Constraining external reverse shock physics of gamma-ray bursts from ROTSE-III limits

NASA Astrophysics Data System (ADS)

Cui, Xiao-Hong; Zou, Yuan-Chuan; Wei, Jun-Jie; Zheng, Wei-Kang; Wu, Xue-Feng

2018-02-01

Assuming that early optical emission is dominated by external reverse shock (RS) in the standard model of gamma-ray bursts (GRBs), we intend to constrain RS models with an initial Lorentz factor Γ0 of the outflows based on the ROTSE-III observations. We consider two cases of RS behaviour: relativistic shock and non-relativistic shock. For a homogeneous interstellar medium (ISM) and the wind circum-burst environment, constraints can be achieved by the fact that the peak flux Fν at the RS crossing time should be lower than the observed upper limit Fν, limit. We consider the different spectral regimes in which the observed optical frequency νopt may locate, which are divided by the orders for the minimum synchrotron frequency νm and the cooling frequency νc. Considering the homogeneous and wind environments around GRBs, we find that the relativistic RS case can be constrained by the (upper and lower) limits of Γ0 in a large range from about hundreds to thousands for 36 GRBs reported by ROTSE-III. Constraints on the non-relativistic RS case are achieved with limits of Γ0 ranging from ∼30 to ∼350 for 26 bursts. The lower limits of Γ0 achieved for the relativistic RS model are disfavored based on the previously discovered correlation between the initial Lorentz factor Γ0 and the isotropic gamma-ray energy Eγ, iso released in the prompt phase.

External Shock in a Multi-bursting Gamma-Ray Burst: Energy Injection Phase Induced by the Later Launched Ejecta

NASA Astrophysics Data System (ADS)

Lin, Da-Bin; Huang, Bao-Quan; Liu, Tong; Gu, Wei-Min; Mu, Hui-Jun; Liang, En-Wei

2018-01-01

Central engines of gamma-ray bursts (GRBs) may be intermittent and launch several episodes of ejecta separated by a long quiescent interval. In this scenario, an external shock is formed due to the propagation of the first launched ejecta into the circum-burst medium and the later launched ejecta may interact with the external shock at a later period. Owing to the internal dissipation, the later launched ejecta may be observed at a later time (t jet). In this paper, we study the relation of t b and t jet, where t b is the collision time of the later launched ejecta with the formed external shock. It is found that the relation of t b and t jet depends on the bulk Lorentz factor (Γjet) of the later launched ejecta and the density (ρ) of the circum-burst medium. If the value of Γjet or ρ is low, the t b would be significantly larger than t jet. However, the t b ∼ t jet can be found if the value of Γjet or ρ is significantly large. Our results can explain the large lag of the optical emission relative to the γ-ray/X-ray emission in GRBs, e.g., GRB 111209A. For GRBs with a precursor, our results suggest that the energy injection into the external shock and thus more than one external-reverse shock may appear in the main prompt emission phase. According to our model, we estimate the Lorentz factor of the second launched ejecta in GRB 160625B.

Propagation of nonlinear shock waves for the generalised Oskolkov equation and its dynamic motions in the presence of an external periodic perturbation

NASA Astrophysics Data System (ADS)

Ak, Turgut; Aydemir, Tugba; Saha, Asit; Kara, Abdul Hamid

2018-06-01

Propagation of nonlinear shock waves for the generalised Oskolkov equation and dynamic motions of the perturbed Oskolkov equation are investigated. Employing the unified method, a collection of exact shock wave solutions for the generalised Oskolkov equations is presented. Collocation finite element method is applied to the generalised Oskolkov equation for checking the accuracy of the proposed method by two test problems including the motion of shock wave and evolution of waves with Gaussian and undular bore initial conditions. Considering an external periodic perturbation, the dynamic motions of the perturbed generalised Oskolkov equation are studied depending on the system parameters with the help of phase portrait and time series plot. The perturbed generalised Oskolkov equation exhibits period-3, quasiperiodic and chaotic motions for some special values of the system parameters, whereas the generalised Oskolkov equation presents shock waves in the absence of external periodic perturbation.

Does Radiative Feedback by the First Stars Promote or Prevent Second Generation Star Formation?

NASA Astrophysics Data System (ADS)

Ahn, Kyungjin; Shapiro, Paul R.

2008-03-01

We present a self-consistent study of formation of Pop III stars in the early stage of cosmic reionization. We study the effect of starlight from the first stars on the ability of other minihalos in their neighborhood to form additional stars. We show that the ionization front (I-front) is trapped by the neighboring minihalos, after it is transformed from R-type to D-type and preceded by a shock front. The fate of the core of nearby minihalos is mostly determined by the response of the core to this shock front, which leads to molecular cooling and collapse that, when compared to the same halo without external radiation, is (a) expedited, (b) delayed, (c) unaltered, or (d) reversed and prevented, depending upon the flux and halo mass and evolutionary stage. Roughly speaking, most halos that were destined to cool, collapse and form stars in the absence of external radiation are found to do so even when exposed to the first Pop III star in their neighborhood, while those that would not have done so are still not able to.

Internal and external axial corner flows

NASA Technical Reports Server (NTRS)

Kutler, P.; Shankar, V.; Anderson, D. A.; Sorenson, R. L.

1975-01-01

The inviscid, internal, and external axial corner flows generated by two intersecting wedges traveling supersonically are obtained by use of a second-order shock-capturing, finite-difference approach. The governing equations are solved iteratively in conical coordinates to yield the complicated wave structure of the internal corner and the simple peripheral shock of the external corner. The numerical results for the internal flows compare favorably with existing experimental data.

[Phaeochromocytoma as an unusual aetiology of cardiogenic shock].

PubMed

Ouchikhe, A; Lehoux, P; Gringore, A; Renouf, P; Deredec, R; Tasle, M; Massetti, M; Khayat, A; Saloux, E; Grollier, G; Samama, G; Gérard, J-L

2006-01-01

The authors reported a case involving a young patient with a cardiogenic shock associated to an acute pulmonary oedema. According to the seriousness of the shock, an external ventricular assist device (VAD) was initially inserted and replaced thereafter because of the cardiovascular instability, by an external pneumatic biventricular assist device. A cardiogenic shock induced by an acute adrenergic myocarditis due to a phaeochromocytoma was diagnosed. The patient was weaned from the VAD on day 84 and was scheduled for elective surgery of the phaeochromocytoma on day 93. The authors discussed the time of the surgery according to the anticoagulation therapy necessary to the VAD and the necessary caution taken if a cardiogenic shock appeared around surgery.

Comparative performance assessment of commercially available automatic external defibrillators: A simulation and real-life measurement study of hands-off time.

PubMed

Savastano, Simone; Vanni, Vincenzo; Burkart, Roman; Raimondi, Maurizio; Canevari, Fabrizio; Molinari, Simone; Baldi, Enrico; Danza, Aurora I; Caputo, Maria Luce; Mauri, Romano; Regoli, Francois; Conte, Giulio; Benvenuti, Claudio; Auricchio, Angelo

2017-01-01

Early and good quality cardiopulmonary resuscitation (CPR) and the use of automated external defibrillators (AEDs) improve cardiac arrest patients' survival. However, AED peri- and post-shock/analysis pauses may reduce CPR effectiveness. The time performance of 12 different commercially available AEDs was tested in a manikin based scenario; then the AEDs recordings from the same tested models following the clinical use both in Pavia and Ticino were analyzed to evaluate the post-shock and post-analysis time. None of the AEDs was able to complete the analysis and to charge the capacitors in less than 10s and the mean post-shock pause was 6.7±2.4s. For non-shockable rhythms, the mean analysis time was 10.3±2s and the mean post-analysis time was 6.2±2.2s. We analyzed 154 AED records [104 by Emergency Medical Service (EMS) rescuers; 50 by lay rescuers]. EMS rescuers were faster in resuming CPR than lay rescuers [5.3s (95%CI 5-5.7) vs 8.6s (95%CI 7.3-10). AEDs showed different performances that may reduce CPR quality mostly for those rescuers following AED instructions. Both technological improvements and better lay rescuers training might be needed. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

High-energy non-thermal and thermal emission from GRB 141207A detected by Fermi

DOE PAGES

Arimoto, Makoto; Asano, Katsuaki; Ohno, Masanori; ...

2016-12-13

A bright long gamma-ray burst GRB 141207A was observed by the Fermi Gamma-ray Space Telescope and detected by both instruments onboard. The observations show that the spectrum in the prompt phase is not well described by the canonical empirical Band function alone, and that an additional power-law component is needed. In the early phase of the prompt emission, a modified blackbody with a hard low-energy photon index (α = +0.2 to +0.4) is detected, which suggests a photospheric origin. In a finely time-resolved analysis, the spectra are also well fitted by the modified blackbody combined with a power-law function. Heremore » we discuss the physical parameters of the photosphere such as the bulk Lorentz factor of the relativistic flow and the radius. We also discuss the physical origin of the extra power-law component observed during the prompt phase in the context of different models such as leptonic and hadronic scenarios in the internal shock regime and synchrotron emission in the external forward shock. In the afterglow phase, the temporal and spectral behaviors of the temporally extended high-energy emission and the fading X-ray emission detected by the X-Ray Telescope on-board Swift are consistent with synchrotron emission in a radiative external forward shock.« less

External front instabilities induced by a shocked particle ring.

PubMed

Rodriguez, V; Saurel, R; Jourdan, G; Houas, L

2014-10-01

The dispersion of a cylindrical particle ring by a blast or shock wave induces the formation of coherent structures which take the form of particle jets. A blast wave, issuing from the discharge of a planar shock wave at the exit of a conventional shock tube, is generated in the center of a granular medium ring initially confined inside a Hele-Shaw cell. With the present experimental setup, under impulsive acceleration, a solid particle-jet formation is observed in a quasi-two-dimensional configuration. The aim of the present investigation is to observe in detail the formation of very thin perturbations created around the external surface of the dispersed particle layer. By means of fast flow visualization with an appropriate recording window, we focus solely on the first instants during which the external particle ring becomes unstable. We find that the critical area of the destabilization of the external ring surface is constant regardless of the acceleration of the initial layer. Moreover, we observe in detail the external front perturbation wavelength, rendered dimensionless by the initial ring perimeter, and follow its evolution with the initial particle layer acceleration. We report this quantity to be constant regardless of the evolution of the initial particle layer acceleration. Finally, we can reasonably assert that external front perturbations depend solely on the material of the particles.

Relativistic simulations of long-lived reverse shocks in stratified ejecta: the origin of flares in GRB afterglows

NASA Astrophysics Data System (ADS)

Lamberts, A.; Daigne, F.

2018-02-01

The X-ray light curves of the early afterglow phase from gamma-ray bursts (GRBs) present a puzzling variability, including flares. The origin of these flares is still debated, and often associated with a late activity of the central engine. We discuss an alternative scenario where the central engine remains short-lived and flares are produced by the propagation of a long-lived reverse shock in a stratified ejecta. Here we focus on the hydrodynamics of the shock interactions. We perform one-dimensional ultrarelativistic hydrodynamic simulations with different initial internal structure in the GRB ejecta. We use them to extract bolometric light curves and compare with a previous study based on a simplified ballistic model. We find a good agreement between both approaches, with similar slopes and variability in the light curves, but identify several weaknesses in the ballistic model: the density is underestimated in the shocked regions, and more importantly, late shock reflections are not captured. With accurate dynamics provided by our hydrodynamic simulations, we confirm that internal shocks in the ejecta lead to the formation of dense shells. The interaction of the long-lived reverse shock with a dense shell then produces a fast and intense increase of the dissipated power. Assuming that the emission is due to the synchrotron radiation from shock-accelerated electrons, and that the external forward shock is radiatively inefficient, we find that this results in a bright flare in the X-ray light curve, with arrival times, shapes, and duration in agreement with the observed properties of X-ray flares in GRB afterglows.

Simulation of Flow Through Breach in Leading Edge at Mach 24

NASA Technical Reports Server (NTRS)

Gnoffo, Peter A.; Alter, Stephen J.

2004-01-01

A baseline solution for CFD Point 1 (Mach 24) in the STS-107 accident investigation was modified to include effects of holes through the leading edge into a vented cavity. The simulations were generated relatively quickly and early in the investigation by making simplifications to the leading edge cavity geometry. These simplifications in the breach simulations enabled: 1) A very quick grid generation procedure; 2) High fidelity corroboration of jet physics with internal surface impingements ensuing from a breach through the leading edge, fully coupled to the external shock layer flow at flight conditions. These simulations provided early evidence that the flow through a 2 inch diameter (or larger) breach enters the cavity with significant retention of external flow directionality. A normal jet directed into the cavity was not an appropriate model for these conditions at CFD Point 1 (Mach 24). The breach diameters were of the same order or larger than the local, external boundary-layer thickness. High impingement heating and pressures on the downstream lip of the breach were computed. It is likely that hole shape would evolve as a slot cut in the direction of the external streamlines. In the case of the 6 inch diameter breach the boundary layer is fully ingested.

Endogenous versus exogenous shocks in systems with memory

NASA Astrophysics Data System (ADS)

Sornette, D.; Helmstetter, A.

2003-02-01

Systems with long-range persistence and memory are shown to exhibit different precursory as well as recovery patterns in response to shocks of exogenous versus endogenous origins. By endogenous, we envision either fluctuations resulting from an underlying chaotic dynamics or from a stochastic forcing origin which may be external or be an effective coarse-grained description of the microscopic fluctuations. In this scenario, endogenous shocks result from a kind of constructive interference of accumulated fluctuations whose impacts survive longer than the large shocks themselves. As a consequence, the recovery after an endogenous shock is in general slower at early times and can be at long times either slower or faster than after an exogenous perturbation. This offers the tantalizing possibility of distinguishing between an endogenous versus exogenous cause of a given shock, even when there is no “smoking gun”. This could help in investigating the exogenous versus self-organized origins in problems such as the causes of major biological extinctions, of change of weather regimes and of the climate, in tracing the source of social upheaval and wars, and so on. Sornette et al., Volatility fingerprints of large stocks: endogenous versus exogenous, cond-mat/0204626 has already shown how this concept can be applied concretely to differentiate the effects on financial markets of the 11 September 2001 attack or of the coup against Gorbachev on 19 August 1991 (exogenous) from financial crashes such as October 1987 (endogenous).

Pharmacy students' retention of knowledge and skills following training in automated external defibrillator use.

PubMed

Kopacek, Karen Birckelbaw; Dopp, Anna Legreid; Dopp, John M; Vardeny, Orly; Sims, J Jason

2010-08-10

To assess pharmacy students' retention of knowledge about appropriate automated external defibrillator use and counseling points following didactic training and simulated experience. Following a lecture on sudden cardiac arrest and automated external defibrillator use, second-year doctor of pharmacy (PharmD) students were assessed on their ability to perform basic life support and deliver a shock at baseline, 3 weeks, and 4 months. Students completed a questionnaire to evaluate recall of counseling points for laypeople/the public. Mean time to shock delivery at baseline was 74 ± 25 seconds, which improved significantly at 3 weeks (50 ± 17 seconds, p < 0.001) and was maintained at 4 months (47 ± 18 seconds, p < 0.001). Recall of all signs and symptoms of sudden cardiac arrest and automated external defibrillator counseling points was diminished after 4 months. Pharmacy students can use automated external defibrillators to quickly deliver a shock and are able to retain this ability after 4 months. Refresher training/courses will be required to improve students' retention of automated external defibrillator counseling points to ensure their ability to deliver appropriate patient education.

Density Shock Waves in Confined Microswimmers

NASA Astrophysics Data System (ADS)

Tsang, Alan Cheng Hou; Kanso, Eva

2016-01-01

Motile and driven particles confined in microfluidic channels exhibit interesting emergent behavior, from propagating density bands to density shock waves. A deeper understanding of the physical mechanisms responsible for these emergent structures is relevant to a number of physical and biomedical applications. Here, we study the formation of density shock waves in the context of an idealized model of microswimmers confined in a narrow channel and subject to a uniform external flow. Interestingly, these density shock waves exhibit a transition from "subsonic" with compression at the back to "supersonic" with compression at the front of the population as the intensity of the external flow increases. This behavior is the result of a nontrivial interplay between hydrodynamic interactions and geometric confinement, and it is confirmed by a novel quasilinear wave model that properly captures the dependence of the shock formation on the external flow. These findings can be used to guide the development of novel mechanisms for controlling the emergent density distribution and the average population speed, with potentially profound implications on various processes in industry and biotechnology, such as the transport and sorting of cells in flow channels.

Effects of simulated flight on the structure and noise of underexpanded jets

NASA Technical Reports Server (NTRS)

Norum, T. D.; Shearin, J. G.

1984-01-01

Mean plume static and pitot pressures and far-field acoustic pressure were measured for an underexpanded convergent nozzle in simulated flight. Results show that supersonic jet mixing noise behaves in flight in the same way that subsonic jet mixing noise does. Regarding shock-associated noise, the frequencies of both screech and peak broadband shock noise were found to decrease with flight speed. The external flow determines the dominant screech mode over a wide range of nozzle pressure rations. Change in the screech mode strongly affects both the development of the downstream shock structure and the characteristic frequency of the broadband shock-associated noise. When no mode change occurs, the main effect of the external flow is to stretch the axial development of the shock cells.

New Probe of Early Phases of Jet Formation and Evolution using Stellar Tidal Disruption Flares

NASA Astrophysics Data System (ADS)

Ranga Reddy Pasham, Dheeraj; van Velzen, Sjoert

2018-01-01

The tidal disruption of a star by a supermassive black hole can result in transient radio emission. The electrons producing these synchrotron radio flares could either be accelerated inside a relativistic jet or externally by shocks resulting from an outflow interacting with the circumnuclear medium. Until now, evidence for the internal emission mechanism has been lacking; nearly all tidal disruption flare studies have adopted the external shock model to explain the observed properties of radio flares. I will talk about a result that presents a challenge to external emission models: we discovered a cross-correlation between the soft X-ray (0.3-1 keV) and 16 GHz radio flux of Rosetta Stone tidal disruption flare ASASSN-14li. Variability features in the X-ray light curve appear again in the radio light curve, but after a time lag of about 13 days. This demonstrates that soft X-ray emitting accretion disk regulates the radio emission. This coupling appears to be inconsistent with all previous external emission models for this source but is naturally explained if the radio emission originates from a freely expanding jet. I will show that emission internal to an adiabatically expanding jet can also reproduce the observed evolution of the radio spectral energy distribution. Furthermore, both the correlation between X-ray and radio luminosity as well as our radio spectral modeling imply an approximately linear coupling between the accretion rate and jet power. I will also discuss how future tidal disruption events can help us understand how jets form and evolve in general.

Shock absorbency of factors in the shoe/heel interaction--with special focus on role of the heel pad.

PubMed

Jørgensen, U; Bojsen-Møller, F

1989-06-01

The heel pad acts as a shock absorber in walking and in heel-strike running. In some patients, a reduction of its shock-absorbing capacity has been connected to the development of overuse injuries. In this article, the shock absorption of the heel pad as well as external shock absorbers are studied. Individual variation and the effect of trauma and confinement on the heel pad were specifically investigated. Drop tests, imitating heel impacts, were performed on a force plate. The test specimens were cadaver heel pads (n = 10); the shoe sole component consisted of ethyl vinyl acetate (EVA) foam and Sorbothane inserts. The shock absorption was significantly greater in the heel pad than in the external shock absorbers. The mean heel pad shock absorption was 1.1 times for EVA foam and 2.1 times for Sorbothane. The shock absorption varied by as much as 100% between heel pads. Trauma caused a decrease in the heel pad shock absorbency (24%), whereas heel pad confinement increased the shock absorbency (49% in traumatized heel pads and 29.5% in nontraumatized heel pads). These findings provide a biomechanical rationale for the clinical observations of a correlation between heel pad shock absorbency loss and heel strike-dependent overuse injuries. To increase shock absorbency, confinement of the heel pad should be attempted in vivo.

GRB 110530A: Peculiar Broad Bump and Delayed Plateau in Early Optical Afterglows

NASA Astrophysics Data System (ADS)

Zhong, Shu-Qing; Xin, Li-Ping; Liang, En-Wei; Wei, Jian-Yan; Urata, Yuji; Huang, Kui-Yun; Qiu, Yu-Lei; Deng, Can-Min; Wang, Yuan-Zhu; Deng, Jin-Song

2016-11-01

We report our very early optical observations of GRB 110530A and investigate its jet properties together with its X-ray afterglow data. A peculiar broad onset bump followed by a plateau is observed in its early R band afterglow light curve. The optical data in the other bands and the X-ray data are well consistent with the temporal feature of the R band light curve. Our joint spectral fits of the optical and X-ray data show that they are in the same regime, with a photon index of ∼1.70. The optical and X-ray afterglow light curves are well fitted with the standard external shock model by considering a delayed energy injection component. Based on our modeling results, we find that the radiative efficiency of the gamma-ray burst jet is ∼ 1 % and the magnetization parameter of the afterglow jet is \\lt 0.04 with a derived extremely low {ε }B (the ratio of shock energy to the magnetic field) of (1.64+/- 0.25)× {10}-6. These results indicate that the jet may be matter dominated. A discussion on delayed energy injection from the accretion of the late fall-back material of its pre-supernova star is also presented.

Pharmacy Students' Retention of Knowledge and Skills Following Training in Automated External Defibrillator Use

PubMed Central

Dopp, Anna Legreid; Dopp, John M.; Vardeny, Orly; Sims, J. Jason

2010-01-01

Objectives To assess pharmacy students' retention of knowledge about appropriate automated external defibrillator use and counseling points following didactic training and simulated experience. Design Following a lecture on sudden cardiac arrest and automated external defibrillator use, second-year doctor of pharmacy (PharmD) students were assessed on their ability to perform basic life support and deliver a shock at baseline, 3 weeks, and 4 months. Students completed a questionnaire to evaluate recall of counseling points for laypeople/the public. Assessment Mean time to shock delivery at baseline was 74 ± 25 seconds, which improved significantly at 3 weeks (50 ± 17 seconds, p < 0.001) and was maintained at 4 months (47 ± 18 seconds, p < 0.001). Recall of all signs and symptoms of sudden cardiac arrest and automated external defibrillator counseling points was diminished after 4 months. Conclusion Pharmacy students can use automated external defibrillators to quickly deliver a shock and are able to retain this ability after 4 months. Refresher training/courses will be required to improve students' retention of automated external defibrillator counseling points to ensure their ability to deliver appropriate patient education. PMID:21045951

The Origin of the Optical Flashes: The Case Study of GRB 080319B and GRB 130427A

NASA Astrophysics Data System (ADS)

Fraija, N.; Veres, P.

2018-05-01

Correlations between optical flashes and gamma-ray emissions in gamma-ray bursts (GRBs) have been searched in order to clarify the question of whether these emissions occur at internal and/or external shocks. Among the most powerful GRBs ever recorded are GRB 080319B and GRB 130427A, which at early phases presented bright optical flashes possibly correlated with γ-ray components. Additionally, both bursts were fortuitously located within the field of view of the TeV γ-ray Milagro and HAWC observatories, and although no statistically significant excess of counts were collected, upper limits were placed on the GeV–TeV emission. Considering the synchrotron self-Compton emission from internal shocks and requiring the GeV–TeV upper limits, we found that the optical flashes and the γ-ray components are produced by different electron populations. Analyzing the optical flashes together with the multiwavelength afterglow observation, we found that these flashes can be interpreted in the framework of the synchrotron reverse shock model when outflows have arbitrary magnetizations.

Experimental investigation of the inlet detector configuration variation in the flow field at Mach 1.9

NASA Technical Reports Server (NTRS)

Hwang, Kyu C.; Tiwari, Surrendra N.; Miley, Stanley J.

1995-01-01

In recent years, active research has been conducted to study the technological feasibility of supersonic laminar flow control on the wing of the High Speed Civil Transport (HSCT). For this study, the F-16XL has been chosen due to its highly swept crank wing planform that closely resembles the HSCT configurations. During flights, it is discovered that the shock wave generated from the aircraft inlet introduces disturbances on the wing where the data acquisition is conducted. The flow field about a supersonic inlet is characterized by a complex three dimensional pattern of shock waves generated by the geometrical configuration of a deflector and a cowl lip. Hence, in this study, experimental method is employed to investigate the effects of the variation of deflector configuration on the flow field, and consequently, the possibility of diverting the incoming shock-disturbances away from the test section. In the present experiments, a model composed of a simple circular tube with a triangular deflector is designed to study the deflector length and the deflector base width variation in the flow field. Experimental results indicate that the lowest external pressure ratio is observed at the junction where the deflector lip and the inlet cowl lip merge. Also, it is noted that the external pressure ratio, the internal pressure ratio, the coefficient of spillage drag, and the shock standoff distance decrease as the deflector length increases. In addition, the Redefined Total Pressure Recovery Ratio (RTPRR) increases with an increase in the deflector length. Results from the study of the effect of the deflector's base width variation on the flow field indicate that the lowest external pressure ratio is observed at the junction between the inlet cowl lip and the deflector lip. As the base width of the deflector increases, the external pressure ratio at 0 rotation increases, whereas the external pressure ratio at 180 rotation decreases. In addition, the internal pressure ratio and the coefficient of spillage drag decrease as the base width of the deflector increases. However, RTPRR and shock standoff distance increase as the base width increases. In conclusion, as deflector dimensions vary, distinctive patterns in the pressure variation around the inlet deflector are observed. With an increase in the deflector length and base width, the magnitude of shock-disturbances are weakened due to a decrease in the external pressure ratio. Also, as the deflector length and base width increase, a smaller bow shock angle is formed. Therefore, the inlet shock wave formation would be significantly altered, and consequently, shock disturbances on the wing test section can be avoided through appropriately designing the deflector.

Physical activity, muscle, and the HSP70 response.

PubMed

Kilgore, J L; Musch, T I; Ross, C R

1998-06-01

Selye (1936) described how organisms react to various external stimuli (i.e., stressors). These reactions generally follow a programmed series of events and help the organism adapt to the imposed stress. The heat shock response is a common cellular reaction to external stressors, including physical activity. A characteristic set of proteins is synthesised shortly after the organism is exposed to stress. Researchers have not determined how heat shock proteins affect the exercise response. However, their role in adaptation to exercise and training might be inferred, since the synthetic patterns correlate well with the stress adaptation syndrome that Selye described. This review addresses the 70 kilodalton heat shock protein family (HSP70), the most strongly induced heat shock proteins. This paper provides an overview of the general heat shock response and a brief review of literature on HSP70 function, structure, regulation, and potential applications. Potential applications in health, exercise, and medicine are provided.

Ventricular fibrillation

MedlinePlus

... arrives. VF is treated by delivering a quick electric shock through the chest. It is done using a device called an external defibrillator. The electric shock can immediately restore the heartbeat to a ...

Riata silicone defibrillation lead with normal electrical measures at routine ambulatory check: The role of high-voltage shock testing

PubMed Central

De Maria, Elia; Borghi, Ambra; Bonetti, Lorenzo; Fontana, Pier Luigi; Cappelli, Stefano

2016-01-01

AIM To describe our experience with shock testing for the evaluation of patients with Riata™ leads. METHODS Among 51 patients with normal baseline electrical parameters, 20 died during follow-up. Of the remaining 31 patients, 15 underwent the test: In 10 cases a defibrillation testing with ventricular fibrillation (VF) induction and in 5 cases a R-wave-synchronized shock (> 20 J, without inducing VF). The test was performed under sedation with Midazolam. RESULTS Twelve patients (80%) had a normal behavior during shock testing: In 8 cases induced VF was correctly detected and treated; in 4 cases of R-wave-synchronized shock electrical parameters remained stable and normal. Three patients (20%) failed the test. One patient with externalized conductors showed a sudden drop of high-voltage impedance (< 10 Ohm) after a 25 J R-wave-synchronized shock. Two other patients with externalized conductors, undergoing defibrillation testing, showed a short-circuit during shock delivery and the implantable cardioverter defibrillator was unable to interrupt VF. CONCLUSION In Riata™ leads the delivery of a low current during routine measurement of high-voltage impedance may not reveal a small short circuit, that can only be evident by attempting to deliver a true shock, either for spontaneous arrhythmias or in the context of a shock testing. PMID:27957252

A Large Catalog of Multiwavelength GRB Afterglows. I. Color Evolution and Its Physical Implication

NASA Astrophysics Data System (ADS)

Li, Liang; Wang, Yu; Shao, Lang; Wu, Xue-Feng; Huang, Yong-Feng; Zhang, Bing; Ryde, Felix; Yu, Hoi-Fung

2018-02-01

The spectrum of gamma-ray burst (GRB) afterglows can be studied with color indices. Here, we present a large comprehensive catalog of 70 GRBs with multiwavelength optical transient data on which we perform a systematic study to find the temporal evolution of color indices. We categorize them into two samples based on how well the color indices are evaluated. The Golden sample includes 25 bursts mostly observed by GROND, and the Silver sample includes 45 bursts observed by other telescopes. For the Golden sample, we find that 96% of the color indices do not vary over time. However, the color indices do vary during short periods in most bursts. The observed variations are consistent with effects of (i) the cooling frequency crossing the studied energy bands in a wind medium (43%) and in a constant-density medium (30%), (ii) early dust extinction (12%), (iii) transition from reverse-shock to forward-shock emission (5%), or (iv) an emergent SN emission (10%). We also study the evolutionary properties of the mean color indices for different emission episodes. We find that 86% of the color indices in the 70 bursts show constancy between consecutive ones. The color index variations occur mainly during the late GRB–SN bump, the flare, and early reverse-shock emission components. We further perform a statistical analysis of various observational properties and model parameters (spectral index {β }o{CI}, electron spectral indices p CI, etc.) using color indices. Overall, we conclude that ∼90% of colors are constant in time and can be accounted for by the simplest external forward-shock model, while the varying color indices call for more detailed modeling.

Inconsistent shock advisories for monomorphic VT and Torsade de Pointes--A prospective experimental study on AEDs and defibrillators.

PubMed

Fitzgerald, Abi; Johnson, Meshell; Hirsch, Jan; Rich, Mary-Ann; Fidler, Richard

2015-07-01

Cardiovascular disease and sudden cardiac arrest are the leading causes of death in the United States. Early defibrillation is key to successful resuscitation for patients who experience shockable rhythms during a cardiac arrest. It is therefore vital that the shock advisory of AEDs (automated external defibrillators) or defibrillators in AED mode be reliable and appropriate. The goal of this study was to better understand the performance of multiple lay-rescuer and hospital professional defibrillators in AED mode in their analysis of ventricular arrhythmias. The measurable objectives of this study sought to quantify: 1. No shock advisory for sinus rhythms at any rate. 2. Recognition and shock advisory for ventricular fibrillation (VF). 3. Recognition and shock advisory for monomorphic ventricular tachycardia (VT). 4. Recognition and shock advisory for Torsades de Pointes (TdP). This is a prospective evaluation of two AEDs and four semi-automatic, hospital professional defibrillators. This study represents post-marketing evaluation of FDA approved devices. Each defibrillator was connected to multiple rhythm simulators and presented with simulated ECG waveforms 20 consecutive times at various rates when possible. All four defibrillators and both AEDs tested consistently recognized normal sinus rhythm (NSR) from all rhythm sources, and did not recommend a shock for NSR at any rate (from 80 to 220 bpm). All four defibrillators and both AEDs recognized VF from all rhythm sources tested and recommended a shock 100% of the time. Variations were found in the shock advisory rates among defibrillators when testing simulated VT heart rates at or below 150 bpm. One AED tested did not consistently advise a shock for monomorphic VT or TdP at any tested rate. Lay-rescuer AEDs and professional hospital defibrillators tested in AED mode did not reliably recommend a shock for sustained monomorphic VT or TdP at certain rates, despite the fact that it is a critical component of the currently recommended treatment. These findings require further examination of the risk benefit analysis of shocking or not shocking rhythms such as TdP or pulseless VT. Published by Elsevier Ireland Ltd.

Aeroacoustics of supersonic jet flows from contoured and solid/porous conical plug-nozzles

NASA Technical Reports Server (NTRS)

Dosanjh, Darshan S.; Das, Indu S.

1987-01-01

The results of an experimental study of the acoustic far-field, the shock associated noise, and the nature of the repetitive shock structure of supersonic jet flows issuing from plug-nozzles having externally-expanded plugs with pointed termination operated at a range of supercritical pressure ratios Xi approaching 2 to 4.5 are reported. The plug of one of these plug-nozzles was contoured. The other plug-nozzles had short conical plugs with either a solid surface or a combination of solid/porous surface of different porosities. The contoured and the uncontoured plug-nozzles had the same throat area and the same annulus-radius ratio K = R sub p/R sub N = 0.43. As the result of modifications of the shock structure, the acoustic performance of improperly expanded jet flows of an externally-expanded short uncontoured plug of an appropriate geometry with suitably perforated plug and a pointed termination, is shown to approach the acoustic performance of a shock-free supersonic jet issuing from an equivalent externally-expanded contoured plug-nozzle.

[Semi-automatic defibrillators does not always interpret heart rhythms correctly. Five patients were defibrillated despite non-shockable rhythms].

PubMed

Wangenheim, Burkard; Israelsson, Johan; Lindstaedt, Michael; Carlsson, Jörg

2015-08-04

Automated external defibrillators (AED) have become an important part of the »the chain of survival« in case of sudden cardiac arrest (SCA), where early defibrillation is lifesaving. The American Heart Association demands that AEDs have a specificity of >99 % to recognize normal sinus rhythm and >95 % for the other non-shockable rhythms. Reports on their performance in the field are scarce. We present five cases in which AED recommended shock for apparently non-shockable rhythms. This indicates the necessity to systematically reevaluate AED performance.

Septic shock with no diagnosis at 24 hours: a pragmatic multicenter prospective cohort study.

PubMed

Contou, Damien; Roux, Damien; Jochmans, Sébastien; Coudroy, Rémi; Guérot, Emmanuel; Grimaldi, David; Ricome, Sylvie; Maury, Eric; Plantefève, Gaëtan; Mayaux, Julien; Mekontso Dessap, Armand; Brun-Buisson, Christian; de Prost, Nicolas

2016-11-06

The lack of a patent source of infection after 24 hours of management of shock considered septic is a common and disturbing scenario. We aimed to determine the prevalence and the causes of shock with no diagnosis 24 hours after its onset, and to compare the outcomes of patients with early-confirmed septic shock to those of others. We conducted a pragmatic, prospective, multicenter observational cohort study in ten intensive care units (ICU) in France. We included all consecutive patients admitted to the ICU with suspected septic shock defined by clinical suspicion of infection leading to antibiotic prescription plus acute circulatory failure requiring vasopressor support. A total of 508 patients were admitted with suspected septic shock. Among them, 374 (74 %) had early-confirmed septic shock, while the 134 others (26 %) had no source of infection identified nor microbiological documentation retrieved 24 hours after shock onset. Among these, 37/134 (28 %) had late-confirmed septic shock diagnosed after 24 hours, 59/134 (44 %) had a condition mimicking septic (septic shock mimicker, mainly related to adverse drug reactions, acute mesenteric ischemia and malignancies) and 38/134 (28 %) had shock of unknown origin by the end of the ICU stay. There were no differences between patients with early-confirmed septic shock and the remainder in ICU mortality and the median duration of ICU stay, of tracheal intubation and of vasopressor support. The multivariable Cox model showed that the risk of day-60 mortality did not differ between patients with or without early-confirmed septic shock. A sensitivity analysis was performed in the subgroup (n = 369/508) of patients meeting the Sepsis-3 definition criteria and displayed consistent results. One quarter of the patients admitted in the ICU with suspected septic shock had no infection identified 24 hours after its onset and almost half of them were eventually diagnosed with a septic shock mimicker. Outcome did not differ between patients with early-confirmed septic shock and other patients.

Inaccurate treatment decisions of automated external defibrillators used by emergency medical services personnel: incidence, cause and impact on outcome.

PubMed

Calle, Paul A; Mpotos, Nicolas; Calle, Simon P; Monsieurs, Koenraad G

2015-03-01

The rhythm analysis algorithm (RAA) of automated external defibrillators (AEDs) may be deceived by many factors. In this observational study we assessed RAA accuracy in prehospital interventions. For every rhythm analysis judged to be inaccurate, we looked for causal factors and estimated the impact on outcome. In 135 consecutive patients, two physicians reviewed 837 rhythm analyses independently. When they disagreed, a third physician made the final decision. Among 148 shockable episodes, 23 (16%) were not recognized by the RAA due to external artifacts (n=7), fine ventricular fibrillation (VF; n=7), RAA error without external artifacts (n=4) or a combination of factors (n=5). In six cases the omitted/delayed shock was judged to be of clinical relevance: survival with some neurological deficit (n=4), death without regaining consciousness (n=1) and no restoration of spontaneous circulation (n=1). In 689 non-shockable episodes, the RAA decided "shockable" 25 times (4%). This wrongful decision was due to external artifacts (n=9), a concurrent shock of an internal cardioverter defibrillator (n=1), RAA error without external artifacts (n=13) or a combination of factors (n=2). Fifteen spurious shocks were delivered. As these non-shockable rhythms did not deteriorate after the shock, we assumed that no significant harm was done. Up to 16% of shockable rhythms were not detected and 4% of non-shockable rhythms were interpreted as shockable. Therefore, all AED interventions should be reviewed. Feedback to caregivers may avoid future deleterious interactions with the AED, whereas AED manufacturers may use this information to improve RAA accuracy. This approach may improve the outcome of some VF patients. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Off-center blast in a shocked medium

NASA Astrophysics Data System (ADS)

Duncan-Miller, G. C.; Stone, W. D.

2018-07-01

When multiple blasts occur at different times, the situation arises in which a blast wave is propagating into a medium that has already been shocked. Determining the evolution in the shape of the second shock is not trivial, as it is propagating into air that is not only non-uniform, but also non-stationary. To accomplish this task, we employ the method of Kompaneets to determine the shape of a shock in a non-uniform media. We also draw from the work of Korycansky (Astrophys J 398:184-189. https://doi.org/10.1086/171847 , 1992) on an off-center explosion in a medium with radially varying density. Extending this to treat non-stationary flow, and making use of approximations to the Sedov solution for the point blast problem, we are able to determine an analytic expression for the evolving shape of the second shock. In particular, we consider the case of a shock in air at standard ambient temperature and pressure, with the second shock occurring shortly after the original blast wave reaches it, as in a sympathetic detonation.

Endo- vs. exogenous shocks and relaxation rates in book and music “sales”

NASA Astrophysics Data System (ADS)

Lambiotte, R.; Ausloos, M.

2006-04-01

In this paper, we analyse the response of music and book sales to an external field and a buyer herding. We distinguish endogenous and exogenous shocks. We focus on some case studies, whose data have been collected from ranking on amazon.com. We show that an ensemble of equivalent systems quantitatively respond in a same way to a similar “external shock”, indicating roads to universality features. In contrast to Sornette et al. [Phys. Rev. Lett. 93 (2004) 228701] who seemed to find power-law behaviours, in particular at long times, a law interpreted in terms of an epidemic activity, we observe that the relaxation process can be as well seen as an exponential one that saturates toward an asymptotic state, itself different from the pre-shock state. By studying an ensemble of 111 shocks, on books or records, we show that exogenous and endogenous shocks are discriminated by their short-time behaviour: the relaxation time seems to be twice shorter in endogenous shocks than in exogenous ones. We interpret the finding through a simple thermodynamic model with a dissipative force.

On a Stochastic Failure Model under Random Shocks

NASA Astrophysics Data System (ADS)

Cha, Ji Hwan

2013-02-01

In most conventional settings, the events caused by an external shock are initiated at the moments of its occurrence. In this paper, we study a new classes of shock model, where each shock from a nonhomogeneous Poisson processes can trigger a failure of a system not immediately, as in classical extreme shock models, but with delay of some random time. We derive the corresponding survival and failure rate functions. Furthermore, we study the limiting behaviour of the failure rate function where it is applicable.

Early Health Shocks, Intra-household Resource Allocation and Child Outcomes*

PubMed Central

Yi, Junjian; Heckman, James J.; Zhang, Junsen; Conti, Gabriella

2016-01-01

An open question in the literature is whether families compensate or reinforce the impact of child health shocks. Discussions usually focus on one dimension of child investment. This paper examines multiple dimensions using household survey data on Chinese child twins whose average age is 11. We find that, compared with a twin sibling who did not suffer from negative early health shocks at ages 0–3, the other twin sibling who did suffer negative health shocks received RMB 305 more in terms of health investments, but received RMB 182 less in terms of educational investments in the 12 months prior to the survey. In terms of financial transfers over all dimensions of investment, the family acts as a net equalizer in response to early health shocks for children. We estimate a human capital production function and establish that, for this sample, early health shocks negatively affect child human capital, including health, education, and socioemotional skills. Compensating investments in health as measured by BMI reduce the adverse effects of health shocks by 50%, but exacerbate the adverse impact of shocks on educational attainment by 30%. PMID:27019517

Investigation of Inlet Control Parameters for an External-internal-compression Inlet from Mach 2.1 to 3.0

NASA Technical Reports Server (NTRS)

Anderson, B. H.; Bowditch, D. N.

1958-01-01

Investigation of the control parameters of an external-internal compression inlet indicates that the cowl-lip shock provides a signal to position the spike and to start the inlet over a Mach number range from 2.1 to 3.0. Use of a single fixed probe position to control the spike over the range of conditions resulted in a 3.7-count loss in total-pressure recovery at Mach 3.0 and 0 deg angle of attack. Three separate shock-sensing-probe positions were required to set the spike for peak recovery from Mach 2.1 to 3.0 and angles of attack from 0 deg to 6 deg. When the inlet was unstarted, an erroneous signal was obtained from the normal-shock control through most of the starting cycle that prevented the inlet from starting. Therefore, it was necessary to over-ride the normal-shock control signal and not allow the control to position the terminal shock until the spike was positioned.

A Prospective Randomized Controlled Trial of the Efficacy of External Physical Vibration Lithecbole after Extracorporeal Shock Wave Lithotripsy for a Lower Pole Renal Stone Less Than 2 cm.

PubMed

Long, Qilai; Zhang, Jian; Xu, Zhibing; Zhu, Yanjun; Liu, Li; Wang, Hang; Guo, Jianming; Wang, Guomin

2016-04-01

We evaluate the efficacy and safety of external physical vibration lithecbole in improving the clearance rates of lower pole renal stones after shock wave lithotripsy. A total of 71 patients with lower pole renal stones (6 to 20 mm) were prospectively randomized into 2 groups. In the treatment group 34 patients were treated with external physical vibration lithecbole after shock wave lithotripsy. In the control group 37 patients underwent shock wave lithotripsy only. External physical vibration lithecbole was performed without anesthesia by the same team using the Friend-I External Physical Vibration Lithecbole (Fu Jian Da Medical Instrument Co., Ltd, Zhengzhou, China). The stone-free rate, stone expulsion rate, stone expulsion time and incidence of complications were monitored. External physical vibration lithecbole was successful in assisting the discharge of stone fragments. The stone-free status was 76.5% in the treatment group and 48.6% in the control group (p=0.008). Stone expulsion rates at day 1, week 1 and week 3 were 76.5% (26), 94.1% (32) and 94.1% (32) in the treatment group vs 43.2% (16), 73.0% (27) and 89.2% (33) in the control group, respectively. Mean stone fragment expulsion time was 11.2 minutes in the treatment group and 9.17 hours in the control group (p=0.016). There was no significant difference in complications between the 2 groups (p >0.05). External physical vibration lithecbole was efficacious in assisting the discharge of lower pole renal stone fragments and can be used as an adjunctive method of minimally invasive stone treatment. However, additional investigations are needed to confirm the efficacy. Copyright © 2016 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Measurement of the shock front velocity produced in a T-tube

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

Djurović, S.; Mijatović, Z.; Vujičić, B.

2015-01-15

A set of shock front velocity measurements is described in this paper. The shock waves were produced in a small electromagnetically driven shock T-tube. Most of the measurements were performed in hydrogen. The shock front velocity measurements in other gases and the velocity of the gas behind the shock front were also analyzed, as well as the velocity dependence on applied input energy. Some measurements with an applied external magnetic field were also performed. The used method of shock front velocity is simple and was shown to be very reliable. Measured values were compared with the calculated ones for themore » incident and reflected shock waves.« less

Swift and Fermi observations of the early afterglow of the short gamma-ray burst 090510

DOE PAGES

De Pasquale, M.

2010-01-14

Here, we present the observations of GRB090510 performed by the Fermi Gamma-Ray Space Telescope and the Swift observatory. In a GeV range, we detected a bright, short burst that shows an extended emission. Furthermore, its optical emission initially rises, a feature so far observed only in long bursts, while the X-ray flux shows an initial shallow decrease, followed by a steeper decay. This exceptional behavior enables us to investigate the physical properties of the gamma-ray burst outflow, poorly known in short bursts. Here, we discuss internal and external shock models for the broadband energy emission of this object.

STS-33 Discovery, OV-103, early morning liftoff from KSC LC Pad 39B

NASA Image and Video Library

1989-11-22

STS033-S-002 (22 Nov 1989) --- The Space Shuttle Discovery heads for Earth orbit on the first post-Challenger nocturnal launch. Liftoff occurred at 7:23:29:989 p.m. (EST), November 22, 1989. This picture shows a side view of Discovery, one of its two solid rocket boosters (SRB) and the external tank. It represents a good example of the "diamond shock" effect, in the plume from the main engine, associated with Shuttle launches. Onboard for the DOD-devoted mission were Astronauts Frederick D. Gregory, John E. Blaha, F. Story Musgrave, Kathryn C. Thornton and Manley L. Carter.

Early afterglows in wind environments revisited

NASA Astrophysics Data System (ADS)

Zou, Y. C.; Wu, X. F.; Dai, Z. G.

2005-10-01

When a cold shell sweeps up the ambient medium, a forward shock and a reverse shock will form. We analyse the reverse-forward shocks in a wind environment, including their dynamics and emission. An early afterglow is emitted from the shocked shell, e.g. an optical flash may emerge. The reverse shock behaves differently in two approximations: the relativistic and Newtonian cases, which depend on the parameters, e.g. the initial Lorentz factor of the ejecta. If the initial Lorentz factor is much less than 114E1/453Δ-1/40,12A-1/4*,-1, the early reverse shock is Newtonian. This may take place for the wider of a two-component jet, an orphan afterglow caused by a low initial Lorentz factor and so on. The synchrotron self-absorption effect is significant especially for the Newtonian reverse shock case, as the absorption frequency νa is larger than the cooling frequency νc and the minimum synchrotron frequency νm for typical parameters. For the optical to X-ray band, the flux is nearly unchanged with time during the early period, which may be a diagnostic for the low initial Lorentz factor of the ejecta in a wind environment. We also investigate the early light curves with different wind densities and compare them with those in the interstellar medium model.

Coagulopathy and shock on admission is associated with mortality for children with traumatic injuries at combat support hospitals.

PubMed

Patregnani, Jason T; Borgman, Matthew A; Maegele, Marc; Wade, Charles E; Blackbourne, Lorne H; Spinella, Philip C

2012-05-01

In adults, early traumatic coagulopathy and shock are both common and independently associated with mortality. There are little data regarding both the incidence and association of early coagulopathy and shock on outcomes in pediatric patients with traumatic injuries. Our objective was to determine whether coagulopathy and shock on admission are independently associated with mortality in children with traumatic injuries. A retrospective review of the Joint Theater Trauma Registry from U.S. combat support hospitals in Iraq and Afghanistan from 2002 to 2009 was performed. Coagulopathy was defined as an international normalized ratio of ≥1.5 and shock as a base deficit of ≥6. Laboratory values were measured on admission. Primary outcome was inhospital mortality. Univariate analyses were performed on all admission variables followed by reverse stepwise multivariate logistic regression to determine independent associations. Combat support hospitals in Iraq and Afghanistan. Patients <18 yrs of age with Injury Severity Score, international normalized ratio, base deficit, and inhospital mortality were included. Of 1998 in the cohort, 744 (37%) had a complete set of data for analysis. None. The incidence of early coagulopathy and shock were 27% and 38.3% and associated with mortality of 22% and 16.8%, respectively. After multivariate logistic regression, early coagulopathy had an odds ratio of 2.2 (95% confidence interval 1.1-4.5) and early shock had an odds ratio of 3.0 (95% confidence interval 1.2-7.5) for mortality. Patients with coagulopathy and shock had an odds ratio of 3.8 (95% confidence interval 2.0-7.4) for mortality. In children with traumatic injuries treated at combat support hospitals, coagulopathy and shock on admission are common and independently associated with a high incidence of inhospital mortality. Future studies are needed to determine whether more rapid and accurate methods of measuring coagulopathy and shock as well as if early goal-directed treatment of these states can improve outcomes in children.

Streptococcus agalactiae Toxic Shock-Like Syndrome

PubMed Central

Al Akhrass, Fadi; Abdallah, Lina; Berger, Steven; Hanna, Rami; Reynolds, Nina; Thompson, Shellie; Hallit, Rabih; Schlievert, Patrick M.

2013-01-01

Abstract We present 2 patients with Streptococcus agalactiae toxic shock-like syndrome and review another 11 well-reported cases from the literature. Streptococcal toxic shock-like syndrome is a devastating illness with a high mortality rate, therefore we stress the importance of early supportive management, antimicrobial therapy, and surgical intervention. Toxic shock-like syndrome is likely to be underestimated in patients with invasive Streptococcus agalactiae infection who present with shock. Early diagnosis requires high suspicion of the illness, along with a thorough mucocutaneous examination. Streptococcus agalactiae produces uncharacterized pyrogenic toxins, which explains the ability of the organism to cause toxic shock-like syndrome. PMID:23263717

Extracorporeal Shock Wave Therapy Suppresses the Early Proinflammatory Immune Response to a Severe Cutaneous Burn Injury

DTIC Science & Technology

2009-02-01

Burn wound model Mice were anaesthetised using isoflurane inha- lation. After shaving the dorsum, the exposed skin was washed gently with room...Extracorporeal shock wave therapy suppresses the early proinflammatory immune response to a severe cutaneous burn injury* Thomas A Davis, Alexander...S, Peoples GE, Tadaki D, Elster EA. Extracorporeal shock wave therapy suppresses the early proinflammatory immune response to a severe cutaneous burn

Prospects for detection of very high-energy emission from GRB in the context of the external shock model

NASA Astrophysics Data System (ADS)

Galli, A.; Piro, L.

2008-10-01

Context: The detection of the 100 GeV-TeV emission by a gamma-ray burst (GRB) will provide an unprecedented opportunity to study the nature of the central engine and the interaction between the relativistic flow and the environment of the burst's progenitor. Aims: In this paper we show that there are exciting prospects of detecting from the burst by MAGIC high-energy (HE) emission during the early X-ray flaring activity and, later, during the normal afterglow phase. We also identify the best observational strategy: trigger conditions and time period of observation. Methods: We determine the expected HE emission from the flaring and afterglow phases of GRBs in the context of the external shock scenario and compare them with the MAGIC threshold. Results: We find that an X-ray flare with the average properties of the class can be detected in the 100 GeV range by MAGIC, provided that z ≲ 0.7. The requested observational window with MAGIC should then start from 10-20 s after the burst and cover about 1000-2000 s. Furthermore, we demonstrate that there are solid prospects of detecting the late afterglow emission in the same energy range for most of the bursts with z ≲ 0.5 if the density of the external medium is n ≳ a few cm-3. In this case, the MAGIC observation shall extend to about 10-20 ks. We provide recipes for tailoring this prediction to the observational properties of each burst, in particular the fluence in the prompt emission and the redshift, thus allowing an almost real time decision procedure to decide whether to continue the follow-up observation of a burst at late times.

Effects of Wing Leading Edge Penetration with Venting and Exhaust Flow from Wheel Well at Mach 24 in Flight

NASA Technical Reports Server (NTRS)

Gnoffo, Peter A.

2003-01-01

A baseline solution for CFD Point 1 (Mach 24) in the STS-107 accident investigation was modified to include effects of: (1) holes through the leading edge into a vented cavity; and (2) a scarfed, conical nozzle directed toward the centerline of the vehicle from the forward, inboard corner of the landing gear door. The simulations were generated relatively quickly and early in the investigation because simplifications were made to the leading edge cavity geometry and an existing utility to merge scarfed nozzle grid domains with structured baseline external domains was implemented. These simplifications in the breach simulations enabled: (1) a very quick grid generation procedure; and (2) high fidelity corroboration of jet physics with internal surface impingements ensuing from a breach through the leading edge, fully coupled to the external shock layer flow at flight conditions. These simulations provided early evidence that the flow through a two-inch diameter (or larger) breach enters the cavity with significant retention of external flow directionality. A normal jet directed into the cavity was not an appropriate model for these conditions at CFD Point 1 (Mach 24). The breach diameters were of the same order or larger than the local, external boundary-layer thickness. High impingement heating and pressures on the downstream lip of the breach were computed. It is likely that hole shape would evolve as a slot cut in the direction of the external streamlines. In the case of the six-inch diameter breach the boundary layer is fully ingested. The intent of externally directed jet simulations in the second scenario was to approximately model aerodynamic effects of a relatively large internal wing pressure, fueled by combusting aluminum, which deforms the corner of the landing gear door and directs a jet across the windside surface. These jet interactions, in and of themselves, were not sufficiently large to explain observed aerodynamic behavior.

Streptococcus agalactiae toxic shock-like syndrome: two case reports and review of the literature.

PubMed

Al Akhrass, Fadi; Abdallah, Lina; Berger, Steven; Hanna, Rami; Reynolds, Nina; Thompson, Shellie; Hallit, Rabih; Schlievert, Patrick M

2013-01-01

We present 2 patients with Streptococcus agalactiae toxic shock-like syndrome and review another 11 well-reported cases from the literature. Streptococcal toxic shock-like syndrome is a devastating illness with a high mortality rate, therefore we stress the importance of early supportive management, antimicrobial therapy, and surgical intervention. Toxic shock-like syndrome is likely to be underestimated in patients with invasive Streptococcus agalactiae infection who present with shock. Early diagnosis requires high suspicion of the illness, along with a thorough mucocutaneous examination. Streptococcus agalactiae produces uncharacterized pyrogenic toxins, which explains the ability of the organism to cause toxic shock-like syndrome.

Supersonic flow with feeding of energy

NASA Technical Reports Server (NTRS)

Zaremba, W.

1985-01-01

The present work discusses the results of some experimental studies on the possibility of attenuating shock waves in a supersonic flow. The shock waves were formed by an external source of electrical energy. An electromechanical method is described that permits partial recovery of the expended energy.

Asymmetric Shock Wave Generation in a Microwave Rocket Using a Magnetic Field

NASA Astrophysics Data System (ADS)

Takahashi, Masayuki

2017-10-01

A plasma pattern is reproduced by coupling simulations between a particle-in- cell with Monte Carlo collisions model and a finite-difference time-domain simulation for an electromagnetic wave propagation when an external magnetic field is applied to the breakdown volume inside a microwave-rocket nozzle. The propagation speed and energy-absorption rate of the plasma are estimated based on the breakdown simulation, and these are utilized to reproduce shock wave propagation, which provides impulsive thrust for the microwave rocket. The shock wave propagation is numerically reproduced by solving the compressible Euler equation with an energy source of the microwave heating. The shock wave is asymmetrically generated inside the nozzle when the electron cyclotron resonance region has a lateral offset, which generates lateral and angular impulses for postural control of the vehicle. It is possible to develop an integrated device to maintain beaming ight of the microwave rocket, achieving both axial thrust improvement and postural control, by controlling the spatial distribution of the external magnetic field.

[Group A streptococcus-induced toxic shock syndrome in pregnancy: a case report of cesarean section].

PubMed

Yamada, Kumiko; Fukuda, Taeko; Kimura, Maiko; Hagiya, Keiichi; Danmura, Masato; Nakayama, Shin; Ogura, Tsuyoshi; Tanaka, Makoto

2012-12-01

Group A streptococcus (GAS)-induced toxic shock syndrome (TSS) in pregnancy is rare, but its clinical course is fulminant. The mortality rates of mother and fetus are reported to be 58 and 66%, respectively. We report a case of GAS-TSS after cesarean section. A 38-year-old pregnant woman of 38 weeks gestation was admitted to our hospital because of vomiting, fever of 39 degrees C, and continuous abdominal pain with scanty genital bleeding. She had complained of sore throat several days before. One hour after admission, external fetal monitoring revealed periodic pulse deceleration to 90 x beats min(-1). The emergent cesarean section was performed under general anesthesia. Approximately 8 hours after the cesarean section, she developed coma, shock and respiratory insufficiency requiring intubation. Streptococcus pyogens were isolated from her blood sample and the patient met criteria for GAS-TSS. She was treated with antibiotics (penicillin and clindamycin), antithrombin III, recomodulin, catecholamins, and continuous hemodialysis with filtration of toxins. Although the patient recovered and was discharged on 63rd day, the infant died on postpartum day 4. Early recognition and intensive treatment for GAS is recommended in a late stage pregnancy with an episode of sore throat, vomiting, high fever, strong labor pain, and DIC signs.

Shock-capturing parabolized Navier-Stokes model /SCIPVIS/ for the analysis of turbulent underexpanded jets

NASA Technical Reports Server (NTRS)

Dash, S. M.; Wolf, D. E.

1983-01-01

A new computational model, SCIPVIS, has been developed to predict the multiple-cell wave/shock structure in under or over-expanded turbulent jets. SCIPVIS solves the parabolized Navier-Stokes jet mixing equations utilizing a shock-capturing approach in supersonic regions of the jet and a pressure-split approach in subsonic regions. Turbulence processes are represented by the solution of compressibility corrected two-equation turbulence models. The formation of Mach discs in the jet and the interactive turbulent mixing process occurring behind the disc are handled in a detailed fashion. SCIPVIS presently analyzes jets exhausting into a quiescent or supersonic external stream for which a single-pass spatial marching solution can be obtained. The iterative coupling of SCIPVIS with a potential flow solver for the analysis of subsonic/transonic external streams is under development.

Interactive calculation procedures for mixed compression inlets

NASA Technical Reports Server (NTRS)

Reshotko, Eli

1983-01-01

The proper design of engine nacelle installations for supersonic aircraft depends on a sophisticated understanding of the interactions between the boundary layers and the bounding external flows. The successful operation of mixed external-internal compression inlets depends significantly on the ability to closely control the operation of the internal compression portion of the inlet. This portion of the inlet is one where compression is achieved by multiple reflection of oblique shock waves and weak compression waves in a converging internal flow passage. However weak these shocks and waves may seem gas-dynamically, they are of sufficient strength to separate a laminar boundary layer and generally even strong enough for separation or incipient separation of the turbulent boundary layers. An understanding was developed of the viscous-inviscid interactions and of the shock wave boundary layer interactions and reflections.

Early identification of patients requiring massive transfusion, embolization, or hemostatic surgery for traumatic hemorrhage: a systematic review protocol.

PubMed

Tran, Alexandre; Matar, Maher; Steyerberg, Ewout W; Lampron, Jacinthe; Taljaard, Monica; Vaillancourt, Christian

2017-04-13

Hemorrhage is a major cause of early mortality following a traumatic injury. The progression and consequences of significant blood loss occur quickly as death from hemorrhagic shock or exsanguination often occurs within the first few hours. The mainstay of treatment therefore involves early identification of patients at risk for hemorrhagic shock in order to provide blood products and control of the bleeding source if necessary. The intended scope of this review is to identify and assess combinations of predictors informing therapeutic decision-making for clinicians during the initial trauma assessment. The primary objective of this systematic review is to identify and critically assess any existing multivariable models predicting significant traumatic hemorrhage that requires intervention, defined as a composite outcome comprising massive transfusion, surgery for hemostasis, or angiography with embolization for the purpose of external validation or updating in other study populations. If no suitable existing multivariable models are identified, the secondary objective is to identify candidate predictors to inform the development of a new prediction rule. We will search the EMBASE and MEDLINE databases for all randomized controlled trials and prospective and retrospective cohort studies developing or validating predictors of intervention for traumatic hemorrhage in adult patients 16 years of age or older. Eligible predictors must be available to the clinician during the first hour of trauma resuscitation and may be clinical, lab-based, or imaging-based. Outcomes of interest include the need for surgical intervention, angiographic embolization, or massive transfusion within the first 24 h. Data extraction will be performed independently by two reviewers. Items for extraction will be based on the CHARMS checklist. We will evaluate any existing models for relevance, quality, and the potential for external validation and updating in other populations. Relevance will be described in terms of appropriateness of outcomes and predictors. Quality criteria will include variable selection strategies, adequacy of sample size, handling of missing data, validation techniques, and measures of model performance. This systematic review will describe the availability of multivariable prediction models and summarize evidence regarding predictors that can be used to identify the need for intervention in patients with traumatic hemorrhage. PROSPERO CRD42017054589.

Enhancing the Analysis of Rural Community Resilience: Evidence from Community land Ownership

ERIC Educational Resources Information Center

Skerratt, Sarah

2013-01-01

Resilience, and specifically the resilience of (rural) communities, is an increasingly-ubiquitous concept, particularly in the contexts of resistance to shocks, climate change, and environmental disasters. The dominant discourse concerning (community) resilience centres around bounce-back from external shocks. In this paper, I argue that it is…

Neuroendocrine Derangements in Early Septic Shock: Pharmacotherapy for Relative Adrenal and Vasopressin Insufficiency.

PubMed

Schurr, James W; Szumita, Paul M; DeGrado, Jeremy R

2017-09-01

Septic shock is a leading cause of mortality in intensive care units throughout the world. While this disease state represents a highly complex pathophysiology involving numerous organ systems, the early approach to care includes adequate hemodynamic support traditionally achieved via infusions of vasoactive medications after adequate fluid resuscitation. Relative adrenal and vasopressin deficiencies are a common feature of septic shock that contribute to impaired hemodynamics. Hydrocortisone and vasopressin are endocrine system hormone analogues that target the acute neuroendocrine imbalance associated with septic shock. This clinically focused annotated review describes the pathophysiological mechanisms behind their use and explores the potential clinical roles of early administration and synergy when combined.

Inhibition of intraluminal pancreatic enzymes with nafamostat mesilate improves clinical outcomes after hemorrhagic shock in swine.

PubMed

Kim, Hubert D; Malinoski, Darren J; Borazjani, Boris; Patel, Madhukar S; Chen, Joseph; Slone, Johnathan; Nguyen, Xuan-Mai T; Steward, Earl; Schmid-Schonbein, Geert W; Hoyt, David B

2010-05-01

Recent studies suggest that intraluminal pancreatic enzymes play a major role in the initiation of the inflammatory cascade by the gut after hemorrhagic shock. Previous animal models have shown that the inhibition of enteral pancreatic enzymes with a serine protease inhibitor, nafamostat mesilate (NM), decreases leukocyte activation and transfusion requirements after hemorrhagic shock. The objective of this study was to determine whether enteroclysis with NM would improve the clinical outcomes in swine after hemorrhagic shock and intestinal hypoperfusion. Thirty-three male Yucatan minipigs weighing 25 kg to 30 kg underwent a controlled hemorrhage of 25 mL/kg with mesenteric clamp for further gut ischemia. Animals were allocated to three groups: (1) shock only (n = 15), (2) shock + enteroclysis with 100 mL/kg GoLYTELY (GL) as a carrier (n = 11), and (3) shock + enteroclysis with GL + 0.37 mmol/L NM (GL+NM, n = 7). Animals were resuscitated, recovered from anesthesia, observed for 3 days, and graded on a daily 4-point clinical scoring system. A score of 0 indicated a moribund state or early death, and a score of 4 indicated normal behavior. Pigs treated with GL + NM had significantly higher mean postoperative recovery scores (3.8 +/- 0.4, essentially normal behavior with no early deaths) compared with animals within the shock only and shock + GL groups (2.1 +/- 1 with one early death and 2.2 +/- 1.2 with two early deaths, respectively, analysis of variance p < 0.003). The inhibition of intraluminal pancreatic enzymes using enteroclysis with the serine protease inhibitor, NM, after hemorrhagic shock significantly improves the clinical outcome.

A probabilistic method to establish the reliability of carbon-carbon rocket motor nozzles. Volume 3: Stress and reliability analysis of layered composite cylinders under thermal shock

NASA Astrophysics Data System (ADS)

Heller, R. A.; Thangjitham, S.; Wang, X.

1992-04-01

The state of stress in a cylindrical structure consisting of multiple layers of carbon-carbon composite and subjected to thermal and pressure shock are analyzed using an elasticity approach. The reliability of the structure based on the weakest link concept and the Weibull distribution is also calculated. Coupled thermo-elasticity is first assumed and is shown to be unnecessary for the material considered. The effects of external and internal thermal shock as well as a superimposed pressure shock are examined. It is shown that for the geometry chosen, the structure may fail when exposed to thermal shock alone while a superimposed pressure shock can mitigate the probability of failure.

Early administration of hydrocortisone replacement after the advent of septic shock: impact on survival and immune response*.

PubMed

Katsenos, Chrysostomos S; Antonopoulou, Anastasia N; Apostolidou, Efterpi N; Ioakeimidou, Aikaterini; Kalpakou, Georgia Th; Papanikolaou, Metaxia N; Pistiki, Aikaterini C; Mpalla, Margarita C; Paraschos, Michael D; Patrani, Maria A; Pratikaki, Maria E; Retsas, Theodoros A; Savva, Athina A; Vassiliagkou, Spyridoula D; Lekkou, Alexandra A; Dimopoulou, Ioanna; Routsi, Christina; Mandragos, Konstantinos E

2014-07-01

To investigate the impact of early initiation of hydrocortisone therapy on the clinical course of septic shock and on cytokine release. Prospective study in patients with septic shock treated with low doses of hydrocortisone. ICUs and general wards. Over a 2-year period, 170 patients with septic shock treated with low doses of hydrocortisone were enrolled. Blood was sampled from 34 patients for isolation of peripheral blood mononuclear cells and cytokine stimulation before and 24 hours after the start of hydrocortisone. None. After quartile analysis, patients were divided into those with early initiation of hydrocortisone (< 9 hr after vasopressors, n = 46) and those with late initiation of hydrocortisone (> 9 hr after vasopressors, n = 124). After adjusting for disease severity and type of infection, a protective effect of early hydrocortisone administration against unfavorable outcome was found (hazard ratio, 0.20; p = 0.012). Time of discontinuation of vasopressors was earlier among patients with initiation of hydrocortisone within 9 hours. Production of tumor necrosis factor-α was lower among patients who had had hydrocortisone early. In patients receiving hydrocortisone for septic shock, early initiation of treatment was associated with improved survival. This treatment was also associated with attenuated stimulation of tumor necrosis factor-α.

Prebiotic hydrocarbon synthesis in impacting reduced astrophysical icy mixtures

DOE PAGES

Koziol, Lucas; Goldman, Nir

2015-04-21

We present results of prebiotic organic synthesis in shock-compressed reducing mixtures of simple ices from quantum molecular dynamics simulations extended to close to chemical equilibrium timescales. Given the relative abundance of carbon in reduced forms in astrophysical ices as well as the tendency of these mixtures to form complex hydrocarbons under the presence of external stimuli, it is possible that cometary impacts on a planetary surface could have yielded a larger array of prebiotic organic compounds than previously investigated. We find that the high pressures and temperatures due to shock compression yield a large assortment of carbon- and nitrogen-bonded extendedmore » structures that are highly reactive with short molecular lifetimes. Expansion and cooling causes these materials to break apart and form a wide variety of stable, potentially life-building compounds, including long-chain linear and branched hydrocarbons, large heterocyclic compounds, and a variety of different amines and exotic amino acids. Lastly, our results help provide a bottom-up understanding of hydrocarbon impact synthesis on the early Earth and its role in producing life-building molecules from simple starting materials.« less

Prebiotic hydrocarbon synthesis in impacting reduced astrophysical icy mixtures

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

Koziol, Lucas; Goldman, Nir

We present results of prebiotic organic synthesis in shock-compressed reducing mixtures of simple ices from quantum molecular dynamics simulations extended to close to chemical equilibrium timescales. Given the relative abundance of carbon in reduced forms in astrophysical ices as well as the tendency of these mixtures to form complex hydrocarbons under the presence of external stimuli, it is possible that cometary impacts on a planetary surface could have yielded a larger array of prebiotic organic compounds than previously investigated. We find that the high pressures and temperatures due to shock compression yield a large assortment of carbon- and nitrogen-bonded extendedmore » structures that are highly reactive with short molecular lifetimes. Expansion and cooling causes these materials to break apart and form a wide variety of stable, potentially life-building compounds, including long-chain linear and branched hydrocarbons, large heterocyclic compounds, and a variety of different amines and exotic amino acids. Lastly, our results help provide a bottom-up understanding of hydrocarbon impact synthesis on the early Earth and its role in producing life-building molecules from simple starting materials.« less

Shocks in the Early Universe.

PubMed

Pen, Ue-Li; Turok, Neil

2016-09-23

We point out a surprising consequence of the usually assumed initial conditions for cosmological perturbations. Namely, a spectrum of Gaussian, linear, adiabatic, scalar, growing mode perturbations not only creates acoustic oscillations of the kind observed on very large scales today, it also leads to the production of shocks in the radiation fluid of the very early Universe. Shocks cause departures from local thermal equilibrium as well as create vorticity and gravitational waves. For a scale-invariant spectrum and standard model physics, shocks form for temperatures 1  GeV

Outcomes of out-of-hospital cardiac arrest by public location in the public-access defibrillation era.

PubMed

Murakami, Yukiko; Iwami, Taku; Kitamura, Tetsuhisa; Nishiyama, Chika; Nishiuchi, Tatsuya; Hayashi, Yasuyuki; Kawamura, Takashi

2014-04-22

The strategy to place public-access automated external defibrillators (AEDs) has not yet been established in real settings. This, prospective, population-based observational study in Osaka, Japan, included consecutive out-of-hospital cardiac arrest (OHCA) patients with resuscitation attempts during 7 years, from January 2005 through December 2011. The trends in the proportion of public-access AED use and 1-month survival with neurologically favorable outcome were evaluated by location. Factors associated with neurologically favorable outcome (defined as cerebral performance category 1 or 2) after ventricular fibrillation were also assessed using multiple logistic regression analysis. A total of 9453 bystander-witnessed OHCAs of cardiac origin were documented and 894 (9.5%) of them occurred at public places. The proportion of public-access AED use significantly increased from 0.0% (0/20) in 2005 to 41.2% (7/17) in 2011 at railway stations and from 0.0% (0/7) to 56.5% (13/23) at sports facilities. Mean time from collapse to shock was 5.0 minutes among those who received shocks with public-access AEDs. The proportion of neurologically favorable outcome was 28.0% (33/118) at railway stations, 51.6% (48/93) at sports facilities, 23.3% (20/86) in public buildings, and 41.9% (13/31) in schools. In multivariate analysis, early defibrillation, irrespective of bystander or emergency medical service (EMS) personnel, was significantly associated with neurologically favorable outcome (adjusted odds ratio for 1-minute increment, 0.89; 95% confidence interval, 0.87 to 0.92). This large, population-based OHCA registry demonstrated that earlier shock, irrespective the shock provider (bystander or EMS personnel), contributed to improving outcome, and a public-access defibrillation program was successfully implemented so that shocks with public-access AEDs were delivered to over 40% of bystander-witnessed OHCAs and time to shock was shortened in some kinds of public places.

Model experiment of magnetic field amplification in laser-produced plasmas via the Richtmyer-Meshkov instability

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

Kuramitsu, Y., E-mail: yasu@ncu.edu.tw; Moritaka, T.; Ohnishi, N.

2016-03-15

A model experiment of magnetic field amplification (MFA) via the Richtmyer-Meshkov instability (RMI) in supernova remnants (SNRs) was performed using a high-power laser. In order to account for very-fast acceleration of cosmic rays observed in SNRs, it is considered that the magnetic field has to be amplified by orders of magnitude from its background level. A possible mechanism for the MFA in SNRs is stretching and mixing of the magnetic field via the RMI when shock waves pass through dense molecular clouds in interstellar media. In order to model the astrophysical phenomenon in laboratories, there are three necessary factors formore » the RMI to be operative: a shock wave, an external magnetic field, and density inhomogeneity. By irradiating a double-foil target with several laser beams with focal spot displacement under influence of an external magnetic field, shock waves were excited and passed through the density inhomogeneity. Radiative hydrodynamic simulations show that the RMI evolves as the density inhomogeneity is shocked, resulting in higher MFA.« less

Shock wave propagation in a magnetic flux tube

NASA Astrophysics Data System (ADS)

Ferriz-Mas, A.; Moreno-Insertis, F.

1992-12-01

The propagation of a shock wave in a magnetic flux tube is studied within the framework of the Brinkley-Kirkwood theory adapted to a radiating gas. Simplified thermodynamic paths along which the compressed plasma returns to its initial state are considered. It is assumed that the undisturbed medium is uniform and that the flux tube is optically thin. The shock waves investigated, which are described with the aid of the thin flux-tube approximation, are essentially slow magnetohydrodynamic shocks modified by the constraint of lateral pressure balance between the flux tube and the surrounding field-free fluid; the confining external pressure must be balanced by the internal gas plus magnetic pressures. Exact analytical solutions giving the evolution of the shock wave are obtained for the case of weak shocks.

Jet or Shock Breakout? The Low-Luminosity GRB 060218

NASA Astrophysics Data System (ADS)

Irwin, Christopher; Chevalier, Roger

2016-01-01

We consider a model for the long-duration, low-luminosity gamma-ray burst GRB 060218 that plausibly accounts for multiwavelength observations to day 20. The components of our model are: (1) a long-lived (tj ~ 3000 s) central engine and accompanying low-luminosity (Lj ~ 1045 erg s-1), mildly relativistic jet; (2) a low-mass (~ 10-2 Msun) envelope surrounding the progenitor star; and (3) a modest amount of dust (AV ~ 0.1) in the circumstellar or interstellar environment. Blackbody emission from the transparency radius in a low-power jet outflow can fit the prompt thermal X-ray emission, and the prompt nonthermal X-rays and γ-rays may be produced via Compton scattering of thermal photons from hot leptons in the jet interior or the external shocks. The later mildly relativistic phase of this outflow can produce the radio emission via synchrotron radiation from the forward shock. Meanwhile, interaction of the associated SN 2006aj with a circumstellar envelope extending to ~ 1013 cm can explain the early optical peak. The X-ray afterglow can be interpreted as a light echo of the prompt emission from dust at ~ 30 pc. Our model is a plausible alternative to that of Nakar, who recently proposed shock breakout of a jet smothered by an extended envelope as the source of prompt emission. Both our results and Nakar's suggest that ultra-long bursts such as GRB 060218 and GRB 100316D may originate from unusual progenitors with extended circumstellar envelopes, and that a jet is necessary to decouple the prompt high-energy emission from the supernova.

Jet or shock breakout? The low-luminosity GRB 060218

NASA Astrophysics Data System (ADS)

Irwin, Christopher M.; Chevalier, Roger A.

2016-08-01

We consider a model for the low-luminosity gamma-ray burst GRB 060218 that plausibly accounts for multiwavelength observations to day 20. The model components are: (1) a long-lived (tj ˜ 3000 s) central engine and accompanying low-luminosity (Lj ˜ 1047 erg s-1), mildly relativistic (γ ˜ 10) jet; (2) a low-mass (˜4 × 10-3 M⊙) envelope surrounding the progenitor star; and (3) a modest amount of dust (AV ˜ 0.1 mag) in the circumstellar or interstellar environment. Blackbody emission from the transparency radius in a low-power jet outflow can fit the prompt thermal X-ray emission, and the non-thermal X-rays and gamma-rays may be produced via Compton scattering of thermal photons from hot leptons in the jet interior or the external shocks. The later mildly relativistic phase of this outflow can produce the radio emission via synchrotron radiation from the forward shock. Meanwhile, interaction of the associated SN 2006aj with a circumstellar envelope extending to ˜1013 cm can explain the early optical emission. The X-ray afterglow can be interpreted as a light echo of the prompt emission from dust at ˜30 pc. Our model is a plausible alternative to that of Nakar, who recently proposed shock breakout of a jet smothered by an extended envelope as the source of prompt emission. Both our results and Nakar's suggest that bursts such as GRB 060218 may originate from unusual progenitors with extended circumstellar envelopes, and that a jet is necessary to decouple the prompt emission from the supernova.

Attenuated adult biphasic shocks for prolonged pediatric ventricular fibrillation: support for pediatric automated defibrillators.

PubMed

Berg, Robert A

2004-09-01

To evaluate published data regarding the treatment of prolonged pediatric defibrillation, with special emphasis on the use of attenuated adult biphasic shocks for pediatric defibrillation. Review relevant human and animal literature. Rhythm analysis algorithms from two manufacturers of automated external defibrillators can accurately distinguish shockable from nonshockable rhythms in children. Theoretical considerations and transthoracic impedance data from animals and children suggest that pediatric defibrillation doses should not necessarily vary in a simple weight-based manner. Two piglet studies have established that an attenuated adult biphasic dosage can be successfully used for 3.5- to 24-kg animals in ventricular fibrillation. One study established that the attenuated adult biphasic dosage was at least as safe and effective as the standard monophasic weight-based dosing. This review supports the American Heart Association's new guidelines for pediatric automated external defibrillator usage: "Automated external defibrillators may be used for children 1 to 8 yrs of age who have no signs of circulation. Ideally the device should deliver a pediatric dose. The arrhythmia detection system used in the device should demonstrate high specificity for pediatric shockable rhythms, i.e., it will not recommend delivery of a shock for nonshockable rhythms."

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

Ro, Stephen; Matzner, Christopher D., E-mail: ro@astro.utoronto.ca

Wave-driven outflows and non-disruptive explosions have been implicated in pre-supernova outbursts, supernova impostors, luminous blue variable eruptions, and some narrow-line and superluminous supernovae. To model these events, we investigate the dynamics of stars set in motion by strong acoustic pulses and wave trains, focusing on nonlinear wave propagation, shock formation, and an early phase of the development of a weak shock. We identify the shock formation radius, showing that a heuristic estimate based on crossing characteristics matches an exact expansion around the wave front and verifying both with numerical experiments. Our general analytical condition for shock formation applies to one-dimensionalmore » motions within any static environment, including both eruptions and implosions. We also consider the early phase of shock energy dissipation. We find that waves of super-Eddington acoustic luminosity always create shocks, rather than damping by radiative diffusion. Therefore, shock formation is integral to super-Eddington outbursts.« less

Dispatcher assistance and automated external defibrillator performance among elders.

PubMed

Ecker, R; Rea, T D; Meischke, H; Schaeffer, S M; Kudenchuk, P; Eisenberg, M S

2001-10-01

Automated external defibrillators (AEDs) provide an opportunity to improve survival in out-of-hospital, ventricular fibrillation (VF) cardiac arrest by enabling laypersons not trained in rhythm recognition to deliver lifesaving therapy. The potential role of emergency dispatchers in the layperson use of AEDs is uncertain. This study was performed to examine whether dispatcher telephone assistance affected AED skill performance during a simulated VF cardiac arrest among a cohort of older adults. The hypothesis was that dispatcher assistance would increase the proportion who were able to correctly deliver a shock, but might require additional time. One hundred fifty community-dwelling persons aged 58-84 years were recruited from eight senior centers in King County, Washington. All participants had received AED training approximately six months previously. For this study, the participants were randomized to AED operation with or without dispatcher assistance during a simulated VF cardiac arrest. The proportions who successfully delivered a shock and the time intervals from collapse to shock were compared between the two groups. The participants who received dispatcher assistance were more likely to correctly deliver a shock with the AED during the simulated VF cardiac arrest (91% vs 68%, p = 0.001). Among those who were able to deliver a shock, the participants who received dispatcher assistance required a longer time interval from collapse to shock [median (25th, 75th percentile) = 193 seconds (165, 225) for dispatcher assistance, and 148 seconds (138, 166) for no dispatcher assistance, p = 0.001]. Among older laypersons previously trained in AED operation, dispatcher assistance may increase the proportion who can successfully deliver a shock during a VF cardiac arrest.

Investigation of shock-acoustic-wave interaction in transonic flow

NASA Astrophysics Data System (ADS)

Feldhusen-Hoffmann, Antje; Statnikov, Vladimir; Klaas, Michael; Schröder, Wolfgang

2018-01-01

The buffet flow field around supercritical airfoils is dominated by self-sustained shock wave oscillations on the suction side of the wing. Theories assume that this unsteadiness is driven by an acoustic feedback loop of disturbances in the flow field downstream of the shock wave whose upstream propagating part is generated by acoustic waves. Therefore, in this study, first variations in the sound pressure level of the airfoil's trailing-edge noise during a buffet cycle, which force the shock wave to move upstream and downstream, are detected, and then, the sensitivity of the shock wave oscillation during buffet to external acoustic forcing is analyzed. Time-resolved standard and tomographic particle-image velocimetry (PIV) measurements are applied to investigate the transonic buffet flow field over a supercritical DRA 2303 airfoil. The freestream Mach number is M_{∞} = 0.73, the angle of attack is α = {3.5}°, and the chord-based Reynolds number is Re_c = 1.9× 10^6. The perturbed Lamb vector field, which describes the major acoustic source term of trailing-edge noise, is determined from the tomographic PIV data. Subsequently, the buffet flow field is disturbed by an artificially generated acoustic field, the acoustic intensity of which is comparable to the Lamb vector that is determined from the PIV data. The results confirm the hypothesis that buffet is driven by an acoustic feedback loop and show the shock wave oscillation to directly respond to external acoustic forcing. That is, the amplitude modulation frequency of the artificial acoustic perturbation determines the shock oscillation.

Lyman alpha radiation in external galaxies

NASA Technical Reports Server (NTRS)

Neufeld, David A.; Mckee, Christopher F.

1990-01-01

The Ly alpha line of atomic hydrogen is often a luminous component of the radiation emitted by distant galaxies. Except for those galaxies which have a substantial central source of non-stellar ionizing radiation, most of the Ly alpha radiation emitted by galaxies is generated within regions of the interstellar medium which are photoionized by starlight. Conversely, much of the energy radiated by photoionized regions is carried by the Ly alpha line. Only hot, massive stars are capable of ionizing hydrogen in the interstellar medium which surrounds them, and because such stars are necessarily short-lived, Ly alpha emission traces regions of active star formation. Researchers argue that the strength of the Ly alpha emission observed from external galaxies may be used to estimate quantitatively the dust content of the emitting region, while the Ly alpha line profile is sensitive to the presence of shock waves. Interstellar dust particles and shock waves are intimately associated with the process of star formation in two senses. First, both dust particles and shock waves owe their existence to stellar activity; second, they may both serve as agents which facilitate the formation of stars, shocks by triggering gravitational instabilities in the interstellar gas that they compress, and dust by shielding star-forming molecular clouds from the ionizing and dissociative effects of external UV radiation. By using Ly alpha observations as a probe of the dust content in diffuse gas at high redshift, we might hope to learn about the earliest epochs of star formation.

Experimental evaluation of low-pass shock isolation performance of elastomers using frequency-based Kolsky bar analyses

DOE PAGES

Knight, Marlene E.; Sanborn, Brett; Song, Bo; ...

2017-01-26

Elastomeric materials are used as shock isolation materials in a variety of environments to dampen vibrations and/or absorb energy from external impact to minimize energy transfer between two objects or bodies. Some applications require the shock isolation materials to behave as a low-pass mechanical filter to mitigate the shock/impact at high frequencies but transmit the energy at low frequencies with minimal attenuation. To fulfill this requirement, a shock isolation material needs to be carefully evaluated and selected with proper experimental design, procedures, and analyses. In this study, a Kolsky bar was modified with precompression (up to 15.5 kN) and confinementmore » capabilities to evaluate low-pass shock isolation performance in terms of acceleration attenuation through a variety of elastomers. Also investigated were the effects of preload and specimen geometry on the low-pass shock isolation response.« less

Vibration, acoustic, and shock design and test criteria for components on the Solid Rocket Boosters (SRB), Lightweight External Tank (LWT), and Space Shuttle Main Engines (SSME)

NASA Technical Reports Server (NTRS)

1984-01-01

The vibration, acoustics, and shock design and test criteria for components and subassemblies on the space shuttle solid rocket booster (SRB), lightweight tank (LWT), and main engines (SSME) are presented. Specifications for transportation, handling, and acceptance testing are also provided.

Detection of high-energy gamma-ray emission during the X-ray flaring activity in GRB 100728A

DOE PAGES

Abdo, A. A.; Ackermann, M.; Ajello, M.; ...

2011-05-26

Here, we present the simultaneous Swift and Fermi observations of the bright GRB 100728A and its afterglow. The early X-ray emission is dominated by a vigorous flaring activity continuing until 1 ks after the burst. In the same time interval, high-energy emission is significantly detected by the Fermi/Large Area Telescope. Marginal evidence of GeV emission is observed up to later times. As a result, we discuss the broadband properties of this burst within both the internal and external shock scenarios, with a particular emphasis on the relation between X-ray flares, the GeV emission, and a continued long-duration central engine activitymore » as their power source.« less

Shock to the system: How catastrophic events and institutional relationships impact Japanese energy policymaking, resilience, and innovation

NASA Astrophysics Data System (ADS)

Sklarew, Jennifer F.

External shocks do not always generate energy system transformation. This dissertation examines how government relationships with electric utilities and the public impact whether shocks catalyze energy system change. The study analyzes Japanese energy policymaking from the oil crises through the Fukushima nuclear disaster. Findings reveal that policymakers' cooperation with and clout over electric utilities and the public can enable shocks to transform energy systems. When electric utilities wield clout, public trust in and influence on the government determine the existing system's resilience and the potential for a new system to emerge. Understanding this effect informs energy policy design and innovation.

Use of Vortex Generators to Reduce Distortion for Mach 1.6 Streamline-Traced Supersonic Inlets

NASA Technical Reports Server (NTRS)

Baydar, Ezgihan; Lu, Frank; Slater, John W.; Trefny, Chuck

2016-01-01

Reduce the total pressure distortion at the engine-fan face due to low-momentum flow caused by the interaction of an external terminal shock at the turbulent boundary layer along a streamline-traced external-compression (STEX) inlet for Mach 1.6.

Early Identification of Circulatory Shock in Critical Care Transport

DTIC Science & Technology

2008-09-30

disclosure and community consultation. Early Identification of Circulatory Shock in Critical Care Transport 2 Community consultation for this...in two aircraft types (Eurocopter EC 135 and EC 145), in IFR weather conditions, and during both day and night operations. We calculated the

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

Knight, Marlene E.; Sanborn, Brett; Song, Bo

Elastomeric materials are used as shock isolation materials in a variety of environments to dampen vibrations and/or absorb energy from external impact to minimize energy transfer between two objects or bodies. Some applications require the shock isolation materials to behave as a low-pass mechanical filter to mitigate the shock/impact at high frequencies but transmit the energy at low frequencies with minimal attenuation. To fulfill this requirement, a shock isolation material needs to be carefully evaluated and selected with proper experimental design, procedures, and analyses. In this study, a Kolsky bar was modified with precompression (up to 15.5 kN) and confinementmore » capabilities to evaluate low-pass shock isolation performance in terms of acceleration attenuation through a variety of elastomers. Also investigated were the effects of preload and specimen geometry on the low-pass shock isolation response.« less

On Interplanetary Shocks Driven by Coronal Mass Ejections

NASA Technical Reports Server (NTRS)

Gopalswarmy, Nat

2011-01-01

Traveling interplanetary (IP) shocks were first detected in the early 1960s, but their solar origin has been controversial. Early research focused on solar flares as the source of the shocks, but when CMEs were discovered, it became clear that fast CMEs are the shock drivers. Type radio II bursts are excellent signatures of shocks near the Sun (Type II radio bursts were known long before the detection of shocks and CMEs). The excellent correspondence between type II bursts and solar energetic particle (SEP) events made it clear that the same shock accelerates ions and electrons. Shocks near the Sun are also seen occasionally in white-light coronagraphic images. In the solar wind, shocks are observed as discontinuities in plasma parameters such as density and speed. Energetic storm particle events and sudden commencement of geomagnetic storm are also indicators of shocks arriving at Earth. After an overview on these shock signatures, I will summarize the results of a recent investigation of a large number of IP shocks. The study revealed that about 35% of IP shocks do not produce type II bursts (radio quiet - RQ) or SEPs. Comparing the RQ shocks with the radio loud (RL) ones revealed some interesting results: (1) There is no evidence for blast wave shocks. (2) A small fraction (20%) of RQ shocks is associated with ion enhancements at the shock when the shock passes the spacecraft. (3) The primary difference between the RQ and RL shocks can be traced to the different kinematic properties of the associated CMEs. On the other hand the shock properties measured at 1 AU are not too different for the RQ and RL cases. This can be attributed to the interaction with the IP medium, which seems to erase the difference between the shocks.

X-Ray Emission from Supernova Remnants.

NASA Astrophysics Data System (ADS)

Sackville Hamilton, Andrew James

1984-12-01

This thesis deals with the x-ray spectra of supernova remnants (SNRs), and in particular the x-ray spectra of the two young Type I SNRs SN1006 and Tycho. Firstly an extensive grid of nonequilibrium model spectra of SNRs in the adiabatic blast wave stage of evolution is computed, and numerous diagnostics of the state and composi- tion of the blast wave plasma are plotted over parameter space. It is demonstrated that the spectrum of an adiabatic blast wave is a good approximation to several other model SNR structures in which emission is dominated by gas undergoing quasi steady state ioni- zation near a shock front, including the one-fluid isothermal blast wave similarity solution, and the reverse shock similarity solution advocated by Chevalier for the early evolution of Type I SNe. None of these structures appears able to account for the observed spectra of SN1006 or Tycho. A new similarity solution for the early time evolution of uniform ejecta moving into an external medium is presented. It is argued that the x-ray spectra of SN1006 and Tycho are consistent with emission mainly from a reverse shock into 1.4M(,o) of initially uniform density SN ejecta consisting of pure heavy elements, moving into a uniform medium. Satisfactory fits to the observed spectra are obtained with a two layer structure of ejecta, an outer layer of unprocessed material, and an inner layer of mixed processed heavy elements. The structure of ejecta inferred is similar for both SN1006 and Tycho, the marked difference between the two spectra being attributed largely to the lower density of the ambient medium around SN1006. The results are consistent with the theory of Type I SNe as exploded white dwarfs, and resolve the apparent problems of too little iron, and too much total mass, deduced by other authors from earlier analyses of the x-ray emission of SN1006 and Tycho. Various salient aspects of the physics of a shock-heated pure heavy element plasma are discussed.

Early and Definitive Diagnosis of Toxic Shock Syndrome by Detection of Marked Expansion of T-Cell-Receptor Vβ2-Positive T Cells

PubMed Central

Kato, Hidehito; Yamada, Ritsuko; Okano, Hiroya; Ohta, Hiroaki; Imanishi, Ken’ichi; Kikuchi, Ken; Totsuka, Kyouichi; Uchiyama, Takehiko

2003-01-01

We describe two cases of early toxic shock syndrome, caused by the superantigen produced from methicillin-resistant Staphylococcus aureus and diagnosed on the basis of an expansion of T-cell-receptor Vβ2-positive T cells. One case-patient showed atypical symptoms. Our results indicate that diagnostic systems incorporating laboratory techniques are essential for rapid, definitive diagnosis of toxic shock syndrome. PMID:12643839

GRB afterglows in the nonrelativistic phase

NASA Astrophysics Data System (ADS)

Huang, Y. F.; Lu, T.

2008-10-01

When discussing the afterglows of gamma-ray bursts analytically, it is usually assumed that the external shock is always ultra-relativisitc, with the bulk Lorentz factor much larger than 1. However, we show that the deceleration of the external shock is actually very quick. The afterglow may typically enter the nonrelativistic phase in several days to teens of days, and may even enter the deep Newtonian phase in tens of days to several months. One thus should be careful in using those familiar analytical expressions that are derived only under the ultra-relativistic assumption. To explain the observed afterglows that typically last for a few weeks to several months, we need to consider the dynamics and radiation in the nonrelativisitic phase.

Influences of the Driver and Ambient Medium Characteristics on the Formation of Shocks in the Solar Atmosphere

NASA Technical Reports Server (NTRS)

Nat, Gopalswamy; Hong, Xie; Seiji, Yashiro; Pertti, Makela; Sachiko, Akiyama

2010-01-01

Traveling interplanetary (IP) shocks were discovered in the early 1960s, but their solar origin has been controversial. Early research focused on solar flares as the source of the shocks, but when coronal mass ejections (CMEs) were discovered, it became clear that fast CMEs clearly can drive the shocks. Type II radio bursts are excellent signatures of shocks near the Sun. The close correspondence between type II radio bursts and solar energetic particles (SEPs) makes it clear that the same shock accelerates ions and electrons. A recent investigation involving a large number of IP shocks revealed that about 35% of IP shocks do not produce type II bursts or SEPs. Comparing these radio quiet (RQ) shocks with the radio loud (RL) ones revealed some interesting results: (1) there is no evidence for blast waves, in that all IP shocks can be attributed to CMEs, (2) a small fraction (20%) of RQ shocks is associated with ion enhancements at the shocks when they move past the observing spacecraft, (3) the primary difference between the RQ and RL shocks can be traced to the different kinematic properties of the associated CMEs and the variation of the characteristic speeds of the ambient medium, and (4) the shock properties measured at 1 AU are not too different for the RQ and RL cases due to the interaction of the shock driver with the IP medium that seems to erase the difference.

CFD application to supersonic/hypersonic inlet airframe integration. [computational fluid dynamics (CFD)

NASA Technical Reports Server (NTRS)

Benson, Thomas J.

1988-01-01

Supersonic external compression inlets are introduced, and the computational fluid dynamics (CFD) codes and tests needed to study flow associated with these inlets are outlined. Normal shock wave turbulent boundary layer interaction is discussed. Boundary layer control is considered. Glancing sidewall shock interaction is treated. The CFD validation of hypersonic inlet configurations is explained. Scramjet inlet modules are shown.

The behavior of a compressible turbulent boundary layer in a shock-wave-induced adverse pressure gradient. Ph.D. Thesis - Washington Univ., Seattle, Aug. 1972

NASA Technical Reports Server (NTRS)

Rose, W. C.

1973-01-01

The results of an experimental investigation of the mean- and fluctuating-flow properties of a compressible turbulent boundary layer in a shock-wave-induced adverse pressure gradient are presented. The turbulent boundary layer developed on the wall of an axially symmetric nozzle and test section whose nominal free-stream Mach number and boundary-layer thickness Reynolds number were 4 and 100,000, respectively. The adverse pressure gradient was induced by an externally generated conical shock wave. Mean and time-averaged fluctuating-flow data, including the complete experimental Reynolds stress tensor and experimental turbulent mass- and heat-transfer rates are presented for the boundary layer and external flow, upstream, within and downstream of the pressure gradient. The mean-flow data include distributions of total temperature throughout the region of interest. The turbulent mixing properties of the flow were determined experimentally with a hot-wire anemometer. The calibration of the wires and the interpretation of the data are discussed. From the results of the investigation, it is concluded that the shock-wave - boundary-layer interaction significantly alters the turbulent mixing characteristics of the boundary layer.

High-energy cosmic ray nuclei from tidal disruption events: Origin, survival, and implications

NASA Astrophysics Data System (ADS)

Zhang, B. Theodore; Murase, Kohta; Oikonomou, Foteini; Li, Zhuo

2017-09-01

Tidal disruption events (TDEs) by supermassive or intermediate mass black holes have been suggested as candidate sources of ultrahigh-energy cosmic rays (UHECRs) and high-energy neutrinos. Motivated by the recent measurements from the Pierre Auger Observatory, which indicates a metal-rich cosmic-ray composition at ultrahigh energies, we investigate the fate of UHECR nuclei loaded in TDE jets. First, we consider the production and survival of UHECR nuclei at internal shocks, external forward and reverse shocks, and nonrelativistic winds. Based on the observations of Swift J 1644 +57 , we show that the UHECRs can survive for external reverse and forward shocks, and disk winds. On the other hand, UHECR nuclei are significantly disintegrated in internal shocks, although they could survive for low-luminosity TDE jets. Assuming that UHECR nuclei can survive, we consider implications of different composition models of TDEs. We find that the tidal disruption of main sequence stars or carbon-oxygen white dwarfs does not successfully reproduce UHECR observations, namely the observed composition or spectrum. The observed mean depth of the shower maximum and its deviation could be explained by oxygen-neon-magnesium white dwarfs, although they may be too rare to be the sources of UHECRs.

Interacting supernovae from photoionization-confined shells around red supergiant stars

NASA Astrophysics Data System (ADS)

Mackey, Jonathan; Mohamed, Shazrene; Gvaramadze, Vasilii V.; Kotak, Rubina; Langer, Norbert; Meyer, Dominique M.-A.; Moriya, Takashi J.; Neilson, Hilding R.

2014-08-01

Betelgeuse, a nearby red supergiant, is a fast-moving star with a powerful stellar wind that drives a bow shock into its surroundings. This picture has been challenged by the discovery of a dense and almost static shell that is three times closer to the star than the bow shock and has been decelerated by some external force. The two physically distinct structures cannot both be formed by the hydrodynamic interaction of the wind with the interstellar medium. Here we report that a model in which Betelgeuse's wind is photoionized by radiation from external sources can explain the static shell without requiring a new understanding of the bow shock. Pressure from the photoionized wind generates a standing shock in the neutral part of the wind and forms an almost static, photoionization-confined shell. Other red supergiants should have much more massive shells than Betelgeuse, because the photoionization-confined shell traps up to 35 per cent of all mass lost during the red supergiant phase, confining this gas close to the star until it explodes. After the supernova explosion, massive shells dramatically affect the supernova light curve, providing a natural explanation for the many supernovae that have signatures of circumstellar interaction.

Interacting supernovae from photoionization-confined shells around red supergiant stars.

PubMed

Mackey, Jonathan; Mohamed, Shazrene; Gvaramadze, Vasilii V; Kotak, Rubina; Langer, Norbert; Meyer, Dominique M-A; Moriya, Takashi J; Neilson, Hilding R

2014-08-21

Betelgeuse, a nearby red supergiant, is a fast-moving star with a powerful stellar wind that drives a bow shock into its surroundings. This picture has been challenged by the discovery of a dense and almost static shell that is three times closer to the star than the bow shock and has been decelerated by some external force. The two physically distinct structures cannot both be formed by the hydrodynamic interaction of the wind with the interstellar medium. Here we report that a model in which Betelgeuse's wind is photoionized by radiation from external sources can explain the static shell without requiring a new understanding of the bow shock. Pressure from the photoionized wind generates a standing shock in the neutral part of the wind and forms an almost static, photoionization-confined shell. Other red supergiants should have much more massive shells than Betelgeuse, because the photoionization-confined shell traps up to 35 per cent of all mass lost during the red supergiant phase, confining this gas close to the star until it explodes. After the supernova explosion, massive shells dramatically affect the supernova light curve, providing a natural explanation for the many supernovae that have signatures of circumstellar interaction.

Effectiveness of Lower Energy Density Extracorporeal Shock Wave Therapy in the Early Stage of Avascular Necrosis of the Femoral Head.

PubMed

Han, Yong; Lee, June-Kyung; Lee, Bong-Yeon; Kee, Hoi-Sung; Jung, Kwang-Ik; Yoon, Seo-Ra

2016-10-01

To evaluate the effectiveness of lower energy flux density (EFD) extracorporeal shock wave therapy (ESWT) in the early stage of avascular necrosis (AVN) of the femoral head. Nineteen patients and 30 hips were enrolled. All subjects received 4 weekly sessions of ESWT, at different energy levels; group A (n=15; 1,000 shocks/session, EFD per shock 0.12 mJ/mm 2 ) and group B (n=15; 1,000 shocks/session, EFD per shock 0.32 mJ/mm 2 ). We measured pain by using the visual analog scale (VAS), and disability by using the Harris hip score, Hip dysfunction and Osteoarthritis Outcome Score (HOOS), and the Western Ontario and McMaster University Osteoarthritis Index (WOMAC). To determine the effect of the lower EFD ESWT, we assessed the VAS, Harris hip score, HOOS, WOMAC of the subjects before and at 1, 3, and 6 months. In both groups, the VAS, Harris hip score, HOOS, and WOMAC scores improved over time (p<0.05). Lower EFD ESWT may be an effective method to improve the function and to relieve pain in the early stage of AVN.

Hepatic Shock Differential Diagnosis and Risk Factors: A Review Article.

PubMed

Soleimanpour, Hassan; Safari, Saeid; Rahmani, Farzad; Nejabatian, Arezu; Alavian, Seyed Moayed

2015-10-01

Liver as an important organ has a vital role in physiological processes in the body. Different causes can disrupt normal function of liver. Factors such as hypo-perfusion, hypoxemia, infections and some others can cause hepatic injury and hepatic shock. Published research resources from 2002 to May 2015 in some databases (PubMed, Scopus, Index Copernicus, DOAJ, EBSCO-CINAHL, Science direct, Cochrane library and Google scholar and Iranian search database like SID and Iranmedex) were investigated for the present study. Different causes can lead to hepatic shock. Most of these causes can be prevented by early resuscitation and treatment of underlying factors. Hepatic shock is detected in ill patients, especially those with hemodynamic disorders. It can be prevented by early treatment of underlying disease. There is no definite treatment for hepatic shock and should be managed conservatively. Hepatic shock in patients can increase the mortality rate.

Hepatic Shock Differential Diagnosis and Risk Factors: A Review Article

PubMed Central

Soleimanpour, Hassan; Safari, Saeid; Rahmani, Farzad; Nejabatian, Arezu; Alavian, Seyed Moayed

2015-01-01

Context: Liver as an important organ has a vital role in physiological processes in the body. Different causes can disrupt normal function of liver. Factors such as hypo-perfusion, hypoxemia, infections and some others can cause hepatic injury and hepatic shock. Evidence Acquisition: Published research resources from 2002 to May 2015 in some databases (PubMed, Scopus, Index Copernicus, DOAJ, EBSCO-CINAHL, Science direct, Cochrane library and Google scholar and Iranian search database like SID and Iranmedex) were investigated for the present study. Results: Different causes can lead to hepatic shock. Most of these causes can be prevented by early resuscitation and treatment of underlying factors. Conclusions: Hepatic shock is detected in ill patients, especially those with hemodynamic disorders. It can be prevented by early treatment of underlying disease. There is no definite treatment for hepatic shock and should be managed conservatively. Hepatic shock in patients can increase the mortality rate. PMID:26587034

Micro-Ramps for External Compression Low-Boom Inlets

NASA Technical Reports Server (NTRS)

Rybalko, Michael; Loth, Eric; Chima, Rodrick V.; Hirt, Stefanie M.; DeBonis, James R.

2010-01-01

The application of vortex generators for flow control in an external compression, axisymmetric, low-boom concept inlet was investigated using RANS simulations with three-dimensional (3-D), structured, chimera (overset) grids and the WIND-US code. The low-boom inlet design is based on previous scale model 1- by 1-ft wind tunnel tests and features a zero-angle cowl and relaxed isentropic compression centerbody spike, resulting in defocused oblique shocks and a weak terminating normal shock. Validation of the methodology was first performed for micro-ramps in supersonic flow on a flat plate with and without oblique shocks. For the inlet configuration, simulations with several types of vortex generators were conducted for positions both upstream and downstream of the terminating normal shock. The performance parameters included incompressible axisymmetric shape factor, separation area, inlet pressure recovery, and massflow ratio. The design of experiments (DOE) methodology was used to select device size and location, analyze the resulting data, and determine the optimal choice of device geometry. The optimum upstream configuration was found to substantially reduce the post-shock separation area but did not significantly impact recovery at the aerodynamic interface plane (AIP). Downstream device placement allowed for fuller boundary layer velocity profiles and reduced distortion. This resulted in an improved pressure recovery and massflow ratio at the AIP compared to the baseline solid-wall configuration.

To shunt or not to shunt? An experimental study comparing temporary vascular shunts and venous ligation as damage control techniques for vascular trauma.

PubMed

Marinho de Oliveira Góes Junior, Adenauer; de Campos Vieira Abib, Simone; de Seixas Alves, Maria Teresa; Venerando da Silva Ferreira, Paulo Sérgio; Carvalho de Andrade, Mariseth

2014-04-01

To evaluate vascular flow through temporary vascular shunts inserted into peripheral arteries and veins and the repercussion, on the arterial perfusion, of venous ligation and venous shunt insertion in an experimental model for damage control. Experimental study in pigs. Animals were distributed in 5 groups: group 1, right external iliac artery (EIA) shunting and right external iliac vein (EIV) ligation; group 2, right EIA shunting and right EIV shunting; group 3, right EIV ligation; group 4, right EIV shunting; group 5, no vascular shunting and no venous ligation. Flowmeters were used to measure vascular flow on right and left external iliac vessels, and blood samples were collected from the EIVs for biochemical analysis. A right anterior limb biopsy was performed before shock. Hemorrhagic shock was induced through the external right jugular vein, until the vascular flow through right iliac external artery shunt or right iliac external vein shunt (group 4) ceased or until the animal's death. After the end of the experiments, biopsies of bilateral hind limb were obtained for histologic analysis. For statistical analysis, Microsoft Office Excel 2007 and BioEstat 5.0 (2007) were used. In the absence of hemorrhagic shock, venous ligation (group 1) was associated with a 38.8% reduction (P < 0.05) and venous shunting with a 28.4% reduction on the vascular flow through the arterial shunt. When associated with hemorrhagic shock, the mean vascular flow on the right EIA was 13 mL/min and on the left EIA was 41.2 mL/min; on group 2, the right EIA flow was 8.5 mL/min and the left EIA flow was 8.1 mL/min. When associated with hemorrhagic shock, the pO2 was 25.8 mm Hg on right EIV and 33.8 mm Hg on the left EIV for group 1 (P < 0.05), whereas for group 2, the pO2 was 22.6 mm Hg on right EIV and 22.8 mm Hg on the left EIV. On group 1, serum potassium was 3.84 mEq/L on the right EIV and 3.96 mEq/L on the left EIV, whereas on group 2, it was 7.1 mEq/L on the right EIV and 5.88 mEq/L on the left EIV (P < 0.05). In the developed experimental model, venous shunting, when compared with venous ligation, offered less resistance to vascular flow through the arterial shunt and allowed a more efficient limb venous drainage than simple vein ligature. Copyright © 2014 Elsevier Inc. All rights reserved.

[Automatic external defibrillator--mode of operation and clinical use].

PubMed

Wieneke, H; Konorza, T; Breuckmann, F; Reinsch, N; Erbel, R

2008-10-01

Every year about 100,000 persons die from sudden cardiac death (SCD) in Germany. Although many efforts have been undertaken, mortality remains high. Only 2 - 10% of patients with out-off hospital SCD can finally be discharged from hospital after resuscitation. Observational studies show that ventricular fibrillation and ventricular tachycardia are the primary arrhythmias underlying SCD. For both arrhythmias the main determinant for survival is the time between onset and termination by defibrillation. The chance of survival declines by 10% for every minute of delay. These findings prompted the concept of early defibrillation by first responders. Many studies have shown that non-medical professionals, like police men, firemen or security officers, often arrive at the patient more early than emergency medical service. Thus, "smart" automated external defibrillators (AEDs), designed to identify VT/VF and prompt the user when to deliver a shock were introduced. These devices allow lay rescuers to terminate ventricular arrhythmias before the arrival of medical professionals. By this approach the time to defibrillation could be reduced and a significant reduction in mortality could be documented in selected situation. These encouraging results initialled the installation of AED at public places like aircrafts, airports, underground stations and shopping males. Due to the success of this approach doctors are more and more confronted with questions about technical details, reliability and cost effectiveness of these devices. The present review should give an overview about the current studies and guidelines.

Toxic Shock Syndrome Caused by Methicillin-Resistant Staphylococcus aureus (MRSA) After Expander-Based Breast Reconstruction.

PubMed

Suga, Hirotaka; Shiraishi, Tomohiro; Takushima, Akihiko; Harii, Kiyonori

2016-01-01

Toxic shock syndrome is a rare but life-threatening complication after plastic surgery procedures. We experienced 2 cases of toxic shock syndrome after expander-based breast reconstruction caused by methicillin-resistant Staphylococcus aureus. The first patient took a severe clinical course due to the delayed diagnosis and treatment, and the second patient recovered rapidly after the early diagnosis and treatment based on our experience of the first case. Fever, rash, and gastrointestinal symptoms (diarrhea and/or vomiting) were characteristic and important for the early diagnosis of toxic shock syndrome. Considering the increased prevalence of methicillin-resistant Staphylococcus aureus, we should suspect methicillin-resistant Staphylococcus aureus in cases of toxic shock syndrome that occur postoperatively, and the empiric administration of vancomycin should be initiated in such cases.

A reduced-form intensity-based model under fuzzy environments

NASA Astrophysics Data System (ADS)

Wu, Liang; Zhuang, Yaming

2015-05-01

The external shocks and internal contagion are the important sources of default events. However, the external shocks and internal contagion effect on the company is not observed, we cannot get the accurate size of the shocks. The information of investors relative to the default process exhibits a certain fuzziness. Therefore, using randomness and fuzziness to study such problems as derivative pricing or default probability has practical needs. But the idea of fuzzifying credit risk models is little exploited, especially in a reduced-form model. This paper proposes a new default intensity model with fuzziness and presents a fuzzy default probability and default loss rate, and puts them into default debt and credit derivative pricing. Finally, the simulation analysis verifies the rationality of the model. Using fuzzy numbers and random analysis one can consider more uncertain sources in the default process of default and investors' subjective judgment on the financial markets in a variety of fuzzy reliability so as to broaden the scope of possible credit spreads.

Non-invasive timing of gas gun-launched projectiles using external surface-mounted optical fiber-Bragg grating strain gauges

NASA Astrophysics Data System (ADS)

Goodwin, Peter M.; Marshall, Bruce R.; Stevens, Gerald D.; Dattelbaum, Dana M.

2013-03-01

Non-invasive detection methods for tracking gun-launched projectiles are important not only for assessment of gun performance but are also essential for timing a variety of diagnostics, for example, to investigate plate-impact events for shock compression experiments. Measurement of the time of passage of a projectile moving inside of the gun barrel can be achieved by detection of the transient hoop strain induced in the barrel of a light-gas gun by the passage of the projectile using external, barrel surface-mounted optical fiber-Bragg grating strain gauges. Optical fiber-Bragg gratings have been implemented and their response characterized on single-stage and two-stage light gas guns routinely used for dynamic experimentation at Los Alamos National Laboratory. Two approaches, using either broadband or narrowband illumination, were used to monitor changes in the Bragg wavelength of the fiber-Bragg gratings. The second approach, using narrowband laser illumination, offered the highest sensitivity. The feasibility of using these techniques to generate early, pre-event signals useful for triggering high-latency diagnostics was demonstrated.

Non-invasive timing of gas gun-launched projectiles using external surface-mounted optical fiber-Bragg grating strain gauges.

PubMed

Goodwin, Peter M; Marshall, Bruce R; Stevens, Gerald D; Dattelbaum, Dana M

2013-03-01

Non-invasive detection methods for tracking gun-launched projectiles are important not only for assessment of gun performance but are also essential for timing a variety of diagnostics, for example, to investigate plate-impact events for shock compression experiments. Measurement of the time of passage of a projectile moving inside of the gun barrel can be achieved by detection of the transient hoop strain induced in the barrel of a light-gas gun by the passage of the projectile using external, barrel surface-mounted optical fiber-Bragg grating strain gauges. Optical fiber-Bragg gratings have been implemented and their response characterized on single-stage and two-stage light gas guns routinely used for dynamic experimentation at Los Alamos National Laboratory. Two approaches, using either broadband or narrowband illumination, were used to monitor changes in the Bragg wavelength of the fiber-Bragg gratings. The second approach, using narrowband laser illumination, offered the highest sensitivity. The feasibility of using these techniques to generate early, pre-event signals useful for triggering high-latency diagnostics was demonstrated.

Early initiation of low-dose hydrocortisone treatment for septic shock in adults: A randomized clinical trial.

PubMed

Lv, Qing-Quan; Gu, Xiao-Hua; Chen, Qi-Hong; Yu, Jiang-Quan; Zheng, Rui-Qiang

2017-12-01

Physiologic dose hydrocortisone is part of the suggested adjuvant therapies for patients with septic shock. However, the association between the corticosteroid therapy and mortality in patients with septic shock is still not clear. Some authors considered that the mortality is related to the time frame between development of septic shock and start of low dose hydrocortisone. Thus we designed a placebo-controlled, randomized clinical trial to assess the importance of early initiation of low dose hydrocortisone for the final outcome. A total of 118 patients with septic shock were recruited in the study. All eligible patients were randomized to receive hydrocortisone (n=58) or normal saline (n=60). The study medication (hydrocortisone and normal saline) was initiated simultaneously with vasopressors. The primary end-point was 28-day mortality. The secondary end-points were the reversal of shock, in-hospital mortality and the duration of ICU and hospital stay. The proportion of patients with reversal of shock was similar in the two groups (P=0.602); There were no significant differences in 28-day or hospital all-cause mortality; length of stay in the ICU or hospital between patients treated with hydrocortisone or normal saline. The early initiation of low-dose of hydrocortisone did not decrease the risk of mortality, and the length of stay in the ICU or hospital in adults with septic shock. www.clinicaltrials.govNCT02580240. Copyright © 2017 Elsevier Inc. All rights reserved.

External cardiac compression may be harmful in some scenarios of pulseless electrical activity.

PubMed

Hogan, T S

2012-10-01

Pulseless electrical activity occurs when organised or semi-organised electrical activity of the heart persists but the product of systemic vascular resistance and the increase in systemic arterial flow generated by the ejection of the left venticular stroke volume is not sufficient to produce a clinically detectable pulse. Pulseless electrical activity encompasses a very heterogeneous variety of severe circulatory shock states ranging in severity from pseudo-cardiac arrest to effective cardiac arrest. Outcomes of cardiopulmonary resuscitation for pulseless electrical activity are generally poor. Impairment of cardiac filling is the limiting factor to cardiac output in many scenarios of pulseless electrical activity, including extreme vasodilatory shock states. There is no evidence that external cardiac compression can increase cardiac output when impaired cardiac filling is the limiting factor to cardiac output. If impaired cardiac filling is the limiting factor to cardiac output and the heart is effectively ejecting all the blood returning to it, then external cardiac compression can only increase cardiac output if it increases venous return and cardiac filling. Repeated cardiac compression asynchronous with the patient's cardiac cycle and raised mean intrathoracic pressure due to chest compression can be expected to reduce rather than to increase cardiac filling and therefore to reduce rather than to increase cardiac output in such circumstances. The hypothesis is proposed that the performance of external cardiac compression will have zero or negative effect on cardiac output in pulseless electrical activity when impaired cardiac filling is the limiting factor to cardiac output. External cardiac compression may be both directly and indirectly harmful to significant sub-groups of patients with pulseless electrical activity. We have neither evidence nor theory to provide comfort that external cardiac compression is not harmful in many scenarios of pulseless electrical activity. Investigation using a variety of animal models of pulseless electrical activity produced by different shock-inducing mechanisms is required to provide an evidence base for resuscitation guidelines. Copyright © 2012 Elsevier Ltd. All rights reserved.

Spatial-temporal evolutions of early aftershocks following the 2013 Mw 6.6 Lushan earthquake in Sichuan, China

NASA Astrophysics Data System (ADS)

Wu, Jing; Yao, Dongdong; Meng, Xiaofeng; Peng, Zhigang; Su, Jinrong; Long, Feng

2017-04-01

We perform a comprehensive detection of early aftershocks following the 2013 Mw 6.6 Lushan earthquake, which occurred in the southern Longmenshan Fault Zone in Sichuan Province, China, about 5 years after the 2008 Mw 7.9 Wenchuan earthquake. We use events in both standard and relocated catalogs as templates to scan through continuous waveforms 2 days before and 3 days after the main shock. We successfully reduce the magnitude of completeness Mc by more than 1 order and obtain up to 6 times more events than listed in both catalogs. Aftershocks in the first hour mostly occur around the main shock slip region, and aftershocks at later times show systematic expansions in the along-strike, perpendicular-strike, and updip directions. Although postseismic deformation following the Lushan main shock has not been clearly identified, we suggest that early aftershock expansions are likely driven by afterslip of the Lushan main shock. This is consistent with the observations that most aftershocks were in the stress shadow of the Lushan main shock and that there was significant slip deficit in the top 10 km of the crust. We also find that seismicity on the back thrust fault was activated as soon as 20 min after the main shock, earlier than previously reported. We are unable to detect any clear foreshocks in the last 2 days before the Lushan main shock.

Successful treatment of blunt trauma involving complete laceration of the pancreas and duodenum in a 7-year-old child: report of a case.

PubMed

Yagi, M; Mishina, T; Fujishima, T; Date, K; Saito, H; Suzuki, N

1997-01-01

The acute onset of peritoneal signs and shock in a 7-year-old boy who had been hit in the epigastrium by a log-seesaw mandated surgical treatment. Enhanced computed tomography (CT) demonstrated complete laceration of the pancreas as well as duodenal injury, and a duodenoduodenostomy with distal pancreaticogastrostomy was subsequently performed. Temporary external drainage of the stomach and distal pancreas led to an uneventful recovery in the early postoperative period. Although the patient's postoperative development was appropriate for his age, the orifice of the distal pancreas spontaneously closed 2.5 years following surgery. We present this report to stress the fact that every effort should be made to preserve the pancreas following abdominal injury in children.

The Curious Events Leading to the Theory of Shock Waves

NASA Technical Reports Server (NTRS)

Salas, Manuel D.

2006-01-01

We review the history of the development of the modern theory of shock waves. Several attempts at an early-theory quickly collapsed for lack of foundations in mathematics and thermodynamics. It is not until the works of Rankine and later Hugoniot that a full theory is established. Rankine is the first to show that within the shock a non-adiabatic process must occur. Hugoniot showed that in the absence of viscosity and heat conduction conservation of energy implies conservation of entropy in smooth regions and a jump in entropy across a shock. Even after the theory is fully developed, old notions continue to pervade the literature well into the early part of the 20th Century.

Experimental study of subcritical laboratory magnetized collisionless shocks using a laser-driven magnetic piston

NASA Astrophysics Data System (ADS)

Schaeffer, D. B.; Everson, E. T.; Bondarenko, A. S.; Clark, S. E.; Constantin, C. G.; Winske, D.; Gekelman, W.; Niemann, C.

2015-11-01

Recent experiments at the University of California, Los Angeles have successfully generated subcritical magnetized collisionless shocks, allowing new laboratory studies of shock formation relevant to space shocks. The characteristics of these shocks are compared with new data in which no shock or a pre-shock formed. The results are consistent with theory and 2D hybrid simulations and indicate that the observed shock or shock-like structures can be organized into distinct regimes by coupling strength. With additional experiments on the early time parameters of the laser plasma utilizing Thomson scattering, spectroscopy, and fast-gate filtered imaging, these regimes are found to be in good agreement with theoretical shock formation criteria.

δ opioid receptor antagonist, ICI 174,864, is suitable for the early treatment of uncontrolled hemorrhagic shock in rats.

PubMed

Liu, Liangming; Tian, Kunlun; Zhu, Yu; Ding, Xiaoli; Li, Tao

2013-08-01

Fluid resuscitation is the essential step for early treatment of traumatic hemorrhagic shock. However, its implementation is greatly limited before hospital or during evacuation. The authors investigated whether δ opioid receptor antagonist ICI 174,864 was suitable for the early treatment of traumatic hemorrhagic shock. With uncontrolled hemorrhagic-shock rats, the antishock effects of six dosages of ICI 174,864 (0.1, 0.3, 0.5, 1, 3, and 5 mg/kg) infused with or without a small volume of lactated Ringer's solution (LR) before bleeding controlled or bleeding cessation at different times were observed. ICI 174,864 (0.1-3 mg/kg) with or without 1/4 volume of LR infusion showed dose-dependent increase in the mean arterial blood pressure, and significantly prolonged the survival time and 8-h survival rate, as compared with ICI 174,864 plus 1/2 volume of LR infusion. The best effect was shown with 3 mg/kg of ICI 174,864. Bleeding cessation at 1, 2, or 3 h during infusion of ICI 174,864 (3 mg/kg) plus 1/4 volume of LR improved subsequent treatment (70% 24-h survival rate vs. 50 and 10% 24-h survival rate in hypotensive resuscitation and LR group, respectively). There was significant improvement in hemodynamic parameters, oxygen delivery, and tissue perfusion of hemorrhagic-shock rats with 3 mg/kg of ICI 174,864 plus 1/4 volume of LR infusion. δ Opioid receptor antagonist ICI 174,864 alone or with small volume of fluid infusion has good beneficial effect on uncontrolled hemorrhagic shock. Its early application can "buy" time for subsequent treatment of traumatic shock.

Real-Time Control of the Embedded Waveform for External Defibrillation

DTIC Science & Technology

2001-10-25

independently from transthoracic electrical impedance changes during shock time. Keywords - External defibrillation, real-time control I. INTRODUCTION ...Additional such possibilities may be useful for development a new electrotherapy methods, as electrochemotherapy for cancer treatment [6]. II...Department, Moscow State Institute of Electronic Technology , Moscow, Russia Fig.1. High voltage delivery unit. Report Documentation Page Report Date 25

Implementation of a Cardiogenic Shock Team and Clinical Outcomes (INOVA-SHOCK Registry): Observational and Retrospective Study.

PubMed

Tehrani, Behnam; Truesdell, Alexander; Singh, Ramesh; Murphy, Charles; Saulino, Patricia

2018-06-28

The development and implementation of a Cardiogenic Shock initiative focused on increased disease awareness, early multidisciplinary team activation, rapid initiation of mechanical circulatory support, and hemodynamic-guided management and improvement of outcomes in cardiogenic shock. The objectives of this study are (1) to collect retrospective clinical outcomes for acute decompensated heart failure cardiogenic shock and acute myocardial infarction cardiogenic shock, and compare current versus historical survival rates and clinical outcomes; (2) to evaluate Inova Heart and Vascular Institute site specific outcomes before and after initiation of the Cardiogenic Shock team on January 1, 2017; (3) to compare outcomes related to early implementation of mechanical circulatory support and hemodynamic-guided management versus historical controls; (4) to assess survival to discharge rate in patients receiving intervention from the designated shock team and (5) create a clinical archive of Cardiogenic Shock patient characteristics for future analysis and the support of translational research studies. This is an observational, retrospective, single center study. Retrospective and prospective data will be collected in patients treated at the Inova Heart and Vascular Institute with documented cardiogenic shock as a result of acute decompensated heart failure or acute myocardial infarction. This registry will include data from patients prior to and after the initiation of the multidisciplinary Cardiogenic Shock team on January 1, 2017. Clinical outcomes associated with early multidisciplinary team intervention will be analyzed. In the study group, all patients evaluated for documented cardiogenic shock (acute decompensated heart failure cardiogenic shock, acute myocardial infarction cardiogenic shock) treated at the Inova Heart and Vascular Institute by the Cardiogenic Shock team will be included. An additional historical Inova Heart and Vascular Institute control group will be analyzed as a comparator. Means with standard deviations will be reported for outcomes. For categorical variables, frequencies and percentages will be presented. For continuous variables, the number of subjects, mean, standard deviation, minimum, 25th percentile, median, 75th percentile and maximum will be reported. Reported differences will include standard errors and 95% CI. Preliminary data analysis for the year 2017 has been completed. Compared to a baseline 2016 survival rate of 47.0%, from 2017 to 2018, CS survival rates were increased to 57.9% (58/110) and 81.3% (81/140), respectively (P=.01 for both). Study data will continue to be collected until December 31, 2018. The preliminary results of this study demonstrate that the INOVA SHOCK team approach to the treatment of Cardiogenic Shock with early team activation, rapid initiation of mechanical circulatory support, hemodynamic-guided management, and strict protocol adherence is associated with superior clinical outcomes: survival to discharge and overall survival when compared to 2015 and 2016 outcomes prior to Shock team initiation. What may limit the generalization of these results of this study to other populations are site specific; expertise of the team, strict algorithm adherence based on the INOVA SHOCK protocol, and staff commitment to timely team activation. Retrospective clinical outcomes (acute decompensated heart failure cardiogenic shock, acute myocardial infarction cardiogenic shock) demonstrated an increase in current survival rates when compared to pre-Cardiogenic Shock team initiation, rapid team activation and diagnosis and timely utilization of mechanical circulatory support. ClinicalTrials.gov NCT03378739; https://clinicaltrials.gov/ct2/show/NCT03378739 (Archived by WebCite at http://www.webcitation.org/701vstDGd). ©Behnam Tehrani, Alexander Truesdell, Ramesh Singh, Charles Murphy, Patricia Saulino. Originally published in JMIR Research Protocols (http://www.researchprotocols.org), 28.06.2018.

Preliminary vibration, acoustic, and shock design and test criteria for components on the Lightweight External Tank (LWT)

NASA Technical Reports Server (NTRS)

1981-01-01

The Space Shuttle LWT is divided into zones and subzones. Zones are designated primarily to assist in determining the applicable specifications. A subzone (general Specification) is available for use when the location of the component is known but component design and weight are not well defined. When the location, weight, and mounting configuration of the component are known, specifications for appropriate subzone weight ranges are available. Along with the specifications are vibration, acoustic, shock, transportation, handling, and acceptance test requirements and procedures. A method of selecting applicable vibration, acoustic, and shock specifications is presented.

Shell shock, trauma, and the First World War: the making of a diagnosis and its histories.

PubMed

Loughran, Tracey

2012-01-01

During the First World War, thousands of soldiers were treated for "shell shock," a condition which encompassed a range of physical and psychological symptoms. Shell shock has most often been located within a "genealogy of trauma," and identified as an important marker in the gradual recognition of the psychological afflictions caused by combat. In recent years, shell shock has increasingly been viewed as a powerful emblem of the suffering of war. This article, which focuses on Britain, extends scholarly analyses which question characterizations of shell shock as an early form of post-traumatic stress disorder. It also considers some of the methodological problems raised by recasting shell shock as a wartime medical construction rather than an essentially timeless manifestation of trauma. It argues that shell shock must be analyzed as a diagnosis shaped by a specific set of contemporary concerns, knowledges, and practices. Such an analysis challenges accepted understandings of what shell shock "meant" in the First World War, and also offers new perspectives on the role of shell shock in shaping the emergence of psychology and psychiatry in the early part of the twentieth century. The article also considers what relation, if any, might exist between intellectual and other histories, literary approaches, and perceptions of trauma as timeless and unchanging.

Viscous Effects on Blast Wave Flowfields.

DTIC Science & Technology

1984-12-01

18 3-7 Grids used in shock-cylinder interaction calculations ....... ...................... ... 21 3-8 Pressure-time histories ...structure flow ........ .. 32 iv LIST OF ILLUSTRATIONS (concluded) r ~ue Pa e 4-2 Calculated pressure-time histories for shock-field structure...written in dimensionless, conservative-law formll ,r e orf t jas without external forces as follows: : *1 t, ’ yF 1 - v 4 yFv ) (2-1) K r V --, ~ V F F j

Physiology and Endocrinology Symposium: The current status of heat shock in early embryonic survival and reproductive efficiency

USDA-ARS?s Scientific Manuscript database

The Physiology and Endocrinology Symposium entitled “The Current Status of Heat Shock in Early Embryonic Survival and Reproductive Efficiency” was held at the Joint ADSA-CSAS-AMPA-WSAS-ASAS Meeting in Phoenix, Arizona, July 15 to 19, 2012. In recent years, data has accumulated suggesting a role for...

Dislocation structure produced by an ultrashort shock pulse

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

Matsuda, Tomoki, E-mail: t-matsu@mapse.eng.osaka-u.ac.jp; Hirose, Akio; Sano, Tomokazu

We found an ultrashort shock pulse driven by a femtosecond laser pulse on iron generates a different dislocation structure than the shock process which is on the nanosecond timescale. The ultrashort shock pulse produces a highly dense dislocation structure that varies by depth. According to transmission electron microscopy, dislocations away from the surface produce microbands via a network structure similar to a long shock process, but unlike a long shock process dislocations near the surface have limited intersections. Considering the dislocation motion during the shock process, the structure near the surface is attributed to the ultrashort shock duration. This approachmore » using an ultrashort shock pulse will lead to understanding the whole process off shock deformation by clarifying the early stage.« less

Severe hepatic trauma: nonoperative management, definitive repair, or damage control surgery?

PubMed

Leppäniemi, Ari K; Mentula, Panu J; Streng, Mari H; Koivikko, Mika P; Handolin, Lauri E

2011-12-01

Management of severe liver injuries has evolved to include the options for nonoperative management and damage control surgery. The present study analyzes the criteria for choosing between nonoperative management and early surgery, and definitive repair versus damage control strategy during early surgery. In a retrospective analysis of 144 patients with severe (AAST grade III-V) liver injuries (94% blunt trauma), early laparotomy was performed in 50 patients. Initial management was nonoperative in 94 blunt trauma patients with 8 failures. Uni- and multivariate analyses were used to calculate predictor odds ratios (OR) with 95% confidence intervals (CI). Factors associated with early laparotomy in blunt trauma included shock on admission, associated grade IV-V splenic injury, grade IV-V head injury, and grade V liver injury. Only shock was an independent predictor (OR, 26.1; 95% CI, 8.9-77.1; P < 0.001). The presence of a grade IV-V splenic injury predicted damage control strategy (OR infinite; P = 0.021). Failed nonoperative management was associated with grade IV-V splenic injury (OR, 14.00; 95% CI, 1.67-117.55), and shock (OR, 6.82; 95% CI, 1.49-31.29). The hospital mortality rate was 15%; 8 of 21 deaths were liver-related. Shock (OR, 9.3; 95% CI, 2.4-35.8; P = 0.001) and severe head injury (OR, 9.25; 95% CI, 3.0-28.9; P = 0.000) were independent predictors for mortality. In patients with severe liver injury, associated severe splenic injury favors early laparotomy and damage control strategy. Patients who arrive in shock or have an associated severe splenic injury should not be managed nonoperatively. In addition to severe head injury, uncontrollable bleeding from the liver injury is still a major cause of early death.

Transcriptional profiling of the early stages of germination in Candida albicans by real-time RT-PCR.

PubMed

Toyoda, Mika; Cho, Tamaki; Kaminishi, Hidenori; Sudoh, Masayuki; Chibana, Hiroji

2004-12-01

By using real-time RT-PCR, we profiled the expression of CGR1, CaMSI3, EFG1, NRG1, and TUP1 in Candida albicans strains JCM9061 and CAI4 under several conditions, including induction of morphological transition, heat shock, and treatment with calcium inhibitors. Expression of CaMSI3 changed under these growth conditions except during heat shock. CGR1 expression increased during the early stages of hyphal growth in JCM9061, while expression was strain-dependent during heat shock. Both EFG1 and NRG1 were similarly expressed under hypha-inducing conditions and heat shock. Expression of TUP1 was slightly different from the expression of EFG1 or NRG1.

Early reversible acute kidney injury is associated with improved survival in septic shock.

PubMed

Sood, Manish M; Shafer, Leigh Anne; Ho, Julie; Reslerova, Martina; Martinka, Greg; Keenan, Sean; Dial, Sandra; Wood, Gordon; Rigatto, Claudio; Kumar, Anand

2014-10-01

The fact that acute kidney injury (AKI) is associated with worse clinical outcomes forms the basis of most AKI prognostic scoring systems. However, early reversibility of renal dysfunction in acute illness is not considered in such systems. We sought to determine whether early (≤24 hours after shock documentation) reversibility of AKI was independently associated with in-hospital mortality in septic shock. Patient information was derived from an international database of septic shock cases from 28 different institutions in Canada, the United States and Saudi Arabia. Data from a final cohort of 5443 patients admitted with septic shock between Jan 1996 and Dec 2009 was analyzed. The following 4 definitions were used in regards to AKI status: (1) reversible AKI = AKI of any RIFLE severity prevalent at shock diagnosis or incident at 6 hours post-diagnosis that reverses by 24 hours, (2) persistent AKI = AKI prevalent at shock diagnosis and persisting during the entire 24 hours post-shock diagnosis, (3) new AKI = AKI incident between 6 and 24 hours post-shock diagnosis, and (4) improved AKI = AKI prevalent at shock diagnosis or incident at 6 hours post followed by improvement of AKI severity across at least one RIFLE category over the first 24 hours. Cox proportional hazards were used to determine the association between AKI status and in-hospital mortality. During the first 24 hours, reversible AKI occurred in 13.0%, persistent AKI in 54.9%, new AKI in 11.7%, and no AKI in 22.4%. In adjusted analyses, reversible AKI was associated with improved survival (HR, 0.64; 95% CI, 0.53-0.77) compared to no AKI (referent), persistent AKI (HR, 0.99; 95% CI, 0.88-1.11), and new AKI (HR, 1.41; 95% CI, 1.22-1.62). Improved AKI occurred in 19.1% with improvement across any RIFLE category associated with a significant decrease in mortality (HR, 0.53; 95% CI, 0.45-0.63). More rapid antimicrobial administration, lower Acute Physiology and Chronic Health Evaluation II score, lower age, and a smaller number of failed organs (excluding renal) on the day of shock as well as community-acquired infection were independently associated with reversible AKI. In septic shock, reversible AKI within the first 24 hours of admission confers a survival benefit compared to no, new, or persistent AKI. Prognostic AKI classification schemes should consider integration of early AKI reversibility into the scoring system. Copyright © 2014 Elsevier Inc. All rights reserved.

Early-time VLA Observations and Broadband Afterglow Analysis of the Fermi/LAT Detected GRB 130907A

NASA Astrophysics Data System (ADS)

Veres, Péter; Corsi, Alessandra; Frail, Dale A.; Cenko, S. Bradley; Perley, Daniel A.

2015-09-01

We present multi-wavelength observations of the hyper-energetic gamma-ray burst (GRB) 130907A, a Swift-discovered burst with early radio observations starting at ≈4 hr after the γ-ray trigger. GRB 130907A was also detected by the Fermi/LAT instrument and at late times showed a strong spectral evolution in X-rays. We focus on the early-time radio observations, especially at >10 GHz, to attempt to identify reverse shock signatures. While our radio follow-up of GRB 130907A ranks among the earliest observations of a GRB with the Karl G. Jansky Very Large Array, we did not see an unambiguous signature of a reverse shock. While a model with both reverse and forward shock can correctly describe the observations, the data is not constraining enough to decide upon the presence of the reverse-shock component. We model the broadband data using a simple forward-shock synchrotron scenario with a transition from a wind environment to a constant density interstellar medium (ISM) in order to account for the observed features. Within the confines of this model, we also derive the underlying physical parameters of the fireball, which are within typical ranges except for the wind density parameter (A*), which is higher than those for bursts with wind-ISM transition, but typical for the general population of bursts. We note the importance of early-time radio observations of the afterglow (and of well-sampled light curves) for unambiguously identifying the potential contribution of the reverse shock.

Lactate clearance cut off for early mortality prediction in adult sepsis and septic shock patients

NASA Astrophysics Data System (ADS)

Sinto, R.; Widodo, D.; Pohan, H. T.

2018-03-01

Previous lactate clearance cut off for early mortality prediction in sepsis and septic shock patient was determined by consensus from small sample size-study. We investigated the best lactate clearance cut off and its ability to predict early mortality in sepsis and septic shock patients. This cohort study was conducted in Intensive Care Unit of CiptoMangunkusumo Hospital in 2013. Patients’ lactate clearance and eight other resuscitationendpoints were recorded, and theoutcome was observed during the first 120 hours. The clearance cut off was determined using receiver operating characteristic (ROC) analysis, and its ability was investigated with Cox’s proportional hazard regression analysis using other resuscitation endpoints as confounders. Total of 268 subjects was included, of whom 70 (26.11%) subjects died within the first 120 hours. The area under ROC of lactate clearance to predict early mortality was 0.78 (95% % confidence interval [CI] 0.71-0.84) with best cut off was <7.5% (sensitivity and specificity 88.99% and 81.4% respectively). Compared with group achieving lactate clearance target, group not achieving lactate clearance target had to increase early mortality risk (adjusted hazard ratio 13.42; 95%CI 7.19-25.07). In conclusion, the best lactate clearance cut off as anearly mortality predictor in sepsis and septic shock patients is 7.5%.

Adapter for mounting a microphone flush with the external surface of the skin of a pressurized aircraft

NASA Technical Reports Server (NTRS)

Cohn, R. B. (Inventor)

1983-01-01

A mounting device for securing a microphone pick up head flush with respect to the external surfaces of the skin of an aircraft for detecting shock waves passing thereover is described. The mount includes a sleeve mounted internally of the aircraft for capturing and supporting an electronics package having the microphone pick up head attached thereto in a manner such that the head is flush with the external surface of the aircraft skin and a pressure seal is established between the internal and external surfaces of the aircraft skin.

Skill acquisition and retention in automated external defibrillator (AED) use and CPR by lay responders: a prospective study.

PubMed

Woollard, Malcolm; Whitfeild, Richard; Smith, Anna; Colquhoun, Michael; Newcombe, Robert G; Vetteer, Norman; Chamberlain, Douglas

2004-01-01

This prospective study evaluated the acquisition and retention of skills in cardio-pulmonary resuscitation (CPR) and the use of the automated external defibrillator (AED) by lay volunteers involved in the Department of Health, England National Defibrillator Programme. One hundred and twelve trainees were tested immediately before and after and initial 4-h class; 76 were similarly reassessed at refresher training 6 months later. A standardised test scenario that required assessment of the casualty, CPR and the use of on AED was evaluated using recording manikin data and video recordings. Before training only 44% of subjects delivered a shock. Afterwards, all did so and the average delay to first shock was reduced by 57 s. All trainees placed the defibrillator electrodes in an "acceptable" position after training, but very few did so in the recommended "ideal" position. After refresher training 80% of subjects used the correct sequence for CPR and shock delivery, yet a third failed to perform adequate safety checks before all shocks. The trainees self-assessed AED competence score was 86 (scale 0-100) after the initial class and their confidence that they would act in a real emergency was rated at a similar level. Initial training improved performance of all CPR skills, although all except compression rate had deteriorated after 6 months. The proportion of subjects able to correctly perform most CPR skill was higher following refresher training that after the initial class. Although this course was judged to be effective in teaching delivery of counter-shocks, the need was identified for more emphasis on positioning of electrodes, pre-shock safety checks, airway opening, ventilation volume, checking for signs of a circulation, hand positioning, and depth and rate of chest compressions.

Peer rejection in childhood, involvement with antisocial peers in early adolescence, and the development of externalizing behavior problems

PubMed Central

Laird, Robert D.; Jordan, Kristi Y.; Dodge, Kenneth A.; Pettit, Gregory S.; Bates, John E.

2009-01-01

A longitudinal, prospective design was used to examine the roles of peer rejection in middle childhood and antisocial peer involvement in early adolescence in the development of adolescent externalizing behavior problems. Both early starter and late starter pathways were considered. Classroom sociometric interviews from ages 6 through 9 years, adolescent reports of peers' behavior at age 13 years, and parent, teacher, and adolescent self-reports of externalizing behavior problems from age 5 through 14 years were available for 400 adolescents. Results indicate that experiencing peer rejection in elementary school and greater involvement with antisocial peers in early adolescence are correlated but that these peer relationship experiences may represent two different pathways to adolescent externalizing behavior problems. Peer rejection experiences, but not involvement with antisocial peers, predict later externalizing behavior problems when controlling for stability in externalizing behavior. Externalizing problems were most common when rejection was experienced repeatedly. Early externalizing problems did not appear to moderate the relation between peer rejection and later problem behavior. Discussion highlights multiple pathways connecting externalizing behavior problems from early childhood through adolescence with peer relationship experiences in middle childhood and early adolescence. PMID:11393650

An experimental investigation of the impingement of a planar shock wave on an axisymmetric body at Mach 3

NASA Technical Reports Server (NTRS)

Brosh, A.; Kussoy, M. I.

1983-01-01

An experimental study of the flow caused by a planar shock wave impinging obliquely on a cylinder is presented. The complex three dimensional shock wave and boundary layer interaction occurring in practical problems, such as the shock wave impingement from the shuttle nose on an external fuel tank, and store carriage interference on a supersonic tactical aircraft were investigated. A data base for numerical computations of complex flows was also investigated. The experimental techniques included pressure measurements and oil flow patterns on the surface of the cylinder, and shadowgraphs and total and static pressure surveys on the leeward and windward planes of symmetry. The complete data is presented in tabular form. The results reveal a highly complex flow field with two separation zones, regions of high crossflow, and multiple reflected shocks and expansion fans.

Magnetic Diagnostics on the Magnetized Shock Experiment (MSX)

NASA Astrophysics Data System (ADS)

Hutchinson, T. M.; Weber, T. E.; Boguski, J. C.; Intrator, T. P.; Smith, R. J.; Dunn, J. P.

2013-10-01

The Magnetized Shock Experiment (MSX) at Los Alamos National Laboratory was built to investigate the physics of high-Alfvénic, supercritical, magnetized shocks through the acceleration and subsequent stagnation of a Field Reversed Configuration (FRC) plasmoid against a magnetic mirror and/or plasma target. An array of high-bandwidth, multi-axis, robust, internal magnetic probes has been constructed to characterize flux compression ratios, instability formation, and turbulent macro-scale features of the post-shock plasma. The mirror magnet is mounted on a linear translation stage, providing a capability to axially move the shock layer through the probe field of view. An independent, external probe array also provides conventional information on the FRC shape, velocity, and total pressure during the formation and acceleration phases. Probe design, characterization, configuration, and initial results are presented. This work is supported by the DOE OFES and NNSA under LANS contract DE-AC52-06NA25369. LA-UR-13-25189.

THE ANATOMY OF A LONG GAMMA-RAY BURST: A SIMPLE CLASSIFICATION SCHEME FOR THE EMISSION MECHANISM(S)

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

Bégué, D.; Burgess, J. Michael, E-mail: jamesb@kth.se, E-mail: damienb@kth.se

2016-03-20

Ultra-relativistic motion and efficient conversion of kinetic energy to radiation are required by gamma-ray burst (GRB) observations, yet they are difficult to simultaneously achieve. Three leading mechanisms have been proposed to explain the observed emission emanating from GRB outflows: radiation from either relativistic internal or external shocks, or thermal emission from a photosphere. Previous works were dedicated to independently treating these three mechanisms and arguing for a sole, unique origin of the prompt emission of GRBs. In contrast, herein, we first explain why all three models are valid mechanisms and that a contribution from each of them is expected inmore » the prompt phase. Additionally, we show that a single parameter, the dimensionless entropy of the GRB outflow, determines which mechanism contributes the most to the emission. More specifically, internal shocks dominate for low values of the dimensionless entropy, external shocks for intermediate values, and finally, photospheric emission for large values. We present a unified framework for the emission mechanisms of GRBs with easily testable predictions for each process.« less

Computational models for the analysis of three-dimensional internal and exhaust plume flowfields

NASA Technical Reports Server (NTRS)

Dash, S. M.; Delguidice, P. D.

1977-01-01

This paper describes computational procedures developed for the analysis of three-dimensional supersonic ducted flows and multinozzle exhaust plume flowfields. The models/codes embodying these procedures cater to a broad spectrum of geometric situations via the use of multiple reference plane grid networks in several coordinate systems. Shock capturing techniques are employed to trace the propagation and interaction of multiple shock surfaces while the plume interface, separating the exhaust and external flows, and the plume external shock are discretely analyzed. The computational grid within the reference planes follows the trace of streamlines to facilitate the incorporation of finite-rate chemistry and viscous computational capabilities. Exhaust gas properties consist of combustion products in chemical equilibrium. The computational accuracy of the models/codes is assessed via comparisons with exact solutions, results of other codes and experimental data. Results are presented for the flows in two-dimensional convergent and divergent ducts, expansive and compressive corner flows, flow in a rectangular nozzle and the plume flowfields for exhausts issuing out of single and multiple rectangular nozzles.

Gamma-Ray Burst Spectral Indices: Evidence for Deceleration of Synchrotron Shocks

NASA Technical Reports Server (NTRS)

Preece, R. D.; Briggs, M. S.; Giblin, T.; Mallozzi, R. S.; Pendleton, G. N.; Paciesas, W. S.; Band, D. L.

2000-01-01

The current scenario for gamma-ray bursts (GRBs) involves internal shocks for the prompt GRB emission phase and external shocks for the afterglow phase. Assuming synchrotron emission from energetic shocked electrons. GRB spectra observed with a low-energy power-law spectral index greater than -2/3 (for positive photon number indices E(sup alpha) indicate a problem with this model. The remaining spectra can test the synchrotron shock model prediction that the emission from a single distribution of electrons, cooling rapidly, is responsible for both the low-energy and high-energy power-low portions of the spectra. We find that the inferred relationship between the two spectral indices of observed GRB spectra is inconsistent with the constraints from the model, posing another problem for the synchrotron shock emission model. To overcome this problem, we describe a model where the average of -1, rather than the value of -3/2 predicted for cooling electrons. Situations where this might arise have been discussed in other contexts, and involve deceleration of the internal shocks during the GRB phase.

In vivo effect of shock-waves on the healing of fractured bone.

PubMed

Augat, P; Claes, L; Suger, G

1995-10-01

In a controlled animal experiment we attempted to clarify the question of whether there is a stimulating effect of extracorporeal shock-waves on the repair process of fractured long bones. As a fracture model we used an osteotomy in the diaphysis of the ovine tibia and an external fixation device. Shock-wave treatment at two levels of intensity and with four different numbers of applied shocks was performed with an electromagnetic acoustic source. Healing of the osteotomized bone was evaluated by biomechanical and radiological investigations on the whole bone as well as on bone sections from areas of the fracture gap and the periosteal fracture callus. We found a non-significant tendency to deterioration of the fracture healing with increasing shock-wave intensities. The study of treatment parameters led neither to significantly different biomechanical outcomes nor to altered radiological results in comparison to the untreated control group. RELEVANCE:--While we cannot comment upon the effectiveness of extracorporeal shock-waves in the delayed treatment of fractures or pseudarthrosis, our results suggest that shock-waves have no beneficial effect in acute fracture repair.

From Parent to Child to Parent…: Paths In and Out of Problem Behavior

PubMed Central

Bradley, Robert H.; Corwyn, Robert

2014-01-01

This study used data from the NICHD Study of Early Child Care and Youth Development to examine relations between parenting, self-control and externalizing behavior from early childhood to mid-adolescence (N=956; 49.9% male). Results indicated that maternal sensitivity, parental harshness and productive activity are related to externalizing problems but that patterns of relations change from early childhood to middle childhood to adolescence, with evidence suggesting that externalizing behavior influences parenting more than the reverse from middle childhood onward. Self-control measured during early adolescence partially mediated relations between maternal sensitivity and adolescent-reported externalizing behavior. Parental monitoring during adolescence was also related to externalizing behavior at age 15. Monitoring partially mediated the relation between externalizing behavior in early adolescence and externalizing at age 15. PMID:23135289

Timing and causes of death in septic shock.

PubMed

Daviaud, Fabrice; Grimaldi, David; Dechartres, Agnès; Charpentier, Julien; Geri, Guillaume; Marin, Nathalie; Chiche, Jean-Daniel; Cariou, Alain; Mira, Jean-Paul; Pène, Frédéric

2015-12-01

Most studies about septic shock report a crude mortality rate that neither distinguishes between early and late deaths nor addresses the direct causes of death. We herein aimed to determine the modalities of death in septic shock. This was a 6-year (2008-2013) monocenter retrospective study. All consecutive patients diagnosed for septic shock within the first 48 h of intensive care unit (ICU) admission were included. Early and late deaths were defined as occurring within or after 3 days following ICU admission, respectively. The main cause of death in the ICU was determined from medical files. A multinomial logistic regression analysis using the status alive as the reference category was performed to identify the prognostic factors associated with early and late deaths. Five hundred forty-three patients were included, with a mean age of 66 ± 15 years and a high proportion (67 %) of comorbidities. The in-ICU and in-hospital mortality rates were 37.2 and 45 %, respectively. Deaths occurred early for 78 (32 %) and later on for 166 (68 %) patients in the ICU (n = 124) or in the hospital (n = 42). Early deaths were mainly attributable to intractable multiple organ failure related to the primary infection (82 %) and to mesenteric ischemia (6.4 %). In-ICU late deaths were directly related to end-of-life decisions in 29 % of patients and otherwise mostly related to ICU-acquired complications, including nosocomial infections (20.4 %) and mesenteric ischemia (16.6 %). Independent determinants of early death were age, malignancy, diabetes mellitus, no pathogen identification, and initial severity. Among 3-day survivors, independent risk factors for late death were age, cirrhosis, no pathogen identification, and previous corticosteroid treatment. Our study provides a comprehensive assessment of septic shock-related deaths. Identification of risk factors of early and late deaths may determine differential prognostic patterns.

The dynamics analysis of a ferrofluid shock absorber

NASA Astrophysics Data System (ADS)

Yao, Jie; Chang, Jianjun; Li, Decai; Yang, Xiaolong

2016-03-01

The paper presents a shock absorber using three magnets as the inertial mass. Movement of the inertial mass inside a cylindrical body filled with ferrofluid will lead to a viscous dissipation of the oscillating system energy. The influence of a dumbbell-like ferrofluid structure on the energy dissipation is considered and the magnetic restoring force is investigated by experiment and theoretical calculation. A theoretical model of the hydrodynamics and energy dissipation processes is developed, which includes the geometrical characteristics of the body, the fluid viscosity, and the external magnetic field. The theory predicts the experimental results well under some condition. The shock absorber can be used in spacecraft technology.

Numerical Simulation Of Shock Response To Wall Changes In High Speed Intakes

NASA Astrophysics Data System (ADS)

Fincham, J.; Taylor, N. V.

2011-05-01

Hypersonic flight presents a number of challenges to the designer, one of which is the intake behaviour. Minimising drag requires careful positioning of the intake shock structure, while accurate understanding of the dynamic behaviour is required to allow minimisation of margins. In this paper, a two shock external compression intake derived from the Reaction Engines Limited SABRE engine is examined using inviscid axisymmetric CFD analysis to determine the response of the normal shockwave to axial motion of the intake centrebody. An approximately linear relationship between centrebody position and both the normal shock position and additive drag in steady flow is demonstrated. Initial results from an unsteady analysis are also given, which show complex behaviours may be triggered by rapid motion of the centrebody in response to control input.

Experimental Study of Shock Wave Interference Heating on a Cylindrical Leading Edge. Ph.D. Thesis

NASA Technical Reports Server (NTRS)

Wieting, Allan R.

1987-01-01

An experimental study of shock wave interference heating on a cylindrical leading edge representative of the cowl of a rectangular hypersonic engine inlet at Mach numbers of 6.3, 6.5, and 8.0 is presented. Stream Reynolds numbers ranged from 0.5 x 106 to 4.9 x 106 per ft. and stream total temperature ranged from 2100 to 3400 R. The model consisted of a 3" dia. cylinder and a shock generation wedge articulated to angles of 10, 12.5, and 15 deg. A fundamental understanding was obtained of the fluid mechanics of shock wave interference induced flow impingement on a cylindrical leading edge and the attendant surface pressure and heat flux distributions. The first detailed heat transfer rate and pressure distributions for two dimensional shock wave interference on a cylinder was provided along with insight into the effects of specific heat variation with temperature on the phenomena. Results show that the flow around a body in hypersonic flow is altered significantly by the shock wave interference pattern that is created by an oblique shock wave from an external source intersecting the bow shock wave produced in front of the body.

Characteristics of energy exchange between inter- and intramolecular degrees of freedom in crystalline 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) with implications for coarse-grained simulations of shock waves in polyatomic molecular crystals

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

Kroonblawd, Matthew P.; Sewell, Thomas D., E-mail: sewellt@missouri.edu; Maillet, Jean-Bernard, E-mail: jean-bernard.maillet@cea.fr

2016-02-14

In this report, we characterize the kinetics and dynamics of energy exchange between intramolecular and intermolecular degrees of freedom (DoF) in crystalline 1,3,5-triamino-2,4,6-trinitrobenzene (TATB). All-atom molecular dynamics (MD) simulations are used to obtain predictions for relaxation from certain limiting initial distributions of energy between the intra- and intermolecular DoF. The results are used to parameterize a coarse-grained Dissipative Particle Dynamics at constant Energy (DPDE) model for TATB. Each TATB molecule in the DPDE model is represented as an all-atom, rigid-molecule mesoparticle, with explicit external (molecular translational and rotational) DoF and coarse-grained implicit internal (vibrational) DoF. In addition to conserving linearmore » and angular momentum, the DPDE equations of motion conserve the total system energy provided that particles can exchange energy between their external and internal DoF. The internal temperature of a TATB molecule is calculated using an internal equation of state, which we develop here, and the temperatures of the external and internal DoF are coupled using a fluctuation-dissipation relation. The DPDE force expression requires specification of the input parameter σ that determines the rate at which energy is exchanged between external and internal DoF. We adjusted σ based on the predictions for relaxation processes obtained from MD simulations. The parameterized DPDE model was employed in large-scale simulations of shock compression of TATB. We show that the rate of energy exchange governed by σ can significantly influence the transient behavior of the system behind the shock.« less

On the stability of bow shocks generated by red supergiants: the case of IRC -10414

NASA Astrophysics Data System (ADS)

Meyer, D. M.-A.; Gvaramadze, V. V.; Langer, N.; Mackey, J.; Boumis, P.; Mohamed, S.

2014-03-01

In this Letter, we explore the hypothesis that the smooth appearance of bow shocks around some red supergiants (RSGs) might be caused by the ionization of their winds by external sources of radiation. Our numerical simulations of the bow shock generated by IRC -10414 (the first-ever RSG with an optically detected bow shock) show that the ionization of the wind results in its acceleration by a factor of 2, which reduces the difference between the wind and space velocities of the star and makes the contact discontinuity of the bow shock stable for a range of stellar space velocities and mass-loss rates. Our best-fitting model reproduces the overall shape and surface brightness of the observed bow shock and suggests that the space velocity and mass-loss rate of IRC -10414 are ≈50 km s-1 and ≈10-6 M⊙ yr-1, respectively, and that the number density of the local interstellar medium is ≈3 cm-3. It also shows that the bow shock emission comes mainly from the shocked stellar wind. This naturally explains the enhanced nitrogen abundance in the line-emitting material, derived from the spectroscopy of the bow shock. We found that photoionized bow shocks are ≈15-50 times brighter in optical line emission than their neutral counterparts, from which we conclude that the bow shock of IRC -10414 must be photoionized.

Central venous pressure and shock index predict lack of hemodynamic response to volume expansion in septic shock: a prospective, observational study.

PubMed

Lanspa, Michael J; Brown, Samuel M; Hirshberg, Eliotte L; Jones, Jason P; Grissom, Colin K

2012-12-01

Volume expansion is a common therapeutic intervention in septic shock, although patient response to the intervention is difficult to predict. Central venous pressure (CVP) and shock index have been used independently to guide volume expansion, although their use is questionable. We hypothesize that a combination of these measurements will be useful. In a prospective, observational study, patients with early septic shock received 10-mL/kg volume expansion at their treating physician's discretion after brief initial resuscitation in the emergency department. Central venous pressure and shock index were measured before volume expansion interventions. Cardiac index was measured immediately before and after the volume expansion using transthoracic echocardiography. Hemodynamic response was defined as an increase in a cardiac index of 15% or greater. Thirty-four volume expansions were observed in 25 patients. A CVP of 8 mm Hg or greater and a shock index of 1 beat min(-1) mm Hg(-1) or less individually had a good negative predictive value (83% and 88%, respectively). Of 34 volume expansions, the combination of both a high CVP and a low shock index was extremely unlikely to elicit hemodynamic response (negative predictive value, 93%; P = .02). Volume expansion in patients with early septic shock with a CVP of 8 mm Hg or greater and a shock index of 1 beat min(-1) mm Hg(-1) or less is unlikely to lead to an increase in cardiac index. Copyright © 2012 Elsevier Inc. All rights reserved.

Virtual water trade and country vulnerability: A network perspective

NASA Astrophysics Data System (ADS)

Sartori, Martina; Schiavo, Stefano

2015-04-01

This work investigates the relationship between countries' participation in virtual water trade and their vulnerability to external shocks from a network perspective. In particular, we investigate whether (i) possible sources of local national crises may interact with the system, propagating through the network and affecting the other countries involved; (ii) the topological characteristics of the international agricultural trade network, translated into virtual water-equivalent flows, may favor countries' vulnerability to external crises. Our work contributes to the debate on the potential merits and risks associated with openness to trade in agricultural and food products. On the one hand, trade helps to ensure that even countries with limited water (and other relevant) resources have access to sufficient food and contribute to the global saving of water. On the other hand, there are fears that openness may increase the vulnerability to external shocks and thus make countries worse off. Here we abstract from political considerations about food sovereignty and independence from imports and focus instead on investigating whether the increased participation in global trade that the world has witnessed in the last 30 years has made the system more susceptible to large shocks. Our analysis reveals that: (i) the probability of larger supply shocks has not increased over time; (ii) the topological characteristics of the VW network are not such as to favor the systemic risk associated with shock propagation; and (iii) higher-order interconnections may reveal further important information about the structure of a network. Regarding the first result, fluctuations in output volumes, among the sources of shock analyzed here, are more likely to generate some instability. The first implication is that, on one side, past national or regional economic crises were not necessarily brought about or strengthened by global trade. The second, more remarkable, implication is that, on the other side, supporting a national policy of self-sufficiency in food production while progressively reducing the participation in international agricultural trade does not necessarily protect a country from economic instability. Moreover, it is well established in the literature that, over time, international food trade has favored more efficient use of water resources, at the global level. This fact, together with our conclusions, highlights the important role of international trade in driving the efficient allocation of water resources. To sum up, our evidence reveals that the increased globalization witnessed in the last 30 years is not associated with an increased frequency of adverse shocks (in either precipitation or food production). Furthermore, building on recent advances in network analysis that connect the stability of a complex system to the interaction between the distribution of shocks and the network topology, we find that the world is more interconnected, but not necessarily less stable.

21 CFR 870.5310 - Automated external defibrillator.

Code of Federal Regulations, 2010 CFR

2010-04-01

... shock of a maximum of 360 joules of energy used for defibrillating (restoring normal heart rhythm) the atria or ventricles of the heart. An AED analyzes the patient's electrocardiogram, interprets the...

21 CFR 870.5310 - Automated external defibrillator.

Code of Federal Regulations, 2014 CFR

2014-04-01

... shock of a maximum of 360 joules of energy used for defibrillating (restoring normal heart rhythm) the atria or ventricles of the heart. An AED analyzes the patient's electrocardiogram, interprets the...

21 CFR 870.5310 - Automated external defibrillator.

Code of Federal Regulations, 2012 CFR

2012-04-01

... shock of a maximum of 360 joules of energy used for defibrillating (restoring normal heart rhythm) the atria or ventricles of the heart. An AED analyzes the patient's electrocardiogram, interprets the...

21 CFR 870.5310 - Automated external defibrillator.

Code of Federal Regulations, 2011 CFR

2011-04-01

... shock of a maximum of 360 joules of energy used for defibrillating (restoring normal heart rhythm) the atria or ventricles of the heart. An AED analyzes the patient's electrocardiogram, interprets the...

21 CFR 870.5310 - Automated external defibrillator.

Code of Federal Regulations, 2013 CFR

2013-04-01

... shock of a maximum of 360 joules of energy used for defibrillating (restoring normal heart rhythm) the atria or ventricles of the heart. An AED analyzes the patient's electrocardiogram, interprets the...

[Monitoring early toxicity of heavy metals including Hg using a HSE-SEAP reporter gene].

PubMed

Yu, Zhan-Jiang; Yang, Qin; Yang, Xiao-Da; Wang, Kui

2006-08-01

To develop a cellular assay based on heat shock signal pathway and secreted alkaline phosphatase (SEAP) reporter gene for investigating/predicting the early toxicity of heavy metals on HeLa cells in Chinese traditional medicine (TCM). The pHSE-SEAP plasmid was transfected into HeLa cells to build a HSE-SEAP-HeLa cell model. For validation of the model, the transfected cells were treated by either heating at 42 degrees C for 1 h or incubated with 5 mol x L(-1) CdCl2 for 4 h. Then the cells were covered in complete DMEM culture medium for 48 h and the activity of SEAP (reflecting the cellular level of heat shock protein) in cultural supernatants was measured; meanwhile, cell viability was determined by MTT assays. In addition, the cells were treated by four mercury compounds, HgCl2, merthilate sodium, HgS and cinnabar at the sub-lethal concentrations (determined by MTT assays). Then the heat shock response was detected likewise. Significant level of secreted alkaline phosphatase (SEAP) was found in pHSE-SEAP transfected HeLa cells treated either by heating (42 degrees C) or incubating with CdCl2. The heat shock protein was induced by CdCl2 before decrease of cell viability was observed. All four mercury compounds induced heat shock response in both time and concentration-dependant manner. However, there were big differences among the mercury compounds, suggesting potential differences for early-stage toxicity in vivo. The pHSE-SEAP transfected HeLa cells respond effectively to heat shock and metal stresses, and therefore provide a practical and repeatable assay for investigating/predicting the early toxicity of heavy metals and mineral-containing drugs in TCM.

Properties of large scale plasma flow during the early stage of the plasmaspheric refilling

NASA Technical Reports Server (NTRS)

Singh, Nagendra; Craven, P.; Torr, D. G.; Richards, P. G.

1990-01-01

The objective is to better characterize the macroscopic properties of the interhemisphere plasma flow by solving a more complete set of hydrodynamic equations than that solved previously. Specifically, the ion continuity, momentum and energy equations were solved for the plasma flow along the closed magnetic field lines. During the initial stage of the supersonic outflow in the equatorial region, the ions cool substantially. Using the hydrodynamic model for the large-scale plasma flow, the dynamics of shocks was examined which form in the geomagnetic flux tubes during the early stages of refilling. These shocks are more like those forming in neutral gases than the electrostatic shocks driven by microinstabilities involving ion-ion interaction. Therefore, the shocks seen in the hydrodynamic model are termed as hydrodynamic shocks. Such shocks are generally unsteady and therefore the usual shock jump conditions given by Rankine-Hugoniot relations are not strictly applicable to them. The density, flow velocity and temperature structures associated with the shocks are examined for both asymmetrical and symmetrical flows. In the asymmetrical flow the outflow from one of two conjugate ionospheres is dominant. On the other hand, in the symmetrical case outflows from the two ionospheric sources are identical. Both cases are treated by a two-stream model. In the late type of flow, the early-time refilling shows a relaxation type of oscillation, which is driven by the large-scale interactions between the two identical streams. After this early stage, the resulting temperature structure shows some interesting features. In the equatorial region the streams are isothermal, but in the off-equatorial regions the streams have quite different temperatures, and also densities and flow velocities. The dense and slow stream is found to be warmer than the low-density fast stream. In the late stage of refilling, the temperature is found to steadily increase from the conjugate ionospheres towards the equator; the equatorial temperature is found to be as high as about 8000 K compared to the ionospheric temperature of 3600 K.

Heat transfer tests on a 0.01-scale Rockwell configuration 3 space shuttle orbiter and tank (37-OT) in the Calspan 48-inch hypersonic shock tunnel (OH12/IH21), volume 1

NASA Technical Reports Server (NTRS)

Kotch, M.

1975-01-01

Model information and data are presented from wind tunnel tests conducted on 0.01-scale models of the space shuttle orbiter and external tank. These tests were conducted in a hypersonic shock tunnel to determine heating rates on ascent and reentry configurations at various Reynolds numbers, Mach numbers, and angles of attack.

Renal Blood Flow, Glomerular Filtration Rate, and Renal Oxygenation in Early Clinical Septic Shock.

PubMed

Skytte Larsson, Jenny; Krumbholz, Vitus; Enskog, Anders; Bragadottir, Gudrun; Redfors, Bengt; Ricksten, Sven-Erik

2018-06-01

Data on renal hemodynamics, function, and oxygenation in early clinical septic shock are lacking. We therefore measured renal blood flow, glomerular filtration rate, renal oxygen consumption, and oxygenation in patients with early septic shock. Prospective comparative study. General and cardiothoracic ICUs. Patients with norepinephrine-dependent early septic shock (n = 8) were studied within 24 hours after arrival in the ICU and compared with postcardiac surgery patients without acute kidney injury (comparator group, n = 58). None. Data on systemic hemodynamics and renal variables were obtained during two 30-minute periods. Renal blood flow was measured by the infusion clearance of para-aminohippuric acid, corrected for renal extraction of para-aminohippuric acid. Renal filtration fraction was measured by renal extraction of chromium-51 labeled EDTA. Renal oxygenation was estimated from renal oxygen extraction. Renal oxygen delivery (-24%; p = 0.037) and the renal blood flow-to-cardiac index ratio (-21%; p = 0.018) were lower, renal vascular resistance was higher (26%; p = 0.027), whereas renal blood flow tended to be lower (-19%; p = 0.068) in the septic group. Glomerular filtration rate (-32%; p = 0.006) and renal sodium reabsorption (-29%; p = 0.014) were both lower in the septic group. Neither renal filtration fraction nor renal oxygen consumption differed significantly between groups. Renal oxygen extraction was significantly higher in the septic group (28%; p = 0.022). In the septic group, markers of tubular injury were elevated. In early clinical septic shock, renal function was lower, which was accompanied by renal vasoconstriction, a lower renal oxygen delivery, impaired renal oxygenation, and tubular sodium reabsorption at a high oxygen cost compared with controls.

On the interplay between cosmological shock waves and their environment

NASA Astrophysics Data System (ADS)

Martin-Alvarez, Sergio; Planelles, Susana; Quilis, Vicent

2017-05-01

Cosmological shock waves are tracers of the thermal history of the structures in the Universe. They play a crucial role in redistributing the energy within the cosmic structures and are also amongst the main ingredients of galaxy and galaxy cluster formation. Understanding this important function requires a proper description of the interplay between shocks and the different environments where they can be found. In this paper, an Adaptive Mesh Refinement (AMR) Eulerian cosmological simulation is analysed by means of a shock-finding algorithm that allows to generate shock wave maps. Based on the population of dark matter halos and on the distribution of density contrast in the simulation, we classify the shocks in five different environments. These range from galaxy clusters to voids. The shock distribution function and the shocks power spectrum are studied for these environments dynamics. We find that shock waves on different environments undergo different formation and evolution processes, showing as well different characteristics. We identify three different phases of formation, evolution and dissipation of these shock waves, and an intricate migration between distinct environments and scales. Shock waves initially form at external, low density regions and are merged and amplified through the collapse of structures. Shock waves and cosmic structures follow a parallel evolution. Later on, shocks start to detach from them and dissipate. We also find that most of the power that shock waves dissipate is found at scales of k ˜0.5 Mpc^{-1}, with a secondary peak at k ˜8 Mpc^{-1}. The evolution of the shocks power spectrum confirms that shock waves evolution is coupled and conditioned by their environment.

Laser-shocked energetic materials with metal additives: evaluation of chemistry and detonation performance.

PubMed

Gottfried, Jennifer L; Bukowski, Eric J

2017-01-20

A focused, nanosecond-pulsed laser has been used to ablate, atomize, ionize, and excite milligram quantities of metal-doped energetic materials that undergo exothermic reactions in the laser-induced plasma. The subsequent shock wave expansion in the air above the sample has been monitored using high-speed schlieren imaging in a recently developed technique, laser-induced air shock from energetic materials (LASEM). The method enables the estimation of detonation velocities based on the measured laser-induced air-shock velocities and has previously been demonstrated for organic military explosives. Here, the LASEM technique has been extended to explosive formulations with metal additives. A comparison of the measured laser-induced air-shock velocities for TNT, RDX, DNTF, and LLM-172 doped with Al or B to the detonation velocities predicted by the thermochemical code CHEETAH for inert or active metal participation demonstrates that LASEM has potential for predicting the early time (<10  μs) participation of metal additives in detonation events. The LASEM results show that while Al is mostly inert at early times in the detonation event (confirmed from large-scale detonation testing), B is active-and reducing the amount of hydrogen present during the early chemical reactions increases the resulting estimated detonation velocities.

Vulnerability to shocks in the global seafood trade network

NASA Astrophysics Data System (ADS)

Gephart, Jessica A.; Rovenskaya, Elena; Dieckmann, Ulf; Pace, Michael L.; Brännström, Åke

2016-03-01

Trade can allow countries to overcome local or regional losses (shocks) to their food supply, but reliance on international food trade also exposes countries to risks from external perturbations. Countries that are nutritionally or economically dependent on international trade of a commodity may be adversely affected by such shocks. While exposure to shocks has been studied in financial markets, communication networks, and some infrastructure systems, it has received less attention in food-trade networks. Here, we develop a forward shock-propagation model to quantify how trade flows are redistributed under a range of shock scenarios and assess the food-security outcomes by comparing changes in national fish supplies to indices of each country’s nutritional fish dependency. Shock propagation and distribution among regions are modeled on a network of historical bilateral seafood trade data from UN Comtrade using 205 reporting territories grouped into 18 regions. In our model exposure to shocks increases with total imports and the number of import partners. We find that Central and West Africa are the most vulnerable to shocks, with their vulnerability increasing when a willingness-to-pay proxy is included. These findings suggest that countries can reduce their overall vulnerability to shocks by reducing reliance on imports and diversifying food sources. As international seafood trade grows, identifying these types of potential risks and vulnerabilities is important to build a more resilient food system.

Cold-shock based method to induce the discharge of extrusomes in ciliated protists and its efficiency.

PubMed

Buonanno, Federico; Ortenzi, Claudio

2016-05-01

Extrusomes are ejectable organelles in protists, which are able to discharge their contents to the outside of the cell in response to external stimuli. It is known that a large number of extrusomes functions as organelles for offense or defense in predator-prey interactions among protists and/or microinvertebrates. To date, the main approach to study these interactions was to compare artificially-induced extrusome-deficient cells with normal cells as prey for predators. Commonly applied methods to obtain extrusome-deficient cells use external chemicals, which could alter the viability of cells and/or interfere with the subsequent analysis of the substances (secondary metabolites) contained in the extrusomes. The cold-shock based method here presented has proven to be effective to remove different kinds of extrusomes from several protist species without harming the treated cells and without adding external reagents. This method could be also useful to simplify the related analysis of the chemical nature of the secreted secondary metabolites. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Effective date of requirement for premarket approval for automated external defibrillator systems. Final rule.

PubMed

2015-01-29

The Food and Drug Administration (FDA or the Agency) is issuing a final order to require the filing of premarket approval applications (PMA) for automated external defibrillator (AED) systems, which consist of an AED and those AED accessories necessary for the AED to detect and interpret an electrocardiogram and deliver an electrical shock (e.g., pad electrodes, batteries, adapters, and hardware keys for pediatric use).

Shock Transmission and Fatigue in Human Running.

PubMed

Verbitsky, Oleg; Mizrahi, Joseph; Voloshin, Arkady; Treiger, July; Isakov, Eli

1998-08-01

The goal of this research was to analyze the effects of fatigue on the shock waves generated by foot strike. Twenty-two subjects were instrumented with an externally attached, lightweight accelerometer placed over the tibial tuberosity. The subjects ran on a treadmill for 30 min at a speed near their anaerobic threshold. Fatigue was established when the end-tidal CO 2 pressure decreased. The results indicated that approximately half of the subjects reached the fatigue state toward the end of the test. Whenever fatigue occurred, the peak acceleration was found to increase. It was thus concluded that there is a clear association between fatigue and increased heel strike-induced shock waves. These results have a significant implication for the etiology of running injuries, since shock wave attenuation has been previously reported to play an important role in preventing such injuries.

Heat shock protein-containing exosomes in mid-trimester amniotic fluids.

PubMed

Asea, Alexzander; Jean-Pierre, Claudel; Kaur, Punit; Rao, Preethi; Linhares, Iara M; Skupski, Daniel; Witkin, Steven S

2008-10-01

Exosomes are multivesicular bodies formed by inverse membrane budding into the lumen of an endocytic compartment. Fusion with the plasma membrane leads to their release into the external milieu. The incorporation of heat shock proteins into exosomes has been associated with immune regulatory activity. We have examined whether heat shock protein-containing exosomes are present in mid-trimester amniotic fluid. Exosomes were isolated from mid-trimester amniotic fluids by sequential low-speed and high-speed centrifugation followed by sucrose density gradient centrifugation. Biochemical characterization included floatation pattern in sucrose gradients, acetylcholinesterase (AChE) activity and Western blot analysis for exosome-containing proteins. Exosomes were present in each of 23 amniotic fluids tested. They banded at a density of 1.17g/ml in sucrose gradients, were positive for AChE activity and contained tubulin, the inducible 72kDa heat shock protein, Hsp72 and the constitutively expressed heat shock protein, Hsc73; they were negative for calnexin. Exosome concentrations correlated positively with the number of pregnancies. Heat shock protein-containing exosomes are constituents of mid-trimester amniotic fluids and may contribute to immune regulation within the amniotic cavity.

Shock-induced CO2 loss from CaCO3: Implications for early planetary atmospheres

NASA Technical Reports Server (NTRS)

Lange, M. A.; Ahrens, T. J.

1984-01-01

Recovered samples from shock recovery experiments on single crystal calcite were subjected to thermogravimetric analysis to determine the amount of post-shock CO2, the decarbonization interval and the activation energy, for the removal of remaining CO2 in shock-loaded calcite. Comparison of post-shock CO2 with that initially present determines shock-induced CO2 loss as a function of shock pressure. Incipient to complete CO2 loss occurs over a pressure range of approximately 10 to approximately 70 GPa. Optical and scanning electron microscopy reveal structural changes, which are related to the shock-loading. The occurrence of dark, diffuse areas, which can be resolved as highly vesicular areas as observed with a scanning electron microscope are interpreted as representing quenched partial melts, into which shock-released CO2 was injected. The experimental results are used to constrain models of shock-produced, primary CO2 atmospheres on the accreting terrestrial planets.

[Damage control resuscitation of severe multiple trauma in the pelvic fractures].

PubMed

Fu, Chang-guo

2015-05-01

To discuss the clinical effects of damage control resuscitation (DCR) in treating severe multiple trauma in the pelvic fractures. From March 2009 to September 2013, a restrospective analysis was conducted on the clinical data of 28 patients with multiple trauma in the pelvic fractures, including 19 males and 9 females, ranging in age from 21 to 51 years old with an average of 32.5 years old. According to Tile classification of pelvic fractures, 16 cases were type B and 12 cases were type C. Injury severity score (ISS) averaged 32.0±3.4. All cases were treated with damage contral orthopaedics and DCR strategy, namely that used immediately with small capacity of balanced salt solution on admission so as to maintain the blood pressure between 80 to 90 mmHg. At the same time, emergency phase I simple debridement plus external fixator or bundled with fixed pelvic was done, and the chest or abdomen combined injury was treated at first. And limbs fracture was temporary dealing with bone traction or plaster external fixation, etc. After bleeding was controlled by operation, fluid resuscitation was done as fast as possible and the plasma was transfused early according to the proportion of plasma and red cell suspension (2 U:1 U-3 U:2 U). Dosage of balanced salt solution and blood before remedy shock was recorded, and the removal of time of lactic acid and coagulation were observed. Five cases were died after 4 to 15 hours into hospital (3 cases died for severe trauma-hemorrhagic shock and 2 cases for acute respiratory distress syndrome). Twenty-three cases were remedy shock at 1.6 to 4.3 hours after injury with an average of 2.4 hours. Period I operation duration was (78.2±10.3) minutes. Dosage of balanced salt solution was (3,798±340) ml and red cell suspension was 14 to 18 U, fresh frozen plasma (FFP) was (1,267±58) ml (1U FFP=100 ml), blood platelet was 8 to 12 U for 9 patients. The removal time of lactic acid and PT-APTT was (11.4±2.1) hours and (4.3±0.8) hours. Measures were taken to correct electrolyte and acid-base imbalance was normal. The success rat of recovery was 82.2% (23/28). Damage control resuscitation (DCR) integrates the main links such as damage control operation and allowable low blood pressure (or limited liquid resuscitation) and hemostatic control resuscitation, was early effective treatment measures for the patients with severe multiple trauma in the pelvic fractures.

Vasopressin compared with norepinephrine augments the decline of plasma cytokine levels in septic shock.

PubMed

Russell, James A; Fjell, Chris; Hsu, Joseph L; Lee, Terry; Boyd, John; Thair, Simone; Singer, Joel; Patterson, Andrew J; Walley, Keith R

2013-08-01

Changes in plasma cytokine levels may predict mortality, and therapies (vasopressin versus norepinephrine) could change plasma cytokine levels in early septic shock. Our hypotheses were that changes in plasma cytokine levels over 24 hours differ between survivors and nonsurvivors, and that there are different effects of vasopressin and norepinephrine on plasma cytokine levels in septic shock. We studied 394 patients in a randomized, controlled trial of vasopressin versus norepinephrine in septic shock. We used hierarchical clustering and principal components analysis of the baseline cytokine concentrations to subgroup cytokines; we then compared survivors to nonsurvivors (28 d) and compared vasopressin- versus norepinephrine-induced changes in cytokine levels over 24 hours. A total of 39 plasma cytokines were measured at baseline and at 24 hours. Hierarchical clustering and principal components analysis grouped cytokines similarly. Survivors (versus nonsurvivors) had greater decreases of overall cytokine levels (P < 0.001). Vasopressin decreased overall 24-hour cytokine concentration compared with norepinephrine (P = 0.037). In less severe septic shock, the difference in plasma cytokine reduction over 24 hours between survivors and nonsurvivors was less pronounced than that seen in more severe septic shock. Furthermore, vasopressin decreased interferon-inducible protein 10 and granulocyte colony-stimulating factor more than did norepinephrine in less severe septic shock, whereas vasopressin decreased granulocyte-macrophage colony-stimulating factor in patients who had more severe shock. Survivors of septic shock had greater decreases of cytokines, chemokines and growth factors in early septic shock. Vasopressin decreased 24-hour plasma cytokine levels more than did norepinephrine. The vasopressin-associated decrease of cytokines differed according to severity of shock. Clinical trial registered with www.controlled-trials.com (ISRCTN94845869).

Revisiting the “Golden Hour”: An Evaluation of Out-of-Hospital Time in Shock and Traumatic Brain Injury

PubMed Central

Newgard, Craig D.; Meier, Eric N.; Bulger, Eileen M.; Buick, Jason; Sheehan, Kellie; Lin, Steve; Minei, Joseph P.; Barnes-Mackey, Roxy A.; Brasel, Karen

2015-01-01

Study Objective We evaluated shock and traumatic brain injury (TBI) patients previously enrolled in an out-of-hospital clinical trial to test the association between out-of-hospital time and outcome. Methods This was a secondary analysis of shock and TBI patients ≥ 15 years enrolled in a Resuscitation Outcomes Consortium out-of-hospital clinical trial by 81 EMS agencies transporting to 46 Level I and II trauma centers in 11 sites (May 2006 through May 2009). Inclusion criteria were: SBP ≤ 70 mmHg or SBP 71 - 90 mmHg with heart rate ≥ 108 beats per minute (shock cohort) and Glasgow Coma Scale score ≤ 8 (TBI cohort); patients meeting both criteria were placed in the shock cohort. Primary outcomes were 28-day mortality (shock cohort) and 6-month Glasgow Outcome Scale - Extended (GOSE) ≤ 4 (TBI cohort). Results There were 778 patients in the shock cohort (26% 28-day mortality) and 1,239 patients in the TBI cohort (53% 6-month GOSE ≤ 4). Out-of-hospital time > 60 minutes was not associated with worse outcomes after accounting for important confounders in the shock cohort (adjusted odds ratio [aOR] 1.42, 95% CI 0.77-2.62) or TBI cohort (aOR 0.80, 95% CI 0.52-1.21). However, shock patients requiring early critical hospital resources and arriving > 60 minutes had higher 28-day mortality (aOR 2.37, 95% CI 1.05-5.37); this finding was not observed among a similar TBI subgroup. Conclusions Among out-of-hospital trauma patients meeting physiologic criteria for shock and TBI, there was no association between time and outcome. However, the subgroup of shock patients requiring early critical resources arriving after 60 minutes had higher mortality. PMID:25596960

A first city-wide early defibrillation project in a German city: 5-year results of the Bochum against sudden cardiac arrest study

PubMed Central

2010-01-01

Background Immediate defibrillation is the decisive determinant of prognosis in patients suffering from cardiac/circulatory arrest caused by ventricular fibrillation (VF). Therefore, various national and international associations recommend that first responders use defibrillators as soon as possible and also recommend public access to early defibrillation programmes. Here we report the results of the first city-wide early defibrillation project in a large German urban area. Methods There were 155 automated external defibrillators (AEDs) put into operation in the Bochum municipal area, and 6,294 people took part in cardiopulmonary resuscitation (CPR) and AED training. Free, accessible AEDs were installed in places with large volumes of people. Additionally, emergency forces were progressively equipped with AEDs. Results Twelve AED administrations prior to the arrival of an emergency physician were recorded and analysed over a period of 5 years (08/2004-08/2009). Rhythm analysis via AED demonstrated VF in seven cases, non-malignant dysrhythmias in four cases and asystole in one case. Two of the seven patients with VF were successfully defibrillated and survived cardiac/circulatory arrest without any neurological sequelae. Eight of the 12 AED applications were performed by laymen. The mean time between switching the unit on and applying the electrodes to the patient was 39 seconds (SD +/-20 sec). On average, another 20 seconds elapsed before the AED recommendation of "shock delivery" was displayed, and a total of 96 seconds elapsed before shock administration (± 56 sec). Conclusion Consistent with other reports, our findings show that the organisation of a city-wide initiative by a project office combining public access and first-responder defibrillation programmes can be safe, feasible and successful. Our experiences confirm that strategic planning of AED placement is a prerequisite for successful, cost-effective resuscitation. PMID:20550655

Dynamic loads on human and animal surrogates at different test locations in compressed-gas-driven shock tubes

NASA Astrophysics Data System (ADS)

Alay, E.; Skotak, M.; Misistia, A.; Chandra, N.

2018-01-01

Dynamic loads on specimens in live-fire conditions as well as at different locations within and outside compressed-gas-driven shock tubes are determined by both static and total blast overpressure-time pressure pulses. The biomechanical loading on the specimen is determined by surface pressures that combine the effects of static, dynamic, and reflected pressures and specimen geometry. Surface pressure is both space and time dependent; it varies as a function of size, shape, and external contour of the specimens. In this work, we used two sets of specimens: (1) anthropometric dummy head and (2) a surrogate rodent headform instrumented with pressure sensors and subjected them to blast waves in the interior and at the exit of the shock tube. We demonstrate in this work that while inside the shock tube the biomechanical loading as determined by various pressure measures closely aligns with live-fire data and shock wave theory, significant deviations are found when tests are performed outside.

Role of temperament in early adolescent pure and co-occurring internalizing and externalizing problems using a bifactor model: Moderation by parenting and gender

PubMed Central

WANG, FRANCES L.; EISENBERG, NANCY; VALIENTE, CARLOS; SPINRAD, TRACY L.

2015-01-01

We contribute to the literature on the relations of temperament to externalizing and internalizing problems by considering parental emotional expressivity and child gender as moderators of such relations and examining prediction of pure and co-occurring problem behaviors during early to middle adolescence using bifactor models (which provide unique and continuous factors for pure and co-occurring internalizing and externalizing problems). Parents and teachers reported on children’s (4.5- to 8-year-olds; N = 214) and early adolescents’ (6 years later; N = 168) effortful control, impulsivity, anger, sadness, and problem behaviors. Parental emotional expressivity was measured observationally and with parents’ self-reports. Early-adolescents’ pure externalizing and co-occurring problems shared childhood and/or early-adolescent risk factors of low effortful control, high impulsivity, and high anger. Lower childhood and early-adolescent impulsivity and higher early-adolescent sadness predicted early-adolescents’ pure internalizing. Childhood positive parental emotional expressivity more consistently related to early-adolescents’ lower pure externalizing compared to co-occurring problems and pure internalizing. Lower effortful control predicted changes in externalizing (pure and co-occurring) over 6 years, but only when parental positive expressivity was low. Higher impulsivity predicted co-occurring problems only for boys. Findings highlight the probable complex developmental pathways to adolescent pure and co-occurring externalizing and internalizing problems. PMID:26646352

Role of temperament in early adolescent pure and co-occurring internalizing and externalizing problems using a bifactor model: Moderation by parenting and gender.

PubMed

Wang, Frances L; Eisenberg, Nancy; Valiente, Carlos; Spinrad, Tracy L

2016-11-01

We contribute to the literature on the relations of temperament to externalizing and internalizing problems by considering parental emotional expressivity and child gender as moderators of such relations and examining prediction of pure and co-occurring problem behaviors during early to middle adolescence using bifactor models (which provide unique and continuous factors for pure and co-occurring internalizing and externalizing problems). Parents and teachers reported on children's (4.5- to 8-year-olds; N = 214) and early adolescents' (6 years later; N = 168) effortful control, impulsivity, anger, sadness, and problem behaviors. Parental emotional expressivity was measured observationally and with parents' self-reports. Early-adolescents' pure externalizing and co-occurring problems shared childhood and/or early-adolescent risk factors of low effortful control, high impulsivity, and high anger. Lower childhood and early-adolescent impulsivity and higher early-adolescent sadness predicted early-adolescents' pure internalizing. Childhood positive parental emotional expressivity more consistently related to early-adolescents' lower pure externalizing compared to co-occurring problems and pure internalizing. Lower effortful control predicted changes in externalizing (pure and co-occurring) over 6 years, but only when parental positive expressivity was low. Higher impulsivity predicted co-occurring problems only for boys. Findings highlight the probable complex developmental pathways to adolescent pure and co-occurring externalizing and internalizing problems.

Effects of Prenatal Cocaine Exposure on Early Sexual Behavior: Gender Difference in Externalizing Behavior as a Mediator

PubMed Central

Min, Meeyoung O.; Minnes, Sonia; Lang, Adelaide; Yoon, Susan; Singer, Lynn T.

2015-01-01

Background Prenatal cocaine exposure (PCE) is associated with increased risk for externalizing behavior problems; childhood externalizing behavior problems are linked with subsequent early sexual behavior. The present study examined the effects of PCE on early sexual initiation (sexual intercourse prior to age 15) and whether externalizing behavior in preadolescence mediated the relationship. Methods Three hundred fifty-four (180 PCE and 174 non-cocaine exposed; 192 girls, 142 boys), primarily African-American, low socioeconomic status, 15-year old adolescents participated in a prospective longitudinal study. Adolescents’ sexual behavior was assessed at 15 years using the Youth Risk Behavior Surveillance System. Externalizing behavior was assessed at 12 years using the Youth Self-Report. Results Logistic regression models indicated that adolescents with PCE (n=69, 38%) were 2.2 times more likely (95% CI= 1.2 – 4.1, p < .01) to engage in early sexual intercourse than non-exposed peers (n=49, 28%) controlling for covariates. This relationship was fully mediated by self-reported externalizing behavior in girls but not in boys, suggesting childhood externalizing behavior as a gender moderated mediator. Blood lead level during preschool years was also related to a greater likelihood of early sexual intercourse (OR=2.6, 95% CI=1.4 – 4.7, p < .002). Greater parental monitoring decreased the likelihood of early sexual intercourse, while violence exposure increased the risk. Conclusions PCE is related to early sexual intercourse, and externalizing behavior problems mediate PCE effects in female adolescents. Interventions targeting externalizing behavior may reduce early sexual initiation and thereby reduce HIV risk behaviors and early, unplanned pregnancy in girls with PCE. PMID:26088698

Effects of prenatal cocaine exposure on early sexual behavior: Gender difference in externalizing behavior as a mediator.

PubMed

Min, Meeyoung O; Minnes, Sonia; Lang, Adelaide; Yoon, Susan; Singer, Lynn T

2015-08-01

Prenatal cocaine exposure (PCE) is associated with increased risk for externalizing behavior problems; childhood externalizing behavior problems are linked with subsequent early sexual behavior. The present study examined the effects of PCE on early sexual initiation (sexual intercourse prior to age 15) and whether externalizing behavior in preadolescence mediated the relationship. Three hundred fifty-four (180 PCE and 174 non-cocaine exposed; 192 girls, 142 boys), primarily African-American, low socioeconomic status, 15-year-old adolescents participated in a prospective longitudinal study. Adolescents' sexual behavior was assessed at 15 years using the Youth Risk Behavior Surveillance System. Externalizing behavior was assessed at 12 years using the Youth Self-Report. Logistic regression models indicated that adolescents with PCE (n=69, 38%) were 2.2 times more likely (95% CI=1.2-4.1, p<.01) to engage in early sexual intercourse than non-exposed peers (n=49, 28%) controlling for covariates. This relationship was fully mediated by self-reported externalizing behavior in girls but not in boys, suggesting childhood externalizing behavior as a gender moderated mediator. Blood lead level during preschool years was also related to a greater likelihood of early sexual intercourse (OR=2.6, 95% CI=1.4-4.7, p<.002). Greater parental monitoring decreased the likelihood of early sexual intercourse, while violence exposure increased the risk. PCE is related to early sexual intercourse, and externalizing behavior problems mediate PCE effects in female adolescents. Interventions targeting externalizing behavior may reduce early sexual initiation and thereby reduce HIV risk behaviors and early, unplanned pregnancy in girls with PCE. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Evidence for Coordination and Redox Changes of Iron in Shocked Feldspar from Synchrotron MicroXANES

NASA Technical Reports Server (NTRS)

Delaney, J. S.; Dyar, M. D.; Hoerz, F.; Johnson, J. R.

2003-01-01

Shock modification of feldspar has been documented and experimentally reproduced in many studies since the recognition of maskelynite in Shergotty. Experimentally shocked feldspar samples have been well studied using chemical and crystallographic techniques. The crystallographic, site-specific characterization of major and minor elements is less well documented. We present early x-ray absorption (XAS) spectral data for a suite of albitite samples that were experimentally shocked at pressures between 17 and 50 Gpa.

General relativistic study of astrophysical jets with internal shocks

NASA Astrophysics Data System (ADS)

Vyas, Mukesh K.; Chattopadhyay, Indranil

2017-08-01

We explore the possibility of the formation of steady internal shocks in jets around black holes. We consider a fluid described by a relativistic equation of state, flowing about the axis of symmetry (θ = 0) in a Schwarzschild metric. We use two models for the jet geometry: (I) a conical geometry and (II) a geometry with non-conical cross-section. A jet with conical geometry has a smooth flow, while the jet with non-conical cross-section undergoes multiple sonic points and even standing shock. The jet shock becomes stronger, as the shock location is situated farther from the central black hole. Jets with very high energy and very low energy do not harbour shocks, but jets with intermediate energies do harbour shocks. One advantage of these shocks, as opposed to shocks mediated by external medium, is that these shocks have no effect on the jet terminal speed, but may act as possible sites for particle acceleration. Typically, a jet with specific energy 1.8c2 will achieve a terminal speed of v∞ = 0.813c for jet with any geometry, where, c is the speed of light in vacuum. But for a jet of non-conical cross-section for which the length scale of the inner torus of the accretion disc is 40rg, then, in addition, a steady shock will form at rsh ˜ 7.5rg and compression ratio of R ˜ 2.7. Moreover, electron-proton jet seems to harbour the strongest shock. We will discuss possible consequences of such a scenario.

ACTIVATION OF COMMON ANTIVIRAL PATHWAYS CAN POTENTIATE INFLAMMATORY RESPONSES TO SEPTIC SHOCK

PubMed Central

Doughty, Lesley A.; Carlton, Stacey; Galen, Benjamin; Cooma-Ramberan, Indranie; Chung, Chung-Shiang; Ayala, Alfred

2006-01-01

Induction of the antiviral cytokine interferon α/β (IFN-α/β) is common in many viral infections. The impact of ongoing antiviral responses on subsequent bacterial infection is not well understood. In human disease, bacterial superinfection complicating a viral infection can result in significant morbidity and mortality. We injected mice with polyinosinic-polycytidylic (PIC) acid, a TLR3 ligand and known IFN-α/β inducer as well as nuclear factor κB (NF-κB) activator to simulate very early antiviral pathways. We then challenged mice with an in vivo septic shock model characterized by slowly evolving bacterial infection to simulate bacterial superinfection early during a viral infection. Our data demonstrated robust induction of IFN-α in serum within 24 h of PIC injection with IFN-α/β–dependent major histocompatibility antigen class II up-regulation on peritoneal macrophages. PIC pretreatment before septic shock resulted in augmented tumor necrosis factor alpha and interleukins 6 and 10 and heightened lethality compared with septic shock alone. Intact IFN-α/β signaling was necessary for augmentation of the inflammatory response to in vivo septic shock and to both TLR2 and TLR4 agonists in vitro. To assess the NF-κB contribution to PIC-modulated inflammatory responses to septic shock, we treated with parthenolide an NF-κB inhibitor before PIC and septic shock. Parthenolide did not inhibit IFN-α induction by PIC. Inhibition of NF-κB by parthenolide did reduce IFN-α–mediated potentiation of the cytokine response and lethality from septic shock. Our data demonstrate that pathways activated early during many viral infections can have a detrimental impact on the outcome of subsequent bacterial infection. These pathways may be critical to understanding the heightened morbidity and mortality from bacterial superinfection after viral infection in human disease. PMID:16878028

[Learning to use semiautomatic external defibrillators through audiovisual materials for schoolchildren].

PubMed

Jorge-Soto, Cristina; Abelairas-Gómez, Cristian; Barcala-Furelos, Roberto; Gregorio-García, Carolina; Prieto-Saborit, José Antonio; Rodríguez-Núñez, Antonio

2016-01-01

To assess the ability of schoolchildren to use a automated external defibrillator (AED) to provide an effective shock and their retention of the skill 1 month after a training exercise supported by audiovisual materials. Quasi-experimental controlled study in 205 initially untrained schoolchildren aged 6 to 16 years old. SAEDs were used to apply shocks to manikins. The students took a baseline test (T0) of skill, and were then randomized to an experimental or control group in the first phase (T1). The experimental group watched a training video, and both groups were then retested. The children were tested in simulations again 1 month later (T2). A total of 196 students completed all 3 phases. Ninety-six (95.0%) of the secondary school students and 54 (56.8%) of the primary schoolchildren were able to explain what a SAED is. Twenty of the secondary school students (19.8%) and 8 of the primary schoolchildren (8.4%) said they knew how to use one. At T0, 78 participants (39.8%) were able to simulate an effective shock. At T1, 36 controls (34.9%) and 56 experimental-group children (60.2%) achieved an effective shock (P< .001). At T2, 53 controls (51.4%) and 61 experimental-group children (65.6%) gave effective shocks (P=.045). All the students completed the tests in 120 seconds. Their average times decreased with each test. The secondary school students achieved better results. Previously untrained secondary school students know what a AED is and half of them can manage to use one in simulations. Brief narrative, audiovisual instruction improves students' skill in managing a SAED and helps them retain what they learned for later use.

Diagnostic Accuracy of Commercially Available Automated External Defibrillators.

PubMed

Nishiyama, Takahiko; Nishiyama, Ako; Negishi, Masachika; Kashimura, Shin; Katsumata, Yoshinori; Kimura, Takehiro; Nishiyama, Nobuhiro; Tanimoto, Yoko; Aizawa, Yoshiyasu; Mitamura, Hideo; Fukuda, Keiichi; Takatsuki, Seiji

2015-12-01

Although automated external defibrillators (AEDs) have contributed to a better survival of out-of-hospital cardiac arrests, there have been reports of their malfunctioning. We investigated the diagnostic accuracy of commercially available AEDs using surface ECGs of ventricular fibrillation (VF), ventricular tachycardia (VT), and supraventricular tachycardia (SVT). ECGs(VF 31, VT 48, SVT 97) were stored during electrophysiological studies and transmitted to 4 AEDs, the LifePak CR Plus (CR Plus), HeartStart FR3 (FR3), and CardioLife AED-2150 (CL2150) and -9231 (CL9231), through the pad electrode cables. For VF, the CL2150 and CL9231 advised shocks in all cases, and the CR Plus and FR3 advised shocks in all but one VF case. For VTs faster than 180 bpm, the ratios for advising shocks were 79%, 36%, 89%, and 96% for the CR Plus, FR3, CL2150, and CL9231, respectively. The FR3 and CR Plus did not advise shocks for narrow QRS SVTs, whereas the CL9231 tended to treat high-rate tachycardias faster than 180 bpm even with narrow QRS complexes. The characteristics of the shock advice for the FR3 differed from that for the CL9231 (kappa coefficient [κ]=0.479, P<0.001), and the CR Plus and CL2150 had characteristics somewhere between the 2 former AEDs (κ=0.818, P<0.001). Commercially available AEDs diagnosed VF almost always correctly. For VT and SVT diagnoses, a discrepancy was evident among the 4 investigated AEDs. The differences in the arrhythmia diagnosis algorithms for differentiating SVT from VT were thought to account for these differences. © 2015 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

PIV Measurements of Supersonic Internally-Mixed Dual-Stream Jets

NASA Technical Reports Server (NTRS)

Bridges, James E.; Wernet, Mark P.

2012-01-01

While externally mixed, or separate flow, nozzle systems are most common in high bypass-ratio aircraft, they are not as attractive for use in lower bypass-ratio systems and on aircraft that will fly supersonically. The noise of such propulsion systems is also dominated by jet noise, making the study and noise reduction of these exhaust systems very important, both for military aircraft and future civilian supersonic aircraft. This paper presents particle image velocimetry of internally mixed nozzle with different area ratios between core and bypass, and nozzles that are ideally expanded and convergent. Such configurations independently control the geometry of the internal mixing layer and of the external shock structure. These allow exploration of the impact of shocks on the turbulent mixing layers, the impact of bypass ratio on broadband shock noise and mixing noise, and the impact of temperature on the turbulent flow field. At the 2009 AIAA/CEAS Aeroacoustics Conference the authors presented data and analysis from a series of tests that looked at the acoustics of supersonic jets from internally mixed nozzles. In that paper the broadband shock and mixing noise components of the jet noise were independently manipulated by holding Mach number constant while varying bypass ratio and jet temperature. Significant portions of that analysis was predicated on assumptions regarding the flow fields of these jets, both shock structure and turbulence. In this paper we add to that analysis by presenting particle image velocimetry measurements of the flow fields of many of those jets. In addition, the turbulent velocity data documented here will be very useful for validation of computational flow codes that are being developed to design advanced nozzles for future aircraft.

Shock-isolation material selection for electronic packages in hard-target environment

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

Stotts, Jarrett Eugene

High velocity munitions and kinetic penetrators experience monumental external forces, impulses, and accelerations. The hard target environment is immensely taxing on sophisticated electronic components and recorders designed to retrieve valuable data related to the systems performance and characteristics in the periods of flight, impact, and post-impact. Such electronic systems have upper limits of overall shock intensity which, if exceeded, will either shorten the operating life of the parts or risk destruction resulting in loss of both the data and the principal value of the recorder. The focus of this project was to refine the categorization of leading material types formore » encapsulation and passive shock isolation and implement them in a method useable for a wide variety of environments. Namely, a design methodology capable of being tailored to the specific impact conditions to maximize the lively hood of sensitive electronics and the information recorded. The results of the study concluded that the materials observed under consistent dynamic high strain rate tests, which include Conathane® EN-4/9, Slygard®-184, and Stycast™-2651, behaved well in certain aspects of energy transmission and shock when considering the frequency environment or package coupled with the isolation material’s application. Key points about the implementation of the materials in extreme shock environments is discussed with the connection to energy analysis, loss attributes, and pulse transmissibility modeling. However, attempts to model the materials solely based on energy transmissibility in the frequency domain using only external experimental data and simplified boundary conditions was not found to be consistent with that acquired from the pressure bar experiments. Further work will include the addition of further material experimentation of the encapsulants in other frequency and temperature states, confined and pre-load boundary states, and composite constructions.« less

Broadband observations of the naked-eye gamma-ray burst GRB 080319B.

PubMed

Racusin, J L; Karpov, S V; Sokolowski, M; Granot, J; Wu, X F; Pal'shin, V; Covino, S; van der Horst, A J; Oates, S R; Schady, P; Smith, R J; Cummings, J; Starling, R L C; Piotrowski, L W; Zhang, B; Evans, P A; Holland, S T; Malek, K; Page, M T; Vetere, L; Margutti, R; Guidorzi, C; Kamble, A P; Curran, P A; Beardmore, A; Kouveliotou, C; Mankiewicz, L; Melandri, A; O'Brien, P T; Page, K L; Piran, T; Tanvir, N R; Wrochna, G; Aptekar, R L; Barthelmy, S; Bartolini, C; Beskin, G M; Bondar, S; Bremer, M; Campana, S; Castro-Tirado, A; Cucchiara, A; Cwiok, M; D'Avanzo, P; D'Elia, V; Valle, M Della; de Ugarte Postigo, A; Dominik, W; Falcone, A; Fiore, F; Fox, D B; Frederiks, D D; Fruchter, A S; Fugazza, D; Garrett, M A; Gehrels, N; Golenetskii, S; Gomboc, A; Gorosabel, J; Greco, G; Guarnieri, A; Immler, S; Jelinek, M; Kasprowicz, G; La Parola, V; Levan, A J; Mangano, V; Mazets, E P; Molinari, E; Moretti, A; Nawrocki, K; Oleynik, P P; Osborne, J P; Pagani, C; Pandey, S B; Paragi, Z; Perri, M; Piccioni, A; Ramirez-Ruiz, E; Roming, P W A; Steele, I A; Strom, R G; Testa, V; Tosti, G; Ulanov, M V; Wiersema, K; Wijers, R A M J; Winters, J M; Zarnecki, A F; Zerbi, F; Mészáros, P; Chincarini, G; Burrows, D N

2008-09-11

Long-duration gamma-ray bursts (GRBs) release copious amounts of energy across the entire electromagnetic spectrum, and so provide a window into the process of black hole formation from the collapse of massive stars. Previous early optical observations of even the most exceptional GRBs (990123 and 030329) lacked both the temporal resolution to probe the optical flash in detail and the accuracy needed to trace the transition from the prompt emission within the outflow to external shocks caused by interaction with the progenitor environment. Here we report observations of the extraordinarily bright prompt optical and gamma-ray emission of GRB 080319B that provide diagnostics within seconds of its formation, followed by broadband observations of the afterglow decay that continued for weeks. We show that the prompt emission stems from a single physical region, implying an extremely relativistic outflow that propagates within the narrow inner core of a two-component jet.

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.

The Atacama Large Millimeter/submillimeter Array (alma): Early Results

NASA Astrophysics Data System (ADS)

Wootten, Alwyn

2012-06-01

New radioastronomical instruments, such as ALMA or the Jansky VLA, have increased spectral throughput by orders of magnitude over previously available capabilities. ALMA brings orders of magnitude increases in spectral sensitivity and spatial resolution over what has previously been available. These increased capabilities open new possibilities for studies of complex molecules in the interstellar medium. Complex interstellar molecules may form on the surfaces of interstellar grains, after which they may be liberated into the gas phase by shocks, radiation, or other external influences. Emission from complex molecules may be diluted owing to the large number of transitions large molecules may undergo, particularly in warm regions of interstellar clouds. High sensitivity and spatial resolution are necessary to explore the distributions and relationships of these molecules. Of particular interest are the distributions of large organic molecules. Observations which establish the relationships between various large molecules are now emerging from these new instruments and will be discussed.

Fever in sepsis.

PubMed

Schortgen, F

2012-11-01

Fever is a common symptom of sepsis usually believed to predict better survival. Experimental data suggest that body temperature elevation may slow micro-organism growth and enhance host immune responses. In patients with sepsis, however, the high energy cost of fever may exacerbate the life-threatening situation. Fever control is widely used in the ICU, mainly in patients with infections. The efficacy of antipyretic drugs in lowering body temperature remains uncertain, however, and all antipyretics have well known adverse effects. Surface cooling methods are efficient but require sedation to avoid the harmful effects of shivering. A recent controlled trial in patients with septic shock suggests that external cooling for fever control may diminish vasopressor requirements and improve early survival. In this review, we examine the benefits and risks of fever and of controlled normothermia. The fever control modalities that provide the best risk/benefit ratio in sepsis are discussed.

Exploring the Early Structure of a Rapidly Decompressed Particle Bed

NASA Astrophysics Data System (ADS)

Zunino, Heather; Adrian, R. J.; Clarke, Amanda; Johnson, Blair; Arizona State University Collaboration

2017-11-01

Rapid expansion of dense, pressurized beds of fine particles subjected to rapid reduction of the external pressure is studied in a vertical shock tube. A near-sonic expansion wave impinges on the particle bed-gas interface and rapidly unloads the particle bed. A high-speed video camera captures events occurring during bed expansion. The particle bed does not expand homogeneously, but breaks down into horizontal slabs and then transforms into a cellular-type structure. There are several key parameters that affect the particle bed evolution, including particle size and initial bed height. Analyses of this bed structure evolution from experiments with varying particle sizes and initial bed heights is presented. This work is supported by the U.S. Department of Energy, National Nuclear Security Administration, Advanced Simulation and Computing Program, as a Cooperative Agreement under the Predictive Science and Academic Alliance Program, under Contract No. DE-NA0002378.

Behavior problems in late childhood: the roles of early maternal attachment and teacher-child relationship trajectories.

PubMed

O'Connor, Erin E; Collins, Brian A; Supplee, Lauren

2012-01-01

The purposes of the current study were: (1) to examine the roles of early maternal attachment relationships and teacher-child relationships during childhood for externalizing and internalizing behaviors in late childhood, and (2) to investigate teacher-child relationships, as well as externalizing and internalizing behaviors in early childhood as possible mechanisms linking early maternal attachment relationships to behavior problems in late childhood. Longitudinal data from the National Institute of Child Health and Human Development Early Child Care Research Network Study of Early Child Care and Youth Development (N = 1140 mothers and children) were used in this investigation. There were three main findings. First, insecure/other maternal attachment relationships in early childhood (i.e., 36 months) were associated with externalizing and internalizing behaviors in late childhood (Grade 5). Second, elevated levels of teacher-child conflict during childhood were associated with externalizing behaviors in late childhood whereas low levels of teacher-child closeness were associated with internalizing behaviors. Third, the effects of insecure/other attachment on externalizing and internalizing behaviors in late childhood were mediated through teacher-child relationships during childhood and early externalizing and internalizing behaviors. Implications for attachment theory are discussed.

Subliminal modulation of voluntary action experience: A neuropsychological investigation.

PubMed

Khalighinejad, N; Kunnumpurath, A; Bertini, C; Ladavas, E; Haggard, P

2017-05-01

Human voluntary actions are often associated with a distinctive subjective experience termed 'sense of agency'. This experience could be a reconstructive inference triggered by monitoring one's actions and their outcomes, or a read-out of brain processes related to action preparation, or some hybrid of these. Participants pressed a key with the right index finger at a time of their own choice, while viewing a rotating clock. Occasionally they received a mild shock on the same finger. They were instructed to press the key as quickly as possible if they felt a shock. On some trials, trains of subliminal shocks were also delivered, to investigate whether such subliminal cues could influence the initiation of voluntary actions, or the subjective experience of such actions. Participants' keypress were always followed by a tone 250 ms later. At the end of each trial they reported the time of the keypress using the rotating clock display. Shifts in the perceived time of the action towards the following tone, compared to a baseline condition containing only a keypress but no tone, were taken as implicit measures of sense of agency. The subliminal shock train enhanced this "action binding" effect in healthy participants, relative to trials without such shocks. This difference could not be attributed to retrospective inference, since the perceptual events were identical in both trial types. Further, we tested the same paradigm in a patient with anarchic hand syndrome (AHS). Subliminal shocks again enhanced our measure of sense of agency in the unaffected hand, but had a reversed effect on the 'anarchic' hand. These findings suggest an interaction between internal volitional signals and external cues afforded by the external environment. Damage to the neural pathways that mediate interactions between internal states and the outside world may explain some of the clinical signs of AHS. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

Organic synthesis in experimental impact shocks

NASA Technical Reports Server (NTRS)

McKay, C. P.; Borucki, W. J.

1997-01-01

Laboratory simulations of shocks created with a high-energy laser demonstrate that the efficacy of organic production depends on the molecular, not just the elemental composition of the shocked gas. In a methane-rich mixture that simulates a low-temperature equilibrium mixture of cometary material, hydrogen cyanide and acetylene were produced with yields of 5 x 10(17) molecules per joule. Repeated shocking of the methane-rich mixture produced amine groups, suggesting the possible synthesis of amino acids. No organic molecules were produced in a carbon dioxide-rich mixture, which is at odds with thermodynamic equilibrium approaches to shock chemistry and has implications for the modeling of shock-produced organic molecules on early Earth.

Hydrodynamics of Gamma-Ray Burst Afterglow

NASA Astrophysics Data System (ADS)

Sari, Re'em

1997-11-01

The detection of delayed emission at X-ray optical and radio wavelengths (``afterglow'') following gamma-ray bursts (GRBs) suggests that the relativistic shell that emitted the initial GRB as the result of internal shocks decelerates on encountering an external medium, giving rise to the afterglow. We explore the interaction of a relativistic shell with a uniform interstellar medium (ISM) up to the nonrelativistic stage. We demonstrate the importance of several effects that were previously ignored and must be included in a detailed radiation analysis. At a very early stage (few seconds), the observed bolometric luminosity increases as t2. On longer timescales (more than ~10 s), the luminosity drops as t-1. If the main burst is long enough, an intermediate stage of constant luminosity will form. In this case, the afterglow overlaps the main burst; otherwise there is a time separation between the two. On the long timescale, the flow decelerates in a self-similar way, reaching nonrelativistic velocities after ~30 days. Explicit expressions for the radial profiles of this self-similar deceleration are given. As a result of the deceleration and the accumulation of ISM material, the relation between the observed time, the shock radius, and its Lorentz factor is given by t=R/16γ2c, which is a factor of 8 different from the usual expression. We show that even though only a small fraction of the internal energy is given to the electrons, most of the energy can be radiated over time. If the fraction of energy in electrons is greater than ~10%, radiation losses will significantly influence the hydrodynamical evolution at early times (less than ~1 day).

An Interactive, Design and Educational Tool for Supersonic External-Compression Inlets

NASA Technical Reports Server (NTRS)

Benson, Thomas J.

1994-01-01

A workstation-based interactive design tool called VU-INLET was developed for the inviscid flow in rectangular, supersonic, external-compression inlets. VU-INLET solves for the flow conditions from free stream, through the supersonic compression ramps, across the terminal normal shock region and the subsonic diffuser to the engine face. It calculates the shock locations, the capture streamtube, and the additive drag of the inlet. The inlet geometry can be modified using a graphical user interface and the new flow conditions recalculated interactively. Free stream conditions and engine airflow can also be interactively varied and off-design performance evaluated. Flow results from VU-INLET can be saved to a file for a permanent record, and a series of help screens make the simulator easy to learn and use. This paper will detail the underlying assumptions of the models and the numerical methods used in the simulator.

Biomechanics of stair walking and jumping.

PubMed

Loy, D J; Voloshin, A S

1991-01-01

Physical activities such as stair walking and jumping result in increased dynamic loading on the human musculoskeletal system. Use of light weight, externally attached accelerometers allows for in-vivo monitoring of the shock waves invading the human musculoskeletal system during those activities. Shock waves were measured in four subjects performing stair walking up and down, jumping in place and jumping off a fixed elevation. The results obtained show that walking down a staircase induced shock waves with amplitude of 130% of that observed in walking up stairs and 250% of the shock waves experienced in level gait. The jumping test revealed levels of the shock waves nearly eight times higher than that in level walking. It was also shown that the shock waves invading the human musculoskeletal system may be generated not only by the heel strike, but also by the metatarsal strike. To moderate the risk of degenerative joint disorders four types of viscoelastic insoles were utilized to reduce the impact generated shock waves. The insoles investigated were able to reduce the amplitude of the shock wave by between 9% and 41% depending on the insole type and particular physical activity. The insoles were more effective in the reduction of the heel strike impacts than in the reduction of the metatarsal strike impacts. In all instances, the shock attenuation capacities of the insoles tested were greater in the jumping trials than in the stair walking studies. The insoles were ranked in three groups on the basis of their shock absorbing capacity.

Early outcome of early-goal directed therapy for patients with sepsis or septic shock: a systematic review and meta-analysis of randomized controlled trials.

PubMed

Chen, Xiaofan; Zhu, Weifeng; Tan, Jing; Nie, Heyun; Liu, Liangming; Yan, Dongmei; Zhou, Xu; Sun, Xin

2017-04-18

Various trials and meta-analyses have reported conflicting results concerning the application of early goal-directed therapy (EGDT) for sepsis and septic shock. The aim of this study was to update the evidence by performing a systematic review and meta-analysis. Multiple databases were searched from initial through August, 2016 for randomized controlled trials (RCTs) which investigated the associations between the use of EGDT and mortality in patients with sepsis or septic shock. Meta-analysis was performed using random-effects model and heterogeneity was examined through subgroup analyses. The primary outcome of interest was patient all-cause mortality including hospital or ICU mortality. Seventeen RCTs including 6207 participants with 3234 in the EGDT group and 2973 in the control group were eligible for this study. Meta-analysis showed that EGDT did not significantly reduce hospital or intensive care unit (ICU) mortality (relative risk [RR] 0.89, 95% CI 0.78 to 1.02) compared with control group for patients with sepsis or septic shock. The findings of subgroup analyses stratified by study region, number of research center, year of enrollment, clinical setting, sample size, timing of EGDT almost remained constant with that of the primary analysis. Our findings provide evidence that EGDT offers neutral survival effects for patients with sepsis or septic shock. Further meta-analyses based on larger well-designed RCTs or individual patient data meta-analysis are required to explore the survival benefits of EDGT in patients with sepsis or septic shock.

SNR-shock impact on star formation

NASA Astrophysics Data System (ADS)

Sasaki, M.; Dincel, B.

2016-06-01

While stars form out of cores of molecular clouds due to gravitational collapse of the clouds, external pressure caused by shock waves of stellar winds or supernovae are believed to be responsible for triggering star formation. However, since massive stars evolve fast and their supernova remnants (SNRs) can only be observed up to an age of around 10^5 years, SNRs found near star-forming regions have most likely resulted from the same generation of stars as the young stellar objects (YSOs). Shock waves of these SNRs might show interaction with the existing YSOs and change their nature. We study YSO candidates in Galactic SNRs CTB 109, IC 443 and HB21, which are known to show interaction with molecular clouds and have associated infrared emission. By photometric and spectroscopic studies of YSOs in the optical and the near-infrared, we aim to find clear observational evidences for an interaction of SNR-shocks with YSOs.

Revisiting first type self-similar solutions of explosions containing ultrarelativistic shocks

NASA Astrophysics Data System (ADS)

Tian, Jun

2018-05-01

We revisit the first type self-similar solutions for ultrarelativistic shock waves produced by explosions propagating into cold external medium whose density profile decreases with radius as ρ ∝ r-k. The first-type solutions proposed by Blandford and McKee (hereafter BM solution) conforms to the global conservation of energy and applies when k < 4. They have been found to be invalid when k > 17/4 because of the divergence of total energy contained in the shocked fluids. So far no attention has been paid to the particle number. We use the BM solution to calculate the total particle number traversed by the shock and find that it diverges when k > 3. This is inconsistent with the finite particles in the surrounding medium. We propose a possible solution when k > 3 based on the conservation of particle number and discuss its implication for the second-type solutions.

Early Adolescent Risk Behavior Outcomes of Childhood Externalizing Behavioral Trajectories

ERIC Educational Resources Information Center

Thompson, Richard; Tabone, Jiyoung Kim; Litrownik, Alan J.; Briggs, Ernestine C.; Hussey, Jon M.; English, Diana J.; Dubowitz, Howard

2011-01-01

Little is known about the early childhood indicators of adolescent risk. The link between trajectories of externalizing behavioral problems and early adolescent risk behavior was examined in a longitudinal sample of 875 child participants in the LONGSCAN studies. Five trajectory groups of children defined by externalizing behavior problems were…

Genetic vulnerability interacts with parenting and early care education to predict increasing externalizing behavior.

PubMed

Lipscomb, Shannon T; Laurent, Heidemarie; Neiderhiser, Jenae M; Shaw, Daniel S; Natsuaki, Misaki N; Reiss, David; Leve, Leslie D

2014-01-01

The current study examined interactions among genetic influences and children's early environments on the development of externalizing behaviors from 18 months to 6 years of age. Participants included 233 families linked through adoption (birth parents and adoptive families). Genetic influences were assessed by birth parent temperamental regulation. Early environments included both family (overreactive parenting) and out-of-home factors (center-based Early Care and Education; ECE). Overreactive parenting predicted more child externalizing behaviors. Attending center-based ECE was associated with increasing externalizing behaviors only for children with genetic liability for dysregulation. Additionally, children who were at risk for externalizing behaviors due to both genetic variability and exposure to center-based ECE were more sensitive to the effects of overreactive parenting on externalizing behavior than other children.

Genetic vulnerability interacts with parenting and early care education to predict increasing externalizing behavior

PubMed Central

Lipscomb, Shannon T.; Laurent, Heidemarie; Neiderhiser, Jenae M.; Shaw, Daniel S.; Natsuaki, Misaki N.; Reiss, David; Leve, Leslie D.

2014-01-01

The current study examined interactions among genetic influences and children’s early environments on the development of externalizing behaviors from 18 months to 6 years of age. Participants included 233 families linked through adoption (birth parents and adoptive families). Genetic influences were assessed by birth parent temperamental regulation. Early environments included both family (overreactive parenting) and out-of-home factors (center-based Early Care and Education; ECE). Overreactive parenting predicted more child externalizing behaviors. Attending center-based ECE was associated with increasing externalizing behaviors only for children with genetic liability for dysregulation. Additionally, children who were at risk for externalizing behaviors due to both genetic variability and exposure to center-based ECE were more sensitive to the effects of overreactive parenting on externalizing behavior than other children. PMID:25067867

Contribution of ethylenetetrafluoroethylene (ETFE) insulation to the electrical performance of Riata® silicone leads having externalized conductors.

PubMed

Fischer, Avi; Klehn, Russell

2013-08-01

The insulation of St. Jude Medical Riata® leads contains a polytetrafluoroethylene (PTFE) liner, silicone tubing, and ethylenetetrafluoroethylene (ETFE) coating on individual cable conductors. ETFE has sufficient dielectric strength to assure electrical function. This investigation intended to analyze performance of leads with and without externalized conductors and with intact and breached ETFE. Testing was performed on ETFE-coated conductors to determine their ability to deliver high-voltage therapy. Tests were performed on samples under different conditions and current leakage was measured. A high-voltage test and a cyclic pulse test were performed, and the effect of lead modifications on the potential gradient from a high-voltage shock was used to determine functionality. Measurements from modified Riata® leads were compared with a control lead with all insulation and conducting elements intact. Current leakage for all conditions tested, was within the acceptance criteria for the high-voltage test and the cyclic pulse test. In conductors that underwent cyclic testing, the highest value of current leakage was within the limit of acceptability for both phases of the test. Testing of leads with externalized conductors and breached ETFE showed similar potential gradients compared with a control lead. Testing of ETFE-coated conductors following multiple preconditioning steps showed that ETFE serves as a redundant layer of insulation. In the event that the ETFE coating is breached, the potential gradient seen resulting from a high-voltage defibrillation shock was similar to a lead with no breach to the ETFE, even after 100 shocks.

Preliminary vibration, acoustic, and shock design and test criteria for components on the SRB, ET, and SSME

NASA Technical Reports Server (NTRS)

1976-01-01

Specifications for vibration, acoustic and shock design for components and subassemblies on the External Tank (ET), Solid Rocket Booster (SRB), and Space Shuttle Main Engine (SSME). Included are vibration, acoustic, shock, transportation, handling, and acceptance test requirements and procedures. The space shuttle ET, SRB, and SSME have been divided into zones and subzones. Zones are designated primarily to assist in determining the applicable specifications. A subzone (General Specification) is available for use when the location of the component is known but component design and weight are not well defined. When the location, weight, and mounting configuration of the component are known, specifications for appropriate subzone weight ranges are available. Criteria for some specific components are also presented.

NASA GSFC Mechanical Engineering Latest Inputs for Verification Standards (GEVS) Updates

NASA Technical Reports Server (NTRS)

Kaufman, Daniel

2003-01-01

This viewgraph presentation provides information on quality control standards in mechanical engineering. The presentation addresses safety, structural loads, nonmetallic composite structural elements, bonded structural joints, externally induced shock, random vibration, acoustic tests, and mechanical function.

Preschool Externalizing Behavior Predicts Gender-Specific Variation in Adolescent Neural Structure

PubMed Central

Caldwell, Jessica Z. K.; Armstrong, Jeffrey M.; Hanson, Jamie L.; Sutterer, Matthew J.; Stodola, Diane E.; Koenigs, Michael; Kalin, Ned H.

2015-01-01

Dysfunction in the prefrontal cortex, amygdala, and hippocampus is believed to underlie the development of much psychopathology. However, to date only limited longitudinal data relate early behavior with neural structure later in life. Our objective was to examine the relationship of early life externalizing behavior with adolescent brain structure. We report here the first longitudinal study linking externalizing behavior during preschool to brain structure during adolescence. We examined the relationship of preschool externalizing behavior with amygdala, hippocampus, and prefrontal cortex volumes at age 15 years in a community sample of 76 adolescents followed longitudinally since their mothers’ pregnancy. A significant gender by externalizing behavior interaction revealed that males—but not females—with greater early childhood externalizing behavior had smaller amygdala volumes at adolescence (t = 2.33, p = .023). No significant results were found for the hippocampus or the prefrontal cortex. Greater early externalizing behavior also related to smaller volume of a cluster including the angular gyrus and tempoparietal junction across genders. Results were not attributable to the impact of preschool anxiety, preschool maternal stress, school-age internalizing or externalizing behaviors, or adolescent substance use. These findings demonstrate a novel, gender-specific relationship between early-childhood externalizing behavior and adolescent amygdala volume, as well as a cross-gender result for the angular gyrus and tempoparietal junction. PMID:25658357

FLOW FIELD IN SUPERSONIC MIXED-COMPRESSION INLETS AT ANGLE OF ATTACK USING THE THREE DIMENSIONAL METHOD OF CHARACTERISTICS WITH DISCRETE SHOCK WAVE FITTING

NASA Technical Reports Server (NTRS)

Bishop, A. R.

1994-01-01

This computer program calculates the flow field in the supersonic portion of a mixed-compression aircraft inlet at non-zero angle of attack. This approach is based on the method of characteristics for steady three-dimensional flow. The results of this program agree with those produced by the two-dimensional method of characteristics when axisymmetric flow fields are calculated. Except in regions of high viscous interaction and boundary layer removal, the results agree well with experimental data obtained for threedimensional flow fields. The flow field in a variety of axisymmetric mixed compression inlets can be calculated using this program. The bow shock wave and the internal shock wave system are calculated using a discrete shock wave fitting procedure. The internal flow field can be calculated either with or without the discrete fitting of the internal shock wave system. The influence of molecular transport can be included in the calculation of the external flow about the forebody and in the calculation of the internal flow when internal shock waves are not discretely fitted. The viscous and thermal diffussion effects are included by treating them as correction terms in the method of characteristics procedure. Dynamic viscosity is represented by Sutherland's law and thermal conductivity is represented as a quadratic function of temperature. The thermodynamic model used is that of a thermally and calorically perfect gas. The program assumes that the cowl lip is contained in a constant plane and that the centerbody contour and cowl contour are smooth and have continuous first partial derivatives. This program cannot calculate subsonic flow, the external flow field if the bow shock wave does not exist entirely around the forebody, or the internal flow field if the bow flow field is injected into the annulus. Input to the program consists of parameters to control execution, to define the geometry, and the vehicle orientation. Output consists of a list of parameters used, solution planes, and a description of the shock waves. This program is written in FORTRAN IV for batch execution and has been implemented on a CDC 6000 series machine with a central memory requirement of 110K (octal) of 60 bit words when it is overlayed. This flow analysis program was developed in 1978.

Calculation of external-internal flow fields for mixed-compression inlets

NASA Technical Reports Server (NTRS)

Chyu, W. J.; Kawamura, T.; Bencze, D. P.

1986-01-01

Supersonic inlet flows with mixed external-internal compressions were computed using a combined implicit-explicit (Beam-Warming-Steger/MacCormack) method for solving the three-dimensional unsteady, compressible Navier-Stokes equations in conservation form. Numerical calculations were made of various flows related to such inlet operations as the shock-wave intersections, subsonic spillage around the cowl lip, and inlet started versus unstarted conditions. Some of the computed results were compared with wind tunnel data.

Calculation of external-internal flow fields for mixed-compression inlets

NASA Technical Reports Server (NTRS)

Chyu, W. J.; Kawamura, T.; Bencze, D. P.

1987-01-01

Supersonic inlet flows with mixed external-internal compressions were computed using a combined implicit-explicit (Beam-Warming-Steger/MacCormack) method for solving the three-dimensional unsteady, compressible Navier-Stokes equations in conservation form. Numerical calculations were made of various flows related to such inlet operations as the shock-wave intersections, subsonic spillage around the cowl lip, and inlet started versus unstarted conditions. Some of the computed results were compared with wind tunnel data.

Methodology for the investigation of ignition near hot surfaces in a high-pressure shock tube

NASA Astrophysics Data System (ADS)

Niegemann, P.; Fikri, M.; Wlokas, I.; Röder, M.; Schulz, C.

2018-05-01

Autoignition of fuel/air mixtures is a determining process in internal combustion engines. Ignition can start either homogeneously in the gas phase after compression or in the vicinity of hot surfaces. While ignition properties of commercial fuels are conventionally described by a single quantity (octane number), it is known that some fuels have a varying propensity to the two processes. We present a new experimental concept that generates well-controlled temperature inhomogeneities in the shock-heated gases of a high-pressure shock tube. A shock-heated reactive mixture is brought into contact with a heated silicon nitride ceramic glow plug. The glow-plug temperature can be set up to 1200 K, higher than the post-reflected-shock gas temperatures (650-1050 K). High-repetition-rate chemiluminescence imaging is used to localize the onset of ignition in the vicinity of the hot surface. In experiments with ethanol, the results show that in most cases under shock-heated conditions, the ignition begins inhomogeneously in the vicinity of the glow plug and is favored because of the high wall temperature. Additionally, the interaction of geometry, external heating, and gas-dynamic effects was investigated by numerical simulations of the shock wave in a non-reactive flow.

Methodology for the investigation of ignition near hot surfaces in a high-pressure shock tube.

PubMed

Niegemann, P; Fikri, M; Wlokas, I; Röder, M; Schulz, C

2018-05-01

Autoignition of fuel/air mixtures is a determining process in internal combustion engines. Ignition can start either homogeneously in the gas phase after compression or in the vicinity of hot surfaces. While ignition properties of commercial fuels are conventionally described by a single quantity (octane number), it is known that some fuels have a varying propensity to the two processes. We present a new experimental concept that generates well-controlled temperature inhomogeneities in the shock-heated gases of a high-pressure shock tube. A shock-heated reactive mixture is brought into contact with a heated silicon nitride ceramic glow plug. The glow-plug temperature can be set up to 1200 K, higher than the post-reflected-shock gas temperatures (650-1050 K). High-repetition-rate chemiluminescence imaging is used to localize the onset of ignition in the vicinity of the hot surface. In experiments with ethanol, the results show that in most cases under shock-heated conditions, the ignition begins inhomogeneously in the vicinity of the glow plug and is favored because of the high wall temperature. Additionally, the interaction of geometry, external heating, and gas-dynamic effects was investigated by numerical simulations of the shock wave in a non-reactive flow.

[Inappropriate analyses of automated external defibrillators used during out-of-hospital cardiac arrests].

PubMed

Ballesteros Peña, Sendoa

2013-04-01

To estimate the frequency of therapeutic errors and to evaluate the diagnostic accuracy in the recognition of shockable rhythms by automated external defibrillators. A retrospective descriptive study. Nine basic life support units from Biscay (Spain). Included 201 patients with cardiac arrest, since 2006 to 2011. The study was made of the suitability of treatment (shock or not) after each analysis and medical errors identified. The sensitivity, specificity and predictive values with 95% confidence intervals were then calculated. A total of 811 electrocardiographic rhythm analyses were obtained, of which 120 (14.1%), from 30 patients, corresponded to shockable rhythms. Sensitivity and specificity for appropriate automated external defibrillators management of a shockable rhythm were 85% (95% CI, 77.5% to 90.3%) and 100% (95% CI, 99.4% to 100%), respectively. Positive and negative predictive values were 100% (95% CI, 96.4% to 100%) and 97.5% (95% CI, 96% to 98.4%), respectively. There were 18 (2.2%; 95% CI, 1.3% to 3.5%) errors associated with defibrillator management, all relating to cases of shockable rhythms that were not shocked. One error was operator dependent, 6 were defibrillator dependent (caused by interaction of pacemakers), and 11 were unclassified. Automated external defibrillators have a very high specificity and moderately high sensitivity. There are few operator dependent errors. Implanted pacemakers interfere with defibrillator analyses. Copyright © 2012 Elsevier España, S.L. All rights reserved.

A shock absorber model for structure-borne noise analyses

NASA Astrophysics Data System (ADS)

Benaziz, Marouane; Nacivet, Samuel; Thouverez, Fabrice

2015-08-01

Shock absorbers are often responsible for undesirable structure-borne noise in cars. The early numerical prediction of this noise in the automobile development process can save time and money and yet remains a challenge for industry. In this paper, a new approach to predicting shock absorber structure-borne noise is proposed; it consists in modelling the shock absorber and including the main nonlinear phenomena responsible for discontinuities in the response. The model set forth herein features: compressible fluid behaviour, nonlinear flow rate-pressure relations, valve mechanical equations and rubber mounts. The piston, base valve and complete shock absorber model are compared with experimental results. Sensitivity of the shock absorber response is evaluated and the most important parameters are classified. The response envelope is also computed. This shock absorber model is able to accurately reproduce local nonlinear phenomena and improves our state of knowledge on potential noise sources within the shock absorber.

Reducing the effects of X-ray pre-heat in double shell NIF capsules by over-coating the high Z shell

NASA Astrophysics Data System (ADS)

Wilson, Douglas; Milovich, J. L.; Daughton, W. S.; Loomis, E. N.; Sauppe, J. P.; Dodd, E. S.; Merritt, E. C.; Montgomery, D. S.; Renner, D. B.; Haines, B. M.; Cardenas, T.; Desjardins, T.; Palaniyappan, S.; Batha, S. H.

2017-10-01

Hohlraum generated X-rays will penetrate the ablator of a double shell capsule and be absorbed in the outer surface of the inner capsule. The ablative pressure this generates drives a shock into the central fuel, and a reflected shock that reaches the inner high-Z shell surface before the main shock even enters the fuel. With a beryllium over-coat preheat X-rays deposit just inside the beryllium/high z interface. The beryllium tamps the preheat expansion, eliminating ablation, and dramatically reducing pressure. The slow shock or pressure wave it generates is then overtaken by the main shock, avoiding an early shock in the fuel and increasing capsule yield.

Use of recombinant human activated protein C in nonmenstrual staphylococcal toxic shock syndrome.

PubMed

Nasa, Prashant; Sehrawat, Deepak; Kansal, Sudha; Chawla, Rajesh

2010-07-01

Toxic shock syndrome (TSS) is a serious, potentially life-threatening condition resulting from an overwhelming immunological response to an exotoxin released by Staphylococcus aureus and group A streptococci. High index of suspicion, early diagnosis and aggressive therapeutic measures must be instituted in view of high mortality of the TSS. In recent years, new agents have been tested to reduce morbidity and mortality in patients with severe sepsis, in addition to standard supportive measures. Among them, recombinant human activated protein C (rhAPC) has been reported to significantly reduce mortality and morbidity in patients with severe sepsis and two or more acute organ failures. We describe our experience with this drug in the early reversal of septic shock from TSS.

Use of recombinant human activated protein C in nonmenstrual staphylococcal toxic shock syndrome

PubMed Central

Nasa, Prashant; Sehrawat, Deepak; kansal, Sudha; Chawla, Rajesh

2010-01-01

Toxic shock syndrome (TSS) is a serious, potentially life-threatening condition resulting from an overwhelming immunological response to an exotoxin released by Staphylococcus aureus and group A streptococci. High index of suspicion, early diagnosis and aggressive therapeutic measures must be instituted in view of high mortality of the TSS. In recent years, new agents have been tested to reduce morbidity and mortality in patients with severe sepsis, in addition to standard supportive measures. Among them, recombinant human activated protein C (rhAPC) has been reported to significantly reduce mortality and morbidity in patients with severe sepsis and two or more acute organ failures. We describe our experience with this drug in the early reversal of septic shock from TSS. PMID:21253349

A molecular dynamic investigation for shock induced phase transition of water

NASA Astrophysics Data System (ADS)

Mitra, Nilanjan; Neogi, Anupam

2015-06-01

Atomistic equilibrium molecular dynamics (EMD) was carried out to investigate shock induced phase transition of bulk liquid water. Multi-scale shock technique (MSST) was utilized to investigate low (US = 2 . 5km /s) to strong (US = 6 . 5km /s) intensity shock response on an extended flexible three point model up to 100 ns. The thermodynamic pathway of phase transition from liquid water to ice VII was investigated using temporal variation of thermodynamic state variables, power spectrum analyses of O-H bond vibration along with temporal evolution of pair correlation function between O-O, O-H and H-H atoms. Static structure factor along with pair-distribution function extended up to 20 Å was calculated and compared against the ideal ice VII to get information regarding long range ordering. Bragg reflection at different crystal planes were evaluated to investigate percentage of crystallinity of the shocked sample. Specific questions answered in this work involves: What is the exact time frame after the passage of shock at certain intensity in which nucleation of solid phase can be observed? Is it a complete or partial phase transition? Are external nucleators essential for this transformation? What is the percentage of crystallinity of the nucleated phase?

Influence of exothermic chemical reactions on laser-induced shock waves.

PubMed

Gottfried, Jennifer L

2014-10-21

Differences in the excitation of non-energetic and energetic residues with a 900 mJ, 6 ns laser pulse (1064 nm) have been investigated. Emission from the laser-induced plasma of energetic materials (e.g. triaminotrinitrobenzene [TATB], cyclotrimethylene trinitramine [RDX], and hexanitrohexaazaisowurtzitane [CL-20]) is significantly reduced compared to non-energetic materials (e.g. sugar, melamine, and l-glutamine). Expansion of the resulting laser-induced shock wave into the air above the sample surface was imaged on a microsecond timescale with a high-speed camera recording multiple frames from each laser shot; the excitation of energetic materials produces larger heat-affected zones in the surrounding atmosphere (facilitating deflagration of particles ejected from the sample surface), results in the formation of additional shock fronts, and generates faster external shock front velocities (>750 m s(-1)) compared to non-energetic materials (550-600 m s(-1)). Non-explosive materials that undergo exothermic chemical reactions in air at high temperatures such as ammonium nitrate and magnesium sulfate produce shock velocities which exceed those of the inert materials but are less than those generated by the exothermic reactions of explosive materials (650-700 m s(-1)). The most powerful explosives produced the highest shock velocities. A comparison to several existing shock models demonstrated that no single model describes the shock propagation for both non-energetic and energetic materials. The influence of the exothermic chemical reactions initiated by the pulsed laser on the velocity of the laser-induced shock waves has thus been demonstrated for the first time.

Physics of gamma-ray bursts and multi-messenger signals from double neutron star mergers

NASA Astrophysics Data System (ADS)

Gao, He

My dissertation includes two parts: Physics of Gamma-Ray Bursts (GRBs): Gamma-ray bursts are multi-wavelength transients, with both prompt gamma-ray emission and late time afterglow emission observed by telescopes in different wavelengths. I have carried out three investigations to understand GRB prompt emission and afterglow. Chapter 2 develops a new method, namely, "Stepwise Filter Correlation" method, to decompose the variability components in a light curve. After proving its reliability through simulations, we apply this method to 266 bright GRBs and find that the majority of the bursts have clear evidence of superposition of fast and slow variability components. Chapter 3 gives a complete presentation of the analytical approximations for synchrotron self-compton emission for all possible orders of the characteristic synchrotron spectral breaks (nua, nu m, and nuc). We identify a "strong absorption" regime whennua > nuc, and derive the critical condition for this regime. The external shock theory is an elegant theory to model GRB afterglows. It invokes a limit number of model parameters, and has well predicted spectral and temporal properties. Chapter 4 gives a complete reference of all the analytical synchrotron external shock afterglow models by deriving the temporal and spectral indices of all the models in all spectral regimes. This complete reference will serve as a useful tool for afterglow observers to quickly identify relevant models to interpret their data and identify new physics when the models fail. Milti-messenger signals from double neutron star merger: As the multi-messenger era of astronomy ushers in, the second part of the dissertation studies the possible electromagnetic (EM) and neutrino emission counterparts of double neutron star mergers. Chapter 6 suggests that if double neutron star mergers leave behind a massive magnetar rather than a black hole, the magnetar wind could push the ejecta launched during the merger process, and under certain conditions, accelerates it to a relativistic speed. Such a magnetar-powered ejecta, when interacting with the ambient medium, would develop a bright broad-band afterglow due to external shock synchrotron radiation. We study this physical scenario in detail, and present the predicted X-ray, optical and radio light curves for a range of magnetar and ejecta parameters. Chapter 7 applies the model to interpret one optical transient discovered recently. In chapter 8, we show that protons accelerated in the external shock would interact with photons generated in the dissipating magnetar wind and emit high energy neutrinos and photons. We find that PeV neutrinos could be emitted from the shock front as long as the ejecta could be accelerated to a relativistic speed. These events would contribute to the diffuse Pev neutrino background and sub-Tev gamma-ray background.

Uncovering the Secret of Shock Wave Lithotripsy

NASA Astrophysics Data System (ADS)

Zhong, P.

Shock wave lithotripsy (SWL) is an engineering innovation that has revolutionized the treatment of kidney stone disease since the early 1980s [1] - [3]. Today, SWL is the first-line therapy for millions of patients worldwide with renal and upper urinary stones [3, 4].

Sepsis in Obstetrics: Clinical Features and Early Warning Tools.

PubMed

Parfitt, Sheryl E; Bogat, Mary L; Hering, Sandra L; Ottley, Charlotte; Roth, Cheryl

Morbidity and mortality associated with sepsis has gained widespread attention on a local, state, and national level, yet, it remains a complicated disorder that can be difficult to identify in a timely manner. Sepsis in obstetric patients further complicates the diagnosis as alterations in physiology related to pregnancy can mask sepsis indicators normally seen in the general population. If early signs of sepsis go unrecognized, septic shock can develop, leading to organ dysfunction and potential death. Maternal early warning tools have been designed to assist clinicians in recognizing early indications of illness. Through use of clinical pathway-specific tools, disease processes may be detected early, subsequently benefitting patients with aggressive treatment management and intervention.This article is the second in a series of three that discuss the importance of sepsis and septic shock in pregnancy. Risk factors, causes of sepsis, signs and symptoms, and maternal early warning tools are discussed.

76 FR 64223 - Cardiovascular Devices; Reclassification of External Pacemaker Pulse Generator Devices

Federal Register 2010, 2011, 2012, 2013, 2014

2011-10-17

... arrhythmias; and 4. Micro/macro shocks--Uncontrolled leakage currents or patient auxiliary currents can cause...); Medtronic, Inc. v. Lohr, 518 U.S. 470 (1996); and Riegel v. Medtronic, Inc. 128 S. Ct. 999 (2008)). If this...

Trajectories of pure and co-occurring internalizing and externalizing problems from age 2 to age 12: findings from the National Institute of Child Health and Human Development Study of Early Child Care.

PubMed

Fanti, Kostas A; Henrich, Christopher C

2010-09-01

How and why do internalizing and externalizing problems, psychopathological problems from different diagnostic classes representing separate forms of psychopathology, co-occur in children? We investigated the development of pure and co-occurring internalizing and externalizing problems from ages 2 to 12 with the use of latent class growth analysis. Furthermore, we examined how early childhood factors (temperament, cognitive functioning, maternal depression, and home environment) and early adolescent social and behavioral adjustment variables were related to differential trajectories of pure and co-occurring internalizing and externalizing problems. The sample (National Institute of Child Health and Human Development Study of Early Child Care) consisted of 1,232 children (52% male). Mother reports on the Child Behavior Checklist (Achenbach, 1991, 1992) were used to construct the trajectories of externalizing and internalizing problems. Analyses identified groups of children exhibiting pure and co-occurring internalizing and externalizing problems. Children exhibiting continuous externalizing or continuous co-occurring internalizing and externalizing problems across the 10-year period under investigation were more likely to (a) engage in risky behaviors, (b) be associated with deviant peers, (c) be rejected by peers, and (d) be asocial with peers at early adolescence. However, children exhibiting pure internalizing problems over time were only at higher risk for being asocial with peers as early adolescents. Moreover, the additive effects of individual and environmental early childhood risk factors influenced the development of chronic externalizing problems, although pure internalizing problems were uniquely influenced by maternal depression. Results also provided evidence for the concepts of equifinality and multifinality.

Propagation and dispersion of shock waves in magnetoelastic materials

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

Crum, R. S.; Domann, J. P.; Carman, G. P.

Previous studies examining the response of magnetoelastic materials to shock waves have predominantly focused on applications involving pulsed power generation, with limited attention given to the actual wave propagation characteristics. This study provides detailed magnetic and mechanical measurements of magnetoelastic shock wave propagation and dispersion. Laser generated rarefacted shock waves exceeding 3 GPa with rise times of 10 ns were introduced to samples of the magnetoelastic material Galfenol. The resulting mechanical measurements reveal the evolution of the shock into a compressive acoustic front with lateral release waves. Importantly, the wave continues to disperse even after it has decayed into anmore » acoustic wave, due in large part to magnetoelastic coupling. The magnetic data reveal predominantly shear wave mediated magnetoelastic coupling, and were also used to noninvasively measure the wave speed. The external magnetic field controlled a 30% increase in wave propagation speed, attributed to a 70% increase in average stiffness. Lastly, magnetic signals propagating along the sample over 20× faster than the mechanical wave were measured, indicating these materials can act as passive antennas that transmit information in response to mechanical stimuli.« less

Dynamic Electromechanical Characterization of the Ferroelectric Ceramic PZT 95/5

NASA Astrophysics Data System (ADS)

Setchell, R. E.; Chhabildas, L. C.; Furnish, M. D.; Montgomery, S. T.; Holman, G. T.

1997-07-01

Shock-induced depoling of the ferroelectric ceramic PZT 95/5 has been utilized in a number of pulsed power applications. The dynamic behavior of the poled ceramic is complex, with nonlinear coupling between mechanical and electrical variables. Recent efforts to improve numerical simulations of this process have been limited by the scarcity of relevant experimental studies within the last twenty years. Consequently, we have initiated an extensive experimental study of the dynamic electromechanical behavior of this material. Samples of the poled ceramic are shocked to axial stresses from 0.5 to 5 GPa in planar impact experiments and observed with laser interferometry (VISAR) to obtain transmitted wave profiles. Current generation due to shock-induced depoling is observed using different external loads to vary electric field strengths within the samples. Experimental configurations either have the remanent polarization parallel to the direction of shock motion (axially poled) or perpendicular (normally poled). Initial experiments on unpoled samples utilized PVDF stress gauges as well as VISAR, and extended prior data on shock loading and release behavior. (Supported by the U. S. Department of Energy under contract DE-AC04-94AL85000). abstract.

Propagation and dispersion of shock waves in magnetoelastic materials

NASA Astrophysics Data System (ADS)

Crum, R. S.; Domann, J. P.; Carman, G. P.; Gupta, V.

2017-12-01

Previous studies examining the response of magnetoelastic materials to shock waves have predominantly focused on applications involving pulsed power generation, with limited attention given to the actual wave propagation characteristics. This study provides detailed magnetic and mechanical measurements of magnetoelastic shock wave propagation and dispersion. Laser generated rarefacted shock waves exceeding 3 GPa with rise times of 10 ns were introduced to samples of the magnetoelastic material Galfenol. The resulting mechanical measurements reveal the evolution of the shock into a compressive acoustic front with lateral release waves. Importantly, the wave continues to disperse even after it has decayed into an acoustic wave, due in large part to magnetoelastic coupling. The magnetic data reveal predominantly shear wave mediated magnetoelastic coupling, and were also used to noninvasively measure the wave speed. The external magnetic field controlled a 30% increase in wave propagation speed, attributed to a 70% increase in average stiffness. Finally, magnetic signals propagating along the sample over 20× faster than the mechanical wave were measured, indicating these materials can act as passive antennas that transmit information in response to mechanical stimuli.

Propagation and dispersion of shock waves in magnetoelastic materials

DOE PAGES

Crum, R. S.; Domann, J. P.; Carman, G. P.; ...

2017-11-15

Previous studies examining the response of magnetoelastic materials to shock waves have predominantly focused on applications involving pulsed power generation, with limited attention given to the actual wave propagation characteristics. This study provides detailed magnetic and mechanical measurements of magnetoelastic shock wave propagation and dispersion. Laser generated rarefacted shock waves exceeding 3 GPa with rise times of 10 ns were introduced to samples of the magnetoelastic material Galfenol. The resulting mechanical measurements reveal the evolution of the shock into a compressive acoustic front with lateral release waves. Importantly, the wave continues to disperse even after it has decayed into anmore » acoustic wave, due in large part to magnetoelastic coupling. The magnetic data reveal predominantly shear wave mediated magnetoelastic coupling, and were also used to noninvasively measure the wave speed. The external magnetic field controlled a 30% increase in wave propagation speed, attributed to a 70% increase in average stiffness. Lastly, magnetic signals propagating along the sample over 20× faster than the mechanical wave were measured, indicating these materials can act as passive antennas that transmit information in response to mechanical stimuli.« less

Methodology for the Design of Streamline-Traced External-Compression Supersonic Inlets

NASA Technical Reports Server (NTRS)

Slater, John W.

2014-01-01

A design methodology based on streamline-tracing is discussed for the design of external-compression, supersonic inlets for flight below Mach 2.0. The methodology establishes a supersonic compression surface and capture cross-section by tracing streamlines through an axisymmetric Busemann flowfield. The compression system of shock and Mach waves is altered through modifications to the leading edge and shoulder of the compression surface. An external terminal shock is established to create subsonic flow which is diffused in the subsonic diffuser. The design methodology was implemented into the SUPIN inlet design tool. SUPIN uses specified design factors to design the inlets and computes the inlet performance, which includes the flow rates, total pressure recovery, and wave drag. A design study was conducted using SUPIN and the Wind-US computational fluid dynamics code to design and analyze the properties of two streamline-traced, external-compression (STEX) supersonic inlets for Mach 1.6 freestream conditions. The STEX inlets were compared to axisymmetric pitot, two-dimensional, and axisymmetric spike inlets. The STEX inlets had slightly lower total pressure recovery and higher levels of total pressure distortion than the axisymmetric spike inlet. The cowl wave drag coefficients of the STEX inlets were 20% of those for the axisymmetric spike inlet. The STEX inlets had external sound pressures that were 37% of those of the axisymmetric spike inlet, which may result in lower adverse sonic boom characteristics. The flexibility of the shape of the capture cross-section may result in benefits for the integration of STEX inlets with aircraft.

Wide variation in cardiopulmonary resuscitation interruption intervals among commercially available automated external defibrillators may affect survival despite high defibrillation efficacy.

PubMed

Snyder, David; Morgan, Carl

2004-09-01

Recent studies have associated interruptions of cardiopulmonary resuscitation imposed by automated external defibrillators (AEDs) with poor resuscitation outcome. In particular, the "hands-off" interval between precordial compressions and subsequent defibrillation shock has been implicated. We sought to determine the range of variation among current-generation AEDs with respect to this characteristic. Seven AEDs from six manufacturers were characterized via stopwatch and arrhythmia simulator with respect to the imposed hands-off interval. All AEDs were equipped with new batteries, and measurements were repeated five times for each AED. A wide variation in the hands-off interval between precordial compressions and shock delivery was observed, ranging from 5.2 to 28.4 secs, with only one AED achieving an interruption of <10 secs. Laboratory and clinical data suggest that this range of variation could be responsible for a more than two-fold variation in patient resuscitation success, an effect that far exceeds any defibrillation efficacy differences that may hypothetically exist. In addition to defibrillation waveform and dose, researchers should consider the hands-off cardiopulmonary resuscitation interruption interval between cardiopulmonary resuscitation and subsequent defibrillation shock to be an important covariate of outcome in resuscitation studies. Defibrillator design should minimize this interval to avoid potential adverse consequences on patient survival.

Numerical investigation of interactions of multiple spherical shock waves between themselves and with the underlying surface

NASA Astrophysics Data System (ADS)

Andrushchenko, V. A.; Murashkin, I. V.; Shevelev, Yu. D.

2016-06-01

Within the investigation of various aspects of asteroid and comet danger and, in particular, the explosion of several fragments of meteoroids in the atmosphere above the Earth surface, the toy problem about four point explosions in the case of their special arrangement above the underlying surface is numerically solved. Complex interactions of primary and secondary shock waves between themselves, with the hard surface, and with tangential discontinuities are examined. The structure of flow inside gas regions disturbed by the explosions—the occurrence of eddy structures in them and the influence of reflected shocks waves on them—are investigated. The tendency of the external wave fronts of each explosion to form a unified front and the tendency of their internal hot domains to merge into a joined configuration (where the second process proceeds a little later than the first one) is revealed. This unified front and joined configuration are qualitatively identical to the external internal structure for the solitary explosion. The specially arranged explosions are chosen because the effects of multiple diffraction, interference, and, the main thing, cumulation of spherical waves are manifested more clearly in this caseTwo variants with different altitude of the explosions above the surface are calculated.

On the role of vasopressin and angiotensin in the development of irreversible haemorrhagic shock

PubMed Central

Errington, M. L.; e Silva, M. Rocha

1974-01-01

1. Long-lasting haemorrhagic hypotension (4·5 hr at 35 mmHg) leading to irreversible haemorrhagic shock, has been studied in normal dogs, in dogs treated with a bradykinin potentiating nonapeptide (BPP9a), which blocks the conversion of angiotensin I to angiotensin II, and in dogs with experimental chronic diabetes insipidus (DI dogs). BPP9a was given by I.V. injection before the start of bleeding (BPP pre-treated group), 45 min after blood pressure had reached 35 mmHg (BPP early treated group) or 2 hr after blood pressure had reached 35 mmHg (BPP late-treated group). After retransfusion of blood all dogs were allowed to recover and observed for a further period of 3 days. 2. Untreated control dogs developed haemorrhagic shock with tachycardia, low cardiac output, low total peripheral conductance and low stroke volume. All died within 24 hr of retransfusion, with pathological lesions typical of irreversible haemorrhagic shock. 3. BPP pre-treated dogs developed haemorrhagic shock with bradycardia (during early shock), high cardiac output, high peripheral vascular conductance and high stroke volume when compared with the untreated controls. All pre-treated animals survived the 3 day observation period. They were then killed and on post-mortem showed no signs of irreversible haemorrhagic shock. 4. BPP early-treated animals behaved like controls before BPP, but like pre-treated animals after the drug. Only one out of eight died within the 3 day observation period. 5. BPP late-treated dogs behaved like controls before BPP. They responded to the drug with a rise in cardiac output, peripheral vascular conductance and stroke volume, and with a fall in heart rate. These responses were, however, short-lived. Four out of these eight animals died within the 3 day observation period, with lesions of irreversible haemorrhagic shock. 6. DI dogs developed haemorrhagic shock with tachycardia (like controls), but with high cardiac output and peripheral vascular conductance (like BPP pre-treated dogs). The stroke volume of DI dogs was intermediate between those of controls and pre-treated groups. All six dogs survived the 3 day observation period. 7. BPP9a had no measurable effect on the course of endotoxic shock. 8. It is suggested that the normally severe vasoconstriction of the mesenteric vascular bed, which is thought to be responsible for irreversible haemorrhagic shock, is absent or attenuated in the absence of vasopressin or angiotensin. The consequences of this on the development of irreversibility are discussed. PMID:4373570

Externalized Conductor Cables in QuickSite Left Ventricular Pacing Lead and Riata Right Ventricular Lead in a Single Patient: A Common Problem With Silicone Insulation

PubMed Central

Lakshmanadoss, Umashankar; Hackett, Vera; Deshmukh, Pramod

2012-01-01

QuickSite (St Jude Medical, Sylmar, CA, USA) is a silicone and polyurethane-insulated coronary sinus pacing lead. Riata lead (St Jude Medical, Sylmar, CA, USA) is a silicone insulated right ventricular shock lead. Recently, insulation breach of silicone based leads raised a huge concern. Fluoroscopic examination of these two leads in the same patient revealed externalization of these two leads. Same mechanism producing insulation breach of Riata lead may be involved in externalization of QuickSite LV lead as distal part of insulation is also made of silicone. PMID:28348692

Early Treatment in Shock

DTIC Science & Technology

2011-06-01

mem -6 branes releasing RNA into the lysis solution, and shears the genomic DNA decreasing 7 the viscosity of the lysate. Whole blood lysates from...doses, compared with saline controls. The L-arginine groups 3 showed increased OHP and wound breaking strength as compared with both shocked 4 and

GRB 091208B: FIRST DETECTION OF THE OPTICAL POLARIZATION IN EARLY FORWARD SHOCK EMISSION OF A GAMMA-RAY BURST AFTERGLOW

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

Uehara, T.; Chiyonobu, S.; Fukazawa, Y.

We report that the optical polarization in the afterglow of GRB 091208B is measured at t = 149-706 s after the burst trigger, and the polarization degree is P = 10.4( {+-} 2.5%. The optical light curve at this time shows a power-law decay with index -0.75 {+-} 0.02, which is interpreted as the forward shock synchrotron emission, and thus this is the first detection of the early-time optical polarization in the forward shock (rather than that in the reverse shock reported by Steele et al.). This detection disfavors the afterglow model in which the magnetic fields in the emissionmore » region are random on the plasma skin depth scales, such as those amplified by the plasma instabilities, e.g., Weibel instability. We suggest that the fields are amplified by the magnetohydrodynamic instabilities, which would be tested by future observations of the temporal changes of the polarization degrees and angles for other bursts.« less

Numerical modeling of the early interaction of a planar shock with a dense particle field

NASA Astrophysics Data System (ADS)

Regele, Jonathan; Blanquart, Guillaume

2011-11-01

Dense compressible multiphase flows are of interest for multiphase turbomachinary and energetic material detonations. Still, there is little understanding of the detailed interaction mechanisms between shock waves and dense (particle volume fraction αd > 0 . 001) particle fields. A recent experimental study [Wagner et al, AIAA Aero. Sci., Orlando, 2011-188] has focused on the impingement of a planar shock wave on a dense particle curtain. In the present work, numerical solutions of the Euler equations in one and two dimensions are performed for a planar shock wave impinging on a fixed particle curtain and are compared to the experimental data for early times. Comparison of the one- and two-dimensional results demonstrate that the one-dimensional description captures the large scale flow behavior, but is inadequate to capture all the details observed in the experiments. The two-dimensional solutions are shown to reproduce the experimentally observed flow structures and provide insight into how these details originate.

Retrospective evaluation of current-based impedance compensation defibrillation in out-of-hospital cardiac arrest.

PubMed

Chen, Bihua; Yin, Changlin; Ristagno, Giuseppe; Quan, Weilun; Tan, Qing; Freeman, Gary; Li, Yongqin

2013-05-01

Transthoracic impedance (TTI) is a principal parameter that influences the intracardiac current flow and defibrillation outcome. In this study, we retrospectively evaluated the performance of current-based impedance compensation defibrillation in out-of-hospital cardiac arrest (OHCA) patients. ECG recordings, along with TTI measurements were collected from multiple emergency medical services (EMSs) in the USA. All the EMSs in this study used automated external defibrillators (AEDs) which employing rectilinear biphasic (RLB) waveform. The distribution and change of TTI between successive shocks, the influence of preceding shock results on the subsequent shock outcome, and the performance of current-based impedance compensation defibrillation was evaluated. A total of 1166 shocks from 594 OHCA victims were examined in this study. The average TTI for the 1st shock was 134.8 Ω and a significant decrease in TTI was observed for the 2nd (p<0.001) and 3rd (p=0.033) sequential escalating shock. But TTI did not change after the 3rd shock. A higher success rate was observed for shocks with preceding defibrillation success. The success rate remained unchanged over the whole spectrum of TTI. The average TTI was relatively higher in this OHCA population treated with RLB defibrillation as compared with previously reported data. TTI was significantly decreased after 1st and 2nd successive escalating shock but kept constant after the 3rd shock. Preceding shock success was a better predictor of subsequent defibrillation outcome other than TTI. Current-based impedance compensation defibrillation resulted in equivalent success rate for high impedance patients when compared with those of low impedance. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Examining platelet-fibrin interactions during traumatic shock in a swine model using platelet contractile force and clot elastic modulus.

PubMed

White, Nathan J; Martin, Erika J; Brophy, Donald F; Ward, Kevin R

2011-07-01

A significant proportion of severely injured patients develop early coagulopathy, characterized by abnormal clot formation, which impairs resuscitation and increases mortality. We have previously demonstrated an isolated decrease in clot strength by thrombelastography in a swine model of nonresuscitated traumatic shock. In order to more closely examine platelet-fibrin interactions in this setting, we define the observed decrease in clot strength in terms of platelet-induced clot contraction and clot elastic modulus using the Hemostasis Analysis System (HAS) (Hemodyne Inc., Richmond, Virginia, USA). Whole blood was sampled for HAS measurements, metabolic measurements, cell counts, and fibrinogen concentration at baseline prior to injury and again at a predetermined level of traumatic shock defined by oxygen debt. Male swine (N=17) received femur fracture and controlled arterial hemorrhage to achieve an oxygen debt of 80 ml/kg. Platelet counts were unchanged, but fibrinogen concentration was reduced significantly during shock (167.6 vs. 66.7 mg/dl, P=0.0007). Platelet contractile force generated during clot formation did not change during shock (11.7 vs. 10.4 kdynes, P=0.41), but clot elastic modulus was dynamically altered, resulting in a lower final value (22.9 vs. 17.3 kdynes/cm, P<0.0001). In this model of traumatic shock, platelet function was preserved, whereas terminal clot elastic modulus was reduced during shock in a manner most consistent with early changes in the mechanical properties of the developing fibrin fiber network.

The use of AEDs by police officers in the City of London. Automated external defibrillators.

PubMed

Ross, P; Nolan, J; Hill, E; Dawson, J; Whimster, F; Skinner, D

2001-08-01

The Guidelines 2000 for cardiopulmonary resuscitation recommend shock delivery to victims in ventricular fibrillation within 5 min of call receipt by the Emergency Medical Services. In an effort to achieve this goal, in some parts of the United States, police officers have been trained to use automated external defibrillators (AEDs). We undertook a 3-year pilot evaluation of the use of AEDs by City of London police (CPOL) officers. Over a period of 3 years, 147 CPOL officers were trained in the use of an AED. Four AEDs were placed on rapid response vehicles covering the City of London. An overall call-response interval target was set at 8 min. The CPOL attended 1103 (90%) of the total of 1232 calls to which they were summoned. The mean interval between the first call received and arrival of the CPOL on scene was 8.9+/-4.0 min. The CPOL applied AEDs to 25 victims, 13 of whom were initially in ventricular fibrillation; at least one shock was delivered to all 13. The interval between call reception and delivery of the first shock was 5.5+/-2.5 min. The mean interval between switching on the AED and delivery of the first shock was 24+/-12 s. Two (15%) of these victims survived to hospital discharge. This study has confirmed the feasibility of training police officers in the UK to use AEDs as first responders. The call received to arrival on scene interval should be reduced by improvements in communication between LAS and CPOL.

α-Crystallins Are Small Heat Shock Proteins: Functional and Structural Properties.

PubMed

Tikhomirova, T S; Selivanova, O M; Galzitskaya, O V

2017-02-01

During its life cycle, a cell can be subjected to various external negative effects. Many proteins provide cell protection, including small heat shock proteins (sHsp) that have chaperone-like activity. These proteins have several important functions involving prevention of apoptosis and retention of cytoskeletal integrity; also, sHsp take part in the recovery of enzyme activity. The action mechanism of sHsp is based on the binding of hydrophobic regions exposed to the surface of a molten globule. α-Crystallins presented in chordate cells as two αA- and αB-isoforms are the most studied small heat shock proteins. In this review, we describe the main functions of α-crystallins, features of their secondary and tertiary structures, and examples of their partners in protein-protein interactions.

Design, calibration and testing of a force balance for a hypersonic shock tunnel

NASA Astrophysics Data System (ADS)

Vadassery, Pravin

The forces acting on a flight vehicle are critical for determining its performance. Of particular interest is the hypersonic regime. Force measurements are much more complex in hypersonic flows, where those speeds are simulated in shock tunnels. A force balance for such facilities contains sensitive gages that measure stress waves and ultimately determine the different components of force acting on the model. An external force balance was designed and fabricated for the UTA Hypersonic shock tunnel to measure drag at Mach 10. Static and dynamic calibrations were performed to find the transfer function of the system. Forces were recovered using a deconvolution procedure. To validate the force balance, experiments were conducted on a blunt cone. The measured forces were compared to Newtonian theory.

Calculation of oblique-shock-wave laminar-boundary-layer interaction on a flat plate

NASA Technical Reports Server (NTRS)

Goldberg, U.; Reshotko, E.

1980-01-01

A finite difference solution to the problem of the interaction between an impinging oblique shock wave and the laminar boundary layer on a flat plate is presented. The boundary layer equations coupled with the Prandtl-Meyer relation for the external flow are used to calculate the flow field. A method for the calculation of the separated flow region is presented and discussed. Comparisons between this theory and the experimental results of other investigators show fairly good agreement. Results are presented for the case of a cooled wall with an oncoming flow at Mach number 2.0 without and with suction. The results show that a small amount of suction greatly reduces the extent of the separated region in the vicinity of the shock impingement location.

[Determination of mRNA-transcripts and heat shock proteins HSP70 and HSP90 in retina of the adult Spanish Ribbed Newt Pleurodeles waltl].

PubMed

Avdonin, P P; Markitantova, Yu V; Poplinskaya, V A; Grigoryan, E N

2013-01-01

Expression of genes and heat shock proteins in normal intact retina of the Spanish Ribbed Newt Pleurodeles waltl was studied using polymerase chain reaction, Western blot hybridization, and immunohistochemistry. It was shown that the proteins HSP70 and HSP90, as well as their encoding transcripts of relevant genes, are constitutively expressed in eye tissues. These proteins were distributed differentially, and they were characterized by expression of different levels in the retina: HSP70 dominated in the external retina, while HSP90 dominated in the internal one, in particular, in Muller glial cells and the optic nerve. Transcripts and heat shock proteins HSP70 and HSP90 were also found in the retinal pigment epithelium and eye growth zone.

Probing the early stages of shock-induced chondritic meteorite formation at the mesoscale

PubMed Central

Rutherford, Michael E.; Chapman, David J.; Derrick, James G.; Patten, Jack R. W.; Bland, Philip A.; Rack, Alexander; Collins, Gareth S.; Eakins, Daniel E.

2017-01-01

Chondritic meteorites are fragments of asteroids, the building blocks of planets, that retain a record of primordial processes. Important in their early evolution was impact-driven lithification, where a porous mixture of millimetre-scale chondrule inclusions and sub-micrometre dust was compacted into rock. In this Article, the shock compression of analogue precursor chondrite material was probed using state of the art dynamic X-ray radiography. Spatially-resolved shock and particle velocities, and shock front thicknesses were extracted directly from the radiographs, representing a greatly enhanced scope of data than could be measured in surface-based studies. A statistical interpretation of the measured velocities showed that mean values were in good agreement with those predicted using continuum-level modelling and mixture theory. However, the distribution and evolution of wave velocities and wavefront thicknesses were observed to be intimately linked to the mesoscopic structure of the sample. This Article provides the first detailed experimental insight into the distribution of extreme states within a shocked powder mixture, and represents the first mesoscopic validation of leading theories concerning the variation in extreme pressure-temperature states during the formation of primordial planetary bodies. PMID:28555619

The Association of Birth Complications and Externalizing Behavior in Early Adolescents: Direct and Mediating Effects

PubMed Central

Liu, Jianghong; Raine, Adrian; Wuerker, Anne; Venables, Peter H.; Mednick, Sarnoff

2012-01-01

Prior studies have shown that birth complications interact with psychosocial risk factors in predisposing to increased externalizing behavior in childhood and criminal behavior in adulthood. However, little is known about the direct relationship between birth complications and externalizing behavior. Furthermore, the mechanism by which the birth complications predispose to externalizing behavior is not well explored. This study aims to assess whether birth complications predispose to early adolescent externalizing behavior and to test whether Intelligence Quotient (IQ) mediates relationships between predictor and outcome variables. We used data from a prospective, longitudinal birth cohort of 1,795 3-year-old boys and girls from Mauritius to test hypotheses. Birth complications were assessed from hospital record data, malnutrition from a pediatric exam at age 3 years, psychosocial adversity from parental interviews at age 3 years, and externalizing behavior problems from parental ratings at age 11 years. We found that babies with birth complications are more likely to develop externalizing behavior problems at age 11. Low IQ was associated with birth complications and was found to mediate the link between early predictors and later externalizing behavior. These prospective, longitudinal findings have potential clinical implications for the identification of early adolescent externalizing behavior and for public health attempts to prevent the occurrence of child externalizing behavior problems. PMID:22485069

Revisiting Shock Initiation Modeling of Homogeneous Explosives

NASA Astrophysics Data System (ADS)

Partom, Yehuda

2013-04-01

Shock initiation of homogeneous explosives has been a subject of research since the 1960s, with neat and sensitized nitromethane as the main materials for experiments. A shock initiation model of homogeneous explosives was established in the early 1960s. It involves a thermal explosion event at the shock entrance boundary, which develops into a superdetonation that overtakes the initial shock. In recent years, Sheffield and his group, using accurate experimental tools, were able to observe details of buildup of the superdetonation. There are many papers on modeling shock initiation of heterogeneous explosives, but there are only a few papers on modeling shock initiation of homogeneous explosives. In this article, bulk reaction reactive flow equations are used to model homogeneous shock initiation in an attempt to reproduce experimental data of Sheffield and his group. It was possible to reproduce the main features of the shock initiation process, including thermal explosion, superdetonation, input shock overtake, overdriven detonation after overtake, and the beginning of decay toward Chapman-Jouget (CJ) detonation. The time to overtake (TTO) as function of input pressure was also calculated and compared to the experimental TTO.

Dry and wet granular shock waves.

PubMed

Zaburdaev, V Yu; Herminghaus, S

2007-03-01

The formation of a shock wave in one-dimensional granular gases is considered, for both the dry and the wet cases, and the results are compared with the analytical shock wave solution in a sticky gas. Numerical simulations show that the behavior of the shock wave in both cases tends asymptotically to the sticky limit. In the inelastic gas (dry case) there is a very close correspondence to the sticky gas, with one big cluster growing in the center of the shock wave, and a step-like stationary velocity profile. In the wet case, the shock wave has a nonzero width which is marked by two symmetric heavy clusters performing breathing oscillations with slowly increasing amplitude. All three models have the same asymptotic energy dissipation law, which is important in the context of the free cooling scenario. For the early stage of the shock formation and asymptotic oscillations we provide analytical results as well.

Quantification of heat shock protein mRNA expression in warm and cold anoxic turtles (Trachemys scripta) using an external RNA control for normalization.

PubMed

Stecyk, Jonathan A W; Couturier, Christine S; Fagernes, Cathrine E; Ellefsen, Stian; Nilsson, Göran E

2012-03-01

The mRNA expression of heat-shock protein 90 (HSP90) and heat-shock cognate 70 (HSC70) was examined in cardiac chambers and telencephalon of warm- (21°C) and cold-acclimated (5°C) turtles (Trachemys scripta) exposed to normoxia, prolonged anoxia or anoxia followed by reoxygenation. Additionally, the suitability of total RNA as well as mRNA from β-actin, glyceraldehyde 3-phosphate dehydrogenase (GAPDH) and cyclophilin A (PPIA) for normalizing gene expression data was assessed, as compared to the use of an external RNA control. Measurements of HSP90 and HSC70 mRNA expression revealed that anoxia and reoxygenation have tissue- and gene-specific effects. By and large, the alterations support previous investigations on HSP protein abundance in the anoxic turtle heart and brain, as well as the hypothesized roles of HSP90 and HSC70 during stress and non-stress conditions. However, more prominent was a substantially increased HSP90 and HSC70 mRNA expression in the cardiac chambers with cold acclimation. The finding provides support for the notion that cold temperature induces a number of adaptations in tissues of anoxia-tolerant vertebrates that precondition them for winter anoxia. β-actin, GAPDH and PPIA mRNA expression and total RNA also varied with oxygenation state and acclimation temperature in a tissue- and gene-specific manner, as well as among tissue types, thus disqualifying them as suitable for real-time RT-PCR normalization. Thus, the present data highlights the advantages of normalizing real-time RT-PCR data to an external RNA control, an approach that also allows inter-tissue and potentially inter-species comparisons of target gene expression. Copyright © 2011 Elsevier Inc. All rights reserved.

Liberal Versus Restrictive Intravenous Fluid Therapy for Early Septic Shock: Rationale for a Randomized Trial.

PubMed

Self, Wesley H; Semler, Matthew W; Bellomo, Rinaldo; Brown, Samuel M; deBoisblanc, Bennett P; Exline, Matthew C; Ginde, Adit A; Grissom, Colin K; Janz, David R; Jones, Alan E; Liu, Kathleen D; Macdonald, Stephen P J; Miller, Chadwick D; Park, Pauline K; Reineck, Lora A; Rice, Todd W; Steingrub, Jay S; Talmor, Daniel; Yealy, Donald M; Douglas, Ivor S; Shapiro, Nathan I

2018-05-09

Prompt intravenous fluid therapy is a fundamental treatment for patients with septic shock. However, the optimal approach for administering intravenous fluid in septic shock resuscitation is unknown. Two competing strategies are emerging: a liberal fluids approach, consisting of a larger volume of initial fluid (50 to 75 mL/kg [4 to 6 L in an 80-kg adult] during the first 6 hours) and later use of vasopressors, versus a restrictive fluids approach, consisting of a smaller volume of initial fluid (≤30 mL/kg [≤2 to 3 L]), with earlier reliance on vasopressor infusions to maintain blood pressure and perfusion. Early fluid therapy may enhance or maintain tissue perfusion by increasing venous return and cardiac output. However, fluid administration may also have deleterious effects by causing edema within vital organs, leading to organ dysfunction and impairment of oxygen delivery. Conversely, a restrictive fluids approach primarily relies on vasopressors to reverse hypotension and maintain perfusion while limiting the administration of fluid. Both strategies have some evidence to support their use but lack robust data to confirm the benefit of one strategy over the other, creating clinical and scientific equipoise. As part of the National Heart, Lung, and Blood Institute Prevention and Early Treatment of Acute Lung Injury Network, we designed a randomized clinical trial to compare the liberal and restrictive fluids strategies, the Crystalloid Liberal or Vasopressor Early Resuscitation in Sepsis trial. The purpose of this article is to review the current literature on approaches to early fluid resuscitation in adults with septic shock and outline the rationale for the upcoming trial. Copyright © 2018 American College of Emergency Physicians. Published by Elsevier Inc. All rights reserved.

Simultaneous measurements of concentration and velocity in the Richtmyer-Meshkov instability

NASA Astrophysics Data System (ADS)

Reese, Dan; Ames, Alex; Noble, Chris; Oakley, Jason; Rothamer, David; Bonazza, Riccardo

2017-11-01

The Richtmyer-Meshkov instability (RMI) is studied experimentally in the Wisconsin Shock Tube Laboratory (WiSTL) using a broadband, shear layer initial condition at the interface between a helium-acetone mixture and argon. This interface (Atwood number A=0.7) is accelerated by either a M=1.6 or M=2.2 planar shock wave, and the development of the RMI is investigated through simultaneous planar laser-induced fluorescence (PLIF) and particle image velocimetry (PIV) measurements at the initial condition and four post-shock times. Three Reynolds stresses, the planar turbulent kinetic energy, the Taylor microscale are calculated from the concentration and velocity fields. The external Reynolds number is estimated from the Taylor scale and the velocity statistics. The results suggest that the flow transitions to fully developed turbulence by the third post-shock time for the high Mach number case, while it may not at the lower Mach number. The authors would like to acknowledge the support of the Department of Energy.

Simulating cosmic ray physics on a moving mesh

NASA Astrophysics Data System (ADS)

Pfrommer, C.; Pakmor, R.; Schaal, K.; Simpson, C. M.; Springel, V.

2017-03-01

We discuss new methods to integrate the cosmic ray (CR) evolution equations coupled to magnetohydrodynamics on an unstructured moving mesh, as realized in the massively parallel AREPO code for cosmological simulations. We account for diffusive shock acceleration of CRs at resolved shocks and at supernova remnants in the interstellar medium (ISM) and follow the advective CR transport within the magnetized plasma, as well as anisotropic diffusive transport of CRs along the local magnetic field. CR losses are included in terms of Coulomb and hadronic interactions with the thermal plasma. We demonstrate the accuracy of our formalism for CR acceleration at shocks through simulations of plane-parallel shock tubes that are compared to newly derived exact solutions of the Riemann shock-tube problem with CR acceleration. We find that the increased compressibility of the post-shock plasma due to the produced CRs decreases the shock speed. However, CR acceleration at spherically expanding blast waves does not significantly break the self-similarity of the Sedov-Taylor solution; the resulting modifications can be approximated by a suitably adjusted, but constant adiabatic index. In first applications of the new CR formalism to simulations of isolated galaxies and cosmic structure formation, we find that CRs add an important pressure component to the ISM that increases the vertical scaleheight of disc galaxies and thus reduces the star formation rate. Strong external structure formation shocks inject CRs into the gas, but the relative pressure of this component decreases towards halo centres as adiabatic compression favours the thermal over the CR pressure.

Measurement and Analysis of the Extreme Physical Shock Environment Experienced by Crane-Mounted Radiation Detection Systems.

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

Boyd, M; Erchinger, J; Marianno, C

Potentially, radiation detectors at ports of entry could be mounted on container gantry crane spreaders to monitor cargo containers entering and leaving the country. These detectors would have to withstand the extreme physical environment experienced by these spreaders during normal operations. Physical shock data from the gable ends of a spreader were recorded during the loading and unloading of a cargo ship with two Lansmont SAVER 9X30 units (with padding) and two PCB Piezotronics model 340A50 accelerometers (hard mounted). Physical shocks in the form of rapid acceleration were observed in all accelerometer units with values ranging from 0.20 g’s tomore » 199.99 g’s. The majority of the shocks for all the Lansmont and PCB accelerometers were below 50 g’s. The Lansmont recorded mean shocks of 21.83 ± 13.62 g’s and 24.78 ± 11.49 g’s while the PCB accelerometers experienced mean shocks of 34.39 ± 25.51 g’s and 41.77 ± 22.68 g’s for the landside and waterside units, respectively. Encased detector units with external padding should be designed to withstand at least 200 g’s of acceleration without padding and typical shocks of 30 g’s with padding for mounting on a spreader.« less

Short-term heat shock affects the course of immune response in Galleria mellonella naturally infected with the entomopathogenic fungus Beauveria bassiana.

PubMed

Vertyporokh, Lidiia; Taszłow, Paulina; Samorek-Pieróg, Małgorzata; Wojda, Iwona

2015-09-01

We aimed to investigate how exposition of infected insects to short-term heat shock affects the biochemical and molecular aspects of their immune response. Galleria mellonella larvae were exposed to 43°C for 15min, at the seventy second hour after natural infection with entomopathogenic fungus Beauveria bassiana. As a result, both qualitative and quantitative changes in hemolymph protein profiles, and among them infection-induced changes in the amount of apolipophorin III (apoLp-III), were observed. Heat shock differently affects the expression of the tested immune-related genes. It transiently inhibits expression of antifungal peptides gallerimycin and galiomicin in both the fat body and hemocytes of infected larvae. The same, although to a lesser extent, concerned apoLp-III gene expression and was observed directly after heat shock. Nevertheless, in larvae that had recovered from heat shock, apoLp-III expression was higher in comparison to unshocked larvae in the fat body but not in hemocytes, which was consistent with the higher amount of this protein detected in the hemolymph of the infected, shocked larvae. Furthermore, lysozyme-type activity was higher directly after heat shock, while antifungal activity was significantly higher also in larvae that had recovered from heat shock, in comparison to the respective values in their non-shocked, infected counterparts. These results show how changes in the external temperature modulate the immune response of G. mellonella suffering from infection with its natural pathogen B. bassiana. Copyright © 2015 Elsevier Inc. All rights reserved.

Inflatable stretcher to transport patients

NASA Technical Reports Server (NTRS)

Clark, C. C.; Gordon, F. T., Jr.; Schmidt, C. B.

1970-01-01

Inflatable plastic bag inside strong, inflexible outer bag facilitates emergency transport of seriously burned or disabled patients. When the bag is inflated the patient is completely immobilized and cushioned from external shock. Air for breathing, temperature controls and communications may be provided by appropriate plug-in connections.

Saving Lives.

ERIC Educational Resources Information Center

Moon, Daniel

2002-01-01

Advises schools on how to establish an automated external defibrillator (AED) program. These laptop-size devices can save victims of sudden cardiac arrest by delivering an electrical shock to return the heartbeat to normal. Discusses establishing standards, developing a strategy, step-by-step advice towards establishing an AED program, and school…

21 CFR 870.5225 - External counter-pulsating device.

Code of Federal Regulations, 2014 CFR

2014-04-01

..., prescription device used to assist the heart by applying positive or negative pressure to one or more of the body's limbs in synchrony with the heart cycle. (b) Classification. (1) Class II (special controls... angina pectoris; acute myocardial infarction; cardiogenic shock; congestive heart failure; postoperative...

Optimal Mission Abort Policy for Systems Operating in a Random Environment.

PubMed

Levitin, Gregory; Finkelstein, Maxim

2018-04-01

Many real-world critical systems, e.g., aircrafts, manned space flight systems, and submarines, utilize mission aborts to enhance their survivability. Specifically, a mission can be aborted when a certain malfunction condition is met and a rescue or recovery procedure is then initiated. For systems exposed to external impacts, the malfunctions are often caused by the consequences of these impacts. Traditional system reliability models typically cannot address a possibility of mission aborts. Therefore, in this article, we first develop the corresponding methodology for modeling and evaluation of the mission success probability and survivability of systems experiencing both internal failures and external shocks. We consider a policy when a mission is aborted and a rescue procedure is activated upon occurrence of the mth shock. We demonstrate the tradeoff between the system survivability and the mission success probability that should be balanced by the proper choice of the decision variable m. A detailed illustrative example of a mission performed by an unmanned aerial vehicle is presented. © 2017 Society for Risk Analysis.

What can we learn from "internal plateaus"? The peculiar afterglow of GRB 070110

NASA Astrophysics Data System (ADS)

Beniamini, P.; Mochkovitch, R.

2017-09-01

Context. The origin of the prompt emission of gamma-ray bursts is highly debated. Proposed scenarios involve various dissipation processes (shocks, magnetic reconnection, and inelastic collisions) above or below the photosphere of an ultra-relativistic outflow. Aims: We search for observational features that could help to favour one scenario over the others by constraining the dissipation radius, the magnetization of the outflow, or by indicating the presence of shocks. Bursts showing peculiar behaviours can emphasize the role of a specific physical ingredient, which becomes more apparent under certain circumstances. Methods: We study GRB 070110, which exhibited several remarkable features during its early afterglow; I.e. a very flat plateau terminated by an extremely steep drop and immediately followed by a bump. We modelled the plateau as the photospheric emission from a long-lasting outflow of moderate Lorentz factor (Γ 20), which lags behind an ultra-relativistic (Γ > 100) ejecta that is responsible for the prompt emission. We computed the dissipation of energy in the forward and reverse shocks resulting from the deceleration of this ejecta by the external medium (uniform or stellar wind). Results: We find that photospheric emission from the long-lasting outflow can account for the plateau properties (luminosity and spectrum) assuming that some dissipation takes place in the flow. The geometrical timescale at the photospheric radius is so short that the observed decline at the end of the plateau likely corresponds to the actual shutdown of the activity in the central engine. The bump that follows results from the power dissipated in the reverse shock, which develops when the material making the plateau catches up with the initially fast shell in front, after the fast shell has decelerated. Conclusions: The proposed interpretation suggests that the prompt phase results from dissipation above the photosphere while the plateau has a photospheric origin. If the bump is produced by the reverse shock, it implies an upper limit (σ ≲ 0.1) on the magnetization of the low Γ material making the plateau. A plateau that is terminated by a drop as steep as in GRB 070110 was not observed in any other long burst. It could mean that persistent outflows are very uncommon or that the plateau luminosity or the energy of the emitted photons are generally much lower because the outflow remains mostly adiabatic or has a Lorentz factor below 10.

Modelling socio-metabolic transitions: The historical take-off, the acceleration of fossil fuel use, and the 1970s oil price shock - the first trigger of a future decline?

NASA Astrophysics Data System (ADS)

Wiedenhofer, Dominik; Rovenskaya, Elena; Krausmann, Fridolin; Haas, Willi; Fischer-Kowalski, Marina

2013-04-01

By talking about socio-metabolic transitions, we talk about changes in the energy base of socio-economic systems, leading to fundamental changes in social and environmental relations. This refers to the historical shift from a biomass-based (agrarian) economy to a fossil fuel based (industrial) economy just as much as to a future shift from fossil fuels to renewable energy carriers. In our presentation, • We will first show that this pattern of transition can be identified for most high income industrial countries: the later the transition started, the faster it proceeded, and the turning point to stabilization of metabolic rates in all of them happened in the early 1970ies. Due to the inherent non-linearity of this process, two approaches will be aplied to estimate parameters for the starting point, transition speed and saturation level: firstly a combination of an expontential and a generalized logistic function and secondly a Gompertz function. For both an iterative test procedure is applied to find the global minimum of the residual error for the whole function and all its parameters. This theory-based approach allows us to apply a robust methodology across all cases, thereby yielding results which can be generalized. • Next, we will show that this was not just a "historical" socio-ecological transition, however. Currently, a substantial number of countries comprising more than half of the world's population are following a similar transitional pathway at an ever accelerating pace. Based on empirical data on physical resource use and the above sketched methodology, we can show that these so-called emerging economies are currently in the take-off or acceleration phase of the very same transition. • Apart from these "endogenous" processes of socio-metabolic transition, we will investigate the effect of external shocks and their impact on the dynamics of energy and materials use. The first such shock we will explore is the oil crisis of 1972 that possibly triggered the end of rapid physical growth in high income countries. This could contribute to understanding the potential effect of other such shocks such as the rise in energy prices preceding the recent crisis, or future shocks related to the risks of nuclear energy or unconventional fossil fuels.

Externalizing behavior from early childhood to adolescence: Prediction from inhibition, language, parenting, and attachment.

PubMed

Roskam, Isabelle

2018-03-22

The aim of the current research was to disentangle four theoretically sound models of externalizing behavior etiology (i.e., attachment, language, inhibition, and parenting) by testing their relation with behavioral trajectories from early childhood to adolescence. The aim was achieved through a 10-year prospective longitudinal study conducted over five waves with 111 referred children aged 3 to 5 years at the onset of the study. Clinical referral was primarily based on externalizing behavior. A multimethod (questionnaires, testing, and observations) approach was used to estimate the four predictors in early childhood. In line with previous studies, the results show a significant decrease of externalizing behavior from early childhood to adolescence. The decline was negatively related to mothers' coercive parenting and positively related to attachment security in early childhood, but not related to inhibition and language. The study has implications for research into externalizing behavior etiology recommending to gather hypotheses from various theoretically sound models to put them into competition with one another. The study also has implications for clinical practice by providing clear indications for prevention and early intervention.

Identifying early pathways of risk and resilience: The codevelopment of internalizing and externalizing symptoms and the role of harsh parenting.

PubMed

Wiggins, Jillian Lee; Mitchell, Colter; Hyde, Luke W; Monk, Christopher S

2015-11-01

Psychological disorders co-occur often in children, but little has been done to document the types of conjoint pathways internalizing and externalizing symptoms may take from the crucial early period of toddlerhood or how harsh parenting may overlap with early symptom codevelopment. To examine symptom codevelopment trajectories, we identified latent classes of individuals based on internalizing and externalizing symptoms across ages 3-9 and found three symptom codevelopment classes: normative symptoms (low), severe-decreasing symptoms (initially high but rapidly declining), and severe symptoms (high) trajectories. Next, joint models examined how parenting trajectories overlapped with internalizing and externalizing symptom trajectories. These trajectory classes demonstrated that, normatively, harsh parenting increased after toddlerhood, but the severe symptoms class was characterized by a higher level and a steeper increase in harsh parenting and the severe-decreasing class by high, stable harsh parenting. In addition, a transactional model examined the bidirectional relationships among internalizing and externalizing symptoms and harsh parenting because they may cascade over time in this early period. Harsh parenting uniquely contributed to externalizing symptoms, controlling for internalizing symptoms, but not vice versa. In addition, internalizing symptoms appeared to be a mechanism by which externalizing symptoms increase. Results highlight the importance of accounting for both internalizing and externalizing symptoms from an early age to understand risk for developing psychopathology and the role harsh parenting plays in influencing these trajectories.

Early prediction of norepinephrine dependency and refractory septic shock with a multimodal approach of vascular failure.

PubMed

Conrad, Marie; Perez, Pierre; Thivilier, Carine; Levy, Bruno

2015-08-01

The purpose of the study is to improve our ability to detect catecholamine dependency and refractory septic shock. Fifty-one patients with septic shock were studied within the first 4 hours of norepinephrine administration. Patients were divided into 2 groups according to their evolution in the intensive care unit, namely, group A, shock reversal, and group B, no shock reversal. Reversal of shock was defined as the maintenance of a systolic blood pressure greater than or equal to 90 mm Hg without vasopressor support for 24 hours or more. Vascular reactivity was tested using incremental doses of phenylephrine. Muscle tissue oxygen saturation and its changes during a vascular occlusion test were measured. Group B patients had a higher Sequential Organ Failure Assessment (SOFA) score and lactate level and more frequently received norepinephrine and renal replacement. Overall mortality was 100% in group B (16/16) and 20% (7/35) in group A. Phenylephrine increased mean arterial pressure in a dose-dependent manner more significantly in group A patients than in group B (P = .0004). Basal tissue oxygen saturation and the recovery slope after vascular occlusion test were lower in group B. In multivariate analysis, 4 parameters remained independently associated with mortality: the increase in mean arterial pressure at phenylephrine 6 μg/kg per minute, the recovery slope, SOFA score, and norepinephrine doses at H0. The intensity of septic shock-induced vascular hyporesponsiveness to vasopressor is tightly linked to septic shock severity and evolution and may potentially be identified early with simple to obtain parameters such as near-infrared spectroscopy value, SOFA score, or norepinephrine dose. Copyright © 2015 Elsevier Inc. All rights reserved.

[Use of quantitative electroencephalogram in patients with septic shock].

PubMed

Ma, Yujie; Ouyang, Bin; Guan, Xiangdong

2016-01-19

To observe the quantitative electroencephalogram (qEEG) characteristics of the patients with septic shock in intensive care unit (ICU), and to find the early presence and severity of septic-associated encephalopathy (SAE) in these patients. During November 2014 to August 2015, 26 cases with septic shock were included from the ICU of the First Affiliated Hospital, Sun Yat-sen University.During the same period, 14 healthy volunteers were included as control. The brain function instrument was used to monitor the patients by the bed, placing leads as the internationally used 10-20 system, bipolar longitudinal F3-P3, F4-P4 four channels, and then consecutive clips of 5 minutes was chosen, using the average value of the clips, the amplitude integrated electroencephalogram (aEEG), relative frequency band energy, spectrum entropy, relative alpha ariability to carry out statistical analysis.And the qEEG features of septic shock patients with different Glasgow coma scale (GCS) levels were also analyzed. (1) 96% of the patients with septic shock had EEG abnormalities.Alpha frequency band energy, alpha ariability, aEEG amplitude, spectrum entropy decreased significantly (P<0.05=, while the delta frequency band energy significantly increased (P<0.05=. (2) aEEG amplitude decline appeared in 34% of patients with septic shock, and within the septic shock groups, amplitude decreased significantly (P<0.05= in patients with GCS under five. Patients with septic shock tends to have diffuse inhibition in EEG, and the inhibition degree can reflect cerebral lesion degree; changes of EEG frequency as early warning indicators of brain damage are sensitive, and the decline of amplitude often indicates critical injury.

Developmental timing and continuity of exposure to interparental violence and externalizing behavior as prospective predictors of dating violence.

PubMed

Narayan, Angela J; Englund, Michelle M; Egeland, Byron

2013-11-01

This study investigated the prospective pathways of children's exposure to interparental violence (EIPV) in early and middle childhood and externalizing behavior in middle childhood and adolescence as developmental predictors of dating violence perpetration and victimization at ages 23 and 26 years. Participants (N = 168) were drawn from a longitudinal study of low-income families. Path analyses examined whether timing or continuity of EIPV predicted dating violence and whether timing or continuity of externalizing behavior mediated these pathways. Results indicated that EIPV in early childhood directly predicted perpetration and victimization at age 23. There were significant indirect effects from EIPV to dating violence through externalizing behavior in adolescence and life stress at age 23. Independent of EIPV, externalizing behavior in middle childhood also predicted dating violence through externalizing behavior in adolescence and life stress at age 23, but this pathway stemmed from maltreatment. These results highlight that the timing of EIPV and both the timing and the continuity of externalizing behavior are critical risks for the intergenerational transmission of dating violence. The findings support a developmental perspective that negative early experiences and children's externalizing behavior are powerful influences for dating violence in early adulthood.

Developmental Timing and Continuity of Exposure to Interparental Violence and Externalizing Behavior as Prospective Predictors of Dating Violence

PubMed Central

Narayan, Angela J.; Englund, Michelle M.; Egeland, Byron

2014-01-01

This study investigated the prospective pathways of children's exposure to interparental violence (EIPV) in early and middle childhood and externalizing behavior in middle childhood and adolescence as developmental predictors of dating violence perpetration and victimization at ages 23 and 26 years. Participants (N = 168) were drawn from a longitudinal study of low-income families. Path analyses examined whether timing or continuity of EIPV predicted dating violence and whether timing or continuity of externalizing behavior mediated these pathways. Results indicated that EIPV in early childhood directly predicted perpetration and victimization at age 23. There were significant indirect effects from EIPV to dating violence through externalizing behavior in adolescence and life stress at age 23. Independent of EIPV, externalizing behavior in middle childhood also predicted dating violence through externalizing behavior in adolescence and life stress at age 23, but this pathway stemmed from maltreatment. These results highlight that the timing of EIPV and both the timing and continuity of externalizing behavior are critical risks for the intergenerational transmission of dating violence. Findings support a developmental perspective that negative early experiences and children's externalizing behavior are powerful influences for dating violence in early adulthood. PMID:24229543

Energy Security Role of Biofuels in Evolving Liquid Fuel Markets

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

Brown, Maxwell; Uria-Martinez, Rocio; Leiby, Paul N.

We explore the role of biofuels in mitigating the negative impacts of oil supply shocks on fuel markets under a range of oil price trajectories and biofuel blending mandate levels. Using a partial equilibrium model of US biofuels production and petroleum fuels trade, we discuss the adjustments in light-duty vehicle fuel mix, fuel prices, and renewable identification number (RIN) prices following each shock as well as the distribution of shock costs across market participants. Ethanol is used as both a complement (blend component in E10) and a substitute (in E15 and E85 blends) to gasoline. Results show that, during oilmore » supply shocks, the role of ethanol as a substitute dominates and allows some mitigation of the shock. As US petroleum imports decrease with growing US oil production, the net economic welfare effect of sudden oil price changes and the energy security role of biofuels becomes less clear than it has been in the past. Although fuel consumers lose when oil price increases due to an external shock, domestic fuel producers gain. In some cases, depending on import share and supply and demand elasticities, we show that the gain to producers could more than offset consumer losses. However, in most cases evaluated here, sudden oil-price increases remain costly.« less

Involvement of the Sieve Element Cytoskeleton in Electrical Responses to Cold Shocks1[W

PubMed Central

Hafke, Jens B.; Ehlers, Katrin; Föller, Jens; Höll, Sabina-Roxana; Becker, Stefanie; van Bel, Aart J.E.

2013-01-01

This study dealt with the visualization of the sieve element (SE) cytoskeleton and its involvement in electrical responses to local cold shocks, exemplifying the role of the cytoskeleton in Ca2+-triggered signal cascades in SEs. High-affinity fluorescent phalloidin as well as immunocytochemistry using anti-actin antibodies demonstrated a fully developed parietal actin meshwork in SEs. The involvement of the cytoskeleton in electrical responses and forisome conformation changes as indicators of Ca2+ influx was investigated by the application of cold shocks in the presence of diverse actin disruptors (latrunculin A and cytochalasin D). Under control conditions, cold shocks elicited a graded initial voltage transient, ΔV1, reduced by external La3+ in keeping with the involvement of Ca2+ channels, and a second voltage transient, ΔV2. Cytochalasin D had no effect on ΔV1, while ΔV1 was significantly reduced with 500 nm latrunculin A. Forisome dispersion was triggered by cold shocks of 4°C or greater, which was indicative of an all-or-none behavior. Forisome dispersion was suppressed by incubation with latrunculin A. In conclusion, the cytoskeleton controls cold shock-induced Ca2+ influx into SEs, leading to forisome dispersion and sieve plate occlusion in fava bean (Vicia faba). PMID:23624858

Involvement of the sieve element cytoskeleton in electrical responses to cold shocks.

PubMed

Hafke, Jens B; Ehlers, Katrin; Föller, Jens; Höll, Sabina-Roxana; Becker, Stefanie; van Bel, Aart J E

2013-06-01

This study dealt with the visualization of the sieve element (SE) cytoskeleton and its involvement in electrical responses to local cold shocks, exemplifying the role of the cytoskeleton in Ca(2+)-triggered signal cascades in SEs. High-affinity fluorescent phalloidin as well as immunocytochemistry using anti-actin antibodies demonstrated a fully developed parietal actin meshwork in SEs. The involvement of the cytoskeleton in electrical responses and forisome conformation changes as indicators of Ca(2+) influx was investigated by the application of cold shocks in the presence of diverse actin disruptors (latrunculin A and cytochalasin D). Under control conditions, cold shocks elicited a graded initial voltage transient, ΔV1, reduced by external La(3+) in keeping with the involvement of Ca(2+) channels, and a second voltage transient, ΔV2. Cytochalasin D had no effect on ΔV1, while ΔV1 was significantly reduced with 500 nm latrunculin A. Forisome dispersion was triggered by cold shocks of 4°C or greater, which was indicative of an all-or-none behavior. Forisome dispersion was suppressed by incubation with latrunculin A. In conclusion, the cytoskeleton controls cold shock-induced Ca(2+) influx into SEs, leading to forisome dispersion and sieve plate occlusion in fava bean (Vicia faba).

[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.

Internal defibrillation: where we have been and where we should be going?

PubMed

Lévy, Samuel

2005-08-01

Internal cardioversion has been developed as an alternative technique for patients who are resistant to external DC cardioversion of atrial fibrillation (AF) and was found to be associated with higher success rates. It used initially high energies (200-300 J) delivered between an intracardiac catheter and a backplate. Subsequent studies have shown that it is possible to terminate with energies of 1 to 6 Joules, paroxysmal or induced AF in 90 percent of patients and persistent AF in 75 percent of patients, using biphasic shocks delivered between a right atrium-coronary sinus vectors. Consequently, internal atrial defibrillation can be performed under sedation only without the need for general anesthesia. Recently developed external defibrillators, capable of delivering biphasic shocks, have increased the success rates of external cardioversion and reduced the need for internal cardioversion. However, internal defibrillation is still useful in overweight or obese patients, in patients with chronic obstructive pulmonary disease or asthma who are more difficult to defibrillate, and in patients with implanted devices which may be injured by high energy shocks. Low energy internal defibrillation has also proven to be safe and this has prompted the development of implantable devices for terminating AF. The first device used was the Metrix system, a stand-alone atrial defibrillator (without ventricular defibrillation) which was found to be safe and effective in selected groups of patients. Unfortunately, this device is no longer being marketed. Only double chamber defibrillators with pacing capabilities are presently available: the Medtronic GEM III AT, an updated version of the Jewel AF and the Guidant PRIZM AVT. These devices can be patient-activated or programmed to deliver automatically ounce atrial tachyarrhythmias are detected, therapies including pacing or/and shocks. Attempts to define the group of patients who might benefit from these devices are described but the respective role of atrial defibrillators versus other non-pharmacologic therapies for AF, such as surgery and radiofrequency catheter ablation, remains to be determined. Advantages and limitations or atrial defibrillators and approaches to reduce shock related discomfort which may be a concern in some patients, are reviewed. Studies have shown that despite shock discomfort, quality of life was improved in patients with atrial defibrillators and the need for repeated hospitalizations was reduced. The cost of these devices remains a concern for the treatment of a non-lethal arrhythmia. Attention that atrial defibrillators will receive from cardiologists and from the industry in the future, will depend of the long-term results of other non-pharmacological options and of the identification of the group of AF patients which will require restoration and maintenance of sinus rhythm. But there is no doubt that selected subsets of patients with AF could benefit from atrial defibrillation.

The History of the APS Topical Group on Shock Compression of Condensed Matter

NASA Astrophysics Data System (ADS)

Forbes, Jerry W.

2002-07-01

In order to provide broader scientific recognition and to advance the science of shock compressed condensed matter, a group of American Physical Society (APS) members worked within the Society to make this field an active part of the APS. Individual papers were presented at APS meetings starting in the 1940's and shock wave sessions were organized starting with the 1967 Pasadena meeting. Shock wave topical conferences began in 1979 in Pullman, WA. Signatures were obtained on a petition in 1984 from a balanced cross-section of the shock wave community to form an APS Topical Group (TG). The APS Council officially accepted the formation of the Shock Compression of Condensed Matter (SCCM) TG at its October 1984 meeting. This action firmly aligned the shock wave field with a major physical science organization. Most early topical conferences were sanctioned by the APS while those held after 1992 were official APS meetings. The topical group organizes a shock wave topical conference in odd numbered years while participating in shock wave/high pressure sessions at APS general meetings in even numbered years.

EARLY IMPACT MELTING AND SPACE EXPOSURE HISTORY OF THE PAT91501 LCHONDRITE

NASA Technical Reports Server (NTRS)

Bogard, Donald D.; Garrison, D. H.; Herzog, G. F.; Xue, S.; Klein, J.; Middleton, R.

2004-01-01

Collisions probably occurred frequently in the early history of the asteroid belt. Their effects, which should be recorded in meteorites, must have included heating and melting along with shock alteration of mineral textures. Some non-chondritic meteorite types e.g., eucrites and IIE and IAB irons - do indeed give evidence of extensive impact heating more than 3.4 Gyr ago. The ordinary chondrites, in contrast, show little evidence of early impact heating. The Ar-Ar and Rb-Sr ages of ordinary chondrites that experienced intense shock are for the most part relatively young, many less than 1.5 Gyr. The numerous L-chondrites with Ar- Ar ages clustering near 0.5 Gy are a well-known example. One of them, the 105-kg Chico Lchondrite, shows the effects of unusually intense heating. It is approximately 60% impact melt and likely formed as a dyke beneath a large crater when the L-chondrite parent body underwent a very large impact approximately 0.5 Gyr ago. In rare instances, older shock dates are indicated for ordinary chondrites. Dixon et al show early impact resetting of Ar-Ar ages of a few LL-chondrites including MIL 99301 at 4.23 0.03 Gyr, but in none of these stones did shock lead to extensive melting. As of 2003, searches for chondritic melts attributable to early shock had turned up only the Shaw L-chondrite, which has an Ar-Ar age of approximately 4.42 Gyr. PAT91501 is an 8.55-kg L-chondrite containing vesicles and metal-troilite nodules. It is a unique, near-total impact melt, unshocked, depleted in siderophile and chalcophile elements, and contains only approximately 10% relic chondritic material. The authors conclude that PAT91501 crystallized rapidly and from a much more homogeneous melt than did Shaw. They suggest that PAT resembles Chico and likely formed as an impact melt vein within an impact crater. To define the history of PAT, we have determined its Ar-39-Ar-40 age and measured several radioactive and stable nuclides produced during its space exposure to cosmic rays.

Early decreased neutrophil responsiveness is related to late onset sepsis in multitrauma patients: An international cohort study.

PubMed

Groeneveld, Kathelijne M; Koenderman, Leo; Warren, Brian L; Jol, Saskia; Leenen, Luke P H; Hietbrink, Falco

2017-01-01

Severe trauma can lead to the development of infectious complications after several days, such as sepsis. Early identification of patients at risk will aid anticipating these complications. The aim of this study was to test the relation between the acute (<24 hours) inflammatory response after injury measured by neutrophil responsiveness and the late (>5 days) development of septic complications and validate this in different trauma populations. Two prospective, observational, cohort series in the Netherlands and South Africa, consisting of severely injured trauma patients. Neutrophil responsiveness by fMLF-induced active FcγRII was measured in whole blood flowcytometry, as read out for the systemic immune response within hours after trauma. Sepsis was scored daily. Ten of the 36 included Dutch patients developed septic shock. In patients with septic shock, neutrophils showed a lower expression of fMLF-induced active FcγRII immediately after trauma when compared to patients without septic shock (P = 0.001). In South Africa 11 of 73 included patients developed septic shock. Again neutrophils showed lower expression of fMLF induced active FcγRII (P = 0.001). In the combined cohort, all patients who developed septic shock demonstrated a decreased neutrophil responsiveness. Low responsiveness of neutrophils for the innate stimulus fMLF immediately after trauma preceded the development of septic shock during admission by almost a week and did not depend on a geographical/racial background, hospital protocols and health care facilities. Decreased neutrophil responsiveness appears to be a prerequisite for septic shock after trauma. This might enable anticipation of this severe complication in trauma patients.

Shock Test Program. Shock Isolation Design Manual for SAFEGUARD TSE Systems and Equipment.

DTIC Science & Technology

1973-08-01

under the direction of the Huntsville Division, Corps of Engineers. Much of the information in Part I and Part II is extracted from " Development of...49 3.2.2 Configuration Development 1-50 3.2.3 Suspension Arrangements 1-51 TABLE OF CONTENTS (Continued) Page 3.2.4 Platform Design 1-56 3.2.5 Elastic...shock isolation systems were considered in the design of the early NIKE-X facilities. As more descriptive prediction methods were developed and employed

Combined Measurement of Soluble ST2 and Amino-Terminal Pro-B-Type Natriuretic Peptide Provides Early Assessment of Severity in Cardiogenic Shock Complicating Acute Coronary Syndrome.

PubMed

Tolppanen, Heli; Rivas-Lasarte, Mercedes; Lassus, Johan; Sadoune, Malha; Gayat, Etienne; Pulkki, Kari; Arrigo, Mattia; Krastinova, Evguenia; Sionis, Alessandro; Parissis, John; Spinar, Jindrich; Januzzi, James; Harjola, Veli-Pekka; Mebazaa, Alexandre

2017-07-01

Mortality in cardiogenic shock complicating acute coronary syndrome is high, and objective risk stratification is needed for rational use of advanced therapies such as mechanical circulatory support. Traditionally, clinical variables have been used to judge risk in cardiogenic shock. The aim of this study was to assess the added value of serial measurement of soluble ST2 and amino-terminal pro-B-type natriuretic peptide to clinical parameters for risk stratification in cardiogenic shock. CardShock (www.clinicaltrials.gov NCT01374867) is a prospective European multinational study of cardiogenic shock. The main study introduced CardShock risk score, which is calculated from seven clinical variables at baseline, and was associated with short-term mortality. Nine tertiary care university hospitals. Patients with cardiogenic shock caused by acute coronary syndrome (n=145). In this substudy, plasma samples from the study patients were analyzed at eight time points during the ICU or cardiac care unit stay. Additional prognostic value of the biomarkers was assessed with incremental discrimination improvement. The combination of soluble ST2 and amino-terminal pro-B-type natriuretic peptide showed excellent discrimination for 30-day mortality (area under the curve, 0.77 at 12 hr up to 0.93 at 5-10 d after cardiogenic shock onset). At 12 hours, patients with both biomarkers elevated (soluble ST2, ≥ 500 ng/mL and amino-terminal pro-B-type natriuretic peptide, ≥ 4,500 ng/L) had higher 30-day mortality (79%) compared to those with one or neither biomarkers elevated (31% or 10%, respectively; p < 0.001). Combined measurement of soluble ST2 and amino-terminal pro-B-type natriuretic peptide at 12 hours added value to CardShock risk score, correctly reclassifying 11% of patients. The combination of results for soluble ST2 and amino-terminal pro-B-type natriuretic peptide provides early risk assessment beyond clinical variables in patients with acute coronary syndrome-related cardiogenic shock and may help therapeutic decision making in these patients.

DebtRank: A Microscopic Foundation for Shock Propagation.

PubMed

Bardoscia, Marco; Battiston, Stefano; Caccioli, Fabio; Caldarelli, Guido

2015-01-01

The DebtRank algorithm has been increasingly investigated as a method to estimate the impact of shocks in financial networks, as it overcomes the limitations of the traditional default-cascade approaches. Here we formulate a dynamical "microscopic" theory of instability for financial networks by iterating balance sheet identities of individual banks and by assuming a simple rule for the transfer of shocks from borrowers to lenders. By doing so, we generalise the DebtRank formulation, both providing an interpretation of the effective dynamics in terms of basic accounting principles and preventing the underestimation of losses on certain network topologies. Depending on the structure of the interbank leverage matrix the dynamics is either stable, in which case the asymptotic state can be computed analytically, or unstable, meaning that at least one bank will default. We apply this framework to a dataset of the top listed European banks in the period 2008-2013. We find that network effects can generate an amplification of exogenous shocks of a factor ranging between three (in normal periods) and six (during the crisis) when we stress the system with a 0.5% shock on external (i.e. non-interbank) assets for all banks.

DebtRank: A Microscopic Foundation for Shock Propagation

PubMed Central

Bardoscia, Marco; Battiston, Stefano; Caccioli, Fabio; Caldarelli, Guido

2015-01-01

The DebtRank algorithm has been increasingly investigated as a method to estimate the impact of shocks in financial networks, as it overcomes the limitations of the traditional default-cascade approaches. Here we formulate a dynamical “microscopic” theory of instability for financial networks by iterating balance sheet identities of individual banks and by assuming a simple rule for the transfer of shocks from borrowers to lenders. By doing so, we generalise the DebtRank formulation, both providing an interpretation of the effective dynamics in terms of basic accounting principles and preventing the underestimation of losses on certain network topologies. Depending on the structure of the interbank leverage matrix the dynamics is either stable, in which case the asymptotic state can be computed analytically, or unstable, meaning that at least one bank will default. We apply this framework to a dataset of the top listed European banks in the period 2008–2013. We find that network effects can generate an amplification of exogenous shocks of a factor ranging between three (in normal periods) and six (during the crisis) when we stress the system with a 0.5% shock on external (i.e. non-interbank) assets for all banks. PMID:26091013

Diagnostic Progress and Results on the Magnetized Shock Experiment

NASA Astrophysics Data System (ADS)

Smith, R. J.; Weber, T. E.

2015-11-01

The Magnetized Shock Experiment (MSX) at LANL is reliably producing Field Reversed Configuration (FRC) plasmas spanning peak densities of ~ 1021-23 m-3, combined Te +Ti of 10s-500eV and velocities of 100-300km/s as a means to producing a laboratory supercritical collision-less shock. Visible light images showing discontinuities indicative of shocks and jetting have been obtained on various targets: co-solenoid B field, a metal wall and counter-solenoidal B fields (FRC capture and reconnection). Two chord interferometry, external and internal magnetic probing are routinely employed and x-ray diagnostic capability has recently been added. The pulsed polarimetry technique is being deployed which can measure the local magnetic field using Lidar Thomson scattering. In addition, a fiber optic version of pulsed polarimetry using a new specialty fiber that enhances fiber backscatter with Fiber Bragg Gratings is being developed. Magnetic fields of order ~ 1T have been measured, however a new modified shock chamber geometry and recent machine modifications enabling operation at increased θ-coil voltage are expected to improve translation speed and hence stagnation pressures. Progress on these diagnostics and results will be presented. DOE support Grant No DE-SC00010559.

Early Immune Function and Duration of Organ Dysfunction in Critically Ill Septic Children.

PubMed

Muszynski, Jennifer A; Nofziger, Ryan; Moore-Clingenpeel, Melissa; Greathouse, Kristin; Anglim, Larissa; Steele, Lisa; Hensley, Josey; Hanson-Huber, Lisa; Nateri, Jyotsna; Ramilo, Octavio; Hall, Mark W

2018-02-22

Late immune suppression is associated with nosocomial infection and mortality in septic adults and children. Relationships between early immune suppression and outcomes in septic children remain unclear. Prospective observational study to test the hypothesis that early innate and adaptive immune suppression are associated with longer duration of organ dysfunction in children with severe sepsis/septic shock. Methods, Measurements and Main Results: Children aged < 18 years meeting consensus criteria for severe sepsis or septic shock were sampled within 48 hours of sepsis onset. Healthy controls were sampled once. Innate immune function was quantified by whole blood ex vivo lipopolysaccharide-induced TNFα production capacity. Adaptive immune function was quantified by ex vivo phytohemagglutinin-induced IFNγ production capacity. 102 septic children and 35 healthy children were enrolled. Compared to healthy children, septic children demonstrated lower LPS-induced TNFα production (p < 0.0001) and lower PHA-induced IFNγ production (p<0.0001). Among septic children, early innate and adaptive immune suppression were associated with greater number of days with multiple organ dysfunction (MODS) and greater number of days with any organ dysfunction. On multivariable analyses, early innate immune suppression remained independently associated with increased MODS days [aRR 1.2 (1.03, 1.5)] and organ dysfunction days [aRR 1.2 (1.1, 1.3)]. Critically ill children with severe sepsis or septic shock demonstrate early innate and adaptive immune suppression. Early suppression of both innate and adaptive immunity are associated with longer duration of organ dysfunction and may be useful markers to guide investigations of immunomodulatory therapies in septic children.

The role of complement system in septic shock.

PubMed

Charchaflieh, Jean; Wei, Jiandong; Labaze, Georges; Hou, Yunfang Joan; Babarsh, Benjamin; Stutz, Helen; Lee, Haekyung; Worah, Samrat; Zhang, Ming

2012-01-01

Septic shock is a critical clinical condition with a high mortality rate. A better understanding of the underlying mechanisms is important to develop effective therapies. Basic and clinical studies suggest that activation of complements in the common cascade, for example, complement component 3 (C3) and C5, is involved in the development of septic shock. The involvement of three upstream complement pathways in septic shock is more complicated. Both the classical and alternative pathways appear to be activated in septic shock, but the alternative pathway may be activated earlier than the classical pathway. Activation of these two pathways is essential to clear endotoxin. Recent investigations have shed light on the role of lectin complement pathway in septic shock. Published reports suggest a protective role of mannose-binding lectin (MBL) against sepsis. Our preliminary study of MBL-associated serine protease-2 (MASP-2) in septic shock patients indicated that acute decrease of MASP-2 in the early phase of septic shock might correlate with in-hospital mortality. It is unknown whether excessive activation of these three upstream complement pathways may contribute to the detrimental effects in septic shock. This paper also discusses additional complement-related pathogenic mechanisms and intervention strategies for septic shock.

[Streptococcal toxic shock syndrome].

PubMed

Gvozdenović, Ljiljana; Pasternak, Janko; Milovanović, Stanislav; Ivanov, Dejan; Milić, Sasa

2010-01-01

Streptococcal toxic shock syndrome is now recognized as a toxin-mediated, multisystem illness. It is characterized by an early onset of shock with multiorgan failure and continues to be associated with high morbidity and mortality, caused by group A Streptococcus pyogenes. The symptoms for staphylococcal and streptococcal toxic shock syndrome are similar. Streptococcal toxic shock syndrome was not well described until 1993, when children who had suffered from varicella presented roughly 2-4 weeks later with a clinical syndrome highly suggestive of toxic shock syndrome. It is characterized by a sudden onset of fever, chills, vomiting, diarrhea, muscle aches and rash. It can rapidly progress to severe and intractable hypotension and multisystem dysfunction. Almost every organ system can he involved. Complications of streptococcal toxic shock syndrome may include kidney failure, liver failure (and even death. Crystalloids and inotropic agents are used to treat the hypovolemic shock aggressively, with close monitoring of the patient's mean arterial pressure and central venous pressure. An immediate and aggressive management of hypovolemic shock is essential in streptococcal toxic shock syndrome. Targeted antibiotics are indicated: penicillin or a beta-lactam antibiotic is used for treating group A streptococci, and clindamycin has emerged as a key portion of the standard treatment.

Transplant shock of northern red oak seedlings following simulated drought as influenced by root morphology

Treesearch

Douglass F. Jacobs; Francis Salifu; Anthony Davis

2005-01-01

Transplant shock, implicated by depressed seedling physiological response associated with moisture or nutrient stress immediately following planting, limits early plantation establishment. We investigated the impacts of simulated drought and transplant root volume on predawn leaf xylem water potential, photosynthetic assimilation rates, stomatal conductance, and growth...

Early Emission from Type Ia Supernovae

NASA Astrophysics Data System (ADS)

Rabinak, Itay; Livne, Eli; Waxman, Eli

2012-09-01

A unique feature of deflagration-to-detonation (DDT) white dwarf explosion models of supernovae of type Ia is the presence of a strong shock wave propagating through the outer envelope. We consider the early emission expected in such models, which is produced by the expanding shock-heated outer part of the ejecta and precedes the emission driven by radioactive decay. We expand on earlier analyses by considering the modification of the pre-detonation density profile by the weak shocks generated during the deflagration phase, the time evolution of the opacity, and the deviation of the post-shock equation of state from that obtained for radiation pressure domination. A simple analytic model is presented and shown to provide an acceptable approximation to the results of one-dimensional numerical DDT simulations. Our analysis predicts a ~103 s long UV/optical flash with a luminosity of ~1 to ~3 × 1039 erg s-1. Lower luminosity corresponds to faster (turbulent) deflagration velocity. The luminosity of the UV flash is predicted to be strongly suppressed at t > t drop ~ 1 hr due to the deviation from pure radiation domination.

Meteorite Impact-Induced Rapid NH3 Production on Early Earth: Ab Initio Molecular Dynamics Simulation.

PubMed

Shimamura, Kohei; Shimojo, Fuyuki; Nakano, Aiichiro; Tanaka, Shigenori

2016-12-14

NH 3 is an essential molecule as a nitrogen source for prebiotic amino acid syntheses such as the Strecker reaction. Previous shock experiments demonstrated that meteorite impacts on ancient oceans would have provided a considerable amount of NH 3 from atmospheric N 2 and oceanic H 2 O through reduction by meteoritic iron. However, specific production mechanisms remain unclear, and impact velocities employed in the experiments were substantially lower than typical impact velocities of meteorites on the early Earth. Here, to investigate the issues from the atomistic viewpoint, we performed multi-scale shock technique-based ab initio molecular dynamics simulations. The results revealed a rapid production of NH 3 within several picoseconds after the shock, indicating that shocks with greater impact velocities would provide further increase in the yield of NH 3 . Meanwhile, the picosecond-order production makes one expect that the important nitrogen source precursors of amino acids were obtained immediately after the impact. It was also observed that the reduction of N 2 proceeded according to an associative mechanism, rather than a dissociative mechanism as in the Haber-Bosch process.

Infancy Parenting and Externalizing Psychopathology from Childhood through Adulthood: Developmental Trends

ERIC Educational Resources Information Center

Lorber, Michael F.; Egeland, Byron

2009-01-01

Developmental models and previous findings suggest that early parenting is more strongly associated with externalizing problems in early childhood than it is in adolescence. In this article, the authors address whether the association of poor-quality infancy parenting and externalizing problems "rebounds" in adulthood. Poor-quality infancy…

Early Callous-Unemotional Behavior, Theory-of-mind, and a Fearful/Inhibited Temperament Predict Externalizing Problems in Middle and Late Childhood

PubMed Central

Song, Ju-Hyun; Waller, Rebecca; Hyde, Luke W.; Olson, Sheryl L.

2016-01-01

Childhood externalizing problems are more likely to be severe and persistent when combined with high levels of callous-unemotional (CU) behavior. A handful of recent studies have shown that CU behavior can also be reliably measured in the early preschool years, which may help to identify young children who are less likely to desist from early externalizing behaviors. The current study extends previous literature by examining the role of CU behavior in very early childhood in the prediction of externalizing problems in both middle and late childhood, and tests whether other relevant child characteristics, including Theory-of-Mind (ToM) and fearful/inhibited temperament moderate these pathways. Multi-method data, including parent reports of child CU behavior and fearful/inhibited temperament, observations of ToM, and teacher-reported externalizing problems were drawn from a prospective, longitudinal study of children assessed at ages 3, 6, and 10 (N=241; 48% female). Results demonstrated that high levels of CU behavior predicted externalizing problems at ages 6 and 10 over and above the effect of earlier externalizing problems at age 3, but that these main effects were qualified by two interactions. High CU behavior was related to higher levels of externalizing problems specifically for children with low ToM and a low fearful/inhibited temperament. The results show that a multitude of child characteristics likely interact across development to increase or buffer risk for child externalizing problems. These findings can inform the development of targeted early prevention and intervention for children with high CU behavior. PMID:26582182

Early Callous-Unemotional Behavior, Theory-of-Mind, and a Fearful/Inhibited Temperament Predict Externalizing Problems in Middle and Late Childhood.

PubMed

Song, Ju-Hyun; Waller, Rebecca; Hyde, Luke W; Olson, Sheryl L

2016-08-01

Childhood externalizing problems are more likely to be severe and persistent when combined with high levels of callous-unemotional (CU) behavior. A handful of recent studies have shown that CU behavior can also be reliably measured in the early preschool years, which may help to identify young children who are less likely to desist from early externalizing behaviors. The current study extends previous literature by examining the role of CU behavior in very early childhood in the prediction of externalizing problems in both middle and late childhood, and tests whether other relevant child characteristics, including Theory-of-Mind (ToM) and fearful/inhibited temperament moderate these pathways. Multi-method data, including parent reports of child CU behavior and fearful/inhibited temperament, observations of ToM, and teacher-reported externalizing problems were drawn from a prospective, longitudinal study of children assessed at ages 3, 6, and 10 (N = 241; 48 % female). Results demonstrated that high levels of CU behavior predicted externalizing problems at ages 6 and 10 over and above the effect of earlier externalizing problems at age 3, but that these main effects were qualified by two interactions. High CU behavior was related to higher levels of externalizing problems specifically for children with low ToM and a low fearful/inhibited temperament. The results show that a multitude of child characteristics likely interact across development to increase or buffer risk for child externalizing problems. These findings can inform the development of targeted early prevention and intervention for children with high CU behavior.

Pathway to a Phenocopy: Heat Stress Effects in Early Embryogenesis

PubMed Central

Crews, Sarah M.; McCleery, W. Tyler; Hutson, M. Shane

2015-01-01

Background Heat shocks applied at the onset of gastrulation in early Drosophila embryos frequently lead to phenocopies of U-shaped mutants – having characteristic failures in the late morphogenetic processes of germband retraction and dorsal closure. The pathway from non-specific heat stress to phenocopied abnormalities is unknown. Results Drosophila embryos subjected to 30-min, 38-°C heat shocks at gastrulation appear to recover and restart morphogenesis. Post-heat-shock development appears normal, albeit slower, until a large fraction of embryos develop amnioserosa holes (diameters > 100 μm). These holes are positively correlated with terminal U-shaped phenocopies. They initiate between amnioserosa cells and open over tens of minutes by evading normal wound healing responses. They are not caused by tissue-wide increases in mechanical stress or decreases in cell-cell adhesion, but instead appear to initiate from isolated apoptosis of amnioserosa cells. Conclusions The pathway from heat shock to U-shaped phenocopies involves the opening of one or more large holes in the amnioserosa that compromise its structural integrity and lead to failures in morphogenetic processes that rely on amnioserosa-generated tensile forces. The proposed mechanism by which heat shock leads to hole initiation and expansion is heterochonicity – i.e., disruption of morphogenetic coordination between embryonic and extra-embryonic cell types. PMID:26498920

[Fluid management and cause of death during shock period in patients with severe burns or burns complicated by inhalation injury].

PubMed

Zhang, Ming-liang; Li, Chi; Ma, Chun-xu

2003-11-01

To explore fluid management and cause of death during shock period in severe burns or burns with inhalation injury. One hundred and twelve patients with severe burns or burn complicated by inhalation injury admitted to our hospital from 1991 to 2000 were analyzed. The fluid management and death conditions during shock period were discussed. The fluid volume for resuscitation could be described as follows: the total fluid volume was 2.2 ml/(%TBSA.kg) including colloid fluid 0.5 ml/(%TBSA.kg), crystalloid fluid 1 ml/(%TBSA.kg)and water 0.7 ml/(%TBSA.kg) during first 24 hours. The total fluid volume was 1.8 ml/(%TBSA.kg) including colloid fluid 0.4 ml/(%TBSA.kg), crystalloid fluid 0.7 ml/(%TBSA.kg) and water 0.7 ml/(%TBSA.kg) during second 24 hours. There were no difference in fluid management between burns and burns with inhalation injury. Seven patients died due to respiratory failure during shock period. Many fluid formula can provide guidance for resuscitation and it is very important that early fluid therapy should accord with concrete clinical conditions of patients in order to pass smoothly through shock period. Early fluid management is not different between burns and burns with inhalation injury.

Lack of species-specific difference in pulmonary function when using mouse versus human plasma in a mouse model of hemorrhagic shock.

PubMed

Peng, Zhanglong; Pati, Shibani; Fontaine, Magali J; Hall, Kelly; Herrera, Anthony V; Kozar, Rosemary A

2016-11-01

Clinical studies have demonstrated that the early and empiric use of plasma improves survival after hemorrhagic shock. We have demonstrated in rodent models of hemorrhagic shock that resuscitation with plasma is protective to the lungs compared with lactated Ringer's solution. As our long-term objective is to determine the molecular mechanisms that modulate plasma's protective effects in injured bleeding patients, we have used human plasma in a mouse model of hemorrhagic shock. The goal of the current experiments is to determine if there are significant adverse effects on lung injury when using human versus mouse plasma in an established murine model of hemorrhagic shock and laparotomy. Mice underwent laparotomy and 90 minutes of hemorrhagic shock to a mean arterial pressure (MAP) of 35 ± 5 mm Hg followed by resuscitation at 1× shed blood using either mouse fresh frozen plasma (FFP), human FFP, or human lyophilized plasma. Mean arterial pressure was recorded during shock and for the first 30 minutes of resuscitation. After 3 hours, animals were killed, and lungs collected for analysis. There was a significant increase in early MAP when mouse FFP was used to resuscitate animals compared with human FFP or human lyophilized plasma. However, despite these differences, analysis of the mouse lungs revealed no significant differences in pulmonary histopathology, lung permeability, or lung edema between all three plasma groups. Analysis of neutrophil infiltration in the lungs revealed that mouse FFP decreased neutrophil influx as measured by neutrophil staining; however, myeloperoxidase immunostaining revealed no significant differences in between groups. The study of human plasma in a mouse model of hemorrhagic shock is feasible but does reveal some differences compared with mouse plasma-based resuscitation in physiologic measures such as MAP postresuscitation. Measures of end organ function such as lung injury appear to be comparable in this acute model of hemorrhagic shock and resuscitation.

Attenuated pediatric electrode pads for automated external defibrillator use in children.

PubMed

Atkins, Dianne L; Jorgenson, Dawn B

2005-07-01

This post-market, observational study is intended to evaluate reported uses of pediatric pads that reduce the energy delivered by some adult automated external defibrillators (AEDs) so that they may be used with pediatric patients. Users of the pediatric pads were asked to report any use of the pads, even if no shock was delivered and to provide detailed information about the event, caregiver and the patient. Reports of the use of pediatric pads have been received and confirmed for 27 patients, age range 0 days to 23 years, median 2 years. Ventricular fibrillation (VF) was reported in eight cases, age range 4.5 months to 10 years, median 3 years. Shocks were delivered to all VF patients, the average shock number was 1.9, range 1-4. All patients had termination of VF, were admitted to the hospital and five survived to hospital discharge. Non-shockable rhythms were reported in 16 patients, and the AED appropriately did not advise a shock. Eleven of these patients had asystole or PEA as their initial rhythm and did not survive to hospital discharge. One report contained no additional information other than that the patient did not survive, and in two other reports, the pads were not applied to patients. Voluntary reports of the use of attenuated pediatric defibrillation pads indicate the devices performed appropriately. All eight VF patients had termination of VF and five survived to hospital discharge. These data support the rapid deployment of AEDs for young children as well as adolescents and adults. Since the pediatric pads are available and deliver an appropriate dose for children, their use should be strongly encouraged.

On the Exit Boundary Condition for One-Dimensional Calculations of Pulsed Detonation Engine Performance

NASA Technical Reports Server (NTRS)

Wilson, Jack; Paxson, Daniel E.

2002-01-01

In one-dimensional calculations of pulsed detonation engine (PDE) performance, the exit boundary condition is frequently taken to be a constant static pressure. In reality, for an isolated detonation tube, after the detonation wave arrives at the exit plane, there will be a region of high pressure, which will gradually return to ambient pressure as an almost spherical shock wave expands away from the exit, and weakens. Initially, the flow is supersonic, unaffected by external pressure, but later becomes subsonic. Previous authors have accounted for this situation either by assuming the subsonic pressure decay to be a relaxation phenomenon, or by running a two-dimensional calculation first, including a domain external to the detonation tube, and using the resulting exit pressure temporal distribution as the boundary condition for one-dimensional calculations. These calculations show that the increased pressure does affect the PDE performance. In the present work, a simple model of the exit process is used to estimate the pressure decay time. The planar shock wave emerging from the tube is assumed to transform into a spherical shock wave. The initial strength of the spherical shock wave is determined from comparison with experimental results. Its subsequent propagation, and resulting pressure at the tube exit, is given by a numerical blast wave calculation. The model agrees reasonably well with other, limited, results. Finally, the model was used as the exit boundary condition for a one-dimensional calculation of PDE performance to obtain the thrust wall pressure for a hydrogen-air detonation in tubes of length to diameter ratio (L/D) of 4, and 10, as well as for the original, constant pressure boundary condition. The modified boundary condition had no performance impact for values of L/D > 10, and moderate impact for L/D = 4.

Identifying early pathways of risk and resilience: The co-development of internalizing and externalizing symptoms and the role of harsh parenting

PubMed Central

Wiggins, Jillian Lee; Mitchell, Colter; Hyde, Luke W.; Monk, Christopher S.

2016-01-01

Psychological disorders co-occur often in children, but little has been done to document the types of conjoint pathways internalizing and externalizing symptoms may take from the crucial early period of toddlerhood or how harsh parenting may overlap with early symptom co-development. To examine symptom co-development trajectories, we identified latent classes of individuals based on internalizing and externalizing symptoms across ages 3–9 and found three symptom co-development classes: normative symptoms (low), severe-decreasing symptoms (initially high but rapidly declining) and severe symptoms (high) trajectories. Next, joint models examined how parenting trajectories overlapped with internalizing and externalizing symptom trajectories. These trajectory classes demonstrated that, normatively, harsh parenting increased after toddlerhood, but the severe symptoms class was characterized by a higher level and steeper increase in harsh parenting and the severe-decreasing class by high, stable harsh parenting. Additionally, a transactional model examined the bi-directional relationships among internalizing and externalizing symptoms and harsh parenting as they may cascade over time in this early period. Harsh parenting uniquely contributed to externalizing symptoms, controlling for internalizing symptoms, but not vice versa. Also, internalizing symptoms appeared to be a mechanism by which externalizing symptoms increase. Results highlight the importance accounting for both internalizing and externalizing symptoms from an early age to understand risk for developing psychopathology and the role harsh parenting plays in influencing these trajectories. PMID:26439075

The influence of the energy emitted by solar flare soft X-ray bursts on the propagation of their associated interplanetary shock waves

NASA Technical Reports Server (NTRS)

Pinter, S.; Dryer, M.

1985-01-01

The relationship between the thermal energy released from 29 solar flares and the propagation features of their associated interplanetary shock waves that were detected at 1 AU is investigated. The 29 interplanetary shock waves were identified unambiguously and their tracking from each solar flare was deduced by tracking their associated interplanetary type-II radio emission. The thermal energy released in the solar flares was estimated from the time-intensity profiles of 1-8 A soft X-ray bursts from each flare. A good relationship is found between the flares' thermal energy with the IP shock-waves' transient velocity and arrival time at the earth - that is, the largest flare energy released is associated with the faster shock waves. Finally, a possible scenario of formation of a shock wave during the early phase of the flare and its propagation features is discussed.

Did College Choice Change during the Seventies?

ERIC Educational Resources Information Center

Jackson, Gregory A.

1988-01-01

Despite steady enrollment growth and external shocks to U.S. higher education system, high school graduates' college-going decisions in 1980, as much as in 1972, depended on their social, academic, and financial attributes. Analyses of two national longitudinal surveys underlie this finding, implying traditional students' college decisions are…

The Epidemiology of Hospital Death Following Pediatric Severe Sepsis: When, Why, and How Children With Sepsis Die.

PubMed

Weiss, Scott L; Balamuth, Fran; Hensley, Josey; Fitzgerald, Julie C; Bush, Jenny; Nadkarni, Vinay M; Thomas, Neal J; Hall, Mark; Muszynski, Jennifer

2017-09-01

The epidemiology of in-hospital death after pediatric sepsis has not been well characterized. We investigated the timing, cause, mode, and attribution of death in children with severe sepsis, hypothesizing that refractory shock leading to early death is rare in the current era. Retrospective observational study. Emergency departments and ICUs at two academic children's hospitals. Seventy-nine patients less than 18 years old treated for severe sepsis/septic shock in 2012-2013 who died prior to hospital discharge. None. Time to death from sepsis recognition, cause and mode of death, and attribution of death to sepsis were determined from medical records. Organ dysfunction was assessed via daily Pediatric Logistic Organ Dysfunction-2 scores for 7 days preceding death with an increase greater than or equal to 5 defined as worsening organ dysfunction. The median time to death was 8 days (interquartile range, 1-12 d) with 25%, 35%, and 49% of cumulative deaths within 1, 3, and 7 days of sepsis recognition, respectively. The most common cause of death was refractory shock (34%), then multiple organ dysfunction syndrome after shock recovery (27%), neurologic injury (19%), single-organ respiratory failure (9%), and nonseptic comorbidity (6%). Early deaths (≤ 3 d) were mostly due to refractory shock in young, previously healthy patients while multiple organ dysfunction syndrome predominated after 3 days. Mode of death was withdrawal in 72%, unsuccessful cardiopulmonary resuscitation in 22%, and irreversible loss of neurologic function in 6%. Ninety percent of deaths were attributable to acute or chronic manifestations of sepsis. Only 23% had a rise in Pediatric Logistic Organ Dysfunction-2 that indicated worsening organ dysfunction. Refractory shock remains a common cause of death in pediatric sepsis, especially for early deaths. Later deaths were mostly attributable to multiple organ dysfunction syndrome, neurologic, and respiratory failure after life-sustaining therapies were limited. A pattern of persistent, rather than worsening, organ dysfunction preceded most deaths.

A VERY DEEP CHANDRA OBSERVATION OF THE GALAXY GROUP NGC 5813: AGN SHOCKS, FEEDBACK, AND OUTBURST HISTORY

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

Randall, S. W.; Nulsen, P. E. J.; Jones, C.

2015-06-01

We present results from a very deep (650 ks) Chandra X-ray observation of the galaxy group NGC 5813, the deepest Chandra observation of a galaxy group to date. This system uniquely shows three pairs of collinear cavities, with each pair associated with an unambiguous active galactic nucleus (AGN) outburst shock front. The implied mean kinetic power is roughly the same for each outburst, demonstrating that the average AGN kinetic luminosity can remain stable over long timescales (∼50 Myr). The two older outbursts have larger, roughly equal total energies as compared with the youngest outburst, implying that the youngest outburst ismore » ongoing. We find that the gas radiative cooling rate and mean shock heating rate are well balanced at each shock front, suggesting that shock heating alone is sufficient to offset cooling and establish AGN/intracluster medium (ICM) feedback within at least the central 30 kpc. This heating takes place roughly isotropically and most strongly at small radii, as is required for feedback to operate. We suggest that shock heating may play a significant role in AGN feedback at smaller radii in other systems, where weak shocks are more difficult to detect. We find non-zero shock front widths that are too large to be explained by particle diffusion. Instead, all measured widths are consistent with shock broadening due to propagation through a turbulent ICM with a mean turbulent speed of ∼70 km s{sup −1}. Finally, we place lower limits on the temperature of any volume-filling thermal gas within the cavities that would balance the internal cavity pressure with the external ICM.« less

Lunar highland meteorite Dhofar 026 and Apollo sample 15418: Two strongly shocked, partially melted, granulitic breccias

USGS Publications Warehouse

Cohen, B. A.; James, O.B.; Taylor, L.A.; Nazarov, M.A.; Barsukova, L.D.

2004-01-01

Studies of lunar meteorite Dhofar 026, and comparison to Apollo sample 15418, indicate that Dhofar 026 is a strongly shocked granulitic breccia (or a fragmental breccia consisting almost entirely of granulitic breccia clasts) that experienced considerable post-shock heating, probably as a result of diffusion of heat into the rock from an external, hotter source. The shock converted plagioclase to maskelynite, indicating that the shock pressure was between 30 and 45 GPa. The post-shock heating raised the rock's temperature to about 1200 ??C; as a result, the maskelynite devitrified, and extensive partial melting took place. The melting was concentrated in pyroxene-rich areas; all pyroxene melted. As the rock cooled, the partial melts crystallized with fine-grained, subophitic-poikilitic textures. Sample 15418 is a strongly shocked granulitic breccia that had a similar history, but evidence for this history is better preserved than in Dhofar 026. The fact that Dhofar 026 was previously interpreted as an impact melt breccia underscores the importance of detailed petrographic study in interpretation of lunar rocks that have complex textures. The name "impact melt" has, in past studies, been applied only to rocks in which the melt fraction formed by shock-induced total fusion. Recently, however, this name has also been applied to rocks containing melt formed by heating of the rocks by conductive heat transfer, assuming that impact is the ultimate source of the heat. We urge that the name "impact melt" be restricted to rocks in which the bulk of the melt formed by shock-induced fusion to avoid confusion engendered by applying the same name to rocks melted by different processes. ?? Meteoritical Society, 2004.

Internalizing and externalizing psychopathology as predictors of cannabis use disorder onset during adolescence and early adulthood.

PubMed

Farmer, Richard F; Seeley, John R; Kosty, Derek B; Gau, Jeff M; Duncan, Susan C; Lynskey, Michael T; Lewinsohn, Peter M

2015-09-01

Risk-related liabilities associated with the development of cannabis use disorders (CUDs) during adolescence and early adulthood are thought to be established well before the emergence of the index episode. In this study, internalizing and externalizing psychopathology from earlier developmental periods were evaluated as risk factors for CUDs during adolescence and early adulthood. Participants (N = 816) completed 4 diagnostic assessments between the ages 16 and 30, during which current and past CUDs were assessed as well as a full range of psychiatric disorders associated with internalizing and externalizing psychopathology domains. In unadjusted and adjusted time-to-event analyses, externalizing but not internalizing psychopathology from proximal developmental periods predicted subsequent CUD onset. A large proportion of adolescent and early adult cases, however, did not manifest any externalizing or internalizing psychopathology during developmental periods before CUD onset. Findings are consistent with the emerging view that externalizing disorders from proximal developmental periods are robust risk factors for CUDs. Although the identification of externalizing liabilities may aid in the identification of individuals at risk for embarking on developmental pathways that culminate in CUDs, such liabilities are an incomplete indication of overall risk. (c) 2015 APA, all rights reserved).

Even the best laid plans sometimes go askew: career self-management processes, career shocks, and the decision to pursue graduate education.

PubMed

Seibert, Scott E; Kraimer, Maria L; Holtom, Brooks C; Pierotti, Abigail J

2013-01-01

Drawing on career self-management frameworks as well as image theory and the unfolding model of turnover, we developed a model predicting early career employees' decisions to pursue graduate education. Using a sample of 337 alumni from 2 universities, we found that early career individuals with intrinsic career goals, who engaged in career planning, who were less satisfied with their career, or who experienced impactful positive career shocks were more likely to intend to go to graduate school. In contrast, individuals with extrinsic career goals who were highly satisfied with their careers were less likely to intend to go to graduate school. Graduate education intentions, career planning, and the impact of having one's mentor leave the organization positively related to actual applications to graduate school. However, having extrinsic career goals, an impactful sooner than expected raise or promotion (a positive career shock), and a negative organizational change (a negative career shock) negatively related to the likelihood of applying. The career shocks' direct relationship to applications to graduate school, regardless of one's intentions, suggests that "the best laid plans" can sometimes be altered by unplanned events. This study contributes to the literatures on career self-management and graduate education and extends the application of the shock construct from the unfolding model of turnover to other career-related decisions. PsycINFO Database Record (c) 2013 APA, all rights reserved.

Early Parenting, Represented Family Relationships, and Externalizing Behavior Problems in Children Born Preterm

PubMed Central

Poehlmann, Julie; Burnson, Cynthia; Weymouth, Lindsay A.

2015-01-01

Through assessment of 173 preterm infants and their mothers at hospital discharge and at 9, 16, 24, 36, and 72 months, the study examined early parenting, attachment security, effortful control, and children’s representations of family relationships in relation to subsequent externalizing behavior problems. Less intrusive early parenting predicted more secure attachment, better effortful control skills, and fewer early behavior problems, although it did not directly relate to the structural or content characteristics of children’s represented family relationships. Children with higher effortful control scores at 24 months had more coherent family representations at 36 months. Moreover, children who exhibited less avoidance in their family representations at 36 months had fewer mother-reported externalizing behavior problems at 72 months. The study suggests that early parenting quality and avoidance in children’s represented relationships are important for the development of externalizing behavior problems in children born preterm. PMID:24580068

Early parenting, represented family relationships, and externalizing behavior problems in children born preterm.

PubMed

Poehlmann, Julie; Burnson, Cynthia; Weymouth, Lindsay A

2014-01-01

Through assessment of 173 preterm infants and their mothers at hospital discharge and at 9, 16, 24, 36, and 72 months, the study examined early parenting, attachment security, effortful control, and children's representations of family relationships in relation to subsequent externalizing behavior problems. Less intrusive early parenting predicted more secure attachment, better effortful control skills, and fewer early behavior problems, although it did not directly relate to the structural or content characteristics of children's represented family relationships. Children with higher effortful control scores at 24 months had more coherent family representations at 36 months. Moreover, children who exhibited less avoidance in their family representations at 36 months had fewer mother-reported externalizing behavior problems at 72 months. The study suggests that early parenting quality and avoidance in children's represented relationships are important for the development of externalizing behavior problems in children born preterm.

Nonlinear development of shocklike structure in the solar wind.

PubMed

Lee, E; Parks, G K; Wilber, M; Lin, N

2009-07-17

We report first in situ multispacecraft observations of nonlinear steepening of compressional pulses in the solar wind upstream of Earth's bow shock. The magnetic field of a compressional pulse formed at the upstream edge of density holes is shown to suddenly break and steepen into a shocklike structure. During the early phase of development thermalization of ions is insignificant. Substantial thermalization of ions occurs as gyrating ions are observed at the steepened edge. These observations indicate that the mechanisms causing the dissipation of magnetic fields (currents) and ions are different in the early phase of shock development.

Burnett-Cattaneo continuum theory for shock waves.

PubMed

Holian, Brad Lee; Mareschal, Michel; Ravelo, Ramon

2011-02-01

We model strong shock-wave propagation, both in the ideal gas and in the dense Lennard-Jones fluid, using a refinement of earlier work, which accounts for the cold compression in the early stages of the shock rise by a nonlinear, Burnett-like, strain-rate dependence of the thermal conductivity, and relaxation of kinetic-temperature components on the hot, compressed side of the shock front. The relaxation of the disequilibrium among the three components of the kinetic temperature, namely, the difference between the component in the direction of a planar shock wave and those in the transverse directions, particularly in the region near the shock front, is accomplished at a much more quantitative level by a rigorous application of the Cattaneo-Maxwell relaxation equation to a reference solution, namely, the steady shock-wave solution of linear Navier-Stokes-Fourier theory, along with the nonlinear Burnett heat-flux term. Our new continuum theory is in nearly quantitative agreement with nonequilibrium molecular-dynamics simulations under strong shock-wave conditions, using relaxation parameters obtained from the reference solution. ©2011 American Physical Society

PSR J2124-3358: A Bow Shock Nebula with an X-ray Tail

NASA Astrophysics Data System (ADS)

Chatterjee, S.; Gaensler, B. M.; Vigelius, M.; Cordes, J. M.; Arzoumanian, Z.; Stappers, B.; Ghavamian, P.; Melatos, A.

2005-12-01

As neutron stars move supersonically through the interstellar medium, their relativistic winds are confined by the ram pressure of the interstellar medium. The outer shocked layers may emit in Hα , producing a visible bow shock nebula, while the confined relativistic wind may produce radio or X-ray emission. The Hα bow shock nebula powered by the recycled pulsar J2124-3358 is asymmetric about the velocity vector and shows a marked kink. In recent observations with the Chandra X-ray Observatory, we have detected a long, curved X-ray tail associated with the pulsar. The tail is not aligned with the pulsar velocity, but is confined within the optical bow shock. The X-ray spectrum of the tail is well-fit by a power law, consistent with synchrotron emission from the wind termination shock and the post-shock flow. The presence of Hα and X-ray emission allows us to trace both the external ambient medium and the confined wind. In magnetohydrodynamic simulations, we verify that a bulk flow and non-uniformities in the ambient medium can produce the observed shape of the nebula, possibly in combination with an anisotropic pulsar wind. Support for this work was provided by the National Aeronautics and Space Administration through Chandra Award Number GO5-6075X issued by the Chandra X-ray Observatory Center, which is operated by the Smithsonian Astrophysical Observatory for and on behalf of the National Aeronautics Space Administration under contract NAS8-03060.

AED use in a passenger during a long-haul flight: repeated defibrillation with a successful outcome.

PubMed

Harve, Heini; Hämäläinen, Olavi; Kurola, Jouni; Silfvast, Tom

2009-04-01

Sudden cardiac arrest is one of the leading causes of death, and early defibrillation of ventricular fibrillation (VF) is the single most important intervention for improving survival. The automated external defibrillator (AED) and the concept of public access defibrillation provide a solution to shorten defibrillation delays. Commercial aircraft create a unique environment for the use of the AED since an emergency medical service system (EMS) response is not available. We review published studies on this subject and describe the case of a passenger who developed VF during an intercontinental flight and was successfully resuscitated despite recurrent episodes of VF. A 60-yr-old man developed VF during a flight from Tokyo to Helsinki. VF frequently recurred and shocks were delivered 21 times altogether. The aircraft was diverted to the city of Kuopio. When the local EMS crew encountered the patient 3 h after the onset of the cardiac arrest, the rhythm again converted to VF and three further shocks were delivered. The patient recovered, and 3 wk later he was transported to his home country, fully alert. There are three large studies reporting placing AEDs on commercial aircraft. No harm for co-passengers or malfunctions were reported. Survival rates have been higher than those obtained by well-performing EMS. According to previous studies, placing AEDs on commercial aircraft is also cost effective. The absence of a suitable diversion destination should not influence the rescuers' decision to attempt CPR on board.

[Septic shock due to infective endocarditis of stimulation system of implantable cardioverter-defibrillator].

PubMed

Porubčinová, I; Porubčin, S; Stančák, B; Beňa, M; Sabol, F

2012-01-01

We present a case of a 60-year old patient hospitalized at the Department of Infectious Diseases and Travel Medicine, Medical faculty of UPJS and L. Pasteurs University Hospital in Kosice with suspected gastroenteritis. The patient was admitted to an intensive care unit because of the signs of septic shock. Within one hour from admission, the patient was administered early goal directed therapy for septic shock. Subsequently, infectious endocarditis of stimulation electrodes and tricuspid valve was identified as the origin of the infection. The stimulation system was then explanted from a stabilized and afebrile patient at the Department of cardiac Surgery of Eastern Slovak Institute of Cardiac and Vascular Diseases in Kosice. This case should emphasise frequently atypical course of this serious disease and the need for early identification of severe sepsis to enable timely management to affect mortality.

Chemical studies of H chondrites. I - Mobile trace elements and gas retention ages

NASA Technical Reports Server (NTRS)

Lingner, David W.; Huston, Ted J.; Hutson, Melinda; Lipschutz, Michael E.

1987-01-01

Trends for 16 trace elements (Ag, As, Au, Bi, Cd, Co, Cs, Ga, In, K, Rb, Sb, Se, Te, Tl, and Zn), chosen to span a broad geochemical and thermal response range, in 44 H4-6 chondrites, differ widely from those in L4-6 chondrites. In particular, H chondrites classified as heavily shocked petrologically do not necessarily exhibit Ar-40 loss and vice versa. The clear-cut causal relationship between siderophile and mobile element loss with increasing late shock seen in L chondrites is not generally evident in the H group. H chondrite parent material experienced an early high temperature genetic episode that mobilized a substantial proportion of these trace elements so that later thermal episodes resulted in more subtle, collateral fractionations. Mildly shocked L chondrites escaped this early high temperature event, indicating that the two most numerous meteorite groups differ fundamentally in genetic history.

Emergency medical care requirements for large public assemblies and a new strategy for managing cardiac arrest in this setting.

PubMed

Weaver, W D; Sutherland, K; Wirkus, M J; Bachman, R

1989-02-01

During the 1986 World's Exposition held in Vancouver, British Columbia, the types and frequencies of emergency medical problems were assessed. The average number of patients seeking care was 3.93 +/- 0.95 per 1,000 visitors (daily range, 1.94 to 6.8). Patient loads were linearly related to gate attendance, but the correlation was imperfect (P less than .001, r = .63). Only 4.4% of patients evaluated on site by nurses and paramedics were referred for additional testing and treatment: of these patients, 30% had suspected serious musculoskeletal injury, 16% had abdominal pain, and 25% had complaints of chest pain, dizziness, or loss of consciousness. Lay employees (security personnel) were trained to use automatic external defibrillators. There were six cardiac arrests (0.3 per million visitors). Two patients collapsed with ventricular fibrillation, were defibrillated by lay personnel, quickly regained consciousness, and survived. The other arrests were associated with asystole or electromechanical dissociation; no shocks were inappropriately given, and all four died. We conclude that four of every 1,000 persons at this assembly sought emergency medical care, that 95% of the problems seen were minor with few requiring physician skills, and that the automatic external defibrillator was suited for this setting and could be used by lay responders to provide early definitive treatment.

Successful early romiplostim use in a case of severe immune thrombocytopenia with critical carotid arterial injury.

PubMed

Watanabe, Reiko; Tabayashi, Takayuki; Tomikawa, Tatsuki; Sagawa, Morihiko; Anan-Nemoto, Tomoe; Kimura, Yuta; Takahashi, Yasuyuki; Tokuhira, Michihide; Otaki, Satoshi; Oi, Hidenori; Sawano, Makoto; Sugiyama, Satoshi; Kizaki, Masahiro

2017-01-01

Thrombopoietin receptor (TPO-R) agonists have been shown to be effective in refractory chronic immune thrombocytopenia (ITP); however, their efficacy in patients under critical care is not known. We report the case of a female patient with a newly diagnosed ITP who experienced severe bleeding from an external wound. The patient was administered the standard treatments for ITP, which are high-dose intravenous immunoglobulin (IVIg) and corticosteroids. However, following failure of these treatments, we administered romiplostim on day 6 after the onset of ITP. On day 6 after the initiation of romiplostim, there was improvement in platelet count and bleeding tendency. We were subsequently able to perform a splenectomy successfully. The efficacy of TPO-R agonists in ITP has been reported in several situations, including before surgery in an ITP patient; however, the use of TPO-R for arterial bleeding with shock has not been reported. To our knowledge, the present article is a rare case report of the use of a TPO-R agonist in a patient with critical artery injury. Our data suggest that the early use of romiplostim is effective in emergency cases of newly diagnosed ITP with life-threatening bleeding, which is refractory to standard treatment.

The Observational Consequences of Proton-Generated Waves at Shocks

NASA Technical Reports Server (NTRS)

Reames, Donald V.

2000-01-01

In the largest solar energetic particle (SEP) events, acceleration takes place at shock waves driven out from the Sun by fast coronal mass ejections. Protons streaming away from strong shocks generate Alfven waves that trap particles in the acceleration region, limiting outflowing intensities but increasing the efficiency of acceleration to higher energies. Early in the events, with the shock still near the Sun, intensities at 1 AU are bounded and spectra are flattened at low energies. Elements with different charge-to-mass ratios, Q/A, differentially probe the wave spectra near shocks, producing abundance ratios that vary in space and time. An initial rise in He/H, while Fe/O declines, is a typical symptom of the non-Kolmogorov wave spectra in the largest events. Strong wave generation can cause cross-field scattering near the shock and unusually rapid reduction in anisotropies even far from the shock. At the highest energies, shock spectra steepen to form a "knee." For protons, this spectral knee can vary from approx. 10 MeV to approx. 1 GeV depending on shock conditions for wave growth. In one case, the location of the knee scales approximately as Q/A in the energy/nucleon spectra of other species.

Differential susceptibility to discipline: the moderating effect of child temperament on the association between maternal discipline and early childhood externalizing problems.

PubMed

van Zeijl, Jantien; Mesman, Judi; Stolk, Mirjam N; Alink, Lenneke R A; van Ijzendoorn, Marinus H; Bakermans-Kranenburg, Marian J; Juffer, Femmie; Koot, Hans M

2007-12-01

This study investigated the interaction of child temperament and maternal discipline in the prediction of externalizing problems in early childhood. Interaction effects were evaluated in a sample of 227 one- to three-year-old children with relatively high externalizing problems scores on the Child Behavior Checklist/1 1/2-5. Child temperament was reported by the mothers, maternal discipline was observed in a laboratory session, and child outcome measures included both mother-reported externalizing problems and observed physical aggression. Results indicate that children with difficult temperaments are more susceptible to negative discipline (i.e., they showed more externalizing problems) as well as more susceptible to positive discipline (i.e., they showed fewer externalizing problems and less physical aggression), as compared with children with relatively easy temperaments. These findings provide empirical evidence for the differential susceptibility hypothesis and suggest directions for enhancing the effectiveness of interventions aimed at reducing early childhood externalizing problems.

Gamma-Ray Bursts and Fast Transients. Multi-wavelength Observations and Multi-messenger Signals

NASA Astrophysics Data System (ADS)

Willingale, R.; Mészáros, P.

2017-07-01

The current status of observations and theoretical models of gamma-ray bursts and some other related transients, including ultra-long bursts and tidal disruption events, is reviewed. We consider the impact of multi-wavelength data on the formulation and development of theoretical models for the prompt and afterglow emission including the standard fireball model utilizing internal shocks and external shocks, photospheric emission, the role of the magnetic field and hadronic processes. In addition, we discuss some of the prospects for non-photonic multi-messenger detection and for future instrumentation, and comment on some of the outstanding issues in the field.

Opto-mechatronics issues in solid immersion lens based near-field recording

NASA Astrophysics Data System (ADS)

Park, No-Cheol; Yoon, Yong-Joong; Lee, Yong-Hyun; Kim, Joong-Gon; Kim, Wan-Chin; Choi, Hyun; Lim, Seungho; Yang, Tae-Man; Choi, Moon-Ho; Yang, Hyunseok; Rhim, Yoon-Chul; Park, Young-Pil

2007-06-01

We analyzed the effects of an external shock on a collision problem in a solid immersion lens (SIL) based near-field recording (NFR) through a shock response analysis and proposed a possible solution to this problem with adopting a protector and safety mode. With this proposed method the collision between SIL and media can be avoided. We showed possible solution for contamination problem in SIL based NFR through a numerical air flow analysis. We also introduced possible solid immersion lens designs to increase the fabrication and assembly tolerances of an optical head with replicated lens. Potentially, these research results could advance NFR technology for commercial product.

The Radiation, Interplanetary Shocks, and Coronal Sources (RISCS) Toolset

NASA Technical Reports Server (NTRS)

Zank, G. P.; Spann, James F.

2014-01-01

The goal of this project is to serve the needs of space system designers and operators by developing an interplanetary radiation environment model within 10 AU:Radiation, Interplanetary Shocks, and Coronal Sources (RISCS) toolset: (1) The RISCS toolset will provide specific reference environments for space system designers and nowcasting and forecasting capabilities for space system operators; (2) We envision the RISCS toolset providing the spatial and temporal radiation environment external to the Earth's (and other planets') magnetosphere, as well as possessing the modularity to integrate separate applications (apps) that can map to specific magnetosphere locations and/or perform the subsequent radiation transport and dosimetry for a specific target.

Method and System for Weakening Shock Wave Strength at Leading Edge Surfaces of Vehicle in Supersonic Atmospheric Flight

NASA Technical Reports Server (NTRS)

Pritchett, Victor E., II (Inventor); Wang, Ten-See (Inventor); Blankson, Isaiah M. (Inventor); Daso, Endwell O. (Inventor); Farr, Rebecca Ann (Inventor); Auslender, Aaron Howard (Inventor); Plotkin, Kenneth J. (Inventor)

2015-01-01

A method and system are provided to weaken shock wave strength at leading edge surfaces of a vehicle in atmospheric flight. One or more flight-related attribute sensed along a vehicle's outer mold line are used to control the injection of a non-heated, non-plasma-producing gas into a local external flowfield of the vehicle from at least one leading-edge surface location along the vehicle's outer mold line. Pressure and/or mass flow rate of the gas so-injected is adjusted in order to cause a Rankine-Hugoniot Jump Condition along the vehicle's outer mold line to be violated.

Is Thrombocytopenia an Early Prognostic Marker in Septic Shock?

PubMed

Thiery-Antier, Nadiejda; Binquet, Christine; Vinault, Sandrine; Meziani, Ferhat; Boisramé-Helms, Julie; Quenot, Jean-Pierre

2016-04-01

To assess whether early thrombocytopenia during septic shock is associated with an increased risk of death at day 28 and to identify risk factors associated with a low platelet count. Prospective, multicenter, observational cohort study. Fourteen ICUs from 10 French university teaching and nonacademic hospitals. Consecutive adult patients with septic shock admitted between November 2009 and September 2011 were eligible. None. Of the 1,495 eligible patients, 1,486 (99.4%) were included. Simplified Acute Physiology Score II score of greater than or equal to 56, immunosuppression, age of more than 65 years, cirrhosis, bacteremia (p ≤ 0.001 for each), and urinary sepsis (p = 0.005) were globally associated with an increased risk of thrombocytopenia within the first 24 hours following the onset of septic shock. Survival at day 28 estimated by the Kaplan-Meier method was lower in patients with thrombocytopenia and decreased with thrombocytopenia severity. By multivariate Cox regression, a platelet count of less than or equal to 100,000/mm3 was independently associated with a significantly increased risk of death within the 28 days following septic shock onset. The risk of death increased with the severity of thrombocytopenia (hazard ratio, 1.65; 95% CI, 1.31-2.08 for a platelet count below 50,000/mm3 vs > 150,000/mm3; p < 0.0001). This is the first study to investigate thrombocytopenia within the first 24 hours of septic shock onset as a prognostic marker of survival at day 28 in a large cohort of ICU patients. Measuring platelet count is inexpensive and easily feasible for the physician in routine practice, and thus, it could represent an easy "alert system" among patients in septic shock.

Discovery of a Time Lag between the Soft X-Ray and Radio Emission of the Tidal Disruption Flare ASASSN-14li: Evidence for Linear Disk–Jet Coupling

NASA Astrophysics Data System (ADS)

Pasham, Dheeraj R.; van Velzen, Sjoert

2018-03-01

The tidal disruption of a star by a supermassive black hole can result in transient radio emission. The electrons producing these synchrotron radio flares could either be accelerated inside a relativistic jet or externally by shocks resulting from an outflow interacting with the circumnuclear medium. Until now, evidence for the internal emission mechanism has been lacking; nearly all tidal disruption flare studies have adopted the external shock model to explain the observed properties of radio flares. Here we report a result that presents a challenge to external emission models: we discovered a cross-correlation between the soft X-ray (0.3–1 keV) and 16 GHz radio flux of the tidal disruption flare ASASSN-14li. Variability features in the X-ray light curve appear again in the radio light curve, but after a time lag of {12}-5+6 days. This demonstrates that the soft X-ray-emitting accretion disk regulates the radio emission. This coupling appears to be inconsistent with all previous external emission models for this source but is naturally explained if the radio emission originates from a freely expanding jet. We show that emission internal to an adiabatically expanding jet can also reproduce the observed evolution of the radio spectral energy distribution. Furthermore, both the correlation between X-ray and radio luminosity as well as our radio spectral modeling imply an approximately linear coupling between the accretion rate and jet power.

Constraining Gamma-ray Burst Initial Lorentz Factor with the Afterglow Onset Feature and Discovery of a Tight Γ0-E γ,iso Correlation

NASA Astrophysics Data System (ADS)

Liang, En-Wei; Yi, Shuang-Xi; Zhang, Jin; Lü, Hou-Jun; Zhang, Bin-Bin; Zhang, Bing

2010-12-01

The onset of gamma-ray burst (GRB) afterglow is characterized by a smooth bump in the early afterglow light curve as the GRB fireball is decelerated by the circumburst medium. We extensively search for GRBs with such an onset feature in their optical and X-ray light curves from the literature and from the catalog established with the Swift/XRT. Twenty optically selected GRBs and 12 X-ray-selected GRBs are obtained, among which 17 optically selected and 2 X-ray-selected GRBs have redshift measurements. We fit these light curves with a smooth broken power law and measure the width (w), rising timescale (t r), and decaying timescale (t d) at full width at half-maximum. Strong mutual correlations among these timescales and with the peak time (t p) are found. The ratio t r/t d is almost universal among bursts, but the ratio t r/t p varies from 0.3 to ~1. The optical peak luminosity in the R band (L R,p) is anti-correlated with t p and w in the burst frame, indicating a dimmer and broader bump peaking at a later time. The isotropic prompt gamma-ray energy (E γ,iso) is also tightly correlated with L R,p and t p in the burst frame. Assuming that the bumps signal the deceleration of the GRB fireballs in a constant density medium, we calculate the initial Lorentz factor (Γ0) and the deceleration radius (R d) of the GRBs with redshift measurements. The derived Γ0 is typically a few hundreds, and the deceleration radius is R dec ~ 2 × 1017 cm. More intriguingly, a tight correlation between Γ0 and E γ,iso is found, namely Γ0 ~= 182(E γ,iso/1052 erg)0.25. This correlation also applies to the small sample of GRBs which show the signature of the afterglow onset in their X-ray afterglow, and to two bursts (GRBs 990123 and 080319B) whose early optical emission is dominated by a reverse shock. The lower limits of Γ0 derived from a sample of optical afterglow light curves showing a decaying feature from the beginning of the observation are also generally consistent with such a correlation. The tight lower limits of Γ0 of GRBs 080916C and 090902B derived from the opacity constraints with Fermi/LAT observations are also consistent with the correlation at the 2σ confidence level, but the short GRB 090510 is a clear outlier of this relation. This correlation may give insight to GRB physics and could serve as an indicator of Γ0 for long GRBs without early afterglow detections. A comparison of the early X-ray and optical afterglow light curves shows that the early bright X-ray emission is usually dominated by a non-forward-shock component, but occasionally (for one case) the forward shock emission is observable, and an achromatic deceleration feature is observed. The superposition of the internal and external components in X-rays causes the diversity of the observed X-ray light curves.

Proton Radiography of a Thermal Explosion in PBX9501

NASA Astrophysics Data System (ADS)

Smilowitz, L.; Henson, B. F.; Romero, J. J.; Sandstrom, M. M.; Asay, B. W.; Schwartz, C.; Saunders, A.; Merrill, F.; Morris, C.; Murray, M. M.; McNeil, W. V.; Marr-Lyon, M.; Rightley, P. M.

2007-12-01

The understanding of thermal explosions and burn propagation lags that of detonations and shock propagation. Diagnostics such as high energy radiography have been used to image shocks, but have been previously precluded from use in thermal explosions due to their stringent timing requirements: shock propagation can be synchronized to an external diagnostic while thermal explosion can not. This issue is solved by following the evolution of the ignition volume in a thermal explosion and using a laser pulse to provide a temperature jump in that central volume during the final thermal runaway leading to ignition. Thermal explosion experiments have been conducted at the Los Alamos Proton Radiography facility and have yielded images of the evolution of ignition, post-ignition burn propagation, and case failure in a radially confined cylinder of PBX 9501. This paper presents images taken during the hours long quasistatic heating, the final minutes of thermal runaway, and the post ignition burn propagation.

Magnetic fields and radiative shocks in protogalaxies and the origin of globular clusters

NASA Technical Reports Server (NTRS)

Shapiro, Paul R.; Clocchiatti, Alejandro; Kang, Hyesung

1992-01-01

The paper examines the hypothesis that globular clusters formed from gravitational instability in dense sheets of gas produced behind radiative shocks inside protogalaxies, such as those produced by the collision of subgalactic mass fragments partaking of the virial motions within the protogalaxy, in order to determine the differences which result if a magnetic field is present in the preshock medium. The MHD conservation equations are solved along with rate equations for nonequilibrium ionization, recombination, molecular formation and dissociation, and the equations of radiative transfer for steady-state shocks of velocity 300 km/s in a gas of preshock densities of 0.1-1 cu cm, and magnetic field strengths of 0.1-6 micro-G. The magnetic field is found to limit the degree of postshock compression and, thereby, to reduce the level of external radiation flux required to suppress H2 formation and cooling.

Is Survival Time After Hemorrhage a Heritable, Quantitative Trait?: An Initial Assessment

DTIC Science & Technology

2008-06-01

The epidemiology of traumatic death. A population-based analysis. Arch Surg 128:571Y575, 1993. 5. Sauaia A, Moore FA, Moore EE, Moser KS, Brennan R...therapeutic goals and early warning of death. Arch Surg 106:630Y636, 1973. 752 SHOCK VOL. 29, NO. 6 KLEMCKE ET AL. Copyright @ 200 by the Shock...Hemorrhagic shock in rats. Measured blood volumes as the basis for the extent of hemorrhage. Arch Surg 99:484Y488, 1969. 19. Nose H, Morita M, Yawata T

Initial observations of the pioneer venus orbiter solar wind plasma experiment.

PubMed

Wolfe, J; Intriligator, D S; Mihalov, J; Collard, H; McKibbin, D; Whitten, R; Barnes, A

1979-02-23

Initial results of observations of the solar wind interaction with Venus indicate that Venus has a well-defined, strong, standing bow shock wave. Downstream from the shock, an ionosheath is observed in which the compressed and heated postshock plasma evidently interacts directly with the Venus ionosphere. Plasma ion velocity deflections observed within the ionosheath are consistent with flow around the blunt shape of the ionopause. The ionopause boundary is observed and defined by this experiment as the location where the ionosheath ion flow is first excluded. The positions of the bow shock and ionopause are variable and appear to respond to changes in the external solar wind pressure. Near the terminator the bow shock was observed at altitudes of approximately 4600 to approximately 12,000 kilometers. The ionopause altitutde ranged fromn as low as approximately 450 to approximately 1950 kilometers. Within the Venus ionosphere low-energy ions (energy per untit charge < 30 volts) were detected and have been tentatively idtentified as nonflowing ionospheric ions incident from a direction along the spacecraft velocity vector.

Combination of Acute Physiology and Chronic Health Evaluation II score, early lactate area, and N-terminal prohormone of brain natriuretic peptide levels as a predictor of mortality in geriatric patients with septic shock.

PubMed

Wang, Hao; Li, Zhong; Yin, Mei; Chen, Xiao-Mei; Ding, Shi-Fang; Li, Chen; Zhai, Qian; Li, Yuan; Liu, Han; Wu, Da-Wei

2015-04-01

Given the high mortality rates in elderly patients with septic shock, the early recognition of patients at greatest risk of death is crucial for the implementation of early intervention strategies. Serum lactate and N-terminal prohormone of brain natriuretic peptide (NT-proBNP) levels are often elevated in elderly patients with septic shock and are therefore important biomarkers of metabolic and cardiac dysfunction. We hypothesized that a risk stratification system that incorporates the Acute Physiology and Chronic Health Evaluation (APACHE) II score and lactate and NT-proBNP biomarkers would better predict mortality in geriatric patients with septic shock than the APACHE II score alone. A single-center prospective study was conducted from January 2012 to December 2013 in a 30-bed intensive care unit of a triservice hospital. The lactate area score was defined as the sum of the area under the curve of serial lactate levels measured during the 24 hours following admission divided by 24. The NT-proBNP score was assigned based on NT-proBNP levels measured at admission. The combined score was calculated by adding the lactate area and NT-proBNP scores to the APACHE II score. Multivariate logistic regression analyses and receiver operating characteristic curves were used to evaluate which variables and scoring systems served as the best predictors of mortality in elderly septic patients. A total of 115 patients with septic shock were included in the study. The overall 28-day mortality rate was 67.0%. When compared to survivors, nonsurvivors had significantly higher lactate area scores, NT-proBNP scores, APACHE II scores, and combined scores. In the multivariate regression model, the combined score, lactate area score, and mechanical ventilation were independent risk factors associated with death. Receiver operating characteristic curves indicated that the combined score had significantly greater predictive power when compared to the APACHE II score or the NT-proBNP score (P < .05). A combined score that incorporates the APACHE II score with early lactate area and NT-proBNP levels is a useful method for risk stratification in geriatric patients with septic shock. Copyright © 2014 Elsevier Inc. All rights reserved.

Validating a pragmatic definition of shock in adult patients presenting to the ED.

PubMed

Li, Yan-ling; Chan, Cangel Pui-yee; Sin, King-keung; Chan, Stewart S W; Lin, Pei-yi; Chen, Xiao-hui; Smith, Brendan E; Joynt, Gavin M; Graham, Colin A; Rainer, Timothy H

2014-11-01

The importance of the early recognition of shock in patients presenting to emergency departments is well recognized, but at present, there is no agreed practical definition for undifferentiated shock. The main aim of this study was to validate an a priori clinical definition of shock against 28-day mortality. This prospective, observational, cross-sectional, single-center study was conducted in Hong Kong, China. Data were collected between July 1, 2012, and January 31, 2013. An a priori definition of shock was designed, whereby patients admitted to the resuscitation room or high dependency area of the emergency department were divided into 1 of 3 groups-no shock, possible shock, and shock. The primary outcome was 28-day mortality. Secondary outcomes were in-hospital mortality or admission to the intensive or coronary care unit. A total of 111 patients (mean age, 67.2 ± 17.1 years; male = 69 [62%]) were recruited, of which 22 were classified as no shock, 54 as possible shock, and 35 as shock. Systolic blood pressure, mean arterial pressure, lactate, and base deficit correlated well with shock classifications (P < .05). Patients who had 3 or more positively defined shock variables had a 100% poor composite outcome rate (5 of 5). Patients with 2 shock variables had a 66.7% (4 of 6) poor composite outcome rate. A simple, practical definition of undifferentiated shock has been proposed and validated in a group of patients presenting to an emergency department in Hong Kong. This definition needs further validation in a larger population and other settings. Copyright © 2014 Elsevier Inc. All rights reserved.

Infant-Mother Attachment and the Growth of Externalizing Problems across the Primary-School Years

ERIC Educational Resources Information Center

Pasco Fearon, R. M.; Belsky, Jay

2011-01-01

Background: Some contend that attachment insecurity increases risk for the development of externalizing behavior problems in children. Method: Latent-growth curve analyses were applied to data on 1,364 children from the NICHD Study of Early Child Care to evaluate the association between early attachment and teacher-rated externalizing problems…

Patterns of protein synthesis in oocytes and early embryos of Rana esculenta complex.

PubMed

Chen, P S; Stumm-Zollinger, E

1986-01-01

We have used isotopic labelling and both one-and two-dimensional electrophoretic procedures to analyse the protien synthesis patterns in oocytes and early embryos of three phenotypes of the European green frogs. The results demonstrated that protein patterns of Rana ridibunda and R. esculenta are identical, but that they differ from those of R. lessonae. Progeny of the lethal cross R. esculenta × R. esculenta showed a distinct delay in the appearance of stage-specific proteins during early embryogenesis. The heat-shock response of R. ridibunda and R. esculenta oocytes was found to be identical, but different from that of Xenopus laevis. The implications of these findings, with respect to hybridogenesis in R. esculenta complex and variations in the regulations of heat shock genes in different amphibian species, are discussed.

Early and innovative interventions for severe sepsis and septic shock: taking advantage of a window of opportunity

PubMed Central

Rivers, Emanuel P.; McIntyre, Lauralyn; Morro, David C.; Rivers, Kandis K.

2005-01-01

The pathogenic, diagnostic and therapeutic landscape of sepsis is no longer confined to the intensive care unit: many patients from other portals of entry to care, both outside and within the hospital, progress to severe disease. Approaches that have led to improved outcomes with other diseases (e.g., acute myocardial infarction, stroke and trauma) can now be similarly applied to sepsis. Improved understanding of the pathogenesis of severe sepsis and septic shock has led to the development of new therapies that place importance on early identification and aggressive management. This review emphasizes approaches to the early recognition, diagnosis and therapeutic management of sepsis, giving the clinician the most contemporary and practical approaches with which to treat these patients. PMID:16247103

The continuity of psychopathology from early childhood to preadolescence: a prospective cohort study of 3-12-year-old children.

PubMed

Pihlakoski, Leena; Sourander, Andre; Aromaa, Minna; Rautava, Päivi; Helenius, Hans; Sillanpää, Matti

2006-10-01

To study the continuity of psychopathology from the age of 3-12 years. In a population-based birth cohort, children's emotional and behavioral problems were assessed at age 3 using the Child Behavior Checklist 2-3 (CBCL 2-3), and at age 12 by parents using the CBCL 11-18, and the Youth Self Report (YSR) completed by the children. Behavioral ratings were obtained from 800 subjects at both time points. externalizing problems at age 3 predicted both externalizing and internalizing problems among both genders in preadolescence. In girls, internalizing behavior at age 3 predicted parent-reported internalizing behavior, and associated negatively with externalizing behavior in self-reports at age 12. Aggressive behavior was found to be remarkably stable, and both aggressive and destructive behavior independently predicted a wide range of later externalizing and internalizing problems. Parent ratings of withdrawal showed stability from early childhood to preadolescence in both genders. Somatic complaints of 3-year-old girls independently predicted both externalizing and internalizing problems. The results show the complexity of pathways in psychopathology from early childhood to preadolescence. In particular, aggressive and destructive behaviors in very early childhood predict later problems and necessitate early recognition and possible intervention at an early age. An instrument like the CBCL 2-3 is valuable in the early detection of children at risk of long-term problems.

The thermal and deformational history of apollo 15418, A partly shock-melted lunar breccia

USGS Publications Warehouse

Nord, G.L.; Christie, J.M.; Lally, J.S.; Heuer, A.H.

1977-01-01

A thermal and mechanical history of lunar gabbroic anorthosite 15418 (1140g) has been deduced from petrographic examination of both exterior and interior thin sections and electron microprobe analysis and transmission electron microscopy of interior thin sections. We suggest that the rock underwent two major shock events - an early brecciation and annealing that produced a recrystallized breccia, followed by a second shock event that melted the surface of the rock, vitrified the interior plagioclase and heavily deformed the mafic phases. This latter shock even was also followed by annealing which crystallized the shock-produced glass and promoted recovery and recrystallization of the deformed crystalline phases. The complex mechanical and thermal history of 15418 compared with other ANT suite rocks at Spur Crater suggests that it had a different provenance. ?? 1977 D. Reidel Publishing Company, Dordrecht-Holland.

Women's experiences of participating in the early external cephalic version 2 trial.

PubMed

Murray-Davis, Beth; Marion, Anya; Malott, Anne; Reitsma, Angela; Hutton, Eileen K

2012-03-01

The international, multicenter External Cephalic Version 2 (ECV2) Trial compared early external cephalic version at 34(0/7) to 35(6/7) weeks with that at greater than 37 weeks. A total of 1,543 women were randomized from 68 centers in 21 countries. The goal of this component of the trial was to understand women's views about participation in a research trial and timing of external cephalic version. A postpartum questionnaire was completed containing a 5-point Likert scale examining contact and availability of staff, choice of timing of external cephalic version, preference of randomization, convenience of participating, and overall satisfaction. Participants also completed two open-ended questions related to timing of external cephalic version and satisfaction with the trial. Descriptive statistics and content analysis were used to analyze data. A total of 1,458 women completed the questionnaire, of whom 86 percent said "yes"-they would participate in the trial again. Themes influencing decisions about participating were perceptions of the external cephalic version experience, preferred mode of delivery, preferred timing of external cephalic version, and perceptions of the effectiveness of external cephalic version and of the trial environment. Many participants preferred the early timing of the procedure offered through the trial because of perceived advantages of a smaller baby being easier to turn and the opportunity for repeat procedures. Women were positive about their participation in the trial. Early external cephalic version was preferred over the traditional timing as it was perceived to afford both physiologic and practical advantages. © 2012, Copyright the Authors. Journal compilation © 2012, Wiley Periodicals, Inc.

Essays on Academic Achievement and Student Behavior in Public Schools

ERIC Educational Resources Information Center

Moussa, Wael Soheil

2013-01-01

This dissertation examines the student academic achievement through various mechanisms, put in place by the public school district, classroom student behavior, and negative external shocks to the students' living environment. I examine the impacts of various treatments on student short and long run academic outcomes such as math and English test…

The Politics of Co-Production: Risks, Limits and Pollution

ERIC Educational Resources Information Center

Flinders, Matthew; Wood, Matthew; Cunningham, Malaika

2016-01-01

Co-production is a risky method of social inquiry. It is time-consuming, ethically complex, emotionally demanding, inherently unstable, vulnerable to external shocks, subject to competing demands and it challenges many disciplinary norms. This is what makes it so fresh and innovative. And yet these research-related risks are rarely discussed and,…

Origin of crashes in three US stock markets: shocks and bubbles

NASA Astrophysics Data System (ADS)

Johansen, Anders

2004-07-01

This paper presents an exclusive classification of the largest crashes in Dow Jones industrial average, SP500 and NASDAQ in the past century. Crashes are objectively defined as the top-rank filtered drawdowns (loss from the last local maximum to the next local minimum disregarding noise fluctuations), where the size of the filter is determined by the historical volatility of the index. It is shown that all crashes can be linked to either an external shock, e.g., outbreak of war, or a log-periodic power law (LPPL) bubble with an empirically well-defined complex value of the exponent. Conversely, with one sole exception all previously identified LPPL bubbles are followed by a top-rank drawdown. As a consequence, the analysis presented suggest a one-to-one correspondence between market crashes defined as top-rank filtered drawdowns on one hand and surprising news and LPPL bubbles on the other. We attribute this correspondence to the efficient market hypothesis effective on two quite different time scales depending on whether the market instability the crash represent is internally or externally generated.

Qualification tests for {sup 192}Ir sealed sources

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

Iancso, Georgeta, E-mail: georgetaiancso@yahoo.com; Iliescu, Elena, E-mail: georgetaiancso@yahoo.com; Iancu, Rodica, E-mail: georgetaiancso@yahoo.com

This paper describes the results of qualification tests for {sup 192}Ir sealed sources, available in Testing and Nuclear Expertise Laboratory of National Institute for Physics and Nuclear Engineering 'Horia Hulubei' (I.F.I.N.-HH), Romania. These sources had to be produced in I.F.I.N.-HH and were tested in order to obtain the authorization from The National Commission for Nuclear Activities Control (CNCAN). The sources are used for gammagraphy procedures or in gammadefectoscopy equipments. Tests, measurement methods and equipments used, comply with CNCAN, AIEA and International Quality Standards and regulations. The qualification tests are: 1. Radiological tests and measurements: dose equivalent rate at 1 m;more » tightness; dose equivalent rate at the surface of the transport and storage container; external unfixed contamination of the container surface. 2. Mechanical and climatic tests: thermal shock; external pressure; mechanic shock; vibrations; boring; thermal conditions for storage and transportation. Passing all tests, it was obtained the Radiological Security Authorization for producing the {sup 192}Ir sealed sources. Now IFIN-HH can meet many demands for this sealed sources, as the only manufacturer in Romania.« less

Diagnostic accuracy of a screening electronic alert tool for severe sepsis and septic shock in the emergency department.

PubMed

Alsolamy, Sami; Al Salamah, Majid; Al Thagafi, Majed; Al-Dorzi, Hasan M; Marini, Abdellatif M; Aljerian, Nawfal; Al-Enezi, Farhan; Al-Hunaidi, Fatimah; Mahmoud, Ahmed M; Alamry, Ahmed; Arabi, Yaseen M

2014-12-05

Early recognition of severe sepsis and septic shock is challenging. The aim of this study was to determine the diagnostic accuracy of an electronic alert system in detecting severe sepsis or septic shock among emergency department (ED) patients. An electronic sepsis alert system was developed as a part of a quality-improvement project for severe sepsis and septic shock. The system screened all adult ED patients for a combination of systemic inflammatory response syndrome and organ dysfunction criteria (hypotension, hypoxemia or lactic acidosis). This study included all patients older than 14 years who presented to the ED of a tertiary care academic medical center from Oct. 1, 2012 to Jan. 31, 2013. As a comparator, emergency medicine physicians or the critical care physician identified the patients with severe sepsis or septic shock. In the ED, vital signs were manually entered into the hospital electronic heath record every hour in the critical care area and every two hours in other areas. We also calculated the time from the alert to the intensive care unit (ICU) referral. Of the 49,838 patients who presented to the ED, 222 (0.4%) were identified to have severe sepsis or septic shock. The electronic sepsis alert had a sensitivity of 93.18% (95% CI, 88.78% - 96.00%), specificity of 98.44 (95% CI, 98.33% - 98.55%), positive predictive value of 20.98% (95% CI, 18.50% - 23.70%) and negative predictive value of 99.97% (95% CI, 99.95% - 99.98%) for severe sepsis and septic shock. The alert preceded ICU referral by a median of 4.02 hours (Q1 - Q3: 1.25-8.55). Our study shows that electronic sepsis alert tool has high sensitivity and specificity in recognizing severe sepsis and septic shock, which may improve early recognition and management.

Laboratory Studies of Survival Limits of Bacteria During Shock Compression: Application to Impacts on the Early Earth

NASA Astrophysics Data System (ADS)

Willis, M. J.; Ahrens, T. J.; Bertani, L. E.; Nash, C. Z.

2004-12-01

Shock recovery experiments on suspensions of 106 mm-3 E. coli bacteria contained in water-based medium, within stainless steel containers, are used to simulate the impact environment of bacteria residing in water-filled cracks in rocks. Early Earth life is likely to have existed in such environments. Some 10-2 to 10-4 of the bacteria population survived initial (800 ns duration) shock pressures in water of 219 and 260 MPa. TEM images of shock recovered bacteria indicate cell wall indentations and rupture, possibly induced by inward invasion of medium into the cell wall. Notably cell wall rupture occurs dynamically at ˜0.1 times the static pressures E.coli have been demonstrated (Sharma et al., 2002) to survive and may be caused by Rayleigh-Taylor instabilities. We infer the invading fluid pressure may exceed the tensile strength of the cell wall. We assume the overpressures are limited to the initial shock pressure in water. Parameters for the Grady & Lipkin (1980) model of tensile failure versus time-scale (strain rate) are fit to present data, assuming that at low strain rates, overpressures exceeding cell Turgor pressure require ˜103 sec. This model, if validated by experiments at other timescales, may permit using short loading duration laboratory data to infer response of organisms to lower shock overpressures for the longer times (100 to 103 s) of planetary impacts. An Ahrens & O'Keefe (1987) shock attenuation model is then applied for Earth impactors. This model suggests that Earth impactors of radius 1.5 km induce shocks within water-filled cracks in rock to dynamic pressure such that stresses exceeding the survivability threshold of E. coli bacteria, to radii of 1.7-2.6×102 km. In contrast, a giant (1500 km radius) impactor produces a non survival zone for E. coli that encompasses the entire Earth.

Early detection strategy and mortality reduction in severe sepsis.

PubMed

Westphal, Glauco Adrieno; Feijó, Janaína; Andrade, Patrícia Silva de; Trindade, Louise; Suchard, Cezar; Monteiro, Márcio Andrei Gil; Martins, Sheila Fonseca; Nunes, Fernanda; Caldeira Filho, Milton

2009-06-01

To evaluate the impact of implementing an institutional policy for detection of severe sepsis and septic shock. Study before (stage I), after (stage II) with prospective data collection in a 195 bed public hospital.. Stage I: Patients with severe sepsis or septic shock were included consecutively over 15 months and treated according to the Surviving Sepsis Campaign guidelines. Stage II: In the 10 subsequent months, patients with severe sepsis or septic shock were enrolled based on an active search for signs suggesting infection (SSI) in hospitalized patients. The two stages were compared for demographic variables, time needed for recognition of at least two signs suggesting infection (SSI-Δt), compliance to the bundles of 6 and 24 hours and mortality. We identified 124 patients with severe sepsis or septic shock, 68 in stage I and 56 in stage II. The demographic variables were similar in both stages. The Δt-SSI was 34 ± 54 hours in stage I and 7 ± 8.4 hours in stage II (p <0.001). There was no difference in compliance to the bundles. In parallel there was significant reduction of mortality rates at 28 days (54.4% versus 30%, p <0.02) and hospital (67.6% versus 41%, p <0.003). The strategy used helped to identify early risk of sepsis and resulted in decreased mortality associated with severe sepsis and septic shock.

Transcription of exogenous and endogenous deoxyribonucleic acid templates in cold-shocked Bacillus subtilis.

PubMed Central

Kuhl, S J; Brown, L R

1980-01-01

Ribonucleic acid (RNA) synthesis was examined in cold-shocked Bacillus subtilis cells. The cells were grown to mid-log stage, harvested, and cold shocked. RNA synthesis was monitored by the incorporation of [3H]uridine triphosphate or [alpha 32P]adenosine triphosphate into trichloroacetic acid-precipitable material in the presence of all four nucleoside triphosphates. The inhibition of RNA synthesis in cold-shocked cells by lipiarmycin, ethidium bromide, rifampin. or streptolydigin was analyzed using mutant or wild-type cells. Also examined were the effects of temperature, salt concentration, and the addition of polyamines or highly phosphorylated nucleotides. In ultraviolet-irradiated and cold-shocked cells, RNA wynthesis decreased to low levels. The addition of exogenous phi 29 or TSP-1 template to these cells caused a 13- to 20-fold increase in RNA synthesis, as monitored by trichloroacetic acid-precipitable counts. RNA synthesized in the presence of phi 29 deoxyribonucleic acid (DNA) hybridizes mainly to EcoRI fragments A and C of phi 29 DBA, These two fragments direct transcription by purified RNA polymerase in vitro and hybridize to early phi 29 DNA produced in vivo. Our results with TSP-1 DNA in this system indicated that the RNA produced hybridizes to the same fragments as early RNA produced in vivo. Plasmic pUB110 DNA was not transcribed in this system. Images PMID:6157674

Time- and fluid-sensitive resuscitation for hemodynamic support of children in septic shock: barriers to the implementation of the American College of Critical Care Medicine/Pediatric Advanced Life Support Guidelines in a pediatric intensive care unit in a developing world.

PubMed

Oliveira, Cláudio F; Nogueira de Sá, Flávio R; Oliveira, Débora S F; Gottschald, Adriana F C; Moura, Juliana D G; Shibata, Audrey R O; Troster, Eduardo J; Vaz, Flávio A C; Carcillo, Joseph A

2008-12-01

To analyze mortality rates of children with severe sepsis and septic shock in relation to time-sensitive fluid resuscitation and treatments received and to define barriers to the implementation of the American College of Critical Care Medicine/Pediatric Advanced Life Support guidelines in a pediatric intensive care unit in a developing country. Retrospective chart review and prospective analysis of septic shock treatment in a pediatric intensive care unit of a tertiary care teaching hospital. Ninety patients with severe sepsis or septic shock admitted between July 2002 and June 2003 were included in this study. Of the 90 patients, 83% had septic shock and 17% had severe sepsis; 80 patients had preexisting severe chronic diseases. Patients with septic shock who received less than a 20-mL/kg dose of resuscitation fluid in the first hour of treatment had a mortality rate of 73%, whereas patients who received more than a 40-mL/kg dose in the first hour of treatment had a mortality rate of 33% (P < 0.05). Patients treated less than 30 minutes after diagnosis of severe sepsis and septic shock had a significantly lower mortality rate (40%) than patients treated more than 60 minutes after diagnosis (P < 0.05). Controlling for the risk of mortality, early fluid resuscitation was associated with a 3-fold reduction in the odds of death (odds ratio, 0.33; 95% confidence interval, 0.13-0.85). The most important barriers to achieve adequate severe sepsis and septic shock treatment were lack of adequate vascular access, lack of recognition of early shock, shortage of health care providers, and nonuse of goals and treatment protocols. The mortality rate was higher for children older than 2 years, for those who received less than 40 mL/kg in the first hour, and for those whose treatment was not initiated in the first 30 minutes after the diagnosis of septic shock. The acknowledgment of existing barriers to a timely fluid administration and the establishment of objectives to overcome these barriers may lead to a more successful implementation of the American College of Critical Care Medicine guidelines and reduced mortality rates for children with septic shock in the developing world.

Temporal profile of inflammatory response to fracture and hemorrhagic shock: Proposal of a novel long-term survival murine multiple trauma model.

PubMed

Kleber, Christian; Becker, Christopher A; Malysch, Tom; Reinhold, Jens M; Tsitsilonis, Serafeim; Duda, Georg N; Schmidt-Bleek, Katharina; Schaser, Klaus D

2015-07-01

Hemorrhagic shock (hS) interacts with the posttraumatic immune response and fracture healing in multiple trauma. Due to the lack of a long-term survival multiple trauma animal models, no standardized analysis of fracture healing referring the impact of multiple trauma on fracture healing was performed. We propose a new long-term survival (21 days) murine multiple trauma model combining hS (microsurgical cannulation of carotid artery, withdrawl of blood and continuously blood pressure measurement), femoral (osteotomy/external fixation) and tibial fracture (3-point bending technique/antegrade nail). The posttraumatic immune response was measured via IL-6, sIL-6R ELISA. The hS was investigated via macrohemodynamics, blood gas analysis, wet-dry lung ration and histologic analysis of the shock organs. We proposed a new murine long-term survival (21 days) multiple trauma model mimicking clinical relevant injury patterns and previously published human posttraumatic immune response. Based on blood gas analysis and histologic analysis of shock organs we characterized and standardized our murine multiple trauma model. Furthermore, we revealed hemorrhagic shock as a causative factor that triggers sIL-6R formation underscoring the fundamental pathophysiologic role of the transsignaling mechanism in multiple trauma. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

Exhaust Nozzle Plume Effects on Sonic Boom Test Results for Vectored Nozzles

NASA Technical Reports Server (NTRS)

Castner, Raymond

2012-01-01

Reducing or eliminating the operational restrictions of supersonic aircraft over populated areas has led to extensive research at NASA. Restrictions were due to the disturbance of the sonic boom, caused by the coalescence of shock waves formed off the aircraft. Recent work has been performed to reduce the magnitude of the sonic boom N-wave generated by airplane components with a focus on shock waves caused by the exhaust nozzle plume. Previous Computational Fluid Dynamics (CFD) analysis showed how the shock wave formed at the nozzle lip interacts with the nozzle boat-tail expansion wave. An experiment was conducted in the 1- by 1-foot Supersonic Wind Tunnel (SWT) at the NASA Glenn Research Center. Results show how the shock generated at the nozzle lip affects the near field pressure signature, and thereby the potential sonic boom contribution for a nozzle at vector angles from 3 to 8 . The experiment was based on the NASA F-15 nozzle used in the Lift and Nozzle Change Effects on Tail Shock experiment, which possessed a large external boat-tail angle. In this case, the large boat-tail angle caused a dramatic expansion, which dominated the near field pressure signature. The impact of nozzle vector angle and nozzle pressure ratio are summarized.

Resuscitation and Transfusion Principles for Traumatic Hemorrhagic Shock

DTIC Science & Technology

2009-11-01

hyperfibrinolysis. We also describe the concept of damage control resuscitation (DCR), an early and aggressive prevention and treatment of hemorrhagic shock... prevention and treatment of acidosis, hypothermia, and hypocalcemia, avoidance of hemodilution, and hemostatic resuscitation with transfusion of red...are potentially preventable and 66–80% of these deaths occur from hemorrhage.3,4 Rural civilian data indicate that approximately 10% of traumatic

Early Treatment in Shock

DTIC Science & Technology

2007-06-01

Dehydroepiandrosterone protects muscle flap microcirculatory hemodynamics from ischemia / reperfusion injury : an experimental in vivo study. J Trauma. 1997...haemorrhagic shock and reperfusion . British J of Pharmacol, 1986; 89:149-155 2 . Van Way, CW III, Dhar, A, Reddy R, Evans, L, Wogahn B, Helling TS. Changes in...grammed cell death, apoptosis, is a major pathway causing reperfusion injury . During apoptosis, cytosolic cytochrome-c is released from damaged

Infancy parenting and externalizing psychopathology from childhood through adulthood: developmental trends.

PubMed

Lorber, Michael F; Egeland, Byron

2009-07-01

Developmental models and previous findings suggest that early parenting is more strongly associated with externalizing problems in early childhood than it is in adolescence. In this article, the authors address whether the association of poor-quality infancy parenting and externalizing problems "rebounds" in adulthood. Poor-quality infancy parenting was associated with externalizing problems at kindergarten and first grade (mother report) as well as at 23 and 26 years (self report). Infancy parenting was not significantly associated with either mothers' or youths' reports of externalizing problems at 16 years. These findings are consistent with the notion that poor-quality infancy parenting is a risk factor for externalizing problems in developmental periods for which externalizing behavior is most deviant.

Acute Neonatal Parotitis with Late-Onset Septic Shock due to Streptococcus agalactiae

PubMed Central

Boulyana, M.

2014-01-01

Acute neonatal parotitis (ANP) is a very rare disease. Most cases are managed conservatively; early antibiotics and adequate hydration may reduce the need for surgery. The most common cause of ANP is Staphylococcus aureus. We report a rare case of acute neonatal parotitis with late-onset septic shock due to Streptococcus agalactiae. The diagnosis was confirmed with ultrasound and isolation of Streptococcus agalactiae from blood culture. The patient was treated successfully with 10 days of intravenous antibiotics and supportive measures. Despite being rare, streptococcal ANP should be considered in the etiological diagnosis of neonatal sepsis. Early diagnosis and appropriate antibiotic might prevent serious complications. PMID:24653847

Wind-Interaction Models for the Early Afterglows of Gamma-Ray Bursts: The Case of GRB 021004

NASA Astrophysics Data System (ADS)

Li, Zhi-Yun; Chevalier, Roger A.

2003-06-01

Wind-interaction models for gamma-ray burst (GRB) afterglows predict that the optical emission from the reverse shock drops below that from the forward shock within hundreds of seconds of the burst. The typical frequency νm of the synchrotron emission from the forward shock passes through the optical band typically on a timescale of minutes to hours. Before the passage of νm, the optical flux evolves as t-1/4, and after the passage, the decay steepens to t-(3p-2)/4, where p is the exponent for the assumed power-law energy distribution of nonthermal electrons and is typically ~2. The steepening in the slope of temporal decay should be readily identifiable in the early afterglow light curves. We propose that such a steepening was observed in the R-band light curve of GRB 021004 around day 0.1. Available data at several radio frequencies are consistent with this interpretation, as are the X-ray observations around day 1. The early evolution of GRB 021004 contrasts with that of GRB 990123, which can be described by emission from interaction with a constant density medium.

Wind tunnel tests of Space Shuttle external tank insulation material in the aerothermal tunnel at elevated (1440 deg F) total temperatures

NASA Technical Reports Server (NTRS)

Hartman, A. S.; Nutt, K. W.

1982-01-01

Tests of the space shuttle external tank foam insulation were conducted in the von Karman Gas Dynamics Facility Tunnel C. For these tests, Tunnel C was run at Mach 4 with a total temperature of 1440 F and a total pressure which varied from 30-100 psia. Cold wall heating rates were changed by varying the test article support wedge angle and by adding and removing a shock generator or a cylindrical protuberance. Selected results are presented to illustrate the test techniques and typical data obtained.

Fractal attractors in economic growth models with random pollution externalities

NASA Astrophysics Data System (ADS)

La Torre, Davide; Marsiglio, Simone; Privileggi, Fabio

2018-05-01

We analyze a discrete time two-sector economic growth model where the production technologies in the final and human capital sectors are affected by random shocks both directly (via productivity and factor shares) and indirectly (via a pollution externality). We determine the optimal dynamics in the decentralized economy and show how these dynamics can be described in terms of a two-dimensional affine iterated function system with probability. This allows us to identify a suitable parameter configuration capable of generating exactly the classical Barnsley's fern as the attractor of the log-linearized optimal dynamical system.

Associations of Perceived Sibling and Parent-Child Relationship Quality with Internalizing and Externalizing Problems: Comparing Indian and Dutch Early Adolescents

ERIC Educational Resources Information Center

Buist, Kirsten L.; Verhoeven, Marjolein; Hoksbergen, René; ter Laak, Jan; Watve, Sujala; Paranjpe, Analpa

2017-01-01

The aims of the present study were (a) to examine whether Dutch and Indian early adolescents differ concerning sibling and parent-child relationship quality and externalizing and internalizing problems, and (b) to compare the associations between sibling and parent-child relationship quality and externalizing and internalizing problems for Indian…

The Effects of FUV Radiation on C-Shocks: Implications for Water and Other O-bearing Species

NASA Astrophysics Data System (ADS)

Kaufman, Michael; Melick, Gary; Tolls, Volker

2015-08-01

Protostellar outflows have long been known to drive endothermic reactions that produce high abundances of oxygen-bearing species. Models of shocks in well-shielded gas made the strong prediction that essentially all of the pre-shock oxygen gets driven into water, so that the post-shock water abundances are order 10-4. Herschel observations, however, including those from the key program “Water in Star Forming Regions with Herschel (WISH)” show that for most sources, the shocked gas water abundances of are far lower, 10-7 - 10-5.This pattern of lower-than-predicted water abundance has led us to consider that our C-shock model (Kaufman & Neufeld 1996) is incomplete. In particular, we did not previously take into account that many outflow sources have higher than average far-ultraviolet radiation fields within their outflow cavities. Strong FUV radiation has important effects on the structure of C-shocks: the ionization fraction is larger than in well-shielded gas, decreasing the coupling length between neutrals and ions, and leading to higher temperatures and a lower breakdown speeds; the pre-shock gas composition, including the presence of ice mantles and the dominant charge carriers, is strongly affected; and abundant species such as water are diminished by photodissociation in the cooled down stream gas.In addition to the normal parameters of density, shock velocity, and magnetic field strength, we now include the external FUV field strength and the extinction between the FUV source and the shock. We use the results of a detailed PDR model to compute pre-shock chemical conditions, including the ionization fraction, the increase of which decreases the maximum velocities of C- shocks. FUV also keeps oxygen in the gas phase, making more available for H2O formarion ; however, photodissociation beyond the temperature peak keeps the average H2O abundance down. We present comparisons of our model results with the inferred water abundances and with observations of H2O, CO, O and OH lines from the Herschel archive.

Extremely Bright GRB 160625B with Multiple Emission Episodes: Evidence for Long-term Ejecta Evolution

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

Lü, Hou-Jun; Lü, Jing; Zhong, Shu-Qing

GRB 160625B is an extremely bright GRB with three distinct emission episodes. By analyzing its data observed with the Gamma-Ray Burst Monitor (GBM) and Large Area Telescope (LAT) on board the Fermi mission, we find that a multicolor blackbody (mBB) model can be used to fit very well the spectra of the initial short episode (Episode I) within the hypothesis of photosphere emission of a fireball model. The time-resolved spectra of its main episode (Episode II), which was detected with both GBM and LAT after a long quiescent stage (∼180 s) following the initial episode, can be fitted with amore » model comprising an mBB component plus a cutoff power-law (CPL) component. This GRB was detected again in the GBM and LAT bands with a long extended emission (Episode III) after a quiescent period of ∼300 s. The spectrum of Episode III is adequately fitted with CPL plus single power-law models, and no mBB component is required. These features may imply that the emission of the three episodes are dominated by distinct physics processes, i.e., Episode I is possible from the cocoon emission surrounding the relativistic jet, Episode II may be from photosphere emission and internal shock of the relativistic jet, and Episode III is contributed by internal and external shocks of the relativistic jet. On the other hand, both X-ray and optical afterglows are consistent with the standard external shocks model.« less

Extremely Bright GRB 160625B with Multiple Emission Episodes: Evidence for Long-term Ejecta Evolution

NASA Astrophysics Data System (ADS)

Lü, Hou-Jun; Lü, Jing; Zhong, Shu-Qing; Huang, Xiao-Li; Zhang, Hai-Ming; Lan, Lin; Xie, Wei; Lu, Rui-Jing; Liang, En-Wei

2017-11-01

GRB 160625B is an extremely bright GRB with three distinct emission episodes. By analyzing its data observed with the Gamma-Ray Burst Monitor (GBM) and Large Area Telescope (LAT) on board the Fermi mission, we find that a multicolor blackbody (mBB) model can be used to fit very well the spectra of the initial short episode (Episode I) within the hypothesis of photosphere emission of a fireball model. The time-resolved spectra of its main episode (Episode II), which was detected with both GBM and LAT after a long quiescent stage (˜180 s) following the initial episode, can be fitted with a model comprising an mBB component plus a cutoff power-law (CPL) component. This GRB was detected again in the GBM and LAT bands with a long extended emission (Episode III) after a quiescent period of ˜300 s. The spectrum of Episode III is adequately fitted with CPL plus single power-law models, and no mBB component is required. These features may imply that the emission of the three episodes are dominated by distinct physics processes, I.e., Episode I is possible from the cocoon emission surrounding the relativistic jet, Episode II may be from photosphere emission and internal shock of the relativistic jet, and Episode III is contributed by internal and external shocks of the relativistic jet. On the other hand, both X-ray and optical afterglows are consistent with the standard external shocks model.

Point-of-care optical tool to detect early stage of hemorrhage and shock

NASA Astrophysics Data System (ADS)

Gurjar, Rajan S.; Riccardi, Suzannah L.; Johnson, Blair D.; Johnson, Christopher P.; Paradis, Norman A.; Joyner, Michael J.; Wolf, David E.

2014-02-01

There is a critical unmet clinical need for a device that can monitor and predict the onset of shock: hemorrhagic shock or bleeding to death, septic shock or systemic infection, and cardiogenic shock or blood flow and tissue oxygenation impairment due to heart attack. Together these represent 141 M patients per year. We have developed a monitor for shock based on measuring blood flow in peripheral (skin) capillary beds using diffuse correlation spectroscopy, a form of dynamic light scattering, and have demonstrated proof-of-principle both in pigs and humans. Our results show that skin blood flow measurement, either alone or in conjunction with other hemodynamic properties such as heart rate variability, pulse pressure variability, and tissue oxygenation, can meet this unmet need in a small self-contained patch-like device in conjunction with a hand-held processing unit. In this paper we describe and discuss the experimental work and the multivariate statistical analysis performed to demonstrate proof-of-principle of the concept.

[Incidence and influencing factors of distal external iliac lymph node metastasis in early cervical cancer].

PubMed

Yin, Yueju; Sheng, Xiugui; Li, Xinglan; Li, Dapeng; Han, Xiaoyun; Zhang, Xiaoling; Zhang, Tingting

2014-06-01

The distal external iliac lymph nodes are located along the external iliac artery between the deep circumflex iliac vein and the inguinal canal. Our study aimed to investigate the incidence of metastasis in distal external iliac lymph nodes and its association with clinicopathological factors in patients with early stage cervical cancer, and to determine the role of distal external iliac lymph nodes dissection in the surgery. Five hundred and twenty-four patients with early stage cervical cancer underwent radical hysterectomy and bilateral pelvic lymphadenectomy in the Shandong Province Cancer Hospital between June 1995 and December 2011, and their clinicopathological features were analyzed retrospectively. Of the 524 patients, 124 (23.7%) had pelvic lymph node metastasis. The metastasis rates were 16.2% (85 of 524 patients) in the obturator lymph nodes, 12.2% (64 of 524 patients) in the internal and external iliac lymph nodes, 2.9% (15 of 524 patients) in the common iliac lymph nodes, 2.1% (11 of 524 patients) in the distal external iliac lymph nodes, and 1.7% (9 of 524 patients) in the para-aortic nodes. The incidence of isolated positive distal external iliac lymph nodes was 0.2%. Univariate analysis showed that lymphovascular space invasion, pelvic lymph node metastases (excluding distal external iliac lymph nodes) were significantly associated with distal external iliac lymph node metastasis (P < 0.05). Logistic regression analysis showed that pelvic lymph node metastasis (excluding distal external iliac lymph nodes) was the independent risk factor for metastasis to distal external iliac lymph nodes. In early stage cervical cancer, distal external iliac lymph node metastasis is rare, especially in cases with stage IA or without pelvic lymph node metastasis. Less extensive pelvic lymphadenectomy may be considered in these patients in order to reduce operative complications and improve patients' quality of life. The deep circumflex iliac vein may be an appropriate landmark for the caudal limit of external iliac lymphadenectomy. However, if pelvic lymph node metastasis (excluding distal external iliac lymph nodes) is found by intraoperative rapid pathological diagnosis, systematic pelvic lymphadenectomy including removal of the distal external iliac lymph nodes should be performed in order to reduce the risk of distant metastasis.

Early Adolescent Friendship Selection Based on Externalizing Behavior: the Moderating Role of Pubertal Development. The SNARE Study.

PubMed

Franken, Aart; Prinstein, Mitchell J; Dijkstra, Jan Kornelis; Steglich, Christian E G; Harakeh, Zeena; Vollebergh, Wilma A M

2016-11-01

This study examined friendship (de-)selection processes in early adolescence. Pubertal development was examined as a potential moderator. It was expected that pubertal development would be associated with an increased tendency for adolescents to select their friends based on their similarities in externalizing behavior engagement (i.e., delinquency, alcohol use, and tobacco use). Data were used from the first three waves of the SNARE (Social Network Analysis of Risk behavior in Early adolescence) study (N = 1144; 50 % boys; M age  = 12.7; SD = 0.47), including students who entered the first year of secondary school. The hypothesis was tested using Stochastic Actor-Based Modeling in SIENA. While taking the network structure into account, and controlling for peer influence effects, the results supported this hypothesis. Early adolescents with higher pubertal development were as likely as their peers to select friends based on similarity in externalizing behavior and especially likely to remain friends with peers who had a similar level of externalizing behavior, and thus break friendship ties with dissimilar friends in this respect. As early adolescents are actively engaged in reorganizing their social context, adolescents with a higher pubertal development are especially likely to lose friendships with peers who do not engage in externalizing behavior, thus losing an important source of adaptive social control (i.e., friends who do not engage in externalizing behavior).

Discrimination and externalizing problems among Moroccan- and Romanian-origin early adolescents in Italy: Moderating role of cultural orientations and impulse control.

PubMed

Miconi, Diana; Altoè, Gianmarco; Salcuni, Silvia; Di Riso, Daniela; Schiff, Sami; Moscardino, Ughetta

2018-05-24

Although discrimination is a common stressor in the everyday life of immigrant youth, individuals are not equally susceptible to its adverse effects. This cross-sectional study aimed to examine whether cultural orientation preferences and impulse control (IC) moderate the association between perceived discrimination and externalizing problems among Moroccan- and Romanian-origin early adolescents in Italy. The sample included 126 Moroccan and 126 Romanian youths (46% girls, 42% first-generation) aged 11-13 years and their parents. Perceived discrimination and cultural orientations were assessed using self-report questionnaires, while IC was evaluated via a computerized version of the Iowa Gambling Task. Externalizing behaviors were assessed via parental report. Cluster analysis identified separated, assimilated, and integrated early adolescents. Regression analyses revealed that when facing discrimination, youths who endorsed separation and exhibited low levels of IC were more vulnerable to externalizing problems. In contrast, among assimilated adolescents the discrimination-externalizing difficulties link was significant at high levels of IC. Furthermore, low levels of IC were associated with more externalizing problems for Romanian, but not for Moroccan early adolescents. Findings underscore the need to consider both cultural orientation processes and early adolescents' ability to control their impulses when developing interventions aimed to reduce discrimination-related problem behaviors in immigrant youth. Implications for theory and practice are discussed. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Onion-shell model of cosmic ray acceleration in supernova remnants

NASA Technical Reports Server (NTRS)

Bogdan, T. J.; Volk, H. J.

1983-01-01

A method is devised to approximate the spatially averaged momentum distribution function for the accelerated particles at the end of the active lifetime of a supernova remnant. The analysis is confined to the test particle approximation and adiabatic losses are oversimplified, but unsteady shock motion, evolving shock strength, and non-uniform gas flow effects on the accelerated particle spectrum are included. Monoenergetic protons are injected at the shock front. It is found that the dominant effect on the resultant accelerated particle spectrum is a changing spectral index with shock strength. High energy particles are produced in early phases, and the resultant distribution function is a slowly varying power law over several orders of magnitude, independent of the specific details of the supernova remnant.

Nonhuman primate model of polytraumatic hemorrhagic shock recapitulates early platelet dysfunction observed following severe injury in humans.

PubMed

Schaub, Leasha J; Moore, Hunter B; Cap, Andrew P; Glaser, Jacob J; Moore, Ernest E; Sheppard, Forest R

2017-03-01

Platelet dysfunction has been described as an early component of trauma-induced coagulopathy. The platelet component of trauma-induced coagulopathy remains to be fully elucidated and translatable animal models are required to facilitate mechanistic investigations. We sought to determine if the early platelet dysfunction described in trauma patients could be recapitulated in a nonhuman primate model of polytraumatic hemorrhagic shock. Twenty-four male rhesus macaques weighting 7 to 14 kg were subjected to 60 minutes (min) of severe pressure-targeted controlled hemorrhagic shock (HS) with and without other injuries. After 60 min, resuscitation with 0.9% NaCl and whole blood was initiated. Platelet counts and platelet aggregation assays were performed at baseline (BSLN), end of shock (EOS; T = 60 min), end of resuscitation (EOR; T = 180 min), and T = 360 min on overall cohort. Results are reported as mean ± standard deviation (SD) or median (interquartile range). Statistical analysis was conducted using Spearmen correlation, one-way analysis of variance, two-way repeated-measures analysis of variance, paired t-test or Wilcoxon nonparametric test, with p < 0.05 considered significant. Platelet count in all injury cohorts decreased over time, but no animals developed thrombocytopenia. Correlations were observed between platelet aggregation and platelet count for all agonists: adenosine diphosphate, thrombin recognition-activating peptide-6, collagen, and arachidonic acid. Overall, compared to BSLN, platelet aggregation decreased for all agonist at EOS, EOR, and T = 360 min. When normalized to platelet count, platelet aggregation in response to agonist thrombin recognition-activating peptide-6 demonstrated no change from BSLN at subsequent time points. Aggregation to adenosine diphosphate was significantly less at EOR but not EOS or T = 360 min compared to BSLN. Platelet aggregation to collagen and arachidonic acid was not significantly different at EOS compared to BSLN but was significantly less at EOR and T = 360 min. Nonhuman primates manifest early platelet dysfunction in response to polytraumatic hemorrhagic shock, consistent with that reported in severely injured human patients. Nonhuman primate models potentially are translationally valuable for understanding the mechanisms and pathophysiology of trauma-induced platelet dysfunction.

5HTTLPR genotype moderates the longitudinal impact of early caregiving on externalizing behavior

PubMed Central

Smyke, Anna T.; Gleason, Mary Margaret; Nelson, Charles A.; Zeanah, Charles H.; Fox, Nathan A; Drury, Stacy S.

2014-01-01

We examined caregiver report of externalizing behavior from 12 to 54 months of age in 102 children randomized to care as usual in institutions or to newly-created high quality foster care. At baseline no differences by group or genotype in externalizing were found. However, changes in externalizing from baseline to 42 months of age were moderated by 5HTTLPR genotype and intervention group, where the slope for s/s individuals differed as a function of intervention group. The slope for individuals carrying the l allele did not significantly differ between groups. At 54 months of age, s/s children in the foster care group had the lowest levels of externalizing behavior, while children with the s/s genotype in the care as usual group demonstrated the highest rates of externalizing behavior. No intervention group differences were found in externalizing behavior among children who carried the l allele. These findings, within a randomized control trial of foster care compared to continued care as usual, indicate that 5HTTLPR genotype moderates the relation between early caregiving environments to predict externalizing behavior in children exposed to early institutional care in a manner most consistent with differential susceptibility. PMID:25640827

Lattice-level observation of the elastic-to-plastic relaxation process with subnanosecond resolution in shock-compressed Ta using time-resolved in situ Laue diffraction

DOE PAGES

Wehrenberg, C. E.; Comley, A. J.; Barton, N. R.; ...

2015-09-29

We report direct lattice level measurements of plastic relaxation kinetics through time-resolved, in-situ Laue diffraction of shock-compressed single-crystal [001] Ta at pressures of 27-210 GPa. For a 50 GPa shock, a range of shear strains is observed extending up to the uniaxial limit for early data points (<0.6 ns) and the average shear strain relaxes to a near steady state over ~1 ns. For 80 and 125 GPa shocks, the measured shear strains are fully relaxed already at 200 ps, consistent with rapid relaxation associated with the predicted threshold for homogeneous nucleation of dislocations occurring at shock pressure ~65 GPa.more » The relaxation rate and shear stresses are used to estimate the dislocation density and these quantities are compared to the Livermore Multiscale Strength model as well as various molecular dynamics simulations.« less

Fluid dynamic modeling of nano-thermite reactions

NASA Astrophysics Data System (ADS)

Martirosyan, Karen S.; Zyskin, Maxim; Jenkins, Charles M.; Yuki Horie, Yasuyuki

2014-03-01

This paper presents a direct numerical method based on gas dynamic equations to predict pressure evolution during the discharge of nanoenergetic materials. The direct numerical method provides for modeling reflections of the shock waves from the reactor walls that generates pressure-time fluctuations. The results of gas pressure prediction are consistent with the experimental evidence and estimates based on the self-similar solution. Artificial viscosity provides sufficient smoothing of shock wave discontinuity for the numerical procedure. The direct numerical method is more computationally demanding and flexible than self-similar solution, in particular it allows study of a shock wave in its early stage of reaction and allows the investigation of "slower" reactions, which may produce weaker shock waves. Moreover, numerical results indicate that peak pressure is not very sensitive to initial density and reaction time, providing that all the material reacts well before the shock wave arrives at the end of the reactor.

Fluid dynamic modeling of nano-thermite reactions

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

Martirosyan, Karen S., E-mail: karen.martirosyan@utb.edu; Zyskin, Maxim; Jenkins, Charles M.

2014-03-14

This paper presents a direct numerical method based on gas dynamic equations to predict pressure evolution during the discharge of nanoenergetic materials. The direct numerical method provides for modeling reflections of the shock waves from the reactor walls that generates pressure-time fluctuations. The results of gas pressure prediction are consistent with the experimental evidence and estimates based on the self-similar solution. Artificial viscosity provides sufficient smoothing of shock wave discontinuity for the numerical procedure. The direct numerical method is more computationally demanding and flexible than self-similar solution, in particular it allows study of a shock wave in its early stagemore » of reaction and allows the investigation of “slower” reactions, which may produce weaker shock waves. Moreover, numerical results indicate that peak pressure is not very sensitive to initial density and reaction time, providing that all the material reacts well before the shock wave arrives at the end of the reactor.« less

Tactical Damage Control Resuscitation.

PubMed

Fisher, Andrew D; Miles, Ethan A; Cap, Andrew P; Strandenes, Geir; Kane, Shawn F

2015-08-01

Recently the Committee on Tactical Combat Casualty Care changed the guidelines on fluid use in hemorrhagic shock. The current strategy for treating hemorrhagic shock is based on early use of components: Packed Red Blood Cells (PRBCs), Fresh Frozen Plasma (FFP) and platelets in a 1:1:1 ratio. We suggest that lack of components to mimic whole blood functionality favors the use of Fresh Whole Blood in managing hemorrhagic shock on the battlefield. We present a safe and practical approach for its use at the point of injury in the combat environment called Tactical Damage Control Resuscitation. We describe pre-deployment preparation, assessment of hemorrhagic shock, and collection and transfusion of fresh whole blood at the point of injury. By approaching shock with goal-directed therapy, it is possible to extend the period of survivability in combat casualties. Reprint & Copyright © 2015 Association of Military Surgeons of the U.S.

Social Status of Adolescents with an Early Onset of Externalizing Behavior: The SNARE Study

ERIC Educational Resources Information Center

Franken, Aart; Harakeh, Zeena; Veenstra, Rene; Vollebergh, Wilma; Dijkstra, Jan Kornelis

2017-01-01

This study investigated the social status (i.e., popularity, likeability, and friendships) of adolescents with an early onset of externalizing behavior (i.e., alcohol use, tobacco use, and antisocial behavior). Building on Moffitt's dual-taxonomy model, it was hypothesized that early onset adolescents were more popular, but not necessarily more…

Mediated Pathways from Maternal Depression and Early Parenting to Children's Executive Function and Externalizing Behaviour Problems

ERIC Educational Resources Information Center

Baker, Claire; Kuhn, Laura

2018-01-01

Structural equation models were used to examine pathways from maternal depression and early parenting to children's executive function (EF) and externalizing behaviours in the first nationally representative study to obtain direct assessments of children's kindergarten EF skills (i.e., the Early Childhood Longitudinal Study Kindergarten Class of…

Numerical and experimental investigation of VG flow control for a low-boom inlet

NASA Astrophysics Data System (ADS)

Rybalko, Michael

The application of vortex generators (VGs) for shock/boundary layer interaction flow control in a novel external compression, axisymmetric, low-boom concept inlet was studied using numerical and experimental methods. The low-boom inlet design features a zero-angle cowl and relaxed isentropic compression centerbody spike, resulting in defocused oblique shocks and a weak terminating normal shock. This allows reduced external gas dynamic waves at high mass flow rates but suffers from flow separation near the throat and a large hub-side boundary layer at the Aerodynamic Interface Plane (AIP), which marks the inflow to the jet engine turbo-machinery. Supersonic VGs were investigated to reduce the shock-induced flow separation near the throat while subsonic VGs were investigated to reduce boundary layer radial distortion at the AIP. To guide large-scale inlet experiments, Reynolds-Averaged Navier-Stokes (RANS) simulations using three-dimensional, structured, chimera (overset) grids and the WIND-US code were conducted. Flow control cases included conventional and novel types of vortex generators at positions both upstream of the terminating normal shock (supersonic VGs) and downstream (subsonic VGs). The performance parameters included incompressible axisymmetric shape factor, post-shock separation area, inlet pressure recovery, and mass flow ratio. The design of experiments (DOE) methodology was used to select device size and location, analyze the resulting data, and determine the optimal choice of device geometry. Based on the above studies, a test matrix of supersonic and subsonic VGs was adapted for a large-scale inlet test to be conducted at the 8'x6' supersonic wind tunnel at NASA Glenn Research Center (GRC). Comparisons of RANS simulations with data from the Fall 2010 8'x6' inlet test showed that predicted VG performance trends and case rankings for both supersonic and subsonic devices were consistent with experimental results. For example, experimental surface oil flow visualization revealed a significant post-shock separation bubble with flow recirculation for the baseline (no VG) case that was substantially broken up in the micro-ramp VG case, consistent with simulations. Furthermore, the predicted subsonic VG performance with respect to a reduction in radial distortion (quantified in terms of axisymmetric incompressible shape factor) was found to be consistent with boundary layer rake measurements. To investigate the unsteady turbulent flow features associated with the shock-induced flow separation and the hub-side boundary layer, a detached eddy simulation (DES) approach using the WIND-US code was employed to model the baseline inlet flow field. This approach yielded improved agreement with experimental data for time-averaged diffuser stagnation pressure profiles and allowed insight into the pressure fluctuations and turbulent kinetic energy distributions which may be present at the AIP. In addition, streamwise shock position statistics were obtained and compared with experimental Schlieren results. The predicted shock oscillations were much weaker than those seen experimentally (by a factor of four), which indicates that the mechanism for the experimental shock oscillations was not captured. In addition, the novel supersonic vortex generator geometries were investigated experimentally (prior to the large-scale inlet 8'x6' wind tunnel tests) in an inlet-relevant flow field containing a Mach 1.4 normal shock wave followed by a subsonic diffuser. A parametric study of device height and distance upstream of the normal shock was undertaken for split-ramp and ramped-vane geometries. Flow field diagnostics included high-speed Schlieren, oil flow visualization, and Pitot-static pressure measurements. Parameters including flow separation, pressure recovery, centerline incompressible boundary layer shape factor, and shock stability were analyzed and compared to the baseline uncontrolled case. While all vortex generators tested eliminated centerline flow separation, the presence of VGs also increased the significant three-dimensionality of the flow via increased side-wall interaction. The stronger streamwise vorticity generated by ramped-vanes also yielded improved pressure recovery and fuller boundary layer velocity profiles within the subsonic diffuser. (Abstract shortened by UMI.)

Sepsis and Septic Shock Strategies.

PubMed

Armstrong, Bracken A; Betzold, Richard D; May, Addison K

2017-12-01

Three therapeutic principles most substantially improve organ dysfunction and survival in sepsis: early, appropriate antimicrobial therapy; restoration of adequate cellular perfusion; timely source control. The new definitions of sepsis and septic shock reflect the inadequate sensitivity, specify, and lack of prognostication of systemic inflammatory response syndrome criteria. Sequential (sepsis-related) organ failure assessment more effectively prognosticates in sepsis and critical illness. Inadequate cellular perfusion accelerates injury and reestablishing perfusion limits injury. Multiple organ systems are affected by sepsis and septic shock and an evidence-based multipronged approach to systems-based therapy in critical illness results in improve outcomes. Copyright © 2017 Elsevier Inc. All rights reserved.

The New Sepsis Definitions: Implications for the Basic and Translational Research Communities.

PubMed

Coopersmith, Craig M; Deutschman, Clifford S

2017-03-01

New definitions of sepsis and septic shock were published in early 2016, updating old definitions that have not been revisited since 2001. These new definitions should profoundly affect sepsis research. In addition, these papers present clinical criteria for identifying infected patients who are highly likely to have or to develop sepsis or septic shock. In contrast to previous approaches, these new clinical criteria are evidence based. In this review, two of the authors of the new definitions detail the content of the papers and explore the implications for shock and sepsis researchers.

["Shock" therapies in Nazi Germany. The example of Berlin psychiatry].

PubMed

Rzesnitzek, L

2014-09-01

The idea that "shock" therapies were introduced by "Nazi-Psychiatry" very early and used radically in a cruel way darkens the image of these therapies until today. A case analysis of patient files of psychiatric hospitals in Berlin is used to recapitulate the introduction of insulin coma, metrazol and electroconvulsive therapy during the National Socialism era. Contrary to the false assumption that these "shock" therapies would have been introduced and preferred by psychiatrists involved with the Nazi regime and "euthanasia", in the case of Berlin these therapies were delayed by them and seldom used.

Supersonic compressor

DOEpatents

Lawlor, Shawn P [Bellevue, WA; Novaresi, Mark A [San Diego, CA; Cornelius, Charles C [Kirkland, WA

2008-02-26

A gas compressor based on the use of a driven rotor having an axially oriented compression ramp traveling at a local supersonic inlet velocity (based on the combination of inlet gas velocity and tangential speed of the ramp) which forms a supersonic shockwave axially, between adjacent strakes. In using this method to compress inlet gas, the supersonic compressor efficiently achieves high compression ratios while utilizing a compact, stabilized gasdynamic flow path. Operated at supersonic speeds, the inlet stabilizes an oblique/normal shock system in the gasdyanamic flow path formed between the gas compression ramp on a strake, the shock capture lip on the adjacent strake, and captures the resultant pressure within the stationary external housing while providing a diffuser downstream of the compression ramp.

Launch of the STS 51-F Challenger

NASA Image and Video Library

1985-07-29

51F-S-157 (29 July 1985) --- Just moments following ignition, the Space Shuttle Challenger, mated to its two solid rocket boosters and an external fuel tank, soars toward a week-long mission in Earth orbit. Note the diamond shock effect in the vicinity of the three main engines. Launch occurred at 5:00 p.m. (EDT), July 29, 1985.

Development of an external ceramic insulation for the space shuttle orbiter. Part 3: Development of stabilized aluminum phosphate fibers

NASA Technical Reports Server (NTRS)

Ormiston, T.; Tanzilli, R. A.

1973-01-01

The development of reusable surface insulation materials that are thermal shock resistant and highly refractory is discussed. A stabilized, high-cristobalite, aluminum orthophosphate fiber was developed and found to possess the desired qualities. The application of such a material to heat shielding for space shuttles is examined.

Sensitivity and specificity of two different automated external defibrillators.

PubMed

Israelsson, Johan; Wangenheim, Burkard von; Årestedt, Kristofer; Semark, Birgitta; Schildmeijer, Kristina; Carlsson, Jörg

2017-11-01

The aim was to investigate the clinical performance of two different types of automated external defibrillators (AEDs). Three investigators reviewed 2938 rhythm analyses performed by AEDs in 240 consecutive patients (median age 72, q1-q3=62-83) who had suffered cardiac arrest between January 2011 and March 2015. Two different AEDs were used (AED A n=105, AED B n=135) in-hospital (n=91) and out-of-hospital (n=149). Among 194 shockable rhythms, 17 (8.8%) were not recognized by AED A, while AED B recognized 100% (n=135) of shockable episodes (sensitivity 91.2 vs 100%, p<0.01). In AED A, 8 (47.1%) of these episodes were judged to be algorithm errors while 9 (52.9%) were caused by external artifacts. Among 1039 non-shockable rhythms, AED A recommended shock in 11 (1.0%), while AED B recommended shock in 63 (4.1%) of 1523 episodes (specificity 98.9 vs 95.9, p<0.001). In AED A, 2 (18.2%) of these episodes were judged to be algorithm errors (AED B, n=40, 63.5%), while 9 (81.8%) were caused by external artifacts (AED B, n=23, 36.5%). There were significant differences in sensitivity and specificity between the two different AEDs. A higher sensitivity of AED B was associated with a lower specificity while a higher specificity of AED A was associated with a lower sensitivity. AED manufacturers should work to improve the algorithms. In addition, AED use should always be reviewed with a routine for giving feedback, and medical personnel should be aware of the specific strengths and shortcomings of the device they are using. Copyright © 2017 Elsevier B.V. All rights reserved.

Aspherical Supernovae: Effects on Early Light Curves

NASA Astrophysics Data System (ADS)

Afsariardchi, Niloufar; Matzner, Christopher D.

2018-04-01

Early light from core-collapse supernovae, now detectable in high-cadence surveys, holds clues to a star and its environment just before it explodes. However, effects that alter the early light have not been fully explored. We highlight the possibility of nonradial flows at the time of shock breakout. These develop in sufficiently nonspherical explosions if the progenitor is not too diffuse. When they do develop, nonradial flows limit ejecta speeds and cause ejecta–ejecta collisions. We explore these phenomena and their observational implications using global, axisymmetric, nonrelativistic FLASH simulations of simplified polytropic progenitors, which we scale to representative stars. We develop a method to track photon production within the ejecta, enabling us to estimate band-dependent light curves from adiabatic simulations. Immediate breakout emission becomes hidden as an oblique flow develops. Nonspherical effects lead the shock-heated ejecta to release a more constant luminosity at a higher, evolving color temperature at early times, effectively mixing breakout light with the early light curve. Collisions between nonradial ejecta thermalize a small fraction of the explosion energy; we will address emission from these collisions in a subsequent paper.

The Coronal Analysis of SHocks and Waves (CASHeW) framework

NASA Astrophysics Data System (ADS)

Kozarev, Kamen A.; Davey, Alisdair; Kendrick, Alexander; Hammer, Michael; Keith, Celeste

2017-11-01

Coronal bright fronts (CBF) are large-scale wavelike disturbances in the solar corona, related to solar eruptions. They are observed (mostly in extreme ultraviolet (EUV) light) as transient bright fronts of finite width, propagating away from the eruption source location. Recent studies of individual solar eruptive events have used EUV observations of CBFs and metric radio type II burst observations to show the intimate connection between waves in the low corona and coronal mass ejection (CME)-driven shocks. EUV imaging with the atmospheric imaging assembly instrument on the solar dynamics observatory has proven particularly useful for detecting large-scale short-lived CBFs, which, combined with radio and in situ observations, holds great promise for early CME-driven shock characterization capability. This characterization can further be automated, and related to models of particle acceleration to produce estimates of particle fluxes in the corona and in the near Earth environment early in events. We present a framework for the coronal analysis of shocks and waves (CASHeW). It combines analysis of NASA Heliophysics System Observatory data products and relevant data-driven models, into an automated system for the characterization of off-limb coronal waves and shocks and the evaluation of their capability to accelerate solar energetic particles (SEPs). The system utilizes EUV observations and models written in the interactive data language. In addition, it leverages analysis tools from the SolarSoft package of libraries, as well as third party libraries. We have tested the CASHeW framework on a representative list of coronal bright front events. Here we present its features, as well as initial results. With this framework, we hope to contribute to the overall understanding of coronal shock waves, their importance for energetic particle acceleration, as well as to the better ability to forecast SEP events fluxes.

Characteristics of ventricular fibrillation in relation to cardiac aetiology and shock success: A waveform analysis study in ICD-patients.

PubMed

Bonnes, Judith L; Keuper, Wessel; Westra, Sjoerd W; Zegers, Erwin S; Oostendorp, Thom F; Brouwer, Marc A; Smeets, Joep L R M

2015-01-01

Ventricular fibrillation (VF) waveform characteristics are associated with cardiac arrest duration and defibrillation success. Recent animal studies found that VF characteristics and shock success also depend on the presence of myocardial infarction (MI). In patients, VF induction after implantable cardioverter defibrillator (ICD) implantation offers a unique setting to study early VF characteristics: we studied the relation with cardiac disease--either presence or absence of a previous MI--and with shock success. Retrospective cohort study of ICD-patients who underwent defibrillation testing, 117 (63%) with and 69 (37%) without a previous MI. Intracardiac recordings of induced VF were analysed using Fourier analysis. In previous MI-patients, the fundamental frequency and organisation index of the VF signal were significantly lower as compared with patients without a previous MI: 4.9 Hz ± 0.6 vs. 5.2 Hz ± 0.6 (p = 0.005) and 56% ± 10 vs. 60% ± 9 (p = 0.001), respectively. The median frequency was not different (p = 0.25). We found no association between VF characteristics and ICD shock success. In analogy with observations in animals, we found that a history of a previous MI was associated with slower and less organised VF. In our cohort of ICD-patients, early VF waveform characteristics were not associated with shock outcomes. Further study is warranted to determine to what extent VF characteristics are influenced by the underlying aetiology on the one hand, and time delay on the other. These findings could improve insight into the potential value of VF analysis to guide shock delivery. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Early life stress in rats sex-dependently affects remote endocrine rather than behavioral consequences of adult exposure to contextual fear conditioning.

PubMed

Fuentes, Sílvia; Daviu, Núria; Gagliano, Humberto; Belda, Xavier; Armario, Antonio; Nadal, Roser

2018-05-30

Exposure to electric foot-shocks can induce in rodents contextual fear conditioning, generalization of fear to other contexts and sensitization of the hypothalamic-pituitary-adrenal (HPA) axis to further stressors. All these aspects are relevant for the study of post-traumatic stress disorder. In the present work we evaluated in rats the sex differences and the role of early life stress (ELS) in fear memories, generalization and sensitization. During the first postnatal days subjects were exposed to restriction of nesting material along with exposure to a "substitute" mother. In the adulthood they were exposed to (i) a contextual fear conditioning to evaluate long-term memory and extinction and (ii) to a novel environment to study cognitive fear generalization and HPA axis heterotypic sensitization. ELS did not alter acquisition, expression or extinction of context fear conditioned behavior (freezing) in either sex, but reduced activity in novel environments only in males. Fear conditioning associated hypoactivity in novel environments (cognitive generalization) was greater in males than females but was not specifically affected by ELS. Although overall females showed greater basal and stress-induced levels of ACTH and corticosterone, an interaction between ELS, shock exposure and sex was found regarding HPA hormones. In males, ELS did not affect ACTH response in any situation, whereas in females, ELS reduced both shock-induced sensitization of ACTH and its conditioned response to the shock context. Also, shock-induced sensitization of corticosterone was only observed in males and ELS specifically reduced corticosterone response to stressors in males but not females. In conclusion, ELS seems to have only a minor impact on shock-induced behavioral conditioning, while affecting the unconditioned and conditioned responses of HPA hormones in a sex-dependent manner. Copyright © 2018. Published by Elsevier Inc.

Hydrodynamic instability of elastic-plastic solid plates at the early stage of acceleration.

PubMed

Piriz, A R; Sun, Y B; Tahir, N A

2015-03-01

A model is presented for the linear Rayleigh-Taylor instability taking place at the early stage of acceleration of an elastic-plastic solid, when the shock wave is still running into the solid and is driven by a time varying pressure on the interface. When the the shock is formed sufficiently close to the interface, this stage is considered to follow a previous initial phase controlled by the Ritchmyer-Meshkov instability that settles new initial conditions. The model reproduces the behavior of the instability observed in former numerical simulation results and provides a relatively simpler physical picture than the currently existing one for this stage of the instability evolution.

Curious kinetic behavior in silica polymorphs solves seifertite puzzle in shocked meteorite

PubMed Central

Kubo, Tomoaki; Kato, Takumi; Higo, Yuji; Funakoshi, Ken-ichi

2015-01-01

The presence of seifertite, one of the high-pressure polymorphs of silica, in achondritic shocked meteorites has been problematic because this phase is thermodynamically stable at more than ~100 GPa, unrealistically high-pressure conditions for the shock events in the early solar system. We conducted in situ x-ray diffraction measurements at high pressure and temperatures, and found that it metastably appears down to ~11 GPa owing to the clear difference in kinetics between the metastable seifertite and stable stishovite formations. The temperature-insensitive but time-sensitive kinetics for the formation of seifertite uniquely constrains that the critical shock duration and size of the impactor on differentiated parental bodies are at least ~0.01 s and ~50 to 100 m, respectively, from the presence of seifertite. PMID:26601182

The Effects of Prenatal and Early-Postnatal Exposure to Mexico's "Oportunidades" on Long-Term Cognitive Achievement

ERIC Educational Resources Information Center

Sanchez, Alonso

2016-01-01

It is well established that children's early life environments can have significant consequences on their long-term outcomes. Yet, there is still limited empirical evidence on the effects that being exposed during the prenatal and early postnatal periods to positive shocks, such as conditional cash transfers, has on long-term cognitive function.…

Static Performance of a Fixed-Geometry Exhaust Nozzle Incorporating Porous Cavities for Shock-Boundary Layer Interaction Control

NASA Technical Reports Server (NTRS)

Asbury, Scott C.; Hunter, Craig A.

1999-01-01

An investigation was conducted in the model preparation area of the Langley 16-Foot Transonic Tunnel to determine the internal performance of a fixed-geometry exhaust nozzle incorporating porous cavities for shock-boundary layer interaction control. Testing was conducted at static conditions using a sub-scale nozzle model with one baseline and 27 porous configurations. For the porous configurations, the effects of percent open porosity, hole diameter, and cavity depth were determined. All tests were conducted with no external flow at nozzle pressure ratios from 1.25 to approximately 9.50. Results indicate that baseline nozzle performance was dominated by unstable, shock-induced, boundary-layer separation at over-expanded conditions. Porous configurations were capable of controlling off-design separation in the nozzle by either alleviating separation or encouraging stable separation of the exhaust flow. The ability of the porous nozzle concept to alternately alleviate separation or encourage stable separation of exhaust flow through shock-boundary layer interaction control offers tremendous off-design performance benefits for fixed-geometry nozzle installations. In addition, the ability to encourage separation on one divergent flap while alleviating it on the other makes it possible to generate thrust vectoring using a fixed-geometry nozzle.

Prebiotic Chemistry and Atmospheric Warming of Early Earth by an Active Young Sun

NASA Technical Reports Server (NTRS)

Airapetian, V. S.; Glocer, A.; Gronoff, G.; Hebrard, E.; Danchi, W.

2016-01-01

Nitrogen is a critical ingredient of complex biological molecules. Molecular nitrogen, however, which was outgassed Into the Earth's early atmosphere, is relatively chemically inert and nitrogen fixation into more chemically reactive compounds requires high temperatures. Possible mechanisms of nitrogen fixation include lightning, atmospheric shock heating by meteorites, and solar ultraviolet radiation. Here we show that nitrogen fixation in the early terrestrial atmosphere can be explained by frequent and powerful coronal mass ejection events from the young Sun -- so-called superflares. Using magnetohydrodynamic simulations constrained by Kepler Space Telescope observations, we find that successive superflare ejections produce shocks that accelerate energetic particles, which would have compressed the early Earth's magnetosphere. The resulting extended polar cap openings provide pathways for energetic particles to penetrate into the atmosphere and, according to our atmospheric chemistry simulations, initiate reactions converting molecular nitrogen, carbon dioxide and methane to the potent greenhouse gas nitrous oxide as well as hydrogen cyanide, an essential compound for life. Furthermore, the destruction of N2, C02 and CH, suggests that these greenhouse gases cannot explain the stability of liquid water on the early Earth. Instead, we propose that the efficient formation of nitrous oxide could explain a warm early Earth.

Peptide synthesis triggered by comet impacts: A possible method for peptide delivery to the early Earth and icy satellites

NASA Astrophysics Data System (ADS)

Sugahara, Haruna; Mimura, Koichi

2015-09-01

We performed shock experiments simulating natural comet impacts in an attempt to examine the role that comet impacts play in peptide synthesis. In the present study, we selected a mixture of alanine (DL-alanine), water ice, and silicate (forsterite) to make a starting material for the experiments. The shock experiments were conducted under cryogenic conditions (77 K), and the shock pressure range achieved in the experiments was 4.8-25.8 GPa. The results show that alanine is oligomerized into peptides up to tripeptides due to the impact shock. The synthesized peptides were racemic, indicating that there was no enantioselective synthesis of peptides from racemic amino acids due to the impact shock. We also found that the yield of linear peptides was a magnitude higher than those of cyclic diketopiperazine. Furthermore, we estimated the amount of cometary-derived peptides to the early Earth based on two models (the Lunar Crating model and the Nice model) during the Late Heavy Bombardment (LHB) using our experimental data. The estimation based on the Lunar Crating model gave 3 × 109 mol of dialanine, 4 × 107 mol of trialanine, and 3 × 108 mol of alanine-diketopiperazine. Those based on the Nice model, in which the main impactor of LHB is comets, gave 6 × 1010 mol of dialanine, 1 × 109 mol of trialanine, and 8 × 109 mol of alanine-diketopiperazine. The estimated amounts were comparable to those originating from terrestrial sources (Cleaves, H.J., Aubrey, A.D., Bada, J.L. [2009]. Orig. Life Evol. Biosph. 39, 109-126). Our results indicate that comet impacts played an important role in chemical evolution as a supplier of linear peptides, which are important for further chemical evolution on the early Earth. Our study also highlights the importance of icy satellites, which were formed by comet accumulation, as prime targets for missions searching for extraterrestrial life.

Footwear affects the behavior of low back muscles when jogging.

PubMed

Ogon, M; Aleksiev, A R; Spratt, K F; Pope, M H; Saltzman, C L

2001-08-01

Use of modified shoes and insole materials has been widely advocated to treat low back symptoms from running impacts, although considerable uncertainty remains regarding the effects of these devices on the rate of shock transmission to the spine. This study investigated the effects of shoes and insole materials on a) the rate of shock transmission to the spine, b) the temporal response of spinal musculature to impact loading, and c) the time interval between peak lumbar acceleration and peak lumbar muscle response. It was hypothesised that shoes and inserts a) decrease the rate of shock transmission, b) decrease the low back muscle response time, and c) shorten the time interval between peak lumbar acceleration and peak lumbar muscle response. Twelve healthy subjects were tested while jogging barefoot (unshod) or wearing identical athletic shoes (shod). Either no material, semi-rigid (34 Shore A), or soft (9.5 Shore A) insole material covered the force plate in the barefoot conditions and was placed as insole when running shod. Ground reaction forces, acceleration at the third lumbar level, and erector spinae myoelectric activity were recorded simultaneously. The rate of shock transmission to the spine was greater (p < 0.0003) unshod (acceleration rate: Means +/- SD 127.35 +/- 87.23 g/s) than shod (49.84 +/- 33.98 g/s). The temporal response of spinal musculature following heel strike was significantly shorter (p < 0.023) unshod (0.038 +/- 0.021 s) than shod (0.047 +/- 0.036 s). The latency between acceleration peak (maximal external force) and muscle response peak (maximal internal force) was significantly (p < 0.021) longer unshod (0.0137 +/- 0.022s) than shod (0.004 +/- 0.040 s). These results suggest that one of the benefits of running shoes and insoles is improved temporal synchronization between potentially destabilizing external forces and stabilizing internal forces around the lumbar spine.

Minimal instructions improve the performance of laypersons in the use of semiautomatic and automatic external defibrillators

PubMed Central

Beckers, Stefan; Fries, Michael; Bickenbach, Johannes; Derwall, Matthias; Kuhlen, Ralf; Rossaint, Rolf

2005-01-01

Introduction There is evidence that use of automated external defibrillators (AEDs) by laypersons improves rates of survival from cardiac arrest, but there is no consensus on the optimal content and duration of training for this purpose. In this study we examined the use of semiautomatic or automatic AEDs by laypersons who had received no training (intuitive use) and the effects of minimal general theoretical instructions on their performance. Methods In a mock cardiac arrest scenario, 236 first year medical students who had not previously attended any preclinical courses were evaluated in their first study week, before and after receiving prespecified instructions (15 min) once. The primary end-point was the time to first shock for each time point; secondary end-points were correct electrode pad positioning, safety of the procedure and the subjective feelings of the students. Results The mean time to shock for both AED types was 81.2 ± 19.2 s (range 45–178 s). Correct pad placement was observed in 85.6% and adequate safety in 94.1%. The time to shock after instruction decreased significantly to 56.8 ± 9.9 s (range 35–95 s; P ≤ 0.01), with correct electrode placement in 92.8% and adequate safety in 97%. The students were significantly quicker at both evaluations using the semiautomatic device than with the automatic AED (first evaluation: 77.5 ± 20.5 s versus 85.2 ± 17 s, P ≤ 0.01; second evaluation: 55 ± 10.3 s versus 59.6 ± 9.6 s, P ≤ 0.01). Conclusion Untrained laypersons can use semiautomatic and automatic AEDs sufficiently quickly and without instruction. After one use and minimal instructions, improvements in practical performance were significant. All tested laypersons were able to deliver the first shock in under 1 min. PMID:15774042

Sequential N-Terminal Pro-B-Type Natriuretic Peptide and High-Sensitivity Cardiac Troponin Measurements During Albumin Replacement in Patients With Severe Sepsis or Septic Shock.

PubMed

Masson, Serge; Caironi, Pietro; Fanizza, Caterina; Carrer, Sara; Caricato, Anselmo; Fassini, Paola; Vago, Tarcisio; Romero, Marilena; Tognoni, Gianni; Gattinoni, Luciano; Latini, Roberto

2016-04-01

Myocardial dysfunction is a frequent complication in patients with severe sepsis and can worsen the prognosis. We investigated whether circulating biomarkers related to myocardial function and injury predicted outcome and were associated with albumin replacement. A multicenter, randomized clinical trial about albumin replacement in severe sepsis or septic shock (the Albumin Italian Outcome Sepsis trial). Forty ICUs in Italy. Nine hundred and ninety-five patients with severe sepsis or septic shock. Randomization to albumin and crystalloid solutions or crystalloid solutions alone. Plasma concentrations of N- terminal pro-B-type natriuretic peptide and high-sensitivity cardiac troponin T were measured 1, 2, and 7 days after enrollment. We tested the relationship of single marker measurements or changes over time with clinical events, organ dysfunctions, albumin replacement, and ICU or 90-day mortality in the overall population and after stratification by shock. N-terminal pro-B-type natriuretic peptide levels were abnormal in 97.4% of the patients and high-sensitivity cardiac troponin T in 84.5%, with higher concentrations in those with shock. After extensive adjustments, N-terminal pro-B-type natriuretic peptide concentrations predicted ICU or 90-day mortality, better than high-sensitivity cardiac troponin T. Early changes in N-terminal pro-B-type natriuretic peptide or high-sensitivity cardiac troponin T concentrations were independently associated with subsequent mortality in patients with shock. Patients given albumin had significantly higher N-terminal pro-B-type natriuretic peptide levels; in addition, early rise in N-terminal pro-B-type natriuretic peptide was associated with a better outcome in this subgroup. Circulating N-terminal pro-B-type natriuretic peptide and high-sensitivity cardiac troponin T are frequently elevated in severe sepsis or septic shock and have relevant prognostic value, which may be important in monitoring the clinical efficacy of supporting therapy.

Attentional Bias for Uncertain Cues of Shock in Human Fear Conditioning: Evidence for Attentional Learning Theory

PubMed Central

Koenig, Stephan; Uengoer, Metin; Lachnit, Harald

2017-01-01

We conducted a human fear conditioning experiment in which three different color cues were followed by an aversive electric shock on 0, 50, and 100% of the trials, and thus induced low (L), partial (P), and high (H) shock expectancy, respectively. The cues differed with respect to the strength of their shock association (L < P < H) and the uncertainty of their prediction (L < P > H). During conditioning we measured pupil dilation and ocular fixations to index differences in the attentional processing of the cues. After conditioning, the shock-associated colors were introduced as irrelevant distracters during visual search for a shape target while shocks were no longer administered and we analyzed the cues’ potential to capture and hold overt attention automatically. Our findings suggest that fear conditioning creates an automatic attention bias for the conditioned cues that depends on their correlation with the aversive outcome. This bias was exclusively linked to the strength of the cues’ shock association for the early attentional processing of cues in the visual periphery, but additionally was influenced by the uncertainty of the shock prediction after participants fixated on the cues. These findings are in accord with attentional learning theories that formalize how associative learning shapes automatic attention. PMID:28588466

Serotonin transporter linked polymorphic region (5-HTTLPR) genotype moderates the longitudinal impact of early caregiving on externalizing behavior.

PubMed

Brett, Zoë H; Humphreys, Kathryn L; Smyke, Anna T; Gleason, Mary Margaret; Nelson, Charles A; Zeanah, Charles H; Fox, Nathan A; Drury, Stacy S

2015-02-01

We examined caregiver report of externalizing behavior from 12 to 54 months of age in 102 children randomized to care as usual in institutions or to newly created high-quality foster care. At baseline no differences by group or genotype in externalizing were found. However, changes in externalizing from baseline to 42 months of age were moderated by the serotonin transporter linked polymorphic region genotype and intervention group, where the slope for short-short (S/S) individuals differed as a function of intervention group. The slope for individuals carrying the long allele did not significantly differ between groups. At 54 months of age, S/S children in the foster care group had the lowest levels of externalizing behavior, while children with the S/S genotype in the care as usual group demonstrated the highest rates of externalizing behavior. No intervention group differences were found in externalizing behavior among children who carried the long allele. These findings, within a randomized controlled trial of foster care compared to continued care as usual, indicate that the serotonin transporter linked polymorphic region genotype moderates the relation between early caregiving environments to predict externalizing behavior in children exposed to early institutional care in a manner most consistent with differential susceptibility.

Are infants differentially sensitive to parenting? Early maternal care, DRD4 genotype and externalizing behavior during adolescence.

PubMed

Nikitopoulos, Jörg; Zohsel, Katrin; Blomeyer, Dorothea; Buchmann, Arlette F; Schmid, Brigitte; Jennen-Steinmetz, Christine; Becker, Katja; Schmidt, Martin H; Esser, Günter; Brandeis, Daniel; Banaschewski, Tobias; Laucht, Manfred

2014-12-01

Insensitive and unresponsive caregiving during infancy has been linked to externalizing behavior problems during childhood and adolescence. The 7-repeat (7r) allele of the dopamine D4 receptor (DRD4) gene has meta-analytically been associated with a heightened susceptibility to adverse as well as supportive environments. In the present study, we examined long-term effects of early maternal care, DRD4 genotype and the interaction thereof on externalizing and internalizing psychopathology during adolescence. As part of an ongoing epidemiological cohort study, early maternal care was assessed at child's age 3 months during a nursing and playing situation. In a sample of 296 offspring, externalizing and internalizing symptoms were assessed using a psychiatric interview conducted at age 15 years. Parents additionally filled out a questionnaire on their children's psychopathic behaviors. Results indicated that adolescents with the DRD4 7r allele who experienced less responsive and stimulating early maternal care exhibited more symptoms of ADHD and CD/ODD as well as higher levels of psychopathic behavior. In accordance with the hypothesis of differential susceptibility, 7r allele carriers showed fewer ADHD symptoms and lower levels of psychopathic behavior when exposed to especially beneficial early caregiving. In contrast, individuals without the DRD4 7r allele proved to be insensitive to the effects of early maternal care. This study replicates earlier findings with regard to an interaction between DRD4 genotype and early caregiving on externalizing behavior problems in preschoolers. It is the first one to imply continuity of this effect until adolescence. Copyright © 2014 Elsevier Ltd. All rights reserved.

Euler-Lagrange Simulations of Shock Wave-Particle Cloud Interaction

NASA Astrophysics Data System (ADS)

Koneru, Rahul; Rollin, Bertrand; Ouellet, Frederick; Park, Chanyoung; Balachandar, S.

2017-11-01

Numerical experiments of shock interacting with an evolving and fixed cloud of particles are performed. In these simulations we use Eulerian-Lagrangian approach along with state-of-the-art point-particle force and heat transfer models. As validation, we use Sandia Multiphase Shock Tube experiments and particle-resolved simulations. The particle curtain upon interaction with the shock wave is expected to experience Kelvin-Helmholtz (KH) and Richtmyer-Meshkov (RM) instabilities. In the simulations evolving the particle cloud, the initial volume fraction profile matches with that of Sandia Multiphase Shock Tube experiments, and the shock Mach number is limited to M =1.66. Measurements of particle dispersion are made at different initial volume fractions. A detailed analysis of the influence of initial conditions on the evolution of the particle cloudis presented. The early time behavior of the models is studied in the fixed bed simulations at varying volume fractions and shock Mach numbers.The mean gas quantities are measured in the context of 1-way and 2-way coupled simulations. This work was supported by the U.S. Department of Energy, National Nuclear Security Administration, Advanced Simulation and Computing Program, as a Cooperative Agreement under the Predictive Science Academic Alliance Program, Contract No. DE-NA0002378.

Treatment outcomes of open pelvic fractures associated with extensive perineal injuries.

PubMed

Hasankhani, Ebrahim Ghayem; Omidi-Kashani, Farzad

2013-12-01

The main causes of death in patients with open pelviperineal injuries are uncontrollable bleeding and pelvic sepsis. The aim of this study was to evaluate the management outcomes of open pelvic fractures associated with extensive perineal injuries. We retrospectively studied 15 cases with open pelvic fractures associated with extensive perineal injuries (urethral and anal canal laceration) admitted between August 2006 and September 2010. Mechanism of injury, Injury Severity Score, associated injuries, hemodynamic status on arrival, resuscitation and transfusion requirements, operative techniques, intra- and postoperative complications, length of intensive care unit and hospital stay, and mortality were recorded in a computerised database for further evaluation and analysis. The male to female ratio was 12:3 with an average age of 38.6 years (ranged, 11 to 65 years). The average packed red blood cell units used were 8 units (ranged, 4 to 21 units). All patients were initially transferred to the operating room for colostomy, radical debridement and fixation of the pelvic fracture by an external fixator. One patient had acute renal failure, which improved with medical treatment and 2 patients (13.3%) died, one with type III anteroposterior compression fracture due to hemorrhagic shock and the other due to septicemia. Open pelvic fractures with extensive perineal injuries are associated with high mortality rates. Early diagnosis and appropriate treatment, including reanimation, colostomy, cystostomy, vigorous and repeated irrigation and debridement, and fixation by an external fixator can improve the outcomes and reduce the mortality rate.

[In-hospital resuscitation. Concept of first-responder resuscitation using semi-automated external defibrillators (AED)].

PubMed

Hanefeld, C; Lichte, C; Laubenthal, H; Hanke, E; Mügge, A

2006-09-29

The prognosis after in-hospital resuscitation has not significantly improved in the last 40 years. This account presents the results over a three-year period of a hospital-wide emergency plan which implements the use of an automated external defibrillator (AED) by the first responder to the emergency call. 15 "defibrillator points" were installed, which could be reached within 30 s from all wards, out-patient departments and other areas, thus making them accessible for immediate defibrillator application. The hospital personnel is trained periodically in the alarm sequence, cardiopulmonary resuscitation and use of the defibrillator. Data on 57 patients who had sustained a cardiac arrest were prospectively recorded and analysed. In 46 patients (81%) the "on-the-spot" personnel (first-responder) was able to apply AED before arrival of the hospital's resuscitation team. Mean period between arrest alarm and activation of the AED was 2.2 (0.7-4.7) min. Ventricular fibrillation or ventricular tachyarrhythmia was recorded in 40 patients, making immediate shock delivery by AED possible. Restoration of the circulation was achieved in 23 (80%) of the patients and 20 (50%) were discharged home, 17 (43%) without neurological deficit. The high proportion of first-responder AED applications and evaluation of the personnel training indicate a wide acceptance of the emergency plan among the personnel. An immediate resuscitation plan consisting of an integrated programme of early defibrillation is feasible and seems to achieve an improved prognosis for patients who have sustained an in-hospital cardiac arrest.

Synthesis of the low molecular weight heat shock proteins in plants

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

Mansfield, M.A.; Key, J.L.

1987-08-01

Heat shock of living tissue induces the synthesis of a unique group of proteins, the heat shock proteins. In plants, the major group of heat shock proteins has a molecular mass of 15 to 25 kilodaltons. Accumulation to these proteins to stainable levels has been reported in only a few species. To examine accumulation of the low molecular weight heat shock proteins in a broader range of species, two-dimensional electrophoresis was used to resolve total protein from the following species: soybean (Glycine max L. Merr., var Wayne), pea (Pisum sativum L., var Early Alaska), sunflower (Helianthus annuus L.), wheat (Triticummore » asetivum L.), rice (Oryza sativa L., cv IR-36), maize (Zea mays L.), pearl millet (Pennisetum americanum L. Leeke, line 23DB), and Panicum miliaceum L. When identified by both silver staining and incorporation of radiolabel, a diverse array of low molecular weight heat shock proteins was synthesized in each of these species. These proteins accumulated to significant levels after three hours of heat shock but exhibited considerable heterogeneity in isoelectric point, molecular weight, stainability, and radiolabel incorporation. Although most appeared to be synthesized only during heat shock, some were detectable at low levels in control tissue. Compared to the monocots, a higher proportion of low molecular weight heat shock proteins was detectable in control tissues from dicots.« less

Intraoperative Defibrillation Testing of Subcutaneous Implantable Cardioverter-Defibrillator Systems-A Simple Issue?

PubMed

Frommeyer, Gerrit; Zumhagen, Sven; Dechering, Dirk G; Larbig, Robert; Bettin, Markus; Löher, Andreas; Köbe, Julia; Reinke, Florian; Eckardt, Lars

2016-03-15

The results of the recently published randomized SIMPLE trial question the role of routine intraoperative defibrillation testing. However, testing is still recommended during implantation of the entirely subcutaneous implantable cardioverter-defibrillator (S-ICD) system. To address the question of whether defibrillation testing in S-ICD systems is still necessary, we analyzed the data of a large, standard-of-care prospective single-center S-ICD registry. In the present study, 102 consecutive patients received an S-ICD for primary (n=50) or secondary prevention (n=52). Defibrillation testing was performed in all except 4 patients. In 74 (75%; 95% CI 0.66-0.83) of 98 patients, ventricular fibrillation was effectively terminated by the first programmed internal shock. In 24 (25%; 95% CI 0.22-0.44) of 98 patients, the first internal shock was ineffective and further internal or external shock deliveries were required. In these patients, programming to reversed shock polarity (n=14) or repositioning of the sensing lead (n=1) or the pulse generator (n=5) led to successful defibrillation. In 4 patients, a safety margin of <10 J was not attained. Nevertheless, in these 4 patients, ventricular arrhythmias were effectively terminated with an internal 80-J shock. Although it has been shown that defibrillation testing is not necessary in transvenous ICD systems, it seems particular important for S-ICD systems, because in nearly 25% of the cases the primary intraoperative test was not successful. In most cases, a successful defibrillation could be achieved by changing shock polarity or by optimizing the shock vector caused by the pulse generator or lead repositioning. © 2016 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

High-Speed Edge-Detecting Line Scan Smart Camera

NASA Technical Reports Server (NTRS)

Prokop, Norman F.

2012-01-01

A high-speed edge-detecting line scan smart camera was developed. The camera is designed to operate as a component in a NASA Glenn Research Center developed inlet shock detection system. The inlet shock is detected by projecting a laser sheet through the airflow. The shock within the airflow is the densest part and refracts the laser sheet the most in its vicinity, leaving a dark spot or shadowgraph. These spots show up as a dip or negative peak within the pixel intensity profile of an image of the projected laser sheet. The smart camera acquires and processes in real-time the linear image containing the shock shadowgraph and outputting the shock location. Previously a high-speed camera and personal computer would perform the image capture and processing to determine the shock location. This innovation consists of a linear image sensor, analog signal processing circuit, and a digital circuit that provides a numerical digital output of the shock or negative edge location. The smart camera is capable of capturing and processing linear images at over 1,000 frames per second. The edges are identified as numeric pixel values within the linear array of pixels, and the edge location information can be sent out from the circuit in a variety of ways, such as by using a microcontroller and onboard or external digital interface to include serial data such as RS-232/485, USB, Ethernet, or CAN BUS; parallel digital data; or an analog signal. The smart camera system can be integrated into a small package with a relatively small number of parts, reducing size and increasing reliability over the previous imaging system..

Time-resolved GRB spectra in the complex radiation of synchrotron and Compton processes

NASA Astrophysics Data System (ADS)

Jiang, Y. G.; Hu, S. M.; Chen, X.; Li, K.; Guo, D. F.; Li, Y. T.; Li, H. Z.; Zhao, Y. Y.; Lin, H. N.; Chang, Z.

2016-03-01

Under the steady-state condition, the spectrum of electrons is investigated by solving the continuity equation under the complex radiation of both the synchrotron and Compton processes. The resulted gamma-ray burst (GRB) spectrum is a broken power law in both the fast and slow cooling phases. On the basis of this electron spectrum, the spectral indices of the Band function in four different phases are presented. In the complex radiation frame, the detail investigation on physical parameters reveals that three models can answer the α ˜ -1 problem, which are the synchrotron plus synchrotron self-Compton in the internal and the external shock models, and the synchrotron plus the external Compton processes in the external shock model. A possible marginal to fast cooling phase transition in GRB 080916C is discussed. The time-resolved spectra in different main pulses of GRB 100724B, GRB 100826A and GRB 130606B are investigated. We found that the flux is proportional to the peak energy in almost all main pulses. A significant (5σ) correlation for Fp ˜ Ep is evident the first main pulse of GRB 100826A, and three marginally significant (3σ) correlations Fp ˜ Ep are found in main pulses of GRB 100826A and GRB 130606B. The correlation between spectral index and Ep at 3 ˜ 4σ level are observed in the first main pulse of GRB 100826A. Such correlations are possible explained in the complex radiation scenario.

Interaction between a normal shock wave and a turbulent boundary layer at high transonic speeds. Part 1: Pressure distribution. Part 2: Wall shear stress. Part 3: Simplified formulas for the prediction of surface pressures and skin friction

NASA Technical Reports Server (NTRS)

Adamson, T. C., Jr.; Liou, M. S.; Messiter, A. F.

1980-01-01

An asymptotic description is derived for the interaction between a shock wave and a turbulent boundary layer in transonic flow, for a particular limiting case. The dimensionless difference between the external flow velocity and critical sound speed is taken to be much smaller than one, but large in comparison with the dimensionless friction velocity. The basic results are derived for a flat plate, and corrections for longitudinal wall curvature and for flow in a circular pipe are also shown. Solutions are given for the wall pressure distribution and the shape of the shock wave. Solutions for the wall shear stress are obtained, and a criterion for incipient separation is derived. Simplified solutions for both the wall pressure and skin friction distributions in the interaction region are given. These results are presented in a form suitable for use in computer programs.

A novel free floating accelerometer force balance system for shock tunnel applications

NASA Astrophysics Data System (ADS)

Joarder, R.; Mahaptra, D. R.; Jagadeesh, G.

In order to overcome the interference of the model mounting system with the external aerodynamics of the body during shock tunnel testing, a new free floating internally mountable balance system that ensures unrestrained model motion during testing has been designed, fabricated and tested. Minimal friction ball bearings are used for ensuring the free floating condition of the model during tunnel testing. The drag force acting on a blunt leading edge flat plate at hypersonic Mach number has been measured using the new balance system. Finite element model (FEM) and CFD are exhaustively used in the design as well as for calibrating the new balance system. The experimentally measured drag force on the blunt leading edge flat plate at stagnation enthalpy of 0.7 and 1.2 MJ/kg and nominal Mach number of 5.75 matches well with FEM results. The concept can also be extended for measuring all the three fundamental aerodynamic forces in short duration test facilities like free piston driven shock tunnels.

Severe soft tissue infections.

PubMed

Napolitano, Lena M

2009-09-01

Severe skin and soft tissue infections (SSTIs) frequently require management in the ICU, in part related to associated septic shock or toxic shock syndrome or associated organ failure. Four fundamental management principles are key to a successful outcome in caring for patients who have severe SSTIs, including (1) early diagnosis and differentiation of necrotizing versus nonnecrotizing SSTI, (2) early initiation of appropriate empiric broad-spectrum antimicrobial therapy with consideration of risk factors for specific pathogens and mandatory coverage for methicillin-resistant Staphylococcus aureus (MRSA), (3) source control (ie, early aggressive surgical intervention for drainage of abscesses and debridement of necrotizing soft tissue infections), and (4) pathogen identification and appropriate de-escalation of antimicrobial therapy. MRSA has emerged as the most common identifiable cause of severe SSTIs; therefore, initiation of empiric anti-MRSA antimicrobials is warranted in all cases of severe SSTIs. In addition, appropriate critical care management-including fluid resuscitation, organ support and nutritional support-is a necessary component in treating severe SSTIs.

Initial fractal exponent of heart-rate variability is associated with success of early resuscitation in patients with severe sepsis or septic shock: a prospective cohort study

PubMed Central

Brown, Samuel M.; Tate, Quinn; Jones, Jason P.; Knox, Daniel; Kuttler, Kathryn G.; Lanspa, Michael; Rondina, Matthew T.; Grissom, Colin K.; Behera, Subhasis; Mathews, V.J.; Morris, Alan

2013-01-01

Introduction Heart-rate variability reflects autonomic nervous system tone as well as the overall health of the baroreflex system. We hypothesized that loss of complexity in heart-rate variability upon ICU admission would be associated with unsuccessful early resuscitation of sepsis. Methods We prospectively enrolled patients admitted to ICUs with severe sepsis or septic shock from 2009 to 2011. We studied 30 minutes of EKG, sampled at 500 Hz, at ICU admission and calculated heart-rate complexity via detrended fluctuation analysis. Primary outcome was vasopressor independence at 24 hours after ICU admission. Secondary outcome was 28-day mortality. Results We studied 48 patients, of whom 60% were vasopressor independent at 24 hours. Five (10%) died within 28 days. The ratio of fractal alpha parameters was associated with both vasopressor independence and 28-day mortality (p=0.04) after controlling for mean heart rate. In the optimal model, SOFA score and the long-term fractal alpha parameter were associated with vasopressor independence. Conclusions Loss of complexity in heart rate variability is associated with worse outcome early in severe sepsis and septic shock. Further work should evaluate whether complexity of heart rate variability (HRV) could guide treatment in sepsis. PMID:23958243

On the dynamics of a shock-bubble interaction

NASA Technical Reports Server (NTRS)

Quirk, James J.; Karni, Smadar

1994-01-01

We present a detailed numerical study of the interaction of a weak shock wave with an isolated cylindrical gas inhomogenity. Such interactions have been studied experimentally in an attempt to elucidate the mechanisms whereby shock waves propagating through random media enhance mixing. Our study concentrates on the early phases of the interaction process which are dominated by repeated refractions of acoustic fronts at the bubble interface. Specifically, we have reproduced two of the experiments performed by Haas and Sturtevant : M(sub s) = 1.22 planar shock wave, moving through air, impinges on a cylindrical bubble which contains either helium or Refrigerant 22. These flows are modelled using the two-dimensional, compressible Euler equations for a two component fluid (air-helium or air-Refrigerant 22). Although simulations of shock wave phenomena are now fairly commonplace, they are mostly restricted to single component flows. Unfortunately, multi-component extensions of successful single component schemes often suffer from spurious oscillations which are generated at material interfaces. Here we avoid such problems by employing a novel, nonconservative shock-capturing scheme. In addition, we have utilized a sophisticated adaptive mesh refinement algorithm which enables extremely high resolution simulations to be performed relatively cheaply. Thus we have been able to reproduce numerically all the intricate mechanisms that were observed experimentally (e.g., transitions from regular to irregular refraction, cusp formation and shock wave focusing, multi-shock and Mach shock structures, jet formation, etc.), and we can now present an updated description for the dynamics of a shock-bubble interaction.

Vortex ring formation at the open end of a shock tube: A particle image velocimetry study

NASA Astrophysics Data System (ADS)

Arakeri, J. H.; Das, D.; Krothapalli, A.; Lourenco, L.

2004-04-01

The vortex ring generated subsequent to the diffraction of a shock wave from the open end of a shock tube is studied using particle image velocimetry. We examine the early evolution of the compressible vortex ring for three-exit shock Mach numbers, 1.1, 1.2, and 1.3. For the three cases studied, the ring formation is complete at about tUb/D=2, where t is time, Ub is fluid velocity behind shock as it exits the tube and D is tube diameter. Unlike in the case of piston generated incompressible vortex rings where the piston velocity variation with time is usually trapezoidal, in the shock-generated vortex ring case the exit fluid velocity doubles from its initial value Ub before it slowly decays to zero. At the end of the ring formation, its translation speed is observed to be about 0.7 Ub. During initial formation and propagation, a jet-like flow exists behind the vortex ring. The vortex ring detachment from the tailing jet, commonly referred to as pinch-off, is briefly discussed.

SN 1987 A: A Unique Laboratory for Shock Physics

NASA Technical Reports Server (NTRS)

Sonneborn, George

2012-01-01

Supernova 1987 A has given us an unprecedented view of the evolution of the explosion debris and its interaction with circumstellar matter. The outer supernova debris, now expanding with velocities approx.8000 km/s, encountered the relatively dense circumstellar ring formed by presupernova mass loss in the early 1990s. The shock interaction is manifested by UV-optical "hotspots", an expanding X-ray ring, an expanding ring of knotty non-thermal radio emission, and a ring of thermal IR emission from silicate dust Recent ultraviolet observations of the emissions from the reverse shock and the ring with the HST/COS reveal new details about the shock interaction. Lyman alpha emission from the reverse shock is much stronger than H alpha and they have different emission morphologies, pointing to different emission mechanisms. The reverse shock was detected for the first time in C IV 1550. The N V to C IV brightness ratio indicates the N/C abundance ratio in the expanding debris is about 100X solar, about 3X N/C in the inner ring.

Initial decomposition of the condensed-phase β-HMX under shock waves: molecular dynamics simulations.

PubMed

Ge, Ni-Na; Wei, Yong-Kai; Ji, Guang-Fu; Chen, Xiang-Rong; Zhao, Feng; Wei, Dong-Qing

2012-11-26

We have performed quantum-based multiscale simulations to study the initial chemical processes of condensed-phase octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) under shock wave loading. A self-consistent charge density-functional tight-binding (SCC-DFTB) method was employed. The results show that the initial decomposition of shocked HMX is triggered by the N-NO(2) bond breaking under the low velocity impact (8 km/s). As the shock velocity increases (11 km/s), the homolytic cleavage of the N-NO(2) bond is suppressed under high pressure, the C-H bond dissociation becomes the primary pathway for HMX decomposition in its early stages. It is accompanied by a five-membered ring formation and hydrogen transfer from the CH(2) group to the -NO(2) group. Our simulations suggest that the initial chemical processes of shocked HMX are dependent on the impact velocity, which gain new insights into the initial decomposition mechanism of HMX upon shock loading at the atomistic level, and have important implications for understanding and development of energetic materials.

Unaccompanied evacuation and adult mortality: evaluating the finnish policy of evacuating children to foster care during World War II.

PubMed

Santavirta, Torsten

2014-09-01

I examined associations between evacuation of Finnish children to temporary foster care in Sweden during World War II and all-cause mortality between ages 38 and 78 years. I used a Cox proportional hazards model to estimate mortality risk according to whether the individual was evacuated during childhood or not. I used within-sibling analysis to control for all unobserved socioeconomic and genetic characteristics shared among siblings. Individual-level data for Finnish cohorts born in 1933 to 1944 were derived from wartime government records, Finnish census data from 1950 and 1970, and death cause registry from 1971 to 2011. I found no statistically significant association between evacuation and all-cause mortality when all exposed individuals were included in the analysis. However, subgroup analysis showed that men evacuated before age 4 years had a 1.31 higher mortality risk (95% confidence interval = 1.01, 1.69) than their nonevacuated counterparts. In the aggregate, individuals do not have elevated mortality risk as a consequence of foster care during early childhood owing to the onset of sudden external shocks (e.g., wars).

GRB 050717: A Long, Short-Lag Burst Observed by Swift and Konus

NASA Technical Reports Server (NTRS)

Krimm, H. A.; Hurkett, C.; Pal'shin, V.; Norris, J. P.; Zhang, B.; Barthelmy, S. D.; Burrows, D. N.; Gehrels, N.; Golenetskii, S.; Osborne, J. P.;

Pubertal Timing and Mexican-Origin Girls’ Internalizing and Externalizing Symptoms: The Influence of Harsh Parenting

PubMed Central

Deardorff, J.; Cham, H.; Gonzales, NA.; White, R.M.B.; Tein, J.-Y.; Wong, J.; Roosa, M.W.

2012-01-01

Early-maturing girls are at risk for internalizing and externalizing problems. Scarce research has examined pubertal timing and mental health among Mexican Americans, or examined the influence of parenting behaviors on these relations. This study addressed these gaps. This was a prospective examination of 362 Mexican-origin girls and their mothers using three waves of data. Measures included girls’ self-report of pubertal development and girls’ and mothers’ report of maternal harsh parenting and daughters’ mental health. Using structural equation modeling, we examined whether pubertal timing in 5th grade predicted girls’ internalizing and externalizing outcomes in 10th grade. We also examined the mediating and moderating effects of harsh parenting on the relations between pubertal timing and internalizing and externalizing behaviors, as well as the influence of mothers’ and daughters’ nativity on these relations. Results differed depending on reporter and maternal nativity. Using daughters’ report, Mexican American mothers’ harsh parenting acted as a moderator. At high levels of harsh parenting, early pubertal timing predicted higher externalizing scores, while at low levels of harsh parenting, early timing predicted lower externalizing scores. For Mexican immigrant mothers, harsh parenting mediated the effects of pubertal timing on girls’ internalizing and externalizing problems. There were no significant pubertal effects for mothers’ report. Findings suggest that maternal harsh parenting plays a key role in the relations between early pubertal timing and behavioral and emotional outcomes among Mexican-origin girls. PMID:23231686

Pubertal timing and Mexican-origin girls' internalizing and externalizing symptoms: the influence of harsh parenting.

PubMed

Deardorff, Julianna; Cham, Heining; Gonzales, Nancy A; White, Rebecca M B; Tein, Jenn-Yun; Wong, Jessie J; Roosa, Mark W

2013-09-01

Early-maturing girls are at risk for internalizing and externalizing problems. Research concerning pubertal timing and mental health among Mexican Americans or the influence of parenting behaviors on these relations has been scarce. This study addressed these gaps. This was a prospective examination of 362 Mexican-origin girls and their mothers in 3 waves of data. Measures included girls' self-report of pubertal development and girls' and mothers' report of maternal harsh parenting and daughters' mental health. Using structural equation modeling, we examined whether pubertal timing in 5th grade predicted girls' internalizing and externalizing outcomes in 10th grade. We also examined the mediating and moderating effects of harsh parenting on the relations between pubertal timing and internalizing and externalizing behaviors, as well as the influence of mothers' and daughters' nativity on these relations. Results differed depending on reporter and maternal nativity. Using daughters' report, we found that Mexican American mothers' harsh parenting acted as a moderator. At high levels of harsh parenting, early pubertal timing predicted higher externalizing scores, while at low levels of harsh parenting, early timing predicted lower externalizing scores. For Mexican immigrant mothers, harsh parenting mediated the effects of pubertal timing on girls' internalizing and externalizing problems. There were no significant pubertal effects for mothers' report. Findings suggest that maternal harsh parenting plays a key role in the relations between early pubertal timing and behavioral and emotional outcomes among Mexican-origin girls. PsycINFO Database Record (c) 2013 APA, all rights reserved.

The role of extracorporeal membrane oxygenation circulatory support in the 'crash and burn' patient: from implantation to weaning.

PubMed

Ghodsizad, Ali; Koerner, Michael M; Brehm, Christoph E; El-Banayosy, Aly

2014-05-01

In advanced cardiogenic shock, early mechanical circulatory support may prevent multiorgan failure and death. In this article, we are describing our experience with extracorporeal membrane oxygenation (ECMO) application. Venoarterial ECMO has been used successfully as a therapeutic option for patients with advanced cardiogenic shock and cardiac arrest. In this review, based on the daily routine of the Hershey group using ECMO for therapy of advanced cardiogenic shock, the application of ECMO is described. The aim is to share our hands-on experience during emergent implantation and to contribute to the knowledge within the field of mechanical circulatory support.

Early lactate clearance is associated with biomarkers of inflammation, coagulation, apoptosis, organ dysfunction and mortality in severe sepsis and septic shock

PubMed Central

2010-01-01

Background Lactate clearance, a surrogate for the magnitude and duration of global tissue hypoxia, is used diagnostically, therapeutically and prognostically. This study examined the association of early lactate clearance with selected inflammatory, coagulation, apoptosis response biomarkers and organ dysfunction scores in severe sepsis and septic shock. Methods Measurements of serum arterial lactate, biomarkers (interleukin-1 receptor antagonist, interleukin-6, interleukin-8, interleukin-10, tumor necrosis factor-alpha, intercellular adhesion molecule-1, high mobility group box-1, D-Dimer and caspase-3), and organ dysfunction scores (Acute Physiology and Chronic Health Evaluation II, Simplified Acute Physiology Score II, Multiple Organ Dysfunction Score, and Sequential Organ Failure Assessment) were obtained in conjunction with a prospective, randomized study examining early goal-directed therapy in severe sepsis and septic shock patients presenting to the emergency department (ED). Lactate clearance was defined as the percent change in lactate levels after six hours from a baseline measurement in the ED. Results Two-hundred and twenty patients, age 65.0 +/- 17.1 years, were examined, with an overall lactate clearance of 35.5 +/- 43.1% and in-hospital mortality rate of 35.0%. Patients were divided into four quartiles of lactate clearance, -24.3 +/- 42.3, 30.1 +/- 7.5, 53.4 +/- 6.6, and 75.1 +/- 7.1%, respectively (p < 0.01). The mean levels of all biomarkers and organ dysfunction scores over 72 hours were significantly lower with higher lactate clearance quartiles (p < 0.01). There was a significant decreased in-hospital, 28-day, and 60-day mortality in the higher lactate clearance quartiles (p < 0.01). Conclusions Early lactate clearance as a surrogate for the resolution of global tissue hypoxia is significantly associated with decreased levels of biomarkers, improvement in organ dysfunction and outcome in severe sepsis and septic shock. PMID:20181046

Accurate recognition and effective treatment of ventricular fibrillation by automated external defibrillators in adolescents.

PubMed

Atkins, D L; Hartley, L L; York, D K

1998-03-01

To evaluate the accuracy and efficacy of automated external defibrillators (AEDs) in patients <16 years old. AEDs are standard therapy in out-of-hospital resuscitation of adults and have led to higher success rates. Their use in children and adolescents has never been evaluated, despite recommendations from the American Heart Association that they be used in children >8 years of age. This was a retrospective cohort study of children <16 years old who underwent out-of-hospital cardiac resuscitation and on whom an AED was used during the resuscitation. The setting was rural and urban prehospital emergency medical systems. Patients were identified by review of a database of cardiac arrests maintained by a large surveillance program of these services. AEDs were used to assess cardiac rhythm in 18 patients with a mean age of 12.1 +/- 3.7 years. The cardiac rhythms were analyzed 67 times and included ventricular fibrillation (25), asystole/pulseless electrical activity (32), sinus bradycardia (6), and sinus tachycardia (4). The AEDs recognized all nonshockable rhythms accurately and advised no shock. Ventricular fibrillation was recognized accurately in 22 (88%) of 25 episodes and advised or administered a shock 22 times. Sensitivity and specificity for accurate rhythm analysis were 88% and 100%, respectively. One patient with a nonshockable rhythm survived, whereas 3 of 9 patients with ventricular fibrillation survived. These data furnish evidence that AEDs provide accurate rhythm detection and shock delivery to children and young adolescents. AED use is potentially as effective for children as it is for adults.

The School Nurse Role in Preparing for Sudden Cardiac Arrest in the School Setting

ERIC Educational Resources Information Center

Evans, Warna K.; Ficca, Michelle

2012-01-01

Automated external defibrillators (AEDs) were introduced for first responders in 1992 to manage adult cardiac arrest and are now common in many public places. Today AEDs are capable of shocking children under 8 years of age, or less than 55 pounds. This presents a challenge for school nurses, particularly as the prevalence of chronic medical…

Do Magnetic Fields Drive High-Energy Explosive Transients?

NASA Astrophysics Data System (ADS)

Mundell, Carole

2017-10-01

I will review the current state-of-the-art in real-time, rapid response optical imaging and polarimetric followup of transient sources such as Gamma Ray Bursts. I will interpret current results within the context of the external shock model and present predictions for future mm- and cm-wave radio observatories. Recent observational results from new radio pilot studies will also be presented.

Comparison of Turbulence Models for Nozzle-Afterbody Flows with Propulsive Jets

NASA Technical Reports Server (NTRS)

Compton, William B., III

1996-01-01

A numerical investigation was conducted to assess the accuracy of two turbulence models when computing non-axisymmetric nozzle-afterbody flows with propulsive jets. Navier-Stokes solutions were obtained for a Convergent-divergent non-axisymmetric nozzle-afterbody and its associated jet exhaust plume at free-stream Mach numbers of 0.600 and 0.938 at an angle of attack of 0 deg. The Reynolds number based on model length was approximately 20 x 10(exp 6). Turbulent dissipation was modeled by the algebraic Baldwin-Lomax turbulence model with the Degani-Schiff modification and by the standard Jones-Launder kappa-epsilon turbulence model. At flow conditions without strong shocks and with little or no separation, both turbulence models predicted the pressures on the surfaces of the nozzle very well. When strong shocks and massive separation existed, both turbulence models were unable to predict the flow accurately. Mixing of the jet exhaust plume and the external flow was underpredicted. The differences in drag coefficients for the two turbulence models illustrate that substantial development is still required for computing very complex flows before nozzle performance can be predicted accurately for all external flow conditions.

Markets, Herding and Response to External Information.

PubMed

Carro, Adrián; Toral, Raúl; San Miguel, Maxi

2015-01-01

We focus on the influence of external sources of information upon financial markets. In particular, we develop a stochastic agent-based market model characterized by a certain herding behavior as well as allowing traders to be influenced by an external dynamic signal of information. This signal can be interpreted as a time-varying advertising, public perception or rumor, in favor or against one of two possible trading behaviors, thus breaking the symmetry of the system and acting as a continuously varying exogenous shock. As an illustration, we use a well-known German Indicator of Economic Sentiment as information input and compare our results with Germany's leading stock market index, the DAX, in order to calibrate some of the model parameters. We study the conditions for the ensemble of agents to more accurately follow the information input signal. The response of the system to the external information is maximal for an intermediate range of values of a market parameter, suggesting the existence of three different market regimes: amplification, precise assimilation and undervaluation of incoming information.

Direct measurements of wall shear stress by buried wire gages in a shock-wave boundary-layer interaction region

NASA Technical Reports Server (NTRS)

Murthy, V. S.; Rose, W. C.

1977-01-01

Detailed measurements of wall shear stress (skin friction) were made with specially developed buried wire gages in the interaction regions of a Mach 2.9 turbulent boundary layer with externally generated shocks. Separation and reattachment points inferred by these measurements support the findings of earlier experiments which used a surface oil flow technique and pitot profile measurements. The measurements further indicate that the boundary layer tends to attain significantly higher skin-friction values downstream of the interaction region as compared to upstream. Comparisons between measured wall shear stress and published results of some theoretical calculation schemes show that the general, but not detailed, behavior is predicted well by such schemes.

Experimental studies on the tripping behavior of narrow T-stiffened flat plates subjected to hydrostatic pressure and underwater shock

NASA Technical Reports Server (NTRS)

Budweg, H. L.; Shin, Y. S.

1987-01-01

An experimental investigation was conducted to determine the static and dynamic responses of a specific stiffened flat plate design. The air-backed rectangular flat plates of 6061-T6 aluminum with an externally machined longitudinal narrow-flanged T-stiffener and clamped boundary conditions were subjected to static loading by water hydropump pressure and shock loading from an eight pound TNT charge detonated underwater. The dynamic test plate was instrumented to measure transient strains and free field pressure. The static test plate was instrumented to measure transient strains, plate deflection, and pressure. Emphasis was placed upon forcing static and dynamic stiffener tripping, obtaining relevant strain and pressure data, and studying the associated plate-stiffener behavior.

Effects of triploidy induction on antioxidant defense status in rainbow trout (Oncorhynchus mykiss) during early development.

PubMed

Taghipoor, Kaveh; Keyvanshokooh, Saeed; Salati, Amir Parviz; Pasha-Zanoosi, Hossein; Babaheydari, Samad Bahrami

2016-08-01

The objective of the present study was to examine the antioxidant status of rainbow trout (Oncorhynchus mykiss) during the early stages of development (fertilized egg, eyed egg, alevin and fry) as an effect of triploidy induction. Eggs and milt were taken from eight females and six males. After insemination, the eggs were incubated at 10°C for 10min. Half of the fertilized eggs were then subjected to heat-shock for 10min submerged in a 28°C water bath to induce triploidy. The remainder were incubated normally and used as diploid controls. Three batches of eggs were randomly selected from each group (control and heat-shocked) and were incubated at 10-11°C under the same environmental conditions in hatchery troughs until the fry stage. Triplicate samples of fertilized eggs from each experimental group were randomly selected 1.5h post-fertilization and at the eyed egg stage of development (18 days post-fertilization, dpf). At 27 dpf, triplicate samples of alevins were chosen from each group. Based on ploidy determination experiment performed on both groups, nine diploid and nine triploid fry (76 dpf) were also selected. The triploidy induction success rate was 87.1%. Vitamin C was in lesser concentrations in fertilized eggs and eyed eggs of the heat-shock treatment group as compared with eggs of the diploid group. Alevins of the heat-shock treatment group had a lower superoxide dismutase (SOD) activity than alevins of the diploid group. Glutathione peroxidase (GPx) level was greater in fertilized eggs and alevins of the heat-shock treatment group as compared to diploids. Catalse (CAT) activity was greater in fertilized eggs, alevins and fry of the heat-shock treatment group than those of the diploid group. Malondialdehyde (MDA), as an index of lipid peroxidation, was in greater concentration in fertilized eggs of the group that was heat-shocked, but it was lesser in alevins and fry of the group in which the eggs were heat-shocked as compared to diploid counterparts. The results demonstrate that heat-shock treatment leads to changes in the values of antioxidant enzymes such as SOD, CAT and GPx, and low molecular weight free-radical scavengers such as vitamin C, as well as level of lipid peroxidation. Copyright © 2016 Elsevier B.V. All rights reserved.

Growth trajectories of early aggression, overactivity, and inattention: Relations to second-grade reading.

PubMed

Gray, Sarah A O; Carter, Alice S; Briggs-Gowan, Margaret J; Jones, Stephanie M; Wagmiller, Robert L

2014-09-01

The link between behavior problems and low academic achievement is well established, but few studies have examined longitudinal relations between early externalizing behaviors before school entry and low academic achievement following transition to formal schooling. Early inattention has been particularly overlooked, despite strong associations between inattention and reading difficulties later in development. Trajectories of infant and toddler aggression, overactivity, and inattention, developed from parent reports about 1- to 3-year-old children, were examined as predictors of direct assessments of 2nd-grade reading in an at-risk epidemiological study subsample (N = 359). Reports of inattentive and overactive behaviors at ages 1-3 years and changes in inattention through toddlerhood predicted reading achievement in 2nd grade. A parallel process model suggested that the effects of early inattention on reading appear to be most robust. Findings underscore the contribution of social-emotional development to school readiness and the importance of early identification of children with externalizing problems, as early interventions designed to reduce externalizing problems may improve later reading skills.

Growth Trajectories of Early Aggression, Overactivity, and Inattention: Relations to Second Grade Reading

PubMed Central

Gray, Sarah A. O.; Carter, Alice S.; Briggs-Gowan, Margaret J.; Jones, Stephanie M.; Wagmiller, Robert L.

2015-01-01

The link between behavior problems and low academic achievement is well established, but few studies have examined longitudinal relations between early externalizing behaviors before school entry and low academic achievement following transition to formal schooling. Early inattention has been particularly overlooked, despite strong associations between inattention and reading difficulties later in development. Trajectories of infant/toddler aggression, overactivity, and inattention, developed from parent reports about 1- to 3-year-old children, were examined as predictors of direct assessments of second grade reading in an at-risk epidemiological study subsample (N = 359). Reports of inattentive and overactive behaviors at age 1-to-3 years and changes in inattention through toddlerhood predicted reading achievement in second grade. A parallel process model suggested that the effects of early inattention on reading appear to be most robust. Findings underscore the contribution of social-emotional development to school readiness and the importance of early identification of children with externalizing problems, as early interventions designed to reduce externalizing problems may improve later reading skills. PMID:25046126

Laser-shocked energetic materials with metal additives: evaluation of detonation performance

NASA Astrophysics Data System (ADS)

Gottfried, Jennifer; Bukowski, Eric

A focused, nanosecond-pulsed laser with sufficient energy to exceed the breakdown threshold of a material generates a laser-induced plasma with high peak temperatures, pressures, and shock velocities. Depending on the laser parameters and material properties, nanograms to micrograms of material is ablated, atomized, ionized and excited in the laser-induced plasma. The subsequent shock wave expansion into the air above the sample has been monitored using high-speed schlieren imaging in a recently developed technique, laser-induced air shock from energetic materials (LASEM). The estimated detonation velocities using LASEM agree well with published experimental values. A comparison of the measured shock velocities for various energetic materials including RDX, DNTF, and LLM-172 doped with Al or B to the detonation velocities predicted by CHEETAH for inert or active metal participation demonstrates that LASEM has potential for predicting the early time participation of metal additives in detonation events. The LASEM results show that reducing the amount of hydrogen present in B formulations increases the resulting detonation velocities

Use of infrared thermography in children with shock: A case series

PubMed Central

Ortiz-Dosal, Alejandra; Rivera-Vega, Rosalina; Simón, Jorge; González, Francisco J

2014-01-01

Shock is a complex clinical syndrome caused by an acute failure of circulatory function resulting in inadequate tissue and organ perfusion. Digital infrared thermal imaging is a non-invasive technique that can detect changes in blood perfusion by detecting small changes in the temperature of the skin. In this preliminary study, eight pediatric patients (five boys, three girls), ages ranging from 6 to 14 years (average: 9.8 years), were admitted to the Intensive Care Unit at “Dr. Ignacio Morones Prieto” Central Hospital; here, the patients were examined using digital infrared thermal imaging. Patients in shock showed a significant decrease in distal temperature (at least 7°), compared to critically ill patients without shock. The latter group presented a skin temperature pattern very similar to the one previously reported for healthy children. The results show that infrared thermography can be used as a non-invasive method for monitoring the temperature in pediatric patients in intensive care units in order to detect shock in its early stages. PMID:27489669

Use of infrared thermography in children with shock: A case series.

PubMed

Ortiz-Dosal, Alejandra; Kolosovas-Machuca, Eleazar S; Rivera-Vega, Rosalina; Simón, Jorge; González, Francisco J

2014-01-01

Shock is a complex clinical syndrome caused by an acute failure of circulatory function resulting in inadequate tissue and organ perfusion. Digital infrared thermal imaging is a non-invasive technique that can detect changes in blood perfusion by detecting small changes in the temperature of the skin. In this preliminary study, eight pediatric patients (five boys, three girls), ages ranging from 6 to 14 years (average: 9.8 years), were admitted to the Intensive Care Unit at "Dr. Ignacio Morones Prieto" Central Hospital; here, the patients were examined using digital infrared thermal imaging. Patients in shock showed a significant decrease in distal temperature (at least 7°), compared to critically ill patients without shock. The latter group presented a skin temperature pattern very similar to the one previously reported for healthy children. The results show that infrared thermography can be used as a non-invasive method for monitoring the temperature in pediatric patients in intensive care units in order to detect shock in its early stages.

High-resolution imaging of a shock front in plastic by phase contrast imaging at LCLS

NASA Astrophysics Data System (ADS)

Beckwith, M.; Jiang, S.; Zhao, Y.; Schropp, A.; Fernandez-Panella, A.; Rinderknecht, H. G.; Wilks, S.; Fournier, K.; Galtier, E.; Xing, Z.; Granados, E.; Gamboa, E.; Glenzer, S. H.; Heimann, P.; Zastrau, U.; Cho, B. I.; Eggert, J. H.; Collins, G. W.; Ping, Y.

2017-10-01

Understanding the propagation of shock waves is important for many areas of high energy density physics, including inertial confinement fusion (ICF) and shock compression science. In order to probe the shock front structures in detail, a diagnostic capable of detecting both the small spatial and temporal changes in the material is required. Here we show the experiment using hard X-ray phase contrast imaging (PCI) to probe the shock wave propagation in polyimide with submicron spatial resolution. The experiment was performed at the Matter in Extreme Conditions (MEC) endstation of the Linac Coherent Lightsource (LCLS). PCI together with the femtosecond time scales of x-ray free electron lasers enables the imaging of optically opaque materials that undergo rapid temporal and spatial changes. The result reveals the evolution of the density profile with time. Work performed under DOE Contract No. DE-AC52-07NA27344 with support from OFES Early Career and LLNL LDRD program.

Tissue-specific Requirements of β-Catenin in External Genitalia Development

PubMed Central

Lin, Congxing; Yin, Yan; Long, Fanxin; Ma, Liang

2008-01-01

SUMMARY External genitalia are body appendages specialized for internal fertilization. Its development can be divided into two phases, an early androgen-independent phase and a late androgen-dependant sexual differentiation phase. In the early phase, the embryonic anlage of external genitalia, the genital tubercle (GT), are morphologically identical in both sexes. Although congenital external genitalia malformations represent the second most common birth defect in humans, the genetic pathways governing early external genitalia development and urethra formation are poorly understood. Proper development of the GT requires coordinated outgrowth of the mesodermally-derived mesenchyme and extension of the endodermal urethra within an ectodermal epithelial capsule. Here we demonstrate that β-Catenin plays indispensable and distinct roles in each of the aforementioned three tissue layers in early androgen-independent GT development. WNT-β-Catenin signaling is required in the endodermal urethra to activate and maintain Fgf8 expression and direct GT outgrowth, as well as to maintain homeostasis of the urethra. Moreover, β-Catenin is required in the mesenchyme to promote cell proliferation. In contrast, β-Catenin is required in the ectoderm to maintain tissue integrity possibly through cell-cell adhesion during GT outgrowth. The fact that both endodermal and ectodermal β-Catenin knockout animals develop severe hypospadias in both sexes raises the possibility that deregulation of any of these functions can contribute to the etiology of congenital external genital defects in humans. PMID:18635608

Mass spectrometric measurements of driver gas arrival in the T4 free-piston shock-tunnel

NASA Astrophysics Data System (ADS)

Boyce, R. R.; Takahashi, M.; Stalker, R. J.

2005-12-01

Available test time is an important issue for ground-based flow research, particularly for impulse facilities such as shock tunnels, where test times of the order of several ms are typical. The early contamination of the test flow by the driver gas in such tunnels restricts the test time. This paper reports measurements of the driver gas arrival time in the test section of the T4 free-piston shock-tunnel over the total enthalpy range 3 17 MJ/kg, using a time-of-flight mass spectrometer. The results confirm measurements made by previous investigators using a choked duct driver gas detector at these conditions, and extend the range of previous mass spectrometer measurements to that of 3 20 MJ/kg. Comparisons of the contamination behaviour of various piston-driven reflected shock tunnels are also made.

Computational and Experimental Study of Supersonic Nozzle Flow and Shock Interactions

NASA Technical Reports Server (NTRS)

Carter, Melissa B.; Elmiligui, Alaa A.; Nayani, Sudheer N.; Castner, Ray; Bruce, Walter E., IV; Inskeep, Jacob

2015-01-01

This study focused on the capability of NASA Tetrahedral Unstructured Software System's CFD code USM3D capability to predict the interaction between a shock and supersonic plume flow. Previous studies, published in 2004, 2009 and 2013, investigated USM3D's supersonic plume flow results versus historical experimental data. This current study builds on that research by utilizing the best practices from the early papers for properly capturing the plume flow and then adding a wedge acting as a shock generator. This computational study is in conjunction with experimental tests conducted at the Glenn Research Center 1'x1' Supersonic Wind Tunnel. The comparison of the computational and experimental data shows good agreement for location and strength of the shocks although there are vertical shifts between the data sets that may be do to the measurement technique.

A-1 Test Stand modifications

NASA Image and Video Library

2011-09-14

Team members check the progress of a liquid nitrogen cold shock test on the A-1 Test Stand at Stennis Space Center on Sept. 15. The cold shock test is used to confirm the test stand's support system can withstand test conditions, when super-cold rocket engine propellant is piped. The A-1 Test Stand is preparing to conduct tests on the powerpack component of the J-2X rocket engine, beginning in early 2012.

Effects of AED device features on performance by untrained laypersons.

PubMed

Mosesso, Vincent N; Shapiro, Alan H; Stein, Karen; Burkett, Kelly; Wang, Henry

2009-11-01

Our study evaluates the impact of features of automated external defibrillators (AEDs) on the performance and speed of untrained laypersons to deliver a shock and initiate CPR after a shock. This was a randomized trial of volunteer laypersons without AED or advanced medical training. Subjects were assigned to use one of six different models of AEDs on a manikin in simulated cardiac arrest. No instructions on AED operation were provided. Primary endpoints were shock delivery and elapsed time from start to shock. Secondary endpoints included time to power-on, initiation of CPR, adequacy of pad placement and subjects' ratings of ease of use (1=very easy, 5=very difficult). Most subjects (109/120; 91%) were able to deliver a shock. Median time from start of scenario to shock delivery was 79 s (IQR: 67-99). Of the 11 participants who did not deliver shock, eight never powered on the device. Time to power-on was shorter in devices with open lid (median 12s, IQR 8-27 s) and pull handle (17s, IQR 9-20s) mechanisms than with a push button (37s, IQR 18-69 s; p=0.000). Pad position on the manikin was judged adequate for 86 (77%) of the 111 subjects who placed pads. Devices which gave more detailed voice instruction for pad placement had higher rates of adequate pad position [38/39 (97%) versus 50/73 (68%), p=0.001]. With AEDs that provided step-by-step CPR instruction, 49/58 (84%) subjects began CPR compared to 26/51 (51%) with AEDs that only prompted to start CPR (p=0.01). Participants rated all the models easy to use (overall mean 1.48; individual device means 1.28-1.71). Most untrained laypersons were successful in delivering a shock. Device features had the most impact on these functions: ability and time to power-on device, adequacy of pad position and initiation of CPR.

What childhood characteristics predict psychological resilience to economic shocks in adulthood?

PubMed Central

Powdthavee, Nattavudh

2015-01-01

This paper investigates whether people’s psychological resilience to one of the most important economic shocks – job loss – can be predicted using early childhood characteristics. Using a longitudinal data that tracked almost 3000 children into adulthood, we showed that the negative effect of unemployment on mental well-being and life satisfaction is significantly larger for workers who, as adolescents, had a relatively poor father-child relationship. Maternal unemployment, on the other hand, is a good predictor of how individuals react psychologically to future unemployment. Although the results should be viewed as illustrative and more research is needed, the current article provides new longitudinal evidence that psychological resilience to job loss may be determined early on in the life cycle. PMID:26997688

The Early X-ray Emission From V382 Velorum (=Nove Vel 1999): An Internal Shock Model

NASA Technical Reports Server (NTRS)

Mukai, Koji; Ishida, Manabu

2000-01-01

We present the results of ASCA and RXTE observations of the early X-ray emission from the classical nova V382 Velorum. Its ASCA spectrum was hard (kT approximately 10 KeV) with a strong (10(exp 13)/sq cm) intrinsic absorption. In the subsequent RXTE data, the spectra became softer both due to a declining temperature and a diminishing column. We argue that this places the X-ray emission interior to the outermost ejecta produced by V382 Vel in 1999, and therefore must have been the result of a shock internal to the nova ejecta. The weakness of the Fe K.alpha lines probably indicates that the X-ray emitting plasmas are not in ionization equilibrium.

Exposure to socioeconomic adversity in early life and risk of depression at 18 years: The mediating role of locus of control.

PubMed

Culpin, Iryna; Stapinski, Lexine; Miles, Ömür Budanur; Araya, Ricardo; Joinson, Carol

2015-09-01

Previous studies have linked exposure to early socioeconomic adversity to depression, but the mechanisms of this association are not well understood. Locus of control (LoC), an individual's control-related beliefs, has been implicated as a possible mechanism, however, longitudinal evidence to support this is lacking. The study sample comprised 8803 participants from a UK cohort, the Avon Longitudinal Study of Parents and Children (ALSPAC). Indicators of early socioeconomic adversity were collected from the antenatal period to 5 years and modelled as a latent factor. Depression was assessed using the Clinical Interview Schedule-Revised (CIS-R) at 18 years. LoC was assessed with the Nowicki-Strickland Internal-External (CNSIE) scale at 16 years. Using structural equation modelling, we found that 34% of the total estimated association between early socioeconomic adversity and depression at 18 years was explained by external LoC at 16 years. There was weak evidence of a direct pathway from early socioeconomic adversity to depression after accounting for the indirect effect via external locus of control. Socioeconomic adversity was associated with more external LoC, which, in turn, was associated with depression. Attrition may have led to an underestimation of the direct and indirect effect sizes in the complete case analysis. Results suggest that external LoC in adolescence is one of the factors mediating the link between early adversity and depression at 18 years. Cognitive interventions that seek to modify maladaptive control beliefs in adolescence may be effective in reducing risk of depression following early life adversity. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

The Cost Implications in Ontario, Alberta, and British Columbia of Early Versus Delayed External Cephalic Version in the Early External Cephalic Version 2 (EECV2) Trial.

PubMed

Ahmed, Rashid J; Gafni, Amiram; Hutton, Eileen K

2016-03-01

According to the Early External Cephalic Version (EECV2) Trial, planning external cephalic version (ECV) early in pregnancy results in fewer breech presentations at delivery compared with delayed external cephalic version. A Cochrane review conducted after the EECV2 Trial identified an increase in preterm birth associated with early ECV. We examined whether a policy of routine early ECV (i.e., before 37 weeks' gestation) is more or less costly than a policy of delayed ECV. We undertook this analysis from the perspective of a third-party payer (Ministry of Health). We applied data, using resources reported in the EECV2 Trial, to the Canadian context using 10 hospital unit costs and 17 physician service/procedure unit costs. The data were derived from the provincial health insurance plan schedule of medical benefits in three Canadian provinces (Ontario, Alberta, and British Columbia). The difference in mean total costs between study groups was tested for each province separately. We found that planning early ECV results in higher costs than planning delayed ECV. The mean costs of all physician services/procedures and hospital units for planned ECV compared with delayed ECV were $7997.32 versus $7263.04 in Ontario (P < 0.001), $8162.82 versus $7410.55 in Alberta (P < 0.001), and $8178.92 versus $7417.04 in British Columbia (P < 0.001), respectively. From the perspective of overall cost, our analyses do not support a policy of routinely planning ECV before 37 weeks' gestation. Copyright © 2016 The Society of Obstetricians and Gynaecologists of Canada/La Société des obstétriciens et gynécologues du Canada. Published by Elsevier Inc. All rights reserved.

Pathways from maternal distress and child problem behavior to adolescent depressive symptoms: a prospective examination from early childhood to adolescence.

PubMed

Nilsen, Wendy; Gustavson, Kristin; Røysamb, Espen; Kjeldsen, Anne; Karevold, Evalill

2013-06-01

The main aim of this study was to identify the pathways from maternal distress and child problem behaviors (i.e., internalizing and externalizing problems) across childhood and their impact on depressive symptoms during adolescence among girls and boys. Data from families of 921 Norwegian children in a 15-year longitudinal community sample were used. Using structural equation modeling, the authors explored the interplay between maternal-reported distress and child problem behaviors measured at 5 time points from early (ages 1.5, 2.5, and 4.5 years) and middle (age 8.5 years) childhood to early adolescence (age 12.5 years), and their prediction of self-reported depressive symptoms during adolescence (ages 14.5 and 16.5 years). The findings revealed paths from internalizing and externalizing problems throughout the development for corresponding problems (homotypic paths) and paths from early externalizing to subsequent internalizing problems (heterotypic paths). The findings suggest 2 pathways linking maternal-rated risk factors to self-reported adolescent depressive symptoms. There was a direct path from early externalizing problems to depressive symptoms. There was an indirect path from early maternal distress going through child problem behavior to depressive symptoms. In general, girls and boys were similar, but some gender-specific effects appeared. Problem behaviors in middle childhood had heterotypic paths to subsequent problems only for girls. The findings highlight the developmental importance of child externalizing problems, as well as the impact of maternal distress as early as age 1.5 years for the development of adolescent depressive symptoms. Findings also indicate a certain vulnerable period in middle childhood for girls. NOTE: See Supplemental Digital Content 1, at http://links.lww.com/JDBP/A45, for a video introduction to this article.

Effect of Early Vasopressin vs Norepinephrine on Kidney Failure in Patients With Septic Shock: The VANISH Randomized Clinical Trial.

PubMed

Gordon, Anthony C; Mason, Alexina J; Thirunavukkarasu, Neeraja; Perkins, Gavin D; Cecconi, Maurizio; Cepkova, Magda; Pogson, David G; Aya, Hollmann D; Anjum, Aisha; Frazier, Gregory J; Santhakumaran, Shalini; Ashby, Deborah; Brett, Stephen J

2016-08-02

Norepinephrine is currently recommended as the first-line vasopressor in septic shock; however, early vasopressin use has been proposed as an alternative. To compare the effect of early vasopressin vs norepinephrine on kidney failure in patients with septic shock. A factorial (2×2), double-blind, randomized clinical trial conducted in 18 general adult intensive care units in the United Kingdom between February 2013 and May 2015, enrolling adult patients who had septic shock requiring vasopressors despite fluid resuscitation within a maximum of 6 hours after the onset of shock. Patients were randomly allocated to vasopressin (titrated up to 0.06 U/min) and hydrocortisone (n = 101), vasopressin and placebo (n = 104), norepinephrine and hydrocortisone (n = 101), or norepinephrine and placebo (n = 103). The primary outcome was kidney failure-free days during the 28-day period after randomization, measured as (1) the proportion of patients who never developed kidney failure and (2) median number of days alive and free of kidney failure for patients who did not survive, who experienced kidney failure, or both. Rates of renal replacement therapy, mortality, and serious adverse events were secondary outcomes. A total of 409 patients (median age, 66 years; men, 58.2%) were included in the study, with a median time to study drug administration of 3.5 hours after diagnosis of shock. The number of survivors who never developed kidney failure was 94 of 165 patients (57.0%) in the vasopressin group and 93 of 157 patients (59.2%) in the norepinephrine group (difference, -2.3% [95% CI, -13.0% to 8.5%]). The median number of kidney failure-free days for patients who did not survive, who experienced kidney failure, or both was 9 days (interquartile range [IQR], 1 to -24) in the vasopressin group and 13 days (IQR, 1 to -25) in the norepinephrine group (difference, -4 days [95% CI, -11 to 5]). There was less use of renal replacement therapy in the vasopressin group than in the norepinephrine group (25.4% for vasopressin vs 35.3% for norepinephrine; difference, -9.9% [95% CI, -19.3% to -0.6%]). There was no significant difference in mortality rates between groups. In total, 22 of 205 patients (10.7%) had a serious adverse event in the vasopressin group vs 17 of 204 patients (8.3%) in the norepinephrine group (difference, 2.5% [95% CI, -3.3% to 8.2%]). Among adults with septic shock, the early use of vasopressin compared with norepinephrine did not improve the number of kidney failure-free days. Although these findings do not support the use of vasopressin to replace norepinephrine as initial treatment in this situation, the confidence interval included a potential clinically important benefit for vasopressin, and larger trials may be warranted to assess this further. clinicaltrials.gov Identifier: ISRCTN 20769191.

It's what's on the outside that matters: an advantage for external features in children's word recognition.

PubMed

Webb, Tessa M; Beech, John R; Mayall, Kate M; Andrews, Antony S

2006-06-01

The relative importance of internal and external letter features of words in children's developing reading was investigated to clarify further the nature of early featural analysis. In Experiment 1, 72 6-, 8-, and 10-year-olds read aloud words displayed as wholes, external features only (central features missing, thereby preserving word shape information), or internal features only (central features preserved). There was an improvement in the processing of external features compared with internal features as reading experience increased. Experiment 2 examined the processing of the internal and external features of words employing a forward priming paradigm with 60 8-, 10-, and 12-year-olds. Reaction times to internal feature primes were equivalent to a nonprime blank condition, whereas responses to external feature primes were faster than those to the other two prime types. This advantage for the external features of words is discussed in terms of an early and enduring role for processing the external visual features in words during reading development.

A novel electrochemical immunosensor based on PG for early screening of depression markers-heat shock protein 70.

PubMed

Sun, Bolu; Cai, Jinying; Li, Wuyan; Gou, Xiaodan; Gou, Yuqiang; Li, Dai; Hu, Fangdi

2018-07-15

In this study, a novel electrochemical immunosensor for early screening of depression markers-heat shock protein 70 (HSP70) was successfully developed based on the porous graphene (PG) with huge specific surface area and excellent structure. Benefiting from the strong adsorption and good bioactivity of PG which was initially prepared via a simple pyrolysis process, a variety of heat shock protein70 (HSP70) can be firmly loaded on the PG to construct the basic electrode (HSP70/PG/GCE)，which was characterized by the cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS), respectively. Due to the HSP70 fixed on the surface of basic electrode and the HSP70 in the samples can competitively combine with the horseradish peroxidase labeled human HSP 70 antibody (HRP-Strept-Biotin-Ab). As a result, it presented a negative correlation between the concentration of HSP70 in samples and the detection signal of the proposed electrochemical immunosensor (HRP-Strept-Biotin-Ab-HSP70/PG/GCE) in the test liquid. The application of PG with excellent electrical conductivity in construction of immunosensor remarkably improved the sensitivity of the immunosensor for detection of HSP70. The proposed immunosensor demonstrated a wide linear range of 0.0448 ~ 100 ng/mL with a low detection limit of 0.02 ng/mL at 3σ. Moreover, the proposed immunosensor could be applied for the sensitive and efficient detection of HSP70 in real samples with good precision, acceptable stability, reproducibility and satisfactory results. Therefore, the HSP70 immunosensor provides a novel and convenient method for early clinical screening of depression markers-heat shock protein 70. Copyright © 2018 Elsevier B.V. All rights reserved.

Early Differentiation of Kawasaki Disease Shock Syndrome and Toxic Shock Syndrome in a Pediatric Intensive Care Unit.

PubMed

Lin, Ying-Jui; Cheng, Ming-Chou; Lo, Mao-Hung; Chien, Shao-Ju

2015-11-01

Kawasaki disease shock syndrome (KDSS) and toxic shock syndrome (TSS) can present as shock and fever with skin rash, but the management of these 2 groups of patients is different. This report proposes to help clinicians earlier distinguish these 2 diseases and expedite institution of appropriate therapy. We retrospectively reviewed the medical records of patients admitted to the pediatric intensive care unit with the diagnosis of KDSS or TSS from January 2000 through December 2010. Clinical, laboratory and echocardiographic data were collected for analysis of differences between them. Seventeen patients met the inclusion criteria of KDSS and 16 had a confirmed diagnosis of TSS. The mean age of the KDSS group was significantly younger than that of the TSS group (36.8 ± 41.1 vs. 113.3 ± 55.6 months, P < 0.001). Significantly lower hemoglobulin and age-adjusted hemoglobulin concentrations were noted in the KDSS group [Hb, age-adjusted Z score, -1.88 (range, -3.9 to 3.9) vs. 0.89 (range, -6.4 to 10.8), P = 0.006]. The median platelet count of the KDSS group was nearly twice that of the TSS group [312 × 10³ per μL (range, 116-518) vs. 184.5 × 10³ per μL (range: 31-629), P = 0.021]. Echocardiographic abnormalities, such as valvulitis (mitral or tricuspid regurgitation) and coronary artery lesions, were significantly more common in the KDSS group (P = 0.022). Echocardiography, anemia and thrombocytosis are useful early differentiating features between KDSS and TSS patients.

The Relationship Between Early Sexual Debut and Psychosocial Outcomes: A Longitudinal Study of Dutch Adolescents

PubMed Central

Sandfort, Theo; Reitz, Ellen; Bos, Henny; Dekovic, Maja

2010-01-01

In a longitudinal dataset of 470 Dutch adolescents, the current study examined the ways in which early sexual initiation was related to subsequent attachment, self-perception, internalizing problems, and externalizing problems. For male adolescents, analyses revealed general attachment to mother and externalizing problems at Wave 1 to predict to early transition at Wave 2. However, there was no differential change in these psychosocial factors over time for early initiators of sexual intercourse and their non-initiating peers. For female adolescents, the model including psychosocial factors at Wave 1 did not predict to sexual initiation at Wave 2. However, univariate repeated measures analyses revealed early initiators to have significantly larger increases in self-concept and externalizing problems than their non-initiating female peers. While the difference between female early initiators and non-initiators were statistically significant, the mean levels of problem behaviors were very low. The findings suggest that, contrary to previous research, early sexual initiation does not seem to be clustered with problem behaviors for this sample of Dutch adolescents. PMID:20119696

Early Parenting and the Development of Externalizing Behavior Problems: Longitudinal Mediation through Children’s Executive Function

PubMed Central

Sulik, Michael J.; Blair, Clancy; Mills-Koonce, Roger; Berry, Daniel; Greenberg, Mark

2015-01-01

Path analysis was used to investigate the longitudinal associations among parenting and children’s executive function and externalizing behavior problems from 36 to 90 months of age in the Family Life Project (N = 1,115), a study of child development in the context of rural poverty. While controlling for stability in the constructs, semi-structured observations of parenting prospectively predicted performance on a battery of executive function tasks and primary caregivers’ reports of externalizing behavior. Furthermore, the association between early parenting and later externalizing behavior was longitudinally mediated by executive function, providing support for a process model in which sensitive parenting promotes children’s self-regulation, which in turn reduces children’s externalizing behavior. PMID:26082032

Broad band simulation of Gamma Ray Bursts (GRB) prompt emission in presence of an external magnetic field

NASA Astrophysics Data System (ADS)

Ziaeepour, Houri; Gardner, Brian

2011-12-01

The origin of prompt emission in GRBs is not yet well understood. The simplest and most popular model is Synchrotron Self-Compton (SSC) emission produced by internal shocks inside an ultra-relativistic jet. However, recent observations of a delayed high energy component by the Fermi-LAT instrument have encouraged alternative models. Here we use a recently developed formulation of relativistic shocks for GRBs to simulate light curves and spectra of synchrotron and self-Compton emissions in the framework of internal shock model. This model takes into account the evolution of quantities such as densities of colliding shells, and fraction of kinetic energy transferred to electrons and to induced magnetic field. We also extend this formulation by considering the presence of a precessing external magnetic field. These simulations are very realistic and present significant improvement with respect to previous phenomenological GRB simulations. They reproduce light curves of separate peaks of real GRBs and variety of spectral slopes at E > Epeak observed by the Fermi-LAT instrument. The high energy emission can be explained by synchrotron emission and a subdominant contribution from inverse Compton. We also suggest an explanation for extended tail emission and relate it to the screening of the magnetic field and/or trapping of accelerated electrons in the electromagnetic energy structure of the plasma in the shock front. Spectral slopes of simulated bursts at E << Epeak are consistent with theoretical prediction and at E < Epeak can be flatter if the spectrum of electrons is roughly flat or has a shallow slope at low energies. The observed flat spectra at soft gamma-ray and hard x-ray bands is the evidence that there is a significant contribution at E < Epeak from lower Lorentz factor wing of electron distribution which have a roughly random acceleration rather than being thermal. This means that the state of matter in the jet at the time of ejection is most probably nonthermal. As for the effect of a precessing external magnetic field, we show that due to the fast variation of other quantities, its signature in the Power Distribution Spectrum (PDS) is significantly suppressed and only when the duration of the burst is few times longer than the oscillation period it can be detected, otherwise either it is confused with the Poisson noise or with intrinsic variations of the emission. Therefore, low significant oscillations observed in the PDS of GRB 090709a are most probably due to a precessing magnetic field.

Decreased delivery of inappropriate shocks achieved by remote monitoring of ICD: a substudy of the ECOST trial.

PubMed

Guédon-Moreau, Laurence; Kouakam, Claude; Klug, Didier; Marquié, Christelle; Brigadeau, François; Boulé, Stéphane; Blangy, Hugues; Lacroix, Dominique; Clémenty, Jacques; Sadoul, Nicolas; Kacet, Salem

2014-07-01

Inappropriate shocks remain a highly challenging complication of implantable cardioverter defibrillators (ICD). We examined whether automatic wireless remote monitoring (RM) of ICD, by providing early notifications of triggering events, lowers the incidence of inappropriate shocks. We studied 433 patients randomly assigned to RM (n = 221; active group) versus ambulatory follow-up (n = 212; control group). Patients in the active group were seen in the ambulatory department once a year, unless RM reported an event requiring an earlier ambulatory visit. Patients in the control group were seen in the ambulatory department every 6 months. The occurrence of first and further inappropriate shocks, and their causes in each group were compared. The characteristics of the study groups, including pharmaceutical regimens, were similar. Over a follow-up of 27 months, 5.0% of patients in the active group received ≥1 inappropriate shocks versus 10.4% in the control group (P = 0.03). A total of 28 inappropriate shocks were delivered in the active versus 283 in the control group. Shocks were triggered by supraventricular tachyarrhythmias (SVTA) in 48.5%, noise oversensing in 21.2%, T wave oversensing in 15.2%, and lead dysfunction in 15.2% of patients. The numbers of inappropriate shocks delivered per patient, triggered by SVTA and by lead dysfunction, were 74% and 98% lower, respectively, in the active than in the control group. RM was highly effective in the long-term prevention of inappropriate ICD shocks. © 2014 Wiley Periodicals, Inc.

Early risk pathways to physical versus relational peer aggression: The interplay of externalizing behavior and corporal punishment varies by child sex.

PubMed

Zulauf, Courtney A; Sokolovsky, Alexander W; Grabell, Adam S; Olson, Sheryl L

2018-03-01

Children who aggress against their peers may use physical or relational forms, yet little research has looked at early childhood risk factors and characteristics that uniquely predict high levels of relational versus physical aggression in preadolescence. Accordingly, the main aim of our study was to link early corporal punishment and externalizing behavior to children's physical and relational peer aggression during preadolescence and to examine how these pathways differed by sex. Participants were 193, 3-year-old boys (39%) and girls who were reassessed following the transition to kindergarten (5.5 years) and preadolescence (10.5 years). A series of autoregressive, cross-lagged path analyses were conducted to examine the relationships between child externalizing problems and corporal punishment at ages 3 and 5.5 years, and their association with physical and relational aggression at age 10.5. Multiple group analysis was used to determine whether pathways differed by sex. Three developmental pathways were identified: (i) direct associations between stable childhood externalizing problems and later physical aggression; (ii) a direct pathway from early corporal punishment to preadolescent relational and physical peer aggression; and (iii) an indirect pathway from early corporal punishment to later physical aggression via continuing externalizing problems in middle childhood. Child sex moderated the nature of these pathways, as well as the direction of association between risk and outcome variables. These data advance our understanding of the etiology of distinct forms of peer aggression and highlight the potential for more efficacious prevention and intervention efforts in the early childhood years. © 2018 Wiley Periodicals, Inc.

Spanking and children's externalizing behavior across the first decade of life: evidence for transactional processes.

PubMed

MacKenzie, Michael J; Nicklas, Eric; Brooks-Gunn, Jeanne; Waldfogel, Jane

2015-03-01

Despite a growing literature associating physical discipline with later child aggression, spanking remains a typical experience for American children. The directionality of the associations between aggression and spanking and their continuity over time has received less attention. This study examined the transactional associations between spanking and externalizing behavior across the first decade of life, examining not only how spanking relates to externalizing behavior leading up to the important transition to adolescence, but whether higher levels of externalizing lead to more spanking over time as well. We use data from the Fragile families and child well-being (FFCW) study to examine maternal spanking and children's behavior at ages 1, 3, 5, and 9 (N = 1,874; 48% girls). The FFCW is a longitudinal birth cohort study of children born between 1998 and 2000 in 20 medium to large US cities. A little over a quarter of this sample was spanked at age 1, and about half at age 3, 5, and 9. Estimates from a cross-lagged path model provided evidence of developmental continuity in both spanking and externalizing behavior, but results also highlighted important reciprocal processes taking hold early, with spanking influencing later externalizing behavior, which, in turn, predicted subsequent spanking. These bidirectional effects held across race/ethnicity and child's gender. The findings highlight the lasting effects of early spanking, both in influencing early child's behavior, and in affecting subsequent child's externalizing and parental spanking in a reciprocal manner. These amplifying transactional processes underscore the importance of early intervention before patterns may cascade across domains in the transition to adolescence.

A new method to study he effective shear modulus of shocked material

NASA Astrophysics Data System (ADS)

Xiaojuan, Ma; Fusheng, Liu

2013-06-01

Shear modulus is a crucial material parameter for description of mechanical behavior. However, at strong shock compression, it is generally deduced from the longitudinal and bulk sound velocity evaluated by unloading wave profile measurement. Here, a new method called the disturbed amplitude damping method of shock wave is presented, that can directly measure the shear modulus of material. This method relies on the correlation between the shear modulus of shock compressed state and amplitude damping and oscillation of an initial sinusoidal disturbance on shock front in concerned substance. Two important steps are required to determine the shear modulus of material. The first is to measure the damping and oscillation feature of disturbance by the flyer impacted method. The second is to find the quantitative relationship between the disturbed amplitude damping and shear modulus by the finite difference method which is applied to obtain the numerical solutions for disturbance amplitude damping behavior of sinusoidal shock front in flyer impacted flow field. When aluminum shocked to 80 GPa is taken as an example, the shape of perturbed shock front and its disturbed amplitude development with propagation distance, are approximately mapped out. The figure shows an oscillatory damping characteristic. At the early stage the perturbation amplitude on the shock front experiences a decaying process until to zero point, then it rises to a maximum but in reverse phase, and then it decays again. Comparing these data with those simulated using the SCG constitutive model, the effective shear modulus for aluminum shocked to 80 GPa is determined to be about 90 GPa, which is higher than the result given by Yu.

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

Parkin, E. R.; Sim, S. A., E-mail: parkin@mso.anu.edu.au, E-mail: s.sim@qub.ac.uk

In an early-type, massive star binary system, X-ray bright shocks result from the powerful collision of stellar winds driven by radiation pressure on spectral line transitions. We examine the influence of the X-rays from the wind-wind collision shocks on the radiative driving of the stellar winds using steady-state models that include a parameterized line force with X-ray ionization dependence. Our primary result is that X-ray radiation from the shocks inhibits wind acceleration and can lead to a lower pre-shock velocity, and a correspondingly lower shocked plasma temperature, yet the intrinsic X-ray luminosity of the shocks, L{sub X}, remains largely unaltered,more » with the exception of a modest increase at small binary separations. Due to the feedback loop between the ionizing X-rays from the shocks and the wind driving, we term this scenario as self-regulated shocks. This effect is found to greatly increase the range of binary separations at which a wind-photosphere collision is likely to occur in systems where the momenta of the two winds are significantly different. Furthermore, the excessive levels of X-ray ionization close to the shocks completely suppress the line force, and we suggest that this may render radiative braking less effective. Comparisons of model results against observations reveal reasonable agreement in terms of log (L{sub X}/L{sub bol}). The inclusion of self-regulated shocks improves the match for kT values in roughly equal wind momenta systems, but there is a systematic offset for systems with unequal wind momenta (if considered to be a wind-photosphere collision).« less

Marital stress and children's externalizing behavior as predictors of mothers' and fathers' parenting.

PubMed

Elam, Kit K; Chassin, Laurie; Eisenberg, Nancy; Spinrad, Tracy L

2017-10-01

Previous research suggests that mothers' and fathers' parenting may be differentially influenced by marital and child factors within the family. Some research indicates that marital stress is more influential in fathers' than mothers' parenting, whereas other research shows that children's difficult behavior preferentially affects mothers' parenting. The present study examined marital stress and children's externalizing behavior in middle childhood as predictors of mothers' versus fathers' consistency, monitoring, and support and care in early adolescence, and the subsequent associations of these parenting behaviors with externalizing behavior 1.5 years later. Pathways were examined within a longitudinal mediation model testing for moderation by parent gender (N = 276 mothers, N = 229 fathers). Children's externalizing behavior in middle childhood was found to more strongly inversely predict mothers' versus fathers' monitoring in early adolescence. In contrast, marital stress more strongly predicted low monitoring for fathers than for mothers. Regardless of parent gender, marital stress predicted lower levels of parental consistency, and children's externalizing behavior predicted lower levels of parental support. Mothers' monitoring and fathers' support in early adolescence predicted lower levels of externalizing behavior 1.5 years later. The results are discussed with respect to family transactions relative to parent gender and implications for intervention.

Effects of early maternal distress and parenting on the development of children's self-regulation and externalizing behavior.

PubMed

Choe, Daniel Ewon; Olson, Sheryl L; Sameroff, Arnold J

2013-05-01

Emotional distress experienced by mothers increases young children's risk of externalizing problems through suboptimal parenting and child self-regulation. An integrative structural equation model tested hypotheses that mothers' parenting (i.e., low levels of inductive discipline and maternal warmth) would mediate adverse effects of early maternal distress on child effortful control, which in turn would mediate effects of maternal parenting on child externalizing behavior. This longitudinal study spanning ages 3, 6, and 10 included 241 children, mothers, and a subset of teachers. The hypothesized model was partially supported. Elevated maternal distress was associated with less inductive discipline and maternal warmth, which in turn were associated with less effortful control at age 3 but not at age 6. Inductive discipline and maternal warmth mediated adverse effects of maternal distress on children's effortful control. Less effortful control at ages 3 and 6 predicted smaller relative decreases in externalizing behavior at 6 and 10, respectively. Effortful control mediated effects of inductive discipline, but not maternal warmth, on externalizing behavior. Findings suggest elevated maternal distress increases children's risk of externalizing problems by compromising early parenting and child self-regulation.

Septic shock: desperately seeking treatment.

PubMed

Huet, Olivier; Chin-Dusting, Jaye P F

2014-01-01

Septic shock results from the dysregulation of the innate immune response following infection. Despite major advances in fundamental and clinical research, patients diagnosed with septic shock still have a poor prognostic outcome, with a mortality rate of up to 50%. Indeed, the reasons leading to septic shock are still poorly understood. First postulated 30 years ago, the general view of septic shock as an acute and overwhelming inflammatory response still prevails today. Recently, the fact that numerous clinical trials have failed to demonstrate any positive medical outcomes has caused us to question our fundamental understanding of this condition. New and sophisticated technologies now allow us to accurately profile the various stages and contributory components of the inflammatory response defining septic shock, and many studies now report a more complex inflammatory response, particularly during the early phase of sepsis. In addition, novel experimental approaches, using more clinically relevant animal models, to standardize and stratify research outcomes are now being argued for. In the present review, we discuss the most recent findings in relation to our understanding of the underlying mechanisms involved in septic shock, and highlight the attempts made to improve animal experimental models. We also review recent studies reporting promising results with two vastly different therapeutic approaches influencing the renin-angiotensin system and applying mesenchymal stem cells for clinical intervention.

Prebiotic chemistry and atmospheric warming of early Earth by an active young Sun

NASA Astrophysics Data System (ADS)

Airapetian, V. S.; Glocer, A.; Gronoff, G.; Hébrard, E.; Danchi, W.

2016-06-01

Nitrogen is a critical ingredient of complex biological molecules. Molecular nitrogen, however, which was outgassed into the Earth’s early atmosphere, is relatively chemically inert and nitrogen fixation into more chemically reactive compounds requires high temperatures. Possible mechanisms of nitrogen fixation include lightning, atmospheric shock heating by meteorites, and solar ultraviolet radiation. Here we show that nitrogen fixation in the early terrestrial atmosphere can be explained by frequent and powerful coronal mass ejection events from the young Sun--so-called superflares. Using magnetohydrodynamic simulations constrained by Kepler Space Telescope observations, we find that successive superflare ejections produce shocks that accelerate energetic particles, which would have compressed the early Earth’s magnetosphere. The resulting extended polar cap openings provide pathways for energetic particles to penetrate into the atmosphere and, according to our atmospheric chemistry simulations, initiate reactions converting molecular nitrogen, carbon dioxide and methane to the potent greenhouse gas nitrous oxide as well as hydrogen cyanide, an essential compound for life. Furthermore, the destruction of N2, CO2 and CH4 suggests that these greenhouse gases cannot explain the stability of liquid water on the early Earth. Instead, we propose that the efficient formation of nitrous oxide could explain a warm early Earth.

The Effects of Calcitonin on the Development of and Ca2+ Levels in Heat-shocked Bovine Preimplantation Embryos In Vitro

PubMed Central

KAMANO, Shumpei; IKEDA, Shuntaro; SUGIMOTO, Miki; KUME, Shinichi

2014-01-01

Intracellular calcium homeostasis is essential for proper cell function. We investigated the effects of heat shock on the development of and the intracellular Ca2+ levels in bovine preimplantation embryos in vitro and the effects of calcitonin (CT), a receptor-mediated Ca2+ regulator, on heat shock-induced events. Heat shock (40.5 C for 10 h between 20 and 30 h postinsemination) of in vitro-produced bovine embryos did not affect the cleavage rate; however, it significantly decreased the rates of development to the 5- to 8-cell and blastocyst stages as compared with those of the control cultured for the entire period at 38.5 C (P < 0.05). The relative intracellular Ca2+ levels at the 1-cell stage (5 h after the start of heat shock), as assessed by Fluo-8 AM, a fluorescent probe for Ca2+, indicated that heat shock significantly lowered the Ca2+ level as compared with the control level. Semiquantitative reverse transcription PCR and western blot analyses revealed the expression of CT receptor in bovine preimplantation embryos. The addition of CT (10 nM) to the culture medium ameliorated the heat shock-induced impairment of embryonic development beyond the 5- to 8-cell stage. The Ca2+ level in the heat-shocked embryos cultured with CT was similar to that of the control embryos, suggesting that heat shock lowers the Ca2+ level in fertilized embryos in vitro and that a lower Ca2+ level is implicated in heat shock-induced impairment of embryonic development. Intracellular Ca2+-mobilizing agents, e.g., CT, may effectively circumvent the detrimental effects of heat shock on early embryonic development. PMID:24899099

Anisotropic responses and initial decomposition of condensed-phase β-HMX under shock loadings via molecular dynamics simulations in conjunction with multiscale shock technique.

PubMed

Ge, Ni-Na; Wei, Yong-Kai; Song, Zhen-Fei; Chen, Xiang-Rong; Ji, Guang-Fu; Zhao, Feng; Wei, Dong-Qing

2014-07-24

Molecular dynamics simulations in conjunction with multiscale shock technique (MSST) are performed to study the initial chemical processes and the anisotropy of shock sensitivity of the condensed-phase HMX under shock loadings applied along the a, b, and c lattice vectors. A self-consistent charge density-functional tight-binding (SCC-DFTB) method was employed. Our results show that there is a difference between lattice vector a (or c) and lattice vector b in the response to a shock wave velocity of 11 km/s, which is investigated through reaction temperature and relative sliding rate between adjacent slipping planes. The response along lattice vectors a and c are similar to each other, whose reaction temperature is up to 7000 K, but quite different along lattice vector b, whose reaction temperature is only up to 4000 K. When compared with shock wave propagation along the lattice vectors a (18 Å/ps) and c (21 Å/ps), the relative sliding rate between adjacent slipping planes along lattice vector b is only 0.2 Å/ps. Thus, the small relative sliding rate between adjacent slipping planes results in the temperature and energy under shock loading increasing at a slower rate, which is the main reason leading to less sensitivity under shock wave compression along lattice vector b. In addition, the C-H bond dissociation is the primary pathway for HMX decomposition in early stages under high shock loading from various directions. Compared with the observation for shock velocities V(imp) = 10 and 11 km/s, the homolytic cleavage of N-NO2 bond was obviously suppressed with increasing pressure.

PHYSICAL CONDITIONS OF CORONAL PLASMA AT THE TRANSIT OF A SHOCK DRIVEN BY A CORONAL MASS EJECTION

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

Susino, R.; Bemporad, A.; Mancuso, S., E-mail: susino@oato.inaf.it

2015-10-20

We report here on the determination of plasma physical parameters across a shock driven by a coronal mass ejection using white light (WL) coronagraphic images and radio dynamic spectra (RDS). The event analyzed here is the spectacular eruption that occurred on 2011 June 7, a fast CME followed by the ejection of columns of chromospheric plasma, part of them falling back to the solar surface, associated with a M2.5 flare and a type-II radio burst. Images acquired by the Solar and Heliospheric Observatory/LASCO coronagraphs (C2 and C3) were employed to track the CME-driven shock in the corona between 2–12 R{submore » ⊙} in an angular interval of about 110°. In this interval we derived two-dimensional (2D) maps of electron density, shock velocity, and shock compression ratio, and we measured the shock inclination angle with respect to the radial direction. Under plausible assumptions, these quantities were used to infer 2D maps of shock Mach number M{sub A} and strength of coronal magnetic fields at the shock's heights. We found that in the early phases (2–4 R{sub ⊙}) the whole shock surface is super-Alfvénic, while later on (i.e., higher up) it becomes super-Alfvénic only at the nose. This is in agreement with the location for the source of the observed type-II burst, as inferred from RDS combined with the shock kinematic and coronal densities derived from WL. For the first time, a coronal shock is used to derive a 2D map of the coronal magnetic field strength over intervals of 10 R{sub ⊙} altitude and ∼110° latitude.« less

Propellant Expulsion in Unmanned Spacecraft

DTIC Science & Technology

1966-07-01

29 19. Experimental WAC Corporal piston tank .. ......... . 33 20. Three piston tank designs used in the Corporal program ..... 34 21...propellant. The only universal F. Filling seal at this writing is a metal bellows. Usually, piston tank assemblies are filled by a vacuum technique...externally gener- Piston tank assemblies are subjected to essentially the ated loads due to shock and vibration may be the sever- same tests as bladders. 31

Altered Standards of Care: An Analysis of Existing Federal, State, and Local Guidelines

DTIC Science & Technology

2011-12-01

Approved for public release; distribution is unlimited 12b. DISTRIBUTION CODE A 13. ABSTRACT (maximum 200 words ) A...data systems for communications and the transference of data. Losing data systems during disasters cuts off access to electronic medical records...emergency procedures as mouth - to- mouth resuscitation, external chest compression, electric shock, insertion of a tube to open the patient’s airway

Amplitudes of solar modulation of low energy cosmic rays

NASA Technical Reports Server (NTRS)

Von Rosenvinge, T. T.; Paizis, C.

1982-01-01

There have been differences of opinion regarding the origin and behavior of the solar modulation of galactic cosmic rays. It has been shown that the return to solar maximum intensity levels beginning in early 1978 was dominated by Forbush decreases. These Forbush decreases were caused by radially moving interplanetary shocks resulting from large solar flares. The present investigation is concerned with solar modulation effects which were observed during the previous solar minimum. The effects were associated with high-speed streams in the solar wind. These streams caused the formation of corotating interaction regions with both forward and reverse shocks. The modulation effects seen near earth are intimately connected with these shocks.

Fault Detection for Automotive Shock Absorber

NASA Astrophysics Data System (ADS)

Hernandez-Alcantara, Diana; Morales-Menendez, Ruben; Amezquita-Brooks, Luis

2015-11-01

Fault detection for automotive semi-active shock absorbers is a challenge due to the non-linear dynamics and the strong influence of the disturbances such as the road profile. First obstacle for this task, is the modeling of the fault, which has been shown to be of multiplicative nature. Many of the most widespread fault detection schemes consider additive faults. Two model-based fault algorithms for semiactive shock absorber are compared: an observer-based approach and a parameter identification approach. The performance of these schemes is validated and compared using a commercial vehicle model that was experimentally validated. Early results shows that a parameter identification approach is more accurate, whereas an observer-based approach is less sensible to parametric uncertainty.

Early Treatment in Shock

DTIC Science & Technology

2010-06-17

the present study was that pre-feeding experimental animals with 8 fish oil rich in • -3 fatty acids (FAs), specifically eicosapentaenoic acid (EPA...Précis of presentation to be given at ESPEN 2010, 24-28 August, 2010 2. Manuscript on use of omega-3 fatty acids in shock, accepted for publication...use of DHEA, but studies in our laboratories have failed to show a useful effect (6). Studies with omega-3 fatty acids have shown promise, but are

[Acute heart failure: acute cardiogenic pulmonary edema and cardiogenic shock].

PubMed

Sánchez Marteles, Marta; Urrutia, Agustín

2014-03-01

Acute cardiogenic pulmonary edema and cardiogenic shock are two of the main forms of presentation of acute heart failure. Both entities are serious, with high mortality, and require early diagnosis and prompt and aggressive management. Acute pulmonary edema is due to the passage of fluid through the alveolarcapillary membrane and is usually the result of an acute cardiac episode. Correct evaluation and clinical identification of the process is essential in the management of acute pulmonary edema. The initial aim of treatment is to ensure hemodynamic stability and to correct hypoxemia. Other measures that can be used are vasodilators such as nitroglycerin, loop diuretics and, in specific instances, opioids. Cardiogenic shock is characterized by sustained hypoperfusion, pulmonary wedge pressure > 18 mmHg and a cardiac index < 2.2l/min/m(2). The process typically presents with hypotension (systolic blood pressure < 90 mmHg or a decrease in mean arterial pressure > 30 mmHg) and absent or reduced diuresis (< 0.5 ml/kg/h). The most common cause is left ventricular failure due to acute myocardial infarction. Treatment consists of general measures to reverse acidosis and hypoxemia, as well as the use of vasopressors and inotropic drugs. Early coronary revascularization has been demonstrated to improve survival in shock associated with ischaemic heart disease. Copyright © 2014 Elsevier España, S.L. All rights reserved.

Effects and mechanisms of cavidine protecting mice against LPS-induced endotoxic shock

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

Li, Weifeng, E-mail: liwf@mail.xjtu.edu.cn; Zhang,

LPS sensitized mice are usually considered as an experimental model of endotoxin shock. The present study aims to evaluate effects of cavidine on LPS-induced endotoxin shock. Mice were intraperitoneally administrated with cavidine (1, 3 and 10 mg/kg) or DEX (5 mg/kg) at 1 and 12 h before injecting LPS (30 mg/kg) intraperitoneally. Blood samples, liver, lung and kidney tissues were harvested after LPS injection. The study demonstrated that pretreatment with cavidine reduced the mortality of mice during 72 h after endotoxin injection. In addition, cavidine administration significantly attenuated histological pathophysiology features of LPS-induced injury in lung, liver and kidney. Furthermore,more » cavidine administration inhibited endotoxin-induced production of pro-inflammatory cytokines including TNF-α, IL-6 and HMGB1. Moreover, cavidine pretreatment attenuated the phosphorylation of mitogen-activated protein kinase primed by LPS. In summary, cavidine protects mice against LPS-induced endotoxic shock via inhibiting early pro-inflammatory cytokine TNF-α, IL-6 and late-phase cytokine HMGB1, and the modulation of HMGB1 may be related with MAPK signal pathway. - Highlights: • Cavidine significantly reduced mortality in mice during 72 h after LPS injection. • Cavidine attenuated histopathological changes in lung, liver and kidney. • Cavidine decreased the level of early inflammatory cytokine TNF-α, IL-6 in LPS- stimulated mice. • Cavidine inhibited late inflammatory cytokine HMGB1 through MAPK pathway.« less

Moderators of Negative Peer Influence on Early Adolescent Externalizing Behaviors: Individual Behavior, Parenting, and School Connectedness

ERIC Educational Resources Information Center

Mrug, Sylvie; Windle, Michael

2009-01-01

This study examined the extent to which antisocial behavior, parenting, and school connectedness moderated the association between peer deviancy in preadolescence and externalizing problems in early adolescence. The participants included 500 boys and girls, most of them African Americans. Peer deviancy was measured with teacher reports of…

Gene-by-Preschool Interaction on the Development of Early Externalizing Problems

ERIC Educational Resources Information Center

Tucker-Drob, Elliot M.; Harden, K. Paige

2013-01-01

Background: Preschool involves an array of new social experiences that may impact the development of early externalizing behavior problems over the transition to grade school. Methods: Using longitudinal data from a nationally representative sample of over 600 pairs of US twins, we tested whether the genetic and environmental influences on…

Genetic Vulnerability Interacts with Parenting and Early Care and Education to Predict Increasing Externalizing Behavior

ERIC Educational Resources Information Center

Lipscomb, Shannon T.; Laurent, Heidemarie; Neiderhiser, Jenae M.; Shaw, Daniel S.; Natsuaki, Misaki N.; Reiss, David; Leve, Leslie D.

2014-01-01

The current study examined interactions among genetic influences and children's early environments on the development of externalizing behaviors from 18 months to 6 years of age. Participants included 233 families linked through adoption (birth parents and adoptive families). Genetic influences were assessed by birth parent temperamental…

Parental Discipline and Externalizing Behavior Problems in Early Childhood: The Roles of Moral Regulation and Child Gender

ERIC Educational Resources Information Center

Kerr, David C.R.; Lopez, Nestor L.; Olson, Sheryl L.; Sameroff, Arnold J.

2004-01-01

We tested whether individual differences in a component of early conscience mediated relations between parental discipline and externalizing behavior problems in 238 3.5-year-olds. Parents contributed assessments of discipline practices and child moral regulation. Observations of children's behavioral restraint supplemented parental reports.…

Survey of Aerothermodynamics Facilities Useful for the Design of Hypersonic Vehicles Using Air-Breathing Propulsion

NASA Technical Reports Server (NTRS)

Arnold, James O.; Deiwert, George S.

1997-01-01

This paper surveys the use of aerothermodynamic facilities which have been useful in the study of external flows and propulsion aspects of hypersonic, air-breathing vehicles. While the paper is not a survey of all facilities, it covers the utility of shock tunnels and conventional hypersonic blow-down facilities which have been used for hypersonic air-breather studies. The problems confronting researchers in the field of aerothermodynamics are outlined. Results from the T5 GALCIT tunnel for the shock-on lip problem are outlined. Experiments on combustors and short expansion nozzles using the semi-free jet method have been conducted in large shock tunnels. An example which employed the NASA Ames 16-Inch shock tunnel is outlined, and the philosophy of the test technique is described. Conventional blow-down hypersonic wind tunnels are quite useful in hypersonic air-breathing studies. Results from an expansion ramp experiment, simulating the nozzle on a hypersonic air-breather from the NASA Ames 3.5 Foot Hypersonic wind tunnel are summarized. Similar work on expansion nozzles conducted in the NASA Langley hypersonic wind tunnel complex is cited. Free-jet air-frame propulsion integration and configuration stability experiments conducted at Langley in the hypersonic wind tunnel complex on a small generic model are also summarized.

The Synchrotron Spectrum of Fast Cooling Electrons Revisited.

PubMed

Granot; Piran; Sari

2000-05-10

We discuss the spectrum arising from synchrotron emission by fast cooling (FC) electrons, when fresh electrons are continually accelerated by a strong blast wave, into a power-law distribution of energies. The FC spectrum has so far been described by four power-law segments divided by three break frequencies nusa

Localization of small arms fire using acoustic measurements of muzzle blast and/or ballistic shock wave arrivals.

PubMed

Lo, Kam W; Ferguson, Brian G

2012-11-01

The accurate localization of small arms fire using fixed acoustic sensors is considered. First, the conventional wavefront-curvature passive ranging method, which requires only differential time-of-arrival (DTOA) measurements of the muzzle blast wave to estimate the source position, is modified to account for sensor positions that are not strictly collinear (bowed array). Second, an existing single-sensor-node ballistic model-based localization method, which requires both DTOA and differential angle-of-arrival (DAOA) measurements of the muzzle blast wave and ballistic shock wave, is improved by replacing the basic external ballistics model (which describes the bullet's deceleration along its trajectory) with a more rigorous model and replacing the look-up table ranging procedure with a nonlinear (or polynomial) equation-based ranging procedure. Third, a new multiple-sensor-node ballistic model-based localization method, which requires only DTOA measurements of the ballistic shock wave to localize the point of fire, is formulated. The first method is applicable to situations when only the muzzle blast wave is received, whereas the third method applies when only the ballistic shock wave is received. The effectiveness of each of these methods is verified using an extensive set of real data recorded during a 7 day field experiment.

Material-Model-Based Determination of the Shock-Hugoniot Relations in Nanosegregated Polyurea

NASA Astrophysics Data System (ADS)

Grujicic, Mica; Snipes, J. S.; Galgalikar, R.; Ramaswami, S.

2014-02-01

Previous experimental investigations reported in the open literature have indicated that applying polyurea external coatings and/or internal linings can substantially improve ballistic penetration resistance and blast survivability of buildings, vehicles, and laboratory/field test-plates, as well as the blast-mitigation capacity of combat helmets. The protective role of polyurea coatings/linings has been linked to polyurea microstructure, which consists of discrete hard-domains distributed randomly within a compliant/soft matrix. When this protective role is investigated computationally, the availability of reliable, high-fidelity constitutive models for polyurea is vitally important. In the present work, a comprehensive overview and a critical assessment of a polyurea material constitutive model, recently proposed by Shim and Mohr (Int J Plast 27:868-886, 2011), are carried out. The review revealed that this model can accurately account for the experimentally measured uniaxial-stress versus strain data obtained under monotonic and multistep compressive loading/unloading conditions, as well as under stress relaxation conditions. On the other hand, by combining analytical and finite-element procedures with the material model in order to define the basic shock-Hugoniot relations for this material, it was found that the computed shock-Hugoniot relations differ significantly from their experimental counterparts. Potential reasons for the disagreement between the computed and experimental shock-Hugoniot relations are identified.

A high-voltage cardiac stimulator for field shocks of a whole heart in a bath

NASA Astrophysics Data System (ADS)

Mashburn, David N.; Hinkson, Stephen J.; Woods, Marcella C.; Gilligan, Jonathan M.; Holcomb, Mark R.; Wikswo, John P.

2007-10-01

Defibrillators are a critical tool for treating heart disease; however, the mechanisms by which they halt fibrillation are still not fully understood and are the subject of ongoing research. Clinical defibrillators do not provide the precise control of shock timing, duration, and voltage or other features needed for detailed scientific inquiry, and there are few, if any, commercially available units designed for research applications. For this reason, we have developed a high-voltage, programmable, capacitive-discharge stimulator optimized to deliver defibrillation shocks with precise timing and voltage control to an isolated animal heart, either in air or in a bath. This stimulator is capable of delivering voltages of up to 500V and energies of nearly 100J with timing accuracy of a few microseconds and with rise and fall times of 5μs or less and is controlled only by two external timing pulses and a control computer that sets the stimulation parameters via a LABVIEW interface. Most importantly, the stimulator has circuits to protect the high-voltage circuitry and the operator from programming and input-output errors. This device has been tested and used successfully in field shock experiments on rabbit hearts as well as other protocols requiring high voltage.

Magnetic field generation, Weibel-mediated collisionless shocks, and magnetic reconnection in colliding laser-produced plasmas

NASA Astrophysics Data System (ADS)

Fox, W.; Bhattacharjee, A.; Fiksel, G.

2016-10-01

Colliding plasmas are ubiquitous in astrophysical environments and allow conversion of kinetic energy into heat and, most importantly, the acceleration of particles to extremely high energies to form the cosmic ray spectrum. In collisionless astrophysical plasmas, kinetic plasma processes govern the interaction and particle acceleration processes, including shock formation, self-generation of magnetic fields by kinetic plasma instabilities, and magnetic field compression and reconnection. How each of these contribute to the observed spectra of cosmic rays is not fully understood, in particular both shock acceleration processes and magnetic reconnection have been proposed. We will review recent results of laboratory astrophysics experiments conducted at high-power, inertial-fusion-class laser facilities, which have uncovered significant results relevant to these processes. Recent experiments have now observed the long-sought Weibel instability between two interpenetrating high temperature plasma plumes, which has been proposed to generate the magnetic field necessary for shock formation in unmagnetized regimes. Secondly, magnetic reconnection has been studied in systems of colliding plasmas using either self-generated magnetic fields or externally applied magnetic fields, and show extremely fast reconnection rates, indicating fast destruction of magnetic energy and further possibilities to accelerate particles. Finally, we highlight kinetic plasma simulations, which have proven to be essential tools in the design and interpretation of these experiments.

Turning up the heat in the lungs. A key mechanism to preserve their function.

PubMed

Sartori, Claudio; Scherrer, Urs

2003-01-01

Life threatening events cause important alterations in the structure of proteins creating the urgent need of repair to preserve function and ensure survival of the cell. In eukariotic cells, an intrinsic mechanism allows them to defend against external stress. Heat shock proteins are a group of highly preserved molecular chaperones, playing a crucial role in maintaining proper protein assembly, transport and function. Stress-induced upregulation of heat shock proteins provides a unique defense system to ensure survival and function of the cell in many organ systems during conditions such as high temperature, ischemia, hypoxia, inflammation, and exposure to endotoxin or reactive oxygen species. Induction of this cellular defense mechanism prior to imposing one of these noxious insults, allows the cell/organ to withstand a subsequent insult that would otherwise be lethal, a phenomenon referred to as "thermo-tolerance" or "preconditioning". In the lung, stress-induced heat shock protein synthesis, in addition to its cyto-protective and anti-inflammatory effect, helps to preserve vectorial ion transport and alveolar fluid clearance. In this review, we describe the function of heat shock proteins in the lung, with particular emphasis on their role in the pathophysiology of experimental pulmonary edema, and their potential beneficial effects in the prevention and/or treatment of this life-threatening disease in humans.

Skull flexure as a contributing factor in the mechanism of injury in the rat when exposed to a shock wave.

PubMed

Bolander, Richard; Mathie, Blake; Bir, Cynthia; Ritzel, David; VandeVord, Pamela

2011-10-01

The manner in which energy from an explosion is transmitted into the brain is currently a highly debated topic within the blast injury community. This study was conducted to investigate the injury biomechanics causing blast-related neurotrauma in the rat. Biomechanical responses of the rat head under shock wave loading were measured using strain gauges on the skull surface and a fiber optic pressure sensor placed within the cortex. MicroCT imaging techniques were applied to quantify skull bone thickness. The strain gauge results indicated that the response of the rat skull is dependent on the intensity of the incident shock wave; greater intensity shock waves cause greater deflections of the skull. The intracranial pressure (ICP) sensors indicated that the peak pressure developed within the brain was greater than the peak side-on external pressure and correlated with surface strain. The bone plates between the lambda, bregma, and midline sutures are probable regions for the greatest flexure to occur. The data provides evidence that skull flexure is a likely candidate for the development of ICP gradients within the rat brain. This dependency of transmitted stress on particular skull dynamics for a given species should be considered by those investigating blast-related neurotrauma using animal models.

Trajectories of child externalizing problems between ages 3 and 10 years: Contributions of children's early effortful control, theory of mind, and parenting experiences.

PubMed

Olson, Sheryl L; Choe, Daniel Ewon; Sameroff, Arnold J

2017-10-01

Preventing problem behavior requires an understanding of earlier factors that are amenable to intervention. The main goals of our prospective longitudinal study were to trace trajectories of child externalizing behavior between ages 3 and 10 years, and to identify patterns of developmentally significant child and parenting risk factors that differentiated pathways of problem behavior. Participants were 218 3-year-old boys and girls who were reassessed following the transition to kindergarten (age 5-6 years) and during the late school-age years (age 10). Mothers contributed ratings of children's externalizing behavior at all three time points. Children's self-regulation abilities and theory of mind were assessed during a laboratory visit, and parenting risk (frequent corporal punishment and low maternal warmth) was assessed using interview-based and questionnaire measures. Four developmental trajectories of externalizing behavior yielded the best balance of parsimony and fit with our longitudinal data and latent class growth analysis. Most young children followed a pathway marked by relatively low levels of symptoms that continued to decrease across the school-age years. Atypical trajectories marked chronically high, increasing, and decreasing levels of externalizing problems across early and middle childhood. Three-year-old children with low levels of effortful control were far more likely to show the chronic pattern of elevated externalizing problems than changing or low patterns. Early parental corporal punishment and maternal warmth, respectively, differentiated preschoolers who showed increasing and decreasing patterns of problem behavior compared to the majority of children. The fact that children's poor effortful regulation skills predicted chronic early onset problems reinforces the need for early childhood screening and intervention services.

Detrital shocked minerals: microstructural provenance indicators of impact craters

NASA Astrophysics Data System (ADS)

Cavosie, A. J.

2014-12-01

The study of detrital shocked minerals (DSMs) merges planetary science, sedimentology, mineralogy/crystallography, accessory mineral geochemistry, and geochronology, with the goal of identifying and determining provenance of shock metamorphosed sand grains. Diagnostic high-pressure impact-generated microstructures (planar fractures, planar deformation features) are readily identified on external grain surfaces using standard SEM imaging methods (BSE), and when found, unambiguously confirm an impact origin for a given sand grain. DSMs, including quartz, zircon, monazite, and apatite, have thus far been documented at the Vredefort Dome [1,2,3], Sudbury [4], Rock Elm [5], and Santa Fe [6,7] impact structures. DSMs have been identified in alluvium, colluvium, beach sand, and glacial deposits. Two main processes are recognized that imply the global siliciclastic record contains DSMs: they survive extreme distal transport, and they survive 'deep time' lithification. Distal transport: In South Africa, shocked minerals are preserved in alluvium from the Vaal River >750 km downstream from the Vredefort impact; SHRIMP U-Pb geochronology has confirmed the origin of detrital shocked zircon and monazite from shocked Vredefort bedrock [2]. Vredefort-derived shocked zircons have also been found at the mouth of the Orange River on the Atlantic coast, having travelled ~2000 km downriver from Vredefort [8]. Deep time preservation: Vredefort-derived shocked zircon and quartz has been documented in glacial diamictite from the 300 Myr-old Dwyka Group in South Africa. Shocked minerals were thus entrained and transported in Paleozoic ice sheets that passed over Vredefort [9]. An impact crater can thus be viewed as a unique 'point source', in some cases for billions of years [2,4]; DSMs thus have applications in studying eroded impact craters, sedimentary provenance, landscape evolution, and long-term sediment transport processes throughout the geologic record. This work was supported by NSF (EAR-1145118) and NASA Astrobiology [1] Cavosie et al. 2010 GSA Bulletin. [2] Erickson et al. 2013 GCA. [3] Erickson et al. 2013 Am. Min. [4] Thomson et al. 2014 GSA Bulletin. [5] Roig et al. 2013 LPSC. [6] Lugo and Cavosie 2014 LPSC. [7] Cavosie and Lugo, 2014 LPSC. [8] Montalvo and Cavosie, 2014 GSA. [9] Pincus et al. 2014 GSA.

An exploration of Lasnex designs to support the MShock campaign at NIF

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

DeVolder, Barbara Gloria

In support of planned MShock experiments at NIF, Lasnex is being used to explore possible laser sources and halfraum designs that launch two shocks into an ablator - shock tube configuration. Two design features were investigated: (1) launching a two-component laser source consisting of an early pre-pulse separated in time from a later main pulse, to create two shocks, and (2) adding a liner on the inner surface of the gold wall of the halfraum, to delay or prevent gold stagnation on-axis and to preserve the effectiveness of the second laser pulse. The clearest indication of two shocks propagating inmore » the shock tube occurred when the pre-pulse mimicked a direct drive, achieved by re-pointing the inner beam cones, and when a liner was used to ensure that the free-electron number density was below the critical density for NIF. Additional simulations (presented in the Appendix) that used the two-component laser source but focused on specific choices in laser-pulse design space, as proposed by Kirk Flippo for use in the first MShock experiments at NIF, also demonstrated the presence of two shocks.« less

Myocardial oxygen delivery after experimental hemorrhagic shock.

PubMed Central

Archie, J P; Mertz, W R

1978-01-01

The two components of myocardial oxygen delivery, coronary blood flow to capillaries and diffusion from capillaries to mitochondria, were studied in six dogs, (1) prior to shock, (2) after three hours of hemorrhage shock at a mean systemic arterial pressure of 40 torr, (3) after reinfusion of shed blood, and (4) during the irreversible late posttransfusion stage. There was a maldistribution of left ventricular coronary flow during late shock consistent with subendocardial ischemia. Cardiac performance was significantly impaired after resuscitation and all dogs became irreversible. Total and regional left ventricular coronary blood flow and myocardial oxygen delivery to capillaries were significantly greater than preshock values in (3) but not different from preshock values in (4). However, the myocardial oxygen diffusion area to distance ratio was significantly lower than preshock values in (3), and slightly lower in (4). These data suggest that myocardial oxygen diffusion may be impaired in the early post transfusion period, (3). Accordingly, the probable etiology of left ventricular dysfunction and possibly irreversibility after resuscitation from hemorrhagic shock is subendocardial ischemia during shock with either post-resuscitation impairment of myocardial oxygen diffusion, or in cellular oxygen utilization, or both. PMID:629622

Metal ions induced heat shock protein response by elevating superoxide anion level in HeLa cells transformed by HSE-SEAP reporter gene.

PubMed

Yu, Zhanjiang; Yang, Xiaoda; Wang, Kui

2006-06-01

The aim of this work is to define the relationship between heat shock protein (HSP) and reactive oxygen species (ROS) in the cells exposed to different concentrations of metal ions, and to evaluate a new method for tracing the dynamic levels of cellular reactive oxygen species using a HSE-SEAP reporter gene. The expression of heat shock protein was measured using a secreted alkaline phosphatase (SEAP) reporter gene transformed into HeLa cell strain, the levels of superoxide anion (O(2)(-)) and hydrogen peroxide (H(2)O(2)) were determined by NBT reduction assay and DCFH staining flow cytometry (FCM), respectively. The experimental results demonstrated that the expression of heat shock protein induced by metal ions was linearly related to the cellular superoxide anion level before cytotoxic effects were observed, but not related to the cellular hydrogen peroxide level. The experimental results suggested that metal ions might induce heat shock protein by elevating cellular superoxide anion level, and thus the expression of heat shock protein indicated by the HSE-SEAP reporter gene can be an effective model for monitoring the dynamic level of superoxide anion and early metal-induced oxidative stress/cytotoxicity.

Incidence and outcome of out-of-hospital cardiac arrest with public-access defibrillation. A descriptive epidemiological study in a large urban community.

PubMed

Sasaki, Mie; Iwami, Taku; Kitamura, Tetsuhisa; Nomoto, Shinichi; Nishiyama, Chika; Sakai, Tomohiko; Tanigawa, Kayo; Kajino, Kentaro; Irisawa, Taro; Nishiuchi, Tatsuya; Hayashida, Sumito; Hiraide, Atsushi; Kawamura, Takashi

2011-01-01

Detailed characteristics of those who experience an out-of-hospital cardiac arrest (OHCA) with public-access defibrillation (PAD) are unknown. A prospective, population-based observational study involving consecutive OHCA patients with emergency responder resuscitation attempts was conducted from July 1, 2004 through December 31, 2008 in Osaka City. We extracted data for OHCA patients shocked by a public-access automated external defibrillator (AED) and evaluated the patients' and rescuers' characteristics. The main outcome measure was neurologically favorable 1-month survival. During the study period, 10,375 OHCA patients were registered and of 908 patients suffering ventricular fibrillation arrest, 53 (6%) received public-access AED shocks by lay-rescuers, with the proportion increasing from 0% in 2004 to 11% in 2008 (P for trend<0.001). Railway stations (34%) were the places where PAD shocks were most frequently delivered, followed by nursing homes (11%), medical facilities (9%), and fitness facilities (7%). In 57% of cases, the subject received public-access AED shocks delivered by non-medical persons, including employees of railway companies (13%), school teachers (6%), employees of fitness facilities (6%), and security guards (6%). The proportion of neurologically favorable 1-month survival tended to increase from 0% in 2005 to 58% in 2008 (P for trend=0.081). Railway stations are the most common places where shocks by public-access AEDs were delivered in large urban communities of Japan, and among lay-rescuers railway station workers use AEDs more frequently.

[The expression and significance of IgE in anaphylactic shock guinea-pigs].

PubMed

Gong, Zhi-qiang; Xiao, Feng; Feng, Qiong; Xu, Xiao-ming; Zheng, Jian

2006-02-01

To seek the pathomorphological targets for forensic expertise in anaphylactic shock. The expression of IgE in hearts, lungs, livers, spleens, kidneys, gastrics, intestinals, tracheas and tonsils of anaphylactic shock guinea-pigs was observed at 0, 6, 12 h and 24 h respectively by tissue chip S-P immuno-histochemical method. Positive expression of IgE presented in lungs and tracheas in the test group with the peak at 0 hour and it declined as time advanced, and also there were significant differences at different times (P<0.05). The immuno-histochemical method of detecting the expression of IgE in lungs, tracheas and spleens can be supposed to be the pathomorphological targets for forensic expertise in anaphylactic shock. The weakening of the positive expression of IgE in lungs and tracheas as the time advanced suggested that in this kind of case the autopsy should be arried out as early as possible.

Real-time Interplanetary Shock Prediction System

NASA Astrophysics Data System (ADS)

Vandegriff, J. D.; Ho, G. C.; Plauger, J. M.

2002-05-01

We are creating a system to predict the arrival times and maximum intensities of energetic storm particle (ESP) events at the earth using particle fluxes measured by the EPAM instrument aboard NASA's ACE spacecraft. Real-time flux measurements, consisting of 5 minute averages made available 24 hours per day by the NOAA Space Environment Center, are fed into algorithms looking for characteristic changes in flux, velocity dispersion, and anisotropy. These quantities typically show changes up to 3 hours before shock passage, and thus we expect our system to deliver enhanced probabilities for shock arrival with approximately the same lead time. Forecasting information will be made publicly available through http://sd-www.jhuapl.edu/ACE/EPAM/, the Johns Hopkins University Applied Physics Lab web site for the ACE/EPAM instrument. Early results on the training of our algorithms and comparisons with past shock data will be presented.

Measurement of Preheat Due to Nonlocal Electron Transport in Warm Dense Matter

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

Falk, K.; Holec, M.; Fontes, C. J.

This work presents a novel approach to study electron transport in warm dense matter. It also includes the first x-ray Thomson scattering (XRTS) measurement from low-density CH foams compressed by a strong laser-driven shock at the OMEGA laser facility. The XRTS measurement is combined with velocity interferometry (VISAR) and optical pyrometry (SOP) providing a robust measurement of thermodynamic conditions in the shock. Evidence of significant preheat contributing to elevated temperatures reaching 17.5–35 eV in shocked CH foam is measured by XRTS. These measurements are complemented by abnormally high shock velocities observed by VISAR and early emission seen by SOP. Thesemore » results are compared to radiation hydrodynamics simulations that include first-principles treatment of nonlocal electron transport in warm dense matter with excellent agreement. Additional simulations confirm that the x-ray contribution to this preheat is negligible.« less

Measurement of Preheat Due to Nonlocal Electron Transport in Warm Dense Matter

DOE PAGES

Falk, K.; Holec, M.; Fontes, C. J.; ...

2018-01-10

This work presents a novel approach to study electron transport in warm dense matter. It also includes the first x-ray Thomson scattering (XRTS) measurement from low-density CH foams compressed by a strong laser-driven shock at the OMEGA laser facility. The XRTS measurement is combined with velocity interferometry (VISAR) and optical pyrometry (SOP) providing a robust measurement of thermodynamic conditions in the shock. Evidence of significant preheat contributing to elevated temperatures reaching 17.5–35 eV in shocked CH foam is measured by XRTS. These measurements are complemented by abnormally high shock velocities observed by VISAR and early emission seen by SOP. Thesemore » results are compared to radiation hydrodynamics simulations that include first-principles treatment of nonlocal electron transport in warm dense matter with excellent agreement. Additional simulations confirm that the x-ray contribution to this preheat is negligible.« less

[Whole-blood transfusion for hemorrhagic shock resuscitation: two cases in Djibouti].

PubMed

Cordier, P Y; Eve, O; Dehan, C; Topin, F; Menguy, P; Bertani, A; Massoure, P L; Kaiser, E

2012-01-01

Hemorrhagic shock requires early aggressive treatment, including transfusion of packed red blood cells and hemostatic resuscitation. In austere environments, when component therapy is not available, warm fresh whole-blood transfusion is a convenient treatment. It provides red blood cells, clotting factors, and functional platelets. Therefore it is commonly used in military practice to treat hemorrhagic shock in combat casualties. At Bouffard Hospital Center in Djibouti, the supply of packed red blood cells is limited, and apheresis platelets are unavailable. We used whole blood transfusion in two civilian patients with life-threatening non-traumatic hemorrhages. One had massive bleeding caused by disseminated intravascular coagulation due to septic shock; the second was a 39 year-old pregnant woman with uterine rupture. In both cases, whole blood transfusion (twelve and ten 500 mL bags respectively), combined with etiological treatment, enabled coagulopathy correction, hemorrhage control, and satisfactory recovery.

Cosmic Rays and Gamma-Rays in Large-Scale Structure

NASA Astrophysics Data System (ADS)

Inoue, Susumu; Nagashima, Masahiro; Suzuki, Takeru K.; Aoki, Wako

2004-12-01

During the hierarchical formation of large scale structure in the universe, the progressive collapse and merging of dark matter should inevitably drive shocks into the gas, with nonthermal particle acceleration as a natural consequence. Two topics in this regard are discussed, emphasizing what important things nonthermal phenomena may tell us about the structure formation (SF) process itself. 1. Inverse Compton gamma-rays from large scale SF shocks and non-gravitational effects, and the implications for probing the warm-hot intergalactic medium. We utilize a semi-analytic approach based on Monte Carlo merger trees that treats both merger and accretion shocks self-consistently. 2. Production of 6Li by cosmic rays from SF shocks in the early Galaxy, and the implications for probing Galaxy formation and uncertain physics on sub-Galactic scales. Our new observations of metal-poor halo stars with the Subaru High Dispersion Spectrograph are highlighted.

Measurement of Preheat Due to Nonlocal Electron Transport in Warm Dense Matter

NASA Astrophysics Data System (ADS)

Falk, K.; Holec, M.; Fontes, C. J.; Fryer, C. L.; Greeff, C. W.; Johns, H. M.; Montgomery, D. S.; Schmidt, D. W.; Šmíd, M.

2018-01-01

This Letter presents a novel approach to study electron transport in warm dense matter. It also includes the first x-ray Thomson scattering (XRTS) measurement from low-density CH foams compressed by a strong laser-driven shock at the OMEGA laser facility. The XRTS measurement is combined with velocity interferometry (VISAR) and optical pyrometry (SOP) providing a robust measurement of thermodynamic conditions in the shock. Evidence of significant preheat contributing to elevated temperatures reaching 17.5-35 eV in shocked CH foam is measured by XRTS. These measurements are complemented by abnormally high shock velocities observed by VISAR and early emission seen by SOP. These results are compared to radiation hydrodynamics simulations that include first-principles treatment of nonlocal electron transport in warm dense matter with excellent agreement. Additional simulations confirm that the x-ray contribution to this preheat is negligible.

Callous-Unemotional Traits and Autonomic Functioning in Toddlerhood Interact to Predict Externalizing Behaviors in Preschool.

PubMed

Wagner, Nicholas J; Hastings, Paul D; Rubin, Kenneth H

2017-11-29

Callous-unemotional (CU) traits are one meaningful risk factor which helps to explain heterogeneity in the emergence of externalizing behavior problems. While the extant literature demonstrates links between early CU traits and later externalizing problems, there is a dearth of research examining for whom early CU traits confer risk. Data from a longitudinal study (n = 108) were used to examine the extent to which parasympathetic functioning moderated links between CU traits in toddlerhood (m age  = 24.99 months) and externalizing behavior problems at preschool-age (m age  = 51 months). Neither CU traits nor parasympathetic functioning at age 2 directly predicted later externalizing behaviors. However, results show that high levels of CU traits predict elevated externalizing behavior problems, but only for toddlers exhibiting either high baseline respiratory sinus arrhythmia (RSA) or little to no RSA suppression in response to a fear stimulus.

Differential risk for late adolescent conduct problems and mood dysregulation among children with early externalizing behavior problems.

PubMed

Okado, Yuko; Bierman, Karen L

2015-05-01

To investigate the differential emergence of antisocial behaviors and mood dysregulation among children with externalizing problems, the present study prospectively followed 317 high-risk children with early externalizing problems from school entry (ages 5-7) to late adolescence (ages 17-19). Latent class analysis conducted on their conduct and mood symptoms in late adolescence revealed three distinct patterns of symptoms, characterized by: 1) criminal offenses, conduct disorder symptoms, and elevated anger ("conduct problems"), 2) elevated anger, dysphoric mood, and suicidal ideation ("mood dysregulation"), and 3) low levels of severe conduct and mood symptoms. A diathesis-stress model predicting the first two outcomes was tested. Elevated overt aggression at school entry uniquely predicted conduct problems in late adolescence, whereas elevated emotion dysregulation at school entry uniquely predicted mood dysregulation in late adolescence. Experiences of low parental warmth and peer rejection in middle childhood moderated the link between early emotion dysregulation and later mood dysregulation but did not moderate the link between early overt aggression and later conduct problems. Thus, among children with early externalizing behavior problems, increased risk for later antisocial behavior or mood dysfunction may be identifiable in early childhood based on levels of overt aggression and emotion dysregulation. For children with early emotion dysregulation, however, increased risk for mood dysregulation characterized by anger, dysphoric mood, and suicidality--possibly indicative of disruptive mood dysregulation disorder--emerges only in the presence of low parental warmth and/or peer rejection during middle childhood.

Early Parenting and the Development of Externalizing Behavior Problems: Longitudinal Mediation Through Children's Executive Function.

PubMed

Sulik, Michael J; Blair, Clancy; Mills-Koonce, Roger; Berry, Daniel; Greenberg, Mark

2015-01-01

Path analysis was used to investigate the longitudinal associations among parenting and children's executive function and externalizing behavior problems from 36 to 90 months of age in the Family Life Project (N = 1,115), a study of child development in the context of rural poverty. While controlling for stability in the constructs, semistructured observations of parenting prospectively predicted performance on a battery of executive function tasks and primary caregivers' reports of externalizing behavior. Furthermore, the association between early parenting and later externalizing behavior was longitudinally mediated by executive function, providing support for a process model in which sensitive parenting promotes children's self-regulation, which in turn reduces children's externalizing behavior. © 2015 The Authors. Child Development © 2015 Society for Research in Child Development, Inc.

Developmental cascades: Externalizing, internalizing, and academic competence from middle childhood to early adolescence

PubMed Central

Moilanen, Kristin L.; Shaw, Daniel S.; Maxwell, Kari L.

2011-01-01

The current study was initiated to increase understanding of developmental cascades in childhood in a sample of at-risk boys (N = 291; 52% White). Mothers, teachers, and boys reported on boys’ externalizing problems, internalizing difficulties, and academic competence. Consistent with hypotheses regarding school-related transitions, high levels of externalizing problems were associated with both low levels of academic competence and high levels of internalizing problems during the early school-age period, and with elevations in internalizing problems during the transition to adolescence. Low levels of academic competence were associated with high levels of internalizing problems in middle childhood, and with high levels of externalizing problems during the transition from elementary school to middle school. Shared risk factors played a minimal role in these developmental cascades. Results suggest that there are cascading effects of externalizing problems and academic competence in childhood and early adolescence, and that some cascading effects are more likely to occur during periods of school-related transitions. Implications of developmental cascade effects for research and intervention are discussed. PMID:20576184

Shock/vortex interaction and vortex-breakdown modes

NASA Technical Reports Server (NTRS)

Kandil, Osama A.; Kandil, H. A.; Liu, C. H.

1992-01-01

Computational simulation and study of shock/vortex interaction and vortex-breakdown modes are considered for bound (internal) and unbound (external) flow domains. The problem is formulated using the unsteady, compressible, full Navier-Stokes (NS) equations which are solved using an implicit, flux-difference splitting, finite-volume scheme. For the bound flow domain, a supersonic swirling flow is considered in a configured circular duct and the problem is solved for quasi-axisymmetric and three-dimensional flows. For the unbound domain, a supersonic swirling flow issued from a nozzle into a uniform supersonic flow of lower Mach number is considered for quasi-axisymmetric and three-dimensional flows. The results show several modes of breakdown; e.g., no-breakdown, transient single-bubble breakdown, transient multi-bubble breakdown, periodic multi-bubble multi-frequency breakdown and helical breakdown.

Ion Acceleration by Flux Transfer Events in the Terrestrial Magnetosheath

NASA Astrophysics Data System (ADS)

Jarvinen, R.; Vainio, R.; Palmroth, M.; Juusola, L.; Hoilijoki, S.; Pfau-Kempf, Y.; Ganse, U.; Turc, L.; von Alfthan, S.

2018-02-01

We report ion acceleration by flux transfer events in the terrestrial magnetosheath in a global two-dimensional hybrid-Vlasov polar plane simulation of Earth's solar wind interaction. In the model we find that propagating flux transfer events created in magnetic reconnection at the dayside magnetopause drive fast-mode bow waves in the magnetosheath, which accelerate ions in the shocked solar wind flow. The acceleration at the bow waves is caused by a shock drift-like acceleration process under stationary solar wind and interplanetary magnetic field upstream conditions. Thus, the energization is not externally driven but results from plasma dynamics within the magnetosheath. Energetic proton populations reach the energy of 30 keV, and their velocity distributions resemble time-energy dispersive ion injections observed by the Cluster spacecraft in the magnetosheath.

Next generation maternal health: external shocks and health-system innovations

PubMed Central

Kruk, Margaret E; Kujawski, Stephanie; Moyer, Cheryl A; Adanu, Richard M; Afsana, Kaosar; Cohen, Jessica; Glassman, Amanda; Labrique, Alain; Reddy, K Srinath; Yamey, Gavin

2016-01-01

In this Series we document the substantial progress in the reduction of maternal mortality and discuss the current state of science in reducing maternal mortality. However, maternal health is also powerfully influenced by the structures and resources of societies, communities, and health systems. We discuss the shocks from outside of the field of maternal health that will influence maternal survival including economic growth in low-income and middle-income countries, urbanisation, and health crises due to disease outbreaks, extreme weather, and conflict. Policy and technological innovations, such as universal health coverage, behavioural economics, mobile health, and the data revolution, are changing health systems and ushering in new approaches to affect the health of mothers. Research and policy will need to reflect the changing maternal health landscape. PMID:27642020

A new class of galactic discrete gamma ray sources: Chaotic winds of massive stars

NASA Technical Reports Server (NTRS)

Chen, Wan; White, Richard L.

1992-01-01

We propose a new class of galactic discrete gamma-ray sources, the chaotic, high mass-loss-rate winds from luminous early-type stars. Early-type stellar winds are highly unstable due to intrinsic line-driven instabilities, and so are permeated by numerous strong shocks. These shocks can accelerate a small fraction of thermal electrons and ions to relativistic energies via the first-order Fermi mechanism. A power-law-like photon spectrum extending from keV to above 10 MeV energies is produced by inverse Compton scattering of the extremely abundant stellar UV photons by the relativistic electrons. In addition, a typical pi(sup 0)-decay gamma-ray spectrum is generated by proton-ion interactions in the densest part of the winds.

Early psychosocial interventions after disasters, terrorism and other shocking events: is there a gap between norms and practice in Europe?

PubMed Central

Te Brake, Hans

2013-01-01

Background Internationally, several initiatives exist to describe standards for post-disaster psychosocial care. Objective This study explored the level of consensus of experts within Europe on a set of recommendations on early psychosocial intervention after shocking events (Dutch guidelines), and to what degree these standards are implemented into mental health care practice. Methods Two hundred and six (mental) health care professionals filled out a questionnaire to assess the extent to which they consider the guidelines’ scope and recommendations relevant and part of the regular practice in their own country. Forty-five European experts from 24 EU countries discussed the guidelines at an international seminar. Results The data suggest overall agreement on the standards although many of the recommendations appear not (yet) to be embedded in everyday practice. Conclusions Although large consensus exists on standards for early psychosocial care, a chasm between norms and practice appears to exist throughout the EU, stressing the general need for investments in guideline development and implementation. PMID:23393613

Spanking and Children’s Externalizing Behavior Across the First Decade of Life: Evidence for Transactional Processes

PubMed Central

MacKenzie, Michael J.; Nicklas, Eric; Brooks-Gunn, Jeanne; Waldfogel, Jane

2016-01-01

Despite a growing literature associating physical discipline with later child aggression, spanking remains a typical experience for American children. The directionality of the associations between aggression and spanking and their continuity over time has received less attention. This study examined the transactional associations between spanking and externalizing behavior across the first decade of life, examining not only how spanking relates to externalizing behavior leading up to the important transition to adolescence, but whether higher levels of externalizing lead to more spanking over time as well. We use data from the Fragile families and child well-being (FFCW) study to examine maternal spanking and children’s behavior at ages 1, 3, 5, and 9 (N=1,874; 48 % girls). The FFCW is a longitudinal birth cohort study of children born between 1998 and 2000 in 20 medium to large US cities. A little over a quarter of this sample was spanked at age 1, and about half at age 3, 5, and 9. Estimates from a cross-lagged path model provided evidence of developmental continuity in both spanking and externalizing behavior, but results also highlighted important reciprocal processes taking hold early, with spanking influencing later externalizing behavior, which, in turn, predicted subsequent spanking. These bidirectional effects held across race/ethnicity and child’s gender. The findings highlight the lasting effects of early spanking, both in influencing early child’s behavior, and in affecting subsequent child’s externalizing and parental spanking in a reciprocal manner. These amplifying transactional processes underscore the importance of early intervention before patterns may cascade across domains in the transition to adolescence. PMID:24664147

Deconstructing the externalizing spectrum: Growth patterns of overt aggression, covert aggression, oppositional behavior, impulsivity/inattention, and emotion dysregulation between school entry and early adolescence

PubMed Central

Olson, Sheryl L.; Sameroff, Arnold J.; Lansford, Jennifer E.; Sexton, Holly; Davis-Kean, Pamela; Bates, John E.; Pettit, Gregory S.; Dodge, Kenneth A.

2013-01-01

The purpose of this study was to determine whether five subcomponents of children's externalizing behavior showed distinctive patterns of long-term growth and predictive correlates. We examined growth in teachers' ratings of overt aggression, covert aggression, oppositional defiance, impulsivity/inattention, and emotion dysregulation across three developmental periods spanning kindergarten through Grade 8 (ages 5–13 years). We also determined whether three salient background characteristics, family socioeconomic status, child ethnicity, and child gender, differentially predicted growth in discrete categories of child externalizing symptoms across development. Participants were 543 kindergarten-age children (52% male, 81% European American, 17% African American) whose problem behaviors were rated by teachers each successive year of development through Grade 8. Latent growth curve analyses were performed for each component scale, contrasting with overall externalizing, in a piecewise fashion encompassing three developmental periods: kindergarten–Grade 2, Grades 3–5, and Grades 6–8. We found that most subconstructs of externalizing behavior increased significantly across the early school age period relative to middle childhood and early adolescence. However, overt aggression did not show early positive growth, and emotion dysregulation significantly increased across middle childhood. Advantages of using subscales were most clear in relation to illustrating different growth functions between the discrete developmental periods. Moreover, growth in some discrete subcomponents was differentially associated with variations in family socioeconomic status and ethnicity. Our findings strongly affirmed the necessity of adopting a developmental approach to the analysis of growth in children's externalizing behavior and provided unique data concerning similarities and differences in growth between subconstructs of child and adolescent externalizing behavior. PMID:23880394

Relative contributions of external forcing factors to circulation and hydrographic properties in a micro-tidal bay

NASA Astrophysics Data System (ADS)

Yoon, Seokjin; Kasai, Akihide

2017-11-01

The dominant external forcing factors influencing estuarine circulation differ among coastal environments. A three-dimensional regional circulation model was developed to estimate external influence indices and relative contributions of external forcing factors such as external oceanic forcing, surface heat flux, wind stress, and river discharge to circulation and hydrographic properties in Tango Bay, Japan. Model results show that in Tango Bay, where the Tsushima Warm Current passes offshore of the bay, under conditions of strong seasonal winds and river discharge, the water temperature and salinity are strongly influenced by surface heat flux and river discharge in the surface layer, respectively, while in the middle and bottom layers both are mainly controlled by open boundary conditions. The estuarine circulation is comparably influenced by all external forcing factors, the strong current, surface heat flux, wind stress, and river discharge. However, the influence degree of each forcing factor varies with temporal variations in external forcing factors as: the influence of open boundary conditions is higher in spring and early summer when the stronger current passes offshore of the bay, that of surface heat flux reflects the absolute value of surface heat flux, that of wind stress is higher in late fall and winter due to strong seasonal winds, and that of river discharge is higher in early spring due to snow-melting and summer and early fall due to flood events.

Human Capital Development before Age Five. NBER Working Paper No. 15827

ERIC Educational Resources Information Center

Almond, Douglas; Currie, Janet

2010-01-01

This chapter seeks to set out what Economists have learned about the effects of early childhood influences on later life outcomes, and about ameliorating the effects of negative influences. We begin with a brief overview of the theory which illustrates that evidence of a causal relationship between a shock in early childhood and a future outcome…