Search

Your search keyword '"YEAGER, S."' showing total 189 results
Start Over Author "YEAGER, S."
189 results on '"YEAGER, S."'

1. Eastern Boundary Upwelling Systems in Ocean–Sea Ice Simulations Forced by CORE and JRA55-do: Mean State and Variability at the Surface.

Author

Small, R. J., Kurian, J., Chang, P., Xu, G., Tsujino, H., Yeager, S., Danabasoglu, G., Kim, W. M., Altuntas, A., and Castruccio, F.

Abstract

In this paper we summarize improvements in climate model simulation of eastern boundary upwelling systems (EBUS) when changing the forcing dataset from the Coordinated Ocean-Ice Reference Experiments (CORE; ∼2° winds) to the higher-resolution Japanese 55-year Atmospheric Reanalysis for driving ocean–sea ice models (JRA55-do, ∼0.5°) and also due to refining ocean grid spacing from 1° to 0.1°. The focus is on sea surface temperature (SST), a key variable for climate studies, and which is typically too warm in climate model representation of EBUS. The change in forcing leads to a better-defined atmospheric low-level coastal jet, leading to more equatorward ocean flow and coastal upwelling, both in turn acting to reduce SST over the upwelling regions off the west coast of North America, Peru, and Chile. The refinement of ocean resolution then leads to narrower and stronger alongshore ocean flow and coastal upwelling, and the emergence of strong across-shore temperature gradients not seen with the coarse ocean model. Off northwest Africa the SST bias mainly improves with ocean resolution but not with forcing, while in the Benguela, JRA55-do with high-resolution ocean leads to lower SST but a substantial bias relative to observations remains. Reasons for the Benguela bias are discussed in the context of companion regional ocean model simulations. Finally, we address to what extent improvements in mean state lead to changes to the monthly to interannual variability. It is found that large-scale SST variability in EBUS on monthly and longer time scales is largely governed by teleconnections from climate modes and less sensitive to model resolution and forcing than the mean state. [ABSTRACT FROM AUTHOR]

Published
2024
Full Text
View/download PDF

5. North Atlantic climate far more predictable than models imply

Author

Smith, D. M., Scaife, A. A., Eade, R., Athanasiadis, P., Bellucci, A., Bethke, I., Bilbao, R., Borchert, L. F., Caron, L.-P., Counillon, F., Danabasoglu, G., Delworth, T., Doblas-Reyes, F. J., Dunstone, N. J., Estella-Perez, V., Flavoni, S., Hermanson, L., Keenlyside, N., Kharin, V., Kimoto, M., Merryfield, W. J., Mignot, J., Mochizuki, T., Modali, K., Monerie, P.-A., Müller, W. A., Nicolí, D., Ortega, P., Pankatz, K., Pohlmann, H., Robson, J., Ruggieri, P., Sospedra-Alfonso, R., Swingedouw, D., Wang, Y., Wild, S., Yeager, S., Yang, X., and Zhang, L.

Published
2020
Full Text
View/download PDF

6. Systematics of quadrupole moments and energies

Author

Yeager, S., Zamick, L., Sharon, Y. Y., Yu, Xiaofei, and Robinson, S. J. Q.

Subjects
Nuclear Theory, Nuclear Experiment
Abstract

We define the "quadrupole ratio" r_{Q}=\dfrac{Q_{0}(S)}{Q_{0}(B)} where Q_{0}(S) is the intrinsic quadrupole moment obtained from the static quadrupole moment of the 2_{1}^{+} state of an even-even nucleus and Q_{0}(B) the intrinsic quadrupole moment obtained from B(E2)_{0\rightarrow2} . In both cases we assume a simple rotational formula connecting the rotating frame to the laboratory frame. The quantity r_{Q} would be one if the rotational model were perfect and the energy ratio E(4)/E(2) would be 10/3. In the simple vibrational model, r_{Q} would be zero and E(4)/E(2) would be two. There are some regions where the rotational limit is almost met and fewer where the vibrational limit is also almost met. For most cases, however, it is between these two limits, i.e. 0<|r_{Q}|<1 . There are a few cases where r_{Q} is bigger than one, especially for light nuclei. In most cases the quadrupole ratio is positive but there are two regions with negative ratios. The first case is that of light nuclei and the second has certain nuclei close to ^{208} Pb., Comment: 1 figure many pages; 56621. arXiv admin note: substantial text overlap with arXiv:0807.4679

Published
2012

7. Lawson Method for Obtaining Wave Functions and $g$ Factors of Ar Isotopes

Author

Zamick, L., Yeager, S., and Sharon, Y. Y.

Subjects
Nuclear Theory
Abstract

Lawson has shown that one can obtain sensible wave functions even in the weak deformation limit of the Nilsson model as long as one projects out states of good total angular momentum. We apply this method to obtain wave functions and magnetic $g$ factors of excited states of select even-even Ar isotopes.

Published
2008
Full Text
View/download PDF

8. Isoscalar g Factors of Even-Even and Odd-Odd Nuclei

Author

Yeager, S., Zamick, L., Sharon, Y. Y., and Robinson, S. J. Q.

Subjects
Nuclear Theory
Abstract

We consider T=0 states in even-even and odd-odd N=Z nuclei. The g factors that emerge are isoscalar. We find that the single j shell model gives simple expressions for these g factors which for even-even nuclei are suprisingly close to the collective values for K=0 bands. The g factors of many 2+ in even-even nuclei and 1+ and 3+ states in odd-odd nuclei have g factors close to 0.5.

Published
2008
Full Text
View/download PDF

10. Robust skill of decadal climate predictions

Author

Smith, D. M., Eade, R., Scaife, A. A., Caron, L.-P., Danabasoglu, G., DelSole, T. M., Delworth, T., Doblas-Reyes, F. J., Dunstone, N. J., Hermanson, L., Kharin, V., Kimoto, M., Merryfield, W. J., Mochizuki, T., Müller, W. A., Pohlmann, H., Yeager, S., and Yang, X.

Published
2019
Full Text
View/download PDF

11. Reviews

Author

Zoller, L.P., primary, Bellis, J., additional, Enderwitz, A., additional, Weidle, R., additional, Broders, S., additional, Müller, A., additional, Richter, V., additional, Althans, K., additional, Schwalm, H., additional, Tönnies, M., additional, Hundt, S., additional, Trotta, J., additional, Cortiel, J., additional, Yeager, S., additional, and Zähringer, R., additional

Published
2023
Full Text
View/download PDF

14. Predictable Variations of the Carbon Sinks and Atmospheric CO2Growth in a Multi‐Model Framework

Author

Ilyina, T., primary, Li, H., additional, Spring, A., additional, Müller, W. A., additional, Bopp, L., additional, Chikamoto, M. O., additional, Danabasoglu, G., additional, Dobrynin, M., additional, Dunne, J., additional, Fransner, F., additional, Friedlingstein, P., additional, Lee, W., additional, Lovenduski, N. S., additional, Merryfield, W.J., additional, Mignot, J., additional, Park, J.Y., additional, Séférian, R., additional, Sospedra‐Alfonso, R., additional, Watanabe, M., additional, and Yeager, S., additional

Published
2021
Full Text
View/download PDF

16. Author Correction: Robust skill of decadal climate predictions (npj Climate and Atmospheric Science, (2019), 2: 13, 10.1038/s41612-019-0071-y)

Author

Smith, D., Eade, R., Scaife, A., Caron, L., Danabasoglu, G., DelSole, T., Delworth, T., Doblas-Reyes, F., Dunstone, N., Hermanson, L., Kharin, V., Kimoto, M., Merryfield, W., Mochizuki, T., Müller, W., Pohlmann, H., Yeager, S., and Yang, X.

Abstract

An amendment to this paper has been published and can be accessed via a link at the top of the paper. © 2020, Crown.

Published
2020

18. Variability in the Northern North Atlantic and Arctic Oceans Across the Last Two Millennia: A Review

Author

Moffa‐Sánchez, P., primary, Moreno‐Chamarro, E., additional, Reynolds, D. J., additional, Ortega, P., additional, Cunningham, L., additional, Swingedouw, D., additional, Amrhein, D. E., additional, Halfar, J., additional, Jonkers, L., additional, Jungclaus, J. H., additional, Perner, K., additional, Wanamaker, A., additional, and Yeager, S., additional

Published
2019
Full Text
View/download PDF

20. Decadal Climate Prediction: An Update from the Trenches

Author

Meehl, G., Goddard, L., Kirtman, B., Branstator, G., Danabasoglu, G., Hawkins, E., Kumar, A., Rosati, T., Smith, D., Sutton, R., Boer, G., Burgman, R., Carson, C., Corti, S., Karspeck, A., Keenlyside, N., Kimoto, M., Matei, D., https://orcid.org/0000-0002-3735-8802, Mignot, J., Msadek, R., Navarra, A., Pohlmann, H., Rienecker, M., Schneider, E., Tebaldi, C., Teng, H., van Oldenborgh, G., Vecchi, G., Yeager, S., National Center for Atmospheric Research [Boulder] ( NCAR ), International Research Institute for Climate and Society ( IRI ), Earth Institute at Columbia University, Columbia University [New York]-Columbia University [New York], CERFACS [Toulouse], Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ), Department of Neurological Sciences, University of Milan, Institut Català de Ciències del Clima, Institució Catalana de Recerca i Estudis Avançats ( ICREA ), Department of Meteorology [Reading], University of Reading ( UOR ), Laboratoire Interdisciplinaire Carnot de Bourgogne ( LICB ), Université de Bourgogne ( UB ) -Centre National de la Recherche Scientifique ( CNRS ), Max Planck Institute for Meteorology ( MPI-M ), Processus de la variabilité climatique tropicale et impacts ( PARVATI ), Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques ( LOCEAN ), Muséum National d'Histoire Naturelle ( MNHN ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ) -Muséum National d'Histoire Naturelle ( MNHN ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ), NOAA Geophysical Fluid Dynamics Laboratory ( GFDL ), National Oceanic and Atmospheric Administration ( NOAA ), Dipartimento di Matematica e Informatica [Perugia] ( DMI ), Università degli Studi di Perugia ( UNIPG ), NASA Goddard Space Flight Center ( GSFC ), Espaces et Sociétés ( ESO ), Université de Caen Normandie ( UNICAEN ), Normandie Université ( NU ) -Normandie Université ( NU ) -Le Mans Université ( UM ) -Université d'Angers ( UA ) -AGROCAMPUS OUEST-Université de Rennes 2 ( UR2 ), Université de Rennes ( UNIV-RENNES ) -Université de Rennes ( UNIV-RENNES ) -Institut de Géographie et d'Aménagement ( IGARUN ), Université de Nantes ( UN ) -Université de Nantes ( UN ) -Centre National de la Recherche Scientifique ( CNRS ), Royal Netherlands Meteorological Institute ( KNMI ), National Center for Atmospheric Research [Boulder] (NCAR), International Research Institute for Climate and Society (IRI), Canadian Centre for Climate Modelling and Analysis (CCCma), Environment and Climate Change Canada, Florida International University [Miami] (FIU), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Institució Catalana de Recerca i Estudis Avançats (ICREA), University of Reading (UOR), The University of Tokyo (UTokyo), Laboratoire Interdisciplinaire Carnot de Bourgogne (LICB), Université de Bourgogne (UB)-Centre National de la Recherche Scientifique (CNRS), Max Planck Institute for Meteorology (MPI-M), Max-Planck-Gesellschaft, Processus de la variabilité climatique tropicale et impacts (PARVATI), Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques (LOCEAN), Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Muséum national d'Histoire naturelle (MNHN)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Muséum national d'Histoire naturelle (MNHN)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), NOAA Geophysical Fluid Dynamics Laboratory (GFDL), National Oceanic and Atmospheric Administration (NOAA), Dipartimento di Matematica e Informatica [Perugia] (DMI), Università degli Studi di Perugia (UNIPG), NASA Goddard Space Flight Center (GSFC), Espaces et Sociétés (ESO), Institut de Géographie et d'Aménagement Régional de l'Université de Nantes (IGARUN), Université de Nantes (UN)-Université de Nantes (UN)-Centre National de la Recherche Scientifique (CNRS)-Université de Rennes 2 (UR2), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-AGROCAMPUS OUEST, Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Université d'Angers (UA)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-Le Mans Université (UM), Met Office Hadley Centre for Climate Change (MOHC), United Kingdom Met Office [Exeter], National Centre for Atmospheric Science, University of Reading, Reading, United Kingdom, Royal Netherlands Meteorological Institute (KNMI), Meehl GA, Goddard L, Boer G, Burgman R, Branstator G, Cassou C, Corti S, Danabasoglu G, Doblas-Reyes F, Hawkins E, Karspeck A, Kimoto M, Kumar A, Matei D, Mignot J, Msadek R, Navarra A, Pohlmann H, Rienecker M, Rosati T, Schneider E, Smith D, Sutton R, Teng HY, van Oldenborgh GJ, Vecchi G, and Yeager S

Subjects
Atmospheric Science, 010504 meteorology & atmospheric sciences, Atmosphere, Climate system, Initialization, [PHYS.PHYS.PHYS-GEO-PH]Physics [physics]/Physics [physics]/Geophysics [physics.geo-ph], Forcing (mathematics), Hiatus, 010502 geochemistry & geophysics, 01 natural sciences, [ PHYS.PHYS.PHYS-GEO-PH ] Physics [physics]/Physics [physics]/Geophysics [physics.geo-ph], Climatic changes--Simulation methods, Climatic changes--Forecasting, 13. Climate action, Climatology, Environmental science, decadal predictions, climate, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences
Abstract

This paper provides an update on research in the relatively new and fast-moving field of decadal climate prediction, and addresses the use of decadal climate predictions not only for potential users of such information but also for improving our understanding of processes in the climate system. External forcing influences the predictions throughout, but their contributions to predictive skill become dominant after most of the improved skill from initialization with observations vanishes after about 6–9 years. Recent multimodel results suggest that there is relatively more decadal predictive skill in the North Atlantic, western Pacific, and Indian Oceans than in other regions of the world oceans. Aspects of decadal variability of SSTs, like the mid-1970s shift in the Pacific, the mid-1990s shift in the northern North Atlantic and western Pacific, and the early-2000s hiatus, are better represented in initialized hindcasts compared to uninitialized simulations. There is evidence of higher skill in initialized multimodel ensemble decadal hindcasts than in single model results, with multimodel initialized predictions for near-term climate showing somewhat less global warming than uninitialized simulations. Some decadal hindcasts have shown statistically reliable predictions of surface temperature over various land and ocean regions for lead times of up to 6–9 years, but this needs to be investigated in a wider set of models. As in the early days of El Niño–Southern Oscillation (ENSO) prediction, improvements to models will reduce the need for bias adjustment, and increase the reliability, and thus usefulness, of decadal climate predictions in the future.

Published
2014

21. Predictable Variations of the Carbon Sinks and Atmospheric CO2 Growth in a Multi‐Model Framework.

Author

Ilyina, T., Li, H., Spring, A., Müller, W. A., Bopp, L., Chikamoto, M. O., Danabasoglu, G., Dobrynin, M., Dunne, J., Fransner, F., Friedlingstein, P., Lee, W., Lovenduski, N. S., Merryfield, W.J., Mignot, J., Park, J.Y., Séférian, R., Sospedra‐Alfonso, R., Watanabe, M., and Yeager, S.

Subjects
CARBON cycle, ATMOSPHERIC carbon dioxide, GLOBAL warming, LEAD time (Supply chain management), CARBON analysis
Abstract

Inter‐annual to decadal variability in the strength of the land and ocean carbon sinks impede accurate predictions of year‐to‐year atmospheric carbon dioxide (CO2) growth rate. Such information is crucial to verify the effectiveness of fossil fuel emissions reduction measures. Using a multi‐model framework comprising prediction systems initialized by the observed state of the physical climate, we find a predictive skill for the global ocean carbon sink of up to 6 years for some models. Longer regional predictability horizons are found across single models. On land, a predictive skill of up to 2 years is primarily maintained in the tropics and extra‐tropics enabled by the initialization of the physical climate. We further show that anomalies of atmospheric CO2 growth rate inferred from natural variations of the land and ocean carbon sinks are predictable at lead time of 2 years and the skill is limited by the land carbon sink predictability horizon. Plain Language Summary: Variations of the natural land and ocean carbon sinks in response to climate variability strongly regulate year‐to‐year variations in the growth rate of atmospheric carbon dioxide (CO2). Information on the near‐term evolution of the carbon sinks and CO2 in the atmosphere is necessary to understand where the anthropogenic carbon would go in response to emission reduction efforts addressing global warming mitigation. Predictions of this near‐term evolution would thus assist policy‐relevant analysis and carbon management activities. Here we use a set of prediction systems based on Earth system models to establish predictive skills of the ocean and land carbon sinks and to infer predictability of atmospheric CO2 growth rate. We show predictability horizons of up to 6 years for some models for the globally integrated ocean carbon sink, with even higher regional predictive skill. Variations of the land carbon sink are predictable up to 2 years and limit predictability of changes in atmospheric CO2 growth rate at lead time of 2 years. Our study thereby demonstrates an emerging capacity of the initialized simulations for predicting the global carbon cycle and the planet's breath maintained by variations of atmospheric CO2. Key Points: Predictive skill of the global ocean carbon sink due to initialization is up to 6 years for some models, with longer regional predictability in single modelsPredictive skill due to initialization for the land carbon sink of up to 2 years is primarily maintained in the tropics and extra‐tropicsAnomalies of atmospheric CO2 growth rate are predictable up to 2 years and are limited by the land carbon sink predictability horizon [ABSTRACT FROM AUTHOR]

Published
2021
Full Text
View/download PDF

23. Predicted Chance That Global Warming Will Temporarily Exceed 1.5 °C

Author

Smith, D. M., primary, Scaife, A. A., additional, Hawkins, E., additional, Bilbao, R., additional, Boer, G. J., additional, Caian, M., additional, Caron, L.‐P., additional, Danabasoglu, G., additional, Delworth, T., additional, Doblas‐Reyes, F. J., additional, Doescher, R., additional, Dunstone, N. J., additional, Eade, R., additional, Hermanson, L., additional, Ishii, M., additional, Kharin, V., additional, Kimoto, M., additional, Koenigk, T., additional, Kushnir, Y., additional, Matei, D., additional, Meehl, G. A., additional, Menegoz, M., additional, Merryfield, W. J., additional, Mochizuki, T., additional, Müller, W. A., additional, Pohlmann, H., additional, Power, S., additional, Rixen, M., additional, Sospedra‐Alfonso, R., additional, Tuma, M., additional, Wyser, K., additional, Yang, X., additional, and Yeager, S., additional

Published
2018
Full Text
View/download PDF

28. 2014 U.S. AMOC Science Team Annual Report on Progress and Priorities

Author

Danabasoglu, G., Curry, R., Karspeck, A., Meinen, C., Msadek, R., Patterson, M., Perez, R., Schmittner, A., Thompson, L., and Yeager, S.

Abstract

The seventh annual report for the U.S. AMOC Science Team features progress made in the past year on the main objectives of the program, identifies programmatic gaps, and makes recommendations on near and long-term research priorities and goals for the program. Over 50 research projects are featured in the report. Furthermore, the report lists action items for each Task Team to address, which are based upon the discussions from the 2014 Annual Science Team meeting in Seattle.

Published
2015
Full Text
View/download PDF

29. 2013 U.S. AMOC Science Team Annual Report on Progress and Priorities

Author

Danabasoglu, G., Curry, R., Heimbach, P., Kushnir, Y., Meinen, C., Msadek, R., Patterson, M., Thompson, L., Yeager, S., and Zhang, R.

Abstract

The sixth annual report for the U.S. AMOC Science Team features progress made in the past year on the main objectives of the program, identifies any programmatic gaps, and makes recommendations on near-term research priorities for the program. Findings and recommendations from an external review process conducted in 2012-2013 and highlights from the U.S. AMOC/UK Rapid international meeting are also featured.

Published
2014
Full Text
View/download PDF

34. SUDDEN CARDIAC DEATH AND THE USE OF IMPLANTABLE CARDIOVERTER-DEFIBRILLATORS IN PEDIATRIC-PATIENTS

Author

SILKA, MJ, KRON, J, DUNNIGAN, A, DICK, M, BINKBOELKENS, M, ERICKSON, CC, JEDEIKIN, R, WETZEL, GT, VANHARE, GF, CAMPBELL, R, WALSH, E, SAUL, JP, SCHAFFER, MS, KARPAWICH, P, VOGEL, RL, BENSON, DW, DEAL, B, SCAGLIOTTI, D, STERBA, R, HORDOF, AJ, KRONGRAD, E, KANTER, RJ, EPSTEIN, M, COHEN, M, BEDER, S, HAMILTON, R, FOURNIER, A, HUBBARD, J, CHRISTIANSEN, JL, JENNINGS, J, VILLAFANE, J, PORTER, CBJ, CASE, C, GILLETTE, PC, BELAND, M, KUGLER, JD, OCONNOR, BK, ALLENDER, H, HERNDON, SP, SMITH, RT, BURTON, D, KURER, CC, BYRUM, C, GUAM, WE, FRIEDMAN, R, PERRY, JC, SCOTT, W, MEHTA, AV, PICKHOFF, AS, FISH, F, YEAGER, S, KAWABORI, [No Value], TRIPPLE, M, ROSENFELD, LE, and Faculteit Medische Wetenschappen/UMCG

Subjects
STIMULATION, SURVIVORS, CARDIOMYOPATHY, CHILDREN, PEDIATRIC CARDIOLOGY, CONGENITAL HEART DISEASE, THERAPY, DISEASE, CARDIOVERTER-DEFIBRILLATOR, UNEXPECTED DEATH, MANAGEMENT, HEART, VENTRICULAR ARRHYTHMIA, SUDDEN CARDIAC DEATH, MALIGNANT VENTRICULAR ARRHYTHMIAS
Abstract

Background. During the past decade. the implantable cardioverter-defibrillator (ICD) has emerged as the primary therapeutic option for survivors of sudden cardiac death (SCD). Investigation of the clinical efficacy of these devices has primarily assessed outcome in adults with coronary artery disease. The purpose of this cooperative, international study was to evaluate the impact of ICDs on the pediatric population of SCD survivors, based on an analysis of the clinical characteristics and outcomes of young patients who underwent ICD implantation following an episode of life-threatening ventricular tachycardia or resuscitation from SCD. Methods and Results. An initial data base, established by contacting the manufacturers of the various commercially and investigationally available devices, identified 177 patients who were less than 20 years of age at the time of initial implantation of an ICD. With this data base as a reference, detailed responses were subsequently obtained from physicians involved in the care of 125 (71%) of these patients. The patients ranged in age from 1.9 to 19.9 years (mean, 14.5+/-4 years) and weighed 9.7-117 kg (mean, 44.6+/-14 kg). Of the 125 patients, 76% were survivors of SCD, 10% had drug refractory ventricular tachycardia, and 10% had syncope with heart disease and inducible sustained ventricular tachyarrhythmias. The most common types of associated cardiovascular disease were hypertrophic and dilated cardiomyopathies (54%), primary electrical diseases (26%), and congenital heart defects (18%). Ventricular function was abnormal in 46% of the patients. During a mean follow-up of 31+/-23 months, at least one ICD discharge occurred in 85 of the 125 (68%) patients. Seventy-three patients (59%) received at least one appropriate ICD discharge, and 25 patients (20%) had one or more spurious or indeterminate discharges. Duration of follow-up >24 months (p=0.001) and inducibility of a sustained ventricular arrhythmia (p=0.05) were correlated with appropriate ICD discharges. There were nine deaths during the study period: five sudden, two due to recurrent ventricular arrhythmias, and two related to congestive heart failure. Abnormal ventricular function (p=0.002) and prior ICD discharge (p=0.01) were univariate correlates of patient mortality; by multivariate logistic regression, abnormal ventricular function was the only significant correlate of death (p=0.005). By actuarial analysis, the estimated overall post-ICD implant survival rates at 1, 2, and 5 years were 95%, 93%, and 85%, respectively. The corresponding sudden death-free survival rates were 97%, 95%, and 90%. Conclusions. Pediatric patients resuscitated from SCD appear to remain at risk for recurrence of life-threatening tachyarrhythmias. During a mean follow-up of 31 months, the ICD provided an effective therapy for such arrhythmias in the majority of patients in this study. Following ICD implant, impaired ventricular function was the primary factor correlated with mortality. The patterns or ICD discharge observed in young patients and. thus, inferred risk of recurrent life threatening arrhythmias are similar to those of adult survivors of SCD. Thus, the use of ICDs in pediatric patients, with implant selection criteria similar to adults. appear valid.

Published
1993

38. An evaluation of experimental decadal predictions using CCSM4.

Author

Karspeck, A., Yeager, S., Danabasoglu, G., and Teng, H.

Subjects
*OCEAN temperature, *PREDICTION models, *SEA ice, *METEOROLOGICAL research, *SIMULATION methods & models, *WEATHER forecasting
Abstract

This study assesses retrospective decadal prediction skill of sea surface temperature (SST) variability in initialized climate prediction experiments with the Community Climate System Model version 4 (CCSM4). Ensemble forecasts initialized with two different historical ocean and sea-ice states are evaluated and compared to an ensemble of uninitialized coupled simulations. Both experiments are subject to identical twentieth century historical radiative forcings. Each forecast consists of a 10-member ensemble integrated over a 10-year period. One set of historical ocean and sea-ice conditions used for initialization comes from a forced ocean-ice simulation driven by the Coordinated Ocean-ice Reference Experiments interannually varying atmospheric dataset. Following the Coordinated Model Intercomparison Project version 5 (CMIP5) protocol, these forecasts are initialized every 5 years from 1961 to 1996, and every year from 2000 to 2006. A second set of initial conditions comes from historical ocean state estimates obtained through the assimilation of in-situ temperature and salinity data into the CCSM4 ocean model. These forecasts are only available over a limited subset of the CMIP5 recommended start dates. Both methods result in retrospective SST prediction skill over broad regions of the Indian Ocean, western Pacific Ocean and North Atlantic Ocean that are significantly better than reference skill levels from a spatio-temporal auto-regressive statistical model of SST. However the subpolar gyre region of the North Atlantic stands out as the only region where the CCSM4 initialized predictions outperform uninitialized simulations. Some features of the ocean state estimates used for initialization and their impact on the forecasts are discussed. [ABSTRACT FROM AUTHOR]

Published
2015
Full Text
View/download PDF

41. THE PENNSYLVANIA DEAD MAN'S STATUTE.

Author

Yeager, S. Michael

Subjects
*DEAD man's statute, *ACTIONS & defenses (Law), *LEGAL procedure, *LEGAL testimony, *FAIR trial
Abstract

The article presents information on the Pennsylvania Dead Man's Statute and its application in civil action or proceeding. The purpose of the statute, rejection of testimony due to the incompetence of the witness and fair trial provisions are discussed. The necessary criteria for disqualifying a witness as incompetent, application of relevant statutes and the exceptions available in the statute are also discussed.

Published
2012

45. Measurement of Independent Variables Which Affect Communication: A Replication of Roberts and O'Reilly

Author

Yeager, S. J.

Abstract

This study examines Roberts and O'Reilly's scales measuring trust in the immediate superior, desire for promotion, and perceived supervisory influence for 2700 personnel in a soft-goods company. These measures are particularly important since these variables have traditionally been identified as major factors affecting communications within organizations. Results partially support use of these scales. However, methodological difficulties with these scales are also pointed out, and it is suggested that they need further development.

Published
1978
Full Text
View/download PDF

47. Consistency of Response Style across Types of Response Formats

Author

Bardo, J. W. and Yeager, S. J.

Abstract

Effects of response style on various commonly used fixed-response formats are examined. Data suggest that Likert-type formats are relatively consistently affected by response style regardless of the number of categories in the format. Non-anchored numbers were less affected by stylistic responses, while linear formats and various forms of human faces are the most problematic. Across types, strongest correlations were obtained for the various forms of linear formats and human faces making their use problematic.

Published
1982
Full Text
View/download PDF

48. Examination of Response Formats without Anchoring Items

Author

Bardo, J. W., Yeager, S. J., and Burdsal, C. A.

Abstract

Bartlett's chi squared, Cattell's scree test, and the Kaiser criterion for the number of factors were examined for susceptibility to error variance using non-anchored responses (N= 292) to various sets of fixed-response formats (4-, 5-, and 7-point Likert and numeric, lines with end points anchored, and several forms of human faces). Results demonstrated that Cattell's scree test is the most conservative under these conditions followed by Bartlett's chi squared with alpha set at .001. The Kaiser criterion was generally the most liberal. The factor pattern of the first principal component for each set of response formats was then examined for consistency using congruence coefficients. High congruences were found among most formats with the exception of 4-point formats. Of formats tested 4-position response formats seem least susceptible to systematic error based both on eigenvalue criteria and congruence with other formats.

Published
1985
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results