h after the intake of the thyme extract. PMID:22939267

  20. An improved thin-layer chromatography/mass spectrometry coupling using a surface sampling probe electrospray ion trap system

    SciTech Connect

    Ford, Michael J; Van Berkel, Gary J

    2004-01-01

    A combined surface sampling probe/electrospray emitter coupled with an ion trap mass spectrometer was used for the direct read out of unmodified reversed-phase C18 thin-layer chromatography (TLC) plates. The operation of the surface sampling electrospray ionization interface in positive and negative ionization modes was demonstrated through the direct analysis of TLC plates on which a commercial test mix comprised of four dye compounds viz., rhodamine B, fluorescein, naphthol blue black, and fast green FCF, and an extract of the caffeine-containing plant Ilex vomitoria, were spotted and developed. Acquisition of full-scan mass spectra and automated collection of MS/MS product ion spectra while scanning a development lane along the surface of a TLC plate demonstrated the advantages of using an ion trap in this combination. Details of the sampling system, benefits of analyzing a developed lane in both positive ion and negative ion modes, levels of detection while surface scanning, surface scan speed effects, and the utility of three-dimensional data display, are also discussed.

  1. Running at Double Pace: Women in Dual-Profession Marriages.

    ERIC Educational Resources Information Center

    Arfken, Deborah Elwell

    Although the problems facing dual-profession couples are almost universally acknowledged, studies on dual-profession couples have only recently emerged from those on dual-worker or dual-career families. To explore the perceptions that women in dual-profession marriages have of their roles, conflicts, and coping strategies, focus group interviews…

  2. Improved feedback control of wall-stabilized kink modes with different plasma-wall couplings and mode rotation

    NASA Astrophysics Data System (ADS)

    Peng, Q.; Levesque, J. P.; Stoafer, C. C.; Rhodes, D. J.; Hughes, P. E.; Byrne, P. J.; Mauel, M. E.; Navratil, G. A.

    2015-11-01

    The HBT-EP tokamak can excite strong, saturated kink modes whose growth rates and rotation frequencies evolve on a millisecond timescale. To control such modes, HBT-EP uses a GPU-based feedback system in a low latency architecture. When feedback is applied, the mode amplitude and rotation frequency can change quickly. We describe an improved algorithm that captures the rapid phase changes in the mode while also removing transient amplitude jumps. Additionally, the control coil driving signal is implemented using a current-controller instead of a voltage-controller. The feedback performance is improved and has been tested under more unstable regimes, including different wall configurations and plasmas slowed by a bias probe. Feedback suppression is observed in all cases and the feedback parameters' dependency on different experimental conditions is studied. Supported by U.S. DOE Grant DE-FG02-86ER53222.

  3. Psychophysically based site selection coupled with dichotic stimulation improves speech recognition in noise with bilateral cochlear implants

    PubMed Central

    Zhou, Ning; Pfingst, Bryan E.

    2012-01-01

    The ability to perceive important features of electrical stimulation varies across stimulation sites within a multichannel implant. The aim of this study was to optimize speech processor MAPs for bilateral implant users by identifying and removing sites with poor psychophysical performance. The psychophysical assessment involved amplitude-modulation detection with and without a masker, and a channel interaction measure quantified as the elevation in modulation detection thresholds in the presence of the masker. Three experimental MAPs were created on an individual-subject basis using data from one of the three psychophysical measures. These experimental MAPs improved the mean psychophysical acuity across the electrode array and provided additional advantages such as increasing spatial separations between electrodes and/or preserving frequency resolution. All 8 subjects showed improved speech recognition in noise with one or more experimental MAPs over their everyday-use clinical MAP. For most subjects, phoneme and sentence recognition in noise were significantly improved by a dichotic experimental MAP that provided better mean psychophysical acuity, a balanced distribution of selected stimulation sites, and preserved frequency resolution. The site-selection strategies serve as useful tools for evaluating the importance of psychophysical acuities needed for good speech recognition in implant users. PMID:22894220

  4. 42 CFR 460.136 - Internal quality assessment and performance improvement activities.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... standards of practice for the delivery of care and periodically track performance to ensure that any... performance improvement activities. (1) A PACE organization must ensure that all interdisciplinary...

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

    PubMed

    Galappaththige, Suran; Roth, Bradley J

    2015-01-01

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

  6. Paleoclimatology: Second clock supports orbital pacing of the ice ages

    SciTech Connect

    Kerr, R.A.

    1997-05-02

    For a while, it looked as if a water-filled crack in the Nevada desert might doom the accepted explanation of the ice ages. Twenty years ago, the so-called astronomical theory had carried the day. Oceanographers had found evidence implying that the march of ice ages over the last million years was paced by the cyclical stretching and squeezing of Earth`s orbit around the sun, which would have altered the way sunlight fell on the planet`s surface. But in 1988, researchers scuba diving in Nevada`s Devils Hole came up with a climate record--captured in carbonate deposits in the crack-that seemed to contradict this chronology. This article discusses the findings and the puzzles that still remain. The records of sea-level change in Barbados coral appear to be right and the astronomical theory is on solid ground using a new clock based on the radioactive decay of uranium-235 to protactinium-231. However, the Devils Hole record also seems to be correct.

  7. Sex Differences in Time Perception during Self-paced Running

    PubMed Central

    HANSON, NICHOLAS J.; BUCKWORTH, JANET

    2016-01-01

    Time perception during exercise may be affected by chosen intensity, and may also affect enjoyment of exercise and subsequent long-term adherence. However, little is known about how individuals perceive the passage of time during exercise, or if factors such as sex are influential. The purpose of this study was to determine if there are sex related differences in perception of time during a bout of exercise in experienced runners. Twenty-two recreational runners (11 men, 11 women) participated in a bout of treadmill running where they were allowed to select their intensity. Sixty second prospective time estimations were taken before, during (at 33%, 66% and 90% of the completed distance), and after the run. Heart rate (HR) was also recorded throughout. The women (M = 91.9, SD = 3.3) ran at a significantly higher percentage of their maximum HR than the men (M = 86.5, SD = 6.4; p = 0.022), choosing to run at a higher relative intensity than the men when given the opportunity to self-pace. The women had relatively lower time estimations overall, showing that they perceived time to be passing by more slowly compared to the men. These results may help to explain sex related differences in exercise adherence. PMID:27766135

  8. Piston designs keep pace with increased engine performance

    SciTech Connect

    Mullins, P.

    1996-12-01

    Piston technology for medium-speed diesel engines is having to keep pace with steadily increasing engine performance criteria. Specific output of medium-speed diesel engines has increased some 50% since 1970, according to Walter Griffiths, chief engineer at the UK-based AE Geotze Special Products Ltd. To satisfy the higher performance now required, a two-piece piston has been developed and went into production in 1995. This type still uses an aluminum alloy forged body, but incorporates a steel crown. The composite piston can carry higher engine ratings and resists the abrasive deposits formed by heavy fuel operation. It has become well established for bore sizes above 300 mm and is becoming increasingly specified for engines down to 200 mm. The latest solution to the carbon deposits on the top of the piston that has gained widespread acceptance within the industry is to reduce the diameter of the bore above the top ring and cut back the top land to maintain the normal operating clearance. This requires an insert to be fitted into the liner after the piston has been assembled. The effect is to limit the carbon build-up on the top land to a specific diameter, which is always less than the bore diameter. Thus there is no possibility of top land contact with the bore over the effective stroke of the piston rings. 2 figs.

  9. Muscle-Type Specific Autophosphorylation of CaMKII Isoforms after Paced Contractions

    PubMed Central

    Eilers, Wouter; Gevers, Wouter; van Overbeek, Daniëlle; de Haan, Arnold; Jaspers, Richard T.; Hilbers, Peter A.; van Riel, Natal; Flück, Martin

    2014-01-01

    We explored to what extent isoforms of the regulator of excitation-contraction and excitation-transcription coupling, calcium/calmodulin protein kinase II (CaMKII) contribute to the specificity of myocellular calcium sensing between muscle types and whether concentration transients in its autophosphorylation can be simulated. CaMKII autophosphorylation at Thr287 was assessed in three muscle compartments of the rat after slow or fast motor unit-type stimulation and was compared against a computational model (CaMuZclE) coupling myocellular calcium dynamics with CaMKII Thr287 phosphorylation. Qualitative differences existed between fast- (gastrocnemius medialis) and slow-type muscle (soleus) for the expression pattern of CaMKII isoforms. Phospho-Thr287 content of δA CaMKII, associated with nuclear functions, demonstrated a transient and compartment-specific increase after excitation, which contrasted to the delayed autophosphorylation of the sarcoplasmic reticulum-associated βM CaMKII. In soleus muscle, excitation-induced δA CaMKII autophosphorylation demonstrated frequency dependence (P = 0.02). In the glycolytic compartment of gastrocnemius medialis, CaMKII autophosphorylation after excitation was blunted. In silico assessment emphasized the importance of mitochondrial calcium buffer capacity for excitation-induced CaMKII autophosphorylation but did not predict its isoform specificity. The findings expose that CaMKII autophosphorylation with paced contractions is regulated in an isoform and muscle type-specific fashion and highlight properties emerging for phenotype-specific regulation of CaMKII. PMID:25054156

  10. Coupled expression of Cu/Zn-superoxide dismutase and catalase in cassava improves tolerance against cold and drought stresses

    PubMed Central

    Xu, Jia; Duan, Xiaoguang; Yang, Jun; Beeching, John R.; Zhang, Peng

    2013-01-01

    Recently we reported that the joint expression of cassava Cu/Zn superoxide dismutase (MeCu/ZnSOD) and catalase (MeCAT1) prolonged the shelf life of cassava storage-roots by the stabilization of reactive oxygen species (ROS) homeostasis after harvest. Since oxidative damage is a major feature of plants exposed to environmental stresses, transgenic cassava showing increased expression of the cytosolic MeCu/ZnSOD and the peroxisomal MeCAT1 should have improved resistance against other abiotic stresses. After cold treatment, the transgenic cassava maintained higher SOD and CAT activities and lower malendialdehyde content than those of wild type plants (WT). Detached leaves of transgenic cassava also showed slower transpirational water loss than those of WT. When plants were not watered for 30 d, transgenic lines exhibited a significant increase in water retention ability, accumulated 13% more proline and 12% less malendialdehyde than WT’s, and showed enhanced activity of SOD and CAT. These results imply that manipulation of the antioxidative mechanism allows the development of staple crops with improved tolerance to abiotic stresses. PMID:23603959

  11. Coupled expression of Cu/Zn-superoxide dismutase and catalase in cassava improves tolerance against cold and drought stresses.

    PubMed

    Xu, Jia; Duan, Xiaoguang; Yang, Jun; Beeching, John R; Zhang, Peng

    2013-06-01

    Recently we reported that the joint expression of cassava Cu/Zn superoxide dismutase (MeCu/ZnSOD) and catalase (MeCAT1) prolonged the shelf life of cassava storage-roots by the stabilization of reactive oxygen species (ROS) homeostasis after harvest. Since oxidative damage is a major feature of plants exposed to environmental stresses, transgenic cassava showing increased expression of the cytosolic MeCu/ZnSOD and the peroxisomal MeCAT1 should have improved resistance against other abiotic stresses. After cold treatment, the transgenic cassava maintained higher SOD and CAT activities and lower malendialdehyde content than those of wild type plants (WT). Detached leaves of transgenic cassava also showed slower transpirational water loss than those of WT. When plants were not watered for 30 d, transgenic lines exhibited a significant increase in water retention ability, accumulated 13% more proline and 12% less malendialdehyde than WT's, and showed enhanced activity of SOD and CAT. These results imply that manipulation of the antioxidative mechanism allows the development of staple crops with improved tolerance to abiotic stresses.

  12. Coupled Ethical–Epistemic Analysis of Public Health Research and Practice: Categorizing Variables to Improve Population Health and Equity

    PubMed Central

    Katikireddi, S. Vittal; Valles, Sean A

    2015-01-01

    The categorization of variables can stigmatize populations, which is ethically problematic and threatens the central purpose of public health: to improve population health and reduce health inequities. How social variables (e.g., behavioral risks for HIV) are categorized can reinforce stigma and cause unintended harms to the populations practitioners and researchers strive to serve. Although debates about the validity or ethical consequences of epidemiological variables are familiar for specific variables (e.g., ethnicity), these issues apply more widely. We argue that these tensions and debates regarding epidemiological variables should be analyzed simultaneously as ethical and epistemic challenges. We describe a framework derived from the philosophy of science that may be usefully applied to public health, and we illustrate its application. PMID:25393193

  13. Improvement of l-lactic acid productivity from sweet sorghum juice by repeated batch fermentation coupled with membrane separation.

    PubMed

    Wang, Yong; Meng, Hongyu; Cai, Di; Wang, Bin; Qin, Peiyong; Wang, Zheng; Tan, Tianwei

    2016-07-01

    In order to efficiently produce l-lactic acid from non-food feedstocks, sweet sorghum juice (SSJ), which is rich of fermentable sugars, was directly used for l-lactic acid fermentation by Lactobacillus rhamnosus LA-04-1. A membrane integrated repeated batch fermentation (MIRB) was developed for productivity improvement. High-cell-density fermentation was achieved with a final cell density (OD620) of 42.3, and the CCR effect was overcomed. When SSJ (6.77gL(-1) glucose, 4.51gL(-1) fructose and 50.46gL(-1) sucrose) was used as carbon source in MIRB process, l-lactic acid productivity was increased significantly from 1.45gL(-1)h(-1) (batch 1) to 17.55gL(-1)h(-1) (batch 6). This process introduces an effective way to produce l-lactic acid from SSJ.

  14. Kinematic hand parameters in front crawl at different paces of swimming.

    PubMed

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

    2015-11-01

    The aim of this study was to investigate the evolution of kinematic hand parameters (sweepback angle, angle of attack, velocity, acceleration and orientation of the hand relative to the absolute coordinate system) throughout an aquatic stroke and to study the possible modifications caused by a variation of the swimming pace. Seventeen competitive swimmers swam at long distance, middle distance and sprint paces. Parameters were calculated from the trajectory of seven markers on the hand measured with an optoelectronic system. Results showed that kinematic hand parameters evolve differently depending on the pace. Angle of attack, sweepback angle, acceleration and orientation of the hand do not vary significantly. The velocity of the hand increases when the pace increases, but only during the less propulsive phases (entry and stretch and downsweep to catch). The more the pace increases and the more the absolute durations of the entry and stretch and downsweep to catch phases decrease. Absolute durations of the insweep and upsweep phases remain constant. During these phases, the propulsive hand forces calculated do not vary significantly when the pace increases. The increase of swimming pace is then explained by the swimmer's capacity to maintain propulsive phases rather than increasing the force generation within each cycle. PMID:26433921

  15. Baseline and post-atrial pacing release of atrial natriuretic factor in mitral stenosis.

    PubMed

    Malatino, L S; Stancanelli, B; Greco, G; Polizzi, G; Leonardi, C; Russo, G; Tamburino, C; Greco, G; Giuffrida, G; Tamburino, G

    1990-01-01

    To investigate the release of atrial natriuretic factor (ANF) in mitral stenosis and the influence of the increase on the frequency of atrial contraction or atrial distention on ANF secretion, we studied 10 patients with symptoms of congestive heart failure (New York Heart Association classes II and III) in sinus rhythm, who were undergoing cardiac catheterization as part of an evaluation workup for mitral stenosis. Echocardiographic tracings, repeat determinations of mean pulmonary artery wedge pressure (MPAWP) and mean right atrial pressure, and blood sampling from the pulmonary artery for measurements of ANF were performed at baseline, during atrial pacing (pacing rate of 125 beats/min for 5 minutes), and 5 minutes after the pacing protocol was completed. Baseline ANF levels were closely related to right atrial pressure (r = 0.89; p less than 0.001) and increased markedly after atrial pacing from 205.6 +/- 39.8 (SEM) to 343.9 +/- 57.9 (SEM) pg/ml. A similar pacing-induced increase was shown for MPAWP and left atrial size. Our data indicate that pacing-induced increases in atrial distention and intracavitary pressure further stimulate release of ANF. However, an independent effect of frequency of atrial pacing on plasma ANF in humans could not be identified. PMID:2136967

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

    PubMed Central

    Ferrari, Andrés Di Leoni; Borges, Anibal Pires; Albuquerque, Luciano Cabral; Sussenbach, Carolina Pelzer; da Rosa, Priscila Raupp; Piantá, Ricardo Medeiros; Wiehe, Mario; Goldani, Marco Antônio

    2014-01-01

    Implantable cardiac pacing systems are a safe and effective treatment for symptomatic irreversible bradycardia. Under the proper indications, cardiac pacing might bring significant clinical benefit. Evidences from literature state that the action of the artificial pacing system, mainly when the ventricular lead is located at the apex of the right ventricle, produces negative effects to cardiac structure (remodeling, dilatation) and function (dissinchrony). Patients with previously compromised left ventricular function would benefit the least with conventional right ventricle apical pacing, and are exposed to the risk of developing higher incidence of morbidity and mortality for heart failure. However, after almost 6 decades of cardiac pacing, just a reduced portion of patients in general would develop these alterations. In this context, there are not completely clear some issues related to cardiac pacing and the development of this cardiomyopathy. Causality relationships among QRS widening with a left bundle branch block morphology, contractility alterations within the left ventricle, and certain substrates or clinical (previous systolic dysfunction, structural heart disease, time from implant) or electrical conditions (QRS duration, percentage of ventricular stimulation) are still subjecte of debate. This review analyses contemporary data regarding this new entity, and discusses alternatives of how to use cardiac pacing in this context, emphasizing cardiac resynchronization therapy. PMID:25372916

  17. Kinematic hand parameters in front crawl at different paces of swimming.

    PubMed

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

    2015-11-01

    The aim of this study was to investigate the evolution of kinematic hand parameters (sweepback angle, angle of attack, velocity, acceleration and orientation of the hand relative to the absolute coordinate system) throughout an aquatic stroke and to study the possible modifications caused by a variation of the swimming pace. Seventeen competitive swimmers swam at long distance, middle distance and sprint paces. Parameters were calculated from the trajectory of seven markers on the hand measured with an optoelectronic system. Results showed that kinematic hand parameters evolve differently depending on the pace. Angle of attack, sweepback angle, acceleration and orientation of the hand do not vary significantly. The velocity of the hand increases when the pace increases, but only during the less propulsive phases (entry and stretch and downsweep to catch). The more the pace increases and the more the absolute durations of the entry and stretch and downsweep to catch phases decrease. Absolute durations of the insweep and upsweep phases remain constant. During these phases, the propulsive hand forces calculated do not vary significantly when the pace increases. The increase of swimming pace is then explained by the swimmer's capacity to maintain propulsive phases rather than increasing the force generation within each cycle.

  18. Increased work pace is unprofitable: a beef-cutting case study.

    PubMed

    Vogel, K; Karltun, J; Yeow, P H P; Eklund, J

    2015-07-01

    The beef industry worldwide is showing a trend towards increased cutting pace aimed at higher profits. However, prior research in the duck meat industry suggested that a higher cutting pace reduced quality and yield, leading to losses. This study aimed to test this hypothesis by investigating the effects of varying beef-cutting paces on yield, quality and economy. A field experiment was conducted on six workers cutting beef fillet, sirloin and entrecôte. Three types of paces were sequentially tested: Baseline (i.e., status quo), 'Quantity focus' (i.e., pace required to maximise quantity) and 'Quality focus' (i.e., pace required to minimise errors). The results showed a significant drop in yield, increased rate of quality deficiency and economic losses with the change to 'Quantity focus' (from Baseline and 'Quality focus') for all meat types. Workers supported these results and also added health problems to the list. The results confirmed that an increased cutting pace is unprofitable. PMID:25828161

  19. Microvolt T-wave alternans during exercise and pacing in patients with acute myocardial infarction.

    PubMed

    Raatikainen, M J Pekka; Jokinen, Vesa; Virtanen, Vesa; Hartikainen, Juha; Hedman, Antti; Huikuri, Heikki V

    2005-01-01

    Cardiac Arrhythmias and Risk Stratification after Myocardial infarction (CARISMA) is a prospective multicenter trial designed to document the incidence of cardiac arrhythmias after acute myocardial infarction (AMI), and to assess the predictive accuracy of various arrhythmic risk markers. In this substudy of the CARISMA trial, microvolt T-wave alternans (TWA) was assessed with specific equipment 6 weeks after AMI during bicycle exercise, atrial (A) pacing, and simultaneous ventricular and atrial (V + A) pacing in 80 patients with left ventricular ejection fraction (LVEF) <40%. The agreement between the acute test results was determined by overall proportion of concordance and the kappa statistic. Sustained TWA was observed in 24, 45, and 50% of the patients during the exercise test, A pacing, and V + A pacing, respectively. The number of indeterminate TWA was significantly lower during V + A pacing (n = 7) than exercise test (n = 34). The TWA concordance rate was 71% between exercise and V + A pacing (kappa= 0.53, P = 0.001), 79% between exercise and A pacing (kappa= 0.54, P < 0.001), and 95% between the two pacing modes (kappa= 0.89, P < 0.001). Patients with positive TWA in all tests had lower LVEF (28 +/- 7% vs 35 +/- 9%, P < 0.01) and wider QT dispersion (99 +/- 44 ms vs 67 +/- 38 ms, P < 0.01) than those with inconsistent test result. The low number of indeterminate tests and high concordance between the test results indicate that V + A pacing may provide a valuable means to assess TWA in patients who cannot complete the exercise test.

  20. 77 FR 60732 - PACE Select Advisors Trust and UBS Global Asset Management (Americas) Inc.; Notice of Application

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-04

    ... COMMISSION PACE Select Advisors Trust and UBS Global Asset Management (Americas) Inc.; Notice of Application... requirements. The requested order would supersede two prior orders.\\1\\ \\1\\ PaineWebber PACE Select Advisors...) and 21666 (Jan. 11, 1996) (order). Applicants: PACE Select Advisors Trust (the ``Trust'') and...

  1. A Closer Look at Split Visual Attention in System- and Self-Paced Instruction in Multimedia Learning

    ERIC Educational Resources Information Center

    Schmidt-Weigand, Florian; Kohnert, Alfred; Glowalla, Ulrich

    2010-01-01

    Two experiments examined visual attention distribution in learning from text and pictures. Participants watched a 16-step multimedia instruction on the formation of lightning. In Experiment 1 (N=90) the instruction was system-paced (fast, medium, slow pace), while it was self-paced in Experiment 2 (N=31). In both experiments the text modality was…

  2. Design and development of back reflectors for improved light coupling and absorption enhancement in thin MQW solar cells

    NASA Astrophysics Data System (ADS)

    Wang, Wei; Freundlich, Alex

    2015-03-01

    Optimization of non-planar antireflective coating and back- (or front-) surface texturing are widely studied to further reduce the reflection losses and increase the sunlight absorption path in solar cells. Back reflectors have been developed from perfect mirror to textured mirror in order to further increase light path, which can significantly improve the efficiency and allow for much thinner devices. A Lambertian surface, which has the most random texture, can theoretically raise the light path to 4n2 times that of a smooth surface. It's a challenge however to fabricate ideal Lambertian texture, especially in a fast and low cost way. In this work we have developed a method to overcome this challenge that combines the use of laser interference lithography (LIL) and selective wet etching. The approach allows for a rapid wafer scale texture processing with sub-wavelength (nano)- scale control of the pattern and the pitch. The technique appears as being particularly attractive for the development of ultra-thin III-V devices, or in overcoming the weak sub-bandgap absorption in devices incorporating quantum dots or quantum wells. Preliminary results on the application of the technique for the development of back reflector for 1-1.3 eV (MQW bearing) GaAs solar cells are presented.

  3. Coupling landscape water storage and supplemental irrigation to increase productivity and improve environmental stewardship in the U.S. Midwest

    NASA Astrophysics Data System (ADS)

    Baker, John M.; Griffis, Timothy J.; Ochsner, Tyson E.

    2012-05-01

    Agriculture must increase production for a growing population while simultaneously reducing its environmental impacts. These goals need not be in tension with one another. Here we outline a vision for improving both the productivity and environmental performance of agriculture in the U.S. Midwest, also known as the Corn Belt. Mean annual precipitation has increased throughout the region over the past 50 years, consistent with climate models that attribute the increase to a warming troposphere. Stream gauge data indicate that higher precipitation has been matched or exceeded by higher stream flows, contributing to flooding, soil loss, and excessive nutrient flux to the Gulf of Mexico. We propose increasing landscape hydrologic storage through construction of ponds and restoration of wetlands to retain water for supplemental irrigation while also reducing flood risks. Primary productivity is proportional to transpiration, and analysis shows that in the U.S. Midwest both can be sustainably increased with supplemental irrigation. The proposed strategy should reduce interannual yield variability by limiting losses due to transient drought, while facilitating adoption of cropping systems that "perennialize" the landscape to take advantage of the full potential growing season. When implemented in concert, these practices should reduce the riverine nitrogen export that is a primary cause of hypoxia in the Gulf of Mexico. Erosive sediment losses should also be reduced through the combination of enhanced hydrologic storage and increased vegetative cover. Successful implementation would require watershed-scale coordination among producers and landowners. An obvious mechanism to encourage this is governmental farm policy.

  4. Coupling chemical transport model source attributions with positive matrix factorization: application to two IMPROVE sites impacted by wildfires.

    PubMed

    Sturtz, Timothy M; Schichtel, Bret A; Larson, Timothy V

    2014-10-01

    Source contributions to total fine particle carbon predicted by a chemical transport model (CTM) were incorporated into the positive matrix factorization (PMF) receptor model to form a receptor-oriented hybrid model. The level of influence of the CTM versus traditional PMF was varied using a weighting parameter applied to an object function as implemented in the Multilinear Engine (ME-2). The methodology provides the ability to separate features that would not be identified using PMF alone, without sacrificing fit to observations. The hybrid model was applied to IMPROVE data taken from 2006 through 2008 at Monture and Sula Peak, Montana. It was able to separately identify major contributions of total carbon (TC) from wildfires and minor contributions from biogenic sources. The predictions of TC had a lower cross-validated RMSE than those from either PMF or CTM alone. Two unconstrained, minor features were identified at each site, a soil derived feature with elevated summer impacts and a feature enriched in sulfate and nitrate with significant, but sporadic contributions across the sampling period. The respective mean TC contributions from wildfires, biogenic emissions, and other sources were 1.18, 0.12, and 0.12 ugC/m(3) at Monture and 1.60, 0.44, and 0.06 ugC/m(3) at Sula Peak.

  5. Design of molecular beacons: 3' couple quenchers improve fluorogenic properties of a probe in real-time PCR assay.

    PubMed

    Ryazantsev, Dmitry Y; Kvach, Maksim V; Tsybulsky, Dmitry A; Prokhorenko, Igor A; Stepanova, Irina A; Martynenko, Yury V; Gontarev, Sergey V; Shmanai, Vadim V; Zavriev, Sergey K; Korshun, Vladimir A

    2014-06-01

    Convenient preparation of fluorogenic hairpin DNA probes (molecular beacons) carrying a pair of FAM fluorophores (located close to 5'-terminus of the probe) or a pair of BHQ1 quenchers on 3'-terminus (with (BHQ1)2 or BHQ1-BHQ1 composition) is reported. These probes were used for the first time in a real-time PCR assay and showed considerable improvements in fluorogenic properties (the total fluorescence increase or signal-to-background ratio) in assay conditions vs. conventional one-FAM-one-BHQ1 molecular beacon probes as well as vs. hydrolyzable one-FAM-one-BHQ1 TaqMan probes. At the same time, such multiple modifications of the probe do not influence its Cq (a fractional PCR cycle used for quantification). The probe MB14 containing a BHQ1-BHQ1 pair showed a PCR fluorescence/background value of 9.6 which is more than two times higher than that of a regular probe MB2 (4.6). This study demonstrates prospects for the design of highly fluorogenic molecular beacon probes suitable for quantitative real-time PCR and for other potential applications (e.g. intracellular RNA detection and SNP/mutation analysis).

  6. Gas Chromatography Coupled to Atmospheric Pressure Chemical Ionization FT-ICR Mass Spectrometry for Improvement of Data Reliability.

    PubMed

    Schwemer, Theo; Rüger, Christopher P; Sklorz, Martin; Zimmermann, Ralf

    2015-12-15

    Atmospheric pressure chemical ionization (APCI) offers the advantage of molecular ion information with low fragmentation. Hyphenating APCI to gas chromatography (GC) and ultrahigh resolution mass spectrometry (FT-ICR MS) enables an improved characterization of complex mixtures. Data amounts acquired by this system are very huge, and existing peak picking algorithms are usually extremely time-consuming, if both gas chromatographic and ultrahigh resolution mass spectrometric data are concerned. Therefore, automatic routines are developed that are capable of handling these data sets and further allow the identification and removal of known ionization artifacts (e.g., water- and oxygen-adducts, demethylation, dehydrogenation, and decarboxylation). Furthermore, the data quality is enhanced by the prediction of an estimated retention index, which is calculated simply from exact mass data combined with a double bond equivalent correction. This retention index is used to identify mismatched elemental compositions. The approach was successfully tested for analysis of semivolatile components in heavy fuel oil and diesel fuel as well as primary combustion particles emitted by a ship diesel research engine. As a result, 10-28% of the detected compounds, mainly low abundant species, classically assigned by using only the mass spectrometric information, were identified as not valid and removed. Although GC separation is limited by the slow acquisition rate of the FT-ICR MS (<1 Hz), a database driven retention time comparison, as commonly used for low resolution GC/MS, can be applied for revealing isomeric information.

  7. Gas Chromatography Coupled to Atmospheric Pressure Chemical Ionization FT-ICR Mass Spectrometry for Improvement of Data Reliability.

    PubMed

    Schwemer, Theo; Rüger, Christopher P; Sklorz, Martin; Zimmermann, Ralf

    2015-12-15

    Atmospheric pressure chemical ionization (APCI) offers the advantage of molecular ion information with low fragmentation. Hyphenating APCI to gas chromatography (GC) and ultrahigh resolution mass spectrometry (FT-ICR MS) enables an improved characterization of complex mixtures. Data amounts acquired by this system are very huge, and existing peak picking algorithms are usually extremely time-consuming, if both gas chromatographic and ultrahigh resolution mass spectrometric data are concerned. Therefore, automatic routines are developed that are capable of handling these data sets and further allow the identification and removal of known ionization artifacts (e.g., water- and oxygen-adducts, demethylation, dehydrogenation, and decarboxylation). Furthermore, the data quality is enhanced by the prediction of an estimated retention index, which is calculated simply from exact mass data combined with a double bond equivalent correction. This retention index is used to identify mismatched elemental compositions. The approach was successfully tested for analysis of semivolatile components in heavy fuel oil and diesel fuel as well as primary combustion particles emitted by a ship diesel research engine. As a result, 10-28% of the detected compounds, mainly low abundant species, classically assigned by using only the mass spectrometric information, were identified as not valid and removed. Although GC separation is limited by the slow acquisition rate of the FT-ICR MS (<1 Hz), a database driven retention time comparison, as commonly used for low resolution GC/MS, can be applied for revealing isomeric information. PMID:26560682

  8. A self-paced brain-computer interface system with a low false positive rate.

    PubMed

    Fatourechi, M; Ward, R K; Birch, G E

    2008-03-01

    The performance of current EEG-based self-paced brain-computer interface (SBCI) systems is not suitable for most practical applications. In this paper, an improved SBCI that uses features extracted from three neurological phenomena (movement-related potentials, changes in the power of Mu rhythms and changes in the power of Beta rhythms) to detect an intentional control command in noisy EEG signals is proposed. The proposed system achieves a high true positive (TP) to false positive (FP) ratio. To extract features for each neurological phenomenon in every EEG signal, a method that consists of a stationary wavelet transform followed by matched filtering is developed. For each neurological phenomenon in every EEG channel, features are classified using a support vector machine classifier (SVM). For each neurological phenomenon, a multiple classifier system (MCS) then combines the outputs of the SVMs. Another MCS combines the outputs of MCSs designed for the three neurological phenomena. Various configurations for combining the outputs of these MCSs are considered. A hybrid genetic algorithm (HGA) is proposed to simultaneously select the features, the values of the classifiers' parameters and the configuration for combining MCSs that yield the near optimal performance. Analysis of the data recorded from four able-bodied subjects shows a significant performance improvement over previous SBCIs.

  9. Primary ST changes. Diagnostic aid in paced patients with acute myocardial infarction.

    PubMed Central

    Niremberg, V; Amikam, S; Roguin, N; Pelled, B; Riss, E

    1977-01-01

    In 34 out of 36 patients with apical right ventricular endocardial pacing, primary ischaemic ST alterations were observed during the early stage of acute myocardial infarction. These ST changes, indicating acute injury, were detected in the paced beats in inferior and in anterior infarct. The primary ST changes were consistent only during the early stages of acute myocardial infarction and were not detected when the electrode tip was not in the apex of the right ventricle. It is suggested that the primary ST changes should be used to diagnose acute myocardial infarction in paced patients. Images PMID:861092

  10. Right ventricular septal pacing- clinical and electrical predictors for LV contraction asynchrony

    PubMed Central

    Iorgulescu, C; Radu, DA; Constantinescu, D; Caldararu, C; Dorobantu, M

    2014-01-01

    Purpose: Prolonged pacing from the right ventricular apex (RV) is associated with the LV dyssynchrony leading to progressive left ventricular dysfunction and increased morbidity and mortality. Alternate RV pacing sites-in particular the mid- RV septum and the RV outflow tract (RVOT) septum were considered, but no clear benefit was proven till now for this pacing sites. This may be due to the heterogeneity of the RV septal positions and to the significant number of leads placed on the RV free wall. The aim of this study is to find a reliable method of septal lead placement and to identify those pacing sites which provide better LV electrical activation Methods: 50 consecutive patients referred for pacemaker implants due to AV block were included. Patients with history of heart failure or LVEF < 50% at the implant were excluded. All patients had RV leads placed in septal position. This was achieved with a double curved stilet with the distal curve aimed posteriorly. RV septum and RVOT were mapped during implant aiming for a narrow paced QRS with an axis as close to normal as possible. Pacing lead position was evaluated during the implant using fluoroscopy (AP and LAO 40 °) and than by 12 lead ECG and echo. IntraLV dyssynchrony was evaluated during pacing using SPWMD in short axis parasternal view and the TDI septal to lateral ∆ t. Paced QRS duration and axis were also recorded. The correlation was sought between lead position evaluated by Rx and by echo and between paced QRS duration and axis and LV dyssynchrony. Results: 92%(46) of the patients had the lead in septal position RV (32 in the mid-septal RV and 14 in RVOT), while 8% (4 pts) had the lead on the RVOT RV free wall as shown by echo. An anterior-oriented lead in the left anterior oblique fluoroscopic projection was specific for free wall position while positive QRS in DI in RVOT position was suggestive for free wall position on the ECG. No correlation was made between paced QRS axis and LV dyssynchrony

  11. Improving the flood prediction capability of the Xinanjiang model in ungauged nested catchments by coupling it with the geomorphologic instantaneous unit hydrograph

    NASA Astrophysics Data System (ADS)

    Yao, Cheng; Zhang, Ke; Yu, Zhongbo; Li, Zhijia; Li, Qiaoling

    2014-09-01

    Improving the predictive capabilities of rainfall-runoff models in ungauged catchments is a challenging task but has important theoretical and practical significance. In this study, we investigated the predictive capabilities of the conceptual Xinanjiang model (XAJ), which is widely used for flood forecasting and simulation in China, in ungauged catchments. We further produced a hybrid rainfall-runoff model (named XAJ-GIUH) by coupling the XAJ model with the geomorphologic instantaneous unit hydrograph (GIUH) to achieve improved flood predictions in ungauged catchments. The flood prediction capabilities of the original XAJ model and the XAJ-GIUH model were investigated and compared at an hourly time scale in a mountainous catchment with six nested catchments located in the south of Anhui province, China. The two models were first calibrated for each individual catchment by comparing with the observed streamflows. Then, the nested catchments were treated as ungauged and modeled using the parameter values regionalized by transposition from the downstream catchments. The results show that the performance of both models is comparable and satisfactory on different catchment scales in the case that model parameters are calibrated in each catchment. However, the models perform differently in the case that model parameters are transposed from the downstream catchments. The XAJ-GIUH model produced markedly improved estimates of peak discharge and peak time as compared to the original XAJ model in the latter case, indicating that the runoff routing is a major uncertainty source for the application of the XAJ model in this case. Coupling XAJ with topography-based GIUH has the potential to substantially improve the flood prediction capability of the XAJ model in ungauged catchments. Our analysis further reveals that the models do not necessarily perform better when the parameter values are transposed from closer donor catchment. Instead, adopting the parameter values from the

  12. Brief Exposure to a Self-Paced Computer-Based Reading Programme and How It Impacts Reading Ability and Behaviour Problems

    PubMed Central

    Hughes, J. Antony; Phillips, Gordon; Reed, Phil

    2013-01-01

    Basic literacy skills underlie much future adult functioning, and are targeted in children through a variety of means. Children with reading problems were exposed either to a self-paced computer programme that focused on improving phonetic ability, or underwent a classroom-based reading intervention. Exposure was limited to 3 40-min sessions a week, for six weeks. The children were assessed in terms of their reading, spelling, and mathematics abilities, as well as for their externalising and internalising behaviour problems, before the programme commenced, and immediately after the programme terminated. Relative to the control group, the computer-programme improved reading by about seven months in boys (but not in girls), but had no impact on either spelling or mathematics. Children on the programme also demonstrated fewer externalising and internalising behaviour problems than the control group. The results suggest that brief exposure to a self-paced phonetic computer-teaching programme had some benefits for the sample. PMID:24223125

  13. An improved methodology of asymmetric flow field flow fractionation hyphenated with inductively coupled mass spectrometry for the determination of size distribution of gold nanoparticles in dietary supplements.

    PubMed

    Mudalige, Thilak K; Qu, Haiou; Linder, Sean W

    2015-11-13

    Engineered nanoparticles are available in large numbers of commercial products claiming various health benefits. Nanoparticle absorption, distribution, metabolism, excretion, and toxicity in a biological system are dependent on particle size, thus the determination of size and size distribution is essential for full characterization. Number based average size and size distribution is a major parameter for full characterization of the nanoparticle. In the case of polydispersed samples, large numbers of particles are needed to obtain accurate size distribution data. Herein, we report a rapid methodology, demonstrating improved nanoparticle recovery and excellent size resolution, for the characterization of gold nanoparticles in dietary supplements using asymmetric flow field flow fractionation coupled with visible absorption spectrometry and inductively coupled plasma mass spectrometry. A linear relationship between gold nanoparticle size and retention times was observed, and used for characterization of unknown samples. The particle size results from unknown samples were compared to results from traditional size analysis by transmission electron microscopy, and found to have less than a 5% deviation in size for unknown product over the size range from 7 to 30 nm.

  14. Improved Radiometric Capabilities of Landsat 8, Coupled With Lidar, Estimate Semi-arid Rangeland Biomass and Cover

    NASA Astrophysics Data System (ADS)

    Dhakal, S.; Glenn, N. F.; Li, A.; Spaete, L.; Shinneman, D. J.; Arkle, R.; Pilliod, D.; Mcllroy, S.; Baun, C.

    2015-12-01

    Remote sensing based quantification of semi-arid rangeland vegetation provides the large scale observations necessary for monitoring native plants distribution, estimating fuel loads and measuring carbon storage. Improved signal to noise ratio and radiometric resolution of recent satellite imagery and fine scale 3-dimensional information from lidar provides opportunities for refined measurements of vegetation structure. We leverage a large number of Landsat 8 and lidar-based metrics for prediction of biomass and cover of shrubs in the semi-arid rangeland of the western United States. Time-series Landsat 8 images were used to develop 20 ratio based vegetation indices. Similarly, 35 vegetation metrics, including metrics based on numerical values (e.g. elevation, canopy height) and on density of points (e.g. canopy density) were developed from airborne lidar point clouds. These vegetation indices and metrics were trained and linked to insitu measurements (n=141) with the Random Forest regression to impute biomass and cover map across a large scale. We also validate our model with an independent data-set (n=44), explaining up to 63% of variation in cover and 53% in biomass. The preliminary results suggest that Landsat performs better in estimating vegetation cover whereas lidar performs better in estimating biomass with no significant relationship to topographic variables (e.g. slope, aspect and elevation). We further compare our results with historical fire data to show that both biomass and cover decreases with the increase of fire frequency in the study site. This study demonstrates the new opportunities of using Landsat 8 with established lidar approaches to better quantify vegetation in semiarid ecosystems.

  15. Transmembrane current imaging in the heart during pacing and fibrillation.

    PubMed

    Gray, Richard A; Mashburn, David N; Sidorov, Veniamin Y; Roth, Bradley J; Pathmanathan, Pras; Wikswo, John P

    2013-10-01

    Recently, we described a method to quantify the time course of total transmembrane current (Im) and the relative role of its two components, a capacitive current (Ic) and a resistive current (Iion), corresponding to the cardiac action potential during stable propagation. That approach involved recording high-fidelity (200 kHz) transmembrane potential (Vm) signals with glass microelectrodes at one site using a spatiotemporal coordinate transformation via measured conduction velocity. Here we extend our method to compute these transmembrane currents during stable and unstable propagation from fluorescence signals of Vm at thousands of sites (3 kHz), thereby introducing transmembrane current imaging. In contrast to commonly used linear Laplacians of extracellular potential (Ve) to compute Im, we utilized nonlinear image processing to compute the required second spatial derivatives of Vm. We quantified the dynamic spatial patterns of current density of Im and Iion for both depolarization and repolarization during pacing (including nonplanar patterns) by calibrating data with the microelectrode signals. Compared to planar propagation, we found that the magnitude of Iion was significantly reduced at sites of wave collision during depolarization but not repolarization. Finally, we present uncalibrated dynamic patterns of Im during ventricular fibrillation and show that Im at singularity sites was monophasic and positive with a significant nonzero charge (Im integrated over 10 ms) in contrast with nonsingularity sites. Our approach should greatly enhance the understanding of the relative roles of functional (e.g., rate-dependent membrane dynamics and propagation patterns) and static spatial heterogeneities (e.g., spatial differences in tissue resistance) via recordings during normal and compromised propagation, including arrhythmias. PMID:24094412

  16. Growth, innovation, scaling, and the pace of life in cities

    PubMed Central

    Bettencourt, Luís M. A.; Lobo, José; Helbing, Dirk; Kühnert, Christian; West, Geoffrey B.

    2007-01-01

    Humanity has just crossed a major landmark in its history with the majority of people now living in cities. Cities have long been known to be society's predominant engine of innovation and wealth creation, yet they are also its main source of crime, pollution, and disease. The inexorable trend toward urbanization worldwide presents an urgent challenge for developing a predictive, quantitative theory of urban organization and sustainable development. Here we present empirical evidence indicating that the processes relating urbanization to economic development and knowledge creation are very general, being shared by all cities belonging to the same urban system and sustained across different nations and times. Many diverse properties of cities from patent production and personal income to electrical cable length are shown to be power law functions of population size with scaling exponents, β, that fall into distinct universality classes. Quantities reflecting wealth creation and innovation have β ≈1.2 >1 (increasing returns), whereas those accounting for infrastructure display β ≈0.8 <1 (economies of scale). We predict that the pace of social life in the city increases with population size, in quantitative agreement with data, and we discuss how cities are similar to, and differ from, biological organisms, for which β<1. Finally, we explore possible consequences of these scaling relations by deriving growth equations, which quantify the dramatic difference between growth fueled by innovation versus that driven by economies of scale. This difference suggests that, as population grows, major innovation cycles must be generated at a continually accelerating rate to sustain growth and avoid stagnation or collapse. PMID:17438298

  17. Are postglacial sediment yields of mountain headwaters out of pace?

    NASA Astrophysics Data System (ADS)

    Hoffmann, Thomas

    2014-05-01

    Many high mountains have been sculpted by strong glacial erosion during the Pleistocene that resulted in valley widening and overdeepening and the formation of glacial cirques, U-shaped valleys, and widespread glacial deposits. The retreat of glacial ice exposes oversteepened hillslopes that are susceptible to rockfalls, deep-seated landsliding, gully erosion, and debris flows, and can also result in valley aggradation and reworking of valley deposits through debris flow activity and fluvial processes. It has been argued that sediment fluxes caused by these processes remain elevated even several thousand years after the retreat of valley glaciers. Yet, our knowledge on the response times of postglacial mountain systems to Pleistocene glacial erosion remains insufficient. Here I represent an approach to calculate the response times of postglacial geomorphic systems to Pleistocene glacial erosion based on reservoir theory and the compilation of postglacial sediment budgets in alpine systems. The study is conducted in the Kananaskis Country in the Canadian Rocky Mountains, in which sediment budgets of 5 headwater basins have been complied. The sediment budgets show that sediment delivery from formerly glaciated headwaters is limited indicated by average postglacial sediment delivery ratios (SDR) ranging between 0 and 0.3. The low SDRs are controlled by the glacial history of the headwater and suggest that the response times of sediment flux in alpine headwater basins is in the order of 100-500 kyr. Thus postglacial adjustment of alpine sediment flux exceeds the recurrence interval of the large ice ages during the Pleistocene suggesting that mountain headwaters in the Canadian Rockies are out of pace with respect to glacially-induced changes.

  18. Transmembrane Current Imaging in the Heart during Pacing and Fibrillation

    PubMed Central

    Gray, Richard A.; Mashburn, David N.; Sidorov, Veniamin Y.; Roth, Bradley J.; Pathmanathan, Pras; Wikswo, John P.

    2013-01-01

    Recently, we described a method to quantify the time course of total transmembrane current (Im) and the relative role of its two components, a capacitive current (Ic) and a resistive current (Iion), corresponding to the cardiac action potential during stable propagation. That approach involved recording high-fidelity (200 kHz) transmembrane potential (Vm) signals with glass microelectrodes at one site using a spatiotemporal coordinate transformation via measured conduction velocity. Here we extend our method to compute these transmembrane currents during stable and unstable propagation from fluorescence signals of Vm at thousands of sites (3 kHz), thereby introducing transmembrane current imaging. In contrast to commonly used linear Laplacians of extracellular potential (Ve) to compute Im, we utilized nonlinear image processing to compute the required second spatial derivatives of Vm. We quantified the dynamic spatial patterns of current density of Im and Iion for both depolarization and repolarization during pacing (including nonplanar patterns) by calibrating data with the microelectrode signals. Compared to planar propagation, we found that the magnitude of Iion was significantly reduced at sites of wave collision during depolarization but not repolarization. Finally, we present uncalibrated dynamic patterns of Im during ventricular fibrillation and show that Im at singularity sites was monophasic and positive with a significant nonzero charge (Im integrated over 10 ms) in contrast with nonsingularity sites. Our approach should greatly enhance the understanding of the relative roles of functional (e.g., rate-dependent membrane dynamics and propagation patterns) and static spatial heterogeneities (e.g., spatial differences in tissue resistance) via recordings during normal and compromised propagation, including arrhythmias. PMID:24094412

  19. Obliquity-paced Pliocene West Antarctic ice sheet oscillations

    USGS Publications Warehouse

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

    2009-01-01

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

  20. Improving the Thermochemical Energy Storage Performance of the Mn2 O3 /Mn3 O4 Redox Couple by the Incorporation of Iron.

    PubMed

    Carrillo, Alfonso J; Serrano, David P; Pizarro, Patricia; Coronado, Juan M

    2015-06-01

    Redox cycles of manganese oxides (Mn2 O3 /Mn3 O4 ) are a promising alternative for thermochemical heat storage systems coupled to concentrated solar power plants as manganese oxides are abundant and inexpensive materials. Although their cyclability for such a purpose has been proved, sintering processes, related to the high-temperature conditions at which charge-discharge cycles are performed, generally cause a cycle-to-cycle decrease in the oxidation rate of Mn3 O4 . To guarantee proper operation, both reactions should present stable reaction rates. In this study, it has been demonstrated that the incorporation of Fe, which is also an abundant material, into the manganese oxides improves the redox performance of this system by increasing the heat storage density, narrowing the redox thermal hysteresis, and, above all, stabilizing and enhancing the oxidation rate over long-term operation, which counteracts the negative effects caused by sintering, although its presence is not avoided.