Characteristics of an axisymmetric sudden expansion flow

NASA Technical Reports Server (NTRS)

Stevenson, W. H.; Thompson, H. D.

1985-01-01

A two-color, two component Laser Doppler Velocimeter (LDV) system operating in forward scatter has been developed in order to make simultaneous measurements of the axial and radial velocity components in an axisymmetric sudden expansion flow with and without combustion. The LDV system includes Bragg cell modulators in the four beam paths to allow a net frequency shift of 5MHz in both the green and blue beams. This permits an unambiguous measurement of negative velocities and also eliminates incomplete signal bias. The green beam probe volume has a waist diameter of 0.200 mm and is approximately 2mm long. The blue beam has a probe volume waist of 0.250 mm and is approximately 1 mm long. The scattered light from the probe volume is separated so that approximately 80% of each color passes to its respective photomultiplier tube by using a dichroic filter. Narrow bandpass filters are used to further filter unwanted signals before they are detected. A schematic diagram of the LDV system is shown.

Epidemiological characteristics of sudden cardiac arrest in schools.

PubMed

Nishiuchi, Tatsuya; Hayashino, Yasuaki; Iwami, Taku; Kitamura, Tetsuhisa; Nishiyama, Chika; Kajino, Kentaro; Nitta, Masahiko; Hayashi, Yasuyuki; Hiraide, Atsushi

2014-08-01

The present study aimed to clarify the incidence and outcomes of sudden cardiac arrests in schools and the clinically relevant characteristics of individuals who experienced sudden cardiac arrests. We obtained data on sudden cardiac arrests that occurred in schools between January 1, 2005 and December 31, 2009 from the database of the Utstein Osaka Project, a population-based observational study on out-of-hospital cardiac arrests in Osaka, Japan. The data were analyzed to show the epidemiological features of sudden cardiac arrests in schools in conjunction with prehospital documentation. In total, 44 cases were registered as sudden cardiac arrests in schools during the study period. Of these, 34 cases had nontraumatic cardiac arrests. Twenty-one cases (62%) had pre-existing cardiac diseases and/or collapsed during physical exercise. Twenty-three cases (68%) presented with ventricular fibrillation or pulseless ventricular tachycardia, with cases of survival 1 month after cardiac arrest and those having favourable neurological outcome (Cerebral Performance Category 1 or 2) being 12 (52%) and 10 (43%), respectively. The incidence of sudden cardiac arrests in students was 0.23 per 100,000 persons per year, ranging from 0.08 in junior high school to 0.64 in high school. The incidence of sudden cardiac arrests in school faculty and staff was 0.51 per 100,000 persons per year, a rate approximately 2 times of that observed in the students. Although sudden cardiac arrests in schools is rare, they majorly occurred in individuals with cardiac diseases and/or during physical exercise and presented as ventricular fibrillation or pulseless ventricular tachycardia observed initially as cardiac arrhythmia. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Coupled electron-nuclear dynamics: Charge migration and charge transfer initiated near a conical intersection

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mendive-Tapia, David; Vacher, Morgane; Bearpark, Michael J.

Coupled electron-nuclear dynamics, implemented using the Ehrenfest method, has been used to study charge migration with fixed nuclei, together with charge transfer when nuclei are allowed to move. Simulations were initiated at reference geometries of neutral benzene and 2-phenylethylamine (PEA), and at geometries close to potential energy surface crossings in the cations. Cationic eigenstates, and the so-called sudden approximation, involving removal of an electron from a correlated ground-state wavefunction for the neutral species, were used as initial conditions. Charge migration without coupled nuclear motion could be observed if the Ehrenfest simulation, using the sudden approximation, was started near a conicalmore » intersection where the states were both strongly coupled and quasi-degenerate. Further, the main features associated with charge migration were still recognizable when the nuclear motion was allowed to couple. In the benzene radical cation, starting from the reference neutral geometry with the sudden approximation, one could observe sub-femtosecond charge migration with a small amplitude, which results from weak interaction with higher electronic states. However, we were able to engineer large amplitude charge migration, with a period between 10 and 100 fs, corresponding to oscillation of the electronic structure between the quinoid and anti-quinoid cationic electronic configurations, by distorting the geometry along the derivative coupling vector from the D{sub 6h} Jahn-Teller crossing to lower symmetry where the states are not degenerate. When the nuclear motion becomes coupled, the period changes only slightly. In PEA, in an Ehrenfest trajectory starting from the D{sub 2} eigenstate and reference geometry, a partial charge transfer occurs after about 12 fs near the first crossing between D{sub 1}, D{sub 2} (N{sup +}-Phenyl, N-Phenyl{sup +}). If the Ehrenfest propagation is started near this point, using the sudden approximation without coupled nuclear motion, one observes an oscillation of the spin density – charge migration – between the N atom and the phenyl ring with a period of 4 fs. When the nuclear motion becomes coupled, this oscillation persists in a damped form, followed by an effective charge transfer after 30 fs.« less

Coupled electron-nuclear dynamics: Charge migration and charge transfer initiated near a conical intersection

NASA Astrophysics Data System (ADS)

Mendive-Tapia, David; Vacher, Morgane; Bearpark, Michael J.; Robb, Michael A.

2013-07-01

Coupled electron-nuclear dynamics, implemented using the Ehrenfest method, has been used to study charge migration with fixed nuclei, together with charge transfer when nuclei are allowed to move. Simulations were initiated at reference geometries of neutral benzene and 2-phenylethylamine (PEA), and at geometries close to potential energy surface crossings in the cations. Cationic eigenstates, and the so-called sudden approximation, involving removal of an electron from a correlated ground-state wavefunction for the neutral species, were used as initial conditions. Charge migration without coupled nuclear motion could be observed if the Ehrenfest simulation, using the sudden approximation, was started near a conical intersection where the states were both strongly coupled and quasi-degenerate. Further, the main features associated with charge migration were still recognizable when the nuclear motion was allowed to couple. In the benzene radical cation, starting from the reference neutral geometry with the sudden approximation, one could observe sub-femtosecond charge migration with a small amplitude, which results from weak interaction with higher electronic states. However, we were able to engineer large amplitude charge migration, with a period between 10 and 100 fs, corresponding to oscillation of the electronic structure between the quinoid and anti-quinoid cationic electronic configurations, by distorting the geometry along the derivative coupling vector from the D6h Jahn-Teller crossing to lower symmetry where the states are not degenerate. When the nuclear motion becomes coupled, the period changes only slightly. In PEA, in an Ehrenfest trajectory starting from the D2 eigenstate and reference geometry, a partial charge transfer occurs after about 12 fs near the first crossing between D1, D2 (N+-Phenyl, N-Phenyl+). If the Ehrenfest propagation is started near this point, using the sudden approximation without coupled nuclear motion, one observes an oscillation of the spin density - charge migration - between the N atom and the phenyl ring with a period of 4 fs. When the nuclear motion becomes coupled, this oscillation persists in a damped form, followed by an effective charge transfer after 30 fs.

Geomagnetically Induced Currents Around the World During the 17 March 2015 Storm

NASA Technical Reports Server (NTRS)

Carter, B. A.; Yizengaw, E.; Pradipta, R.; Weygand, J. M.; Piersanti, M.; Pulkkinen, Antti Aleksi; Moldwin, M. B.; Norman, R.; Zhang, K.

2016-01-01

Geomagnetically induced currents (GICs) represent a significant space weather issue for power grid and pipeline infrastructure, particularly during severe geomagnetic storms. In this study, magnetometer data collected from around the world are analyzed to investigate the GICs caused by the 2015 St. Patricks Day storm. While significant GIC activity in the high-latitude regions due to storm time substorm activity is shown for this event, enhanced GIC activity was also measured at two equatorial stations in the American and Southeast Asian sectors. This equatorial GIC activity is closely examined, and it is shown that it is present both during the arrival of the interplanetary shock at the storm sudden commencement (SSC) in Southeast Asia and during the main phase of the storm approximately 10 h later in South America. The SSC caused magnetic field variations at the equator in Southeast Asia that were twice the magnitude of those observed only a few degrees to the north, strongly indicating that the equatorial electrojet (EEJ) played a significant role. The large equatorial magnetic field variations measured in South America are also examined, and the coincident solar wind data are used to investigate the causes of the sudden changes in the EEJ approximately 10 h into the storm. From this analysis it is concluded that sudden magnetopause current increases due to increases in the solarwind dynamic pressure, and the sudden changes in the resultant magnetospheric and ionospheric current systems, are the primary drivers of equatorial GICs.

Examining the accuracy of the infinite order sudden approximation using sensitivity analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Eno, L.; Rabitz, H.

1981-08-15

A method is developed for assessing the accuracy of scattering observables calculated within the framework of the infinite order sudden (IOS) approximation. In particular, we focus on the energy sudden assumption of the IOS method and our approach involves the determination of the sensitivity of the IOS scattering matrix S/sup IOS/ with respect to a parameter which reintroduces the internal energy operator h/sub 0/ into the IOS Hamiltonian. This procedure is an example of sensitivity analysis of missing model components (h/sub 0/ in this case) in the reference Hamiltonian. In contrast to simple first-order perturbation theory a finite result ismore » obtained for the effect of h/sub 0/ on S/sup IOS/. As an illustration, our method of analysis is applied to integral state-to-state cross sections for the scattering of an atom and rigid rotor. Results are generated within the He+H/sub 2/ system and a comparison is made between IOS and coupled states cross sections and the corresponding IOS sensitivities. It is found that the sensitivity coefficients are very useful indicators of the accuracy of the IOS results. Finally, further developments and applications are discussed.« less

Medication and Driving-Appropriate Interventions.

PubMed

Hitosugi, Masahito

2017-01-01

Sudden illness while driving has been identified as a major cause of vehicle collisions, accounting for approximately 1 in 10 collisions. Because most drivers who experience sudden illnesses while driving do not perform avoidance maneuvers, the improvement of drivers' health is being promoted as a traffic safety strategy. Although stroke, heart disease, and epilepsy are common causes of sudden illness, common symptoms, such as abdominal cramps, vertigo, and syncope can also cause problems during driving. We found that regular referral to physicians was significantly less common among drivers who experienced health-related vehicle collisions or incidents. Inadequate control of chronic disease might lead to unusual symptoms and the onset of major attacks. Medications are prescribed to patients to relieve their symptoms and/or bring their diseases under control. However, pharmacists and doctors should ensure that patients are treated with appropriate medications to avoid drivers being distracted due to adverse reactions to medications. The author suggests that it is important to keep drivers in good health and administer appropriate medications if necessary. Both pharmacists and doctors should warn drivers that sudden illness or medication-associated distractions can cause vehicle collisions. Such interventions might contribute to reducing the frequency of sudden illness-related vehicle collisions.

Sudden stretching of a four layered composite plate

NASA Technical Reports Server (NTRS)

Sih, G. C.; Chen, E. P.

1980-01-01

An approximate theory of laminated plates is developed by assuming that the extensioral and thickness mode of vibration are coupled. The mixed boundary value crack problem of a four layered composite plate is solved. Dynamic stress intensity factors for a crack subjected to suddenly applied stress are found to vary as a function of time and depend on the material properties of the laminate. Stress intensification in the region near the crack front can be reduced by having the shear modulus of the inner layers to be larger than that of the outer layers.

Genetic and forensic implications in epilepsy and cardiac arrhythmias: a case series.

PubMed

Partemi, Sara; Vidal, Monica Coll; Striano, Pasquale; Campuzano, Oscar; Allegue, Catarina; Pezzella, Marianna; Elia, Maurizio; Parisi, Pasquale; Belcastro, Vincenzo; Casellato, Susanna; Giordano, Lucio; Mastrangelo, Massimo; Pietrafusa, Nicola; Striano, Salvatore; Zara, Federico; Bianchi, Amedeo; Buti, Daniela; La Neve, Angela; Tassinari, Carlo Alberto; Oliva, Antonio; Brugada, Ramon

2015-05-01

Epilepsy affects approximately 3% of the world's population, and sudden death is a significant cause of death in this population. Sudden unexpected death in epilepsy (SUDEP) accounts for up to 17% of all these cases, which increases the rate of sudden death by 24-fold as compared to the general population. The underlying mechanisms are still not elucidated, but recent studies suggest the possibility that a common genetic channelopathy might contribute to both epilepsy and cardiac disease to increase the incidence of death via a lethal cardiac arrhythmia. We performed genetic testing in a large cohort of individuals with epilepsy and cardiac conduction disorders in order to identify genetic mutations that could play a role in the mechanism of sudden death. Putative pathogenic disease-causing mutations in genes encoding cardiac ion channel were detected in 24% of unrelated individuals with epilepsy. Segregation analysis through genetic screening of the available family members and functional studies are crucial tasks to understand and to prove the possible pathogenicity of the variant, but in our cohort, only two families were available. Despite further research should be performed to clarify the mechanism of coexistence of both clinical conditions, genetic analysis, applied also in post-mortem setting, could be very useful to identify genetic factors that predispose epileptic patients to sudden death, helping to prevent sudden death in patients with epilepsy.

IOS and ECS line coupling calculation for the CO-He system - Influence on the vibration-rotation band shapes

NASA Technical Reports Server (NTRS)

Boissoles, J.; Boulet, C.; Robert, D.; Green, S.

1987-01-01

Line coupling coefficients resulting from rotational excitation of CO perturbed by He are computed within the infinite order sudden approximation (IOSA) and within the energy corrected sudden approximation (ECSA). The influence of this line coupling on the 1-0 CO-He vibration-rotation band shape is then computed for the case of weakly overlapping lines in the 292-78 K temperature range. The IOS and ECS results differ only at 78 K by a weak amount at high frequencies. Comparison with an additive superposition of Lorentzian lines shows strong modifications in the troughs between the lines. These calculated modifications are in excellent quantitative agreement with recent experimental data for all the temperatures considered. The applicability of previous approaches to CO-He system, based on either the strong collision model or exponential energy gap law, is also discussed.

Update on sideline and event preparation for management of sudden cardiac arrest in athletes.

PubMed

Harmon, Kimberly G; Drezner, Jonathan A

2007-06-01

Sudden death in athletes occurs approximately once every 3 days in the United States. Each school or venue should have an emergency action plan that is coordinated with local emergency medical services (EMS). Access to early defibrillation to treat sudden cardiac arrest (SCA) is critical. If EMS response times are greater than 3 to 5 minutes from collapse to first shock, an on-site automated external defibrillator (AED) should be available. Delays in recognition of SCA in athletes occur commonly. Any collapsed and unresponsive athlete should be considered to be in cardiac arrest and an AED should be applied for rhythm analysis as soon as possible. Cardiopulmonary resuscitation should be provided while waiting for an AED and interruptions in chest compressions should be minimized. Rehearsal of the emergency action plan with potential first responders is essential to ensuring an efficient response to SCA in athletics.

A synoptic study of Sudden Phase Anomalies (SPA's) effecting VLF navigation and timing

NASA Technical Reports Server (NTRS)

Swanson, E. R.; Kugel, C. P.

1973-01-01

Sudden phase anomalies (SPA's) observed on VLF recordings are related to sudden ionospheric disturbances due to solar flares. Results are presented for SPA statistics on 500 events observed in New York during the ten year period 1961 to 1970. Signals were at 10.2kHz and 13.6kHz emitted from the OMEGA transmitters in Hawaii and Trinidad. A relationship between SPA frequency and sun spot number was observed. For sun spot number near 85, about one SPA per day will be observed somewhere in the world. SPA activity nearly vanishes during periods of low sun spot number. During years of high solar activity, phase perturbations observed near noon are dominated by SPA effects beyond the 95th percentile. The SPA's can be represented by a rapid phase run-off which is approximately linear in time, peaking in about 6 minutes, and followed by a linear recovery. Typical duration is 49 minutes.

Rapid estimation of characteristics of gas dynamic lasers

NASA Technical Reports Server (NTRS)

Murty, S. S. R.

1974-01-01

Sudden-freeze approximation is applied to the flow of a CO2-N2-He mixture in wedge-type nozzles. This approximation permits rapid estimation of the freezing temperature of the upper laser level as a function of the stagnation pressure and the nozzle geometry. The stagnation temperature and the composition of the mixture appear as parameters. Gain and power output may then be estimated and calculations are presented for two cases.

Multi-reference approach to the calculation of photoelectron spectra including spin-orbit coupling.

PubMed

Grell, Gilbert; Bokarev, Sergey I; Winter, Bernd; Seidel, Robert; Aziz, Emad F; Aziz, Saadullah G; Kühn, Oliver

2015-08-21

X-ray photoelectron spectra provide a wealth of information on the electronic structure. The extraction of molecular details requires adequate theoretical methods, which in case of transition metal complexes has to account for effects due to the multi-configurational and spin-mixed nature of the many-electron wave function. Here, the restricted active space self-consistent field method including spin-orbit coupling is used to cope with this challenge and to calculate valence- and core-level photoelectron spectra. The intensities are estimated within the frameworks of the Dyson orbital formalism and the sudden approximation. Thereby, we utilize an efficient computational algorithm that is based on a biorthonormal basis transformation. The approach is applied to the valence photoionization of the gas phase water molecule and to the core ionization spectrum of the [Fe(H2O)6](2+) complex. The results show good agreement with the experimental data obtained in this work, whereas the sudden approximation demonstrates distinct deviations from experiments.

[Worldwide experience with automated external defibrillators: What have we achieved? What else can we expect?].

PubMed

Trappe, Hans-Joachim

2016-03-01

In Germany approximately 70,000-100,000 SCD patients die from sudden cardiac death (SCD). SCD is not caused by a single factor but is a multifactorial problem. In 50 % of SCD victims, sudden cardiac death is the first manifestation of heart disease. SCD is caused by ventricular tachyarrhythmias in approximately 90 % of patients, whereas SCD is caused by bradyarrhythmias in 5-10 % of the patients. Risk stratification is not possible in the majority of them prior to the fatal event. Early defibrillation is the method of choice to terminate ventricular fibrillation. Therefore, it is mandatory to install automatic external defibrillators (AED) in places with many people. There is general agreement that early defibrillation with automated external defibrillators (AED) is an effective tool to treat patients with ventricular fibrillation and will improve survival. It seems necessary to teach cardiocompression and AED use, also to children and adolescents. AED therapy "at home" did not improve survival in patients with cardiac arrest and can not be recommended.

Binary-selectable detector holdoff circuit

NASA Technical Reports Server (NTRS)

Kadrmas, K. A.

1974-01-01

High-speed switching circuit protects detectors from sudden, extremely-intense backscattered radiation that results from short-range atmospheric dust layers, or low-level clouds, entering laser/radar field of view. Function of circuit is to provide computer-controlled switching of photodiode detector, preamplifier power-supply voltages, in approximately 10 nanoseconds.

Sudden spreading of infections in an epidemic model with a finite seed fraction

NASA Astrophysics Data System (ADS)

Hasegawa, Takehisa; Nemoto, Koji

2018-03-01

We study a simple case of the susceptible-weakened-infected-removed model in regular random graphs in a situation where an epidemic starts from a finite fraction of initially infected nodes (seeds). Previous studies have shown that, assuming a single seed, this model exhibits a kind of discontinuous transition at a certain value of infection rate. Performing Monte Carlo simulations and evaluating approximate master equations, we find that the present model has two critical infection rates for the case with a finite seed fraction. At the first critical rate the system shows a percolation transition of clusters composed of removed nodes, and at the second critical rate, which is larger than the first one, a giant cluster suddenly grows and the order parameter jumps even though it has been already rising. Numerical evaluation of the master equations shows that such sudden epidemic spreading does occur if the degree of the underlying network is large and the seed fraction is small.

Distribution of Phytophthora ramorum, P. nemorosa, and P.pseudosyringae in native coastal California forest communities

Treesearch

S.K. Murphy; A.C. Wickland; S.C. Lynch; C.E. Jensen; P.E. Maloney; D.M. Rizzo

2008-01-01

Phytophthora ramorum, causal agent of sudden oak death, is well established over approximately 450 km of native forest along the California coast. In the course of research on this invasive exotic pathogen, two other putatively exotic aerial Phytophthora species, P. nemorosa and P. pseudosyringae...

Sudden Cardiac Death During Sports Activities in the General Population.

PubMed

Narayanan, Kumar; Bougouin, Wulfran; Sharifzadehgan, Ardalan; Waldmann, Victor; Karam, Nicole; Marijon, Eloi; Jouven, Xavier

2017-12-01

Regular exercise reduces cardiovascular and overall mortality. Participation in sports is an important determinant of cardiovascular health and fitness. Regular sports activity is associated with a smaller risk of sudden cardiac death (SCD). However, there is a small risk of sports-related SCD. Sports-related SCD accounts for approximately 5% of total SCD. SCD among athletes comprises only a fraction of all sports-related SCD. Sport-related SCD has a male predominance and an average age of affliction of 45 to 50 years. Survival is better than for other SCD. This review summarizes links between sports and SCD and discusses current knowledge and controversies. Copyright © 2017 Elsevier Inc. All rights reserved.

Infinite order sudden approximation for rotational energy transfer in gaseous mixtures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Goldflam, R.; Green, S.; Kouri, D.J.

1977-11-01

Rotational energy transfer in gaseous mixtures has been considered within the framework of the infinite order sudden (IOS) approximation. A new derivation of the IOS from the coupled states Lippmann--Schwinger equation is given. This approach shows the relation between the IOS and CS T matrices and also shows in a rather transparent fashion Sencrest's result that the IOS method does not truncate closed channels but rather employs a closure relation to sum over all rotor states. The general CS effective cross section formula for relaxation processes is used, along with the IOS approximation to the CS T matrix, to derivemore » the general IOS effctive cross section.Factorization permits one to calculate other types of cross sections if any one type of cross section has been obtained by some procedure. The functional form can also be used to compact data. This formalism has been applied to calculate pressure broadening for the systems HD--He, HCl--He, CO--He, HCN--He, HCl--Ar, and CO/sub 2/--Ar. To test the IOS approximation, comparisons have been made to the CS results, which are known to be accurate for all these systems. The IOS approximation is found to be very accurate whenever the rotor spacings are small compared to the kinetic energy, provided closed channels do not play too great a role. For the systems CO--He, HCN--He, and CO/sub 2/--Ar, these conditions are well satisfied and the IOS is found to yield results accurate to within 10%--15%.« less

Effects of reactant rotation on the dynamics of the OH + CH4 → H2O + CH3 reaction: a six-dimensional study.

PubMed

Song, Hongwei; Li, Jun; Jiang, Bin; Yang, Minghui; Lu, Yunpeng; Guo, Hua

2014-02-28

The dynamics of the hydrogen abstraction reaction between methane and hydroxyl radical is investigated using an initial state selected time-dependent wave packet method within a six-dimensional model. The ab initio calibrated global potential energy surface of Espinosa-García and Corchado was used. Integral cross sections from several low-lying rotational states of both reactants have been obtained using the centrifugal sudden and J-shifting approximations. On the empirical potential energy surface, the rotational excitation of methane has little effect on the reaction cross section, but excited rotational states of OH inhibit the reactivity slightly. These results are rationalized with the newly proposed sudden vector projection model.

Using Buoy and Radar Data to Study Sudden Wind Gusts Over Coastal Regions

NASA Technical Reports Server (NTRS)

Priftis, Georgios; Chronis, Themis; Lang, Timothy J.

2017-01-01

Significant sudden wind gusts can pose a threat to aviation near the coastline, as well as small (sailing) boats and commercial ships approaching the ports. Such cases can result in wind speed changes of more than an order of magnitude within 5 minutes, which can then last up to 20 minutes or more. Although the constellation of scatterometers is a good means of studying maritime convection, those sudden gusts are not easily captured because of the low time resolution. The National Data Buoy Center (NDBC) provides continuous measurements of wind speed and direction along the US coastal regions every 6 minutes. Buoys are platforms placed at specific places on the seas, especially along coastlines, providing data for atmospheric and oceanic studies. Next Generation Radars (NEXRADs), after the recent upgrade of the network to dual-pol systems, offer enhanced capabilities to study atmospheric phenomena. NEXRADs provide continuous full-volume scans approximately every 5 minutes and therefore are close to the time resolution of the buoy measurements. Use of single- Doppler retrievals might also provide a means of further validation.

Optimal harvesting policy of a stochastic two-species competitive model with Lévy noise in a polluted environment

NASA Astrophysics Data System (ADS)

Zhao, Yu; Yuan, Sanling

2017-07-01

As well known that the sudden environmental shocks and toxicant can affect the population dynamics of fish species, a mechanistic understanding of how sudden environmental change and toxicant influence the optimal harvesting policy requires development. This paper presents the optimal harvesting of a stochastic two-species competitive model with Lévy noise in a polluted environment, where the Lévy noise is used to describe the sudden climate change. Due to the discontinuity of the Lévy noise, the classical optimal harvesting methods based on the explicit solution of the corresponding Fokker-Planck equation are invalid. The object of this paper is to fill up this gap and establish the optimal harvesting policy. By using of aggregation and ergodic methods, the approximation of the optimal harvesting effort and maximum expectation of sustainable yields are obtained. Numerical simulations are carried out to support these theoretical results. Our analysis shows that the Lévy noise and the mean stress measure of toxicant in organism may affect the optimal harvesting policy significantly.

Degree Of Diminution In Vagal-Cardiac Activity Predicts Sudden Death In Familial Dysautonomia When Resting Tachycardia Is Absent

NASA Technical Reports Server (NTRS)

Schlegel, T. T.; Marthol, H.; Bucchner, S.; Tutaj, M.; Berlin, D.; Axelrod, F. B.; Hilz, M. J.

2004-01-01

Patients with familial dysautonomia (FD) have an increased risk of sudden death, but sensitive and specific predictors of sudden death in FD are lacking. Methods. We recorded 10-min resting high-fidelity 12-lead ECGs in 14 FD patients and in 14 age/gender-matched healthy subjects and studied 25+ different heart rate variability (HRV) indices for their ability to predict sudden death in the FD patients. Indices studied included those from 4 "nonlinear" HRV techniques (detrended fluctuation analysis, approximate entropy, correlation dimension, and PoincarC analyses). The predictive value of PR, QRS, QTc and JTc intervals, QT dispersion (QTd), beat-to-beat QT and PR interval variability indices (QTVI and PRVI) and 12- lead high frequency QRS ECG (150-250 Hz) were also studied. FD patients and controls (C) differed (Pless than 0.0l) with respect to 20+ of the HRV indices (FD less than C) and with respect to QTVI and PRVI (FDBC) and HF QRS- related root mean squared voltages (FDBC) and reduced amplitude zone counts (FD less than C). They differed less with respect to PR intervals (FD less than C) and JTc intervals (FD greater than C) (P less than 0.05 for both) and did not differ at all with respect to QRS and QTc intervals and to QTd. Within 12 months after study, 2 of the 14 patients succumbed to sudden cardiac arrest. The best predictor of sudden death was the degree of diminution in HRV vagal-cardiac (parasympathetic) parameters such as RMSSD, the SDl of Poincare plots, and HF spectral power. Excluding the two FD patients who had resting tachycardia (HR greater than 100, which confounds traditional HRV analyses), the following criteria were independently 100% sensitive and 100% specific for predicting sudden death in the remaining 12 FD patients during spontaneous breathing: RMSSD less than 13 ms and/or PoincarC SD1 less than 9 ms. In FD patients without supine tachycardia, the degree of diminution in parasympathetic HRV parameters (by high-fidelity ECG) predicts incipient death.

Risk and Causes of Death in Patients After Alcohol Septal Ablation for Hypertrophic Obstructive Cardiomyopathy.

PubMed

Veselka, Josef; Zemánek, David; Jahnlová, Denisa; Krejčí, Jan; Januška, Jaroslav; Dabrowski, Maciej; Bartel, Thomas; Tomašov, Pavol

2015-10-01

Because the final myocardial scar might be theoretically associated with an increased risk of sudden cardiac death, the long-term clinical course of patients who undergo alcohol septal ablation (ASA) is still a matter of debate. In this retrospective multicentre study, we report outcomes after ASA, including survival, analysis of causes of deaths, and association between time and cause of death. We enrolled 366 consecutive patients (58 ± 12 years, 54% women) who were treated using ASA and followed-up for 5.1 ± 4.5 years. The in-hospital and 30-day mortality were 0.5% and 0.8%, respectively; the ASA-related morbidity was < 20%. Overall, 52 patients died during 1867 patient-years, which means the all-cause mortality rate was 2.8% per year. The mortality rates of sudden death and sudden death with an appropriate implantable cardioverter-defibrillator (ICD) discharge were 0.4% and 1% per year, respectively. Patients with sudden death or appropriate ICD discharge experienced these mortality events at younger age than patients who died of other hypertrophic obstructive cardiomyopathy-related causes (60.8 years [range, 52-71.5 years] vs 72.4 years [range, 64.2-75.2 years]; P = 0.048). A total of 292 patients (80%) had an outflow gradient ≤ 30 mm Hg, and 327 patients (89%) were in New York Heart Association class ≤ II at the last clinical check-up. ASA had low procedure-related mortality, with subsequent 1% occurrence of sudden mortality events per year and 2.8% mortality rate per year in the long-term follow-up. Patients with sudden death or ICD discharge experienced the mortality events approximately 1 decade earlier than patients who died from other causes not related to hypertrophic cardiomyopathy. Copyright © 2015 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.

Genetic analysis of sudden cardiac death victims: a survey of current forensic autopsy practices.

PubMed

Michaud, Katarzyna; Mangin, Patrice; Elger, Bernice S

2011-05-01

Autopsy-negative sudden cardiac deaths (SCD) seen in forensic practice are most often thought to be the result of sudden arrhythmic death syndrome. Postmortem genetic analysis is recommended in such cases, but is currently performed in only a few academic centers. In order to determine actual current practice, an on-line questionnaire was sent by e-mail to members of various forensic medical associations. The questions addressed routine procedures employed in cases of sudden cardiac death (autopsy ordering, macroscopic and microscopic cardiac examination, conduction tissue examination, immunohistochemistry and electron microscopy, biochemical markers, sampling and storage of material for genetic analyses, toxicological analyses, and molecular autopsy). Some questions concerned the legal and ethical aspects of genetic analyses in postmortem examinations, as well as any existing multidisciplinary collaborations in SCD cases. There were 97 respondents, mostly from European countries. Genetic testing in cases of sudden cardiac death is rarely practiced in routine forensic investigation. Approximately 60% of respondents reported not having the means to perform genetic postmortem testing and 40% do not collect adequate material to perform these investigations at a later date, despite working at university hospitals. The survey demonstrated that many of the problems involved in the adequate investigation of SCD cases are often financial in origin, due to the fact that activities in forensic medicine are often paid by and dependent on the judicial authorities. Problems also exist concerning the contact with family members and/or the family doctor, as well as the often-nonexistent collaboration with others clinicians with special expertise beneficial in the investigation of SCD cases, such as cardiologists and geneticists. This study highlights the importance in establishing guidelines for molecular autopsies in forensic medicine.

Eradication of Phytophthora ramorum in Oregon forests--status after 3 years

Treesearch

Alan Kanaskie; Nancy Osterbauer; Michael McWilliams; Ellen Goheen; Everett Hansen; Wendy Sutton

2006-01-01

Sudden oak death (SOD) was first discovered in Oregon forests in July 2001 near the city of Brookings. Since September 2001 we have been attempting to eradicate the pathogen by cutting and burning all infected host plants and adjacent apparently uninfected plants. Eradication currently is in progress on approximately 42 sites, totaling 72 acres. The majority of sites...

The Ekman Layer and Why Tea Leaves Go to the Center of the Cup

ERIC Educational Resources Information Center

Heavers, Richard M.; Dapp, Rachel M.

2010-01-01

Consider a transparent, cylindrical container filled with water and sitting in the center of a record player turntable. When the turntable is started suddenly, the container rotates with the turntable, but the bulk of the fluid initially remains at rest. A thin ([approximately]1 mm) viscous boundary layer (Ekman layer) forms almost immediately at…

Adverse outcome of using tilmicosin in a lamb with multiple ventricular septal defects.

PubMed

Christodoulopoulos, Georgios

2009-01-01

A 15-day-old, 6.08 kg, lamb was injected subcutaneously with tilmicosin 15 mg/kg body weight. Approximately 15 min later, the lamb died. During necropsy, the heart was found to have multiple ventricular septal defects. Death was attributed to sudden heart failure due to the cardiac effects of tilmicosin in a heart having congenital defects.

Sugarberry Dieback and Mortality in Southern Louisiana: Cause, Impact, and Prognosis

Treesearch

J.D. Solomon; A. Dan Wilson; Theodor D. Leininger; D.G. Lester; C.S. McCasland; S. Clarke; C. Affeltranger

1997-01-01

A sudden widespread decline of sugarberry trees (Celfis laevigufu) was observed in southern Louisiana during the period between the early fall of 1988 and spring of 1990. Approximately 3 million acres or 5,000 square miles of forested lands were affected by the decline. In addition, sporadic reports of sugarberry decline also were reported at numerous locations in...

Experimental data and model for the turbulent boundary layer on a convex, curved surface

NASA Technical Reports Server (NTRS)

Gillis, J. C.; Johnson, J. P.; Moffat, R. J.; Kays, W. M.

1981-01-01

Experiments were performed to determine how boundary layer turbulence is affected by strong convex curvature. The data gathered on the behavior of the Reynolds stress suggested the formulation of a simple turbulence model. Data were taken on two separate facilities. Both rigs had flow from a flat surface, over a convex surface with 90 deg of turning and then onto a flat recovery surface. The geometry was adjusted so that, for both rigs, the pressure gradient along the test surface was zero. Two experiments were performed at delta/R approximately 0.10, and one at weaker curvature with delta/R approximately 0.05. Results show that after a sudden introduction of curvature the shear stress in the outer part of the boundary layer is sharply diminished and is even slightly negative near the edge. The wall shear also drops off quickly downstream. When the surface suddenly becomes flat again, the wall shear and shear stress profiles recover very slowly towards flat wall conditions. A simple turbulence model, which was based on the theory that the Prandtl mixing length in the outer layer should scale on the velocity gradient layer, was shown to account for the slow recovery.

Interpretation of ES, CS, and IOS approximations within a translational-internal coupling scheme. II. Application to atom--diatom kinetic cross sections

DOE Office of Scientific and Technical Information (OSTI.GOV)

Coombe, D.A.; Snider, R.F.

1980-02-15

ES, CS, and IOS approximations to atom--diatom kinetic cross sections are derived. In doing so, reduced S-matrices in a translational-internal coupling scheme are stressed. This entails the insertion of recently obtained approximate reduced S-matrices in the translational-internal coupling scheme into previously derived general expressions for the kinetic cross sections. Of special interest is the structure (rotational j quantum number dependence) of the kinetic cross sections associated with the Senftleben Beenakker effects and of pure internal state relaxation phenomena. The viscomagnetic effect is used as an illustrative example. It is found in particular that there is a great similarity of structuremore » between the energy sudden (and IOS) approximation and the previously derived distorted wave Born results.« less

Sudden cardiac death: a critical appraisal of the implantable cardioverter defibrillator.

PubMed

Rajabali, A; Heist, E K

2014-04-01

Approximately 350,000 Americans still die of sudden cardiac death each year. This exceeds the number of patients who die annually from stroke, lung cancer, breast cancer and AIDS combined. This review aims to trace the history of implantable cardioverter defibrillators (ICD) with reference to landmark trials and their influence on the formulation of Medicare guidelines for ICD implantation criteria. This paper will also discuss the cost-effectiveness of ICDs and the quality of life after implantation. The reasons for the disparity between guidelines for implantation and actual clinical practice will be elucidated, with suggestions for improving overall clinical performance. The ICD has been shown to be cost-effective in reducing sudden cardiac death and all-cause mortality. However, the existing recommendations for ICD implantation have yet to translate completely into clinical practice. Barriers to implementation of existing guidelines include knowledge gaps in the referring physician practices, lack of validated screening tools to assess patient candidacy for the device and patient understanding of the need for the device. Future strategies to increase compliance with the existing guidelines and improve clinical performance are areas of potential research focus. © 2013 John Wiley & Sons Ltd.

Adverse outcome of using tilmicosin in a lamb with multiple ventricular septal defects

PubMed Central

Christodoulopoulos, Georgios

2009-01-01

A 15-day-old, 6.08 kg, lamb was injected subcutaneously with tilmicosin 15 mg/kg body weight. Approximately 15 min later, the lamb died. During necropsy, the heart was found to have multiple ventricular septal defects. Death was attributed to sudden heart failure due to the cardiac effects of tilmicosin in a heart having congenital defects. PMID:19337615

Transcriptome analysis of tanoak reveals divergent mechanisms of innate and phosphite-induced resistance to Phytophthora ramorum

Treesearch

Catherine A. Eyre; Katherine J. Hayden; Peter Croucher; Shannon Schechter; Jessica W. Wright; Matteo Garbelotto

2017-01-01

Phosphite compounds have been used in the control of sudden oak death; however, their precise mode of action is not fully understood. To study the action of phosphite compounds in the context of naturally occurring host resistance, we first identified open-pollinated family groups that carried resistance, that is in which approximately 20% of offspring demonstrated a...

Formation of a black hole in the dark.

PubMed

Mirabel, I Félix; Rodrigues, Irapuan

2003-05-16

We show that the black hole in the x-ray binary Cygnus X-1 was formed in situ and did not receive an energetic trigger from a nearby supernova. The progenitor of the black hole had an initial mass greater than 40 solar masses, and during the collapse to form the approximately 10-solar mass black hole of Cygnus X-1, the upper limit for the mass that could have been suddenly ejected is approximately 1 solar mass, much less than the mass ejected in a supernova. The observations suggest that high-mass stellar black holes may form promptly, when massive stars disappear silently.

Sudden improvement of insulin sensitivity related to an endodontic treatment.

PubMed

Schulze, A; Schönauer, M; Busse, M

2007-12-01

Inflammation contributes to the pathogenesis of diabetes. A reciprocal relationship exists between diabetes and chronic periodontitis. This report describes the effects of an acute focal dental inflammation and subsequent endodontic treatment on the required insulin dosage of a 70-year-old man who had moderately controlled diabetes. Following an exacerbation of a combined endodontic-periodontic (endo-perio) lesion of tooth #3, the patient noticed a sudden increase in his insulin demand. After 3 weeks, the required dosage was approximately 100% greater. In association with hyperglycemic incidents, he reported a prickling sensation in this tooth. The radiograph showed circular bone loss around the tooth. Just 1 day after the root-canal preparation, the insulin need decreased to approximately 50% of that required prior to treatment. Subsequently, an incision and systemic antibiotics were necessary because of the formation of a periodontal abscess. The insulin demand remained low despite this complication. Forty days after endodontic treatment, the insulin dosage was at a level comparable to that taken 4 weeks before the root-canal preparation. This clinical case revealed a highly relevant correlation between insulin resistance and a local dental inflammation. To avoid an increase in insulin resistance, it seems important to attend to radically non-vital teeth as well as any other dental inflammation in diabetic patients.

A Rare Case of Acute Coronary Syndrome in a Patient With Turner Syndrome.

PubMed

Kemaloglu, Tugba; Ozer, Nihat; Fikri Yapici, Mehmet

2016-05-01

In Turner syndrome, cardiovascular complications are the most important causes of early mortality. Congenital cardiovascular abnormalities are found in approximately one third of Turner syndrome patients. Developments in diagnosis and treatment have decreased the rate of mortality related to these abnormalities. In recent years, many papers have mentioned that coronary artery disease developing at early ages in patients with Turner syndrome causes sudden deaths. The patient, a 27-year-old female was admitted to the emergency room with chest pain at rest. She was diagnosed with Turner Syndrome in her teenage years due to amenorrhea. Patients with ECG changes and cardiac enzyme elevations were treated with acute coronary syndrome. The young woman with Turner Syndrome have several risk factors for early Coronary Artery Disease development. In such cases, dramatic results like sudden death or heart attack at an early age may occur in cases of insufficient follow-up and treatment.

Theory of the stopping power of fast multicharged ions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yudin, G.L.

1991-12-01

The processes of Coulomb excitation and ionization of atoms by a fast charged particle moving along a classical trajectory are studied. The target electrons are described by the Dirac equation, while the field of the incident particle is described by the Lienard-Wiechert potential. The theory is formulated in the form most convenient for investigation of various characteristics of semiclassical atomic collisions. The theory of sudden perturbations, which is valid at high enough velocities for a high projectile charge, is employed to obtain probabilities and cross sections of the Coulomb excitation and ionization of atomic hydrogen by fast multiply charged ions.more » Based on the semiclassical sudden Born approximation, the ionization cross section and the average electronic energy loss of a fast ion in a single collision with an atom are investigated over a wide specific energy range from 500 keV/amu to 50 MeV/amu.« less

MAOA/B deletion syndrome in male siblings with severe developmental delay and sudden loss of muscle tonus.

PubMed

Saito, Mari; Yamagata, Takanori; Matsumoto, Ayumi; Shiba, Yusuke; Nagashima, Masako; Taniguchi, Shuhei; Jimbo, Eriko; Momoi, Mariko Y

2014-01-01

Deletion of the monoamine oxidase (MAO)-A and MAO-B was detected in two male siblings and in their mother. The approximately 800-kb deletion, extending from about 43.0MB to 43.8MB, was detected by array comparative genomic hybridization analysis. The MAOA and MAOB genes were included in the deletion, but the adjacent Norrie disease gene, NDP, was not deleted. The boys had short stature, hypotonia, severe developmental delays, episodes of sudden loss of muscle tone, exiting behavior, lip-smacking and autistic features. The serotonin levels in their cerebrospinal fluid were extremely elevated. Another set of siblings with this deletion was reported previously. We propose recognition of MAOA/B deletion syndrome as a distinct disorder. Copyright © 2013 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.

Ryanodine receptor phosphorylation by calcium/calmodulin-dependent protein kinase II promotes life-threatening ventricular arrhythmias in mice with heart failure.

PubMed

van Oort, Ralph J; McCauley, Mark D; Dixit, Sayali S; Pereira, Laetitia; Yang, Yi; Respress, Jonathan L; Wang, Qiongling; De Almeida, Angela C; Skapura, Darlene G; Anderson, Mark E; Bers, Donald M; Wehrens, Xander H T

2010-12-21

approximately half of patients with heart failure die suddenly as a result of ventricular arrhythmias. Although abnormal Ca(2+) release from the sarcoplasmic reticulum through ryanodine receptors (RyR2) has been linked to arrhythmogenesis, the molecular mechanisms triggering release of arrhythmogenic Ca(2+) remain unknown. We tested the hypothesis that increased RyR2 phosphorylation by Ca(2+)/calmodulin-dependent protein kinase II is both necessary and sufficient to promote lethal ventricular arrhythmias. mice in which the S2814 Ca(2+)/calmodulin-dependent protein kinase II site on RyR2 is constitutively activated (S2814D) develop pathological sarcoplasmic reticulum Ca(2+) release events, resulting in reduced sarcoplasmic reticulum Ca(2+) load on confocal microscopy. These Ca(2+) release events are associated with increased RyR2 open probability in lipid bilayer preparations. At baseline, young S2814D mice have structurally and functionally normal hearts without arrhythmias; however, they develop sustained ventricular tachycardia and sudden cardiac death on catecholaminergic provocation by caffeine/epinephrine or programmed electric stimulation. Young S2814D mice have a significant predisposition to sudden arrhythmogenic death after transverse aortic constriction surgery. Finally, genetic ablation of the Ca(2+)/calmodulin-dependent protein kinase II site on RyR2 (S2814A) protects mutant mice from pacing-induced arrhythmias versus wild-type mice after transverse aortic constriction surgery. our results suggest that Ca(2+)/calmodulin-dependent protein kinase II phosphorylation of RyR2 Ca(2+) release channels at S2814 plays an important role in arrhythmogenesis and sudden cardiac death in mice with heart failure.

The development of antisocial behaviour and sudden violent death.

PubMed

Rydelius, P A

1988-04-01

In order to detect possible relationships between antisocial behaviour and the incidence of "sudden violent death" in young people, information relating to mortality in antisocial Swedish adolescents has been traced and compiled. A register was drawn up covering those young persons (1,056; 832 boys and 224 girls; mean age 16 years) who were admitted to Swedish probationary schools during the period 1 January - 31 December 1967. Using the registers of immigration and emigration, and causes of death kept by SCB (Statistiska Centralbyrån), mortality occurring between 1 January 1967 - 31 December 1985 was tabulated. One hundred and ten boys (13%) and 22 girls (10%) had died. The deaths had occurred at a rate of approximately seven new deaths per observation year, the youngest being still in their teens when they died. For comparison, the criteria set up by insurance companies for life insurance premiums are based on a death expectancy for healthy Swedish boys and girls in the age groups corresponding to the subjects under observation of 1.2-3.1% for boys and 1.1-2.6% for girls. Eighty-eight percent of the dead boys and 77% of the dead girls had died "sudden violent deaths" - accidents, suicides, death from uncertain causes, murder/manslaughter, or alcohol/drug abuse. For both sexes, death from uncertain causes and suicides were the most frequent single causes of death. Death as a direct result of alcohol/drug abuse occurred only in boys. The results give support to the assumption that a link exists between childhood environment, the development of antisocial behaviour/mental insufficiency and a "sudden violent death" at an early age.(ABSTRACT TRUNCATED AT 250 WORDS)

Reliability Studies of Ceramic Capacitors.

DTIC Science & Technology

1983-07-01

increases. This case has been found to be a good approximation for single crystals with high chemical and structural purity. Shallow traps may arise as a...theory, this sudden increase may be otherwise explained. Single crystals of ZnS have been found to exhibit this vertical increase in the current...Smith and Rose observed SCLC behavior in CdS single crystals . Branwood and Tredgold 2 8 and Branwood et al. 2 9 measured BaTiO 3 single crystals and

Technology Insertion-Engineering Services Process Characterization. Task Order No. 1. Book 1. Database Documentation Book. OO-ALC MANPRC (Overview Layouts)

DTIC Science & Technology

1989-12-15

density from 185-465 amp./sq. ft. Elffect of Secondary Variables (a) Trivalent Chromium and Ferric Iron The trivalent chromium concentration of the...centration also increases. The cathode efficiency is almost independent of the concentra- tion of trivalent chromium and iron as demonstrated in Fig...and temnperatures (SCHNEMDEWIND). However, if the total concentration of trivalent chromium and iron exceeds approximately 3 oz./gal., sudden changes

Processes of energy deposition by heavy-particle and electron impact. Final progress report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Salop, A.; Smith, F.T.

1978-04-18

Progress is reported in three areas of reasearch during the present period: K-shell ionization in high energy collisions of heavy ions with light target atoms using the sudden (Magnus) approximation, K-L level matching phenomena associated with K-shell vacancy production in heavy-ion collisions, and studies of low energy collisions of electrons with molecules using semi-classical perturbation theory. A brief discussion of each of these activities is given.

Usefulness of running wheel for detection of congestive heart failure in dilated cardiomyopathy mouse model.

PubMed

Sugihara, Masami; Odagiri, Fuminori; Suzuki, Takeshi; Murayama, Takashi; Nakazato, Yuji; Unuma, Kana; Yoshida, Ken-ichi; Daida, Hiroyuki; Sakurai, Takashi; Morimoto, Sachio; Kurebayashi, Nagomi

2013-01-01

Inherited dilated cardiomyopathy (DCM) is a progressive disease that often results in death from congestive heart failure (CHF) or sudden cardiac death (SCD). Mouse models with human DCM mutation are useful to investigate the developmental mechanisms of CHF and SCD, but knowledge of the severity of CHF in live mice is necessary. We aimed to diagnose CHF in live DCM model mice by measuring voluntary exercise using a running wheel and to determine causes of death in these mice. A knock-in mouse with a mutation in cardiac troponin T (ΔK210) (DCM mouse), which results in frequent death with a t(1/2) of 70 to 90 days, was used as a DCM model. Until 2 months of age, average wheel-running activity was similar between wild-type and DCM mice (approximately 7 km/day). At approximately 3 months, some DCM mice demonstrated low running activity (LO: <1 km/day) while others maintained high running activity (HI: >5 km/day). In the LO group, the lung weight/body weight ratio was much higher than that in the other groups, and the lungs were infiltrated with hemosiderin-loaded alveolar macrophages. Furthermore, echocardiography showed more severe ventricular dilation and a lower ejection fraction, whereas Electrocardiography (ECG) revealed QRS widening. There were two patterns in the time courses of running activity before death in DCM mice: deaths with maintained activity and deaths with decreased activity. Our results indicate that DCM mice with low running activity developed severe CHF and that running wheels are useful for detection of CHF in mouse models. We found that approximately half of ΔK210 DCM mice die suddenly before onset of CHF, whereas others develop CHF, deteriorate within 10 to 20 days, and die.

Approximate Solutions for Ideal Dam-Break Sediment-Laden Flows on Uniform Slopes

NASA Astrophysics Data System (ADS)

Ni, Yufang; Cao, Zhixian; Borthwick, Alistair; Liu, Qingquan

2018-04-01

Shallow water hydro-sediment-morphodynamic (SHSM) models have been applied increasingly widely in hydraulic engineering and geomorphological studies over the past few decades. Analytical and approximate solutions are usually sought to verify such models and therefore confirm their credibility. Dam-break flows are often evoked because such flows normally feature shock waves and contact discontinuities that warrant refined numerical schemes to solve. While analytical and approximate solutions to clear-water dam-break flows have been available for some time, such solutions are rare for sediment transport in dam-break flows. Here we aim to derive approximate solutions for ideal dam-break sediment-laden flows resulting from the sudden release of a finite volume of frictionless, incompressible water-sediment mixture on a uniform slope. The approximate solutions are presented for three typical sediment transport scenarios, i.e., pure advection, pure sedimentation, and concurrent entrainment and deposition. Although the cases considered in this paper are not real, the approximate solutions derived facilitate suitable benchmark tests for evaluating SHSM models, especially presently when shock waves can be numerically resolved accurately with a suite of finite volume methods, while the accuracy of the numerical solutions of contact discontinuities in sediment transport remains generally poorer.

Deep Sequencing Analysis of RNAs from Citrus Plants Grown in a Citrus Sudden Death-Affected Area Reveals Diverse Known and Putative Novel Viruses.

PubMed

Matsumura, Emilyn E; Coletta-Filho, Helvecio D; Nouri, Shahideh; Falk, Bryce W; Nerva, Luca; Oliveira, Tiago S; Dorta, Silvia O; Machado, Marcos A

2017-04-24

Citrus sudden death (CSD) has caused the death of approximately four million orange trees in a very important citrus region in Brazil. Although its etiology is still not completely clear, symptoms and distribution of affected plants indicate a viral disease. In a search for viruses associated with CSD, we have performed a comparative high-throughput sequencing analysis of the transcriptome and small RNAs from CSD-symptomatic and -asymptomatic plants using the Illumina platform. The data revealed mixed infections that included Citrus tristeza virus (CTV) as the most predominant virus, followed by the Citrus sudden death-associated virus (CSDaV), Citrus endogenous pararetrovirus (CitPRV) and two putative novel viruses tentatively named Citrus jingmen-like virus (CJLV), and Citrus virga-like virus (CVLV). The deep sequencing analyses were sensitive enough to differentiate two genotypes of both viruses previously associated with CSD-affected plants: CTV and CSDaV. Our data also showed a putative association of the CSD-symptomatic plants with a specific CSDaV genotype and a likely association with CitPRV as well, whereas the two putative novel viruses showed to be more associated with CSD-asymptomatic plants. This is the first high-throughput sequencing-based study of the viral sequences present in CSD-affected citrus plants, and generated valuable information for further CSD studies.

Exciton recombination in lasing contributing an opposite abrupt change of the electrical behavior near threshold between GaN- and GaAs- multi-quantum-well laser diodes

NASA Astrophysics Data System (ADS)

Feng, Liefeng; Wang, Shupeng; Li, Yang; Li, Ding; Wang, Cunda

2018-03-01

The opposite sudden change of electrical characteristics between narrow and wide bang-gap multi-quantum-well (MQW) laser diodes (LDs) in the threshold region (which is defined as a current region between two kinks of IdV/dI-I curve) shows an interesting phenomenon that the slope changes of IdV/dI-I or V j -I curve between two adjacent regions (‘below’ and ‘in’, or ‘in’ and ‘above’ threshold region) display an approximate e-exponential relationship with the wavelengths of LDs. After comparing the exciton binding energy in different MQW LDs, and analyzing the temperature dependence of V j -I and IdV/dI-I of GaN MQW LDs, we suggested that the fraction of exciton recombination into lasing is a reason causing the relationship of sudden changes of the electrical characteristics with wavelengths of LDs.

BAD knockout provides metabolic seizure resistance in a genetic model of epilepsy with sudden unexplained death in epilepsy.

PubMed

Foley, Jeannine; Burnham, Veronica; Tedoldi, Meghan; Danial, Nika N; Yellen, Gary

2018-01-01

Metabolic alteration, either through the ketogenic diet (KD) or by genetic alteration of the BAD protein, can produce seizure protection in acute chemoconvulsant models of epilepsy. To assess the seizure-protective role of knocking out (KO) the Bad gene in a chronic epilepsy model, we used the Kcna1 -/- model of epilepsy, which displays progressively increased seizure severity and recapitulates the early death seen in sudden unexplained death in epilepsy (SUDEP). Beginning on postnatal day 24 (P24), we continuously video monitored Kcna1 -/- and Kcna1 -/- Bad -/- double knockout mice to assess survival and seizure severity. We found that Kcna1 -/- Bad -/- mice outlived Kcna1 -/- mice by approximately 2 weeks. Kcna1 -/- Bad -/- mice also spent significantly less time in seizure than Kcna1 -/- mice on P24 and the day of death, showing that BadKO provides seizure resistance in a genetic model of chronic epilepsy. Wiley Periodicals, Inc. © 2017 International League Against Epilepsy.

Influence of January 2009 stratospheric warming on HF radio wave propagation in the low-latitude ionosphere

NASA Astrophysics Data System (ADS)

Kotova, Darya; Klimenko, Maksim; Klimenko, Vladimir; Zaharov, Veniamin; Bessarab, Fedor; Korenkov, Yuriy

2016-12-01

We have considered the influence of the January 23-27, 2009 sudden stratospheric warming (SSW) event on HF radio wave propagation in the equatorial ionosphere. This event took place during extremely low solar and geomagnetic activity. We use the simulation results obtained with the Global Self-consistent Model of the Thermosphere, Ionosphere and Protonosphere (GSM TIP) for simulating environmental changes during the SSW event. We both qualitatively and quantitatively reproduced total electron content disturbances obtained from global ground network receiver observations of GPS navigation satellite signals, by setting an additional electric potential and TIME-GCM model output at a height of 80 km. In order to study the influence of this SSW event on HF radio wave propagation and attenuation, we used the numerical model of radio wave propagation based on geometrical optics approximation. It is shown that the sudden stratospheric warming leads to radio signal attenuation and deterioration of radio communication in the daytime equatorial ionosphere.

[Subcutaneous implantable cardioverter-defibrillator in prevention of sudden cardiac death in Poland - opinion paper endorsed by the Polish Cardiac Society Working Group on Heart Rhythm].

PubMed

Ptaszyński, Paweł; Grabowski, Marcin; Kowalski, Oskar; Kempa, Maciej; Mitkowski, Przemysław; Przybylski, Andrzej; Sterliński, Maciej

2017-01-01

In the past years, cardiovascular mortality has decreased but despite these cardiovascular diseases are responsible for millions of deaths every year in the world and approximately 25% of which are sudden cardiac death (SCD). Implantable defibrillators (ICD) is proven therapy used in primary and secondary SCD prevention. Currently majority of devices use transvenous leads inserted predominantly into the right heart for both pacing and defibrillation. On the other hand, ICD may cause complica-tions, including inappropriate shocks, device-related infection and lead failure. Problems with transvenous leads prompted the development of a subcutaneous defibrillator (S-ICD) with an electrode system that is placed entirely subcutaneously, outside the thoracic cavity. The device may be useful when venous access is difficult, in young patients and in patients at particular risk of infection. S-ICD is not suitable for patients with indications for bradycardia pacing, cardiac resynchronisation therapy and in cases with tachyarrhythmia easily terminated by antitachycardia pacing.

The sudden death and sudden birth of quantum discord.

PubMed

Xia, Wei; Hou, Jin-Xing; Wang, Xiao-Hui; Liu, Si-Yuan

2018-03-28

The interaction of quantum system and its environment brings out abundant quantum phenomenons. The sudden death of quantum resources, including entanglement, quantum discord and coherence, have been studied from the perspective of quantum breaking channels (QBC). QBC of quantum resources reveal the common features of quantum resources. The definition of QBC implies the relationship between quantum resources. However, sudden death of quantum resources can also appear under some other quantum channels. We consider the dynamics of Bell-diagonal states under a stochastic dephasing noise along the z-direction, and the sudden death and sudden birth of quantum discord are investigated. Next we explain this phenomenon from the geometric structure of quantum discord. According to the above results, the states with sudden death and sudden birth can be filtered in three-parameter space. Then we provide two necessary conditions to judge which kind of noise channels can make Bell-diagonal states sudden death and sudden birth. Moreover, the relation between quantum discord and coherence indicates that the sudden death and sudden birth of quantum discord implies the sudden death and sudden birth of coherence in an optimal basis.

The "Approximate 150 Day Quasi-Periodicity" in Interplanetary and Solar Phenomena During Cycle 23

NASA Technical Reports Server (NTRS)

Richardson, I. G.; Cane, H. V.

2004-01-01

A"quasi-periodicity" of approx. 150 days in various solar and interplanetary phenomena has been reported in earlier solar cycles. We suggest that variations in the occurrence of solar energetic particle events, inter-planetary coronal mass ejections, and geomagnetic storm sudden commenceents during solar cycle 23 show evidence of this quasi-periodicity, which is also present in the sunspot number, in particular in the northern solar hemisphere. It is not, however, prominent in the interplanetary magnetic field strength.

Sudden Unexpected Death in Epilepsy Among Patients With Benign Childhood Epilepsy With Centrotemporal Spikes.

PubMed

Doumlele, Kyra; Friedman, Daniel; Buchhalter, Jeffrey; Donner, Elizabeth J; Louik, Jay; Devinsky, Orrin

2017-06-01

Children with benign epilepsy with centrotemporal spikes (BECTS) have traditionally been considered to have a uniformly good prognosis. However, benign may be a misnomer because BECTS is linked to cognitive deficits, a more severe phenotype with intractable seizures, and the potential for sudden unexpected death in epilepsy (SUDEP). To determine if cases of BECTS are present in the North American SUDEP Registry (NASR). The NASR is a clinical and biospecimen repository established in 2011 to promote SUDEP research. The NASR database, which includes medical records, results of electroencephalographic tests, and interviews with family members of patients with epilepsy who died suddenly without other identifiable causes of death, was queried from June 3, 2011, to June 3, 2016, for cases of BECTS. The patients with epilepsy had died suddenly without other identifiable causes of death (eg, drowning, trauma, exposure to toxic substances, or suicide); SUDEP classification was determined by the consensus of 2 epileptologists. Cases of SUDEP among children who received a diagnosis of BECTS among patients reported in the NASR. Three boys (median age at death, 12 years; range, 9-13 years) who received a diagnosis of BECTS by their pediatric epileptologist or neurologists were identified among 189 cases reported in the NASR. The median age of epilepsy onset was 5 years (range, 3-11 years), and the median duration of epilepsy was 4 years (range, 1-10 years). Two deaths were definite SUDEP, and 1 was probable SUDEP. Independent review of clinical and electroencephalographic data supported the diagnosis of BECTS in all 3 patients. None of the patients was prescribed antiseizure drugs, either owing to physician recommendation or mutual decision by the physician and parents. All 3 patients were found dead in circumstances typical of SUDEP. The 3 patients spanned the spectrum of BECTS severity: 1 had only a few seizures, 1 had more than 30 focal motor seizures, and 1 had 4 witnessed generalized tonic-clonic seizures and approximately 30 suspected generalized tonic-clonic seizures. Sudden unexpected death in epilepsy is a very rare outcome in BECTS that clinicians should consider discussing in appropriate circumstances and possibly factoring into treatment decisions.

Should the implantable cardiac defibrillator be used for primary prevention of sudden death? A review of the issues relevant to hospital decision making.

PubMed

McGregor, Maurice; Chen, Jun

2004-10-01

New evidence suggests that the implantable cardiac defibrillator (ICD) may be effective for primary prevention of sudden death. High instrumental cost and the potentially large number of candidates will significantly impact hospital budgets. To review the information relevant to hospital policy decisions on the use of ICDs for primary prevention. Modelling based on an evaluation of reported studies and Canadian costs, detailed in a comprehensive review available at . Health outcomes: Two high-quality primary prevention trials suggest a reduction in annual mortality of 2.9% with bounds of probability (PB) of 2.0% to 3.8%, in early years. To undertake 100 implants per year may result in an increasing annual saving of life-years of acceptable quality, stabilizing by 15 years at 110 (PB 72 to 154) each year. Economic impact: The annual costs would stabilize at 15 years at approximately 4.3 million dollars. Cost-effectiveness: The incremental cost-effectiveness from the point of view of the health care system would be approximately 47,000 dollars (PB 35,000 dollars to 70,000 dollars), discounted at 3%. Ethical and legal issues: The decision should not be individual but institutional, using a process that is transparent, consistent and fair. The ICD can prolong life, with acceptable quality. Restriction of its use would be solely on grounds of expense.

Electron-impact excitation of diatomic hydride cations II: OH+ and SH+

NASA Astrophysics Data System (ADS)

Hamilton, James R.; Faure, Alexandre; Tennyson, Jonathan

2018-05-01

R-matrix calculations combined with the adiabatic-nuclei-rotation and Coulomb-Born approximations are used to compute electron-impact rotational rate coefficients for two open-shell diatomic cations of astrophysical interest: the hydoxyl and sulphanyl ions, OH+ and SH+. Hyperfine resolved rate coefficients are deduced using the infinite-order-sudden approximation. The propensity rule ΔF = Δj = ΔN = ±1 is observed, as is expected for cations with a large dipole moment. A model for OH+ excitation in the Orion Bar photon-dominated region is presented which nicely reproduces Herschel observations for an electron fraction xe = 10-4 and an OH+ column density of 3 × 1013 cm-2. Electron-impact electronic excitation cross-sections and rate coefficients for the ions are also presented.

Sudden bending of cracked laminates

NASA Technical Reports Server (NTRS)

Sih, G. C.; Chen, E. P.

1980-01-01

A dynamic approximate laminated plate theory is developed with emphasis placed on obtaining effective solution for the crack configuration where the 1/square root of r stress singularity and the condition of plane strain are preserved. The radial distance r is measured from the crack edge. The results obtained show that the crack moment intensity tends to decrease as the crack length to laminate plate thickness is increased. Hence, a laminated plate has the desirable feature of stabilizing a through crack as it increases its length at constant load. Also, the level of the average load intensity transmitted to a through crack can be reduced by making the inner layers to be stiffer than the outer layers. The present theory, although approximate, is useful for analyzing laminate failure to crack propagation under dynamic load conditions.

Sudden gains in cognitive therapy and interpersonal therapy for social anxiety disorder.

PubMed

Bohn, Christiane; Aderka, Idan M; Schreiber, Franziska; Stangier, Ulrich; Hofmann, Stefan G

2013-02-01

The present study examined the effects of sudden gains on treatment outcome in a randomized controlled trial including individual cognitive therapy (CT) and interpersonal therapy (IPT) for social anxiety disorder (SAD). Participants were 67 individuals with SAD who received 16 treatment sessions. Symptom severity at each session was assessed using the Social Phobia Weekly Summary Scale (Clark et al., 2003). Results indicate that 22.4% of participants experienced a sudden gain during treatment. Individuals with sudden gains had significantly lower social anxiety symptoms at post-treatment and follow-up compared to individuals without sudden gains. Sudden gains in CT and IPT had similar magnitudes, frequencies, and timings. However, sudden gains resulted in lower levels of post-treatment symptoms in CT compared to IPT. Cognitive changes did not precede sudden gains, but sudden gains resulted in cognitive changes. Sudden gains in CT and IPT for SAD are predictive of long-term outcome. In addition, the effect of sudden gains may be greater in CT compared to IPT.

Lessons from the Tōhoku tsunami: A model for island avifauna conservation prioritization.

PubMed

Reynolds, Michelle H; Berkowitz, Paul; Klavitter, John L; Courtot, Karen N

2017-08-01

Earthquake-generated tsunamis threaten coastal areas and low-lying islands with sudden flooding. Although human hazards and infrastructure damage have been well documented for tsunamis in recent decades, the effects on wildlife communities rarely have been quantified. We describe a tsunami that hit the world's largest remaining tropical seabird rookery and estimate the effects of sudden flooding on 23 bird species nesting on Pacific islands more than 3,800 km from the epicenter. We used global positioning systems, tide gauge data, and satellite imagery to quantify characteristics of the Tōhoku earthquake-generated tsunami (11 March 2011) and its inundation extent across four Hawaiian Islands. We estimated short-term effects of sudden flooding to bird communities using spatially explicit data from Midway Atoll and Laysan Island, Hawai'i. We describe variation in species vulnerability based on breeding phenology, nesting habitat, and life history traits. The tsunami inundated 21%-100% of each island's area at Midway Atoll and Laysan Island. Procellariformes (albatrosses and petrels) chick and egg losses exceeded 258,500 at Midway Atoll while albatross chick losses at Laysan Island exceeded 21,400. The tsunami struck at night and during the peak of nesting for 14 colonial seabird species. Strongly philopatric Procellariformes were vulnerable to the tsunami. Nonmigratory, endemic, endangered Laysan Teal ( Anas laysanensis ) were sensitive to ecosystem effects such as habitat changes and carcass-initiated epizootics of avian botulism, and its populations declined approximately 40% on both atolls post-tsunami. Catastrophic flooding of Pacific islands occurs periodically not only from tsunamis, but also from storm surge and rainfall; with sea-level rise, the frequency of sudden flooding events will likely increase. As invasive predators occupy habitat on higher elevation Hawaiian Islands and globally important avian populations are concentrated on low-lying islands, additional conservation strategies may be warranted to increase resilience of island biodiversity encountering tsunamis and rising sea levels.

Lessons from the Tōhoku tsunami: A model for island avifauna conservation prioritization

USGS Publications Warehouse

Reynolds, Michelle H.; Berkowitz, Paul; Klavitter, John; Courtot, Karen

2017-01-01

Earthquake-generated tsunamis threaten coastal areas and low-lying islands with sudden flooding. Although human hazards and infrastructure damage have been well documented for tsunamis in recent decades, the effects on wildlife communities rarely have been quantified. We describe a tsunami that hit the world's largest remaining tropical seabird rookery and estimate the effects of sudden flooding on 23 bird species nesting on Pacific islands more than 3,800 km from the epicenter. We used global positioning systems, tide gauge data, and satellite imagery to quantify characteristics of the Tōhoku earthquake-generated tsunami (11 March 2011) and its inundation extent across four Hawaiian Islands. We estimated short-term effects of sudden flooding to bird communities using spatially explicit data from Midway Atoll and Laysan Island, Hawai'i. We describe variation in species vulnerability based on breeding phenology, nesting habitat, and life history traits. The tsunami inundated 21%–100% of each island's area at Midway Atoll and Laysan Island. Procellariformes (albatrosses and petrels) chick and egg losses exceeded 258,500 at Midway Atoll while albatross chick losses at Laysan Island exceeded 21,400. The tsunami struck at night and during the peak of nesting for 14 colonial seabird species. Strongly philopatric Procellariformes were vulnerable to the tsunami. Nonmigratory, endemic, endangered Laysan Teal (Anas laysanensis) were sensitive to ecosystem effects such as habitat changes and carcass-initiated epizootics of avian botulism, and its populations declined approximately 40% on both atolls post-tsunami. Catastrophic flooding of Pacific islands occurs periodically not only from tsunamis, but also from storm surge and rainfall; with sea-level rise, the frequency of sudden flooding events will likely increase. As invasive predators occupy habitat on higher elevation Hawaiian Islands and globally important avian populations are concentrated on low-lying islands, additional conservation strategies may be warranted to increase resilience of island biodiversity encountering tsunamis and rising sea levels.

[Seasonal variations in the myocardial infarction incidence and possible effects of geomagnetic micropulsations on the cardiovascular system in humans].

PubMed

Kleĭmenova, N G; Kozyreva, O V; Breus, T K; Rapoport, S I

2007-01-01

The analysis of the ambulance calls in Moscow, related to myocardial infarction (85.000 events), sudden death (71.700 events), and hypertension crises (165.500 events) over the period of 1979-1981 demonstrated their clear seasonal variations with a profound summer minimum and a winter maximum. The same results were obtained in the analysis of statistical monthly data on sudden death from infarction in Bulgaria over the period of 15 years (1970-1985). However, there are a great number of clinical and statistical studies confirming the rises in the incidence of myocardial infarction, hypertension crise, and sudden death during geomagnetic disturbances, which have maximum occurrence near equinox, not in winter. In order to explain this contradiction, we suggested that one of critical factors that affect the human cardiovascular system is geomagnetic micropulsations Pc1 having the frequency comparable with the frequency of heart rate beatings and winter maximum in their occurrence. The results of a comparative analysis of data of ambulance calls in Moscow related to myocardial infarction and sudden death and the catalog of Pc1 observations at the geophysical observatory "Borok" (Yaroslavl region) are presented. It is shown that in approximately 70% of days with an anomalously large number of ambulance calls related to myocardial infarction, Pc1 micropulsations have been registered. The probability of simultaneous occurrence of myocardial infarction and Pc1 in the winter season was 1.5 times greater than their accidental coincidence. Moreover, it was found that in winter the effects of magnetic storms and Pc1 IM(A) were much higher than in summer. We suggested that one of possible reasons for the seasonal variations in the occurrence of myocardial infarction is an increase in the production of the pineal hormone melatonin in winter which leads to an unstable state of the human organism and an increase in its sensitivity to the effect of geomagnetic pulsations.

CC, CS, and IOS generalized phenomenological cross sections for atom--diatom mixtures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fitz, D.E.; Kouri, D.J.; Evans, D.

1981-05-01

Close coupled expressions for phenomenological cross sections which describe transport properties of atom--diatom mixtures are obtained in the total-J coupling scheme and are related to the bracket integrals of kinetic theory. Coupled states and infinite order sudden expressions for the generalized phenomenological cross sections using initial, final, and average l-labeling are also given. Particular care is taken to use a phase convention for the CS and IOS approximations which is consistent with the Arthurs--Dalgarno formalism and which gives the correct behavior of degeneracy averaged differential cross sections.

Sudden birth versus sudden death of entanglement for the extended Werner-like state in a dissipative environment

NASA Astrophysics Data System (ADS)

Shan, Chuan-Jia; Chen, Tao; Liu, Ji-Bing; Cheng, Wei-Wen; Liu, Tang-Kun; Huang, Yan-Xia; Li, Hong

2010-06-01

In this paper, we investigate the dynamical behaviour of entanglement in terms of concurrence in a bipartite system subjected to an external magnetic field under the action of dissipative environments in the extended Werner-like initial state. The interesting phenomenon of entanglement sudden death as well as sudden birth appears during the evolution process. We analyse in detail the effect of the purity of the initial entangled state of two qubits via Heisenberg XY interaction on the apparition time of entanglement sudden death and entanglement sudden birth. Furthermore, the conditions on the conversion of entanglement sudden death and entanglement sudden birth can be generalized when the initial entangled state is not pure. In particular, a critical purity of the initial mixed entangled state exists, above which entanglement sudden birth vanishes while entanglement sudden death appears. It is also noticed that stable entanglement, which is independent of different initial states of the qubits (pure or mixed state), occurs even in the presence of decoherence. These results arising from the combination of the extended Werner-like initial state and dissipative environments suggest an approach to control and enhance the entanglement even after purity induced sudden birth, death and revival.

Sudden gains in exposure therapy for obsessive-compulsive disorder.

PubMed

Collins, Lindsey M; Coles, Meredith E

2017-06-01

Prior research in the treatment of depression and anxiety has demonstrated that a sudden reduction in symptoms between two consecutive sessions (sudden gain) is related to lower post-treatment symptom severity (e.g. Hofmann, Schulz, Meuret, Moscovitch, & Suvak, 2006; Tang & DeRubeis, 1999). However, only one study has examined sudden gains in the treatment of obsessive compulsive disorder (OCD). In that study, one-third of the patients with OCD experienced a sudden gain (Aderka et al., 2012). Further, patients who had a sudden gain had lower clinician-rated OCD symptom severity post-treatment (Aderka et al., 2012). In replication, the current study examined the frequency, characteristics, and clinical impact of sudden gains in 27 OCD patients during exposure and response prevention (ERP) therapy. Fifty two percent of patients experienced a sudden gain. The mean magnitude of a sudden gain represented, on average, 61.4% of total symptom reduction. Following treatment, individuals who had experienced a sudden gain were rated as less severe on the clinical global impression scale, but they did not experience a greater reduction in OCD symptoms (pre-to post-treatment) than those without a sudden gain. None of the pre-treatment characteristics tested were found to significantly predict whether a patient would have a sudden gain. Additional research examining predictors of, and patterns of, change in OCD symptoms is warranted. Copyright © 2017 Elsevier Ltd. All rights reserved.

Low-lying intruder and tensor-driven structures in 82As revealed by β decay at a new movable-tape-based experimental setup

NASA Astrophysics Data System (ADS)

Etilé, A.; Verney, D.; Arsenyev, N. N.; Bettane, J.; Borzov, I. N.; Cheikh Mhamed, M.; Cuong, P. V.; Delafosse, C.; Didierjean, F.; Gaulard, C.; Van Giai, Nguyen; Goasduff, A.; Ibrahim, F.; Kolos, K.; Lau, C.; Niikura, M.; Roccia, S.; Severyukhin, A. P.; Testov, D.; Tusseau-Nenez, S.; Voronov, V. V.

2015-06-01

The β decay of 82Ge Ge was re-investigated using the newly commissioned tape station BEDO at the electron-driven ISOL (isotope separation on line) facility ALTO operated by the Institut de Physique Nucléaire, Orsay. The original motivation of this work was focused on the sudden occurrence in the light N =49 odd-odd isotonic chain of a large number of J ≤1 states (positive or negative parity) in 80Ga by providing a reliable intermediate example, viz., 82As. The extension of the 82As level scheme towards higher energies from the present work has revealed three potential 1+ states above the already known one at 1092 keV. In addition our data allow ruling out the hypothesis that the 843 keV level could be a 1+ state. A detailed analysis of the level scheme using both an empirical core-particle coupling model and a fully microscopic treatment within a Skyrme-QRPA (quasiparticle random-phase approximation) approach using the finite-rank separable approximation was performed. From this analysis two conclusions can be drawn: (i) the presence of a large number of low-lying low-spin negative parity states is due to intruder states stemming from above the N =50 shell closure, and (ii) the sudden increase, from 82As to 80Ga, of the number of low-lying 1+ states and the corresponding Gamow-Teller fragmentation are naturally reproduced by the inclusion of tensor correlations and couplings to 2p-2h excitations.

Lassa fever-induced sensorineural hearing loss: A neglected public health and social burden.

PubMed

Mateer, Elizabeth J; Huang, Cheng; Shehu, Nathan Y; Paessler, Slobodan

2018-02-01

Although an association between Lassa fever (LF) and sudden-onset sensorineural hearing loss (SNHL) was confirmed clinically in 1990, the prevalence of LF-induced SNHL in endemic countries is still underestimated. LF, a viral hemorrhagic fever disease caused by Lassa virus (LASV), is endemic in West Africa, causing an estimated 500,000 cases and 5,000 deaths per year. Sudden-onset SNHL, one complication of LF, occurs in approximately one-third of survivors and constitutes a neglected public health and social burden. In the endemic countries, where access to hearing aids is limited, SNHL results in a decline of the quality of life for those affected. In addition, hearing loss costs Nigeria approximately 43 million dollars per year. The epidemiology of LF-induced SNHL has not been characterized well. The complication of LF induced by SNHL is also an important consideration for vaccine development and treatments. However, research into the mechanism has been hindered by the lack of autopsy samples and relevant small animal models. Recently, the first animal model that mimics the symptoms of SNHL associated with LF was developed. Preliminary data from the new animal model as well as the clinical case studies support the mechanism of immune-mediated injury that causes SNHL in LF patients. This article summarizes clinical findings of hearing loss in LF patients highlighting the association between LASV infection and SNHL as well as the potential mechanism(s) for LF-induced SNHL. Further research is necessary to identify the mechanism and the epidemiology of LF-induced SNHL.

Unexpected early extinction of the European pond turtle (Emys orbicularis) in Sweden and climatic impact on its Holocene range.

PubMed

Sommer, Robert S; Lindqvist, Charlotte; Persson, Arne; Bringsøe, Henrik; Rhodin, Anders G J; Schneeweiss, Norbert; Siroký, Pavel; Bachmann, Lutz; Fritz, Uwe

2009-03-01

Using ancient DNA sequences of subfossil European pond turtles (Emys orbicularis) from Britain, Central and North Europe and accelerator mass spectrometry radiocarbon dating for turtle remains from most Swedish sites, we provide evidence for a Holocene range expansion of the pond turtle from the southeastern Balkans into Britain, Central Europe and Scandinavia, according to the 'grasshopper pattern' of Hewitt. Northeastern Europe and adjacent Asia were colonized from another refuge located further east. With increasing annual mean temperatures, pond turtles reached southern Sweden approximately 9800 years ago. Until approximately 5500 years ago, rising temperatures facilitated a further range expansion up to Ostergötland, Sweden (approximately 58 degrees 30'N). However, around 5500 years ago pond turtle records suddenly terminate in Sweden, some 1500 years before the Holocene thermal maximum ended in Scandinavia and distinctly earlier than previously thought. This extinction coincides with a temporary cooling oscillation during the Holocene thermal maximum and is likely related to lower summer temperatures deteriorating reproductive success. Although climatic conditions improved later again, recolonization of Sweden from southern source populations was prevented by the Holocene submergence of the previous land connection via the Danish Straits that occurred approximately 8500 years ago.

Population growth enhances the mean fixation time of neutral mutations and the persistence of neutral variation.

PubMed

Waxman, D

2012-06-01

A fundamental result of population genetics states that a new mutation, at an unlinked neutral locus in a randomly mating diploid population, has a mean time of fixation of ∼4N(e) generations, where N(e) is the effective population size. This result is based on an assumption of fixed population size, which does not universally hold in natural populations. Here, we analyze such neutral fixations in populations of changing size within the framework of the diffusion approximation. General expressions are derived for the mean and variance of the fixation time in changing populations. Some explicit results are given for two cases: (i) the effective population size undergoes a sudden change, representing a sudden population expansion or a sudden bottleneck; (ii) the effective population changes linearly for a limited period of time and then remains constant. Additionally, a lower bound for the mean time of fixation is obtained for an effective population size that increases with time, and this is applied to exponentially growing populations. The results obtained in this work show, among other things, that for populations that increase in size, the mean time of fixation can be enhanced, sometimes substantially so, over 4N(e,0) generations, where N(e,0) is the effective population size at the time the mutation arises. Such an enhancement is associated with (i) an increased probability of neutral polymorphism in a population and (ii) an enhanced persistence of high-frequency neutral variation, which is the variation most likely to be observed.

Long-term follow-up of Fontan completion in adults and adolescents.

PubMed

Fuchigami, Tai; Nagashima, Mitsugi; Hiramatsu, Takeshi; Matsumura, Goki; Tateishi, Minori; Masuda, Noriyasu; Yamazaki, Kenji

2017-07-01

The Fontan procedure is rarely performed in adults and adolescents in the present era. We review our results with the Fontan procedure in adolescents and young adults. Between 1974 and 2010, 79 consecutive patients underwent the Fontan procedure at an age ≥ 15 years (mean age at Fontan operation, 20.3 years ± 4.5 years). Forty-five patients underwent atriopulmonary connection, 11 underwent the Bjork procedure, and 23 underwent total cavopulmonary connection. Ten hospital deaths (HDs) and/or early Fontan takedowns (TDs) occurred. The median follow-up period was 18.2 years (range, 0.6-37.6 years). The estimated freedom from death or TD rates was 79.7% at 5 years, 77.0% at 10 years, 73.9% at 15 years, and 63.9% at 20 years. Age was not a predictor of HD and/or TD. Freedom from death or TD after 1998 was 69.1% at 5 years, 69.1% at 10 years, and 69.1% at 15 years, and before 1997 was 82.3% at 5 years, 79.0% at 10 years, 75.5% at 15 years, and 65.1% at 20 years; there were no significant differences between the two groups. In 19 late-death patients, nine (47.4%) experienced sudden death. Among these patients, five had known arrhythmias before sudden death. In patients who were ≥15 years old, the surgical results of the Fontan operation were acceptable. Approximately half of the late deaths were sudden deaths, mainly occurring 10-20 years postoperatively. © 2017 Wiley Periodicals, Inc.

More on the alleged 1970 geomagnetic jerk

USGS Publications Warehouse

Alldredge, L.R.

1985-01-01

French and United Kingdom workers have published reports describing a sudden change in the secular acceleration, called an impulse or a jerk, which took place around 1970. They claim that this change took place in a period of a year or two and that the sources of the alleged jerk are internal. An earlier paper by this author questioned their method of analysis pointing out that their method of piecemeal fitting of parabolas to the data will always create a discontinuity in the secular acceleration where the parabolas join and that the place where the parabolas join is an a priori assumption and not a result of the analysis. This paper gives a very brief summary of this first paper and then adds additional reasons for questioning the allegation that there was a worldwide sudden jerk in the magnetic field of internal origin around 1970. These new reasons are based largely on new field models which give cubic approximations of the field right through the 1970 timeframe and therefore have no discontinuities in the second derivative (jerk) around 1970. Some recent Japanese work shows several sudden changes in the secular variation pattern which cover limited areas and do not seem to be closely related to each other or to the irregularity noted in the European area near 1970. The secular variation picture which seems to be emerging is one with many local or limited-regional secular variation changes which appear to be almost unrelated to each other in time or space. A worldwide spherical harmonic model including coefficients up to degree 13 could never properly depict such a situation. ?? 1985.

Sudden gains in group cognitive-behavioral therapy for panic disorder.

PubMed

Clerkin, Elise M; Teachman, Bethany A; Smith-Janik, Shannan B

2008-11-01

The current study investigates sudden gains (rapid symptom reduction) in group cognitive-behavioral therapy for panic disorder. Sudden gains occurring after session 2 of treatment predicted overall symptom reduction at treatment termination and some changes in cognitive biases. Meanwhile, sudden gains occurring immediately following session 1 were not associated with symptom reduction or cognitive change. Together, this research points to the importance of examining sudden gains across the entire span of treatment, as well as the potential role of sudden gains in recovery from panic disorder.

Sudden Gains in Group Cognitive-Behavioral Therapy for Panic Disorder

PubMed Central

Clerkin, Elise M.; Teachman, Bethany A.; Smith-Janik, Shannan B.

2008-01-01

The current study investigates sudden gains (rapid symptom reduction) in group cognitive-behavioral therapy for panic disorder. Sudden gains occurring after session 2 of treatment predicted overall symptom reduction at treatment termination and some changes in cognitive biases. Meanwhile, sudden gains occurring immediately following session 1 were not associated with symptom reduction or cognitive change. Together, this research points to the importance of examining sudden gains across the entire span of treatment, as well as the potential role of sudden gains in recovery from panic disorder. PMID:18804199

Sudden Death in Young People--Heart Problems Often Blamed

MedlinePlus

Sudden death in young people: Heart problems often blamed Sudden death in young people is rare, but those at ... causes and treatments. By Mayo Clinic Staff Sudden death in people younger than 35, often due to ...

Geomagnetic sudden impulses and storm sudden commencements - A note on terminology

NASA Technical Reports Server (NTRS)

Joselyn, J. A.; Tsurutani, B. T.

1990-01-01

The definitions of and distinctions between storm sudden commencements (SSCs) and geomagnetic sudden impulses (SIs) are examined and present definitions of SIs and SSCs are modernized. Quantitative definitions of the two terms are recommended.

Periaortic haemangiosarcoma in an African wild dog (Lycaon pictus).

PubMed

Newell-Fugate, A; Lane, E

2009-06-01

A 9-year-old apparently healthy male African wild dog (Lycaon pictus) was found dead in its enclosure at the De Wildt Cheetah and Wildlife Centre. Necropsy revealed a pericardium distended by approximately 250 ml of thick blood. A soft, red, lobulated mass was attached to the periaortic fat between the level of the aortic valves and the pericardial reflection. Histologically, the mass was consistent with a haemangiosarcoma. Other findings in the heart included mild to moderate ventricular hypertrophy and moderate, acute perivascular myocardial necrosis. Sudden death was attributed to acute heart failure precipitated by cardiac tamponade.

Helium Atom Scattering from C2H6, F2HCCH3, F3CCH2F and C2F6 in Crossed Molecular Beams

NASA Astrophysics Data System (ADS)

Hammer, Markus; Seidel, Wolfhart

1997-10-01

Rotationally unresolved differential cross sections were measured in crossed molecular beam experiments by scattering Helium atoms from Ethane, 1,1-Difluoroethane, 1,1,1,2-Tetrafluoroethane and Hexafluoroethane. The damping of observed diffraction oscillations was used to extract anisotropic interaction potentials for these scattering systems applying the infinite order sudden approximation (IOSA). Binary macroscopic parameters such as second heterogeneous virial coefficients and the coefficients of diffusion and viscosity were computed from these potentials and compared to results from macroscopic experiments.

Reemission spectra and inelastic processes at interaction of attosecond and shorter duration electromagnetic pulses with atoms

NASA Astrophysics Data System (ADS)

Makarov, D. N.; Matveev, V. I.

2017-01-01

Inelastic processes and the reemission of attosecond and shorter electromagnetic pulses by atoms have been considered within the analytical solution of the Schrödinger equation in the sudden perturbation approximation. A method of calculations with the exact inclusion of spatial inhomogeneity of the field of an ultrashort pulse and the momenta of photons in the reemission processes has been developed. The probabilities of inelastic processes and spectra of reemission of ultrashort electromagnetic pulses by one- and many-electron atoms have been calculated. The results have been presented in the form of analytical formulas.

Effect of reheating on predictions following multiple-field inflation

NASA Astrophysics Data System (ADS)

Hotinli, Selim C.; Frazer, Jonathan; Jaffe, Andrew H.; Meyers, Joel; Price, Layne C.; Tarrant, Ewan R. M.

2018-01-01

We study the sensitivity of cosmological observables to the reheating phase following inflation driven by many scalar fields. We describe a method which allows semianalytic treatment of the impact of perturbative reheating on cosmological perturbations using the sudden decay approximation. Focusing on N -quadratic inflation, we show how the scalar spectral index and tensor-to-scalar ratio are affected by the rates at which the scalar fields decay into radiation. We find that for certain choices of decay rates, reheating following multiple-field inflation can have a significant impact on the prediction of cosmological observables.

The histological basis of late gadolinium enhancement cardiovascular magnetic resonance in a patient with Anderson-Fabry disease.

PubMed

Moon, James C; Sheppard, Mary; Reed, Emma; Lee, Phillip; Elliott, Perry M; Pennell, Dudley J

2006-01-01

Anderson-Fabry Disease (AFD) is a storage disease that mimics hypertrophic cardiomyopathy. Late gadolinium enhancement (LGE) by cardiovascular magnetic resonance occurs in approximately 50% of patients in the basal inferolateral LV wall, but how an intracellular storage disease causes focal LGE is unknown. We present a whole-heart histological validation that LGE is caused by focal myocardial collagen scarring. This scarring may be the substrate for electrical re-entry and sudden arrhythmic death. The reasons for this distribution of fibrosis are unclear, but may reflect inhomogeneous left ventricular wall stress.

Nonthermal steady states after an interaction quench in the Falicov-Kimball model.

PubMed

Eckstein, Martin; Kollar, Marcus

2008-03-28

We present the exact solution of the Falicov-Kimball model after a sudden change of its interaction parameter using nonequilibrium dynamical mean-field theory. For different interaction quenches between the homogeneous metallic and insulating phases the system relaxes to a nonthermal steady state on time scales on the order of variant Planck's over 2pi/bandwidth, showing collapse and revival with an approximate period of h/interaction if the interaction is large. We discuss the reasons for this behavior and provide a statistical description of the final steady state by means of generalized Gibbs ensembles.

Quasi-static evolution of coronal magnetic fields

NASA Technical Reports Server (NTRS)

Longcope, D. W.; Sudan, R. N.

1992-01-01

A formalism is developed to describe the purely quasi-static part of the evolution of a coronal loop driven by its footpoints. This is accomplished under assumptions of a long, thin loop. The quasi-static equations reveal the possibility for sudden 'loss of equilibrium' at which time the system evolves dynamically rather than quasi-statically. Such quasi-static crises produce high-frequency Alfven waves and, in conjunction with Alfven wave dissipation models, form a viable coronal heating mechanism. Furthermore, an approximate solution to the quasi-static equations by perturbation method verifies the development of small-scale spatial current structure.

A review of patients who suddenly deteriorate in the presence of paramedics.

PubMed

Boyle, Malcolm J; Smith, Erin C; Archer, Frank

2008-07-26

The report of the Ministerial Review of Trauma and Emergency Services in Victoria, Australia, recommended that paramedics be permitted to divert to the closest hospital in incidences of life threatening situations prior to and during transport. An audit of patients that suddenly deteriorated in paramedic care was recommended by the Ministerial Review. The objective of the study was to identify the number and outcome of patients who suddenly deteriorated in the presence of paramedics. A retrospective cohort study of trauma patients who suddenly deteriorated in the presence of paramedics during 2002. As there was no standard definition, sudden deterioration was defined using a predetermined set of physiological criteria. Patient care record data of patients who suddenly deteriorated were compared with the State Trauma Registry to determine those who sustained hospital defined major trauma. Patient care records where hospital bypass was undertaken were identified and analysed. Ethics committee approval was obtained. There were 2,893 patients that suddenly deteriorated according to predefined criteria. 2,687 (5.1% of the total trauma patients for 2002) were suitable for further analysis. The majority of patients had a sudden decrease in BP (n = 2,463) with 4.3% having hospital defined major trauma. For patients with a sudden decrease in conscious state or a total GCS score of less than 13 (n = 77), 37.7% had hospital defined major trauma; and a sudden increase/decrease in pulse rate and sudden decrease in BP (n = 65), 26.2% had hospital defined major trauma. Only 28 documented incidents of hospital bypass were identified. This study suggests that the incidents of patients suddenly deteriorating in the presence of paramedics are low and the incidence of hospital bypass is not well documented.

Sudden gains in exposure-focused cognitive-behavioral group therapy for panic disorder.

PubMed

Nogueira-Arjona, Raquel; Santacana, Martí; Montoro, María; Rosado, Silvia; Guillamat, Roser; Vallès, Vicenç; Fullana, Miquel A

2017-11-01

In the context of psychological treatment, a sudden gain is a large and enduring improvement in symptom severity that occurs between two single therapy sessions. The influence of sudden gains on long-term outcomes and functional impairment in anxiety disorders is not well understood, and little is known with regard to panic disorder in particular. In addition, previous research on patients with anxiety disorders has produced inconsistent results regarding the relationship between sudden gains and cognitive change. We examined the incidence of sudden gains in a large sample (n = 116) of panic disorder patients undergoing exposure-focused cognitive-behavioral group therapy, and compared panic severity, functional impairment, and cognitive change in patients with and without sudden gains at posttreatment and 6-month follow-up. Participants who experienced sudden gains displayed lower levels of panic severity and functional impairment at posttreatment and 6-month follow-up than those who did not experience sudden gains. However, we observed no difference in cognitive changes between groups, either at posttreatment or at follow-up. Our results demonstrate that the beneficial effects of sudden gains on therapeutic outcomes not only extend to long-term and functional outcome measures but are also evident in less cognitive (i.e., exposure-focused) forms of psychological treatment. Sudden gains are common in panic disorder patients undergoing exposure-based cognitive-behavioral group therapy. Sudden gains during exposure-focused therapy are linked to greater improvement in panic disorder severity and functional impairment. The positive impact of sudden gains on panic disorder severity and functional impairment is maintained in the long term. Copyright © 2017 John Wiley & Sons, Ltd.

Utility of the CS and IOS approximations for calculating generalized phenomenological cross sections in atom-diatom systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fitz, D.E.; Kouri, D.J.; Liu, W.K.

1982-04-01

The calculation of shear viscosity and thermal conductivity coefficients in the presence of a magnetic field requires the accurate calculation of several types of generalized phenomenological cross sections in which velocity and angular momentum tensors are coupled with the orbital and rotational motion of the system. These cross sections are then averaged over energy in a fashion appropriate for the phenomenon of interest. The coupled states (CS) and/or infinite order sudden (IOS) approximations have been used to calculate several such cross sections for systems such as He-HCl, He-CO, He-H/sub 2/, HD-Ne, Ar-N/sub 2/, and Ne-H/sub 2/. Excellent results are obtainedmore » compared with close-coupled methods for cross sections which are symmetric in tensor index, especially in the CS approximation, and these results are not very sensitive to the choice of orbital wave parameter. On the other hand, the cross sections which are asymmetric in tensor index are much more sensitive to interference effects and are unsatisfactory in many cases.« less

Preliminary assessment of possible aerosol contamination effects on SAGE ozone trends in the lower stratosphere

NASA Technical Reports Server (NTRS)

Cunnold, Derek M.; Veiga, Robert E.

1991-01-01

An investigation of the validity of long-term ozone trends in the lower stratosphere derived from SAGE I and II measurements is described. At altitudes below approximately 20 km, it is important to separate the ozone and aerosol contributions to SAGE extinction at 600 nm. The correlation between SAGE II measurements of ozone and aerosols indicates that most of the variability in these parameters is associated with physically induced variations resulting from quasi-horizontal motions of air parcels. The SAGE ozone measurements are however found to be as much as 20 percent larger than coincident ozonesonde measurements between 15 and 20 km altitude. A sudden change in the difference at approximately 14.5 km altitude for which there is a change in the SAGE aerosol retrieval procedure suggests that SAGE ozone trends below 20 km altitude may be more sensitive to aerosol variations. Between 20 and 25 km altitude, however, both SAGE and the ozonesondes indicate a reduction in ozone of approximately 0.5 percent/year over the period 1979 to 1989 at midlatitudes of the Northern Hemisphere.

Iloprost-induced sudden hearing loss.

PubMed

Dursun, E; Dogru, S; Cincik, H; Cekin, E; Gungor, A; Poyrazoglu, E

2007-06-01

We report a patient who developed sudden, bilateral, sensorineural hearing loss during therapeutic use of iloprost for Raynaud's phenomenon. The sudden hearing loss was attributed to iloprost use and completely reversed in eight days with conservative therapy. Iloprost may be a potentially ototoxic drug, causing sudden hearing loss.

Sudden Event Recognition: A Survey

PubMed Central

Suriani, Nor Surayahani; Hussain, Aini; Zulkifley, Mohd Asyraf

2013-01-01

Event recognition is one of the most active research areas in video surveillance fields. Advancement in event recognition systems mainly aims to provide convenience, safety and an efficient lifestyle for humanity. A precise, accurate and robust approach is necessary to enable event recognition systems to respond to sudden changes in various uncontrolled environments, such as the case of an emergency, physical threat and a fire or bomb alert. The performance of sudden event recognition systems depends heavily on the accuracy of low level processing, like detection, recognition, tracking and machine learning algorithms. This survey aims to detect and characterize a sudden event, which is a subset of an abnormal event in several video surveillance applications. This paper discusses the following in detail: (1) the importance of a sudden event over a general anomalous event; (2) frameworks used in sudden event recognition; (3) the requirements and comparative studies of a sudden event recognition system and (4) various decision-making approaches for sudden event recognition. The advantages and drawbacks of using 3D images from multiple cameras for real-time application are also discussed. The paper concludes with suggestions for future research directions in sudden event recognition. PMID:23921828

Sudden unexpected death in epilepsy genetics: Molecular diagnostics and prevention.

PubMed

Goldman, Alica M; Behr, Elijah R; Semsarian, Christopher; Bagnall, Richard D; Sisodiya, Sanjay; Cooper, Paul N

2016-01-01

Epidemiologic studies clearly document the public health burden of sudden unexpected death in epilepsy (SUDEP). Clinical and experimental studies have uncovered dynamic cardiorespiratory dysfunction, both interictally and at the time of sudden death due to epilepsy. Genetic analyses in humans and in model systems have facilitated our current molecular understanding of SUDEP. Many discoveries have been informed by progress in the field of sudden cardiac death and sudden infant death syndrome. It is becoming apparent that SUDEP genomic complexity parallels that of sudden cardiac death, and that there is a pauci1ty of analytically useful postmortem material. Because many challenges remain, future progress in SUDEP research, molecular diagnostics, and prevention rests in international, collaborative, and transdisciplinary dialogue in human and experimental translational research of sudden death. Wiley Periodicals, Inc. © 2016 International League Against Epilepsy.

Malnutrition related deaths.

PubMed

Sparre-Sørensen, Maja; Kristensen, Gustav N

2016-10-01

Studies have shown that malnutrition increases the risk of morbidity, mortality, the length of hospital stay, and costs in the elderly population. Approximately one third of all patients admitted to geriatric wards in Denmark are malnourished according to the Danish Geriatric database. The aim of this study is to describe and examine the sudden increase in deaths due to malnutrition in the elderly population in Denmark from 1999 and, similarly, the sudden decline in malnutrition related deaths in 2007. A descriptive epidemiologic study was performed. All Danes listed in the national death registry who died from malnutrition in the period from 1994 to 2012 are included. The number of deaths from malnutrition increased significantly during the period from 1999 to 2007, especially in the age group 70 years and over. Additionally, we document a surprising similarity between the development in excess mortality from malnutrition in the five Danish regions during the same period. During the period 1999-2007 malnutrition was the direct cause of 340 extra deaths, and probably ten times more registered under other diseases. This development in excess mortality runs parallel in all five Danish regions over time. Copyright © 2016 European Society for Clinical Nutrition and Metabolism. Published by Elsevier Ltd. All rights reserved.

When a water drop freezes before it solidifies

NASA Astrophysics Data System (ADS)

Kavehpour, Pirouz; Davis, Stephen; Tavakoli, Faryar

2012-11-01

When a drop of liquid is placed on a substrate which temperature is below the melting point of the liquid, one would expect the drop to solidify instantaneously. However, many liquids, such as water, must be subcooled to solidify below its melting temperature due to homogeneous nucleation's high activation energy. Most of the drop solidification research, particularly for water, phase change is assumed to occur at equilibrium freezing temperature; however, this is not the case. We found that after a certain degree of supercooling, a kinetic based nucleation begins and latent heat of fusion is suddenly liberated, causing an increase in liquid temperature. At the end of this stage, approximately 20% of the drop is crystallized. This phenomenon is known among metallurgists as recalescence. This is followed by a slow solidification process at the melting point. As a water droplet spreads on a cold substrate, its contact line stops just prior to freezing inception from the liquid-solid interface. In this study, we assert that recalescence prior to solidification may be the cause of water's sudden immobility, which results in a fixed contact angle and droplet diameter. In our experiments, the nucleation front initiates from the trijunction point and propagates to the drop volume.

Quench dynamics of a dissipative Rydberg gas in the classical and quantum regimes

NASA Astrophysics Data System (ADS)

Gribben, Dominic; Lesanovsky, Igor; Gutiérrez, Ricardo

2018-01-01

Understanding the nonequilibrium behavior of quantum systems is a major goal of contemporary physics. Much research is currently focused on the dynamics of many-body systems in low-dimensional lattices following a quench, i.e., a sudden change of parameters. Already such a simple setting poses substantial theoretical challenges for the investigation of the real-time postquench quantum dynamics. In classical many-body systems, the Kolmogorov-Mehl-Johnson-Avrami model describes the phase transformation kinetics of a system that is quenched across a first-order phase transition. Here, we show that a similar approach can be applied for shedding light on the quench dynamics of an interacting gas of Rydberg atoms, which has become an important experimental platform for the investigation of quantum nonequilibrium effects. We are able to gain an analytical understanding of the time evolution following a sudden quench from an initial state devoid of Rydberg atoms and identify strikingly different behaviors of the excitation growth in the classical and quantum regimes. Our approach allows us to describe quenches near a nonequilibrium phase transition and provides an approximate analytical solution deep in the quantum domain.

Proceedings of the Sudden Oak Death Fourth Science Symposium

Treesearch

Susan J. Frankel; John T. Kliejunas; Katharine M. Palmieri

2010-01-01

The Sudden Oak Death Fourth Science Symposium provided a forum for current research on sudden oak death, caused by the exotic, quarantine pathogen, Phytophthora ramorum. Ninety submissions describing papers or posters on the following sudden oak death/P. ramorum topics are included: biology, genetics, nursery and wildland...

Proceedings of the sudden oak death third science symposium

Treesearch

Susan J. Frankel; John T. Kliejunas; Katharine M. Palmieri

2008-01-01

The Sudden Oak Death Third Science Symposium provided a forum for current research on sudden oak death, caused by the exotic, quarantine pathogen, Phytophthora ramorum. One hundred and seventeen submissions describing papers and posters on the following sudden oak death/ P. ramorum topics are included: biology, genetics, nursery,...

Proceedings of the sudden oak death sixth science symposium

Treesearch

Susan J. Frankel; Katharine M. Harrell

2017-01-01

The Sudden Oak Death Sixth Science Symposium provided a forum for current research on sudden oak death, caused by the exotic quarantine pathogen Phytophthora ramorum. More than 50 submissions describing papers or posters on the following sudden oak death/P. ramorum topics are included: biology, genetics, nursery and wildland...

Sudden Death in Sleep of Laotian-Hmong Refugees in Thailand: A Case-Control Study.

ERIC Educational Resources Information Center

Munger, Ronald G.

1987-01-01

Surveillance for sudden deaths conducted among Laotian-Hmong refugees in Thailand revealed associations between sudden death in sleep and membership in the Green-Hmong subgroup, a family history of sudden death, and previous non-fatal sleep disturbances. Most victims are young men. (PS)

Instrument Failure, Stress, and Spatial Disorientation Leading to a Fatal Crash With a Large Aircraft.

PubMed

Tribukait, Arne; Eiken, Ola

2017-11-01

An aircraft's orientation relative to the ground cannot be perceived via the sense of balance or the somatosensory system. When devoid of external visual references, the pilot must rely on instruments. A sudden unexpected instrument indication is a challenge to the pilot, who might have to question the instrument instead of responding with the controls. In this case report we analyze, from a human-factors perspective, how a limited instrument failure led to a fatal accident. During straight-ahead level flight in darkness, at 33,000 ft, the commander of a civil cargo airplane was suddenly confronted by an erroneous pitch-up indication on his primary flight display. He responded by pushing the control column forward, making a bunt maneuver with reduced/negative Gz during approximately 15 s. The pilots did not communicate rationally or cross-check instruments. Recordings of elevator and aileron positions suggest that the commander made intense efforts to correct for several extreme and erroneous roll and pitch indications. Gz displayed an increasing trend with rapid fluctuations and peaks of approximately 3 G. After 50 s the aircraft entered a turn with decreasing radius and finally hit the ground in an inverted attitude. A precipitate maneuvring response can, even if occurring in a large aircraft at high altitude, result in a seemingly inexorable course of events, ending with a crash. In the present case both pilots were probably incapacitated by acute psychological stress and spatial disorientation. Intense variations in Gz may have impaired the copilot's reading of the functioning primary flight display.Tribukait A, Eiken O. Instrument failure, stress, and spatial disorientation leading to a fatal crash with a large aircraft. Aerosp Med Hum Perform. 2017; 88(11):1043-1048.

Infrasonic wave accompanying a crack opening during the 2015 Hakone eruption

NASA Astrophysics Data System (ADS)

Yukutake, Yohei; Ichihara, Mie; Honda, Ryou

2018-03-01

To understand the initial process of the phreatic eruption of the Hakone volcano from June 29 to July 01, 2015, we analyzed infrasound data using the cross-correlation between infrasound and vertical ground velocity and compared the results of our analysis to the crustal deformation detected by tiltmeters and broadband seismometers. An infrasound signal and vertical ground motion due to an infrasound wave coupled to the ground were detected simultaneously with the opening of a crack source beneath the Owakudani geothermal region during the 2-min time period after 07:32 JST on June 29, 2015 (JST = UTC + 8 h). Given that the upper end of the open crack was approximately 150 m beneath the surface, the time for the direct emission of highly pressurized fluid from the upper end of the open crack to the surface should have exceeded the duration of the inflation owing to the hydraulic diffusivity in the porous media. Therefore, the infrasound signal coincident with the opening of the crack may reflect a sudden emission of volcanic gas resulting from the rapid vaporization of pre-existing groundwater beneath Owakudani because of the transfer of the volumetric strain change from the deformation source. We also noticed a correlation pattern corresponding to discrete impulsive infrasound signals during vent formation, which occurred several hours to 2 days after the opening of the crack. In particular, we noted that the sudden emission of vapor coincided with the inflation of the shallow pressure source, whereas the eruptive burst events accompanied by the largest vent formation were delayed by approximately 2 days. Furthermore, we demonstrated that the correlation method is a useful tool in detecting small infrasound signals and provides important information regarding the initial processes of the eruption.[Figure not available: see fulltext.

Cost-effectiveness of Project ADAM: a project to prevent sudden cardiac death in high school students.

PubMed

Berger, S; Whitstone, B N; Frisbee, S J; Miner, J T; Dhala, A; Pirrallo, R G; Utech, L M; Sachdeva, R C

2004-01-01

Public access defibrillation (PAD) in the adult population is thought to be both efficacious and cost-effective. Similar programs aimed at children and adolescents have not been evaluated for their cost-effectiveness. This study evaluates the potential cost-effectiveness of implementing Project ADAM, a program targeting children and adolescents in high schools in the Milwaukee Public School System. Project ADAM provides education about cardiopulmonary resuscitation (CPR) and the warning signs of sudden cardiac death (SCD) and training in the use and placement of automated external defibrillators (AEDs) in high schools. We developed decision analysis models to evaluate the cost-effectiveness of the decision to implement Project ADAM in public high schools in Milwaukee. We examined clinical model and public policy applications. Data on costs included estimates of hospital-based charges derived from a pediatric medical center where a series of patients were treated for SCD, educational programming, and the direct costs of one AED and training for 15 personnel per school. We performed sensitivity analyses to assess the variation in outputs with respect to changes to input data. The main outcome measures were Life years saved and incremental cost-effectiveness ratios. At an arbitrary societal willingness to pay $100,000 per life year saved, the policy to implement Project ADAM in schools is a cost-effective strategy at a threshold of approximately 5 patients over 5 years for the clinical model and approximately 8 patients over 5 years for the public policy model. Implementation of Project ADAM in high schools in the United States is potentially associated with an incremental cost-effectiveness ratio that is favorable.

Three-dimensional infinite order sudden quantum theory for indirect photodissociation processes. Application to the photofragment yield spectrum of NOCl in the region of the T1(13A″) ←S0(11A') transition. Fragment rotational distributions and thermal averages

NASA Astrophysics Data System (ADS)

Grinberg, Horacio; Freed, Karl F.; Williams, Carl J.

1997-08-01

The analytical infinite order sudden (IOS) quantum theory of triatomic photodissociation, developed in paper I, is applied to study the indirect photodissociation of NOCl through a real or virtual intermediate state. The theory uses the IOS approximation for the dynamics in the final dissociative channels and an Airy function approximation for the continuum functions. The transition is taken as polarized in the plane of the molecule; symmetric top wave functions are used for both the initial and intermediate bound states; and simple semiempirical model potentials are employed for each state. The theory provides analytical expressions for the photofragment yield spectrum for producing particular final fragment ro-vibrational states as a function of the photon excitation energy. Computations are made of the photofragment excitation spectrum of NOCl in the region of the T1(13A″)←S0(11A') transition for producing the NO fragment in the vibrational states nNO=0, 1, and 2. The computed spectra for the unexcited nNO==0 and excited nNO=2 states are in reasonable agreement with experiment. However, some discrepancies are observed for the singly excited nNO=1 vibrational state, indicating deficiencies in the semiempirical potential energy surface. Computations for two different orientations of the in-plane transition dipole moment produce very similar excitation spectra. Calculations of fragment rotational distributions are performed for high values of the total angular momentum J, a feature that would be very difficult to perform with close-coupled methods. Computations are also made of the thermally averaged rotational energy distributions to simulate the conditions in actual supersonic jet experiments.

Sudden Gains During Therapy of Social Phobia

PubMed Central

Hofmann, Stefan G.; Schulz, Stefan M.; Meuret, Alicia E.; Moscovitch, David A.; Suvak, Michael

2007-01-01

The present study investigated the phenomenon of sudden gains in 107 participants with social phobia (social anxiety disorder) who received either cognitive–behavioral group therapy or exposure group therapy without explicit cognitive interventions, which primarily used public speaking situations as exposure tasks. Twenty-two out of 967 session-to-session intervals met criteria for sudden gains, which most frequently occurred in Session 5. Individuals with sudden gains showed similar improvements in the 2 treatment groups. Although cognitive–behavioral therapy was associated with more cognitive changes than exposure therapy, cognitive changes did not precede sudden gains. In general, the results of this study question the clinical significance of sudden gains in social phobia treatment. PMID:16881776

Sudden unexpected death from natural diseases: Fifteen years' experience with 484 cases in Seychelles.

PubMed

Zhao, Peng; Wang, Ji-Gang; Gao, Peng; Li, Xia; Brewer, Rubell

2016-01-01

The aim of this study is to identify and subclassify sudden natural death (sudden death from natural diseases) cases in Seychelles. A total of 484 sudden natural death cases with autopsy at the Clinical Pathology Laboratory, Victoria Hospital, Seychelles between 1997 through 2012 were retrospectively reviewed. Among them, 363 cases (75%) were male and 121 (25%) were female. The most frequent sudden deaths were attributed to cardiovascular diseases (78.5%), and then followed by infectious diseases (9.9%), and gastrointestinal diseases (9.1%). This is the largest population-based study on sudden natural deaths in Seychelles. Copyright © 2015 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.

Bilateral sudden sensorineural hearing loss as a first symptom of infective endocarditis: two case reports.

PubMed

Chroni, M; Prappa, E; Kokkevi, I

2018-04-01

Septic emboli are an unusual cause of sudden sensorineural hearing loss, for which few reports exist in the literature. This paper presents two cases of sudden sensorineural hearing loss, initially considered as idiopathic, but which were caused by septic emboli. Hearing loss in these cases was bilateral, sequential and total. The first patient had mild fever one week prior to their presentation with sudden sensorineural hearing loss; the other patient had no additional symptoms at presentation. These patients were later diagnosed with infective endocarditis, at two and seven months following the sudden sensorineural hearing loss respectively, showing that septic emboli had been the cause of sudden sensorineural hearing loss. Septic emboli should be considered as a possible cause of sudden sensorineural hearing loss in cases of total hearing loss. This form of hearing loss should prompt the otolaryngologist to further investigate for infective endocarditis.

Proceedings of the sudden oak death second science symposium: the state of our knowledge

Treesearch

Susan J. Frankel; Patrick J. Shea; Michael I. Haverty

2006-01-01

The Sudden Oak Death Second Science Symposium provided a forum for current research on sudden oak death, caused by the exotic, quarantine pathogen, Phytophthora ramorum. Ninety papers and forty-six posters on the following sudden oak death/P. ramorum topics are included: biology, genetics, nursery and wildland management,...

Sudden Gains in Cognitive Therapy of Depression and Depression Relapse/Recurrence

ERIC Educational Resources Information Center

Tang, Tony Z.; DeRubeis, Robert J.; Hollon, Steven D.; Amsterdam, Jay; Shelton, Richard

2007-01-01

Cognitive therapy (CT) may have significant advantages over antidepressants in preventing depression relapses. Many CT patients experience sudden gains: large symptom improvement in 1 between-session interval. Past studies have associated CT sudden gains with in-session cognitive changes but not with life events. This study examined sudden gains…

Blunt trauma to large vessels: a mathematical study

PubMed Central

Ismailov, Rovshan M; Shevchuk, Nikolai A; Schwerha, Joseph; Keller, Lawrence; Khusanov, Higmat

2004-01-01

Background Blunt trauma causes short-term compression of some or all parts of the chest, abdomen or pelvis and changes hemodynamics of the blood. Short-term compression caused by trauma also results in a short-term decrease in the diameter of blood vessels. It has been shown that with a sudden change in the diameter of a tube or in the direction of the flow, the slower-moving fluid near the wall stops or reverses direction, which is known as boundary layer separation (BLS). We hypothesized that a sudden change in the diameter of elastic vessel that results from compression may lead not only to BLS but also to other hemodynamic changes that can damage endothelium. Methods We applied Navier-Stokes, multiphase and boundary layer equations to examine such stress. The method of approximation to solve the BL equations was used. Experiments were conducted in an aerodynamic tube, where incident flow velocity and weight of carriage with particles before and after blowing were measured. Results We found that sudden compression resulting from trauma leads to (1) BLS on the curved surface of the vessel wall; (2) transfer of laminar boundary layer into turbulent boundary layer. Damage to the endothelium can occur if compression is at least 25% and velocity is greater than 2.4 m/s or if compression is at least 10% and velocity is greater than 2.9 m/s. Conclusion Our research may point up new ways of reducing the damage from blunt trauma to large vessels. It has the potential for improvement of safety features of motor vehicles. This work will better our understanding of the precise mechanics and critical variables involved in diagnosis and prevention of blunt trauma to large vessels. PMID:15153246

[Ten years of early defibrillation: "Bochum against sudden cardiac death". Acceptance and critical analysis of using automated external defibrillators].

PubMed

Hanefeld, C; Kloppe, C; Breger, W; Kloppe, A; Mügge, A; Wiemer, M

2015-04-01

There is a comprehensive early defibrillation program in Bochum (Germany); since 2003 a total of 175 automated external defibrillators (AEDs) have been installed in urban areas by the city of Bochum and private companies. These were preferably installed in places with high foot traffic, e.g., public buildings, companies, and event/shopping centers. Approximately 15,000 laypeople who work in the vicinity of the AED locations were trained in the use of defibrillators and in basic resuscitation. In addition, rescue workers on fire trucks and medically trained personnel in physicians' medical practices were equipped as "first responders" with AEDs. After an initiation phase, all available information after each AED use since August 2004 has been collected by the project coordinator. During the period of data collection (August 2004 to August 2013), an AED was used in a total of 17 patients who had suffered sudden cardiac death (SCD) under the project in Bochum. Eleven patients had primary ventricular fibrillation (VF). Six of these survived without neurological deficit. In another 6 patients, a nondefibrillatable rhythm disorder was diagnosed. The AEDs are reliable and showed impeccable rhythm analysis before the instructions to provide any necessary shock. Compared to the number of existing units and an estimated number of 37-100 SCD/100,000, the use of the AEDs only 17 times appears relatively small. To improve the effectiveness of the AED program in Bochum, an analysis of the emergency service responses, which were necessary because of sudden circulatory collapse, is currently being performed. This will allow areas with an increased incidence of SCD to be identified and a plan for the strategic placement of AED and emergency services can be made.

Sudden death after pediatric heart transplantation: analysis of data from the Pediatric Heart Transplant Study Group.

PubMed

Daly, Kevin P; Chakravarti, Sujata B; Tresler, Margaret; Naftel, David C; Blume, Elizabeth D; Dipchand, Anne I; Almond, Christopher S

2011-12-01

Sudden death is a well-recognized complication of heart transplantation. Little is known about the incidence and risk factors for sudden death after transplant in children. The purpose of this study was to determine the incidence of and risk factors for sudden death. This retrospective multicenter cohort study used the Pediatric Heart Transplant Study Group (PHTS) database, an event-driven registry of children aged <18 at listing undergoing heart transplantation between 1993 and 2007. Standard Kaplan-Meier and parametric analyses were used for survival analysis. Multivariate analysis in the hazard-function domain was used to identify risk factors for sudden death after transplant. Of 604 deaths in 2,491 children who underwent heart transplantation, 94 (16%) were classified as sudden. Freedom from sudden death was 97% at 5 years, and the hazard for sudden death remained constant over time at 0.01 deaths/year. Multivariate risk factors associated with sudden death included black race (hazard ratio [HR], 2.6; p < 0.0001), United Network of Organ Sharing (UNOS) status 2 at transplant (HR, 1.8; p = 0.008), older age (HR, 1.4/10 years of age; p = 0.03), and an increased number of rejection episodes in the first post-transplant year (HR, 1.6/episode; p = 0.03). Sudden death accounts for 1 in 6 deaths after heart transplant in children. Older recipient age, recurrent rejection within the first year, black race, and UNOS status 2 at listing were associated with sudden death. Patients with 1 or more of these risk factors may benefit from primary prevention efforts. Copyright © 2011 International Society for Heart and Lung Transplantation. Published by Elsevier Inc. All rights reserved.

Haloperidol and sudden cardiac death in dementia: autopsy findings in psychiatric inpatients.

PubMed

Ifteni, Petru; Grudnikoff, Eugene; Koppel, Jeremy; Kremen, Neil; Correll, Christoph U; Kane, John M; Manu, Peter

2015-12-01

Treatment with haloperidol has been shown, in studies using death certificates and prescription files, to be associated with an excess of sudden cardiac deaths, and regulatory warnings highlight this risk in patients with dementia. We used autopsy findings to determine whether the rate of sudden cardiac death is greater in cases of unexpected deaths of patients with dementia treated with haloperidol. From 1989 through 2013, 1219 patients with a primary diagnosis of dementia with behavioral disturbance were admitted to a psychiatric hospital, and 65 (5.3%) died suddenly. Sixty-five patients (5.3%) died unexpectedly. Complete post-mortem examinations after the sudden death were performed in 55 (84.6%) patients. Twenty-seven of the autopsied cases (49.1%) had been treated with haloperidol orally (2.2 mg ± 2.1 mg/day), the only antipsychotic used in this cohort. Univariable comparisons and multivariable regression analyses compared the groups of patients with or without sudden cardiac death. The leading causes of death were sudden cardiac death (32.7%), myocardial infarction (25.5% of patients), pneumonia (23.6%), and stroke (10.9%). Patients with sudden cardiac death and those with anatomically established cause of death were similar regarding the use of haloperidol (p = 0.5). Sudden cardiac death patients were more likely to suffer from Alzheimer's dementia (p = 0.027) and to have a past history of heart disease (p = 0.0094), and less likely to have been treated with a mood stabilizer (p = 0.024), but none of these variables were independent predictors of sudden cardiac death. Autopsy data suggest that oral haloperidol is not associated with increased risk of sudden cardiac death in psychiatric inpatients with dementia. Copyright © 2015 John Wiley & Sons, Ltd.

Structural imaging biomarkers of sudden unexpected death in epilepsy

PubMed Central

Wandschneider, Britta; Koepp, Matthias; Scott, Catherine; Micallef, Caroline; Balestrini, Simona; Sisodiya, Sanjay M.; Thom, Maria; Harper, Ronald M.; Sander, Josemir W.; Vos, Sjoerd B.; Duncan, John S.; Lhatoo, Samden

2015-01-01

Sudden unexpected death in epilepsy is a major cause of premature death in people with epilepsy. We aimed to assess whether structural changes potentially attributable to sudden death pathogenesis were present on magnetic resonance imaging in people who subsequently died of sudden unexpected death in epilepsy. In a retrospective, voxel-based analysis of T1 volume scans, we compared grey matter volumes in 12 cases of sudden unexpected death in epilepsy (two definite, 10 probable; eight males), acquired 2 years [median, interquartile range (IQR) 2.8] before death [median (IQR) age at scanning 33.5 (22) years], with 34 people at high risk [age 30.5 (12); 19 males], 19 at low risk [age 30 (7.5); 12 males] of sudden death, and 15 healthy controls [age 37 (16); seven males]. At-risk subjects were defined based on risk factors of sudden unexpected death in epilepsy identified in a recent combined risk factor analysis. We identified increased grey matter volume in the right anterior hippocampus/amygdala and parahippocampus in sudden death cases and people at high risk, when compared to those at low risk and controls. Compared to controls, posterior thalamic grey matter volume, an area mediating oxygen regulation, was reduced in cases of sudden unexpected death in epilepsy and subjects at high risk. The extent of reduction correlated with disease duration in all subjects with epilepsy. Increased amygdalo-hippocampal grey matter volume with right-sided changes is consistent with histo-pathological findings reported in sudden infant death syndrome. We speculate that the right-sided predominance reflects asymmetric central influences on autonomic outflow, contributing to cardiac arrhythmia. Pulvinar damage may impair hypoxia regulation. The imaging findings in sudden unexpected death in epilepsy and people at high risk may be useful as a biomarker for risk-stratification in future studies. PMID:26264515

Counter-rotating effects and entanglement dynamics in strongly coupled quantum-emitter-metallic-nanoparticle structures

NASA Astrophysics Data System (ADS)

Iliopoulos, Nikos; Thanopulos, Ioannis; Yannopapas, Vassilios; Paspalakis, Emmanuel

2018-03-01

We study the spontaneous emission of a two-level quantum emitter next to a plasmonic nanoparticle beyond the Markovian approximation and the rotating-wave approximation (RWA) by combining quantum dynamics and classical electromagnetic calculations. For emitters with decay times in the picosecond to nanosecond time regime, as well as located at distances from the nanoparticle up to its radius, the dynamics with and without the RWA and the transition from the non-Markovian to the Markovian regime are investigated. For emitters with longer decay times, the Markov approximation proves to be adequate for distances larger than half the nanoparticle radius. However, the RWA is correct for all distances of the emitter from the nanoparticle. For short decay time emitters, the Markov approximation and RWA are both inadequate, with only the RWA becoming valid again at a distance larger than half the nanoparticle radius. We also show that the entanglement dynamics of two initially entangled qubits interacting independently with the nanoparticle may have a strong non-Markovian character when counter-rotating effects are included. Interesting effects such as entanglement sudden death, periodic entanglement revival, entanglement oscillations, and entanglement trapping are further observed when different initial two-qubit states and different distances between the qubit and the nanoparticle are considered.

"The grave yawns for the horseman." Equestrian deaths in South Australia 1973-1983.

PubMed

Pounder, D J

1984-11-10

The fatalities associated with the riding and handling of horses in South Australia over the 11-year period 1973-1983 are reviewed. There were 18 deaths, including two sudden natural deaths in the saddle and one drowning. The 15 cases of horse-related trauma represent a death rate of approximately one per million population per annum. Thirteen of the deaths were the result of a head injury after a fall. Nine persons were not wearing protective headgear. The two principal groups at risk were male professional riders with a mean age of 32 years and female amateurs with a mean age of 19 years.

Sudden transition and sudden change from open spin environments

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hu, Zheng-Da; School of Science, Jiangnan University, Wuxi 214122; Xu, Jing-Bo, E-mail: xujb@zju.edu.cn

2014-11-15

We investigate the necessary conditions for the existence of sudden transition or sudden change phenomenon for appropriate initial states under dephasing. As illustrative examples, we study the behaviors of quantum correlation dynamics of two noninteracting qubits in independent and common open spin environments, respectively. For the independent environments case, we find that the quantum correlation dynamics is closely related to the Loschmidt echo and the dynamics exhibits a sudden transition from classical to quantum correlation decay. It is also shown that the sudden change phenomenon may occur for the common environment case and stationary quantum discord is found at themore » high temperature region of the environment. Finally, we investigate the quantum criticality of the open spin environment by exploring the probability distribution of the Loschmidt echo and the scaling transformation behavior of quantum discord, respectively. - Highlights: • Sudden transition or sudden change from open spin baths are studied. • Quantum discord is related to the Loschmidt echo in independent open spin baths. • Steady quantum discord is found in a common open spin bath. • The probability distribution of the Loschmidt echo is analyzed. • The scaling transformation behavior of quantum discord is displayed.« less

Sudden Infant Death Syndrome: Facts for Caregivers.

ERIC Educational Resources Information Center

Texas Child Care, 2000

2000-01-01

Presents risk factors and prevention measures related to Sudden Infant Death Syndrome. Offers infant sleep recommendations and five discussion questions to test knowledge of Sudden Infant Death Syndrome. (DLH)

Sudden cardiac death in adults: causes, incidence and interventions.

PubMed

Walker, Wendy Marina

Many nurses will be familiar with the unexpected death of an adult patient following a sudden, life-threatening cardiac event. It is a situation that demands sensitive nursing care and skilled interventions to provide a foundation for recovery and promote healthy bereavement. This article examines the causes and incidence of sudden cardiac death in adults. Possible reactions of those who are suddenly bereaved are described and immediate care interventions aimed at dealing with the grief process are discussed. The article concludes by identifying ways in which the incidence of sudden cardiac death may be reduced.

Declining Risk of Sudden Death in Heart Failure.

PubMed

Shen, Li; Jhund, Pardeep S; Petrie, Mark C; Claggett, Brian L; Barlera, Simona; Cleland, John G F; Dargie, Henry J; Granger, Christopher B; Kjekshus, John; Køber, Lars; Latini, Roberto; Maggioni, Aldo P; Packer, Milton; Pitt, Bertram; Solomon, Scott D; Swedberg, Karl; Tavazzi, Luigi; Wikstrand, John; Zannad, Faiez; Zile, Michael R; McMurray, John J V

2017-07-06

The risk of sudden death has changed over time among patients with symptomatic heart failure and reduced ejection fraction with the sequential introduction of medications including angiotensin-converting-enzyme inhibitors, angiotensin-receptor blockers, beta-blockers, and mineralocorticoid-receptor antagonists. We sought to examine this trend in detail. We analyzed data from 40,195 patients who had heart failure with reduced ejection fraction and were enrolled in any of 12 clinical trials spanning the period from 1995 through 2014. Patients who had an implantable cardioverter-defibrillator at the time of trial enrollment were excluded. Weighted multivariable regression was used to examine trends in rates of sudden death over time. Adjusted hazard ratios for sudden death in each trial group were calculated with the use of Cox regression models. The cumulative incidence rates of sudden death were assessed at different time points after randomization and according to the length of time between the diagnosis of heart failure and randomization. Sudden death was reported in 3583 patients. Such patients were older and were more often male, with an ischemic cause of heart failure and worse cardiac function, than those in whom sudden death did not occur. There was a 44% decline in the rate of sudden death across the trials (P=0.03). The cumulative incidence of sudden death at 90 days after randomization was 2.4% in the earliest trial and 1.0% in the most recent trial. The rate of sudden death was not higher among patients with a recent diagnosis of heart failure than among those with a longer-standing diagnosis. Rates of sudden death declined substantially over time among ambulatory patients with heart failure with reduced ejection fraction who were enrolled in clinical trials, a finding that is consistent with a cumulative benefit of evidence-based medications on this cause of death. (Funded by the China Scholarship Council and the University of Glasgow.).

Back muscle response to sudden trunk loading can be modified by training among healthcare workers.

PubMed

Pedersen, Mogens Theisen; Essendrop, Morten; Skotte, Jørgen H; Jørgensen, Kurt; Schibye, Bente; Fallentin, Nils

2007-06-01

Experimental study of the effect of physical training on the reaction to sudden back loading. To investigate the effect and sustainability of "on the job training" on the reaction to sudden back loading among employees at a geriatric ward. Available data suggest that a delayed muscle reflex response to sudden trunk loading may increase the risk of low back injuries. We have previously shown that training may alter the response to sudden trunk loading in healthy subjects and decrease the time elapsed until stopping of the forward movement of the trunk (stopping time). Data on the possibilities of a training-induced improvement in the reflex response among workers exposed to sudden trunk loading on the job are, however, nonexistent, and there is no evidence of long-term benefits, i.e., the sustainability of a positive training effect. The study included 23 participants and 14 controls. All were healthy without prior history of low back pain (LBP). The training group participated in a total of 18 training sessions during a 9-week period. The training focused on reactions to a variety of sudden trunk loadings. Before and after the training intervention and at a 1-year follow-up, all subjects were tested for their reaction to expected and unexpected sudden trunk loading by applying a horizontal force of 58 N to the upper back of the subjects and measuring the electromyographic (EMG) response from the erector spinae muscles. In the training group, the stopping time and the distance moved after unexpected sudden trunk loading decreased significantly (13%-19%, P = 0.02). The improved stopping time was associated with marked changes in the time-wise distribution of the EMG signal after training. In addition, the follow-up study showed a high sustainability of the training effect. The results demonstrated a training-induced improvement of the response to sudden trunk loading that may be beneficial in workers, such as nurses, who are exposed to sudden trunk perturbations during patient handling.

Advanced Electrocardiographic Predictors of Sudden Death in Familial Dysautonomia

NASA Technical Reports Server (NTRS)

Solaimanzadeh, I.; Schlegel, T. T.; Greco, E. C.; DePalma, J. L.; Starc, V.; Marthol, H.; Tutaj, M.; Buechner, S.; Axelrod, F. B.; Hilz, M. J.

2007-01-01

To identify accurate predictors for the risk of sudden death in patients with familial dysautonomia (FD). Ten-minute resting high-fidelity 12-lead ECGs were obtained from 14 FD patients and 14 age/gender-matched healthy subjects. Multiple conventional and advanced ECG parameters were studied for their ability to predict sudden death in FD over a subsequent 4.5-year period, including multiple indices of linear and non-linear heart rate variability (HRV); QT variability; waveform complexity; high frequency QRS; and derived Frank-lead parameters. Four of the 14 FD patients died suddenly during the follow-up period, usually with concomitant pulmonary disorder. The presence of low vagally-mediated HRV was the ECG finding most predictive of sudden death. Concomitant left ventricular hypertrophy and other ECG abnormalities such as increased QTc and JTc intervals, spatial QRS-T angles, T-wave complexity, and QT variability were also present in FD patients, suggesting that structural heart disease is fairly common in FD. Although excessive or unopposed cardiac vagal (relative to sympathetic) activity has been postulated as a contributor to sudden death in FD, the presence of low vagally-mediated HRV was paradoxically the best predictor of sudden death. However, we suggest that low vagally-mediated HRV be construed not as a direct cause of sudden death in FD, but rather as an effect of concurrent pathological processes, especially hypoxia due to pulmonary disorders and sleep apnea, that themselves increase the risk of sudden death in FD and simultaneously diminish HRV. We speculate that adenosine may play a role in sudden death in FD, possibly independently of vagal activity, and that adenosine inhibitors such as theophylline might therefore be useful as prophylaxis in this disorder.

The Metabolic Syndrome and Risk of Sudden Cardiac Death: The Atherosclerosis Risk in Communities Study.

PubMed

Hess, Paul L; Al-Khalidi, Hussein R; Friedman, Daniel J; Mulder, Hillary; Kucharska-Newton, Anna; Rosamond, Wayne R; Lopes, Renato D; Gersh, Bernard J; Mark, Daniel B; Curtis, Lesley H; Post, Wendy S; Prineas, Ronald J; Sotoodehnia, Nona; Al-Khatib, Sana M

2017-08-23

Prior studies have demonstrated a link between the metabolic syndrome and increased risk of cardiovascular mortality. Whether the metabolic syndrome is associated with sudden cardiac death is uncertain. We characterized the relationship between sudden cardiac death and metabolic syndrome status among participants of the ARIC (Atherosclerosis Risk in Communities) Study (1987-2012) free of prevalent coronary heart disease or heart failure. Among 13 168 participants, 357 (2.7%) sudden cardiac deaths occurred during a median follow-up of 23.6 years. Participants with the metabolic syndrome (n=4444) had a higher cumulative incidence of sudden cardiac death than those without it (n=8724) (4.1% versus 2.3%, P <0.001). After adjustment for participant demographics and clinical factors other than components of the metabolic syndrome, the metabolic syndrome was independently associated with sudden cardiac death (hazard ratio, 1.70, 95% confidence interval, 1.37-2.12, P <0.001). This relationship was not modified by sex (interaction P =0.10) or race (interaction P =0.62) and was mediated by the metabolic syndrome criteria components. The risk of sudden cardiac death varied according to the number of metabolic syndrome components (hazard ratio 1.31 per additional component of the metabolic syndrome, 95% confidence interval, 1.19-1.44, P <0.001). Of the 5 components, elevated blood pressure, impaired fasting glucose, and low high-density lipoprotein were independently associated with sudden cardiac death. We observed that the metabolic syndrome was associated with a significantly increased risk of sudden cardiac death irrespective of sex or race. The risk of sudden cardiac death was proportional to the number of metabolic syndrome components. © 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.

[EPIDEMIOLOGY OF SUDDEN CARDIAC DEATH: DATA FROM THE PARIS SUDDEN DEATH EXPERTISE CENTER REGISTRY].

PubMed

Jouven, Xavier; Bougouin, Wulfran; Karam, Nicole; Marijon, Eloi

2015-09-01

Sudden cardiac death is an unexpected cardiac arrest without obvious extra-cardiac cause. Epidemiology of sudden cardiac death has been poorly documented in France, mainly because of challenging requirement in order to capture all cases in a specific area. The Parisian registry (Sudden Death Expertise Center, European Georges Pompidou Hospital, Paris) was initiated in May 2011 and analyzed data of all sudden death in Paris and suburbs (6.6 millions inhabitants). Over 3 years, the annual incidence estimated to 50-70 per 100,000. Those occurred mainly in men (69%), with a mean age of 65 year, and at home (75%). The event was witnessed in 80% of cases, but bystander cardiopulmonary resuscitation was initiated in only half of cases. Initial cardiac rhythm was ventricular fibrillation in 25%. Survival to hospital discharge remains low (8%).

[Radiofrequency catheter ablation in children with Wolff-Parkinson-White syndrome and sudden cardiac death who had been resuscitated].

PubMed

Benito Bartolomé, F; Sánchez Fernández-Bernal, C

2001-04-01

Sudden death may be the first manifestation of the Wolff-Parkinson-White syndrome, especially in children and adolescents. The aim of this study was to evaluate the usefulness of radiofrequency catheter ablation in children with Wolff-Parkinson-White syndrome with aborted sudden death. We report four patients with Wolff-Parkinson-White syndrome who survived cardiac arrest. The patients were aged from 2.5 months to 16 years. The two first patients were lactating infants; in the first sudden death occurred during digoxin treatment for supraventricular tachycardia secondary to Wolff-Parkinson-White syndrome and in the second the syndrome was diagnosed after an episode of sudden death. In these patients a free wall accessory pathway (left posterior and left lateral, respectively) was successfully ablated using a transseptal approach. The third patient was diagnosed with asymptomatic Wolff-Parkinson-White syndrome; sudden death occurred during exercise. In the fourth patient, sudden death occurred after intravenous therapy with adenosine triphosphate and amiodarone for rapid atrial fibrillation. In both patients, one accessory pathway, located in right posteroseptal and right anterior free wall, respectively, was ablated. After a mean follow-up of 43.5 26.4 months, no recurrence of sudden death had occurred and electrocardiogram showed sinus rhythm without delta wave. The third patient presented severe sequelae of hypoxemic encephalopathy, which persisted during the follow-up. Radiofrequency catheter ablation is the treatment of choice in Wolff-Parkinson-White syndrome with episodes of aborted sudden death.

Unusual cause of aborted sudden cardiac death in a teen athlete: homozygosity for the 4G allele of the plasminogen activase inhibitor type 1 gene.

PubMed

Phillips, Susie B; Batlivala, Sarosh; Knudson, Jarrod D

2015-10-01

Common aetiologies of sudden cardiac death in children include coronary anomalies, channelopathies, and cardiomyopathies. Less frequently, hypercoagulable states cause sudden arrest. We report an unusual case of aborted sudden cardiac death in a teenager, ultimately found to have homozygosity for the 4G allele of the plasminogen activase inhibitor type 1 gene.

Sudden death: bereavement sequelae and interventions.

PubMed

Davidson, G P

1981-10-14

Just the phrase "sudden death' carries its sense of trepidation and even horror. So fear-inducing is its reality and prospect, that we have attempted to sanitise it by the colloquialisms such as a "sudden death play off' in sport, and even (recalling my days in military service) as the name of a particularly ferocious mix of alcoholic beverage. One of the reasons why the phrase is so evocative is the force of the unexpected bereavement that follows sudden death. This paper purports to examine, using a systems approach, the psychological sequelae of the emotionally involved survivors of sudden death, and to relate this to possible intervention strategies.

Sudden Cardiac Arrest (SCA) Risk Assessment

MedlinePlus

... HRS Find a Specialist Share Twitter Facebook SCA Risk Assessment Sudden Cardiac Arrest (SCA) occurs abruptly and without ... people of all ages and health conditions. Start Risk Assessment The Sudden Cardiac Arrest (SCA) Risk Assessment Tool ...

A staggered conservative scheme for every Froude number in rapidly varied shallow water flows

NASA Astrophysics Data System (ADS)

Stelling, G. S.; Duinmeijer, S. P. A.

2003-12-01

This paper proposes a numerical technique that in essence is based upon the classical staggered grids and implicit numerical integration schemes, but that can be applied to problems that include rapidly varied flows as well. Rapidly varied flows occur, for instance, in hydraulic jumps and bores. Inundation of dry land implies sudden flow transitions due to obstacles such as road banks. Near such transitions the grid resolution is often low compared to the gradients of the bathymetry. In combination with the local invalidity of the hydrostatic pressure assumption, conservation properties become crucial. The scheme described here, combines the efficiency of staggered grids with conservation properties so as to ensure accurate results for rapidly varied flows, as well as in expansions as in contractions. In flow expansions, a numerical approximation is applied that is consistent with the momentum principle. In flow contractions, a numerical approximation is applied that is consistent with the Bernoulli equation. Both approximations are consistent with the shallow water equations, so under sufficiently smooth conditions they converge to the same solution. The resulting method is very efficient for the simulation of large-scale inundations.

Mobile phone usage does not affect sudden sensorineural hearing loss.

PubMed

Sagiv, D; Migirov, L; Madgar, O; Nakache, G; Wolf, M; Shapira, Y

2018-01-01

Recent studies found that mobile phone users had a significantly greater risk of having elevated thresholds in speech frequencies. This study investigated the correlation between the laterality of sudden sensorineural hearing loss, handedness and the preferred ear for mobile phone use. The study included all patients who presented with sudden sensorineural hearing loss to the Department of Otolaryngology - Head and Neck Surgery in our tertiary referral medical centre between 2014 and 2016. Patients were asked to indicate their dominant hand and preferred ear for mobile phone use. The study comprised 160 patients. No correlation was found between the dominant hand or preferred ear for mobile phone use and the side of sudden sensorineural hearing loss. There was no correlation between the side of the sudden sensorineural hearing loss (preferable or non-preferable for mobile phone use) and audiometric characteristics. No correlation was found between the laterality of ears used for mobile phone and sudden sensorineural hearing loss.

Entanglement dynamics of two independent Jaynes-Cummings atoms without the rotating-wave approximation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen Qinghu; Department of Physics, Zhejiang University, Hangzhou 310027; Yang Yuan

2010-11-15

Entanglement evolution of two independent Jaynes-Cummings atoms without the rotating-wave approximation (RWA) is studied by a numerically exact approach. Previous results based on the RWA are essentially modified in the strong-coupling regime (g{>=}0.1), which has been reached in the recent experiments on the flux qubit coupled to the LC resonator. For the initial Bell state with anticorrelated spins, entanglement sudden death (ESD) is absent in the RWA but does appear in the present numerical calculation without the RWA. Aperiodic entanglement evolution in the strong-coupling regime is observed. The strong atom-cavity coupling facilitates the ESD. The sign of the detuning playsmore » an essential role in the entanglement evolution for strong coupling, which is irrelevant in the RWA. Analytical results based on an unitary transformation are also given, which could not modify the RWA picture essentially. It is suggested that the activation of the photons may be the origin of ESD in this system.« less

Signaling Pathway in Early Brain Injury after Subarachnoid Hemorrhage: News Update.

PubMed

Ji, Chengyuan; Chen, Gang

2016-01-01

The annual incidence of subarachnoid hemorrhage (SAH) caused by intracranial aneurysm rupture is approximately 10.5/10 million people in China, making SAH the third most frequently occurring hemorrhage of the intracranial type after cerebral embolism and hypertensive intracerebral hemorrhage. SAH caused by ruptured aneurysm leads to a mortality rate as high as 67 %, and, because of the sudden onset of this disease, approximately 12-15 % of patients die before they can receive effective treatment. Early brain injury (EBI) is the brain damage occurring within the first 72 h after SAH. Two-thirds of mortality caused by SAH occurs within 48 h, mainly as a result of EBI. With the development of molecular biology and medicine microscopy techniques, various signaling pathways involved in EBI after SAH have been revealed. Understanding these signaling pathways may help clinicians treat EBI after SAH and improve long-term prognosis of SAH patients. This chapter summarizes several important signaling pathways implicated in EBI caused by SAH.

Fatalities among volunteer and career firefighters--United States, 1994-2004.

PubMed

2006-04-28

Approximately 800,000 firefighters in the United States are volunteer firefighters and 300,000 are career firefighters. Volunteer firefighters primarily serve communities with fewer than 25,000 inhabitants, whereas most career firefighters serve communities of more than 25,000 persons. To characterize fatalities among volunteer and career firefighters, CDC analyzed data from the U.S. Fire Administration (USFA). This report summarizes the results of that analysis and, to illustrate the most common types of volunteer and career firefighter fatalities, describes two cases investigated by the National Institute for Occupational Safety and Health (NIOSH) Firefighter Fatality Investigation and Prevention Program. Fifty-three percent (610 of 1,141) of U.S. firefighters who died while on duty during 1994-2004 were volunteers, and 32% (368) were career firefighters. The remaining 15% (163) of deaths were among other firefighters (e.g., wildland, paid on-call, and part-time paid firefighters). Among volunteer firefighters, sudden cardiac death (e.g., from myocardial infarction or arrhythmia) and motor vehicle (MV) crashes during emergency response were the leading causes of fatality. Among career firefighters, sudden cardiac death and asphyxiation were leading causes of death. Adoption and enforcement of existing fire-service recommendations regarding fitness standards, mandatory medical evaluations with appropriate work restrictions, and emergency vehicle response protocols are needed to prevent these fatalities among firefighters.

Shakeoff Ionization near the Coulomb Barrier Energy.

PubMed

Sharma, Prashant; Nandi, T

2017-11-17

We measure the projectile K x-ray spectra as a function of the beam energies around the Coulomb barrier in different collision systems. The energy is scanned in small steps around the barrier aiming to explore the nuclear effects on the elastically scattered projectile ions. The variation of the projectile x-ray energy with the ion-beam energies exhibits an unusual increase in between the interaction barrier and fusion barrier energies. This additional contribution to the projectile ionization can be attributed to the shakeoff of outer-shell electrons of the projectile ions due to the sudden nuclear recoil (∼10^{-21}  sec) caused by the attractive nuclear potential, which gets switched on near the interaction barrier energy. In the sudden approximation limit, the theoretical shakeoff probability calculation due to the nuclear recoil explains the observed data well. In addition to its fundamental interest, such processes can play a significant role in dark matter detection through the possible mechanism of x-ray emissions, where the weakly interacting massive particle-nucleus elastic scattering can lead to the nuclear-recoil-induced inner-shell vacancy creations. Furthermore, the present work may provide new prospects for atomic physics research at barrier energies as well as provide a novel technique to perform barrier distribution studies for two-body systems.

Shakeoff Ionization near the Coulomb Barrier Energy

NASA Astrophysics Data System (ADS)

Sharma, Prashant; Nandi, T.

2017-11-01

We measure the projectile K x-ray spectra as a function of the beam energies around the Coulomb barrier in different collision systems. The energy is scanned in small steps around the barrier aiming to explore the nuclear effects on the elastically scattered projectile ions. The variation of the projectile x-ray energy with the ion-beam energies exhibits an unusual increase in between the interaction barrier and fusion barrier energies. This additional contribution to the projectile ionization can be attributed to the shakeoff of outer-shell electrons of the projectile ions due to the sudden nuclear recoil (˜10-21 sec ) caused by the attractive nuclear potential, which gets switched on near the interaction barrier energy. In the sudden approximation limit, the theoretical shakeoff probability calculation due to the nuclear recoil explains the observed data well. In addition to its fundamental interest, such processes can play a significant role in dark matter detection through the possible mechanism of x-ray emissions, where the weakly interacting massive particle-nucleus elastic scattering can lead to the nuclear-recoil-induced inner-shell vacancy creations. Furthermore, the present work may provide new prospects for atomic physics research at barrier energies as well as provide a novel technique to perform barrier distribution studies for two-body systems.

Expressions of Mast Cell Tryptase and Brain Natriuretic Peptide in Myocardium of Sudden Death due to Hypersensitivity and Coronary Atherosclerotic Heart Disease.

PubMed

Shi, J R; Tian, C J; Zeng, Q; Guo, X J; Lu, J; Gao, C R

2016-06-01

To explore the value of mast cell tryptase and brain natriuretic peptide（BNP） in the differential diagnostic of sudden death due to hypersensitivity and coronary atherosclerotic heart disease. Totally 30 myocardial samples were collected from the autopsy cases in the Department of Forensic Pathology, Shanxi Medical University during 2010-2015. All samples were divided into three groups： death of craniocerebral injury group, sudden death of hypersensitivity group and sudden death of coronary atherosclerotic heart disease group, 10 cases in each group. Mast cell tryptase and BNP in myocardium were detected by immunofluorescence staining and Western Blotting. Immunofluorescence staining showed that the positive staining mast cell tryptase appeared in myocardium of sudden death of hypersensitivity group and coronary atherosclerotic heart disease group. Among the three groups, the expression of mast cell tryptase showed significantly differences through pairwise comparison （ P <0.05）; The expression level of BNP in sudden death of coronary atherosclerotic heart disease group were significantly higher than the sudden death of hypersensitivity group and death of craniocerebral injury group （ P <0.05）. The difference of the expression level of BNP between the sudden death of hypersensitivity group and the death of craniocerebral injury group had no statistical significance （ P >0.05）. The combined detection of the mast cell tryptase and BNP in myocardium is expected to provide help for the forensic differential diagnosis of sudden death due to hypersensitivity and coronary atherosclerotic heart disease. Copyright© by the Editorial Department of Journal of Forensic Medicine

Genetics Home Reference: sudden infant death with dysgenesis of the testes syndrome

MedlinePlus

... Facebook Twitter Home Health Conditions SIDDT Sudden infant death with dysgenesis of the testes syndrome Printable PDF ... view the expand/collapse boxes. Description Sudden infant death with dysgenesis of the testes syndrome ( SIDDT ) is ...

Talking heads or talking eyes? Effects of head orientation and sudden onset gaze cues on attention capture.

PubMed

van der Wel, Robrecht P; Welsh, Timothy; Böckler, Anne

2018-01-01

The direction of gaze towards or away from an observer has immediate effects on attentional processing in the observer. Previous research indicates that faces with direct gaze are processed more efficiently than faces with averted gaze. We recently reported additional processing advantages for faces that suddenly adopt direct gaze (abruptly shift from averted to direct gaze) relative to static direct gaze (always in direct gaze), sudden averted gaze (abruptly shift from direct to averted gaze), and static averted gaze (always in averted gaze). Because changes in gaze orientation in previous study co-occurred with changes in head orientation, it was not clear if the effect is contingent on face or eye processing, or whether it requires both the eyes and the face to provide consistent information. The present study delineates the impact of head orientation, sudden onset motion cues, and gaze cues. Participants completed a target-detection task in which head position remained in a static averted or direct orientation while sudden onset motion and eye gaze cues were manipulated within each trial. The results indicate a sudden direct gaze advantage that resulted from the additive role of motion and gaze cues. Interestingly, the orientation of the face towards or away from the observer did not influence the sudden direct gaze effect, suggesting that eye gaze cues, not face orientation cues, are critical for the sudden direct gaze effect.

State of the art in forensic investigation of sudden cardiac death.

PubMed

Oliva, Antonio; Brugada, Ramon; D'Aloja, Ernesto; Boschi, Ilaria; Partemi, Sara; Brugada, Josep; Pascali, Vincenzo L

2011-03-01

The sudden death of a young person is a devastating event for both the family and community. Over the last decade, significant advances have been made in understanding both the clinical and genetic basis of sudden cardiac death. Many of the causes of sudden death are due to genetic heart disorders, which can lead to both structural (eg, hypertrophic cardiomyopathy) and arrhythmogenic abnormalities (eg, familial long QT syndrome, Brugada syndrome). Most commonly, sudden cardiac death can be the first presentation of an underlying heart problem, leaving the family at a loss as to why an otherwise healthy young person has died. Not only is this a tragic event for those involved, but it also presents a great challenge to the forensic pathologist involved in the management of the surviving family members. Evaluation of families requires a multidisciplinary approach, which should include cardiologists, a clinical geneticist, a genetic counselor, and the forensic pathologist directly involved in the sudden death case. This multifaceted cardiac genetic service is crucial in the evaluation and management of the clinical, genetic, psychological, and social complexities observed in families in which there has been a young sudden cardiac death. The present study will address the spectrum of structural substrates of cardiac sudden death with particular emphasis given to the possible role of forensic molecular biology techniques in identifying subtle or even merely functional disorders accounting for electrical instability.

Experimental tests of a superposition hypothesis to explain the relationship between the vestibuloocular reflex and smooth pursuit during horizontal combined eye-head tracking in humans

NASA Technical Reports Server (NTRS)

Huebner, W. P.; Leigh, R. J.; Seidman, S. H.; Thomas, C. W.; Billian, C.; DiScenna, A. O.; Dell'Osso, L. F.

1992-01-01

1. We used a modeling approach to test the hypothesis that, in humans, the smooth pursuit (SP) system provides the primary signal for cancelling the vestibuloocular reflex (VOR) during combined eye-head tracking (CEHT) of a target moving smoothly in the horizontal plane. Separate models for SP and the VOR were developed. The optimal values of parameters of the two models were calculated using measured responses of four subjects to trials of SP and the visually enhanced VOR. After optimal parameter values were specified, each model generated waveforms that accurately reflected the subjects' responses to SP and vestibular stimuli. The models were then combined into a CEHT model wherein the final eye movement command signal was generated as the linear summation of the signals from the SP and VOR pathways. 2. The SP-VOR superposition hypothesis was tested using two types of CEHT stimuli, both of which involved passive rotation of subjects in a vestibular chair. The first stimulus consisted of a "chair brake" or sudden stop of the subject's head during CEHT; the visual target continued to move. The second stimulus consisted of a sudden change from the visually enhanced VOR to CEHT ("delayed target onset" paradigm); as the vestibular chair rotated past the angular position of the stationary visual stimulus, the latter started to move in synchrony with the chair. Data collected during experiments that employed these stimuli were compared quantitatively with predictions made by the CEHT model. 3. During CEHT, when the chair was suddenly and unexpectedly stopped, the eye promptly began to move in the orbit to track the moving target. Initially, gaze velocity did not completely match target velocity, however; this finally occurred approximately 100 ms after the brake onset. The model did predict the prompt onset of eye-in-orbit motion after the brake, but it did not predict that gaze velocity would initially be only approximately 70% of target velocity. One possible explanation for this discrepancy is that VOR gain can be dynamically modulated and, during sustained CEHT, it may assume a lower value. Consequently, during CEHT, a smaller-amplitude SP signal would be needed to cancel the lower-gain VOR. This reduction of the SP signal could account for the attenuated tracking response observed immediately after the brake. We found evidence for the dynamic modulation of VOR gain by noting differences in responses to the onset and offset of head rotation in trials of the visually enhanced VOR.(ABSTRACT TRUNCATED AT 400 WORDS).

Gastrointestinal causes of sudden unexpected death: A review.

PubMed

Menezes, Ritesh G; Ahmed, Saba; Pasha, Syed Bilal; Hussain, Syed Ather; Fatima, Huda; Kharoshah, Magdy A; Madadin, Mohammed

2018-01-01

Gastrointestinal conditions are a less common cause of sudden unexpected death when compared to other conditions such as cardiovascular conditions, but they are equally important. Various congenital and acquired gastrointestinal conditions that have resulted in sudden unexpected death are discussed. The possible lethal mechanisms behind each condition, along with any associated risk factors or secondary diseases, have been described. Through this article, we aim to highlight the need for physicians to prevent death in such conditions by ensuring that subclinical cases are diagnosed correctly before it is too late and by providing timely and efficacious treatment to the patient concerned. In addition, this review would certainly benefit the forensic pathologist while dealing with cases of sudden unexpected death due to gastrointestinal causes. This article is a review of the major gastrointestinal causes of sudden unexpected death. In addition, related fatal cases encountered occasionally in forensic autopsy practice are also included. There are several unusual and rare causes of life-threatening gastrointestinal bleeding that may lead to sudden unexpected death to cover all the entities in detail. Nevertheless, this article is a general guide to the topic of gastrointestinal causes of sudden unexpected death.

Sudden Cardiac Arrest in Athletic Medicine

PubMed Central

Kyle, James M.; Ellis, James M.; Cantwell, John; Courson, Ron; Medlin, Ron

2001-01-01

Objective: To emphasize the importance of decreasing the response time by a trained target responder to increase the survival rate among athletes experiencing sudden cardiac arrest at an athletic event. Background: Death due to sudden cardiac arrest that is witnessed is preventable in many cases. However, most people who experience this condition die because of a prolonged response time from onset of the fatal arrhythmia to defibrillation by trained treatment providers. If athletic trainers or other members of the athletic care medical team are trained as target responders and equipped with automated electronic defibrillators, they can immediately treat an athlete who experiences a sudden, life-threatening tachyarrhythmia. This prompt response to the life-threatening emergency should result in a higher survival rate. Description: We review the causes of sudden cardiac arrest during athletic events, note some unusual clinical presentations, discuss improved methods of response and new equipment for treatment, and define the athletic trainer's role as a target responder trained to treat people experiencing sudden cardiac arrest at an athletic event. Clinical Advantages: An athletic care team willing to become part of an emergency response team can help improve the survival rate of athletes experiencing sudden cardiac arrest at an athletic event. PMID:12937464

F-MARC: promoting the prevention and management of sudden cardiac arrest in football

PubMed Central

Kramer, Efraim Benjamin; Dvorak, J; Schmied, C; Meyer, T

2015-01-01

Sudden cardiac death is the most common cause of unnatural death in football. To prevent and urgently manage sudden cardiac arrest on the football field-of-play, F-MARC (FIFA Medical and Research Centre) has been fully committed to a programme of research, education, standardisation and practical implementation. This strategy has detected football players at medical risk during mandatory precompetition medical assessments. Additionally, FIFA has (1) sponsored internationally accepted guidelines for the interpretation of an athlete's ECG, (2) developed field-of-play-specific protocols for the recognition, response, resuscitation and removal of a football player having sudden cardiac arrest and (3) introduced and distributed the FIFA medical emergency bag which has already resulted in the successful resuscitation of a football player who had a sudden cardiac arrest on the field-of-play. Recently FIFA, in association with the Institute of Sports and Preventive Medicine in Saarbrücken, Germany, established a worldwide Sudden Death Registry with a view to documenting fatal events on the football field-of-play. These activities by F-MARC are testimony to FIFA's continued commitment to minimising sudden cardiac arrest while playing football. PMID:25878076

Exploring links between greenspace and sudden unexpected death: a spatial analysis

EPA Science Inventory

Greenspace has been increasingly recognized as having numerous health benefits. However, its effects are unknown concerning sudden unexpected death (SUD), commonly referred to as sudden cardiac death, which constitutes a large proportion of mortality in the United States. Because...

Residual entanglement and sudden death: A direct connection

NASA Astrophysics Data System (ADS)

de Oliveira, J. G. G.; Peixoto de Faria, J. G.; Nemes, M. C.

2011-11-01

We explore the results of [V. Coffman, et al., Phys. Rev. A 61 (2000) 052306] derived for general tripartite states in a dynamical context. We study a class of physically motivated tripartite systems. We show that whenever entanglement sudden death occurs in one of the partitions residual entanglement will appear. For fourpartite systems however, the appearance of residual entanglement is not conditioned by sudden death of entanglement. We can only say that if sudden death of entanglement occurs in some partition there will certainly be residual entanglement.

The link between rapid enigmatic amphibian decline and the globally emerging chytrid fungus.

PubMed

Lötters, Stefan; Kielgast, Jos; Bielby, Jon; Schmidtlein, Sebastian; Bosch, Jaime; Veith, Michael; Walker, Susan F; Fisher, Matthew C; Rödder, Dennis

2009-09-01

Amphibians are globally declining and approximately one-third of all species are threatened with extinction. Some of the most severe declines have occurred suddenly and for unknown reasons in apparently pristine habitats. It has been hypothesized that these "rapid enigmatic declines" are the result of a panzootic of the disease chytridiomycosis caused by globally emerging amphibian chytrid fungus. In a Species Distribution Model, we identified the potential distribution of this pathogen. Areas and species from which rapid enigmatic decline are known significantly overlap with those of highest environmental suitability to the chytrid fungus. We confirm the plausibility of a link between rapid enigmatic decline in worldwide amphibian species and epizootic chytridiomycosis.

Ar-40 to Ar-39 dating of pseudotachylites from the Witwatersrand basin, South Africa, with implications for the formation of the Vredefort Dome

NASA Technical Reports Server (NTRS)

Trieloff, M.; Kunz, J.; Jessberger, E. K.; Reimold, W. U.; Boer, R. H.; Jackson, M. C.

1992-01-01

The formation of the Vredefort Dome, a structure in excess of 100 km in diameter and located in the approximate center of the Witwatersrand basin, is still the subject of lively geological controversy. It is widely accepted that its formation seems to have taken place in a single sudden event, herein referred to as the Vredefort event, accompanied by the release of gigantic amounts of energy. It is debated, however, whether this central event was an internal one, i.e., a cryptoexplosion triggered by volcanic or tectonic processes, or the impact of an extraterrestrial body. The results of this debate are presented.

Ambient ammonia measurements using laser photo-acoustic spectroscopy

NASA Technical Reports Server (NTRS)

Aldridge, M. D., III; Copeland, G. E.; Harward, C. N.

1981-01-01

Ammonia concentrations reached minimal levels (approximately 0.1 ppb) in early winter, followed by a sudden later winter increase. A direct relationship between ambient ammonia levels and air temperature was inferred from the data (linear correlation coefficient r=0.53). Ammonia concentrations were determined to be directly related to the absolute humidity of the air (r=0.72); a weaker relationship between ammonia concentrations and relative humidity was discovered (r=0.37). The data also indicated that ammonia levels were generally higher within continental air masses than those of maritime origin. Soil parameters such as pH and moisture content were found to have a major bearing on the release of gaseous ammonia from soils in the region.

Sleeping beauties in pediatrics.

PubMed

Završnik, Jernej; Kokol, Peter

2016-10-01

Sleeping beauties (SBs) in science have been known for few decades; however, it seems that only recently have they become popular. An SB is a publication that "sleeps" for a long time and then almost suddenly awakes and becomes highly cited. SBs present interesting findings in science. Pediatrics research literature has not yet been analyzed for their presence, and 5 pediatrics SBs were discovered in this research. Their prevalence was approximately 0.011%. Some environments or periods are more "SB fertile" than others: 3 of 5 SBs were published in the journal Pediatrics, 4 originated from the United States, and 4 were published in the period from 1992 to 1993. No institutions or authors published more than 1 SB.

[Diagnostic of secondary hypertension in clinical practice].

PubMed

Somlóová, Z; Rosa, J; Petrák, O; Strauch, B; Zelinka, T; Holaj, R; Widimský, J

2011-09-01

Arterial hypertension is a common worldwide disease with a prevalence of approximately 26%. Secondary cause is known in 5-10% of patients with hypertension. We should think of secondary hypertension in all patients with resistant hypertension, in patients with sudden deterioration in the control of hypertension and in patients with laboratory and clinical signs of diseases associated with secondary hypertension. It is important to distinguish between secondary hypertension and pseudo-resistance (noncompliance to treatment, white coat syndrome). Secondary causes of hypertension can be divided into endocrine (primary aldosteronism, pheochromocytoma, hypercortisolism, hyperparathyreoidism), renal - renovascular and renal parenchymal hypertension, and other causes as sleep apnoe syndrome, hypertension in pregnancy, coarctation of the aorta and intracranial tumors.

Cardiac pathologic findings reveal a high rate of sudden cardiac death of undetermined etiology in younger women.

PubMed

Chugh, Sumeet S; Chung, Kiyon; Zheng, Zhi-Jie; John, Benjamin; Titus, Jack L

2003-10-01

Between 1989 and 1998 there was a 21% increase in estimated sudden cardiac death among US women aged 35 to 44 years. In contrast, the sudden cardiac death rate in age-matched men showed a decreasing trend (-2.8%). Due to under-representation of younger adults in published autopsy series, etiologies of sudden cardiac death merit further investigation. We reviewed autopsy and detailed cardiac pathologic findings in younger women (age 35-44 years) from a 270-patient, 13-year (1984-1996) autopsy series of sudden cardiac death, and performed comparisons with findings in age-matched men. Women aged 35 to 44 years constituted 32% of all women in the series compared to men, who constituted 24% of total men (P =.004 vs women). A presumptive cause of sudden cardiac death could not be determined in 13 women (50%). Among women, 6 cases (22%) had significant coronary artery disease. Findings in others included coronary artery anomalies (n = 3), myocarditis (n = 2), hypertrophic cardiomyopathy (n = 1), coronary artery dissection (n = 1) and accessory pathway (n = 1). In younger men, a presumptive cause of sudden cardiac death remained undetermined in only 24% (P =.025 vs younger women), and coronary artery disease accounted for 40% of cases. In younger women, despite autopsy and detailed cardiac pathologic examination, an attributable cause of sudden cardiac death was not determined in 50% of cases; a 2-fold increase compared to men of the same age. Given the dynamic and multifactorial nature of sudden cardiac death, comprehensive population-based investigations are likely to be necessary to further investigate this unexpected sex-based disparity.

A sudden death risk score specifically for hypertension: based on 25 648 individual patient data from six randomized controlled trials.

PubMed

Le, Hai-Ha; Subtil, Fabien; Cerou, Marc; Marchant, Ivanny; Al-Gobari, Muaamar; Fall, Mor; Mimouni, Yanis; Kassaï, Behrouz; Lindholm, Lars; Thijs, Lutgarde; Gueyffier, François

2017-11-01

To construct a sudden death risk score specifically for hypertension (HYSUD) patients with or without cardiovascular history. Data were collected from six randomized controlled trials of antihypertensive treatments with 8044 women and 17 604 men differing in age ranges and blood pressure eligibility criteria. In total, 345 sudden deaths (1.35%) occurred during a mean follow-up of 5.16 years. Risk factors of sudden death were examined using a multivariable Cox proportional hazards model adjusted on trials. The model was transformed to an integer system, with points added for each factor according to its association with sudden death risk. Antihypertensive treatment was not associated with a reduction of the sudden death risk and had no interaction with other factors, allowing model development on both treatment and placebo groups. A risk score of sudden death in 5 years was built with seven significant risk factors: age, sex, SBP, serum total cholesterol, cigarette smoking, diabetes, and history of myocardial infarction. In terms of discrimination performance, HYSUD model was adequate with areas under the receiver operating characteristic curve of 77.74% (confidence interval 95%, 74.13-81.35) for the derivation set, of 77.46% (74.09-80.83) for the validation set, and of 79.17% (75.94-82.40) for the whole population. Our work provides a simple risk-scoring system for sudden death prediction in hypertension, using individual data from six randomized controlled trials of antihypertensive treatments. HYSUD score could help assessing a hypertensive individual's risk of sudden death and optimizing preventive therapeutic strategies for these patients.

Preprohypocretin polymorphisms in Parkinson disease patients reporting "sleep attacks".

PubMed

Rissling, Ida; Körner, Yvonne; Geller, Frank; Stiasny-Kolster, Karin; Oertel, Wolfgang H; Möller, J Carsten

2005-07-01

Previously, we found a significant association between the dopamine D2 receptor gene polymorphism Taq IA and sudden onset of sleep in patients with Parkinson disease. Here we evaluated the association between the preprohypocretin (-909T/C), (-22C/T), and (-20C/A) polymorphisms and sudden onset of sleep in the same population of patients with Parkinson disease. We conducted an association study analyzing the distribution of preprohypocretin polymorphisms in Germanic, caucasian Parkinson disease patients with and without sudden onset of sleep, matched according to drug therapy, disease duration, sex, and age. Movement disorders section at a university hospital. 132 Parkinson disease patients with sudden onset of sleep and 132 Parkinson disease patients without sudden onset of sleep. Blood samples were taken from each participant and used for DNA extraction. Polymorphisms were analyzed by established polymerase chain reaction protocols or direct sequencing. The variant allele T of the (-909T/C) preprohypocretin polymorphism was more commonly found in Parkinson disease patients with sudden onset of sleep. Statistical analysis showed that there were significant differences in the genotype (P = .024) and allele (P = .018) distribution between both groups. For heterozygous and homozygous carriers of allele T, the genotype relative-risk estimates for the presence of sudden onset of sleep were 2.01 (95% confidence interval: 0.76-5.34) and 2.81 (95% confidence interval: 1.09-7.25), respectively. Our results show a significant association between the (-909T/C) preprohypocretin polymorphism and sudden onset of sleep in Parkinson disease. However, we could not demonstrate any interaction between the Taq IA and (-909T/C) polymorphisms with respect to the occurrence of sudden onset of sleep, suggesting that multiple genetic factors may contribute to the pathogenesis of this phenomenon.

Is adenosine associated with sudden death in schizophrenia? A new framework linking the adenosine pathway to risk of sudden death.

PubMed

Gadelha, Ary; Zugman, André; Calzavara, Mariana Bendlin; de Mendonça Furtado, Remo Holanda; Scorza, Fulvio Alexandre; Bressan, Rodrigo Afonsecca

2018-01-01

Schizophrenia is associated with an increased mortality from cardiovascular disease. Relatively few studies have assessed the putative association of schizophrenia pathophysiology with sudden death. Low adenosine levels have been associated with schizophrenia. In cardiology, increased mortality among patients with congestive heart failure has been associated with genetic polymorphisms that potentially lead to lower adenosine levels. Thus, we hypothesize that adenosine could link schizophrenia and cardiovascular mortality, with decreased adenosine levels leading to increased vulnerability to hyperexcitability following hypoxic insults, increasing the odds of fatal arrhythmias. Low adenosine levels might also lead to a small increase in overall mortality rates and a major increase in the sudden death rate. This hypothesis paves the way for further investigation of the increased cardiac mortality associated with schizophrenia. Potentially, a better characterization of adenosine-related mechanisms of sudden death in schizophrenia could lead to new evidence of factors leading to sudden death in the general population. Copyright © 2017. Published by Elsevier Ltd.

The molecular autopsy: an indispensable step following sudden cardiac death in the young?

PubMed Central

Boczek, Nicole J.; Tester, David J.; Ackerman, Michael J.

2013-01-01

Annually thousands of sudden deaths involving young individuals (< 35 years of age) remain unexplained following a complete medicolegal investigation that includes an autopsy. In fact, epidemiological studies have estimated that over half of sudden deaths involving previously healthy young individuals have no morphological abnormalities identifiable at autopsy. Cardiac channelopathies associated with structurally normal hearts such as long QT syndrome (LQTS), catecholaminergic polymorphic ventricular tachycardia (CPVT), and Brugada syndrome (BrS), leave no evidence to be found at autopsy, leaving investigators to only speculate that a lethal arrhythmia might lie at the heart of a sudden unexplained death (SUD). In cases of autopsy-negative SUD, continued investigation, through the use of a cardiological and genetic evaluation of first- or second-degree relatives and/or a molecular autopsy, may pinpoint the underlying mechanism attributing to the sudden death and allow for the identification of living family members with the pathogenic substrate that renders them vulnerable to an increased risk for cardiac events, including sudden death. PMID:22993115

Major Life Events as Potential Triggers of Sudden Cardiac Arrest

PubMed Central

Wicks, April F; Lumley, Thomas; Lemaitre, Rozenn N; Sotoodehnia, Nona; Rea, Thomas D; McKnight, Barbara; Strogatz, David S; Bovbjerg, Viktor E; Siscovick, David S

2012-01-01

Background We investigated recent loss of or separation from afamily member or friend and risk of sudden cardiac arrest. Methods Our case-crossover study included 490 apparently-healthy married residents of King County, Washington, who suffered sudden cardiac arrest between 1988 and 2005. We compared exposure to spouse-reported family/friend events occurring ≤ 1 month before sudden cardiac arrest with events occurring n the previous 5 months. We evaluated potential effect modification by habitual vigorous physical activity. Results Recent family/friend events were associated with a higher risk of sudden cardiac arrest (odds ratio (OR) = 1.6 [95% confidence interval (CI) = 1.1-2.4]). ORs for cases with and without habitual vigorous physical activity were 1.1 (0.6-2.2) and 2.0 (1.2-3.1), respectively, (interaction P = 0.02). Conclusions These results suggest family/friend events may trigger sudden cardiac arrest and raise the hypothesis that habitual vigorous physical activity may lower susceptibility to these potential triggers. PMID:22415111

Major life events as potential triggers of sudden cardiac arrest.

PubMed

Wicks, April F; Lumley, Thomas; Lemaitre, Rozenn N; Sotoodehnia, Nona; Rea, Thomas D; McKnight, Barbara; Strogatz, David S; Bovbjerg, Viktor E; Siscovick, David S

2012-05-01

We investigated the risk of sudden cardiac arrest in association with the recent loss of, or separation from, a family member or friend. Our case-crossover study included 490 apparently healthy married residents of King County, Washington, who suffered sudden cardiac arrest between 1988 and 2005. We compared exposure to spouse-reported family/friend events occurring ≤ 1 month before sudden cardiac arrest with events occurring in the previous 5 months. We evaluated potential effect modification by habitual vigorous physical activity. Recent family/friend events were associated with a higher risk of sudden cardiac arrest (odds ratio [OR] = 1.6; 95% confidence interval [CI] = 1.1-2.4). ORs for cases with and without habitual vigorous physical activity were 1.1 (0.6-2.2) and 2.0 (1.2-3.1), respectively (interaction P = 0.02). These results suggest family/friend events may trigger sudden cardiac arrest and raise the hypothesis that habitual vigorous physical activity may lower susceptibility to these potential triggers.

Sudden cardiac death in haemodialysis: clinical epidemiology and mechanisms.

PubMed

Banerjee, Debasish

Sudden cardiac death, which causes premature loss of lives on haemodialysis of the elderly, youths and even children; cannot be prevented, because the aetiology is poorly understood and effective interventions are yet unknown. Improving our knowledge of mechanisms causing sudden cardiac death in haemodialysis patients may help us to design better interventions; and clinical epidemiology of sudden cardiac death could be an important tool to further guide human and animal studies. This review researches the clinical epidemiology of sudden cardiac death to suggest possible mechanisms, although they require further studies. The research shows how traditional cardiovascular risk factors such as age, diabetes and smoking have an impact; non-traditional risk factors such as inflammation, mineral-bone disease and even uraemia itself have higher impact; and how cardiac structural, functional and electrocardiographic markers predict sudden cardiac death in dialysis patients. More in-depth human and animal studies, guided with existing knowledge, are necessary to better understand the mechanisms and design successful interventions. Copyright © 2016 Elsevier Inc. All rights reserved.

Sudden oronasal bleeding in a young child.

PubMed

Hey, Edmund

2008-10-01

Sudden severe upper-airway obstruction occurring in a hospital setting can sometimes precipitate an episode of acute haemorrhagic pulmonary oedema. A review of 197 published case reports shows that the presenting feature is almost always the sudden appearance of blood stained fluid coming up through the larynx or out through the mouth and nose of an adult or child in obvious respiratory distress. Such overt features are seen in 10-15% of cases of sudden severe, but sub-lethal, upper-airway obstruction. Signs normally appear within minutes once the obstruction is relieved but are occasionally only recognized after 1-4 h. All signs and symptoms usually resolve within 12-24 h. Other causes of acute pulmonary haemorrhage are rare in young children. If what looks like blood is seen in, or coming from, the mouth or nose of a previously healthy young child who has suddenly become distressed and started to struggle for breath, that child has most probably suffered an episode of acute pulmonary oedema, and the commonest precipitating cause is sudden upper-airway obstruction.

Toroidal standing waves excited by a storm sudden commencement - DE 1 observations

NASA Technical Reports Server (NTRS)

Cahill, L. J., Jr.; Lin, N. G.; Engebretson, M. J.; Waite, J. H.; Sugiura, M.

1990-01-01

A 74-nT sudden commencement on July 13, 1982, was observed in the magnetosphere, with instruments on the Dynamics Explorer 1 satellite. Inbound, near L = 4.5, the satellite was located at 1524 magnetic local time and 20 deg magnetic latitude. The sudden commmencement established a strong, east-west oscillation, with 100-s period, which was observed in the magnetic field, the electric field, and the plasma flow velocity records. There was also a compressional component of this 100-s oscillation and a rapidly damped 300-s compressional pulsation. The compressional oscillations may be an evidence of cavity resonances, excited by the sudden commencement. The cavity waves may, in turn, couple to toroidal waves in field line resonance at the satellite location. In addition, the sudden commencement caused the onset of waves with frequencies from 0.1 up to at least 0.5 Hz. The observations are compared with similar reports from earlier pulsations related to sudden commencements.

Sudden cardiac death and sarcoidosis of the heart in a young patient.

PubMed

Jotterand, Morgane; Grabherr, Silke; Lobrinus, Johannes Alexandre; Michaud, Katarzyna

Sarcoidosis is a granulomatous disease of unknown etiology affecting any organ, microscopically characterized by noncaseating granulomata. Cardiac involvement in sarcoidosis has been reported. It might be symptomatic or not and even revealed by sudden death. Heart conduction system is rarely investigated at autopsy, even in cases of sudden cardiac death. We present a case of a 32-year-old woman who died suddenly. The examination of the heart conduction system revealed a cardiac sarcoidosis that could explain the sudden death. The review of clinical data of the patient revealed some symptoms consistent/in agreement with this hypothesis. Cardiac sarcoidosis remains a diagnostic challenge and can be easily missed, clinically and pathologically. The retrospective analysis of clinical data and autopsy results of fatal and unusual cases might help to better understand sarcoidosis and its clinical presentations. Examination of the cardiac conduction system is crucial in selected cases of sudden cardiac death. Copyright © 2017 Elsevier Inc. All rights reserved.

Nonesterified fatty acids and risk of sudden cardiac death in older adults.

PubMed

Djoussé, Luc; Biggs, Mary L; Ix, Joachim H; Kizer, Jorge R; Lemaitre, Rozenn N; Sotoodehnia, Nona; Zieman, Susan J; Mozaffarian, Dariush; Tracy, Russell P; Mukamal, Kenneth J; Siscovick, David S

2012-04-01

Although nonesterified fatty acids (NEFA) have been positively associated with coronary heart disease risk factors, limited and inconsistent data are available on the relation between NEFA and sudden cardiac death. Using a prospective design, we studied 4657 older men and women (mean age, 75 years) from the Cardiovascular Health Study (1992-2006) to evaluate the association between plasma NEFA and the risk of sudden cardiac death in older adults. Plasma concentrations of NEFA were measured using established enzymatic methods, and sudden death was adjudicated using medical records, death certificates, proxy interview, and autopsy reports. We used Cox proportional hazard models to estimate multivariable-adjusted relative risks. During a median follow-up of 10.0 years, 221 new cases of sudden cardiac death occurred. In a multivariable model adjusting for age, sex, race, clinic site, alcohol intake, smoking, prevalent coronary heart disease and heart failure, and self-reported health status, relative risks (95% confidence interval) for sudden cardiac death were 1.0 (ref), 1.15 (0.81-1.64), 1.06 (0.72-1.55), and 0.91 (0.60-1.38) across consecutive quartiles of NEFA concentration. In secondary analyses restricted to the first 5 years of follow-up, we also did not observe a statistically significant association between plasma NEFA and sudden cardiac death. Our data do not provide evidence for an association between plasma NEFA measured late in life and the risk of sudden cardiac death in older adults.

Sudden Unexpected Death in Fetal Life Through Early Childhood

PubMed Central

Kinney, Hannah C.; Willinger, Marian

2016-01-01

In March 2015, the Eunice Kennedy Shriver National Institute of Child Health and Human Development held a workshop entitled “Sudden Unexpected Death in Fetal Life Through Early Childhood: New Opportunities.” Its objective was to advance efforts to understand and ultimately prevent sudden deaths in early life, by considering their pathogenesis as a potential continuum with some commonalities in biological origins or pathways. A second objective of this meeting was to highlight current issues surrounding the classification of sudden infant death syndrome (SIDS), and the implications of variations in the use of the term “SIDS” in forensic practice, and pediatric care and research. The proceedings reflected the most current knowledge and understanding of the origins and biology of vulnerability to sudden unexpected death, and its environmental triggers. Participants were encouraged to consider the application of new technologies and “omics” approaches to accelerate research. The major advances in delineating the intrinsic vulnerabilities to sudden death in early life have come from epidemiologic, neural, cardiac, metabolic, genetic, and physiologic research, with some commonalities among cases of unexplained stillbirth, SIDS, and sudden unexplained death in childhood observed. It was emphasized that investigations of sudden unexpected death are inconsistent, varying by jurisdiction, as are the education, certification practices, and experience of death certifiers. In addition, there is no practical consensus on the use of “SIDS” as a determination in cause of death. Major clinical, forensic, and scientific areas are identified for future research. PMID:27230764

Substance P/Neurokinin 1 and Trigeminal System: A Possible Link to the Pathogenesis in Sudden Perinatal Deaths

PubMed Central

Mehboob, Riffat

2017-01-01

Sudden demise of a healthy fetus or a neonate is a very tragic episode in the life of parents. These deaths have been a mystery since ages but still remain unexplained. This review proposes the involvement of trigeminal nerve, neurotransmitter substance P (SP), and its receptor neurokinin 1 (NK-1R) in regulation of cardiorespiratory control in fetuses and newborns. Anomalies and immaturity of neuroregulatory systems such as trigeminal system in medulla oblongata of brainstem may provide a possible mechanism of sudden perinatal deaths. Vulnerable infants are born with respiratory center immaturity which in combination with any stressor such as cold, hypoxia, and smoking may lead to cessation of breathing and ventilatory response. SP/NK-1R may be involved in regulating the ventilatory control in neonates while it is decreased in fetal and adult life in humans, and any alterations from these may lead to irreversible sleep apnea and fatal breathing, ultimately sudden death. This review summarizes the studies performed to highlight the expression of SP or NK-1R in sudden perinatal deaths and proposes the involvement of trigeminal ganglion along with its nerve and SP/NK-1R expression alteration as one of the possible pathophysiological underlying mechanism. However, further studies are required to explore the role of SP, NK-1R, and trigeminal system in the pathogenesis of sudden infant deaths, sudden intrauterine deaths, stillbirths, and sudden deaths later in human life. PMID:28348544

Substance P/Neurokinin 1 and Trigeminal System: A Possible Link to the Pathogenesis in Sudden Perinatal Deaths.

PubMed

Mehboob, Riffat

2017-01-01

Sudden demise of a healthy fetus or a neonate is a very tragic episode in the life of parents. These deaths have been a mystery since ages but still remain unexplained. This review proposes the involvement of trigeminal nerve, neurotransmitter substance P (SP), and its receptor neurokinin 1 (NK-1R) in regulation of cardiorespiratory control in fetuses and newborns. Anomalies and immaturity of neuroregulatory systems such as trigeminal system in medulla oblongata of brainstem may provide a possible mechanism of sudden perinatal deaths. Vulnerable infants are born with respiratory center immaturity which in combination with any stressor such as cold, hypoxia, and smoking may lead to cessation of breathing and ventilatory response. SP/NK-1R may be involved in regulating the ventilatory control in neonates while it is decreased in fetal and adult life in humans, and any alterations from these may lead to irreversible sleep apnea and fatal breathing, ultimately sudden death. This review summarizes the studies performed to highlight the expression of SP or NK-1R in sudden perinatal deaths and proposes the involvement of trigeminal ganglion along with its nerve and SP/NK-1R expression alteration as one of the possible pathophysiological underlying mechanism. However, further studies are required to explore the role of SP, NK-1R, and trigeminal system in the pathogenesis of sudden infant deaths, sudden intrauterine deaths, stillbirths, and sudden deaths later in human life.

Perceived Stigma of Sudden Bereavement as a Risk Factor for Suicidal Thoughts and Suicide Attempt: Analysis of British Cross-Sectional Survey Data on 3387 Young Bereaved Adults.

PubMed

Pitman, Alexandra; Rantell, Khadija; Marston, Louise; King, Michael; Osborn, David

2017-03-09

The sudden death of a friend or relative, particularly by suicide, is a risk factor for suicide. People who experience sudden bereavement report feeling highly stigmatised by the loss, potentially influencing access to support. We assessed whether perceived stigma following sudden bereavement is associated with suicidal thoughts and suicide attempt. We analysed cross-sectional survey data on 3387 young adults bereaved by the sudden death of a close contact. We tested the association of high versus low perceived stigma (on the stigma sub-scale of the Grief Experience Questionnaire) with post-bereavement suicidal ideation and suicide attempt, using random effects logistic regression, adjusting for socio-demographic factors, pre-bereavement psychopathology, and mode of sudden bereavement (natural causes/unnatural causes/suicide). Subjects with high perceived stigma scores were significantly more likely to report post-bereavement suicidal thoughts (adjusted odds ratio (AOR) = 2.74; 95% confidence interval (CI) = 1.93-3.89) and suicide attempt (AOR = 2.73; 95% CI = 2.33-3.18) than those with low stigma scores. People who feel highly stigmatised by a sudden bereavement are at increased risk of suicidal thoughts and suicide attempt, even taking into account prior suicidal behaviour. General practitioners, bereavement counsellors, and others who support people bereaved suddenly, should consider inquiring about perceived stigma, mental wellbeing, and suicidal thoughts, and directing them to appropriate sources of support.

Proceedings of the sudden oak death fifth science symposium

Treesearch

Susan J. Frankel; John T. Kliejunas; Katharine M. Palmieri; Janice M. Alexander

2013-01-01

The Proceedings of the Sudden Oak Death Fifth Science Symposium provides an update on research to address sudden oak death, caused by the exotic, quarantine pathogen, Phytophthora ramorum. Over 60 submissions present national and international investigations covering pathogen biology, biosecurity, genetics, monitoring, fire ecology, and diagnostics...

Sudden Fiction: What Is It?

ERIC Educational Resources Information Center

Tindall, James

Initially an assignment for a library science class, this paper presents various definitions of the current creative writing phenomenon called "sudden fiction" (very short short stories with concise character sketches, and terse tales limited in length to several pages). The paper includes: (1) a list of well regarded sudden fiction…

Sudden Oak Death - Western (Pest Alert)

Treesearch

Susan Frankel

2002-01-01

Tens of thousands of tanoak (Lithocarpus densiflorus), coast live oak (Quercus agrifolia), California black oak (Quercus kelloggii), Shreve oak (Quercus parvula var. shrevei), and madrone (Arbutus menziesii) have been killed by a newly identified species, Phytophthora ramorum, which causes Sudden Oak Death. Sudden Oak Death was first reported in 1995 in central coastal...

Sudden oak death and Phytophthora ramorum: a summary of the literature

Treesearch

John T. Kliejunas

2010-01-01

Sudden oak death and Phytophthora ramorum, both first recognized about a decade ago, have been the subject of hundreds of scientific and popular press articles. This document presents a comprehensive, concise summary of sudden oak death and P. ramorum research findings and management activities. Topics covered include...

Sudden Infant Death Syndrome.

ERIC Educational Resources Information Center

Barnett, Henry L.; And Others

There is a growing body of evidence that Sudden Infant Death Syndrome (SIDS) victims are not completely normal and healthy, as was once believed. A variety of new information from several disciplines strongly suggests that the infant who dies suddenly and unexpectedly may do so because of subtle developmental, neurologic, cardiorespiratory, and…

Athletes at Risk for Sudden Cardiac Death

ERIC Educational Resources Information Center

Subasic, Kim

2010-01-01

High school athletes represent the largest group of individuals affected by sudden cardiac death, with an estimated incidence of once or twice per week. Structural cardiovascular abnormalities are the most frequent cause of sudden cardiac death. Athletes participating in basketball, football, track, soccer, baseball, and swimming were found to…

[Genetics of sudden unexplained death].

PubMed

Campuzano, Oscar; Allegue, Catarina; Brugada, Ramon

2014-03-20

Sudden unexplained death is defined by death without a conclusive diagnosis after autopsy and it is responsible for a large percentage of sudden deaths. The progressive interaction between genetics and forensics in post-mortem studies has identified inheritable alterations responsible for pathologies associated with arrhythmic sudden death. The genetic diagnosis of the deceased enables the undertaking of preventive measures in family members, many of them asymptomatic but at risk. The implications of this multidisciplinary translational medical approach are complex, requiring the dedication of a specialized team. Copyright © 2013 Elsevier España, S.L. All rights reserved.

Sudden unexpected infant death: differentiating natural from abusive causes in the emergency department.

PubMed

Bechtel, Kirsten

2012-10-01

Sudden unexpected infant deaths (SUIDs) are deaths in infants younger than 12 months that occur suddenly, unexpectedly, and without obvious cause in the emergency department (ED). Sudden infant death syndrome, the leading cause of SUID in the United States, is much more common, but fatal child abuse and neglect have been sometimes mistaken for sudden infant death syndrome. The distinction between these 2 entities can only be made after a thorough investigation of the scene, interview of caregivers, and a complete forensic autopsy. Development of ED guidelines for the reporting and evaluation of SUID, in collaboration with the local medical examiner and child death review teams, will enable ED practitioners to collect important information in a compassionate manner that will be valuable to the investigating personnel.

Relationship between sudden natural death and abdominal fat evaluated on postmortem CT scans.

PubMed

Kaichi, Y; Sakane, H; Higashibori, H; Honda, Y; Tatsugami, F; Baba, Y; Iida, M; Awai, K

2017-06-01

This study examined the association between sudden natural death and abdominal fat using postmortem computed tomography (CT) scans. Postmortem CT images at the umbilical level of 241 subjects were used to measure abdominal areas of subcutaneous- and visceral fat, the rate of visceral fat and the waist circumference. Of the study subjects, 174 died of sudden natural death (130 men and 44 women), and 67 died of different causes (46 men and 21 women). All were between 40 and 75 years of age. Logistic regression analysis was performed to identify independent abdominal parameters associated with sudden natural death. By univariate analysis, the areas of subcutaneous and visceral fat were significantly larger in sudden natural death than who died of different causes (subcutaneous fat, odds ratio [OR] = 1.004, 95% confidence interval [CI] = 1.000-1.007, p  = 0.03; visceral fat, OR = 1.008, 95% CI = 1.003-1.013, p  < 0.01). Multivariate analysis showed that the area of visceral fat was an independent factor associated with the risk of sudden natural death (OR = 1.008, 95% CI = 1.002-1.015, p  = 0.02). Postmortem CT revealed that sudden natural death was related to abdominal fat deposits.

F-MARC: promoting the prevention and management of sudden cardiac arrest in football.

PubMed

Kramer, Efraim Benjamin; Dvorak, J; Schmied, C; Meyer, T

2015-05-01

Sudden cardiac death is the most common cause of unnatural death in football. To prevent and urgently manage sudden cardiac arrest on the football field-of-play, F-MARC (FIFA Medical and Research Centre) has been fully committed to a programme of research, education, standardisation and practical implementation. This strategy has detected football players at medical risk during mandatory precompetition medical assessments. Additionally, FIFA has (1) sponsored internationally accepted guidelines for the interpretation of an athlete's ECG, (2) developed field-of-play-specific protocols for the recognition, response, resuscitation and removal of a football player having sudden cardiac arrest and (3) introduced and distributed the FIFA medical emergency bag which has already resulted in the successful resuscitation of a football player who had a sudden cardiac arrest on the field-of-play. Recently FIFA, in association with the Institute of Sports and Preventive Medicine in Saarbrücken, Germany, established a worldwide Sudden Death Registry with a view to documenting fatal events on the football field-of-play. These activities by F-MARC are testimony to FIFA's continued commitment to minimising sudden cardiac arrest while playing football. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Excitation of interstellar hydrogen chloride

NASA Technical Reports Server (NTRS)

Neufild, David A.; Green, Sheldon

1994-01-01

We have computed new rate coefficients for the collisional excitation of HCl by He, in the close-coupled formalism and using an interaction potential determined recently by Willey, Choong, & DeLucia. Results have been obtained for temperatures between 10 K and 300 K. With the use of the infinite order sudden approximation, we have derived approximate expressions of general applicability which may be used to estimate how the rate constant for a transition (J to J prime) is apportioned among the various hyperfine states F prime of the final state J prime. Using these new rate coefficients, we have obtained predictions for the HCl rotational line strengths expected from a dense clump of interstellar gas, as a function of the HCl fractional abundance. Over a wide range of HCl abundances, we have found that the line luminosities are proportional to abundance(exp 2/3), a general result which can be explained using a simple analytical approximation. Our model for the excitation of HCl within a dense molecular cloud core indicates that the J = 1 goes to 0 line strengths measured by Blake, Keene, & Phillips toward the Orion Molecular Cloud (OMC-1) imply a fractional abundance n(HCl)/n(H2) approximately 2 x 10(exp -9), a value which amounts to only approximately 0.3% of the cosmic abundance of chlorine nuclei. Given a fractional abundance of 2 x 10(exp -9), the contribution of HCl emission to the total radiative cooling of a dense clump is small. For Orion, we predict a flux approximately 10(exp -19) W/sq cm for the HCl J = 3 goes to 2 line near 159.8 micrometers, suggesting that the strength of this line could be measured using the Infrared Space Observatory.

Healthy-side dominance of middle- and long-latency neuromagnetic fields in idiopathic sudden sensorineural hearing loss.

PubMed

Li, L P H; Shiao, A S; Chen, L F; Niddam, D M; Chang, S Y; Lien, C F; Lee, S K; Hsieh, J C

2006-08-01

Any lesion along the neural axis may induce a subsequent functional reorganization at the level above. The present study used magnetoencephalography to investigate auditory-evoked magnetic fields [a component of the middle-latency auditory evoked fields peaking at approximately 50 ms (P50m) and a component of the long-latency auditory evoked fields peaking at approximately 100 ms (N100m)] on stimulation of both healthy and affected ears in patients with acute unilateral idiopathic sudden sensorineural hearing loss (ISSNHL) of moderate degree in order to elucidate the functional plasticity of the auditory system. Sixteen right-handed, previously untreated adult patients with acute unilateral left (n = 8) or right (n = 8) ISSNHL of moderate degree were studied. Sixteen right-handed healthy volunteers with normal hearing served as control. Auditory neuromagnetic responses, measured by a whole-head 306-channel neuromagnetometer, were detected by monaural tone stimulation applied to affected and healthy ears, respectively, in different sessions. Intragroup and intergroup interhemispheric differences of peak dipole strengths and latencies of P50m and N100m, respectively, to monaural tones were evaluated. Healthy-side amplitude dominance of both P50m and N100m was found in ISSNHL, i.e. contralateral dominance was preserved on affected-ear stimulation but ipsilateral dominance was seen on healthy-ear stimulation. The phenomena could be attributed to the combined contralateral attenuation and ipsilateral enhancement of P50m and N100m activity in response to healthy-ear stimulation. Our findings confirmed that functional modulation can occur within the first few tens of milliseconds of evoked response at the auditory cortex in ISSNHL. The mechanisms of healthy-side dominance might be ascribed to a functional retune of auditory pathways, i.e. conjoined contralateral inhibition and ipsilateral excitation of the auditory pathway in response to healthy-ear stimulation. The effect could be registered in cortical responses.

The response of Antarctica MLT region for the recent Sudden Stratospheric Warming (SSW) over Southern Hemisphere (SH): An overview

NASA Astrophysics Data System (ADS)

Eswaraiah, S.; Kim, Y.; Lee, J.; Kim, J. H.; Venkat Ratnam, M.; Riggin, D. M.; Vijaya Bhaskara Rao, S.

2017-12-01

A minor Sudden Stratospheric Warming (SSW) was noticed in the southern hemisphere (SH) during the September (day 259) 2010 along with two episodic warmings in early August (day 212) and late October (day 300) 2010. The signature of the mesosphere and lower thermosphere (MLT) response was detected using the ground based and space borne observations along with the model predictions. The changes in the mesosphere wind field were studied from the observations of both meteor radar and MF radar located at King Sejong Station (62.22°S, 58.78°W) and Rothera (68oS, 68oW), Antarctica, respectively. The zonal winds in the mesosphere reversed approximately a week before the September SSW occurrence. We have also analyzed the MLT tides using both the radars and noticed strong enhancement of semi-diurnal tide (SDT) a few days later the cessation of 2010 SSW. We note the similar enhancement during the 2002 major SSW. Specifically, the SDT amplitude enhancement is greater for the 2010 SSW than 2002 SSW. We found that strong 14-16 day PWs prevailed prior to the 2010 minor SSW and disappeared suddenly after the SSW in the mesosphere by generating the quasi-secondary waves of periodicity 3-9 days. The mesosphere wind reversal is also noticed in "Specified Dynamics" version of Whole Atmosphere Community Climate Model (SD-WACCM) and Ground-to-topside model of Atmosphere and Ionosphere for Aeronomy (GAIA) simulations. The similar zonal wind weakening/reversal in the lower thermosphere between 100 and 140 km are simulated by GAIA. Further, we observed the mesospheric cooling in consistency with SSWs using Microwave Limb Sounder (MLS) data. However, the GAIA simulations showed warming between 130 and 140 km after few days of SSW. Thus, the observation and model simulation indicate for the first time that the 2010 minor SSW also affects dynamics of the MLT region over SH in a manner similar to the 2002 major SSW.

Sudden Cardiac Arrest during Participation in Competitive Sports.

PubMed

Landry, Cameron H; Allan, Katherine S; Connelly, Kim A; Cunningham, Kris; Morrison, Laurie J; Dorian, Paul

2017-11-16

The incidence of sudden cardiac arrest during participation in sports activities remains unknown. Preparticipation screening programs aimed at preventing sudden cardiac arrest during sports activities are thought to be able to identify at-risk athletes; however, the efficacy of these programs remains controversial. We sought to identify all sudden cardiac arrests that occurred during participation in sports activities within a specific region of Canada and to determine their causes. In this retrospective study, we used the Rescu Epistry cardiac arrest database (which contains records of every cardiac arrest attended by paramedics in the network region) to identify all out-of-hospital cardiac arrests that occurred from 2009 through 2014 in persons 12 to 45 years of age during participation in a sport. Cases were adjudicated as sudden cardiac arrest (i.e., having a cardiac cause) or as an event resulting from a noncardiac cause, on the basis of records from multiple sources, including ambulance call reports, autopsy reports, in-hospital data, and records of direct interviews with patients or family members. Over the course of 18.5 million person-years of observation, 74 sudden cardiac arrests occurred during participation in a sport; of these, 16 occurred during competitive sports and 58 occurred during noncompetitive sports. The incidence of sudden cardiac arrest during competitive sports was 0.76 cases per 100,000 athlete-years, with 43.8% of the athletes surviving until they were discharged from the hospital. Among the competitive athletes, two deaths were attributed to hypertrophic cardiomyopathy and none to arrhythmogenic right ventricular cardiomyopathy. Three cases of sudden cardiac arrest that occurred during participation in competitive sports were determined to have been potentially identifiable if the athletes had undergone preparticipation screening. In our study involving persons who had out-of-hospital cardiac arrest, the incidence of sudden cardiac arrest during participation in competitive sports was 0.76 cases per 100,000 athlete-years. The occurrence of sudden cardiac arrest due to structural heart disease was uncommon during participation in competitive sports. (Funded by the National Heart, Lung, and Blood Institute and others.).

Congenital and hereditary causes of sudden cardiac death in young adults: diagnosis, differential diagnosis, and risk stratification.

PubMed

Stojanovska, Jadranka; Garg, Anubhav; Patel, Smita; Melville, David M; Kazerooni, Ella A; Mueller, Gisela C

2013-01-01

Sudden cardiac death is defined as death from unexpected circulatory arrest-usually a result of cardiac arrhythmia-that occurs within 1 hour of the onset of symptoms. Proper and timely identification of individuals at risk for sudden cardiac death and the diagnosis of its predisposing conditions are vital. A careful history and physical examination, in addition to electrocardiography and cardiac imaging, are essential to identify conditions associated with sudden cardiac death. Among young adults (18-35 years), sudden cardiac death most commonly results from a previously undiagnosed congenital or hereditary condition, such as coronary artery anomalies and inherited cardiomyopathies (eg, hypertrophic cardiomyopathy, arrhythmogenic right ventricular cardiomyopathy [ARVC], dilated cardiomyopathy, and noncompaction cardiomyopathy). Overall, the most common causes of sudden cardiac death in young adults are, in descending order of frequency, hypertrophic cardiomyopathy, coronary artery anomalies with an interarterial or intramural course, and ARVC. Often, sudden cardiac death is precipitated by ventricular tachycardia or fibrillation and may be prevented with an implantable cardioverter defibrillator (ICD). Risk stratification to determine the need for an ICD is challenging and involves imaging, particularly echocardiography and cardiac magnetic resonance (MR) imaging. Coronary artery anomalies, a diverse group of congenital disorders with a variable manifestation, may be depicted at coronary computed tomographic angiography or MR angiography. A thorough understanding of clinical risk stratification, imaging features, and complementary diagnostic tools for the evaluation of cardiac disorders that may lead to sudden cardiac death is essential to effectively use imaging to guide diagnosis and therapy.

Non-locality Sudden Death in Tripartite Systems

NASA Astrophysics Data System (ADS)

Jaeger, Gregg; Ann, Kevin

2009-03-01

Bell non-locality sudden death is the disappearance of non-local properties in finite times under local phase noise, which decoheres states only in the infinite-time limit. We consider the relationship between decoherence, disentanglement, and Bell non-locality sudden death in bipartite and tripartite systems in specific large classes of state preparation.

77 FR 69485 - Proposed Data Collections Submitted for Public Comment and Recommendations

Federal Register 2010, 2011, 2012, 2013, 2014

2012-11-19

... days of this notice. Proposed Project Determining Causes of Sudden, Unexpected Infant Death: A National... immediately obvious. Half of these sudden unexpected infant deaths (SUID) are attributed to Sudden Infant Death Syndrome (SIDS), which is the leading cause of death in infants between one and twelve months of...

Exercise-Related Sudden Death: Risks and Causes (Part 1 of 2).

ERIC Educational Resources Information Center

Van Camp, Steven P.

1988-01-01

The causes of exercise-related sudden death are discussed. Multiple structural cardiovascular diseases are the primary cause of death in athletes under 30; severe coronary artery disease is the culprit in deaths of those over 30. These diseases and the mechanisms of sudden death, as well as preventive measures, are detailed. (JL)

Strong, sudden cooling alleviates the inflammatory responses in heat-stressed dairy cows based on iTRAQ proteomic analysis

NASA Astrophysics Data System (ADS)

Cheng, Jianbo; Min, Li; Zheng, Nan; Fan, Caiyun; Zhao, Shengguo; Zhang, Yangdong; Wang, Jiaqi

2018-02-01

This study was designed to investigate the effects of sudden cooling on the physiological responses of 12 heat-stressed Holstein dairy cows using an isobaric tags for relative and absolute quantification (iTRAQ) labeling approach. Plasma samples were collected from these cows during heat stress (HS), and after strong, sudden cooling in the summer (16 days later). We compared plasma proteomic data before and after sudden cooling to identify the differentially abundant proteins. The results showed that sudden cooling in summer effectively alleviated the negative consequences of HS on body temperature and production variables. Expressions of plasma hemoglobin alpha and hemoglobin beta were upregulated, whereas lipopolysaccharide-binding protein (LBP) and haptoglobin were downregulated in this process. The increase of hemoglobin after cooling may improve oxygen transport and alleviate the rise in respiration rates in heat-stressed dairy cows. The decrease of LBP and haptoglobin suggests that the inflammatory responses caused by HS are relieved after cooling. Our findings provide new insight into the physiological changes that occur when heat-stressed dairy cows experience strong, sudden cooling.

Child Protective Services referrals in cases of sudden infant death: a 10-year, population-based analysis in San Diego County, California.

PubMed

Krous, Henry F; Haas, Elisabeth A; Manning, Julie M; Deeds, Anita; Silva, Patricia D; Chadwick, Amy E; Stanley, Christina

2006-08-01

The potential diagnostic significance of prior family referral to Child Protective Services (CPS) in cases of sudden infant death is unknown. Therefore, the authors retrospectively searched for CPS data for the 5-year referral history on all 533 families whose infants died suddenly from Sudden Infant Death Syndrome (SIDS), other natural diseases, accidents, or inflicted injuries and underwent postmortem examination by the medical examiner during a 10-year period. No family had more than one infant death. At least 27% of the families in each group had at least one CPS referral. The data suggest that a family's referral to CPS prior to their sudden death of their infant does not increase the likelihood that it was caused by inflicted injuries, and prior referral should not preclude a diagnosis of SIDS. The authors recommend future prospective studies that include refined exposure histories and that are large enough to have sufficient statistical power to compare family CPS referrals and outcomes in groups of infants who died suddenly with a matched group of living infants.

Trends in socioeconomic inequalities in risk of sudden infant death syndrome, other causes of infant mortality, and stillbirth in Scotland: population based study

PubMed Central

Wood, Angela M; Pasupathy, Dharmintra; Pell, Jill P; Fleming, Michael

2012-01-01

Objectives To compare changes in inequalities in sudden infant death syndrome with other causes of infant mortality and stillbirth in Scotland, 1985-2008. Design Retrospective cohort study. Setting Scotland 1985-2008, analysed by four epochs of six years. Participants Singleton births of infants with birth weight >500 g born at 28-43 weeks’ gestation. Main outcome measures Sudden infant death syndrome, other causes of postneonatal infant death, neonatal death, and stillbirth. Odds ratios expressed as the association across the range of seven categories of Carstairs deprivation score. Results The association between deprivation and the risk of all cause stillbirth and infant death varied between the four epochs (P=0.04). This was wholly explained by variation in the risk of sudden infant death syndrome (P<0.001 for interaction). Among women living in areas of low deprivation, there was a sharp decline in the rate of sudden infant death syndrome from 1990 to 1993. Among women living in areas of high deprivation, there was a slower decline in sudden infant death syndrome rates between 1992 and 2004. Consequently, the odds ratio for the association between socioeconomic deprivation and sudden infant death syndrome increased from 2.04 (95% confidence interval 1.53 to 2.72) in 1985-90, to 7.52 (4.62 to 12.25) in 1991-6, and 9.50 (5.46 to 16.53) in 1997-2002 but fell to 1.78 (0.87 to 3.65) in 2002-8. The interaction remained significant after adjustment for maternal characteristics. Conclusion The rate of sudden infant death syndrome declined throughout Scotland in the early 1990s. The decline had a later onset and was slower among women living in areas of high deprivation, probably because of slower uptake of recommended changes in infant sleeping position. The effect was to create a strong independent association between deprivation and sudden infant death syndrome where one did not exist before. PMID:22427307

Trends in socioeconomic inequalities in risk of sudden infant death syndrome, other causes of infant mortality, and stillbirth in Scotland: population based study.

PubMed

Wood, Angela M; Pasupathy, Dharmintra; Pell, Jill P; Fleming, Michael; Smith, Gordon C S

2012-03-16

To compare changes in inequalities in sudden infant death syndrome with other causes of infant mortality and stillbirth in Scotland, 1985-2008. Retrospective cohort study. Scotland 1985-2008, analysed by four epochs of six years. Singleton births of infants with birth weight >500 g born at 28-43 weeks' gestation. Sudden infant death syndrome, other causes of postneonatal infant death, neonatal death, and stillbirth. Odds ratios expressed as the association across the range of seven categories of Carstairs deprivation score. The association between deprivation and the risk of all cause stillbirth and infant death varied between the four epochs (P=0.04). This was wholly explained by variation in the risk of sudden infant death syndrome (P<0.001 for interaction). Among women living in areas of low deprivation, there was a sharp decline in the rate of sudden infant death syndrome from 1990 to 1993. Among women living in areas of high deprivation, there was a slower decline in sudden infant death syndrome rates between 1992 and 2004. Consequently, the odds ratio for the association between socioeconomic deprivation and sudden infant death syndrome increased from 2.04 (95% confidence interval 1.53 to 2.72) in 1985-90, to 7.52 (4.62 to 12.25) in 1991-6, and 9.50 (5.46 to 16.53) in 1997-2002 but fell to 1.78 (0.87 to 3.65) in 2002-8. The interaction remained significant after adjustment for maternal characteristics. The rate of sudden infant death syndrome declined throughout Scotland in the early 1990s. The decline had a later onset and was slower among women living in areas of high deprivation, probably because of slower uptake of recommended changes in infant sleeping position. The effect was to create a strong independent association between deprivation and sudden infant death syndrome where one did not exist before.

The assessment of material-handling strategies in dealing with sudden loading: the effect of uneven ground surface on trunk biomechanical responses.

PubMed

Zhou, Jie; Ning, Xiaopeng; Nimbarte, Ashish D; Dai, Fei

2015-01-01

As a major risk factor of low back injury, sudden loading often occurs when performing manual material-handling tasks on uneven ground surfaces. Therefore, the purpose of the current study was to investigate the effects of a laterally slanted ground on trunk biomechanical responses during sudden loading events. Thirteen male subjects were subjected to suddenly released loads of 3.4 and 6.8 kg, while standing on a laterally slanted ground of 0°, 15° and 30°. The results showed that 8.3% and 5.6% larger peak L5/S1 joint compression forces were generated in the 30° condition compared with the 0° and 15° conditions, respectively. The increase of L5/S1 joint moment in the 30° condition was 8.5% and 5.0% greater than the 0° and 15° conditions, respectively. Findings of this study suggest that standing on a laterally slanted ground could increase mechanical loading on the spine when experiencing sudden loading. Practitioner Summary: Sudden loading is closely related to occupational low back injuries. The results of this study showed that the increase of slanted ground angle and magnitude of load significantly increase the mechanical loading on the spine during sudden loading. Therefore, both of these two components should be controlled in task design.

Sudden death in young athletes: HCM or ARVC?

PubMed

Firoozi, Sam; Sharma, Sanjay; Hamid, M Shoaib; McKenna, William J

2002-01-01

Sudden non-traumatic death in young athletes is due to underlying congenital/inherited cardiac diseases in over 80% of cases. The two commonest conditions leading to sudden cardiac death in athletes below the age of 25 years are hypertrophic cardiomyopathy (HCM) and arrhythmogenic right ventricular cardiomyopathy (ARVC). Hypertrophic cardiomyopathy is caused by mutations in genes, which code for sarcomeric contractile proteins. It can present with symptoms such as palpitation, presyncope or syncope. In a small number of cases, sudden death is the first clinical manifestation of the condition. It is well established that HCM accounts for over half of all cases sudden cardiac death in young individuals below 25 years of age. The management of HCM broadly encompasses symptom control, familial evaluation and the prevention of sudden death. Arrhythmogenic right ventricular cardiomyopathy, similarly, is a genetic disorder of the heart muscle and leads to symptoms such as palpitation and syncope and more rarely sudden death. The diagnosis of ARVC is most likely underestimated due to the lack of a single diagnostic test and subtle morphological changes in some cases. The diagnosis is based on clinical and family history and non-invasive investigations. The physiological adaptations seen in some athletes, as a response to physical training, may resemble phenotypically mild forms HCM and ARVC. Therefore, a diagnostic algorithm enabling this differentiation would be of importance especially bearing in mind the consequences of a misdiagnosis.

Detection of a sudden change of the field time series based on the Lorenz system.

PubMed

Da, ChaoJiu; Li, Fang; Shen, BingLu; Yan, PengCheng; Song, Jian; Ma, DeShan

2017-01-01

We conducted an exploratory study of the detection of a sudden change of the field time series based on the numerical solution of the Lorenz system. First, the time when the Lorenz path jumped between the regions on the left and right of the equilibrium point of the Lorenz system was quantitatively marked and the sudden change time of the Lorenz system was obtained. Second, the numerical solution of the Lorenz system was regarded as a vector; thus, this solution could be considered as a vector time series. We transformed the vector time series into a time series using the vector inner product, considering the geometric and topological features of the Lorenz system path. Third, the sudden change of the resulting time series was detected using the sliding t-test method. Comparing the test results with the quantitatively marked time indicated that the method could detect every sudden change of the Lorenz path, thus the method is effective. Finally, we used the method to detect the sudden change of the pressure field time series and temperature field time series, and obtained good results for both series, which indicates that the method can apply to high-dimension vector time series. Mathematically, there is no essential difference between the field time series and vector time series; thus, we provide a new method for the detection of the sudden change of the field time series.

Sudden death in eating disorders

PubMed Central

Jáuregui-Garrido, Beatriz; Jáuregui-Lobera, Ignacio

2012-01-01

Eating disorders are usually associated with an increased risk of premature death with a wide range of rates and causes of mortality. “Sudden death” has been defined as the abrupt and unexpected occurrence of fatality for which no satisfactory explanation of the cause can be ascertained. In many cases of sudden death, autopsies do not clarify the main cause. Cardiovascular complications are usually involved in these deaths. The purpose of this review was to report an update of the existing literature data on the main findings with respect to sudden death in eating disorders by means of a search conducted in PubMed. The most relevant conclusion of this review seems to be that the main causes of sudden death in eating disorders are those related to cardiovascular complications. The predictive value of the increased QT interval dispersion as a marker of sudden acute ventricular arrhythmia and death has been demonstrated. Eating disorder patients with severe cardiovascular symptoms should be hospitalized. In general, with respect to sudden death in eating disorders, some findings (eg, long-term eating disorders, chronic hypokalemia, chronically low plasma albumin, and QT intervals >600 milliseconds) must be taken into account, and it must be highlighted that during refeeding, the adverse effects of hypophosphatemia include cardiac failure. Monitoring vital signs and performing electrocardiograms and serial measurements of plasma potassium are relevant during the treatment of eating disorder patients. PMID:22393299

Gas dispersal potential of infant bedding of sudden death cases (II): Mathematical simulation of O2 deprivation around the face of infant mannequin model.

PubMed

Sakai, Jun; Takahashi, Shirushi; Funayama, Masato

2009-04-01

We assessed O(2) gas deprivation potential of bedding that had actually been used by 26 infants diagnosed with sudden unexpected infant death using FiCO(2) time course of baby mannequin model. All cases were the same ones in our poster paper (I). Mathematically, time-FiCO(2) (t) graphs were given as FiCO(2) (t)=C(1-e(Dt)). Here, "C" approximates the maximum FiCO(2) value, while "D" is the velocity to reach maximum FiCO(2). FiO(2) in a potential space around the mannequin's nares was estimated using a formula: FiO(2)=0.21-FiCO(2)/RQ. RQ is the respiratory quotient, and the normal human value is 0.8. The graph pattern of FiO(2) is roughly the inverse of the FiCO(2) time course. Four cases showed the bottom of estimated FiO(2) to be more than 15%, 15 were 15-6%, and the other seven were 6% or less. Considering the minimal tissue stores of O(2), changes in FiO(2) may be affected by both CO(2) production and gas movement around the infant's face. Especially, the latter seven cases may suggest the participation of the role not only of CO(2) accumulation but also of the decrease of O(2) around the face.

Clotting and fibrinolytic changes after firefighting activities.

PubMed

Smith, Denise L; Horn, Gavin P; Petruzzello, Steven J; Fahey, George; Woods, Jeffrey; Fernhall, Bo

2014-03-01

Approximately 45%-50% of all duty-related deaths among firefighters are due to sudden cardiovascular events, and a disproportionate number of these fatalities occur after strenuous fire suppression activities. The objective of this study is to evaluate the effect of strenuous firefighting activities on platelets, coagulation, and fibrinolytic activity and to document the extent to which these variables recovered 2 h after completion of the firefighting activity. Firefighters performed 18 min of simulated firefighting activities in a training structure that contained live fires. After firefighting activities, firefighters were provided with fluid and allowed to cool down and then recovered for 2 h in an adjacent room. Blood samples were obtained prefirefighting, postfirefighting, and 2 h postfirefighting. Platelet number, platelet activity, and coagulatory potential increased immediately postfirefighting and many variables (platelet function, partial thromboplastin time, and factor VIII) reflected a procoagulatory state even after 2 h of recovery. Fibrinolysis, as reflected by tissue plasminogen activator, also was enhanced immediately postfirefighting but returned to baseline values by 2 h postfirefighting. In contrast, inhibition of fibrinolysis, as evidenced by a reduction in plasminogen activator inhibitor-1, was depressed at 2 h postfirefighting. Firefighting resulted in elevated coagulatory and fibrinolytic activity. However, 2 h postfirefighting, tissue plasminogen activator returned to baseline and coagulatory potential remained elevated. The procoagulatory state that exists after firefighting may provide a mechanistic link to the reports of sudden cardiac events after strenuous fire suppression activities.

Results from sudden loss of vacuum on scaled superconducting radio frequency cryomodule experiment

NASA Astrophysics Data System (ADS)

Dalesandro, Andrew A.; Dhuley, Ram C.; Theilacker, Jay C.; Van Sciver, Steven W.

2014-01-01

Superconducting radio frequency (SRF) cavities for particle accelerators are at risk of failure due to sudden loss of vacuum (SLV) adjacent to liquid helium (LHe) spaces. To better understand this failure mode and its associated risks an experiment is designed to test the longitudinal effects of SLV within the beam tube of a scaled SRF cryomodule that has considerable length relative to beam tube cross section. The scaled cryomodule consists of six individual SRF cavities each roughly 350 mm long, initially cooled to 2 K by a superfluid helium bath and a beam tube pumped to vacuum. A fast-acting solenoid valve is used to simulate SLV on the beam tube, from which point it takes over 3 s for the beam tube pressure to equalize with atmosphere, and 30 s for the helium space to reach the relief pressure of 4 bara. A SLV longitudinal effect in the beam tube is evident in both pressure and temperature data, but interestingly the temperatures responds more quickly to SLV than do the pressures. It takes 500 ms (roughly 100 ms per cavity) for the far end of the 2 m long beam tube to respond to a pressure increase compared to 300 ms for temperature (approximately 50 ms per cavity). The paper expands upon these and other results to better understand the longitudinal effect for SRF cryomodules due to SLV.

Identification of Fusarium virguliforme FvTox1-Interacting Synthetic Peptides for Enhancing Foliar Sudden Death Syndrome Resistance in Soybean

PubMed Central

Wang, Bing; Swaminathan, Sivakumar; Bhattacharyya, Madan K.

2015-01-01

Soybean is one of the most important crops grown across the globe. In the United States, approximately 15% of the soybean yield is suppressed due to various pathogen and pests attack. Sudden death syndrome (SDS) is an emerging fungal disease caused by Fusarium virguliforme. Although growing SDS resistant soybean cultivars has been the main method of controlling this disease, SDS resistance is partial and controlled by a large number of quantitative trait loci (QTL). A proteinacious toxin, FvTox1, produced by the pathogen, causes foliar SDS. Earlier, we demonstrated that expression of an anti-FvTox1 single chain variable fragment antibody resulted in reduced foliar SDS development in transgenic soybean plants. Here, we investigated if synthetic FvTox1-interacting peptides, displayed on M13 phage particles, can be identified for enhancing foliar SDS resistance in soybean. We screened three phage-display peptide libraries and discovered four classes of M13 phage clones displaying FvTox1-interacting peptides. In vitro pull-down assays and in vivo interaction assays in yeast were conducted to confirm the interaction of FvTox1 with these four synthetic peptides and their fusion-combinations. One of these peptides was able to partially neutralize the toxic effect of FvTox1 in vitro. Possible application of the synthetic peptides in engineering SDS resistance soybean cultivars is discussed. PMID:26709700

Adjusting to a sudden “aging” of the lens

PubMed Central

Tregillus, Katherine E.M.; Werner, John S.; Webster, Michael A.

2016-01-01

Color perception is known to remain largely stable across the lifespan despite the pronounced changes in sensitivity from factors such as the progressive brunescence of the lens. However, the mechanisms and timescales controlling these compensatory adjustments are still poorly understood. In a series of experiments, we tracked adaptation in observers after introducing a sudden change in lens density by having observers wear glasses with yellow filters that approximated the average spectral transmittance of a 70-year-old lens. Individuals were young adults and wore the glasses for 5 days for 8 hours per day while engaged in their normal activities. Achromatic settings were measured on a CRT before and after each daily exposure with the lenses on and off, and were preceded by 5 minutes of dark adaptation to control for short-term chromatic adaptation. During each day, there was a large shift in the white settings consistent with a partial compensation for the added lens density. However, there was little to no evidence of an after-image at the end of each daily session, and participants’ perceptual nulls were roughly aligned with the nulls for short-term chromatic adaptation, suggesting a rapid renormalization when the lenses were removed. The long-term drift was also extinguished by brief exposure to a white adapting field. The results point to distinct timescales and potentially distinct mechanisms compensating for changes in the chromatic sensitivity of the observer. PMID:26924924

Validity of Sudden Gains in Acute Phase Treatment of Depression

ERIC Educational Resources Information Center

Vittengl, Jeffrey R.; Clark, Lee Anna; Jarrett, Robin B.

2005-01-01

The authors examined the validity of sudden gains identified with T. Z. Tang and R. J. DeRubeis's (1999) method in 2 clinical data sets that involved treatment of major depressive disorder (N=227). Sudden gains replicated among self- and clinician reports of depressive symptoms and predicted better psychosocial functioning at the acute phase…

Cognitive Changes, Critical Sessions, and Sudden Gains in Cognitive-Behavioral Therapy for Depression

ERIC Educational Resources Information Center

Tang, Tony Z.; DeRubeis, Robert J.; Beberman, Rachel; Pham, Thu

2005-01-01

Using an independent cognitive-behavioral therapy (CBT) data set, the authors replicated T. Z. Tang and R. J. DeRubeis' (1999) discovery of sudden gains--sudden and large decreases in depression severity in a single between-session interval. By incorporating therapy session transcripts, the authors of this study improved the reliability of the…

Sudden Gains during Psychological Treatments of Anxiety and Depression: A Meta-Analysis

ERIC Educational Resources Information Center

Aderka, Idan M.; Nickerson, Angela; Boe, Hans Jakob; Hofmann, Stefan G.

2012-01-01

Objective: The present study quantitatively reviewed the literature on sudden gains in psychological treatments for anxiety and depression. The authors examined the short- and long-term effects of sudden gains on treatment outcome as well as moderators of these effects. Method: The authors conducted a literature search using PubMed, PsycINFO, the…

Rationale and design for the Predictors of Arrhythmic and Cardiovascular Risk in End Stage Renal Disease (PACE) study.

PubMed

Parekh, Rulan S; Meoni, Lucy A; Jaar, Bernard G; Sozio, Stephen M; Shafi, Tariq; Tomaselli, Gordon F; Lima, Joao A; Tereshchenko, Larisa G; Estrella, Michelle M; Kao, W H Linda

2015-04-24

Sudden cardiac death occurs commonly in the end-stage renal disease population receiving dialysis, with 25% dying of sudden cardiac death over 5 years. Despite this high risk, surprisingly few prospective studies have studied clinical- and dialysis-related risk factors for sudden cardiac death and arrhythmic precursors of sudden cardiac death in end-stage renal disease. We present a brief summary of the risk factors for arrhythmias and sudden cardiac death in persons with end-stage renal disease as the rationale for the Predictors of Arrhythmic and Cardiovascular Risk in End Stage Renal Disease (PACE) study, a prospective cohort study of patients recently initiated on chronic hemodialysis, with the overall goal to understand arrhythmic and sudden cardiac death risk. Participants were screened for eligibility and excluded if they already had a pacemaker or an automatic implantable cardioverter defibrillator. We describe the study aims, design, and data collection of 574 incident hemodialysis participants from the Baltimore region in Maryland, U.S.A.. Participants were recruited from 27 hemodialysis units and underwent detailed clinical, dialysis and cardiovascular evaluation at baseline and follow-up. Cardiovascular phenotyping was conducted on nondialysis days with signal averaged electrocardiogram, echocardiogram, pulse wave velocity, ankle, brachial index, and cardiac computed tomography and angiography conducted at baseline. Participants were followed annually with study visits including electrocardiogram, pulse wave velocity, and ankle brachial index up to 4 years. A biorepository of serum, plasma, DNA, RNA, and nails were collected to study genetic and serologic factors associated with disease. Studies of modifiable risk factors for sudden cardiac death will help set the stage for clinical trials to test therapies to prevent sudden cardiac death in this high-risk population.

Risk factors and causes of sudden noncardiac death: A nationwide cohort study in Denmark.

PubMed

Risgaard, Bjarke; Lynge, Thomas Hadberg; Wissenberg, Mads; Jabbari, Reza; Glinge, Charlotte; Gislason, Gunnar Hilmar; Haunsø, Stig; Winkel, Bo Gregers; Tfelt-Hansen, Jacob

2015-05-01

On the performance of an autopsy, sudden deaths may be divided into 2 classifications: (1) sudden cardiac deaths and (2) sudden noncardiac deaths (SNCDs). Families of SNCD victims should not be followed up as a means of searching for cardiac disease. The purpose of this study was to report the risk factors and causes of SNCD. We conducted a retrospective, nationwide study including all deaths between 2000 and 2006 of individuals aged 1-35 years and all deaths between 2007 and 2009 of individuals aged 1-49 years. Two physicians identified all sudden death cases through review of death certificates. Autopsy reports were collected. A multivariable logistic regression model was used to identify both clinical characteristics and risk factors associated with SNCD. We identified 1039 autopsied cases of sudden death, of which 286 (28%) were classified as SNCD. The median age in the SNCD death population was 32 years. Increasing age was inversely associated with SNCD (odds ratio [OR] 0.93, 95% confidence interval [CI] 0.87-0.98). Female sex, in-hospital location, and the absence of cardiac comorbidities were positively associated with SNCD (OR 1.7, 95% CI 1.3-2.3; OR 3.0, 95% CI 2.0-4.4; and OR 4.3, 95% CI 2.5-7.4, respectively). The most common cause of SNCD was pulmonary disease (n = 115 [40%]). Sudden death among individuals aged <50 years was caused by noncardiac diseases in 28% of cases. Risk factors were female sex, age, and the absence of cardiac comorbidities. These data may guide future strategies for the follow-up of family members of nonautopsied sudden death victims, improve risk stratification, and influence public health strategies. Copyright © 2015 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Law enforcement duties and sudden cardiac death among police officers in United States: case distribution study

PubMed Central

Varvarigou, Vasileia; Farioli, Andrea; Korre, Maria; Sato, Sho; Dahabreh, Issa J

2014-01-01

Objective To assess the association between risk of sudden cardiac death and stressful law enforcement duties compared with routine/non-emergency duties. Design Case distribution study (case series with survey information on referent exposures). Setting United States law enforcement. Participants Summaries of deaths of over 4500 US police officers provided by the National Law Enforcement Officers Memorial Fund and the Officer Down Memorial Page from 1984 to 2010. Main outcome measures Observed and expected sudden cardiac death counts and relative risks for sudden cardiac death events during specific strenuous duties versus routine/non-emergency activities. Independent estimates of the proportion of time that police officers spend across various law enforcement duties obtained from surveys of police chiefs and front line officers. Impact of varying exposure assessments, covariates, and missing cases in sensitivity and stability analyses. Results 441 sudden cardiac deaths were observed during the study period. Sudden cardiac death was associated with restraints/altercations (25%, n=108), physical training (20%, n=88), pursuits of suspects (12%, n=53), medical/rescue operations (8%, n=34), routine duties (23%, n=101), and other activities (11%, n=57). Compared with routine/non-emergency activities, the risk of sudden cardiac death was 34-69 times higher during restraints/altercations, 32-51 times higher during pursuits, 20-23 times higher during physical training, and 6-9 times higher during medical/rescue operations. Results were robust to all sensitivity and stability analyses. Conclusions Stressful law enforcement duties are associated with a risk of sudden cardiac death that is markedly higher than the risk during routine/non-emergency duties. Restraints/altercations and pursuits are associated with the greatest risk. Our findings have public health implications and suggest that primary and secondary cardiovascular prevention efforts are needed among law enforcement officers. PMID:25406189

Next of kin’s experiences of sudden and unexpected death from stroke - a study of narratives

PubMed Central

2013-01-01

Background Death always evokes feelings in those close to the afflicted person. When death comes suddenly the time for preparation is minimal and the next of kin have to cope with the situation despite their own sorrow. The suddenness is found to be stressful for the next of kin and communication both with healthcare professionals and information about what has happened has been found helpful. The aim of this study was to illuminate the experiences of next of kin from the sudden and unexpected death of a relative from acute stroke. Methods Data was collected over a 12-month period in 2009–2010. Twelve next of kin of patients cared for in stroke units who died suddenly and unexpectedly from stroke were interviewed using a narrative method. The narratives were analyzed using narrative thematic analysis. Results Three themes emerged showing facets of next of kin’s experiences of a relative’s sudden and unexpected death from stroke: Divided feelings about the sudden and unexpected death; Perception of time and directed attention when keeping vigil; Contradictions and arbitrary memories when searching for understanding. Conclusions To have to live in the aftermath of severe stroke is absolute horror in people’s imagination and death is seen as the lesser of two evils. The sudden and unexpected death totally pervades the next of kin’s life, directs their attention to the dying person and even causes them to forget themselves and their own needs, and leads to difficulties in information intake. It is a challenge for the healthcare professionals to be able to identify the individual needs of the next of kin in this situation. PMID:23590246

Reduced risk of sudden death from chest wall blows (commotio cordis) with safety baseballs.

PubMed

Link, Mark S; Maron, Barry J; Wang, Paul J; Pandian, Natesa G; VanderBrink, Brian A; Estes, N A Mark

2002-05-01

In an experimental model of sudden death from baseball chest wall impact (commotio cordis), we sought to determine if sudden death by baseball impact could be reduced with safety baseballs. Sudden cardiac death can occur after chest wall impact with a baseball (commotio cordis). Whether softer-than-standard (safety) baseballs reduce the risk of sudden death is unresolved from the available human data. In a juvenile swine model, ventricular fibrillation (VF) has been shown to be induced reproducibly by precordial impact with a 30-mph baseball 10 to 30 ms before the T-wave peak, and this likelihood was reduced with the softest safety baseballs (T-balls). To further test whether safety baseballs would reduce the risk of sudden death at velocities more relevant to youth sports competition, we used our swine model of commotio cordis to test baseballs propelled at the 40-mph velocity commonly attained in that sport. Forty animals received up to 3 chest wall impacts at 40 mph during the vulnerable period of repolarization for VF with 1 of 3 different safety baseballs of varying hardness, and also by a standard baseball. Safety baseballs propelled at 40 mph significantly reduced the risk for VF. The softest safety baseballs triggered VF in only 11% of impacts, compared with 19% and 22% with safety baseballs of intermediate hardness, and 69% with standard baseballs. In this experimental model of low-energy chest wall impact, safety baseballs reduced (but did not abolish) the risk of sudden cardiac death. More universal use of these safety baseballs may decrease the risk of sudden death on the playing field for young athletes.

Law enforcement duties and sudden cardiac death among police officers in United States: case distribution study.

PubMed

Varvarigou, Vasileia; Farioli, Andrea; Korre, Maria; Sato, Sho; Dahabreh, Issa J; Kales, Stefanos N

2014-11-18

To assess the association between risk of sudden cardiac death and stressful law enforcement duties compared with routine/non-emergency duties. Case distribution study (case series with survey information on referent exposures). United States law enforcement. Summaries of deaths of over 4500 US police officers provided by the National Law Enforcement Officers Memorial Fund and the Officer Down Memorial Page from 1984 to 2010. Observed and expected sudden cardiac death counts and relative risks for sudden cardiac death events during specific strenuous duties versus routine/non-emergency activities. Independent estimates of the proportion of time that police officers spend across various law enforcement duties obtained from surveys of police chiefs and front line officers. Impact of varying exposure assessments, covariates, and missing cases in sensitivity and stability analyses. 441 sudden cardiac deaths were observed during the study period. Sudden cardiac death was associated with restraints/altercations (25%, n=108), physical training (20%, n=88), pursuits of suspects (12%, n=53), medical/rescue operations (8%, n=34), routine duties (23%, n=101), and other activities (11%, n=57). Compared with routine/non-emergency activities, the risk of sudden cardiac death was 34-69 times higher during restraints/altercations, 32-51 times higher during pursuits, 20-23 times higher during physical training, and 6-9 times higher during medical/rescue operations. Results were robust to all sensitivity and stability analyses. Stressful law enforcement duties are associated with a risk of sudden cardiac death that is markedly higher than the risk during routine/non-emergency duties. Restraints/altercations and pursuits are associated with the greatest risk. Our findings have public health implications and suggest that primary and secondary cardiovascular prevention efforts are needed among law enforcement officers. © Varvarigou et al 2014.

Three-dimensional dynamics of scientific balloon systems in response to sudden gust loadings. [including a computer program user manual

NASA Technical Reports Server (NTRS)

Dorsey, D. R., Jr.

1975-01-01

A mathematical model was developed of the three-dimensional dynamics of a high-altitude scientific research balloon system perturbed from its equilibrium configuration by an arbitrary gust loading. The platform is modelled as a system of four coupled pendula, and the equations of motion were developed in the Lagrangian formalism assuming a small-angle approximation. Three-dimensional pendulation, torsion, and precessional motion due to Coriolis forces are considered. Aerodynamic and viscous damping effects on the pendulatory and torsional motions are included. A general model of the gust field incident upon the balloon system was developed. The digital computer simulation program is described, and a guide to its use is given.

A silent slip event on the deeper Cascadia subduction interface.

PubMed

Dragert, G; Wang, K; James, T S

2001-05-25

Continuous Global Positioning System sites in southwestern British Columbia, Canada, and northwestern Washington state, USA, have been moving landward as a result of the locked state of the Cascadia subduction fault offshore. In the summer of 1999, a cluster of seven sites briefly reversed their direction of motion. No seismicity was associated with this event. The sudden displacements are best explained by approximately 2 centimeters of aseismic slip over a 50-kilometer-by-300-kilometer area on the subduction interface downdip from the seismogenic zone, a rupture equivalent to an earthquake of moment magnitude 6.7. This provides evidence that slip of the hotter, plastic part of the subduction interface, and hence stress loading of the megathrust earthquake zone, can occur in discrete pulses.

Factors Promoting Survival After Prolonged Resuscitation Attempts: A Case of Survival With Good Neurological Outcome Following 60 Minutes of Downtime After Out-of-Hospital Cardiac Arrest.

PubMed

Bell, Douglas; Gluer, Robert; Murdoch, Dale

2018-03-01

Sudden cardiac arrest is a significant cause of death affecting approximately 25,000 people in Australia annually. We present an out-of-hospital cardiac arrest (OHCA) with prolonged down time and recurrent ventricular arrhythmias treated with extra-corporeal membrane oxygenation. The patient survived to hospital discharge with good neurological outcome. The patient's excellent outcome was a result of immediate good quality CPR, high level premorbid function, reversible cause of arrest and rapid access to an ECMO centre. Copyright © 2017 Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) and the Cardiac Society of Australia and New Zealand (CSANZ). Published by Elsevier B.V. All rights reserved.

Comments on filament-disintegration and its relation to other aspects of solar activity.

NASA Technical Reports Server (NTRS)

Dodson, H. W.; Hedeman, E. R.; Rovira De Miceli, M.

1972-01-01

Studies of sudden disintegrations of filaments in solar cycles 19 and 20 (to 1969) indicate that such events occur frequently. Approximately 30% of all large filaments in these cycles disintegrated in the course of their transit across the solar disk. 'Major' flares occurred with above average frequency on the last day on which 141 large disappearing filaments were observed. Relationships between a disintegrating filament on July 10-11, 1959, a prior major flare, a newly formed spot, and concomitant growth of H-alpha plage are presented. Observation of prior descending prominence material apparently directed towards the location of the flare of July 15, 1959 is reported. The development of the filament-associated flare of Feb. 13, 1967 is described.

Electron shakeoff following the β+ decay of +19Ne and +35Ar trapped ions

NASA Astrophysics Data System (ADS)

Fabian, X.; Fléchard, X.; Pons, B.; Liénard, E.; Ban, G.; Breitenfeldt, M.; Couratin, C.; Delahaye, P.; Durand, D.; Finlay, P.; Guillon, B.; Lemière, Y.; Mauger, F.; Méry, A.; Naviliat-Cuncic, O.; Porobic, T.; Quéméner, G.; Severijns, N.; Thomas, J.-C.

2018-02-01

The electron shakeoff of 19F and 35Cl atoms resulting from the β+ decay of +19Ne and +35Ar ions has been investigated using a Paul trap coupled to a time of flight recoil-ion spectrometer. The charge-state distributions of the recoiling daughter nuclei were compared to theoretical calculations based on the sudden approximation and accounting for subsequent Auger processes. The excellent agreement obtained for 35Cl is not reproduced in 19F. The shortcoming is attributed to the inaccuracy of the independent particle model employed to calculate the primary shakeoff probabilities in systems with rather low atomic numbers. This calls for more elaborate calculations, including explicitly the electron-electron correlations.

Spectra for the reemission of attosecond and shorter electromagnetic pulses by multielectron atoms

NASA Astrophysics Data System (ADS)

Makarov, D. N.; Matveev, V. I.

2017-08-01

Based on the analytical solution of the Schrödinger equation, we have considered the reemission of attosecond and shorter electromagnetic pulses by multielectron atoms in the sudden perturbation approximation. We have developed a technique of calculating the spectra for the reemission of attosecond and shorter electromagnetic pulses by neutral multielectron atoms with nuclear charges from 1 to 92. The results are presented in the form of analytical formulas dependent on several coefficients and screening parameters tabulated for all of the atoms whose electron densities are described by the well-known Dirac-Hartree-Fock-Slater model. As examples we have calculated the spectra for the reemission by lithium, carbon, calcium, and iron atoms for two types of incident pulse: Gaussian and "sombrero."

Response of spermatozoa to hyposmotic stress reflects cryopreservation success

DOE Office of Scientific and Technical Information (OSTI.GOV)

Watson, P.F.; Curry, M.R.; Noiles, E.E.

1992-01-01

Spermatozoa of several species were washed and then subjected to dilution in hyposmotic Tyrode's based solutions. The cells were stained with fluorescent viability stains, carboxyfluorescein diacetate and propidium iodide, and proportions with intact plasma membranes determined by flow cytometry or fluorescence microscopy. Fowl spermatozoa remained almost 100% intact until very low osmolality, and then ruptured. Human spermatozoa showed a similar response with only a small decrease in intact cells before the precipitous decline at low osmolality. Bull spermatozoa were more readily disrupted at higher osmolality, some 40% being damaged before the sudden decline at low osmolality. Ram and boar spermatozoamore » were progressively disrupted even at mild hyposmotic stress, showing approximately 50% of cells ruptured at 150 mOsm.« less

Response of spermatozoa to hyposmotic stress reflects cryopreservation success

DOE Office of Scientific and Technical Information (OSTI.GOV)

Watson, P.F.; Curry, M.R.; Noiles, E.E.

1992-06-01

Spermatozoa of several species were washed and then subjected to dilution in hyposmotic Tyrode`s based solutions. The cells were stained with fluorescent viability stains, carboxyfluorescein diacetate and propidium iodide, and proportions with intact plasma membranes determined by flow cytometry or fluorescence microscopy. Fowl spermatozoa remained almost 100% intact until very low osmolality, and then ruptured. Human spermatozoa showed a similar response with only a small decrease in intact cells before the precipitous decline at low osmolality. Bull spermatozoa were more readily disrupted at higher osmolality, some 40% being damaged before the sudden decline at low osmolality. Ram and boar spermatozoamore » were progressively disrupted even at mild hyposmotic stress, showing approximately 50% of cells ruptured at 150 mOsm.« less

Dust Storm Covers Opportunity

NASA Image and Video Library

2018-06-10

This global map of Mars shows a growing dust storm as of June 6, 2018. The map was produced by the Mars Color Imager (MARCI) camera on NASA's Mars Reconnaissance Orbiter spacecraft. The blue dot shows the approximate location of Opportunity. The storm was first detected on June 1. The MARCI camera has been used to monitor the storm ever since. Full dust storms like this one are not surprising, but are infrequent. They can crop up suddenly but last weeks, even months. During southern summer, sunlight warms dust particles, lifting them higher into the atmosphere and creating more wind. That wind kicks up yet more dust, creating a feedback loop that NASA scientists still seek to understand. https://photojournal.jpl.nasa.gov/catalog/PIA22329

Acute otitis media associated bilateral sudden hearing loss: case report and literature review.

PubMed

Smith, A; Gutteridge, I; Elliott, D; Cronin, M

2017-07-01

Sudden sensorineural hearing loss is a rare otological condition with potential for dire outcomes including permanent hearing loss. Although the majority of cases are deemed idiopathic, bilateral sudden sensorineural hearing loss represents a rare subset typically related to systemic conditions, with higher morbidity and mortality. A controversial association with acute otitis media has been reported, with few bilateral cases published in the literature. A very rare case of bilateral sudden sensorineural hearing loss associated with acute otitis media is described, with a review of the literature. The limited evidence available suggests that acute otitis media with tinnitus and/or bacterial pathology may have an increased risk of sudden sensorineural hearing loss, which is consistent with the case described. Although there is no sufficiently powered published evidence to provide definitive treatment guidelines, the literature reviewed suggests that early myringotomy and antibiotics may greatly improve treatment outcomes.

Stimulants and sudden death: what is a physician to do?

PubMed

Wilens, Timothy E; Prince, Jefferson B; Spencer, Thomas J; Biederman, Joseph

2006-09-01

Recently, a US Food and Drug Administration advisory committee raised concerns about cardiovascular risks and sudden death in children and adolescents with attention-deficit/hyperactivity disorder who are receiving stimulants. We comment on the risk of sudden death in children/adolescents taking stimulants compared with population rates, biological plausibility, and known cardiovascular effects of stimulants to determine specific risk. There does not seem to be higher risk of sudden death in stimulant-treated individuals compared with the general population. Although there is evidence of biological plausibility, the known effects of the stimulants on cardiovascular electrophysiology and vital signs seem to be benign. There does not seem to be compelling findings of a medication-specific risk necessitating changes in our stimulant treatment of children and adolescents with attention-deficit/hyperactivity disorder. The use of existing guidelines on the use of stimulants (and psychotropic agents) may identify children, adolescents, and adults who are vulnerable to sudden death.

Sudden unexpected death from oligodendroglioma: a case report and review of the literature.

PubMed

Manousaki, Maria; Papadaki, Helen; Papavdi, Asteria; Kranioti, Elena F; Mylonakis, Panagiotis; Varakis, John; Michalodimitrakis, Manolis

2011-12-01

Sudden and unexpected deaths due to asymptomatic 5 primary brain tumors are extremely rare, with an incidence that ranges from 0.16 to 3.2%. Usually, such tumors are glioblastomas or, less commonly, astrocytomas. Asymptomatic oligodendrogliomas causing sudden death are hardly ever reported among medico-legal investigated cases.We report a rare case of sudden and unexpected death from a previously asymptomatic and undiagnosed, well-differentiated, grade II oligodendrogloioma (WHO classification). According to the autopsy and the microscopic findings brain edema as a result of obstruction of the cerebrospinal fluid flow due to hemorrhagic leakage of the oligodendroglioma is incriminated as the most probable physiopathological mechanism for the sudden death. Diagnosis is mainly based on the special microscopic features of the tumor cells (typical "fried-egg" appearance), interrupted by a dense network of branching capillaries. We discuss further the pathophysiological mechanisms of death and present a short review of literature.

Observation and modeling of energetic particles at synchronous orbit on July 29, 1977

NASA Technical Reports Server (NTRS)

Baker, D. N.; Higbie, P. R.; Fritz, T. A.; Wilken, B.; Stuedemann, W.; Kaye, S. M.; Kivelson, M. G.; Moore, T. E.; Masley, A. J.; Smith, P. H.

1982-01-01

In the 12 hours immediately after a worldwide storm sudden commencement at 0027 UT on July 29, there was a series of at least four magnetospheric substorms, the last and largest of which exhibited an expansion phase onset at approximately 1200 UT. Data from six spacecraft in three general local time groupings (0300, 0700, and 1300 LT) are examined, and vector magnetic field data and energetic electron and ion data from approximately 15 keV to more than 2MeV are employed. Four primary types of studies are carried out: (1) timing and morphology of energetic particle injections; (2) variation of particle phase space densities, using local magnetic field and particle flux data; (3) measurement of boundary motions, using high-energy ion gradient anisotropies; and (4) adiabatic modeling, which included injection, large-scale convection, corotation, and gradient drifts. For the 1200 UT substorms, it is concluded that there was a substantial flux dropout in a broad sector near local midnight because of a large-scale boundary motion, followed by a recovery to a predropout configuration.

Interplanetary and Geomagnetic Consequences of Interacting CMEs of 13 - 14 June 2012

NASA Astrophysics Data System (ADS)

Srivastava, Nandita; Mishra, Wageesh; Chakrabarty, D.

2018-01-01

We report on the kinematics of two interacting CMEs observed on 13 and 14 June 2012. The two CMEs originated from the same active region NOAA 11504. After their launches which were separated by several hours, they were observed to interact at a distance of 100 R_{⊙} from the Sun. The interaction led to a moderate geomagnetic storm at the Earth with minimum D_{st} index of approximately -86 nT. The kinematics of the two CMEs is estimated using data from the Sun Earth Connection Coronal and Heliospheric Investigation (SECCHI) instrument onboard the Solar Terrestrial Relations Observatory (STEREO). Assuming a head-on collision scenario, we find that the collision is inelastic in nature. Further, the signatures of their interaction are examined using the in situ observations obtained by Wind and the Advance Composition Explorer (ACE) spacecraft. It is also found that this interaction event led to the strongest sudden storm commencement (SSC) ({≈ }150 nT) of the present Solar Cycle 24. The SSC was of long duration, approximately 20 hours. The role of interacting CMEs in enhancing the geoeffectiveness is examined.

The OakMapper WebGIS: improved access to sudden oak death spatial data

Treesearch

K. Tuxen; M. Kelly

2008-01-01

Access to timely and accurate sudden oak death (SOD) location data is critical for SOD monitoring, management and research. Several websites (hereafter called the OakMapper sites) associated with sudden oak death monitoring efforts have been maintained with up-todate SOD location information for over five years, providing information and maps of the most current...

[Sport's related sudden death].

PubMed

Carré, François

2014-01-01

Non-traumatic sudden death related to sport is a rare but always dramatic event. Its causes are mainly cardiovascular. Prevention of sudden death depends on effective medical examination involving history, physical examination and resting ECG, as education of athletes who must follow the rules for safe sport practice and lastly training for emergency actions of the population. Copyright © 2014. Published by Elsevier Masson SAS.

Sudden Gains in Cognitive Therapy for Depression: A Replication and Extension

ERIC Educational Resources Information Center

Hardy, Gillian E.; Cahill, Jane; Stiles, William B.; Ispan, Caroline; Macaskill, Norman; Barkham, Michael

2005-01-01

Of 76 clients receiving 8-20 sessions of cognitive therapy (CT) in a joint university and a national health service clinic, 31 experienced sudden gains that appeared very similar to those first reported in clinical trials of CT by T. Z. Tang and R. J. DeRubeis (1999) and subsequently replicated in other studies. The sudden gains appeared less…

76 FR 54399 - Airworthiness Directives; The Boeing Company Model 737-200, -200C, -300, -400, and -500 Series...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-09-01

... result in sudden fracture and failure of the fuselage skin panels, and consequent rapid decompression of..., which could result in sudden fracture and failure of the fuselage skin panels, and consequent rapid... fuselage skin panels at the chem-milled steps, which could result in sudden fracture and failure of the...

Welcome to the sudden oak death third science symposium

Treesearch

Susan J. Frankel

2008-01-01

On behalf of the United States Department of Agriculture (USDA)-Forest Service, Pacific Southwest Research Station and the California Oak Mortality Task Force, it is my pleasure to welcome you to the Sudden Oak Death Third Science Symposium. Looking back at the first sudden oak death science symposium held in Monterey in December 2002, it is amazing to see how far we...

Sudden infant death syndrome caused by poliomyelitis.

PubMed

Dunne, J W; Harper, C G; Hilton, J M

1984-07-01

Most seemingly well infants who die suddenly and unexpectedly have no adequate cause of death found on thorough postmortem examination. Respiratory and enteric viruses are often present, especially in the upper respiratory tract, but the infective process seems, of itself, insufficient to cause death. In the remainder of the cases, a variety of lesions will be discovered, including viral myocarditis, bronchiolitis, and sepsis. We report a case of sudden and unexpected death in a 5-week-old male infant due to acute anterior poliomyelitis. This case illustrates the importance of a thorough postmortem examination, including histologic studies of the brain stem and spinal cord in cases of sudden infant death syndrome.

Enhanced seasonal forecast skill following stratospheric sudden warmings

NASA Astrophysics Data System (ADS)

Sigmond, M.; Scinocca, J. F.; Kharin, V. V.; Shepherd, T. G.

2013-02-01

Advances in seasonal forecasting have brought widespread socio-economic benefits. However, seasonal forecast skill in the extratropics is relatively modest, prompting the seasonal forecasting community to search for additional sources of predictability. For over a decade it has been suggested that knowledge of the state of the stratosphere can act as a source of enhanced seasonal predictability; long-lived circulation anomalies in the lower stratosphere that follow stratospheric sudden warmings are associated with circulation anomalies in the troposphere that can last up to two months. Here, we show by performing retrospective ensemble model forecasts that such enhanced predictability can be realized in a dynamical seasonal forecast system with a good representation of the stratosphere. When initialized at the onset date of stratospheric sudden warmings, the model forecasts faithfully reproduce the observed mean tropospheric conditions in the months following the stratospheric sudden warmings. Compared with an equivalent set of forecasts that are not initialized during stratospheric sudden warmings, we document enhanced forecast skill for atmospheric circulation patterns, surface temperatures over northern Russia and eastern Canada and North Atlantic precipitation. We suggest that seasonal forecast systems initialized during stratospheric sudden warmings are likely to yield significantly greater forecast skill in some regions.

Postmortem ICD interrogation in mode of death classification.

PubMed

Nikolaidou, Theodora; Johnson, Miriam J; Ghosh, Justin M; Marincowitz, Carl; Shah, Saumil; Lammiman, Michael J; Schilling, Richard J; Clark, Andrew L

2018-04-01

The definition of sudden death due to arrhythmia relies on the time interval between onset of symptoms and death. However, not all sudden deaths are due to arrhythmia. In patients with an implantable cardioverter defibrillator (ICD), postmortem device interrogation may help better distinguish the mode of death compared to a time-based definition alone. This study aims to assess the proportion of "sudden" cardiac deaths in patients with an ICD that have confirmed arrhythmia. We conducted a literature search for studies using postmortem ICD interrogation and a time-based classification of the mode of death. A modified QUADAS-2 checklist was used to assess risk of bias in individual studies. Outcome data were pooled where sufficient data were available. Our search identified 22 studies undertaken between 1982 and 2015 with 23,600 participants. The pooled results (excluding studies with high risk of bias) suggest that ventricular arrhythmias are present at the time of death in 76% of "sudden" deaths (95% confidence interval [CI] 67-85; range 42-88). Postmortem ICD interrogation identifies 24% of "sudden" deaths to be nonarrhythmic. Postmortem device interrogation should be considered in all cases of unexplained sudden cardiac death. © 2018 Wiley Periodicals, Inc.

Inheritance of Febrile Seizures in Sudden Unexplained Death in Toddlers

PubMed Central

Holm, Ingrid A.; Poduri, Annapurna; Crandall, Laura; Haas, Elisabeth; Grafe, Marjorie R.; Kinney, Hannah C.; Krous, Henry F.

2014-01-01

Sudden unexplained death in toddlers has been associated with febrile seizures, family history of febrile seizures, and hippocampal anomalies. We investigated the mode of inheritance for febrile seizures in these families. A three-generation pedigree was obtained from families enrolled in the San Diego Sudden Unexplained Death in Childhood Research Project, involving toddlers with sudden unexplained death, febrile seizures, and family history of febrile seizures. In our six cases, death was unwitnessed and related to sleep. The interval from last witnessed febrile seizure to death ranged from 3 weeks to 6 months. Hippocampal abnormalities were identified in one of three cases with available autopsy sections. Autosomal dominant inheritance of febrile seizures was observed in three families. A fourth demonstrated autosomal dominant inheritance with incomplete penetrance or variable expressivity. In two families, the maternal and paternal sides manifested febrile seizures. In this series, the major pattern of inheritance in toddlers with sudden unexplained death and febrile seizures was autosomal dominant. Future studies should develop markers (including genetic) to identify which patients with febrile seizures are at risk for sudden unexplained death in childhood, and to provide guidance for families and physicians. PMID:22490769

Asymptomatic ST-segment depression during exercise testing and the risk of sudden cardiac death in middle-aged men: a population-based follow-up study

PubMed Central

Laukkanen, Jari A.; Mäkikallio, Timo H.; Rauramaa, Rainer; Kurl, Sudhir

2009-01-01

Aims Silent electrocardiographic ST change predicts future coronary events in patients with coronary heart disease (CHD), but the prognostic significance of asymptomatic ST-segment depression with respect to sudden cardiac death in subjects without apparent CHD is not well known. Methods and results We investigated the association between silent ST-segment depression during and after maximal symptom-limited exercise test and the risk of sudden cardiac death in a population-based sample of 1769 men without evident CHD. A total of 72 sudden cardiac death occurred during the median follow-up of 18 years. The risk of sudden cardiac death was increased among men with asymptomatic ST-segment depression during exercise [hazard ratio (HR) 2.1, 95% confidence interval (CI) 1.2–3.9] as well as among those with asymptomatic ST-segment depression during recovery period (HR 3.2, 95% CI 1.7–6.0). Asymptomatic ST-depression during exercise testing was a stronger predictor for the risk of sudden cardiac death especially among smokers as well as in hypercholesterolaemic and hypertensive men than in men without these risk factors. Conclusion Asymptomatic ST-segment depression was a very strong predictor of sudden cardiac death in men with any conventional risk factor but no previously diagnosed CHD, emphasizing the value of exercise testing to identify asymptomatic high-risk men who could benefit from preventive measures. PMID:19168533

Detection of a sudden change of the field time series based on the Lorenz system

PubMed Central

Li, Fang; Shen, BingLu; Yan, PengCheng; Song, Jian; Ma, DeShan

2017-01-01

We conducted an exploratory study of the detection of a sudden change of the field time series based on the numerical solution of the Lorenz system. First, the time when the Lorenz path jumped between the regions on the left and right of the equilibrium point of the Lorenz system was quantitatively marked and the sudden change time of the Lorenz system was obtained. Second, the numerical solution of the Lorenz system was regarded as a vector; thus, this solution could be considered as a vector time series. We transformed the vector time series into a time series using the vector inner product, considering the geometric and topological features of the Lorenz system path. Third, the sudden change of the resulting time series was detected using the sliding t-test method. Comparing the test results with the quantitatively marked time indicated that the method could detect every sudden change of the Lorenz path, thus the method is effective. Finally, we used the method to detect the sudden change of the pressure field time series and temperature field time series, and obtained good results for both series, which indicates that the method can apply to high-dimension vector time series. Mathematically, there is no essential difference between the field time series and vector time series; thus, we provide a new method for the detection of the sudden change of the field time series. PMID:28141832

Risk of Peripheral Artery Occlusive Disease in Patients with Vertigo, Tinnitus, or Sudden Deafness: A Secondary Case-Control Analysis of a Nationwide, Population-Based Health Claims Database.

PubMed

Koo, Malcolm; Chen, Jin-Cherng; Hwang, Juen-Haur

2016-01-01

Cochleovestibular symptoms, such as vertigo, tinnitus, and sudden deafness, are common manifestations of microvascular diseases. However, it is unclear whether these symptoms occurred preceding the diagnosis of peripheral artery occlusive disease (PAOD). Therefore, the aim of this case-control study was to investigate the risk of PAOD among patients with vertigo, tinnitus, and sudden deafness using a nationwide, population-based health claim database in Taiwan. We identified 5,340 adult patients with PAOD diagnosed between January 1, 2006 and December 31, 2010 and 16,020 controls, frequency matched on age interval, sex, and year of index date, from the Taiwan National Health Insurance Research Database. Risks of PAOD in patients with vertigo, tinnitus, or sudden deafness were separately evaluated with multivariate logistic regression analyses. Of the 5,340 patients with PAOD, 12.7%, 6.7%, and 0.3% were diagnosed with vertigo, tinnitus, and sudden deafness, respectively. In the controls, 10.6%, 6.1%, and 0.3% were diagnosed with vertigo (P < 0.001), tinnitus (P = 0.161), and sudden deafness (P = 0.774), respectively. Results from the multivariate logistic regression analyses showed that the risk of PAOD was significantly increased in patients with vertigo (adjusted odds ratio = 1.12, P = 0.027) but not in those with tinnitus or sudden deafness. A modest increase in the risk of PAOD was observed among Taiwanese patients with vertigo, after adjustment for comorbidities.

New relationships among the sudden oak death pathogen, bark and ambrosia beetles, and fungi colonizing coast live oaks

Treesearch

Nadir Erbilgin; Brice A. McPherson; Pierluigi Bonello; David L. Wood; Andrew J. Nelson

2008-01-01

Sudden oak death (SOD) has had devastating effects on several oak species in many California coastal forests. Phytophthora ramorum has been identified as the primary causal agent of sudden oak death. While the pathogen may be capable of killing mature trees, it is likely that in nature opportunistic organisms play significant roles in the decline and...

Sudden Oak Death, Phytophthora ramorum: A Persistent Threat to Oaks and Other Tree Species

Treesearch

S.J. Frankel; K.M. Palmieri

2014-01-01

This paper reviews the status and management of sudden oak death and “sudden larch death” in the urban and wildland forests of California, Oregon, and the UK. The causal pathogen, Phytophthora ramorum, was discovered in all three locations over a decade ago; however, efforts to contain and eliminate infestations have been unsuccessful. These less...

Interaction between bedding and sleeping position in the sudden infant death syndrome: a population based case-control study.

PubMed Central

Fleming, P J; Gilbert, R; Azaz, Y; Berry, P J; Rudd, P T; Stewart, A; Hall, E

1990-01-01

OBJECTIVE--To determine the relation between sleeping position and quantity of bedding and the risk of sudden unexpected infant death. DESIGN--A study of all infants dying suddenly and unexpectedly and of two controls matched for age and date with each index case. The parents of control infants were interviewed within 72 hours of the index infant's death. Information was collected on bedding, sleeping position, heating, and recent signs of illness for index and control infants. SETTING--A defined geographical area comprising most of the county of Avon and part of Somerset. SUBJECTS--72 Infants who had died suddenly and unexpectedly (of whom 67 had died from the sudden infant death syndrome) and 144 control infants. RESULTS--Compared with the control infants the infants who had died from the sudden infant death syndrome were more likely to have been sleeping prone (relative risk 8.8; 95% confidence interval 7.0 to 11.0; p less than 0.001), to have been more heavily wrapped (relative risk 1.14 per tog above 8 tog; 1.03 to 1.28; p less than 0.05), and to have had the heating on all night (relative risk 2.7; 1.4 to 5.2; p less than 0.01). These differences were less pronounced in the younger infants (less than 70 days) than the older ones. The risk of sudden unexpected death among infants older than 70 days, nursed prone, and with clothing and bedding of total thermal resistance greater than 10 tog was increased by factors of 15.1 (2.6 to 89.6) and 25.2 (3.7 to 169.0) respectively compared with the risk in infants of the same age nursed supine or on their side and under less than 6 tog of bedding. CONCLUSIONS--Overheating and the prone position are independently associated with an increased risk of sudden unexpected infant death, particularly in infants aged more than 70 days. Educating parents about appropriate thermal care and sleeping position of infants may help to reduce the incidence of the sudden infant death syndrome. PMID:2390588

Sudden Death: An Uncommon Occurrence in Dementia with Lewy Bodies.

PubMed

Molenaar, Joery P; Wilbers, Joyce; Aerts, Marjolein B; Leijten, Quinten H; van Dijk, Jan G; Esselink, Rianne A; Bloem, Bastiaan R

2016-01-01

We present a 75-year-old woman with dementia and parkinsonism who developed severe orthostatic hypotension and eventually died. Autopsy revealed extensive Lewy body formation in the midbrain, limbic system, intermediate spinal cord, and medulla oblongata. Furthermore, a vast amount of Lewy bodies was seen in the paravertebral sympathetic ganglia which likely explained the severe autonomic failure. We speculate that this autonomic failure caused sudden death through dysregulation of respiration or heart rhythm, reminiscent of sudden death in multiple system atrophy (MSA). Clinicians should be aware of this complication in patients presenting with parkinsonism and autonomic dysfunction, and that sudden death may occur in dementia with Lewy bodies (DLB) as it does in MSA.

CKD and Sudden Cardiac Death: Epidemiology, Mechanisms, and Therapeutic Approaches

PubMed Central

Whitman, Isaac R.; Feldman, Harold I.

2012-01-01

Multiple studies demonstrate a strong independent association between CKD and cardiovascular events including death, heart failure, and myocardial infarction. This review focuses on recent clinical studies that expand this spectrum of adverse cardiovascular events to include ventricular arrhythmias and sudden cardiac death. In addition, experimental models suggest structural remodeling of the heart and electrophysiologic changes in this population. These processes may explain the increased arrhythmic risk in kidney disease and aid in identifying patients who are at higher risk for sudden cardiac death. Finally, we review here the data to support the use of pharmacologic and device-based therapies for both the primary and secondary prevention of sudden cardiac death. PMID:23100219

[Three good reasons to perform a postmortem examination in all cases of juvenile sudden death].

PubMed

d'Amati, Giulia; di Gioia, Cira R T; Silenzi, Paola F; Gallo, Pietro

2009-04-01

The aim of this review is to underline the reasons why a post-mortem examination has to be performed in all cases of juvenile sudden death. Sudden death in children and young adults can be caused by potentially heritable cardiovascular disorders and fatal outcome is often the first symptom in apparently healthy subjects. In these cases, a careful autopsy, performed according to a standardized protocol, becomes the sole diagnostic tool to guide clinical and molecular genetic family screening and to adopt the proper therapeutic and preventive strategies. Thus, a post-mortem examination is a fundamental part of a multidisciplinary approach to the issue of juvenile sudden death.

Pericardial Cyst: Cause of Sudden Cardiac Death?

PubMed

Ley, Marie Brix; Larsen, Maiken Kudahl

2018-05-21

Cardiovascular disease is the leading cause of sudden death in the world. The etiology of sudden cardiac death involves a wide range of diseases, but seldom pericardial cysts. A pericardial cyst is an uncommon cyst usually located in the middle mediastinum and rarely in the posterior part. They are usually harmless and asymptomatic. Here, we present a case of a 63-year-old woman who presented with dyspnea and hoarseness, but died suddenly after a CT scan was attempted. The detailed forensic pathologic and histologic examination revealed a pericardial cyst located in the posterior mediastinum. Toxicology and biochemistry tests, including tryptase, found no competing cause of death. © 2018 American Academy of Forensic Sciences.

Progressive Primary Pulmonary Tuberculosis Presenting as the Sudden Unexpected Death in Infancy: A Case Report

PubMed Central

Dempers, Johan; Sens, Mary Ann; Wadee, Shabbir Ahmed; Kinney, Hannah C.; Odendaal, Hein J.; Wright, Colleen A.

2010-01-01

The classification of an unexpected infant death as the sudden infant death syndrome (SIDS) depends upon a complete autopsy and death scene investigation to exclude known causes of death. Here we report the death of a four-month-old infant in a tuberculosis endemic area that presented as a sudden unexpected death in infancy (SUDI) with no apparent explanation based on the death scene characteristics. The autopsy, however, revealed progressive primary pulmonary tuberculosis with intrathoracic adenopathy, compression of the tracheobronchial tree and miliary lesions in the liver. This case underscores the clinical difficulties in the diagnosis of infantile tuberculosis, as well as the possibility of sudden death as part of its protean manifestations. The pathology and clinical progression of tuberculosis in infants differs from older children and adults due to the immature immune response in infants. This case dramatically highlights the need for complete autopsies in all sudden and unexpected infant deaths, as well as the public health issues in a sentinel infant tuberculosis diagnosis. PMID:20705406

Laryngeal dystonia gravidarum: sudden onset of adductor spasmodic dysphonia in pregnancy.

PubMed

Ankola, Ashish; Sulica, Lucian; Murry, Thomas

2013-12-01

The purpose of this study was to identify the presence or absence of known factors related to onset of adductor spasmodic dysphonia (ADSD) in a population with sudden onset during or after pregnancy. Retrospective review. A review of 350 patient records identified five patients with sudden onset of ADSD related to pregnancy. An age-matched group with sudden onset of ADSD not related to pregnancy served as controls. All subjects completed a 20-question survey of risk factors relevant to ADSD. The average age of onset in both groups was 31 years. Three had onset of ADSD in the postpartum period, the other two during pregnancy. Significantly increased avocational voice use was found in the pregnant group compared to the control group. There was a significant difference in the two groups regarding cumulative risk factors traditionally associated with ADSD. Sudden onset of ADSD can occur in pregnancy in women with clinical profiles that differ from traditional ADSD patients. Copyright © 2013 The American Laryngological, Rhinological and Otological Society, Inc.

ECPR for Refractory Out-Of-Hospital Cardiac Arrest

ClinicalTrials.gov

2018-05-09

Cardiac Arrest; Heart Arrest; Sudden Cardiac Arrest; Cardiopulmonary Arrest; Death, Sudden, Cardiac; Cardiopulmonary Resuscitation; CPR; Extracorporeal Cardiopulmonary Resuscitation; Extracorporeal Membrane Oxygenation

The Not-So-Sudden Results of the Sudden Saw Log Study - Growth and Yield Through Age 45

Treesearch

V. Clark Baldwin; Daniel J. Leduc; Robert B. Ferguson; James B. Baker; Rodney L. Busby

1998-01-01

The Sudden-Saw Log Study, located near Crossett, AR, was established to test the hypothesis that lobfolly pine plantations can produce sawtimber on good sites in 30 years. Study measurements reported at stand age 33 years show that the hypothesis is true. Fortunately, the study was not terminated at that time. Inventory data were also collected at stand ages 36, 39,...

The Molecular Autopsy: Should the Evaluation Continue After the Funeral?

PubMed Central

Tester, David J.; Ackerman, Michael J.

2012-01-01

Sudden cardiac death (SCD) is one of the most common causes of death in developed countries, with most SCDs involving the elderly, and structural heart disease evident at autopsy. Each year, however, thousands of sudden deaths involving individuals younger than 35 years of age remain unexplained after a comprehensive medicolegal investigation that includes an autopsy. In fact, several epidemiologic studies have estimated that at least 3% and up to 53% of sudden deaths involving previously healthy children, adolescents, and young adults show no morphologic abnormalities identifiable at autopsy. Cardiac channelopathies associated with structurally normal hearts such as long QT syndrome (LQTS), catecholaminergic polymorphic ventricular tachycardia (CPVT), and Brugada syndrome (BrS) yield no evidence to be found at autopsy, leaving coroners, medical examiners, and forensic pathologists only to speculate that a lethal arrhythmia might lie at the heart of a sudden unexplained death (SUD). In cases of autopsy-negative SUD, continued investigation through either a cardiologic and genetic evaluation of first- or second-degree relatives or a molecular autopsy may elucidate the underlying mechanism contributing to the sudden death and allow for identification of living family members with the pathogenic substrate that renders them vulnerable, with an increased risk for cardiac events including syncope, cardiac arrest, and sudden death. PMID:22307399

Sudden cardiac death in adults with congenital heart disease.

PubMed

Yap, Sing-Chien; Harris, Louise

2009-12-01

Sudden cardiac death is one of the leading causes of death in patients with congenital heart disease, especially in patients with repaired cyanotic and left heart obstructive lesions. While the overall annual incidence of sudden cardiac death is relatively low, estimated at 0.09% per year, this nonetheless represents a many-fold increase over that of comparable age-matched control populations. The most frequent cause of sudden cardiac death is believed to be arrhythmic, usually ventricular arrhythmia. Most studies investigating risk factors for ventricular arrhythmia and/or sudden cardiac death have focused on patients with repaired tetralogy of Fallot and patients with Mustard/Senning repair for complete transposition of the great arteries. Despite a multitude of risk factors, their predictive value for the occurrence of sudden cardiac death is relatively low. Current experience with implantable cardioverter defibrillators in this patient population is limited to observational studies and the selection of patients for prophylactic implantable cardioverter defibrillator implantation is impeded both by the absence of randomized trials and weak predictors. Catheter ablation of ventricular tachycardia has emerged as a promising therapy for abolishing or reducing the burden of arrhythmia but experience is still limited and the impact on long-term outcome uncertain. Future studies will have to focus on improving risk stratification of patients with congenital heart disease.

Increased serum cholesterol esterification rates predict coronary heart disease and sudden death in a general population.

PubMed

Tanaka, Shin-ichiro; Yasuda, Tomoyuki; Ishida, Tatsuro; Fujioka, Yoshio; Tsujino, Takeshi; Miki, Tetsuo; Hirata, Ken-ichi

2013-05-01

Lecithin:cholesterol acyltransferase (LCAT) is thought to be important in reverse cholesterol transport. However, its association with coronary heart disease (CHD) and sudden death is controversial. We prospectively studied 1927 individuals from the general population. Serum concentrations of apolipoprotein A-I, A-II, B, C-II, C-III, E, and LCAT activity measured as a serum cholesterol esterification rate were evaluated. We documented 61 events of CHD and sudden death during 10.9 years of follow-up. After adjustment for age and sex, LCAT activity was significantly associated with the risk of CHD and sudden death (hazard ratio, 3.02; 95% confidence interval, 1.49-6.12; P=0.002). In multivariate analysis adjusted for age, sex, current smoking status, history of diabetes mellitus, body mass index, systolic blood pressure, serum total cholesterol, and serum high-density lipoprotein cholesterol concentrations, the hazard ratio of LCAT activity for the risk of CHD and sudden death remained significant (hazard ratio, 3.07; 95% confidence interval, 1.35-7.01; P=0.008). However, when it was analyzed for men and women separately, this association remained significant only in women. Increased LCAT activity measured as a serum cholesterol esterification rate was a risk for CHD and sudden death in a Japanese general population.

Cardiovascular causes of maternal sudden death. Sudden arrhythmic death syndrome is leading cause in UK.

PubMed

Krexi, Dimitra; Sheppard, Mary N

2017-05-01

This study aims to determine the causes of sudden cardiac death during pregnancy and in the postpartum period and patients' characteristics. There are few studies in the literature. Eighty cases of sudden unexpected death due to cardiac causes in relation to pregnancy and postpartum period in a database of 4678 patients were found and examined macroscopically and microscopically. The mean age was 30±7 years with a range from 16 to 43 years. About 30% were 35 years old or older; 50% of deaths occurred during pregnancy and 50% during the postpartum period. About 59.18% were obese or overweight where body mass index data were available. The leading causes of death were sudden arrhythmic death syndrome (SADS) (53.75%) and cardiomyopathies (13.80%). Other causes include dissection of aorta or its branches (8.75%), congenital heart disease (2.50%) and valvular disease (3.75%). This study highlights sudden cardiac death in pregnancy or in the postpartum period, which is mainly due to SADS with underlying channelopathies and cardiomyopathy. We wish to raise awareness of these frequently under-recognised entities in maternal deaths and the need of cardiological screening of the family as a result of the diagnosis. Copyright © 2017 Elsevier B.V. All rights reserved.

Cardiovascular causes of maternal sudden death. Sudden Arrhythmic Death Syndrome is leading cause in UK.

PubMed

Krexi, Dimitra; Sheppard, Mary N

2017-09-01

This study aims to determine the causes of sudden cardiac death during pregnancy and in the postpartum period and patients' characteristics. There are few studies in the literature. Eighty cases of sudden unexpected death due to cardiac causes in relation to pregnancy and postpartum period in a database of 4678 patients were found and examined macroscopically and microscopically. The mean age was 30±7years with a range from 16 to 43 years. About 30% were 35 years old or older; 50% of deaths occurred during pregnancy and 50% during the postpartum period. About 59.18% were obese or overweight where body mass index data were available. The leading causes of death were sudden arrhythmic death syndrome (SADS) (53.75%) and cardiomyopathies (13.80%). Other causes include dissection of aorta or its branches (8.75%), congenital heart disease (2.50%) and valvular disease (3.75%). This study highlights sudden cardiac death in pregnancy or in the postpartum period, which is mainly due to SADS with underlying channelopathies and cardiomyopathy. We wish to raise awareness of these frequently under-recognised entities in maternal deaths and the need of cardiological screening of the family as a result of the diagnosis. Copyright © 2017 Elsevier B.V. All rights reserved.

Multi-phase post-mortem CT-angiography: a pathologic correlation study on cardiovascular sudden death

PubMed Central

Turillazzi, Emanuela; Frati, Paola; Pascale, Natascha; Pomara, Cristoforo; Grilli, Giampaolo; Viola, Rocco Valerio; Fineschi, Vittorio

2016-01-01

Multi-phase post-mortem CT-angiography (MPMCTA) has the great potential to increase the quality of the post-mortem investigation, especially in the area of sudden death; however, its role as routine complement to the pathology toolbox is still questioned as it needs to be further standardized. The aim of this study is to investigate the contribution of MPMCTA in cases of sudden unexplained death in adults and in particular in sudden cardiovascular death. Sixty-eight sudden unexpected deaths of adults were investigated at our institution between 2012 and 2013. Ten cases underwent MPMCTA and autopsy and were included in the study. Before the angiographic step by complete filling of the vascular system, prior to any manipulation of the body, a non-contrast CT-scan was carried out. Image reconstructions were performed on a CT workstation (Vitrea) and two radiologists experienced with post mortem imaging interpreted the MPMCTA findings. In all 10 cases, we could state a good correlation between combination of post-mortem CT and MPMCTA and autopsy procedures, confirming a high diagnostic sensitivity. With this case series we want to illustrate the advantages offered by performing MPMCTA when facing a sudden death, regardless of specific suspicion for acute coronary syndrome or other vascular or ischemic disease. PMID:27928228

A Policy Impact Analysis of the Mandatory NCAA Sickle Cell Trait Screening Program

PubMed Central

Tarini, Beth A; Brooks, Margaret Alison; Bundy, David G

2012-01-01

Objective To estimate the impact of the mandatory National Collegiate Athletic Association (NCAA) sickle cell trait (SCT) screening policy on the identification of sickle cell carriers and prevention of sudden death. Data Source We used NCAA reports, population-based SCT prevalence estimates, and published risks for exercise-related sudden death attributable to SCT. Study Design We estimated the number of sickle cell carriers identified and the number of potentially preventable sudden deaths with mandatory SCT screening of NCAA Division I athletes. We calculated the number of student-athletes with SCT using a conditional probability based upon SCT prevalence data and self-identified race/ethnicity status. We estimated sudden deaths over 10 years based on published attributable risk of exercise-related sudden death due to SCT. Principal Findings We estimate that over 2,000 NCAA Division I student-athletes with SCT will be identified under this screening policy and that, without intervention, about seven NCAA Division I student-athletes would die suddenly as a complication of SCT over a 10-year period. Conclusion Universal sickle cell screening of NCAA Division I student-athletes will identify a substantial number of sickle cell carriers. A successful intervention could prevent about seven deaths over a decade. PMID:22150647

Catatonia Secondary to Sudden Clozapine Withdrawal: A Case with Three Repeated Episodes and a Literature Review

PubMed Central

Bilbily, John; McCollum, Betsy

2017-01-01

A literature search identified 9 previously published cases that were considered as possible cases of catatonia secondary to sudden clozapine withdrawal. Two of these 9 cases did not provide enough information to make a diagnosis of catatonia according to the Diagnostic and Statistical Manual, 5th Edition (DSM-5). The Liverpool Adverse Drug Reaction (ADR) Causality Scale was modified to assess ADRs secondary to drug withdrawal. From the 7 published cases which met DSM-5 catatonia criteria, using the modified scale, we established that 3 were definitive and 4 were probable cases of catatonia secondary to clozapine withdrawal. A new definitive case is described with three catatonic episodes which (1) occurred after sudden discontinuation of clozapine in the context of decades of follow-up, (2) had ≥3 of 12 DSM-5 catatonic symptoms and serum creatinine kinase elevation, and (3) required medical hospitalization and intravenous fluids. Clozapine may be a gamma-aminobutyric acid (GABA) receptor agonist; sudden clozapine withdrawal may explain a sudden decrease in GABA activity that may contribute to the development of catatonic symptoms in vulnerable patients. Based on the limited information from these cases, the pharmacological treatment for catatonia secondary to sudden clozapine withdrawal can include benzodiazepines and/or restarting clozapine. PMID:28396815

The association between pro-arrhythmic agents and aortic stenosis in young adults: is it sufficient to clarify the sudden unexpected deaths?

PubMed

Radnic, Bojana; Radojevic, Nemanja; Vucinic, Jelena; Duborija-Kovacevic, Natasa

2017-07-01

Most young patients with mild-to-moderate aortic stenosis show no symptoms, and sudden death appears only occasionally. We hypothesised that malignant ventricular arrhythmias could be responsible for the high incidence of sudden death in such patients. If multiple factors such as asymptomatic aortic stenosis in association with arrhythmia-provoking agents are involved, could it be sufficient to account for sudden unexpected death? In this study, eight cases of sudden death in young adults, with ages ranging from 22 to 36 years, who had never reported any symptoms that could be related to aortic stenosis, were investigated. Full autopsies were performed, and congenital aortic stenosis in all eight cases was confirmed. DNA testing for channelopathies was negative. Comprehensive toxicological analyses found an electrolyte imbalance, or non-toxic concentrations of amitriptyline, terfenadine, caffeine, and ethanol. Collectively, these results suggest that congenital asymptomatic aortic stenosis without cardiac hypertrophy in young adults is not sufficient to cause sudden death merely on its own; rather, an additional provoking factor is necessary. According to our findings, the provoking factor may be a state of physical or emotional stress, a state of electrolyte imbalance, or even taking a therapeutic dose of a particular drug.

Potential asphyxia and brainstem abnormalities in sudden and unexpected death in infants.

PubMed

Randall, Bradley B; Paterson, David S; Haas, Elisabeth A; Broadbelt, Kevin G; Duncan, Jhodie R; Mena, Othon J; Krous, Henry F; Trachtenberg, Felicia L; Kinney, Hannah C

2013-12-01

Sudden and unexplained death is a leading cause of infant mortality. Certain characteristics of the sleep environment increase the risk for sleep-related sudden and unexplained infant death. These characteristics have the potential to generate asphyxial conditions. We tested the hypothesis that infants may be exposed to differing degrees of asphyxia in sleep environments, such that vulnerable infants with a severe underlying brainstem deficiency in serotonergic, γ-aminobutyric acid-ergic, or 14-3-3 transduction proteins succumb even without asphyxial triggers (e.g., supine), whereas infants with intermediate or borderline brainstem deficiencies require asphyxial stressors to precipitate death. We classified cases of sudden infant death into categories relative to a "potential asphyxia" schema in a cohort autopsied at the San Diego County Medical Examiner's Office. Controls were infants who died with known causes of death established at autopsy. Analysis of covariance tested for differences between groups. Medullary neurochemical abnormalities were present in both infants dying suddenly in circumstances consistent with asphyxia and infants dying suddenly without obvious asphyxia-generating circumstances. There were no differences in the mean neurochemical measures between these 2 groups, although mean measures were both significantly lower (P < .05) than those of controls dying of known causes. We found no direct relationship between the presence of potentially asphyxia conditions in the sleep environment and brainstem abnormalities in infants dying suddenly and unexpectedly. Brainstem abnormalities were associated with both asphyxia-generating and non-asphyxia generating conditions. Heeding safe sleep messages is essential for all infants, especially given our current inability to detect underlying vulnerabilities.

Potential Asphyxia and Brainstem Abnormalities in Sudden and Unexpected Death in Infants

PubMed Central

Randall, Bradley B.; Paterson, David S.; Haas, Elisabeth A.; Broadbelt, Kevin G.; Duncan, Jhodie R.; Mena, Othon J.; Krous, Henry F.; Trachtenberg, Felicia L.

2013-01-01

OBJECTIVE: Sudden and unexplained death is a leading cause of infant mortality. Certain characteristics of the sleep environment increase the risk for sleep-related sudden and unexplained infant death. These characteristics have the potential to generate asphyxial conditions. We tested the hypothesis that infants may be exposed to differing degrees of asphyxia in sleep environments, such that vulnerable infants with a severe underlying brainstem deficiency in serotonergic, γ-aminobutyric acid-ergic, or 14-3-3 transduction proteins succumb even without asphyxial triggers (eg, supine), whereas infants with intermediate or borderline brainstem deficiencies require asphyxial stressors to precipitate death. METHODS: We classified cases of sudden infant death into categories relative to a “potential asphyxia” schema in a cohort autopsied at the San Diego County Medical Examiner’s Office. Controls were infants who died with known causes of death established at autopsy. Analysis of covariance tested for differences between groups. RESULTS: Medullary neurochemical abnormalities were present in both infants dying suddenly in circumstances consistent with asphyxia and infants dying suddenly without obvious asphyxia-generating circumstances. There were no differences in the mean neurochemical measures between these 2 groups, although mean measures were both significantly lower (P < .05) than those of controls dying of known causes. CONCLUSIONS: We found no direct relationship between the presence of potentially asphyxia conditions in the sleep environment and brainstem abnormalities in infants dying suddenly and unexpectedly. Brainstem abnormalities were associated with both asphyxia-generating and non–asphyxia generating conditions. Heeding safe sleep messages is essential for all infants, especially given our current inability to detect underlying vulnerabilities. PMID:24218471

Risk of Peripheral Artery Occlusive Disease in Patients with Vertigo, Tinnitus, or Sudden Deafness: A Secondary Case-Control Analysis of a Nationwide, Population-Based Health Claims Database

PubMed Central

Hwang, Juen-Haur

2016-01-01

Background Cochleovestibular symptoms, such as vertigo, tinnitus, and sudden deafness, are common manifestations of microvascular diseases. However, it is unclear whether these symptoms occurred preceding the diagnosis of peripheral artery occlusive disease (PAOD). Therefore, the aim of this case-control study was to investigate the risk of PAOD among patients with vertigo, tinnitus, and sudden deafness using a nationwide, population-based health claim database in Taiwan. Methods We identified 5,340 adult patients with PAOD diagnosed between January 1, 2006 and December 31, 2010 and 16,020 controls, frequency matched on age interval, sex, and year of index date, from the Taiwan National Health Insurance Research Database. Risks of PAOD in patients with vertigo, tinnitus, or sudden deafness were separately evaluated with multivariate logistic regression analyses. Results Of the 5,340 patients with PAOD, 12.7%, 6.7%, and 0.3% were diagnosed with vertigo, tinnitus, and sudden deafness, respectively. In the controls, 10.6%, 6.1%, and 0.3% were diagnosed with vertigo (P < 0.001), tinnitus (P = 0.161), and sudden deafness (P = 0.774), respectively. Results from the multivariate logistic regression analyses showed that the risk of PAOD was significantly increased in patients with vertigo (adjusted odds ratio = 1.12, P = 0.027) but not in those with tinnitus or sudden deafness. Conclusions A modest increase in the risk of PAOD was observed among Taiwanese patients with vertigo, after adjustment for comorbidities. PMID:27631630

Systematic review of the incidence of sudden cardiac death in the United States.

PubMed

Kong, Melissa H; Fonarow, Gregg C; Peterson, Eric D; Curtis, Anne B; Hernandez, Adrian F; Sanders, Gillian D; Thomas, Kevin L; Hayes, David L; Al-Khatib, Sana M

2011-02-15

The need for consistent and current data describing the true incidence of sudden cardiac arrest (SCA) and/or sudden cardiac death (SCD) was highlighted during the most recent Sudden Cardiac Arrest Thought Leadership Alliance's (SCATLA) Think Tank meeting of national experts with broad representation of key stakeholders, including thought leaders and representatives from the American College of Cardiology, American Heart Association, and the Heart Rhythm Society. As such, to evaluate the true magnitude of this public health problem, we performed a systematic literature search in MEDLINE using the MeSH headings, "death, sudden" OR the terms "sudden cardiac death" OR "sudden cardiac arrest" OR "cardiac arrest" OR "cardiac death" OR "sudden death" OR "arrhythmic death." Study selection criteria included peer-reviewed publications of primary data used to estimate SCD incidence in the U.S. We used Web of Science's Cited Reference Search to evaluate the impact of each primary estimate on the medical literature by determining the number of times each "primary source" has been cited. The estimated U.S. annual incidence of SCD varied widely from 180,000 to >450,000 among 6 included studies. These different estimates were in part due to different data sources (with data age ranging from 1980 to 2007), definitions of SCD, case ascertainment criteria, methods of estimation/extrapolation, and sources of case ascertainment. The true incidence of SCA and/or SCD in the U.S. remains unclear, with a wide range in the available estimates that are badly dated. As reliable estimates of SCD incidence are important for improving risk stratification and prevention, future efforts are clearly needed to establish uniform definitions of SCA and SCD and then to prospectively and precisely capture cases of SCA and SCD in the overall U.S. population. Copyright © 2011 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Sensorineural hearing loss in hemorrhagic dengue?

PubMed

Ribeiro, Bruna Natália Freire; Guimarães, Alexandre Caixeta; Yazawa, Felipe; Takara, Tammy Fumiko Messias; de Carvalho, Guilherme Machado; Zappelini, Carlos Eduardo Monteiro

2015-01-01

Dengue is an acute febrile infectious disease, with high fever followed by symptoms flu-like. Dengue hemorrhagic fever (DHF) is a vascular leak syndrome and could present spontaneous bleeding and worsening of symptoms after some days. Dengue could have some ENT manifestations, however hearing loss is not one of them. Sudden hearing loss is considered as sensorineural or perceptual hearing loss with a sudden onset in a person without other prior otological history. The relation between infectious diseases and sudden hearing are been investigated, some viruses were already linked, but the relation between dengue virus and sudden hearing still remains unknown. This article has the goal of presenting a case of DHF that evolved with SSHL in his hospitalization process. We report a 60 years-male patient of with DHF who developed bilateral secretory otitis media and sensorineural hearing loss after the fifth day of onset of symptoms. His hearing loss remained even after 7 months and the patient was referred for hearing aid fitting. This is the first case report that brings together DHF and sudden hearing loss. In the development of this case no other cause to sudden hearing loss was found and the correlation between dengue and hearing loss was questioned. In the literature review was found that some viruses, as mumps virus, varicella-zoster virus and HSV-1 and HSV-2 are related to sudden hearing loss, all of them fit in the viral theory. Besides the viral theory of sudden hearing loss, there is the vascular theory that is the occlusion of the end artery that supplies the cochlea. DHF has a vascular commitment, and the hypothesis of a vascular cause could be elicited in this case. Many studies in this area are needed and this article has the objective of elicit the discussion about the subject. Could dengue be associated with sensorineural hearing loss? Copyright © 2015. Published by Elsevier Ltd.

Innovation and dedication underpin management of sudden oak death (Phytophthora ramorum) in California and Oregon forests

Treesearch

Susan J. Frankel

2017-01-01

This special issue of Forest Phytophthoras serves as part of the proceedings from the Sixth Sudden Oak Death Science Symposium held June 21 -23, 2016 at Fort Mason Center in San Francisco, CA, USA. The symposium marked almost 16 years to the day that David Rizzo (UC Davis) and Matteo Garbelotto (UC Berkeley) identified the cause of sudden oak death to be a previously...

Sudden death of effective entanglement

DOE Office of Scientific and Technical Information (OSTI.GOV)

Roszak, K.; Institute of Physics, Wroclaw University of Technology, 50-370 Wroclaw; Horodecki, P.

2010-04-15

Sudden death of entanglement is a well-known effect resulting from the finite volume of separable states. We study the case when the observer has a limited measurement capability and analyze the effective entanglement (i.e., entanglement minimized over the output data). We show that in the well-defined system of two quantum dots monitored by single-electron transistors, one may observe a sudden death of effective entanglement when real, physical entanglement is still alive. For certain measurement setups, this occurs even for initial states for which sudden death of physical entanglement is not possible at all. The principles of the analysis may bemore » applied to other analogous scenarios, such as estimation of the parameters arising from quantum process tomography.« less

Compressing turbulence and sudden viscous dissipation with compression-dependent ionization state

DOE Office of Scientific and Technical Information (OSTI.GOV)

Davidovits, Seth; Fisch, Nathaniel J.

Turbulent plasma flow, amplified by rapid three-dimensional compression, can be suddenly dissipated under continuing compression. Furthermore, this effect relies on the sensitivity of the plasma viscosity to the temperature, μ ~ T 5 / 2 . The plasma viscosity is also sensitive to the plasma ionization state. Here, we show that the sudden dissipation phenomenon may be prevented when the plasma ionization state increases during compression, and we demonstrate the regime of net viscosity dependence on compression where sudden dissipation is guaranteed. In addition, it is shown that, compared to cases with no ionization, ionization during compression is associated withmore » larger increases in turbulent energy and can make the difference between growing and decreasing turbulent energy.« less

Compressing turbulence and sudden viscous dissipation with compression-dependent ionization state

DOE PAGES

Davidovits, Seth; Fisch, Nathaniel J.

2016-11-14

Turbulent plasma flow, amplified by rapid three-dimensional compression, can be suddenly dissipated under continuing compression. Furthermore, this effect relies on the sensitivity of the plasma viscosity to the temperature, μ ~ T 5 / 2 . The plasma viscosity is also sensitive to the plasma ionization state. Here, we show that the sudden dissipation phenomenon may be prevented when the plasma ionization state increases during compression, and we demonstrate the regime of net viscosity dependence on compression where sudden dissipation is guaranteed. In addition, it is shown that, compared to cases with no ionization, ionization during compression is associated withmore » larger increases in turbulent energy and can make the difference between growing and decreasing turbulent energy.« less

Rotationally and vibrationally inelastic scattering in the rotational IOS approximation. Ultrasimple calculation of total (differential, integral, and transport) cross sections for nonspherical molecules

DOE Office of Scientific and Technical Information (OSTI.GOV)

Parker, G.A.; Pack, R.T

1978-02-15

A simple, direct derivation of the rotational infinite order sudden (IOS) approximation in molecular scattering theory is given. Connections between simple scattering amplitude formulas, choice of average partial wave parameter, and magnetic transitions are reviewed. Simple procedures for calculating cross sections for specific transitions are discussed and many older model formulas are given clear derivations. Total (summed over rotation) differential, integral, and transport cross sections, useful in the analysis of many experiments involving nonspherical molecules, are shown to be exceedingly simple: They are just averages over the potential angle of cross sections calculated using simple structureless spherical particle formulas andmore » programs. In the case of vibrationally inelastic scattering, the IOSA, without further approximation, provides a well-defined way to get fully three dimensional cross sections from calculations no more difficult than collinear calculations. Integral, differential, viscosity, and diffusion cross sections for He-CO/sub 2/ obtained from the IOSA and a realistic intermolecular potential are calculated as an example and compared with experiment. Agreement is good for the complete potential but poor when only its spherical part is used, so that one should never attempt to treat this system with a spherical model. The simplicity and accuracy of the IOSA make it a viable method for routine analysis of experiments involving collisions of nonspherical molecules.« less

Simulation and scaling analysis of a spherical particle-laden blast wave

NASA Astrophysics Data System (ADS)

Ling, Y.; Balachandar, S.

2018-02-01

A spherical particle-laden blast wave, generated by a sudden release of a sphere of compressed gas-particle mixture, is investigated by numerical simulation. The present problem is a multiphase extension of the classic finite-source spherical blast-wave problem. The gas-particle flow can be fully determined by the initial radius of the spherical mixture and the properties of gas and particles. In many applications, the key dimensionless parameters, such as the initial pressure and density ratios between the compressed gas and the ambient air, can vary over a wide range. Parametric studies are thus performed to investigate the effects of these parameters on the characteristic time and spatial scales of the particle-laden blast wave, such as the maximum radius the contact discontinuity can reach and the time when the particle front crosses the contact discontinuity. A scaling analysis is conducted to establish a scaling relation between the characteristic scales and the controlling parameters. A length scale that incorporates the initial pressure ratio is proposed, which is able to approximately collapse the simulation results for the gas flow for a wide range of initial pressure ratios. This indicates that an approximate similarity solution for a spherical blast wave exists, which is independent of the initial pressure ratio. The approximate scaling is also valid for the particle front if the particles are small and closely follow the surrounding gas.

Simulation and scaling analysis of a spherical particle-laden blast wave

NASA Astrophysics Data System (ADS)

Ling, Y.; Balachandar, S.

2018-05-01

A spherical particle-laden blast wave, generated by a sudden release of a sphere of compressed gas-particle mixture, is investigated by numerical simulation. The present problem is a multiphase extension of the classic finite-source spherical blast-wave problem. The gas-particle flow can be fully determined by the initial radius of the spherical mixture and the properties of gas and particles. In many applications, the key dimensionless parameters, such as the initial pressure and density ratios between the compressed gas and the ambient air, can vary over a wide range. Parametric studies are thus performed to investigate the effects of these parameters on the characteristic time and spatial scales of the particle-laden blast wave, such as the maximum radius the contact discontinuity can reach and the time when the particle front crosses the contact discontinuity. A scaling analysis is conducted to establish a scaling relation between the characteristic scales and the controlling parameters. A length scale that incorporates the initial pressure ratio is proposed, which is able to approximately collapse the simulation results for the gas flow for a wide range of initial pressure ratios. This indicates that an approximate similarity solution for a spherical blast wave exists, which is independent of the initial pressure ratio. The approximate scaling is also valid for the particle front if the particles are small and closely follow the surrounding gas.

Surface activity of lipid extract surfactant in relation to film area compression and collapse.

PubMed

Schürch, S; Schürch, D; Curstedt, T; Robertson, B

1994-08-01

The physical properties of modified porcine surfactant (Curosurf), isolated from minced lungs by extraction with chloroform-methanol and further purified by liquid-gel chromatography, were investigated with the captive bubble technique. Bubble size, and thus the surface tension of an insoluble film at the bubble surface, is altered by changing the pressure within the closed bubble chamber. The film surface tension and area are determined from the shape (height and diameter) of the bubble. Adsorption of fresh Curosurf is characterized by stepwise decreases in surface tension, which can easily be observed by sudden quick movements of the bubble apex. These "adsorption clicks" imply a cooperative movement of large collective units of molecules, approximately 10(14) (corresponding to approximately 120 ng of phospholipid) or approximately 10(18) molecules/m2, into the interface during adsorption. Films formed in this manner are already highly enriched in dipalmitoyl phosphatidylcholine, as seen by the extremely low compressibility, close to that of dipalmitoyl phosphatidylcholine. Near-zero minimum tensions are obtained, even at phospholipid concentrations as low as 50 micrograms/ml. During dynamic cycling (20-50 cycles/min), low minimum surface tensions, good film stability, low compressibility, and maximum surface tensions between 30 and 40 mN/m are possible only if the films are not overcompressed near zero surface tension; i.e., the overall film area compression should not substantially exceed 30%.

The effect of solar array degradation on electric propulsion spacecraft performance.

NASA Technical Reports Server (NTRS)

Sauer, C. G., Jr.; Bourke, R. D.

1972-01-01

Current estimates of solar-electric-propulsion spacecraft performance are based upon a solar-array output power which is degraded by approximately 10-13% to account for possible losses caused by proton, electron and micrometeorite damage. Past studies have used a worst case analysis in which the maximum degradation was taken to occur at the beginning of the mission. This paper presents a comparison of mission studies using a hypothetical exponential decrease in power with time, with those using a sudden degradation of solar power. These comparisons indicate that the performance gain by using a time varying degradation during the mission is quite small for outbound missions in the solar system. In addition an indication of the power allocation strategy to be followed during a mission is presented.

On PMWs and two-stroke engines.

PubMed Central

Bell, W.; Yassi, A.; Cole, D. C.

1998-01-01

On Saturday, August 24, 1996, a 40-year-old man from Edmonton was riding a personal motorized watercraft (PMW, a Seadoo or Jet Ski type of machine) on Shuswap Lake, in south-central British Columbia. He was approximately 200 m offshore. The man motioned to his sister, who was riding another PMW, to follow him across the lake. She did so, but as the turned her head to check for other boat traffic, her brother suddenly slowed down and her machine rode right up on his back, crushing him against his handlebars. His sister, a nurse, held her brother's head above water until help arrived but, 48 minutes after the moment of impact, he was pronounced dead at the Shuswap Lake General Hospital. He had suffered a ruptured aorta. PMID:9789655

SARS-CoV and Emergent Coronaviruses: Viral Determinants of Interspecies Transmission

PubMed Central

Bolles, Meagan; Donaldson, Eric; Baric, Ralph

2011-01-01

Most new emerging viruses are derived from strains circulating in zoonotic reservoirs. Coronaviruses, which had an established potential for cross-species transmission within domesticated animals, suddenly became relevant with the unexpected emergence of the highly pathogenic human SARS-CoV strain from zoonotic reservoirs in 2002. SARS-CoV infected approximately 8000 people worldwide before public health measures halted the epidemic. Supported by robust time-ordered sequence variation, structural biology, well-characterized patient pools, and biological data, the emergence of SARS-CoV represents one of the best studied natural models of viral disease emergence from zoonotic sources. This review article summarizes previous and more recent advances into the molecular and structural characteristics, with particular emphasis on host-receptor interactions, that drove this remarkable virus disease outbreak in human populations. PMID:22180768

Pleiotropy, redundancy and the evolution of flowers.

PubMed

Albert, Victor A; Oppenheimer, David G; Lindqvist, Charlotte

2002-07-01

Most angiosperm flowers are tightly integrated, functionally bisexual shoots that have carpels with enclosed ovules. Flowering plants evolved from within the gymnosperms, which lack this combination of innovations. Paradoxically, phylogenetic reconstructions suggest that the flowering plant lineage substantially pre-dates the evolution of flowers themselves. We provide a model based on known gene regulatory networks whereby positive selection on a single, partially redundant gene duplicate 'trapped' the ancestors of flower-bearing plants into the condensed, bisexual state approximately 130 million years ago. The LEAFY (LFY) gene of Arabidopsis encodes a master regulator that functions as the main conduit of environmental signals to the reproductive developmental program. We directly link the elimination of one LFY paralog, pleiotropically maintained in gymnosperms, to the sudden appearance of flowers in the fossil record.

Accurate collision-induced line-coupling parameters for the fundamental band of CO in He - Close coupling and coupled states scattering calculations

NASA Technical Reports Server (NTRS)

Green, Sheldon; Boissoles, J.; Boulet, C.

1988-01-01

The first accurate theoretical values for off-diagonal (i.e., line-coupling) pressure-broadening cross sections are presented. Calculations were done for CO perturbed by He at thermal collision energies using an accurate ab initio potential energy surface. Converged close coupling, i.e., numerically exact values, were obtained for coupling to the R(0) and R(2) lines. These were used to test the coupled states (CS) and infinite order sudden (IOS) approximate scattering methods. CS was found to be of quantitative accuracy (a few percent) and has been used to obtain coupling values for lines to R(10). IOS values are less accurate, but, owing to their simplicity, may nonetheless prove useful as has been recently demonstrated.

Market reaction to a bid-ask spread change: A power-law relaxation dynamics

NASA Astrophysics Data System (ADS)

Ponzi, Adam; Lillo, Fabrizio; Mantegna, Rosario N.

2009-07-01

We study the relaxation dynamics of the bid-ask spread and of the midprice after a sudden variation of the spread in a double auction financial market. We find that the spread decays as a power law to its normal value. We measure the price reversion dynamics and the permanent impact, i.e., the long-time effect on price, of a generic event altering the spread and we find an approximately linear relation between immediate and permanent impact. We hypothesize that the power-law decay of the spread is a consequence of the strategic limit order placement of liquidity providers. We support this hypothesis by investigating several quantities, such as order placement rates and distribution of prices and times of submitted orders, which affect the decay of the spread.

Comparison of Theoretically and Experimentally Determined Effects of Oxide Coatings Supplied by Fuel Additives on Uncooled Turbine-blade Temperature During Transient Turbojet-engine Operation

NASA Technical Reports Server (NTRS)

Schafer, Louis J; Stepka, Francis S; Brown, W Byron

1953-01-01

An analysis was made to permit the calculation of the effectiveness of oxide coatings in retarding the transient heat flow into turbine blades when the combustion gas temperature of a turbojet engine is suddenly changed. The analysis is checked with experimental data obtained from a turbojet engine whose blades were coated with two different coating materials (silicon dioxide and boric oxide) by adding silicone oil and tributyl borate to the engine fuel. The very thin coatings (approximately 0.001 in.) that formed on the blades produced a negligible effect on the turbine-blade transient temperature response. With the analysis discussed here, it was possible to predict the turbine rotor-blade temperature response with a maximum error of 40 F.

Case Report: Lightning-Induced Pneumomediastinum.

PubMed

Blumenthal, Ryan; Saayman, Gert

2017-06-01

We present the case of a 41-year-old woman who was fatally injured during a witnessed lightning strike event and in whom autopsy revealed the unusual keraunopathological finding of overt pneumomediastinum. The possible pathophysiological mechanism(s) of causation of this phenomenon are discussed, with specific reference also to the "Macklin" effect and the role of blast overpressures associated with lightning strike. It is suggested that the latter may lead to sudden alveolar rupture, with subsequent rapid tracking of air along bronchovascular sheaths in a centripetal manner toward the hilum of the lung and thus into the mediastinum. A review of the blast literature suggests that this victim would have been exposed to a blast pressure wave of approximately 29-psi (200 kPa) to 72-psi (500 kPa) magnitude.

Mayo AVC Registry and BioBank

ClinicalTrials.gov

2018-03-05

Arrhythmogenic Right Ventricular Cardiomyopathy; Cardiomyopathies; Heart Diseases; Cardiovascular Diseases; Sudden Cardiac Arrest; Sudden Cardiac Death; Arrhythmogenic Right Ventricular Dysplasia; Arrhythmogenic Ventricular Cardiomyopathy; Familial Dilated Cardiomyopathy; Cardiovascular Abnormalities

Mesospheric signatures observed during 2010 minor stratospheric warming at King Sejong Station (62°S, 59°W)

NASA Astrophysics Data System (ADS)

Eswaraiah, S.; Kim, Yong Ha; Hong, Junseok; Kim, Jeong-Han; Ratnam, M. Venkat; Chandran, A.; Rao, S. V. B.; Riggin, Dennis

2016-03-01

A minor stratospheric sudden warming (SSW) event was noticed in the southern hemisphere (SH) during September (day 259) 2010 along with two episodic warmings in early August (day 212) and late October (day 300) 2010. Among the three warming events, the signature of mesosphere response was detected only for the September event in the mesospheric wind dataset from both meteor radar and MF radar located at King Sejong Station (62°S, 59°W) and Rothera (68°S, 68°W), Antarctica, respectively. The zonal winds in the mesosphere reversed approximately a week before the September SSW event, as has been observed in the 2002 major SSW. Signatures of mesospheric cooling (MC) in association with stratospheric warmings are found in temperatures measured by the Microwave Limb Sounder (MLS). Simulations of specified dynamics version of Whole Atmosphere Community Climate Model (SD-WACCM) are able to reproduce these observed features. The mesospheric wind field was found to differ significantly from that of normal years probably due to enhanced planetary wave (PW) activity before the SSW. From the wavelet analysis of wind data of both stations, we find that strong 14-16 day PWs prevailed prior to the SSW and disappeared suddenly after the SSW in the mesosphere. Our study provides evidence that minor SSWs in SH can result in significant effects on the mesospheric dynamics as in the northern hemisphere.

Infant sleep positioning by nursery staff and mothers in newborn hospital nurseries.

PubMed

Stastny, Penny F; Ichinose, Travers Y; Thayer, Sharon D; Olson, Robert J; Keens, Thomas G

2004-01-01

Although advice from healthcare professionals may influence parental infant placement choice to reduce sudden infant death syndrome risk, literature on nursery staff infant placement behaviors and the degree to which they influence maternal infant sleep positioning is limited. To assess newborn placement practices of the mother and nursery staff and their interrelationship in the hospital setting. A cross-sectional survey-based study was conducted among hospital newborn nursery staff (n = 96) and mothers of newborns (n = 579) at eight perinatal hospitals in Orange County, California. Although a majority of sampled nursery staff (72%) identified the supine position as the placement that most lowers sudden infant death syndrome risk, only 30% reported most often placing infants to sleep in that position, with most staff (91%) citing fear of aspiration as the motivation for supine position avoidance. Only 34% of staff reported advising exclusive supine infant positioning to mothers. Approximately 36% of mothers reported using supine infant placement exclusively. Maternal infant placement choice varied by both the advice (p <.01) and the placement modeling (p <.01) provided by staff, with the highest proportion of usual supine infant placement found among mothers who reported receiving both. A mother's race/ethnicity also affected the reception of exclusive supine placement recommendations (p <.01). Exclusive supine infant placement appears to be underused by both nursery staff and mothers of newborn infants. Culturally grounded educational intervention with nursery staff regarding infant positioning and placement in the hospital setting is indicated.

Two Sudden and Unexpected Deaths of Patients with Schizophrenia Associated with Intramuscular Injections of Antipsychotics and Practice Guidelines to Limit the Use of High Doses of Intramuscular Antipsychotics

PubMed Central

Brenzel, Allen

2016-01-01

Intravenous haloperidol has been associated with torsades de pointes (TdP). These two sudden deaths were probable adverse drug reactions (ADRs) following intramuscular (IM) antipsychotics. The autopsies described lack of heart pathology and were highly compatible with the possibility of TdP in the absence of risk factors other than the accumulation of antipsychotics with a high serum peak after the last injection, leading to death within hours. The first case was a 27-year-old African-American male with schizophrenia but no medical issues. His death was probably caused by repeated IM haloperidol injections of 10 mg (totaling 35 mg in 2 days). The second case involves a 42-year-old African-American female with metabolic syndrome. Her probable cause of death was the last ziprasidone IM injection of 20 mg in addition to (1) three extra haloperidol doses (2 hours before the ziprasidone injection, 5 mg oral haloperidol; approximately 21 hours earlier, 5 mg oral haloperidol; and 2 days prior, one 10 mg IM haloperidol injection), (2) 10 mg/day of scheduled oral haloperidol for 6 days before death, and (3) a long-acting paliperidone injection of 156 mg 18 days before death. The study of haloperidol glucuronidation and its impairment in some African-Americans is urgently recommended. PMID:27597919

Toddler run-overs--a persistent problem.

PubMed

Byard, Roger W; Jensen, Lisbeth L

2009-05-01

Trauma accounts for a high percentage of unexpected deaths in toddlers and young children, mostly due to vehicle accidents, drowning and fires. Given recent efforts to publicise the dangers of toddler run-overs a study was undertaken to determine how significant this problem remains in South Australia. Review of coronial files over 7 years from 2000 to 2006 revealed 50 cases of sudden and unexpected death in children aged between 1 and 3 years of which 12 of 28 accidents involved motor vehicles (6 run-overs and 6 passengers). The 6 children who were killed by vehicle run-overs were aged from 12 months to 22 months (ave=16.8 months) with a male to female ratio of 1:1. Four deaths occurred with reversing vehicles in home driveways and one at a community centre. The remaining death involved a child being run over at the beach by a forward moving vehicle. Vehicles included sedans in four cases and a four-wheel drive in one case (one vehicle was not described), and were driven by the victim's parent in four cases, a friend of the family in one, and an unrelated person in the final case. Deaths were all due to blunt cranial trauma. Despite initiatives to prevent these deaths, toddler run-overs in South Australia approximate the number of sudden deaths due to homicides, drownings and natural diseases, respectively, for the same age group; deaths are also occurring in places other than home driveways, and sedans were more often involved than four-wheel drive vehicles.

Sudden unexpected death related to enterovirus myocarditis: histopathology, immunohistochemistry and molecular pathology diagnosis at post-mortem

PubMed Central

2012-01-01

Background Viral myocarditis is a major cause of sudden unexpected death in children and young adults. Until recently, coxsackievirus B3 (CVB3) has been the most commonly implicated virus in myocarditis. At present, no standard diagnosis is generally accepted due to the insensitivity of traditional diagnostic tests. This has prompted health professionals to seek new diagnostic approaches, which resulted in the emergence of new molecular pathological tests and a more detailed immunohistochemical and histopathological analysis. When supplemented with immunohistochemistry and molecular pathology, conventional histopathology may provide important clues regarding myocarditis underlying etiology. Methods This study is based on post-mortem samples from sudden unexpected death victims and controls who were investigated prospectively. Immunohistochemical investigations for the detection of the enteroviral capsid protein VP1 and the characterization and quantification of myocardial inflammatory reactions as well as molecular pathological methods for enteroviral genome detection were performed. Results Overall, 48 sudden unexpected death victims were enrolled. As for controls, 37 cases of unnatural traffic accident victims were studied. Enterovirus was detected in 6 sudden unexpected death cases (12.5 %). The control samples were completely enterovirus negative. Furthermore, the enteroviral capsid protein VP1 in the myocardium was detected in enterovirus-positive cases revealed by means of reverse transcriptase-polymerase chain reaction (RT-PCR). Unlike control samples, immunohistochemical investigations showed a significant presence of T and B lymphocytes in sudden unexpected death victims. Conclusions Our findings demonstrate clearly a higher prevalence of viral myocarditis in cases of sudden unexpected death compared to control subjects, suggesting that coxsackie B enterovirus may contribute to myocarditis pathogenesis significantly. PMID:22966951

[Expression of proBNP and NT-proBNP in Sudden Death of Coronary Heart Disease].

PubMed

Zeng, Q; Sun, R F; Li, Z; Zhai, L Q; Liu, M Z; Guo, X J; Gao, C R

2017-10-01

To study the expression change of pro-brain natriuretic peptide （proBNP） and N-terminal pro-brain natriuretic peptide （NT-proBNP） in sudden death of coronary atherosclerotic heart disease, and to explore its application in forensic diagnosis. Myocardial and blood samples were collected from normal control group, sudden death of coronary atherosclerotic heart disease group and single coronary stenosis group （20 cases in each group）. The expression of proBNP in myocardial samples were detected by immunohistochemical staining and Western blotting, and that of BNP mRNA were detected by reverse transcription PCR （RT-PCR）. The content of NT-proBNP in plasma were detected by ELISA. Immunohistochemical staining showed positive expression of proBNP in both sudden death of coronary atherosclerotic heart disease group and single coronary stenosis group. There was no positive expression in normal control group. For sudden death of coronary atherosclerotic heart disease group and single coronary stenosis group, the relative expression of proBNP protein and BNP mRNA in myocardial tissue and the NT-proBNP content in plasma were higher than that of normal control group （ P <0.05）. The NT-proBNP content in plasma of sudden death of coronary atherosclerotic heart disease group was higher than that of single coronary stenosis group （ P <0.05）. In myocardial ischemia condition, the higher expression of proBNP in cardiac muscle cell shows that the detection of NT-proBNP in plasma can be useful to differentially diagnose the degree of coronary atherosclerotic heart disease and determine whether the sudden death due to coronary atherosclerotic heart disease. Copyright© by the Editorial Department of Journal of Forensic Medicine

High-Dose Citalopram and Escitalopram and the Risk of Out-of-Hospital Death.

PubMed

Ray, Wayne A; Chung, Cecilia P; Murray, Katherine T; Hall, Kathi; Stein, C Michael

2017-02-01

Studies demonstrating that higher doses of citalopram (> 40 mg) and escitalopram (> 20 mg) prolong the corrected QT interval prompted regulatory agency warnings, which are controversial, given the absence of confirmatory clinical outcome studies. We compared the risk of potential arrhythmia-related deaths for high doses of these selective serotonin reuptake inhibitors (SSRIs) to that for equivalent doses of fluoxetine, paroxetine, and sertraline. The Tennessee Medicaid retrospective cohort study included 54,220 persons 30-74 years of age without cancer or other life-threatening illness who were prescribed high-dose SSRIs from 1998 through 2011. The mean age was 47 years, and 76% were female. Demographic characteristics and comorbidity for individual SSRIs were comparable. Because arrhythmia-related deaths are typically sudden and occur outside the hospital, we analyzed out-of-hospital sudden unexpected death as well as sudden cardiac deaths, a more specific indicator of proarrhythmic effects. The adjusted risk of sudden unexpected death for citalopram did not differ significantly from that for the other SSRIs. The respective hazard ratios (HRs) for citalopram versus escitalopram, fluoxetine, paroxetine, and sertraline were 0.84 (95% CI, 0.40-1.75), 1.24 (95% CI, 0.75-2.05), 0.75 (95% CI, 0.45-1.24), and 1.53 (95% CI, 0.91-2.55). There were no significant differences for sudden cardiac death or all study deaths, nor were there significant differences among high-risk patients (≥ 60 years of age, upper quartile baseline cardiovascular risk). Escitalopram users had no significantly increased risk for any study end point. We found no evidence that risk of sudden unexpected death, sudden cardiac death, or total mortality for high-dose citalopram and escitalopram differed significantly from that for comparable doses of fluoxetine, paroxetine, and sertraline. © Copyright 2016 Physicians Postgraduate Press, Inc.

High-Dose Citalopram and Escitalopram and the Risk of Out-of-Hospital Death

PubMed Central

Ray, Wayne A.; Chung, Cecilia P.; Murray, Katherine T.; Hall, Kathi; Stein, C. Michael

2018-01-01

Objective Studies demonstrating higher doses of citalopram (>40mg) and escitalopram (>20mg) prolong the QTc interval prompted regulatory agency warnings, which are controversial, given the absence of confirmatory clinical outcome studies. We compared the risk of potential arrhythmia-related deaths for high doses of these SSRIs to that for equivalent doses of fluoxetine, paroxetine, and sertraline. Method The Tennessee Medicaid retrospective cohort study included 54,220 persons 30–74 years of age without cancer or other life-threatening illness prescribed high-dose SSRIs. The mean age was 47 years and 76% were female. Demographic characteristics and comorbidity for individual SSRIs were comparable. Because arrhythmia-related deaths are typically sudden and occur outside the hospital, we analyzed out-of-hospital sudden unexpected death as well as sudden cardiac deaths, a more specific indicator of pro-arrhythmic effects. Results The adjusted risk of sudden unexpected death for citalopram did not differ significantly from that for the other SSRIs. The respective hazard ratios (HRs) for citalopram versus escitalopram, fluoxetine, paroxetine, and sertraline were 0.84 (95% confidence interval [CI], 0.40–1.75), 1.24 (0.75–2.05), 0.75 (0.45–1.24), and 1.53 (0.91–2.55). There were no significant differences for sudden cardiac death or all study deaths, nor were there significant differences among high-risk patients (≥60 years of age, upper quartile baseline cardiovascular risk). Escitalopram users had no significantly increased risk for any study endpoint. Conclusions We found no evidence that risk of sudden unexpected death, sudden cardiac death, or total mortality for high-dose citalopram and escitalopram differed significantly from that for comparable doses of fluoxetine, paroxetine, and sertraline. PMID:27736049

Obesity paradox and risk of sudden death in heart failure results from the MUerte Subita en Insuficiencia cardiaca (MUSIC) study.

PubMed

Gastelurrutia, Paloma; Pascual-Figal, Domingo; Vazquez, Rafael; Cygankiewicz, Iwona; Shamagian, Lillian Grigorian; Puig, Teresa; Ferrero, Andreu; Cinca, Juan; de Luna, Antoni Bayes; Bayes-Genis, Antoni

2011-01-01

among patients with heart failure (HF), body mass index (BMI) has been inversely associated with mortality, giving rise to the so-called obesity paradox. The aim of this study was to examine the relationship between BMI and two modes of cardiac death: pump failure death and sudden death. nine hundred seventy-nine patients with mild to moderate chronic symptomatic HF from the MUSIC (MUerte Subita en Insuficiencia Cardiaca) Study, a prospective, multicenter, and longitudinal study designed to assess risk predictors of cardiac mortality, were followed up during a median of 44 months. Independent predictors of death were identified by a multivariable Cox proportional hazards model. higher BMI emerged as an independent predictor of all-cause mortality (hazard ratio [HR] = 0.94, 95% confidence interval [CI] = 0.91-0.97, P = .0003) and pump failure death (HR = 0.93, 95% CI = 0.88-0.98, P = .004). Sudden death accounted for 45% of deaths in obese patients, 53% in overweight patients, and 37% in lean patients. No significant relationship between BMI and sudden death was observed (HR = 0.97, 95% CI = 0.92-1.02, P = .28). The only independent predictors of sudden death were prior history of myocardial infarction (HR = 1.89, 95% CI = 1.23-2.90, P = .004), hypertension (HR = 1.66, 95% CI = 1.05-2.63, P = .03), left ventricular ejection fraction (HR = 0.88, 95% CI = 0.79-0.96, P = .006), and N-terminal pro-B-type natriuretic peptide (HR = 1.01, 95% CI = 1.00-1.02, P = .048). the obesity paradox in HF affects all-cause mortality and pump failure death but not sudden death. The risk of dying suddenly was similar across BMI categories in this cohort of ambulatory patients with HF.

Severe Respiratory Acidosis in Status Epilepticus as a Possible Etiology of Sudden Death in Lesch-Nyhan Disease: A Case Report and Review of the Literature.

PubMed

Christy, Alison; Nyhan, William; Wilson, Jenny

2017-01-01

Lesch-Nyhan disease (LND) is an X-linked disorder of purine metabolism, associated with self-mutilation, dystonia, and chorea. Seizures are uncommon in LND. Patients with LND are at risk for sudden and unexpected death. The etiology of this is unknown, but appears to occur from a respiratory process. We propose that respiratory failure secondary to subclinical seizure may lead to sudden death in these patients. We report a case of an 11-year-old boy with LND who had two episodes of nocturnal gasping. The second event was immediately followed by a 10 min generalized seizure. Upon arrival at the hospital, an arterial blood gas test revealed a severe respiratory acidosis. Following aggressive treatment of his seizures, this patient did well, and was discharged home on oxcarbazepine with rectal diazepam. No further seizures have been noted in 1 year of follow-up. In this case report and review, we hypothesize that sudden death from respiratory failure in Lesch-Nyhan disease may in some cases be due to seizure-induced respiratory failure, akin to sudden unexpected death in epilepsy (SUDEP). We suggest screening for paroxysmal respiratory events; consideration of electroencephalography for patients with LND presenting in respiratory distress or failure; and consideration of more aggressive treatment of seizures in these patients. Brief Summary:We present an 11-year-old boy with Lesch-Nyhan disease (LND) who developed respiratory failure and severe respiratory acidosis from his first known seizure, which evolved to subclinical status epilepticus. We propose that patients with LND have a predisposition to respiratory failure and sudden death, which in some cases may be provoked by seizure (sudden unexpected death in epilepsy, or SUDEP).

Cardiovascular Risk Factors in Primary Relatives of Sudden Cardiac Death Victims

DTIC Science & Technology

1991-01-01

hypertriglyceridemia and hypertension as risk factors in relatives of sudden death victims. The sample for both studies will be the same. 5 Chapter II The...provided most of the research information on SCD. Pathology of Sudden Cardiac Death There appear to be several different pathologic scenarios which render a...had severe two or three vessel disease. By comparison, 100 age matched controls who died of other causes, had a combined 27% incidence of two and

Is there an association between depression and cardiovascular mortality or sudden death?

PubMed

Alboni, Paolo; Favaron, Elisa; Paparella, Nelly; Sciammarella, Massimo; Pedaci, Mario

2008-04-01

The results of many studies and recent meta-analyses strongly suggest that depression is a risk factor for total and cardiovascular mortality, both in the general population and in patients with known heart disease. By contrast, the association between depression and sudden death or cardiac arrest has received little attention. This issue has been investigated in three recent studies; two were carried out in the general population and showed depression to be a independent risk factor for sudden death. The other study was carried out in patients with acute myocardial infarction (AMI); the adjusted relative risk (RR) of sudden death was significantly increased in depressed patients but, after adjustment for dyspnea/fatigue (a common symptom for heart disease and depression), the RR was no longer statistically significant. However, when the cognitive-affective depressive symptoms were examined separately from the somatic ones (dyspnea/fatigue, etc.), there was a clear trend for an association between cognitive-affective symptoms and sudden death. Because a risk factor can be defined as 'independent' only in a multivariate analysis in which variables are dichotomized, the presence of common symptoms between heart disease and depression represents a very difficult problem. However, taken together, the results of studies carried out in the general population and in patients with AMI strongly suggest that depression is a significant risk factor for sudden death.

Relationship between KCNQ1 (LQT1) and KCNH2 (LQT2) gene mutations and sudden death during illegal drug use.

PubMed

Nagasawa, Sayaka; Saitoh, Hisako; Kasahara, Shiori; Chiba, Fumiko; Torimitsu, Suguru; Abe, Hiroko; Yajima, Daisuke; Iwase, Hirotaro

2018-05-31

Long QT syndrome (LQTS), a congenital genetic disorder, can cause torsades de pointes (TdP), and lethal cardiac arrhythmia may result from ingestion of cardiotoxic drugs. Methamphetamine (MP) and new psychoactive substances (NPSs) can trigger TdP due to QT prolongation, leading to sudden death. We therefore analysed variations in the LQTS-associated genes KCNQ1 (LQT1) and KCNH2 (LQT2) using cardiac blood and myocardial tissue from subjects having died suddenly during MP or NPS use to investigate the relationship between congenital genetic abnormalities and sudden death during illegal drug use. We amplified and sequenced all exons of these genes using samples from 20 subjects, half of whom had died taking MP and half after using NPSs. G643S, a KCNQ1 missense polymorphism, was significantly more common among sudden deaths involving NPSs (6 subjects) than those involving MP (1 subject) and healthy Japanese subjects (P = 0.001). Notably, synthetic cathinones were detected in 2 of 3 cases involving G643S carriers. Previous functional analyses have indicated that the G643S polymorphism in the KCNQ1 potassium channel gene causes mild I Ks channel dysfunction. Our data suggest that use of NPSs, particularly synthetic cathinones, is associated with elevated risk of serious cardiac arrhythmia and sudden death for subjects carrying KCNQ1 G643S.

Registry of Malignant Arrhythmias and Sudden Cardiac Death - Influence of Diagnostics and Interventions

ClinicalTrials.gov

2016-11-30

Ventricular Tachycardia; Ventricular Fibrillation; Sudden Cardiac Death; Coronary Angiography; Electrophysiologic Testing (EP); Catheter Ablation; Percutaneous Coronary Intervention (PCI); Internal Cardioverter Defibrillator (ICD)

Maximum Expected Wall Heat Flux and Maximum Pressure After Sudden Loss of Vacuum Insulation on the Stratospheric Observatory for Infrared Astronomy (SOFIA) Liquid Helium (LHe) Dewars

NASA Technical Reports Server (NTRS)

Ungar, Eugene K.

2014-01-01

The aircraft-based Stratospheric Observatory for Infrared Astronomy (SOFIA) is a platform for multiple infrared observation experiments. The experiments carry sensors cooled to liquid helium (LHe) temperatures. A question arose regarding the heat input and peak pressure that would result from a sudden loss of the dewar vacuum insulation. Owing to concerns about the adequacy of dewar pressure relief in the event of a sudden loss of the dewar vacuum insulation, the SOFIA Program engaged the NASA Engineering and Safety Center (NESC). This report summarizes and assesses the experiments that have been performed to measure the heat flux into LHe dewars following a sudden vacuum insulation failure, describes the physical limits of heat input to the dewar, and provides an NESC recommendation for the wall heat flux that should be used to assess the sudden loss of vacuum insulation case. This report also assesses the methodology used by the SOFIA Program to predict the maximum pressure that would occur following a loss of vacuum event.

Validation of a computer case definition for sudden cardiac death in opioid users.

PubMed

Kawai, Vivian K; Murray, Katherine T; Stein, C Michael; Cooper, William O; Graham, David J; Hall, Kathi; Ray, Wayne A

2012-08-31

To facilitate the use of automated databases for studies of sudden cardiac death, we previously developed a computerized case definition that had a positive predictive value between 86% and 88%. However, the definition has not been specifically validated for prescription opioid users, for whom out-of-hospital overdose deaths may be difficult to distinguish from sudden cardiac death. We assembled a cohort of persons 30-74 years of age prescribed propoxyphene or hydrocodone who had no life-threatening non-cardiovascular illness, diagnosed drug abuse, residence in a nursing home in the past year, or hospital stay within the past 30 days. Medical records were sought for a sample of 140 cohort deaths within 30 days of a prescription fill meeting the computer case definition. Of the 140 sampled deaths, 81 were adjudicated; 73 (90%) were sudden cardiac deaths. Two deaths had possible opioid overdose; after removing these two the positive predictive value was 88%. These findings are consistent with our previous validation studies and suggest the computer case definition of sudden cardiac death is a useful tool for pharmacoepidemiologic studies of opioid analgesics.

Theoretical and experimental investigation on the sudden unbalance and rub-impact in rotor system caused by blade off

NASA Astrophysics Data System (ADS)

Wang, Cun; Zhang, Dayi; Ma, Yanhong; Liang, Zhichao; Hong, Jie

2016-08-01

Blade loss from a running turbofan rotor will introduce sudden unbalance into the dynamical system, and as a consequence leads to the rub-impact, the asymmetry of rotor and a series of interesting dynamic characteristics. The paper focuses on the theoretical study on the sudden unbalance and rub-impact caused by blade loss, in particular investigates the response of the rotor on a rotor test rig with sudden unbalance and rub-impact device designed respectively. The results reveal that the sudden unbalance will induce impact effect on the rotor, and critical speed frequency is excited in frequency spectrum. Meantime, the impact effect is more obvious for the rotor operating above critical speed. The influence of rub-impact is considered as additional constraint to the rotor, analyzed by the theory of time-varying system for the first time, and the results are evaluated by experimental tests. The study shows that great attention should be paid to the dynamical design for the overhung rotor system, additional constraint and corresponding analysis method in rub-impact need to be intensively studied.

Thyroid gland and cerebella lesions: New risk factors for sudden cardiac death in schizophrenia?

PubMed

Scorza, Fulvio A; Cavalheiro, Esper A; de Albuquerque, Marly; de Albuquerque, Juliana; Cysneiros, Roberta M; Terra, Vera C; Arida, Ricardo M

2011-02-01

People with schizophrenia show a two to threefold increased risk to die prematurely than those without schizophrenia. Patients' life style, suicide, premature development of cardiovascular disease, high prevalence of metabolic syndrome and sudden cardiac death are well-known causes of the excess mortality. The exact pathophysiological cause of sudden death in schizophrenia is unknown, but it is likely that cardiac arrhythmia and respiratory abnormalities play potential role. Some antipsychotics may be associated with cardiovascular adverse events (e.g., QT interval prolongation) and lesions in specific brain regions, such as cerebella may be associated with respiratory abnormalities, suggesting that metabolic and brain dysfunction could lead to sudden cardiac death in patients with schizophrenia. However, exact knowledge regarding the association of these findings and schizophrenia is lacking. As subclinical hyperthyroidism has been linked with increased risk of cardiovascular disease and cerebella progressive atrophy has been observed in patients with schizophrenia, we propose in this paper that subclinical thyroid dysfunction and cerebella volume loss could be considered as new risk factor for sudden cardiac death in schizophrenia. Copyright © 2010 Elsevier Ltd. All rights reserved.

Bedsharing at home, breastfeeding and sudden infant death.Recommendations for health professionals

PubMed

Jenik, Alejandro; Conti, Roxana

2017-10-01

The Sudden and Unexpected Infant Death Task Force together with the Subcommittee on Breastfeeding of the Sociedad Argentina de Pediatría have issued updated recommendations on bedsharing with the parents, a practice which remains controversial. Sleeping with the mother maximizes breastfeeding, which is protective against Sudden Infant Death. There is a small group of infants that have been associated with an increased risk of Sudden Infant Death and fatal sleeping accidents in certain circumstances. These hazards include parental smoking, sedating drugs or medication and alcohol consumption prior to sleep and sofa sharing situations. Bedsharing by breastfeeding mothers with their infants, in the absence of the above-mentioned risk factors, and with parents aware of how to ensure a safe infant sleep environment has not been shown to be associated with increased risk of Sudden Infant Death. This guidance does not advise on telling parents that they must never sleep with the baby, but rather instructs health professionals to give parents balanced advice to allow informed decision making, emphasizing the concept that parental room sharing without bedsharing is the safest place for the babies to sleep

Severe decrease in high-density lipoprotein cholesterol with the combination of fibrates and ezetimibe: A case series.

PubMed

Nobecourt, Estelle; Cariou, Bertrand; Lambert, Gilles; Krempf, Michel

A sudden and severe drug-induced decrease in plasma high-density lipoprotein cholesterol (HDL-C) is a rare condition. We report 2 patients with familial hypercholesterolemia treated with statins and fibrates and 2 others with mixed dyslipidemia treated with fibrates, who presented with a sudden and severe decrease in HDL-C (from -44% to -95%, compared with baseline). Three of the patients were treated with fibrates and had a sudden decrease in HDL-C after the adjunction of ezetimibe. HDL-C returned to normal levels after discontinuation of the offending therapies. In 2 of these patients, the reintroduction of ezetimibe with no fibrates did not affect HDL-C. In conclusion, we report a new profile of patients who are at risk for a sudden drop of HDL-C related to treatment with a combination of fibrates and ezetimibe. Although a sudden drop of HDL-C is a rare event, we recommend to carefully monitor plasma HDL-C in patients submitted to both drugs. Copyright © 2016 National Lipid Association. Published by Elsevier Inc. All rights reserved.

Anxiety disorders

MedlinePlus

... Anxiety can also be a sudden attack of terror when there is no threat. What are anxiety ... People with panic disorder have sudden attacks of terror when there is no actual danger. Panic attacks ...

A Model of a Sudden-Death Field-Goal Football Game as a Sequential Duel,

DTIC Science & Technology

1985-05-25

AD-RI58 232 A MODEL OF A SUDDEN-DEATH FIEL-D-GOAL FOOTBALL GAME AS A 1/1 SEGUENTIAL DUEL .. (U) VALE UNIV NEW HAVEN CT COWIES FOUNDATION FOR RESEARCH...author to pro- tect the tentative character of these papers. A MODEL OF A SUDDEN-DEATH FIELD-GOAL FOOTBALL GAME LUJ-. j AS A SEQUENTIAL DUEL S -ELECTE...abstraction. Yet an interesting extension of the military dueling literature appears to be feasible. Rather than claim Immediate relevance to football as

Rotational Energy Transfer and Collisional Induced Raman Linewidths in N2 Gas. 1; Energy Transfer Rates

NASA Technical Reports Server (NTRS)

Huo, Winifred M.; Green, Sheldon; Langhoff, Stephen R. (Technical Monitor)

1995-01-01

Rotationally inelastic transitions of N2 have been studied in the coupled state (CS) and infinite-order-sudden (IOS) approximations, using the N2-N2 rigidrotor potential of van der Avoird et al. For benchmarking purposes, close coupling (CC) calculations have also been carried out over a limited energy range. The CC and CS cross sections have been obtained both with and without identical molecule exchange symmetry, whereas exchange was neglected in the IOS calculations. The CS results track the CC cross sections rather well; between 113 - 219 cm(exp -1) the average deviation is 14%. Comparison between the CS and IOS cross sections at the high energy end of the CS calculation, 500 - 680 cm(exp -1), shows that IOS is sensitive to the amount of inelasticity and the results for large DELTA J transitions are subject to larger errors. It is found that the state-to-state cross sections with even and odd exchange symmetry agree to better than 2% and are well represented as a sum of direct and exchange cross sections for distinguishable molecules, an indication of the applicability of a classical treatment for this system. This result, however, does not apply to partial cross sections for given total J, but arises from a near cancellation in summing over partial waves. In order to use rigid-rotor results for the calculation of effective rotational excitation rates of N2 in the v=1 vibrational level colliding with bath N2 molecules in the v=0 level, it is assumed that exchange scattering between molecules in different vibrational levels is negligible and direct scattering is independent of Y. Good agreement with room temperature experimental data is obtained. The effective rates determined using the IOS and energy corrected sudden (ECS) approximations are also in reasonable agreement with experiment, with the ECS results being somewhat better. The problem with a degeneracy factor in earlier cross section expressions for collisions between identical molecules is pointed out and corrected.

Genetic anticipation in a special form of hypertrophic cardiomyopathy with sudden cardiac death in a family with 74 members across 5 generations.

PubMed

Guo, Xiying; Fan, Chaomei; Wang, Yanping; Wang, Miao; Cai, Chi; Yang, Yinjian; Zhao, Shihua; Duan, Fujian; Li, Yishi

2017-03-01

Hypertrophic cardiomyopathy (HCM) is the most common heritable heart disease. The genetic anticipation of HCM and its associated etiology, sudden cardiac death (SCD), remains unclear. The aim of this study was to investigate the mechanism underlying the genetic anticipation of HCM and associated SCD.An HCM family including 5 generations and 74 members was studied. Two-dimensional echocardiography was performed to diagnose HCM. The age of onset of HCM was defined as the age at first diagnosis according to hospital records. The information on SCD was confirmed by verification by ≥2 family members and a review of hospital records. Whole-genome sequencing was performed on 4 HCM subjects and 1 healthy control in the family. The identified mutations were screened in all available family members and 216 unrelated healthy controls by Sanger sequencing.The median ages of onset of HCM were 63.5, 38.5, and 18.0 years in members of the second, third, and fourth generations of the family, respectively, and the differences between the generations were significant (P < 0.001). The age at SCD also decreased with each subsequent generation (P < 0.05). In particular, among the third-generation family members, SCD occurred between 30 and 40 years of age at approximately 8 AM, whereas among the fourth-generation family members, all 5 males who experienced SCD were 16 years of age and died at approximately 8 AM. The sarcomere gene mutations MYH7-A719H and MYOZ2-L169G were detected in the HCM individuals in this pedigree. Increases in the number of mutations and the frequency of multiple gene mutations were observed in the younger generations. Moreover, a structural variant was present in the HCM phenotype-positive subjects but was absent in the HCM phenotype-negative subjects.HCM may exhibit genetic anticipation, with a decreased age of onset and increased severity in successive generations. Multiple gene mutations may contribute to genetic anticipation in HCM and thus may be of prognostic value.

The epidemiology of sudden oak death in Oregon forests

Treesearch

Ebba K. Peterson

2011-01-01

The phytopathogen Phytophthora ramorum (Werres, DeCock & Man in't Veld), causal agent of Sudden Oak Death (SOD) of oaks (Quercus spp.) and tanoaks (Notholithocarpus densiflorus syn. Lithocarpus densiflorus...

RBC indices

MedlinePlus

... sudden blood loss, long-term diseases, kidney failure , aplastic anemia , or man-made heart valves). MCV above normal. ... sudden blood loss, long-term diseases, kidney failure, aplastic anemia, or man-made heart valves). MCH above normal. ...

Quantum coherence behaviors of fermionic system in non-inertial frame

NASA Astrophysics Data System (ADS)

Huang, Zhiming; Situ, Haozhen

2018-04-01

In this paper, we analyze the quantum coherence behaviors of a single qubit in the relativistic regime beyond the single-mode approximation. Firstly, we investigate the freezing condition of quantum coherence in fermionic system. We also study the quantum coherence tradeoff between particle and antiparticle sector. It is found that there exists quantum coherence transfer between particle and antiparticle sector, but the coherence lost in particle sector is not entirely compensated by the coherence generation of antiparticle sector. Besides, we emphatically discuss the cohering power and decohering power of Unruh channel with respect to the computational basis. It is shown that cohering power is vanishing and decohering power is dependent of the choice of Unruh mode and acceleration. Finally, we compare the behaviors of quantum coherence with geometric quantum discord and entanglement in relativistic setup. Our results show that this quantifiers in two region converge at infinite acceleration limit, which implies that this measures become independent of Unruh modes beyond the single-mode approximations. It is also demonstrated that the robustness of quantum coherence and geometric quantum discord are better than entanglement under the influence of acceleration, since entanglement undergoes sudden death.

Proton--H/sub 2/ scattering on an ab initio CI potential energy surface. I. Vibrational excitation at 10 eV

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schinke, R.; Dupuis, M.; Lester, W.A. Jr.

1980-04-01

A complete configuration interaction (CI) ground state surface for the H/sub 3//sup +/ system has been calculated using 5S and 3(P/sub x/,P/sub y/,P/sub x/) basis functions at each center. A total of 650 nuclear geometries has been considered which makes the new surface appropriate not only for scattering calculations, but also for the evaluation of the vibrational--rotational spectrum of the H/sub 3//sup +/ molecule. Significant deviations are found from the analytic Giese and Gentry potential used in many previous theoretical studies, especially for large and small nonequilibrium H--H separations which are important for vibrational excitation of the H/sub 2/ molecule.more » Vibrational--rotational excitation cross sections have been calculated in the rotational sudden approximation where the vibrational degree of freedom is treated exactly by solving seven vibrationally coupled radial equations. The use of the new surface leads to increased vibrational excitation compared to previous calculations utilizing the same scattering approximation and to excellent agreement at 10 eV with the angle-dependent measurements of Hermann, Schmidt, and Linder.« less

Wave packet and statistical quantum calculations for the He + NeH⁺ → HeH⁺ + Ne reaction on the ground electronic state.

PubMed

Koner, Debasish; Barrios, Lizandra; González-Lezana, Tomás; Panda, Aditya N

2014-09-21

A real wave packet based time-dependent method and a statistical quantum method have been used to study the He + NeH(+) (v, j) reaction with the reactant in various ro-vibrational states, on a recently calculated ab initio ground state potential energy surface. Both the wave packet and statistical quantum calculations were carried out within the centrifugal sudden approximation as well as using the exact Hamiltonian. Quantum reaction probabilities exhibit dense oscillatory pattern for smaller total angular momentum values, which is a signature of resonances in a complex forming mechanism for the title reaction. Significant differences, found between exact and approximate quantum reaction cross sections, highlight the importance of inclusion of Coriolis coupling in the calculations. Statistical results are in fairly good agreement with the exact quantum results, for ground ro-vibrational states of the reactant. Vibrational excitation greatly enhances the reaction cross sections, whereas rotational excitation has relatively small effect on the reaction. The nature of the reaction cross section curves is dependent on the initial vibrational state of the reactant and is typical of a late barrier type potential energy profile.

Evolution of the entanglement of the N00N-type of states in a coupled two cavity system via an adiabatic approximation

NASA Astrophysics Data System (ADS)

Chakrabarti, R.; Sreekumari, G.; Yogesh, V.

2018-06-01

We study a system of two cavities each encapsulating a qubit and an oscillator degrees of freedom. An ultrastrong interaction between the qubit and the oscillator is assumed, and the photons are allowed to hop between the cavities. A partition of the time scale between the fast-moving oscillator and the slow moving qubit allows us to set up an adiabatic approximation procedure where we employ the delocalized degrees of freedom to diagonalize the Hamiltonian. The time evolution of the N00N-type initial states now furnishes, for instance, the reduced density matrix of a bipartite system of two qubits. For a macroscopic size of the N00N component of the initial state the sudden death of the entanglement between the qubits and its continued null value are prominently manifest as the information percolates to the qubits after long intervals. For the low photon numbers of the initial states the dynamics produces almost maximally entangled two-qubit states, which by utilizing the Hilbert–Schmidt distance between the density matrices, are observed to be nearly pure generalized Bell states.

Analytical Model for Gyro-Phase Drift Arising from Abrupt Inhomogeneity

NASA Technical Reports Server (NTRS)

Walker, Jeffrey J.; Koepke, M. E.; Zimmerman, M. I.; Farrell, W. M.; Demidov, V. I.

2013-01-01

If a magnetized-orbit-charged grain encounters any abrupt inhomogeneity in plasma conditions during a gyro-orbit, such that the resulting in-situ equilibrium charge is significantly different between these regions (q(sub1)/q(sub 2) approximately 2, where q(sub 1) is the in-situ equilibrium charge on one side of the inhomogeneity, q(sub 2) is the in-situ equilibrium charge on the other side, and q(sub1) less than q(sub 2) less than 0), then the capacitive effects of charging and discharging of the dust grain can result in a modification to the orbit-averaged grain trajectory, i.e. gyro-phase drift. The special case of q(sub 1)/q(sub 2) is notioned for the purpose of illustrating the utility of the method. An analytical expression is derived for the grain velocity, assuming a capacitor approximation to the OML charging model. For cases in which a strong electric field suddenly appears in the wake or at the space-plasma-to-crater interface from solar wind and/or ultraviolet illumination and in which a magnetic field permeates an asteroid, comet, or moon, this model could contribute to the interpretation of the distribution of fields and particles.

Respiratory herpesvirus infection in two Indian Ringneck parakeets.

PubMed

Lazic, Tatjana; Ackermann, Mark R; Drahos, Jo M; Stasko, Judith; Haynes, Joseph S

2008-03-01

A flock of Indian Ringneck parakeets (Psittacula krameri manillensis) was imported to the United States from Australia. Soon after, 1 parakeet suddenly died, and a second parakeet died after a 2-day course of illness, which consisted of anorexia, lethargy, emaciation, and dyspnea. At necropsy, the affected birds had diffuse consolidation and red discoloration of the lungs, as well as thickened, congested air sacs. The microscopic examination revealed multifocal, necrotizing bronchitis, parabronchitis, and interstitial pneumonia. The lumen of the affected airways contained numerous, large syncytial cells with up to 15 nuclei. The nuclei of these syncytial cells often contained large, eosinophilic inclusion bodies, consistent with herpesvirus. The epithelium of the trachea and air sacs was hypertrophied and contained syncytial cells with intranuclear inclusion bodies similar to the bronchi. In addition, a few intranuclear inclusion bodies were also present in the epithelial cells that line the air capillaries. On ultrastructural examination, the nuclei of degenerating epithelial cells contained clusters of viral nucleocapsid proteins and unenveloped, icosahedral, viral particles that were approximately 90 nm in diameter. In addition, some epithelial cells contained clusters of enveloped viral particles approximately 105 nm in diameter, within the cytocavitary network. These lesions are characteristic of those caused by respiratory herpesvirus of parakeets.

Microscopic origin of the charge transfer in single crystals based on thiophene derivatives: A combined NEXAFS and density functional theory approach

NASA Astrophysics Data System (ADS)

Chernenkaya, A.; Morherr, A.; Backes, S.; Popp, W.; Witt, S.; Kozina, X.; Nepijko, S. A.; Bolte, M.; Medjanik, K.; Öhrwall, G.; Krellner, C.; Baumgarten, M.; Elmers, H. J.; Schönhense, G.; Jeschke, H. O.; Valentí, R.

2016-07-01

We have investigated the charge transfer mechanism in single crystals of DTBDT-TCNQ and DTBDT-F4TCNQ (where DTBDT is dithieno[2,3-d;2',3'-d'] benzo[1,2-b;4,5-b']dithiophene) using a combination of near-edge X-ray absorption spectroscopy (NEXAFS) and density functional theory calculations (DFT) including final state effects beyond the sudden state approximation. In particular, we find that a description that considers the partial screening of the electron-hole Coulomb correlation on a static level as well as the rearrangement of electronic density shows excellent agreement with experiment and allows to uncover the details of the charge transfer mechanism in DTBDT-TCNQ and DTBDT-F4 TCNQ, as well as a reinterpretation of previous NEXAFS data on pure TCNQ. Finally, we further show that almost the same quality of agreement between theoretical results and experiment is obtained by the much faster Z+1/2 approximation, where the core hole effects are simulated by replacing N or F with atomic number Z with the neighboring atom with atomic number Z+1/2.

Sudden Infant Death Syndrome (SIDS) and Vaccines

MedlinePlus

... this? Submit What's this? Submit Button Sudden Infant Death Syndrome (SIDS) Recommend on Facebook Tweet Share Compartir ... an international network of vaccine safety experts. SIDS deaths declined due to recommendations to put infants on ...

Earthquakes

MedlinePlus

An earthquake happens when two blocks of the earth suddenly slip past one another. Earthquakes strike suddenly, violently, and without warning at any time of the day or night. If an earthquake occurs in a populated area, it may cause ...

Preventing Knee Injuries

MedlinePlus

... adolescent athletes may be the result of acute, traumatic injuries, such as a sudden fall, or chronic, repetitive ... that suddenly becomes worse due to an acute traumatic event. these injuries may result in various symptoms including pain, instability, ...

Work distributions for random sudden quantum quenches

NASA Astrophysics Data System (ADS)

Łobejko, Marcin; Łuczka, Jerzy; Talkner, Peter

2017-05-01

The statistics of work performed on a system by a sudden random quench is investigated. Considering systems with finite dimensional Hilbert spaces we model a sudden random quench by randomly choosing elements from a Gaussian unitary ensemble (GUE) consisting of Hermitian matrices with identically, Gaussian distributed matrix elements. A probability density function (pdf) of work in terms of initial and final energy distributions is derived and evaluated for a two-level system. Explicit results are obtained for quenches with a sharply given initial Hamiltonian, while the work pdfs for quenches between Hamiltonians from two independent GUEs can only be determined in explicit form in the limits of zero and infinite temperature. The same work distribution as for a sudden random quench is obtained for an adiabatic, i.e., infinitely slow, protocol connecting the same initial and final Hamiltonians.

Bilateral sudden sensorineural hearing loss as a presenting feature of systemic lupus erythematosus

PubMed Central

Chawki, Sylvain; Aouizerate, Jessie; Trad, Selim; Prinseau, Jacques; Hanslik, Thomas

2016-01-01

Abstract Introduction: Sudden sensorineural hearing loss is an unusual presenting clinical feature of systemic lupus erythematosus. Case report: We report the case of a young woman who was admitted to hospital for sudden sensorineural hearing loss and hemophagocytic syndrome which was attributed to systemic lupus erythematosus on the basis of specific renal involvement, thrombocytopenia, and consistent autoantibodies. Favorable outcome was obtained on high-dose corticosteroids, and the hearing fully recovered. Discussion: Sudden sensorineural hearing loss in systemic lupus erythematosus is seemingly more frequently associated with severe systemic involvement and antiphospholipid antibodies may be present. Although management remains empirical, the high risk of permanent hearing impairment seems to justify emergency treatment with high-dose corticosteroids. When the clinical and laboratory criteria of antiphospholipid syndrome are met, antiplatelets agents or anticoagulation therapy shall be considered. PMID:27603334

Sudden headache, third nerve palsy and visual deficit: thinking outside the subarachnoid haemorrhage box.

PubMed

Ní Chróinín, Danielle; Lambert, John

2013-11-01

A 75-year-old lady presented with sudden severe headache and vomiting. Examination was normal, and CT and lumbar puncture not convincing for subarachnoid haemorrhage. Shortly thereafter, she developed painless diplopia. Examination confirmed right third cranial nerve palsy plus homonymous left inferior quadrantanopia. Urgent cerebral MRI with angiography was requested to assess for a possible posterior communicating artery aneurysm, but revealed an unsuspected pituitary mass. Pituitary adenoma with pituitary apoplexy was diagnosed. Pituitary apopolexy is a syndrome comprising sudden headache, meningism, visual and/or oculomotor deficits, with an intrasellar mass. It is commonly due to haemorrhage or infarction within a pituitary adenoma. Treatment includes prompt steroid administration, and potentially surgical decompression. While subarachnoid haemorrhage is an important, well-recognised cause of sudden severe headache, other aetiologies, including pituitary apoplexy, should be considered and sought.

Competitive behavior of photons contributing to junction voltage jump in narrow band-gap semiconductor multi-quantum-well laser diodes at lasing threshold

DOE Office of Scientific and Technical Information (OSTI.GOV)

Feng, Liefeng, E-mail: fengliefeng@tju.edu.cn, E-mail: lihongru@nankai.edu.cn; Yang, Xiufang; Wang, Cunda

2015-04-15

The junction behavior of different narrow band-gap multi-quantum-well (MQW) laser diodes (LDs) confirmed that the jump in the junction voltage in the threshold region is a general characteristic of narrow band-gap LDs. The relative change in the 1310 nm LD is the most obvious. To analyze this sudden voltage change, the threshold region is divided into three stages by I{sub th}{sup l} and I{sub th}{sup u}, as shown in Fig. 2; I{sub th}{sup l} is the conventional threshold, and as long as the current is higher than this threshold, lasing exists and the IdV/dI-I plot drops suddenly; I{sub th}{sup u}more » is the steady lasing point, at which the separation of the quasi-Fermi levels of electron and holes across the active region (V{sub j}) is suddenly pinned. Based on the evolutionary model of dissipative structure theory, the rate equations of the photons in a single-mode LD were deduced in detail at I{sub th}{sup l} and I{sub th}{sup u}. The results proved that the observed behavior of stimulated emission suddenly substituting for spontaneous emission, in a manner similar to biological evolution, must lead to a sudden increase in the injection carriers in the threshold region, which then causes the sudden increase in the junction voltage in this region.« less

Validation of a computer case definition for sudden cardiac death in opioid users

PubMed Central

2012-01-01

Background To facilitate the use of automated databases for studies of sudden cardiac death, we previously developed a computerized case definition that had a positive predictive value between 86% and 88%. However, the definition has not been specifically validated for prescription opioid users, for whom out-of-hospital overdose deaths may be difficult to distinguish from sudden cardiac death. Findings We assembled a cohort of persons 30-74 years of age prescribed propoxyphene or hydrocodone who had no life-threatening non-cardiovascular illness, diagnosed drug abuse, residence in a nursing home in the past year, or hospital stay within the past 30 days. Medical records were sought for a sample of 140 cohort deaths within 30 days of a prescription fill meeting the computer case definition. Of the 140 sampled deaths, 81 were adjudicated; 73 (90%) were sudden cardiac deaths. Two deaths had possible opioid overdose; after removing these two the positive predictive value was 88%. Conclusions These findings are consistent with our previous validation studies and suggest the computer case definition of sudden cardiac death is a useful tool for pharmacoepidemiologic studies of opioid analgesics. PMID:22938531

Damage detection on sudden stiffness reduction based on discrete wavelet transform.

PubMed

Chen, Bo; Chen, Zhi-wei; Wang, Gan-jun; Xie, Wei-ping

2014-01-01

The sudden stiffness reduction in a structure may cause the signal discontinuity in the acceleration responses close to the damage location at the damage time instant. To this end, the damage detection on sudden stiffness reduction of building structures has been actively investigated in this study. The signal discontinuity of the structural acceleration responses of an example building is extracted based on the discrete wavelet transform. It is proved that the variation of the first level detail coefficients of the wavelet transform at damage instant is linearly proportional to the magnitude of the stiffness reduction. A new damage index is proposed and implemented to detect the damage time instant, location, and severity of a structure due to a sudden change of structural stiffness. Numerical simulation using a five-story shear building under different types of excitation is carried out to assess the effectiveness and reliability of the proposed damage index for the building at different damage levels. The sensitivity of the damage index to the intensity and frequency range of measurement noise is also investigated. The made observations demonstrate that the proposed damage index can accurately identify the sudden damage events if the noise intensity is limited.

Electrophysiological evaluation of Wolff-Parkinson-White Syndrome

PubMed Central

Brembilla-Perrot, Beatrice

2002-01-01

Sudden death might complicate the follow-up of symptomatic patients with the Wolff-Parkinson-White syndrome (WPW) and might be the first event in patients with asymptomatic WPW. The risk of sudden death is increased in some clinical situations. Generally, the noninvasive studies are unable to predict the risk of sudden death correctly . The electrophysiological study is the best means to detect the risk of sudden death and to evaluate the nature of symptoms. Methods used to define the prognosis of WPW are well-defined. At first the maximal rate of conduction through the accessory pathway is evaluated; programmed atrial stimulation using 1 and 2 extrastimuli delivered at different cycle lengths is then used to determine the accessory pathway refractory period and to induce a supraventricular tachycardia. These methods should be performed in the control state and repeated in adrenergic situations either during exercise test or more simply during a perfusion of small doses of isoproterenol. The induction of an atrial fibrillation with rapid conduction through the accessory pathway (> 240/min in control state, > 300/min after isoproterenol) is the sign of a form of WPW at risk of sudden death. PMID:16951730

An examination of sudden acceleration

DOT National Transportation Integrated Search

1989-01-01

This report describes the results of a study to identify and evaluate factors which could potentially cause or contribute to the occurrence of "Sudden Acceleration Incidents" (SAI). SAI are defined in this report as unintended, unexpected, high-power...

77 FR 36134 - Airworthiness Directives; The Boeing Company Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-18

... chem- mill steps, which could result in sudden fracture and failure of the fuselage skin panels, and...-mill steps, which could result in sudden fracture and failure of the fuselage skin panels, and...

Psychosocial Aspects of the Sudden Infant Death Syndrome ("Cot Death").

ERIC Educational Resources Information Center

Bluglass, Kerry

1981-01-01

Reviews literature on reactions of parents and siblings to Sudden Infant Death Syndrome (SIDS). The prospects for prolonged, adverse reactions are considered, and professional concerns regarding abnormal adaptation are noted. (Author/DB)

Sudden Unexpected Infant Death and Sudden Infant Death Syndrome: Reducing the Risk

MedlinePlus

... the National Institute of Child Health and Human Development (NICHD) to learn more about these and other actions. Creating a Safe Sleep Environment Learn more about safe sleep environments and reducing ...

Invasion of Flukes of the Echinostomatidae Family in Racing Pigeon ( Columba livia var. domestica) Lofts.

PubMed

Ledwoń, Aleksandra; Dolka, Beata; Piasecki, Tomasz; Dolka, Izabella; Szeleszczuk, Piotr

2016-06-01

Over 4 years, only two known cases of fluke invasions were diagnosed in racing pigeons ( Columba livia ) originating from different regions of Poland. In both cases, the invasion was characterized by a very high mortality (approximately 70%), and the source of the infestation was snails of the Lymnaeidae family eaten by pigeons. Fluke invasions in pigeons are extremely rare and to date have not been described in Poland. Therefore, the occurrence of the symptoms of hemorrhagic diarrhea and sudden deaths of either adult pigeons or nestlings were suspected to be associated with poisoning. Autopsy revealed an invasion of flukes causing hemorrhagic enteritis. Renal failure and spleen atrophy were also found in the birds. Using molecular biology techniques, infestation with the fluke Echinostoma revolutum was determined in the second case.

Binary selectable detector holdoff circuit: Design, testing, and application. [to laser radar data acquisition system

NASA Technical Reports Server (NTRS)

Kadrmas, K. A.

1973-01-01

A very high speed switching circuit, part of a laser radar data acquisition system, has been designed and tested. The primary function of this circuit was to provide computer controlled switching of photodiode detector preamplifier power supply voltages, typically less than plus or minus 20 volts, in approximately 10 nanoseconds. Thus, in actual use, detector and/or detector preamplifier damage can be avoided as a result of sudden extremely large values of backscattered radiation being detected, such as might be due to short range, very thin atmospheric dust layers. Switching of the power supply voltages was chosen over direct switching the photodiode detector input to the preamplifier, based on system noise considerations. Also, the circuit provides a synchronized trigger pulse output for triggering devices such as the Biomation Model 8100 100 MHz analog to digital converter.

A fatal bite from the burrowing asp Atractaspis corpulenta (Hallowell 1854).

PubMed

Tilbury, Colin R; Verster, Janette

2016-08-01

Bites from the various species of Atractaspis are a common occurrence in Africa but deaths are very unusual. Of the 19 described species, the clinical effects of the bite of only seven have been described, and in only three (Atractaspis irregularis, Atractaspis microlepidota and Atractaspis engaddensis) have fatalities been documented. A case of envenomation is described following a bite to a finger by Atractaspis corpulenta, which resulted in sudden death approximately two and a half hours later. The victim received antivenom and although anaphylaxis to this cannot be ruled out, we consider it to be unlikely to be the cause of death. A late autopsy was performed and the findings and their interpretation are discussed. The previous case fatalities, toxic fractions and clinical effects of Atractaspis venom are briefly reviewed. Copyright © 2016 Elsevier Ltd. All rights reserved.

Dynamical photoionization observables of the CS molecule: The role of electron correlation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ponzi, Aurora; Coriani, Sonia; Decleva, Piero

2014-05-28

Highly correlated calculations are performed on the primary ionic states and the prominent satellite present in the outer valence photoelectron spectrum of carbon monosulfide (CS). Dyson orbitals are coupled to accurate one particle continuum orbitals to provide a correlated description of energy dependent cross sections, asymmetry parameters, branching ratios, and molecular frame photoelectron angular distributions. The comparison with results obtained at the Hartree-Fock and Density Functional Theory level shows the strong sensitivity of these observables to details of the correlation in the bound states. The behaviour of the well characterized satellite state is analyzed in detail, and shows differences frommore » the relevant primary states, revealing the limitations of a simple intensity borrowing mechanism. The results resolve the intensity disagreement with experiment obtained at the level of the sudden approximation.« less

Seed particle response and size characterization in high speed flows

NASA Technical Reports Server (NTRS)

Rudoff, Roger C.; Bachalo, William D.

1991-01-01

The response of seed particles ranging between 0.7 and 8.7 micron is determined using a phase Doppler particle analyzer which simultaneously measures particle size and velocity. The stagnant seed particles are entrained into a high speed free jet at velocities ranging from 40 to 300 m/s. The size-mean axial velocity correlation and size-rms velocity correlations are used to determine the particle response to the sudden acceleration. It was determined that at the lower speeds, seed particles up to approximately 5 microns are adequate, but as velocities approach 300 m/s only particles on the order of one micron are suitable. The ability to determine size and velocity simultaneously is essential if seeding with polydispersions is used since it allows the rejection of data which will not accurately represent the flow field.

Mass mortality of the vermetid gastropod Ceraesignum maximum

NASA Astrophysics Data System (ADS)

Brown, A. L.; Frazer, T. K.; Shima, J. S.; Osenberg, C. W.

2016-09-01

Ceraesignum maximum (G.B. Sowerby I, 1825), formerly Dendropoma maximum, was subject to a sudden, massive die-off in the Society Islands, French Polynesia, in 2015. On Mo'orea, where we have detailed documentation of the die-off, these gastropods were previously found in densities up to 165 m-2. In July 2015, we surveyed shallow back reefs of Mo'orea before, during and after the die-off, documenting their swift decline. All censused populations incurred 100% mortality. Additional surveys and observations from Mo'orea, Tahiti, Bora Bora, and Huahine (but not Taha'a) suggested a similar, and approximately simultaneous, die-off. The cause(s) of this cataclysmic mass mortality are currently unknown. Given the previously documented negative effects of C. maximum on corals, we expect the die-off will have cascading effects on the reef community.

A subharmonic dynamical bifurcation during in vitro epileptiform activity

NASA Astrophysics Data System (ADS)

Perez Velazquez, Jose L.; Khosravani, Houman

2004-06-01

Epileptic seizures are considered to result from a sudden change in the synchronization of firing neurons in brain neural networks. We have used an in vitro model of status epilepticus (SE) to characterize dynamical regimes underlying the observed seizure-like activity. Time intervals between spikes or bursts were used as the variable to construct first-return interpeak or interburst interval plots, for studying neuronal population activity during the transition to seizure, as well as within seizures. Return maps constructed for a brief epoch before seizures were used for approximating the local system dynamics during that time window. Analysis of the first-return maps suggests that intermittency is a dynamical regime underlying the observed epileptic activity. This type of analysis may be useful for understanding the collective dynamics of neuronal populations in the normal and pathological brain.

Pressure driven flow of superfluid 4He through a nanopipe

NASA Astrophysics Data System (ADS)

Botimer, Jeffrey; Taborek, Peter

2016-09-01

Pressure driven flow of superfluid helium through single high-aspect-ratio glass nanopipes into a vacuum has been studied for a wide range of pressure drop (0-30 bars), reservoir temperature (0.8-2.5 K), pipe lengths (1-30 mm), and pipe radii (131 and 230 nm). As a function of pressure drop we observe two distinct flow regimes above and below a critical pressure drop Pc. For P

Role of quantum statistics in multi-particle decay dynamics

NASA Astrophysics Data System (ADS)

Marchewka, Avi; Granot, Er'el

2015-04-01

The role of quantum statistics in the decay dynamics of a multi-particle state, which is suddenly released from a confining potential, is investigated. For an initially confined double particle state, the exact dynamics is presented for both bosons and fermions. The time-evolution of the probability to measure two-particle is evaluated and some counterintuitive features are discussed. For instance, it is shown that although there is a higher chance of finding the two bosons (as oppose to fermions, and even distinguishable particles) at the initial trap region, there is a higher chance (higher than fermions) of finding them on two opposite sides of the trap as if the repulsion between bosons is higher than the repulsion between fermions. The results are demonstrated by numerical simulations and are calculated analytically in the short-time approximation. Furthermore, experimental validation is suggested.

Classical stability of sudden and big rip singularities

DOE Office of Scientific and Technical Information (OSTI.GOV)

Barrow, John D.; Lip, Sean Z. W.

2009-08-15

We introduce a general characterization of sudden cosmological singularities and investigate the classical stability of homogeneous and isotropic cosmological solutions of all curvatures containing these singularities to small scalar, vector, and tensor perturbations using gauge-invariant perturbation theory. We establish that sudden singularities at which the scale factor, expansion rate, and density are finite are stable except for a set of special parameter values. We also apply our analysis to the stability of Big Rip singularities and find the conditions for their stability against small scalar, vector, and tensor perturbations.

National Athletic Trainers' Association Position Statement: Preventing Sudden Death in Sports

PubMed Central

Casa, Douglas J.; Guskiewicz, Kevin M.; Anderson, Scott A.; Courson, Ronald W.; Heck, Jonathan F.; Jimenez, Carolyn C.; McDermott, Brendon P.; Miller, Michael G.; Stearns, Rebecca L.; Swartz, Erik E.; Walsh, Katie M.

2012-01-01

Objective: To present recommendations for the prevention and screening, recognition, and treatment of the most common conditions resulting in sudden death in organized sports. Background: Cardiac conditions, head injuries, neck injuries, exertional heat stroke, exertional sickling, asthma, and other factors (eg, lightning, diabetes) are the most common causes of death in athletes. Recommendations: These guidelines are intended to provide relevant information on preventing sudden death in sports and to give specific recommendations for certified athletic trainers and others participating in athletic health care. PMID:22488236

[Presentation of 2 cases of sudden deafness in patients with sickle-cell anemia and trait].

PubMed

García Callejo, F J; Sebastián Gil, E; Morant Ventura, A; Marco Algarra, J

2002-05-01

We report two cases of sudden deafness which appeared during vaso-occlusive crisis of a sickle cell anaemia (homozygous form of disease) and a sickle cell trait (heterozygous form) in two males aged sixteen and twenty-two, respectively. A high erythrocyte aggregability and low deformability were proved in both young men. Although hearing disorders have been reported in this disease, a sudden onset is not common. The treatment used was useful in the removal of painful crisis and infections, but deafness did not improve in either of then.

Sudden death of distillability in qutrit-qutrit systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Song Wei; Zhu Shiliang; Chen Lin

2009-07-15

We introduce the concept of distillability sudden death, i.e., free entangled states can evolve into nondistillable (bound entangled or separable) states in finite time under local noise. We describe the phenomenon through a specific model of local dephasing noise and compare the behavior of states in terms of the Bures fidelity. Then we propose a few methods to avoid distillability sudden death of states under (general) local dephasing noise so that free entangled states can be robust against decoherence. Moreover, we find that bound entangled states are unstable in the limit of infinite time.

[Analyses of clinical features and efficacy of sudden deafness with vertigo and dizziness].

PubMed

Liu, Bo; Han, Demin; Zhang, Yi; Li, Yongxin; Gong, Shusheng; Chen, Xiuwu; Meng, Xixi; Tang, Junxiang; Xiang, Jie; Jiang, Xuejun; Yang, Ning; Tian, Ying; Hui, Lian; Feng, Shuai

2015-06-01

To investigate the clinical characteristics and the effect of drug treatment for sudden hearing loss with vertigo or dizziness. In a prospective, randomized, single blinded randomized multicenter clinical study, patients with sudden deafness, ranging in age from 18 to 65 years old, with a duration less than 2 weeks, and with no any medical treatments were collected. In accordance with the hearing curve, those patients were divided into four types, i.e., low and intermediate frequency descent type; high frequency descent type; fall flat type; and total deafness type. Each type was treated by four different treatment options, according to the unified design of the random table, and randomly selected one of the options for treatment. The efficacy of the patients with sudden deafness with vertigo and dizziness was analyzed statistically after the follow-up for 4 weeks. SPSS 13.0 software was used to analyze the data. In August 2007 to October 2011, 33 hospitals in the country included 1 024 patients with sudden deafness in line with the inclusion criteria, of whom 296 (28.91%) were accompanied by vertigo/dizziness symptoms, 126 were males and 170 were females, with an average age of (41.2 ± 13.5) years old. types of the different audiometric curves of sudden deafness, the occurrence of complete deafness with vertigo/dizziness was the highest (44.93%), followed by flat down type (25.87%), high frequency descent type (21.28%) and low intermediate frequency descent type (18.54%). After the standard treatment, the vertigo and dizziness symptoms of the sudden deafness patients could disappear, and the hearing in each group was obviously improved. The hearing curative effect on patients accompanied by vertigo/dizziness of low frequency and intermediate frequency descent type was the best, and the total efficiency can reach up to 94.74%, with the cure rate of 68.42%; followed by flat type, in which the total effective rate was 80.76%, with the recovery rate of 22.12%; and the effects on patients in high frequency descent type and total deafness type effect were relatively poor, in which the total effective rates were 70.00% (recovery rate of 10.00%) and 65.32% (recovery rate of 5.65%), respectively. The total effective rate of patients with sudden deafness associated with halo had no statistical significance (P > 0.05), in comparison to that of patients without halo; but, the cure rate of patients with no vertigo/dizziness of total deafness and the high frequency decreased patients with sudden deafness was significantly higher than that of vertigo/dizziness patients, with a statistical difference (P < 0.05). The patients with sudden deafness in each type have a certain proportion of vertigo/dizziness, especially the deaf type. The possibility of hearing complete recovery in patients with vertigo/dizziness was significantly lower than that without vertigo/dizziness.

HYDROSTATIC PRESSURE AND TEMPERATURE IN RELATION TO STIMULATION AND CYCLOSIS IN NITELLA FLEXILIS

PubMed Central

Harvey, E. Newton

1942-01-01

Nitella flexilis cells are not stimulated to "shock stoppage" of cyclosis by suddenly evacuating the air over the water or on sudden readmission of air, or on suddenly striking a piston in the water-filled chamber in which they are kept with a ball whose energy is 7.6 joules, provided the Nitella cell is not moved by currents against the side of the chamber. Sudden increases in hydrostatic pressure from zero to 1000 lbs. or 0 to 5000 lbs. per square inch or 5000 to 9000 lbs. per square inch usually do not stimulate to "shock stoppage" of cyclosis, but some cells are stimulated. Sudden decreases of pressure are more likely to stimulate, again with variation depending on the cell. In the absence of stimulation, the cyclosis velocity at 23°C. slows as the pressure is increased in steps of 1000 lbs. per square inch. In some cells a regular slowing is observed, in others there is little slowing until 4000 to 6000 lbs. per square inch, when a rapid slowing appears, with only 50 per cent to 30 per cent of the original velocity at 9000 lbs. per square inch. The cyclosis does not completely stop at 10000 lbs. per square inch. The pressure effect is reversible unless the cells have been kept too long at the high pressure. At low temperatures (10°C.) and at temperatures near and above (32°–38°C.) the optimum temperature for maximum cyclosis (35–36°C.) pressures of 3000 to 6000 lbs. per square inch cause only further slowing of cyclosis, with no reversal of the temperature effect, such as has been observed in pressure-temperature studies on the luminescence of luminous bacteria. Sudden increase in temperature may cause shock stoppage of cyclosis as well as sudden decrease in temperature. PMID:19873318

A systematic review of causes of sudden and severe headache (Thunderclap Headache): should lists be evidence based?

PubMed Central

2014-01-01

Background There are many potential causes of sudden and severe headache (thunderclap headache), the most important of which is aneurysmal subarachnoid haemorrhage. Published academic reviews report a wide range of causes. We sought to create a definitive list of causes, other than aneurysmal subarachnoid haemorrhage, using a systematic review. Methods Systematic Review of EMBASE and MEDLINE databases using pre-defined search criteria up to September 2009. We extracted data from any original research paper or case report describing a case of someone presenting with a sudden and severe headache, and summarized the published causes. Results Our search identified over 21,000 titles, of which 1224 articles were scrutinized in full. 213 articles described 2345 people with sudden and severe headache, and we identified 6 English language academic review articles. A total of 119 causes were identified, of which 46 (38%) were not mentioned in published academic review articles. Using capture-recapture analysis, we estimate that our search was 98% complete. There is only one population-based estimate of the incidence of sudden and severe headache at 43 cases per 100,000. In cohort studies, the most common causes identified were primary headaches or headaches of uncertain cause. Vasoconstriction syndromes are commonly mentioned in case reports or case series. The most common cause not mentioned in academic reviews was pneumocephalus. 70 non-English language articles were identified but these did not contain additional causes. Conclusions There are over 100 different published causes of sudden and severe headache, other than aneurysmal subarachnoid haemorrhage. We have now made a definitive list of causes for future reference which we intend to maintain. There is a need for an up to date population based description of cause of sudden and severe headache as the modern epidemiology of thunderclap headache may require updating in the light of research on cerebral vasoconstriction syndromes. PMID:25123846

Incidence and Etiology of Sudden Cardiac Death: New Updates for Athletic Departments.

PubMed

Asif, Irfan M; Harmon, Kimberly G

Sudden cardiac death (SCD) in a young athlete is a tragic event and is the leading medical cause of death in this population. The precise incidence of SCD in young athletes has been subject of debate, with studies reporting drastically different rates (1:917,000 athlete-years (AYs) to 1:3000 AYs) depending on the methodological design of the investigation or the targeted population. A literature search was performed in PubMed using the terms: incidence, sudden cardiac death, sudden death, sudden cardiac arrest, etiology, pathology, registry, athlete, young, children, and adolescents. Articles were reviewed for relevance and included if they contained information on the incidence of SCD in athletes or young persons up to the age of 35 years. Clinical review. Level 5. Studies of high quality and rigor consistently yield an incidence of 1:50,000 AYs in college athletes and between 1:50,000 and 1:80,000 AYs for high school athletes, with certain subgroups that appear to be at particularly high risk, including the following: men, basketball players, and African Americans. Initial reports suggest that the most common cause of SCD is hypertrophic cardiomyopathy (HCM). However, more comprehensive investigations in the United States and international populations-athletes, nonathletes, and military-support that the most common finding on autopsy in young individuals with SCD is actually a structurally normal heart (autopsy-negative sudden unexplained death). SCD is the leading cause of death in athletes during exercise and usually results from intrinsic cardiac conditions that are triggered by the physiologic demands of vigorous exercise. Current rates of SCD appear to be at least 4 to 5 times higher than previously estimated, with men, African Americans, and male basketball players being at greatest risk. Emerging data suggest that the leading finding associated with SCD in athletes is actually a structurally normal heart (autopsy-negative sudden unexplained death).

[The forensic medical aspects of sudden cardiac death among the athletes].

PubMed

Khodasevich, L S; Kuzin, S G; Khodasevich, A L

2012-01-01

The present review is focused on the main causes responsible for cardiac death among the athletes and the clinico-morphological characteristics of various forms of cardiac pathology leading to sudden death in the athletes.

Realistic vs sudden turn-on of natural incoherent light: Coherences and dynamics in molecular excitation and internal conversion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Grinev, Timur; Brumer, Paul

2015-12-28

Molecular excitation with incoherent light is examined using realistic turn-on time scales, and results are compared to those obtained via commonly used sudden turn-on, or pulses. Two significant results are obtained. First, in contrast to prior studies involving sudden turn-on, realistic turn-on is shown to lead to stationary coherences for natural turn-on time scales. Second, the time to reach the final stationary mixed state, known to result from incoherent excitation, is shown to depend directly on the inverse of the molecular energy level spacings, in both sudden and realistic turn-on cases. The S{sub 0} → S{sub 2}/S{sub 1} internal conversionmore » process in pyrazine is used as an example throughout. Implications for studies of natural light harvesting systems are noted.« less

Risk stratification for sudden death in arrhythmogenic right ventricular cardiomyopathy.

PubMed

Cadrin-Tourigny, Julia; Tadros, Rafik; Talajic, Mario; Rivard, Lena; Abadir, Sylvia; Khairy, Paul

2015-06-01

Arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC) is an uncommon but increasingly recognized inherited cardiomyopathy that is associated with malignant ventricular arrhythmias and sudden cardiac death, particularly in young individuals. The implantable cardioverter-defibrillator (ICD) is widely regarded as the only treatment modality with evidence to support improved survival in patients with ARVC and secondary prevention indications. In contrast, there is no universally accepted risk stratification scheme to guide ICD therapy for primary prevention against sudden cardiac death. Potential benefits must be weighed against the considerable risks of complications and inappropriate shocks in this young patient population. This article tackles the challenges of risk stratification for sudden cardiac death in ARVC and critically appraises available evidence for various proposed risk factors. The authors' over-arching objective is to provide the clinician with evidence-based guidance to inform decisions regarding the selection of appropriate candidates with ARVC for ICD therapy.

Sudden death in Lesch-Nyhan disease.

PubMed

Neychev, Vladimir Kostadinov; Jinnah, H A

2006-11-01

To increase awareness of sudden and unexpected death in Lesch-Nyhan disease (LND) and to explore its potential causes, we report the anteceding clinical features and laboratory evaluations of five males with LND who ultimately experienced sudden and unexpected death, along with three additional males who suffered serious respiratory events during life. The ages of patients ranged from 2 to 45 years. The cause of sudden death in LND appears to have a respiratory rather than a cardiogenic basis. All cases cannot be linked readily with a single respiratory process. Instead, different respiratory processes appear to operate in different cases. These may include aspiration, laryngospasm, central apnea, cyanotic breath-holding spells, and high cervical spine damage. Better recognition of these processes will help to guide appropriate workup and management that could include chest imaging, endoscopy of the airways, polysomnography, electroencephalogram, and brain and/or spine imaging.

Stratification of the Risk of Sudden Death in Nonischemic Heart Failure

PubMed Central

Pimentel, Maurício; Zimerman, Leandro Ioschpe; Rohde, Luis Eduardo

2014-01-01

Despite significant therapeutic advancements, heart failure remains a highly prevalent clinical condition associated with significant morbidity and mortality. In 30%-40% patients, the etiology of heart failure is nonischemic. The implantable cardioverter-defibrillator (ICD) is capable of preventing sudden death and decreasing total mortality in patients with nonischemic heart failure. However, a significant number of patients receiving ICD do not receive any kind of therapy during follow-up. Moreover, considering the situation in Brazil and several other countries, ICD cannot be implanted in all patients with nonischemic heart failure. Therefore, there is an urgent need to identify patients at an increased risk of sudden death because these would benefit more than patients at a lower risk, despite the presence of heart failure in both risk groups. In this study, the authors review the primary available methods for the stratification of the risk of sudden death in patients with nonischemic heart failure. PMID:25352509

The serotonin axis: Shared mechanisms in seizures, depression and SUDEP

PubMed Central

Richerson, George B.; Buchanan, Gordon F.

2010-01-01

Summary There is a growing appreciation that patients with seizures are also affected by a number of co-morbid conditions, including an increase in prevalence of depression (Kanner, 2009), sleep apnea (Chihorek et al, 2007), and sudden death (Ryvlin et al, 2006; Tomson et al, 2008). The mechanisms responsible for these associations are unclear. Here we discuss the possibility that underlying pathology in the serotonin (5-HT) system of epilepsy patients lowers the threshold for seizures, while also increasing the risk of depression and sudden death. We propose that post-ictal dysfunction of 5-HT neurons causes depression of breathing and arousal in some epilepsy patients, and this can lead to sudden unexpected death in epilepsy (SUDEP). We further draw parallels between SUDEP and sudden infant death syndrome (SIDS), which may share pathophysiological mechanisms, and which have both been linked to defects in the 5-HT system. PMID:21214537

Hepatic Hemangioendothelioma Presenting as Sudden Unexpected Death in Infancy: A Case Report

PubMed Central

Dempers, Johan; Wadee, Shabbir Ahmed; Boyd, Theonia; Wright, Colleen; OdendaaL, Hein J; Sens, Mary Ann

2014-01-01

The classification of an unexpected infant death as the sudden infant death syndrome (SIDS) depends upon a complete autopsy, death scene investigation and review of medical history to exclude known causes of death. Death from occult neoplastic disease in infancy is extremely rare but is within the broad differential of SIDS. We report the sudden and unexpected death of a one-month-old infant from a hepatic (infantile) hemangioendothelioma. The physiologic mechanism of death was likely cardiac failure induced by the circulatory demands of this large vascular tumor and respiratory compromise from diaphragmatic thoracic incursion. The clinical progression and pathology of these relatively common tumors of infant livers are extremely variable. This case dramatically illustrates the potential for fatal outcome of this tumor, as well as the need for the autopsy to determine the cause of sudden and unexpected death in an infant PMID:20465426

Left Ventricular Aneurysm: Sudden Unexpected Deaths in a 29-Year-Old Man.

PubMed

Srettabunjong, Supawon

2018-05-01

Left ventricular aneurysm (LVA) is an abnormal dilated heart structure, either congenital or acquired. LVA is a rare cardiac condition with no symptoms in most cases, thus occasionally diagnosed during investigations of other diseases. Its association with certain cardiac complications and sudden cardiac deaths has been reported. However, its role as a cause of sudden unexpected death is rare. The author reported a sudden cardiac death in a 29-year-old man with LVA. Without a significant coronary artery disease and known etiologies of LVA, such an abnormal heart structure in the present case was considered congenital LVA. As no other possible mechanisms of death could be identified other than LVA with its associated pathologic lesions, mural thrombi, and dilated cardiomegaly, his death was attributable to fatal cardiac arrhythmia (most commonly ventricular tachycardia) secondary to LVA. © 2017 American Academy of Forensic Sciences.

Constraint-induced sound therapy for sudden sensorineural hearing loss – behavioral and neurophysiological outcomes

PubMed Central

Okamoto, Hidehiko; Fukushima, Munehisa; Teismann, Henning; Lagemann, Lothar; Kitahara, Tadashi; Inohara, Hidenori; Kakigi, Ryusuke; Pantev, Christo

2014-01-01

Sudden sensorineural hearing loss is characterized by acute, idiopathic hearing deterioration. We report here the development and evaluation of “constraint-induced sound therapy”, which is based on a well-established neuro-rehabilitation approach, and which is characterized by the plugging of the intact ear (“constraint”) and the simultaneous, extensive stimulation of the affected ear with music. The sudden sensorineural hearing loss patients who received the constraint-induced sound therapy in addition to the standard corticosteroid therapy showed significantly better recovery of hearing function compared to those who had only received corticosteroid treatments. Additionally, the brain activity obtained in a subgroup of patients suggested that the constraint-induced sound therapy could have prevented maladaptive auditory cortex reorganization. Constraint-induced sound therapy thus appears to be an effective, practical, and safe treatment option for sudden sensorineural hearing loss. PMID:24473277

Ignored Disease or Diagnostic Dustbin? Sudden Infant Death Syndrome in the British Context

PubMed Central

Ferguson, Angus H.

2015-01-01

Sudden Infant Death Syndrome (SIDS) was defined in 1969 and incorporated into the International Classification of Diseases a decade later. To advocates of SIDS as a diagnosis, medical interest in sudden infant death was long overdue. However, the definition of SIDS lacked positive diagnostic criteria, provoking some to view it as a ‘diagnostic dustbin’ for the disposal of problematic cases where cause of death was unclear. This paper examines the development of medical interest in sudden infant death in Britain during the middle decades of the twentieth century. It highlights the importance of recognising the historicity of SIDS as a diagnosis facilitated by changes in law and medicine over the course of the nineteenth and twentieth centuries. It suggests that SIDS provides a definitive case study of the medicalisation of life and death, and a unique example of an officially recognised disease that had no symptoms, signs, pathology or patients. PMID:26217070

Cosmic Rays Variation Before Changes in Sun-Earth Environment

NASA Astrophysics Data System (ADS)

Mukherjee, S.

2011-12-01

Influence of cosmic rays variations on the Sun-Earth Environment has been observed before the changes in the atmospheric temperature, outbreak of influenza, cyclone, earthquake and tsunami. It has been recorded by Sun Observatory Heleospheric Observatory (SOHO) satellite data. Before the earthquake and tsunami the planetary indices (Kp) and Electron flux (E-flux) shows sudden changes followed by the atmospheric perturbations including very high temperature rise to sudden fall resulting snowfall in high altitude and rainfall in tropical areas. The active fault zones shows sudden faulting after the sudden drop in cosmic ray intensity and rise in Kp and E-flux. Besides the geo-environment the extraterrestrial influence on outbreak of H1N1 influenza has also been recorded based on the Mexico Cosmic ray data and its correlation with SOHO records. Distant stars have the potential to influence the heliophysical parameters by showering cosmic rays.

Rainbows in rotationally inelastic scattering: a comparative study of different model potential surfaces and dynamical approximations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schinke, R.; Korsch, H.J.; Poppe, D.

1982-12-15

Rainbow structures in rotationally elastic and inelastic differential cross sections in atom--diatom collisions are investigated by comparison of three model potential energy surfaces labeled I, II, and III which are represented by V(R,..gamma..) = V/sub 0/(R)+V/sub 2/(R)P/sub 2/(cos ..gamma..). The cross sections are calculated within the quantal infinite-order-sudden (IOS) approximation. The anisotropic part V/sub 2/ is the same for all potentials and purely repulsive. The isotropic part V/sub 0/ for potential I is also repulsive and the differential cross sections show the well-studied rotational rainbow structures. Structural changes occur for collisions in potential II and III which have V/sub 0/more » terms being attractive at intermediate and large atom--molecule separations and having well depths of 10% and 25% of the collision energy, respectively. For example, the elastic cross section has no classical rainbow in the case of potential I but three in the case of potential III. The rainbow structures are analyzed within the classical and semiclassical versions of the IOS approximation and interpreted in terms of catastrophe theory. The quantitative comparison of the classical with the quantal IOS cross sections manifests possible quantum effects, i.e., tunneling into nonclassical regions and interference effects due to the superposition of several contributions (up to six in the present study). They can be very prominent and thus we conclude that much caution is needed if experimental data are compared with classical calculations. The accuracy of the IOS approximation is tested by comparison of classical IOS cross sections with cross sections obtained from exact classical trajectory calculations. The agreement is generally good with the exemption of the rainbow region and small angle, rotationally elastic scattering.« less

Characteristics and possible formation mechanisms of severe storms in the outer rainbands of Typhoon Mujiga (1522)

NASA Astrophysics Data System (ADS)

Wang, Bingyun; Wei, Ming; Hua, Wei; Zhang, Yongli; Wen, Xiaohang; Zheng, Jiafeng; Li, Nan; Li, Han; Wu, Yu; Zhu, Jie; Zhang, Mingjun

2017-06-01

To better understand how severe storms form and evolve in the outer rainbands of typhoons, in this study, we investigate the evolutionary characteristics and possible formation mechanisms for severe storms in the rainbands of Typhoon Mujigae, which occurred during 2-5 October 2015, based on the NCEP-NCAR reanalysis data, conventional observations, and Doppler radar data. For the rainbands far from the inner core (eye and eyewall) of Mujigae (distance of approximately 70-800 km), wind speed first increased with the radius expanding from the inner core, and then decreased as the radius continued to expand. The Rankine Vortex Model was used to explore such variations in wind speed. The areas of strong stormy rainbands were mainly located in the northeast quadrant of Mujigae, and overlapped with the areas of high winds within approximately 300-550 km away from the inner core, where the strong winds were conducive to the development of strong storms. A severe convective cell in the rainbands developed into waterspout at approximately 500 km to the northeast of the inner core, when Mujigae was strengthening before it made landfall. Two severe convective cells in the rainbands developed into two tornadoes at approximately 350 km to the northeast of the inner core after Mujigae made landfall. The radar echo bands enhanced to 60 dBZ when mesocyclones occurred in the rainbands and induced tornadoes. The radar echoes gradually weakened after the mesocyclones weakened. The tops of parent clouds of the mesocyclones elevated at first, and then suddenly dropped about 20 min before the tornadoes appeared. Thereby, the cloud top variation has the potential to be used as an early warning of tornado occurrence.

Calculations of low-frequency radio emission by cosmic-ray-induced particle showers

NASA Astrophysics Data System (ADS)

García-Fernández, Daniel; Revenu, Benoît; Charrier, Didier; Dallier, Richard; Escudie, Antony; Martin, Lilian

2018-05-01

The radio technique for the detection of high-energy cosmic rays consists in measuring the electric field created by the particle showers created inside a medium by the primary cosmic ray. The electric field is then used to infer the properties of the primary particle. Nowadays, the radio technique is a standard, well-established technique. While most current experiments measure the field at frequencies above 20 MHz, several experiments have reported a large emission at low frequencies, below 10 MHz. The EXTASIS experiment aims at measuring again and understanding this low-frequency electric field. Since at low frequencies the standard far-field approximation for the calculation of the electric field does not necessarily hold, in order to comprehend the low-frequency emission we need to go beyond the far-field approximation. We present in this work a formula for the electric field created by a particle track inside a dielectric medium that is valid for all frequencies. We then implement this formula in the SELFAS Monte Carlo code and calculate the low-frequency electric field of the extensive air shower (EAS). We also study the electric field of a special case of the transition radiation mechanism when the EAS particles cross the air-soil boundary. We introduce the sudden death pulse, the direct emission caused by the coherent deceleration of the shower front at the boundary, as a first approximation to the whole electric field for the air-soil transition, and study its properties. We show that at frequencies larger than 20 MHz and distances larger than 100 m, the standard far-field approximation for the horizontal polarizations of the field is always accurate at the 1% level.

Dynamic interneuron-principal cell interplay leads to a specific pattern of in vitro ictogenesis.

PubMed

Lévesque, Maxime; Chen, Li-Yuan; Hamidi, Shabnam; Avoli, Massimo

2018-07-01

Ictal discharges induced by 4-aminopyridine in the in vitro rodent entorhinal cortex present with either low-voltage fast or sudden onset patterns. The role of interneurons in initiating low-voltage fast onset ictal discharges is well established but the processes leading to sudden onset ictal discharges remain unclear. We analysed here the participation of interneurons (n = 75) and principal cells (n = 13) in the sudden onset pattern by employing in vitro tetrode wire recordings in the entorhinal cortex of brain slices from Sprague-Dawley rats. Ictal discharges emerged from a background of frequently occurring interictal spikes that were associated to a specific interneuron/principal cell interplay. High rates of interneuron firing occurred 12 ms before interictal spike onset while principal cells fired later during low interneuron firing. In contrast, the onset of sudden ictal discharges was characterized by increased firing from principal cells 627 ms before ictal onset whereas interneurons increased their firing rates 161 ms before ictal onset. Our data show that sudden onset ictogenesis is associated with frequently occurring interictal spikes resting on the interplay between interneurons and principal cells while ictal discharges stem from enhanced principal cell firing leading to increased interneuron activity. These findings indicate that specific patterns of interactions between interneurons and principal cells shape interictal and ictal discharges with sudden onset in the rodent entorhinal cortex. We propose that specific neuronal interactions lead to the generation of distinct onset patterns in focal epileptic disorders. Copyright © 2018 Elsevier Inc. All rights reserved.

A computer case definition for sudden cardiac death.

PubMed

Chung, Cecilia P; Murray, Katherine T; Stein, C Michael; Hall, Kathi; Ray, Wayne A

2010-06-01

To facilitate studies of medications and sudden cardiac death, we developed and validated a computer case definition for these deaths. The study of community dwelling Tennessee Medicaid enrollees 30-74 years of age utilized a linked database with Medicaid inpatient/outpatient files, state death certificate files, and a state 'all-payers' hospital discharge file. The computerized case definition was developed from a retrospective cohort study of sudden cardiac deaths occurring between 1990 and 1993. Medical records for 926 potential cases had been adjudicated for this study to determine if they met the clinical definition for sudden cardiac death occurring in the community and were likely to be due to ventricular tachyarrhythmias. The computerized case definition included deaths with (1) no evidence of a terminal hospital admission/nursing home stay in any of the data sources; (2) an underlying cause of death code consistent with sudden cardiac death; and (3) no terminal procedures inconsistent with unresuscitated cardiac arrest. This definition was validated in an independent sample of 174 adjudicated deaths occurring between 1994 and 2005. The positive predictive value of the computer case definition was 86.0% in the development sample and 86.8% in the validation sample. The positive predictive value did not vary materially for deaths coded according to the ICO-9 (1994-1998, positive predictive value = 85.1%) or ICD-10 (1999-2005, 87.4%) systems. A computerized Medicaid database, linked with death certificate files and a state hospital discharge database, can be used for a computer case definition of sudden cardiac death. Copyright (c) 2009 John Wiley & Sons, Ltd.

Research Priorities in Sudden Unexpected Infant Death: An International Consensus.

PubMed

Hauck, Fern R; McEntire, Betty L; Raven, Leanne K; Bates, Francine L; Lyus, Lucy A; Willett, Alexis M; Blair, Peter S

2017-07-27

Despite the success of safe sleep campaigns and the progress in understanding risk factors, the rate of reduction in the cases of sudden infant death syndrome has now slowed and it remains a leading cause of postneonatal mortality in many developed countries. Strategic action is needed to tackle this problem and it is now vital to identify how the sudden infant death research community may best target its efforts. The Global Action and Prioritization of Sudden Infant Death Project was an international consensus process that aimed to define and direct future research by investigating the priorities of expert and lay members of the sudden unexpected infant death (SUID) community across countries. The aim was to identify which areas of research should be prioritized to reduce the number of SUID deaths globally. Scientific researchers, clinicians, counselors, educators, and SUID parents from 25 countries took part across 2 online surveys to identify potential research priorities. Workshops subsequently took place in the United Kingdom, United States, and Australia to reach consensus and 10 priority areas for research were established. Three main themes among the priorities emerged: (1) a better understanding of mechanisms underlying SUID, (2) ensuring best practice in data collection, management and sharing, and (3) a better understanding of target populations and more effective communication of risk. SUID is a global problem and this project provides the international SUID community with a list of shared research priorities to more effectively work toward explaining and reducing the number of sudden infant deaths. Copyright © 2017 by the American Academy of Pediatrics.

Sudden unexpected nocturnal death in Chiari type 1 malformation and potential role of opioid analgesics

PubMed Central

Roohi, Fereydoon; Gropen, Toby; Kula, Roger W.

2014-01-01

Background: Chiari malformation type 1 (CM1) is a common congenital anomaly of the craniocervical junction. CM1 is reported to run a usually benign course and patients typically experience no symptoms or chronic, slowly progressive symptoms. However, recent reports indicate that a subset of patients with CM1 may present with acute deterioration and sudden unexpected death (SUD). We report a case of SUD during sleep in a young man with CM1, which we believe was related to the administration of common and therapeutic doses of narcotic analgesics for the management of pain. We will clarify the pathophysiology of acute deterioration and SUD in CM1 and the possibility that the adverse effects of opiate analgesics likely were the leading cause of death in our patient. Case Description: In this review, we present a 29-year-old male with worsening headache secondary to previously diagnosed CM1. The patient died suddenly and unexpectedly after administration of common and therapeutic doses of narcotic analgesics for the management of pain. Conclusion: The mechanism(s) of acute neurological deterioration and sudden death in patients with CM1 remains poorly understood. We believe the rapid fatal deterioration in our patient following administration of opioids suggests that this category of medication may cause sudden unexpected “neurogenic” cardiac death in CM1 patients by inducing sleep-related breathing difficulties and associated hypercapnia. Hypercapnia by further increasing intracranial pressure can result in a sudden pressure-induced decompensation of the cardiopulmonary control centers in the brain stem and cause instantaneous cardiorespiratory arrest. PMID:24778905

Regeneration concerns in areas impacted by sudden oak death

Treesearch

Douglas D. McCreary

2005-01-01

Sudden Oak Death (SOD) is a new disease affecting several oak (Quercus spp.) species in California. It is caused by Phytophthora ramorum, a fungus-like water mold that causes bark cankers that girdles and kills mature trees.

Biomarkers of Myocardial Stress and Fibrosis as Predictors of Mode of Death in Patients with Chronic Heart Failure

PubMed Central

Ahmad, Tariq; Fiuzat, Mona; Neely, Ben; Neely, Megan; Pencina, Michael J.; Kraus, William E.; Zannad, Faiez; Whellan, David J.; Donahue, Mark; Piña, Ileana L.; Adams, Kirkwood; Kitzman, Dalane W.; O’Connor, Christopher M.; Felker, G. Michael

2014-01-01

Objective To determine whether biomarkers of myocardial stress and fibrosis improve prediction of mode of death in patients with chronic heart failure. Background The two most common modes of death in patients with chronic heart failure are pump failure and sudden cardiac death. Prediction of mode of death may facilitate treatment decisions. The relationship between NT-proBNP, galectin-3, and ST2, biomarkers that reflect different pathogenic pathways in heart failure (myocardial stress and fibrosis), and mode of death is unknown. Methods HF-ACTION was a randomized controlled trial of exercise training vs. usual care in patients with chronic heart failure due to left ventricular systolic dysfunction (LVEF<35%). An independent clinical events committee prospectively adjudicated mode of death. NT-proBNP, galectin-3, and ST2 levels were assessed at baseline in 813 subjects. Associations between biomarkers and mode of death were assessed using cause-specific Cox-proportional hazards modeling, and interaction testing was used to measure differential association between biomarkers and pump failure versus sudden cardiac death. Discrimination and risk reclassification metrics were used to assess the added value of galectin-3 and ST2 in predicting mode of death risk beyond a clinical model that included NT-proBNP. Results After a median follow up of 2.5 years, there were 155 deaths: 49 from pump failure 42 from sudden cardiac death, and 64 from other causes. Elevations in all biomarkers were associated with increased risk of both pump failure and sudden cardiac death in both adjusted and unadjusted analyses. In each case, increases in the biomarker had a stronger association with pump failure than sudden cardiac death but this relationship was attenuated after adjustment for clinical risk factors. Clinical variables along with NT-proBNP levels were stronger predictors of pump failure (C statistic: 0.87) than sudden cardiac death (C statistic: 0.73). Addition of ST2 and galectin-3 led to improved net risk classification of 11% for sudden cardiac death, but not pump failure. Conclusions Clinical predictors along with NT-proBNP levels were strong predictors of pump failure risk, with insignificant incremental contributions of ST2 and galectin-3. Predictability of sudden cardiac death risk was less robust and enhanced by information provided by novel biomarkers. PMID:24952693

Sudden cardiac death rates in an Australian population: a data linkage study.

PubMed

Feng, Jia-Li; Hickling, Siobhan; Nedkoff, Lee; Knuiman, Matthew; Semsarian, Christopher; Ingles, Jodie; Briffa, Tom G

2015-11-01

The aim of the present study was to develop criteria to identify sudden cardiac death (SCD) and estimate population rates of SCD using administrative mortality and hospital morbidity records in Western Australia. Four criteria were developed using place, death within 24 h, principal and secondary diagnoses, underlying and associated cause of death, and/or occurrence of a post mortem to identify SCD. Average crude, age-standardised and age-specific rates of SCD were estimated using population person-linked administrative data. In all, 9567 probable SCDs were identified between 1997 and 2010, with one-third aged ≥ 35 years having no prior admission for cardiovascular disease. SCD was more frequent in men (62.1%). The estimated average annual crude SCD rate for the period was 34.6 per 100 000 person-years with an average annual age-standardised rate of 37.8 per 100 000 person-years. Age-specific standardised rates were 1.1 per 100 000 person-years and 70.7 per 100 000 person-years in people aged 1-34 and ≥ 35 years, respectively. Ischaemic heart disease (IHD) was recorded as the underlying cause of death in approximately 80% of patients aged ≥ 35 years, followed by valvular heart disease and heart failure. IHD was the most common cause of death in those aged 1-34 years, followed by unspecified cardiomyopathy and dysrhythmias. Administrative morbidity and mortality data can be used to estimate rates of SCD and therefore provide a suitable methodology for monitoring SCD over time. The findings highlight the magnitude of SCD and its potential for public health prevention.

Effect of short-term regulated temperature variations on the swimming economy of Atlantic salmon smolts

PubMed Central

Palstra, A. P.

2017-01-01

Abstract Migratory species travelling long distances between habitats to spawn or feed are well adapted to optimize their swimming economy. However, human activities, such as river regulation, represent potential threats to fish migration by changing environmental parameters that will have impact on their metabolism. The main objective of this study was to evaluate the changes in the swimming energetics of a salmonid species, Atlantic salmon (Salmo salar L.), caused by short-term temperature variations that usually result from the operation of hydroelectrical dams. Intermittent flow respirometry in swim tunnels allows to obtain high resolution data on oxygen consumption of swimming fish which can reflect aerobic and anaerobic metabolism. This method was used to compare the metabolic rates of oxygen consumption before, during and after sudden thermal change. Control (no temperature variation) and experimental (temperature variation of approximately 4°C in 1 h) swimming trials were conducted to achieve the following objectives: (i) quantify the variations in oxygen consumption associated with abrupt temperature decrease, and (ii) assess if the tested fish return quickly to initial oxygen consumption rates. Main results revealed that Atlantic salmon smolts show a strong response to sudden temperature variation, significantly reducing the oxygen consumption rate up to a seven-fold change. Fish quickly returned to initial swimming costs shortly after reestablishment of temperature values. Results from this study can be used to evaluate the species-specific effects of the applied operation modes by hydroelectrical dams and to increase the success of conservation and management actions directed to fish species inhabiting regulated rivers. PMID:28480037

Effect of short-term regulated temperature variations on the swimming economy of Atlantic salmon smolts.

PubMed

Alexandre, C M; Palstra, A P

2017-01-01

Migratory species travelling long distances between habitats to spawn or feed are well adapted to optimize their swimming economy. However, human activities, such as river regulation, represent potential threats to fish migration by changing environmental parameters that will have impact on their metabolism. The main objective of this study was to evaluate the changes in the swimming energetics of a salmonid species, Atlantic salmon ( Salmo salar L.), caused by short-term temperature variations that usually result from the operation of hydroelectrical dams. Intermittent flow respirometry in swim tunnels allows to obtain high resolution data on oxygen consumption of swimming fish which can reflect aerobic and anaerobic metabolism. This method was used to compare the metabolic rates of oxygen consumption before, during and after sudden thermal change. Control (no temperature variation) and experimental (temperature variation of approximately 4°C in 1 h) swimming trials were conducted to achieve the following objectives: (i) quantify the variations in oxygen consumption associated with abrupt temperature decrease, and (ii) assess if the tested fish return quickly to initial oxygen consumption rates. Main results revealed that Atlantic salmon smolts show a strong response to sudden temperature variation, significantly reducing the oxygen consumption rate up to a seven-fold change. Fish quickly returned to initial swimming costs shortly after reestablishment of temperature values. Results from this study can be used to evaluate the species-specific effects of the applied operation modes by hydroelectrical dams and to increase the success of conservation and management actions directed to fish species inhabiting regulated rivers.

Testing for thresholds of ecosystem collapse in seagrass meadows.

PubMed

Connell, Sean D; Fernandes, Milena; Burnell, Owen W; Doubleday, Zoë A; Griffin, Kingsley J; Irving, Andrew D; Leung, Jonathan Y S; Owen, Samuel; Russell, Bayden D; Falkenberg, Laura J

2017-10-01

Although the public desire for healthy environments is clear-cut, the science and management of ecosystem health has not been as simple. Ecological systems can be dynamic and can shift abruptly from one ecosystem state to another. Such unpredictable shifts result when ecological thresholds are crossed; that is, small cumulative increases in an environmental stressor drive a much greater change than could be predicted from linear effects, suggesting an unforeseen tipping point is crossed. In coastal waters, broad-scale seagrass loss often occurs as a sudden event associated with human-driven nutrient enrichment (eutrophication). We tested whether the response of seagrass ecosystems to coastal nutrient enrichment is subject to a threshold effect. We exposed seagrass plots to different levels of nutrient enrichment (dissolved inorganic nitrogen) for 10 months and measured net production. Seagrass response exhibited a threshold pattern when nutrient enrichment exceeded moderate levels: there was an abrupt and large shift from positive to negative net leaf production (from approximately 0.04 leaf production to 0.02 leaf loss per day). Epiphyte load also increased as nutrient enrichment increased, which may have driven the shift in leaf production. Inadvertently crossing such thresholds, as can occur through ineffective management of land-derived inputs such as wastewater and stormwater runoff along urbanized coasts, may account for the widely observed sudden loss of seagrass meadows. Identification of tipping points may improve not only adaptive-management monitoring that seeks to avoid threshold effects, but also restoration approaches in systems that have crossed them. © 2017 Society for Conservation Biology.

Safe Sleep Guideline Adherence in Nationwide Marketing of Infant Cribs and Products.

PubMed

Kreth, Matthew; Shikany, Tammy; Lenker, Claire; Troxler, R Bradley

2017-01-01

Sudden infant death syndrome and sleep-related sudden unexpected infant death remain leading causes of infant mortality in the United States despite 4 safe sleep guideline restatements over the previous 24 years. Advertising and retail crib displays often promote infant sleep environments that are counter to the most recent American Academy of Pediatrics (AAP) guidelines. Magazine advertisements featuring sleep in parenting magazines from 1992, 2010, and 2015 were reviewed for adherence. Crib displays from nationwide retailers were surveyed for adherence to the latest AAP safe sleep guidelines. The primary outcome was adherence to the guidelines. Of 1758 retail crib displays reviewed, only half adhered to the latest AAP guidelines. The most common reasons for nonadherence were the use of bumper pads and loose bedding. The depiction of infant cribs and sleep products in magazine advertising has become significantly more adherent over time; however, 35% of current advertisements depict nonadherent, unsafe sleep environments. Magazine advertising portraying safe sleep environments revealed racial and ethnic disparities. Although improvements have been made over time with increased adherence to AAP safe sleep guidelines, significant deficiencies remain. Advertising continues to depict unsafe sleep environments. Crib manufacturers and retail establishments continue to market and sell bedding and sleep products considered unsafe by the AAP in approximately half of retail crib displays. Pediatric and public health care providers should continue educational and advocacy efforts aimed at the public, but should also include retailers, manufacturers, and advertising professionals to foster improved sleep environments for all children. Copyright © 2017 by the American Academy of Pediatrics.

Risk Factors in the Initial Presentation of Specific Cardiovascular Disease Syndromes

ClinicalTrials.gov

2013-03-03

Heart Diseases; Cardiovascular Diseases; Acute Myocardial Infarction; Unstable Angina; Chronic Stable Angina; Ischemic Stroke; Cerebrovascular Accident; Subarachnoid Hemorrhage; Transient Ischemic Attack; Abdominal Aortic Aneurysm; Peripheral Arterial Disease; Sudden Coronary Death; Ventricular Arrhythmia; Sudden Death; Cardiac Arrest; Heart Failure

75 FR 1363 - Integrated System Power Rates

Federal Register 2010, 2011, 2012, 2013, 2014

2010-01-11

... service load immediately when disturbance conditions are experienced due to a sudden loss of generation or... conditions are experienced due to a sudden loss of generation or load. ``Supplemental Operating Reserve... Secretary has approved and placed into effect on an [[Page 1364

Heart Attack or Sudden Cardiac Arrest: How Are They Different?

MedlinePlus

... Peripheral Artery Disease Venous Thromboembolism Aortic Aneurysm More Heart Attack or Sudden Cardiac Arrest: How Are They Different? ... and procedures related to heart disease and stroke. Heart Attack • Home • About Heart Attacks Acute Coronary Syndrome (ACS) ...

[Research Progress of Sudden Cardiac Death in Forensic Medicine].

PubMed

Zheng, D; Yin, K; Zheng, J J; Zhou, N; Liu, Y; Fu, X; Cheng, J D

2017-10-01

Sudden death （SD） is a special kind of death owing to disease, which severely threatening the lives of community population. As the most common type of SD, sudden cardiac death （SCD） has always been a crucial content of identification and research in forensic pathology. This article reviews the research progress from the aspects of epidemiology, morphology, molecular pathology and virtual anatomy of SCD in forensic medicine, so as to provide a reference for the morphological identification, determination of cause of death, and integrated control of this kind of SD. Copyright© by the Editorial Department of Journal of Forensic Medicine.

Racial differences in sudden cardiac death

PubMed Central

Fender, Erin A.; Henrikson, Charles A.; Tereshchenko, Larisa

2014-01-01

There is an increased risk of sudden cardiac death (SCD) and sudden cardiac arrest (SCA), in African Americans, the basis of which is likely multifactorial. African Americans have higher rates of traditional cardiac risk factors including hypertension, left ventricular hypertrophy, diabetes, coronary heart disease, and heart failure. There are also significant disparities in health care delivery. While these factors undoubtedly affect health outcomes, there is also growing evidence that genetics may have a significant impact as well. In this paper, we discuss data and hypotheses in support of both sides of the controversy around racial differences in SCD/SCA. PMID:25155390

Solar activity and myocardial infarction.

PubMed

Szczeklik, E; Mergentaler, J; Kotlarek-Haus, S; Kuliszkiewicz-Janus, M; Kucharczyk, J; Janus, W

1983-01-01

The correlation between the incidence of myocardial infarction, sudden cardiac death, the solar activity and geomagnetism in the period 1969-1976 was studied, basing on Wrocław hospitals material registered according to WHO standards; sudden death was assumed when a person died within 24 hours after the onset of the disease. The highest number of infarctions and sudden deaths was detected for 1975, which coincided with the lowest solar activity, and the lowest one for the years 1969-1970 coinciding with the highest solar activity. Such an inverse, statistically significant correlation was not found to exist between the studied biological phenomena and geomagnetism.

Effects of pushing height on trunk posture and trunk muscle activity when a cart suddenly starts or stops moving.

PubMed

Lee, Yun-Ju; Hoozemans, Marco J M; van Dieën, Jaap H

2012-01-01

Unexpected sudden (un)loading of the trunk may induce inadequate responses of trunk muscles and uncontrolled trunk motion. These unexpected perturbations may occur in pushing tasks, when the cart suddenly starts moving (unloading) or is blocked by an obstacle (loading). In pushing, handle height affects the user's working posture, which may influence trunk muscle activity and trunk movement in response to the perturbation. Eleven healthy male subjects pushed a 200 kg cart with handles at shoulder and hip height in a start condition (sudden release of brakes) and a stop condition (bumping into an obstacle). Before the perturbation, the baseline of the trunk inclination, internal moment and trunk extensor muscle activity were significantly higher when pushing at hip height than at shoulder height. After the perturbation, the changes in trunk inclination and internal moment were significantly larger when pushing at shoulder height than at hip height in both conditions. The opposite directions of changes in trunk inclination and internal moment suggest that the unexpected perturbations caused uncontrolled trunk motion. Pushing at shoulder height may impose a high risk of low-back injury due to the low trunk stiffness and large involuntary trunk motion occurring after carts suddenly move or stop.

Reproductive Decision Making and Genetic Predisposition to Sudden Cardiac Death

PubMed Central

Barlevy, Dorit; Wasserman, David; Stolerman, Marina; Erskine, Kathleen E.; Dolan, Siobhan M.

2012-01-01

Background With current genetic technology, it is possible to detect mutations associated with long QT syndrome (LQTS), a hereditary cardiac arrhythmia syndrome. As a result, prospective parents diagnosed with LQTS will have to decide whether or not to prevent its transmission to future generations, either by not procreating or through the use of assisted reproductive technologies or prenatal testing. This paper explores how a hereditary predisposition to sudden cardiac death can influence reproductive decision making. Methods This study draws from interviews and focus groups with individuals who have personal or family histories of cardiac arrhythmia or sudden death. A keyword search was conducted on interview transcripts to identify quotes for analysis. Results Participants expressed complex, often ambivalent attitudes about the prospect of having a child with a predisposition to sudden cardiac death. Their comments reveal conflicting understandings of genetic responsibility and reflect the variable effects of personal experience on reproductive decision making. This paper compares attitudes towards LQTS and other genetic conditions in analyzing the themes that emerged in interviews and focus groups. Conclusions The “disability critique” of prenatal testing should be applied carefully to a context of genetic predisposition to sudden cardiac death in order to understand reproductive decision making. Firsthand experience with the condition, among other factors, can weigh heavily in those decisions. PMID:22822470

Risky Behaviors of Mothers with Infants on Sudden Infant Death Syndrome in Turkey.

PubMed

Erdoğan, Çiğdem; Turan, Türkan

Sudden infant death syndrome is the most common cause of death during the post-neonatal period. Factors such as sleeping position, bed sharing, pillow use, smoking during pregnancy and the breastfeeding period constitute risk factors for sudden infant death syndrome. This study aims to identify the risky behaviors of mothers with infants that may put their children at risk for sudden infant death syndrome. This is a cross-sectional, descriptive study. Data were collected using a questionnaire that was developed by the researchers. The questionnaire was filled out by 456 mothers who applied to the family health center between October 2014 and January 2015. The greatest risk factor is the infant's sleeping position. A total of 77.9% of the mothers put their babies in bed in a non-supine position; 65.8% used a pillow when they put their babies in bed, 52.9% used a soft mattress, and 28.5% shared their beds with their babies. Prone sleeping was more likely to occur when smoke was present in the home or a pillow was used. Nurses should notify families of the risky behaviors that can cause sudden infant death syndrome and plan appropriate nursing care. Copyright © 2017 Elsevier Inc. All rights reserved.

Finding the rhythm of sudden cardiac death: new opportunities using induced pluripotent stem cell-derived cardiomyocytes.

PubMed

Sallam, Karim; Li, Yingxin; Sager, Philip T; Houser, Steven R; Wu, Joseph C

2015-06-05

Sudden cardiac death is a common cause of death in patients with structural heart disease, genetic mutations, or acquired disorders affecting cardiac ion channels. A wide range of platforms exist to model and study disorders associated with sudden cardiac death. Human clinical studies are cumbersome and are thwarted by the extent of investigation that can be performed on human subjects. Animal models are limited by their degree of homology to human cardiac electrophysiology, including ion channel expression. Most commonly used cellular models are cellular transfection models, which are able to mimic the expression of a single-ion channel offering incomplete insight into changes of the action potential profile. Induced pluripotent stem cell-derived cardiomyocytes resemble, but are not identical, adult human cardiomyocytes and provide a new platform for studying arrhythmic disorders leading to sudden cardiac death. A variety of platforms exist to phenotype cellular models, including conventional and automated patch clamp, multielectrode array, and computational modeling. Induced pluripotent stem cell-derived cardiomyocytes have been used to study long QT syndrome, catecholaminergic polymorphic ventricular tachycardia, hypertrophic cardiomyopathy, and other hereditary cardiac disorders. Although induced pluripotent stem cell-derived cardiomyocytes are distinct from adult cardiomyocytes, they provide a robust platform to advance the science and clinical care of sudden cardiac death. © 2015 American Heart Association, Inc.

[Sudden cardiac death, a major scientific challenge].

PubMed

Haissaguerre, Michel; Hocini, Meleze; Sacher, Frédéric; Shah, Ashok

2010-06-01

Sudden death is responsible for 350,000 deaths each year in Europe, or 1000 deaths each day, equivalent to the combined mortality from the most lethal cancers (breast, lung and colorectal). Unfortunately, sudden death is widely considered to be "natural", being due to unknown but critical cardiac disorders leading to sudden arrest of cardiac activity. Awareness of its potential preventability is inadequate. Indeed, 80% of cases of sudden death are associated with extremely rapid heartbeats, an "electric tornado" called ventricular fibrillation, caused by ultrarapid firing of ectopic foci or chaotic wave propagation. This arrhythmia strikes like lightning Although it can be associated with myocardial infarction, most victims have structurally normal or slightly altered hearts. The cells which cause this ultrarapid firing originate from the Purkinje system, which constitutes just a fraction (2%) of total cardiac mass. This is borne out by the fact that the risk of fatal arrhythmic events can be reduced by focal thermoablation. What is most important is to identify subjects at risk of such events. It has been suggested that there exists an unidentified subclinical electrical disharmony, which converts into a tornado of ultimately fatal clinical events at a certain threshold level. High-resolution bioelectrical cardiac mapping, functional imaging, and treatment of electrical field disorders are major scientific challenges given their complexity, intraindividual dynamics and interindividual variability.

Pre-participation examination of competitive athletes: role of the ECG.

PubMed

Hirzinger, Corinna; Froelicher, Victor F; Niebauer, Josef

2010-08-01

Sudden cardiac death in athletes is rare but has a wide social impact because it confronts the general population with the paradox that athletes perceived and admired as the fittest and healthiest suddenly drop dead during their sport. Mass media coverage is guaranteed in the case of sudden cardiac death of a top athlete, while other competitive and noncompetitive athletes of all ages, team members, sponsors, as well as huge parts of society remain puzzled and frightened. Therefore, debate is ongoing regarding how to minimize the number of fatalities, and the search continues for a cost-effective preparticipation screening for competitive athletes. Despite the fact that routine ECG screening would be widely available and rather inexpensive, debate continues regarding whether this should be part of initial screening for every athlete before starting to train at high intensity as well as during annual checkups. The role of ECGs in preparticipation examinations of competitive athletes is intensively discussed because there is a lack of strict criteria for which ECG findings should generate further workup. In this article, we analyze the main publications on sudden cardiac death, focusing on the benefit of ECG screening in preparticipation examination as it has been shown to be feasible and effective in identifying athletes at risk of sudden cardiac death. Copyright © 2010 Elsevier Inc. All rights reserved.

Malignant Course of Anomalous Left Coronary Artery Causing Sudden Cardiac Arrest: A Case Report and Review of the Literature.

PubMed

Anantha Narayanan, Mahesh; DeZorzi, Christopher; Akinapelli, Abhilash; Mahfood Haddad, Toufik; Smer, Aiman; Baskaran, Janani; Biddle, William P

2015-01-01

Sudden cardiac arrest has been reported to occur in patients with congenital anomalous coronary artery disease. About 80% of the anomalies are benign and incidental findings at the time of catheterization. We present a case of sudden cardiac arrest caused by anomalous left anterior descending artery. 61-year-old African American female was brought to the emergency department after sudden cardiac arrest. Initial EKG showed sinus rhythm with RBBB and LAFB with nonspecific ST-T wave changes. Coronary angiogram revealed no atherosclerotic disease. The left coronary artery was found to originate from the right coronary cusp. Cardiac CAT scan revealed similar findings with interarterial and intramural course. Patient received one-vessel arterial bypass graft to her anomalous coronary vessel along with a defibrillator for secondary prevention. Sudden cardiac arrest secondary to congenital anomalous coronary artery disease is characterized by insufficient coronary flow by the anomalous left coronary artery to meet elevated left ventricular (LV) myocardial demand. High risk defects include those involved with the proximal coronary artery or coursing of the anomalous artery between the aorta and pulmonary trunk. Per guidelines, our patient received one vessel bypass graft to her anomalous vessel. It is important for clinicians to recognize such presentations of anomalous coronary artery.

A micromechanical model of rate and state friction: 2. Effect of shear and normal stress changes

NASA Astrophysics Data System (ADS)

Molinari, A.; Perfettini, H.

2017-04-01

In this paper we analyze the influence of shear and normal stress changes on frictional properties. This problem is fundamental as, for instance, sudden stress changes are naturally induced on active faults by nearby earthquakes. As any stress changes can be seen as resulting from a succession of infinitesimal stress steps, the role of sudden stress changes is crucial to our understanding of fault dynamics. Laboratory experiments carried out by Linker and Dieterich (1992) and Nagata et al. (2012), considering steps in normal and shear stress, respectively, show an instantaneous response of the state variable (a proxy for the evolution of contact surface in our model) to a sudden stress change. We interpret this response as being due to an (instantaneous) elastic response of the plastic and elastic contacts. We assume that the anelastic response of the plastic contacts is frozen during sudden stress changes. The contacts, which were driven by plasticity before the stress change, are elastically accommodated during the sudden variation of the load. On the contrary, when the loading is slowly varying, elastic deformation of plastic contacts can be neglected. Our model is able to explain the evolution law for the state variable reported by Linker and Dieterich (1992).

Causes of sudden death in Addis Ababa, Ethiopia.

PubMed

Schneider, J; Bezabih, K

2001-10-01

The aim of this study was to evaluate the causes of death in individuals who died suddenly in Addis Ababa, Ethiopia. The selection of the cases was based on police reports, which contained a description of sudden unexpected or instantaneous death. The study was performed on necropsies of the Medico legal Department of Menelik II Hospital, in Addis Ababa during the years 1998 and 1999. According to the pathological features of the heart, we classified 92 dead bodies in 3 groups: Group A: Hearts showing adequate morphological changes to explain sudden death (n = 63). Group B: Hearts showing some structural changes, but inadequate to explain sudden death (n = 20). Group C: Normal hearts (n = 7). In two bodies the general autopsy revealed an extra cardiac cause of death. The single most relevant cause of death in group A was coronary artery disease (44 cases) followed by excessive myocardial hypertrophy due to post-rheumatic valvular lesions (7 cases). While the high prevalence of rheumatic heart disease in Ethiopia is well known, the proportion of cases who died due to coronary heart disease is surprising. Though during the last years some African authors assumed that coronary atherosclerosis is on the increase in developing countries the percentage is higher than expected and higher than in other countries where similar studies exist.

Sudden neurologic deficit.

PubMed

Kellogg, Marissa; Liang, Conrad W; Liebeskind, David S

2016-01-01

Clinicians treating sudden neurologic deficit are being faced with an increasing number of available imaging modalities. In this chapter we discuss a general approach to acute neuroimaging and weigh the considerations that determine which modality or modalities should be utilized. © 2016 Elsevier B.V. All rights reserved.

40 CFR 265.31 - Maintenance and operation of facility.

Code of Federal Regulations, 2014 CFR

2014-07-01

... WASTES (CONTINUED) INTERIM STATUS STANDARDS FOR OWNERS AND OPERATORS OF HAZARDOUS WASTE TREATMENT... any unplanned sudden or non-sudden release of hazardous waste or hazardous waste constituents to air, soil, or surface water which could threaten human health or the -environment. ...

40 CFR 265.31 - Maintenance and operation of facility.

Code of Federal Regulations, 2012 CFR

2012-07-01

... WASTES (CONTINUED) INTERIM STATUS STANDARDS FOR OWNERS AND OPERATORS OF HAZARDOUS WASTE TREATMENT... any unplanned sudden or non-sudden release of hazardous waste or hazardous waste constituents to air, soil, or surface water which could threaten human health or the -environment. ...

40 CFR 265.31 - Maintenance and operation of facility.

Code of Federal Regulations, 2013 CFR

2013-07-01

... WASTES (CONTINUED) INTERIM STATUS STANDARDS FOR OWNERS AND OPERATORS OF HAZARDOUS WASTE TREATMENT... any unplanned sudden or non-sudden release of hazardous waste or hazardous waste constituents to air, soil, or surface water which could threaten human health or the -environment. ...

Decomposition and N cycling changes in redwood forests caused by sudden oak death

Treesearch

Richard C. Cobb; David M. Rizzo

2012-01-01

Phytophthora ramorum is an emergent pathogen in redwood forests which causes the disease sudden oak death. Although the disease does not kill coast redwood (Sequoia sempervirens), extensive and rapid mortality of tanoak (Notholithocarpus densiflorus) has removed this...

40 CFR 265.31 - Maintenance and operation of facility.

Code of Federal Regulations, 2011 CFR

2011-07-01

... WASTES (CONTINUED) INTERIM STATUS STANDARDS FOR OWNERS AND OPERATORS OF HAZARDOUS WASTE TREATMENT... any unplanned sudden or non-sudden release of hazardous waste or hazardous waste constituents to air, soil, or surface water which could threaten human health or the -environment. ...

Common cold - how to treat at home

MedlinePlus

... you have: Difficulty breathing Sudden chest pain or abdominal pain Sudden dizziness Acting strangely Severe vomiting that does not go away Also call your provider if: You start acting strangely Your symptoms get worse or do not improve after 7 to 10 days

78 FR 23768 - Agency Information Collection Activities: Proposed Collection; Comment Request

Federal Register 2010, 2011, 2012, 2013, 2014

2013-04-22

... Beneficiaries Receiving Implantable Cardioverter- Defibrillators for Primary Prevention of Sudden Cardiac Death; Use: CMS provides coverage for implantable cardioverter-defibrillators (ICDs) for secondary prevention... Defibrillators'' on January 27, 2005, indicating that ICDs will be covered for primary prevention of sudden...

Tobacco smoking and the risk of sudden cardiac death: a systematic review and meta-analysis of prospective studies.

PubMed

Aune, Dagfinn; Schlesinger, Sabrina; Norat, Teresa; Riboli, Elio

2018-06-01

Smoking is an established risk factor for cardiovascular disease including coronary heart disease and stroke, however, data regarding smoking and sudden cardiac death have not been summarized in a meta-analysis previously. We therefore conducted a systematic review and meta-analysis to clarify this association. We searched the PubMed and Embase databases for studies of smoking and sudden cardiac death up to July 20th 2017. Prospective studies were included if they reported adjusted relative risk (RR) estimates and 95% confidence intervals (CIs) for smoking and sudden cardiac death. Summary RRs were estimated by use of a random effects model. Twelve prospective studies were included. The summary RR was 3.06 (95% CI 2.46-3.82, I 2  = 41%, p heterogeneity  = 0.12, n = 7) for current smokers and 1.38 (95% CI 1.20-1.60, I 2  = 0%, p heterogeneity  = 0.55, n = 7) for former smokers compared to never smokers. For four studies using non-current (never + former) smokers as the reference category the summary RR among current smokers was 2.08 (95% CI 1.70-2.53, I 2  = 18%, p heterogeneity  = 0.30). The results persisted in most of the subgroup analyses. There was no evidence of publication bias. These results confirm that smoking increases the risk of sudden cardiac death. Any further studies should investigate in more detail the effects of duration of smoking, number of cigarettes per day, pack-years, and time since quitting smoking and sudden cardiac death.

Incidence and causes of sudden death in U.S. college athletes.

PubMed

Maron, Barry J; Haas, Tammy S; Murphy, Caleb J; Ahluwalia, Aneesha; Rutten-Ramos, Stephanie

2014-04-29

The goal of this study was to reliably define the incidence and causes of sudden death in college student-athletes. The frequency with which cardiovascular-related sudden death occurs in competitive athletes importantly influences considerations for pre-participation screening strategies. We assessed databases (including autopsy reports) from both the U.S. National Registry of Sudden Death in Athletes and the National Collegiate Athletic Association (2002 to 2011). Over the 10-year study period, 182 sudden deaths occurred (age 20 ± 1.7 years; 85% male; 64% white), 52 resulting from suicide (n = 31) or drug abuse (n = 21) and 64 probably or likely attributable to cardiovascular causes (6/year). Of these 64 athletes, 47 had a confirmed post-mortem diagnosis; the most common were hypertrophic cardiomyopathy in 21 and congenital coronary anomalies in 8. The 4,052,369 athlete participations (in 30 sports over 10 years) incurred mortality risks as follows: suicide and drugs combined, 1.3/100,000 athlete participation-years (5 deaths/year); and documented cardiovascular disease, 1.2/100,000 athlete participation-years (4 deaths/year). Notably, cardiovascular deaths were 5-fold more common in African-American athletes than in white athletes (3.8 vs. 0.7/100,000 athlete participation-years; p < 0.01) but did not differ from the general population of the same age and race (p = 0.6). In college student-athletes, risk of sudden death due to cardiovascular disease is relatively low, with mortality rates similar to suicide and drug abuse, but less than expected in the general population, although highest in African-American athletes. A substantial minority of confirmed cardiovascular deaths would not likely have been reliably detected by pre-participation screening with 12-lead electrocardiograms. Copyright © 2014 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Relationships between sudden weather changes in summer and mortality in the Czech Republic, 1986-2005

NASA Astrophysics Data System (ADS)

Plavcová, Eva; Kyselý, Jan

2010-09-01

The study examines the relationship between sudden changes in weather conditions in summer, represented by (1) sudden air temperature changes, (2) sudden atmospheric pressure changes, and (3) passages of strong atmospheric fronts; and variations in daily mortality in the population of the Czech Republic. The events are selected from data covering 1986-2005 and compared with the database of daily excess all-cause mortality for the whole population and persons aged 70 years and above. Relative deviations of mortality, i.e., ratios of the excess mortality to the expected number of deaths, were averaged over the selected events for days D-2 (2 days before a change) up to D+7 (7 days after), and their statistical significance was tested by means of the Monte Carlo method. We find that the periods around weather changes are associated with pronounced patterns in mortality: a significant increase in mortality is found after large temperature increases and on days of large pressure drops; a decrease in mortality (partly due to a harvesting effect) occurs after large temperature drops, pressure increases, and passages of strong cold fronts. The relationship to variations in excess mortality is better expressed for sudden air temperature/pressure changes than for passages of atmospheric fronts. The mortality effects are usually more pronounced in the age group 70 years and above. The impacts associated with large negative changes of pressure are statistically independent of the effects of temperature; the corresponding dummy variable is found to be a significant predictor in the ARIMA model for relative deviations of mortality. This suggests that sudden weather changes should be tested also in time series models for predicting excess mortality as they may enhance their performance.

Sudden death victims <45 years: Agreement between cause of death established by the forensic physician and autopsy results.

PubMed

Ceelen, Manon; van der Werf, Christian; Hendrix, Anneke; Naujocks, Tatjana; Woonink, Frits; de Vries, Philip; van der Wal, Allard; Das, Kees

2015-08-01

The goal of this study was to ascertain accordance between cause of death established by the forensic physician and autopsy results in young sudden death victims in the Netherlands. Sudden death victims aged 1-45 years examined by forensic physicians operating in the participating regions which also underwent an autopsy between January 2006 and December 2011 were included (n = 70). Cause of death established by the forensic physician based on the external medicolegal examination was compared with autopsy findings using the ICD10-classification. Autopsy findings revealed that the majority of sudden death victims have died from a cardiac disease (n = 51, 73%). Most of the presumed heart disease related cases were confirmed by autopsy (n = 13, 87%). On the contrary, a large number of deaths caused by circulatory diseases were not recognised by the forensic physician (n = 38, 75%). In most of these cases, the forensic physician was forced to report an undetermined cause due to the lack of a solid explanation for death. Cause of death reported by the forensic physician appeared to be in agreement with the autopsy results in 12 cases (17%). Cause of death determination in young sudden death victims is a difficult task for forensic physicians due to the limited tools available during the medicolegal examination. An effort should be made to standardize extensive post-mortem investigation after sudden death in the young. Autopsy can provide valuable information regarding the cause of death, which is of great importance in view of the identification of inheritable diseases among decedents and their families. Copyright © 2015 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.

Sudden and unexpected childhood deaths investigated at the Pretoria Medico-Legal Laboratory, South Africa, 2007 - 2011.

PubMed

Van Deventer, B S; Rossouw, S H; Du Toit-Prinsloo, L

2016-09-06

 Sudden and unexpected death is well known to occur in infants, and although sudden deaths are less frequent after the first birthday, they still account for a significant proportion of childhood deaths. In 2009, 1.9% of the total deaths in the USA were childhood deaths. In South Africa (SA) this proportion was much higher at 11.85%. According to the law, sudden and unexpected deaths are generally investigated as unnatural deaths. Establishing an exact underlying anatomical cause of death will depend on available resources and can be difficult in a substantial proportion of cases.  A retrospective descriptive case audit was conducted at the Pretoria Medico-Legal Laboratory (PMLL), SA, from 1 January 2007 through to 31 December 2011. All children aged 1 - 18 years who died suddenly and unexpectedly were included.  Ninety-eight cases were identified, which constituted nearly 1% of total admissions to the PMLL. The majority of the deaths were of children aged 1 - 5 years, and the male/female ratio was 1.04:1. In the largest proportion of cases (n=28, 28.6%), the medicolegal investigation, including autopsy and ancillary investigations, did not establish an underlying anatomical cause of death. In the cases where a cause of death was established, pneumonia was the most common diagnosis (n=22, 22.4%).  The fact that the cause of the largest proportion of deaths could not be ascertained emphasises the need for consideration of additional investigative techniques, such as molecular/genetic screening, which have provided an underlying cause of death in a significant number of cases in other countries. There is a lack of published research on the causes and incidence of sudden unexpected deaths in children in SA, and further research in this area is needed.

Phytophthora ramorum and sudden oak death in California: II. transmission and survival

Treesearch

Jennifer M. Davidson; David M. Rizzo; Matteo Garbelotto; Steven Tjosvold; Garey W. Slaughter

2002-01-01

The newly discovered Phytophthora ramorum canker disease of oak (Sudden Oak Death Syndrome) threatens millions of acres of California woodlands where coast live oak (Quercus agrifolia), tanoak (Lithocarpus densiflorus), or black oak (Quercus kelloggii) are dominant species. An important step in...

76 FR 74667 - Airworthiness Directives; The Boeing Company Model 737-200, -200C, -300, -400, and -500 Series...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-12-01

... at the chem-milled steps, which could result in sudden fracture and failure of the fuselage skin... chem-milled steps, which could result in sudden fracture and failure of the fuselage skin panels, and...

Investigating Insight as Sudden Learning

ERIC Educational Resources Information Center

Ash, Ivan K.; Jee, Benjamin D.; Wiley, Jennifer

2012-01-01

Gestalt psychologists proposed two distinct learning mechanisms. Associative learning occurs gradually through the repeated co-occurrence of external stimuli or memories. Insight learning occurs suddenly when people discover new relationships within their prior knowledge as a result of reasoning or problem solving processes that re-organize or…

Role of sudden commencements in triggering magnetospheric substorms. M.S. Thesis; [based on ATS 1 data

NASA Technical Reports Server (NTRS)

Newell, R. E.

1974-01-01

Sudden commencement events are examined in terms of available auroral-zone and low-latitude magnetic field, data, interplanetary plasma and magnetic field data, and magnetospheric electron flux and magnetic field data from the geostationary satellite ATS 1.

Survivor-Victim Status, Attachment, and Sudden Death Bereavement.

ERIC Educational Resources Information Center

Reed, Mark D.; Greenwald, Jason Y.

1991-01-01

Examined significance of survivor-victim relationship in understanding grief following sudden death bereavement by suicide or accident. Results showed that survivor-victim attachment was more important than survivor status (parent versus sibling/child) in explaining grief reactions. Compared to accident survivors, suicide survivors experienced…

Regeneration and tanoak mortality in coast redwood stands affected by sudden oak death

Treesearch

Benjamin S. Ramage; Kevin L. OHara; Alison B. Forreste

2012-01-01

Sudden oak death, an emerging disease caused by the exotic pathogen Phytophthora ramorum, is impacting coast redwood (Sequoia sempervirens) forests throughout coastal California. The most severely affected species, tanoak (Notholithocarpus densiflorus), is currently widespread and abundant in the redwood...

Sudden unexpected death due to Graves' disease during physical altercation.

PubMed

Wei, Dengming; Yuan, Xiaogang; Yang, Tiantong; Chang, Lin; Zhang, Xiang; Burke, Allen; Fowler, David; Li, Ling

2013-09-01

We report a case of a 30-year-old woman who suddenly collapsed after having a physical altercation with her husband. Despite immediate resuscitation, she died on arrival at the hospital. The victim's parents requested an autopsy because they believed that their daughter was killed by her husband. Postmortem examination revealed that the victim had a diffusely enlarged thyroid gland and cardiomegaly with left ventricular hypertrophy. There was no evidence of significant trauma on the body. Further postmortem thyroid function tests and review of her medical history indicated that her death was due to Graves' disease. To the best of our knowledge, this is the first case reported of sudden death due to cardiac arrhythmia from Graves' disease induced by physical and emotional stress associated with the criminal activity of another person. The autopsy findings are described. In addition, the literature is reviewed and the significance of postmortem evaluation of thyroid hormones in the cases of sudden death is discussed. © 2013 American Academy of Forensic Sciences.

Possibilities of post-mortem diagnostics, including immunodiagnostics, in cases of sudden death due to anaphylactic and anaphylactoid reactions.

PubMed

Kobek, M; Jankowski, Z; Chowaniec, C; Chowaniec, M; Jabłoński, C; Skowronek, R

Postmortem diagnostics of anaphylactic and anaphylactoid reaction as the cause of death in cases of sudden deaths without witnesses, as well as those in which circumstances of sudden disease and then death are known, seems to be very difficult. This is caused by the lack of characteristic macro- or microscopic changes to internal organs resulting from a short, or even very short time, that elapses from the action of the etiological factor till death. In the above mentioned cases it is often impossible to establish univocally the cause of death, despite considering information on the cause of disease and its clinical symptoms. On the basis of 2 cases of sudden deaths resulted from the intake of hazel nuts, and the administration of contrast agent before radiological examination, the authors discuss the usefulness of postmortem determinations of tryptase and IgE in blood for diagnostics of deaths resulting from anaphylactic and anaphylactoid reaction, respectively.

Cardiac Channelopathies and Sudden Death: Recent Clinical and Genetic Advances.

PubMed

Fernández-Falgueras, Anna; Sarquella-Brugada, Georgia; Brugada, Josep; Brugada, Ramon; Campuzano, Oscar

2017-01-29

Sudden cardiac death poses a unique challenge to clinicians because it may be the only symptom of an inherited heart condition. Indeed, inherited heart diseases can cause sudden cardiac death in older and younger individuals. Two groups of familial diseases are responsible for sudden cardiac death: cardiomyopathies (mainly hypertrophic cardiomyopathy, dilated cardiomyopathy, and arrhythmogenic cardiomyopathy) and channelopathies (mainly long QT syndrome, Brugada syndrome, short QT syndrome, and catecholaminergic polymorphic ventricular tachycardia). This review focuses on cardiac channelopathies, which are characterized by lethal arrhythmias in the structurally normal heart, incomplete penetrance, and variable expressivity. Arrhythmias in these diseases result from pathogenic variants in genes encoding cardiac ion channels or associated proteins. Due to a lack of gross structural changes in the heart, channelopathies are often considered as potential causes of death in otherwise unexplained forensic autopsies. The asymptomatic nature of channelopathies is cause for concern in family members who may be carrying genetic risk factors, making the identification of these genetic factors of significant clinical importance.

Sudden-On-Chronic Death and Complicated Grief in Bereaved Dementia Caregivers: Two Case Studies of Complicated Grief Group Therapy.

PubMed

Supiano, Katherine P; Andersen, Troy C; Haynes, Lara Burns

2015-01-01

Caring for a person with Alzheimer's disease is challenging and often has negative health and mental health effects that, for 7-20% of caregivers, persist into bereavement in the form of complicated grief. Complicated grief is a state of prolonged and ineffective mourning. An under-recognized phenomenon in dementia care and bereavement is "sudden-on-chronic death." In these situations, the caregiver is preparing for a gradual dying process from dementia, but the care recipient dies instead from a sudden death. In this study, an application of complicated grief group therapy for bereaved dementia caregivers with complicated grief is presented, and the effect of therapy with two bereaved caregivers who experienced the sudden death of their spouses who had a diagnosis of dementia is described. The unique treatment elements of complicated grief group therapy facilitated resolution of the 'trauma-like" features of bereavement and progression to a healthy grief process.

Prevention of sudden cardiac death in young athletes: controversies and conundrums.

PubMed

Rowland, Thomas

2011-01-01

Strategies for preventing sudden cardiac death in young athletes are predicated on the assumption that: (1) these events reflect pre-existing, clinically silent heart disease, and (2) means for detecting these abnormalities on the pre-participation evaluation are both feasible and accurate. Recent controversy has surrounded both of these presumptions. Some evidence suggests that the myocardial hypertrophy accompanying sports training itself might serve as a substrate for fatal arrhythmias. As well, vigorous debate has arisen over the optimal content of the pre-participation evaluation, particularly regarding the inclusion of routine screening electrocardiograms. As the rarity of these fatal events does not lend itself to an experimental approach, such disagreements are not easily resolved. Consequently, it is expected that decisions regarding approaches to prevention of sudden death in athletes will be dictated largely by region-specific financial, political, and cultural factors. This chapter examines the aetiologies of sudden cardiac death in young athletes as well as the controversies surrounding the prevention of these tragedies. Copyright © 2011 S. Karger AG, Basel.

Primordial spectra from sudden turning trajectory

NASA Astrophysics Data System (ADS)

Noumi, Toshifumi; Yamaguchi, Masahide

2013-12-01

Effects of heavy fields on primordial spectra of curvature perturbations are discussed in inflationary models with a sudden turning trajectory. When heavy fields are excited after the sudden turn and oscillate around the bottom of the potential, the following two effects are generically induced: deformation of the inflationary background spacetime and conversion interactions between adiabatic and isocurvature perturbations, both of which can affect the primordial density perturbations. In this paper, we calculate primordial spectra in inflationary models with sudden turning potentials taking into account both of the two effects appropriately. We find that there are some non-trivial correlations between the two effects in the power spectrum and, as a consequence, the primordial scalar power spectrum has a peak around the scale exiting the horizon at the turn. Though both effects can induce parametric resonance amplifications, they are shown to be canceled out for the case with the canonical kinetic terms. The peak feature and the scale dependence of bispectra are also discussed.

Alternative research funding to improve clinical outcomes: model of prediction and prevention of sudden cardiac death.

PubMed

Myerburg, Robert J; Ullmann, Steven G

2015-04-01

Although identification and management of cardiovascular risk markers have provided important population risk insights and public health benefits, individual risk prediction remains challenging. Using sudden cardiac death risk as a base case, the complex epidemiology of sudden cardiac death risk and the substantial new funding required to study individual risk are explored. Complex epidemiology derives from the multiple subgroups having different denominators and risk profiles, while funding limitations emerge from saturation of conventional sources of research funding without foreseeable opportunities for increases. A resolution to this problem would have to emerge from new sources of funding targeted to individual risk prediction. In this analysis, we explore the possibility of a research funding strategy that would offer business incentives to the insurance industries, while providing support for unresolved research goals. The model is developed for the case of sudden cardiac death risk, but the concept is applicable to other areas of the medical enterprise. © 2015 American Heart Association, Inc.

Therapeutic effect of lipoprostaglandin E1 on sudden hearing loss.

PubMed

Ahn, Joong Ho; Kim, Mi Ra; Kim, Hyang Cho

2005-01-01

The authors conducted a prospective, comparative clinical trial for the purpose of additional effect of lipoprostaglandin E 1 (lipo-PGE 1 ) on sudden hearing loss. With the approval of the institute ethics committee, a total of 128 consecutive patients with diagnoses of sudden hearing loss were included in the study. The patients in the lipo-PGE 1 group received continuous infusion of 10 microL lipo-PGE 1 and 48 mg methylprednisolone for 5 days, and the patient in the control group were treated with only 48 mg methylprednisolone. The total recovery rate after the treatment was 67.2%. There were 70.5% recovery rate in lipo-PGE 1 group and 60.5% recovery rate in control group. However, no significant differences were observed in the improvements of pure tone average and subjective symptoms between the lipo-PGE 1 and control groups. The results failed to prove a beneficial effect of lipo-PGE 1 in the treatment of sudden hearing loss in spite of its higher cure rate.

Sudden unexpected death in epilepsy.

PubMed

Shorvon, Simon; Tomson, Torbjorn

2011-12-10

Sudden unexpected death in epilepsy (SUDEP) refers to the sudden death of a seemingly healthy individual with epilepsy, usually occurring during, or immediately after, a tonic-clonic seizure. The frequency of SUDEP varies depending on the severity of the epilepsy, but overall the risk of sudden death is more than 20 times higher than that in the general population. Several different mechanisms probably exist, and most research has focused on seizure-related respiratory depression, cardiac arrhythmia, cerebral depression, and autonomic dysfunction. Data from a pooled analysis of risk factors indicate that the higher the frequency of tonic-clonic seizures, the higher the risk of SUDEP; furthermore, risk of SUDEP is also elevated in male patients, patients with long-duration epilepsy, and those on antiepileptic polytherapy. SUDEP usually occurs when the seizures are not witnessed and often at night. In this Seminar, we provide advice to clinicians on ways to minimise the risk of SUDEP, information to pass on to patients, and medicolegal aspects of these deaths. Copyright © 2011 Elsevier Ltd. All rights reserved.

Sudden death in sports among young adults in Norway.

PubMed

Solberg, Erik Ekker; Gjertsen, Finn; Haugstad, Erlend; Kolsrud, Lars

2010-06-01

The aim of the study was to explore sudden cardiac death during physical activity in young adults in Norway. This retrospective study examined adults aged 15-34 years during the period 1990-1997. The Cause of Death Registry was used to identify cases of sudden cardiac death in sports. These cases were validated with information from medical records and autopsy reports. Twenty-three sports-related sudden deaths (22 men), mean age 27 years (17-34 years), were identified. Causes of death were myocardial infarction (11), myocarditis (5), conduction abnormalities (2), aortic stenosis (1), cardiac rupture (1), hypertrophic obstructive cardiomyopathy (1), congenital coronary anomaly (1), and coronary sclerosis without defined infarction (1). The deaths were distributed across different types of sports activities. The incidence of deaths among physically active young men was 0.9 per 100,000. The number of myocardial infarctions is higher than expected. The incidence is similar to that found in other studies. A vast majority of the cases of death were men.

Foreign field hospitals in the recent sudden-onset disasters in Iran, Haiti, Indonesia, and Pakistan.

PubMed

von Schreeb, Johan; Riddez, Louis; Samnegård, Hans; Rosling, Hans

2008-01-01

Foreign field hospitals (FFHs) may provide care for the injured and substitute for destroyed hospitals in the aftermath of sudden-onset disasters. In the aftermath of sudden-onset disasters, FFHs have been focused on providing emergency trauma care for the initial 48 hours following the sudden-onset disasters, while they tend to be operational much later. In addition, many have remained operational even later. The aim of this study was to assess the timing, activities, and capacities of the FFHs deployed after four recent sudden-onset disasters, and also to assess their adherence to the essential criteria for FFH deployment of the World Health Organization (WHO). Secondary information on the sudden-onset disasters in Bam, Iran in 2003, Haiti in 2004, Aceh, Indonesia in 2004, and Kashmir, Pakistan in 2005, including the number of FFHs deployed, their date of arrival, country of origin, length of stay, activities, and costs was retrieved by searching the Internet. Additional information was collected on-site in Iran, Indonesia, and Pakistan through direct observation and key informant interviews. Basic information was found for 43 FFHs in the four disasters. The first FFH was operational on Day 3 in Bam and Kashmir, and on Day 8 in Aceh. The first FFHs were all from the militaries of neighboring countries. The daily cost of a bed was estimated to be US$2,000. The bed occupancy rate generally was < 50%. None of the 43 FFHs met the first WHO/Pan-American Health Organization (PAHO) essential requirement if the aim is to provide emergency trauma care, while 15% followed the essential requirement if follow-up trauma and medical care is the aim of deployment. A striking finding was the lack of detailed information on FFH activities. None of the 43 FFHs arrived early enough to provide emergency medical trauma care. The deployment of FFHs following sudden-onset disasters should be better adapted to the main needs and the context and more oriented toward substituting for pre-existing hospitals, rather than on providing immediate trauma care.

Time-dependent generalized Gibbs ensembles in open quantum systems

NASA Astrophysics Data System (ADS)

Lange, Florian; Lenarčič, Zala; Rosch, Achim

2018-04-01

Generalized Gibbs ensembles have been used as powerful tools to describe the steady state of integrable many-particle quantum systems after a sudden change of the Hamiltonian. Here, we demonstrate numerically that they can be used for a much broader class of problems. We consider integrable systems in the presence of weak perturbations which break both integrability and drive the system to a state far from equilibrium. Under these conditions, we show that the steady state and the time evolution on long timescales can be accurately described by a (truncated) generalized Gibbs ensemble with time-dependent Lagrange parameters, determined from simple rate equations. We compare the numerically exact time evolutions of density matrices for small systems with a theory based on block-diagonal density matrices (diagonal ensemble) and a time-dependent generalized Gibbs ensemble containing only a small number of approximately conserved quantities, using the one-dimensional Heisenberg model with perturbations described by Lindblad operators as an example.

Absence of jamming in ant trails: feedback control of self-propulsion and noise.

PubMed

Chaudhuri, Debasish; Nagar, Apoorva

2015-01-01

We present a model of ant traffic considering individual ants as self-propelled particles undergoing single-file motion on a one-dimensional trail. Recent experiments on unidirectional ant traffic in well-formed natural trails showed that the collective velocity of ants remains approximately unchanged, leading to the absence of jamming even at very high densities [John et al., Phys. Rev. Lett. 102, 108001 (2009)]. Assuming a feedback control mechanism of self-propulsion force generated by each ant using information about the distance from the ant in front, our model captures all the main features observed in the experiment. The distance headway distribution shows a maximum corresponding to separations within clusters. The position of this maximum remains independent of average number density. We find a non-equilibrium first-order transition, with the formation of an infinite cluster at a threshold density where all the ants in the system suddenly become part of a single cluster.

Rotational energy transfer of SH(X2Π, v''=0, J''=0.5-10.5) by collision with Ar: Λ-doublet resolved transition propensity.

PubMed

Tsai, Po-Yu; Lin, King-Chuen

2012-01-16

The behavior of Λ-doublet resolved rotational energy transfer (RET) by Ar collisions within the SH(X(2)Π, v''=0) state is characterized. The matrix elements of terms in the interaction potential responsible for interference effects are calculated to explain the propensity rules for collision-induced transitions within and between spin-orbit manifolds. In this manner, the physical mechanisms responsible for the F(1)-F(1), F(2)-F(2), and F(1)-F(2) transitions may be reasonably identified. As collision energy increases, the propensity for collisional population of the final e or f level is replaced by the e/f-conserving propensity. Such a change in propensity rule can be predicted in terms of energy sudden approximation at high J limit for the pure Hund's case scheme. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Numerical renormalization group method for entanglement negativity at finite temperature

NASA Astrophysics Data System (ADS)

Shim, Jeongmin; Sim, H.-S.; Lee, Seung-Sup B.

2018-04-01

We develop a numerical method to compute the negativity, an entanglement measure for mixed states, between the impurity and the bath in quantum impurity systems at finite temperature. We construct a thermal density matrix by using the numerical renormalization group (NRG), and evaluate the negativity by implementing the NRG approximation that reduces computational cost exponentially. We apply the method to the single-impurity Kondo model and the single-impurity Anderson model. In the Kondo model, the negativity exhibits a power-law scaling at temperature much lower than the Kondo temperature and a sudden death at high temperature. In the Anderson model, the charge fluctuation of the impurity contributes to the negativity even at zero temperature when the on-site Coulomb repulsion of the impurity is finite, while at low temperature the negativity between the impurity spin and the bath exhibits the same power-law scaling behavior as in the Kondo model.

Bilateral neuroretinitis associated with mumps.

PubMed

Khubchandani, Raju; Rane, Tej; Agarwal, Premlata; Nabi, Fazal; Patel, Phiroze; Shetty, Avinash K

2002-10-01

Involvement of the optic nerve is a rare complication of mumps infection. To report a case of bilateral neuroretinitis complicating a mumps infection and to review 5 previously reported cases. Case report and literature review. Tertiary hospital. A 7-year-old girl had sudden-onset blindness due to bilateral neuroretinitis. Approximately 3 weeks prior to the initial examination, she developed a self-limited febrile illness with parotid swelling and subsequent meningoencephalitis. Mumps was determined to be the underlying cause of the meningoencephalitis and bilateral optic neuritis because of the exposure history in this nonvaccinated child, the typical clinical signs and symptoms, and the positive serologic test results. Recovery of visual function was gradual but nearly complete. Physicians should be aware that optic nerve involvement may be a manifestation of mumps infection. The delayed onset of optic neuritis, the bilateral involvement, and the near complete recovery suggest an immune-mediated pathogenesis.

Loss for photoemission versus gain for Auger: Direct experimental evidence of crystal-field splitting and charge transfer in photoelectron spectroscopy

DOE PAGES

Woicik, J. C.; Weiland, C.; Rumaiz, A. K.

2015-05-29

Here, we find a 5 eV satellite in the Ti1s photoelectron spectrum of the transition-metal oxide SrTiO 3. This satellite appears in addition to the well-studied 13 eV structure that is typically associated with the Ti2p core line. We give direct experimental evidence that the presence of two satellites is due to the crystal-field splitting of the metal 3d orbitals. They originate from ligand 2pt 2g → metal3dt 2g and ligand 2pe g → metal 3de g monopole charge-transfer excitations within the sudden approximation of quantum mechanics. This assignment is made by the energetics of the resonant and high-energy thresholdmore » behaviors of the TiK–L 2L 3 Auger decay that follows Ti1s photoionization.« less

Rupture of the thoracic aorta associated with experimental Angiostrongylus vasorum infection in a dog

PubMed Central

Mozzer, L.R.; Lima, W.S.

2012-01-01

This note describes the sudden death of a dog by the rupture of the thoracic aorta caused by the presence of Angiostrongylus vasorum. A female mongrel canine with a history of weight loss and exhaustion died two hours after clinical examination. At necropsy, performed one hour after death, showed the presence of clotted blood in the thoracic cavity. Haemothorax was diagnosed. The thoracic aorta wall was thin, congested and an abnormal hole in the wall was detected approximately 0.5 cm from the entrance to the diaphragm. From clotted blood collected from the thoracic cavity, 224 first stage larvae (L1) and 15 adults of Angiostrongylus vasorum were recovered alive. Also, from a blood clot found in the aorta, four adult females and 47 L1 larvae were recovered alive. Possibly, this parasite was responsible for the aortic rupture and death of the animal. PMID:22550632

Rupture of the thoracic aorta associated with experimental Angiostrongylus vasorum infection in a dog.

PubMed

Mozzer, L R; Lima, W S

2012-05-01

This note describes the sudden death of a dog by the rupture of the thoracic aorta caused by the presence of Angiostrongylus vasorum. A female mongrel canine with a history of weight loss and exhaustion died two hours after clinical examination. At necropsy, performed one hour after death, showed the presence of clotted blood in the thoracic cavity. Haemothorax was diagnosed. The thoracic aorta wall was thin, congested and an abnormal hole in the wall was detected approximately 0.5 cm from the entrance to the diaphragm. From clotted blood collected from the thoracic cavity, 224 first stage larvae (L1) and 15 adults of Angiostrongylus vasorum were recovered alive. Also, from a blood clot found in the aorta, four adult females and 47 L1 larvae were recovered alive. Possibly, this parasite was responsible for the aortic rupture and death of the animal.

Rational use of calcium-channel antagonists in Raynaud's phenomenon.

PubMed

Sturgill, M G; Seibold, J R

1998-11-01

Raynaud's phenomenon (RP) is a peripheral circulatory disorder characterized by sudden episodes of digital artery spasm, often precipitated by cold temperature or emotional stress. Although the cause of RP is not fully known, it appears to involve inappropriate adrenergic response to cold stimuli. Treatment of RP is conservative in most patients, but in patients with severe disease includes the use of agents that promote digital vasodilation. The calcium-channel antagonists, particularly the dihydropyridine derivative nifedipine, are the most thoroughly studied drug class for the treatment of RP. Approximately two thirds of patients respond favorably, with significant reductions in the frequency and severity of vasospastic attacks. Nifedipine use is often limited by the appearance of adverse vasodilatory effects such as headache or peripheral edema. The newer second-generation dihydropyridines such as amlodipine, isradipine, nicardipine, and felodipine also appear to be effective in patients with RP and may be associated with fewer adverse effects.

How Did Climate and Humans Respond to Past Volcanic Eruptions?

NASA Technical Reports Server (NTRS)

Toohey, Matthew; Ludlow, Francis; Legrande, Allegra N.

2016-01-01

To predict and prepare for future climate change, scientists are striving to understand how global-scale climatic change manifests itself on regional scales and also how societies adapt or don't to sometimes subtle and complex climatic changes. In this regard, the strongest volcanic eruptions of the past are powerful test cases, showcasing how the broad climate system responds to sudden changes in radiative forcing and how societies have responded to the resulting climatic shocks. These issues were at the heart of the inaugural workshop of the Volcanic Impacts on Climate and Society (VICS) Working Group, convened in June 2016 at the Lamont-Doherty Earth Observatory of Columbia University in Palisades, N.Y. The 3-day meeting gathered approximately 50 researchers, who presented work intertwining the history of volcanic eruptions and the physical processes that connect eruptions with human and natural systems on a global scale.

New integrable model of propagation of the few-cycle pulses in an anisotropic microdispersed medium

NASA Astrophysics Data System (ADS)

Sazonov, S. V.; Ustinov, N. V.

2018-03-01

We investigate the propagation of the few-cycle electromagnetic pulses in the anisotropic microdispersed medium. The effects of the anisotropy and spatial dispersion of the medium are created by the two sorts of the two-level atoms. The system of the material equations describing an evolution of the states of the atoms and the wave equations for the ordinary and extraordinary components of the pulses is derived. By applying the approximation of the sudden excitation to exclude the material variables, we reduce this system to the single nonlinear wave equation that generalizes the modified sine-Gordon equation and the Rabelo-Fokas equation. It is shown that this equation is integrable by means of the inverse scattering transformation method if an additional restriction on the parameters is imposed. The multisoliton solutions of this integrable generalization are constructed and investigated.

Two-dimensional coupled mathematical modeling of fluvial processes with intense sediment transport and rapid bed evolution

NASA Astrophysics Data System (ADS)

Yue, Zhiyuan; Cao, Zhixian; Li, Xin; Che, Tao

2008-09-01

Alluvial rivers may experience intense sediment transport and rapid bed evolution under a high flow regime, for which traditional decoupled mathematical river models based on simplified conservation equations are not applicable. A two-dimensional coupled mathematical model is presented, which is generally applicable to the fluvial processes with either intense or weak sediment transport. The governing equations of the model comprise the complete shallow water hydrodynamic equations closed with Manning roughness for boundary resistance and empirical relationships for sediment exchange with the erodible bed. The second-order Total-Variation-Diminishing version of the Weighted-Average-Flux method, along with the HLLC approximate Riemann Solver, is adapted to solve the governing equations, which can properly resolve shock waves and contact discontinuities. The model is applied to the pilot study of the flooding due to a sudden outburst of a real glacial-lake.

Line Coupling Effects in the Isotropic Raman Spectra of N2: A Quantum Calculation at Room Temperature

NASA Technical Reports Server (NTRS)

Thibault, Franck; Boulet, Christian; Ma, Qiancheng

2014-01-01

We present quantum calculations of the relaxation matrix for the Q branch of N2 at room temperature using a recently proposed N2-N2 rigid rotor potential. Close coupling calculations were complemented by coupled states studies at high energies and provide about 10200 two-body state-to state cross sections from which the needed one-body cross-sections may be obtained. For such temperatures, convergence has to be thoroughly analyzed since such conditions are close to the limit of current computational feasibility. This has been done using complementary calculations based on the energy corrected sudden formalism. Agreement of these quantum predictions with experimental data is good, but the main goal of this work is to provide a benchmark relaxation matrix for testing more approximate methods which remain of a great utility for complex molecular systems at room (and higher) temperatures.

Chandra Observations of SN 1987A: The Soft X-Ray Light Curve Revisited

NASA Technical Reports Server (NTRS)

Helder, E. A.; Broos, P. S.; Dewey, D.; Dwek, E.; McCray, R.; Park, S.; Racusin, J. L.; Zhekov, S. A.; Burrows, D. N.

2013-01-01

We report on the present stage of SN 1987A as observed by the Chandra X-Ray Observatory. We reanalyze published Chandra observations and add three more epochs of Chandra data to get a consistent picture of the evolution of the X-ray fluxes in several energy bands. We discuss the implications of several calibration issues for Chandra data. Using the most recent Chandra calibration files, we find that the 0.5-2.0 keV band fluxes of SN 1987A have increased by approximately 6 x 10(exp-13) erg s(exp-1)cm(exp-2) per year since 2009. This is in contrast with our previous result that the 0.5-2.0 keV light curve showed a sudden flattening in 2009. Based on our new analysis, we conclude that the forward shock is still in full interaction with the equatorial ring.

Complex patterns of abnormal heartbeats

NASA Technical Reports Server (NTRS)

Schulte-Frohlinde, Verena; Ashkenazy, Yosef; Goldberger, Ary L.; Ivanov, Plamen Ch; Costa, Madalena; Morley-Davies, Adrian; Stanley, H. Eugene; Glass, Leon

2002-01-01

Individuals having frequent abnormal heartbeats interspersed with normal heartbeats may be at an increased risk of sudden cardiac death. However, mechanistic understanding of such cardiac arrhythmias is limited. We present a visual and qualitative method to display statistical properties of abnormal heartbeats. We introduce dynamical "heartprints" which reveal characteristic patterns in long clinical records encompassing approximately 10(5) heartbeats and may provide information about underlying mechanisms. We test if these dynamics can be reproduced by model simulations in which abnormal heartbeats are generated (i) randomly, (ii) at a fixed time interval following a preceding normal heartbeat, or (iii) by an independent oscillator that may or may not interact with the normal heartbeat. We compare the results of these three models and test their limitations to comprehensively simulate the statistical features of selected clinical records. This work introduces methods that can be used to test mathematical models of arrhythmogenesis and to develop a new understanding of underlying electrophysiologic mechanisms of cardiac arrhythmia.

A Cretaceous-Tertiary mass extinction? Were most of Earth's species killed off?

NASA Technical Reports Server (NTRS)

Briggs, J. C.

1991-01-01

For the past decade, the scientific and popular press have carried frequent articles about a catastrophic mass extinction that supposedly destroyed the majority of the earth's species, including the dinosaurs, approximately 65 million years ago. Since 1980, more than 2000 papers and books have dealt with some aspect of a mass extinction at the Cretaceous-Tertiary (K/T) boundary. One authoritative estimate of the severity of the extinctions is that 60-80% of all the living species became extinct at this boundary (Raup 1988). There appears to be a general acceptance of the fact that such a great catastrophe did occur. Most of the argument among scientists now is devoted to the determination of the cause. In this article, I argue that the species changes at the K/T boundary were neither sudden nor catastrophic. They were most likely caused by a regression of sea level that led to a decrease in primary production.

Geometric curvature and phase of the Rabi model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mao, Lijun; Huai, Sainan; Guo, Liping

2015-11-15

We study the geometric curvature and phase of the Rabi model. Under the rotating-wave approximation (RWA), we apply the gauge independent Berry curvature over a surface integral to calculate the Berry phase of the eigenstates for both single and two-qubit systems, which is found to be identical with the system of spin-1/2 particle in a magnetic field. We extend the idea to define a vacuum-induced geometric curvature when the system starts from an initial state with pure vacuum bosonic field. The induced geometric phase is related to the average photon number in a period which is possible to measure inmore » the qubit–cavity system. We also calculate the geometric phase beyond the RWA and find an anomalous sudden change, which implies the breakdown of the adiabatic theorem and the Berry phases in an adiabatic cyclic evolution are ill-defined near the anti-crossing point in the spectrum.« less

Vibrational-rotational deexcitation of HF in collision with He

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bieniek, R.J.

State-to-state cross sections are reported for vibrational-rotational transitions for HF in collisions with He, at collisional energies of 0.5 and 1.0 eV. These were computed within the infinite-order sudden (IOS) approximation using adiabatic, distorted-wave techniques. Values are tabulated for the vibrational-rotational deexcitation sequences (v, j) ..-->.. (v--1, 0), with v = 1, 2, 3, 4 and j = 0 -- 40. These quenching cross sections can be used in conjunction with IOS factorization formulas to compute VRT cross sections for final rotational states other than j/sub f/ = 0. In addition to IOS results, vibrational quenching cross sections were computedmore » using the much more simple breathing-sphere technique. The breathing-sphere results compare favorably to the more accurate IOS results, particularly as to energy dependence. This suggests a simple method of utilizing known quenching cross sections to predict values for different vibrational levels and/or collisional energies.« less

Racial differences in sudden cardiac death.

PubMed

Fender, Erin A; Henrikson, Charles A; Tereshchenko, Larisa

2014-01-01

There is an increased risk of sudden cardiac death (SCD) and sudden cardiac arrest (SCA), in African Americans, the basis of which is likely multifactorial. African Americans have higher rates of traditional cardiac risk factors including hypertension, left ventricular hypertrophy, diabetes, coronary heart disease, and heart failure. There are also significant disparities in health care delivery. While these factors undoubtedly affect health outcomes, there is also growing evidence that genetics may have a significant impact as well. In this paper, we discuss data and hypotheses in support of both sides of the controversy around racial differences in SCD/SCA. Copyright © 2014 Elsevier Inc. All rights reserved.

Takayasu Arteritis of the Coronary Arteries Presenting as Sudden Death in a White Teenager.

PubMed

Hlavaty, Leigh; Diaz, Francisco; Sung, LokMan

2015-09-01

Takayasu arteritis is a rare disease that expresses chronic, large vessel inflammation. The etiology remains unclear and its presentation depends on the affected arteries. With coronary artery involvement, manifestations range from chest pain and shortness of breath to sudden death. We report a case of a 15-year-old white girl who presented with syncope immediately before passing. On autopsy, all 3 major coronary arteries grossly contained multiple proximal lesions that were consistent with Takayasu arteritis, microscopically. Takayasu arteritis solely affecting multiple coronary arteries is exceedingly rare. This report discusses the significance of coronary involvement in Takayasu arteritis at autopsy and sudden death.

Sudden deaths in adult-worn baby carriers: 19 cases.

PubMed

Bergounioux, J; Madre, C; Crucis-Armengaud, A; Briand-Huchet, E; Michard-Lenoir, A P; Patural, H; Dauger, S; Renolleau, S; Teychéne, A M; Henry, S; Biarent, D; Robin, C; Werner, E; Rambaud, C

2015-12-01

Soft infant carriers such as slings have become extremely popular in the west and are usually considered safe. We report 19 cases of sudden unexpected death in infancy (SUDI) linked to infant carrier. Most patients were healthy full-term babies less than 3 months of age, and suffocation was the most frequent cause of death. Infant carriers represent an underestimated cause of death by suffocation in neonates. • Sudden unexpected deaths in infancy linked to infant carrier have been only sparsely reported. • We report a series of 19 cases strongly suggesting age of less than 3 months as a risk factor and suffocation as the mechanism of death.

Comprehensive Assessment of Coronary Artery Disease in Sports-Related Sudden Cardiac Arrest.

PubMed

Karam, Nicole; Pechmajou, Louis; Dumas, Florence; Bougouin, Wulfran; Sharifzadehgan, Ardalan; Beganton, Frankie; Bonnet, Guillaume; Jost, Daniel; Lamhaut, Lionel; Varenne, Olivier; Aubry, Pierre; Sideris, Georgios; Spaulding, Christian; Cariou, Alain; Marijon, Eloi; Jouven, Xavier

2018-05-02

Despite the cardiovascular benefits of regular sports, sudden cardiac arrest (SCA) risk is increased during or shortly after exercise. Association with coronary artery disease (CAD) has been described in small studies, mainly autopsic with potential bias given the high sports-related SCA survival, and focusing on young competitive athletes, whereas sports-related SCA occurs mostly in recreational athletes. 1-5 Through the Paris Sudden Death Expertise Center prospective registry that includes all SCAs in Paris and suburbs since May 2011, we performed the first broad comprehensive CAD description in sports-related SCAs, with a comparison with matched non-sports-related SCAs.

Sudden monocular blindness associated with homozygous B-thalassemia in a young Liberian.

PubMed

Njoh, J; York, S

1990-05-01

A 16-year old Liberian female presented with sudden monocular blindness. Physical examination and laboratory investigations were normal except that the patient had homozygous B-Thalassemia (HbA 58%, HbF 5% and HbA2 7.0%). Family study revealed that both parents had B-Thalassemia trait. We feel that the association of sudden monocular blindness with homozygous B-Thalassemia which has not been reported before, is not fortuitous but causal. It is therefore suggested that homozygous B-Thalassemia be added to the list of haemoglobinopathies (HbAS, SS and SC) that have been reported to cause blindness as complication.

[Sudden death in Versailles: A review of a cardiovascular treatrise by Dionis (1710)].

PubMed

Charlier, P

2018-02-01

In 1710, the surgeon Pierre Dionis publishes a Dissertation on sudden death. Echoing and expanding the work of his Roman colleague Jean Marie Lancisi, he describes and analyzes dozens of cases of sudden death observed by him. A large number of cases was followed by autopsies allowing clinicopathological confrontation. Are proposed causes of death (pulmonary embolism, myocardial infarction, hemorrhagic stroke, arterial rupture, etc.), pathophysiological mechanisms based on the ancient theory of humors, and preventive actions to avoid these unexpected deaths. In this article, we oppose these old data to those of current literature. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Non-arrhythmic therapy of ventricular tachyarrhythmias and sudden cardiac death after acute myocardial infarction.

PubMed

Schweitzer, P

2006-12-01

The management of ventricular tachyarrhythmias and prevention of sudden cardiac death after acute myocardial infarction (AMI) underwent important evolution. In the CAST study, encanaide and other antiarrhythmic drugs were not only ineffective but also increased mortality after myocardial infarction. Amiodarone had some beneficial effect on arrhythmic events without improving survival, and ICDs failed to improve outcome early after AMI. In comparison, short and long term survival benefits of beta blockers, angiotensine converting enzyme inhibitors and aldosterone antagonists after AMI is well established. This review discusses the role of non-arrhythmic therapy in the prevention of ventricular tachyarrhythmia's and sudden cardiac death after AMI.

Sudden Death in a Patient with Carney's Complex

PubMed Central

Rothschild, James Adam; Kreso, Melissa; Slodzinski, Martin

2013-01-01

Carney’s complex is a rare autosomal dominantly inherited multiple endocrine neoplasia syndrome that involves spotty skin pigmentations, recurrent cardiac myxomas, endocrine hyperactivity, pituitary adenomas, peripheral nerve tumors, testicular tumors, and ovarian lesions. We present a case of sudden cardiac death in a 40 year old female with a history of Carney’s complex with recurrent cardiac myxomas presenting for exploratory laparotomy and enblock adnexal resection of a slowly enlarging right sided ovarian mass. This case highlights the risk for sudden death in these patients as well as the preoperative assessment that should be undertaken by the anesthesiologist as it relates to Carney’s complex. PMID:24223358

Assessing Methods to Protect Susceptible Oak and Tanoak Stands from Sudden Oak Death

Treesearch

Tedmund Swiecki; Elizabeth Bernhardt

2010-01-01

Landowners and managers have been seeking ways to protect susceptible oak (Quercus) species and tanoak (Lithocarpus densiflorus) from sudden oak death (SOD) caused by Phytophthora ramorum. Because disease epidemiology differs between tanoaks and susceptible oaks, we are testing different control strategies...

Sudden oak death in California: what is the potential?

Treesearch

Tara M. Barrett; Demetrios Gatziolis; Jeremy S. Fried; Karen L. Waddell

2006-01-01

Sudden oak death, a disease associated with the pathogen Phytophthora ramorum, has a large number of shrub and tree host species. Three of the tree species must susceptible to mortality from the disease, California black oak (Quercus kelloggii), coast live oak (Quercus agrifolia), and tanoak (...

Conditions 10 years after sudden oak death suppression treatments in Humboldt County, California

Treesearch

Yana Valachovic; Richard Cobb; Brendan Twieg

2017-01-01

In 2006, three isolated sudden oak death- (SOD) infested locations within Humboldt County were selected for silvicultural treatments that targeted the removal and/or reduction of tanoak (Notholithocarpus densiflorus Hook. & Arn.) and California bay laurel (Umbellularia californica Hook. & Arn), the main hosts...

40 CFR 279.52 - General facility standards.

Code of Federal Regulations, 2010 CFR

2010-07-01

... gas, or dry chemicals), spill control equipment and decontamination equipment; and (iv) Water at adequate volume and pressure to supply water hose streams, or foam producing equipment, or automatic..., explosion, or any unplanned sudden or non-sudden release of used oil to air, soil, or surface water which...

Emergence of the sudden oak death pathogen Phytophthora ramorum

Treesearch

Niklaus J. Grunwald; Matteo Garbelotto; Erica M. Goss; Kurt Huengens; Simone Prospero

2012-01-01

The recently emerged plant pathogen Phytophthora ramorum is responsible for causing the sudden oak death epidemic. This review documents the emergence of P. ramorum based on evolutionary and population genetic analyses. Currently infection by P. ramorum occurs only in Europe and North America and three...

When My Name Suddenly Was "Murphy"

NASA Technical Reports Server (NTRS)

Mitchell, David

2002-01-01

The author recounts how he was named the Launch Vehicle Manager for the Mars Pathfinder mission, after his project manager suffered a heart attack shortly before launch. He explains that he was prepared for the sudden responsibilities, since his project manager required that he learn many new skills.

Sudden Gains during Therapy of Social Phobia

ERIC Educational Resources Information Center

Hofmann, Stefan G.; Schultz, Stefan M.; Meuret, Alicia E.; Moscovitch, David A.; Suvak, Michael

2006-01-01

The present study investigated the phenomenon of sudden gains in 107 participants with social phobia (social anxiety disorder) who received either cognitive-behavioral group therapy or exposure group therapy without explicit cognitive interventions, which primarily used public speaking situations as exposure tasks. Twenty-two out of 967…

Exercise-Related Sudden Death: Cardiovascular Evaluation of Exercisers (Part 2 of 2).

ERIC Educational Resources Information Center

Van Camp, Steven P.

1988-01-01

A primary goal of the cardiovascular evaluation of exercisers is to identify conditions that carry the risk of exercise-related sudden death. These conditions, which are found in a careful evaluation of the patient, are identifed and described in detail. (Author/JL)

Cardiac fibrosis associated to the poisoning of Amorimia septentrionalis in cattle

USDA-ARS?s Scientific Manuscript database

Amorimia (Mascagnia) septentrionalis contains sodium monofluoracetate and when consumed by ruminants cause outbreaks of sudden death. This study aimed to describe the epidemiology, clinical and pathological signs of outbreaks of sudden deaths in cattle caused by A. septentrionalis in the states of P...

Sudden versus gradual pressure wean from Nasal CPAP in preterm infants: a randomized controlled trial.

PubMed

Amatya, S; Macomber, M; Bhutada, A; Rastogi, D; Rastogi, S

2017-06-01

In preterm infants, nasal continuous positive airway pressure (NCPAP) is widely used for treatment of respiratory distress syndrome. However, the strategies for successfully weaning infants off NCPAP are still not well defined and there remains considerable variation between the methods. The objective of this study is to determine whether gradual weaning of NCPAP pressure is more successful than sudden weaning off NCPAP to room air. A randomized controlled trial was conducted in a level 3 neonatal intensive care unit on 70 preterm neonates who were born between 26 and 32 weeks gestation and required NCPAP for at least 48 h. When infants were stable on NCPAP at 0.21 FiO 2 and 5 cm H 2 O positive end expiratory pressure, neonates were randomized to the gradual wean group (reduction in pressure by 1 cm every 8 h until 3 cm H 2 0 was reached) or to sudden wean group (one time NCPAP removal to room air). The primary outcome was a success at the first trial to wean to room air. Secondary outcomes were a number of trials, and weight and postmenstrual age (PMA) at the time of successful wean. Total number of days on NCPAP and length of stay (LOS) in the hospital were also compared between the groups. Of the 70 infants included in the study, 35 were randomized to sudden group and 33 infants to gradual group (2 excluded for protocol deviation). In sudden and gradual groups, 14 and 22 infants, respectively, were weaned successfully in the first attempt (P=0.03). The infants were successfully weaned at 32.7±1.7 weeks versus 33.1±2.4 weeks (P=0.39) PMA and at a weight of 1651±290 g versus 1589±398 g (P=0.46) in the sudden and gradual groups, respectively. The total number of days on NCPAP was 27±19 days versus 32±24 days (P=0.38) and LOS was 63±25 days versus 63±22 days (P=0.99) in the sudden and gradual groups, respectively. Gradual weaning method was more successful as compared to sudden weaning method in the initial trial off NCPAP. There was no difference in the PMA, weight at the time of successful wean, total days on NCPAP and LOS between the two groups.

Biomarkers of myocardial stress and fibrosis as predictors of mode of death in patients with chronic heart failure.

PubMed

Ahmad, Tariq; Fiuzat, Mona; Neely, Benjamin; Neely, Megan L; Pencina, Michael J; Kraus, William E; Zannad, Faiez; Whellan, David J; Donahue, Mark P; Piña, Ileana L; Adams, Kirkwood F; Kitzman, Dalane W; O'Connor, Christopher M; Felker, G Michael

2014-06-01

The aim of this study was to determine whether biomarkers of myocardial stress and fibrosis improve prediction of the mode of death in patients with chronic heart failure. The 2 most common modes of death in patients with chronic heart failure are pump failure and sudden cardiac death. Prediction of the mode of death may facilitate treatment decisions. The relationship between amino-terminal pro-brain natriuretic peptide (NT-proBNP), galectin-3, and ST2, biomarkers that reflect different pathogenic pathways in heart failure (myocardial stress and fibrosis), and mode of death is unknown. HF-ACTION (Heart Failure: A Controlled Trial Investigating Outcomes of Exercise Training) was a randomized controlled trial of exercise training versus usual care in patients with chronic heart failure due to left ventricular systolic dysfunction (left ventricular ejection fraction ≤35%). An independent clinical events committee prospectively adjudicated mode of death. NT-proBNP, galectin-3, and ST2 levels were assessed at baseline in 813 subjects. Associations between biomarkers and mode of death were assessed using cause-specific Cox proportional hazards modeling, and interaction testing was used to measure differential associations between biomarkers and pump failure versus sudden cardiac death. Discrimination and risk reclassification metrics were used to assess the added value of galectin-3 and ST2 in predicting mode of death risk beyond a clinical model that included NT-proBNP. After a median follow-up period of 2.5 years, there were 155 deaths: 49 from pump failure, 42 from sudden cardiac death, and 64 from other causes. Elevations in all biomarkers were associated with increased risk for both pump failure and sudden cardiac death in both adjusted and unadjusted analyses. In each case, increases in the biomarker had a stronger association with pump failure than sudden cardiac death, but this relationship was attenuated after adjustment for clinical risk factors. Clinical variables along with NT-proBNP levels were stronger predictors of pump failure (C statistic: 0.87) than sudden cardiac death (C statistic: 0.73). Addition of ST2 and galectin-3 led to improved net risk classification of 11% for sudden cardiac death, but not pump failure. Clinical predictors along with NT-proBNP levels were strong predictors of pump failure risk, with insignificant incremental contributions of ST2 and galectin-3. Predictability of sudden cardiac death risk was less robust and enhanced by information provided by novel biomarkers. Copyright © 2014 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Coriolis-coupled wave packet dynamics of H + HLi reaction.

PubMed

Padmanaban, R; Mahapatra, S

2006-05-11

We investigated the effect of Coriolis coupling (CC) on the initial state-selected dynamics of H+HLi reaction by a time-dependent wave packet (WP) approach. Exact quantum scattering calculations were obtained by a WP propagation method based on the Chebyshev polynomial scheme and ab initio potential energy surface of the reacting system. Partial wave contributions up to the total angular momentum J=30 were found to be necessary for the scattering of HLi in its vibrational and rotational ground state up to a collision energy approximately 0.75 eV. For each J value, the projection quantum number K was varied from 0 to min (J, K(max)), with K(max)=8 until J=20 and K(max)=4 for further higher J values. This is because further higher values of K do not have much effect on the dynamics and also because one wishes to maintain the large computational overhead for each calculation within the affordable limit. The initial state-selected integral reaction cross sections and thermal rate constants were calculated by summing up the contributions from all partial waves. These were compared with our previous results on the title system, obtained within the centrifugal sudden and J-shifting approximations, to demonstrate the impact of CC on the dynamics of this system.

An analytical approach to the CMB polarization in a spatially closed background

NASA Astrophysics Data System (ADS)

Niazy, Pedram; Abbassi, Amir H.

2018-03-01

The scalar mode polarization of the cosmic microwave background is derived in a spatially closed universe from the Boltzmann equation using the line of sight integral method. The EE and TE multipole coefficients have been extracted analytically by considering some tolerable approximations such as considering the evolution of perturbation hydrodynamically and sudden transition from opacity to transparency at the time of last scattering. As the major advantage of analytic expressions, CEE,ℓS and CTE,ℓ explicitly show the dependencies on baryon density ΩB, matter density ΩM, curvature ΩK, primordial spectral index ns, primordial power spectrum amplitude As, Optical depth τreion, recombination width σt and recombination time tL. Using a realistic set of cosmological parameters taken from a fit to data from Planck, the closed universe EE and TE power spectrums in the scalar mode are compared with numerical results from the CAMB code and also latest observational data. The analytic results agree with the numerical ones on the big and moderate scales. The peak positions are in good agreement with the numerical result on these scales while the peak heights agree with that to within 20% due to the approximations have been considered for these derivations. Also, several interesting properties of CMB polarization are revealed by the analytic spectra.