A comparison of colour, shape, and flash induced illusory line motion.

PubMed

Hamm, Jeff P

2017-04-01

When a bar suddenly appears between two boxes, the bar will appear to shoot away from the box that matches it in colour or in shape-a phenomenon referred to as attribute priming of illusory line motion (ILM; colour ILM and shape ILM, respectively). If the two boxes are identical, ILM will still occur away from a box if it changes luminance shortly before the presentation of the bar ( flash ILM). This flash condition has been suggested to produce the illusory motion due to the formation of an attentional gradient surrounding the flashed location. However, colour ILM and shape ILM cannot be explained by an attentional gradient as there is no way for attention to select the matching box prior to the presentation of the bar. These findings challenge the attentional gradient explanation for ILM, but only if it is assumed that ILM arises for the same underlying reason. Two experiments are presented that address the question of whether or not flash ILM is the same as colour ILM or shape ILM. The results suggest that while colour ILM and shape ILM reflect a common illusion, flash ILM arises for a different reason. Therefore, the attentional gradient explanation for flash ILM is not refuted by the occurrence of colour ILM or shape ILM, which may reflect transformational apparent motion (TAM).

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

PubMed

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

2017-11-01

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

Dynamics of droplet motion under electrowetting actuation.

PubMed

Annapragada, S Ravi; Dash, Susmita; Garimella, Suresh V; Murthy, Jayathi Y

2011-07-05

The static shape of droplets under electrowetting actuation is well understood. The steady-state shape of the droplet is obtained on the basis of the balance of surface tension and electrowetting forces, and the change in the apparent contact angle is well characterized by the Young-Lippmann equation. However, the transient droplet shape behavior when a voltage is suddenly applied across a droplet has received less attention. Additional dynamic frictional forces are at play during this transient process. We present a model to predict this transient behavior of the droplet shape under electrowetting actuation. The droplet shape is modeled using the volume of fluid method. The electrowetting and dynamic frictional forces are included as an effective dynamic contact angle through a force balance at the contact line. The model is used to predict the transient behavior of water droplets on smooth hydrophobic surfaces under electrowetting actuation. The predictions of the transient behavior of droplet shape and contact radius are in excellent agreement with our experimental measurements. The internal fluid motion is explained, and the droplet motion is shown to initiate from the contact line. An approximate mathematical model is also developed to understand the physics of the droplet motion and to describe the overall droplet motion and the contact line velocities. © 2011 American Chemical Society

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

ERIC Educational Resources Information Center

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

2007-01-01

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

A micromechanical model of rate and state friction: 2. Effect of shear and normal stress changes

NASA Astrophysics Data System (ADS)

Molinari, A.; Perfettini, H.

2017-04-01

In this paper we analyze the influence of shear and normal stress changes on frictional properties. This problem is fundamental as, for instance, sudden stress changes are naturally induced on active faults by nearby earthquakes. As any stress changes can be seen as resulting from a succession of infinitesimal stress steps, the role of sudden stress changes is crucial to our understanding of fault dynamics. Laboratory experiments carried out by Linker and Dieterich (1992) and Nagata et al. (2012), considering steps in normal and shear stress, respectively, show an instantaneous response of the state variable (a proxy for the evolution of contact surface in our model) to a sudden stress change. We interpret this response as being due to an (instantaneous) elastic response of the plastic and elastic contacts. We assume that the anelastic response of the plastic contacts is frozen during sudden stress changes. The contacts, which were driven by plasticity before the stress change, are elastically accommodated during the sudden variation of the load. On the contrary, when the loading is slowly varying, elastic deformation of plastic contacts can be neglected. Our model is able to explain the evolution law for the state variable reported by Linker and Dieterich (1992).

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

Lu, Dingjie; Xie, Yi Min; Huang, Xiaodong

Analytical studies on the size effects of a simply-shaped beam fixed at both ends have successfully explained the sudden changes of effective Young's modulus as its diameter decreases below 100 nm. Yet they are invalid for complex nanostructures ubiquitously existing in nature. In accordance with a generalized Young-Laplace equation, one of the representative size effects is transferred to non-uniformly distributed pressure against an external surface due to the imbalance of inward and outward loads. Because the magnitude of pressure depends on the principal curvatures, iterative steps have to be adopted to gradually stabilize the structure in finite element analysis. Computational resultsmore » are in good agreement with both experiment data and theoretical prediction. Furthermore, the investigation on strengthened and softened Young's modulus for two complex nanostructures demonstrates that the proposed computational method provides a general and effective approach to analyze the size effects for nanostructures in arbitrary shape.« less

Relationships between sudden weather changes in summer and mortality in the Czech Republic, 1986-2005

NASA Astrophysics Data System (ADS)

Plavcová, Eva; Kyselý, Jan

2010-09-01

The study examines the relationship between sudden changes in weather conditions in summer, represented by (1) sudden air temperature changes, (2) sudden atmospheric pressure changes, and (3) passages of strong atmospheric fronts; and variations in daily mortality in the population of the Czech Republic. The events are selected from data covering 1986-2005 and compared with the database of daily excess all-cause mortality for the whole population and persons aged 70 years and above. Relative deviations of mortality, i.e., ratios of the excess mortality to the expected number of deaths, were averaged over the selected events for days D-2 (2 days before a change) up to D+7 (7 days after), and their statistical significance was tested by means of the Monte Carlo method. We find that the periods around weather changes are associated with pronounced patterns in mortality: a significant increase in mortality is found after large temperature increases and on days of large pressure drops; a decrease in mortality (partly due to a harvesting effect) occurs after large temperature drops, pressure increases, and passages of strong cold fronts. The relationship to variations in excess mortality is better expressed for sudden air temperature/pressure changes than for passages of atmospheric fronts. The mortality effects are usually more pronounced in the age group 70 years and above. The impacts associated with large negative changes of pressure are statistically independent of the effects of temperature; the corresponding dummy variable is found to be a significant predictor in the ARIMA model for relative deviations of mortality. This suggests that sudden weather changes should be tested also in time series models for predicting excess mortality as they may enhance their performance.

Monitoring plant response to environmental stimuli by ultrasonic sensing of the leaves.

PubMed

Fariñas, Maria Dolores; Sancho Knapik, Domingo; Peguero Pina, Jose Javier; Gil Pelegrin, Eustaquio; Gómez Álvarez-Arenas, Tomás E

2014-09-01

Described here is the application of a technique based on the excitation, sensing and spectral analysis of thickness resonances of plant leaves using air-coupled and wide-band ultrasound pulses (150-900 kHz) to monitor variations in leaf properties caused by plant responses to different environmental stimuli, such as a sudden variation in light intensity (from 2000 to 150 μmol m(-2) s(-1)), sudden watering after a drought period, and along the diurnal cycle (3-5 days, with continuous variation in light intensity from 150 to 2000 μmol m(-2) s(-1) and change in temperature of about 5°C). Four different widely available species, both monocots and dicots and evergreen and deciduous, with different leaf features (shape, size, thickness, flatness, vascular structure), were selected to test the technique. After a sudden decrease in light intensity, and depending on the species, there was a relative increase in the thickness resonant frequency from 8% to 12% over a 25- to 50-min period. After sudden watering, the relative increase in the resonant frequency varied from 5% to 30% and the period from 10 to 400 min. Finally, along the diurnal cycle, the measured relative variation is between 4% and 10%. The technique revealed differences in both the amplitude of the frequency oscillations and the kinetics of the leaf response for different species and also within the same species, but for specimens grown under different conditions that present different cell structures at the tissue level. The technique can be equally applied to the leaves of any species that present thickness resonances. Copyright © 2014 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

Hot water in the Long Valley Caldera—The benefits and hazards of this large natural resource

USGS Publications Warehouse

Evans, William C.; Hurwitz, Shaul; Bergfeld, Deborah; Howle, James F.

2018-03-26

The volcanic processes that have shaped the Long Valley Caldera in eastern California have also created an abundant supply of natural hot water. This natural resource provides benefits to many users, including power generation at the Casa Diablo Geothermal Plant, warm water for a state fish hatchery, and beautiful scenic areas such as Hot Creek gorge for visitors. However, some features can be dangerous because of sudden and unpredictable changes in the location and flow rate of boiling water. The U.S. Geological Survey monitors several aspects of the hydrothermal system in the Long Valley Caldera including temperature, flow rate, and water chemistry.

Interactions of forest disturbance-recovery dynamics with a changing climate

NASA Astrophysics Data System (ADS)

Anderson-Teixeira, K. J.; Miller, A. D.; Tepley, A. J.; Bennett, A. C.; Wang, M.

2015-12-01

As the climate changes, altered disturbance-recovery dynamics in forests worldwide are likely to result in significant biogeochemical and biophysical feedbacks to the climate system. Climate shapes forest disturbance events including tree mortality and fire, with consequent climate feedbacks. For instance, in forests globally, drought increases tree mortality rates, having a stronger impact on larger trees and resulting in greater feedbacks to climate change than would occur if drought sensitivities were equal across tree size classes. Forest regeneration and associated biogeochemical and biophysical feedbacks are also shaped by climate: across the tropics the rate of biomass accumulation is faster in everwet than in seasonally dry climates, and in the Klamath region (N California / S Oregon), post-fire vegetation dynamics and microclimate are shaped by aridity. Forest recovery dynamics will be affected by elevated CO2 and climate change; for instance, models predict that forest regeneration rate, successional dynamics, and climate feedbacks will all be altered under elevated CO2. In combination, climatic impacts on disturbance and recovery can result in dramatic shifts in forest cover on the landscape level. For instance, in fire-prone forested landscapes, forest cover decreases with increasing frequency of high-severity fire and decreasing forest recovery rate, both of which could be altered by climate change, producing rapid loss of forest on the landscape level. Such effects may be amplified by the existence of alternative stable states, which can cause systems to experience non-reversible changes in cover type. Critical transitions in landscape-level forest cover would have significant biogeochemical and biophysical feedbacks. Thus, altered disturbance-recovery dynamics under a changing climate may have sudden and dramatic impacts on forest-climate interactions.

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

NASA Technical Reports Server (NTRS)

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

1987-01-01

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

Binary asteroid orbit evolution due to primary shape deformation

NASA Astrophysics Data System (ADS)

Hirabayashi, Masatoshi; Jacobson, Seth A.; Davis, Alex

2017-10-01

About a sixth of all small asteroid systems are binary [Margot et al., Science, 2002]. Many binary asteroids consist of an elongated synchronous secondary body orbiting a fast-rotating spheroidal primary body with ridges on its equator. The primary in such systems has experienced a long-term spin-up due to the YORP effect [Vokrouhlick'y et al., Asteroid IV, 2015]. This spin-up process can make the primary reach its spin barrier inducing shape deformation processes that ease the structural condition for failure inside the primary [e.g., Holsapple, Icarus, 2010]. Earlier works have shown that structural heterogeneities in the primary such as the shape and density distribution induce asymmetric deformation [Sánchez and Scheeres, Icarus, 2016]. Here, we investigate how asymmetric shape deformation in the primary affects the mutual motion of a binary system. We use a dynamics model for an irregularly shaped binary system that accounts for possible deformation of the primary [Hirabayashi et al., LPSC, 2017]. In this model, we consider asymmetric deformation that occurs based on structural failure in the primary and thus it modifies the location of the center of mass of the system. Using 1999 KW4 as an example, we study a hypothetical case in which the primary is initially identical to the current shape [Ostro et al., Science, 2006] with an aspect ratio (AR) of 0.83 and then suddenly changes its shape to an AR of 0.76. The results show that the asymmetric deformation process and the shift of the center of mass excite the eccentricity of the mutual orbit. Considering that the original mutual orbit has an eccentricity of 0.0004, after the primary shape change the eccentricity reaches values up to 0.15. Also, since the gravity field is modified after deformation, the secondary’s spin is desynchronized from the mutual orbit. Since synchronicity is a requirement for the binary YORP (BYORP) effect, which modifies the semi-major axis of binary asteroids, a primary shape change temporarily pauses the BYORP effect, in effect lengthening the effective BYORP timescale.

Cosmic Influence on the Sun-Earth Environment

PubMed Central

Mukherjee, Saumitra

2008-01-01

SOHO satellite data reveals geophysical changes before sudden changes in the Earth's Sun-Earth environment. The influence of extragalactic changes on the Sun as well as the Sun-Earth environment seems to be both periodic and episodic. The periodic changes in terms of solar maxima and minima occur every 11 years, whereas the episodic changes can happen at any time. Episodic changes can be monitored by cosmic ray detectors as a sudden increase or decrease of activity. During these solar and cosmic anomaly periods the environment of the Earth is affected. The Star-Sun-Earth connection has the potential to influence the thermosphere, atmosphere, ionosphere and lithosphere. Initial correlation of the cosmic and Sun-Earth connection has shown the possibility of predicting earthquakes, sudden changes in atmospheric temperatures and erratic rainfall/snowfall patterns. PMID:27873955

Performance through Deformation and Instability

NASA Astrophysics Data System (ADS)

Bertoldi, Katia

2015-03-01

Materials capable of undergoing large deformations like elastomers and gels are ubiquitous in daily life and nature. An exciting field of engineering is emerging that uses these compliant materials to design active devices, such as actuators, adaptive optical systems and self-regulating fluidics. Compliant structures may significantly change their architecture in response to diverse stimuli. When excessive deformation is applied, they may eventually become unstable. Traditionally, mechanical instabilities have been viewed as an inconvenience, with research focusing on how to avoid them. Here, I will demonstrate that these instabilities can be exploited to design materials with novel, switchable functionalities. The abrupt changes introduced into the architecture of soft materials by instabilities will be used to change their shape in a sudden, but controlled manner. Possible and exciting applications include materials with unusual properties such negative Poisson's ratio, phononic crystals with tunable low-frequency acoustic band gaps and reversible encapsulation systems.

Serous retinal detachment accompanied by MEWDS in a myopic patient with dome-shaped macula.

PubMed

Shin, Min Kyu; Byon, Ik Soo; Park, Sung Who; Lee, Ji Eun

2014-01-01

Macular serous retinal detachment (MSRD) is a rare complication in highly myopic patients with an inferior staphyloma, tilted disc, or dome-shaped macula. Multiple evanescent white dot syndrome (MEWDS) presents with sudden visual loss and multiple yellowish dots that resolve spontaneously within several weeks. The authors report the development and spontaneous resolution of subretinal fluid accompanied by MEWDS in a myopic patient with a dome-shaped macula. Dysfunction of the retinal pigment epithelium due to MEWDS likely induced temporary MSRD in this patient. Copyright 2014, SLACK Incorporated.

Following The Trail: Factors Underlying the Sudden Expansion of the Egyptian Mongoose (Herpestes ichneumon) in Portugal

PubMed Central

Barros, Tânia; Carvalho, João; Pereira, Maria João Ramos; Ferreira, Joaquim P.; Fonseca, Carlos

2015-01-01

Species range-limits are influenced by a combination of several factors. In our study we aimed to unveil the drivers underlying the expansion of the Egyptian mongoose in Portugal, a carnivore that was confined to southern Portugal and largely increased its range during the last three decades. We evaluated the expansion of the species in three periods (1980-1990, 1990-2000 and 2000-2010), by projecting the presence/absence data of the species in each temporal range and proposed four hypotheses to explain this sudden expansion associated to changes in the barrier effects of human infrastructure and topographic features, and in the availability of suitable areas due to climate change or land use. An exploratory analysis was made using Spearman rank correlation, followed by a hierarchical partitioning analysis to select uncorrelated potential explanatory variables associated with the different hypotheses. We then ran Generalized Linear Models (GLM) for every period for each hypothesis and for every combination of hypotheses. Our main findings suggest that dynamic transitions of land-use coupled with temperature and rainfall variations over the decades are the main drivers promoting the mongoose expansion. The geographic barriers and the human infrastructures functioned as barriers for mongoose expansion and have shaped its distribution. The expansion of the Egyptian mongoose across the Portuguese territory was due to a variety of factors. Our results suggest a rapid shift in species range in response to land-use and climate changes, underlining the close link between species ranges and a changing environment. PMID:26266939

Following the trail: factors underlying the sudden expansion of the Egyptian mongoose (Herpestes ichneumon) in Portugal.

PubMed

Barros, Tânia; Carvalho, João; Pereira, Maria João Ramos; Ferreira, Joaquim P; Fonseca, Carlos

2015-01-01

Species range-limits are influenced by a combination of several factors. In our study we aimed to unveil the drivers underlying the expansion of the Egyptian mongoose in Portugal, a carnivore that was confined to southern Portugal and largely increased its range during the last three decades. We evaluated the expansion of the species in three periods (1980-1990, 1990-2000 and 2000-2010), by projecting the presence/absence data of the species in each temporal range and proposed four hypotheses to explain this sudden expansion associated to changes in the barrier effects of human infrastructure and topographic features, and in the availability of suitable areas due to climate change or land use. An exploratory analysis was made using Spearman rank correlation, followed by a hierarchical partitioning analysis to select uncorrelated potential explanatory variables associated with the different hypotheses. We then ran Generalized Linear Models (GLM) for every period for each hypothesis and for every combination of hypotheses. Our main findings suggest that dynamic transitions of land-use coupled with temperature and rainfall variations over the decades are the main drivers promoting the mongoose expansion. The geographic barriers and the human infrastructures functioned as barriers for mongoose expansion and have shaped its distribution. The expansion of the Egyptian mongoose across the Portuguese territory was due to a variety of factors. Our results suggest a rapid shift in species range in response to land-use and climate changes, underlining the close link between species ranges and a changing environment.

Structural imaging biomarkers of sudden unexpected death in epilepsy

PubMed Central

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

2015-01-01

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

Cosmic Rays Variation Before Changes in Sun-Earth Environment

NASA Astrophysics Data System (ADS)

Mukherjee, S.

2011-12-01

Influence of cosmic rays variations on the Sun-Earth Environment has been observed before the changes in the atmospheric temperature, outbreak of influenza, cyclone, earthquake and tsunami. It has been recorded by Sun Observatory Heleospheric Observatory (SOHO) satellite data. Before the earthquake and tsunami the planetary indices (Kp) and Electron flux (E-flux) shows sudden changes followed by the atmospheric perturbations including very high temperature rise to sudden fall resulting snowfall in high altitude and rainfall in tropical areas. The active fault zones shows sudden faulting after the sudden drop in cosmic ray intensity and rise in Kp and E-flux. Besides the geo-environment the extraterrestrial influence on outbreak of H1N1 influenza has also been recorded based on the Mexico Cosmic ray data and its correlation with SOHO records. Distant stars have the potential to influence the heliophysical parameters by showering cosmic rays.

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

PubMed

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

2018-01-01

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

Quantum Change Point

NASA Astrophysics Data System (ADS)

Sentís, Gael; Bagan, Emilio; Calsamiglia, John; Chiribella, Giulio; Muñoz-Tapia, Ramon

2016-10-01

Sudden changes are ubiquitous in nature. Identifying them is crucial for a number of applications in biology, medicine, and social sciences. Here we take the problem of detecting sudden changes to the quantum domain. We consider a source that emits quantum particles in a default state, until a point where a mutation occurs that causes the source to switch to another state. The problem is then to find out where the change occurred. We determine the maximum probability of correctly identifying the change point, allowing for collective measurements on the whole sequence of particles emitted by the source. Then, we devise online strategies where the particles are measured individually and an answer is provided as soon as a new particle is received. We show that these online strategies substantially underperform the optimal quantum measurement, indicating that quantum sudden changes, although happening locally, are better detected globally.

The experiences of male sudden cardiac arrest survivors and their partners: a gender analysis.

PubMed

Uren, Alan; Galdas, Paul

2015-02-01

To explore how masculinities shape the experiences of men and their partners after survival from out-of-hospital cardiac arrest. Survivors of out-of-hospital cardiac arrest report depression, dependence on others for daily functioning, decreased participation in society and significant decreases in quality of life. There is growing evidence that masculine gender identities play a central role in the recovery experiences of men and their families following other major cardiac events. However, to date, there has been no examination of how masculinities shape men's experiences of recovery following out-of-hospital cardiac arrest. Interview study guided by an interpretive description approach. Data were subjected to thematic analysis. A purposive sample of seven male sudden cardiac arrest survivors and 6 female partners was recruited in 2010 from a secondary care centre in British Columbia, Canada. Three themes were prominent in the experiences of the participants: (1) Support and self-reliance; (2) Dealing with emotional (in) vulnerability; and (3) No longer a 'He-man'. Masculinities played a role in men's experiences of recovery and adaptation following out-of-hospital cardiac arrest. Hegemonic masculinity partly explained men's experiences, notably their reluctance to seek professional support and reactions to changes in lifestyle. However, the study also suggests that the popular stereotype of men being 'strong and silent' in the face of ill-health may only be a part of a more complex story. Nurses would benefit from taking into consideration the potential influence of male gender identities on men's recovery postcardiac arrest. © 2014 John Wiley & Sons Ltd.

Effects of sudden air pressure changes on hospital admissions for cardiovascular diseases in Prague, 1994-2009

NASA Astrophysics Data System (ADS)

Plavcová, Eva; Kyselý, Jan

2014-08-01

Sudden weather changes have long been thought to be associated with negative impacts on human health, but relatively few studies have attempted to quantify these relationships. We use large 6-h changes in atmospheric pressure as a proxy for sudden weather changes and evaluate their association with hospital admissions for cardiovascular diseases (CVD). Winter and summer seasons and positive and negative pressure changes are analysed separately, using data for the city of Prague (population 1.2 million) over a 16-year period (1994-2009). We found that sudden pressure drops in winter are associated with significant rise in hospital admissions. Increased CVD morbidity was observed neither for pressure drops in summer nor pressure increases in any season. Analysis of synoptic weather maps shows that large pressure drops in winter are associated with strong zonal flow and rapidly moving low-pressure systems with centres over northern Europe and atmospheric fronts affecting western and central Europe. Analysis of links between passages of strong atmospheric fronts and hospital admissions, however, shows that the links disappear if weather changes are characterised by frontal passages. Sudden pressure drops in winter are associated also with significant excess CVD mortality. As climate models project strengthening of zonal circulation in winter and increased frequency of windstorms, the negative effects of such weather phenomena and their possible changes in a warmer climate of the twenty-first century need to be better understood, particularly as their importance in inducing excess morbidity and mortality in winter may increase compared to cold spells.

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

ERIC Educational Resources Information Center

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

2005-01-01

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

The boundary of the N=90 shape phase transition: 148Ce

NASA Astrophysics Data System (ADS)

Koseoglou, P.; Werner, V.; Pietralla, N.; Ilieva, S.; Thürauf, M.; Bernards, C.; Blanc, A.; Bruce, A. M.; Cakirli, R. B.; Cooper, N.; Fraile, L. M.; de France, G.; Jentschel, M.; Jolie, J.; Koester, U.; Korten, W.; Kröll, T.; Lalkovski, S.; Mach, H.; Mărginean, N.; Mutti, P.; Patel, Z.; Paziy, V.; Podolyák, Z.; Regan, P. H.; Régis, J.-M.; Roberts, O. J.; Saed-Samii, N.; Simpson, G. S.; Soldner, T.; Ur, C. A.; Urban, W.; Wilmsen, D.; Wilson, E.

2018-05-01

The even-even N=90 isotones with Z=60-66 are known to undergo a first order phase transition. Such a phase transition in atomic nuclei is characterized by a sudden change of the shape of the nucleus due to changes in the location of the potential minimum. In these proceedings we report a measurement of the B4/2 ratio of 148Ce, which will probe the location of the low-Z boundary of the N=90 phase transitional region. The measured B4/2 value is compared to the prediction from the X(5) symmetry within the interacting boson model at the critical point between the geometrical limits of vibrators and rigid/axial rotors. The EXILL&FATIMA campaign took place at the high-flux reactor of the Institut Laue Langevin, Grenoble, were 235U and 241Pu fission fragments were measured by a hybrid spectrometer consisting of high-resolution HPGe and fast LaBr3(Ce)-scintillator detectors. The fast LaBr3(Ce) detectors in combination with the generalized centroid difference method allowed lifetime measurements in the picosecond region. Furthermore, this kind of analysis can serve as preparation for the FATIMA experiments at FAIR.

Analysis of transient thermal stress in heat-generating plates and hollow cylinders caused by sudden environmental temperature changes

NASA Technical Reports Server (NTRS)

Rosenberg, G. S.; Schoeberle, D. F.; Valentin, R. A.

1969-01-01

Analysis and solution are presented for transient thermal stresses in a free heat-generating flat plate and a free, hollow-generating cylinder as a result of sudden environmental changes. The technique used and graphical results obtained are of interest to the heat transfer industry.

Closing the gap: connecting sudden representational change to the subjective Aha! experience in insightful problem solving.

PubMed

Danek, Amory H; Williams, Joshua; Wiley, Jennifer

2018-01-18

Two hallmarks of insightful problem solving are thought to be suddenness in the emergence of solution due to changes in problem representation, and the subjective Aha! Although a number of studies have explored the Aha! experience, few studies have attempted to measure representational change. Following the lead of Durso et al. (Psychol Sci 5(2):94-97, 1994) and Cushen and Wiley (Conscious Cognit 21(3):1166-1175, 2012), in this study, participants made importance-to-solution ratings throughout their solution attempts as a way to assess representational change. Participants viewed a set of magic trick videos with the task of finding out how each trick worked, and rated six action verbs for each trick (including one that implied the correct solution) multiple times during solution. They were also asked to indicate the extent to which they experienced an Aha! moment. Patterns of ratings that showed a sudden change towards a correct solution led to stronger Aha! experiences than patterns that showed a more incremental change towards a correct solution, or a change towards incorrect solutions. The results show a connection between sudden changes in problem representations (leading to correct solutions) and the subjective appraisal of solutions as an Aha! This offers the first empirical support for a close relationship between two theoretical constructs that have traditionally been assumed to be related to insightful problem solving.

Coupled fluid and solid evolution in analogue volcanic vents

NASA Astrophysics Data System (ADS)

Solovitz, Stephen A.; Ogden, Darcy E.; Kim, Dave (Dae-Wook); Kim, Sang Young

2014-07-01

Volcanic eruptions emit rock particulates and gases at high speed and pressure, which change the shape of the surrounding rock. Simplified analytical solutions, field studies, and numerical models suggest that this process plays an important role in the behavior and hazards associated with explosive volcanic eruptions. Here we present results from a newly developed laboratory-scale apparatus designed to study this coupled process. The experiments used compressed air jets expanding into the laboratory through fabricated rock analogue material, which evolves through time during the experiment. The compressed air was injected at approximately 2.5 times atmospheric pressure. We fabricated rock analogues from sand and steel powder samples with a three-dimensional printing process. We studied the fluid development using phase-locked particle image velocimetry, while simultaneously observing the solid development via a video camera. We found that the fluid response was much more rapid than that of the solid, permitting a quasi-steady approximation. In most cases, the solid vent flared out rapidly, increasing its diameter by 20 to 100%. After the initial expansion, the vent and flow field achieved a near-steady condition for a long duration. The new expanded vent shapes permitted lower vent exit pressures and larger jet radii. In one experiment, after an initial vent shape development and establishment of steady flow behavior, rock failure occurred a second time, resulting in a new exit diameter and new steady state. This second failure was not precipitated by changes in the nozzle flow condition, and it radically changed the downstream flow dynamics. This experiment suggests that the brittle nature of volcanic host rock enables sudden vent expansion in the middle of an eruption without requiring a change in the conduit flow.

Sudden gains in exposure therapy for obsessive-compulsive disorder.

PubMed

Collins, Lindsey M; Coles, Meredith E

2017-06-01

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

[Babies with cranial deformity].

PubMed

Feijen, Michelle M W; Claessens, Edith A W M Habets; Dovens, Anke J Leenders; Vles, Johannes S; van der Hulst, Rene R W J

2009-01-01

Plagiocephaly was diagnosed in a baby aged 4 months and brachycephaly in a baby aged 5 months. Positional or deformational plagio- or brachycephaly is characterized by changes in shape and symmetry of the cranial vault. Treatment options are conservative and may include physiotherapy and helmet therapy. During the last two decades the incidence of positional plagiocephaly has increased in the Netherlands. This increase is due to the recommendation that babies be laid on their backs in order to reduce the risk of sudden infant death syndrome. We suggest the following: in cases of positional preference of the infant, referral to a physiotherapist is indicated. In cases of unacceptable deformity of the cranium at the age 5 months, moulding helmet therapy is a possible treatment option.

Inflight Assay of Red Blood Cell Deformability

NASA Technical Reports Server (NTRS)

Ingram, M.; Paglia, D. E.; Eckstein, E. C.; Frazer, R. E.

1985-01-01

Studies on Soviet and American astronauts have demonstrated that red blood cell production is altered in response to low gravity (g) environment. This is associated with changes in individual red cells including increased mean cell volume and altered membrane deformability. During long orbital missions, there is a tendency for the red cell mass deficit to be at least partly corrected although the cell shape anomalies are not. Data currently available suggest that the observed decrease in red cell mass is the result of sudden suppression of erythropoieses and that the recovery trend observed during long missions reflects re-establishment of erythropoietic homeostasis at a "set point" for the red cell mass that is slightly below the normal level at 1 g.

Dynamic interneuron-principal cell interplay leads to a specific pattern of in vitro ictogenesis.

PubMed

Lévesque, Maxime; Chen, Li-Yuan; Hamidi, Shabnam; Avoli, Massimo

2018-07-01

Ictal discharges induced by 4-aminopyridine in the in vitro rodent entorhinal cortex present with either low-voltage fast or sudden onset patterns. The role of interneurons in initiating low-voltage fast onset ictal discharges is well established but the processes leading to sudden onset ictal discharges remain unclear. We analysed here the participation of interneurons (n = 75) and principal cells (n = 13) in the sudden onset pattern by employing in vitro tetrode wire recordings in the entorhinal cortex of brain slices from Sprague-Dawley rats. Ictal discharges emerged from a background of frequently occurring interictal spikes that were associated to a specific interneuron/principal cell interplay. High rates of interneuron firing occurred 12 ms before interictal spike onset while principal cells fired later during low interneuron firing. In contrast, the onset of sudden ictal discharges was characterized by increased firing from principal cells 627 ms before ictal onset whereas interneurons increased their firing rates 161 ms before ictal onset. Our data show that sudden onset ictogenesis is associated with frequently occurring interictal spikes resting on the interplay between interneurons and principal cells while ictal discharges stem from enhanced principal cell firing leading to increased interneuron activity. These findings indicate that specific patterns of interactions between interneurons and principal cells shape interictal and ictal discharges with sudden onset in the rodent entorhinal cortex. We propose that specific neuronal interactions lead to the generation of distinct onset patterns in focal epileptic disorders. Copyright © 2018 Elsevier Inc. All rights reserved.

Metabolite profiling to predict resistance to Phytophthora ramorum in natural populations of coast live oak

Treesearch

A. Conrad; B. Mcpherson; D. Wood; S. Opiyo; S. Mori; P. Bonello

2013-01-01

Sudden oak death, caused by the invasive oomycete pathogen Phytophthora ramorum, continues to shape the dynamics of coastal populations of oak (Quercus spp.) and tanoak (Notholithocarpus densiflorus (Hook. & Arn.) Manos, Cannon & S.H. Oh) in California and tanoak in southwestern Oregon. Over the...

Sudden Event Recognition: A Survey

PubMed Central

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

2013-01-01

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

Localized sudden changes in the geomagnetic secular variation.

USGS Publications Warehouse

Alldredge, L.R.

1987-01-01

There is much debate as to whether there was a worldwide geomagnetic jerk in 1969 or 1970. It is agreed that there was an unusual sharp change in the secular variation in the east component, Y, in Europe at that time. This note points out how a localized sudden change in the secular variation pattern of one component in Europe can occur without having any large worldwide effects in any of the components. The accompanying changes in the spherical harmonic coefficients for such a localized change are also discussed. -after Author

Mechanism of the 2016 giant twin glacier collapse in Aru range, Tibet

NASA Astrophysics Data System (ADS)

Gilbert, A.; Leinss, S.; Kääb, A.; Kargel, J. S.; Yao, T.; Gascoin, S.; Leonard, G. J.; Berthier, E.; Karki, A.

2017-12-01

In northwestern Tibet (34.0°N, 82.2°E) near lake Aru Co, the entire ablation area of two unnamed glaciers (Aru-1 and Aru-2) suddenly collapsed on 17 July 2016 and 21 September 2016 and transformed into a mass flow that ran out over a distance of over several km, killing nine people. These two events are unique and defined a new kind of glacier behavior almost never observed before. The only similar event currently documented is the 2002 Kolka Glacier mass flow (Caucasus Mountains). Using remote sensing observations and 3D thermo-mechanical modeling of the two glaciers, we reconstructed glacier thermal regime, thickness, basal friction evolution and ice damaging state prior to the collapse. We show that frictional change leading to the collapse occurred in the temperate areas of a polythermal structure that is likely close to equilibrium with the local climate. The collapses were driven by a fast and sustained friction change in the temperate part of the glacier for which the glacier shape was not able to adjust due to the cold-based parts providing strong resisting force to sliding. This led to high stresses on the cold margins of the glacier where ice deformation became partially accommodated by fracturing until the final collapse occurred. Field investigations reveal that those two glaciers are flowing on a soft and fine-grained sedimentary lithology prone to landslide activity in the presence of water. This suggests that fast friction change in the temperate part of the glacier is linked to shear strength weakening in the sediment and till underneath the glacier in response to increasing water pore pressure at the glacier base. The Kolka Glacier mass flow also occurred on pyroclastic rocks well known for their landslide activities. This suggests that the three gigantic glacier collapses documented to date involve specific bedrock lithology where failure is driven by shear strength weakening in the glacier till in a landslide-like process. Contrary to a classical surges, these collapses occurred when the glacier shape is not able to adjust to the apparent friction change and maintains high driving stresses either due to polythermal structure (Aru) or due to sudden mass loading from external sources (rock/ice avalanches in the Kolka case).

No Flares from Gamma-Ray Burst Afterglow Blast Waves Encountering Sudden Circumburst Density Change

NASA Astrophysics Data System (ADS)

Gat, Ilana; van Eerten, Hendrik; MacFadyen, Andrew

2013-08-01

Afterglows of gamma-ray bursts are observed to produce light curves with the flux following power-law evolution in time. However, recent observations reveal bright flares at times on the order of minutes to days. One proposed explanation for these flares is the interaction of a relativistic blast wave with a circumburst density transition. In this paper, we model this type of interaction computationally in one and two dimensions, using a relativistic hydrodynamics code with adaptive mesh refinement called RAM, and analytically in one dimension. We simulate a blast wave traveling in a stellar wind environment that encounters a sudden change in density, followed by a homogeneous medium, and compute the observed radiation using a synchrotron model. We show that flares are not observable for an encounter with a sudden density increase, such as a wind termination shock, nor for an encounter with a sudden density decrease. Furthermore, by extending our analysis to two dimensions, we are able to resolve the spreading, collimation, and edge effects of the blast wave as it encounters the change in circumburst medium. In all cases considered in this paper, we find that a flare will not be observed for any of the density changes studied.

Sudden behavior change in a cat.

PubMed

Gelberg, H B

2013-11-01

A 5-year-old, spayed female, domestic short-haired cat had a 10-day history of sudden behavioral changes followed by seizures. Blood parameters were in the reference ranges, and radiographs failed to detect a mass lesion in the brain. Euthanasia was followed by rabies testing, which was negative. Gross lesions were absent. Histologic changes were present only in the brain and consisted of foci of hippocampal pyramidal cell loss, mild gliosis, pallor of the associated neuropil, and neovascularization.

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

PubMed Central

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

2012-01-01

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

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

PubMed

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

2012-03-16

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

Snap-buckling in asymmetrically constrained elastic strips

NASA Astrophysics Data System (ADS)

Sano, Tomohiko G.; Wada, Hirofumi

2018-01-01

When a flat elastic strip is compressed along its axis, it is bent in one of two possible directions via spontaneous symmetry breaking, forming a cylindrical arc. This is a phenomenon well known as Euler buckling. When this cylindrical section is pushed in the other direction, the bending direction can suddenly reverse. This instability is called "snap-through buckling" and is one of the elementary shape transitions in a prestressed thin structure. Combining experiments and theory, we study snap-buckling of an elastic strip with one end hinged and the other end clamped. These asymmetric boundary constraints break the intrinsic symmetry of the strip, generating mechanical behaviors, including largely hysteretic but reproducible force responses and switchlike discontinuous shape changes. We establish the set of exact analytical solutions to fully explain all our major experimental and numerical findings. Asymmetric boundary conditions arise naturally in diverse situations when a thin object is in contact with a solid surface at one end. The introduction of asymmetry through boundary conditions yields new insight into complex and programmable functionalities in material and industrial design.

Motivation to Pursue Genetic Testing in Individuals with a Personal or Family History of Cardiac Events or Sudden Cardiac Death

PubMed Central

Erskine, Kathleen E.; Hidayatallah, Nadia Z.; Walsh, Christine A.; McDonald, Thomas V.; Cohen, Lilian; Marion, Robert W.; Dolan, Siobhan M.

2014-01-01

Genetic testing is becoming increasingly available for cardiac channelopathies, such as long QT syndrome and Brugada syndrome, which can lead to sudden cardiac death. Test results can be used to shape an individual’s medical management and to identify at-risk family members. In our qualitative study, all participants had a personal or family history of a diagnosed cardiac arrhythmia syndrome or sudden cardiac death. Open-ended interviews were conducted individually and in focus groups. Interviews were audio recorded, transcribed verbatim, and analyzed using a qualitative grounded-theory approach. Of 50 participants, 37 described their motivations for pursuing genetic testing for long QT syndrome or another cardiac channelopathy. Participants’ motivations included: to find an explanation for a family member’s sudden death, to relieve uncertainty regarding a diagnosis, to guide future medical management, to allay concern about children or other family members, and to comply with recommendations of physicians or family members. Perceived reasons not to pursue genetic testing included denial, fear, and lack of information. The genetic counseling and informed consent process can be enhanced by understanding and addressing an individual’s internal and external motivations either for or against pursuing genetic testing. PMID:24664857

Decomposition and N cycling changes in redwood forests caused by sudden oak death

Treesearch

Richard C. Cobb; David M. Rizzo

2012-01-01

Phytophthora ramorum is an emergent pathogen in redwood forests which causes the disease sudden oak death. Although the disease does not kill coast redwood (Sequoia sempervirens), extensive and rapid mortality of tanoak (Notholithocarpus densiflorus) has removed this...

NO FLARES FROM GAMMA-RAY BURST AFTERGLOW BLAST WAVES ENCOUNTERING SUDDEN CIRCUMBURST DENSITY CHANGE

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

Gat, Ilana; Van Eerten, Hendrik; MacFadyen, Andrew

2013-08-10

Afterglows of gamma-ray bursts are observed to produce light curves with the flux following power-law evolution in time. However, recent observations reveal bright flares at times on the order of minutes to days. One proposed explanation for these flares is the interaction of a relativistic blast wave with a circumburst density transition. In this paper, we model this type of interaction computationally in one and two dimensions, using a relativistic hydrodynamics code with adaptive mesh refinement called RAM, and analytically in one dimension. We simulate a blast wave traveling in a stellar wind environment that encounters a sudden change inmore » density, followed by a homogeneous medium, and compute the observed radiation using a synchrotron model. We show that flares are not observable for an encounter with a sudden density increase, such as a wind termination shock, nor for an encounter with a sudden density decrease. Furthermore, by extending our analysis to two dimensions, we are able to resolve the spreading, collimation, and edge effects of the blast wave as it encounters the change in circumburst medium. In all cases considered in this paper, we find that a flare will not be observed for any of the density changes studied.« less

Effect of platinum substitution on the structural and magnetic properties of Ni2MnGa ferromagnetic shape memory alloy

NASA Astrophysics Data System (ADS)

Singh, Sanjay; D'Souza, S. W.; Nayak, J.; Caron, L.; Suard, E.; Chadov, S.; Felser, C.

2016-04-01

Ni2MnGa exhibits ideal ferromagnetic shape memory properties, however, brittleness and a low-temperature martensite transition hinder its technological applications motivating the search for novel materials showing better mechanical properties as well as higher transition temperatures. In this work, the crystal structure, phase transitions, and the magnetic properties of quaternary Ni2 -xPtxMnGa (0 ≤x ≤1 ) shape memory alloys were studied experimentally by x-ray diffraction, magnetization measurements, and neutron diffraction and compared to ab initio calculations. Compositions within 0 ≤x ≤0.25 exhibit the cubic austenite phase at room temperature. The x ≈0.3 composition exhibits a seven-layer modulated monoclinic martensite structure. Within 0.4 ≤x ≤1 , the system stabilizes in the nonmodulated tetragonal structure. The martensite transition has very narrow thermal hysteresis 0 ≤x ≤0.3 , which is a typical characteristic of a shape memory alloy. By increasing x , the temperature of the martensite transition increases, while that of the magnetic transition decreases. The x =1 composition (NiPtMnGa) in the martensite phase undergoes a para-to-ferrimagnetic transition. The saturation magnetization exhibits a nontrivial behavior with increasing up to x ≈0.25 , above which, it suddenly decreases. Powder neutron diffraction reveals the presence of antisite disorder, with about 17% of the original Ga sites being occupied by Mn. Computations suggest that the antisite disorder triggers an antiferromagnetic coupling between two Mn atoms in different crystallographic positions, resulting into a sudden drop of the saturation magnetization for higher x .

Evolution of IPv6 Internet topology with unusual sudden changes

NASA Astrophysics Data System (ADS)

Ai, Jun; Zhao, Hai; Kathleen, M. Carley; Su, Zhan; Li, Hui

2013-07-01

The evolution of Internet topology is not always smooth but sometimes with unusual sudden changes. Consequently, identifying patterns of unusual topology evolution is critical for Internet topology modeling and simulation. We analyze IPv6 Internet topology evolution in IP-level graph to demonstrate how it changes in uncommon ways to restructure the Internet. After evaluating the changes of average degree, average path length, and some other metrics over time, we find that in the case of a large-scale growing the Internet becomes more robust; whereas in a top—bottom connection enhancement the Internet maintains its efficiency with links largely decreased.

Sudden change of geometric quantum discord in finite temperature reservoirs

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

Hu, Ming-Liang, E-mail: mingliang0301@163.com; Sun, Jian

2015-03-15

We investigate sudden change (SC) behaviors of the distance-based measures of geometric quantum discords (GQDs) for two non-interacting qubits subject to the two-sided and the one-sided thermal reservoirs. We found that the GQDs defined by different distances exhibit different SCs, and thus the SCs are the combined result of the chosen discord measure and the property of a state. We also found that the thermal reservoir may generate states having different orderings related to different GQDs. These inherent differences of the GQDs reveal that they are incompatible in characterizing quantum correlations both quantitatively and qualitatively. - Highlights: • Comparable studymore » of different distance-based geometric quantum discords. • Evolution of the geometric quantum discords in finite temperature reservoirs. • Different geometric quantum discords exhibit distinct sudden changes. • Nonunique states ordering imposed by different geometric quantum discords.« less

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

PubMed Central

Whitman, Isaac R.; Feldman, Harold I.

2012-01-01

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

A Supersonic/Hypersonic Aerodynamic Investigation of the Saturn 1B/Apollo Upper Stage

NASA Technical Reports Server (NTRS)

1966-01-01

The static stability and axial force characteristics of an upper stage Saturn 1B/Apollo model were investigated in a series of wind tunnel tests at Mach numbers between 1. 93 and 8. 05. This report presents and analyzes the results of these small-scale studies. Test procedures and models are described, and consideration of boundary layer characteristics and violated modeling rules yields an assessment of the validity of the data. Four basic models provided evaluation of the basic launch vehicle characteristics, as well as the effects of two modes of mission abort and jettison of the launch escape system. The launch configuration experienced sudden, strong changes in stability derivatives and axial force coefficients near Mach 5. No similar changes were observed on the other configurations. Effects of Reynolds number, Mach number and boundary layer trips were obtained for each shape. The faired curves are believed to be valid for full-scale flight of the Saturn 1B/Apollo upper stage.

Evidence for a Sudden Magnetic Field Reconfiguration in Soft Gamma Repeater 1900+14

NASA Technical Reports Server (NTRS)

Woods, Peter M.; Kouveliotou, Chryssa; Gogus, Ersin; Finger, Mark H.; Swank, Jean; Smith, Don A.; Hurley, Kevin; Thompson, Christopher

2001-01-01

We report the detection of large flux changes in the persistent X-ray flux of soft gamma repeater (SGR) 1900 + 14 during its burst active episode in 1998. Most notably, we find a factor of approx. 700 increase in the nonburst X-ray flux following the August 27 flare, which decayed in time as a power law. Our measurements indicate that the pulse fraction remains constant throughout this decay. This suggests a global flux enhancement as a consequence of the August 27 flare rather than localized heating. While the persistent flux has since recovered to the preoutburst level, the pulse profile has not. The pulse shape changed to a near sinusoidal profile within the tail of the August 27 flare (in gamma-rays), and this effect has persisted for more than 1.5 years (in X-rays). The results presented here suggest that the magnetic field of the neutron star in SGR 1900 + 14 was significantly altered (perhaps globally) during the giant flare of August 27.

Possible pseudogout in two dogs.

PubMed

Forsyth, S F; Thompson, K G; Donald, J J

2007-03-01

Pseudogout, the acute form of calcium pyrophosphate deposition disease, is a common condition in elderly human beings and is characterised by the sudden onset of intense joint pain and synovitis. It is rarely identified in animals but was diagnosed in two dogs that presented with acute lameness and pyrexia. Cytology of the synovial fluid showed a mildly elevated cell count with both non-degenerate neutrophils and mononuclear cells present. Many of the mononuclear cells and occasional neutrophils contained square or rhomboid-shaped crystals that were variable in shape and size and weakly birefringent on examination under polarised light. Clinical signs resolved following treatment with prednisolone.

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

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

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

2015-04-15

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

Wavelet principal component analysis of fetal movement counting data preceding hospital examinations due to decreased fetal movement: a prospective cohort study

PubMed Central

2013-01-01

Background Fetal movement (FM) counting is a simple and widely used method of assessing fetal well-being. However, little is known about what women perceive as decreased fetal movement (DFM) and how maternally perceived DFM is reflected in FM charts. Methods We analyzed FM counting data from 148 DFM events occurring in 137 pregnancies. The women counted FM daily from pregnancy week 24 until birth using a modified count-to-ten procedure. Common temporal patterns for the two weeks preceding hospital examination due to DFM were extracted from the FM charts using wavelet principal component analysis; a statistical methodology particularly developed for modeling temporal data with sudden changes, i.e. spikes that are frequently found in FM data. The association of the extracted temporal patterns with fetal complications was assessed by including the individuals’ scores on the wavelet principal components as explanatory variables in multivariable logistic regression analyses for two outcome measures: (i) complications identified during DFM-related consultations (n = 148) and (ii) fetal compromise at the time of consultation (including relevant information about birth outcome and placental pathology). The latter outcome variable was restricted to the DFM events occurring within 21 days before birth (n = 76). Results Analyzing the 148 and 76 DFM events, the first three main temporal FM counting patterns explained 87.2% and 87.4%, respectively, of all temporal variation in the FM charts. These three temporal patterns represented overall counting times, sudden spikes around the time of DFM events, and an inverted U-shaped pattern, explaining 75.3%, 8.6%, and 3.3% and 72.5%, 9.6%, and 5.3% of variation in the total cohort and subsample, respectively. Neither of the temporal patterns was significantly associated with the two outcome measures. Conclusions Acknowledging that sudden, large changes in fetal activity may be underreported in FM charts, our study showed that the temporal FM counting patterns in the two weeks preceding DFM-related consultation contributed little to identify clinically important changes in perceived FM. It thus provides insufficient information for giving detailed advice to women on when to contact health care providers. The importance of qualitative features of maternally perceived DFM should be further explored. PMID:24007565

Wavelet principal component analysis of fetal movement counting data preceding hospital examinations due to decreased fetal movement: a prospective cohort study.

PubMed

Winje, Brita Askeland; Røislien, Jo; Saastad, Eli; Eide, Jorid; Riley, Christopher Finne; Stray-Pedersen, Babill; Frøen, J Frederik

2013-09-05

Fetal movement (FM) counting is a simple and widely used method of assessing fetal well-being. However, little is known about what women perceive as decreased fetal movement (DFM) and how maternally perceived DFM is reflected in FM charts. We analyzed FM counting data from 148 DFM events occurring in 137 pregnancies. The women counted FM daily from pregnancy week 24 until birth using a modified count-to-ten procedure. Common temporal patterns for the two weeks preceding hospital examination due to DFM were extracted from the FM charts using wavelet principal component analysis; a statistical methodology particularly developed for modeling temporal data with sudden changes, i.e. spikes that are frequently found in FM data. The association of the extracted temporal patterns with fetal complications was assessed by including the individuals' scores on the wavelet principal components as explanatory variables in multivariable logistic regression analyses for two outcome measures: (i) complications identified during DFM-related consultations (n = 148) and (ii) fetal compromise at the time of consultation (including relevant information about birth outcome and placental pathology). The latter outcome variable was restricted to the DFM events occurring within 21 days before birth (n = 76). Analyzing the 148 and 76 DFM events, the first three main temporal FM counting patterns explained 87.2% and 87.4%, respectively, of all temporal variation in the FM charts. These three temporal patterns represented overall counting times, sudden spikes around the time of DFM events, and an inverted U-shaped pattern, explaining 75.3%, 8.6%, and 3.3% and 72.5%, 9.6%, and 5.3% of variation in the total cohort and subsample, respectively. Neither of the temporal patterns was significantly associated with the two outcome measures. Acknowledging that sudden, large changes in fetal activity may be underreported in FM charts, our study showed that the temporal FM counting patterns in the two weeks preceding DFM-related consultation contributed little to identify clinically important changes in perceived FM. It thus provides insufficient information for giving detailed advice to women on when to contact health care providers. The importance of qualitative features of maternally perceived DFM should be further explored.

Drug and Alcohol Abuse in Booming and Depressed Communities. Services Research Report.

ERIC Educational Resources Information Center

Milkman, Raymond H.; And Others

Boom towns appear to have greater problems of substance abuse associated with economic change indicators than communities suffering from sudden economic declines. A study of 14 communities experiencing sudden economic dislocations revealed a lack of consistent trends, although some depressed communities experienced increases in alcohol abuse. In…

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

PubMed

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

2006-09-01

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

Effects of pushing height on trunk posture and trunk muscle activity when a cart suddenly starts or stops moving.

PubMed

Lee, Yun-Ju; Hoozemans, Marco J M; van Dieën, Jaap H

2012-01-01

Unexpected sudden (un)loading of the trunk may induce inadequate responses of trunk muscles and uncontrolled trunk motion. These unexpected perturbations may occur in pushing tasks, when the cart suddenly starts moving (unloading) or is blocked by an obstacle (loading). In pushing, handle height affects the user's working posture, which may influence trunk muscle activity and trunk movement in response to the perturbation. Eleven healthy male subjects pushed a 200 kg cart with handles at shoulder and hip height in a start condition (sudden release of brakes) and a stop condition (bumping into an obstacle). Before the perturbation, the baseline of the trunk inclination, internal moment and trunk extensor muscle activity were significantly higher when pushing at hip height than at shoulder height. After the perturbation, the changes in trunk inclination and internal moment were significantly larger when pushing at shoulder height than at hip height in both conditions. The opposite directions of changes in trunk inclination and internal moment suggest that the unexpected perturbations caused uncontrolled trunk motion. Pushing at shoulder height may impose a high risk of low-back injury due to the low trunk stiffness and large involuntary trunk motion occurring after carts suddenly move or stop.

Causes of sudden death in Addis Ababa, Ethiopia.

PubMed

Schneider, J; Bezabih, K

2001-10-01

The aim of this study was to evaluate the causes of death in individuals who died suddenly in Addis Ababa, Ethiopia. The selection of the cases was based on police reports, which contained a description of sudden unexpected or instantaneous death. The study was performed on necropsies of the Medico legal Department of Menelik II Hospital, in Addis Ababa during the years 1998 and 1999. According to the pathological features of the heart, we classified 92 dead bodies in 3 groups: Group A: Hearts showing adequate morphological changes to explain sudden death (n = 63). Group B: Hearts showing some structural changes, but inadequate to explain sudden death (n = 20). Group C: Normal hearts (n = 7). In two bodies the general autopsy revealed an extra cardiac cause of death. The single most relevant cause of death in group A was coronary artery disease (44 cases) followed by excessive myocardial hypertrophy due to post-rheumatic valvular lesions (7 cases). While the high prevalence of rheumatic heart disease in Ethiopia is well known, the proportion of cases who died due to coronary heart disease is surprising. Though during the last years some African authors assumed that coronary atherosclerosis is on the increase in developing countries the percentage is higher than expected and higher than in other countries where similar studies exist.

Combustion rate limits of hydrogen plus hydrocarbon fuel: Air diffusion flames from an opposed jet burner technique

NASA Technical Reports Server (NTRS)

Pellett, Gerald L.; Guerra, Rosemary; Wilson, Lloyd G.; Reeves, Ronald N.; Northam, G. Burton

1987-01-01

Combustion of H2/hydrocarbon (HC) fuel mixtures may be considered in certain volume-limited supersonic airbreathing propulsion applications. Effects of HC addition to H2 were evaluated, using a recent argon-bathed, coaxial, tubular opposed jet burner (OJB) technique to measure the extinction limits of counterflow diffusion flames. The OJB flames were formed by a laminar jet of (N2 and/or HC)-diluted H2 mixture opposed by a similar jet of air at ambient conditions. The OJB data, derived from respective binary mixtures of H2 and methane, ethylene, or propane HCs, were used to characterize BLOWOFF and RESTORE. BLOWOFF is a sudden breaking of the dish-shaped OJB flame to a stable torus or ring shape, and RESTORE marks sudden restoration of the central flame by radial inward flame propagation. BLOWOFF is a measure of kinetically-limited flame reactivity/speed under highly stretched, but relatively ideal impingement flow conditions. RESTORE measures inward radial flame propagation rate, which is sensitive to ignition processes in the cool central core. It is concluded that relatively small molar amounts of added HC greatly reduce the reactivity characteristics of counterflow hydrogen-air diffusion flames, for ambient initial conditions.

Disruptions in adaptation of sudden-onset and slow-onset risks: insights from a local case in the Andes of Peru for global policies

NASA Astrophysics Data System (ADS)

Huggel, Christian; Carey, Mark; Frey, Holger; Jurt, Christine; Mechler, Reinhard; Motschmann, Alina; Vicuña, Luis

2017-04-01

Climatic changes involve emergence and changes of both sudden-onset and slow-onset risks. In the field of disaster risk reduction a solid range of strategies and measures has been developed to address sudden-onset risks such as floods, mass movements or storms. Comparably less experience is available for management of slow-onset risks. While, for instance, drought prone regions do have important knowledge how to cope with such conditions in other regions where climatic changes have induced new challenges and risks there is limited experience about how to adapt to slow-onset processes and risks. Examples are impacts of sea level rise in coastal regions or glacier shrinkage in mountain regions. The lack of understanding of how to address impacts from slow-onset processes has recently also been highlighted by the Executive Committee of the Warsaw International Mechanism on Loss and Damage (WIM) acting under the United Nations Framework Convention on Climate Change (UNFCCC). In climate change science, practice and policy it is often assumed that risk management and climate change adaptation would see a seamless continuum when addressing both sudden-onset and slow-onset risks. Here we draw on recent experiences from the Andes of Peru showing that management of, and adaptation to combined sudden-onset and slow-onset impacts of climate change may involve serious social disruption. Carhuaz, a city in the Cordillera Blanca of Peru with a number of local communities pertaining to it, is affected by multiple effects of climate change and glacier shrinkage. After a flood event from glacier lake 513 a flood early warning system has been developed and installed. Multiple use and demand of glacier melt water makes water resource management a challenge and conflicts arise especially during the dry season when water is scarce. The drought at the end of 2016 over much of the tropical Andes has resulted in a situation where local communities started to vigorously and violently turn against the management of sudden-onset risks, more specifically against the technical components of the flood early warning system, because they believed that rainfall measuring and data transmitting devices keep the rains away. The background of this extraordinary local action is complex and rooted, among other, in cultural and historical experiences, mistrust in political and scientific institutions and local power relations. This local case, however, is highly instructive for global climate change policy. It shows that locally perceived priorities in terms of risks can be in great contrast to scientific knowledge and policies with profound implications for adaptation to sudden-onset and slow-onset risks. In fact, there may be a need to re-think current adaptation strategies which is also highly relevant in the context of current discussions on loss and damage related to negative effects of climate change. Furthermore, while the case certainly underlines the need to closely engage with local communities it also indicates where the limits of adaptation may be hit.

Random bursts determine dynamics of active filaments.

PubMed

Weber, Christoph A; Suzuki, Ryo; Schaller, Volker; Aranson, Igor S; Bausch, Andreas R; Frey, Erwin

2015-08-25

Constituents of living or synthetic active matter have access to a local energy supply that serves to keep the system out of thermal equilibrium. The statistical properties of such fluctuating active systems differ from those of their equilibrium counterparts. Using the actin filament gliding assay as a model, we studied how nonthermal distributions emerge in active matter. We found that the basic mechanism involves the interplay between local and random injection of energy, acting as an analog of a thermal heat bath, and nonequilibrium energy dissipation processes associated with sudden jump-like changes in the system's dynamic variables. We show here how such a mechanism leads to a nonthermal distribution of filament curvatures with a non-Gaussian shape. The experimental curvature statistics and filament relaxation dynamics are reproduced quantitatively by stochastic computer simulations and a simple kinetic model.

Friction fluctuations of gold nanoparticles in the superlubric regime

NASA Astrophysics Data System (ADS)

Dietzel, Dirk; de Wijn, Astrid S.; Vorholzer, Matthias; Schirmeisen, Andre

2018-04-01

Superlubricity, or alternatively termed structural (super)lubrictiy, is a concept where ultra-low friction is expected at the interface between sliding surfaces if these surfaces are incommensurate and thus unable to interlock. In this work, we now report on sudden, reversible, friction changes that have been observed during AFM-based nanomanipulation experiments of gold nanoparticles sliding on highly oriented pyrolythic graphite. These effects can be explained by rotations of the gold nanoparticles within the concept of structural superlubricity, where the occurrence of ultra-low friction can depend extremely sensitively on the relative orientation between the slider and the substrate. From our theoretical simulations it will become apparent how even miniscule magnitudes of rotation are compatible to the observed effects and how size and shape of the particles can influence the dependence between friction and relative orientation.

Neural Network Back-Propagation Algorithm for Sensing Hypergols

NASA Technical Reports Server (NTRS)

Perotti, Jose; Lewis, Mark; Medelius, Pedro; Bastin, Gary

2013-01-01

Fast, continuous detection of a wide range of hazardous substances simultaneously is needed to achieve improved safety for personnel working with hypergolic fuels and oxidizers, as well as other hazardous substances, with a requirement for such detection systems to warn personnel immediately upon the sudden advent of hazardous conditions, with a high probability of detection and a low false alarm rate. The primary purpose of this software is to read the voltage outputs from voltage dividers containing carbon nano - tube sensors as a variable resistance leg, and to recognize quickly when a leak has occurred through recognizing that a generalized pattern change in resistivity of a carbon nanotube sensor has occurred upon exposure to dangerous substances, and, further, to identify quickly just what substance is present through detailed pattern recognition of the shape of the response provided by the carbon nanotube sensor.

Random bursts determine dynamics of active filaments

PubMed Central

Weber, Christoph A.; Suzuki, Ryo; Schaller, Volker; Aranson, Igor S.; Bausch, Andreas R.; Frey, Erwin

2015-01-01

Constituents of living or synthetic active matter have access to a local energy supply that serves to keep the system out of thermal equilibrium. The statistical properties of such fluctuating active systems differ from those of their equilibrium counterparts. Using the actin filament gliding assay as a model, we studied how nonthermal distributions emerge in active matter. We found that the basic mechanism involves the interplay between local and random injection of energy, acting as an analog of a thermal heat bath, and nonequilibrium energy dissipation processes associated with sudden jump-like changes in the system’s dynamic variables. We show here how such a mechanism leads to a nonthermal distribution of filament curvatures with a non-Gaussian shape. The experimental curvature statistics and filament relaxation dynamics are reproduced quantitatively by stochastic computer simulations and a simple kinetic model. PMID:26261319

How exaptations facilitated photosensory evolution: Seeing the light by accident.

PubMed

Gavelis, Gregory S; Keeling, Patrick J; Leander, Brian S

2017-07-01

Exaptations are adaptations that have undergone a major change in function. By recruiting genes from sources originally unrelated to vision, exaptation has allowed for sudden and critical photosensory innovations, such as lenses, photopigments, and photoreceptors. Here we review new or neglected findings, with an emphasis on unicellular eukaryotes (protists), to illustrate how exaptation has shaped photoreception across the tree of life. Protist phylogeny attests to multiple origins of photoreception, as well as the extreme creativity of evolution. By appropriating genes and even entire organelles from foreign organisms via lateral gene transfer and endosymbiosis, protists have cobbled photoreceptors and eyespots from a diverse set of ingredients. While refinement through natural selection is paramount, exaptation helps illustrate how novelties arise in the first place, and is now shedding light on the origins of photoreception itself. © 2017 WILEY Periodicals, Inc.

Time-varying volatility in Malaysian stock exchange: An empirical study using multiple-volatility-shift fractionally integrated model

NASA Astrophysics Data System (ADS)

Cheong, Chin Wen

2008-02-01

This article investigated the influences of structural breaks on the fractionally integrated time-varying volatility model in the Malaysian stock markets which included the Kuala Lumpur composite index and four major sectoral indices. A fractionally integrated time-varying volatility model combined with sudden changes is developed to study the possibility of structural change in the empirical data sets. Our empirical results showed substantial reduction in fractional differencing parameters after the inclusion of structural change during the Asian financial and currency crises. Moreover, the fractionally integrated model with sudden change in volatility performed better in the estimation and specification evaluations.

OSCILLATION OF NEWLY FORMED LOOPS AFTER MAGNETIC RECONNECTION IN THE SOLAR CHROMOSPHERE

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

Yang, Shuhong; Xiang, Yongyuan, E-mail: shuhongyang@nao.cas.cn

With the high spatial and temporal resolution Hα images from the New Vacuum Solar Telescope, we focus on two groups of loops with an X-shaped configuration in the dynamic chromosphere. We find that the anti-directed loops approach each other and reconnect continually. The connectivity of the loops is changed and new loops are formed and stack together. The stacked loops are sharply bent, implying that they are greatly impacted by the magnetic tension force. When another reconnection process takes place, one new loop is formed and stacks with the previously formed ones. Meanwhile, the stacked loops retract suddenly and movemore » toward the balance position, performing an overshoot movement, which led to an oscillation with an average period of about 45 s. The oscillation of newly formed loops after magnetic reconnection in the chromosphere is observed for the first time. We suggest that the stability of the stacked loops is destroyed due to the attachment of the last new loop and then suddenly retract under the effect of magnetic tension. Because of the retraction, another lower loop is pushed outward and performs an oscillation with a period of about 25 s. The different oscillation periods may be due to their difference in three parameters, i.e., loop length, plasma density, and magnetic field strength.« less

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

NASA Astrophysics Data System (ADS)

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

2018-02-01

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

Effects of sudden air pressure changes on hospital admissions for cardiovascular diseases in Prague

NASA Astrophysics Data System (ADS)

Kysely, Jan; Plavcova, Eva

2013-04-01

Sudden weather changes have long been supposed to be associated with negative impacts on human health. However, relatively few studies attempted to quantify these relationships. In this study, we use large 6-hour changes of atmospheric sea level pressure as proxy for sudden weather changes, and evaluate their association with hospital admissions for cardiovascular diseases. Winter and summer seasons and positive and negative pressure changes are analyzed separately, using data for the city of Prague (population of 1.2 million) over 16-year period (1994-2009). We find that sudden pressure drops in winter are associated with significant increases in the number of hospital admissions. Increases in morbidity are not observed for pressure drops in summer, nor pressure increases in any season. Analysis of synoptic weather maps shows that the large pressure drops in winter are associated with strong zonal (westerly) flow and rapidly moving low pressure systems with centres over Northern Europe and atmospheric fronts affecting the area of Western and Central Europe. Several of the largest pressure decreases were associated with infamous winter storms (such as Lothar on December 25, 1999 and Kyrill on January 18, 2007). Analysis of links between passages of strong atmospheric fronts and hospital admissions shows that the links are much weaker if weather changes are characterized by frontal passages. Since climate models project strengthening of the zonal circulation in winter and increased frequency of winter storms, the negative effects of such weather phenomena and their possible changes in a warmer climate of the 21st century need to be better understood, particularly as their importance in inducing excess morbidity and mortality in winter may increase compared to cold spells.

Ionospheric traveling convection vortices observed near the polar cleft - A triggered response to sudden changes in the solar wind

NASA Technical Reports Server (NTRS)

Friis-Christensen, E.; Vennerstrom, S.; Mchenry, M. A.; Clauer, C. R.

1988-01-01

Analysis of 20-second resolution magnetometer data from an array of temporary stations operated around Sondre Stromfjord, Greenland, during the summer of 1986 shows the signatures of localized ionospheric traveling convection vortices. An example of an isolated event of this kind observed near 08 local time is presented in detail. This event consists of a twin vortex pattern of convection consistent with the presence of two field-aligned current filaments separated by about 600 km in the east-west direction. This system of currents is observed to move westward (tailward) past the array of stations at about 4 km/sec. The event is associated with relative quiet time ionospheric convection and occurs during an interval of northward IMF. It is, however, associated with a large fluctuation in both the Z and Y components of the IMF and with a large sudden decrease in the solar wind number density. The propagation of the system is inconsistent with existing models of FTE current systems, but nevertheless appears to be related to a readjustment of the magnetopause boundary to a sudden change in the solar wind dynamic pressure and/or to a change in reconnection brought about by a sudden reorientation of the IMF.

Phasic action of the tensor muscle modulates the calling song in cicadas

PubMed

Fonseca; Hennig

1996-01-01

The effect of tensor muscle contraction on sound production by the tymbal was investigated in three species of cicadas (Tettigetta josei, Tettigetta argentata and Tympanistalna gastrica). All species showed a strict time correlation between the activity of the tymbal motoneurone and the discharge of motor units in the tensor nerve during the calling song. Lesion of the tensor nerve abolished the amplitude modulation of the calling song, but this modulation was restored by electrical stimulation of the tensor nerve or by mechanically pushing the tensor sclerite. Electrical stimulation of the tensor nerve at frequencies higher than 30­40 Hz changed the sound amplitude. In Tett. josei and Tett. argentata there was a gradual increase in sound amplitude with increasing frequency of tensor nerve stimulation, while in Tymp. gastrica there was a sudden reduction in sound amplitude at stimulation frequencies higher than 30 Hz. This contrasting effect in Tymp. gastrica was due to a bistable tymbal frame. Changes in sound pulse amplitude were positively correlated with changes in the time lag measured from tymbal motoneurone stimulation to the sound pulse. The tensor muscle acted phasically because electrical stimulation of the tensor nerve during a time window (0­10 ms) before electrical stimulation of the tymbal motoneurone was most effective in eliciting amplitude modulations. In all species, the tensor muscle action visibly changed the shape of the tymbal. Despite the opposite effects of the tensor muscle on sound pulse amplitude observed between Tettigetta and Tympanistalna species, the tensor muscle of both acts by modulating the shape of the tymbal, which changes the force required for the tymbal muscle to buckle the tymbal.

Experimental Study of Sudden Solidification of Supercooled Water

ERIC Educational Resources Information Center

Bochnícek, Zdenek

2014-01-01

The two independent methods of measurement of the mass of ice created at sudden solidification of supercooled water are described. One is based on the calorimetric measurement of heat that is necessary for melting the ice and the second interprets the volume change that accompanies the water freezing. Experimental results are compared with the…

Oscillating flow and heat transfer in a channel with sudden cross section change

NASA Technical Reports Server (NTRS)

Ibrahim, Mounir; Hashim, Waqar

1993-01-01

We have computationally examined oscillating flow (zero mean) between two parallel plates with a sudden change in cross section. The flow was assumed to be laminar incompressible with the inflow velocity uniform over the channel cross section but varying sinusoidally with time. The cases studied cover wide ranges of Re(sub max) (from 187.5 to 2000), Va (from 1 to 10.66), the expansion ratio (1:2 and 1:4) and A(sub r) (2 and 4). Also, three different geometric cases were discussed: (1) asymmetric expansion/contraction; (2) symmetric expansion/contraction; and (3) symmetric blunt body. For these oscillating flow conditions, the fluid undergoes sudden expansion in one-half of the cycle and sudden contraction inthe other half. The instantaneous friction factor, for some ranges of Re(sub max) and Va, deviated substantially from the steady-state friction factor for the same flow parameters. A region has been identified below which the flow is laminar quasi-steady. A videotape showing computer simulations of the oscillating flow demonstrates the usefulness of the current analyses in providing information on the transient hydraulic phenomena.

Characteristics of the interplanetary shocks formed by a sudden increase in the velocity of the solar wind from a coronal hole

NASA Technical Reports Server (NTRS)

Bravo, S.

1995-01-01

Coronal holes are the sources of the solar wind and, according to recent YOKOH observations, may undergo rapid changes which are associated with manifestations of explosive solar activity. Rapid changes in a hole's structure will produce rapid changes in the characteristics of the wind emerging from it and, in the particular c se of a sudden increase in wind velocity, this may lead to the formation of an interplanetary shock. We discuss the characteristics of shocks formed in such a way and compare them with interplanetary observations.

Ecological evidence of intensive cultivation of oaks by California Indians: implications for the treatment of sudden oak death

Treesearch

Lee Klinger

2006-01-01

The native oaks of California are remarkable for being among the oldest and largest oak trees in the United States besides their great age and size, these trees possess various idiosyncrasies in their arrangements and shapes that appear to defy basic principles of ecology and population biology. When taken together, these and other associated patterns present an...

A new disease: pregnancy-induced sudden sensorineural hearing loss?

PubMed

Hou, Zhi-Qiang; Wang, Qiu-Ju

2011-07-01

Sudden sensorineural hearing loss (SSNHL) may occur during pregnancy, but its prevalence is very low. It is conjectured that SSNHL is closely related to the changes in the cardiovascular system, hematological system, endocrine system, and/or some other systems due to pregnancy. These changes possibly evoke disorders of cochlear circulation or cochlear fluid homeostasis leading to SSNHL. Two SSNHL cases were observed in our clinic, and their clinical features were analyzed. In one patient the SSNHL was likely to be related to the disturbance of cochlear fluid homestasis and in the other it might be induced by some disorders in cochlear circulation. Based on their distinct clinic profiles, we defined a new disease, called "pregnancy-induced sudden sensorineural hearing loss," similar to the definition of "pregnancy-induced hypertension." This study also deepened our understanding of the etiology of SSNHL.

Quantification of sudden oak death tree mortality in the Big Sur ecoregion of California

Treesearch

Douglas A. Shoemaker; Christopher B. Oneal; David M. Rizzo; Ross K. Meentemeyer

2008-01-01

Big Sur is one of the most ecologically diverse regions in California and well recognized as a biodiversity hotspot for global conservation priority. Currently the region is experiencing substantial environmental change due to the invasion of Phytophthora ramorum, the plant pathogen causing the forest disease known as sudden oak death. First...

Long-term trends in coast live oak and tanoak stands affected by Phytophthora ramorum canker (Sudden Oak Death)

Treesearch

Tedmund J. Swiecki; Elizabeth Bernhardt

2010-01-01

Permanent plots were established in 2000 to examine how tree and site factors affect risk of Phytophthora ramorum stem canker (sudden oak death [SOD]) and determine how affected stands change over time due to disease. P. ramorum canker was prevalent in the sampled coast live oak (Quercus agrifolia) or...

Genetic diversity, structure, and demographic change in tanoak, Lithocarpus densiflorus (Fagaceae), the most susceptible species to sudden oak death in California

Treesearch

A. Nettel; R. S. Dodd; Z. Afzal-Rafii

2009-01-01

Knowledge of population genetic structure of tanoak (Lithocarpus densiflorus) is of interest to pathologists seeking natural variation in resistance to sudden oak death disease, to resource managers who need indications of conservation priorities in this species now threatened by the introduced pathogen (Phytophthora ramorum),...

Declining Risk of Sudden Death in Heart Failure.

PubMed

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

2017-07-06

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

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

PubMed

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

2007-06-01

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

Long-time behavior of the momentum distribution during the sudden expansion of a spin-imbalanced Fermi gas in one dimension.

PubMed

Bolech, C J; Heidrich-Meisner, F; Langer, S; McCulloch, I P; Orso, G; Rigol, M

2012-09-14

We study the sudden expansion of spin-imbalanced ultracold lattice fermions with attractive interactions in one dimension after turning off the longitudinal confining potential. We show that the momentum distribution functions of majority and minority fermions quickly approach stationary values due to a quantum distillation mechanism that results in a spatial separation of pairs and majority fermions. As a consequence, Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) correlations are lost during the expansion. Furthermore, we argue that the shape of the stationary momentum distribution functions can be understood by relating them to the integrals of motion in this integrable quantum system. We discuss our results in the context of proposals to observe FFLO correlations, related to recent experiments by Liao et al., Nature (London) 467, 567 (2010).

Atezolizumab Injection

MedlinePlus

... headaches, increased thirst or urination, vision changes, decreased sex drive fast heartbeat, increased appetite, sudden weight loss, feeling hot, mood changes muscle weakness, numbness or tingling in ...

Seismic activity noted at Medicine Lake Highlands

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

Blum, D.

1988-12-01

The sudden rumble of earthquakes beneath Medicine Lake Highlands this fall gave geologists an early warning that one of Northern California's volcanoes may be stirring back to life. Researchers stressed that an eruption of the volcano is not expected soon. But the flurry of underground shocks in late September, combined with new evidence of a pool of molten rock beneath the big volcano, has led them to monitor Medicine Lake with new wariness. The volcano has been dormant since 1910, when it ejected a brief flurry of ash - worrying no one. A federal team plans to take measurements ofmore » Medicine Lake, testing for changes in its shape caused by underground pressures. The work is scheduled for spring because snows have made the volcano inaccessible. But the new seismic network is an effective lookout, sensitive to very small increases in activity.« less

Acoustic Emission from Organic Martensites.

PubMed

Panda, Manas K; Etter, Martin; Dinnebier, Robert E; Naumov, Panče

2017-07-03

In salient effects, still crystals of solids that switch between phases acquire a momentum and are autonomously propelled because of rapid release of elastic energy accrued during a latent structural transition induced by heat, light, or mechanical stimulation. When mechanical reconfiguration is induced by change of temperature in thermosalient crystals, bursts of detectable acoustic waves are generated prior to self-actuation. These observations provide compelling evidence that the thermosalient transitions in organic and organic-containing crystals are molecular analogues of the martensitic transitions in some metals, and metal alloys such as steel and shape-memory alloys. Within a broader context, these results reveal that, akin to metallic bonding, the intermolecular interactions in molecular solids are capable of gradual accrual and sudden release of a substantial amount of strain during anisotropic thermal expansion, followed by a rapid transformation of the crystal packing in a diffusionless, non-displacive transition. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Negative differential conductance in doped-silicon nanoscale devices with superconducting electrodes

NASA Astrophysics Data System (ADS)

Shapovalov, A.; Shaternik, V.; Suvorov, O.; Zhitlukhina, E.; Belogolovskii, M.

2018-02-01

We present a proof-of-concept nanoelectronics device with a negative differential conductance, an attractive from the applied viewpoint functionality. The device, characterized by the decreasing current with increasing voltage in a certain voltage region above a threshold bias of about several hundred millivolts, consists of two superconducting electrodes with an amorphous 10-nm-thick silicon interlayer doped by tungsten nano-inclusions. We show that small changes in the W content radically modify the shape of the trilayer current-voltage dependence and identify sudden conductance switching at a threshold voltage as an effect of Andreev fluctuators. The latter entities are two-level systems at the superconductor-doped silicon interface where a Cooper pair tunnels from a superconductor and occupies a pair of localized electronic states. We argue that in contrast to previously proposed devices, our samples permit very large-scale integration and are practically feasible.

The effects of sudden oak death on foliar moisture content and crown fire potential in tanoak

Treesearch

H. Kuljian; J.M. Varner

2010-01-01

The introduction of non-native pathogens can have profound effects on forest ecosystems resulting in loss of species, changes in species composition, and altered fuel structure. The introduction of Phytophthora ramorum, the pathogen recognized as causing Sudden Oak Death (SOD), leads to rapid decline and mortality of tanoak (Lithocarpus densiflorus) in forests of...

Fire behavioral changes as a result of sudden oak death in coastal California forests

Treesearch

Y. Vlachovic; C. Lee; H. Scanlon; J.M. Varner; R. Glebocki; B.D. Graham; D.M. Rizzo

2013-01-01

Field observations and anecdotal evidence suggest that sudden oak death (SOD), a disease caused by the pathogen Phytophthora ramorum, may alter fuel loading in affected forests. Though it is reasonable to assume that a disease resulting in leaf blight, dead branches, and tree mortality would increase forest fuels, little work has been done to...

Sudden oak death-caused changes to surface fuel loading and potential fire behavior in Douglas-fir-tanoak forests

Treesearch

Y.S. Valachovic; C.A. Lee; H. Scanlon; J.M. Varner; R. Glebocki; B.D. Graham; D.M. Rizzo

2011-01-01

We compared stand structure and fuel loading in northwestern California forests invaded by Phytophthora ramorum, the cause of sudden oak death, to assess whether the continued presence of this pathogen alters surface fuel loading and potential fire behavior in ways that may encumber future firefighting response. To attempt to account for these...

Sudden death in young athletes: HCM or ARVC?

PubMed

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

2002-01-01

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

Sudden sensorineural hearing loss: is there a relationship between routine haematological parameters and audiogram shapes?

PubMed

Salvago, Pietro; Rizzo, Serena; Bianco, Antonino; Martines, Francesco

2017-03-01

To investigate the relationship between haematological routine parameters and audiogram shapes in patients affected by sudden sensorineural hearing loss (SSNHL). A retrospective study. All patients were divided into four groups according to the audiometric curve and mean values of haematological parameters (haemoglobin, white blood cell, neutrophils and lymphocytes relative count, platelet count, haematocrit, prothrombin time, activated partial thromboplastin time, fibrinogen and neutrophil-to-lymphocite ratio) of each group were statistically compared. The prognostic role of blood profile and coagulation test was also examined. A cohort of 183 SSNHL patients without comorbidities. With a 48.78% of complete hearing recovery, individuals affected by upsloping hearing loss presented a better prognosis instead of flat (18.36%), downsloping (19.23%) and anacusis (2.45%) groups (p = 0.0001). The multivariate analysis of complete blood count values revealed lower mean percentage of lymphocytes (p = 0.041) and higher platelet levels (p = 0.015) in case of downsloping hearing loss; with the exception of fibrinogen (p = 0.041), none of the main haematological parameters studied resulted associated with poorer prognosis. Our work suggested a lack of association between haematological parameters and a defined audiometric picture in SSNHL patients; furthermore, only fibrinogen seems to influence the prognosis of this disease.

Passive unmanned sky spectroscopy for remote bird classification

NASA Astrophysics Data System (ADS)

Lundin, Patrik; Brydegaard, Mikkel; Cocola, Lorenzo; Runemark, Anna; Åkesson, Susanne; Svanberg, Sune

2011-11-01

We present a method based on passive spectroscopy with aim to remotely study flying birds. A compact spectrometer is continuously recording spectra of a small section of the sky, waiting for birds to obscure part of the field-of-view when they pass the field in flight. In such situations the total light intensity received through the telescope, looking straight up, will change very rapidly as compared to the otherwise slowly varying sky light. On passage of a bird, both the total intensity and the spectral shape of the captured light changes notably. A camera aimed in the same direction as the telescope, although with a wider field-of-view, is triggered by the sudden intensity changes in the spectrometer to record additional information, which may be used for studies of migration and orientation. Example results from a trial are presented and discussed. The study is meant to explore the information that could be gathered and extracted with the help of a spectrometer connected to a telescope. Information regarding the color, size and height of flying birds is discussed. Specifically, an application for passive distance determination utilizing the atmospheric oxygen A-band absorption at around 760 nm is discussed.

Major transitions in information technology

PubMed Central

Valverde, Sergi

2016-01-01

When looking at the history of technology, we can see that all inventions are not of equal importance. Only a few technologies have the potential to start a new branching series (specifically, by increasing diversity), have a lasting impact in human life and ultimately became turning points. Technological transitions correspond to times and places in the past when a large number of novel artefact forms or behaviours appeared together or in rapid succession. Why does that happen? Is technological change continuous and gradual or does it occur in sudden leaps and bounds? The evolution of information technology (IT) allows for a quantitative and theoretical approach to technological transitions. The value of information systems experiences sudden changes (i) when we learn how to use this technology, (ii) when we accumulate a large amount of information, and (iii) when communities of practice create and exchange free information. The coexistence between gradual improvements and discontinuous technological change is a consequence of the asymmetric relationship between complexity and hardware and software. Using a cultural evolution approach, we suggest that sudden changes in the organization of ITs depend on the high costs of maintaining and transmitting reliable information. This article is part of the themed issue ‘The major synthetic evolutionary transitions’. PMID:27431527

SUDDEN PHOTOSPHERIC MOTION AND SUNSPOT ROTATION ASSOCIATED WITH THE X2.2 FLARE ON 2011 FEBRUARY 15

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

Wang, Shuo; Liu, Chang; Deng, Na

2014-02-20

The Helioseismic and Magnetic Imager provides 45 s cadence intensity images and 720 s cadence vector magnetograms. These unprecedented high-cadence and high-resolution data give us a unique opportunity to study the change of photospheric flows and sunspot rotations associated with flares. By using the differential affine velocity estimator method and the Fourier local correlation tracking method separately, we calculate velocity and vorticity of photospheric flows in the flaring NOAA AR 11158, and investigate their temporal evolution around the X2.2 flare on 2011 February 15. It is found that the shear flow around the flaring magnetic polarity inversion line exhibits a sudden decrease,more » and both of the two main sunspots undergo a sudden change in rotational motion during the impulsive phase of the flare. These results are discussed in the context of the Lorentz-force change that was proposed by Hudson et al. and Fisher et al. This mechanism can explain the connections between the rapid and irreversible photospheric vector magnetic field change and the observed short-term motions associated with the flare. In particular, the torque provided by the horizontal Lorentz force change agrees with what is required for the measured angular acceleration.« less

[A sudden rise in INR due to combination of Tribulus terrestris, Avena sativa, and Panax ginseng (Clavis Panax)].

PubMed

Turfan, Murat; Tasal, Abdurrahman; Ergun, Fatih; Ergelen, Mehmet

2012-04-01

Warfarin sodium is an antithrombin agent used in patients with prosthetic valve and atrial fibrillation. However, there are many factors that can change the effectiveness of the drug. Today, herbal mixtures promoted through targeted print and visual media can lead to sudden activity changes in patients using warfarin. In this case report we will present two cases with a sudden rise in INR due to using combination of Tribulus terrestris, Avena sativa and Panax ginseng (Panax Clavis). Two patients who used warfarin due to a history of aortic valve replacement (case 1) and atrial fibrillation (case 2) were admitted to the hospital due very high levels of INR detected during routine follow-up. Both patients had used an herbal medicine called ''Panax'' during the last month. The patients gave no indication regarding a change in diet or the use of another agent that might interact with warfarin. In cases where active bleeding could not be determinated, we terminated the use of the drug and re-evaluated dosage of warfarin before finally discharging the patient.

Visuomotor Map Determines How Visually Guided Reaching Movements are Corrected Within and Across Trials123

PubMed Central

Hirashima, Masaya

2016-01-01

Abstract When a visually guided reaching movement is unexpectedly perturbed, it is implicitly corrected in two ways: immediately after the perturbation by feedback control (online correction) and in the next movement by adjusting feedforward motor commands (offline correction or motor adaptation). Although recent studies have revealed a close relationship between feedback and feedforward controls, the nature of this relationship is not yet fully understood. Here, we show that both implicit online and offline movement corrections utilize the same visuomotor map for feedforward movement control that transforms the spatial location of visual objects into appropriate motor commands. First, we artificially distorted the visuomotor map by applying opposite visual rotations to the cursor representing the hand position while human participants reached for two different targets. This procedure implicitly altered the visuomotor map so that changes in the movement direction to the target location were more insensitive or more sensitive. Then, we examined how such visuomotor map distortion influenced online movement correction by suddenly changing the target location. The magnitude of online movement correction was altered according to the shape of the visuomotor map. We also examined offline movement correction; the aftereffect induced by visual rotation in the previous trial was modulated according to the shape of the visuomotor map. These results highlighted the importance of the visuomotor map as a foundation for implicit motor control mechanisms and the intimate relationship between feedforward control, feedback control, and motor adaptation. PMID:27275006

Visuomotor Map Determines How Visually Guided Reaching Movements are Corrected Within and Across Trials.

PubMed

Hayashi, Takuji; Yokoi, Atsushi; Hirashima, Masaya; Nozaki, Daichi

2016-01-01

When a visually guided reaching movement is unexpectedly perturbed, it is implicitly corrected in two ways: immediately after the perturbation by feedback control (online correction) and in the next movement by adjusting feedforward motor commands (offline correction or motor adaptation). Although recent studies have revealed a close relationship between feedback and feedforward controls, the nature of this relationship is not yet fully understood. Here, we show that both implicit online and offline movement corrections utilize the same visuomotor map for feedforward movement control that transforms the spatial location of visual objects into appropriate motor commands. First, we artificially distorted the visuomotor map by applying opposite visual rotations to the cursor representing the hand position while human participants reached for two different targets. This procedure implicitly altered the visuomotor map so that changes in the movement direction to the target location were more insensitive or more sensitive. Then, we examined how such visuomotor map distortion influenced online movement correction by suddenly changing the target location. The magnitude of online movement correction was altered according to the shape of the visuomotor map. We also examined offline movement correction; the aftereffect induced by visual rotation in the previous trial was modulated according to the shape of the visuomotor map. These results highlighted the importance of the visuomotor map as a foundation for implicit motor control mechanisms and the intimate relationship between feedforward control, feedback control, and motor adaptation.

Ignored Disease or Diagnostic Dustbin? Sudden Infant Death Syndrome in the British Context

PubMed Central

Ferguson, Angus H.

2015-01-01

Sudden Infant Death Syndrome (SIDS) was defined in 1969 and incorporated into the International Classification of Diseases a decade later. To advocates of SIDS as a diagnosis, medical interest in sudden infant death was long overdue. However, the definition of SIDS lacked positive diagnostic criteria, provoking some to view it as a ‘diagnostic dustbin’ for the disposal of problematic cases where cause of death was unclear. This paper examines the development of medical interest in sudden infant death in Britain during the middle decades of the twentieth century. It highlights the importance of recognising the historicity of SIDS as a diagnosis facilitated by changes in law and medicine over the course of the nineteenth and twentieth centuries. It suggests that SIDS provides a definitive case study of the medicalisation of life and death, and a unique example of an officially recognised disease that had no symptoms, signs, pathology or patients. PMID:26217070

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

PubMed Central

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

2009-01-01

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

Recent research on the effects of alcohol policy changes.

PubMed

Room, R

1990-09-01

As the agenda of alcohol problems prevention has broadened, new traditions of research have emerged: of experimental studies at the community or the societal level, of "natural experiment" studies of the effects of sudden changes such as strikes or new legislation, and of sophisticated time-series analyses of the effects of sudden and of long-term changes. While it has been shown that control measures can influence alcohol problems rates, substantial change seems to require changes in the political status quo, often also involving popular movements. Except for taxes, raising the drinking age and drinking-driving countermeasures, the political will to restrict availability has been lacking in market-oriented industrial societies in the modern era, so that the modern experience of the effects of other control measures is based on centrally-planned or non-industrial economies.

Do sudden air temperature and pressure changes affect cardiovascular morbidity and mortality?

NASA Astrophysics Data System (ADS)

Plavcová, E.; Davídkovová, H.; Kyselý, J.

2012-04-01

Previous studies have shown that sudden changes in weather (usually represented by air temperature and/or pressure) are associated with increases in daily mortality. Little is understood about physiological mechanisms responsible for the impacts of weather changes on mortality, and whether similar patterns appear for morbidity as well. Relatively little is known also about differences in the magnitude of the mortality response in provincial regions and in cities, where the impacts may be exacerbated by air pollution effects and/or heat island. The present study examines the effects of sudden air temperature and pressure changes on morbidity (represented by hospital admissions) and mortality due to cardiovascular diseases in the population of the Czech Republic (approx. 10 million inhabitants) and separately in the city of Prague (1.2 million inhabitants). The events are selected from data covering 1994-2009 using the methodology introduced by Plavcová and Kyselý (2010), and they are compared with the datasets on hospital admissions and daily mortality (both standardized to account for long-term changes and the seasonal and weekly cycles). Relative deviations of morbidity/mortality from the baseline were averaged over the selected events for days D-2 (2 days before a change) up to D+7 (7 days after), and their statistical significance was tested by means of the Monte Carlo method. The study aims at (i) identifying those weather changes associated with increased cardiovascular morbidity/mortality, separately in summer and winter, (ii) comparing the effects of weather changes on morbidity and mortality, (iii) identifying whether urban population of Prague is more/less vulnerable in comparison to the population of the whole Czech Republic, (iv) comparing the effects for different cardiovascular diseases (ischaemic heart diseases, ICD-10 codes I20-I25; cerebrovascular diseases, I60-I69; hypertension, I10; atherosclerosis, I70) and individual population groups (by age and gender), and (v) identifying physiological mechanisms which play roles in deteriorating health conditions of vulnerable population groups. Plavcová E., Kyselý J., 2010: Relationships between sudden weather changes in summer and mortality in the Czech Republic, 1986-2005. International Journal of Biometeorology, 54, 539-551 [doi 10.1007/s00484-010-0303-7

Change in Control

NASA Astrophysics Data System (ADS)

Hoogland, John

Change is a popular word since Barack Obama so successfully used it in his campaign to become president of the US. Change almost became a synonym for “yes, we can”. Change, and things will improve. Suddenly change is sexy. We don’t seem to suffer from resistance to change anymore. People now LIKE to change?

Correlations between topography and intraflow width behavior in Martian and terrestrial lava flows

NASA Astrophysics Data System (ADS)

Peitersen, Matthew N.; Crown, David A.

2000-02-01

Local correlations between topography and width behavior within lava flows at Puu Oo, Mount Etna, Glass Mountain, Cerro Bayo, Alba Patera, Tyrrhena Patera, Elysium Mons, and Olympus Mons were investigated. For each flow, width and slope data were both referenced via downflow distance as a sequence of points; the data were then divided into collections of adjacent three-point features and two-point segments. Four discrete types of analyses were conducted: (1) Three-point analysis examined positional correlations between width and slope features, (2) two-point analysis did the same for flow segments, (3) mean slope analysis included segment slope comparisons, and (4) sudden width behavior analysis measured abruptness of width changes. The distribution of types of correlations compared to random combinations of features and segments does not suggest a significant correlation between flow widths and local underlying slopes and indicates that for these flows at least, other factors have more influence on changes in width than changes in underlying topography. Mean slopes underlying narrowing, widening, and constant flow width segments were calculated. An inverse correlation between slope and width was found only at Mount Etna, where slopes underlying narrowing segments were greater than those underlying widening in 62% of the examined flows. For the majority of flows at Mount Etna, Puu Oo, and Olympus Mons, slopes were actually greatest under constant width segments; this may imply a topographically dependent resistance to width changes. The rate of change of width was also examined. Sudden width changes are relatively common at Puu Oo, Mount Etna, Elysium Mons, and Tyrrhena Patera and relatively rare at Glass Mountain, Cerro Bayo, Olympus Mons, and Alba Patera. After correction for mapping scale, Puu Oo, Mount Etna, Olympus Mons, and Alba Patera appear to fall on the same trend; Glass Mount exhibits unusually small amounts of sudden width behavior, and Tyrrhena Patera exhibits a relatively large number of sudden width behavior occurrences.

Intramyocardial arterial narrowing in dogs with subaortic stenosis.

PubMed

Falk, T; Jönsson, L; Pedersen, H D

2004-09-01

Earlier studies have described intramyocardial arterial narrowing based on hyperplasia and hypertrophy of the vessel wall in dogs with subaortic stenosis (SAS). In theory, such changes might increase the risk of sudden death, as they seem to do in heart disease in other species. This retrospective pathological study describes and quantifies intramyocardial arterial narrowing in 44 dogs with naturally occurring SAS and in eight control dogs. The majority of the dogs with SAS died suddenly (n=27); nine had died or been euthanased with signs of heart failure and eight were euthanased without clinical signs. Dogs with SAS had significantly narrower intramyocardial arteries (P<0.001) and more myocardial fibrosis (P<0.001) than control dogs. Male dogs and those with more severe hypertrophy had more vessel narrowing (P=0.02 and P=0.02, respectively), whereas dogs with dilated hearts had slightly less pronounced arterial thickening (P=0.01). Arterial narrowing was not related to age, but fibrosis increased with age (P=0.047). Dogs that died suddenly did not have a greater number of arterial changes than other dogs with SAS. This study suggests that most dogs with SAS have intramyocardial arterial narrowing and that the risk of dying suddenly is not significantly related to the overall degree of vessel obliteration.

Modeling pedestrian crossing speed profiles considering speed change behavior for the safety assessment of signalized intersections.

PubMed

Iryo-Asano, Miho; Alhajyaseen, Wael K M

2017-11-01

Pedestrian safety is one of the most challenging issues in road networks. Understanding how pedestrians maneuver across an intersection is the key to applying countermeasures against traffic crashes. It is known that the behaviors of pedestrians at signalized crosswalks are significantly different from those in ordinary walking spaces, and they are highly influenced by signal indication, potential conflicts with vehicles, and intersection geometries. One of the most important characteristics of pedestrian behavior at crosswalks is the possible sudden speed change while crossing. Such sudden behavioral change may not be expected by conflicting vehicles, which may lead to hazardous situations. This study aims to quantitatively model the sudden speed changes of pedestrians as they cross signalized crosswalks under uncongested conditions. Pedestrian speed profiles are collected from empirical data and speed change events are extracted assuming that the speed profiles are stepwise functions. The occurrence of speed change events is described by a discrete choice model as a function of the necessary walking speed to complete crossing before the red interval ends, current speed, and the presence of turning vehicles in the conflict area. The amount of speed change before and after the event is modeled using regression analysis. A Monte Carlo simulation is applied for the entire speed profile of the pedestrians. The results show that the model can represent the pedestrian travel time distribution more accurately than the constant speed model. Copyright © 2017 Elsevier Ltd. All rights reserved.

Intermittent operation of QC-lasers for mid-IR spectroscopy with low heat dissipation: tuning characteristics and driving electronics.

PubMed

Fischer, M; Tuzson, B; Hugi, A; Brönnimann, R; Kunz, A; Blaser, S; Rochat, M; Landry, O; Müller, A; Emmenegger, L

2014-03-24

Intermittent scanning for continuous-wave quantum cascade lasers is proposed along with a custom-built laser driver optimized for such operation. This approach lowers the overall heat dissipation of the laser by dropping its drive current to zero between individual scans and holding a longer pause between scans. This allows packaging cw-QCLs in TO–3 housings with built-in collimating optics, thus reducing cost and footprint of the device. The fully integrated, largely analog, yet flexible laser driver eliminates the need for any external electronics for current modulation, lowers the demands on power supply performance, and allows shaping of the tuning current in a wide range. Optimized ramp shape selection leads to large and nearly linear frequency tuning (>1.5 cm−1). Experimental characterization of the proposed scheme with a QCL emitting at 7.7 μm gave a frequency stability of 3.2×10−5 cm−1 for the laser emission, while a temperature dependence of 2.3×10−4 cm−1/K was observed when the driver electronics was exposed to sudden temperature changes. We show that these characteristics make the driver suitable for high precision trace gas measurements by analyzing methane absorption lines in the respective spectral region.

Experimental study of the lifetime and phase transition in neutron-rich Zr 98 ,100 ,102

NASA Astrophysics Data System (ADS)

Ansari, S.; Régis, J.-M.; Jolie, J.; Saed-Samii, N.; Warr, N.; Korten, W.; Zielińska, M.; Salsac, M.-D.; Blanc, A.; Jentschel, M.; Köster, U.; Mutti, P.; Soldner, T.; Simpson, G. S.; Drouet, F.; Vancraeyenest, A.; de France, G.; Clément, E.; Stezowski, O.; Ur, C. A.; Urban, W.; Regan, P. H.; Podolyák, Zs.; Larijani, C.; Townsley, C.; Carroll, R.; Wilson, E.; Mach, H.; Fraile, L. M.; Paziy, V.; Olaizola, B.; Vedia, V.; Bruce, A. M.; Roberts, O. J.; Smith, J. F.; Scheck, M.; Kröll, T.; Hartig, A.-L.; Ignatov, A.; Ilieva, S.; Lalkovski, S.; Mǎrginean, N.; Otsuka, T.; Shimizu, N.; Togashi, T.; Tsunoda, Y.

2017-11-01

Rapid shape changes are observed for neutron-rich nuclei with A around 100. In particular, a sudden onset of ground-state deformation is observed in the Zr and Sr isotopic chains at N = 60: Low-lying states in N ≤58 nuclei are nearly spherical, while those with N ≥60 have a rotational character. Nuclear lifetimes as short as a few picoseconds can be measured using fast-timing techniques with LaBr3(Ce) scintillators, yielding a key ingredient in the systematic study of the shape evolution in this region. We used neutron-induced fission of 241Pu and 235U to study lifetimes of excited states in fission fragments in the A ˜100 region with the EXILL-FATIMA array located at the PF1B cold neutron beam line at the Institut Laue-Langevin. In particular, we applied the generalized centroid difference method to deduce lifetimes of low-lying states for the nuclei 98Zr (N = 58), 100Zr, and 102Zr (N ≥60 ). The results are discussed in the context of the presumed phase transition in the Zr chain by comparing the experimental transition strengths with the theoretical calculations using the interacting boson model and the Monte Carlo shell model.

Near-term prediction of sudden cardiac death in older hemodialysis patients using electronic health records.

PubMed

Goldstein, Benjamin A; Chang, Tara I; Mitani, Aya A; Assimes, Themistocles L; Winkelmayer, Wolfgang C

2014-01-01

Sudden cardiac death is the most common cause of death among individuals undergoing hemodialysis. The epidemiology of sudden cardiac death has been well studied, and efforts are shifting to risk assessment. This study aimed to test whether assessment of acute changes during hemodialysis that are captured in electronic health records improved risk assessment. Data were collected from all hemodialysis sessions of patients 66 years and older receiving hemodialysis from a large national dialysis provider between 2004 and 2008. The primary outcome of interest was sudden cardiac death the day of or day after a dialysis session. This study used data from 2004 to 2006 as the training set and data from 2007 to 2008 as the validation set. The machine learning algorithm, Random Forests, was used to derive the prediction model. In 22 million sessions, 898 people between 2004 and 2006 and 826 people between 2007 and 2008 died on the day of or day after a dialysis session that was serving as a training or test data session, respectively. A reasonably strong predictor was derived using just predialysis information (concordance statistic=0.782), which showed modest but significant improvement after inclusion of postdialysis information (concordance statistic=0.799, P<0.001). However, risk prediction decreased the farther out that it was forecasted (up to 1 year), and postdialytic information became less important. Subtle changes in the experience of hemodialysis aid in the assessment of sudden cardiac death and are captured by modern electronic health records. The collected data are better for the assessment of near-term risk as opposed to longer-term risk.

Sudden temperature changes in the Sydney Basin: climatology and case studies during the Olympic months of September and October

NASA Astrophysics Data System (ADS)

Buckley, Bruce W.; Leslie, Lance M.

2000-03-01

The accurate prediction of sudden large changes in the maximum temperature from one day to the next remains one of the major challenges for operational forecasters. It is probably the meteorological parameter most commonly verified and used as a measure of the skill of a meteorological service and one that is immediately evident to the general public. Marked temperature changes over a short period of time have widespread social, economic, health and safety effects on the community. The first part of this paper describes a 40-year climatology for Sydney, Australia, of sudden temperature rises and falls, defined as maximum temperature changes of 5°C or more from one day to the next, for the months of September and October. The nature of the forecasting challenge during the period of the Olympic and Paralympic Games to be held in Sydney in the year 2000 will be described as a special application. The international importance of the accurate prediction of all types of significant weather phenomena during this period has been recognized by the World Meteorological Organisation's Commission for Atmospheric Science. The first World Weather Research Program forecast demonstration project is to be established in the Sydney Office of the Bureau of Meteorology over this period in order to test the ability of existing systems to predict such phenomena. The second part of this study investigates two case studies from the Olympic months in which there were both abrupt temperature rises and falls over a 4-day interval. Currently available high resolution numerical weather prediction systems are found to have significant skill several days ahead in predicting a large amount of the detail of these events, provided they are run at an appropriate resolution. The limitations of these systems are also discussed, with areas requiring further development being identified if the desired levels of accuracy of predictions are to be reliably delivered. Differences between the predictability of sudden temperature rises and sudden temperature falls are also explored.

[Correlation between the changes of fibrinogen and the treatment effect of all-frequency sudden deafness].

PubMed

Fang, X; Yu, L S; Ma, X; Xia, R M; Jiang, Y H; Liu, H X; Jing, Y Y

2018-01-07

Objective: To analyze the correlation between the changes of fibrinogen and the treatment effect of all-frequency sudden deafness, and to explore the individualized treatment strategy for the use of Batroxobin. Methods: Patients with all-frequency sudden deafness who were admitted to Department of Otorhinolaryngology, People's Hospital of Peking University, from January 2010 to September 2016 were selected. All patients were given standard treatment and regular use of Batroxobin. Value of fibrinogen on D1 (before treatment) / D3 / D7 (±1) and D14 (±2) were recorded, at the same time, the correlation between the changes of fibrinogen and prognosis of all-frequency sudden deafness by the audiograms of onset and after-treatment of all patients were analyzed. Independent t -test was used to analyze normal distributed measurement data and chi square linear trend test was used to analyze the curative effect of different fibrinogen groups. Results: A total of 148 patients were included, the outcomes were worst when the patient's fibrinogen was below 2 g/L or above 4 g/L before treatment, ineffective rate were both 50%. The fibrinogen was lowest when the treatment came to the third day. Normally, the patient's prognosis was best when this value waved between 0.7 and 0.9 g/L, with a total effective rate between 73.9% and 83.3%. The fibrinogen value of the 7th day was a good indicator of the outcome, and Fib7 value was significant lower in patients of effective group than ineffective ones ((1.25±0.37)g/L vs (1.38±0.35) g/L, t =-0.27, P =0.04). Patients found a best recovery when Fib7 was below 1 g/L, and the higher the Fib7 value, the higher the inefficiency (χ(2)=7.55, P =0.01). Batroxobin showed safety during the treatment and found no complications. Conclusion: The change of fibrinogen in the process of all-frequency sudden deafness is closely related to the curative effect.

RESILIENCE AND SUSTAINABILITY IN HUMAN ECOLOGICAL SYSTEMS

EPA Science Inventory

Recent ecological research has uncovered examples of ecosystems that suddenly and sometimes catastrophically change in their composition and in their dynamics in response to incremental changes in external pressure. The possibility of such abrupt changes can have dire consequence...

Major transitions in information technology.

PubMed

Valverde, Sergi

2016-08-19

When looking at the history of technology, we can see that all inventions are not of equal importance. Only a few technologies have the potential to start a new branching series (specifically, by increasing diversity), have a lasting impact in human life and ultimately became turning points. Technological transitions correspond to times and places in the past when a large number of novel artefact forms or behaviours appeared together or in rapid succession. Why does that happen? Is technological change continuous and gradual or does it occur in sudden leaps and bounds? The evolution of information technology (IT) allows for a quantitative and theoretical approach to technological transitions. The value of information systems experiences sudden changes (i) when we learn how to use this technology, (ii) when we accumulate a large amount of information, and (iii) when communities of practice create and exchange free information. The coexistence between gradual improvements and discontinuous technological change is a consequence of the asymmetric relationship between complexity and hardware and software. Using a cultural evolution approach, we suggest that sudden changes in the organization of ITs depend on the high costs of maintaining and transmitting reliable information.This article is part of the themed issue 'The major synthetic evolutionary transitions'. © 2016 The Author(s).

Kids and Alcohol (For Parents)

MedlinePlus

... should know the facts about alcohol and your attitudes and beliefs about substance abuse. So use this ... odor of alcohol sudden change in mood or attitude change in attendance or performance at school loss ...

Critical point wetting drop tower experiment

NASA Technical Reports Server (NTRS)

Kaukler, William F.

1990-01-01

The 100 m Drop Tower at NASA-Marshall was used to provide the step change in acceleration from 1.0 to 0.0005 g. An inter-fluid meniscus oscillates vertically within a cylindrical container when suddenly released from earth's gravity and taken into a microgravity environment. Oscillations damp out from energy dissipative mechanisms such as viscosity and interfacial friction. Damping of the oscillations by the later mechanism is affected by the nature of the interfacial junction between the fluid-fluid interface and the container wall. In earlier stages of the project, the meniscus shape which developed during microgravity conditions was applied to evaluations of wetting phenomena near the critical temperature. Variations in equilibrium contact angle against the container wall were expected to occur under critical wetting conditions. However, it became apparent that the meaningful phenomenon was the damping of interfacial oscillations. This latter concept makes up the bulk of this report. Perfluoromethyl cyclohexane and isopropanol in glass were the materials used for the experiment. The wetting condition of the fluids against the wall changes at the critical wetting transition temperature. This change in wetting causes a change in the damping characteristics of the interfacial excursions during oscillation and no measurable change in contact angle. The effect of contact line friction measured above and below the wetting transition temperature was to increase the period of vertical oscillation for the vapor-liquid interface when below the wetting transition temperature.

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

PubMed

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

2014-01-01

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

[Hypertensive crisis and sudden change of vision in young patients].

PubMed

Cortés Fernández, M S; Martín-Castillejos, C; Armario, P

2016-01-01

The sudden change in vision is a medical emergency that must be evaluated immediately to rule out important institutions as systemic vasculitis or ischemic stroke. Its association with hypertensive crisis makes it necessary to rule out accelerated-malignant hypertension, which is accompanied by other retinal disorders (exudates and hemorrhages) and adrenal involvement. Nonarteritic anterior ischemic optic neuropathy (AION) is another entity to consider, as is it not uncommon in the young (12.7% in a series of 848 cases). Its association with hypertension has been described in 32% of cases. Copyright © 2016 SEH-LELHA. Publicado por Elsevier España, S.L.U. All rights reserved.

Age-related changes in human posture control: Motor coordination tests

NASA Technical Reports Server (NTRS)

Peterka, R. J.; Black, F. O.

1989-01-01

Postural responses to support surface displacements were measured in 214 normal human subjects ranging in age from 7 to 81 years. Motor tests measured leg muscle Electromyography (EMG) latencies, body sway, and the amplitude and timing of changes in center of pressure displacements in response to sudden forward and backward horizontal translations of the support surface upon which the subjects stood. There were small increases in both EMG latencies and the time to reach the peak amplitude of center of pressure responses with increasing age. The amplitude of center of pressure responses showed little change with age if the amplitude measures were normalized by a factor related to subject height. In general, postural responses to sudden translations showed minimal changes with age, and all age related trends which were identified were small relative to the variability within the population.

Coupled catastrophes: sudden shifts cascade and hop among interdependent systems

PubMed Central

Barnett, George; D'Souza, Raissa M.

2015-01-01

An important challenge in several disciplines is to understand how sudden changes can propagate among coupled systems. Examples include the synchronization of business cycles, population collapse in patchy ecosystems, markets shifting to a new technology platform, collapses in prices and in confidence in financial markets, and protests erupting in multiple countries. A number of mathematical models of these phenomena have multiple equilibria separated by saddle-node bifurcations. We study this behaviour in its normal form as fast–slow ordinary differential equations. In our model, a system consists of multiple subsystems, such as countries in the global economy or patches of an ecosystem. Each subsystem is described by a scalar quantity, such as economic output or population, that undergoes sudden changes via saddle-node bifurcations. The subsystems are coupled via their scalar quantity (e.g. trade couples economic output; diffusion couples populations); that coupling moves the locations of their bifurcations. The model demonstrates two ways in which sudden changes can propagate: they can cascade (one causing the next), or they can hop over subsystems. The latter is absent from classic models of cascades. For an application, we study the Arab Spring protests. After connecting the model to sociological theories that have bistability, we use socioeconomic data to estimate relative proximities to tipping points and Facebook data to estimate couplings among countries. We find that although protests tend to spread locally, they also seem to ‘hop' over countries, like in the stylized model; this result highlights a new class of temporal motifs in longitudinal network datasets. PMID:26559684

Possibilities of post-mortem diagnostics, including immunodiagnostics, in cases of sudden death due to anaphylactic and anaphylactoid reactions.

PubMed

Kobek, M; Jankowski, Z; Chowaniec, C; Chowaniec, M; Jabłoński, C; Skowronek, R

Postmortem diagnostics of anaphylactic and anaphylactoid reaction as the cause of death in cases of sudden deaths without witnesses, as well as those in which circumstances of sudden disease and then death are known, seems to be very difficult. This is caused by the lack of characteristic macro- or microscopic changes to internal organs resulting from a short, or even very short time, that elapses from the action of the etiological factor till death. In the above mentioned cases it is often impossible to establish univocally the cause of death, despite considering information on the cause of disease and its clinical symptoms. On the basis of 2 cases of sudden deaths resulted from the intake of hazel nuts, and the administration of contrast agent before radiological examination, the authors discuss the usefulness of postmortem determinations of tryptase and IgE in blood for diagnostics of deaths resulting from anaphylactic and anaphylactoid reaction, respectively.

Cardiac Channelopathies and Sudden Death: Recent Clinical and Genetic Advances.

PubMed

Fernández-Falgueras, Anna; Sarquella-Brugada, Georgia; Brugada, Josep; Brugada, Ramon; Campuzano, Oscar

2017-01-29

Sudden cardiac death poses a unique challenge to clinicians because it may be the only symptom of an inherited heart condition. Indeed, inherited heart diseases can cause sudden cardiac death in older and younger individuals. Two groups of familial diseases are responsible for sudden cardiac death: cardiomyopathies (mainly hypertrophic cardiomyopathy, dilated cardiomyopathy, and arrhythmogenic cardiomyopathy) and channelopathies (mainly long QT syndrome, Brugada syndrome, short QT syndrome, and catecholaminergic polymorphic ventricular tachycardia). This review focuses on cardiac channelopathies, which are characterized by lethal arrhythmias in the structurally normal heart, incomplete penetrance, and variable expressivity. Arrhythmias in these diseases result from pathogenic variants in genes encoding cardiac ion channels or associated proteins. Due to a lack of gross structural changes in the heart, channelopathies are often considered as potential causes of death in otherwise unexplained forensic autopsies. The asymptomatic nature of channelopathies is cause for concern in family members who may be carrying genetic risk factors, making the identification of these genetic factors of significant clinical importance.

Sudden Death After Febrile Seizure Case Report: Cerebral Suppression Precedes Severe Bradycardia.

PubMed

Myers, Kenneth A; McPherson, Robyn E; Clegg, Robin; Buchhalter, Jeffrey

2017-11-01

A 20-month-old girl with a complex chromosomal disorder had first presentation of febrile status epilepticus and was admitted to the hospital. Two days after her initial seizure, she died suddenly and unexpectedly during a video EEG monitoring study. An advanced analysis of the physiologic changes in the hours and minutes leading up to death was undertaken. The electrocardiography over the last 19 minutes of life was reviewed, and the R-R intervals were manually measured. Heart rate variability was assessed through calculation of the SD of the R-R intervals and the root mean square of successive differences over successive 100 beat periods. Instantaneous heart rate, SD of the R-R intervals, the root mean square of successive differences, and oxygen saturation were plotted against time over the last 19 minutes of life. Diffuse cerebral suppression on EEG was observed 10 minutes before death, followed minutes later by severe bradycardia and increased heart rate variability. Although the child did not meet criteria for a diagnosis of epilepsy, the sequence of physiologic changes leading up to death suggests a pathophysiology similar to sudden unexplained death in epilepsy. A comparable pattern of diffuse cerebral suppression preceding parasympathetic overactivity has been suggested in some rare cases of adults who have experienced sudden unexplained death in epilepsy during video EEG monitoring. Copyright © 2017 by the American Academy of Pediatrics.

A cry unheard: sudden reductions in blood pressure while talking about feelings of hopelessness and helplessness.

PubMed

Lynch, J J; Lynch, K E; Friedmann, E

1992-01-01

This paper describes sudden extreme drops in blood pressure in both experimental and clinical situations when a person is talking about or describing situations of hopelessness and helplessness. These changes are discussed in the context of historical perspectives about the cardiovascular system. A new perspective is introduced, one in which these blood pressure changes are seen as part of an unheard cry for understanding. It is hypothesized that such changes do not occur in response to a person's attempts to communicate a sense of hopelessness, but rather are the biological foundations of the hopelessness itself. Viewed from such a context an entirely new therapeutic approach is outlined regarding the treatment of patients suffering from a wide variety of psychosomatic as well as psychological disturbances.

The molecular and mathematical basis of Waddington's epigenetic landscape: a framework for post-Darwinian biology?

PubMed

Huang, Sui

2012-02-01

The Neo-Darwinian concept of natural selection is plausible when one assumes a straightforward causation of phenotype by genotype. However, such simple 1:1 mapping must now give place to the modern concepts of gene regulatory networks and gene expression noise. Both can, in the absence of genetic mutations, jointly generate a diversity of inheritable randomly occupied phenotypic states that could also serve as a substrate for natural selection. This form of epigenetic dynamics challenges Neo-Darwinism. It needs to incorporate the non-linear, stochastic dynamics of gene networks. A first step is to consider the mathematical correspondence between gene regulatory networks and Waddington's metaphoric 'epigenetic landscape', which actually represents the quasi-potential function of global network dynamics. It explains the coexistence of multiple stable phenotypes within one genotype. The landscape's topography with its attractors is shaped by evolution through mutational re-wiring of regulatory interactions - offering a link between genetic mutation and sudden, broad evolutionary changes. Copyright © 2012 WILEY Periodicals, Inc.

Experience-dependent shaping of hippocampal CA1 intracellular activity in novel and familiar environments

PubMed Central

Cohen, Jeremy D; Bolstad, Mark; Lee, Albert K

2017-01-01

The hippocampus is critical for producing stable representations of familiar spaces. How these representations arise is poorly understood, largely because changes to hippocampal inputs have not been measured during spatial learning. Here, using intracellular recording, we monitored inputs and plasticity-inducing complex spikes (CSs) in CA1 neurons while mice explored novel and familiar virtual environments. Inputs driving place field spiking increased in amplitude – often suddenly – during novel environment exploration. However, these increases were not sustained in familiar environments. Rather, the spatial tuning of inputs became increasingly similar across repeated traversals of the environment with experience – both within fields and throughout the whole environment. In novel environments, CSs were not necessary for place field formation. Our findings support a model in which initial inhomogeneities in inputs are amplified to produce robust place field activity, then plasticity refines this representation into one with less strongly modulated, but more stable, inputs for long-term storage. DOI: http://dx.doi.org/10.7554/eLife.23040.001 PMID:28742496

[Penetration of external thermal perturbations into homeothermic organisms, part I (author's transl)].

PubMed

Theves, B

1978-03-20

The general importance of the mean surface curvature for heat conduction problems is explained and a special symmetry with constant mean curvature on the isothermal surfaces is defined. The applicability for the body shapes of homeothermic organisms is demonstrated and the partial differential equation of heat conduction for this case is derived. The definition: heat release = real heat production + convective pseudoproduction eliminates the term of convective heat transfer through the blood stream and allows the reduction to a mere heat conduction problem. Formulas for the heat loss to the environment and for steady state temperature profiles are given. In case of sudden change of heat loss the partial differential equation is solved and a formula is derived, using dimensionless coordinates of time and distance. The mean surface curvature has strongest influence to the interior temperature field. The solution shows clearly the importance of thermal inertia of the homeothermic organism, for the external temperature wave penetrates into the body with a long phase displacement in time.

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

PubMed

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

2017-10-01

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

Excitation of nonlinear wave patterns in flowing complex plasmas

NASA Astrophysics Data System (ADS)

Jaiswal, S.; Bandyopadhyay, P.; Sen, A.

2018-01-01

We describe experimental observations of nonlinear wave structures excited by a supersonic mass flow of dust particles over an electrostatic potential hill in a dusty plasma medium. The experiments have been carried out in a Π- shaped experimental (DPEx) device in which micron sized Kaolin particles are embedded in a DC glow discharge Argon plasma. An equilibrium dust cloud is formed by maintaining the pumping speed and gas flow rate and the dust flow is induced either by suddenly reducing the height of a potential hill or by suddenly reducing the gas flow rate. For a supersonic flow of the dust fluid precursor solitons are seen to propagate in the upstream direction while wake structures propagate in the downstream direction. For flow speeds with a Mach number greater than 2 the dust particles flowing over the potential hill give rise to dispersive dust acoustic shock waves. The experimental results compare favorably with model theories based on forced K-dV and K-dV Burger's equations.

Serendipitous discovery of an irregular and a semi-regular type variable in the field of BY Draconis

NASA Astrophysics Data System (ADS)

Messina, S.; Marino, G.; Rodonò, M.; Cutispoto, G.

2000-12-01

We present new evidence of the optical variability of two red giant stars: HD 172468 and HK Dra, based on photometric and spectroscopic observations. These stars had been included as check stars in our photometric monitoring program of BY Dra and turned out to be variable. HD 172468, whereas almost constant for most of the time, suddenly started to drop in brightness to such a low level to become undetectable. We suspect that such an abrupt event may be an ``obscurational'' minimum, that is typical of eruptive RCB stars, or may be due to the variable extinction by circumstellar dust in a young Orion type object. HK Dra, already known as an irregular variable, is characterised by periodic flux modulation with season-to-season changes of the photometric period, as inferred from a periodogram analysis. It also shows changes of the light curve peak-to-peak amplitude and shape. Such a behaviour in giant stars is commonly found among semi-regular giants (SR) at the Asymptotic Giant Branch (AGB). Our radial velocity measurements rule out that HK Dra may be a close binary system.

The Change in Fingertip Contact Area as a Novel Proprioceptive Cue.

PubMed

Moscatelli, Alessandro; Bianchi, Matteo; Serio, Alessandro; Terekhov, Alexander; Hayward, Vincent; Ernst, Marc O; Bicchi, Antonio

2016-05-09

Humans, many animals, and certain robotic hands have deformable fingertip pads [1, 2]. Deformable pads have the advantage of conforming to the objects that are being touched, ensuring a stable grasp for a large range of forces and shapes. Pad deformations change with finger displacements during touch. Pushing a finger against an external surface typically provokes an increase of the gross contact area [3], potentially providing a relative motion cue, a situation comparable to looming in vision [4]. The rate of increase of the area of contact also depends on the compliance of the object [5]. Because objects normally do not suddenly change compliance, participants may interpret an artificially induced variation in compliance, which coincides with a change in the gross contact area, as a change in finger displacement, and consequently they may misestimate their finger's position relative to the touched object. To test this, we asked participants to compare the perceived displacements of their finger while contacting an object varying pseudo-randomly in compliance from trial to trial. Results indicate a bias in the perception of finger displacement induced by the change in compliance, hence in contact area, indicating that participants interpreted the altered cutaneous input as a cue to proprioception. This situation highlights the capacity of the brain to take advantage of knowledge of the mechanical properties of the body and of the external environment. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Coronal hole evolution by sudden large scale changes

NASA Technical Reports Server (NTRS)

Nolte, J. T.; Gerassimenko, M.; Krieger, A. S.; Solodyna, C. V.

1978-01-01

Sudden shifts in coronal-hole boundaries observed by the S-054 X-ray telescope on Skylab between May and November, 1973, within 1 day of CMP of the holes, at latitudes not exceeding 40 deg, are compared with the long-term evolution of coronal-hole area. It is found that large-scale shifts in boundary locations can account for most if not all of the evolution of coronal holes. The temporal and spatial scales of these large-scale changes imply that they are the results of a physical process occurring in the corona. It is concluded that coronal holes evolve by magnetic-field lines' opening when the holes are growing, and by fields' closing as the holes shrink.

Finding the rhythm of sudden cardiac death: new opportunities using induced pluripotent stem cell-derived cardiomyocytes.

PubMed

Sallam, Karim; Li, Yingxin; Sager, Philip T; Houser, Steven R; Wu, Joseph C

2015-06-05

Sudden cardiac death is a common cause of death in patients with structural heart disease, genetic mutations, or acquired disorders affecting cardiac ion channels. A wide range of platforms exist to model and study disorders associated with sudden cardiac death. Human clinical studies are cumbersome and are thwarted by the extent of investigation that can be performed on human subjects. Animal models are limited by their degree of homology to human cardiac electrophysiology, including ion channel expression. Most commonly used cellular models are cellular transfection models, which are able to mimic the expression of a single-ion channel offering incomplete insight into changes of the action potential profile. Induced pluripotent stem cell-derived cardiomyocytes resemble, but are not identical, adult human cardiomyocytes and provide a new platform for studying arrhythmic disorders leading to sudden cardiac death. A variety of platforms exist to phenotype cellular models, including conventional and automated patch clamp, multielectrode array, and computational modeling. Induced pluripotent stem cell-derived cardiomyocytes have been used to study long QT syndrome, catecholaminergic polymorphic ventricular tachycardia, hypertrophic cardiomyopathy, and other hereditary cardiac disorders. Although induced pluripotent stem cell-derived cardiomyocytes are distinct from adult cardiomyocytes, they provide a robust platform to advance the science and clinical care of sudden cardiac death. © 2015 American Heart Association, Inc.

Malignant Course of Anomalous Left Coronary Artery Causing Sudden Cardiac Arrest: A Case Report and Review of the Literature.

PubMed

Anantha Narayanan, Mahesh; DeZorzi, Christopher; Akinapelli, Abhilash; Mahfood Haddad, Toufik; Smer, Aiman; Baskaran, Janani; Biddle, William P

2015-01-01

Sudden cardiac arrest has been reported to occur in patients with congenital anomalous coronary artery disease. About 80% of the anomalies are benign and incidental findings at the time of catheterization. We present a case of sudden cardiac arrest caused by anomalous left anterior descending artery. 61-year-old African American female was brought to the emergency department after sudden cardiac arrest. Initial EKG showed sinus rhythm with RBBB and LAFB with nonspecific ST-T wave changes. Coronary angiogram revealed no atherosclerotic disease. The left coronary artery was found to originate from the right coronary cusp. Cardiac CAT scan revealed similar findings with interarterial and intramural course. Patient received one-vessel arterial bypass graft to her anomalous coronary vessel along with a defibrillator for secondary prevention. Sudden cardiac arrest secondary to congenital anomalous coronary artery disease is characterized by insufficient coronary flow by the anomalous left coronary artery to meet elevated left ventricular (LV) myocardial demand. High risk defects include those involved with the proximal coronary artery or coursing of the anomalous artery between the aorta and pulmonary trunk. Per guidelines, our patient received one vessel bypass graft to her anomalous vessel. It is important for clinicians to recognize such presentations of anomalous coronary artery.

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

NASA Astrophysics Data System (ADS)

Zhao, Yu; Yuan, Sanling

2017-07-01

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

Rotational polarities of sudden impulses in the magnetotail lobe

NASA Technical Reports Server (NTRS)

Kawano, H.; Yamamoto, T.; Kokubun, S.; Lepping, R. P.

1992-01-01

A sudden impulse (SI) is a sudden change in the magnetic field strength which is caused by a change in the solar wind pressure and is observed throughout the magnetosphere. In this report we have examined the rotations of the magnetic field vectors at times of SIs in the magnetotail lobe, by using IMP 6, 7, and 8 magnetometer data. The following properties have been found: (1) at the time of SI the arrowhead of the magnetic vector tends to rotate in one plane; (2) the plane of rotation tends to include the unperturbed magnetic field vector; (3) the plane of rotation tends to be aligned with the radial direction from the magnetotail axis; and (4) the magnetic vectors have a particular rotational polarity: when the plane of rotation is viewed so that the Sun is to the right of the viewed plane and the magnetotail axis is to the bottom, the arrowhead of the vector tends to rotate counterclockwise in this plane. These magnetic vector properties are consistent with those expected when part of an increase in solar wind lateral pressure squeezes the magnetotail axisymmetrically while moving tailward.

Investigation of the Mid-Atlantic coast sudden cold water

NASA Astrophysics Data System (ADS)

Sun, D.; Kafatos, M.; Liu, Z.; Chiu, L.

2003-12-01

In the midsummer of this year, it was reported that there was a tremendous change in ocean temperature along the Mid-Atlantic coast, dropping as much as 10 degrees overnight. This sudden sea surface temperature drop affected local tourism and fishing, keep the tourists out of water at this vacation time, caused local tuna fishing hasn't been as good this year, but the cold water lured chill-loving striped bass close to shore, and has two to three weeks of great rockfish, which fishermen could normally get till fall. This article investigates this event by using satellite observations, numerical model outputs, and surface weather analysis. It is found that the North Atlantic cold current, combined with the coastal upwelling driven by the weather influence might cause this sudden cold SST event.

Identification of sudden stiffness changes in the acceleration response of a bridge to moving loads using ensemble empirical mode decomposition

NASA Astrophysics Data System (ADS)

Aied, H.; González, A.; Cantero, D.

2016-01-01

The growth of heavy traffic together with aggressive environmental loads poses a threat to the safety of an aging bridge stock. Often, damage is only detected via visual inspection at a point when repairing costs can be quite significant. Ideally, bridge managers would want to identify a stiffness change as soon as possible, i.e., as it is occurring, to plan for prompt measures before reaching a prohibitive cost. Recent developments in signal processing techniques such as wavelet analysis and empirical mode decomposition (EMD) have aimed to address this need by identifying a stiffness change from a localised feature in the structural response to traffic. However, the effectiveness of these techniques is limited by the roughness of the road profile, the vehicle speed and the noise level. In this paper, ensemble empirical mode decomposition (EEMD) is applied by the first time to the acceleration response of a bridge model to a moving load with the purpose of capturing sudden stiffness changes. EEMD is more adaptive and appears to be better suited to non-linear signals than wavelets, and it reduces the mode mixing problem present in EMD. EEMD is tested in a variety of theoretical 3D vehicle-bridge interaction scenarios. Stiffness changes are successfully identified, even for small affected regions, relatively poor profiles, high vehicle speeds and significant noise. The latter is due to the ability of EEMD to separate high frequency components associated to sudden stiffness changes from other frequency components associated to the vehicle-bridge interaction system.

[Meniscoids of the intervertebral joints].

PubMed

Kos, J; Hert, J; Sevcík, P

2002-01-01

A large amount of material was used to study the distribution, location and shape of meniscoids in intervertebral joints of the human spine, from the atlanto-occipital joint to the sacrum, in order to find out how many of intervertebral joints had mobile meniscoids. These might be regarded as possible causes of spinal blockade or other vertebrogenous complaints. The materials provided by the Department of Anatomy and Department of Forensic Medicine at the Faculty of Medicine of Charles University in Pilznen included 20 cadaverous spines from humans aged 20 to 80 years. Access to each joint was provided by dissection of the articular capsule from the lower articular processes of the vertebra situated above. In the orthograde view, all meniscoids were described in terms of shape, size, consistence and location. Their structure was ascertained by histological examination of cross sections stained with haematoxylin and eosin. Meniscoids varying in shape and size were found in all of the intervertebral joints. They were classified by their histological structure as synovial, fat and fibrous meniscoids. The first category was observed frequently, the last only rarely. A total of 29 mobile meniscoids were recorded, most of them in the lumbar spine. Most of the meniscoids present in the cervical spine were of synovial and less frequently of fat types. Meniscoids found in the thoracic spine were poorly developed synovial ones and those present in the lumbar spine were of all types and were also largest in size. The most conspicuous meniscoids were seen in the spines that showed degenerative changes in intervertebral joints. Large fat pads were found in atlanto-occipital and atlanto-axial joints. Mobile meniscoids, most of them present in the lumbar spine (6.4% of all joints.), were connected with the capsule by a thin pedicle and it was possible to move them over a half of the articular surface. Some inter-individual changes were also found; in some spines, the most developed meniscoids were fat pads, in the others, these were synovial meniscoids. Spines of younger individuals showed a predominance of synovial meniscoids with smooth surfaces that arched against the articular cavity. In spines of elderly individuals, meniscoids were rough, in some cases fibrous in structure, and had a lobulated or frayed edge. The shape, location of meniscoids and their presence in every joint indicate their definite role for the spine: they compensate the incongruence of articular surfaces, fill in empty spaces and facilitate spread of synovial fluid during translation movements. Variability in shape, size and location of meniscoids give support to the view that meniscoids developed secondarily in relation to the morphogenesis of articular surfaces and that they are fully adapted to the shape and function of the joint. Mobile meniscoids, particularly fibrous ones, can get wedged between articular surfaces due to a sudden, rush movement (entrapment theory) or can be caught between the edge of an articular surface and the articular capsule attachment (extrapment theory). This situation may result in either mechanical or functional blockade of the spine and a subsequent painful condition due to compression of nerves and reflex contraction of muscles. Direct evidence of such blockade and the validity of either hypothesis can today be provided by magnetic resonance imaging. All intervertebral joints, along the length of spine, possess capsule processes, i.e., meniscoids, which can be classified as synovial, fat and fibrous. Meniscoids are most developed in the lumbar and cervical spine. They serve to compensate for the incongruence of articular surfaces and to fill in empty spaces. Mobile, peduncular meniscoids can, at sudden or non-physiological movements, be caught between articular surfaces and cause spinal blockade and painful conditions. Manipulative treatment is, therefore, justified in indicated cases.

Late Wenlock (middle Silurian) bio-events: Caused by volatile boloid impact/s

NASA Technical Reports Server (NTRS)

Berry, W. B. N.; Wilde, P.

1988-01-01

Late Wenlockian (late mid-Silurian) life is characterized by three significant changes or bioevents: sudden development of massive carbonate reefs after a long interval of limited reef growth; sudden mass mortality among colonial zooplankton, graptolites; and origination of land plants with vascular tissue (Cooksonia). Both marine bioevents are short in duration and occur essentially simultaneously at the end of the Wenlock without any recorded major climatic change from the general global warm climate. These three disparate biologic events may be linked to sudden environmental change that could have resulted from sudden infusion of a massive amount of ammonia into the tropical ocean. Impact of a boloid or swarm of extraterrestrial bodies containing substantial quantities of a volatile (ammonia) component could provide such an infusion. Major carbonate precipitation (formation), as seen in the reefs as well as, to a more limited extent, in certain brachiopods, would be favored by increased pH resulting from addition of a massive quantity of ammonia into the upper ocean. Because of the buffer capacity of the ocean and dilution effects, the pH would have returned soon to equilibrium. Major proliferation of massive reefs ceased at the same time. Addition of ammonia as fertilizer to terrestrial environments in the tropics would have created optimum environmental conditions for development of land plants with vascular, nutrient-conductive tissue. Fertilization of terrestrial environments thus seemingly preceded development of vascular tissue by a short time interval. Although no direct evidence of impact of a volatile boloid may be found, the bioevent evidence is suggestive that such an impact in the oceans could have taken place. Indeed, in the case of an ammonia boloid, evidence, such as that of the Late Wenlockian bioevents may be the only available data for impact of such a boloid.

Professions and Working Conditions Associated With Community-Acquired Pneumonia.

PubMed

Almirall, Jordi; Serra-Prat, Mateu; Bolíbar, Ignasi; Palomera, Elisabet; Roig, Jordi; Boixeda, Ramon; Bartolomé, Maria; de la Torre, Mari; Parra, Olga; Torres, Antoni

2015-12-01

Community-acquired pneumonia (CAP) is not considered a professional disease, and the effect of different occupations and working conditions on susceptibility to CAP is unknown. The aim of this study is to determine whether different jobs and certain working conditions are risk factors for CAP. Over a 1-year period, all radiologically confirmed cases of CAP (n=1,336) and age- and sex-matched controls (n=1,326) were enrolled in a population-based case-control study. A questionnaire on CAP risk factors, including work-related questions, was administered to all participants during an in-person interview. The bivariate analysis showed that office work is a protective factor against CAP, while building work, contact with dust and sudden changes of temperature in the workplace were risk factors for CAP. The occupational factor disappeared when the multivariate analysis was adjusted for working conditions. Contact with dust (previous month) and sudden changes of temperature (previous 3 months) were risk factors for CAP, irrespective of the number of years spent working in these conditions, suggesting reversibility. Some recent working conditions such as exposure to dust and sudden changes of temperature in the workplace are risk factors for CAP. Both factors are reversible and preventable. Copyright © 2014 SEPAR. Published by Elsevier Espana. All rights reserved.

Stand changes in the first 10 years after seedbed preparation for paper birch

Treesearch

John C. Bjorkbom; John C. Bjorkbom

1972-01-01

Changes may take place rapidly in young forest stands. Stands that appear good may deteriorate unexpectedly: stands that hold little promise initially may suddenly show great potential. The ability to understand and predict such changes increases our ability to prescribe effective silvicultural treatments.

[Sudden death of twins: botulism because of contamination by pap vegetables].

PubMed

Fischer, D; Freislederer, A; Jorch, G

2004-01-01

Botulism is caused by the blockage of the neural transmission in the cholinergic synapses by botulinum neurotoxin (BoNT) which is produced by Clostridium botulinum or other Clostridia. The classic form of botulism occurs after the ingestion of food contaminated by BoNT. The course of the infection can be asymptomatic, mild with subtle paralysis ("failure to thrive") oder severe with generalized paralysis ("floppy infant"). Infected infants can also die sudden and unexpectedly. These deaths often are attributed to Sudden Infant Death Syndrome (SIDS), unless a thorough postmortem examination reveals Botulism. The rate of fatal Botulism falsely attributed to SIDS is not known, because it is difficult in most cases to show the causal relationship between contamination, disease and death. We report the sudden and unexpected simultaneous death of twins of 22 months which could be attributed to Botulism. Contamination of food, colonization of the gut by Clostridia and infection with specific pathomorphological changes could be proven. The initial suspicion of infanticide could be excluded. lt could be shown, that Botulism is a potential cause of simultaneous unexpected deaths in twins.

[Determination of critical micelle concentration of alkyl polyglucoside (APG) nonionic surfactant aqueous system by multi-peaks Gaussian fitting of visible absorption spectra line shape].

PubMed

Zhang, Jian-Hua; Kong, Kai-Qing; He, Zheng-Ling; Liu, Zi-Li

2007-07-01

A multi-peaks Gaussian fitting on the line shape of visible spectra was used to determine the critical micelle concentration (CMC) of alkyl polyglucoside (APG) nonionic surfactant aqueous system such as octyl beta D mono-glucoside (C8 G1) and decyl beta D mono-glucoside (C10 G1). Visible electronic absorption spectra of a series of different concentration C8G1 or C10G1 with crystal violet (CV) used as a probe were measured respectively and characterized by the overlap of the principal peak with lambda(max) at 598-609 nm and a shoulder at 538-569 nm assigned to monomer and dimer CV respectively. A multi-peaks Gaussian fitting was used to interpret the spectra and give relative integrating absorbance (A2/A1) of two peaks, red-shift (deltalambda) and half-width. A sudden change occurred at CMC in the curves of the relative integrating absorbance (A2/A1), red-shift (deltalambda) and half-width (w1, w2) versus the C8G1 or C10G1 surfactant concentrations. Significantly the dependence of the CMC upon the half-width was ob-served for the first time and successfully used to determine CMC of nonionic surfactant such as APG.

Sickle cell anemia mice develop a unique cardiomyopathy with restrictive physiology

PubMed Central

Bakeer, Nihal; James, Jeanne; Roy, Swarnava; Wansapura, Janaka; Shanmukhappa, Shiva Kumar; Lorenz, John N.; Osinska, Hanna; Backer, Kurt; Huby, Anne-Cecile; Shrestha, Archana; Niss, Omar; Fleck, Robert; Quinn, Charles T.; Taylor, Michael D.; Purevjav, Enkhsaikhan; Aronow, Bruce J.; Towbin, Jeffrey A.; Malik, Punam

2016-01-01

Cardiopulmonary complications are the leading cause of mortality in sickle cell anemia (SCA). Elevated tricuspid regurgitant jet velocity, pulmonary hypertension, diastolic, and autonomic dysfunction have all been described, but a unifying pathophysiology and mechanism explaining the poor prognosis and propensity to sudden death has been elusive. Herein, SCA mice underwent a longitudinal comprehensive cardiac analysis, combining state-of-the-art cardiac imaging with electrocardiography, histopathology, and molecular analysis to determine the basis of cardiac dysfunction. We show that in SCA mice, anemia-induced hyperdynamic physiology was gradually superimposed with restrictive physiology, characterized by progressive left atrial enlargement and diastolic dysfunction with preserved systolic function. This phenomenon was absent in WT mice with experimentally induced chronic anemia of similar degree and duration. Restrictive physiology was associated with microscopic cardiomyocyte loss and secondary fibrosis detectable as increased extracellular volume by cardiac-MRI. Ultrastructural mitochondrial changes were consistent with severe chronic hypoxia/ischemia and sarcomere diastolic-length was shortened. Transcriptome analysis revealed up-regulation of genes involving angiogenesis, extracellular-matrix, circadian-rhythm, oxidative stress, and hypoxia, whereas ion-channel transport and cardiac conduction were down-regulated. Indeed, progressive corrected QT prolongation, arrhythmias, and ischemic changes were noted in SCA mice before sudden death. Sudden cardiac death is common in humans with restrictive cardiomyopathies and long QT syndromes. Our findings may thus provide a unifying cardiac pathophysiology that explains the reported cardiac abnormalities and sudden death seen in humans with SCA. PMID:27503873

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

NASA Technical Reports Server (NTRS)

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

2016-01-01

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

Systems and Methods for Derivative-Free Adaptive Control

NASA Technical Reports Server (NTRS)

Calise, Anthony J. (Inventor); Yucelen, Tansel (Inventor); Kim, Kilsoo (Inventor)

2015-01-01

An adaptive control system is disclosed. The control system can control uncertain dynamic systems. The control system can employ one or more derivative-free adaptive control architectures. The control system can further employ one or more derivative-free weight update laws. The derivative-free weight update laws can comprise a time-varying estimate of an ideal vector of weights. The control system of the present invention can therefore quickly stabilize systems that undergo sudden changes in dynamics, caused by, for example, sudden changes in weight. Embodiments of the present invention can also provide a less complex control system than existing adaptive control systems. The control system can control aircraft and other dynamic systems, such as, for example, those with non-minimum phase dynamics.

Cryotherapy does not affect peroneal reaction following sudden inversion.

PubMed

Berg, Christine L; Hart, Joseph M; Palmieri-Smith, Riann; Cross, Kevin M; Ingersoll, Christopher D

2007-11-01

If ankle joint cryotherapy impairs the ability of the ankle musculature to counteract potentially injurious forces, the ankle is left vulnerable to injury. To compare peroneal reaction to sudden inversion following ankle joint cryotherapy. Repeated measures design with independent variables, treatment (cryotherapy and control), and time (baseline, immediately post treatment, 15 minutes post treatment, and 30 minutes post treatment). University research laboratory. Twenty-seven healthy volunteers. An ice bag was secured to the lateral ankle joint for 20 minutes. The onset and average root mean square amplitude of EMG activity in the peroneal muscles was calculated following the release of a trap door mechanism causing inversion. There was no statistically significant change from baseline for peroneal reaction time or average peroneal muscle activity at any post treatment time. Cryotherapy does not affect peroneal muscle reaction following sudden inversion perturbation.

Changing Families in a Changing Military System.

ERIC Educational Resources Information Center

Hunter, Edna J., Ed.

Recently, the military system has begun to feel the impact of the military family. Whenever sudden dramatic changes or transitions occur, crises may result either for the individual or for the institution. At present both the military system and the military family are in a period of rapid transition. Perhaps one of the most important changes that…

Altitude control in honeybees: joint vision-based learning and guidance.

PubMed

Portelli, Geoffrey; Serres, Julien R; Ruffier, Franck

2017-08-23

Studies on insects' visual guidance systems have shed little light on how learning contributes to insects' altitude control system. In this study, honeybees were trained to fly along a double-roofed tunnel after entering it near either the ceiling or the floor of the tunnel. The honeybees trained to hug the ceiling therefore encountered a sudden change in the tunnel configuration midways: i.e. a "dorsal ditch". Thus, the trained honeybees met a sudden increase in the distance to the ceiling, corresponding to a sudden strong change in the visual cues available in their dorsal field of view. Honeybees reacted by rising quickly and hugging the new, higher ceiling, keeping a similar forward speed, distance to the ceiling and dorsal optic flow to those observed during the training step; whereas bees trained to follow the floor kept on following the floor regardless of the change in the ceiling height. When trained honeybees entered the tunnel via the other entry (the lower or upper entry) to that used during the training step, they quickly changed their altitude and hugged the surface they had previously learned to follow. These findings clearly show that trained honeybees control their altitude based on visual cues memorized during training. The memorized visual cues generated by the surfaces followed form a complex optic flow pattern: trained honeybees may attempt to match the visual cues they perceive with this memorized optic flow pattern by controlling their altitude.

Trends in Modifiable Risk Factors Are Associated With Declining Incidence of Hospitalized and Nonhospitalized Acute Coronary Heart Disease in a Population.

PubMed

Mannsverk, Jan; Wilsgaard, Tom; Mathiesen, Ellisiv B; Løchen, Maja-Lisa; Rasmussen, Knut; Thelle, Dag S; Njølstad, Inger; Hopstock, Laila Arnesdatter; Bønaa, Kaare Harald

2016-01-05

Few studies have used individual person data to study whether contemporary trends in the incidence of coronary heart disease are associated with changes in modifiable coronary risk factors. We identified 29 582 healthy men and women ≥25 years of age who participated in 3 population surveys conducted between 1994 and 2008 in Tromsø, Norway. Age- and sex-adjusted incidence rates were calculated for coronary heart disease overall, out-of-hospital sudden death, and hospitalized ST-segment-elevation and non-ST-segment-elevation myocardial infarction. We measured coronary risk factors at each survey and estimated the relationship between changes in risk factors and changes in incidence trends. A total of 1845 participants had an incident acute coronary heart disease event during 375 064 person-years of follow-up from 1994 to 2010. The age- and sex-adjusted incidence of total coronary heart disease decreased by 3% (95% confidence interval, 2.0-4.0; P<0.001) each year. This decline was driven by decreases in out-of-hospital sudden death and hospitalized ST-segment-elevation myocardial infarction. Changes in coronary risk factors accounted for 66% (95% confidence interval, 48-97; P<0.001) of the decline in total coronary heart disease. Favorable changes in cholesterol contributed 32% to the decline, whereas blood pressure, smoking, and physical activity each contributed 14%, 13%, and 9%, respectively. We observed a substantial decline in the incidence of coronary heart disease that was driven by reductions in out-of-hospital sudden death and hospitalized ST-segment-elevation myocardial infarction. Changes in modifiable coronary risk factors accounted for 66% of the decline in coronary heart disease events. © 2015 American Heart Association, Inc.

Cellular interface morphologies in directional solidification. II - The effect of grain boundaries

NASA Technical Reports Server (NTRS)

Ungar, Lyle H.; Brown, Robert A.

1984-01-01

A singular perturbation analysis valid for small grain-boundary slopes is used with the one-sided model for solidification to show that grain boundaries introduce imperfections into the symmetry of the developing cellular interfaces which rupture the junction between the family of planar shapes and the bifurcating cellular families. Undulating interfaces are shown to develop first near grain boundaries, and to evolve with decreasing temperature gradient either by a smooth transition from the almost planar family or by a sudden jump to moderate-amplitude cellular forms, depending on the growth rate.

Cerebrospinal fluid hypocretin (orexin) levels are elevated by play but are not raised by exercise and its associated heart rate, blood pressure, respiration or body temperature changes.

PubMed

Wu, M-F; Nienhuis, R; Maidment, N; Lam, H A; Siegel, J M

2011-11-07

Hypocretin (Hcrt) has been implicated in the control of motor activity and in respiration and cardiovascular changes. Loss of Hcrt in narcolepsy is linked to sleepiness and to cataplexy, a sudden loss of muscle tone which is triggered by sudden strong emotions. In the current study we have compared the effects of treadmill running, to yard play on cerebrospinal fluid (CSF) Hcrt level in normal dogs. We find that treadmill locomotion, at a wide range of speeds, does not increase Hcrt level beyond baseline, whereas yard play produces a substantial increase in Hcrt, even though both activities produce comparable increases in heart rate, respiration and body temperature. We conclude that motor and cardiovascular changes are not sufficient to elevate CSF levels of Hcrt and we hypothesize that the emotional aspects of yard play account for the observed increase in Hcrt.

Effect of temperature on motility and chemotaxis of Escherichia coli.

PubMed Central

Maeda, K; Imae, Y; Shioi, J I; Oosawa, F

1976-01-01

The swimming velocity of Escherichia coli at various constant temperatures was found to increase with increasing temperature. The frequency of tumbling had a peak at 34 degrees C and was very low both at 20 and at 39 degrees C. The swimming tracks near the surface of a slide glass showed curves, and the curvature increased the temperature. When the temperature of a bacterial suspension was suddenly changed, a transient change of the tumbling frequency was observed. A temperature drop induced a temporary increase in the tumbling frequency, and a quick rise of temperature, on the other hand, resulted in a temporary suppression of the tumbling. These dynamic responses to sudden changes of temperature was not observed in the smoothly swimming nonchemotactic strains bearing the mutations cheA and cheC and also in a mutant with the metF mutation under a smooth swimming condition. Images PMID:783127

Natural and human-induced sinkholes in gypsum terrain and associated environmental problems in NE Spain

NASA Astrophysics Data System (ADS)

Benito, G.; Del Campo, P. Pérez; Gutiérrez-Elorza, M.; Sancho, C.

1995-04-01

The central Ebro Basin comprises thick evaporite materials whose high solubility produces typically karstic landforms. The sinkhole morphology developed in the overlying alluvium has been studied using gravimetry and ground-penetrating radar (GPR) on stream terraces, as well as analyzing the evolution of sinkhole morphologies observed in aerial photographs taken in 1928, 1957, and 1985. The sinkhole morphologies give some idea of possible subsurface processes as well as an indication of the final mechanisms involve in sinkhole development. On stream terraces and cover pediments the most commonly encountered dolines are bowl-shaped in their morphology with both diffuse and scarped edges. In contrast, dolines developed in the gypsiferous silt infilled valleys have a funnel and well-shaped morphology. The diffuse-edged bowl-shaped dolines are developed through the progressive subsidence of the alluvial cover, due to washing down of alluvial particles through small voids and cracks into deeper subsurface caves, resulting in a decrease alluvial density. Future compaction of the alluvial cover will produce surface subsidences. This type of dolines are associated with negative gravity anomalies. In contrast, the scarped-edge dolines are formed by the sudden collapse of a cavity roof. The cavities and cracks formed in the gypsum karst may migrate to the surface through the alluvial deposits by piping, and they may subsequently collapse. In this instance, the cavities can be detected by both gravity and GPR anomalies where the voids are not deeper than 4 5 m from the surface. These processes forming sinkholes can be enhanced by man-induced changes in the groundwater hydrologic regime by both inflows, due to irrigation, ditch losses, or pipe leakages, and by outflows from pumping activities.

Relationship Between Unusual High-Temperature Fatigue Crack Growth Threshold Behavior in Superalloys and Sudden Failure Mode Transitions

NASA Technical Reports Server (NTRS)

Telesman, J.; Smith, T. M.; Gabb, T. P.; Ring, A. J.

2017-01-01

An investigation of high temperature cyclic fatigue crack growth (FCG) threshold behavior of two advanced nickel disk alloys was conducted. The focus of the study was the unusual crossover effect in the near-threshold region of these type of alloys where conditions which produce higher crack growth rates in the Paris regime, produce higher resistance to crack growth in the near threshold regime. It was shown that this crossover effect is associated with a sudden change in the fatigue failure mode from a predominant transgranular mode in the Paris regime to fully intergranular mode in the threshold fatigue crack growth region. This type of a sudden change in the fracture mechanisms has not been previously reported and is surprising considering that intergranular failure is typically associated with faster crack growth rates and not the slow FCG rates of the near-threshold regime. By characterizing this behavior as a function of test temperature, environment and cyclic frequency, it was determined that both the crossover effect and the onset of intergranular failure are caused by environmentally driven mechanisms which have not as yet been fully identified. A plausible explanation for the observed behavior is proposed.

An experimental investigation of the aerodynamic characteristics of slanted base ogive cylinders using magnetic suspension technology

NASA Technical Reports Server (NTRS)

Alcorn, Charles W.; Britcher, Colin

1988-01-01

An experimental investigation is reported on slanted base ogive cylinders at zero incidence. The Mach number range is 0.05 to 0.3. All flow disturbances associated with wind tunnel supports are eliminated in this investigation by magnetically suspending the wind tunnel models. The sudden and drastic changes in the lift, pitching moment, and drag for a slight change in base slant angle are reported. Flow visualization with liquid crystals and oil is used to observe base flow patterns, which are responsible for the sudden changes in aerodynamic characteristics. Hysteretic effects in base flow pattern changes are present in this investigation and are reported. The effect of a wire support attachment on the 0 deg slanted base model is studied. Computational drag and transition location results using VSAERO and SANDRAG are presented and compared with experimental results. Base pressure measurements over the slanted bases are made with an onboard pressure transducer using remote data telemetry.

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

NASA Astrophysics Data System (ADS)

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

2018-03-01

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

Orography and the Boreal Winter Stratosphere: The Importance of the Mongolian Mountains

NASA Astrophysics Data System (ADS)

White, R. H.; Battisti, D. S.; Sheshadri, A.

2018-02-01

The impact of mountains on stratospheric circulation is explored using the Whole Atmosphere Community Climate Model. The "Mongolian mountains" decrease the boreal winter stratospheric jet strength by ˜1/3 and increase the frequency of major sudden stratospheric warmings from 0.08 year-1 to the observed 0.60 year-1. These changes are twice the magnitude of the impacts of the Tibetan plateau and Himalayas. Consistent with the decrease in the zonal jet, there is enhanced Eliassen-Palm flux convergence; this is predominantly from changes in wave propagation pathways through changes to the upper troposphere circulation, not from an increased amplitude of planetary waves reaching the stratosphere. The Mongolian mountains have the greater impact on upper tropospheric circulation due to their meridional location. The Rocky Mountains have no significant impact on the stratospheric jet. Changes in wave propagation in response to the Mongolian mountains are similar to those associated with major sudden stratospheric warming events in observations.

Response properties in the adsorption-desorption model on a triangular lattice

NASA Astrophysics Data System (ADS)

Šćepanović, J. R.; Stojiljković, D.; Jakšić, Z. M.; Budinski-Petković, Lj.; Vrhovac, S. B.

2016-06-01

The out-of-equilibrium dynamical processes during the reversible random sequential adsorption (RSA) of objects of various shapes on a two-dimensional triangular lattice are studied numerically by means of Monte Carlo simulations. We focused on the influence of the order of symmetry axis of the shape on the response of the reversible RSA model to sudden perturbations of the desorption probability Pd. We provide a detailed discussion of the significance of collective events for governing the time coverage behavior of shapes with different rotational symmetries. We calculate the two-time density-density correlation function C(t ,tw) for various waiting times tw and show that longer memory of the initial state persists for the more symmetrical shapes. Our model displays nonequilibrium dynamical effects such as aging. We find that the correlation function C(t ,tw) for all objects scales as a function of single variable ln(tw) / ln(t) . We also study the short-term memory effects in two-component mixtures of extended objects and give a detailed analysis of the contribution to the densification kinetics coming from each mixture component. We observe the weakening of correlation features for the deposition processes in multicomponent systems.

Paroxetine

MedlinePlus

... sleepiness or feeling ''drugged'' nausea vomiting diarrhea constipation gas stomach pain heartburn changes in ability to taste ... symptoms yellowing of the skin and eyes aggressive behavior muscle pain, stiffness, or weakness sudden muscle twitching ...

Aerodynamic and Acoustic Effects of Abrupt Frequency Changes in Excised Larynges

ERIC Educational Resources Information Center

Alipour, Fariborz; Finnegan, Eileen M.; Scherer, Ronald C.

2009-01-01

Purpose: To determine the aerodynamic and acoustic effects due to a sudden change from chest to falsetto register or vice versa. It was hypothesized that the continuous change in subglottal pressure and flow rate alone (pressure-flow sweep [PFS]) can trigger a mode change in the canine larynx. Method: Ten canine larynges were each mounted over a…

Perceptual learning of degraded speech by minimizing prediction error.

PubMed

Sohoglu, Ediz; Davis, Matthew H

2016-03-22

Human perception is shaped by past experience on multiple timescales. Sudden and dramatic changes in perception occur when prior knowledge or expectations match stimulus content. These immediate effects contrast with the longer-term, more gradual improvements that are characteristic of perceptual learning. Despite extensive investigation of these two experience-dependent phenomena, there is considerable debate about whether they result from common or dissociable neural mechanisms. Here we test single- and dual-mechanism accounts of experience-dependent changes in perception using concurrent magnetoencephalographic and EEG recordings of neural responses evoked by degraded speech. When speech clarity was enhanced by prior knowledge obtained from matching text, we observed reduced neural activity in a peri-auditory region of the superior temporal gyrus (STG). Critically, longer-term improvements in the accuracy of speech recognition following perceptual learning resulted in reduced activity in a nearly identical STG region. Moreover, short-term neural changes caused by prior knowledge and longer-term neural changes arising from perceptual learning were correlated across subjects with the magnitude of learning-induced changes in recognition accuracy. These experience-dependent effects on neural processing could be dissociated from the neural effect of hearing physically clearer speech, which similarly enhanced perception but increased rather than decreased STG responses. Hence, the observed neural effects of prior knowledge and perceptual learning cannot be attributed to epiphenomenal changes in listening effort that accompany enhanced perception. Instead, our results support a predictive coding account of speech perception; computational simulations show how a single mechanism, minimization of prediction error, can drive immediate perceptual effects of prior knowledge and longer-term perceptual learning of degraded speech.

Perceptual learning of degraded speech by minimizing prediction error

PubMed Central

Sohoglu, Ediz

2016-01-01

Human perception is shaped by past experience on multiple timescales. Sudden and dramatic changes in perception occur when prior knowledge or expectations match stimulus content. These immediate effects contrast with the longer-term, more gradual improvements that are characteristic of perceptual learning. Despite extensive investigation of these two experience-dependent phenomena, there is considerable debate about whether they result from common or dissociable neural mechanisms. Here we test single- and dual-mechanism accounts of experience-dependent changes in perception using concurrent magnetoencephalographic and EEG recordings of neural responses evoked by degraded speech. When speech clarity was enhanced by prior knowledge obtained from matching text, we observed reduced neural activity in a peri-auditory region of the superior temporal gyrus (STG). Critically, longer-term improvements in the accuracy of speech recognition following perceptual learning resulted in reduced activity in a nearly identical STG region. Moreover, short-term neural changes caused by prior knowledge and longer-term neural changes arising from perceptual learning were correlated across subjects with the magnitude of learning-induced changes in recognition accuracy. These experience-dependent effects on neural processing could be dissociated from the neural effect of hearing physically clearer speech, which similarly enhanced perception but increased rather than decreased STG responses. Hence, the observed neural effects of prior knowledge and perceptual learning cannot be attributed to epiphenomenal changes in listening effort that accompany enhanced perception. Instead, our results support a predictive coding account of speech perception; computational simulations show how a single mechanism, minimization of prediction error, can drive immediate perceptual effects of prior knowledge and longer-term perceptual learning of degraded speech. PMID:26957596

Patient-centred care of patients with ventricular arrhythmias and risk of sudden cardiac death: What do the 2015 European Society of Cardiology guidelines add?

PubMed

Norekvål, Tone M; Kirchhof, Paulus; Fitzsimons, Donna

2017-10-01

Nurses and allied professionals are at the forefront of care delivery in patients with arrythmogenic risk and have a responsibility to deliver care that is focused on their individual needs. The 2015 European Society of Cardiology guideline on prevention of ventricular arrhythmia and sudden cardiac death heralds a step-change in patient and family focus and interdisciplinary involvement. This development reflects a recognition within the European Society of Cardiology that chronic care of patients with cardiovascular conditions can be improved by involving all stakeholders, making use of multidisciplinary interventions, and placing the patient at the centre of the care process. In this article, taskforce contributors discuss the latest evidence and highlight some of the most pertinent issues for nurses involved in patient-centred care of patients and families with ventricular arrhythmias and/or risk of sudden death.

Nonlinear modeling and dynamic analysis of a hydro-turbine governing system in the process of sudden load increase transient

NASA Astrophysics Data System (ADS)

Li, Huanhuan; Chen, Diyi; Zhang, Hao; Wang, Feifei; Ba, Duoduo

2016-12-01

In order to study the nonlinear dynamic behaviors of a hydro-turbine governing system in the process of sudden load increase transient, we establish a novel nonlinear dynamic model of the hydro-turbine governing system which considers the elastic water-hammer model of the penstock and the second-order model of the generator. The six nonlinear dynamic transfer coefficients of the hydro-turbine are innovatively proposed by utilizing internal characteristics and analyzing the change laws of the characteristic parameters of the hydro-turbine governing system. Moreover, from the point of view of engineering, the nonlinear dynamic behaviors of the above system are exhaustively investigated based on bifurcation diagrams and time waveforms. More importantly, all of the above analyses supply theoretical basis for allowing a hydropower station to maintain a stable operation in the process of sudden load increase transient.

Field-aligned particle currents near an auroral arc.

NASA Technical Reports Server (NTRS)

Choy, L. W.; Arnoldy, R. L.; Potter, W.; Kintner, P.; Cahill, L. J., Jr.

1971-01-01

A Nike-Tomahawk rocket equipped to measure electric and magnetic fields and charged particles from a few eV to several hundred keV energy was flown into an auroral band on April 11, 1970. The purpose of this flight was to obtain evidence of the low-energy electrons and protons that constitute a field-aligned sheet current, and also to obtain the magnetic signature of such a current and the electric field in and near the auroral-arc electric current system. Particular attention was given to a sudden increase in the field-aligned current associated with a prior sudden increase in the electric field and a sudden change in the magnetic field, all occurring near the edge of a visual auroral arc. Data obtained are discussed and analyzed; they present an important contribution to the problem of mapping of atmospheric auroral phenomena to the magnetospheric equatorial plane.

Transport of Particle Swarms Through Variable Aperture Fractures

NASA Astrophysics Data System (ADS)

Boomsma, E.; Pyrak-Nolte, L. J.

2012-12-01

Particle transport through fractured rock is a key concern with the increased use of micro- and nano-size particles in consumer products as well as from other activities in the sub- and near surface (e.g. mining, industrial waste, hydraulic fracturing, etc.). While particle transport is often studied as the transport of emulsions or dispersions, particles may also enter the subsurface from leaks or seepage that lead to particle swarms. Swarms are drop-like collections of millions of colloidal-sized particles that exhibit a number of unique characteristics when compared to dispersions and emulsions. Any contaminant or engineered particle that forms a swarm can be transported farther, faster, and more cohesively in fractures than would be expected from a traditional dispersion model. In this study, the effects of several variable aperture fractures on colloidal swarm cohesiveness and evolution were studied as a swarm fell under gravity and interacted with the fracture walls. Transparent acrylic was used to fabricate synthetic fracture samples with (1) a uniform aperture, (2) a converging region followed by a uniform region (funnel shaped), (3) a uniform region followed by a diverging region (inverted funnel), and (4) a cast of a an induced fracture from a carbonate rock. All of the samples consisted of two blocks that measured 100 x 100 x 50 mm. The minimum separation between these blocks determined the nominal aperture (0.5 mm to 20 mm). During experiments a fracture was fully submerged in water and swarms were released into it. The swarms consisted of a dilute suspension of 3 micron polystyrene fluorescent beads (1% by mass) with an initial volume of 5μL. The swarms were illuminated with a green (525 nm) LED array and imaged optically with a CCD camera. The variation in fracture aperture controlled swarm behavior. Diverging apertures caused a sudden loss of confinement that resulted in a rapid change in the swarm's shape as well as a sharp increase in its velocity. Converging apertures caused swarms to decelerate rapidly and become trapped in the transition point between the converging and parallel regions for apertures less than 2.5 mm. In uniform aperture fractures, an optimal aperture range (5 mm to 15 mm) exists where swarm velocity was higher and the swarm maintained cohesion over a longer distance. For apertures below this range the swarms were strongly slowed due to drag from the wall, while for larger apertures the swarm velocity approached an asymptote due to the loss of the walls influence. The transport of particle swarms in fractures is strongly controlled by aperture distribution. While drag from the fracture does slow swarms, especially at small apertures, much of the interesting behavior (shape changes in diverging fracture, optimal aperture in parallel fracture) is best explained by fracture induced preferential confinement that controls the evolution of the swarm. When this confinement is suddenly changed, the swarm responds quickly and dramatically to its new environment. This has important implications for the understanding of contaminant dispersal in subsurface fracture networks because the type of aperture variation can exert a strong influence on particle swarm transport. Acknowledgment: The authors wish to acknowledge support of this work by the Geosciences Research Program, Office of Basic Energy Sciences US Department of Energy (DE-FG02-09ER16022).

Model reference adaptive control of flexible robots in the presence of sudden load changes

NASA Technical Reports Server (NTRS)

Steinvorth, Rodrigo; Kaufman, Howard; Neat, Gregory

1991-01-01

Direct command generator tracker based model reference adaptive control (MRAC) algorithms are applied to the dynamics for a flexible-joint arm in the presence of sudden load changes. Because of the need to satisfy a positive real condition, such MRAC procedures are designed so that a feedforward augmented output follows the reference model output, thus, resulting in an ultimately bounded rather than zero output error. Thus, modifications are suggested and tested that: (1) incorporate feedforward into the reference model's output as well as the plant's output, and (2) incorporate a derivative term into only the process feedforward loop. The results of these simulations give a response with zero steady state model following error, and thus encourage further use of MRAC for more complex flexibile robotic systems.

The sudden death and sudden birth of quantum discord.

PubMed

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

2018-03-28

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

Does Titan's Landscape Betray the Late Acquisitions of Its Current Atmosphere?

NASA Technical Reports Server (NTRS)

Moore, Jeffrey M.; Nimmo, F.

2012-01-01

Titan may have acquired its massive atmosphere relatively recently in solar system history. The sudden appearance of a thick atmosphere may have changed Titan's global topography. This change in global topography may be expressed in the latitudinal distribution of landform types across its surface.

Epilepsy in Adults with TSC

MedlinePlus

... are episodes of disturbed brain function that cause changes in attention or behavior. They are caused by abnormally excited electrical signals in the brain, like a lightning storm in the brain. Seizure types vary ... all seizures result from a sudden change in how the cells of the brain send ...

Relative roles of emissions and meteorology in the diurnal pattern of urban PM10: analysis of the daylight saving time effect.

PubMed

Muñoz, Ricardo C

2012-06-01

Daylight saving time (DST) is a common practice in many countries, in which Official Time (OT) is abruptly shifted 1 hour with respect to solar time on two occasions every year (in fall and spring). All anthropogenic emitting processes tied to OT like job and school commuting traffic, abruptly change in this moment their timing with respect to solar time, inducing a sudden shift between emissions and the meteorological factors that control the dispersion and transport of air pollutants. Analyzing 13 years of hourly particulate matter (PM10) concentrations measured in Santiago, Chile, we demonstrate that the DST practice has observable non-trivial effects in the PM10 diurnal cycle. The clearest impact is in the morning peak of PM10 during the fall DST change, which occurs later and has on average a significant smaller magnitude in the days after the DST change as compared to the days before it. This decrease in magnitude is most remarkable because it occurs in a period of the year when overall PM10 concentrations increase due to generally worsening of the dispersion conditions. Results are shown for seven monitoring stations around the city, and for the fall and spring DST changes. They show clearly the interplay of emissions and meteorology in conditioning urban air pollution problems, highlighting the role of the morning and evening transitions of the atmospheric boundary layer in shaping the diurnal pattern of urban air pollutant concentrations.

43 CFR 1864.0-5 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-10-01

... sudden change in alignment of the channel of a river, or by a comparable change in some other body of water, or that remain as uplands following such a change, or that are located in the bed of the new... the banks of a body of water by deposition of water-borne soil. (c) Avulsed lands have the meaning...

43 CFR 1864.0-5 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-10-01

... sudden change in alignment of the channel of a river, or by a comparable change in some other body of water, or that remain as uplands following such a change, or that are located in the bed of the new... the banks of a body of water by deposition of water-borne soil. (c) Avulsed lands have the meaning...

43 CFR 1864.0-5 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-10-01

... sudden change in alignment of the channel of a river, or by a comparable change in some other body of water, or that remain as uplands following such a change, or that are located in the bed of the new... the banks of a body of water by deposition of water-borne soil. (c) Avulsed lands have the meaning...

43 CFR 1864.0-5 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-10-01

... sudden change in alignment of the channel of a river, or by a comparable change in some other body of water, or that remain as uplands following such a change, or that are located in the bed of the new... the banks of a body of water by deposition of water-borne soil. (c) Avulsed lands have the meaning...

An emergent disease causes directional changes in forest species composition in coastal California

Treesearch

Margaret Metz; Kerri Frangioso; Allison Wickland; Ross Meentemeyer; David Rizzo

2012-01-01

Non-native forest pathogens can cause dramatic and long-lasting changes to the composition of forests, and these changes may have cascading impacts on community interactions and ecosystem functioning. Phytophthora ramorum, the causal agent of the emergent forest disease sudden oak death (SOD), has a wide host range, but mortality is concentrated in...

Saving Babies in Our Communities--A Change of Position, A Change in Tradition.

ERIC Educational Resources Information Center

Moore, Evelyn K.

2000-01-01

Examines Sudden Infant Death Syndrome (SIDS), including: (1) story of a victim's family; (2) risk factors; (3) known preventive measures; (4) change in traditional behaviors to ensure infants are put to sleep on their backs; and (5) the role child care providers should play to educate and ensure the safety of clients. (SD)

Object Recognition using Feature- and Color-Based Methods

NASA Technical Reports Server (NTRS)

Duong, Tuan; Duong, Vu; Stubberud, Allen

2008-01-01

An improved adaptive method of processing image data in an artificial neural network has been developed to enable automated, real-time recognition of possibly moving objects under changing (including suddenly changing) conditions of illumination and perspective. The method involves a combination of two prior object-recognition methods one based on adaptive detection of shape features and one based on adaptive color segmentation to enable recognition in situations in which either prior method by itself may be inadequate. The chosen prior feature-based method is known as adaptive principal-component analysis (APCA); the chosen prior color-based method is known as adaptive color segmentation (ACOSE). These methods are made to interact with each other in a closed-loop system to obtain an optimal solution of the object-recognition problem in a dynamic environment. One of the results of the interaction is to increase, beyond what would otherwise be possible, the accuracy of the determination of a region of interest (containing an object that one seeks to recognize) within an image. Another result is to provide a minimized adaptive step that can be used to update the results obtained by the two component methods when changes of color and apparent shape occur. The net effect is to enable the neural network to update its recognition output and improve its recognition capability via an adaptive learning sequence. In principle, the improved method could readily be implemented in integrated circuitry to make a compact, low-power, real-time object-recognition system. It has been proposed to demonstrate the feasibility of such a system by integrating a 256-by-256 active-pixel sensor with APCA, ACOSE, and neural processing circuitry on a single chip. It has been estimated that such a system on a chip would have a volume no larger than a few cubic centimeters, could operate at a rate as high as 1,000 frames per second, and would consume in the order of milliwatts of power.

Syncope (Fainting)

MedlinePlus

... due to sudden changes in body position, can trigger syncope. It’s important to determine the cause of ... and heart rate malfunctions in response to a trigger, such as emotional stress or pain. NMS typically ...

Blindness to a simultaneous change of all elements in a scene, unless there is a change in summary statistics.

PubMed

Saiki, Jun; Holcombe, Alex O

2012-03-06

Sudden change of every object in a display is typically conspicuous. We find however that in the presence of a secondary task, with a display of moving dots, it can be difficult to detect a sudden change in color of all the dots. A field of 200 dots, half red and half green, half moving rightward and half moving leftward, gave the appearance of two surfaces. When all 200 dots simultaneously switched color between red and green, performance in detecting the switch was very poor. A key display characteristic was that the color proportions on each surface (summary statistics) were not affected by the color switch. When the color switch is accompanied by a change in these summary statistics, people perform well in detecting the switch, suggesting that the secondary task does not disrupt the availability of this statistical information. These findings suggest that when the change is missed, the old and new colors were represented, but the color-location pattern (binding of colors to locations) was not represented or not compared. Even after extended viewing, changes to the individual color-location pattern are not available, suggesting that the feeling of seeing these details is misleading.

Diplacusis, hearing threshold and otoacoustic emissions in an episode of sudden, unilateral cochlear hearing loss.

PubMed

Knight, Richard D

2004-01-01

Limited data are available on the relationship between diplacusis and otoacoustic emissions and sudden hearing threshold changes, and the detail of the mechanism underlying diplacusis is not well understood. Data are presented here from an intensively studied single episode of sudden, non-conductive, mild hearing loss with associated binaural diplacusis, probably due to a viral infection. Treatment with steroids was administered for 1 week. This paper examines the relationships between the hearing loss, diplacusis and otoacoustic emissions during recovery on a day-by-day basis. The hearing thresholds were elevated by up to 20 dB at 4kHz and upwards, and there was an interaural pitch difference up to 12% at 4 and 8 kHz. There was also a frequency-specific change in transient evoked otoacoustic emission (TEOAE) and distortion-product otoacoustic emission (DPOAE) level. DPOAE level was reduced by up to 20 dB. with the greatest change seen when a stimulus with a wide stimulus frequency ratio was used. Frequency shifts in the 2f2-fi DPOAE fine structure corresponded to changes in the diplacusis. Complete recovery to previous levels was observed for TEOAE, DPOAE and hearing threshold. The diplacusis recovered to within normal limits after 4 weeks. The frequency shift seen in the DPOAE fine structure did not quite resolve, suggesting a very slight permanent change. The time-courses of TEOAE. diplacusis and hearing threshold were significantly different: most notably, the hearing threshold was stable over a period when the diplacusis deteriorated. This suggests that the cochlear mechanisms involved in diplacusis, hearing threshold and OAE may not be identical.

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

PubMed

Waxman, D

2012-06-01

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

More on the alleged 1970 geomagnetic jerk

USGS Publications Warehouse

Alldredge, L.R.

1985-01-01

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

Analysis of Alaska transportation sectors to assess energy use and impacts of price shocks and climate change legislation.

DOT National Transportation Integrated Search

2013-04-01

We analyzed the use of energy by Alaskas transportation sectors to assess the impact of sudden fuel prices changes. : We conducted three types of analysis: 1) Development of broad energy use statistics for each transportation sector, : including t...

Education as a Social Control Mechanism.

ERIC Educational Resources Information Center

Bacchus, M. K.

1979-01-01

With the abolition of slavery, most West Indian planters dramatically changed their attitudes toward education for Blacks, suddenly favoring it. This paper examines reasons behind the attitudinal changes, the planters' perceptions on the role of education for Blacks, and the use of education as a mechanism for social control. (DS)

The Year 2000: Teacher Education.

ERIC Educational Resources Information Center

Van Til, William

In speculating about the future, scholar-prophets can account for future social changes (such as those induced by computer technology) by extrapolating current trends, but "systems breaks," or sudden changes in the characteristics of a system (caused by biological transformations for instance) may invalidate their predictions. With that in mind,…

Triaxiality and Exotic Rotations at High Spins in 134Ce

DOE PAGES

Petrache, C. M.; Guo, S.; Ayangeakaa, A. D.; ...

2016-06-06

High-spin states in Ce-134 have been investigated using the Cd-116(Ne-22,4n) reaction and the Gammasphere array. The level scheme has been extended to an excitation energy of similar to 30 MeV and spin similar to 54 (h) over bar. Two new dipole bands and four new sequences of quadrupole transitions were identified. Several new transitions have been added to a number of known bands. One of the strongly populated dipole bands was revised and placed differently in the level scheme, resolving a discrepancy between experiment and model calculations reported previously. Configurations are assigned to the observed bands based on cranked Nilsson-Strutinskymore » calculations. A coherent understanding of the various excitations, both at low and high spins, is thus obtained, supporting an interpretation in terms of coexistence of stable triaxial, highly deformed, and superdeformed shapes up to very high spins. Rotations around different axes of the triaxial nucleus, and sudden changes of the rotation axis in specific configurations, are identified, further elucidating the nature of high-spin collective excitations in the A = 130 mass region.« less

IB-LBM simulation of the haemocyte dynamics in a stenotic capillary.

PubMed

Yuan-Qing, Xu; Xiao-Ying, Tang; Fang-Bao, Tian; Yu-Hua, Peng; Yong, Xu; Yan-Jun, Zeng

2014-01-01

To study the behaviour of a haemocyte when crossing a stenotic capillary, the immersed boundary-lattice Boltzmann method was used to establish a quantitative analysis model. The haemocyte was assumed to be spherical and to have an elastic cell membrane, which can be driven by blood flow to adopt a highly deformable character. In the stenotic capillary, the spherical blood cell was stressed both by the flow and the wall dimension, and the cell shape was forced to be stretched to cross the stenosis. Our simulation investigated the haemocyte crossing process in detail. The velocity and pressure were anatomised to obtain information on how blood flows through a capillary and to estimate the degree of cell damage caused by excessive pressure. Quantitative velocity analysis results demonstrated that a large haemocyte crossing a small stenosis would have a noticeable effect on blood flow, while quantitative pressure distribution analysis results indicated that the crossing process would produce a special pressure distribution in the cell interior and to some extent a sudden change between the cell interior and the surrounding plasma.

Experimental investigation of flow induced dust acoustic shock waves in a complex plasma

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

Jaiswal, S., E-mail: surabhijaiswal73@gmail.com; Bandyopadhyay, P.; Sen, A.

2016-08-15

We report on experimental observations of flow induced large amplitude dust-acoustic shock waves in a complex plasma. The experiments have been carried out in a Π shaped direct current glow discharge experimental device using kaolin particles as the dust component in a background of Argon plasma. A strong supersonic flow of the dust fluid is induced by adjusting the pumping speed and neutral gas flow into the device. An isolated copper wire mounted on the cathode acts as a potential barrier to the flow of dust particles. A sudden change in the gas flow rate is used to trigger themore » onset of high velocity dust acoustic shocks whose dynamics are captured by fast video pictures of the evolving structures. The physical characteristics of these shocks are delineated through a parametric scan of their dynamical properties over a range of flow speeds and potential hill heights. The observed evolution of the shock waves and their propagation characteristics are found to compare well with model numerical results based on a modified Korteweg-de-Vries-Burgers type equation.« less

Sudden cardiac death: epidemiology and risk factors

PubMed Central

Adabag, A. Selcuk; Luepker, Russell V.; Roger, Véronique L.; Gersh, Bernard J.

2016-01-01

Sudden cardiac death (SCD) is an important public-health problem with multiple etiologies, risk factors, and changing temporal trends. Substantial progress has been made over the past few decades in identifying markers that confer increased SCD risk at the population level. However, the quest for predicting the high-risk individual who could be a candidate for an implantable cardioverter-defibrillator, or other therapy, continues. In this article, we review the incidence, temporal trends, and triggers of SCD, and its demographic, clinical, and genetic risk factors. We also discuss the available evidence supporting the use of public-access defibrillators. PMID:20142817

Automatic background updating for video-based vehicle detection

NASA Astrophysics Data System (ADS)

Hu, Chunhai; Li, Dongmei; Liu, Jichuan

2008-03-01

Video-based vehicle detection is one of the most valuable techniques for the Intelligent Transportation System (ITS). The widely used video-based vehicle detection technique is the background subtraction method. The key problem of this method is how to subtract and update the background effectively. In this paper an efficient background updating scheme based on Zone-Distribution for vehicle detection is proposed to resolve the problems caused by sudden camera perturbation, sudden or gradual illumination change and the sleeping person problem. The proposed scheme is robust and fast enough to satisfy the real-time constraints of vehicle detection.

Interaction of doughnut-shaped laser pulses with glasses

DOE PAGES

Zhukov, Vladimir P.; Rubenchik, Alexander M.; Fedoruk, Mikhail P.; ...

2017-01-26

Non-Gaussian laser beams can open new opportunities for microfabrication, including ultrashort laser direct writing. By using a model based on Maxwell’s equations, we investigate the dynamics of doughnut-shaped laser beams focused inside fused silica glass, in comparison with Gaussian pulses of the same energy. The laser propagation dynamics reveals intriguing features of beam splitting and sudden collapse toward the beam axis, overcoming the intensity clamping effect. The resulting structure of light absorption represents a very hot, hollow nanocylinder, which can lead to an implosion process that brings matter to extreme thermodynamic states. Furthermore, by monitoring the simulations of the lasermore » beam scattering we see a considerable difference in both the blueshift and the angular distribution of scattered light for different laser energies, suggesting that investigations of the spectra of scattered radiation can be used as a diagnostic of laser-produced electron plasmas in transparent materials.« less

Functional spasm of accommodation: Changes on scheimpflug imaging

PubMed Central

Sukhija, Jaspreet; Dogra, Mangat R.; Zadeng, Thara; Ram, Jagat

2014-01-01

Spasm of accommodation is a rare condition characterized by a sudden increase in myopia. It can occur in emmetropes, hypermetropes and myopes. All the physiological changes that occur in normal accommodation are exaggerated. Mostly the cause is functional disorder and the condition gradually improves. We hereby present the changes occurring in spasm of accommodation as seen on Scheimpflug imaging. PMID:25378883

Type-2 fuzzy logic control based MRAS speed estimator for speed sensorless direct torque and flux control of an induction motor drive.

PubMed

Ramesh, Tejavathu; Kumar Panda, Anup; Shiva Kumar, S

2015-07-01

In this research study, a model reference adaptive system (MRAS) speed estimator for speed sensorless direct torque and flux control (DTFC) of an induction motor drive (IMD) using two adaptation mechanism schemes are proposed to replace the conventional proportional integral controller (PIC). The first adaptation mechanism scheme is based on Type-1 fuzzy logic controller (T1FLC), which is used to achieve high performance sensorless drive in both transient as well as steady state conditions. However, the Type-1 fuzzy sets are certain and unable to work effectively when higher degree of uncertainties presents in the system which can be caused by sudden change in speed or different load disturbances, process noise etc. Therefore, a new Type-2 fuzzy logic controller (T2FLC) based adaptation mechanism scheme is proposed to better handle the higher degree of uncertainties and improves the performance and also robust to various load torque and sudden change in speed conditions, respectively. The detailed performances of various adaptation mechanism schemes are carried out in a MATLAB/Simulink environment with a speed sensor and speed sensorless modes of operation when an IMD is operating under different operating conditions, such as, no-load, load and sudden change in speed, respectively. To validate the different control approaches, the system also implemented on real-time system and adequate results are reported for its validation. Copyright © 2015 ISA. Published by Elsevier Ltd. All rights reserved.

High vacuum measurements and calibrations, molecular flow fluid transient effects

DOE PAGES

Leishear, Robert A.; Gavalas, Nickolas A.

2015-04-29

High vacuum pressure measurements and calibrations below 1 × 10 -8 Torr are problematic. Specifically, measurement accuracies change drastically for vacuum gauges when pressures are suddenly lowered in vacuum systems. How can gauges perform like this? A brief system description is first required to answer this question. Calibrations were performed using a vacuum calibration chamber with attached vacuum gauges. To control chamber pressures, vacuum pumps decreased the chamber pressure while nitrogen tanks increased the chamber pressure. By balancing these opposing pressures, equilibrium in the chamber was maintained at selected set point pressures to perform calibrations. When pressures were suddenly decreasedmore » during set point adjustments, a sudden rush of gas from the chamber also caused a surge of gas from the gauges to decrease the pressures in those gauges. Gauge pressures did not return to equilibrium as fast as chamber pressures due to the sparse distribution of gas molecules in the system. This disparity in the rate of pressure changes caused the pressures in different gauges to be different than expected. This discovery was experimentally proven to show that different gauge designs return to equilibrium at different rates, and that gauge accuracies vary for different gauge designs due to fluid transients in molecular flow.« less

Case management and quality: have we reached a tipping point?

PubMed

Dulworth, Sherrie

2006-01-01

In The Tipping Point, Malcolm Gladwell describes a phenomenon in which a niche market or fad undergoes transformation into mainstream acceptability, resulting in widespread social change. He concludes that a "tipping point" occurs when a series of small events results in a critical mass of acceptance that produces sudden major changes.

Pressure Distribution Over Airfoils at High Speeds

NASA Technical Reports Server (NTRS)

Briggs, L J; Dryden, H L

1927-01-01

This report deals with the pressure distribution over airfoils at high speeds, and describes an extension of an investigation of the aerodynamic characteristics of certain airfoils which was presented in NACA Technical Report no. 207. The results presented in report no. 207 have been confirmed and extended to higher speeds through a more extensive and systematic series of tests. Observations were also made of the air flow near the surface of the airfoils, and the large changes in lift coefficients were shown to be associated with a sudden breaking away of the flow from the upper surface. The tests were made on models of 1-inch chord and comparison with the earlier measurements on models of 3-inch chord shows that the sudden change in the lift coefficient is due to compressibility and not to a change in the Reynolds number. The Reynolds number still has a large effect, however, on the drag coefficient. The pressure distribution observations furnish the propeller designer with data on the load distribution at high speeds, and also give a better picture of the air-flow changes.

Cluster Headache

MedlinePlus

... after a head injury, even if it's a minor fall or bump, especially if it worsens A sudden, severe headache unlike any you've had A headache that worsens over days and changes in pattern Causes The exact cause of cluster ...

Acute arterial occlusion - kidney

MedlinePlus

... the second kidney can filter the blood. However, high blood pressure (hypertension) may come on suddenly and be difficult ... pain or pain in the side Symptoms of high blood pressure such as headache, change in vision, and swelling ...

Study of Geomagnetic Field Response to Solar Wind Forcing

NASA Astrophysics Data System (ADS)

Kim, S.; Li, X.; Damas, M. C.; Ngwira, C.

2017-12-01

The solar wind is an integral component of space weather that has a huge impact on the near-Earth space conditions, which can in turn adversely impact technological infrastructure. By analyzing solar wind data, we can investigate the response of the Earth's magnetic field to changes in solar wind conditions, such as dynamic pressure, speed, and interplanetary magnetic fields (IMF). When a coronal mass ejection (CME) hits the Earth's magnetosphere, it compresses the dayside magnetosphere, which leads to SSC (Sudden Storm Commencement) seen in Dst or SYM-H index. Dst and SYM-H index are a measure of geomagnetic storm intensity that represents the magnetic field perturbations in the equatorial region originating from ring current. In this study, we focused on SSC intervals with sudden density increase, density, greater than 10 n/cc from 2000 to 2015 using data obtained from the NASA CDAWEB service. A total of 1,049 events were picked for this project. Then using INTERMAGNET service, corresponding horizontal component of magnetic field data were collected from several stations located in equatorial region, mid-latitude region, high-latitude region on the day-side and night-side of Earth. Using MATLAB, we calculated the rate of change of magnetic fields (dB/dt) for each station and each event. We found that in most cases, the sudden increase in proton density is associated with large changes in magnetic fields, dB/dt. The largest magnetic field changes were observed on the day-side than night-side at high latitudes. Interestingly, some exceptions were found such that greater dB/dt was found on night-side than day-side during some events, particularly at high latitudes. We suspect these are driven by magnetospheric substorms, which are manifested by an explosive release of energy in the local midnight sector. The next step will be creating the statistical form to see the correlation between proton density changes and magnetic field changes.

Adaptation of muscles of the lumbar spine to sudden imbalance in patients with lower back pain caused by military training.

PubMed

Gao, Ying; Shi, Jian-guo; Ye, Hong; Liu, Zhi-rong; Zheng, Long-bao; Ni, Zhi-ming; Fan, Liang-quan; Wang, Jian; Hou, Zhen-hai

2014-11-01

This study aims to investigate the effects of sudden load changes (expected and unexpected imbalance) on the activity of muscles of the lumbar spine and their central motor control strategy in military personnel with or without chronic low back pain (LBP). Bilateral sudden imbalance was examined (2 × 2 factorial design). The 117th PLA Hospital, Hangzhou, China Twenty-one male subjects with lower back pain and 21 male healthy control subjects were active members of the Nanjing Military Region land forces. Independent variables: LBP vs. healthy controls and imbalance anticipation (expected and unexpected imbalance). rapid reaction time (RRT) and intensity of rapid reaction (IRR) of bilateral lumbar (L3-L4) erector spinae (ES), lumbar (L5-S1) multifidus (MF), and abdominal external oblique muscles. Results Under expected or unexpected sudden imbalance conditions, subjects with LBP demonstrated significantly greater IRR than healthy controls in ipsilateral and contralateral ES and MF, respectively (P < 0.05 for all). IRR of contralateral ES was significantly larger than that of the ipsilateral ES. A significant group effect of RRT of both ipsilateral and contralateral ES muscles and a significant time expectation effect on RRT of contralateral MF muscles were also observed. RRT of the contralateral ES muscles was significantly lower than that of the ipsilateral ES muscles (P < 0.001). Sudden imbalance prolonged RRT of selected trunk muscles in patients with chronic LBP. The activation amplitude increased. The results may provide a theoretical basis for a study on the pathogenesis of chronic LBP.

An Analytical-Numerical Model for Two-Phase Slug Flow through a Sudden Area Change in Microchannels

DOE PAGES

Momen, A. Mehdizadeh; Sherif, S. A.; Lear, W. E.

2016-01-01

In this article, two new analytical models have been developed to calculate two-phase slug flow pressure drop in microchannels through a sudden contraction. Even though many studies have been reported on two-phase flow in microchannels, considerable discrepancies still exist, mainly due to the difficulties in experimental setup and measurements. Numerical simulations were performed to support the new analytical models and to explore in more detail the physics of the flow in microchannels with a sudden contraction. Both analytical and numerical results were compared to the available experimental data and other empirical correlations. Results show that models, which were developed basedmore » on the slug and semi-slug assumptions, agree well with experiments in microchannels. Moreover, in contrast to the previous empirical correlations which were tuned for a specific geometry, the new analytical models are capable of taking geometrical parameters as well as flow conditions into account.« less

Comprehensive multilevel in vivo and in vitro analysis of heart rate fluctuations in mice by ECG telemetry and electrophysiology.

PubMed

Fenske, Stefanie; Pröbstle, Rasmus; Auer, Franziska; Hassan, Sami; Marks, Vanessa; Pauza, Danius H; Biel, Martin; Wahl-Schott, Christian

2016-01-01

The normal heartbeat slightly fluctuates around a mean value; this phenomenon is called physiological heart rate variability (HRV). It is well known that altered HRV is a risk factor for sudden cardiac death. The availability of genetic mouse models makes it possible to experimentally dissect the mechanism of pathological changes in HRV and its relation to sudden cardiac death. Here we provide a protocol that allows for a comprehensive multilevel analysis of heart rate (HR) fluctuations. The protocol comprises a set of techniques that include in vivo telemetry and in vitro electrophysiology of intact sinoatrial network preparations or isolated single sinoatrial node (SAN) cells. In vitro preparations can be completed within a few hours, with data acquisition within 1 d. In vivo telemetric ECG requires 1 h for surgery and several weeks for data acquisition and analysis. This protocol is of interest to researchers investigating cardiovascular physiology and the pathophysiology of sudden cardiac death.

[The influence of alcohol consumption on the chronological patterns of sudden cardiac death].

PubMed

Sapozhnikov, S P; Kozlov, V A; Golenkov, A V; Kichigin, V A; Karyshev, P B; Samarkina, O Yu

2015-01-01

The objective of the present study was the retrospective analysis of the materials collected by the Republican Bureau of Forensic Medical Expertise, Ministry of Health and Social Development of Chuvash Republic, during the period from 1997 till 2002 for the elucidation of the chronological patterns of sudden cardiac death (SCD) associated with alcohol consumption depending on the sex and age of the victims, days of the week and months of the year as well as weather conditions. It was shown that the peak of mortality among men and women taking no alcohol fell on Monday. It was highest in May and decreased by February. The alcohol consumption significantly changes the chronological patterns of mortality from cardiovascular pathology. It was highest among the women abusing alcohol in August and October. The study has demonstrated a weak negative correlation between the frequency of sudden cardiac death among non-consumers of alcohol and dew-point temperature among the persons having alcohol in blood.

Blunt trauma to large vessels: a mathematical study

PubMed Central

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

2004-01-01

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

Early cortical metabolic rearrangement related to clinical data in idiopathic sudden sensorineural hearing loss.

PubMed

Micarelli, Alessandro; Chiaravalloti, Agostino; Viziano, Andrea; Danieli, Roberta; Schillaci, Orazio; Alessandrini, Marco

2017-07-01

Results in studies concerning cortical changes in idiopathic sudden sensorineural hearing loss (ISSNHL) are not homogeneous, in particular due to the different neuroimaging techniques implemented and the diverse stages of ISSNHL studied. Considering the recent advances in state-of-the-art positron emission tomography (PET) cameras, the aim of this study was to gain more insight into the neuroanatomical differences associated with the earliest stages of unilateral ISSNHL and clinical-perceptual performance changes. After an audiological examination including the mean auditory threshold (mean AT), mean speech discrimination score (mean SDS) and Tinnitus Handicap Inventory (THI), 14 right-handed ISSNHL patients underwent brain [ 18 F]fluorodeoxyglucose (FDG)-PET within 72 h of the onset of symptoms. When compared to an homogeneous group of 35 healthy subjects by means of statistical parametric mapping, a relative increase in FDG uptake was found in the right superior and medial frontal gyrus as well as in the right anterior cingulate cortex in ISSNHL patients. Conversely, the same group showed a significant relative decrease in FDG uptake in the right middle temporal, precentral and postcentral gyrus as well as in the left posterior cingulate cortex, left lingual, superior, middle temporal and middle frontal gyrus and in the left insula. Regression analysis showed a positive correlation between mean THI and glucose consumption in the right anterior cingulate cortex and a positive correlation between mean SDS and glucose consumption in the left precentral gyrus. The relative changes in FDG uptake found in these brain regions and the positive correlation with mean SDS and THI scores in ISSNHL could possibly highlight new aspects of cerebral rearrangement, contributing to further explain changes in those functions that support speech recognition during the sudden impairment of unilateral auditory input. Copyright © 2017 Elsevier B.V. All rights reserved.

Artificial reproduction of magnetic fields produced by a natural geomagnetic storm increases systolic blood pressure in rats.

PubMed

Martínez-Bretón, J L; Mendoza, B; Miranda-Anaya, M; Durán, P; Flores-Chávez, P L

2016-11-01

The incidence of geomagnetic storms may be associated with changes in circulatory physiology. The way in which the natural variations of the geomagnetic field due to solar activity affects the blood pressure are poorly understood and require further study in controlled experimental designs in animal models. In the present study, we tested whether the systolic arterial pressure (AP) in adult rats is affected by simulated magnetic fields resembling the natural changes of a geomagnetic storm. We exposed adult rats to a linear magnetic profile that simulates the average changes associated to some well-known geomagnetic storm phases: the sudden commencement and principal phase. Magnetic stimulus was provided by a coil inductor and regulated by a microcontroller. The experiments were conducted in the electromagnetically isolated environment of a semi-anechoic chamber. After exposure, AP was determined with a non-invasive method through the pulse on the rat's tail. Animals were used as their own control. Our results indicate that there was no statistically significant effect in AP when the artificial profile was applied, neither in the sudden commencement nor in the principal phases. However, during the experimental period, a natural geomagnetic storm occurred, and we did observe statistically significant AP increase during the sudden commencement phase. Furthermore, when this storm phase was artificially replicated with a non-linear profile, we noticed a 7 to 9 % increase of the rats' AP in relation to a reference value. We suggested that the changes in the geomagnetic field associated with a geomagnetic storm in its first day could produce a measurable and reproducible physiological response in AP.

Extreme temperatures and out-of-hospital coronary deaths in six large Chinese cities.

PubMed

Chen, Renjie; Li, Tiantian; Cai, Jing; Yan, Meilin; Zhao, Zhuohui; Kan, Haidong

2014-12-01

The seasonal trend of out-of-hospital coronary death (OHCD) and sudden cardiac death has been observed, but whether extreme temperature serves as a risk factor is rarely investigated. We therefore aimed to evaluate the impact of extreme temperatures on OHCDs in China. We obtained death records of 126,925 OHCDs from six large Chinese cities (Harbin, Beijing, Tianjin, Nanjing, Shanghai and Guangzhou) during the period 2009-2011. The short-term associations between extreme temperature and OHCDs were analysed with time-series methods in each city, using generalised additive Poisson regression models. We specified distributed lag non-linear models in studying the delayed effects of extreme temperature. We then applied Bayesian hierarchical models to combine the city-specific effect estimates. The associations between extreme temperature and OHCDs were almost U-shaped or J-shaped. The pooled relative risks (RRs) of extreme cold temperatures over the lags 0-14 days comparing the 1st and 25th centile temperatures were 1.49 (95% posterior interval (PI) 1.26-1.76); the pooled RRs of extreme hot temperatures comparing the 99th and 75th centile temperatures were 1.53 (95% PI 1.27-1.84) for OHCDs. The RRs of extreme temperature on OHCD were higher if the patients with coronary heart disease were old, male and less educated. This multicity epidemiological study suggested that both extreme cold and hot temperatures posed significant risks on OHCDs, and might have important public health implications for the prevention of OHCD or sudden cardiac death. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Plasmas in the atmosphere, tectonics and earthquake: a possible link for the crustal diagnosis?

NASA Astrophysics Data System (ADS)

Straser, V.

2017-12-01

An important aspect in the crustal surmise is the potential link between luminous phenomena and the earthquake . The study want to added data to this new geophysics concepts. The method is based on the comparison approach and consist in the data connection on a field in the area of Po Plain (Italy) with professional equipment: cameras, video cameras, spectroscopes, ELF / VLF receivers, Geiger counters and EM fields detectors. The Luminous phenomena sighting is compared 24/7 online with INGV and USGS database. The results show the formation of 2 types of plasma near the soil: Spheroidal shape, yellow-orange, constant brightness, sudden appearances, elevation from the ground between 10 ° -20 °, no noise, no wake emitted, estimated size about 2m, and duration of few seconds. Spheroidal shape, intense red fuzzy coloration, constant brightness, sudden appearances and fast movements in a linear fashion or slow movements, elevation from the ground between 2° to 7 °, no noise, no waves emitted, estimated dimensions over 2m, with a duration from a few seconds to a few minutes. We suppose that the formation of gas, also radioactive such as radon, and the electric charges necessary to trigger plasma, are related to the crustal stress. The rocks are exposed to important tectonics efforts and the outcome is the air ionizations near the soil that produce plasma if there are gas. The appearance of plasma forerun the earthquake that will happen some days later. The Anomalous Luminous phenomena may be related to tectonic activity, and the area of investigation can become a "lab" for research in Physics and Geology for the crustal diagnosis of pre-seismic phase.

Effects of H2O, CO2, and N2 Air Contaminants on Critical Airside Strain Rates for Extinction of Hydrogen-Air Counterflow Diffusion Flames

NASA Technical Reports Server (NTRS)

Pellett, G. L.; Wilson, L. G.; Northam, G. B.; Guerra, Rosemary

1989-01-01

Coaxial tubular opposed jet burners (OJB) were used to form dish shaped counterflow diffusion flames (CFDF), centered by opposing laminar jets of H2, N2 and both clean and contaminated air (O2/N2 mixtures) in an argon bath at 1 atm. Jet velocities for flame extinction and restoration limits are shown versus wide ranges of contaminant and O2 concentrations in the air jet, and also input H2 concentration. Blowoff, a sudden breaking of CFDF to a stable ring shape, occurs in highly stretched stagnation flows and is generally believed to measure kinetically limited flame reactivity. Restore, a sudden restoration of central flame, is a relatively new phenomenon which exhibits a H2 dependent hysteresis from Blowoff. For 25 percent O2 air mixtures, mole for mole replacement of 25 percent N2 contaminant by steam increased U(air) or flame strength at Blowoff by about 5 percent. This result is consistent with laminar burning velocity results from analogous substitution of steam for N2 in a premixed stoichiometric H2-O2-N2 (or steam) flame, shown by Koroll and Mulpuru to promote a 10 percent increase in experimental and calculated laminar burning velocity, due to enhanced third body efficiency of water in: H + O2 + M yields HO2 + M. When the OJB results were compared with Liu and MacFarlane's experimental laminar burning velocity of premixed stoichiometric H2 + air + steam, a crossover occurred, i.e., steam enhanced OJB flame strength at extinction relative to laminar burning velocity.

40 CFR 717.12 - Significant adverse reactions that must be recorded.

Code of Federal Regulations, 2013 CFR

2013-07-01

...: (1) Gradual or sudden changes in the composition of animal life or plant life, including fungal or..., whether crops or livestock. (5) Alterations in the behavior or distribution of a species. (6) Long lasting...

40 CFR 717.12 - Significant adverse reactions that must be recorded.

Code of Federal Regulations, 2012 CFR

2012-07-01

...: (1) Gradual or sudden changes in the composition of animal life or plant life, including fungal or..., whether crops or livestock. (5) Alterations in the behavior or distribution of a species. (6) Long lasting...

Transitions between refrigeration regions in extremely short quantum cycles

NASA Astrophysics Data System (ADS)

Feldmann, Tova; Kosloff, Ronnie

2016-05-01

The relation between the geometry of refrigeration cycles and their performance is explored. The model studied is based on a coupled spin system. Small cycle times, termed sudden refrigerators, develop coherence and inner friction. We explore the interplay between coherence and energy of the working medium employing a family of sudden cycles with decreasing cycle times. At the point of maximum coherence the cycle changes geometry. This region of cycle times is characterized by a dissipative resonance where heat is dissipated both to the hot and cold baths. We rationalize the change of geometry of the cycle as a result of a half-integer quantization which maximizes coherence. From this point on, increasing or decreasing the cycle time, eventually leads to refrigeration cycles. The transition point between refrigerators and short circuit cycles is characterized by a transition from finite to singular dynamical temperature. Extremely short cycle times reach a universal limit where all cycles types are equivalent.

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

NASA Astrophysics Data System (ADS)

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

2010-06-01

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

Catastrophic global-avalanche of a hollow pressure filament

NASA Astrophysics Data System (ADS)

van Compernolle, B.; Poulos, M. J.; Morales, G. J.

2017-10-01

New results are presented of a basic heat transport experiment performed in the Large Plasma Device at UCLA. A ring-shaped electron beam source injects low energy electrons along a strong magnetic field into a preexisting, large and cold plasma. The injected electrons are thermalized by Coulomb collisions within a short distance and provide an off-axis heat source that results in a long, hollow, cylindrical region of elevated plasma pressure. The off-axis source is active for a period long compared to the density decay time, i.e., as time progresses the power per particle increases. Two distinct regimes are observed to take place, an early regime dominated by multiple avalanches, identified as a sudden intermittent rearrangement of the pressure profile that repeats under sustained heating, and a second regime dominated by broadband drift-Alfvén fluctuations. The transition between the two regimes is sudden and global, both radially and axially. The initial regime is characterized by peaked density and temperature profiles, while only the peaked temperature profile survives in the second regime. Recent measurements at multiple axial locations provide new insight into the axial dynamics of the global avalanche. Sponsored by NSF Grant 1619505 and by DOE/NSF at BaPSF.

Rendering edge enhancement tactile phenomenon by friction variation in dynamic touch.

PubMed

Abdolvahab, Mohammad

2011-01-04

Variable friction tactile displays have been recently used to render virtual textures and gratings. Neural basis of perceptual mechanism of detection of edge-like features resulting in discrimination of virtual gratings during active touching these tactile actuators is studied using a finite-element biomechanical model of human fingertip. The predicted neural response of the mechanoreceptors, i.e. the computed strain energy density at the location of selected mechanoreceptors as a measure of neural discharge rate of the corresponding receptors, to local reduction of friction between fingerpad and surface are shown to exhibit a similar shape as the edge enhancement phenomenon, particularly in a sudden burst at the boundary of variable friction regions. This phenomenon is supposed to account for the illusion of virtual edges rendered through the modification of contact forces. The presence of this sudden burst under varied model parameters was investigated. It was shown that while the appearance of this phenomenon in simulation results was invariant to model parameters, associated alteration of the edge enhancement ratio might be considered for the purpose of the tuning of the variable friction tactile display. Copyright © 2010 Elsevier Ltd. All rights reserved.

Predicting events in the development of a coal surface mine in the west

Treesearch

Lynn M. Ferrante; Edward C. Thor

1980-01-01

Sudden changes in the level of coal mining activity in an area can cause immediate and profound changes in every facet of life in a rural community. Local officials and administrators of Federal and State governments often bear the brunt of responding to the disruptions that result from these changes. The nature of coal mining in the West is such that the community in...

Ethambutol

MedlinePlus

... doctor immediately: blurred vision inability to see the colors red and green sudden changes in vision skin rash itching If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration's (FDA) MedWatch Adverse Event Reporting ...

Palindromic Rheumatism: Does It Cause Joint Pain?

MedlinePlus

... rheumatoid arthritis? Is palindromic rheumatism a precursor to rheumatoid arthritis? Answers from April Chang-Miller, M.D. About a third of the ... have palindromic rheumatism will go on to develop rheumatoid arthritis. Palindromic rheumatism is characterized by sudden and recurrent ...

Role of the autonomic nervous system in the control of heart rate and blood pressure in the defence reaction in conscious dogs.

PubMed

Federici, A; Rizzo, A; Cevese, A

1985-04-01

The present study was performed on conscious, chronically instrumented dogs, which underwent selective blockade of sympathetic adrenergic and vagal outflows. Excitements were performed on these animals in normal states (N), after chronic treatment with guanethidine, for sympathetic blockade (SB), after cold vagal blockade (VB), and after combined sympathetic and vagal blockade (SB + VB). Heart rate and arterial blood pressure were monitored in all the experiments, while a group of dogs was also tested with an electromagnetic flowmeter on the superior mesenteric artery. The role of the sympathetic and parasympathetic controls in the defence reaction was assumed from comparison of experiments performed in the presence or in the absence of each (or both) autonomic component(s). In the SB + VB condition, excitement was followed by sudden hypotension, without changes in heart rate. In VB experiments, a brief and transient hypotension appeared, followed by gradually developed hypertension, while heart rate progressively rose in about 5 s; there was no sudden increase in mesenteric vascular resistance, which contrasted with the very marked reaction in N experiments. Under vagal control alone (SB), the stimulus elicited prompt tachycardia and hypertension, followed by a period of moderately reduced blood pressure. We conclude that, while the defence reaction leads to a sudden fall of arterial blood pressure, in the absence of compensatory mechanisms, both branches of the autonomic nervous system play a protective role against hypotension. In addition, the modulation of the vagal outflow, leading to sudden changes in the heart performance, seems to be responsible for the initiation of the overall haemodynamic adjustments following excitements. The possibility that withdrawal of the parasympathetic outflow to the heart may raise arterial blood pressure was verified in a special experiment in which artificial vagal stimulation in a conscious (vagal blocked) dog, was turned off for brief periods, before and after guanethidine. This led to changes in blood pressure and heart rate very similar to those seen at the onset of the defence reaction, both in N and SB conditions.

Subject-specific longitudinal shape analysis by coupling spatiotemporal shape modeling with medial analysis

NASA Astrophysics Data System (ADS)

Hong, Sungmin; Fishbaugh, James; Rezanejad, Morteza; Siddiqi, Kaleem; Johnson, Hans; Paulsen, Jane; Kim, Eun Young; Gerig, Guido

2017-02-01

Modeling subject-specific shape change is one of the most important challenges in longitudinal shape analysis of disease progression. Whereas anatomical change over time can be a function of normal aging, anatomy can also be impacted by disease related degeneration. Anatomical shape change may also be affected by structural changes from neighboring shapes, which may cause non-linear variations in pose. In this paper, we propose a framework to analyze disease related shape changes by coupling extrinsic modeling of the ambient anatomical space via spatiotemporal deformations with intrinsic shape properties from medial surface analysis. We compare intrinsic shape properties of a subject-specific shape trajectory to a normative 4D shape atlas representing normal aging to isolate shape changes related to disease. The spatiotemporal shape modeling establishes inter/intra subject anatomical correspondence, which in turn enables comparisons between subjects and the 4D shape atlas, and also quantitative analysis of disease related shape change. The medial surface analysis captures intrinsic shape properties related to local patterns of deformation. The proposed framework jointly models extrinsic longitudinal shape changes in the ambient anatomical space, as well as intrinsic shape properties to give localized measurements of degeneration. Six high risk subjects and six controls are randomly sampled from a Huntington's disease image database for qualitative and quantitative comparison.

The Brittleness and Chemical Stability of Optimized Geopolymer Composites

PubMed Central

Steinerova, Michaela; Matulova, Lenka; Vermach, Pavel; Kotas, Jindrich

2017-01-01

Geopolymers are known as high strength and durable construction materials but have a brittle fracture. In practice, this results in a sudden collapse at ultimate load, without any chance of preventing the breakdown of parts or of withstanding the stress for some time. Glass fiber usage as a total anisotropic shape acting as a compact structure component should hinder the fracture mechanism. The optimized compositions in this study led to a significant reinforcement, especially in the case of flexural strength, but also in terms of the compressive strength and notch toughness. The positive and negative influence of the fibers on the complex composite properties provided chemical stability. PMID:28772756

The Brittleness and Chemical Stability of Optimized Geopolymer Composites.

PubMed

Steinerova, Michaela; Matulova, Lenka; Vermach, Pavel; Kotas, Jindrich

2017-04-09

Geopolymers are known as high strength and durable construction materials but have a brittle fracture. In practice, this results in a sudden collapse at ultimate load, without any chance of preventing the breakdown of parts or of withstanding the stress for some time. Glass fiber usage as a total anisotropic shape acting as a compact structure component should hinder the fracture mechanism. The optimized compositions in this study led to a significant reinforcement, especially in the case of flexural strength, but also in terms of the compressive strength and notch toughness. The positive and negative influence of the fibers on the complex composite properties provided chemical stability.

Shank Muscle Strength Training Changes Foot Behaviour during a Sudden Ankle Supination

PubMed Central

Hagen, Marco; Lescher, Stephanie; Gerhardt, Andreas; Lahner, Matthias; Felber, Stephan; Hennig, Ewald M.

2015-01-01

Background The peroneal muscles are the most effective lateral stabilisers whose tension braces the ankle joint complex against excessive supination. The purpose of this study was to identify the morphological and biomechanical effects of two machine-based shank muscle training methods. Methods Twenty-two healthy male recreationally active sports students performed ten weeks of single-set high resistance strength training with 3 training sessions per week. The subjects conducted subtalar pronator/supinator muscle training (ST) with the right leg by using a custom-made apparatus; the left foot muscles were exercised with machine-based talocrural plantar and dorsiflexor training (TT). Muscle strength (MVIC), muscle volume and foot biomechanics (rearfoot motion, ground reaction forces, muscle reaction times) during a sudden ankle supination were recorded before and after the intervention. Results Compared to TT, ST resulted in significantly higher pronator (14% vs. 8%, P<0.01) and supinator MVIC (25% vs. 12%, P<0.01). During sudden foot inversions, both ST and TT resulted in reduced supination velocity (-12%; P<0.01). The muscle reaction onset time was faster after the training in peroneus longus (PL) (P<0.01). Muscle volume of PL (P<0.01) and TA (P<0.01) increased significantly after both ST and TT. Conclusion After both ST and TT, the ankle joint complex is mechanically more stabilised against sudden supinations due to the muscle volume increase of PL and TA. As the reduced supination velocities indicate, the strength training effects are already present during free-fall. According to a sudden ankle supination in standing position, both machine-based dorsiflexor and pronator strength training is recommended for enhancing the mechanical stability of the ankle. PMID:26110847

Adaptation of muscles of the lumbar spine to sudden imbalance in patients with lower back pain caused by military training

PubMed Central

Gao, Ying; Shi, Jian-guo; Ye, Hong; Liu, Zhi-rong; Zheng, Long-bao; Ni, Zhi-ming; Fan, Liang-quan; Wang, Jian; Hou, Zhen-hai

2014-01-01

Objective This study aims to investigate the effects of sudden load changes (expected and unexpected imbalance) on the activity of muscles of the lumbar spine and their central motor control strategy in military personnel with or without chronic low back pain (LBP). Design Bilateral sudden imbalance was examined (2 × 2 factorial design). Setting The 117th PLA Hospital, Hangzhou, China Participants Twenty-one male subjects with lower back pain and 21 male healthy control subjects were active members of the Nanjing Military Region land forces. Outcome measures Independent variables: LBP vs. healthy controls and imbalance anticipation (expected and unexpected imbalance). Dependent variables: rapid reaction time (RRT) and intensity of rapid reaction (IRR) of bilateral lumbar (L3–L4) erector spinae (ES), lumbar (L5–S1) multifidus (MF), and abdominal external oblique muscles. Results Under expected or unexpected sudden imbalance conditions, subjects with LBP demonstrated significantly greater IRR than healthy controls in ipsilateral and contralateral ES and MF, respectively (P < 0.05 for all). IRR of contralateral ES was significantly larger than that of the ipsilateral ES. A significant group effect of RRT of both ipsilateral and contralateral ES muscles and a significant time expectation effect on RRT of contralateral MF muscles were also observed. RRT of the contralateral ES muscles was significantly lower than that of the ipsilateral ES muscles (P < 0.001). Conclusions Sudden imbalance prolonged RRT of selected trunk muscles in patients with chronic LBP. The activation amplitude increased. The results may provide a theoretical basis for a study on the pathogenesis of chronic LBP. PMID:24621023

Prenatal maternal stress shapes children's theory of mind: the QF2011 Queensland Flood Study.

PubMed

Simcock, G; Kildea, S; Elgbeili, G; Laplante, D P; Cobham, V; King, S

2017-08-01

Research shows that stress in pregnancy has powerful and enduring effects on many facets of child development, including increases in behavior problems and neurodevelopmental disorders. Theory of mind is an important aspect of child development that is predictive of successful social functioning and is impaired in children with autism. A number of factors related to individual differences in theory of mind have been identified, but whether theory of mind development is shaped by prenatal events has not yet been examined. In this study we utilized a sudden onset flood that occurred in Queensland, Australia in 2011 to examine whether disaster-related prenatal maternal stress predicts child theory of mind and whether sex of the child or timing of the stressor in pregnancy moderates these effects. Higher levels of flood-related maternal subjective stress, but not objective hardship, predicted worse theory of mind at 30 months (n=130). Further, maternal cognitive appraisal of the flood moderated the effects of stress in pregnancy on girls' theory of mind performance but not boys'. These results illuminate how stress in pregnancy can shape child development and the findings are discussed in relation to biological mechanisms in pregnancy and stress theory.

Changes in the Perceived Risk of Climate Change: Evidence from Sudden Climatic Events

NASA Astrophysics Data System (ADS)

Anttila-Hughes, J. K.

2009-12-01

In the course of the past two decades the threat of anthropogenic climate change has moved from a scientific concern of relative obscurity to become one of the largest environmental and public goods problems in history. During this period public understanding of the risk of climate change has shifted from negligible to quite large. In this paper I propose a means of quantifying this change by examining how sudden events supporting the theory of anthropogenic climate change have affected carbon intensive companies' stock prices. Using CAPM event study methodology for companies in several carbon-intensive industries, I find strong evidence that markets have been reacting to changes in the scientific evidence for climate change for some time. Specifically, the change in magnitude of response over time seems to indicate that investors believed climate change was a potentially serious risk to corporate profits as early as the mid 1990s. Moreover, market reaction dependence on event type indicates that investors are differentiating between different advances in the scientific knowledge. Announcements by NASA GISS that the previous year was a “record hot year” for the globe are associated with negative excess returns, while news of ice shelf collapses are associated with strong positive excess returns. These results imply that investors are aware of how different aspects of climate change will affect carbon intensive companies, specifically in terms of the link between warming in general and polar ice cover.

Identifying the determinants of premature mortality in Russia: overcoming a methodological challenge

PubMed Central

Tomkins, Susannah; Shkolnikov, Vladimir; Andreev, Evgueni; Kiryanov, Nikolay; Leon, David A; McKee, Martin; Saburova, Lyudmila

2007-01-01

Background It is thought that excessive alcohol consumption is related to the high mortality among working age men in Russia. Moreover it has been suggested that alcohol is a key proximate driver of the very sharp fluctuations in mortality seen in this group since the mid-1980s. Designing an individual-level study suitable to address the potential acute effects of alcohol consumption on mortality in Russia has posed a challenge to epidemiologists, especially because of the need to identify factors that could underlie the rapid changes up and down in mortality rates that have been such a distinctive feature of the Russian mortality crisis. In order to address this study question which focuses on exposures acting shortly before sudden death, a cohort would be unfeasibly large and would suffer from recruitment bias. Methods Although the situation in Russia is unusual, with a very high death rate characterised by many sudden and apparently unexpected deaths in young men, the methodological problem is common to research on any cause of death where many deaths are sudden. Results We describe the development of an innovative approach that has overcome some of these challenges: a case-control study employing proxy informants and external data sources to collect information about proximate determinants of mortality. Conclusion This offers a set of principles that can be adopted by epidemiologists studying sudden and unexpected deaths in other settings. PMID:18045487

Parametric Study on Responses of a Self-Anchored Suspension Bridge to Sudden Breakage of a Hanger

PubMed Central

Jiang, Meng; Huang, Cailiang

2014-01-01

The girder of self-anchored suspension bridge is subjected to large compression force applied by main cables. So, serious damage of the girder due to breakage of hangers may cause the collapse of the whole bridge. With the time increasing, the hangers may break suddenly for their resistance capacities decrease due to corrosion. Using nonlinear static and dynamic analysis methods and adopting 3D finite element model, the responses of an actual self-anchored suspension bridge to sudden breakage of hangers are studied in this paper. The results show that the sudden breakage of a hanger causes violent vibration and large changes in internal forces of the bridge. In the process of the vibration, the maximum tension of hanger produced by breakage of a hanger exceeds 2.22 times its initial value, and the reaction forces of the bearings increase by more than 1.86 times the tension of the broken hanger. Based on the actual bridge, the influences of some factors including flexural stiffness of girder, torsion stiffness of girder, flexural stiffness of main cable, weight of girder, weight of main cable, span to sag ratio of main cable, distance of hangers, span length, and breakage time of hanger on the dynamic responses are studied in detail, and the influencing extent of the factors is presented. PMID:25045734

Parametric study on responses of a self-anchored suspension bridge to sudden breakage of a hanger.

PubMed

Qiu, Wenliang; Jiang, Meng; Huang, Cailiang

2014-01-01

The girder of self-anchored suspension bridge is subjected to large compression force applied by main cables. So, serious damage of the girder due to breakage of hangers may cause the collapse of the whole bridge. With the time increasing, the hangers may break suddenly for their resistance capacities decrease due to corrosion. Using nonlinear static and dynamic analysis methods and adopting 3D finite element model, the responses of an actual self-anchored suspension bridge to sudden breakage of hangers are studied in this paper. The results show that the sudden breakage of a hanger causes violent vibration and large changes in internal forces of the bridge. In the process of the vibration, the maximum tension of hanger produced by breakage of a hanger exceeds 2.22 times its initial value, and the reaction forces of the bearings increase by more than 1.86 times the tension of the broken hanger. Based on the actual bridge, the influences of some factors including flexural stiffness of girder, torsion stiffness of girder, flexural stiffness of main cable, weight of girder, weight of main cable, span to sag ratio of main cable, distance of hangers, span length, and breakage time of hanger on the dynamic responses are studied in detail, and the influencing extent of the factors is presented.

Identifying the determinants of premature mortality in Russia: overcoming a methodological challenge.

PubMed

Tomkins, Susannah; Shkolnikov, Vladimir; Andreev, Evgueni; Kiryanov, Nikolay; Leon, David A; McKee, Martin; Saburova, Lyudmila

2007-11-28

It is thought that excessive alcohol consumption is related to the high mortality among working age men in Russia. Moreover it has been suggested that alcohol is a key proximate driver of the very sharp fluctuations in mortality seen in this group since the mid-1980s. Designing an individual-level study suitable to address the potential acute effects of alcohol consumption on mortality in Russia has posed a challenge to epidemiologists, especially because of the need to identify factors that could underlie the rapid changes up and down in mortality rates that have been such a distinctive feature of the Russian mortality crisis. In order to address this study question which focuses on exposures acting shortly before sudden death, a cohort would be unfeasibly large and would suffer from recruitment bias. Although the situation in Russia is unusual, with a very high death rate characterised by many sudden and apparently unexpected deaths in young men, the methodological problem is common to research on any cause of death where many deaths are sudden. We describe the development of an innovative approach that has overcome some of these challenges: a case-control study employing proxy informants and external data sources to collect information about proximate determinants of mortality. This offers a set of principles that can be adopted by epidemiologists studying sudden and unexpected deaths in other settings.

Transgressive Hybrids as Hopeful Monsters.

PubMed

Dittrich-Reed, Dylan R; Fitzpatrick, Benjamin M

2013-06-01

The origin of novelty is a critical subject for evolutionary biologists. Early geneticists speculated about the sudden appearance of new species via special macromutations, epitomized by Goldschmidt's infamous "hopeful monster". Although these ideas were easily dismissed by the insights of the Modern Synthesis, a lingering fascination with the possibility of sudden, dramatic change has persisted. Recent work on hybridization and gene exchange suggests an underappreciated mechanism for the sudden appearance of evolutionary novelty that is entirely consistent with the principles of modern population genetics. Genetic recombination in hybrids can produce transgressive phenotypes, "monstrous" phenotypes beyond the range of parental populations. Transgressive phenotypes can be products of epistatic interactions or additive effects of multiple recombined loci. We compare several epistatic and additive models of transgressive segregation in hybrids and find that they are special cases of a general, classic quantitative genetic model. The Dobzhansky-Muller model predicts "hopeless" monsters, sterile and inviable transgressive phenotypes. The Bateson model predicts "hopeful" monsters with fitness greater than either parental population. The complementation model predicts both. Transgressive segregation after hybridization can rapidly produce novel phenotypes by recombining multiple loci simultaneously. Admixed populations will also produce many similar recombinant phenotypes at the same time, increasing the probability that recombinant "hopeful monsters" will establish true-breeding evolutionary lineages. Recombination is not the only (or even most common) process generating evolutionary novelty, but might be the most credible mechanism for sudden appearance of new forms.

Families in Troubled Times: Adapting to Change in Rural America. Social Institutions and Social Change.

ERIC Educational Resources Information Center

Conger, Rand D.; Elder, Glen H., Jr.

In Iowa in the 1980s, dreams of prosperity were suddenly replaced by economic nightmares as plummeting land values generated economic decline and dislocation in rural communities and individual lives. This book examines the experience of over 400 Iowa families who lived through the Great Farm Crisis and now face an uncertain future. Interviewed as…

[Clinico-pathological conference report: sudden deterioration of general condition, hypokalemia and diabetes in an elderly man].

PubMed

Metso, Saara; Arola, Johanna; Raade, Merja; Välimäki, Matti

2012-01-01

An elderly man had been treated for prostate cancer with radiation and neoadjuvant hormonal therapy. One year after the cessation of radiation therapy, the PSA value was found to be elevated. A non-steroidal antiandrogen bicalutamide was initiated to the patient. Due to poor treatment response the drug was changed for the GnRH agonist leuprorelin acetate, which upon injection caused a sudden deterioration of the patient's general condition. He was delirious and in pain, and was diagnosed with leukocytosis, hypokalemia, hyperglycemia and metabolic alkalosis. The patient was referred to the endocrinological clinic for evaluation of the metabolic-endocrinological problems. He succumbed to disseminated prostate cancer.

On the Self-Organizing Origins of Agency.

PubMed

Kelso, J A Scott

2016-07-01

The question of agency and directedness in living systems has puzzled philosophers and scientists for centuries. What principles and mechanisms underlie the emergence of agency? Analysis and dynamical modeling of experiments on human infants suggest that the birth of agency is due to a eureka-like, pattern-forming phase transition in which the infant suddenly realizes it can make things happen in the world. The main mechanism involves positive feedback: when the baby's initially spontaneous movements cause the world to change, their perceived consequences have a sudden and sustained amplifying effect on the baby's further actions. The baby discovers itself as a causal agent. Some implications of this theory are discussed. Copyright © 2016 Elsevier Ltd. All rights reserved.

[The causality of lunar changes on cardiovascular mortality].

PubMed

Sitar, J

1990-11-09

The author confirmed, based on different ways of processing of 1437 sudden cardiovascular deaths, that the frequency of these deaths changes in the course of the synodic moon with two maxima during the lunar quarters. Processing by the method of transfer of epochs made it possible to shift steadily the mortality curves according to the phase of solar activity. This made the author assume that the cause of the phenomenon of two-phasic change of mortality during lunation cannot be only gravitation (sudden tides) and that in addition the interfering influence of solar corpuscular radiation is involved. It is known that this radiation causes geomagnetic disorders. Consistent with the above view it was proved that in the course of lunation the greatest number of geomagnetic disorders occur at a time close to the lunar quarters. Then, as the author proved--aurora polaris is more frequent. The increased cardiovascular mortality is thus associated with an increased geomagnetic activity. The relationship is certainly not direct. The author indicates further trends of research to disclose the immediate causes which exert an unfavourable effect on our cardiovascular system.

Diagnosis of Brugada's syndrome after subarachnoid injection of prilocaine.

PubMed

Oliván, B; Arbeláez, A; de Miguel, M; Pelavski, A

2016-10-01

Brugada syndrome is an autosomal dominant genetic disease affecting sodium ion channels. It is characterised by right bundle branch block and ST elevation in the right precordial leads, and with no structural cardiac abnormalities. It is associated with sudden death. This disease may be unmasked by certain drugs and sudden changes in autonomic tone. Local anaesthetics may increase ECG changes due to a blockade of the sodium channels, mainly depending on the dose and the type of anaesthetic. Thus, there have been reported electrocardiographic changes consistent with Brugada syndrome, triggered after epidural or paravertebral infusion of bupivacaine and ropivacaine. The case is described of a 66 years old man, scheduled for inguinal herniorrhaphy as an outpatient. He had no history of syncope or arrhythmias. After spinal anaesthesia with 40mg of prilocaine the ECG showed ST elevation>2mm, and right bundle branch block in V1-V3. Copyright © 2015 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. Publicado por Elsevier España, S.L.U. All rights reserved.

Sudden Death in Young People--Heart Problems Often Blamed

MedlinePlus

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

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

NASA Technical Reports Server (NTRS)

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

1990-01-01

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

Adaptation to extreme environments: structure-function relationships in Emperor penguin haemoglobin.

PubMed

Tamburrini, M; Condò, S G; di Prisco, G; Giardina, B

1994-04-15

The functional properties of the single haemoglobin (Hb) of Emperor penguin (Aptenodytes forsteri) have been investigated at different temperatures as a function of proton and organic phosphate concentration. The complete amino acid sequence has been established. Comparison with that of human HbA shows 12 substitutions in the contact regions of alpha beta dimers. In addition to overall similarities shared with most of the avian Hbs previously described, this Hb shows significant differences, which could be related to the peculiar behaviour of this penguin. In particular we may consider that: (1) the shape of the Bohr effect curve seems well adapted for gas exchange during very prolonged dives, preserving penguin Hb from a sudden and not controlled stripping of oxygen; (2) the very minor enthalpy change observed at lower pH could be an example of molecular adaptation, through which oxygen delivery becomes essentially insensitive to exposure to the extremely low temperatures of the environment. Moreover, the small alkaline Bohr effect has been found to be only chloride-linked, since the pH dependence of the oxygen affinity is totally abolished in the absence of this ion. These functional characteristics are discussed on the basis of the primary structure of alpha and beta-chains.

Results on the energy dependence of cosmic ray charge composition

NASA Technical Reports Server (NTRS)

Balasubrahmanyan, V. K.; Ormes, J. F.

1973-01-01

Measurements using a balloon-borne ionization spectrometer on the differential energy spectra of the heavy nuclei of the galactic cosmic radiation are reported. The spectra of individual elements up to oxygen and groups of nuclei up through iron were measured up to almost 100 GeV/nucleon. The energy spectrum of the secondary nuclei, B+N, is steeper than that of the primary nuclei, C+O, by gamma = 0.21 + or - .09 in agreement with other authors. The spectral shapes found are reasonably well represented by single power laws between 2 and 60 GeV/nucleon. Data are consistent with the decrease in the secondary to primary ratio found by others above 20 GeV/nucleon, but it shows no evidence for any sudden change in this ratio within counting statistics. The most dramatic finding is that the spectrum of the iron nuclei is flatter than that of the carbon and oxygen nuclei by 0.57 + or - 0.14 of a power. The experimental techniques for charge and energy determination are presented and corrections due to nuclear disintegration and losses of energy out the bottom of the spectrometer are discussed.

Space Software for Automotive Design

NASA Technical Reports Server (NTRS)

1988-01-01

John Thousand of Wolverine Western Corp. put his aerospace group to work on an unfamiliar job, designing a brake drum using computer design techniques. Computer design involves creation of a mathematical model of a product and analyzing its effectiveness in simulated operation. Technique enables study of performance and structural behavior of a number of different designs before settling on a final configuration. Wolverine employees attacked a traditional brake drum problem, the sudden buildup of heat during fast and repeated braking. Part of brake drum not confined tends to change its shape under combination of heat, physical pressure and rotational forces, a condition known as bellmouthing. Since bellmouthing is a major factor in braking effectiveness, a solution of problem would be a major advance in automotive engineering. A former NASA employee, now a Wolverine employee, knew of a series of NASA computer programs ideally suited to confronting bellmouthing. Originally developed as aids to rocket engine nozzle design, it's capable of analyzing problems generated in a rocket engine or automotive brake drum by heat, expansion, pressure and rotational forces. Use of these computer programs led to new brake drum concept featuring a more durable axle, and heat transfer ribs, or fins, on hub of drum.

Formation of gold nanorods by a stochastic "popcorn" mechanism.

PubMed

Edgar, Jonathan A; McDonagh, Andrew M; Cortie, Michael B

2012-02-28

Gold nanorods have significant technological potential and are of broad interest to the nanotechnology community. The discovery of the seeded, wet-chemical synthetic process to produce them may be regarded as a landmark in the control of metal nanoparticle shape. However, the mechanism by which the initial spherical gold seeds acquire anisotropy is a critical, yet poorly understood, factor. Here we examine the very early stages of rod growth using a combination of techniques including cryogenic transmission electron microscopy, optical spectroscopy, and computational modeling. Reconciliation of the available experimental observations can only be achieved by invoking a stochastic, "popcorn"-like mechanism of growth, in which individual seeds lie quiescent for some time before suddenly and rapidly growing into rods. This is quite different from the steady, concurrent growth of nanorods that has been previously generally assumed. Furthermore we propose that the shape is controlled by the ratio of surface energy of rod sides to rod ends, with values of this quantity in the range of 0.3-0.8 indicated for typical growth solutions.

Computer simulations of nematic drops: Coupling between drop shape and nematic order

NASA Astrophysics Data System (ADS)

Rull, L. F.; Romero-Enrique, J. M.; Fernandez-Nieves, A.

2012-07-01

We perform Monte Carlo computer simulations of nematic drops in equilibrium with their vapor using a Gay-Berne interaction between the rod-like molecules. To generate the drops, we initially perform NPT simulations close to the nematic-vapor coexistence region, allow the system to equilibrate and subsequently induce a sudden volume expansion, followed with NVT simulations. The resultant drops coexist with their vapor and are generally not spherical but elongated, have the rod-like particles tangentially aligned at the surface and an overall nematic orientation along the main axis of the drop. We find that the drop eccentricity increases with increasing molecular elongation, κ. For small κ the nematic texture in the drop is bipolar with two surface defects, or boojums, maximizing their distance along this same axis. For sufficiently high κ, the shape of the drop becomes singular in the vicinity of the defects, and there is a crossover to an almost homogeneous texture; this reflects a transition from a spheroidal to a spindle-like drop.

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

NASA Technical Reports Server (NTRS)

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

2017-01-01

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

Non-local correlations via Wigner-Yanase skew information in two SC-qubit having mutual interaction under phase decoherence

NASA Astrophysics Data System (ADS)

Mohamed, Abdel-Baset A.

2017-10-01

An analytical solution of the master equation that describes a superconducting cavity containing two coupled superconducting charge qubits is obtained. Quantum-mechanical correlations based on Wigner-Yanase skew information, as local quantum uncertainty and uncertainty-induced quantum non-locality, are compared to the concurrence under the effects of the phase decoherence. Local quantum uncertainty exhibits sudden changes during its time evolution and revival process. Sudden death and sudden birth occur only for entanglement, depending on the initial state of the two coupled charge qubits, while the correlations of skew information does not vanish. The quantum correlations of skew information are found to be sensitive to the dephasing rate, the photons number in the cavity, the interaction strength between the two qubits, and the qubit distribution angle of the initial state. With a proper initial state, the stationary correlation of the skew information has a non-zero stationary value for a long time interval under the phase decoherence, that it may be useful in quantum information and computation processes.

DISTANT GOAL ORIENTATION IN BIRDS.

DTIC Science & Technology

homing to a Bowling Green , Ohio loft. Pigeons with one eye surgically removed were able to home. Helicopter tracking is suitable and efficient for...the observation of pigeon navigation behavior. The homeward path varies considerably from the straight line path, sudden attitude changes occur, very

Magnetic substorms and northward IMF turning

NASA Astrophysics Data System (ADS)

Troshichev, Oleg; Podorozhkina, Nataly

To determine the relation of the northward IMF turnings to substorm sudden onsets, we separated all events with sharp northward IMF turnings observed in years of solar maximum (1999-2002) and solar minimum (2007-2008). The events (N=261) have been classified in 5 groups in accordance with average magnetic activity in auroral zone (low, moderate or high levels of AL index) at unchanged or slightly changed PC index and with dynamics of PC (steady distinct growth or distinct decline) at arbitrary values of AL index. Statistical analysis of relationships between the IMF turning and changes of PC and AL indices has been fulfilled separately for each of 5 classes. Results of the analysis showed that, irrespective of geophysical conditions and solar activity epoch, the magnetic activity in the polar caps and in the auroral zone demonstrate no response to the sudden northward IMF turning, if the moment of northward turning is taken as a key date. Sharp increases of magnetic disturbance in the auroral zone are observed only under conditions of the growing PC index and statistically they are related to moment of the PC index exceeding the threshold level (~1.5 mV/m), not to northward turnings timed, as a rule, after the moment of sudden onset. Magnetic disturbances observed in these cases in the auroral zone (magnetic substorms) are guided by behavior of the PC index, like to ordinary magnetic substorms or substorms developed under conditions of the prolonged northward IMF impact on the magnetosphere. The evident inconsistency between the sharp IMF changes measured outside of the magnetosphere and behavior of the ground-based PC index, the latter determining the substorm development, provides an additional argument in favor of the PC index as a ground-based proxy of the solar wind energy that entered into magnetosphere.

Rho-Kinase Inhibition During Early Cardiac Development Causes Arrhythmogenic Right Ventricular Cardiomyopathy in Mice.

PubMed

Ellawindy, Alia; Satoh, Kimio; Sunamura, Shinichiro; Kikuchi, Nobuhiro; Suzuki, Kota; Minami, Tatsuro; Ikeda, Shohei; Tanaka, Shinichi; Shimizu, Toru; Enkhjargal, Budbazar; Miyata, Satoshi; Taguchi, Yuhto; Handoh, Tetsuya; Kobayashi, Kenta; Kobayashi, Kazuto; Nakayama, Keiko; Miura, Masahito; Shimokawa, Hiroaki

2015-10-01

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is characterized by fibrofatty changes of the right ventricle, ventricular arrhythmias, and sudden death. Though ARVC is currently regarded as a disease of the desmosome, desmosomal gene mutations have been identified only in half of ARVC patients, suggesting the involvement of other associated mechanisms. Rho-kinase signaling is involved in the regulation of intracellular transport and organizes cytoskeletal filaments, which supports desmosomal protein complex at the myocardial cell-cell junctions. Here, we explored whether inhibition of Rho-kinase signaling is involved in the pathogenesis of ARVC. Using 2 novel mouse models with SM22α- or αMHC-restricted overexpression of dominant-negative Rho-kinase, we show that mice with Rho-kinase inhibition in the developing heart (SM22α-restricted) spontaneously develop cardiac dilatation and dysfunction, myocardial fibrofatty changes, and ventricular arrhythmias, resulting in premature sudden death, phenotypes fulfilling the criteria of ARVC in humans. Rho-kinase inhibition in the developing heart results in the development of ARVC phenotypes in dominant-negative Rho-kinase mice through 3 mechanisms: (1) reduction of cardiac cell proliferation and ventricular wall thickness, (2) stimulation of the expression of the proadipogenic noncanonical Wnt ligand, Wnt5b, and the major adipogenic transcription factor, PPARγ (peroxisome proliferator activated receptor-γ), and inhibition of Wnt/β-catenin signaling, and (3) development of desmosomal abnormalities. These mechanisms lead to the development of cardiac dilatation and dysfunction, myocardial fibrofatty changes, and ventricular arrhythmias, ultimately resulting in sudden premature death in this ARVC mouse model. This study demonstrates a novel crucial role of Rho-kinase inhibition during cardiac development in the pathogenesis of ARVC in mice. © 2015 American Heart Association, Inc.

Abrupt climate change and transient climates during the Paleogene: a marine perspective.

PubMed

Zachos, J C; Lohmann, K C; Walker, J C; Wise, S W

1993-03-01

Detailed investigations of high latitude sequences recently collected by the Ocean Drilling Program (ODP) indicate that periods of rapid climate change often culminated in brief transient climates, with more extreme conditions than subsequent long term climates. Two examples of such events have been identified in the Paleogene; the first in latest Paleocene time in the middle of a warming trend that began several million years earlier: the second in earliest Oligocene time near the end of a Middle Eocene to Late Oligocene global cooling trend. Superimposed on the earlier event was a sudden and extreme warming of both high latitude sea surface and deep ocean waters. Imbedded in the latter transition was an abrupt decline in high latitude temperatures and the brief appearance of a full size continental ice-sheet on Antarctica. In both cases the climate extremes were not stable, lasting for less than a few hundred thousand years, indicating a temporary or transient climate state. Geochemical and sedimentological evidence suggest that both Paleogene climate events were accompanied by reorganizations in ocean circulation, and major perturbations in marine productivity and the global carbon cycle. The Paleocene-Eocene thermal maximum was marked by reduced oceanic turnover and decreases in global delta 13C and in marine productivity, while the Early Oligocene glacial maximum was accompanied by intensification of deep ocean circulation and elevated delta 13C and productivity. It has been suggested that sudden changes in climate and/or ocean circulation might occur as a result of gradual forcing as certain physical thresholds are exceeded. We investigate the possibility that sudden reorganizations in ocean and/or atmosphere circulation during these abrupt transitions generated short-term positive feedbacks that briefly sustained these transient climatic states.

Abrupt climate change and transient climates during the Paleogene: a marine perspective

NASA Technical Reports Server (NTRS)

Zachos, J. C.; Lohmann, K. C.; Walker, J. C.; Wise, S. W.

1993-01-01

Detailed investigations of high latitude sequences recently collected by the Ocean Drilling Program (ODP) indicate that periods of rapid climate change often culminated in brief transient climates, with more extreme conditions than subsequent long term climates. Two examples of such events have been identified in the Paleogene; the first in latest Paleocene time in the middle of a warming trend that began several million years earlier: the second in earliest Oligocene time near the end of a Middle Eocene to Late Oligocene global cooling trend. Superimposed on the earlier event was a sudden and extreme warming of both high latitude sea surface and deep ocean waters. Imbedded in the latter transition was an abrupt decline in high latitude temperatures and the brief appearance of a full size continental ice-sheet on Antarctica. In both cases the climate extremes were not stable, lasting for less than a few hundred thousand years, indicating a temporary or transient climate state. Geochemical and sedimentological evidence suggest that both Paleogene climate events were accompanied by reorganizations in ocean circulation, and major perturbations in marine productivity and the global carbon cycle. The Paleocene-Eocene thermal maximum was marked by reduced oceanic turnover and decreases in global delta 13C and in marine productivity, while the Early Oligocene glacial maximum was accompanied by intensification of deep ocean circulation and elevated delta 13C and productivity. It has been suggested that sudden changes in climate and/or ocean circulation might occur as a result of gradual forcing as certain physical thresholds are exceeded. We investigate the possibility that sudden reorganizations in ocean and/or atmosphere circulation during these abrupt transitions generated short-term positive feedbacks that briefly sustained these transient climatic states.

Multiple Motor Learning Strategies in Visuomotor Rotation

PubMed Central

Saijo, Naoki; Gomi, Hiroaki

2010-01-01

Background When exposed to a continuous directional discrepancy between movements of a visible hand cursor and the actual hand (visuomotor rotation), subjects adapt their reaching movements so that the cursor is brought to the target. Abrupt removal of the discrepancy after training induces reaching error in the direction opposite to the original discrepancy, which is called an aftereffect. Previous studies have shown that training with gradually increasing visuomotor rotation results in a larger aftereffect than with a suddenly increasing one. Although the aftereffect difference implies a difference in the learning process, it is still unclear whether the learned visuomotor transformations are qualitatively different between the training conditions. Methodology/Principal Findings We examined the qualitative changes in the visuomotor transformation after the learning of the sudden and gradual visuomotor rotations. The learning of the sudden rotation led to a significant increase of the reaction time for arm movement initiation and then the reaching error decreased, indicating that the learning is associated with an increase of computational load in motor preparation (planning). In contrast, the learning of the gradual rotation did not change the reaction time but resulted in an increase of the gain of feedback control, suggesting that the online adjustment of the reaching contributes to the learning of the gradual rotation. When the online cursor feedback was eliminated during the learning of the gradual rotation, the reaction time increased, indicating that additional computations are involved in the learning of the gradual rotation. Conclusions/Significance The results suggest that the change in the motor planning and online feedback adjustment of the movement are involved in the learning of the visuomotor rotation. The contributions of those computations to the learning are flexibly modulated according to the visual environment. Such multiple learning strategies would be required for reaching adaptation within a short training period. PMID:20195373

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

PubMed

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

2008-07-26

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

Changes in the Perceived Risk of Climate Change: Evidence from Sudden Climatic Events

NASA Astrophysics Data System (ADS)

Anttila-Hughes, J. K.

2009-12-01

In the course of the past two decades the threat of anthropogenic climate change has moved from a scientific concern of relative obscurity to become one of the largest environmental and public goods problems in history. During this period public understanding of the risk of climate change has shifted from negligible to quite large. In this paper I propose a means of quantifying this change by examining how sudden events supporting the theory of anthropogenic climate change have affected carbon intensive companies' stock prices. Using CAPM event study methodology for companies in several carbon-intensive industries, I find strong evidence that markets have been reacting to changes in the scientific evidence for climate change for some time. Specifically, the change in magnitude of response over time seems to indicate that investors believed climate change was a potentially serious risk to corporate profits as early as the mid 1990s. Moreover, market reaction dependence on event type indicates that investors are differentiating between different advances in the scientific knowledge. Announcements by NASA GISS that the previous year was a “record hot year” for the globe are associated with negative excess returns, while news of ice shelf collapses are associated with strong positive excess returns. These results imply that investors are aware of how different aspects of climate change will affect carbon intensive companies, specifically in terms of the link between warming in general and polar ice cover. This implies that policy choices based on observable public opinion have lagged actual private concern over climate change's potential threat.

The Human Engineering Eye Movement Measurement Research Facility.

DTIC Science & Technology

1985-04-01

tracked reliably. When tracking is disrupted (e.g., by gross and sudden head movements, gross change in the head position, sneezing, prolonged eye...these are density ^\\ and " busyness " of the slides (stimulus material), as well as consistency . I„ between successive... change the material being projected based on the subject’s previous performance. The minicomputer relays the calibrated data to one of the magnetic

Change in Language Policy in Malaysia: The Reality of Implementation in Public Universities

ERIC Educational Resources Information Center

Gill, Saran Kaur

2006-01-01

In Malaysia, a sudden change in language policy, from Bahasa Melayu to English, has been instituted for the disciplines of science and technology at varying levels of the educational system. For this paper, it will be the domain of higher education that will be focused on. In 2005, the students who had their pre-university courses in English would…

PROTOPLASMIC POTENTIALS IN HALICYSTIS

PubMed Central

Blinks, L. R.

1933-01-01

The nature and origin of the large "protoplasmic" potential in Halicystis must be studied by altering conditions, not only in external solutions, but in the sap and the protoplasm itself. Such interior alteration caused by the penetration of ammonia is described. Concentrations of NH4Cl in the sea water were varied from 0.00001 M to above 0.01 M. At pH 8.1 there is little effect below 0.0005 M NH4Cl. At about 0.001 M a sudden reversal of the potential difference across the protoplasm occurs, from about 68 mv. outside positive to 30 to 40 mv. outside negative. At this threshold value the time curve is characteristically S-shaped, with a slow beginning, a rapid reversal, and then an irregularly wavering negative value. There are characteristic cusps at the first application of the NH4Cl, also immediately after the reversal. The application of higher NH4Cl concentrations causes a more rapid reversal, and also a somewhat higher negative value. Conversely the reduction of NH4Cl concentrations causes recovery of the normal positive potential, but the threshold for recovery is at a lower concentration than for the original reversal. A temporary overshooting or increase of the positive potential usually occurs on recovery. The reversals may be repeated many times on the same cell without injury. The plot of P.D. against the log of ammonium ion concentration is not the straight line characteristic of ionic concentration effects, but has a break of 100 mv. or more at the threshold value. Further evidence that the potential is not greatly influenced by ammonium ions is obtained by altering the pH of the sea water. At pH 5, no reversal occurs with 0.1 M NH4Cl, while at pH 10.3, the NH4Cl threshold is 0.0001 M or less. This indicates that the reversal is due to undissociated ammonia. The penetration of NH3 into the cells increases both the internal ammonia and the pH. The actual concentration of ammonium salt in the sap is again shown to have little effect on the P.D. The pH is therefore the governing factor. But assuming that NH3 enters the cells until it is in equilibrium between sap and sea water, no sudden break of pH should occur, pH being instead directly proportional to log NH3 for any constant (NH4) concentration. Experimentally, a linear relation is found between the pH of the sap and the log NH3 in sea water. The sudden change of P.D. must therefore be ascribed to some system in the cell upon which the pH change operates. The pH value of the sap at the NH3 threshold is between 6.0 and 6.5 which corresponds well with the pH value found to cause reversal of P.D. by direct perfusion of solutions in the vacuole. PMID:19872757

Iloprost-induced sudden hearing loss.

PubMed

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

2007-06-01

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

75 FR 8966 - Discretionary Grant Program

Federal Register 2010, 2011, 2012, 2013, 2014

2010-02-26

... Health and Safety--1 grant National Sudden and Unexpected Infant/Child Death and Pregnancy Loss Centers... programs into alignment with changes resulting from HRSA's Maternal and Child Health Bureau's developing strategic plan and the Early Learning and Development Initiative of the HHS and Department of Education. The...

Changing Political Landscapes for Latinos in America

ERIC Educational Resources Information Center

Casellas, Jason P.; Ibarra, Joanne D.

2012-01-01

The increased demographic presence of Latino individuals has gradually resulted in growing political influence and representation. This growing presence and influence has altered the American political landscape, drawing sudden attention among scholars, the media, and political pundits. This article investigates four aspects of the growing…

Portfolio management under sudden changes in volatility and heterogeneous investment horizons

NASA Astrophysics Data System (ADS)

Fernandez, Viviana; Lucey, Brian M.

2007-03-01

We analyze the implications for portfolio management of accounting for conditional heteroskedasticity and sudden changes in volatility, based on a sample of weekly data of the Dow Jones Country Titans, the CBT-municipal bond, spot and futures prices of commodities for the period 1992-2005. To that end, we first proceed to utilize the ICSS algorithm to detect long-term volatility shifts, and incorporate that information into PGARCH models fitted to the returns series. At the next stage, we simulate returns series and compute a wavelet-based value at risk, which takes into consideration the investor's time horizon. We repeat the same procedure for artificial data generated from semi-parametric estimates of the distribution functions of returns, which account for fat tails. Our estimation results show that neglecting GARCH effects and volatility shifts may lead to an overestimation of financial risk at different time horizons. In addition, we conclude that investors benefit from holding commodities as their low or even negative correlation with stock and bond indices contribute to portfolio diversification.

[Forensic Analysis for 54 Cases of Suxamethonium Chloride Poisoning].

PubMed

Zhao, Y F; Zhao, B Q; Ma, K J; Zhang, J; Chen, F Y

2017-08-01

To observe and analyze the performance of forensic science in the cases of suxa- methonium chloride poisoning, and to improve the identification of suxamethonium chloride poisoning. Fifty-four cases of suxamethonium chloride poisoning were collected. The rules of determination of suxamethonium chloride poisoning were observed by the retrospective analysis of pathological and toxicological changes as well as case features. The pathological features of suxamethonium chloride poisoning were similar to the general changes of sudden death, which mainly included acute pulmonary congestion and edema, and partly showed myocardial disarray and fracture. Suxamethonium chloride could be detected in the heart blood of all cases and in skin tissue of part cases. Suxa-methonium chloride poisoning has the characteristics with fast death and covert means, which are difficult to rescue and easily miss inspection. For the cases of sudden death or suspicious death, determination of suxamethonium chloride should be taken as a routine detection index to prevent missing inspection. Copyright© by the Editorial Department of Journal of Forensic Medicine

Efficacy of an enterovaccine in recurrent episodes of diarrhea in the dog: a pilot study.

PubMed

Cerquetella, Matteo; Laus, Fulvio; Speranzini, Fabiana; Carnevali, Cristina; Spaterna, Andrea; Battaglia, Edda; Bassotti, Gabrio

2012-02-01

Recurrent episodes of self-limiting diarrhea in the dog, due to sudden dietary changes and to stressful or exciting situations, are conditions sometimes difficult to treat. Colifagina(®), a commercially available bacterial enterovaccine, showed, in previous studies performed on experimentally induced colitis in mice, to be able to improve both disease activity index and histological appearance, increase colonic secretion of IgA, and reduce inflammatory chemokine secretion. In the present study Colifagina(®) was administered to five dogs presenting recurrent episodes of self-limiting diarrhea and to one dog presenting chronic diarrhea. During the follow-up period, almost all patients decreased the number of episodes of abnormal defecation and the fecal score of such episodes improved in five out of six dogs. Even if further studies are needed to understand the exact potential of the compound, in dogs presenting recurrent episodes of self-limiting diarrhea due to sudden dietary changes and/or stressing or exciting situations, Colifagina(®) seems to be helpful in managing most of these patients.

Haltere removal alters responses to gravity in standing flies.

PubMed

Daltorio, Kathryn; Fox, Jessica

2018-05-31

Animals detect the force of gravity with multiple sensory organs, from subcutaneous receptors at body joints to specialized sensors like the vertebrate inner ear. The halteres of flies, specialized mechanoreceptive organs derived from hindwings, are known to detect body rotations during flight, and some groups of flies also oscillate their halteres while walking. The dynamics of halteres are such that they could act as gravity detectors for flies standing on substrates, but their utility during non-flight behaviors is not known. We observed the behaviors of intact and haltere-ablated flies during walking and during perturbations in which the acceleration due to gravity suddenly changed. We found that intact halteres are necessary for flies to maintain normal walking speeds on vertical surfaces and to respond to sudden changes in gravity. Our results suggest that halteres can serve multiple sensory purposes during different behaviors, expanding their role beyond their canonical use in flight. © 2018. Published by The Company of Biologists Ltd.

Sudden gains in the outpatient treatment of anorexia nervosa: A process-outcome study.

PubMed

Cartwright, Anna; Cheng, Yat Ping; Schmidt, Ulrike; Landau, Sabine

2017-10-01

Sudden gains (SGs), broadly defined as sudden symptom reductions occurring between two consecutive treatment sessions, have been associated with improved treatment outcomes in anxiety and depression. The present study is the first to formally define SGs in anorexia nervosa and explore the characteristics, demographic and baseline clinical predictors, and clinical impact of SGs in anorexia nervosa. This is a secondary analysis of data from 89 outpatients with broadly defined anorexia nervosa who received one of two psychotherapeutic interventions as part of the MOSAIC trial (Schmidt et al., 2015). SGs were defined using session-by-session body mass index (BMI) measures. This study investigated whether SGs were associated with changes in BMI, eating disorder symptomology, general psychopathology, and psychosocial impairment between baseline and 6, 12, and 24 months follow-up. SGs, experienced by 61.8% of patients, mostly occurred during the early and middle phases of treatment. A larger proportion of SGs predicted larger increases in BMI between baseline and 6, 12, and 24 months follow-up. Amongst those experiencing at least one SG, fewer days between baseline and a patient's first SG predicted a larger increase in BMI between baseline and both 6 and 12 months follow-up. The proportion and timing of SGs did not predict changes in other outcome measures. SGs in BMI during the outpatient treatment of anorexia nervosa are clinically useful predictors of longer-term weight outcomes. © 2017 Wiley Periodicals, Inc.

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

PubMed

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

2016-01-01

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

Effect of social networks and well-being on acute care needs.

PubMed

Sintonen, Sanna; Pehkonen, Aini

2014-01-01

The effect of social surroundings has been noted as an important component of the well-being of elderly people. A strong social network and strong and steady relationships are necessary for coping when illness or functional limitations occur in later life. Vulnerability can affect well-being and functioning particularly when sudden life changes occur. The objective of this study was to analyse how the determinants of social well-being affect individual acute care needs when sudden life changes occur. Empirical evidence was collected using a cross-sectional mail survey in Finland in January 2011 among individuals aged 55-79 years. The age-stratified random sample covered 3000 individuals, and the eventual response rate was 56% (1680). Complete responses were received from 1282 respondents (42.7%). The study focuses on the compactness of social networks, social disability, the stability of social relationships and the fear of loneliness as well as how these factors influence acute care needs. The measurement was based on a latent factor structure, and the key concepts were measured using two ordinal items. The results of the structural model suggest that the need for care is directly affected by social disability and the fear of loneliness. In addition, social disability is a determinant of the fear of loneliness and therefore plays an important role if sudden life changes occur. The compactness of social networks decreases social disability and partly diminishes the fear of loneliness and therefore has an indirect effect on the need for care. The stability of social relationships was influenced by the social networks and disability, but was an insignificant predictor of care needs. To conclude, social networks and well-being can decrease care needs, and supportive actions should be targeted to avoid loneliness and social isolation so that the informal network could be applied as an aspect of care-giving when acute life changes occur. © 2013 John Wiley & Sons Ltd.

New generation of meteorology cameras

NASA Astrophysics Data System (ADS)

Janout, Petr; Blažek, Martin; Páta, Petr

2017-12-01

A new generation of the WILLIAM (WIde-field aLL-sky Image Analyzing Monitoring system) camera includes new features such as monitoring of rain and storm clouds during the day observation. Development of the new generation of weather monitoring cameras responds to the demand for monitoring of sudden weather changes. However, new WILLIAM cameras are ready to process acquired image data immediately, release warning against sudden torrential rains, and send it to user's cell phone and email. Actual weather conditions are determined from image data, and results of image processing are complemented by data from sensors of temperature, humidity, and atmospheric pressure. In this paper, we present the architecture, image data processing algorithms of mentioned monitoring camera and spatially-variant model of imaging system aberrations based on Zernike polynomials.

Analysis of temporal shear stress gradients during the onset phase of flow over a backward-facing step.

PubMed

Haidekker, M A; White, C R; Frangos, J A

2001-10-01

Endothelial cells in blood vessels are exposed to bloodflow and thus fluid shear stress. In arterial bifurcations and stenoses, disturbed flow causes zones of recirculation and stagnation, which are associated with both spatial and temporal gradients of shear stress. Such gradients have been linked to the generation of atherosclerotic plaques. For in-vitro studies of endothelial cell responses, the sudden-expansion flow chamber has been widely used and described. A two-dimensional numerical simulation of the onset phase of flow through the chamber was performed. The wall shear stress action on the bottom plate was computed as a function of time and distance from the sudden expansion. The results showed that depending on the time for the flow to be established, significant temporal gradients occurred close to the second stagnation point of flow. Slowly ramping the flow over 15 s instead of 200 ms reduces the temporal gradients by a factor of 300, while spatial gradients are reduced by 23 percent. Thus, the effects of spatial and temporal gradients can be observed separately. In experiments on endothelial cells, disturbed flow stimulated cell proliferation only when flow onset was sudden. The spatial patterns of proliferation rate match the exposure to temporal gradients. This study provides information on the dynamics of spatial and temporal gradients to which the cells are exposed in a sudden-expansion flow chamber and relates them to changes in the onset phase of flow.

Control of trunk motion following sudden stop perturbations during cart pushing.

PubMed

Lee, Yun-Ju; Hoozemans, Marco J M; van Dieën, Jaap H

2011-01-04

External perturbations during pushing tasks have been suggested to be a risk factor for low-back symptoms. An experiment was designed to investigate whether self-induced and externally induced sudden stops while pushing a high inertia cart influence trunk motions, and how flexor and extensor muscles counteract these perturbations. Twelve healthy male participants pushed a 200 kg cart at shoulder height and hip height. Pushing while walking was compared to situations in which participants had to stop the cart suddenly (self-induced stop) or in which the wheels of the cart were unexpectedly blocked (externally induced stop). For the perturbed conditions, the peak values and the maximum changes from the reference condition (pushing while walking) of the external moment at L5/S1, trunk inclination and electromyographic amplitudes of trunk muscles were determined. In the self-induced stop, a voluntary trunk extension occurred. Initial responses in both stops consisted of flexor and extensor muscle cocontraction. In self-induced stops this was followed by sustained extensor activity. In the externally induced stops, an external extension moment caused a decrease in trunk inclination. The opposite directions of the internal moment and trunk motion in the externally induced stop while pushing at shoulder height may indicate insufficient active control of trunk posture. Consequently, sudden blocking of the wheels in pushing at shoulder height may put the low back at risk of mechanical injury. Copyright © 2010 Elsevier Ltd. All rights reserved.

Proceedings of the Sudden Oak Death Fourth Science Symposium

Treesearch

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

2010-01-01

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

Proceedings of the sudden oak death third science symposium

Treesearch

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

2008-01-01

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

Proceedings of the sudden oak death sixth science symposium

Treesearch

Susan J. Frankel; Katharine M. Harrell

2017-01-01

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

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

ERIC Educational Resources Information Center

Munger, Ronald G.

1987-01-01

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

THE DISTURBANCE OF A MILLISECOND PULSAR MAGNETOSPHERE

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

Shannon, R. M.; Kerr, M.; Dai, S.

2016-09-01

Pulsar timing has enabled some of the strongest tests of fundamental physics. Central to the technique is the assumption that the detected radio pulses can be used to accurately measure the rotation of the pulsar. Here, we report on a broadband variation in the pulse profile of the millisecond pulsar J1643−1224. A new component of emission suddenly appears in the pulse profile, decays over four months, and results in a permanently modified pulse shape. Profile variations such as these may be the origin of timing noise observed in other millisecond pulsars. The sensitivity of pulsar-timing observations to gravitational radiation canmore » be increased by accounting for this variability.« less

Genomics of Adaptation Depends on the Rate of Environmental Change in Experimental Yeast Populations.

PubMed

Gorter, Florien A; Derks, Martijn F L; van den Heuvel, Joost; Aarts, Mark G M; Zwaan, Bas J; de Ridder, Dick; de Visser, J Arjan G M

2017-10-01

The rate of directional environmental change may have profound consequences for evolutionary dynamics and outcomes. Yet, most evolution experiments impose a sudden large change in the environment, after which the environment is kept constant. We previously cultured replicate Saccharomyces cerevisiae populations for 500 generations in the presence of either gradually increasing or constant high concentrations of the heavy metals cadmium, nickel, and zinc. Here, we investigate how each of these treatments affected genomic evolution. Whole-genome sequencing of evolved clones revealed that adaptation occurred via a combination of SNPs, small indels, and whole-genome duplications and other large-scale structural changes. In contrast to some theoretical predictions, gradual and abrupt environmental change caused similar numbers of genomic changes. For cadmium, which is toxic already at comparatively low concentrations, mutations in the same genes were used for adaptation to both gradual and abrupt increase in concentration. Conversely, for nickel and zinc, which are toxic at high concentrations only, mutations in different genes were used for adaptation depending on the rate of change. Moreover, evolution was more repeatable following a sudden change in the environment, particularly for nickel and zinc. Our results show that the rate of environmental change and the nature of the selection pressure are important drivers of evolutionary dynamics and outcomes, which has implications for a better understanding of societal problems such as climate change and pollution. © The Author 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

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

PubMed

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

2016-01-01

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

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

PubMed

Chroni, M; Prappa, E; Kokkevi, I

2018-04-01

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

Impact of variations in material properties on asphalt pavement life-evaluation of Warren-Scappoose project : interim report.

DOT National Transportation Integrated Search

1981-12-01

Construction and short-term pavement performance problems were noted in the Pacific Northwest and throughout the United States during the past five years. Several reasons have been suggested to explain this sudden change in pavement performance, such...

Sherrington's Model of Successive Induction for Comparative Analysis of Zebrafish Motor Response

EPA Science Inventory

The responses in motor activity of zebrafish to sudden changes in lighting conditions may be modeled by Sherrington’s model of successive induction. Fish left in the dark exhibit very little motion, when exposed to light zebrafish motion increases towards an apparent horizo...

Effects of incubation temperatures on embryonic and larval survival in rainbow trout, Oncorhynchus mykiss

USDA-ARS?s Scientific Manuscript database

Incubation temperature is commonly used by hatcheries to manipulate hatch date in salmonids including rainbow trout (Oncorhynchus mykiss). Target dates for hatching often change during the incubation period and require a sudden adjustment in temperature. Although there are many studies charac...

Career Counsellors and Suicide Risk Assessment

ERIC Educational Resources Information Center

Popadiuk, Natalee Elizabeth

2013-01-01

Recent discussions suggest that career counsellors need to be trained in more holistic frameworks in order to deal with the career and psychological issues of their clients. In particular, research shows a strong connection between employment and suicidality, including changes in socioeconomic status, disruption in employment, sudden unemployment,…

Host-induced aneuploidy and phenotypic diversification in the Sudden Oak Death pathogen Phytophthora ramorum

USDA-ARS?s Scientific Manuscript database

Aneuploidy can result in significant phenotypic changes, which can sometimes be selectively advantageous. For example, aneuploidy confers resistance to antifungal drugs in human pathogenic fungi. Aneuploidy has also been observed in invasive fungal and oomycete plant pathogens in the field. Environm...

Natural Hazards in Your Community

ERIC Educational Resources Information Center

Martinez,Cindy

2004-01-01

The Earth is a powerful, active, and ever-changing planet. Earthquakes and volcanoes reshape the Earth's crust with sudden bursts of movement or with eruptions that last decades. Powerful storms develop in the swirling atmosphere, creating cumulonimbus thunderclouds, lightning storms, and even tornadoes or hurricanes. Geological features and moist…

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

Treesearch

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

2006-01-01

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

Reverse Evolution of Armor Plates in the Threespine Stickleback

USGS Publications Warehouse

Kitano, J.; Bolnick, D.I.; Beauchamp, D.A.; Mazur, M.M.; Mori, S.; Nakano, T.; Peichel, C.L.

2008-01-01

Faced with sudden environmental changes, animals must either adapt to novel environments or go extinct. Thus, study of the mechanisms underlying rapid adaptation is crucial not??only for the understanding of natural evolutionary processes but also for the understanding of human-induced evolutionary change, which is an increasingly important problem [1-8]. In the present study, we demonstrate that the frequency of completely plated threespine stickleback fish (Gasterosteus aculeatus) has increased in an urban freshwater lake (Lake Washington, Seattle, Washington) within the last 40 years. This is a dramatic example of "reverse evolution," [9] because the general evolutionary trajectory is toward armor-plate reduction in freshwater sticklebacks [10]. On the basis of our genetic studies and simulations, we propose that the most likely cause of reverse evolution is increased selection for the completely plated morph, which we suggest could result from higher levels of trout predation after a sudden increase in water transparency during the early 1970s. Rapid evolution was facilitated by the existence of standing allelic variation in Ectodysplasin (Eda), the gene that underlies the major plate-morph locus [11]. The Lake Washington stickleback thus provides a novel example of reverse evolution, which is probably caused by a change in allele frequency at the major plate locus in response to a changing predation regime. ?? 2008 Elsevier Ltd. All rights reserved.

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

PubMed

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

2011-12-01

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

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

PubMed

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

2015-12-01

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

Department of Defense Human Factors Engineering Technical Advisory Group Minutes of the Meeting, (15th), Held at San Diego, California, on 5-7 November 1985

DTIC Science & Technology

1985-11-01

the group to be alert to changes in goals, noting that if the model is not sensitive to goal changes , it will lack validity. Mr. Hartzell announced...This increased emphasis on the soldier-machine interface has not been a sudden change . Instead it has been a gradual one coincident with and...point alone in affecting both design changes and operational doctrine for the system. Analysis of these data should first compare achieved

Short-term forecasting of urban rail transit ridership based on ARIMA and wavelet decomposition

NASA Astrophysics Data System (ADS)

Wang, Xuemei; Zhang, Ning; Chen, Ying; Zhang, Yunlong

2018-05-01

Due to different functions and land use types, there are significant differences in ridership patterns among different urban rail transit stations. Considering the characteristics of different ridership and coping with the uncertainty, periodical and stochastic natures of short-term passenger flow, and this paper proposes a novel hybrid methodology that combines the autoregressive integrated moving average (ARIMA) model and wavelet decomposition, which has strong strengths in signal processing, to short-term ridership forecasting. The seasonal ARIMA is used to represent the relatively stable and regular ridership patterns while the wavelet decomposition is used to capture the stochastic or sometimes drastic changing characteristics of ridership patterns. The inclusion of wavelet decomposition and reconstruction provides the hybrid model with a unique strength in capturing sudden change in ridership patterns associated with certain rail stations. The case study is carried out by analyzing real ridership data of Metro Line 1 in Nanjing, China. The experimental results indicate that the hybrid method is superior to the individual ARIMA model for all ridership patterns, but particularly advantageous in predicting ridership at stations often associated with sudden pattern changes due to special events.

Robust foreground detection: a fusion of masked grey world, probabilistic gradient information and extended conditional random field approach.

PubMed

Zulkifley, Mohd Asyraf; Moran, Bill; Rawlinson, David

2012-01-01

Foreground detection has been used extensively in many applications such as people counting, traffic monitoring and face recognition. However, most of the existing detectors can only work under limited conditions. This happens because of the inability of the detector to distinguish foreground and background pixels, especially in complex situations. Our aim is to improve the robustness of foreground detection under sudden and gradual illumination change, colour similarity issue, moving background and shadow noise. Since it is hard to achieve robustness using a single model, we have combined several methods into an integrated system. The masked grey world algorithm is introduced to handle sudden illumination change. Colour co-occurrence modelling is then fused with the probabilistic edge-based background modelling. Colour co-occurrence modelling is good in filtering moving background and robust to gradual illumination change, while an edge-based modelling is used for solving a colour similarity problem. Finally, an extended conditional random field approach is used to filter out shadow and afterimage noise. Simulation results show that our algorithm performs better compared to the existing methods, which makes it suitable for higher-level applications.

The decline of adult smallpox in eighteenth-century London.

PubMed

Davenport, Romola; Schwarz, Leonard; Boulton, Jeremy

2011-01-01

Smallpox was probably the single most lethal disease in eighteenth-century Britain, but was a minor cause of death by the mid-nineteenth century. Although vaccination was crucial to the decline of smallpox, especially in urban areas, from the beginning of the nineteenth century, it remains disputed the extent to which smallpox mortality declined before vaccination. Analysis of age-specific changes in smallpox burials within the large west London parish of St Martin-in-the-Fields revealed a precipitous reduction in adult smallpox risk from the 1770s, and this pattern was duplicated in the east London parish of St Dunstan's. Most adult smallpox victims were rural migrants, and such a drop in their susceptibility is consistent with a sudden increase in exposure to smallpox in rural areas. We investigated whether this was due to the spread of inoculation, or an increase in smallpox transmission, using changes in the age patterns of child smallpox burials. Smallpox mortality rose among infants, and smallpox burials became concentrated at the youngest ages, suggesting a sudden increase in infectiousness of the smallpox virus. Such a change intensified the process of smallpox endemicization in the English population, but also made cities substantially safer for young adult migrants.

Bumblebees measure optic flow for position and speed control flexibly within the frontal visual field.

PubMed

Linander, Nellie; Dacke, Marie; Baird, Emily

2015-04-01

When flying through narrow spaces, insects control their position by balancing the magnitude of apparent image motion (optic flow) experienced in each eye and their speed by holding this value about a desired set point. Previously, it has been shown that when bumblebees encounter sudden changes in the proximity to nearby surfaces - as indicated by a change in the magnitude of optic flow on each side of the visual field - they adjust their flight speed well before the change, suggesting that they measure optic flow for speed control at low visual angles in the frontal visual field. Here, we investigated the effect that sudden changes in the magnitude of translational optic flow have on both position and speed control in bumblebees if these changes are asymmetrical; that is, if they occur only on one side of the visual field. Our results reveal that the visual region over which bumblebees respond to optic flow cues for flight control is not dictated by a set viewing angle. Instead, bumblebees appear to use the maximum magnitude of translational optic flow experienced in the frontal visual field. This strategy ensures that bumblebees use the translational optic flow generated by the nearest obstacles - that is, those with which they have the highest risk of colliding - to control flight. © 2015. Published by The Company of Biologists Ltd.

Changing roles of propagule, climate, and land use during extralimital colonization of a rose chafer beetle

NASA Astrophysics Data System (ADS)

Horak, Jakub; Hui, Cang; Roura-Pascual, Núria; Romportl, Dusan

2013-04-01

Regardless of their ecosystem functions, some insects are threatened when facing environmental changes and disturbances, while others become extremely successful. It is crucial for successful conservation to differentiate factors supporting species' current distributions from those triggering range dynamics. Here, we studied the sudden extralimital colonization of the rose chafer beetle, Oxythyrea funesta, in the Czech Republic. Specifically, we depicted the range expansion using accumulated historical records of first known occurrences and then explained the colonization events using five transformed indices depicting changes in local propagule pressure (LPP), climate, land use, elevation, and landscape structure. The slow occupancy increase of O. funesta before 1990 changed to a phase of rapid occupancy increase after 1990, driven not only by changes in the environment (climate and land use) but also by the spatial accumulation of LPP. Climate was also found to play a significant role but only during the niche-filling stage before 1990, while land use became important during the phase of rapid expansion after 1990. Inland waters (e.g., riparian corridors) also contributed substantially to the spread in the Czech Republic. Our method of using spatially transformed variables to explain the colonization events provides a novel way of detecting factors triggering range dynamics. The results highlight the importance of LPP in driving sudden occupancy increase of extralimital species and recommend the use of LPP as an important predictor for modeling range dynamics.

The Course of Grief in Children Bereaved by Sudden Parental Death

PubMed Central

Melhem, Nadine M.; Porta, Giovanna; Shamseddeen, Wael; Payne, Monica Walker; Brent, David A.

2014-01-01

Context There have been major advances in our understanding of the phenomenology and course of grief in adults. However, little is known about the course of grief in children. Objective We report on course and impact of children’s grief reactions following parental sudden death on subsequent psychiatric and functional status. Design Longitudinal study of bereaved children and families with yearly comprehensive assessments up to three years after parental death. Setting Bereaved children and their surviving parents recruited through the coroners’ records and advertisement. Participants 182 parentally bereaved children between 7 and 18 years of age whose parent died from suicide, accident, or sudden natural deaths. Main Exposure Sudden parental death. Main Outcome Measures Grief, functional impairment, incident depression. Results There were 3 distinct trajectories of grief reactions with a group, consisting of 10.4% of the sample, with increased grief reactions that showed no change 33 months post-death. Youths with prolonged grief reactions had higher rates of previous personal history of depression. Prolonged grief made unique contribution to increased levels of functional impairment even after controlling for clinical characteristics antecedent and following the death. Conversely, prolonged grief, both in youths and the surviving caregiver, predisposed to an increased hazard of incident depression. Another group (30%) showed increased grief reactions 9 months following the death, which gradually decreased over time. Despite this, grief reactions in this group were also associated with functional impairment and increased risk of incident depression. Conclusions Grief reactions abate over time for most children bereaved by sudden parental death; however, a subset show increased or prolonged grief reactions, which in turn increases the risk for functional impairment and depression. Research on interventions designed to relieve the burden of grief in bereaved children are needed. Such efforts should also assess and address grief reactions in the surviving parent. PMID:21893658

IRON PRECIPITATION AND ARSENIC ATTENUATION - ASSESSMENT OF ARSENIC NATURAL ATTENUATION OF THE SUBSURFACE USING A GEOCHEMICAL MODEL (PHREEQC)

EPA Science Inventory

Laboratory experiments show that amorphous and poorly crystallized ferric iron hydroxides have much greater capacity to attenuate arsenic compared to clays and other aluminosilicate minerals. Studies (e.g., Lin and Qvarfort, 1996) showed that a sudden change in geochemical condit...

The Educational Effects of Rapid Rural Population Growth.

ERIC Educational Resources Information Center

Ross, Peggy J.; Green, Bernal L.

Rapid population growth in rural areas has confronted rural communities and particularly rural educational systems with a number of problems. Sudden, large increases in students crowd school facilities and strain budgets. The different values, attitudes, and orientations toward education of the newcomers act as a catalyst for changes and can cause…

Effects of temperature and moisture on Mormon cricket reproduction with implications for responses to climate change

USDA-ARS?s Scientific Manuscript database

During the last decade, populations of flightless Mormon crickets Anabrus simplex (Orthoptera: Tettigoniidae) increased suddenly over vast areas of the western United States, suggesting that climate is an important factor driving outbreaks. Moreover summer temperatures are predicted to increase and...

Neuropsychological Factors in the Evaluation and Treatment of Childhood and Adolescent Aggression.

ERIC Educational Resources Information Center

French, Laurence

This paper addresses the neuropsychological evaluation of impulsive aggression in emotionally disturbed students. Specific complications of organic aggressive syndrome include its unpredictable nature and basis in organic etiology. Characteristically, there is a sudden onset of unprovoked rage and violence accompanied by a drastic change in…

Teaching Students with Disabilities: A Practical Guide.

ERIC Educational Resources Information Center

Illinois Univ., Urbana. Div. of Rehabilitation Education Services.

This brochure for faculty at the University of Illinois discusses accommodations for students with disabilities. Problems such students have in the areas of time management, accessibility, and coping with sudden changes are considered first. Teachers are urged to address the question of disabilities directly during the first class by inviting any…

Mismatch and Conflict: Neurophysiological and Behavioral Evidence for Conflict Priming

ERIC Educational Resources Information Center

Mager, Ralph; Meuth, Sven G.; Krauchi, Kurt; Schmidlin, Maria; Muller-Spahn, Franz; Falkenstein, Michael

2009-01-01

Conflict-related cognitive processes are critical for adapting to sudden environmental changes that confront the individual with inconsistent or ambiguous information. Thus, these processes play a crucial role to cope with daily life. Generally, conflicts tend to accumulate especially in complex and threatening situations. Therefore, the question…

"A Virtually Limitless Resource"

ERIC Educational Resources Information Center

Stanistreet, Paul

2008-01-01

With skills such as flexibility and originality increasingly required by an economy struggling to adapt to sudden and seismic change, there is renewed interest in what engagement in culture and creativity can offer. This author discovered that the difference such engagement can make to people's lives has long been recognised at Morley College.…

Legal Liability of Individual Board Members.

ERIC Educational Resources Information Center

Leverett, E. Freeman

Twenty-five years ago, law suits seeking recovery against the individual resources of school board members were virtually unheard of. Now, personal judgments impacting upon the individual resources of board members are commonplace. The legal developments that have contributed to this rather sudden change of circumstances are explained in this…

Transforming the History Curriculum with Geospatial Tools

ERIC Educational Resources Information Center

Hammond, Thomas

2014-01-01

Martorella's "sleeping giant" is awakening via geospatial tools. As this technology is adopted, it will transform the history curriculum in three ways: deepening curricular content, making conceptual frameworks more prominent, and increasing connections to local history. These changes may not be profound and they may not be sudden,…

Sudden disintegration of ice in the glacial-proglacial transition zone of the largest glacier in Austria

NASA Astrophysics Data System (ADS)

Kellerer-Pirklbauer, Andreas; Avian, Michael; Hirschmann, Simon; Lieb, Gerhard Karl; Seier, Gernot; Sulzer, Wolfgang; Wakonigg, Herwig

2017-04-01

Rapid deglaciation does not only reveal a landscape which is prone to rapid geomorphic changes and sediment reworking but also the glacier ice itself might be in a state of disintegration by ice melting, pressure relief, crevasse formation, ice collapse or changes in the glacier's hydrology. In this study we considered the sudden disintegration of glacier ice in the glacial-proglacial transition zone of Pasterze Glacier. Pasterze Glacier is a typical alpine valley glacier and covers currently some 16.5 km2 making it to the largest glacier in Austria. This glacier is an important site for alpine mass tourism in Austria related to a public high alpine road and a cable car which enable access to the glacier rather easily also for unexperienced mountaineers. Spatial focus in our research is given on two particular study areas where several ice-mass movement events occurred during the 2015- and 2016-melting seasons. The first study area is a crevasse field at the lower third of the glacier tongue. This lateral crevasse field has been substantially modified during the last two melting seasons particularly because of thermo-erosional effects of a glacial stream which changed at this site from subglacial (until 2015) to glacier-lateral revealing a several tens of meters high unstable ice cliff prone to ice falls of different magnitudes. The second study area is located at the proglacial area. At Pasterze Glacier the proglacial area is widely influenced by dead-ice bodies of various dimensions making this area prone to slow to sudden geomorphic changes caused by ice mass changes. A particular ice-mass movement event took place on 20.09.2016. Within less than one hour the surface of the proglacial area changed substantially by tilting, lateral shifting, and subsidence of the ground accompanied by complete ice disintegration of once-debris covered ice. To understand acting processes at both areas of interest and to quantify mass changes we used field observations, terrain analysis (based on multi-temporal DEM generation derived from terrestrial laser scanning/TLS and unmanned aerial systems/UAS), electrical resistivity tomography (ERT), ground climate monitoring, and data from an automatic remote camera (RDC) system. Results for both areas of interest are presented and discussed regarding its relevance for the glacier itself but also the potential risks for mountaineers.

Transient ST segment depression during Holter monitoring: how to avoid false positive findings.

PubMed

Völler, H; Andresen, D; Brüggemann, T; Jereczek, M; Becker, B; Schröder, R

1992-09-01

To increase the specificity of 24-hour Holter monitoring in detecting transient myocardial ischemia, we separated genuine ST deviations from those dependent on artifacts by adding a detailed shape analysis of real-time printouts to the usual criteria of significant ST segment depression. We screened 116 apparently healthy subjects; 31 had to be excluded, because of pathologic findings in preliminary examinations. The remaining 85 (49 women and 36 men; mean age, 43.1 years) underwent Holter monitoring for assessment of the extent, frequency, and duration of episodes of horizontal and descending ST segment depression of at least 0.1 mV that persisted for at least 60 msec after the J point and that were at least 1 minute apart. On the basis of these criteria, six subjects (7.1%) showed 24 episodes of horizontal or descending ST segment depression with a mean of 0.2 mV (range, 0.15 to 0.25 mV), a frequency of four episodes per 24 hours (one to nine), and a duration of 12.2 minutes (range 3-range 41 minutes). Supplementary criteria--e.g., sudden onset of ST segment depression, identical orientation of PQ and ST segments, or simultaneous increase in R and P wave amplitude--made it possible to identify ST changes caused by artifacts in four volunteers. In only two subjects (2.4%) could true silent ischemia not be differentiated from false positive results. Thus consideration of only the extent, frequency, and duration of episodes does not permit a differentiation between true silent ischemia and false positive results. A supplementary shape analysis increases the specificity of ST segment analysis in detecting transient myocardial ischemia during 24-hour Holter monitoring.

Deciphering infant mortality

NASA Astrophysics Data System (ADS)

Berrut, Sylvie; Pouillard, Violette; Richmond, Peter; Roehner, Bertrand M.

2016-12-01

This paper is about infant mortality. In line with reliability theory, "infant" refers to the time interval following birth during which the mortality (or failure) rate decreases. This definition provides a systems science perspective in which birth constitutes a sudden transition falling within the field of application of the Transient Shock (TS) conjecture put forward in Richmond and Roehner (2016c). This conjecture provides predictions about the timing and shape of the death rate peak. It says that there will be a death rate spike whenever external conditions change abruptly and drastically and also predicts that after a steep rise there will be a much longer hyperbolic relaxation process. These predictions can be tested by considering living organisms for which the transient shock occurs several days after birth. Thus, for fish there are three stages: egg, yolk-sac and young adult phases. The TS conjecture predicts a mortality spike at the end of the yolk-sac phase and this timing is indeed confirmed by observation. Secondly, the hyperbolic nature of the relaxation process can be tested using very accurate Swiss statistics for postnatal death rates spanning the period from one hour immediately after birth through to age 10 years. It turns out that since the 19th century despite a significant and large reduction in infant mortality, the shape of the age-specific death rate has remained basically unchanged. Moreover the hyperbolic pattern observed for humans is also found for small primates as recorded in the archives of zoological gardens. Our overall objective is to identify a series of cases which start from simple systems and move step by step to more complex organisms. The cases discussed here we believe represent initial landmarks in this quest.

Sharp inflaton potentials and bi-spectra: effects of smoothening the discontinuity

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

Martin, Jérôme; Sriramkumar, L.; Hazra, Dhiraj Kumar, E-mail: jmartin@iap.fr, E-mail: sriram@physics.iitm.ac.in, E-mail: dhiraj@apctp.org

Sharp shapes in the inflaton potentials often lead to short departures from slow roll which, in turn, result in deviations from scale invariance in the scalar power spectrum. Typically, in such situations, the scalar power spectrum exhibits a burst of features associated with modes that leave the Hubble radius either immediately before or during the epoch of fast roll. Moreover, one also finds that the power spectrum turns scale invariant at smaller scales corresponding to modes that leave the Hubble radius at later stages, when slow roll has been restored. In other words, the imprints of brief departures from slowmore » roll, arising out of sharp shapes in the inflaton potential, are usually of a finite width in the scalar power spectrum. Intuitively, one may imagine that the scalar bi-spectrum too may exhibit a similar behavior, i.e. a restoration of scale invariance at small scales, when slow roll has been reestablished. However, in the case of the Starobinsky model (viz. the model described by a linear inflaton potential with a sudden change in its slope) involving the canonical scalar field, it has been found that, a rather sharp, though short, departure from slow roll can leave a lasting and significant imprint on the bi-spectrum. The bi-spectrum in this case is found to grow linearly with the wavenumber at small scales, a behavior which is clearly unphysical. In this work, we study the effects of smoothening the discontinuity in the Starobinsky model on the scalar bi-spectrum. Focusing on the equilateral limit, we analytically show that, for smoother potentials, the bi-spectrum indeed turns scale invariant at suitably large wavenumbers. We also confirm the analytical results numerically using our newly developed code BINGO. We conclude with a few comments on certain related points.« less

Deformation and deceleration of coronal wave

NASA Astrophysics Data System (ADS)

Xue, Z. K.; Qu, Z. Q.; Yan, X. L.; Zhao, L.; Ma, L.

2013-08-01

Aims: We studied the kinematics and morphology of two coronal waves to better understand the nature and origin of coronal waves. Methods: Using multi-wavelength observations of the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamics Observatory (SDO) and the Extreme Ultraviolet Imager (EUVI) on board the twin spacecraft Solar-TErrestrial RElations Observatory (STEREO), we present morphological and dynamic characteristics of consecutive coronal waves on 2011 March 24. We also show the coronal magnetic field based on the potential field source surface model. Results: This event contains several interesting aspects. The first coronal wave initially appeared after a surge-like eruption. Its front was changed and deformed significantly from a convex shape to a line-shaped appearance, and then to a concave configuration during its propagation to the northwest. The initial speeds ranged from 947 km s-1 to 560 km s-1. The first wave decelerated significantly after it passed through a filament channel. After the deceleration, the final propagation speeds of the wave were from 430 km s-1 to 312 km s-1. The second wave was found to appear after the first wave in the northwest side of the filament channel. Its wave front was more diffused and the speed was around 250 km s-1, much slower than that of the first wave. Conclusions: The deformation of the first coronal wave was caused by the different speeds along different paths. The sudden deceleration implies that the refraction of the first wave took place at the boundary of the filament channel. The event provides evidence that the first coronal wave may be a coronal MHD shock wave, and the second wave may be the apparent propagation of the brightenings caused by successive stretching of the magnetic field lines.

Self body-size perception in an insect

NASA Astrophysics Data System (ADS)

Ben-Nun, Amir; Guershon, Moshe; Ayali, Amir

2013-05-01

Animals negotiating complex environments encounter a wide range of obstacles of different shapes and sizes. It is greatly beneficial for the animal to react to such obstacles in a precise, context-specific manner, in order to avoid harm or even simply to minimize energy expenditure. An essential key challenge is, therefore, an estimation of the animal's own physical characteristics, such as body size. A further important aspect of self body-size perception (or SBSP) is the need to update it in accordance with changes in the animal's size and proportions. Despite the major role of SBSP in functional behavior, little is known about if and how it is mediated. Here, we demonstrate that insects are also capable of self perception of body size and that this is a vital factor in allowing them to adjust their behavior following the sudden and dramatic growth associated with periodic molting. We reveal that locusts' SBSP is strongly correlated with their body size. However, we show that the dramatic change in size accompanying adult emergence is not sufficient to create a new and updated SBSP. Rather, this is created and then consolidated only following the individuals' experience and interaction with the physical environment. Behavioral or pharmacological manipulations can both result in maintenance of the old larval SBSP. Our results emphasize the importance of learning and memory-related processes in the development and update of SBSP, and highlight the advantage of insects as good models for a detailed study on the neurobiological and molecular aspects of SBSP.

Dynamics of crowd disasters: An empirical study

NASA Astrophysics Data System (ADS)

Helbing, Dirk; Johansson, Anders; Al-Abideen, Habib Zein

2007-04-01

Many observations of the dynamics of pedestrian crowds, including various self-organization phenomena, have been successfully described by simple many-particle models. For ethical reasons, however, there is a serious lack of experimental data regarding crowd panic. Therefore, we have analyzed video recordings of the crowd disaster in Mina/Makkah during the Hajj in 1426H on 12 January 2006. They reveal two subsequent, sudden transitions from laminar to stop-and-go and “turbulent” flows, which question many previous simulation models. While the transition from laminar to stop-and-go flows supports a recent model of bottleneck flows [D. Helbing , Phys. Rev. Lett. 97, 168001 (2006)], the subsequent transition to turbulent flow is not yet well understood. It is responsible for sudden eruptions of pressure release comparable to earthquakes, which cause sudden displacements and the falling and trampling of people. The insights of this study into the reasons for critical crowd conditions are important for the organization of safer mass events. In particular, they allow one to understand where and when crowd accidents tend to occur. They have also led to organizational changes, which have ensured a safe Hajj in 1427H.

Experimental and analytical study of water pipe's rupture for damage identification purposes

NASA Astrophysics Data System (ADS)

Papakonstantinou, Konstantinos G.; Shinozuka, Masanobu; Beikae, Mohsen

2011-04-01

A malfunction, local damage or sudden pipe break of a pipeline system can trigger significant flow variations. As shown in the paper, pressure variations and pipe vibrations are two strongly correlated parameters. A sudden change in the flow velocity and pressure of a pipeline system can induce pipe vibrations. Thus, based on acceleration data, a rapid detection and localization of a possible damage may be carried out by inexpensive, nonintrusive monitoring techniques. To illustrate this approach, an experiment on a single pipe was conducted in the laboratory. Pressure gauges and accelerometers were installed and their correlation was checked during an artificially created transient flow. The experimental findings validated the correlation between the parameters. The interaction between pressure variations and pipe vibrations was also theoretically justified. The developed analytical model explains the connection among flow pressure, velocity, pressure wave propagation and pipe vibration. The proposed method provides a rapid, efficient and practical way to identify and locate sudden failures of a pipeline system and sets firm foundations for the development and implementation of an advanced, new generation Supervisory Control and Data Acquisition (SCADA) system for continuous health monitoring of pipe networks.

Aerobic exercise conditioning: a nonpharmacological antiarrhythmic intervention.

PubMed

Billman, George E

2002-02-01

Sudden, unexpected cardiac death due to ventricular fibrillation is the leading cause of death in most industrially developed countries. Yet, despite the enormity of this problem, the development of safe and effective antiarrhythmic therapies has proven to be an elusive goal. In fact, many initially promising antiarrhythmic medications were subsequently found to increase rather than to decrease cardiac mortality. It is now known that cardiac disease alters cardiac autonomic balance and that the patients with the greatest changes in this cardiac neural regulation (i.e., decreased parasympathetic coupled with increased sympathetic activity) are also the patients at the greatest risk for sudden death. A growing body of experimental and epidemiological data demonstrates that aerobic exercise conditioning can dramatically reduce cardiac mortality, even in patients with preexisting cardiac disease. Conversely, the lack of exercise is strongly associated with an increased incidence of many chronic debilitating diseases, including coronary heart disease. Because it is well established that aerobic exercise conditioning can alter autonomic balance (increasing parasympathetic tone and decreasing sympathetic activity), a prudently designed exercise program could prove to be an effective and nonpharmacological way to enhance cardiac electrical stability, thereby protecting against sudden cardiac death.

Not a slippery slope or sudden subversion: German medicine and national socialism in 1933.

PubMed

Hanauske-Abel, H M

1996-12-07

The history of medicine this century is darkened by the downfall of the German medical profession, exposed during the doctors' trial at Nuremberg in 1946. Relying largely on documents published during 1933 in German medical journals, this paper examines two widely accepted notions of those events, metaphorically termed "slippery slope" and "sudden subversion." The first connotes a gradual slide over infinitesimal steps until, suddenly, all footing is lost; the second conveys forced take over of the profession's leadership and values. Both concepts imply that the medical profession itself became the victim of circumstances. The slippery slope concept is a prominent figure of argument in the current debate on bioethics. The evidence presented here, however, strongly suggests that the German medical community set its own course in 1933. In some respects this course even outpaced the new government, which had to rein in the profession's eager pursuit of enforced eugenic sterilizations. In 1933 the convergence of political, scientific, and economic forces dramatically changed the relationship between the medical community and the government. That same convergence is occurring again and must be approached with great caution if medicine is to remain focused on the preservation of physical and medical integrity.

Increased resistance to sudden noise by audio stimulation during early ontogeny in German shepherd puppies.

PubMed

Chaloupková, Helena; Svobodová, Ivona; Vápeník, Pavel; Bartoš, Luděk

2018-01-01

The period of early ontogeny constitutes a time when the physical immaturity of an organism is highly susceptible to external stimuli. Thus, early development plays a major role in shaping later adult behavior. The aim of the study was to check whether stimulating puppies at this early stage in life with sound would improve their responsiveness towards unfamiliar noises during the selection process of the police behavioral test for puppies. The cohort comprised 37 puppies from the litters of three mothers. At the commencement of the experiment the dogs were aged 16 days, rising to the age of 32 days at its close. The mothers and litters of the treatment group were either exposed to radio broadcasts, (see below; three litters totaling 19 puppies), while the control group was not exposed to any radio programs (eight litters totaling 18 puppies). All three mothers had previously experienced both auditory circumstances, as described herein. Ordinary radio broadcasts were played to the puppies in the treatment group three times a day for 20 minute periods, always during feeding time. The cohort was subjected to the so-called Puppy Test, i.e. analysis of the potential of each animal, once the dogs had reached the age of 7 weeks. Such tests included exposure to a sudden noise caused by a shovel (100 dB), noise when alone in a room, and response to loud distracting stimuli (the latter two at 70 dB). Said tasks were rated by the same analyst on a scale of 0-5 points; the better the response of the dog, the higher the score given. The differences between the treatment and control groups were analyzed via Mixed Models (PROC MIXED) in SAS. The animals comprising the treatment group responded with a higher score to the sudden noise caused by the shovel than the control dogs (P<0.01). Interestingly, gender was seen to affect response, with the males scoring more than the females (P<0.1). In conclusion, the results suggested that audio stimulation early in life improved the response of the dogs to intense sudden noise, as caused by the shovel. Therefore, acoustic stimulation during the very early period of life has the potential to raise the necessary skills of dogs for military and police purposes, or civilian life.

Increased resistance to sudden noise by audio stimulation during early ontogeny in German shepherd puppies

PubMed Central

Svobodová, Ivona; Vápeník, Pavel

2018-01-01

The period of early ontogeny constitutes a time when the physical immaturity of an organism is highly susceptible to external stimuli. Thus, early development plays a major role in shaping later adult behavior. The aim of the study was to check whether stimulating puppies at this early stage in life with sound would improve their responsiveness towards unfamiliar noises during the selection process of the police behavioral test for puppies. The cohort comprised 37 puppies from the litters of three mothers. At the commencement of the experiment the dogs were aged 16 days, rising to the age of 32 days at its close. The mothers and litters of the treatment group were either exposed to radio broadcasts, (see below; three litters totaling 19 puppies), while the control group was not exposed to any radio programs (eight litters totaling 18 puppies). All three mothers had previously experienced both auditory circumstances, as described herein. Ordinary radio broadcasts were played to the puppies in the treatment group three times a day for 20 minute periods, always during feeding time. The cohort was subjected to the so-called Puppy Test, i.e. analysis of the potential of each animal, once the dogs had reached the age of 7 weeks. Such tests included exposure to a sudden noise caused by a shovel (100 dB), noise when alone in a room, and response to loud distracting stimuli (the latter two at 70 dB). Said tasks were rated by the same analyst on a scale of 0–5 points; the better the response of the dog, the higher the score given. The differences between the treatment and control groups were analyzed via Mixed Models (PROC MIXED) in SAS. The animals comprising the treatment group responded with a higher score to the sudden noise caused by the shovel than the control dogs (P<0.01). Interestingly, gender was seen to affect response, with the males scoring more than the females (P<0.1). In conclusion, the results suggested that audio stimulation early in life improved the response of the dogs to intense sudden noise, as caused by the shovel. Therefore, acoustic stimulation during the very early period of life has the potential to raise the necessary skills of dogs for military and police purposes, or civilian life. PMID:29723300

Sudden Infant Death Syndrome: Facts for Caregivers.

ERIC Educational Resources Information Center

Texas Child Care, 2000

2000-01-01

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

Superposed epoch analysis and storm statistics from 25 years of the global geomagnetic disturbance index, USGS-Dst

USGS Publications Warehouse

Gannon, J.L.

2012-01-01

Statistics on geomagnetic storms with minima below -50 nanoTesla are compiled using a 25-year span of the 1-minute resolution disturbance index, U.S. Geological Survey Dst. A sudden commencement, main phase minimum, and time between the two has a magnitude of 35 nanoTesla, -100 nanoTesla, and 12 hours, respectively, at the 50th percentile level. The cumulative distribution functions for each of these features are presented. Correlation between sudden commencement magnitude and main phase magnitude is shown to be low. Small, medium, and large storm templates at the 33rd, 50th, and 90th percentile are presented and compared to real examples. In addition, the relative occurrence of rates of change in Dst are presented.

QuakeCaster, an earthquake physics demonstration and exploration tool

USGS Publications Warehouse

Linton, K.; Stein, R.S.

2012-01-01

A fundamental riddle of earthquake occurrence is that tectonic motions at plate interiors are steady, changing only subtly over millions of years, but at plate boundary faults, the plates are stuck for hundreds of years and then suddenly jerk forward in earthquakes. Why does this happen? The answer, as formulated by Harry F. Reid (Reid 1910, 192) is that the Earth’s crust is elastic, behaving like a very stiff slab of rubber sliding over a substrate of “honey”-like asthenosphere, and that faults are restrained by friction. The crust near the faults—zones of weakness that separate the plates—slowly deforms, building up stress until frictional resistance on the fault is overcome and the fault suddenly slips. For the past century, scientists have sought ways to use this knowledge to forecast earthquakes.

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

PubMed

Walker, Wendy Marina

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

Time-resolved double resonance study of J- and K-changing rotational collisional processes in CH3Cl

NASA Astrophysics Data System (ADS)

Pape, Travis W.; De Lucia, Frank C.; Skatrud, David D.

1994-04-01

Time-resolved double resonance spectroscopy using infrared pump radiation and millimeter-wave and submillimeter-wave probe radiation (IRMMDR) has been used to study rotational energy transfer (RET) in CH3Cl. A collisional energy transfer model using only five parameters for RET plus those needed for vibrational processes is shown to accurately model 350 IRMMDR time responses for two different pump states and 43 probe transitions covering a wide range of rotational states. Previous studies in this laboratory have revealed that J- and K-changing RET have vastly different characters in CH3F [J. Chem. Phys. 92, 6480 (1990)]. Both J- and K-changing RET were accurately modeled with four parameters—one for dipole-dipole collisions, two for the ΔJ scaling law, and one for the cumulative rate of K-changing collisions. As was found for CH3F, J-changing rotational collision rates in CH3Cl are modeled accurately by both the statistical power gap (SPG) law and the infinite order sudden approximation using a power law expression for the basis rates (IOS-P). However, in contrast to CH3F, where all IRMMDR time responses for K-changing collisions have the same shape, many time responses of CH3Cl states populated by K-changing collisions contain an additional early time feature (ETF) that varies with pump and probe states. Nonetheless, a simple generalization of the previously reported model for K-changing collisions is shown to account for all of the additional features observed in CH3Cl. Rather than observing a fixed temperature for K-changing collisions as was the case for CH3F, the temperature is found to be a function of time for CH3Cl. Moreover, the two new parameters this adds to the RET model are related to known physical quantities. A qualitative argument of K-changing collisions based on a classical picture is offered to explain the difference between the measured J- and K-changing state-to-state rates in CH3Cl.

Hibernating myocardium results in partial sympathetic denervation and nerve sprouting.

PubMed

Fernandez, Stanley F; Ovchinnikov, Vladislav; Canty, John M; Fallavollita, James A

2013-01-15

Hibernating myocardium due to chronic repetitive ischemia is associated with regional sympathetic nerve dysfunction and spontaneous arrhythmic death in the absence of infarction. Although inhomogeneity in regional sympathetic innervation is an acknowledged substrate for sudden death, the mechanism(s) responsible for these abnormalities in viable, dysfunctional myocardium (i.e., neural stunning vs. sympathetic denervation) and their association with nerve sprouting are unknown. Accordingly, markers of sympathetic nerve function and nerve sprouting were assessed in subendocardial tissue collected from chronically instrumented pigs with hibernating myocardium (n = 18) as well as sham-instrumented controls (n = 7). Hibernating myocardium exhibited evidence of partial sympathetic denervation compared with the normally perfused region and sham controls, with corresponding regional reductions in tyrosine hydroxylase protein (-32%, P < 0.001), norepinephrine uptake transport protein (-25%, P = 0.01), and tissue norepinephrine content (-45%, P < 0.001). Partial denervation induced nerve sprouting with regional increases in nerve growth factor precursor protein (31%, P = 0.01) and growth associated protein-43 (38%, P < 0.05). All of the changes in sympathetic nerve markers were similar in animals that developed sudden death (n = 9) compared with electively terminated pigs with hibernating myocardium (n = 9). In conclusion, sympathetic nerve dysfunction in hibernating myocardium is most consistent with partial sympathetic denervation and is associated with regional nerve sprouting. The extent of sympathetic remodeling is similar in animals that develop sudden death compared with survivors; this suggests that sympathetic remodeling in hibernating myocardium is not an independent trigger for sudden death. Nevertheless, sympathetic remodeling likely contributes to electrical instability in combination with other factors.

Hibernating myocardium results in partial sympathetic denervation and nerve sprouting

PubMed Central

Fernandez, Stanley F.; Ovchinnikov, Vladislav; Canty, John M.

2013-01-01

Hibernating myocardium due to chronic repetitive ischemia is associated with regional sympathetic nerve dysfunction and spontaneous arrhythmic death in the absence of infarction. Although inhomogeneity in regional sympathetic innervation is an acknowledged substrate for sudden death, the mechanism(s) responsible for these abnormalities in viable, dysfunctional myocardium (i.e., neural stunning vs. sympathetic denervation) and their association with nerve sprouting are unknown. Accordingly, markers of sympathetic nerve function and nerve sprouting were assessed in subendocardial tissue collected from chronically instrumented pigs with hibernating myocardium (n = 18) as well as sham-instrumented controls (n = 7). Hibernating myocardium exhibited evidence of partial sympathetic denervation compared with the normally perfused region and sham controls, with corresponding regional reductions in tyrosine hydroxylase protein (−32%, P < 0.001), norepinephrine uptake transport protein (−25%, P = 0.01), and tissue norepinephrine content (−45%, P < 0.001). Partial denervation induced nerve sprouting with regional increases in nerve growth factor precursor protein (31%, P = 0.01) and growth associated protein-43 (38%, P < 0.05). All of the changes in sympathetic nerve markers were similar in animals that developed sudden death (n = 9) compared with electively terminated pigs with hibernating myocardium (n = 9). In conclusion, sympathetic nerve dysfunction in hibernating myocardium is most consistent with partial sympathetic denervation and is associated with regional nerve sprouting. The extent of sympathetic remodeling is similar in animals that develop sudden death compared with survivors; this suggests that sympathetic remodeling in hibernating myocardium is not an independent trigger for sudden death. Nevertheless, sympathetic remodeling likely contributes to electrical instability in combination with other factors. PMID:23125211

Quantum Correlation Properties in Two Qubits One-axis Spin Squeezing Model

NASA Astrophysics Data System (ADS)

Guo-Hui, Yang

2017-02-01

Using the concurrence (C) and quantum discord (QD) criterions, the quantum correlation properties in two qubits one-axis spin squeezing model with an external magnetic field are investigated. It is found that one obvious difference in the limit case T → 0 (ground state) is the sudden disappearance phenomenon (SDP) occured in the behavior of C, while not in QD. In order to further explain the SDP, we obtain the analytic expressions of ground state C and QD which reveal that the SDP is not really "entanglement sudden disappeared", it is decayed to zero very quickly. Proper tuning the parameters μ(the spin squeezing interaction in x direction) and Ω(the external magnetic field in z direction) not only can obviously broaden the scope of ground state C exists but also can enhance the value of ground state QD. For the finite temperature case, one evident difference is that the sudden birth phenomenon (SBP) is appeared in the evolution of C, while not in QD, and decreasing the coupling parameters μ or Ω can obviously prolong the time interval before entanglement sudden birth. The value of C and QD are both enhanced by increasing the parameters μ or Ω in finite temperature case. In addition, through investigating the effects of temperature T on the quantum correlation properties with the variation of Ω and μ, one can find that the temperature scope of C and QD exists are broadened with increasing the parameters μ or Ω, and one can obtain the quantum correlation at higher temperature through changing these parameters.

Shape memory polymer network with thermally distinct elasticity and plasticity.

PubMed

Zhao, Qian; Zou, Weike; Luo, Yingwu; Xie, Tao

2016-01-01

Stimuli-responsive materials with sophisticated yet controllable shape-changing behaviors are highly desirable for real-world device applications. Among various shape-changing materials, the elastic nature of shape memory polymers allows fixation of temporary shapes that can recover on demand, whereas polymers with exchangeable bonds can undergo permanent shape change via plasticity. We integrate the elasticity and plasticity into a single polymer network. Rational molecular design allows these two opposite behaviors to be realized at different temperature ranges without any overlap. By exploring the cumulative nature of the plasticity, we demonstrate easy manipulation of highly complex shapes that is otherwise extremely challenging. The dynamic shape-changing behavior paves a new way for fabricating geometrically complex multifunctional devices.

Advanced Electrocardiographic Predictors of Sudden Death in Familial Dysautonomia

NASA Technical Reports Server (NTRS)

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

2007-01-01

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

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

PubMed

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

2017-08-23

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

Dome-shaped magnetic order competing with high-temperature superconductivity at high pressures in FeSe.

PubMed

Sun, J P; Matsuura, K; Ye, G Z; Mizukami, Y; Shimozawa, M; Matsubayashi, K; Yamashita, M; Watashige, T; Kasahara, S; Matsuda, Y; Yan, J-Q; Sales, B C; Uwatoko, Y; Cheng, J-G; Shibauchi, T

2016-07-19

The coexistence and competition between superconductivity and electronic orders, such as spin or charge density waves, have been a central issue in high transition-temperature (Tc) superconductors. Unlike other iron-based superconductors, FeSe exhibits nematic ordering without magnetism whose relationship with its superconductivity remains unclear. Moreover, a pressure-induced fourfold increase of Tc has been reported, which poses a profound mystery. Here we report high-pressure magnetotransport measurements in FeSe up to ∼15 GPa, which uncover the dome shape of magnetic phase superseding the nematic order. Above ∼6 GPa the sudden enhancement of superconductivity (Tc≤38.3 K) accompanies a suppression of magnetic order, demonstrating their competing nature with very similar energy scales. Above the magnetic dome, we find anomalous transport properties suggesting a possible pseudogap formation, whereas linear-in-temperature resistivity is observed in the normal states of the high-Tc phase above 6 GPa. The obtained phase diagram highlights unique features of FeSe among iron-based superconductors, but bears some resemblance to that of high-Tc cuprates.

Evidence for glaciation in Elysium

NASA Technical Reports Server (NTRS)

Anderson, Duwayne M.

1987-01-01

Evidence for the existence of permafrost and the surface modification due to frost effects and the presence of ice on Mars dates from early observations. Later analysis of the Viking Orbiter imagery produced evidence suggesting the former presence of ice sheets that could have played a part in shaping the surface of Mars. Similarities were pointed out between a number of streamlined Martian channel features and similar streamlined landforms created by Antarctic ice sheet movement. A study of Viking Orbiter imagery of Granicus Valles and the surrounding terrain in Elysium has produced further evidence of glaciation on Mars. Volcanism has played an important role in developing the landscapes of the Elysium region. A possible explanation is that subsidence occurred during formation of the Martian moberg ridges due to the melting of ground ice near the eruption area while at a distance most of the ground ice in the permafrost is still present and the original elevation was preserved. Meltwater during and following eruptions might be suddenly released during subglacial volcanism into Granicus Valles in one case and into Hrad Valles in the other. Fluvial erosion thus could have played a role in shaping both.

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

PubMed

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

2015-09-01

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

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

PubMed

Benito Bartolomé, F; Sánchez Fernández-Bernal, C

2001-04-01

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

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

PubMed

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

2015-10-01

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

Cavitation in centrifugal pump with rotating walls of axial inlet device

NASA Astrophysics Data System (ADS)

Moloshnyi, O.; Sotnyk, M.

2017-08-01

The article deals with the analysis of cavitation processes in the flowing part of the double entry centrifugal pump. The analysis is conducted using numerical modeling of the centrifugal pump operating process in the software environment ANSYS CFX. Two models of the axial inlet device is researched. It is shaped by a cylindrical section and diffuser section in front of the impeller, which includes fairing. The walls of the axial inlet device rotate with the same speed as the pump rotor. The numerical experiment is conducted under the condition of the flow rate change and absolute pressure at the inlet. The analysis shows that the pump has the average statistical cavitation performance. The occurrence of the cavitation in the axial inlet device is after narrowing the cross-section of flow channel and at the beginning of the diffuser section. Additional sudden expansion at the outlet of the axial inlet diffuser section does not affect the cavitation characteristics of the impeller, however, improves cavitation characteristics of the axial inlet device. For considered geometric parameters of the axial inlet device the cavitation in the impeller begins earlier than in the axial inlet device. That is, the considered design of the axial inlet device will not be subjected to destruction at the ensuring operation without cavitation in the impeller.

The paddle move commonly used in magic tricks as a means for analysing the perceptual limits of combined motion trajectories.

PubMed

Hergovich, Andreas; Gröbl, Kristian; Carbon, Claus-Christian

2011-01-01

Following Gustav Kuhn's inspiring technique of using magicians' acts as a source of insight into cognitive sciences, we used the 'paddle move' for testing the psychophysics of combined movement trajectories. The paddle move is a standard technique in magic consisting of a combined rotating and tilting movement. Careful control of the mutual speed parameters of the two movements makes it possible to inhibit the perception of the rotation, letting the 'magic' effect emerge--a sudden change of the tilted object. By using 3-D animated computer graphics we analysed the interaction of different angular speeds and the object shape/size parameters in evoking this motion disappearance effect. An angular speed of 540 degrees s(-1) (1.5 rev. s(-1)) sufficed to inhibit the perception of the rotary movement with the smallest object showing the strongest effect. 90.7% of the 172 participants were not able to perceive the rotary movement at an angular speed of 1125 degrees s(-1) (3.125 rev. s(-1)). Further analysis by multiple linear regression revealed major influences on the effectiveness of the magic trick of object height and object area, demonstrating the applicability of analysing key factors of magic tricks to reveal limits of the perceptual system.

μ-PIV measurements of the ensemble flow fields surrounding a migrating semi-infinite bubble.

PubMed

Yamaguchi, Eiichiro; Smith, Bradford J; Gaver, Donald P

2009-08-01

Microscale particle image velocimetry (μ-PIV) measurements of ensemble flow fields surrounding a steadily-migrating semi-infinite bubble through the novel adaptation of a computer controlled linear motor flow control system. The system was programmed to generate a square wave velocity input in order to produce accurate constant bubble propagation repeatedly and effectively through a fused glass capillary tube. We present a novel technique for re-positioning of the coordinate axis to the bubble tip frame of reference in each instantaneous field through the analysis of the sudden change of standard deviation of centerline velocity profiles across the bubble interface. Ensemble averages were then computed in this bubble tip frame of reference. Combined fluid systems of water/air, glycerol/air, and glycerol/Si-oil were used to investigate flows comparable to computational simulations described in Smith and Gaver (2008) and to past experimental observations of interfacial shape. Fluorescent particle images were also analyzed to measure the residual film thickness trailing behind the bubble. The flow fields and film thickness agree very well with the computational simulations as well as existing experimental and analytical results. Particle accumulation and migration associated with the flow patterns near the bubble tip after long experimental durations are discussed as potential sources of error in the experimental method.

Sudden death: bereavement sequelae and interventions.

PubMed

Davidson, G P

1981-10-14

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

Sudden Cardiac Arrest (SCA) Risk Assessment

MedlinePlus

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

Transforming America's Universities to Compete in the "New Normal"

ERIC Educational Resources Information Center

Bruininks, Robert H.; Keeney, Brianne; Thorp, Jim

2010-01-01

The challenges faced today by U.S. colleges and universities have been accelerated by the current economic downturn, but they are not the result of it. Consequently, we should not expect a sudden reversal of fortune when the economy rebounds. Changing demographics and spending priorities coupled with increasing competition and demands for…

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

Jeffries, C.; Perez, J.

For a driven nonlinear oscillator we report direct evidence for three cases of an interior crisis of the attractor, as conjectured by Grebogi, Ott, and Yorke. These crises are sudden and discontinuous changes in the attractor, observed directly from bifurcation diagrams and attractor diagrams (Poincare sections) in real time. The crises arise from intersection of an unstable orbit with the chaotic attractor.

How to Create Successful Discussions in Science Classrooms

ERIC Educational Resources Information Center

Grover, Neena

2007-01-01

Professors often expect students to have the skills that are necessary to participate in discussions. Students, on the other hand, have been trained to glean information from the lecture format; their prior experiences in discussions are likely to be limited to personal opinions on topics such as stem-cell research or evolution. Sudden changes in…

Poppers retinopathy

PubMed Central

Luis, Joshua; Virdi, Meena; Nabili, Shahriar

2016-01-01

We present a case of a 52-year-old man with sudden, bilateral central loss of vision as a result of inhalation of ‘poppers’. He was found to have characteristic changes on optical coherence tomography. With conservative treatment, the patient's vision improved marginally at 3 months follow-up. An overview of previous published cases is also included. PMID:26952176

Slow lifelong growth predisposes Populus tremuloides to tree mortality

Treesearch

Kathryn B. Ireland; Margaret M. Moore; Peter Z. Fule; Thomas J. Zegler; Robert E. Keane

2014-01-01

Widespread dieback of aspen forests, sometimes called sudden aspen decline, has been observed throughout much of western North America, with the highest mortality rates in the southwestern United States. Recent aspen mortality has been linked to drought stress and elevated temperatures characteristic of conditions expected under climate change, but the role of...

How Culture Shock Affects Communication.

ERIC Educational Resources Information Center

Barna, LaRay M.

The paper defines the term "culture shock" and discusses the changes that this state can make in a person's behavior. Culture shock refers to the emotional and physiological reaction of high activation that is brought about by sudden immersion in a new culture. Because one's own culture shields one from the unknown and reduces the need to make…

Assessing the impact of emerging forest disease on wildfire using Landsat and KOMPSAT-2 data

Treesearch

Gang Chen; Yinan He; Angela De Santis; Guosheng Li; Richard Cobb; Ross K. Meentemeyer

2017-01-01

Environmental disturbance regimes are more frequently being altered by historically novel events and disturbance interactions, which may trigger reorganizations of new ecosystem states and processes. Here we examine synergies between emerging forest disease and wildfire to determine whether disease outbreak changes environmental drivers of burn severity using sudden...

The Profit Prophets in Higher Education

ERIC Educational Resources Information Center

Halfond, Jay A.

2010-01-01

The nation seems to have suddenly awoken to the reality that for-profit academic institutions are a force to be reckoned with. For so long, they have been ignored as inconsequential, second-rate competition, and vilified for their greed and lack of quality. Two events have changed their image into something far more formidable: (1) the realization…

Resilience of diversity-disease risk interactions following wildfire disturbance

Treesearch

Devon A. Gaydos; Krishna Pacifici; Ross K. Meentemeyer; David. M. Rizzo

2017-01-01

The potential for biodiversity to mitigate risk of infectious diseases in ecological communities – known as the diversity-disease risk hypothesis – is fundamental to understanding links between landscape change and environmental health of forests affected by sudden oak death (SOD). Previous research of the Phytophthora ramorum pathosystem...

Maximizing Credit Accrual and Recovery for Homeless Students. Best Practices in Homeless Education

ERIC Educational Resources Information Center

National Center for Homeless Education at SERVE, 2010

2010-01-01

Middle and high school students experiencing homelessness often face challenges in accruing credits. Class offerings, methods of calculating credits, and graduation requirements can vary greatly among school districts. Students who change schools late in high school can find themselves suddenly in danger of not graduating due to differing class…

Looks like Teen Spirit: Libraries for Youth Are Changing--Thanks to Teen Input

ERIC Educational Resources Information Center

Bolan, Kimberly

2006-01-01

During the last 10 years, many libraries have transformed their young adult areas into more efficient, innovative, and inspirational spaces. Many teens have suddenly found the library warm and inviting--a place that encouraged independence, learning, socialization, and creativity. As more people learn about the positive impact of dynamic teen…

The Professional's Last Will and Testament.

ERIC Educational Resources Information Center

Lancaster, James M.

2003-01-01

In this article a case study illustrates the initial issues arising from the sudden death of key personnel, and then offers an outline for the Professional's Last Will and Testament. This document includes attention to logistical issues and planning for organizational change. It begins with short-term transition issues and continues through other,…

47 CFR 73.865 - Assignment and transfer of LPFM licenses.

Code of Federal Regulations, 2012 CFR

2012-10-01

... transfer an LPFM construction permit at any time. (e) Transfers of control involving a sudden change of... 47 Telecommunication 4 2012-10-01 2012-10-01 false Assignment and transfer of LPFM licenses. 73... SERVICES RADIO BROADCAST SERVICES Low Power FM Broadcast Stations (LPFM) § 73.865 Assignment and transfer...

Emergent high-spin state above 7 GPa in superconducting FeSe

NASA Astrophysics Data System (ADS)

Lebert, B. W.; Balédent, V.; Toulemonde, P.; Ablett, J. M.; Rueff, J.-P.

2018-05-01

The local electronic and magnetic properties of superconducting FeSe have been investigated by K β x-ray emission and simultaneous x-ray absorption spectroscopy (XAS) at the Fe K edge at high pressure and low temperature. Our results indicate a sluggish decrease of the local Fe spin moment under pressure up to 7 GPa, in line with previous reports, followed by a sudden increase at higher pressure. The magnetic surge is preceded by an abrupt change of the Fe local structure as observed by the decrease of the XAS preedge region intensity and corroborated by ab initio simulations. This pressure corresponds to a structural transition from the C m m a form to the denser P b n m form with octahedral coordination of iron. Finally, the near-edge region of the XAS spectra shows a change before this transition at 5 GPa, corresponding well with the onset pressure of the sudden enhancement of Tc. Our results emphasize the delicate interplay between structural, magnetic, and superconducting properties in FeSe under pressure.

Experimental Study of Liquid Jet Impingement in Microgravity: The Hydraulic Jump

NASA Technical Reports Server (NTRS)

Avedisian, C. T.; Zhao, Z.

1996-01-01

A preliminary study of the Circular Hydraulic Jump (CHJ) in microgravity is reported using water as the working fluid. The evolution of the CHJ radius was measured during a sudden transition from normal to microgravity in a drop tower. The downstream height of the CHJ was controlled by submerging the target plate in a tank filled with water to the desired depth, and the measurements are compared with an existing theory for the location of the CHJ. Results showed that the CHJ diameter was larger in microgravity than normal gravity. The adjustment of the CHJ diameter to a sudden change in gravity occurred over a period of about 200 ms for the conditions of the present study, and remained constant thereafter. For flow conditions that a CHJ was not first established at normal gravity but which later appeared during the transition to microgravity, the CHJ diameter was not constant during the period of microgravity but continually changed. Good agreement between the measured and predicted CHJ diameter was found for the normal gravity data, but comparatively poorer agreement was observed for the microgravity measurements.

EUV Waves Driven by the Sudden Expansion of Transequatorial Loops Caused by Coronal Jets

NASA Astrophysics Data System (ADS)

Shen, Yuandeng; Tang, Zehao; Miao, Yuhu; Su, Jiangtao; Liu, Yu

2018-06-01

We present two events to study the driving mechanism of extreme-ultraviolet (EUV) waves that are not associated with coronal mass ejections (CMEs), by using high-resolution observations taken by the Atmospheric Imaging Assembly on board the Solar Dynamics Observatory. Observational results indicate that the observed EUV waves were accompanied by flares and coronal jets, but not the CMEs that were regarded as drivers of most EUV waves in previous studies. In the first case, it is observed that a coronal jet is ejected along a transequatorial loop system at a plane-of-the-sky (POS) speed of 335 ± 22 km s{}-1; in the meantime, an arc-shaped EUV wave appeared on the eastern side of the loop system. In addition, the EUV wave further interacted with another interconnecting loop system and launched a fast propagating (QFP) magnetosonic wave along the loop system, which had a period of 200 s and a speed of 388 ± 65 km s{}-1, respectively. In the second case, we observed a coronal jet that ejected at a POS speed of 282 ± 44 km s{}-1 along a transequatorial loop system as well as the generation of bright EUV waves on the eastern side of the loop system. Based on the observational results, we propose that the observed EUV waves on the eastern side of the transequatorial loop systems are fast-mode magnetosonic waves and that they are driven by the sudden lateral expansion of the transequatorial loop systems due to the direct impingement of the associated coronal jets, while the QFP wave in the fist case formed due to the dispersive evolution of the disturbance caused by the interaction between the EUV wave and the interconnecting coronal loops. It is noted that EUV waves driven by sudden loop expansions have shorter lifetimes than those driven by CMEs.

High-sensitive cardiac troponin hs-TnT levels in sudden deaths related to atherosclerotic coronary artery disease.

PubMed

Beausire, Tim; Faouzi, Mohamed; Palmiere, Cristian; Fracasso, Tony; Michaud, Katarzyna

2018-06-04

Ischemic heart disease (IHD) related to atherosclerotic coronary artery disease (CAD) is one of the most prevalent causes of death in Europe. Postmortem evaluation of IHD remains a challenge because of possible non-specific autopsy finding in some autopsy cases, especially in early myocardial ischemia. High-sensitive cardiac troponin T (hs-TnT) is used today in clinical practice as the "gold standard" to diagnose the myocardial ischemia, and might also be applied as an ancillary tool for post-mortem evaluation. The goal of this study is to evaluate the diagnostic value of post-mortem serum hs-TnT assay in cases of sudden death related to IHD. We will also investigate the influence of cardiopulmonary resuscitation (CPR) attempts on post-mortem hs-TnT levels. The hs-TnT values in serum were retrospectively analysed in 85 autopsy data. 52 cases with clinical history and morphological results suggesting cardiac ischemia were included in the study group (mean age 53.5; age range 34-75) and 33 cases in the control group (mean age 40.4; age range 15-69). The group's statistical comparison was performed using logistic regression model. Our study showed a significant non-linear association between hs-TnT serum values and post-mortem diagnosis of sudden deaths related to IHD (p-value 0.005). The shape of the relationship is showing that the probability of death due to IHD increases quickly with a light level of hs-TnT (maximum around 90ng/L) then decreases slightly while remaining at high in values. No significant difference in the hs-TnT serum values was found between the CPR and the non-CPR cases (p-value 0.304). The measurement of hs-TnT serum values might be considered as an ancillary tool for the evaluation of death related to IHD, while taking necessary precautions in the interpretation of the results. Copyright © 2018 Elsevier B.V. All rights reserved.

Amplitude variations during SIDs in 10.2 and 13.6 kHz waves propagating long distances in the subionospheric waveguide - Theoretical interpretation

NASA Astrophysics Data System (ADS)

Charcosset, G.; Tixier, M.

1981-12-01

During sudden ionospheric disturbances (SIDs), vertical electric field amplitude variations of waves emitted at 10.2 and 13.6 kHz in Norway and Liberia and observed in France were found to result in a regular decrease at the former wavelength and more complex behavior at the latter, where amplitude behavior depends on the importance of the SID. A theoretical interpretation employing a waveguide mode hypothesis of long distance wave propagation is presented, in which it is assumed that the D-region ionization enhancement produced by the solar X-ray flux during SID can be represented by a decrease of the waveguide height in which the shape of the density profile remains unchanged.

Fragmentation of an elastica

NASA Astrophysics Data System (ADS)

Vandenberghe, Nicolas; Villermaux, Emmanuel

2009-03-01

When a thin rod is submitted to an axial force greater than its critical buckling load it takes the shape of an elastica. As the load further increases, a rod made of a brittle material breaks suddenly. More than two fragments may be formed during this fragmentation. In this work we discuss the sequence of events that lead to the final broken state with two or more fragments. We show that the criterion for breaking is not trivial. In particular, we investigate the effect of the duration of the loading and we show that at a given load the waiting time before breaking is broadly distributed. We discuss the consequences of the time delayed breaking on the distributions of fragment sizes and fragment numbers.

Enterotoxigenic Escherichia coli infection in captive black-footed ferrets.

PubMed

Bradley, G A; Orr, K; Reggiardo, C; Glock, R D

2001-07-01

Enterotoxigenic Escherichia coli with genes for heat stabile toxins Sta and STb was isolated from the gastrointestinal tract and multiple visceral organs of three adult and three juvenile black-footed ferrets (Mustela nigripes) that died in a captive breeding colony between 24 May 1998 and 2 July 1998. Similar isolates were obtained from rectal swabs of one adult and one juvenile that were clinically ill. All were fed a diet composed of mink chow, raw rabbit meat, beef liver powder, blood meal and lard. Escherichia coli of the same toxin genotype was isolated from the mixed ration. Clinical signs included sudden death, dehydration, anorexia and diarrhea. Necropsy lesions included acute enteritis with large numbers of rod shaped bacteria microscopically visible on intestinal villi.

Shape memory polymer network with thermally distinct elasticity and plasticity

PubMed Central

Zhao, Qian; Zou, Weike; Luo, Yingwu; Xie, Tao

2016-01-01

Stimuli-responsive materials with sophisticated yet controllable shape-changing behaviors are highly desirable for real-world device applications. Among various shape-changing materials, the elastic nature of shape memory polymers allows fixation of temporary shapes that can recover on demand, whereas polymers with exchangeable bonds can undergo permanent shape change via plasticity. We integrate the elasticity and plasticity into a single polymer network. Rational molecular design allows these two opposite behaviors to be realized at different temperature ranges without any overlap. By exploring the cumulative nature of the plasticity, we demonstrate easy manipulation of highly complex shapes that is otherwise extremely challenging. The dynamic shape-changing behavior paves a new way for fabricating geometrically complex multifunctional devices. PMID:26824077

Principal component analysis of three-dimensional face shape: Identifying shape features that change with age.

PubMed

Kurosumi, M; Mizukoshi, K

2018-05-01

The types of shape feature that constitutes a face have not been comprehensively established, and most previous studies of age-related changes in facial shape have focused on individual characteristics, such as wrinkle, sagging skin, etc. In this study, we quantitatively measured differences in face shape between individuals and investigated how shape features changed with age. We analyzed three-dimensionally the faces of 280 Japanese women aged 20-69 years and used principal component analysis to establish the shape features that characterized individual differences. We also evaluated the relationships between each feature and age, clarifying the shape features characteristic of different age groups. Changes in facial shape in middle age were a decreased volume of the upper face and increased volume of the whole cheeks and around the chin. Changes in older people were an increased volume of the lower cheeks and around the chin, sagging skin, and jaw distortion. Principal component analysis was effective for identifying facial shape features that represent individual and age-related differences. This method allowed straightforward measurements, such as the increase or decrease in cheeks caused by soft tissue changes or skeletal-based changes to the forehead or jaw, simply by acquiring three-dimensional facial images. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Onset of psychosis at age 81? With regard to frontal lobe syndromes

PubMed Central

Pedro, Patrícia; Telles-Correia, Diogo; Godinho, Iolanda; Chagas, Carlos

2015-01-01

When the frontal lobe of the brain is affected important behavioral changes may occur mainly at the level of executive functioning, i.e., planning, decision-making, judgment and self-perception. However, the behavioral changes may be of different nature with marked indifference and apathy. We report a clinical case of an 81-year-old patient with sudden onset of behavioral changes that were initially interpreted as an acute confusional episode of infectious etiology, but actually they were due to an ischemic lesion in the frontal lobe. PMID:26398362

Self-shaping of bioinspired chiral composites

NASA Astrophysics Data System (ADS)

Rong, Qing-Qing; Cui, Yu-Hong; Shimada, Takahiro; Wang, Jian-Shan; Kitamura, Takayuki

2014-08-01

Self-shaping materials such as shape memory polymers have recently drawn considerable attention owing to their high shape-changing ability in response to changes in ambient conditions, and thereby have promising applications in the biomedical, biosensing, soft robotics and aerospace fields. Their design is a crucial issue of both theoretical and technological interest. Motivated by the shape-changing ability of Towel Gourd tendril helices during swelling/deswelling, we present a strategy for realizing self-shaping function through the deformation of micro/nanohelices. To guide the design and fabrication of self-shaping materials, the shape equations of bent configurations, twisted belts, and helices of slender chiral composite are developed using the variation method. Furthermore, it is numerically shown that the shape changes of a chiral composite can be tuned by the deformation of micro/nanohelices and the fabricated fiber directions. This work paves a new way to create self-shaping composites.

Shape memory alloy thaw sensors

DOEpatents

Shahinpoor, M.; Martinez, D.R.

1998-04-07

A sensor permanently indicates that it has been exposed to temperatures exceeding a critical temperature for a predetermined time period. An element of the sensor made from shape memory alloy changes shape when exposed, even temporarily, to temperatures above the austenitic temperature of the shape memory alloy. The shape change of the SMA element causes the sensor to change between two readily distinguishable states. 16 figs.

Shape memory alloy thaw sensors

DOEpatents

Shahinpoor, Mohsen; Martinez, David R.

1998-01-01

A sensor permanently indicates that it has been exposed to temperatures exceeding a critical temperature for a predetermined time period. An element of the sensor made from shape memory alloy changes shape when exposed, even temporarily, to temperatures above the Austenitic temperature of the shape memory alloy. The shape change of the SMA element causes the sensor to change between two readily distinguishable states.

Mobile phone usage does not affect sudden sensorineural hearing loss.

PubMed

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

2018-01-01

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

Hypertrophic cardiomyopathy-linked mutation in troponin T causes myofibrillar disarray and pro-arrhythmic action potential changes in human iPSC cardiomyocytes.

PubMed

Wang, Lili; Kim, Kyungsoo; Parikh, Shan; Cadar, Adrian Gabriel; Bersell, Kevin R; He, Huan; Pinto, Jose R; Kryshtal, Dmytro O; Knollmann, Bjorn C

2018-01-01

Mutations in cardiac troponin T (TnT) are linked to increased risk of ventricular arrhythmia and sudden death despite causing little to no cardiac hypertrophy. Studies in mice suggest that the hypertrophic cardiomyopathy (HCM)-associated TnT-I79N mutation increases myofilament Ca sensitivity and is arrhythmogenic, but whether findings from mice translate to human cardiomyocyte electrophysiology is not known. To study the effects of the TnT-I79N mutation in human cardiomyocytes. Using CRISPR/Cas9, the TnT-I79N mutation was introduced into human induced pluripotent stem cells (hiPSCs). We then used the matrigel mattress method to generate single rod-shaped cardiomyocytes (CMs) and studied contractility, Ca handling and electrophysiology. Compared to isogenic control hiPSC-CMs, TnT-I79N hiPSC-CMs exhibited sarcomere disorganization, increased systolic function and impaired relaxation. The Ca-dependence of contractility was leftward shifted in mutation containing cardiomyocytes, demonstrating increased myofilament Ca sensitivity. In voltage-clamped hiPSC-CMs, TnT-I79N reduced intracellular Ca transients by enhancing cytosolic Ca buffering. These changes in Ca handling resulted in beat-to-beat instability and triangulation of the cardiac action potential, which are predictors of arrhythmia risk. The myofilament Ca sensitizer EMD57033 produced similar action potential triangulation in control hiPSC-CMs. The TnT-I79N hiPSC-CM model not only reproduces key cellular features of TnT-linked HCM such as myofilament disarray, hypercontractility and diastolic dysfunction, but also suggests that this TnT mutation causes pro-arrhythmic changes of the human ventricular action potential. Copyright © 2017 Elsevier Ltd. All rights reserved.

Strategic Competition and Resistance in the 21st Century: Irregular, Catastrophic, Traditional, and Hybrid Challenges in Context

DTIC Science & Technology

2007-05-01

account for changes in the environment would ultimately limit American freedom of action and fundamentally jeopardize American great power. From the...reflect or account for this change in its strategic planning. DoD strategists further believed that the previous QDR, released in September 2001, did...commencement of work on NDS 05, the strategic environment proved more complex than previously articulated or accounted for by DoD. Suddenly the

Fishing out collective memory of migratory schools

PubMed Central

De Luca, Giancarlo; Mariani, Patrizio; MacKenzie, Brian R.; Marsili, Matteo

2014-01-01

Animals form groups for many reasons, but there are costs and benefits associated with group formation. One of the benefits is collective memory. In groups on the move, social interactions play a crucial role in the cohesion and the ability to make consensus decisions. When migrating from spawning to feeding areas, fish schools need to retain a collective memory of the destination site over thousands of kilometres, and changes in group formation or individual preference can produce sudden changes in migration pathways. We propose a modelling framework, based on stochastic adaptive networks, that can reproduce this collective behaviour. We assume that three factors control group formation and school migration behaviour: the intensity of social interaction, the relative number of informed individuals and the strength of preference that informed individuals have for a particular migration area. We treat these factors independently and relate the individuals’ preferences to the experience and memory for certain migration sites. We demonstrate that removal of knowledgeable individuals or alteration of individual preference can produce rapid changes in group formation and collective behaviour. For example, intensive fishing targeting the migratory species and also their preferred prey can reduce both terms to a point at which migration to the destination sites is suddenly stopped. The conceptual approaches represented by our modelling framework may therefore be able to explain large-scale changes in fish migration and spatial distribution. PMID:24647905

Fishing out collective memory of migratory schools.

PubMed

De Luca, Giancarlo; Mariani, Patrizio; MacKenzie, Brian R; Marsili, Matteo

2014-06-06

Animals form groups for many reasons, but there are costs and benefits associated with group formation. One of the benefits is collective memory. In groups on the move, social interactions play a crucial role in the cohesion and the ability to make consensus decisions. When migrating from spawning to feeding areas, fish schools need to retain a collective memory of the destination site over thousands of kilometres, and changes in group formation or individual preference can produce sudden changes in migration pathways. We propose a modelling framework, based on stochastic adaptive networks, that can reproduce this collective behaviour. We assume that three factors control group formation and school migration behaviour: the intensity of social interaction, the relative number of informed individuals and the strength of preference that informed individuals have for a particular migration area. We treat these factors independently and relate the individuals' preferences to the experience and memory for certain migration sites. We demonstrate that removal of knowledgeable individuals or alteration of individual preference can produce rapid changes in group formation and collective behaviour. For example, intensive fishing targeting the migratory species and also their preferred prey can reduce both terms to a point at which migration to the destination sites is suddenly stopped. The conceptual approaches represented by our modelling framework may therefore be able to explain large-scale changes in fish migration and spatial distribution.

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

PubMed

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

2016-06-01

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

Anti-Sigma Factors in E. coli: Common Regulatory Mechanisms Controlling Sigma Factors Availability

PubMed Central

Treviño-Quintanilla, Luis Gerardo; Freyre-González, Julio Augusto; Martínez-Flores, Irma

2013-01-01

In bacteria, transcriptional regulation is a key step in cellular gene expression. All bacteria contain a core RNA polymerase that is catalytically competent but requires an additional σ factor for specific promoter recognition and correct transcriptional initiation. The RNAP core is not able to selectively bind to a given σ factor. In contrast, different σ factors have different affinities for the RNAP core. As a consequence, the concentration of alternate σ factors requires strict regulation in order to properly control the delicate interplay among them, which favors the competence for the RNAP core. This control is archived by different σ/anti-σ controlling mechanisms that shape complex regulatory networks and cascades, and enable the response to sudden environmental cues, whose global understanding is a current challenge for systems biology. Although there have been a number of excellent studies on each of these σ/anti-σ post-transcriptional regulatory systems, no comprehensive comparison of these mechanisms in a single model organism has been conducted. Here, we survey all these systems in E. coli dissecting and analyzing their inner workings and highlightin their differences. Then, following an integral approach, we identify their commonalities and outline some of the principles exploited by the cell to effectively and globally reprogram the transcriptional machinery. These principles provide guidelines for developing biological synthetic circuits enabling an efficient and robust response to sudden stimuli. PMID:24396271

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

MedlinePlus

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

The role of steroids in the development of post-partum mental disorders.

PubMed

Paskova, Andrea; Jirak, Roman; Mikesova, Michaela; Adamcova, Karolina; Fartakova, Zdenka; Horakova, Vladimira; Koucky, Michal; Hill, Martin; Hruskovicova, Hana; Starka, Luboslav; Duskova, Michaela; Parizek, Antonin

2014-09-01

Unfavorable post-partum changes to mental well-being affect more than half of all women, and are a risk to the health of both mother and baby. Their effects place strains on health and social systems. Currently, no generally accepted theory exists of the causes and mechanisms of post-partum mental disorders. Literature search up to 2012, using PubMed and search words: neuroactive steroids, post-partum mental disorders, depression, corticotropin-releasing hormone and estrogens. There are several theories for post-partum depression. One is that autoimmune diseases are involved. Others revolve around genes responsible or that lead to increased disposition to the disorder. It is likely however that the process is associated with the separation of the placenta and the fetal zone of fetal adrenal gland, the main sources of corticotropin-releasing hormone and sexual and neuroactive steroids during pregnancy, and the ability of the receptor system to adapt to these changes. The central nervous system is able to produce neurosteroids, but the drop in levels of peripheral steroids likely leads to a sudden deficit in neuroinhibitory steroids modulating ionotropic receptors in the brain. Post-partum depression is a multifactorial disease with unknown etiology. It is probably associated with sudden changes in the production of hormones influencing the nervous system, and on the other hand the ability of the receptor system to adapt to these changes. When the relative changes in concentrations of hormones, rather than their absolute levels, is likely more important.

Studies of heat source driven natural convection

NASA Technical Reports Server (NTRS)

Kulacki, F. A.; Nagle, M. E.; Cassen, P.

1974-01-01

Natural convection energy transport in a horizontal layer of internally heated fluid with a zero heat flux lower boundary, and an isothermal upper boundary, has been studied. Quantitative information on the time-mean temperature distribution and the fluctuating component of temperature about the mean temperature in steady turbulent convection are obtained from a small thermocouple inserted into the layer through the upper bounding plate. Data are also presented on the development of temperature at several vertical positions when the layer is subject to both a sudden increase and to a sudden decrease in power input. For changes of power input from zero to a value corresponding to a Rayleigh number much greater than the critical linear stability theory value, a slight hysteresis in temperature profiles near the upper boundary is observed between the heat-up and cool-down modes.

Recession Depression: Mental Health Effects of the 2008 Stock Market Crash*

PubMed Central

McInerney, Melissa; Mellor, Jennifer M.; Nicholas, Lauren Hersch

2013-01-01

Do sudden, large wealth losses affect mental health? We use exogenous variation in the interview dates of the 2008 Health and Retirement Study to assess the impact of large wealth losses on mental health among older U.S. adults. We compare cross-wave changes in wealth and mental health for respondents interviewed before and after the October 2008 stock market crash. We find that the crash reduced wealth and increased feelings of depression and use of antidepressant drugs, and that these effects were largest among respondents with high levels of stock holdings prior to the crash. These results suggest that sudden wealth losses cause immediate declines in subjective measures of mental health. However, we find no evidence that wealth losses lead to increases in clinically-validated measures of depressive symptoms or indicators of depression. PMID:24113241

Vestibular selection criteria development. [assessing susceptability to motion sickness during orbital space flight

NASA Technical Reports Server (NTRS)

Lackner, J. R.

1981-01-01

The experimental elicitation of motion sickness using a short arm centrifuge or a rotating chair surrounded by a striped cylindrical enclosure failed to reveal any systematic group or consistent individual relationship between changes in heart rate, blood pressure, and body temperature and the appearance of symptoms of motion sickness. A study of the influence of vision on susceptability to motion sickness during sudden stop simulation shows that having the eyes open during any part of the sudden stop assessment is more stressful than having them closed throughout the test. Subjects were found to be highly susceptible to motion sickness when tested in free fall and in high force phases of flight. The effect of touch and pressure cues on body orientation during rotation and in parabolic flight are considered as sensory as well as motor adaptation.

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

PubMed

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

2011-03-01

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

Evolution of damage during deformation in porous granular materials (Louis Néel Medal Lecture)

NASA Astrophysics Data System (ADS)

Main, Ian

2014-05-01

'Crackling noise' occurs in a wide variety of systems that respond to external forcing in an intermittent way, leading to sudden bursts of energy release similar to those heard when crunching up a piece of paper or listening to a fire. In mineral magnetism ('Barkhausen') crackling noise occurs due to sudden changes in the size and orientation of microscopic ferromagnetic domains when the external magnetic field is changed. In rock physics sudden changes in internal stress associated with microscopically brittle failure events lead to acoustic emissions that can be recorded on the sample boundary, and used to infer the state of internal damage. Crackling noise is inherently stochastic, but the population of events often exhibits remarkably robust scaling properties, in terms of the source area, duration, energy, and in the waiting time between events. Here I describe how these scaling properties emerge and evolve spontaneously in a fully-dynamic discrete element model of sedimentary rocks subject to uniaxial compression at a constant strain rate. The discrete elements have structural disorder similar to that of a real rock, and this is the only source of heterogeneity. Despite the stationary loading and the lack of any time-dependent weakening processes, the results are all characterized by emergent power law distributions over a broad range of scales, in agreement with experimental observation. As deformation evolves, the scaling exponents change systematically in a way that is similar to the evolution of damage in experiments on real sedimentary rocks. The potential for real-time failure forecasting is examined by using synthetic and real data from laboratory tests and prior to volcanic eruptions. The combination of non-linearity and an irreducible stochastic component leads to significant variations in the precision and accuracy of the forecast failure time, leading to a significant proportion of 'false alarms' (forecast too early) and 'missed events' (forecast too late), as well as an over-optimistic assessments of forecasting power and quality when the failure time is known (the 'benefit of hindsight'). The evolution becomes progressively more complex, and the forecasting power diminishes, in going from ideal synthetics to controlled laboratory tests to open natural systems at larger scales in space and time.

Climatic and palaeoecological changes during the mid- to Late Holocene transition in eastern China: high-resolution pollen and non-pollen palynomorph analysis at Pingwang, Yangtze coastal lowlands

NASA Astrophysics Data System (ADS)

Innes, James B.; Zong, Yongqiang; Wang, Zhanghua; Chen, Zhongyuan

2014-09-01

The transition to the Late Holocene/Neoglacial occurred as a worldwide process of climatic deterioration from the optimum thermal conditions of the mid-Holocene, culminating in an abrupt decline around 4200 cal yr ago, in a period of severe climatic deterioration that lasted for two or three centuries. This sudden climatic event has been recorded in many proxy data archives from around the world, and its effects were manifest in different ways depending on the reaction of regional weather systems and conditions, but often as greatly increased aridity and/or cold temperatures. It has been regarded as causing or contributing to the sudden collapse of several well-established human societies at that time, including advanced agricultural Late Neolithic cultures in eastern China. We have used high-resolution pollen and non-pollen palynomorph analysis to examine the nature of this climatic transition through its impacts on the vegetation and hydrology at Pingwang, a site in the Yangtze coastal lowlands which has no evidence of complicating environmental influences such as sea-level rise or significant human land-use activity, factors previously suggested as alternative reasons for changes in forest composition. Our results show two phases of forest alteration, one gradual from about 5500 cal BP and one sudden at about 4200 cal BP., in which the frequencies of subtropical forest elements fall and are replaced by those of conifers and cold-tolerant trees. Total arboreal pollen frequencies do not decline and the proportion of temperate forest trees, tolerant of a wide range of temperatures, remains unchanged throughout, both ruling out human land clearance as a cause of the change in forest composition. As these dates accord very well with the known timings of climate deterioration established from other proxy archives in the region, we conclude that climate was the main driver of vegetation change in eastern China at the mid- to Late Holocene transition. Our hydrological results support the view that a combination of rising local water level and climatic cooling during the 4200 cal BP event was the probable cause of societal collapse in the lower Yangtze valley.

Variations in Ionospheric Peak Electron Density During Sudden Stratospheric Warmings in the Arctic Region

NASA Astrophysics Data System (ADS)

Yasyukevich, A. S.

2018-04-01

The focus of the paper is the ionospheric disturbances during sudden stratospheric warming (SSW) events in the Arctic region. This study examines the ionospheric behavior during 12 SSW events, which occurred in the Northern Hemisphere over 2006-2013, based on vertical sounding data from DPS-4 ionosonde located in Norilsk (88.0°E, 69.2°N). Most of the addressed events show that despite generally quiet geomagnetic conditions, notable changes in the ionospheric behavior are observed during SSWs. During the SSW evolution and peak phases, there is a daytime decrease in NmF2 values at 10-20% relative to background level. After the SSW maxima, in contrast, midday NmF2 surpasses the average monthly values for 10-20 days. These changes in the electron density are observed for both strong and weak stratospheric warmings occurring at midwinter. The revealed SSW effects in the polar ionosphere are assumed to be associated with changes in the thermospheric neutral composition, affecting the F2-layer electron density. Analysis of the Global Ultraviolet Imager data revealed the positive variations in the O/N2 ratio within the thermosphere during SSW peak and recovery periods. Probable mechanisms for SSW impact on the state of the high-latitude neutral thermosphere and ionosphere are discussed.

Spatial distribution and temporal development of high-mountain lakes in western Austria

NASA Astrophysics Data System (ADS)

Merkl, Sarah; Emmer, Adam; Mergili, Martin

2015-04-01

Glacierized high-mountain environments are characterized by active morphodynamics, favouring the rapid appearance and disappearance of lakes. On the one hand, such lakes indicate high-mountain environmental changes such as the retreat of glaciers. On the other hand, they are sometimes susceptible to sudden drainage, leading to glacial lake outburst floods (GLOFs) putting the downstream population at risk. Whilst high-mountain lakes have been intensively studied in the Himalayas, the Pamir, the Andes or the Western Alps, this is not the case for the Eastern Alps. A particular research gap, which is attacked with the present work, concerns the western part of Austria. We consider a study area of approx. 6,140 km², covering the central Alps over most of the province of Tyrol and part of the province of Salzburg. All lakes ≥250 m² located higher than 2000 m asl are mapped from high-resolution Google Earth imagery and orthophotos. The lakes are organized into seven classes: (i) ice-dammed; near-glacial (ii) moraine-dammed and (iii) bedrock-dammed; (iv) moraine-dammed and (v) bedrock-dammed distant to the recent glaciers; (vi) landslide-dammed; (vii) anthropogenic. The temporal development of selected lakes is investigated in detail, using aerial photographs dating back to the 1950s. 1045 lakes are identified in the study area. Only eight lakes are ice-dammed (i). One third of all lakes is located in the immediate vicinity of recent glacier tongues, half of them impounded by moraine (ii), half of them by bedrock (iii). Two thirds of all lakes are impounded by features (either moraines or bedrock) shaped by LIA or Pleistocenic glaciers at some distance to the present glacier tongues (iv and v). Only one landslide-dammed lake (vi) is identified in the study area, whilst 21 lakes are of anthropogenic origin (vii). 72% of all lakes are found at 2250-2750 m asl whilst less than 2% are found above 3000 m asl. The ratio of rock-dammed lakes increases with increasing elevation at the cost of moraine-dammed lakes. Multi-temporal analysis of selected near-glacial lakes reveals cases where lakes have appeared as proglacial lakes, but lost contact to the glacier within few decades or even years, or have even been decoupled from the glacial water supply. This goes hand in hand with rapid changes of lake shape and size, with merging or separating of lakes, and with the disappearance of short-lived lakes or lake systems. Consequently, we distinguish three stages of lake development: (a) a pro-glacial, (b) a periglacial and (c) a non-glacial stage. The dynamics - and also the susceptibility of a lake to sudden drainage - decrease substantially from (a) to (c). Lakes in the stages (a) and (b) are less prominent in our study area, compared to other glacierized high-mountain regions, leading us to the conclusion that (1) the current threat to the population by GLOFs is lower but (2) the future development of emerging lakes has to be monitored carefully.

The role of auditory transient and deviance processing in distraction of task performance: a combined behavioral and event-related brain potential study

PubMed Central

Berti, Stefan

2013-01-01

Distraction of goal-oriented performance by a sudden change in the auditory environment is an everyday life experience. Different types of changes can be distracting, including a sudden onset of a transient sound and a slight deviation of otherwise regular auditory background stimulation. With regard to deviance detection, it is assumed that slight changes in a continuous sequence of auditory stimuli are detected by a predictive coding mechanisms and it has been demonstrated that this mechanism is capable of distracting ongoing task performance. In contrast, it is open whether transient detection—which does not rely on predictive coding mechanisms—can trigger behavioral distraction, too. In the present study, the effect of rare auditory changes on visual task performance is tested in an auditory-visual cross-modal distraction paradigm. The rare changes are either embedded within a continuous standard stimulation (triggering deviance detection) or are presented within an otherwise silent situation (triggering transient detection). In the event-related brain potentials, deviants elicited the mismatch negativity (MMN) while transients elicited an enhanced N1 component, mirroring pre-attentive change detection in both conditions but on the basis of different neuro-cognitive processes. These sensory components are followed by attention related ERP components including the P3a and the reorienting negativity (RON). This demonstrates that both types of changes trigger switches of attention. Finally, distraction of task performance is observable, too, but the impact of deviants is higher compared to transients. These findings suggest different routes of distraction allowing for the automatic processing of a wide range of potentially relevant changes in the environment as a pre-requisite for adaptive behavior. PMID:23874278

Gastrointestinal causes of sudden unexpected death: A review.

PubMed

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

2018-01-01

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

Sudden Cardiac Arrest in Athletic Medicine

PubMed Central

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

2001-01-01

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

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

PubMed Central

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

2015-01-01

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

Solar wind driven empirical forecast models of the time derivative of the ground magnetic field

NASA Astrophysics Data System (ADS)

Wintoft, Peter; Wik, Magnus; Viljanen, Ari

2015-03-01

Empirical models are developed to provide 10-30-min forecasts of the magnitude of the time derivative of local horizontal ground geomagnetic field (|dBh/dt|) over Europe. The models are driven by ACE solar wind data. A major part of the work has been devoted to the search and selection of datasets to support the model development. To simplify the problem, but at the same time capture sudden changes, 30-min maximum values of |dBh/dt| are forecast with a cadence of 1 min. Models are tested both with and without the use of ACE SWEPAM plasma data. It is shown that the models generally capture sudden increases in |dBh/dt| that are associated with sudden impulses (SI). The SI is the dominant disturbance source for geomagnetic latitudes below 50° N and with minor contribution from substorms. However, at occasions, large disturbances can be seen associated with geomagnetic pulsations. For higher latitudes longer lasting disturbances, associated with substorms, are generally also captured. It is also shown that the models using only solar wind magnetic field as input perform in most cases equally well as models with plasma data. The models have been verified using different approaches including the extremal dependence index which is suitable for rare events.

Modelling the work to be done by Escherichia coli to adapt to sudden temperature upshifts.

PubMed

Swinnen, I A M; Bernaerts, K; Van Impe, J F

2006-05-01

This paper studies and models the effect of the amplitude of a sudden temperature upshift DeltaT on the adaptation period of Escherichia coli, in terms of the work to be done by the cells during the subsequent lag phase (i.e., the product of growth rate mumax and lag phase duration lambda). Experimental data are obtained from bioreactor experiments with E. coli K12 MG1655. At a predetermined time instant during the exponential growth phase, a sudden temperature upshift is applied (no other environmental changes take place). The length of the (possibly) induced lag phase and the specific growth rate after the shift are quantified with the growth model of Baranyi and Roberts (Int J Food Microbiol 23, 1994, 277). Different models to describe the evolution of the product lambda x mumax as a function of the amplitude of the temperature shift are statistically compared. The evolution of lambda x mumax is influenced by the amplitude of the temperature shift DeltaT and by the normal physiological temperature range. As some cut-off is observed, the linear model with translation is preferred to describe this evolution. This work contributes to the characterization of microbial lag phenomena, in this case for E. coli K12 MG1655, in view of accurate predictive model building.

Extremely cold events and sudden air temperature drops during winter season in the Czech Republic

NASA Astrophysics Data System (ADS)

Crhová, Lenka; Valeriánová, Anna; Holtanová, Eva; Müller, Miloslav; Kašpar, Marek; Stříž, Martin

2014-05-01

Today a great attention is turned to analysis of extreme weather events and frequency of their occurrence under changing climate. In most cases, these studies are focused on extremely warm events in summer season. However, extremely low values of air temperature during winter can have serious impacts on many sectors as well (e.g. power engineering, transportation, industry, agriculture, human health). Therefore, in present contribution we focus on extremely and abnormally cold air temperature events in winter season in the Czech Republic. Besides the seasonal extremes of minimum air temperature determined from station data, the standardized data with removed annual cycle are used as well. Distribution of extremely cold events over the season and the temporal evolution of frequency of occurrence during the period 1961-2010 are analyzed. Furthermore, the connection of cold events with extreme sudden temperature drops is studied. The extreme air temperature events and events of extreme sudden temperature drop are assessed using the Weather Extremity Index, which evaluates the extremity (based on return periods) and spatial extent of the meteorological extreme event of interest. The generalized extreme value distribution parameters are used to estimate return periods of daily temperature values. The work has been supported by the grant P209/11/1990 funded by the Czech Science Foundation.

Three types of cavitation caused by air seeding.

PubMed

Shen, Fanyi; Wang, Yuansheng; Cheng, Yanxia; Zhang, Li

2012-11-01

There are different opinions of the dynamics of an air bubble entering a xylem conduit. In this paper, we present a thorough mechanical analysis and conclude that there are three types of cavitation caused by air seeding. After an air seed enters a conduit at high xylem pressure P'(1), along with the drop of the water potential, it will expand gradually to a long-shaped bubble and extend continually. This is the first type of air seeding, or the type of expanding gradually. When the xylem pressure is moderate, right after an air seed enters a conduit, it will expand first. Then, as soon as the pressure reaches a threshold the bubble will blow up to form a bubble in long shape, accompanied by acoustic (or ultra-acoustic) emission. It will extend further as xylem pressure decreases continually. This is the second type of air seeding, or the type of expanding-exploding, becoming a long-shaped bubble-lengthening by degrees. In the range of P'(1) ≤ - 3P(o) (P(o) is atmospheric pressure), soon after an air seed is sucked into a conduit it will explode immediately and the conduit will be full of the gas of the bubble instantly. This is the third type of air seeding, or the type of sudden exploding and filling conduit instantly. The third type is the frequent event in daily life of plant.

Metabolomic analysis of urine with Nuclear Magnetic Resonance spectroscopy in patients with idiopathic sudden sensorineural hearing loss: A preliminary study.

PubMed

Carta, Filippo; Lussu, Milena; Bandino, Fabrizio; Noto, Antonio; Peppi, Marcello; Chuchueva, Natalia; Atzori, Luigi; Fanos, Vassilios; Puxeddu, Roberto

2017-08-01

Idiopathic sudden sensorineural hearing loss is a frequent emergency, with unknown aetiology and usually treated with empiric therapy. Steroids represent the only validated treatment but prognosis is unpredictable and the possibility to select the patients who will not respond to steroids could avoid unnecessary treatments. Metabolomic profiling of the biofluids target the analysis of the final product of genic expression and enzymatic activity, defining the biochemical phenotype of a whole biologic system. We studied the metabolomics of the urine of a cohort of patients with idiopathic sudden sensorineural hearing loss, correlating the metabolic profiles with the clinical outcomes. Metabolomic profiling of urine samples was performed by 1 H Nuclear Magnetic Resonance spectroscopy in combination with multivariate statistical approaches. 26 patients were included in the study: 5 healthy controls, 13 patients who did not recover after treatment at 6 months while the remaining 8 patients recovered from the hearing loss. The orthogonal partial least square-discriminant analysis score plot showed a significant separation between the two groups, responders and non-responders after steroid therapy, R 2 Y of 0.83, Q 2 of 0.38 and p value <0.05. The resulting metabolic profiles were characterized by higher levels of urinary B-Alanine, 3-hydroxybutyrate and Trimethylamine N-oxide, and lower levels of Citrate and Creatinine in patients with worst outcome. Idiopathic sudden sensorineural hearing loss is a specific disease with unclear systemic changes, but our data suggest that there are different types of this disorder or patients predisposed to effective action of steroids allowing the recover after treatment. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Evaluation and Management of Wolff-Parkinson-White in Athletes

PubMed Central

Rao, Ashwin L.; Salerno, Jack C.; Asif, Irfan M.; Drezner, Jonathan A.

2014-01-01

Context: Wolff-Parkinson-White (WPW) is a cardiac conduction system disorder characterized by abnormal accessory conduction pathways between the atria and the ventricles. Symptomatic patients classically present with palpitations, presyncope, or syncope that results from supraventricular tachycardia. While rare, sudden cardiac death may be the first manifestation of underlying disease and occurs more frequently in exercising individuals. Evidence Acquisition: Medline and PubMed databases were evaluated through 2012, with the following keywords: WPW, Wolff-Parkinson-White, pre-excitation, sudden cardiac death, risk stratification, and athletes. Selected articles identified through the primary search, along with relevant references from those articles, were reviewed for pertinent clinical information regarding the identification, evaluation, risk stratification, and management of WPW as they pertained to the care of athletes. Study Design: Systematic review. Level of Evidence: Level 1. Results: Diagnosis of WPW is confirmed by characteristic electrocardiogram changes, which include a delta wave, short PR interval, and widened QRS complex. Utilization of the electrocardiogram as part of the preparticipation physical evaluation may allow for early identification of asymptomatic individuals with a WPW pattern. Risk stratification techniques identify individuals at risk for malignant arrhythmias who may be candidates for curative therapy through transcatheter ablation. Conclusion: WPW accounts for at least 1% of sudden death in athletes and has a prevalence of at least 1 to 4.5 per 1000 children and adults. The risk of lethal arrhythmia appears to be higher in asymptomatic children than in adults, and sudden cardiac death is often the sentinel event. The athlete with WPW should be evaluated for symptoms and the presence of intermittent or persistent pre-excitation, which dictates further consultation, treatment, and monitoring strategies as well as return to play. PMID:24982705

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

EPA Science Inventory

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

Residual entanglement and sudden death: A direct connection

NASA Astrophysics Data System (ADS)

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

2011-11-01

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

Epidemiological characteristics of sudden cardiac arrest in schools.

PubMed

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

2014-08-01

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

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

PubMed

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

2003-10-01

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

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

PubMed

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

2017-11-01

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

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

PubMed

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

2005-07-01

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

"Why Do They Hate Us?": Leading amid Criticism, Crisis, and Disrespect

ERIC Educational Resources Information Center

Karpinski, Carol F.

2012-01-01

Laura Dannon, an educator with experience as teacher, assistant principal, and principal, enjoys her profession. Faculty camaraderie and student/teacher busyness at her school have led her to think all is well. A sudden outburst by a new teacher causes her to reflect on what is really happening. What has changed? Have media criticism, movements…

Vibrational spectroscopy-based chemometrics to map host resistance to sudden oak death

Treesearch

Pierluigi (Enrico) Bonello; Anna O. Conrad; Luis Rodriguez Saona; Brice A. McPherson; David L. Wood

2017-01-01

A strong focus on tree germplasm that can resist threats such as non-native insects and pathogens, or a changing climate, is fundamental for successful conservation efforts. This project is predicated on the fact that genetic resistance is the cornerstone for protecting plants against pathogens and insects in environments conducive to the attacking organisms, a...

SOD-induced changes in foraging and nesting behavior of insectivorous, cavity-nesting birds

Treesearch

Kyle Apigian; Barbara Allen-Diaz

2006-01-01

Sudden oak death (SOD) is a tree disease caused by a recently described pathogen, Phytophthora ramorum. The disease affects dozens of plant species, but its effects are particularly pronounced in stands of coast live oak (Quercus agrifolia), often resulting in large stands with dead canopies and many downed trees. Such disease-...

Concussion Awareness: Getting School Psychologists into the Game

ERIC Educational Resources Information Center

Davies, Susan C.

2011-01-01

A concussion is a serious injury--a mild traumatic brain injury (TBI)--that induces physiological disruption of brain function. A concussion is caused by a bump, blow, or jolt to the head or body. The sudden movement causes stretching and tearing of brain cells; cells become damaged and chemical changes occur within the brain. Concussions can lead…

In an Uncertain Summer, Colleges Try to Control Enrollment "Melt"

ERIC Educational Resources Information Center

Hoover, Eric

2009-01-01

Each year, admissions officers know that a small percentage of admitted applicants who sent deposits will not show up. The phenomenon, known as "summer melt," has many causes. Students might change their plans because they suddenly get off their first-choice college's waiting list--or because they opt to spend a year caring for penguins in…

Poppers retinopathy.

PubMed

Luis, Joshua; Virdi, Meena; Nabili, Shahriar

2016-03-07

We present a case of a 52-year-old man with sudden, bilateral central loss of vision as a result of inhalation of 'poppers'. He was found to have characteristic changes on optical coherence tomography. With conservative treatment, the patient's vision improved marginally at 3 months follow-up. An overview of previous published cases is also included. 2016 BMJ Publishing Group Ltd.

Relationships between solar activity and climate change. [sunspot cycle effects on lower atmosphere

NASA Technical Reports Server (NTRS)

Roberts, W. O.

1974-01-01

Recurrent droughts are related to the double sunspot cycle. It is suggested that high solar activity generally increases meridional circulations and blocking patterns at high and intermediate latitudes, especially in winter. This effect is related to the sudden formation of cirrus clouds during strong geomagnetic activity that originates in the solar corpuscular emission.

Monitoring the effectiveness of Phytophthora ramorum eradication treatments in Oregon tanoak forests

Treesearch

Ellen Michaels Goheen; Alan Kanaskie; Everett Hansen; Wendy Sutton; Paul Reeser; Nancy Osterbauer

2013-01-01

Phytophthora ramorum, the cause of sudden oak death, was first discovered in Oregon forests in July 2001. An aggressive eradication treatment program was immediately put into place on all lands where it was found. Eradication treatments have changed over time as we have learned more about pathogen behavior. Treatment prescriptions currently consist...

Can People Recollect Well and Change Their Source Memory Bias of "Aha!" Experiences?

ERIC Educational Resources Information Center

Du, Xiumin; Zhang, Ke; Wang, Jiali; Luo, Junlong; Luo, Jing

2017-01-01

Although many scientific discoveries were frequently reported as kinds of insightful breakthrough that suddenly illuminated in one's mind, we can never exactly know whether these afterward reports were reliable or not. In this study, subjects were asked to solve a list of Remote Associate Test problems and got both subsets of the insightfully and…

For Grown-Ups Too: The Surprising Depth and Complexity of Children's Literature

ERIC Educational Resources Information Center

Lerer, Seth

2015-01-01

Children's literature charts the makings of the literate imagination. It shows children finding worlds within the book and books in the world. It addresses the changing environments of family life and human growth, schooling and scholarship, publishing and publicity in which children--at times suddenly, at times subtly--found themselves…

Spatial estimation of the density and carbon content of host populations for Phytophthora ramorum in California and Oregon

Treesearch

Sanjay Lamsal; Richard C. Cobb; J. Hall Cushman; Qingmin Meng; David M. Rizzo; Ross K. Meentemeyer.

2011-01-01

Outbreak of the emerging infectious disease sudden oak death continues to threaten California and Oregon forests following introduction of the exotic plant pathogen Phytophthora ramorum. Identifying areas at risk and forecasting changes in forest carbon following disease outbreak requires an understanding of the geographical distribution of host...

The U.S. Army Research Laboratory’s Auditory Research for the Dismounted Soldier: Present (2009-2011) and Future

DTIC Science & Technology

2012-03-01

of gunfire interrupting the relative quiet of the countryside, or a sudden reduction in typical city noise, a change in the soundscape serves as an...in realistic soundscapes . Thereby, the Soldiers’ abilities to detect, discriminate, localize, and track can be accurately measured in a controlled

Dips, ramps, and rolls- Evidence for paleotopographic and syn-depositional fault control on the Western Kentucky No. 4 coal bed, tradewater formation (Bolsovian) Illinois Basin

USGS Publications Warehouse

Greb, S.F.; Eble, C.F.; Williams, D.A.; Nelson, W.J.

2001-01-01

The Western Kentucky No. 4 coal is a high-volatile B to high-volatile C bituminous coal that has been heavily mined along the southern margin of the Western Kentucky Coal Field. The seam has a reputation for rolling floor elevation. Elongate trends of floor depressions are referred to as "dips" and "rolls" by miners. Some are relatively narrow and straight to slightly curvilinear in plan view, with generally symmetric to slightly asymmetric cross-sections. Others are broader and asymmetric in section, with sharp dips on one limb and gradual, ramp-like dips on the other. Some limbs change laterally from gradual dip, to sharp dip, to offset of the coal. Lateral changes in the rate of floor elevation dip are often associated with changes in coal thickness, and in underground mines, changes in floor elevation are sometimes associated with roof falls and haulage problems. In order to test if coal thickness changes within floor depressions were associated with changes in palynology, petrography and coal quality, the coal was sampled at a surface mine across a broad. ramp-like depression that showed down-dip coal thickening. Increment samples of coal from a thick (150 cm), down-ramp and thinner (127 cm), up-ramp position at one surface mine correlate well between sample sites (a distance of 60 m) except for a single increment. The anomalous increment (31 cm) in the lower-middle part of the thick coal bed contained 20% more Lycospora orbicula spores. The rolling floor elevations noted in the study mines are inferred to have been formed as a result of pre-peat paleotopographic depressions, syn-depositional faulting, fault-controlled pre-peat paleotopography, and from compaction beneath post-depositional channels and slumps. Although the association of thick coal with linear trends and inferred faults has been used in other basins to infer syn-depositional faulting, changes in palynology within increment samples of the seam along a structural ramp in this study provide subtle evidence of faulting within a specific increment of the coal itself. The sudden increase in L. orbicula (produced by Paralycopodites) in a single increment of a down-ramp sample of the Western Kentucky No. 4 coal records the reestablishment of a rheotrophic mire following a sudden change in edaphic conditions. Paralycopodites was a colonizing lycopod, which in this case became locally abundant after the peat was well established along a fault with obvious growth during peat accumulation. Because many coal-mire plants were susceptible to sudden edaphic changes as might accompany faulting or flooding, changes in palynology would be expected in coals affected by syn-depositional faulting. ?? 2001 Elsevier Science B.V. All rights reserved.

Global bifurcations in fractional-order chaotic systems with an extended generalized cell mapping method

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

Liu, Xiaojun; School of Mathematics and Statistics, Tianshui Normal University, Tianshui 741001; Hong, Ling, E-mail: hongling@mail.xjtu.edu.cn

Global bifurcations include sudden changes in chaotic sets due to crises. There are three types of crises defined by Grebogi et al. [Physica D 7, 181 (1983)]: boundary crisis, interior crisis, and metamorphosis. In this paper, by means of the extended generalized cell mapping (EGCM), boundary and interior crises of a fractional-order Duffing system are studied as one of the system parameters or the fractional derivative order is varied. It is found that a crisis can be generally defined as a collision between a chaotic basic set and a basic set, either periodic or chaotic, to cause a sudden discontinuousmore » change in chaotic sets. Here chaotic sets involve three different kinds: a chaotic attractor, a chaotic saddle on a fractal basin boundary, and a chaotic saddle in the interior of a basin and disjoint from the attractor. A boundary crisis results from the collision of a periodic (or chaotic) attractor with a chaotic (or regular) saddle in the fractal (or smooth) boundary. In such a case, the attractor, together with its basin of attraction, is suddenly destroyed as the control parameter passes through a critical value, leaving behind a chaotic saddle in the place of the original attractor and saddle after the crisis. An interior crisis happens when an unstable chaotic set in the basin of attraction collides with a periodic attractor, which causes the appearance of a new chaotic attractor, while the original attractor and the unstable chaotic set are converted to the part of the chaotic attractor after the crisis. These results further demonstrate that the EGCM is a powerful tool to reveal the mechanism of crises in fractional-order systems.« less

Global Warming Could Have a Chilling Effect on the Military (Defense Horizons, Number 33, October 2003)

DTIC Science & Technology

2003-12-01

Archaeology at the University of California at Santa Barbara, “is a chronicle of human vulnerability in the face of sudden climate change.”15 A bad...droughts. A growing body of evidence from joint archaeological and paleoclimatological studies is demonstrating that abrupt climate shifts may be linked to...Haug et al., “Climate and the Collapse of Maya Civilization,” Science 299 (March 14, 2003). 17 P.B. deMenocal, “Cultural Responses to Climate Change

The discontinuity theory of immunity

PubMed Central

Pradeu, Thomas; Vivier, Eric

2017-01-01

Some biological systems detect the rate of change in a stimulus rather than the stimulus itself only. We suggest that the immune system works in this way. According to the discontinuity theory of immunity, the immune system responds to sudden changes in antigenic stimulation and is rendered tolerant by slow or continuous stimulation. This basic principle, which is supported by recent data on immune checkpoints in viral infections, cancers, and allergies, can be seen as a unifying framework for diverse immune responses. PMID:28239677

Self-shaping composites with programmable bioinspired microstructures.

PubMed

Erb, Randall M; Sander, Jonathan S; Grisch, Roman; Studart, André R

2013-01-01

Shape change is a prevalent function apparent in a diverse set of natural structures, including seed dispersal units, climbing plants and carnivorous plants. Many of these natural materials change shape by using cellulose microfibrils at specific orientations to anisotropically restrict the swelling/shrinkage of their organic matrices upon external stimuli. This is in contrast to the material-specific mechanisms found in synthetic shape-memory systems. Here we propose a robust and universal method to replicate this unusual shape-changing mechanism of natural systems in artificial bioinspired composites. The technique is based upon the remote control of the orientation of reinforcing inorganic particles within the composite using a weak external magnetic field. Combining this reinforcement orientational control with swellable/shrinkable polymer matrices enables the creation of composites whose shape change can be programmed into the material's microstructure rather than externally imposed. Such bioinspired approach can generate composites with unusual reversibility, twisting effects and site-specific programmable shape changes.

Self-shaping composites with programmable bioinspired microstructures

NASA Astrophysics Data System (ADS)

Erb, Randall M.; Sander, Jonathan S.; Grisch, Roman; Studart, André R.

2013-04-01

Shape change is a prevalent function apparent in a diverse set of natural structures, including seed dispersal units, climbing plants and carnivorous plants. Many of these natural materials change shape by using cellulose microfibrils at specific orientations to anisotropically restrict the swelling/shrinkage of their organic matrices upon external stimuli. This is in contrast to the material-specific mechanisms found in synthetic shape-memory systems. Here we propose a robust and universal method to replicate this unusual shape-changing mechanism of natural systems in artificial bioinspired composites. The technique is based upon the remote control of the orientation of reinforcing inorganic particles within the composite using a weak external magnetic field. Combining this reinforcement orientational control with swellable/shrinkable polymer matrices enables the creation of composites whose shape change can be programmed into the material’s microstructure rather than externally imposed. Such bioinspired approach can generate composites with unusual reversibility, twisting effects and site-specific programmable shape changes.

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

PubMed

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

2018-01-01

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

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

PubMed Central

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

2013-01-01

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

Major Life Events as Potential Triggers of Sudden Cardiac Arrest

PubMed Central

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

2012-01-01

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

Major life events as potential triggers of sudden cardiac arrest.

PubMed

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

2012-05-01

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

Sudden cardiac death in haemodialysis: clinical epidemiology and mechanisms.

PubMed

Banerjee, Debasish

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

Causes of sudden death in young female military recruits.

PubMed

Eckart, Robert E; Scoville, Stephanie L; Shry, Eric A; Potter, Robert N; Tedrow, Usha

2006-06-15

This study sought to examine the incidence of sudden death in a large, multiethnic cohort of young women. Approximately 852,300 women entered basic military training from 1977 to 2001. During this period, there were 15 sudden deaths in female recruits (median age 19 years, 73% African-American), occurring at a median of 25 days after arrival for training. Of the sudden deaths, 13 (81%) were due to reasons that may have been cardiac in origin. Presumed arrhythmic sudden death in the setting of a structurally normal heart was seen in 8 recruits (53%), and anomalous coronary origins were found in 2 recruits (13%). The mortality rate was 11.4 deaths per 100,000 recruit-years (95% confidence interval 6.9 to 18.9). The rate was significantly higher for African-American female recruits (risk ratio 10.2, p <0.001). Sudden death with a structurally normal heart was the leading cause of death in female recruits during military training.

Sudden oronasal bleeding in a young child.

PubMed

Hey, Edmund

2008-10-01

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

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

NASA Technical Reports Server (NTRS)

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

1990-01-01

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

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

PubMed

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

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

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

PubMed

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

2012-04-01

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

Sudden Unexpected Death in Fetal Life Through Early Childhood

PubMed Central

Kinney, Hannah C.; Willinger, Marian

2016-01-01

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

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

PubMed Central

Mehboob, Riffat

2017-01-01

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

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

PubMed

Mehboob, Riffat

2017-01-01

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

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

PubMed

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

2017-03-09

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

Proceedings of the sudden oak death fifth science symposium

Treesearch

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

2013-01-01

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

Sudden Fiction: What Is It?

ERIC Educational Resources Information Center

Tindall, James

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

Adult-onset Minimal Change Disease with IgA Nephropathy and Hepatitis C

PubMed Central

Chowdhury, Waliul; Saleem, Tahira Sabeen; Lodhi, Muhammad Uzair; Syed, Intekhab Askari; Iqbal, Hafiz Imran

2018-01-01

Minimal change disease (MCD) is one of the most common causes of nephrotic syndrome in children, leading to heavy proteinuria and edema. However, it is not as common in adults. Adult-onset minimal change disease with IgA nephropathy is rare. The initial presentation of heavy proteinuria and edema with effacement of podocytes on electron microscopy (EM) should lead the physician to suspect minimal change disease regardless of age. We present a 44-year-old male patient with a history of hepatitis C virus (HCV) who presented with sudden onset of lower extremity edema and 6.6 grams (g) of proteinuria per day. PMID:29682437

Synthesis and magnetic properties of LiFePO4 substitution magnesium

NASA Astrophysics Data System (ADS)

Choi, Hyunkyung; Kim, Min Ji; Hahn, Eun Joo; Kim, Sam Jin; Kim, Chul Sung

2017-06-01

LiFe0.9Mg0.1PO4 sample was prepared by using a solid-state reaction method, and the temperature-dependent magnetic properties of the sample were studied. The X-ray diffraction (XRD) pattern showed an olivine-type orthorhombic structure with space group Pnma based on Rietveld refinement method. The effect of Mg substitution in antiferromagnetic LiFe0.9Mg0.1PO4 was investigated using a vibrating sample magnetometer (VSM) and Mössbauer spectroscopy. The temperature-dependence of the magnetization curves of LiFe0.9Mg0.1PO4 shows abnormal antiferromagnetic behavior with ordering temperature. Sudden changes in both the magnetic hyperfine field (Hhf) and its slope below 15 K suggest that magnetic phase transition associated to the abrupt occurrence of spin-reorientation. The Néel temperature (TN) and spin-reorientation temperature (TS) of LiFe0.9Mg0.1PO4 are lower than those of pure LiFePO4 (TN = 51 K, TS = 23 K). This is due to the Fe-O-Fe superexchange interaction being larger than that of the Fe-O-Mg link. Also, we have confirmed a change in the electric quadrupole splitting (ΔEQ) by the spin-orbit coupling effect and the shape of Mössbauer spectrum has provided the evidence for TS and a strong crystalline field. We have found that Mg ions in LiFe0.9Mg0.1PO4 induce an asymmetric charge density due to the presence of Mg2+ ions at the FeO6 octahedral sites.

Transverse Wave Induced Kelvin–Helmholtz Rolls in Spicules

NASA Astrophysics Data System (ADS)

Antolin, P.; Schmit, D.; Pereira, T. M. D.; De Pontieu, B.; De Moortel, I.

2018-03-01

In addition to their jet-like dynamic behavior, spicules usually exhibit strong transverse speeds, multi-stranded structure, and heating from chromospheric to transition region temperatures. In this work we first analyze Hinode and IRIS observations of spicules and find different behaviors in terms of their Doppler velocity evolution and collective motion of their sub-structure. Some have a Doppler shift sign change that is rather fixed along the spicule axis, and lack coherence in the oscillatory motion of strand-like structure, matching rotation models, or long-wavelength torsional Alfvén waves. Others exhibit a Doppler shift sign change at maximum displacement and coherent motion of their strands, suggesting a collective magnetohydrodynamic (MHD) wave. By comparing with an idealized 3D MHD simulation combined with radiative transfer modeling, we analyze the role of transverse MHD waves and associated instabilities in spicule-like features. We find that transverse wave induced Kelvin–Helmholtz (TWIKH) rolls lead to coherence of strand-like structure in imaging and spectral maps, as seen in some observations. The rapid transverse dynamics and the density and temperature gradients at the spicule boundary lead to ring-shaped Mg II k and Ca II H source functions in the transverse cross-section, potentially allowing IRIS to capture the Kelvin–Helmholtz instability dynamics. Twists and currents propagate along the spicule at Alfvénic speeds, and the temperature variations within TWIKH rolls, produce the sudden appearance/disappearance of strands seen in Doppler velocity and in Ca II H intensity. However, only a mild intensity increase in higher-temperature lines is obtained, suggesting there is an additional heating mechanism at work in spicules.

Dynamics of a "low-enrichment high-retention" upwelling center over the southern Senegal shelf

NASA Astrophysics Data System (ADS)

Ndoye, Siny; Capet, Xavier; Estrade, Philippe; Sow, Bamol; Machu, Eric; Brochier, Timothée.; Döring, Julian; Brehmer, Patrice

2017-05-01

Senegal is the southern tip of the Canary upwelling system. Its coastal ocean hosts an upwelling center which shapes sea surface temperatures between latitudes 12° and 15°N. Near this latter latitude, the Cape Verde headland and a sudden change in shelf cross-shore profile are major sources of heterogeneity in the southern Senegal upwelling sector (SSUS). SSUS dynamics is investigated by means of Regional Ocean Modeling System simulations. Configuration realism and resolution (Δx≈ 2 km) are sufficient to reproduce the SSUS frontal system. Our main focus is on the 3-D upwelling circulation which turns out to be profoundly different from 2-D theory: cold water injection onto the shelf and upwelling are strongly concentrated within a few tens of kilometers south of Cape Verde and largely arise from flow divergence in the alongshore direction; a significant fraction of the upwelled waters are retained nearshore over long distances while travelling southward under the influence of northerly winds. Another source of complexity, regional-scale alongshore pressure gradients, also contributes to the overall retention of upwelled waters over the shelf. Varying the degree of realism of atmospheric and oceanic forcings does not appreciably change these conclusions. This study sheds light on the dynamics and circulation underlying the recurrent sea surface temperature pattern observed during the upwelling season and offers new perspectives on the connections between the SSUS physical environment and its ecosystems. It also casts doubt on the validity of upwelling intensity estimations based on simple Ekman upwelling indices at such local scales.

Alteration of the magnetosphere of the Vela pulsar during a glitch.

PubMed

Palfreyman, Jim; Dickey, John M; Hotan, Aidan; Ellingsen, Simon; van Straten, Willem

2018-04-01

As pulsars lose energy, primarily in the form of magnetic dipole radiation, their rotation slows down accordingly. For some pulsars, this spin-down is interrupted by occasional abrupt spin-up events known as glitches 1 . A glitch is hypothesized to be a catastrophic release of pinned vorticity 2 that provides an exchange of angular momentum between the superfluid outer core and the crust. This is manifested by a minute alteration in the rotation rate of the neutron star and its co-rotating magnetosphere, which is revealed by an abrupt change in the timing of observed radio pulses. Measurement of the flux density, polarization and single-pulse arrival times of the glitch with high time resolution may reveal the equation of state of the crustal superfluid, its drag-to-lift ratio and the parameters that describe its friction with the crust 3 . This has not hitherto been possible because glitch events happen unpredictably. Here we report single-pulse radio observations of a glitch in the Vela pulsar, which has a rotation frequency of 11.2 hertz. The glitch was detected on 2016 December 12 at 11:36 universal time, during continuous observations of the pulsar over a period of three years. We detected sudden changes in the pulse shape coincident with the glitch event: one pulse was unusually broad, the next pulse was missing (a 'null') and the following two pulses had unexpectedly low linear polarization. This sequence was followed by a 2.6-second interval during which pulses arrived later than usual, indicating that the glitch affects the magnetosphere.

Effect of supersonic molecular-beam injection on edge fluctuation and particle transport in Heliotron J

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

Zang, L., E-mail: l-zang@center.iae.kyoto-u.ac.jp; Kasajima, K.; Hashimoto, K.

Edge fluctuation in a supersonic molecular-beam injection (SMBI) fueled plasma has been measured using an electrostatic probe array. After SMBI, the plasma stored energy (W{sub p}) temporarily decreased then started to increase. The local plasma fluctuation and fluctuation induced particle transport before and after SMBI have been analyzed. In a short duration (∼4 ms) just after SMBI, the density fluctuation of broad-band low frequency increased, and the probability density function (PDF) changed from a nearly Gaussian to a positively skewed non-Gaussian one. This suggests that intermittent structures were produced due to SMBI. Also the fluctuation induced particle transport was greatly enhancedmore » during this short duration. About 4 ms after SMBI, the low frequency broad-band density fluctuation decreased, and the PDF returned to a nearly Gaussian shape. Also the fluctuation induced particle transport was reduced. Compared with conventional gas puff, W{sub p} degradation window is very short due to the short injection period of SMBI. After this short degradation window, fluctuation induced particle transport was reduced and W{sub p} started the climbing phase. Therefore, the short period of the influence to the edge fluctuation might be an advantage of this novel fueling technique. On the other hand, although their roles are not identified at present, coherent MHD modes are also suppressed as well by the application of SMBI. These MHD modes are thought to be de-exited due to a sudden change of the edge density and/or excitation conditions.« less

Alteration of the magnetosphere of the Vela pulsar during a glitch

NASA Astrophysics Data System (ADS)

Palfreyman, Jim; Dickey, John M.; Hotan, Aidan; Ellingsen, Simon; van Straten, Willem

2018-04-01

As pulsars lose energy, primarily in the form of magnetic dipole radiation, their rotation slows down accordingly. For some pulsars, this spin-down is interrupted by occasional abrupt spin-up events known as glitches1. A glitch is hypothesized to be a catastrophic release of pinned vorticity2 that provides an exchange of angular momentum between the superfluid outer core and the crust. This is manifested by a minute alteration in the rotation rate of the neutron star and its co-rotating magnetosphere, which is revealed by an abrupt change in the timing of observed radio pulses. Measurement of the flux density, polarization and single-pulse arrival times of the glitch with high time resolution may reveal the equation of state of the crustal superfluid, its drag-to-lift ratio and the parameters that describe its friction with the crust3. This has not hitherto been possible because glitch events happen unpredictably. Here we report single-pulse radio observations of a glitch in the Vela pulsar, which has a rotation frequency of 11.2 hertz. The glitch was detected on 2016 December 12 at 11:36 universal time, during continuous observations of the pulsar over a period of three years. We detected sudden changes in the pulse shape coincident with the glitch event: one pulse was unusually broad, the next pulse was missing (a `null') and the following two pulses had unexpectedly low linear polarization. This sequence was followed by a 2.6-second interval during which pulses arrived later than usual, indicating that the glitch affects the magnetosphere.

Environmental Degradation as a Risk Factor for Landslides in the Motozintla Basin, Chiapas, Mexico

NASA Astrophysics Data System (ADS)

Ponce-Pacheco, A. B.; Novelo-Casanova, D. A.

2015-12-01

Motozintla Basin is located southeastern Chiapas, Mexico. Most communities in this region are continously affected by landslides even some locations have disappeared because of this natural phenomenon. This study is focused on the communities that are located along the Xelajú river on this basin. The Motozintla basin has a triangular shape with an area of about 98.6 km2. The slopes in the basin are abrupt ranging from 18° to 45° in about 72.11% of its area. The local altitudes range from 1,024 meters at the lowest point to 2,611 meters at the highest sites. These geomorphological features create unstable slopes which favors slow mass movements processes with different concentrations of sediment that can be transformed in sudden landslides. Many of these processes are accelerated by environmental degradation generated by human activities such as road constructions, land use changes from forest to agriculture or urban development. In this work we focus our research on determining how these human degrading actions increase the susceptibility of mass removal processes, mainly landslides. With this purpose, we generated a landslide inventory of our region of study for the period 1985-2014. We classified the landslides according to their origin (natural or man-made). Based on its location and the local characteristics, we could determine if the identified landslide was caused by natural or human actions. In addition, as environmental factors, we considered the land use characteristics and slope changes to determine the impact of the environmental degradation in the landslide susceptibility.

3D Printed Reversible Shape Changing Components with Stimuli Responsive Materials

PubMed Central

Mao, Yiqi; Ding, Zhen; Yuan, Chao; Ai, Shigang; Isakov, Michael; Wu, Jiangtao; Wang, Tiejun; Dunn, Martin L.; Qi, H. Jerry

2016-01-01

The creation of reversibly-actuating components that alter their shapes in a controllable manner in response to environmental stimuli is a grand challenge in active materials, structures, and robotics. Here we demonstrate a new reversible shape-changing component design concept enabled by 3D printing two stimuli responsive polymers—shape memory polymers and hydrogels—in prescribed 3D architectures. This approach uses the swelling of a hydrogel as the driving force for the shape change, and the temperature-dependent modulus of a shape memory polymer to regulate the time of such shape change. Controlling the temperature and aqueous environment allows switching between two stable configurations – the structures are relatively stiff and can carry load in each – without any mechanical loading and unloading. Specific shape changing scenarios, e.g., based on bending, or twisting in prescribed directions, are enabled via the controlled interplay between the active materials and the 3D printed architectures. The physical phenomena are complex and nonintuitive, and so to help understand the interplay of geometric, material, and environmental stimuli parameters we develop 3D nonlinear finite element models. Finally, we create several 2D and 3D shape changing components that demonstrate the role of key parameters and illustrate the broad application potential of the proposed approach. PMID:27109063

3D Printed Reversible Shape Changing Components with Stimuli Responsive Materials

NASA Astrophysics Data System (ADS)

Mao, Yiqi; Ding, Zhen; Yuan, Chao; Ai, Shigang; Isakov, Michael; Wu, Jiangtao; Wang, Tiejun; Dunn, Martin L.; Qi, H. Jerry

2016-04-01

The creation of reversibly-actuating components that alter their shapes in a controllable manner in response to environmental stimuli is a grand challenge in active materials, structures, and robotics. Here we demonstrate a new reversible shape-changing component design concept enabled by 3D printing two stimuli responsive polymers—shape memory polymers and hydrogels—in prescribed 3D architectures. This approach uses the swelling of a hydrogel as the driving force for the shape change, and the temperature-dependent modulus of a shape memory polymer to regulate the time of such shape change. Controlling the temperature and aqueous environment allows switching between two stable configurations - the structures are relatively stiff and can carry load in each - without any mechanical loading and unloading. Specific shape changing scenarios, e.g., based on bending, or twisting in prescribed directions, are enabled via the controlled interplay between the active materials and the 3D printed architectures. The physical phenomena are complex and nonintuitive, and so to help understand the interplay of geometric, material, and environmental stimuli parameters we develop 3D nonlinear finite element models. Finally, we create several 2D and 3D shape changing components that demonstrate the role of key parameters and illustrate the broad application potential of the proposed approach.

Sudden Oak Death - Western (Pest Alert)

Treesearch

Susan Frankel

2002-01-01

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

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

Treesearch

John T. Kliejunas

2010-01-01

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

Sudden Infant Death Syndrome.

ERIC Educational Resources Information Center

Barnett, Henry L.; And Others

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

Athletes at Risk for Sudden Cardiac Death

ERIC Educational Resources Information Center

Subasic, Kim

2010-01-01

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

[Genetics of sudden unexplained death].

PubMed

Campuzano, Oscar; Allegue, Catarina; Brugada, Ramon

2014-03-20

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

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

PubMed

Bechtel, Kirsten

2012-10-01

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

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

PubMed

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

2017-06-01

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

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

PubMed

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

2015-05-01

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

Fluid oscillation in the Drop Tower

NASA Technical Reports Server (NTRS)

Kaukler, William F.

1988-01-01

An interfluid meniscus oscillates within a cylindrical container when suddenly released from earth's gravity and taken into a microgravity environment. Oscillations damp out from energy dissipative mechanisms such as viscosity and interfacial friction. Damping out of the oscillations by the latter mechanism is affected by the nature of the interfacial junction between the fluid-fluid interface and the container wall. Perfluoromethylcyclohexane and isopropanol in glass were the materials used for the experiment. The wetting condition of the fluids against the wall changes at the critical wetting transition temperature. This change in wetting causes a change in the damping characteristics.

Smoothly deformed light

NASA Technical Reports Server (NTRS)

Stenholm, Stig

1993-01-01

A single mode cavity is deformed smoothly to change its electromagnetic eigenfrequency. The system is modeled as a simple harmonic oscillator with a varying period. The Wigner function of the problem is obtained exactly by starting with a squeezed initial state. The result is evaluated for a linear change of the cavity length. The approach to the adiabatic limit is investigated. The maximum squeezing is found to occur for smooth change lasting only a fraction of the oscillational period. However, only a factor of two improvement over the adiabatic result proves to be possible. The sudden limit cannot be investigated meaningfully within the model.

On the pilot's behavior of detecting a system parameter change

NASA Technical Reports Server (NTRS)

Morizumi, N.; Kimura, H.

1986-01-01

The reaction of a human pilot, engaged in compensatory control, to a sudden change in the controlled element's characteristics is described. Taking the case where the change manifests itself as a variance change of the monitored signal, it is shown that the detection time, defined to be the time elapsed until the pilot detects the change, is related to the monitored signal and its derivative. Then, the detection behavior is modeled by an optimal controller, an optimal estimator, and a variance-ratio test mechanism that is performed for the monitored signal and its derivative. Results of a digital simulation show that the pilot's detection behavior can be well represented by the model proposed here.

Cloud Formation and Water Transport on Mars after Major Outflow Events

NASA Technical Reports Server (NTRS)

Santiago, D. L.; Colaprete, A.; Kreslavsky, M.; Kahre, M. A.; Asphaug, E.

2012-01-01

The triggering of a robust water cycle on Mars might have been caused by the gigantic flooding events evidenced by outflow channels. We use the Ames Mars General Circulation Model (MGCM) to test this hypothesis, studying how these presumably abrupt eruptions of water might have affected the climate of Mars in the past. We model where the water ultimately went as part of a transient atmospheric water cycle, to answer questions including: (1) Can sudden introductions of large amounts of water on the Martian surface lead to a new equilibrated water cycle? (2) What are the roles of water vapor and water ice clouds to sudden changes in the water cycle on Mars? (3) How are radiative feedbacks involved with this? (4) What is the ultimate fate of the outflow water? (5) Can we tie certain geological features to outflow water redistributed by the atmosphere?

Changes in the mean hearing threshold levels in military aircraft maintenance conscripts.

PubMed

Park, Won-Ju; Moon, Jai-Dong

2016-11-01

Aircraft maintenance crews are constantly exposed to severe aircraft noise. The purpose of this study was to verify whether noise from aircraft adversely affects the hearing threshold levels (HTLs) of aircraft maintenance conscripts during their 2 years of mandatory military service. This study included 3,000 male aircraft maintenance conscripts who work in the military runway area. We measured and analyzed HTLs at 2-4 kHz. The duration of exposure to noise increased with an increase in rank; however, HTLs showed a tendency to decrease. We attributed such contradicting results to the learning effect and adaptation to military service. However, we suspected that sudden deafness in 6 conscripts (0.2%) was due to loud noise in the runway area during military service. The effectiveness of the hearing conservation program for short-term military service personnel could be increased by focusing on preventing sudden deafness and preenlistment baseline audiogram tests.

Experimental study of flow reattachment in a single-sided sudden expansion

NASA Technical Reports Server (NTRS)

Westphal, R. V.; Johnston, J. P.; Eaton, J. K.

1984-01-01

The reattachment of a fully turbulent, two dimensional, separated shear layer downstream of a single-sided sudden expansion in a planar duct flow was examined experimentally. The importance of changing the structure of the separated shear layer on the reattachment process itself was examined. For all cases, the Reynolds number based on step height was greater than 20,000, the expansion ratio was 5/3, and the inlet boundary layer was less than one-half step height in thickness. A crucially important phase was the development of a pulsed wall probe for measurement of skin friction in the reattachment region, thus providing an unambiguous definition of the reattachment length. Quantitative features of reattachment - including streamwise development of the mean and fluctuating velocity field, pressure rise, and skin friction - were found to be similar for all cases studied when scaled by the reattachment length. A definition of the reattachment zone is proposed.

Changes in cellular distribution regulate SKD1 ATPase activity in response to a sudden increase in environmental salinity in halophyte ice plant

PubMed Central

Jou, Yingtzy; Chiang, Chih-Pin; Yen, Hungchen Emilie

2013-01-01

Halophyte Mesembryanthemum crystallinum L. (ice plant) rapidly responds to sudden increases in salinity in its environment by activating specific salt-tolerant mechanisms. One major strategy is to regulate a series of ion transporters and proton pumps to maintain cellular Na+/K+ homeostasis. Plant SKD1 (suppressor of K+ transport growth defect 1) proteins accumulate in cells actively engaged in the secretory processes, and play a critical role in intracellular protein trafficking. Ice plant SKD1 redistributes from the cytosol to the plasma membrane hours after salt stressed. In combination with present knowledge of this protein, we suggest that stress facilitates SKD1 movement to the plasma membrane where ADP/ATP exchange occurs, and functions in the regulation of membrane components such as ion transporters to avoid ion toxicity. PMID:24390077

The Dynamics of Quantum Discord and Entanglement of Three Atoms Coupled to Three Spatially Separate Cavities

NASA Astrophysics Data System (ADS)

He, Juan; Wu, Tao; Ye, Liu

2013-10-01

In this paper, we study the dynamics of quantum discord and entanglement of three identical two-level atoms simultaneously resonantly interacting with three spatially separate single-mode of high- Q cavities respectively. Taking advantage of the depiction quantum discord and entanglement of formation (EoF), we conclude that the discord and entanglement of atoms and cavities can be mediated by changing some parameters and the maximum values of discord and entanglement are independent on the couplings of cavities and atoms. In particular, there also exists quantum discord sudden death as well as entanglement sudden death and the time interval of the former is shorter than that of the later in the proposed quantum system. It is shown that the discord and entanglement of any two atoms among three atoms can be transferred to the corresponding cavities, and there exists discord and entanglement exchanging between the atoms and the corresponding cavities.

a Solar Magnetic Flux Emergence Signature in Geomagnetic Storm Sudden Commencements and aa Index

NASA Astrophysics Data System (ADS)

Silva, A. M.

2008-05-01

In this work is studied a signal near 158 days in sunspots areas direcly linked with the emergence of magnetic flux, from historical records between solar cycles 17 to 23, by means of wavelet analysis. Is showed that this periodicity present excitation of subharmonics in certain time intervals, and I found support that the lifetime of larger complex of new sunspots created is the cause of these signature. The result can be important for improve the knowledge of the subphotosferic phenomenon related to the conversion of magnetic toroidal field in poloidal ones. In adition, the wavelet analysis shown evidence of this signal in the geomagnetic storm sudden commencements SSC and in the geomagnetic aa index, synchronically with events de solar flux emergence. Since the SSC are a powerfull mechanism of energy injection in the upper ionosphere that affect several climate variables, it is discussed the relevance of results presented for climate changes.

Progressive dysautonomia in two patients with xeroderma pigmentosum group A.

PubMed

Kobayashi, Osamu; Miyahara, Hiroaki; Abe, Naho; Goto, Chika; Okanari, Kazuo; Akiyoshi, Kensuke; Korematsu, Seigo; Izumi, Tatsuro

2014-06-01

Xeroderma pigmentosum group A (XPA) is a rare autosomal-recessive disorder caused by a defect in nucleotide excision repair. Progressive dysautonomia in patients with XPA is rarely described. Two juvenile male patients with XPA suffered from dysphagia, sleep interruption, and dysuria from the age of 10 to 19 years, successively. These autonomic symptoms might have been caused by progressive descending degeneration of cranial nerves IX and X and the sacral parasympathetic nerve, including Onuf's nucleus. One patient died from sudden cardiopulmonary arrest during postural change and tracheal suction. Heart rate variability analyses of these patients revealed parasympathetic dysautonomia, based on decreased high-frequency values. The insidiously progressive dysautonomia in these two patients with XPA suggested progressive descending degeneration extending from the medulla oblongata to the sacral spinal cord, which is an ominous sign of end-stage disease and a risk factor of sudden death attributable to XPA. Copyright © 2014 Elsevier Inc. All rights reserved.

A regime perspective on the North Atlantic eddy-driven jet stream response to sudden stratospheric warmings

NASA Astrophysics Data System (ADS)

Maycock, A.; Masukwedza, G.; Hitchcock, P.

2017-12-01

The winter North Atlantic eddy-driven jet (NAJ) has been shown to exhibit three preferred latitudinal positions. Here we examine, for the first time, the influence of major Sudden Stratospheric Warmings (SSWs) on the regime behaviour of the NAJ using an ensemble of climate model experiments with stratospheric conditions nudged towards a major SSW, but with each ensemble member having freely evolving tropospheric conditions. The SSW experiment is compared to a control ensemble in which stratospheric variability is absent. The experiments show that the SSW leads to an increased occupancy of the southerly NAJ state and reduced occupancy of the northerly state. This effect is distinct from the mean southward shift of the NAJ identified in many previous studies, and instead suggests changes to the characteristics of NAJ variability as a result of SSWs. These results may aid in understanding the mechanisms by which SSWs impact on Euro-Atlantic climate.

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

PubMed

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

2016-05-01

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

A universal indicator of critical state transitions in noisy complex networked systems

PubMed Central

Liang, Junhao; Hu, Yanqing; Chen, Guanrong; Zhou, Tianshou

2017-01-01

Critical transition, a phenomenon that a system shifts suddenly from one state to another, occurs in many real-world complex networks. We propose an analytical framework for exactly predicting the critical transition in a complex networked system subjected to noise effects. Our prediction is based on the characteristic return time of a simple one-dimensional system derived from the original higher-dimensional system. This characteristic time, which can be easily calculated using network data, allows us to systematically separate the respective roles of dynamics, noise and topology of the underlying networked system. We find that the noise can either prevent or enhance critical transitions, playing a key role in compensating the network structural defect which suffers from either internal failures or environmental changes, or both. Our analysis of realistic or artificial examples reveals that the characteristic return time is an effective indicator for forecasting the sudden deterioration of complex networks. PMID:28230166

Roi Detection and Vessel Segmentation in Retinal Image

NASA Astrophysics Data System (ADS)

Sabaz, F.; Atila, U.

2017-11-01

Diabetes disrupts work by affecting the structure of the eye and afterwards leads to loss of vision. Depending on the stage of disease that called diabetic retinopathy, there are sudden loss of vision and blurred vision problems. Automated detection of vessels in retinal images is a useful study to diagnose eye diseases, disease classification and other clinical trials. The shape and structure of the vessels give information about the severity of the disease and the stage of the disease. Automatic and fast detection of vessels allows for a quick diagnosis of the disease and the treatment process to start shortly. ROI detection and vessel extraction methods for retinal image are mentioned in this study. It is shown that the Frangi filter used in image processing can be successfully used in detection and extraction of vessels.

Design considerations and practical results with long duration systems for manned world flights

NASA Astrophysics Data System (ADS)

Nott, Julian

2004-01-01

This paper describes development of three balloon types by the author, all proposed for piloted flights around the world. The first was a superpressure pumpkin used to cross Australia. However, the balloon took up an incorrect shape when inflated. Because of this and other problems, the pumpkin was abandoned and the author built a combined helium-hot air balloon. This in turn was abandoned because it was cumbersome and costly. The author then developed an entirely new system, carrying cryogenic liquid helium to create lift in flight. Two very successful 24-h flights were made. In addition several inventions were developed for crew safety. Perhaps the most important is an entirely new way to protect pilots against sudden cabin pressure loss, with potentially broad use.

Stretched Inertial Jets

NASA Astrophysics Data System (ADS)

Ghabache, Elisabeth; Antkowiak, Arnaud; Seon, Thomas; Villermaux, Emmanuel

2015-11-01

Liquid jets often arise as short-lived bursting liquid flows. Cavitation or impact-driven jets, bursting champagne bubbles, shaped-charge jets, ballistospores or drop-on-demand inkjet printing are a few examples where liquid jets are suddenly released. The trademark of all these discharge jets is the property of being stretched, due to the quenching injection. the present theoretical and experimental investigation, the structure of the jet flow field will be unraveled experimentally for a few emblematic occurrences of discharge jets. Though the injection markedly depends on each flow configuration, the jet velocity field will be shown to be systematically and rapidly attracted to the universal stretching flow z/t. The emergence of this inertial attractor actually only relies on simple kinematic ingredients, and as such is fairly generic. The universality of the jet velocity structure will be discussed.

Sudden Cardiac Arrest during Participation in Competitive Sports.

PubMed

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

2017-11-16

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

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

PubMed

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

2013-01-01

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

Studies and research on global climate change produced in Dobrogea

NASA Astrophysics Data System (ADS)

Serban, Cristina; Maftei, Carmen; Zagan, Sabina; Chitu, Greti; Zagan, Remus

2013-04-01

Studies and research on global climate change produced in Dobrogea Atmospheric phenomena risk, high acuity products in recent years compels us to a more careful study of the phenomena caused by global climate change produced in Dobrogea. Risk atmospheric phenomena and quick release is characterized by extremely high energies that are catastrophic, sudden and hard to prognosis in current contexts. In our paper we clarify the concept of aridity, and discusses related concepts including indices of aridity, and their influence on Dobrogea area and soil features including climatic water deficit. The drought impact is evaluated by calculating different indices of drought from meteorological and hydrological point of view. In Dobrogea, the phenomena mentioned already manifested by hail, violent storms, tornadoes, heavy precipitation, rainfall, manifested in short periods, producing floods and landslides. Sudden changes, increased environmental air parameters (temperature, humidity, atmospheric pressure) creates, in turn, serious human discomfort and other negative effects of socio-economic. These "risk events" is frequently interleaves severe periods of drought, completing the sequence of natural disasters are difficult to predict. Another characteristic of desertification in Dobrogea is eroding - cruel impoverishment of the soil created by strong winds and violent rain causes strong erosion. Dust storms and sand pits desert areas severely affects state land, forests and degrade air quality breathable, cruelly destroying into ozone. Summarizing, the objective of this paper is to present some results using drought indices and a Grid computing application, which estimates the land surface temperature (LST) and normalized difference vegetation index (NDVI) at regional scale.

Changes in metabolites, antioxidant system, and gene expression in Microcystis aeruginosa under sodium chloride stress.

PubMed

Chen, Lei; Mao, Feijian; Kirumba, George Chira; Jiang, Cheng; Manefield, Mike; He, Yiliang

2015-12-01

Microcystis (M.) aeruginosa, one of the most common bloom-forming cyanobacteria, occurs worldwide. The Qingcaosha (QCS) Reservoir is undergoing eutrophication and faces the problem of saltwater intrusion. The aim of this study was to investigate the effects of sudden salinity changes on physiological parameters and related gene transcription in M. aeruginosa under controlled laboratory conditions. The results showed that sodium chloride (50, 200 and 500 mg L(-1) NaCl) inhibited the algal growth and decreased pigment concentrations (chlorophyll a, carotenoid and phycocyanin). Sodium chloride increased both the intracellular and extracellular microcystin contents and elevated the mcyD transcript level in M. aeruginosa. It also increased the malondialdehyde (MDA) content and caused cytomembrane damage. This damage caused the release of intracellular toxins into the culture medium. In addition, NaCl decreased the maximum electron transport rate, increased the levels of reactive oxygen species (ROS) and changed the cellular redox status. Consequently, NaCl inhibited the expression of cpcB, psbA and rbcL. Furthermore, NaCl increased the activities of superoxide dismutases (SOD), catalase (CAT), glutathione reductase (GR), and total glutathione peroxidase (GPx). The transcript levels of sod and reduced glutathione (gsh) were also increased after exposure to NaCl. Our results indicate that a sudden increase in salinity increases the production and excretion of microcystin, changes the cellular redox status, enhances the activities of antioxidant enzymes, inhibits photosynthesis, and affects transcript levels of related genes in M. aeruginosa. Copyright © 2015 Elsevier Inc. All rights reserved.

Shape-morphing composites with designed micro-architectures

NASA Astrophysics Data System (ADS)

Rodriguez, Jennifer N.; Zhu, Cheng; Duoss, Eric B.; Wilson, Thomas S.; Spadaccini, Christopher M.; Lewicki, James P.

2016-06-01

Shape memory polymers (SMPs) are attractive materials due to their unique mechanical properties, including high deformation capacity and shape recovery. SMPs are easier to process, lightweight, and inexpensive compared to their metallic counterparts, shape memory alloys. However, SMPs are limited to relatively small form factors due to their low recovery stresses. Lightweight, micro-architected composite SMPs may overcome these size limitations and offer the ability to combine functional properties (e.g., electrical conductivity) with shape memory behavior. Fabrication of 3D SMP thermoset structures via traditional manufacturing methods is challenging, especially for designs that are composed of multiple materials within porous microarchitectures designed for specific shape change strategies, e.g. sequential shape recovery. We report thermoset SMP composite inks containing some materials from renewable resources that can be 3D printed into complex, multi-material architectures that exhibit programmable shape changes with temperature and time. Through addition of fiber-based fillers, we demonstrate printing of electrically conductive SMPs where multiple shape states may induce functional changes in a device and that shape changes can be actuated via heating of printed composites. The ability of SMPs to recover their original shapes will be advantageous for a broad range of applications, including medical, aerospace, and robotic devices.

The role of resilience and mindful leadership in oncology nursing.

PubMed

Rishel, Cindy J

2015-03-01

When oncology nurses think of the word resilient, they often describe the term in the context of the patients and families they care for each day. When patients face a diagnosis of cancer, their lives have suddenly been altered in a frightening manner. Everything changes, and they must find a way to navigate the troubled waters ahead. 
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Consideraciones sobre la Ansiedad en la Primera Infancia (Considerations Concerning Anxiety in Early Infancy).

ERIC Educational Resources Information Center

Muller, Elsa

The results of an experience obtained while working with children in the early stages of infancy are presented. They are basically observations taken of a child's reaction to sudden changes, particularly separation from its mother. Anxiety was observed in these infants in diverse circumstances; in some cases it was at a normal level and in others…

Population dynamics of aerial and terrestrial populations Phytophthora ramorum in a California forest under different climatic conditions

Treesearch

C.A. Eyre; M. Kozanitas; M. Garbelotto

2013-01-01

Limited information is available on how soil and leaf populations of the sudden oak death pathogen, Phytophthora ramorum, may differ in their response to changing weather conditions, and their corresponding role in initiating the next disease cycle after unfavorable weather conditions. We sampled and cultured from 425 trees in six sites, three...

Journal of Special Operations Medicine. Volume 1, Edition 3, Fall 2001

DTIC Science & Technology

2001-01-01

Visceral Urethritis, Non-Gonococcal Leprosy Vaccine, Adverse Event Leptospirosis Varicella , Active Duty Only Yellow Fever Figure 2...are favorable and sudden changes in local climate. Today, in the United States, these areas closely resemble the cattle drive trails of the Mexico ...Nebraska, New Mexico , Oklahoma, California, Kansas, and Mississippi. Canada is likewise sporadi- cally afflicted. Among the �economically advanced

Forest health conditions in North America

Treesearch

B. Moody; J.V. Castillo; M.E. Fenn

2008-01-01

Some of the greatest forest health impacts in North America are caused by invasive forest insects and pathogens (e.g., emerald ash borer and sudden oak death in the US), by severe outbreaks of native pests (e.g., mountain pine beetle in Canada), and fires exacerbated by changing climate. Ozone and N and S pollutants continue to impact the health of forests in several...

Age-Related Changes in Antisaccade Task Performance: Inhibitory Control or Working-Memory Engagement?

ERIC Educational Resources Information Center

Eenshuistra, R.M.; Ridderinkhof, K.R.; Molen, M.W.v.d.

2004-01-01

In antisaccade tasks, subjects are required to generate a saccade in the direction opposite to the location of a sudden-onset target stimulus. Compared to young adults, older adults tend to make more reflex-like eye movements towards the target, and/or show longer saccadic onset latencies on correct direct antisaccades. To better understand the…

ESSA and Students in Foster Care. Policy Update. Vol. 23, No. 22

ERIC Educational Resources Information Center

Lorenzo, Sarah-Jane

2016-01-01

For years, students in foster care have been among the most transient in the nation, enduring sudden, sometimes frequent school changes as they move from home to home. The lack of school stability contributes to those children's academic struggles: Students in foster care are more likely than their peers to score lower on assessments and less…

Life Journey through Autism: Navigating the Special Education System

ERIC Educational Resources Information Center

Organization for Autism Research (NJ1), 2012

2012-01-01

As any parent of a child with autism knows, your life changes and you take on new roles after your child receives a diagnosis of autism. Ready or not, you are now expected to be an expert on interventions, support professionals, and special education. Suddenly, your concerns and worries are different from the parents around you. While they may be…

Operation Reputation: How to Manage and Protect Your Institution's Online Image

ERIC Educational Resources Information Center

Fernandez, Kim

2009-01-01

In the past few years, the online world has changed. It seems everyone is suddenly on social media sites like Facebook, Twitter, and MySpace, and anyone who can string words together--and a few who can't--seem to have glommed onto blogs, spouting opinions into the cyberworld with abandon. Prospective students, parents, and alumni not only read…

When Goal Orientations Collide: Effects of Learning and Performance Orientation on Team Adaptability in Response to Workload Imbalance

ERIC Educational Resources Information Center

Porter, Christopher O. L. H.; Webb, Justin W.; Gogus, Celile Itir

2010-01-01

The authors draw on resource allocation theory (Kanfer & Ackerman, 1989) to develop hypotheses regarding the conditions under which collective learning and performance orientation have interactive effects and the nature of those effects on teams' ability to adapt to a sudden and dramatic change in workload. Consistent with the theory, results…

Study of the behaviour of the equatorial ionization anomaly (EIA) during solar flares

NASA Astrophysics Data System (ADS)

Aggarwal, Malini; Astafyeva, Elvira

2014-05-01

A solar flare occurring in the sun's chromosphere is observed in various wavebands (radio to x-rays). The response of the solar flare which causes sudden changes in the earth's ionosphere is not yet well understood though investigations suggested that its impact depends on the size and location of occurrence of solar flare on sun. Considering this, we have carried an investigation to study the response of two strong and gradual solar flares: 2 Apr 2001 (X20, limb) and 7 Feb 2010 (M6.4, disk) on the earth's equatorial-low latitude regions using multi-technique observations of satellite and ground-based instruments. We found a weakening of strength of equatorial ionization anomaly (EIA) in total electron content during both the flares as observed by TOPEX, JASON-1 and JASON-2 altimeter measurements. The H component of the geomagnetic field also shows a sudden change at equatorial and low latitude stations in the sunlit hemisphere during the flare. The observations of ionosonde at low-latitudes indicate a strong absorption of higher-frequency radio signals. The detail response of these flare on EIA of the earth's ionosphere will be presented and discussed.