WorldWideScience

Sample records for catastrophic disruption threshold

  1. Catastrophic disruption experiments: Recent results

    Science.gov (United States)

    Martelli, G.; Ryan, E. V.; Nakamura, A. M.; Giblin, I.

    1994-01-01

    This paper presents a review of the progress in the field of catastrophic disruption experiments over the past 4 years, since the publication of the review paper by Fujiwara et al. (1989). We describe the development of new techniques to produce shattering impacts relevant to the study of the collisional evolution of the asteroids, and summarize the results from numerous experiments which have been performed to date, using a variety of materials for both the impactor and the targets. Some of these, such as ice-on-ice, loose aggregates and pressurized targets, are quite new and have provided novel and exciting results. Some of the gaps existing previously in the data on fragment ejection-angle distributions, as well as translational and rotational velocity fields (including fine fragments) have been filled, and these new results will be surveyed.

  2. Coping with ecological catastrophe: crossing major thresholds

    Directory of Open Access Journals (Sweden)

    John Cairns, Jr.

    2004-08-01

    Full Text Available The combination of human population growth and resource depletion makes catastrophes highly probable. No long-term solutions to the problems of humankind will be discovered unless sustainable use of the planet is achieved. The essential first step toward this goal is avoiding or coping with global catastrophes that result from crossing major ecological thresholds. Decreasing the number of global catastrophes will reduce the risks associated with destabilizing ecological systems, which could, in turn, destabilize societal systems. Many catastrophes will be local, regional, or national, but even these upheavals will have global consequences. Catastrophes will be the result of unsustainable practices and the misuse of technology. However, avoiding ecological catastrophes will depend on the development of eco-ethics, which is subject to progressive maturation, comments, and criticism. Some illustrative catastrophes have been selected to display some preliminary issues of eco-ethics.

  3. Rotation-dependent catastrophic disruption of gravitational aggregates

    Energy Technology Data Exchange (ETDEWEB)

    Ballouz, Ronald-Louis; Richardson, Derek C.; Schwartz, Stephen R. [Department of Astronomy, University of Maryland, College Park, MD 20742-2421 (United States); Michel, Patrick, E-mail: rballouz@astro.umd.edu [Lagrange Laboratory, University of Nice Sophia Antipolis, CNRS, Observatoire de la Côte d' Azur, C.S. 34229, F-06304 Nice Cedex 4 (France)

    2014-07-10

    We carry out a systematic exploration of the effect of pre-impact rotation on the outcomes of low-speed collisions between planetesimals modeled as gravitational aggregates. We use pkdgrav, a cosmology code adapted to collisional problems and recently enhanced with a new soft-sphere collision algorithm that includes more realistic contact forces. A rotating body has lower effective surface gravity than a non-rotating one and therefore might suffer more mass loss as the result of a collision. What is less well understood, however, is whether rotation systematically increases mass loss on average regardless of the impact trajectory. This has important implications for the efficiency of planet formation via planetesimal growth, and also more generally for the determination of the impact energy threshold for catastrophic disruption (leading to the largest remnant retaining 50% of the original mass), as this has generally only been evaluated for non-spinning bodies. We find that for most collision scenarios, rotation lowers the threshold energy for catastrophic dispersal. For head-on collisions, we develop a semi-analytic description of the change in the threshold description as a function of the target's pre-impact rotation rate, and find that these results are consistent with the 'universal law' of catastrophic disruption developed by Leinhardt and Stewart. Using this approach, we introduce re-scaled catastrophic disruption variables that take into account the interacting mass fraction of the target and the projectile in order to translate oblique impacts into equivalent head-on collisions.

  4. Rotation-Dependent Catastrophic Disruption of Gravitational Aggregates

    CERN Document Server

    Ballouz, Ronald-Louis; Michel, Patrick; Schwartz, Stephen R

    2014-01-01

    We carry out a systematic exploration of the effect of pre-impact rotation on the outcomes of low-speed collisions between planetesimals modeled as gravitational aggregates. We use pkdgrav, a cosmology code adapted to collisional problems and recently enhanced with a new soft-sphere collision algorithm that includes more realistic contact forces. A rotating body has lower effective surface gravity than a non-rotating one and therefore might suffer more mass loss as the result of a collision. What is less well understood, however, is whether rotation systematically increases mass loss on average regardless of the impact trajectory. This has important implications for the efficiency of planet formation via planetesimal growth, and also more generally for the determination of the impact energy threshold for catastrophic disruption (leading to the largest remnant retaining 50% of the original mass), as this has generally only been evaluated for non-spinning bodies. We find that for most collision scenarios, rotat...

  5. Observational Constraints on the Catastrophic Disruption Rate of Small Main Belt Asteroids

    CERN Document Server

    Denneau, Larry; Fitzsimmons, Alan; Hsieh, Henry; Kleyna, Jan; Granvik, Mikael; Micheli, Marco; Spahr, T; Vereš, Peter; Wainscoat, Richard; Burgett, W S; Chambers, K C; Draper, P W; Flewelling, H; Huber, M E; Kaiser, N; Morgan, J S; Tonry, J L

    2014-01-01

    We have calculated 90% confidence limits on the steady-state rate of catastrophic disruptions of main belt asteroids in terms of the absolute magnitude at which one catastrophic disruption occurs per year (HCL) as a function of the post-disruption increase in brightness (delta m) and subsequent brightness decay rate (tau). The confidence limits were calculated using the brightest unknown main belt asteroid (V = 18.5) detected with the Pan-STARRS1 (Pan-STARRS1) telescope. We measured the Pan-STARRS1's catastrophic disruption detection efficiency over a 453-day interval using the Pan-STARRS moving object processing system (MOPS) and a simple model for the catastrophic disruption event's photometric behavior in a small aperture centered on the catastrophic disruption event. Our simplistic catastrophic disruption model suggests that delta m = 20 mag and 0.01 mag d-1 99% of main belt catastrophic disruptions in the size range to which this study was sensitive (100 m) are not impact-generated, but are instead due ...

  6. Wavelength dependence of catastrophic optical damage threshold in 980nm semiconductor diode lasers

    OpenAIRE

    Lock, D; Sweeney, SJ; Adams, AR

    2003-01-01

    We investigate the wavelength dependence of the catastrophic optical damage current in 980nm lasers. Using high pressure and low temperature techniques, we find an intrinsic dependence of this threshold on wavelength.

  7. Catastrophic disruption in the solar system - Asteroid collisional history, origin of Hirayama families and disruption of small satellites

    Science.gov (United States)

    Davis, D. R.

    1986-01-01

    The process of collisional catastrophic disruption has played a significantly role in structuring the solar system. Diverse populations of bodies such as the asteroid belt, small satellites of Jupiter and Saturn and perhaps even the rings of Saturn have been created or substantially changed by catastrophic distruption. Understanding the outcome of large scale impacts is essential to learning about the early history of the solar system in the asteroid zone and the reason why a planet failed to form there.

  8. Catastrophic Thresholds: A Synthesis of Concepts, Perspectives, and Applications

    Directory of Open Access Journals (Sweden)

    Tamzen K. Stringham

    2010-09-01

    Full Text Available Research reported in this feature identifies a convergence of interpretations regarding the threshold dynamics of complex ecological systems. This convergence has arisen from a diverse set of investigations addressing rangeland ecosystem dynamics, disease transmission, and fluctuations in the populations of insect pests. Effective application of the threshold concept to ecosystem management will require development of more robust linkages between non-equilibrium theory and protocols to identify triggers that initiate threshold conditions, feedback loops that establish system resilience, and developmental trajectories and attributes of potential alternative stable states. Successful implementation of these theory/application linkages has the potential to underpin an operational framework of resilience-based ecosystem management that is founded upon the identification of structural indicators that are correlated with vulnerability or proximity to thresholds, rather than threshold identification per se. Several investigations indicate that thresholds are strongly influenced by scale; multiple cross-scale interactions demonstrate the need for greater knowledge and analyses to address scale-dependent processes, i.e., critical scales and scaling laws. This feature emphasizes the relevance of thresholds and non-equilibrium dynamics in multiple natural resource management applications and in so doing demonstrates the need for a more comprehensive and integrated ecological framework capable of quantitatively assessing dynamics at multiple scales to inform management and policy recommendations for optimal management and risk assessment.

  9. Fragment shapes in impact experiments ranging from cratering to catastrophic disruption

    Science.gov (United States)

    Michikami, Tatsuhiro; Hagermann, Axel; Kadokawa, Tokiyuki; Yoshida, Akifumi; Shimada, Akira; Hasegawa, Sunao; Tsuchiyama, Akira

    2016-01-01

    Laboratory impact experiments have found that impact fragments tend to be elongated. Their shapes, as defined by axes a, b and c, these being the maximum dimensions of the fragment in three mutually orthogonal planes (a ⩾ b ⩾ c), are distributed around mean values of the axial ratios b/a ∼ 0.7 and c/a ∼ 0.5. This corresponds to a:b:c in the simple proportion 2:√2:1. The shape distributions of some boulders on Asteroid Eros, the small- and fast-rotating asteroids (diameter <200 m and rotation period <1 h), and asteroids in young families, are similar to those of laboratory fragments created in catastrophic disruptions. Catastrophic disruption is, however, a process that is different from impact cratering. In order to systematically investigate the shapes of fragments in the range from impact cratering to catastrophic disruption, impact experiments for basalt targets 5-15 cm in size were performed. A total of 28 impact experiments were carried out by firing a spherical nylon projectile (diameter 7.14 mm) perpendicularly into the target surface at velocities of 1.60-7.13 km/s. More than 12,700 fragments with b ⩾ 4 mm generated in the impact experiments were measured. We found that the mean value of c/a in each impact decreases with decreasing impact energy per unit target mass. For instance, the mean value of c/a in an impact cratering event is nearly 0.2, which is considerably smaller than c/a in a catastrophic disruption (∼0.5). The data presented here can provide important evidence to interpret the shapes of asteroids and boulders on asteroid surfaces, and can constrain current interpretations of asteroid formation. As an example, by applying our experimental results to the boulder shapes on Asteroid Itokawa's surface, we can infer that Itokawa's parent body must have experienced a catastrophic disruption.

  10. Super-catastrophic disruption of asteroids at small perihelion distances.

    Science.gov (United States)

    Granvik, Mikael; Morbidelli, Alessandro; Jedicke, Robert; Bolin, Bryce; Bottke, William F; Beshore, Edward; Vokrouhlický, David; Delbò, Marco; Michel, Patrick

    2016-02-18

    Most near-Earth objects came from the asteroid belt and drifted via non-gravitational thermal forces into resonant escape routes that, in turn, pushed them onto planet-crossing orbits. Models predict that numerous asteroids should be found on orbits that closely approach the Sun, but few have been seen. In addition, even though the near-Earth-object population in general is an even mix of low-albedo (less than ten per cent of incident radiation is reflected) and high-albedo (more than ten per cent of incident radiation is reflected) asteroids, the characterized asteroids near the Sun typically have high albedos. Here we report a quantitative comparison of actual asteroid detections and a near-Earth-object model (which accounts for observational selection effects). We conclude that the deficit of low-albedo objects near the Sun arises from the super-catastrophic breakup (that is, almost complete disintegration) of a substantial fraction of asteroids when they achieve perihelion distances of a few tens of solar radii. The distance at which destruction occurs is greater for smaller asteroids, and their temperatures during perihelion passages are too low for evaporation to explain their disappearance. Although both bright and dark (high- and low-albedo) asteroids eventually break up, we find that low-albedo asteroids are more likely to be destroyed farther from the Sun, which explains the apparent excess of high-albedo near-Earth objects and suggests that low-albedo asteroids break up more easily as a result of thermal effects. PMID:26887492

  11. The shapes of fragments in hypervelocity impact experiments ranging from cratering to catastrophic disruption

    Science.gov (United States)

    Michikami, T.; Hagermann, A.; Kadokawa, T.; Yoshida, A.; Shimada, A.; Hasegawa, S.; Tsuchiyama, A.

    2015-12-01

    Laboratory impact experiments have found that the shapes of impact fragments as defined by axes a, b and c, these being the maximum dimensions of the fragment in three mutually orthogonal planes (a ≥ b ≥ c) are distributed around mean values of the axial ratios b/a ~0.7 and c/a ~0.5, i.e., corresponding to a : b: c in the simple proportion 2: √2: 1. The shape distributions of some boulders on asteroid Eros, the small- and fast-rotating asteroids (diameter 8 m) on asteroid Itokawa. The mean value of c/a of these boulders is 0.46, which is similar to the value for catastrophic disruption. This implies that the parent body of Itokawa could have experienced a catastrophic disruption.

  12. Catastrophic disruption of asteriods and satellites; Proceedings of the International Workshop, Pisa, Italy, July 30-August 2, 1985

    Science.gov (United States)

    Davis, D. R. (Editor); Farinella, P. (Editor); Paolicchi, P. (Editor); Zappala, V. (Editor)

    1986-01-01

    Theoretical, numerical, and experimental investigations of the violent disruption of asteroids or planetary satellites are discussed in reviews and reports. Topics examined include acceleration techniques and results of experiments simulating catastrophic fragmentation events; laboratory simulations of catastrophic impact; scaling laws for the catastrophic collisions of asteroids; asteroid collisional history, the origin of the Hirayama families, and disruption of small satellites; and the implications of the inferred compositions of a steroids for their collisional evolution. Diagrams, graphs, tables, and a summary of the discussion at the workshop are provided.

  13. The relationship of adult attachment to emotion, catastrophizing, control, threshold and tolerance, in experimentally-induced pain.

    Science.gov (United States)

    Meredith, Pamela J; Strong, Jenny; Feeney, Judith A

    2006-01-01

    Although insecure attachment has been associated with a range of variables linked with problematic adjustment to chronic pain, the causal direction of these relationships remains unclear. Adult attachment style is, theoretically, developmentally antecedent to cognitions, emotions and behaviours (and might therefore be expected to contribute to maladjustment). It can also be argued, however, that the experience of chronic pain increases attachment insecurity. This project examined this issue by determining associations between adult attachment characteristics, collected prior to an acute (coldpressor) pain experience, and a range of emotional, cognitive, pain tolerance, intensity and threshold variables collected during and after the coldpressor task. A convenience sample of 58 participants with no history of chronic pain was recruited. Results demonstrated that attachment anxiety was associated with lower pain thresholds; more stress, depression, and catastrophizing; diminished perceptions of control over pain; and diminished ability to decrease pain. Conversely, secure attachment was linked with lower levels of depression and catastrophizing, and more control over pain. Of particular interest were findings that attachment style moderated the effects of pain intensity on the tendency to catastrophize, such that insecurely attached individuals were more likely to catastrophize when reporting high pain intensity. This is the first study to link attachment with perceptions of pain in a pain-free sample. These findings cast anxious attachment as a vulnerability factor for chronic pain following acute episodes of pain, while secure attachment may provide more resilience. PMID:16359795

  14. Catastrophic shifts and lethal thresholds in a propagating front model of unstable tumour progression

    CERN Document Server

    Amor, Daniel R

    2014-01-01

    Unstable dynamics characterizes the evolution of most solid tumors. Because of an increased failure of maintaining genome integrity, a cumulative increase in the levels of gene mutation and loss is observed. Previous work suggests that instability thresholds to cancer progression exist, defining phase transition phenomena separating tumor-winning scenarios from tumor extinction or coexistence phases. Here we present an integral equation approach to the quasispecies dynamics of unstable cancer. The model exhibits two main phases, characterized by either the success or failure of cancer tissue. Moreover, the model predicts that tumor failure can be due to either a reduced selective advantage over healthy cells or excessive instability. We also derive an approximate, analytical solution that predicts the front speed of aggressive tumor populations on the instability space.

  15. The formation of the Baptistina family by catastrophic disruption: Porous versus non-porous parent body

    Science.gov (United States)

    Jutzi, M.; Michel, P.; Benz, W.; Richardson, D. C.

    2009-01-01

    In this paper, we present numerical simulations aimed at reproducing the Baptistina family based on its properties estimated by observations. A previous study by Bottke et al. (2007) indicated that this family is probably at the origin of the K/T impactor, is linked to the CM meteorites and was produced by the disruption of a parent body 170 km in size due to the head-on impact of a projectile 60 km in size at 3 km s-1. This estimate was based on simulations of fragmentation of non-porous materials, while the family was assumed to be of C taxonomic type, which is generally interpreted as being formed from a porous body. Using both a model of fragmentation of non-porous materials, and a model that we developed recently for porous ones, we performed numerical simulations of disruptions aimed at reproducing this family and at analyzing the differences in the outcome between those two models. Our results show that a reasonable match to the estimated size distribution of the real family is produced from the disruption of a porous parent body by the head-on impact of a projectile 54 km in size at 3 km s-1. Thus, our simulations with a model consistent with the assumed dark type of the family requires a smaller projectile than previously estimated, but the difference remains small enough to not affect the proposed scenario of this family history. We then find that the break-up of a porous body leads to different outcomes than the disruption of a non-porous one. The real properties of the Baptistina family still contain large uncertainties, and it remains possible that its formation did not involve the proposed impact conditions. However, the simulations presented here already show some range of outcomes and once the real properties are better constrained, it will be easy to check whether one of them provides a good match.

  16. Climate catastrophes

    Science.gov (United States)

    Budyko, Mikhail

    1999-05-01

    Climate catastrophes, which many times occurred in the geological past, caused the extinction of large or small populations of animals and plants. Changes in the terrestrial and marine biota caused by the catastrophic climate changes undoubtedly resulted in considerable fluctuations in global carbon cycle and atmospheric gas composition. Primarily, carbon dioxide and other greenhouse gas contents were affected. The study of these catastrophes allows a conclusion that climate system is very sensitive to relatively small changes in climate-forcing factors (transparency of the atmosphere, changes in large glaciations, etc.). It is important to take this conclusion into account while estimating the possible consequences of now occurring anthropogenic warming caused by the increase in greenhouse gas concentration in the atmosphere.

  17. Resounding Catastrophe

    DEFF Research Database (Denmark)

    Kristensen, Thomas Bjørnsten

    2012-01-01

    The article discusses specific aesthetic strategies for articulating and describing the catastrophic event of 9/11 by focusing on its auditory aspects. This is done through a reading of the American media- and sound artist Stephen Vitiello’s work and novelist Don DeLillo’s Falling Man....

  18. Catastrophic medical expenditure risk.

    Science.gov (United States)

    Flores, Gabriela; O'Donnell, Owen

    2016-03-01

    We propose a measure of household exposure to particularly onerous medical expenses. The measure can be decomposed into the probability that medical expenditure exceeds a threshold, the loss due to predictably low consumption of other goods if it does and the further loss arising from the volatility of medical expenses above the threshold. Depending on the choice of threshold, the measure is consistent with a model of reference-dependent utility with loss aversion. Unlike the risk premium, the measure is only sensitive to particularly high expenses, and can identify households that expect to incur such expenses and would benefit from subsidised, but not actuarially fair, insurance. An empirical illustration using data from seven Asian countries demonstrates the importance of taking account of informal insurance and reveals clear differences in catastrophic medical expenditure risk across and within countries. In general, risk is higher among poorer, rural and chronically ill populations.

  19. Seizing Catastrophes

    DEFF Research Database (Denmark)

    Kublitz, Anja

    2013-01-01

    Based on fieldwork among Palestinians in Denmark the article investigates the Palestinian temporality of Nakba that is equivalent to a time of security in the sense that it is concerned with existential threats and emergency action. The Arabic term Nakba literally means catastrophe and is in Pale......Based on fieldwork among Palestinians in Denmark the article investigates the Palestinian temporality of Nakba that is equivalent to a time of security in the sense that it is concerned with existential threats and emergency action. The Arabic term Nakba literally means catastrophe...... and is in Palestinian national discourse used to designate the Arab-Israeli war of 1948, when more than half of the Palestinian population were expelled from their homeland – a reverse national myth about how Palestine failed to come into being. Yet, according to Palestinians in Denmark, the Nakba cannot be relegated...... of the Nakba in 2008 and clashes between the police and young Palestinians in 2006, the article demonstrates how Palestinians in Denmark seek to reverse the reverse myth of 1948 by seizing contemporary catastrophes to enact not only past and present Nakbas, but also potential futures. The article concludes...

  20. Catastrophe medicine; Medecine de catastrophe

    Energy Technology Data Exchange (ETDEWEB)

    Lebreton, A. [Service Technique de l`Energie Electrique et des Grands Barrages (STEEGB), (France)

    1996-12-31

    The `Catastrophe Medicine` congress which took place in Amiens (France) in December 5 to 7 1996 was devoted to the assessment and management of risks and hazards in natural and artificial systems. The methods of risk evaluation and prevision were discussed in the context of dams accidents with the analysis of experience feedbacks and lessons gained from the organisation of emergency plans. Three round table conferences were devoted to the importance of psychological aspects during such major crises. (J.S.)

  1. Cosmic Catastrophes

    Science.gov (United States)

    Wheeler, J. Craig

    2014-08-01

    Preface; 1. Setting the stage: star formation and hydrogen burning in single stars; 2. Stellar death: the inexorable grip of gravity; 3. Dancing with stars: binary stellar evolution; 4. Accretion disks: flat stars; 5. White Dwarfs: quantum dots; 6. Supernovae: stellar catastrophes; 7. Supernova 1987A: lessons and enigmas; 8. Neutron stars: atoms with attitude; 9. Black holes in theory: into the abyss; 10. Black holes in fact: exploring the reality; 11. Gamma-ray bursts, black holes and the universe: long, long ago and far, far away; 12. Supernovae and the universe; 13. Worm holes and time machines: tunnels in space and time; 14. Beyond: the frontiers; Index.

  2. Coherent catastrophism

    Science.gov (United States)

    Asher, D. J.; Clube, S. V. M.; Napier, W. M.; Steel, D. I.

    We review the theoretical and observational evidence that, on timescales relevant to mankind, the prime collision hazard is posed by temporally correlated impacts (coherent catastrophism, Δt ˜ 10 2-10 4 yr) rather than random ones (stochastic catastrophism, Δt ˜ 10 5-10 8 yr). The mechanism whereby coherent incursions into and through the terrestrial atmosphere occur is described as being the result of giant cometary bodies arriving in orbits with perihelia in the inner solar system. Hierarchical fragmentation of such large (100 km-plus) bodies — due to thermal stresses near perihelion, collisions in the asteroid belt, or passages through the Jovian Roche radius — results in numerous ˜kilometre-sized objects being left in short-period orbits, and appearing in telescopic searches as Apollo-type asteroids. Many more smaller objects, in the 10-100 metre size range and only recently observed, by the Spacewatch team, are expected to be in replenished clusters in particular orbits as a result of continuing disintegrations of large, differentiated, cometary objects. Gravitational perturbations by Jupiter bring these clusters around to have a node at 1 AU in a cyclic fashion, leading to impacts at certain times of year every few years during active periods lasting a few centuries, such periods being separated by intervals of a few millennia. Furthermore, fragmentations within the hierarchy result in significant bombardment commensurabilities ( Δt ˜ 10-10 2 yr) during active periods occurring at random intervals ( Δt ˜ 10 2-10 3 yr). It appears that the Earth has been subject to such impacts since the break-up of such a comet ˜2×10 4 years ago; currently we are not passing through a high-risk epoch, although some phenomena originating in the products of this break-up have been observed in the 20th century. This most recent hierarchical disintegration, associated with four well-known meteor showers and termed the Taurid Complex, is now recognized as resulting

  3. Catastrophic volcanism

    Science.gov (United States)

    Lipman, Peter W.

    1988-01-01

    Since primitive times, catastrophes due to volcanic activity have been vivid in the mind of man, who knew that his activities in many parts of the world were threatened by lava flows, mudflows, and ash falls. Within the present century, increasingly complex interactions between volcanism and the environment, on scales not previously experienced historically, have been detected or suspected from geologic observations. These include enormous hot pyroclastic flows associated with collapse at source calderas and fed by eruption columns that reached the stratosphere, relations between huge flood basalt eruptions at hotspots and the rifting of continents, devastating laterally-directed volcanic blasts and pyroclastic surges, great volcanic-generated tsunamis, climate modification from volcanic release of ash and sulfur aerosols into the upper atmosphere, modification of ocean circulation by volcanic constructs and attendent climatic implications, global pulsations in intensity of volcanic activity, and perhaps triggering of some intense terrestrial volcanism by planetary impacts. Complex feedback between volcanic activity and additional seemingly unrelated terrestrial processes likely remains unrecognized. Only recently has it become possible to begin to evaluate the degree to which such large-scale volcanic processes may have been important in triggering or modulating the tempo of faunal extinctions and other evolutionary events. In this overview, such processes are examined from the viewpoint of a field volcanologist, rather than as a previous participant in controversies concerning the interrelations between extinctions, impacts, and volcanism.

  4. Reverse Catastrophe

    Directory of Open Access Journals (Sweden)

    Przemysław Czapliński

    2015-01-01

    Full Text Available The principal notion of the article–a “backward catastrophe”– stands for a catastrophe which occurs unseen until it becomes recognized and which broadens its destructive activity until it has been recognized. This concept in the article has been referred to the Shoah. The main thesis is that the recognition of the actual influence of the Holocaust began in Polish culture in the mid-1980s (largely it started with the film by Claude Lanzmann Shoah and the essay by Jan Błoński Biedni Polacy patrzą na getto [“The Poor Poles Look at the Ghetto”], that is when the question: “What happened to the Jews”, assumes the form: “Did the things that happened to the Jews, also happened to the Poles?”. Cognitive and ethical reorientation leads to the revealing of the hidden consequences of the Holocaust reaching as far as the present day and undermining the foundations of collective identity. In order to understand this situation (and adopt potentially preventive actions Polish society should be recognized as a postcatastrophic one.

  5. The reasons for the application of chaos theory to the analysis of catastrophes.

    Science.gov (United States)

    Valery, Kudin

    2014-05-01

    The study of catastrophes is necessary for understanding the nature of the interaction between the individual and the universal in the process of the development of complex systems. Chaos theory, allowing describing adaptation and bifurcation mechanisms for the development of systems, defines the catastrophes as a transition of the system into a different state (change of structure). The previous state of the system is destroyed because of fluctuations, which do not play a role in the development of the system until it reaches the instability region that is inherent to any system. The catastrophe is considered in this theory as a stage in the evolution of the system, and thus emphasizes the importance of catastrophes for the development of any system. We rarely manage events comprehensively, as events are always subject to changes like gas molecules changing the trajectory of motion each moment under the influence of countless blows. The concept of catastrophes is much broader and is generally applicable to any final result of collision of opposing aspirations. Philosophical definition of catastrophes comes down to the destruction of the unity, accompanied by violent collision between different parts, the growing disruption, failure to prevent crossing the dangerous threshold... As a final vertex of action, disaster is not, however, directly its end: the action may continue after the catastrophe, but in the direction that is determined by the character of opposing aspirations. Major catastrophes, which have already destroyed and continue to ravage the world today, come from a superficial use of the laws of the development of complex systems and, in particular, of individual techniques of the chaos theory.

  6. The Ongoing Catastrophe

    DEFF Research Database (Denmark)

    Kublitz, Anja

    2016-01-01

    as camps. Based on fieldwork among Palestinians in the Danish camps, this article explores why my interlocutors describe their current lives as a catastrophe. Al-Nakba literally means the catastrophe and, in Palestinian national discourse, it is used to designate the event of 1948, when the Palestinians...

  7. The Ongoing Catastrophe

    DEFF Research Database (Denmark)

    Kublitz, Anja

    for the girl talk is centred on catastrophes or Nakbas, as they are referred to in Arabic. Not only al-Nakba of 1948 when the Palestinians were displaced from their homeland, but also the many recurring wars and the individual catastrophes that involve dead family members, rapes, loss of children and abusive...

  8. Habitability and cosmic catastrophes

    CERN Document Server

    Hanslmeier, Arnold; McKay, Christopher P

    2008-01-01

    Catastrophic cosmic events such as asteroid impacts appear in the range of some 100 million years and have drastically affected evolution. The author discusses whether and how such events could have occurred in recently found extrasolar planetary systems.

  9. Catastrophic Antiphospholipid Syndrome.

    Science.gov (United States)

    El-Shereef, Rawhya R; El-Abedin, Zein; Abdel Aziz, Rashad; Talat, Ibrahim; Saleh, Mohammed; Abdel-Samia, Hanna; Sameh, Amro; Sharha, Mahmoud

    2016-01-01

    This paper reports one case of successfully treated patients suffering from a rare entity, the catastrophic antiphospholipid syndrome (CAPS). Management of this patient is discussed in detail. PMID:27375916

  10. Catastrophic Antiphospholipid Syndrome

    Directory of Open Access Journals (Sweden)

    Rawhya R. El-Shereef

    2016-01-01

    Full Text Available This paper reports one case of successfully treated patients suffering from a rare entity, the catastrophic antiphospholipid syndrome (CAPS. Management of this patient is discussed in detail.

  11. Entanglement in quantum catastrophes

    CERN Document Server

    Emary, C; Brandes, T; Emary, Clive; Lambert, Neill; Brandes, Tobias

    2005-01-01

    We classify entanglement singularities for various two-mode bosonic systems in terms of catastrophe theory. Employing an abstract phase-space representation, we obtain exact results in limiting cases for the entropy in cusp, butterfly, and two-dimensional catastrophes. We furthermore use numerical results to extract the scaling of the entropy with the non-linearity parameter, and discuss the role of mixing entropies in more complex systems.

  12. Catastrophes in surface scattering

    International Nuclear Information System (INIS)

    Theoretical and experimental studies concerning atom-surface interactions in the energy range from hyperthermal to approximately 100 eV are reported. An extended study of the interaction of low energetic alkalis (sodium and potassium) with a silver crystal is presented. Finally the ultimate experimental result in this research, the first observation of catastrophes in surface scattering, is shown. The results clearly indicate the strength of the catastrophe analysis in gas-surface scattering. 218 refs.; 40 figs.; 170 schemes; 4 tabs

  13. Catastrophic Medical Expenditure Risk

    NARCIS (Netherlands)

    G. Flores (Gabriela); O.A. O'Donnell (Owen)

    2012-01-01

    textabstractMedical expenditure risk can pose a major threat to living standards. We derive decomposable measures of catastrophic medical expenditure risk from reference-dependent utility with loss aversion. We propose a quantile regression based method of estimating risk exposure from cross-section

  14. Catastrophic primary antiphospholipid syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dong Hun; Byun, Joo Nam [Chosun University Hospital, Gwangju (Korea, Republic of); Ryu, Sang Wan [Miraero21 Medical Center, Gwangju (Korea, Republic of)

    2006-09-15

    Catastrophic antiphospholipid syndrome (CAPLS) was diagnosed in a 64-year-old male who was admitted to our hospital with dyspnea. The clinical and radiological examinations showed pulmonary thromboembolism, and so thromboembolectomy was performed. Abdominal distension rapidly developed several days later, and the abdominal computed tomography (CT) abdominal scan revealed thrombus within the superior mesenteric artery with small bowel and gall bladder distension. Cholecystectomy and jejunoileostomy were performed, and gall bladder necrosis and small bowel infarction were confirmed. The anticardiolipin antibody was positive. Anticoagulant agents and steroids were administered, but the patient expired 4 weeks after surgery due to acute respiratory distress syndrome (ARDS). We report here on a case of catastrophic APLS with manifestations of pulmonary thromboembolism, rapidly progressing GB necrosis and bowel infarction.

  15. Valuing Catastrophic Citrus Losses

    OpenAIRE

    Adams, Damian C.; Kilmer, Richard L.; Moss, Charles B.; Schmitz, Andrew

    2004-01-01

    Courts are often required to estimate changes in welfare to agricultural operations from catastrophic events. For example, courts must assign damages in lawsuits, such as with pesticide drift cases, or determine "just compensation" when the government takes private land for public use, as with the removal of dairy farms from environmentally sensitive land or destruction of canker-contaminated citrus trees. In economics, the traditional method of quantifying producer losses is estimating chang...

  16. CATASTROPHIC EVENTS MODELING

    Directory of Open Access Journals (Sweden)

    Ciumas Cristina

    2013-07-01

    Full Text Available This paper presents the emergence and evolution of catastrophe models (cat models. Starting with the present context of extreme weather events and features of catastrophic risk (cat risk we’ll make a chronological illustration from a theoretical point of view of the main steps taken for building such models. In this way the importance of interdisciplinary can be observed. The first cat model considered contains three modules. For each of these indentified modules: hazard, vulnerability and financial losses a detailed overview and also an exemplification of a potential case of an earthquake that measures more than 7 on Richter scale occurring nowadays in Bucharest will be provided. The key areas exposed to earthquake in Romania will be identified. Then, based on past catastrophe data and taking into account present conditions of housing stock, insurance coverage and the population of Bucharest the impact will be quantified by determining potential losses. In order to accomplish this work we consider a scenario with data representing average values for: dwelling’s surface, location, finishing works. On each step we’ll make a reference to the earthquake on March 4 1977 to see what would happen today if a similar event occurred. The value of Bucharest housing stock will be determined taking firstly the market value, then the replacement value and ultimately the real value to quantify potential damages. Through this approach we can find the insurance coverage of potential losses and also the uncovered gap. A solution that may be taken into account by public authorities, for example by Bucharest City Hall will be offered: in case such an event occurs the impossibility of paying compensations to insured people, rebuilding infrastructure and public buildings and helping the suffering persons should be avoided. An actively public-private partnership should be created between government authorities, the Natural Disaster Insurance Pool, private

  17. RPF101, a new capsaicin-like analogue, disrupts the microtubule network accompanied by arrest in the G2/M phase, inducing apoptosis and mitotic catastrophe in the MCF-7 breast cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Sá-Júnior, Paulo Luiz de [Laboratory of Genetics, Butantan Institute, Vital Brasil Avenue 1500, Postal Code: 05503-900, Sao Paulo (Brazil); Pasqualoto, Kerly Fernanda Mesquita [Biochemistry and Biophysical Laboratory, Butantan Institute, Vital Brasil Avenue 1500, Postal Code: 05503-900, Sao Paulo (Brazil); Ferreira, Adilson Kleber [Laboratory of Genetics, Butantan Institute, Vital Brasil Avenue 1500, Postal Code: 05503-900, Sao Paulo (Brazil); Tavares, Maurício Temotheo; Damião, Mariana Celestina Frojuello Costa Bernstorff [Department of Pharmacy, School of Pharmaceutical Sciences, University of Sao Paulo, Prof. Lineu Prestes Avenue, 580, Postal Code: 05508-000, Sao Paulo (Brazil); Azevedo, Ricardo Alexandre de [Biochemistry and Biophysical Laboratory, Butantan Institute, Vital Brasil Avenue 1500, Postal Code: 05503-900, Sao Paulo (Brazil); Câmara, Diana Aparecida Dias; Pereira, Alexandre; Madeiro de Souza, Dener [Laboratory of Genetics, Butantan Institute, Vital Brasil Avenue 1500, Postal Code: 05503-900, Sao Paulo (Brazil); Parise Filho, Roberto, E-mail: roberto.parise@usp.br [Department of Pharmacy, School of Pharmaceutical Sciences, University of Sao Paulo, Prof. Lineu Prestes Avenue, 580, Postal Code: 05508-000, Sao Paulo (Brazil)

    2013-02-01

    Breast cancer is the world's leading cause of death among women. This situation imposes an urgent development of more selective and less toxic agents. The use of natural molecular fingerprints as sources for new bioactive chemical entities has proven to be a quite promising and efficient method. Capsaicin, which is the primary pungent compound in red peppers, was reported to selectively inhibit the growth of a variety tumor cell lines. Here, we report for the first time a novel synthetic capsaicin-like analogue, RPF101, which presents a high antitumor activity on MCF-7 cell line, inducing arrest of the cell cycle at the G2/M phase through a disruption of the microtubule network. Furthermore, it causes cellular morphologic changes characteristic of apoptosis and a decrease of Δψm. Molecular modeling studies corroborated the biological findings and suggested that RPF101, besides being a more reactive molecule towards its target, may also present a better pharmacokinetic profile than capsaicin. All these findings support the fact that RPF101 is a promising anticancer agent. -- Highlights: ► We report for the first time that RPF101 possesses anticancer properties. ► RPF101 induces apoptosis of human breast cancer cells. ► RPF 101 decreases mitochondrial potential and induces DNA fragmentation.

  18. Catastrophic pediatric sports injuries.

    Science.gov (United States)

    Luckstead, Eugene F; Patel, Dilip R

    2002-06-01

    The high school sports of wrestling, gymnastics, ice hockey, baseball, track, and cheerleading should receive closer attention to prevent injury. Safer equipment and sport-specific conditioning should be provided and injuries strictly monitored. Greater attention must also be paid to swimming and diving techniques, and continued observation is needed for heat stroke and heat intolerance in sports such as football, wrestling, basketball, track and field, and cross-country. An increased awareness of commotio cordis in sports other than baseball should include ice hockey, football, track field events, and lacrosse. American football because of the sheer numbers and associated catastrophic injury potential must continue to be monitored at the highest medical levels! PMID:12119866

  19. Catastrophic senescence and semelparity in the Penna aging model

    CERN Document Server

    Pinol, C M N

    2010-01-01

    The catastrophic senescence of the Pacific salmon is among the initial tests used to validate the Penna aging model. Based on the mutation accumulation theory, the sudden decrease in fitness following reproduction may be solely attributed to the semelparity of the species. In this work, we report other consequences of mutation accumulation. Contrary to earlier findings, such dramatic manifestation of aging depends not only on the choice of breeding strategy but also on the value of the reproduction age, R, and the mutation threshold, T. Senescence is catastrophic when T\\leq R. As the organism's tolerance for harmful genetic mutations increases, the aging process becomes more gradual. We observe senescence that is threshold dependent whenever T>R. That is, the sudden drop in survival rate occurs at age equal to the mutation threshold value.

  20. Numerical simulations of collisional disruption of rotating gravitational aggregates: Dependence on material properties

    Science.gov (United States)

    Ballouz, R.-L.; Richardson, D. C.; Michel, P.; Schwartz, S. R.; Yu, Y.

    2015-03-01

    Our knowledge of the strengths of small bodies in the Solar System is limited by our poor understanding of their internal structures, and this, in turn, clouds our understanding of the formation and evolution of these bodies. Observations of the rotational states of asteroids whose diameters are larger than a few hundreds of meters have revealed that they are dominated by gravity and that most are unlikely to be monoliths; however, there is a wide range of plausible internal structures. Numerical and analytical studies of shape and spin limits of gravitational aggregates and their collisional evolution show a strong dependence on shear strength. In order to study this effect, we carry out a systematic exploration of the dependence of collision outcomes on dissipation and friction parameters of the material components making up the bodies. We simulate the catastrophic disruption (leading to the largest remnant retaining 50% of the original mass) of km-size asteroids modeled as gravitational aggregates using pkdgrav, a cosmology N-body code adapted to collisional problems and recently enhanced with a new soft-sphere collision algorithm that includes more realistic contact forces. We find that for a range of three different materials, higher friction and dissipation values increase the catastrophic disruption threshold by about half a magnitude. Furthermore, we find that pre-impact rotation systematically increases mass loss on average, regardless of the target's internal configuration. Our results have important implications for the efficiency of planet formation via planetesimal growth, and also more generally to estimate the impact energy threshold for catastrophic disruption, as this generally has only been evaluated for non-spinning bodies without detailed consideration of material properties.

  1. Impact disruption of gravity-dominated bodies: New simulation data and scaling

    Science.gov (United States)

    Movshovitz, N.; Nimmo, F.; Korycansky, D. G.; Asphaug, E.; Owen, J. M.

    2016-09-01

    We present results from a suite of 169 hydrocode simulations of collisions between planetary bodies with radii from 100 to 1000 km. The simulation data are used to derive a simple scaling law for the threshold for catastrophic disruption, defined as a collision that leads to half the total colliding mass escaping the system post impact. For a target radius 100 ≤ RT ≤ 1000km and a mass MT and a projectile radius rp ≤ RT and mass mp we find that a head-on impact with velocity magnitude v is catastrophic if the kinetic energy of the system in the center of mass frame, K = 0.5MTmpv2 /(MT +mp) , exceeds a threshold value K* that is a few times U =(3 / 5) G MT2/RT +(3 / 5) G mp2 /rp + GMTmp /(RT +rp) , the gravitational binding energy of the system at the moment of impact; G is the gravitational constant. In all head-on collision runs we find K* =(5.5 ± 2.9) U . Oblique impacts are catastrophic when the fraction of kinetic energy contained in the volume of the projectile intersecting the target during impact exceeds ∼2 K* for 30° impacts and ∼3.5 K* for 45° impacts. We compare predictions made with this scaling to those made with existing scaling laws in the literature extrapolated from numerical studies on smaller targets. We find significant divergence between predictions where in general our results suggest a lower threshold for disruption except for highly oblique impacts with rp ≪ RT. This has implications for the efficiency of collisional grinding in the asteroid belt (Morbidelli et al., [2009] Icarus, 204, 558-573), Kuiper belt (Greenstreet et al., [2015] Icarus, 258, 267-288), and early Solar System accretion (Chambers [2013], Icarus, 224, 43-56).

  2. Strategic reasoning and bargaining in catastrophic climate change games

    Science.gov (United States)

    Verendel, Vilhelm; Johansson, Daniel J. A.; Lindgren, Kristian

    2016-03-01

    Two decades of international negotiations show that agreeing on emission levels for climate change mitigation is a hard challenge. However, if early warning signals were to show an upcoming tipping point with catastrophic damage, theory and experiments suggest this could simplify collective action to reduce greenhouse gas emissions. At the actual threshold, no country would have a free-ride incentive to increase emissions over the tipping point, but it remains for countries to negotiate their emission levels to reach these agreements. We model agents bargaining for emission levels using strategic reasoning to predict emission bids by others and ask how this affects the possibility of reaching agreements that avoid catastrophic damage. It is known that policy elites often use a higher degree of strategic reasoning, and in our model this increases the risk for climate catastrophe. Moreover, some forms of higher strategic reasoning make agreements to reduce greenhouse gases unstable. We use empirically informed levels of strategic reasoning when simulating the model.

  3. Global Catastrophes in Perspective: Asteroid Impacts vs Climate Change

    Science.gov (United States)

    Boslough, M. B.; Harris, A. W.

    2008-12-01

    When allocating resources to address threats, decision makers are best served by having objective assessments of the relative magnitude of the threats in question. Asteroids greater than about 1 km in diameter are assumed by the planetary impact community to exceed a "global catastrophe threshold". Impacts from smaller objects are expected to cause local or regional destruction, and would be the proximate cause of most associated fatalities. Impacts above the threshold would be expected to alter the climate, killing billions of people and causing a collapse of civilization. In this apocalyptic scenario, only a small fraction of the casualties would be attributable to direct effects of the impact: the blast wave, thermal radiation, debris, ground motion, or tsunami. The vast majority of deaths would come later and be due to indirect causes: starvation, disease, or violence as a consequence of societal disruption related to the impact-induced global climate change. The concept of a catastrophe threshold comes from "nuclear winter" studies, which form the basis for quantitative estimates of the consequences of a large impact. The probability estimates come from astronomical observations and statistical analysis. Much of the impact threat, at its core, is a climate-change threat. Prior to the Spaceguard Survey of Near-Earth Objects (NEOs), the chance of dying from an asteroid impact was estimated to be 1 in 25,000 (Chapman & Morrison, 1994). Most of the large asteroids have now been discovered, and none is on an impact trajectory. Moreover, new data show that mid-sized asteroids (tens to hundreds of meters across) are less abundant than previously thought, by a factor of three. We now estimate that the lifetime odds of being killed by the impact of one of the remaining undiscovered NEOs are about one in 720,000 for individuals with a life expectancy of 80 years (Harris, 2008). One objective way to compare the relative magnitude of the impact threat to that of

  4. SPH calculations of asteroid disruptions: The role of pressure dependent failure models

    CERN Document Server

    Jutzi, Martin

    2015-01-01

    We present recent improvements of the modeling of the disruption of strength dominated bodies using the Smooth Particle Hydrodynamics (SPH) technique. The improvements include an updated strength model and a friction model, which are successfully tested by a comparison with laboratory experiments. In the modeling of catastrophic disruptions of asteroids, a comparison between old and new strength models shows no significant deviation in the case of targets which are initially non-porous, fully intact and have a homogeneous structure (such as the targets used in the study by Benz&Asphaug (1999). However, for many cases (e.g. initially partly or fully damaged targets, rubble-pile structures, etc.) we find that it is crucial that friction is taken into account and the material has a pressure dependent shear strength. Our investigations of the catastrophic disruption threshold $Q^*_{D}$ as a function of target properties and target sizes up to a few 100 km show that a fully damaged target modeled without frict...

  5. Pain catastrophizing: a critical review.

    Science.gov (United States)

    Quartana, Phillip J; Campbell, Claudia M; Edwards, Robert R

    2009-05-01

    Pain catastrophizing is conceptualized as a negative cognitive-affective response to anticipated or actual pain and has been associated with a number of important pain-related outcomes. In the present review, we first focus our efforts on the conceptualization of pain catastrophizing, highlighting its conceptual history and potential problem areas. We then focus our discussion on a number of theoretical mechanisms of action: appraisal theory, attention bias/information processing, communal coping, CNS pain processing mechanisms, psychophysiological pathways and neural pathways. We then offer evidence to suggest that pain catastrophizing represents an important process factor in pain treatment. We conclude by offering what we believe represents an integrated heuristic model for use by researchers over the next 5 years; a model we believe will advance the field most expediently. PMID:19402782

  6. Modelling Catastrophic Risk in International Equity Markets: An Extreme Value Approach

    OpenAIRE

    COTTER John

    2011-01-01

    This letter uses the Block Maxima Extreme Value approach to quantify catastrophic risk in international equity markets. Risk measures are generated from a set threshold of the distribution of returns that avoids the pitfall of using absolute returns for markets exhibiting diverging levels of risk. From an application to leading markets, the letter finds that the Nikkei is more prone to catastrophic risk than the FTSE and Dow Jones Indexes.

  7. The Climate Catastrophe as Blockbuster

    DEFF Research Database (Denmark)

    Eskjær, Mikkel Fugl

    2013-01-01

    Modern disaster films constitute a specific cultural form that speaks to the anxieties of the “risk society.” This essay looks at how risks like climate change is presented and constructed in popular culture. It regards blockbuster representations as part of a wider discourse of “catastrophism...

  8. Severe catastrophes and public reactions

    International Nuclear Information System (INIS)

    nuclear opposition. Economical basis of nuclear energy stagnation is in not very successful competition of nuclear engineering with fossil energy production technologies. Much money has been spent for improvement of safety of NPPs. Social roots of the opposition are linked with a bad experience of the public with demonstration of the nuclear energy- The explosion of atomic bombs, some contamination of the territories after nuclear arm tests, misfortunes with TMI-2 and Chernobyl have created a stable enmity and non-acceptance of the all connected with 'atom'. The mass media have strongly promoted the dissemination of the fear of radiation exposures. There is also an influence on that attitude the radiation protection regulation via the declaration of the linear no-threshold dependence of the radiation detriments and dose of exposure. Such concept ignores the adoptive features of all living. But modem studies have showed that protracted irradiation at the same dose is much less dangerous compared with sharp one. It could change public attitude to nuclear energy in the society. Role of nuclear communication for public informing: The reactions of public on various technological and man-made events differ significantly and are being determined not scales of catastrophes but the mental impression and a multiplication of psychological stresses in the society by mass -media. In present situation a nuclear community has to improve the contacts with the pubic, to launch more effective campaign for explanation of real adventures of nuclear power. It needs to compare the risks of climate warming and health detriments from different electricity production technologies and to show that nuclear power is a single alternative all fossil burning techniques of electricity production. It's the truth the nuclear power is a real method of fight for suppression of emission the greenhouse gases, isn't it? (author)

  9. THE CATASTROPHIC RISK REINSURANCE: FOREIGN EXPERIENCE

    Directory of Open Access Journals (Sweden)

    T. Tatarina

    2014-03-01

    Full Text Available The article deals with foreign experience of catastrophic risks reinsurance. The directions to ensure savings and increase capitalization of insurance companies under reinsurance protection. The necessary of catastrophic risk reinsurance in Ukraine has brought.

  10. Madame Bovary and Catastrophism: Revolving narratives

    Directory of Open Access Journals (Sweden)

    Ruth Morris

    2011-07-01

    Bovary within the scientific milieu of 1850s French society by reading Flaubert’s narrative as a Cuverian text. The French scientist Georges Cuvier, along with many of his contemporaries, formulated the catastrophist theory as a means of explaining the origins of the world. In catastrophism, the world is divided into very discrete time periods which are punctuated by vast catastrophes, or in Cuverian terminology ‘revolutions’ that have eradicated life and enabled the world to be repopulated afresh. This has implications for the concept of ‘time’. Cuvier theorises the earth as being relatively recent in origin, with the present epoch being only five thousand years old. This compression of time can be inferred in Madame Bovary through references to rapidity and the tempo which increases towards the denouement. In catastrophism and Madame Bovary, time is not constructed in a linear or chronological manner. The ‘revolutions’ disrupt a realisation of continuous time and Emma is frequently unable to distinguish between past, present and future experiences. The ‘revolutions’ also serve to puncture and disrupt the status quo of life by creating massive events within the earth’s history. Emma’s life too parallels this. She regards her existence as being informed by magnitudinous events, such as the ball, which creates dislocated and fragmented time as in Cuviers’ theory. I will also argue for a connection between the suddenness and violence of the ‘revolutions’ and Emma Bovary’s emotional outbursts which occur without for-warning and border on the hysterical. A Cuverian concept of time has implications for other considerations which are arguably the main differences between catastrophism and evolution theory. These include the notions of adaptation, inheritance and death within Flaubert’s narrative.

  11. Disaster risk insurance and catastrophe models in risk-prone small Caribbean islands.

    Science.gov (United States)

    Joyette, Antonio R T; Nurse, Leonard A; Pulwarty, Roger S

    2015-07-01

    Post-catastrophe recovery and financial liquidity have long challenged small Caribbean islands. These states are vulnerable to multifarious natural hazards that often cause considerable socioeconomic dislocation. Such events inflict heavy losses on businesses and households, and significantly disrupt all aspects of government operations. After Hurricane Ivan devastated the economies of some islands in September 2004-with estimated losses of as much as 200 per cent of gross domestic product in some cases-regional governments, aided by the World Bank and international donors, approved the creation of a regional catastrophe insurance scheme. This parametric-based mechanism is underpinned by derivatives-based catastrophe modelling whose outputs determine policy triggers and pay outs. Hazard models, particularly catastrophe models, are not widely accepted as yet. Despite recent advancements, major concerns have rendered them peripheral tools for many establishments. This paper reviews the region's vulnerabilities and examines constraints on the application of these models and suggests a means of improving their efficacy and acceptability.

  12. Catastrophic events and older adults.

    Science.gov (United States)

    Cloyd, Elizabeth; Dyer, Carmel B

    2010-12-01

    The plight of older adults during catastrophic events is a societal concern. Older persons have an increased prevalence of cognitive disorders, chronic illnesses, and mobility problems that limit their ability to cope. These disorders may result in a lack of mental capacity and the ability to discern when they should evacuate or resolve problems encountered during a catastrophe. Some older persons may have limited transportation options, and many of the elderly survivors are at increased risk for abuse, neglect, and exploitation. Recommendations for future catastrophic events include the development of a federal tracking system for elders and other vulnerable adults, the designation of separate shelter areas for elders and other vulnerable adults, and involvement of gerontological professionals in all aspects of emergency preparedness and care delivery, including training of frontline workers. Preparation through preevent planning that includes region-specific social services, medical and public health resources, volunteers, and facilities for elders and vulnerable adults is critical. Elders need to be protected from abuse and fraud during catastrophic events. A public health triage system for elders and other vulnerable populations in pre- and postdisaster situations is useful, and disaster preparedness is paramount. Communities and members of safety and rescue teams must address ethical issues before an event. When older adults are involved, consideration needs to be given to triage decision making, transporting those who are immobile, the care of older adults who receive palliative care, and the equitable distribution of resources. Nurses are perfectly equipped with the skills, knowledge, and training needed to plan and implement disaster preparedness programs. In keeping with the tradition of Florence Nightingale, nurses can assume several crucial roles in disaster preparedness for older adults. Nurses possess the ability to participate and lead community

  13. The Diseconomies of Environmental Catastrophes

    OpenAIRE

    Cairns, John

    2006-01-01

    Four factors are almost certain to lead to one or more catastrophes unless major remedial measures are taken. (1) China has replaced the United States as the world s leading consumer of resources, except for oil (Brown, 2006a), but China is already a major factor in the world market in this area also. Together, China and the United States consume approximately half the world s resources and the global population is still increasing on a finite planet. (2) The over 20% global ecological oversh...

  14. Catastrophic Evaporation of Rocky Planets

    CERN Document Server

    Perez-Becker, Daniel

    2013-01-01

    Short-period exoplanets can have dayside surface temperatures surpassing 2000 K, hot enough to vaporize rock and drive a thermal wind. Small enough planets evaporate completely. We construct a radiative-hydrodynamic model of atmospheric escape from strongly irradiated, low-mass rocky planets, accounting for dust-gas energy exchange in the wind. Rocky planets with masses 2000 K are found to disintegrate entirely in 0.1 M_Earth/Gyr --- our model yields a present-day planet mass of < 0.02 M_Earth or less than about twice the mass of the Moon. Mass loss rates depend so strongly on planet mass that bodies can reside on close-in orbits for Gyrs with initial masses comparable to or less than that of Mercury, before entering a final short-lived phase of catastrophic mass loss (which KIC 12557548b has entered). Because this catastrophic stage lasts only up to a few percent of the planet's life, we estimate that for every object like KIC 12557548b, there should be 10--100 close-in quiescent progenitors with sub-da...

  15. Extensional rheometer based on viscoelastic catastrophes outline

    DEFF Research Database (Denmark)

    2014-01-01

    The present invention relates to a method and a device for determining viscoelastic properties of a fluid. The invention resides inter alia in the generation of viscoelastic catastrophes in confined systems for use in the context of extensional rheology. The viscoelastic catastrophe is according to...... the invention generated in a bistable fluid system, and the flow conditions for which the catastrophe occurs can be used as a fingerprint of the fluid's viscoelastic properties in extensional flow....

  16. One day at a time: The impact of daily satisfaction with spouse responses on pain, negative affect and catastrophizing among individuals with rheumatoid arthritis.

    Science.gov (United States)

    Holtzman, Susan; Delongis, Anita

    2007-09-01

    The majority of research on pain catastrophizing has focused on its negative consequences for adjustment to chronic pain, with few investigations of factors that influence catastrophizing or its detrimental effects. Using a daily process methodology, the current study examined, first, the extent to which a supportive social environment plays a role in reduced catastrophizing, and second, the extent to which support might protect against the detrimental effects of catastrophizing on well-being. Sixty-nine married individuals with rheumatoid arthritis took part in an initial background interview, followed by twice daily telephone interviews (regarding pain intensity, negative affect, catastrophizing and satisfaction with spouse responses) for 1 week. Multi-level modeling indicated several pathways through which satisfaction with spouse responses disrupts the vicious cycle of pain, negative affect and catastrophizing. Consistent with past research, catastrophizing was associated with increases in pain and negative affect. However, when individuals reported increases in satisfaction with spouse responses they were less likely to experience increases in negative affect due to catastrophizing. Satisfaction with spouse responses also reduced the likelihood of feeling overwhelmed and helpless in dealing with daily pain. The relationship between pain and catastrophizing was attenuated in the context of increases in satisfaction with spouse responses. Negative affect was associated with increases in catastrophizing, but only when individuals reported decreases in satisfaction with spouse responses. Overall, findings were consistent with a model in which satisfaction with spouse responses serves as a coping resource, and suggests the importance of involving close others in treatments to reduce pain and catastrophizing.

  17. Catastrophe mechanism & classification of discontinuity behavior in thermal science (Ⅰ) --Fold catastrophe

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The mechanism of discontinuity behavior has important significance in the study of thermal science,such as fire,combustion,explosion and heat transfer.This sort of discontinuity behavior and the catastrophe caused by system nonlinearity may be equivalently classified according to the catastrophe model promulgated by catastrophe theory.Under the conditions of uniform temperature and thermal isolation,the self-ignition behavior of a Semenov System can be viewed as a result of the fold catastrophe of the system.

  18. Disrupting Vestibular Activity Disrupts Body Ownership.

    Science.gov (United States)

    Hoover, Adria E N; Harris, Laurence R

    2015-01-01

    People are more sensitive at detecting asynchrony between a self-generated movement and visual feedback concerning that movement when the movement is viewed from a first-person perspective. We call this the 'self-advantage' and interpret it as an objective measure of self. Here we ask if disruption of the vestibular system in healthy individuals affects the self-advantage. Participants performed finger movements while viewing their hand in a first-person ('self') or third-person ('other') perspective and indicated which of two periods (one with minimum delay and the other with an added delay of 33-264 ms) was delayed. Their sensitivity to the delay was calculated from the psychometric functions obtained. During the testing, disruptive galvanic vestibular stimulation (GVS) was applied in five-minute blocks interleaved with five minutes of no stimulation for a total of 40 min. We confirmed the self-advantage under no stimulation (31 ms). In the presence of disruptive GVS this advantage disappeared and there was no longer a difference in performance between perspectives. The threshold delay for the 'other' perspective was not affected by the GVS. These results suggest that an intact vestibular signal is required to distinguish 'self' from 'other' and to maintain a sense of body ownership. PMID:26595957

  19. From a Catastrophe Itself to Cata/strophic Reading. The Poetry of Charles Baudelaire in the Account of Jorge Semprúna L’écriture ou la vie

    Directory of Open Access Journals (Sweden)

    Judith Kasper

    2015-01-01

    Full Text Available This essay addresses the instable meaning of the term catastrophe over the course of history. The first part takes leave of the “the tiny fissures” in the continuous catastrophe noted by Walter Benjamin to develop a philology of the cata/strophe. This philology does not only register a given meaning (for instance, of the catastrophe, but intervenes actively as disruption. It insists on the strophe in the catastrophe, transforming catastrophe into cata/strophe that, in fatal situations, permits the poetic potential to become a dynamic force that can, at least on the linguistic level, open toward other dimensions without denying the catastrophe itself. The second part is dedicated to a reading of Jorge Semprún’s autobiographical novel L’écriture ou la vie from the perspective of this philological concept. It seeks to show how Semprún’s citing and reciting of Baudelaire’s strophes in the putrid atmosphere of the Buchenwald concentration camp literally produce, on the level of the signifiers, fresh air to breathe.

  20. Academic Training: Predicting Natural Catastrophes

    CERN Multimedia

    Françoise Benz

    2005-01-01

    2005-2006 ACADEMIC TRAINING PROGRAMME LECTURE SERIES 12, 13, 14, 15, 16 December from 11:00 to 12:00 - Main Auditorium, bldg. 500 Predicting Natural Catastrophes E. OKAL / Northwestern University, Evanston, USA 1. Tsunamis -- Introduction Definition of phenomenon - basic properties of the waves Propagation and dispersion Interaction with coasts - Geological and societal effects Origin of tsunamis - natural sources Scientific activities in connection with tsunamis. Ideas about simulations 2. Tsunami generation The earthquake source - conventional theory The earthquake source - normal mode theory The landslide source Near-field observation - The Plafker index Far-field observation - Directivity 3. Tsunami warning General ideas - History of efforts Mantle magnitudes and TREMOR algorithms The challenge of 'tsunami earthquakes' Energy-moment ratios and slow earthquakes Implementation and the components of warning centers 4. Tsunami surveys Principles and methodologies Fifteen years of field surveys and re...

  1. Family Disruptions

    Science.gov (United States)

    ... Spread the Word Shop AAP Find a Pediatrician Family Life Medical Home Family Dynamics Adoption & Foster Care ... Life Listen Español Text Size Email Print Share Family Disruptions Page Content Article Body No matter how ...

  2. Sustainable Disruptions

    DEFF Research Database (Denmark)

    Friis, Silje Alberthe Kamille; Kjær, Lykke Bloch

    2016-01-01

    Since 2012 the Sustainable Disruptions (SD) project at the Laboratory for Sustainability at Design School Kolding (DK) has developed and tested a set of design thinking tools, specifically targeting the barriers to economically, socially, and environmentally sustainable business development...

  3. Disrupted Disclosure

    DEFF Research Database (Denmark)

    Krause Hansen, Hans; Uldam, Julie

    appearances become challenged through disruptive disclosures in mediaenvironments characterized by multiple levels of visibility, with companies both observing andbeing observed by civil society groups that criticize them; (c) why and how the mobilization aroundtransparency and ensuing practices...

  4. Climate Catastrophe - The Giant Swindle

    International Nuclear Information System (INIS)

    Energy is the life-blood of civilization. More than 80% of global energy is supplied by fossil fuels. And this will continue for the foreseeable future - if an implementation of the Kyoto Protocol does not lead to a dramatic decrease of these fuels causing worldwide turmoil of unprecedented dimensions. However, the scaremongering with a 'climate catastrophe' allegedly caused by 'greenhouse gas' emissions from the burning of fossil fuels is a huge hoax. Its only 'scientific' base is the IPCC management's enigmatic assessment: 'The balance of evidence suggests a discernable human influence on climate'. But even IPCC had to admit at the World Energy Conference in Tokyo in 1996: 'We have no evidence'. And all the scaremongering assertions of the protagonists of 'global warming' have been convincingly refuted by the world elite of scientists. This paper will: - show how the whole anti-CO2 campaign has been manipulated from the very beginning till today; - give great many scientific and logical reason why the arguments of the scaremongers are incorrect; - outline the catastrophic economic and social consequences of the proposed anti-CO2 measures - without any benefit for the environment of climate; - name the driving forces behind this campaign and their interests. The witchhunt against CO2 is an incredible scientific and political scandal, CO2 does not damage the environment at all, and labelling it a 'climate killer' is absurd. On the contrary, this gas is vital for the life on our plant, and a stronger concentration of CO2 will be beneficial by doubling plant growth and with this combatting global famine. And to pretend that we could influence - with a CO2 tax - the climate, is insane arrogance. Man is absolutely helpless when confronted with the forces of nature. The squandering of multimillions USD of taxpayer's money for the travelling circus of 'Climate summits' and the stultification of the population must stop. The 'global warming' lie is the biggest

  5. Adaptation to and Recovery from Global Catastrophe

    Directory of Open Access Journals (Sweden)

    Seth D. Baum

    2013-03-01

    Full Text Available Global catastrophes, such as nuclear war, pandemics and ecological collapse threaten the sustainability of human civilization. To date, most work on global catastrophes has focused on preventing the catastrophes, neglecting what happens to any catastrophe survivors. To address this gap in the literature, this paper discusses adaptation to and recovery from global catastrophe. The paper begins by discussing the importance of global catastrophe adaptation and recovery, noting that successful adaptation/recovery could have value on even astronomical scales. The paper then discusses how the adaptation/recovery could proceed and makes connections to several lines of research. Research on resilience theory is considered in detail and used to develop a new method for analyzing the environmental and social stressors that global catastrophe survivors would face. This method can help identify options for increasing survivor resilience and promoting successful adaptation and recovery. A key point is that survivors may exist in small isolated communities disconnected from global trade and, thus, must be able to survive and rebuild on their own. Understanding the conditions facing isolated survivors can help promote successful adaptation and recovery. That said, the processes of global catastrophe adaptation and recovery are highly complex and uncertain; further research would be of great value.

  6. Catastrophizing delays the analgesic effect of distraction.

    Science.gov (United States)

    Campbell, Claudia M; Witmer, Kenny; Simango, Mpepera; Carteret, Alene; Loggia, Marco L; Campbell, James N; Haythornthwaite, Jennifer A; Edwards, Robert R

    2010-05-01

    Behavioral analgesic techniques such as distraction reduce pain in both clinical and experimental settings. Individuals differ in the magnitude of distraction-induced analgesia, and additional study is needed to identify the factors that influence the pain relieving effects of distraction. Catastrophizing, a set of negative emotional and cognitive processes, is widely recognized to be associated with increased reports of pain. We sought to evaluate the relationship between catastrophizing and distraction analgesia. Healthy participants completed three sessions in a randomized order. In one session (Pain Alone), pain was induced by topical application of a 10% capsaicin cream and simultaneous administration of a tonic heat stimulus. In another session (Pain+Distraction), identical capsaicin+heat application procedures were followed, but subjects played video games that required a high level of attention. During both sessions, verbal ratings of pain were obtained and participants rated their degree of catastrophizing. During the other session (Distraction Alone) subjects played the video games in the absence of any pain stimulus. Pain was rated significantly lower during the distraction session compared to the "Pain Alone" session. In addition, high catastrophizers rated pain significantly higher regardless of whether the subjects were distracted. Catastrophizing did not influence the overall degree of distraction analgesia; however, early in the session high catastrophizers had little distraction analgesia, though later in the session low and high catastrophizers rated pain similarly. These results suggest that both distraction and catastrophizing have substantial effects on experimental pain in normal subjects and these variables interact as a function of time.

  7. Environmental Catastrophes Under Time-inconsistent Preferences

    NARCIS (Netherlands)

    Michielsen, T.O.

    2013-01-01

    Abstract I analyze optimal natural resource use in an intergenerational model with the risk of a catastrophe. Each generation maximizes a weighted sum of discounted utility (positive) and the probability that a catastrophe will occur at any point in the future (negative). The model generates time-in

  8. Fracto—emissions in Catastrophic Cleavage Process

    Institute of Scientific and Technical Information of China (English)

    HonglaiTAN; WeiYANG

    1996-01-01

    Fracto-emissions accompanying crack propagation are observed in the recent experiments.The energy impulses during and after fracture stimulate the fracto-emissions.Model concerning atomic scale cleavage processes is proposed to formulate a catastrophic fracure theory relevant to these phenomena.A criterion for catastrophic jump of the cleavage potential is applied to representative crystals.

  9. Catastrophe mechanism and classification of discontinuity behavior in thermal science (Ⅱ) -- Cusp catastrophe

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The catastrophe mechanisms of thermal performance characteristics of the firebox gas combustion system were analyzed from the viewpoint of catastrophe theory. The mathematical models of cusp catastrophe were established. The relationship between the thermal performance characteristics and the changing of system control variables was studied. The cusp catastrophe mechanisms of typical performance characteristics, such as kicking and lagging, and those of transition from quenching to igniting were explained. It was illustrated that discontinuity behavior of thermal systems with an "S" motion feature curve and lagging feature may be equivalently classified according to the topology of cusp catastrophe, influenced by two groups of independent control variables.

  10. Disrupting Business

    DEFF Research Database (Denmark)

    Cox, Geoff; Bazzichelli, Tatiana

    Disruptive Business explores some of the interconnections between art, activism and the business concept of disruptive innovation. With a backdrop of the crisis of financial capitalism, austerity cuts in the cultural sphere, the idea is to focus on potential art strategies in relation to a broken...... economy. In a perverse way, we ask whether this presents new opportunities for cultural producers to achieve more autonomy over their production process. If it is indeed possible, or desirable, what alternative business models emerge? The book is concerned broadly with business as material for reinvention...

  11. CATASTROPHIC ECO-ENVIRONMENTAL CHANGE IN THE SONGNEN PLAIN, NORTHEASTERN CHINA SINCE 1900S

    Institute of Scientific and Technical Information of China (English)

    WANG Hai-xia; WAN Zhong-juan; YU Shao-peng; LUO Xin-zheng; SUN Guang-you

    2004-01-01

    Although the Songnen Plain in the northeastern China was developed relatively late in the temperate zone of the world, its eco-environment has changed greatly. This paper analyzes the changes of land cover and the rates and trends ofdesertification during the past 100 years in the Songnen Plain. According to the macroscopic analysis, we find that the eco-environment in the plain has reached to the threshold of catastrophic change since the 1950s. The Thom Needle Catastrophic Model was used to determine and validate this conclusion. Human activities, including large-scale construction projects, such as huge dams and dikes, and excessive grazing were the primary factors contributing to regional eco-environmental catastrophe. And irrational reclamation of the wilderness also affected the eco-environmental change. The results reveal the complex human-land interactions.

  12. Catastrophes in Scale-Free Networks

    Institute of Scientific and Technical Information of China (English)

    ZHOU Tao; WANG Bing-Hong

    2005-01-01

    @@ An alternative model about cascading occurrences caused by perturbation is established to search the mechanism because catastrophes in networks occur. We investigate the avalanche dynamics of our model on two-dimensional Euclidean lattices and scale-free networks and find that the avalanche dynamic behaviour is sensitive to the topological structure of networks. The simulation results show that the catastrophes occur much more frequently in scale-free networks than those in Euclidean lattices, and the greatest catastrophe in scale-free networks is much more serious than that in Euclidean lattices. Furthermore, we have studied how to reduce the catastrophes'degree, and have schemed out an effective strategy, called the targeted safeguard strategy for scale-free networks.

  13. Catastrophic event modeling. [lithium thionyl chloride batteries

    Science.gov (United States)

    Frank, H. A.

    1981-01-01

    A mathematical model for the catastrophic failures (venting or explosion of the cell) in lithium thionyl chloride batteries is presented. The phenomenology of the various processes leading to cell failure is reviewed.

  14. Insuring catastrophes and the role of governments

    Directory of Open Access Journals (Sweden)

    M. M. Boyer

    2013-08-01

    Full Text Available In this paper we model the cost of providing insurance coverage against natural and man-made hazards. We propose an insurance market model that explains (1 the use of reinsurance to help finance the cost of catastrophic events and (2 the implicit (or explicit presence of government entities acting as (reinsurers of last resort. Using an economic model, we show how insurance programmes should be designed to cover the losses due to a possible catastrophic natural hazard. Our results show that the optimal structure of a reinsurance programme minimizes the cost of offering insurance protection. We also show how government intervention can reduce the cost of insurance against natural catastrophes and increase policyholders' welfare. Our paper therefore offers public policy implications as to the role and presence of government as an insurer of last resort and the minimum insurance premium necessary to cover the cost of catastrophic events.

  15. Valuing Catastrophe Bonds Involving Credit Risks

    OpenAIRE

    Jian Liu; Jihong Xiao; Lizhao Yan; Fenghua Wen

    2014-01-01

    Catastrophe bonds are the most important products in catastrophe risk securitization market. For the operating mechanism, CAT bonds may have a credit risk, so in this paper we consider the influence of the credit risk on CAT bonds pricing that is different from the other literature. We employ the Jarrow and Turnbull method to model the credit risks and get access to the general pricing formula using the Extreme Value Theory. Furthermore, we present an empirical pricing study of the Property C...

  16. The Economic and Policy Consequences of Catastrophes

    OpenAIRE

    Robert S. Pindyck; Neng Wang

    2013-01-01

    How likely is a catastrophic event that would substantially reduce the capital stock, GDP, and wealth? How much should society be willing to pay to reduce the probability or impact of a catastrophe? We answer these questions and provide a framework for policy analysis using a general equilibrium model of production, capital accumulation, and household preferences. Calibrating the model to economic and financial data, we estimate the mean arrival rate of shocks and their size distribution, the...

  17. Catastrophic avalanches and methods of their control

    Directory of Open Access Journals (Sweden)

    N. A. Volodicheva

    2014-01-01

    Full Text Available Definition of such phenomenon as “catastrophic avalanche” is presented in this arti-cle. Several situations with releases of catastrophic avalanches in mountains of Caucasus, Alps, and Central Asia are investigated. Materials of snow-avalanche ob-servations performed since 1960s at the Elbrus station of the Lomonosov Moscow State University (Central Caucasus were used for this work. Complex-valued measures of engineering protection demonstrating different efficiencies are consid-ered.

  18. Mindfulness, acceptance and catastrophizing in chronic pain.

    Directory of Open Access Journals (Sweden)

    Maaike J de Boer

    Full Text Available OBJECTIVES: Catastrophizing is often the primary target of the cognitive-behavioral treatment of chronic pain. Recent literature on acceptance and commitment therapy (ACT suggests an important role in the pain experience for the concepts mindfulness and acceptance. The aim of this study is to examine the influence of mindfulness and general psychological acceptance on pain-related catastrophizing in patients with chronic pain. METHODS: A cross-sectional survey was conducted, including 87 chronic pain patients from an academic outpatient pain center. RESULTS: The results show that general psychological acceptance (measured with the AAQ-II is a strong predictor of pain-related catastrophizing, independent of gender, age and pain intensity. Mindfulness (measured with the MAAS did not predict levels of pain-related catastrophizing. DISCUSSION: Acceptance of psychological experiences outside of pain itself is related to catastrophizing. Thus, acceptance seems to play a role in the pain experience and should be part of the treatment of chronic pain. The focus of the ACT treatment of chronic pain does not necessarily have to be on acceptance of pain per se, but may be aimed at acceptance of unwanted experiences in general. Mindfulness in the sense of "acting with awareness" is however not related to catastrophizing. Based on our research findings in comparisons with those of other authors, we recommend a broader conceptualization of mindfulness and the use of a multifaceted questionnaire for mindfulness instead of the unidimensional MAAS.

  19. Planning for persistence in marine reserves: a question of catastrophic importance.

    Science.gov (United States)

    Game, Edward T; Watts, Matthew E; Wooldridge, Scott; Possingham, Hugh P

    2008-04-01

    Large-scale catastrophic events, although rare, lie generally beyond the control of local management and can prevent marine reserves from achieving biodiversity outcomes. We formulate a new conservation planning problem that aims to minimize the probability of missing conservation targets as a result of catastrophic events. To illustrate this approach we formulate and solve the problem of minimizing the impact of large-scale coral bleaching events on a reserve system for the Great Barrier Reef, Australia. We show that by considering the threat of catastrophic events as part of the reserve design problem it is possible to substantially improve the likely persistence of conservation features within reserve networks for a negligible increase in cost. In the case of the Great Barrier Reef, a 2% increase in overall reserve cost was enough to improve the long-run performance of our reserve network by >60%. Our results also demonstrate that simply aiming to protect the reefs at lowest risk of catastrophic bleaching does not necessarily lead to the best conservation outcomes, and enormous gains in overall persistence can be made by removing the requirement to represent all bioregions in the reserve network. We provide an explicit and well-defined method that allows the probability of catastrophic disturbances to be included in the site selection problem without creating additional conservation targets or imposing arbitrary presence/absence thresholds on existing data. This research has implications for reserve design in a changing climate.

  20. Research on catastrophe control in 1-D system

    Institute of Scientific and Technical Information of China (English)

    SUN Yao; TANG Li-ping; LI Xue-lian

    2003-01-01

    A new method of catastrophe control is described in one dimension nonlinear system. Catastrophe control based on catastrophe theory is a brand new area for control theory. A certain catastrophe is created at a desired location by appropriate control, which has preferred properties. Washout filter is presented and applied to preserve the original equilibrium of a system. Washout filter aided dynamic feedback controller is developed for the creation of catastrophe, and an example is given to illustrate the process. Catastrophe control may provide a new way of designing warning signals of impending collapse or catastrophe for monitoring and control purposes.

  1. Pricing for Catastrophe Bonds Based on Expected-value Model

    Directory of Open Access Journals (Sweden)

    Junfei Chen

    2013-02-01

    Full Text Available As the catastrophes cannot be avoided and result in huge economic losses, therefore the compensation issue for catastrophe losses become an important research topic. Catastrophe bonds can effectively disperse the catastrophe risks which mainly undertaken by the government and the insurance companies currently and focus on capital more effectively in broad capital market, therefore to be an ideal catastrophe securities product. This study adopts Expectancy Theory to supplement and improve the pricing of catastrophe bonds based on Value Theory. A model of expected utility is established to determine the conditions of the expected revenue R of catastrophe bonds. The pricing model of the value function is used to get the psychological value of R,U (R-R‾, for catastrophe bonds. Finally, the psychological value is improved by the value according to expected utility and this can more accurately evaluate catastrophe bonds at a reasonable price. This research can provide decision-making for the pricing of catastrophe bonds.

  2. Critical Amount of Resource in Containing Catastrophic Epidemics

    CERN Document Server

    Chen, Xiaolong; Feng, Ling; Yang, Chun; Wang, Moming; Fan, Xiaoming; Hu, Yanqing

    2016-01-01

    During an epidemic control, the containment of the disease is usually achieved through increasing public health resource to quickly identify, quarantine and cure the infected population. However, the exact impact of this resource expenditure on the physical spreading dynamics remains unknown. In this work we find that the influence of resource expenditure exhibits extreme critical behaviour, which is the first order phase transition in nature. Specifically, if the amount of invested resource is below a critical value, a significant fraction of the total population will become infected; once it is more than that critical value, the disease outbreak can be effectively eradicated or contained. This finding implies that the government expenditure on infectious disease control needs to meet a certain critical threshold to be of any effectiveness. Otherwise, the outbreak could be catastrophic. We have validated our theoretical results on one real contact network and three typical social networks, with all of them e...

  3. Downward Catastrophe of Solar Magnetic Flux Ropes

    Science.gov (United States)

    Zhang, Quanhao; Wang, Yuming; Hu, Youqiu; Liu, Rui

    2016-07-01

    2.5-dimensional time-dependent ideal magnetohydrodynamic (MHD) models in Cartesian coordinates were used in previous studies to seek MHD equilibria involving a magnetic flux rope embedded in a bipolar, partially open background field. As demonstrated by these studies, the equilibrium solutions of the system are separated into two branches: the flux rope sticks to the photosphere for solutions at the lower branch but is suspended in the corona for those at the upper branch. Moreover, a solution originally at the lower branch jumps to the upper, as the related control parameter increases and reaches a critical value, and the associated jump is here referred to as an upward catastrophe. The present paper advances these studies in three aspects. First, the magnetic field is changed to be force-free; the system still experiences an upward catastrophe with an increase in each control parameter. Second, under the force-free approximation, there also exists a downward catastrophe, characterized by the jump of a solution from the upper branch to the lower. Both catastrophes are irreversible processes connecting the two branches of equilibrium solutions so as to form a cycle. Finally, the magnetic energy in the numerical domain is calculated. It is found that there exists a magnetic energy release for both catastrophes. The Ampère's force, which vanishes everywhere for force-free fields, appears only during the catastrophes and does positive work, which serves as a major mechanism for the energy release. The implications of the downward catastrophe and its relevance to solar activities are briefly discussed.

  4. Evolutionary Catastrophes and the Goldilocks Problem

    CERN Document Server

    Cirkovic, Milan M

    2007-01-01

    One of the mainstays of the controversial "rare Earth" hypothesis is the "Goldilocks problem" regarding various parameters describing a habitable planet, partially involving the role of mass extinctions and other catastrophic processes in biological evolution. Usually, this is construed as support for the uniqueness of the Earth's biosphere and intelligent human life. Here I argue that this is a misconstrual and that, on the contrary, observation-selection effects, when applied to catastrophic processes, make it very difficult for us to discern whether the terrestrial biosphere and evolutionary processes which created it are exceptional in the Milky Way or not. In particular, an anthropic overconfidence bias related to the temporal asymmetry of evolutionary processes appears when we try to straightforwardly estimate catastrophic risks from the past records on Earth. This agnosticism, in turn, supports the validity and significance of practical astrobiological and SETI research.

  5. On a new global catastrophic ICT model

    DEFF Research Database (Denmark)

    Riaz, M. Tahir; Bhalerao, Dipashree M.; Madsen, Ole Brun;

    2011-01-01

    Many parts of India are prone to natural disasters, particularly caused by earthquakes and floods because of its geographical location. The Catastrophic areas can be rural, remote or urban anywhere in the world. It has been understood that earthquakes directly do not cause causalities but instead...... of the world's population suffers from affordable ICT solutions and the presence of sufficient ICT infrastructure. The main goal of this paper is to create a framework to define catastrophic areas from an ICT point of view. QOS features like packet loss rate, delay, throughput and delivery ratio for 50 nodes...... coverage before and after calamities. This definition of catastrophic area from ICT point of view has no one tried before. Network parameters behavioural graphs are also important. This paper presents only behavioural part....

  6. Valuing Catastrophe Bonds Involving Credit Risks

    Directory of Open Access Journals (Sweden)

    Jian Liu

    2014-01-01

    Full Text Available Catastrophe bonds are the most important products in catastrophe risk securitization market. For the operating mechanism, CAT bonds may have a credit risk, so in this paper we consider the influence of the credit risk on CAT bonds pricing that is different from the other literature. We employ the Jarrow and Turnbull method to model the credit risks and get access to the general pricing formula using the Extreme Value Theory. Furthermore, we present an empirical pricing study of the Property Claim Services data, where the parameters in the loss function distribution are estimated by the MLE method and the default probabilities are deduced by the US financial market data. Then we get the catastrophe bonds value by the Monte Carlo method.

  7. Mindfulness, Acceptance and Catastrophizing in Chronic Pain

    NARCIS (Netherlands)

    de Boer, Maaike J.; Steinhagen, Hannemike E.; Versteegen, Gerbrig J.; Struys, Michel M. R. F.; Sanderman, Robbert

    2014-01-01

    Objectives: Catastrophizing is often the primary target of the cognitive-behavioral treatment of chronic pain. Recent literature on acceptance and commitment therapy (ACT) suggests an important role in the pain experience for the concepts mindfulness and acceptance. The aim of this study is to exami

  8. Novel percolation transitions and coupled catastrophes

    Science.gov (United States)

    D'Souza, Raissa

    Collections of interdependent networks are at the core of modern society, spanning physical, biological and social systems. Simple mathematical models of the structure and function of networks can provide important insights into real-world systems, enhancing our ability to steer and control them. Here our focus is on abrupt changes in networks, due both to phase transitions and to jumping between bi-stable equilibria. We begin with an overview of novel classes of percolation phase transitions that result from repeated, small interventions intended to delay the transition. These new phenomena allow us to extend percolation approaches to modular networks, Brownian motion, and cluster growth dynamics. We then focus on abrupt transitions due to a system jumping between bi-stable equilibria, modeled as a cusp catastrophe in nonlinear dynamics. We show that when systems that each undergo a cusp catastrophe interact, we can observe a new phenomena of catastrophe-hopping leading to non-local cascading failures. Here an intermediate system facilitates the propagation of a sudden change or collapse, and we show that catastrophe hopping is consistent with the outbreak of protests observed during the Arab Spring of 2011.

  9. The Pain Catastrophizing Scale: Development and Validation.

    Science.gov (United States)

    Sullivan, Michael J. L.; And Others

    1995-01-01

    A series of 4 studies involving 547 college students and community adults report the development of the Pain Catastrophizing Scale, its validity with clinical and nonclinical samples, and its correlation with measures of related constructs. The scale provides information about heightened responses to aversive procedures or events. (SLD)

  10. 78 FR 52832 - Catastrophic Risk Protection Endorsement

    Science.gov (United States)

    2013-08-27

    .... See the Notice related to 7 CFR part 3015, subpart V, published at 48 FR 29115, June 24, 1983... the Federal Register at 76 FR 50929-50931. The public was afforded 60 days to submit written comments... Federal Crop Insurance Corporation 7 CFR Part 402 RIN 0563-AC31 Catastrophic Risk Protection...

  11. THE NONLINEAR CUSP-CATASTROPHE MODEL OF THE SEDIMENT TRANSPORT RATE

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    In the catastrophe theory of nonlinear science,the intensity of water-flow and the coefficient of non-uniformsediment m are regarded as two bound variables, and the in-tensity of bed-load transport Φ as the state variable in the mo-tion of non-uniform sediment in cusp-catastrophe model.Based on the standard equation of the cusp-catastrophe theo-ry, the relation equation between the intensity of bed-loadtransport Φ and the intensity of water-flow has been derivedby used coordinate transform and topology transform. The e-quation of bed load transport rate was built on the cusp-catas-trophe theory of nonlinear science. The others are applied toverify this equation, that the results calculated by the cusp-ca-tastrophe equation agree well with the other equations. Thisindicates that the cusp-catastrophe equation is reasonable, and the results fully reflect the characteristics of threshold motionand transport of non-uniform sediment. The purpose of thispaper is to explore the incipient motion and transport laws ofnon-uniform sediment from the viewpoint of nonlinear science.

  12. CATASTROPHE FRACTURE OF THIN-WALL PRESSURE TUBES

    Institute of Scientific and Technical Information of China (English)

    魏德敏; 杨桂通

    2002-01-01

    Catastrophe theory was used to investigate the fracture behavior of thin-wall cylindrical tubes subjected to nternal explosive pressure. Based on the energy theory and catastrophe theory, a cusp catastrophe model for the fracture was established, and a critical condition associated with the model is given.

  13. Personality and temperament correlates of pain catastrophizing in young adolescents

    NARCIS (Netherlands)

    P.E.H.M. Muris (Peter); C.M.G. Meesters (Cor); M.F.C.M. Van Den Hout (Mari F. C. M.); S. Wessels (Sylvia); I.H.A. Franken (Ingmar); E.G.C. Rassin (Eric)

    2007-01-01

    textabstractPain catastrophizing is generally viewed as an important cognitive factor underlying chronic pain. The present study examined personality and temperament correlates of pain catastrophizing in a sample of young adolescents (N = 132). Participants completed the Pain Catastrophizing Scale f

  14. Microtubule dynamics: Caps, catastrophes, and coupled hydrolysis

    DEFF Research Database (Denmark)

    Flyvbjerg, H.; Holy, T.E.; Leibler, S.

    1996-01-01

    An effective theory is formulated for the dynamics of the guanosine triphosphate (GTP) cap believed to stabilize growing microtubules. The theory provides a ''coarse-grained'' description of the cap's dynamics. ''Microscopic'' details, such as the microtubule lattice structure and the fate of its...... data. A constant nonzero catastrophe rare, identical for both microtubule ends, is predicted at large growth rates. The delay time for dilution-induced catastrophes is stochastic with a simple distribution that fits the experimental one and, like the experimental one, does not depend on the rate of....... A recent experimental result for the size of the minimal cap that can stabilize a microtubule is shown to agree with the result predicted by the cap model, after its parameters have been extracted from previous experimental results. Thus the effective theory and cap model presented here provide a...

  15. On Catastrophe and Cavitation for Spherical Cavity

    Institute of Scientific and Technical Information of China (English)

    MingJIN; KefuHUANG; 等

    1999-01-01

    This work deals with catastrophe of a spherical cavity and cavitation of a spherical cavity for Hooke material with 1/2 Poisson's ratio.A nonlinear problem.which is the Cauchy traction problem,is solved analytically.The governing equations are written on the deformed region or on the present configuration.And the conditions are described on moving boundary.A closed form solution is found.Furthermore,a bifurcation solution in closed form is given from the trivial homogeneous solution of a solid sphere.The results indicate that there is a tangent bifurcation on the displacement-load curve for a sphere with a cavity.On the tangent bifurcation point,the cavity grows up suddenly,which is a kind of catastrophe,And there is a pitchfork bifurcation on the displacement-load curve for a solid sphere.On the pitchfork bifurcation point.there is a cavitation in the solid sphere.

  16. CARA Risk Assessment Thresholds

    Science.gov (United States)

    Hejduk, M. D.

    2016-01-01

    Warning remediation threshold (Red threshold): Pc level at which warnings are issued, and active remediation considered and usually executed. Analysis threshold (Green to Yellow threshold): Pc level at which analysis of event is indicated, including seeking additional information if warranted. Post-remediation threshold: Pc level to which remediation maneuvers are sized in order to achieve event remediation and obviate any need for immediate follow-up maneuvers. Maneuver screening threshold: Pc compliance level for routine maneuver screenings (more demanding than regular Red threshold due to additional maneuver uncertainty).

  17. Recent catastrophic landslides and mitigation in China

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Increasing population density and development of mountainous terrain have brought human settlements within reach of landslide hazards.In recent years,due to the shortening of return period for severe natural events such as heavy rainfall,snowline retreating,great earthquake together with human activities,catastrophic landslides happened more frequently than before,resulting in large-scale casualties due to the increasing occurrences of rapid long-runout rock avalanches,especially in China.This paper present...

  18. Catastrophic health expenditure and impoverishment in Mongolia

    OpenAIRE

    Dorjdagva, Javkhlanbayar; Batbaatar, Enkhjargal; Svensson, Mikael; Dorjsuren, Bayarsaikhan; Kauhanen, Jussi

    2016-01-01

    Background The social health insurance coverage is relatively high in Mongolia; however, escalation of out-of-pocket payments for health care, which reached 41 % of the total health expenditure in 2011, is a policy concern. The aim of this study is to analyse the incidence of catastrophic health expenditures and to measure the rate of impoverishment from health care payments under the social health insurance scheme in Mongolia. Methods We used the data from the Household Socio-Economic Survey...

  19. Valuing Catastrophic Losses for Perennial Agricultural Crops

    OpenAIRE

    Adams, Damian C.; Kilmer, Richard L.; Moss, Charles B.; Schmitz, Andrew

    2003-01-01

    Courts are often required to estimate changes in welfare to agricultural operations from catastrophic events. For example, courts must assign damages in lawsuits, such as with pesticide drift cases, or determine 'just compensation' when the government takes private land for public use, as with the removal of dairy farms from environmentally sensitive land or destruction of canker-contaminated citrus trees. In economics, the traditional method of estimating changes in producer welfare is the c...

  20. Catastrophic Consequences of Kicking the Chameleon

    OpenAIRE

    Erickcek, Adrienne L.; Barnaby, Neil; Burrage, Clare; Huang, Zhiqi

    2013-01-01

    The physics of the "dark energy" that drives the current cosmological acceleration remains mysterious, and the dark sector may involve new light dynamical fields. If these light scalars couple to matter, a screening mechanism must prevent them from mediating an unacceptably strong fifth force locally. Here we consider a concrete example: the chameleon mechanism. We show that the same coupling between the chameleon field and matter employed by the screening mechanism also has catastrophic cons...

  1. Catastrophic Natural Disasters and Economic Growth

    OpenAIRE

    Cavallo, Eduardo; Galiani, Sebastian; Noy, Ilan; Pantano, Juan

    2010-01-01

    We examine the short and long run average causal impact of catastrophic natural disasters on economic growth by combining information from comparative case studies. We assess the counterfactual of the cases studied by constructing synthetic control groups taking advantage of the fact that the timing of large sudden natural disasters is an exogenous event. We find that only extremely large disasters have a negative effect on output both in the short and long run. However, we also show that thi...

  2. Scaling law characterizing the dynamics of the transition of HIV-1 to error catastrophe

    Science.gov (United States)

    Gupta, Vipul; Dixit, Narendra M.

    2015-10-01

    Increasing the mutation rate, μ , of viruses above a threshold, {μ }c, has been predicted to trigger a catastrophic loss of viral genetic information and is being explored as a novel intervention strategy. Here, we examine the dynamics of this transition using stochastic simulations mimicking within-host HIV-1 evolution. We find a scaling law governing the characteristic time of the transition: τ ≈ 0.6/≤ft(μ -{μ }c\\right). The law is robust to variations in underlying evolutionary forces and presents guidelines for treatment of HIV-1 infection with mutagens. We estimate that many years of treatment would be required before HIV-1 can suffer an error catastrophe.

  3. A critical look at catastrophe risk assessments

    CERN Document Server

    Kent, A

    2004-01-01

    Recent papers by Busza et al. (BJSW) and Dar et al. (DDH) argue that astrophysical data can be used to establish bounds on the risk of a catastrophe in forthcoming collider experiments. The safety case set out by BJSW does not rely on these bounds, but on theoretical arguments, which BJSW find sufficiently compelling. However, DDH and other commentators (initially including BJSW) have suggested that the astrophysical bounds alone do give sufficient reassurance. This seems unsupportable when the bounds are expressed in terms of expected cost. For example, DDH's main bound, $p_{\\rm catastrophe} < 2 \\times 10^{-8}$, implies only that the expectation value of the number of deaths is bounded by 120. We thus reappraise the DDH and BJSW risk bounds by comparing risk policy in other areas. We find that requiring a catastrophe risk of no higher than 10^{-15} is necessary to be consistent with established policy for risk optimisation from radiation hazards, even if highly risk tolerant assumptions are made. A respec...

  4. Prediction of Catastrophes: an experimental model

    CERN Document Server

    Peters, Randall D; Pomeau, Yves

    2012-01-01

    Catastrophes of all kinds can be roughly defined as short duration-large amplitude events following and followed by long periods of "ripening". Major earthquakes surely belong to the class of 'catastrophic' events. Because of the space-time scales involved, an experimental approach is often difficult, not to say impossible, however desirable it could be. Described in this article is a "laboratory" setup that yields data of a type that is amenable to theoretical methods of prediction. Observations are made of a critical slowing down in the noisy signal of a solder wire creeping under constant stress. This effect is shown to be a fair signal of the forthcoming catastrophe in both of two dynamical models. The first is an "abstract" model in which a time dependent quantity drifts slowly but makes quick jumps from time to time. The second is a realistic physical model for the collective motion of dislocations (the Ananthakrishna set of equations for creep). Hope thus exists that similar changes in the response to ...

  5. Downward catastrophe of solar magnetic flux ropes

    CERN Document Server

    Zhang, Quanhao; Hu, Youqiu; Liu, Rui

    2016-01-01

    2.5D time-dependent ideal magnetohydrodynamic (MHD) models in Cartesian coordinates were used in previous studies to seek MHD equilibria involving a magnetic flux rope embedded in a bipolar, partially open background field. As demonstrated by these studies, the equilibrium solutions of the system are separated into two branches: the flux rope sticks to the photosphere for solutions at the lower branch but is suspended in the corona for those at the upper branch. Moreover, a solution originally at the lower branch jumps to the upper, as the related control parameter increases and reaches a critical value, and the associated jump is here referred to as upward catastrophe. The present paper advances these studies in three aspects. First, the magnetic field is changed to be force-free. The system still experiences an upward catastrophe with an increase in each control parameter. Secondly, under the force-free approximation, there also exists a downward catastrophe, characterized by a jump of a solution from the u...

  6. Catastrophic fragmentation of asteroids: Evidence from meteorites

    Science.gov (United States)

    Keil, K.; Haack, H.; Scott, E. R. D.

    1994-01-01

    Meteorites are impact-derived fragments from approximately 85 parent bodies. For seven of these bodies, the meteorites record evidence suggesting that they may have been catastrophically fragmented. We identify three types of catastrophic events: (1) impact and reassemble events greater than 4.4 Gy ago, involving molten or very hot parent bodies (greater than 1200 C); this affected the parent bodies of the ureilites, Shallowater, and the mesosiderites. In each case, the fragments cooled rapidly (approximately 1-1000 C/day) and then reassembled. (2) Later impacts involving cold bodies which, in some cases, reassembled; this occurred on the H and L ordinary chondrite parent bodies. The L parent body probably suffered another catastrophic event about 500 My ago. (3) Recent impacts of cold, multi-kilometer-sized bodies that generated meter-sized meteoroids; this occurred on the parent bodies of the IIIAB irons (650 My ago), the IVA irons (400 My ago), and the H ordinary chondrite (7 My ago).

  7. Catastrophe theory and its application status in mechanical engineering

    Directory of Open Access Journals (Sweden)

    Jinge LIU

    Full Text Available Catastrophe theory is a kind of mathematical method which aims to apply and interpret the discontinuous phenomenon. Since its emergence, it has been widely used to explain a variety of emergent phenomena in the fields of natural science, social science, management science and some other science and technology fields. Firstly, this paper introduces the theory of catastrophe in several aspects, such as its generation, radical principle, basic characteristics and development. Secondly, it summarizes the main applications of catastrophe theory in the field of mechanical engineering, focusing on the research progress of catastrophe theory in revealing catastrophe of rotor vibration state, analyzing friction and wear failure, predicting metal fracture, and so on. Finally, it advises that later development of catastrophe theory should pay more attention to the combination of itself with other traditional nonlinear theories and methods. This paper provides a beneficial reference to guide the application of catastrophe theory in mechanical engineering and related fields for later research.

  8. Granular motions near the threshold of entrainment

    Science.gov (United States)

    Valyrakis, Manousos; Alexakis, athanasios-Theodosios

    2016-04-01

    Our society is continuously impacted by significant weather events many times resulting in catastrophes that interrupt our normal way of life. In the context of climate change and increasing urbanisation these "extreme" hydrologic events are intensified both in magnitude and frequency, inducing costs of the order of billions of pounds. The vast majority of such costs and impacts (even more to developed societies) are due to water related catastrophes such as the geomorphic action of flowing water (including scouring of critical infrastructure, bed and bank destabilisation) and flooding. New tools and radically novel concepts are in need, to enable our society becoming more resilient. This presentation, emphasises the utility of inertial sensors in gaining new insights on the interaction of flow hydrodynamics with the granular surface at the particle scale and for near threshold flow conditions. In particular, new designs of the "smart-sphere" device are discussed with focus on the purpose specific sets of flume experiments, designed to identify the exact response of the particle resting at the bed surface for various below, near and above threshold flow conditions. New sets of measurements are presented for particle entrainment from a Lagrangian viewpoint. Further to finding direct application in addressing real world challenges in the water sector, it is shown that such novel sensor systems can also help the research community (both experimentalists and computational modellers) gain a better insight on the underlying processes governing granular dynamics.

  9. Targeting pain catastrophization in patients with fibromyalgia using virtual reality exposure therapy: a proof-of-concept study.

    Science.gov (United States)

    Morris, Linzette Deidrè; Louw, Quinette Abegail; Grimmer, Karen Anne; Meintjes, Ernesta

    2015-11-01

    [Purpose] Pain catastrophizing is a key predictor of poor compliance to exercises among patients with fibromyalgia syndrome. Alteration of pain catastrophizing in this group is thus warranted. This study aimed to provide proof-of-concept of a novel virtual reality exposure therapy program as treatment for exercise-related pain catastrophizing in patients with fibromyalgia syndrome. [Subjects and Methods] An exploratory, case-controlled study was conducted (fibromyalgia syndrome group and matched control group). Functional magnetic resonance imaging was used to acquire neural correlates. The functional magnetic resonance imaging task consisted of two stimuli: active (exercise activity visuals) and passive (relaxing visuals). Structural images and blood-oxygenation-level-dependent contrasts were acquired for the conditions and compared within subjects/groups and between groups. Statistic images were thresholded using corrected clusters (determined by Z>2.3; level of significance: 0.05). [Results] Thirteen fibromyalgia syndrome subjects and nine healthy matched controls were included. The right inferior frontal gyrus, right middle frontal gyrus, right posterior cerebellum, left thalamus, and left supramarginal gyrus were activated in the fibromyalgia syndrome subjects. [Conclusion] The study results provide preliminary proof indicating that exposing patients with fibromyalgia syndrome to visuals of exercises elicits neurophysiological changes in functional brain areas associated with pain catastrophization and add to the current body of knowledge regarding the possibility of objectively identifying cognitive behavioral strategies like pain catastrophization. PMID:26696719

  10. A unified approach of catastrophic events

    Directory of Open Access Journals (Sweden)

    S. Nikolopoulos

    2004-01-01

    Full Text Available Although there is an accumulated charge of theoretical, computational, and numerical work, like catastrophe theory, bifurcation theory, stochastic and deterministic chaos theory, there is an important feeling that these matters do not completely cover the physics of real catastrophic events. Recent studies have suggested that a large variety of complex processes, including earthquakes, heartbeats, and neuronal dynamics, exhibits statistical similarities. Here we are studying in terms of complexity and non linear techniques whether isomorphic signatures emerged indicating the transition from the normal state to the both geological and biological shocks. In the last 15 years, the study of Complex Systems has emerged as a recognized field in its own right, although a good definition of what a complex system is, actually is eluded. A basic reason for our interest in complexity is the striking similarity in behaviour close to irreversible phase transitions among systems that are otherwise quite different in nature. It is by now recognized that the pre-seismic electromagnetic time-series contain valuable information about the earthquake preparation process, which cannot be extracted without the use of important computational power, probably in connection with computer Algebra techniques. This paper presents an analysis, the aim of which is to indicate the approach of the global instability in the pre-focal area. Non-linear characteristics are studied by applying two techniques, namely the Correlation Dimension Estimation and the Approximate Entropy. These two non-linear techniques present coherent conclusions, and could cooperate with an independent fractal spectral analysis to provide a detection concerning the emergence of the nucleation phase of the impending catastrophic event. In the context of similar mathematical background, it would be interesting to augment this description of pre-seismic electromagnetic anomalies in order to cover biological

  11. Catastrophic volcanic collapse: relation to hydrothermal processes.

    Science.gov (United States)

    López, D L; Williams, S N

    1993-06-18

    Catastrophic volcanic collapse, without precursory magmatic activity, is characteristic of many volcanic disasters. The extent and locations of hydrothermal discharges at Nevado del Ruiz volcano, Colombia, suggest that at many volcanoes collapse may result from the interactions between hydrothermal fluids and the volcanic edifice. Rock dissolution and hydrothermal mineral alteration, combined with physical triggers such as earth-quakes, can produce volcanic collapse. Hot spring water compositions, residence times, and flow paths through faults were used to model potential collapse at Ruiz. Caldera dimensions, deposits, and alteration mineral volumes are consistent with parameters observed at other volcanoes.

  12. Observational Features of Large-Scale Structures as Revealed by the Catastrophe Model of Solar Eruptions

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Large-scale magnetic structures are the main carrier of major eruptions in the solar atmosphere. These structures are rooted in the photosphere and are driven by the unceasing motion of the photospheric material through a series of equilibrium configurations. The motion brings energy into the coronal magnetic field until the system ceases to be in equilibrium. The catastrophe theory for solar eruptions indicates that loss of mechanical equilibrium constitutes the main trigger mechanism of major eruptions, usually shown up as solar flares,eruptive prominences, and coronal mass ejections (CMEs). Magnetic reconnection which takes place at the very beginning of the eruption as a result of plasma instabilities/turbulence inside the current sheet, converts magnetic energy into heating and kinetic energy that are responsible for solar flares, and for accelerating both plasma ejecta (flows and CMEs) and energetic particles. Various manifestations are thus related to one another, and the physics behind these relationships is catastrophe and magnetic reconnection. This work reports on recent progress in both theoretical research and observations on eruptive phenomena showing the above manifestations. We start by displaying the properties of large-scale structures in the corona and the related magnetic fields prior to an eruption, and show various morphological features of the disrupting magnetic fields. Then, in the framework of the catastrophe theory,we look into the physics behind those features investigated in a succession of previous works,and discuss the approaches they used.

  13. Threshold Concepts in Biochemistry

    Science.gov (United States)

    Loertscher, Jennifer

    2011-01-01

    Threshold concepts can be identified for any discipline and provide a framework for linking student learning to curricular design. Threshold concepts represent a transformed understanding of a discipline, without which the learner cannot progress and are therefore pivotal in learning in a discipline. Although threshold concepts have been…

  14. Bankruptcy by catastrophes for major multi-nationals: stock exchange sensitivity for three catastrophes

    NARCIS (Netherlands)

    Van Gulijk, C.; Ale, B.J.M.

    2012-01-01

    This paper investigates the effect of major catastrophes have on stock exchange values for the major multi-nationals. The paper demonstrates that the Sharpe analysis is more sensitive in identifying effects than just following the daily stock values for assessing market response. It was found that m

  15. Multiple Sclerosis and Catastrophic Health Expenditure in Iran

    Science.gov (United States)

    Juyani, Yaser; Hamedi, Dorsa; Hosseini Jebeli, Seyede Sedighe; Qasham, Maryam

    2016-01-01

    Background: There are many disabling medical conditions which can result in catastrophic health expenditure. Multiple Sclerosis is one of the most costly medical conditions through the world which encounter families to the catastrophic health expenditures. This study aims to investigate on what extent Multiple sclerosis patients face catastrophic costs. Method: This study was carried out in Ahvaz, Iran (2014). The study population included households that at least one of their members suffers from MS. To analyze data, Logit regression model was employed by using the default software STATA12. Results: 3.37% of families were encountered with catastrophic costs. Important variables including brand of drug, housing, income and health insurance were significantly correlated with catastrophic expenditure. Conclusions: This study suggests that although a small proportion of MS patients met the catastrophic health expenditure, mechanisms that pool risk and cost (e.g. health insurance) are required to protect them and improve financial and access equity in health care.

  16. Inside money, procyclical leverage, and banking catastrophes.

    Science.gov (United States)

    Brummitt, Charles D; Sethi, Rajiv; Watts, Duncan J

    2014-01-01

    We explore a model of the interaction between banks and outside investors in which the ability of banks to issue inside money (short-term liabilities believed to be convertible into currency at par) can generate a collapse in asset prices and widespread bank insolvency. The banks and investors share a common belief about the future value of certain long-term assets, but they have different objective functions; changes to this common belief result in portfolio adjustments and trade. Positive belief shocks induce banks to buy risky assets from investors, and the banks finance those purchases by issuing new short-term liabilities. Negative belief shocks induce banks to sell assets in order to reduce their chance of insolvency to a tolerably low level, and they supply more assets at lower prices, which can result in multiple market-clearing prices. A sufficiently severe negative shock causes the set of equilibrium prices to contract (in a manner given by a cusp catastrophe), causing prices to plummet discontinuously and banks to become insolvent. Successive positive and negative shocks of equal magnitude do not cancel; rather, a banking catastrophe can occur even if beliefs simply return to their initial state. Capital requirements can prevent crises by curtailing the expansion of balance sheets when beliefs become more optimistic, but they can also force larger price declines. Emergency asset price supports can be understood as attempts by a central bank to coordinate expectations on an equilibrium with solvency.

  17. Inside money, procyclical leverage, and banking catastrophes.

    Directory of Open Access Journals (Sweden)

    Charles D Brummitt

    Full Text Available We explore a model of the interaction between banks and outside investors in which the ability of banks to issue inside money (short-term liabilities believed to be convertible into currency at par can generate a collapse in asset prices and widespread bank insolvency. The banks and investors share a common belief about the future value of certain long-term assets, but they have different objective functions; changes to this common belief result in portfolio adjustments and trade. Positive belief shocks induce banks to buy risky assets from investors, and the banks finance those purchases by issuing new short-term liabilities. Negative belief shocks induce banks to sell assets in order to reduce their chance of insolvency to a tolerably low level, and they supply more assets at lower prices, which can result in multiple market-clearing prices. A sufficiently severe negative shock causes the set of equilibrium prices to contract (in a manner given by a cusp catastrophe, causing prices to plummet discontinuously and banks to become insolvent. Successive positive and negative shocks of equal magnitude do not cancel; rather, a banking catastrophe can occur even if beliefs simply return to their initial state. Capital requirements can prevent crises by curtailing the expansion of balance sheets when beliefs become more optimistic, but they can also force larger price declines. Emergency asset price supports can be understood as attempts by a central bank to coordinate expectations on an equilibrium with solvency.

  18. Catastrophizing and Parental Response to Child Symptom Complaints

    OpenAIRE

    Langer, Shelby L.; Romano, Joan M.; Levy, Rona L; Walker, Lynn S.; Whitehead, William E.

    2009-01-01

    This study investigated whether catastrophic thinking about pain by children with functional abdominal pain or by their parents is associated with health outcomes in the child. Subjects were 132 parent-child dyads. Child catastrophizing predicted child depression, anxiety and functional disability. Parents’ catastrophizing cognitions about their own pain predicted self-reported protective responses to their children’s abdominal pain (responding in ways that encourage illness behavior). Protec...

  19. Averting Catastrophes: The Strange Economics of Scylla and Charybdis

    OpenAIRE

    Martin, Ian; Pindyck, R. S.

    2014-01-01

    How should we evaluate public policies or projects to avert, or reduce the likelihood of, a catastrophic event? Examples might include inspection and surveillance programs to avert nuclear terrorism, investments in vaccine technologies to help respond to a "mega-virus," or the construction of levees to avert major flooding. A policy to avert a particular catastrophe considered in isolation might be evaluated in a cost-benefit framework. But because society faces multiple potential catastrophe...

  20. Mutation accumulation and the catastrophic senescence of Pacific salmon

    CERN Document Server

    Penna, T J P; Stauffer, D; Stauffer, Dietrich

    1995-01-01

    The bit-string model of biological aging is used to simulate the catastrophic senescence of Pacific Salmon. We have shown that reproduction occuring only once and at a fixed age is the only ingredient needed to explain the catastrophic senescence according the mutation accumulation theory. Several results are presented, some of them with up to 10^8 fishes, showing how the survival rates in catastrophic senescence are affected by changes in the parameters of the model.

  1. Error Thresholds in Single-Peak Gaussian Distributed Fitness Landscapes

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Based on the Eigen and Crow-Kimura models with a single-peak fitness landscape, we propose the fitness values of all sequence types to be Gaussian distributed random variables to incorporate the effects of the fluctuations of the fitness landscapes (noise of environments) and investigate the concentration distribution and error threshold of quasispecies by performing an ensemble average within this theoretical framework. We find that a small fluctuation of the fitness landscape causes only a slight change in the concentration distribution and error threshold, which implies that the error threshold is stable against small perturbations. However, for a sizable fluctuation, quite different from the previous deterministic models, our statistical results show that the transition from quasispecies to error catastrophe is not so sharp, indicating that the error threshold is located within a certain range and has a shift toward a larger value. Our results are qualitatively in agreement with the experimental data and provide a new implication for antiviral strategies.

  2. Collisional and Rotational Disruption of Asteroids

    Science.gov (United States)

    Walsh, Kevin J.; Michel, Patrick; Richardson, Derek C.

    2011-02-01

    Asteroids are leftover pieces from the era of planet formation that help us understand conditions in the early Solar System. Unlike larger planetary bodies that were subject to global thermal modification during and subsequent to their formation, these small bodies have kept at least some unmodified primordial material from the solar nebula. However, the structural properties of asteroids have been modified considerably since their formation. Thus, we can find among them a great variety of physical configurations and dynamical histories. In fact, with only a few possible exceptions, all asteroids have been modified or completely disrupted many times during the age of the Solar System. This picture is supported by data from space mission encounters with asteroids that show much diversity of shape, bulk density, surface morphology, and other features. Moreover, the gravitational attraction of these bodies is so small that some physical processes occur in a manner far removed from our common experience on Earth. Thus, each visit to a small body has generated as many questions as it has answered. In this review we discuss the current state of research into asteroid disruption processes, focusing on collisional and rotational mechanisms. We find that recent advances in modeling catastrophic disruption by collisions have provided important insights into asteroid internal structures and a deeper understanding of asteroid families. Rotational disruption, by tidal encounters or thermal effects, is responsible for altering many smaller asteroids, and is at the origin of many binary asteroids and oddly shaped bodies.

  3. Exact Threshold Circuits

    DEFF Research Database (Denmark)

    Hansen, Kristoffer Arnsfelt; Podolskii, Vladimir V.

    2010-01-01

    We initiate a systematic study of constant depth Boolean circuits built using exact threshold gates. We consider both unweighted and weighted exact threshold gates and introduce corresponding circuit classes. We next show that this gives a hierarchy of classes that seamlessly interleave with the ......We initiate a systematic study of constant depth Boolean circuits built using exact threshold gates. We consider both unweighted and weighted exact threshold gates and introduce corresponding circuit classes. We next show that this gives a hierarchy of classes that seamlessly interleave...... with the well-studied corresponding hierarchies defined using ordinary threshold gates. A major open problem in Boolean circuit complexity is to provide an explicit super-polynomial lower bound for depth two threshold circuits. We identify the class of depth two exact threshold circuits as a natural subclass...

  4. Polynomial threshold functions and Boolean threshold circuits

    DEFF Research Database (Denmark)

    Hansen, Kristoffer Arnsfelt; Podolskii, Vladimir V.

    2013-01-01

    We study the complexity of computing Boolean functions on general Boolean domains by polynomial threshold functions (PTFs). A typical example of a general Boolean domain is 12n . We are mainly interested in the length (the number of monomials) of PTFs, with their degree and weight being...... of secondary interest. We show that PTFs on general Boolean domains are tightly connected to depth two threshold circuits. Our main results in regard to this connection are: PTFs of polynomial length and polynomial degree compute exactly the functions computed by THRMAJ circuits. An exponential length lower...

  5. Application of catastrophe theory to nuclear structure

    International Nuclear Information System (INIS)

    Three two-parameter models, one describing an A-body system (the atomic nucleus) and two describing many-body systems (the van der Waals gas and the ferroelectric (perovskite) system) are compared within the framework of catastrophe theory. It is shown that each has a critical point (second-order phase transition) when the two counteracting forces controlling it are in balance; further, each undergoes a first-order phase transition when one of the forces vanishes (the deforming force for the nucleus, the attractive force for the van der Waals gas, and the dielectric constant for the perovskite). Finally, when both parameters are kept constant, a kind of phase transition may occur at a critical angular momentum, critical pressure, and critical electric field. 3 figures, 1 table

  6. The perils of thresholding

    CERN Document Server

    Font-Clos, Francesc; Deluca, Anna; Moloney, Nicholas R

    2014-01-01

    The thresholding of time series of activity or intensity is frequently used to define and differentiate events. This is either implicit, for example due to resolution limits, or explicit, in order to filter certain small scale physics from the supposed true asymptotic events. Thresholding the birth-death process, however, introduces a scaling region into the event size distribution, which is characterised by an exponent that is unrelated to the actual asymptote and is rather an artefact of thresholding. As a result, numerical fits of simulation data produce a range of exponents, with the true asymptote visible only in the tail of the distribution. This tail is increasingly difficult to sample as the threshold is increased. In the present case, the exponents and the spurious nature of the scaling region can be determined analytically, thus demonstrating the way in which thresholding conceals the true asymptote. The analysis also suggests a procedure for detecting the influence of the threshold by means of a da...

  7. Grasshopper Population Ecology: Catastrophe, Criticality, and Critique

    Directory of Open Access Journals (Sweden)

    Jeffrey A. Lockwood

    2008-06-01

    Full Text Available Grasshopper population dynamics are an important part of the North American rangeland ecosystem and an important factor in the economies that derive from the rangeland. Outbreak dynamics have plagued management strategies in the rangeland, and attempts to find simple, linear and mechanistic solutions to both understanding and predicting the dynamics have proved fruitless. These efforts to ground theory in a correspondence with the “real” world, including whether the population dynamics are ultimately density dependent or density independent, have generated abundant heat but little light. We suggest that a pragmatic approach, in which theories are taken to be “tools” rather than competing claims of truth, has greater promise to move ecological research in a constructive direction. Two recent non-linear approaches exploiting the tools of complexity science provide insights relevant to explaining and forecasting population dynamics. Observation and data collection were used to structure models derived from catastrophe theory and self-organized criticality. These models indicate that nonlinear processes are important in the dynamics of the outbreaks. And the conceptual structures of these approaches provide clear, albeit constrained or contingent, implications for pest managers. We show that, although these two frameworks, catastrophe theory and self-organized criticality, are very different, the frequency distributions of time series from both systems result in power law relationships. Further, we show that a simple lattice-based model, similar to SOC but structured on the biology of the grasshoppers gives a spatial time series similar to data over a 50-year span and the frequency distribution is also a power law relationship. This demonstration exemplifies how a “both–and” rather than an “either–or” approach to ecological modeling, in which the useful elements of particular theories or conceptual structures are extracted, may

  8. Experiments on Mixotrophic Protists and Catastrophic Darkness

    Science.gov (United States)

    Jones, Harriet; Cockell, Charles S.; Goodson, Claire; Price, Nicola; Simpson, Annika; Thomas, Benjamin

    2009-08-01

    Catastrophically darkened photic zone conditions in water bodies are postulated to be induced by a diversity of mechanisms that are recorded in the geological record, including asteroid and comet impacts and large-scale volcanic eruptions. Giant wildfires, such as those that followed the great fires in Siberia in 1915, have been directly shown to cause large reductions in sunlight penetrating to the ground. Previous studies on the response of phototrophs to s udden prolonged darkness have focused on the survival of axenic strains. In this paper, we describe laboratory experiments to investigate the survival and growth of isolated and mixed cultures of freshwater and marine mixotrophs after 6 months of darkness and in the low light that would follow these events. Mixotrophs could survive 6 months of darkness. Some species used dissolved organic carbon, which can be released from dead biomass after loss of light and was shown to improve feeding rates. Mixotrophs also improved the survival and subsequent growth of obligate phototrophs at low light levels when grown in mixed cultures. The ability of mixotrophs to switch from photosynthesis to heterotrophy following sudden darkening would not only allow them to survive but to grow and contribute to active food chains. The experiments suggest that, following the return of light, resumption of photosynthesis can be rapid. These experiments improve our understanding of the collapse of photosynthesis following catastrophic darkening and emphasize the important role of mixotrophy in the resilience of the photosynthetic biosphere during such periods. We speculate on the implications for the Cretaceous-Tertiary impact event and periods of global freezing.

  9. Purchase of Catastrophe Insurance by Dutch Dairy and Arable Farmers

    NARCIS (Netherlands)

    Ogurtsov, V.; Asseldonk, van M.A.P.M.; Huirne, R.B.M.

    2009-01-01

    This article analyzed the impact of risk perception, risk attitude, and other farmer personal and farm characteristics on the actual purchase of catastrophe insurance by Dutch dairy and arable farmers. The specific catastrophe insurance types considered were hail–fire–storm insurance for buildings,

  10. Cell death by mitotic catastrophe: a molecular definition

    NARCIS (Netherlands)

    Castedo, M.; Perfettini, J.-L.; Roumier, T.; Andreau, K.; Medema, R.H.; Kroemer, G.

    2004-01-01

    The current literature is devoid of a clearcut definition of mitotic catastrophe, a type of cell death that occurs during mitosis. Here, we propose that mitotic catastrophe results from a combination of deficient cell-cycle checkpoints (in particular the DNA structure checkpoints and the spindle ass

  11. Can a stochastic cusp catastrophe model explain housing market crashes?

    NARCIS (Netherlands)

    C. Diks; J. Wang

    2016-01-01

    Like stock market prices, housing prices often exhibit temporary booms and busts. A possible explanation for the observed abrupt changes is offered by the stochastic catastrophe model. This paper addresses the question whether the catastrophe model can describe and predict the dynamics of housing ma

  12. Psychological resilience predicts decreases in pain catastrophizing through positive emotions.

    Science.gov (United States)

    Ong, Anthony D; Zautra, Alex J; Reid, M Carrington

    2010-09-01

    The study used a daily process design to examine the role of psychological resilience and positive emotions in the day-to-day experience of pain catastrophizing. A sample of 95 men and women with chronic pain completed initial assessments of neuroticism, psychological resilience, and demographic data, and then completed short diaries regarding pain intensity, pain catastrophizing, and positive and negative emotions every day for 14 consecutive days. Multilevel modeling analyses indicated that independent of level of neuroticism, negative emotions, pain intensity, income, and age, high-resilient individuals reported greater positive emotions and exhibited lower day-to-day pain catastrophizing compared with low-resilient individuals. Mediation analyses revealed that psychologically resilient individuals rebound from daily pain catastrophizing through experiences of positive emotion. Implications for research on psychological resilience, pain catastrophizing, and positive emotions are discussed.

  13. Grey forewarning and prediction for mine water inflowing catastrophe periods

    Institute of Scientific and Technical Information of China (English)

    MA Qi-hua; CAO Jian-jun

    2007-01-01

    Based on the theory of grey system, established GM (1, 1) grey catastrophe predict model for the first time in order to forecast the catastrophe periods of mine water inflowing (not the volume of water inflowing). After establishing the grey predict system of the catastrophe regularity of 10 month-average volume of water inflowing, the grey forewarning for mine water inflowing catastrophe periods was established which was used to analyze water disaster in -400 meter level of Wennan Colliery. Based on residual analysis,it shows that the result of grey predict system is almost close to the actual value. And the scene actual result also shows the reliability of prediction. Both the theoretical analysis and the scene actual result indicate feasibility and reliability of the method of grey catastrophe predict system.

  14. Manipulation of pain catastrophizing: An experimental study of healthy participants

    Directory of Open Access Journals (Sweden)

    Joel E Bialosky

    2008-11-01

    Full Text Available Joel E Bialosky1*, Adam T Hirsh2,3, Michael E Robinson2,3, Steven Z George1,3*1Department of Physical Therapy; 2Department of Clinical and Health Psychology; 3Center for Pain Research and Behavioral Health, University of Florida, Gainesville, Florida, USAAbstract: Pain catastrophizing is associated with the pain experience; however, causation has not been established. Studies which specifically manipulate catastrophizing are necessary to establish causation. The present study enrolled 100 healthy individuals. Participants were randomly assigned to repeat a positive, neutral, or one of three catastrophizing statements during a cold pressor task (CPT. Outcome measures of pain tolerance and pain intensity were recorded. No change was noted in catastrophizing immediately following the CPT (F(1,84 = 0.10, p = 0.75, partial η2 < 0.01 independent of group assignment (F(4,84 = 0.78, p = 0.54, partial η2 = 0.04. Pain tolerance (F(4 = 0.67, p = 0.62, partial η2 = 0.03 and pain intensity (F(4 = 0.73, p = 0.58, partial η2 = 0.03 did not differ by group. This study suggests catastrophizing may be difficult to manipulate through experimental pain procedures and repetition of specific catastrophizing statements was not sufficient to change levels of catastrophizing. Additionally, pain tolerance and pain intensity did not differ by group assignment. This study has implications for future studies attempting to experimentally manipulate pain catastrophizing.Keywords: pain, catastrophizing, experimental, cold pressor task, pain catastrophizing scale

  15. Applications of modelling historical catastrophic events with implications for catastrophe risk management

    Science.gov (United States)

    Sorby, A.; Grossi, P.; Pomonis, A.; Williams, C.; Nyst, M.; Onur, T.; Seneviratna, P.; Baca, A.

    2009-04-01

    The management of catastrophe risk is concerned with the quantification of financial losses, and their associated probabilities, for potential future catastrophes that might impact a region. Modelling of historical catastrophe events and, in particular, the potential consequences if a similar event were to occur at the present day can provide insight to help bridge the gap between what we know can happen from historical experience and what potential losses might be out there in the "universe" of potential catastrophes. The 1908 Messina Earthquake (and accompanying local tsunami) was one of the most destructive earthquakes to have occurred in Europe and by most accounts remains Europe's most fatal with over 70,000 casualties estimated. However, what would the potential consequences be, in terms of financial and human losses, if a similar earthquake were to occur at the present day? Exposures, building stock and populations can change over time and, therefore, the consequences of a similar earthquake at the present day may sensibly differ from those observed in 1908. The city of Messina has been reconstructed several times in its history, including following the 1908 earthquake and again following the Second World War. The 1908 earthquake prompted the introduction of the first seismic design regulations in Italy and since 1909 parts of the Messina and Calabria regions have been in the zones of highest seismic coefficient. Utilizing commercial catastrophe loss modelling technology - which combines the modelling of hazard, vulnerability, and financial losses on a database of property exposures - a modelled earthquake scenario of M7.2 in the Messina Straits region of Southern Italy is considered. This modelled earthquake is used to assess the potential consequences in terms of financial losses that an earthquake similar to the 1908 earthquake might have if it were to occur at the present day. Loss results are discussed in the context of applications for the financial

  16. Threshold Concepts in Economics

    Science.gov (United States)

    Shanahan, Martin

    2016-01-01

    Purpose: The purpose of this paper is to examine threshold concepts in the context of teaching and learning first-year university economics. It outlines some of the arguments for using threshold concepts and provides examples using opportunity cost as an exemplar in economics. Design/ Methodology/Approach: The paper provides an overview of the…

  17. Avoiding Environmental Catastrophes: Varieties of Principled Precaution

    Directory of Open Access Journals (Sweden)

    Alan R. Johnson

    2012-09-01

    Full Text Available The precautionary principle is often proposed as a guide to action in environmental management or risk assessment, and has been incorporated in various legal and regulatory contexts. For many, it reflects the common sense notion of being safe rather than sorry, but it has attracted numerous critics. At times, proponents and critics talk at cross purposes, due to the multiplicity of ways the precautionary principle has been formulated. The approach taken here is to examine four general varieties of precaution, relating each to arguments made in various contexts by others. First, I examine the parallel between the precautionary principle and an argument referred to as Pascal's wager. Critics are right to dismiss versions of the precautionary principle that follow the logic of Pascal's wager, because that argument requires assumption of an infinite catastrophe, which is seldom the case in environmental decisions. Second, I explore precaution viewed as an instance of the phenomenon of ambiguity aversion as described by Daniel Ellsberg. Third, I evaluate precautionary perspectives on our duties to future generations, drawing inspiration from the views of Gifford Pinchot. Fourth, I consider the precautionary principle as an instance of Aldo Leopold's notion of intelligent tinkering. Although controversy persists, I find that a legitimate theoretical foundation exists to implement Ellsbergian, Pinchotian and Leopoldean varieties of precaution in environmental decision making. Additionally, I remark on the role of adaptive management and maintaining resilience in ecological and social systems as an approach to implementing the precautionary principle.

  18. Catastrophic Cracking Courtesy of Quiescent Cavitation

    CERN Document Server

    Daily, D Jesse; Thomson, Scott L; Truscott, Tadd T

    2012-01-01

    A popular party trick is to fill a glass bottle with water and hit the top of the bottle with an open hand, causing the bottom of the bottle to break open. We investigate the source of the catastrophic cracking through the use of high-speed video and an accelerometer attached to the bottom of a glass bottle. Upon closer inspection, it is obvious that the acceleration caused by hitting the top of the bottle is followed by the formation of bubbles near the bottom. The nearly instantaneous acceleration creates an area of low pressure on the bottom of the bottle where cavitation bubbles form. Moments later, the cavitation bubbles collapse at roughly 10 times the speed of formation, causing the bottle to break. The accelerometer data shows that the bottle is broken after the bubbles collapse and that the magnitude of the bubble collapse is greater than the initial impact. The fluid dynamics video highlights that this trick will not work if the bottle is empty nor if it is filled with a carbonated fluid because the...

  19. Risk Measure and Premium Distribution on Catastrophe Reinsurance

    Institute of Scientific and Technical Information of China (English)

    XUN LI; WANG DE-HUI

    2012-01-01

    In this paper,we propose a new risk measure which is based on the Orlicz premium principle to characterize catastrophe risk premium.The intention is to develop a formulation strategy for Catastrophe Fund.The logarithm equivalent form of reinsurance premium is regarded as the retention of reinsurer,and the differential earnings between the reinsurance premium and the reinsurer's retention is accumulated as a part of Catastrophe Fund.We demonstrate that the aforementioned risk measure has some good properties,which are further confirmed by numerical simulations in R environment.

  20. Top Threshold Physics

    OpenAIRE

    Hoang, Andre H.

    2006-01-01

    Running a future Linear Collider at the top pair threshold allows for precise measurements of the mass, the widths and the couplings of the top quark. I give a nontechnical review on recent theoretical developments and the theory status in top threshold physics concerning QCD corrections and top quark finite lifetime and electroweak effects. I also discuss threshold physics in the context of measurements of the top Yukawa coupling from $e^+e^-\\to t\\bar t H$ and of squark pair production.

  1. A preliminary assessment of asteroid shapes produced by impact disruption and re-creation: Application to the AIDA target.

    Science.gov (United States)

    Barnouin, Olivier; Michel, Patrick; Richardson, Derek

    2016-04-01

    In order to understand the origin of the 65803 Didymos, the target of the Asteroid Impact and Deflection Assessment mission, and gain insights on the origin and evolution of the asteroid's162173 Ryugu and 101955 Bennu, we investigate systematically the shapes of all re-accumulated fragments produced by the catastrophic disruption of a parent body that is 1 km in diameter or larger. These new fragments eventually become new asteroids of the size that current sample-return missions plan to explore. We choose a range of impact conditions by varying the parent bodies' strength, size and porosity, and the velocity and size of the projectile. Impact conditions range from near the catastrophic threshold, usually designated by Q*, where half of the target's mass escapes, to far greater values above this threshold. Our numerical investigations of the catastrophic disruption, which are undertaken using an SPH hydrocode, include a model of fragmentation for porous materials. The gravitationally dominated phase of reaccumulation of our asteroids is computed using the N-body code pkdgrav. At sufficiently slow impact speeds in the N-body model, particles are permitted to stick, forming irregular, competent pieces that can gather into non-idealized rubble piles as a result of re-accumulation. Shape and spin information of re-accumulated bodies are thus preserved. Due to numerical expense, this first study uses what we call a hard-sphere model, rather than a soft-sphere spring and dashpot model. This latter model is more commonly used in granular flow simulations for which detailed treatment of the multicontact physics is needed, which is not the case here, and comes at the expense of much smaller timesteps. With the hard-sphere model, there are three supported collision outcomes for bonded aggregates: sticking on contact (to grow the aggregate); bouncing (computed for these generally non-central impacts); and fragmentation (wherein the particles involved become detached from

  2. Quantum threshold group signature

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    In most situations, the signer is generally a single person. However, when the message is written on behalf of an organization, a valid message may require the approval or consent of several persons. Threshold signature is a solution to this problem. Generally speaking, as an authority which can be trusted by all members does not exist, a threshold signature scheme without a trusted party appears more attractive. Following some ideas of the classical Shamir’s threshold signature scheme, a quantum threshold group signature one is proposed. In the proposed scheme, only t or more of n persons in the group can generate the group signature and any t-1 or fewer ones cannot do that. In the verification phase, any t or more of n signature receivers can verify the message and any t-1 or fewer receivers cannot verify the validity of the signature.

  3. Large-scale coastal impact induced by a catastrophic storm

    DEFF Research Database (Denmark)

    Fruergaard, Mikkel; Andersen, Thorbjørn Joest; Johannessen, Peter N;

    Catastrophic storms and storm surges induce rapid and substantial changes along sandy barrier coasts, potentially causing severe environmental and economic damage. Coastal impacts of modern storms are associated with washover deposition, dune erosion, barrier breaching, and coastline and shoreface...

  4. Pain frequency moderates the relationship between pain catastrophizing and pain

    Science.gov (United States)

    Kjøgx, Heidi; Zachariae, Robert; Pfeiffer-Jensen, Mogens; Kasch, Helge; Svensson, Peter; Jensen, Troels S.; Vase, Lene

    2014-01-01

    Background: Pain frequency has been shown to influence sensitization, psychological distress, and pain modulation. The present study examined if pain frequency moderates the relationship between pain catastrophizing and pain. Method: A non-clinical (247 students) and a clinical (223 pain patients) sample completed the Danish versions of the Pain Catastrophizing Scale (PCS), Beck Depression Inventory, and the State Trait Anxiety Inventory and rated pain intensity, unpleasantness and frequency. Results: In both samples, high pain frequency was found to moderate the association between pain catastrophizing and pain intensity, whereas low pain frequency did not. The psychometric properties and the factor structure of the Danish version of the PCS were confirmed. Conclusions: This is the first study to validate the Danish version of the PCS and to show that pain frequency moderates the relationship between pain catastrophizing and reported pain in both non-clinical and clinical populations. PMID:25646089

  5. Pain frequency moderates the relationship between pain catastrophizing and pain

    Directory of Open Access Journals (Sweden)

    Heidi eKjøgx

    2014-12-01

    Full Text Available Background Pain frequency has been shown to influence sensitization, psychological distress and pain modulation. The present study examined if pain frequency moderates the relationship between pain catastrophizing and pain. Method A non-clinical (247 students and a clinical (223 pain patients sample completed the Danish versions of the Pain Catastrophizing Scale, Beck Depression Inventory and the State Trait Anxiety Inventory and rated pain intensity, unpleasantness and frequency Results In both samples, high pain frequency was found to moderate the association between pain catastrophizing and pain intensity, whereas low pain frequency did not. The psychometric properties and the factor structure of the Danish version of the PCS were confirmed.Conclusions This is the first study to validate the Danish version of the PCS and to show that pain frequency moderates the relationship between pain catastrophizing and reported pain in both non-clinical and clinical populations.

  6. Catastrophic Events and Mass Extinctions: Impacts and Beyond

    Science.gov (United States)

    2000-01-01

    This volume contains extended abstracts that have been accepted for presentation at the conference on Catastrophic Events and Mass Extinctions: Impacts and Beyond, July 9-12, 2000, in Vienna, Austria.

  7. UKRAINIAN EVENTS AS HISTORICAL, INTERNATIONAL CATASTROPHE

    Directory of Open Access Journals (Sweden)

    V. V. Kasyanov

    2016-01-01

    Full Text Available In the scientific article fully examines current events in Ukraine in 2014-2015. The author believes that the causal and comparative historical analysis of the current Ukrainian crisis allows characterizing it as a major historical and ethnic catastrophe on a global scale after the collapse of the USSR in 1991. Obvious microand macroeffects inevitably impact on the history of relations between Ukrainian and Russian brotherly nations, lead (and has led to freeze their contacts, projects and links. It causes a feeling of well-founded anxiety for the fate of not only bilateral relations between Ukraine and Russia and the state of Post-Soviet space, but also for the development of all Slavic ethnic groups in the world. According to the author, it is necessary to review quickly realized Ukrainian direction of Russian state policy. It is necessary, as quickly as possible to get away from officiously promotional activities, technologies and techniques of information war and bring aid all the diversity of cultural cooperation. It is only a means of soft power, understood by us in the manner of the approach of its founder, American political scientist Joseph Nye, are able to restore the broken trust and interaction structures. Only the culture, and more specifically it such areas as language, traditions, generation feats, faith, can gradually normalize, and then to improve the bilateral relations, the each other perception, to restore a sense of respect, friendship and mutual assistance between Ukraine and Russia. It is obvious that bilateral cultural project able to change the existing negative situation.

  8. Pain frequency moderates the relationship between pain catastrophizing and pain

    OpenAIRE

    Heidi eKjøgx; Robert eZachariae; Mogens ePfeiffer-Jensen; Helge eKasch; Peter eSvensson; Troels Staehelin Jensen; Lene eVase

    2014-01-01

    Background Pain frequency has been shown to influence sensitization, psychological distress and pain modulation. The present study examined if pain frequency moderates the relationship between pain catastrophizing and pain. Method A non-clinical (247 students) and a clinical (223 pain patients) sample completed the Danish versions of the Pain Catastrophizing Scale, Beck Depression Inventory and the State Trait Anxiety Inventory and rated pain intensity, unpleasantness and frequency Results In...

  9. Psychological Resilience Predicts Decreases in Pain Catastrophizing Through Positive Emotions

    OpenAIRE

    Ong, Anthony D.; Zautra, Alex J.; Reid, M. Carrington

    2010-01-01

    The study used a daily process design to examine the role of psychological resilience and positive emotions in the day-to-day experience of pain catastrophizing. A sample of 95 men and women with chronic pain completed initial assessments of neuroticism, psychological resilience, and demographic data, and then completed short diaries regarding pain intensity, pain catastrophizing, and positive and negative emotions every day for 14 consecutive days. Multilevel modeling analyses indicated that...

  10. Mathematical modeling of human behaviors during catastrophic events

    OpenAIRE

    Verdière, Nathalie; Lanza, Valentina; Charrier, Rodolphe; Provitolo, Damienne; Dubos-Paillard, Edwige; Bertelle, Cyrille; Aziz-Alaoui, Moulay

    2014-01-01

    In this paper, we introduce a new approach for modeling the human collective behaviors in the speci c scenario of a sudden catastrophe, this catastrophe can be natural (i.e. earthquake, tsunami) or technological (nuclear event). The novelty of our work is to propose a mathematical model taking into account di erent concurrent behaviors in such situation and to include the processes of transition from one behavior to the other during the event. Here, we focus more on the sequence of behaviors ...

  11. Climate change policy in a growing economy under catastrophic risks

    OpenAIRE

    Tsur, Yacov; Zemel, Amos

    2007-01-01

    Under risk of catastrophic climate change, the occurrence hazard is added to the social discount rate. As a result, the social discount rate (i) increases and (ii) turns endogenous to the global warming policy. The second effect bears profound policy implications that are magnifed by economic growth. In particular, it implies that green- house gases (GHG) emission should gradually be brought to a halt. Due to the public bad nature of the catastrophic risk, the second effect is ignored in a co...

  12. Some Aspects of the Economics of Catastrophe Risk Insurance

    OpenAIRE

    Gollier, Christian

    2005-01-01

    The ability to share risk efficiently in the economy is essential to welfare and growth. However, the increased frequency of natural catastrophes over the last decade has raised once again questions associated to the limits of insurability in a free-market economy, and to the relevance of public interventions on risk-sharing markets. In this paper, we explore the potential reasons for the lack of insurance specifically associated to catastrophe environmental risks. Our final aim is to link ea...

  13. Navigating catastrophes: Local but not global optimisation allows for macro-economic navigation of crises

    Science.gov (United States)

    Harré, Michael S.

    2013-02-01

    Two aspects of modern economic theory have dominated the recent discussion on the state of the global economy: Crashes in financial markets and whether or not traditional notions of economic equilibrium have any validity. We have all seen the consequences of market crashes: plummeting share prices, businesses collapsing and considerable uncertainty throughout the global economy. This seems contrary to what might be expected of a system in equilibrium where growth dominates the relatively minor fluctuations in prices. Recent work from within economics as well as by physicists, psychologists and computational scientists has significantly improved our understanding of the more complex aspects of these systems. With this interdisciplinary approach in mind, a behavioural economics model of local optimisation is introduced and three general properties are proven. The first is that under very specific conditions local optimisation leads to a conventional macro-economic notion of a global equilibrium. The second is that if both global optimisation and economic growth are required then under very mild assumptions market catastrophes are an unavoidable consequence. Third, if only local optimisation and economic growth are required then there is sufficient parametric freedom for macro-economic policy makers to steer an economy around catastrophes without overtly disrupting local optimisation.

  14. Pain Catastrophizing Correlates with Early Mild Traumatic Brain Injury Outcome.

    Science.gov (United States)

    Chaput, Geneviève; Lajoie, Susanne P; Naismith, Laura M; Lavigne, Gilles

    2016-01-01

    Background. Identifying which patients are most likely to be at risk of chronic pain and other postconcussion symptoms following mild traumatic brain injury (MTBI) is a difficult clinical challenge. Objectives. To examine the relationship between pain catastrophizing, defined as the exaggerated negative appraisal of a pain experience, and early MTBI outcome. Methods. This cross-sectional design included 58 patients diagnosed with a MTBI. In addition to medical chart review, postconcussion symptoms were assessed by self-report at 1 month (Time 1) and 8 weeks (Time 2) after MTBI. Pain severity, psychological distress, level of functionality, and pain catastrophizing were measured by self-report at Time 2. Results. The pain catastrophizing subscales of rumination, magnification, and helplessness were significantly correlated with pain severity (r = .31 to .44), number of postconcussion symptoms reported (r = .35 to .45), psychological distress (r = .57 to .67), and level of functionality (r = -.43 to -.29). Pain catastrophizing scores were significantly higher for patients deemed to be at high risk of postconcussion syndrome (6 or more symptoms reported at both Time 1 and Time 2). Conclusions. Higher levels of pain catastrophizing were related to adverse early MTBI outcomes. The early detection of pain catastrophizing may facilitate goal-oriented interventions to prevent or minimize the development of chronic pain and other postconcussion symptoms. PMID:27445604

  15. Pain Catastrophizing Correlates with Early Mild Traumatic Brain Injury Outcome

    Directory of Open Access Journals (Sweden)

    Geneviève Chaput

    2016-01-01

    Full Text Available Background. Identifying which patients are most likely to be at risk of chronic pain and other postconcussion symptoms following mild traumatic brain injury (MTBI is a difficult clinical challenge. Objectives. To examine the relationship between pain catastrophizing, defined as the exaggerated negative appraisal of a pain experience, and early MTBI outcome. Methods. This cross-sectional design included 58 patients diagnosed with a MTBI. In addition to medical chart review, postconcussion symptoms were assessed by self-report at 1 month (Time 1 and 8 weeks (Time 2 after MTBI. Pain severity, psychological distress, level of functionality, and pain catastrophizing were measured by self-report at Time 2. Results. The pain catastrophizing subscales of rumination, magnification, and helplessness were significantly correlated with pain severity (r=.31 to .44, number of postconcussion symptoms reported (r=.35 to .45, psychological distress (r=.57 to .67, and level of functionality (r=-.43 to -.29. Pain catastrophizing scores were significantly higher for patients deemed to be at high risk of postconcussion syndrome (6 or more symptoms reported at both Time 1 and Time 2. Conclusions. Higher levels of pain catastrophizing were related to adverse early MTBI outcomes. The early detection of pain catastrophizing may facilitate goal-oriented interventions to prevent or minimize the development of chronic pain and other postconcussion symptoms.

  16. Hydrodynamics of sediment threshold

    Science.gov (United States)

    Ali, Sk Zeeshan; Dey, Subhasish

    2016-07-01

    A novel hydrodynamic model for the threshold of cohesionless sediment particle motion under a steady unidirectional streamflow is presented. The hydrodynamic forces (drag and lift) acting on a solitary sediment particle resting over a closely packed bed formed by the identical sediment particles are the primary motivating forces. The drag force comprises of the form drag and form induced drag. The lift force includes the Saffman lift, Magnus lift, centrifugal lift, and turbulent lift. The points of action of the force system are appropriately obtained, for the first time, from the basics of micro-mechanics. The sediment threshold is envisioned as the rolling mode, which is the plausible mode to initiate a particle motion on the bed. The moment balance of the force system on the solitary particle about the pivoting point of rolling yields the governing equation. The conditions of sediment threshold under the hydraulically smooth, transitional, and rough flow regimes are examined. The effects of velocity fluctuations are addressed by applying the statistical theory of turbulence. This study shows that for a hindrance coefficient of 0.3, the threshold curve (threshold Shields parameter versus shear Reynolds number) has an excellent agreement with the experimental data of uniform sediments. However, most of the experimental data are bounded by the upper and lower limiting threshold curves, corresponding to the hindrance coefficients of 0.2 and 0.4, respectively. The threshold curve of this study is compared with those of previous researchers. The present model also agrees satisfactorily with the experimental data of nonuniform sediments.

  17. Polynomial threshold functions and Boolean threshold circuits

    DEFF Research Database (Denmark)

    Hansen, Kristoffer Arnsfelt; Podolskii, Vladimir V.

    2013-01-01

    secondary interest. We show that PTFs on general Boolean domains are tightly connected to depth two threshold circuits. Our main results in regard to this connection are: PTFs of polynomial length and polynomial degree compute exactly the functions computed by THRMAJ circuits. An exponential length lower...... bound for PTFs that holds regardless of degree, thereby extending known lower bounds for THRMAJ circuits. We generalize two-party unbounded error communication complexity to the multi-party number-on-the-forehead setting, and show that communication lower bounds for 3-player protocols would yield size...... lower bounds for THRTHR circuits. We obtain several other results about PTFs. These include relationships between weight and degree of PTFs, and a degree lower bound for PTFs of constant length. We also consider a variant of PTFs over the max-plus algebra. We show that they are connected to PTFs over...

  18. The race between cooperation and catastrophe

    International Nuclear Information System (INIS)

    If a nuclear weapon were detonated in London, or in any of the world's major cities, it would change our world forever. Beyond the horror and the immediate death, and the lives that would be shortened by radioactive fallout, the casualties could also include civil liberties, privacy, world confidence and the global economy. With so much at stake, our citizens have every reason to ask: 'Are we doing all we can to prevent a nuclear attack?' My emphatic answer is 'No, we are not.' We have, however, taken some important steps, including: - The Nunn-Lugar Cooperative Threat Reduction programme, working since 1991 to secure and destroy weapons and material in the former Soviet Union. This programme helped Kazakhstan, Ukraine and Belarus get rid of all their nuclear weapons, a historic achievement. - The G8 commitment launched three years ago to create and fund the Global Partnership Against the Spread of Weapons and Materials of Mass Destruction. - The recently launched US-Russian Global Threat Reduction Initiative to remove and secure high enriched uranium from research facilities around the globe. - The IAEA Nuclear Security Fund, launched to help Member States strengthen the security of nuclear material worldwide. - The commitment by Libya to give up its nuclear weapons programme following skilful diplomacy led by the United Kingdom and the United States of America, with important oversight by the IAEA. - The recent Bush-Putin summit, in which the President of the Russian Federation and the President of the USA each made a personal commitment to enhance and accelerate efforts to secure nuclear weapons and nuclear material worldwide. These are all indispensable steps for global security, but we have miles to go before we sleep. We must remove roadblocks, we must provide more resources, we must convert pledges to programmes and words to deeds. We must develop a global partnership against catastrophic terrorism that is effective, focused and truly global. This includes

  19. Angular Momentum Transfer in Catastrophic Asteroid Impacts

    Science.gov (United States)

    Love, S. G.; Ahrens, T. J.

    1996-09-01

    Incomplete knowledge of angular momentum transfer in asteroid impacts has hampered efforts to deduce asteroid collisional histories from their rotation rates. This problem traditionally has been investigated using impact experiments on cm-scale, strength-dominated targets. Recent evidence, however, indicates that impacts on asteroids of km size and larger may be controlled by gravity rather than strength, and that the analogy to laboratory impacts may not hold. Accordingly, we have modelled catastrophic impacts on gravitating asteroids to better understand angular momentum transfer in such events. We employ a 3--D, strengthless, gravitating SPH computer code. Target bodies are 10 to 1000 km in diameter and do not initially rotate. Impact speeds are 3--7 km/s; impact angles are 15--75(deg) . Each target is composed of 1791 mass elements: spatial resolution is coarse but acceptable for large scale energy transfer. We simulate the hydrodynamic phase of each impact, after which particle motions are ballistic and treated analytically. Escaping particles have kinetic energy greater than the gravitational energy binding them to the rest of the system; the others reaccrete to form a ``rubble pile'' which is assumed spherical. The rubble pile's size, mass, and angular momentum define its rotation rate. Spin rates for ejected fragments cannot be determined. The target's final spin period depends on the impact angle and the fraction of target mass ejected, but not on impact speed or target size in the ranges tested. The lack of size dependence cannot explain the observed excess of slowly rotating asteroids of ~ 100 km diameter. The fraction of projectile angular momentum retained by the target varies dramatically with impact speed and angle and with target size and fraction of mass removed, complicating its use in models where collision geometry varies. The final spin period of an asteroid losing 50% of its mass is 6--10 hours, comparable to the asteroidal mean of 8 hours

  20. From Catastrophizing to Recovery: a pilot study of a single-session treatment for pain catastrophizing

    Directory of Open Access Journals (Sweden)

    Darnall BD

    2014-04-01

    Full Text Available Beth D Darnall, John A Sturgeon, Ming-Chih Kao, Jennifer M Hah, Sean C MackeyDivision of Pain Medicine, Stanford Systems Neuroscience and Pain Laboratory, Stanford University School of Medicine, Palo Alto, CA, USABackground: Pain catastrophizing (PC – a pattern of negative cognitive-emotional responses to real or anticipated pain – maintains chronic pain and undermines medical treatments. Standard PC treatment involves multiple sessions of cognitive behavioral therapy. To provide efficient treatment, we developed a single-session, 2-hour class that solely treats PC entitled “From Catastrophizing to Recovery”[FCR].Objectives: To determine 1 feasibility of FCR; 2 participant ratings for acceptability, understandability, satisfaction, and likelihood to use the information learned; and 3 preliminary efficacy of FCR for reducing PC.Design and methods: Uncontrolled prospective pilot trial with a retrospective chart and database review component. Seventy-six patients receiving care at an outpatient pain clinic (the Stanford Pain Management Center attended the class as free treatment and 70 attendees completed and returned an anonymous survey immediately post-class. The Pain Catastrophizing Scale (PCS was administered at class check-in (baseline and at 2, and 4 weeks post-treatment. Within subjects repeated measures analysis of variance (ANOVA with Student's t-test contrasts were used to compare scores across time points.Results: All attendees who completed a baseline PCS were included as study participants (N=57; F=82%; mean age =50.2 years; PCS was completed by 46 participants at week 2 and 35 participants at week 4. Participants had significantly reduced PC at both time points (P<0001 and large effect sizes were found (Cohen's d=0.85 and d=1.15.Conclusion: Preliminary data suggest that FCR is an acceptable and effective treatment for PC. Larger, controlled studies of longer duration are needed to determine durability of response, factors

  1. Alcohol disrupts sleep homeostasis.

    Science.gov (United States)

    Thakkar, Mahesh M; Sharma, Rishi; Sahota, Pradeep

    2015-06-01

    Alcohol is a potent somnogen and one of the most commonly used "over the counter" sleep aids. In healthy non-alcoholics, acute alcohol decreases sleep latency, consolidates and increases the quality (delta power) and quantity of NREM sleep during the first half of the night. However, sleep is disrupted during the second half. Alcoholics, both during drinking periods and during abstinences, suffer from a multitude of sleep disruptions manifested by profound insomnia, excessive daytime sleepiness, and altered sleep architecture. Furthermore, subjective and objective indicators of sleep disturbances are predictors of relapse. Finally, within the USA, it is estimated that societal costs of alcohol-related sleep disorders exceeds $18 billion. Thus, although alcohol-associated sleep problems have significant economic and clinical consequences, very little is known about how and where alcohol acts to affect sleep. In this review, we have described our attempts to unravel the mechanism of alcohol-induced sleep disruptions. We have conducted a series of experiments using two different species, rats and mice, as animal models. We performed microdialysis, immunohistochemical, pharmacological, sleep deprivation and lesion studies which suggest that the sleep-promoting effects of alcohol may be mediated via alcohol's action on the mediators of sleep homeostasis: adenosine (AD) and the wake-promoting cholinergic neurons of the basal forebrain (BF). Alcohol, via its action on AD uptake, increases extracellular AD resulting in the inhibition of BF wake-promoting neurons. Since binge alcohol consumption is a highly prevalent pattern of alcohol consumption and disrupts sleep, we examined the effects of binge drinking on sleep-wakefulness. Our results suggest that disrupted sleep homeostasis may be the primary cause of sleep disruption observed following binge drinking. Finally, we have also shown that sleep disruptions observed during acute withdrawal, are caused due to impaired

  2. Pion photoproduction near threshold

    International Nuclear Information System (INIS)

    A review of the high accuracy π+ threshold photoproduction cross-section determinations on deuterium and helium-3 is presented. These must be considered on the same footing as the data on electromagnetic observables, with reference to the important question of the description of the non nucleonic degrees of freedom in the nucleus. The π0 threshold photoproduction on very light nuclei which conveys information on the elementary nucleonic amplitudes in an energy region where one is sensitive to the break down of isospin symmetry as revealed by the π+-, π0 and the n, p mass splittings is discussed

  3. Endocrine disrupting chemicals

    DEFF Research Database (Denmark)

    Mandrup, Karen

    . To improve knowledge on possible influences of endocrine disrupters on female reproductive system, the effects of EDCs on genital malformations in females and the development of mammary glands were studied in the present project. AIMS: The aims for the studies on male and female mammary gland development......BACKGROUND: Endocrine disrupting chemicals (EDCs) may contribute to reproductive changes in boys in the Western world, however, less is known about influence of EDCs in women. The incidence of precocious breast development is increasing in USA and Europe and mammary gland development has been...... suggested as particularly sensitive to endocrine disruption. Mammary gland examination in toxicological studies may be useful for improving knowledge on possible influences of EDCs on human mammary glands and also be useful for detection of endocrine disrupting effects of chemicals as part of safety testing...

  4. Search and Disrupt

    DEFF Research Database (Denmark)

    Ørding Olsen, Anders

    This paper analyzes how external search is affected by strategic interest alignment among knowledge sources. I focus on misalignment arising from the heterogeneous effects of disruptive technologies by analyzing the influence of incumbents on 2,855 non-incumbents? external knowledge search efforts....... The efforts most likely to solve innovation problems obtained funding from the European Commission?s 7th Framework Program (2007-2013). The results show that involving incumbents improves search in complementary technologies, while demoting it when strategic interests are misaligned in disruptive technologies....... However, incumbent sources engaged in capability reconfiguration to accommodate disruption improve search efforts in disruptive technologies. The paper concludes that the value of external sources is contingent on more than their knowledge. Specifically, interdependence of sources in search gives rise...

  5. A test of catastrophic transition mechanisms in the Chihuahuan Desert Grassland

    Science.gov (United States)

    Svejcar, L.; Bestelmeyer, B.; Duniway, M.

    2012-12-01

    Dryland ecosystems are known to undergo transitions from grassland or savanna states to shrub-dominated and/or eroded states with persistent loss of herbaceous vegetation. Theoretical models for predicting critical thresholds between states have been examined in drylands to search for early warning indicators, yet there is scant empirical evidence for the mechanisms. The models postulate that larger patches are favorable environments for plant growth in arid ecosystems due to short-range facilitation. The breakdown of large patches is thought to trigger catastrophic transitions. We tested assumptions underpinning these models using an experiment in black grama grassland (Bouteloua eriopoda Torr.) of the Chihuahuan Desert in which variable grazing intensities produced a wide range of patch sizes in plots with differing mesquite shrub (Prosopis glandulosa Torr.) densities. We tested the hypothesis that growth, reproductive capability, and reproductive success of black grama plants would be greater in larger plant patches than in smaller patches. From 2010-2012 we measured numbers of stolons, ramets, rooted ramets and young individual plants associated with focal black grama plants and fixed areas within each patch. We found that the largest patches did not always feature the highest rates of grass reproduction across years, suggesting that patch size does not consistently indicate the patch persistence mechanisms proposed in catastrophic transition models. Other factors, such as resource competition within patches, may play important roles in black grama grasslands. When assessing rangeland conditions in the Chihuahuan desert grasslands, theoretical models of critical thresholds and early warning indicators should be applied with caution.

  6. Catastrophic destabilization of tunnel under rocks slipping in faultage

    Institute of Scientific and Technical Information of China (English)

    LIU Hai-qing; WANG Xue-qing; YUAN Jing

    2008-01-01

    The model of catastrophic destabilization of tunnel under rock slipping in fault zone based on catastrophic theory and the potential function of fault movement were presented. On the basis of the results above, through Taylor series expansion of the equation of equilibrium surface, its standard form was obtained. Analysis show that catastrophic destabilization of tunnel will occur only when stiffness ratio between elastic sector and strain weakening sector of soft rocks was larger than or equal to 1. On the other hand,sliding behavior and evolution path of fault were directly affected by exogenous process,and it was a major extraneous factor which leads to catastrophic destabilization of tunnel.In the condition of system catastrophe could be generated, if external forces vary from smaller to larger, firstly, fault sticks or creeps, and secondly, when external force equal to or larger than critical value, fault turns to slip suddenly. Inverse, if external forces vary from larger to smaller, fault smoothly slips firstly, when external force equal to or smaller than critical value, and fault turns to stick or creep suddenly.

  7. Chromosome catastrophes involve replication mechanisms generating complex genomic rearrangements.

    Science.gov (United States)

    Liu, Pengfei; Erez, Ayelet; Nagamani, Sandesh C Sreenath; Dhar, Shweta U; Kołodziejska, Katarzyna E; Dharmadhikari, Avinash V; Cooper, M Lance; Wiszniewska, Joanna; Zhang, Feng; Withers, Marjorie A; Bacino, Carlos A; Campos-Acevedo, Luis Daniel; Delgado, Mauricio R; Freedenberg, Debra; Garnica, Adolfo; Grebe, Theresa A; Hernández-Almaguer, Dolores; Immken, LaDonna; Lalani, Seema R; McLean, Scott D; Northrup, Hope; Scaglia, Fernando; Strathearn, Lane; Trapane, Pamela; Kang, Sung-Hae L; Patel, Ankita; Cheung, Sau Wai; Hastings, P J; Stankiewicz, Paweł; Lupski, James R; Bi, Weimin

    2011-09-16

    Complex genomic rearrangements (CGRs) consisting of two or more breakpoint junctions have been observed in genomic disorders. Recently, a chromosome catastrophe phenomenon termed chromothripsis, in which numerous genomic rearrangements are apparently acquired in one single catastrophic event, was described in multiple cancers. Here, we show that constitutionally acquired CGRs share similarities with cancer chromothripsis. In the 17 CGR cases investigated, we observed localization and multiple copy number changes including deletions, duplications, and/or triplications, as well as extensive translocations and inversions. Genomic rearrangements involved varied in size and complexities; in one case, array comparative genomic hybridization revealed 18 copy number changes. Breakpoint sequencing identified characteristic features, including small templated insertions at breakpoints and microhomology at breakpoint junctions, which have been attributed to replicative processes. The resemblance between CGR and chromothripsis suggests similar mechanistic underpinnings. Such chromosome catastrophic events appear to reflect basic DNA metabolism operative throughout an organism's life cycle.

  8. Catastrophic ice lake collapse in Aram Chaos, Mars

    CERN Document Server

    Roda, Manuel; Zegers, Tanja E; Oosthoek, Jelmer H P

    2014-01-01

    Hesperian chaotic terrains have been recognized as the source of outflow channels formed by catastrophic outflows. Four main scenarios have been proposed for the formation of chaotic terrains that involve different amounts of water and single or multiple outflow events. Here, we test these scenarios with morphological and structural analyses of imagery and elevation data for Aram Chaos in conjunction with numerical modeling of the morphological evolution of the catastrophic carving of the outflow valley. The morphological and geological analyses of Aram Chaos suggest large-scale collapse and subsidence (1500 m) of the entire area, which is consistent with a massive expulsion of liquid water from the subsurface in one single event. The combined observations suggest a complex process starting with the outflow of water from two small channels, followed by continuous groundwater sapping and headward erosion and ending with a catastrophic lake rim collapse and carving of the Aram Valley, which is synchronous with ...

  9. Vitality of Neural Networks under Reoccurring Catastrophic Failures.

    Science.gov (United States)

    Sardi, Shira; Goldental, Amir; Amir, Hamutal; Vardi, Roni; Kanter, Ido

    2016-01-01

    Catastrophic failures are complete and sudden collapses in the activity of large networks such as economics, electrical power grids and computer networks, which typically require a manual recovery process. Here we experimentally show that excitatory neural networks are governed by a non-Poissonian reoccurrence of catastrophic failures, where their repetition time follows a multimodal distribution characterized by a few tenths of a second and tens of seconds timescales. The mechanism underlying the termination and reappearance of network activity is quantitatively shown here to be associated with nodal time-dependent features, neuronal plasticity, where hyperactive nodes damage the response capability of their neighbors. It presents a complementary mechanism for the emergence of Poissonian catastrophic failures from damage conductivity. The effect that hyperactive nodes degenerate their neighbors represents a type of local competition which is a common feature in the dynamics of real-world complex networks, whereas their spontaneous recoveries represent a vitality which enhances reliable functionality. PMID:27530974

  10. Catastrophic disasters and the design of disaster medical care systems.

    Science.gov (United States)

    Mahoney, L E; Reutershan, T P

    1987-09-01

    The National Disaster Medical System (NDMS) is aimed at medical care needs resulting from catastrophic earthquakes, which may cause thousands of deaths and injuries. Other geophysical events may cause great mortality, but leave few injured survivors. Weather incidents, technological disasters, and common mass casualty incidents cause much less mortality and morbidity. Catastrophic disasters overwhelm the local medical care system. Supplemental care is provided by disaster relief forces; this care should be adapted to prevalent types of injuries. Most care should be provided at the disaster scene through supplemental medical facilities, while some can be provided by evacuating patients to distant hospitals. Medical response teams capable of stabilizing, sorting, and holding victims should staff supplemental medical facilities. The NDMS program includes hospital facilities, evacuation assets, and medical response teams. The structure and capabilities of these elements are determined by the medical care needs of the catastrophic disaster situation. PMID:3631673

  11. Vitality of Neural Networks under Reoccurring Catastrophic Failures

    Science.gov (United States)

    Sardi, Shira; Goldental, Amir; Amir, Hamutal; Vardi, Roni; Kanter, Ido

    2016-08-01

    Catastrophic failures are complete and sudden collapses in the activity of large networks such as economics, electrical power grids and computer networks, which typically require a manual recovery process. Here we experimentally show that excitatory neural networks are governed by a non-Poissonian reoccurrence of catastrophic failures, where their repetition time follows a multimodal distribution characterized by a few tenths of a second and tens of seconds timescales. The mechanism underlying the termination and reappearance of network activity is quantitatively shown here to be associated with nodal time-dependent features, neuronal plasticity, where hyperactive nodes damage the response capability of their neighbors. It presents a complementary mechanism for the emergence of Poissonian catastrophic failures from damage conductivity. The effect that hyperactive nodes degenerate their neighbors represents a type of local competition which is a common feature in the dynamics of real-world complex networks, whereas their spontaneous recoveries represent a vitality which enhances reliable functionality.

  12. Vitality of Neural Networks under Reoccurring Catastrophic Failures.

    Science.gov (United States)

    Sardi, Shira; Goldental, Amir; Amir, Hamutal; Vardi, Roni; Kanter, Ido

    2016-08-17

    Catastrophic failures are complete and sudden collapses in the activity of large networks such as economics, electrical power grids and computer networks, which typically require a manual recovery process. Here we experimentally show that excitatory neural networks are governed by a non-Poissonian reoccurrence of catastrophic failures, where their repetition time follows a multimodal distribution characterized by a few tenths of a second and tens of seconds timescales. The mechanism underlying the termination and reappearance of network activity is quantitatively shown here to be associated with nodal time-dependent features, neuronal plasticity, where hyperactive nodes damage the response capability of their neighbors. It presents a complementary mechanism for the emergence of Poissonian catastrophic failures from damage conductivity. The effect that hyperactive nodes degenerate their neighbors represents a type of local competition which is a common feature in the dynamics of real-world complex networks, whereas their spontaneous recoveries represent a vitality which enhances reliable functionality.

  13. Gravothermal Catastrophe: the dynamical stability of a fluid model

    CERN Document Server

    Sormani, M C

    2013-01-01

    A re-investigation of the gravothermal catastrophe is presented. By means of a linear perturbation analysis, we study the dynamical stability of a spherical self-gravitating isothermal fluid of finite volume and find that the conditions for the onset of the gravothermal catastrophe, under different external conditions, coincide with those obtained from thermodynamical arguments. This suggests that the gravothermal catastrophe may reduce to Jeans instability, rediscovered in an inhomogeneous framework. We find normal modes and frequencies for the fluid system and show that instability develops on the dynamical time scale. We then discuss several related issues. In particular: (1) For perturbations at constant total energy and constant volume, we introduce a simple heuristic term in the energy budget to mimic the role of binaries. (2) We outline the analysis of the two-component case and show how linear perturbation analysis can be carried out also in this more complex context in a relatively straightforward wa...

  14. Dynamical systems V bifurcation theory and catastrophe theory

    CERN Document Server

    1994-01-01

    Bifurcation theory and catastrophe theory are two of the best known areas within the field of dynamical systems. Both are studies of smooth systems, focusing on properties that seem to be manifestly non-smooth. Bifurcation theory is concerned with the sudden changes that occur in a system when one or more parameters are varied. Examples of such are familiar to students of differential equations, from phase portraits. Moreover, understanding the bifurcations of the differential equations that describe real physical systems provides important information about the behavior of the systems. Catastrophe theory became quite famous during the 1970's, mostly because of the sensation caused by the usually less than rigorous applications of its principal ideas to "hot topics", such as the characterization of personalities and the difference between a "genius" and a "maniac". Catastrophe theory is accurately described as singularity theory and its (genuine) applications. The authors of this book, the first printing of w...

  15. A critical look at risk assessments for global catastrophes.

    Science.gov (United States)

    Kent, Adrian

    2004-02-01

    Recent articles by Busza et al. (BJSW) and Dar et al. (DDH) argue that astrophysical data can be used to establish small bounds on the risk of a "killer strangelet" catastrophe scenario in the RHIC and ALICE collider experiments. The case for the safety of the experiments set out by BJSW does not rely solely on these bounds, but on theoretical arguments, which BJSW find sufficiently compelling to firmly exclude any possibility of catastrophe. Nonetheless, DDH and other commentators (initially including BJSW) suggested that these empirical bounds alone do give sufficient reassurance. This seems unsupportable when the bounds are expressed in terms of expectation value-a good measure, according to standard risk analysis arguments. For example, DDH's main bound, p(catastrophe) future generations, a catastrophe risk no higher than approximately 10(-15) per year would be required for consistency with established policy for radiation hazard risk minimization. Allowing for risk aversion and for future lives, a respectable case can be made for requiring a bound many orders of magnitude smaller. In summary, the costs of small risks of catastrophe have been significantly underestimated by BJSW (initially), by DDH, and by other commentators. Future policy on catastrophe risks would be more rational, and more deserving of public trust, if acceptable risk bounds were generally agreed upon ahead of time and if serious research on whether those bounds could indeed be guaranteed was carried out well in advance of any hypothetically risky experiment, with the relevant debates involving experts with no stake in the experiments under consideration.

  16. Application of Catastrophe Theory in 3D Seismic Data Interpretation of Coal Mine

    Institute of Scientific and Technical Information of China (English)

    ZHAO Mu-hua; YANG Wen-qiang; CUI Hui-xia

    2005-01-01

    In order to detect fault exactly and quickly, cusp catastrophe theory is used to interpret 3D coal seismic data in this paper. By establishing a cusp model, seismic signal is transformed into standard form of cusp catastrophe and catastrophe parameters, including time-domain catastrophe potential, time-domain catastrophe time, frequency-domain catastrophe potential and frequency- domain degree, are calculated. Catastrophe theory is used in 3D seismic structural interpretation in coal mine. The results show that the position of abnormality of the catastrophe parameter profile or curve is related to the location of fault, and the cusp catastrophe theory is effective to automatically pick up geology information and improve the interpretation precision in 3D seismic data.

  17. Catastrophic antiphospholipid syndrome presenting as fever of unknown origin

    Directory of Open Access Journals (Sweden)

    Fatma I Al-Beladi

    2012-01-01

    Full Text Available Antiphospholipid syndrome is characterized by the presence of antiphospholipid antibodies with characteristic clinical manifestation, which include venous, arterial thrombosis, thrombotic microangiopathy, and recurrent fetal loss. The syndrome can be secondary to many causes including systemic lupus erythematosus (SLE or "primary" antiphospholipid syndrome (APLS. We report a case of a man with catastrophic antiphospholipid syndrome (CAPS, which occurs when three or more organ systems are affected by thrombosis in less than a week. Catastrophic antiphospholipid syndrome is uncommon but often fatal. The patient received a successful treatment that controlled this disease and included intravenous heparin, antiplatelet, intravenous corticosteroid, and plasmapheresis.

  18. Crisis Management Aspects of Bam Catastrophic Earthquake: Review Article

    OpenAIRE

    Homayoun Sadeghi-Bazargani; Saber Azami-Aghdash; Abdolhassan Kazemi; Behrad Ziapour

    2015-01-01

    Background: Bam earthquake was the most catastrophic natural disasters in recent years. The aim of this study was to review different aspects of crisis manage­ment during and after the catastrophic earthquake in Bam City, Iran.Methods: Data needed for this systematic review were collected through search­ing PubMed, EMBASE and SID databases, for the period from 2003 to 2011. Keywords included earthquake, Iran and Bam earthquake. The data were summarized and were analyzed using Content Analysis...

  19. Elaborating on threshold concepts

    Science.gov (United States)

    Rountree, Janet; Robins, Anthony; Rountree, Nathan

    2013-09-01

    We propose an expanded definition of Threshold Concepts (TCs) that requires the successful acquisition and internalisation not only of knowledge, but also its practical elaboration in the domains of applied strategies and mental models. This richer definition allows us to clarify the relationship between TCs and Fundamental Ideas, and to account for both the important and the problematic characteristics of TCs in terms of the Knowledge/Strategies/Mental Models Framework defined in previous work.

  20. Grossman's Missing Health Threshold

    OpenAIRE

    Titus J. Galama; Arie Kapteyn

    2009-01-01

    The authors present a generalized solution to Grossman's model of health capital (1972), relaxing the widely used assumption that individuals can adjust their health stock instantaneously to an "optimal" level without adjustment costs. The Grossman model then predicts the existence of a health threshold above which individuals do not demand medical care. Their generalized solution addresses a significant criticism: the model's prediction that health and medical care are positively related is ...

  1. The disruption management model.

    Science.gov (United States)

    McAlister, James

    2011-10-01

    Within all organisations, business continuity disruptions present a set of dilemmas that managers may not have dealt with before in their normal daily duties. The disruption management model provides a simple but effective management tool to enable crisis management teams to stay focused on recovery in the midst of a business continuity incident. The model has four chronological primary headlines, which steer the team through a quick-time crisis decision-making process. The procedure facilitates timely, systematic, rationalised and justified decisions, which can withstand post-event scrutiny. The disruption management model has been thoroughly tested within an emergency services environment and is proven to significantly support clear and concise decision making in a business continuity context. PMID:22130341

  2. Changing circumstances, disrupting habits.

    Science.gov (United States)

    Wood, Wendy; Witt, Melissa Guerrero; Tam, Leona

    2005-06-01

    The present research investigated the mechanisms guiding habitual behavior, specifically, the stimulus cues that trigger habit performance. When usual contexts for performance change, habits cannot be cued by recurring stimuli, and performance should be disrupted. Thus, the exercising, newspaper reading, and TV watching habits of students transferring to a new university were found to survive the transfer only when aspects of the performance context did not change (e.g., participants continued to read the paper with others). In some cases, the disruption in habits also placed behavior under intentional control so that participants acted on their current intentions. Changes in circumstances also affected the favorability of intentions, but changes in intentions alone could not explain the disruption of habits. Furthermore, regardless of whether contexts changed, nonhabitual behavior was guided by intentions. PMID:15982113

  3. Emerging and Disruptive Technologies

    Science.gov (United States)

    2016-01-01

    Several emerging or disruptive technologies can be identified that might, at some point in the future, displace established laboratory medicine technologies and practices. These include increased automation in the form of robots, 3-D printing, technology convergence (e.g., plug-in glucose meters for smart phones), new point-of-care technologies (e.g., contact lenses with sensors, digital and wireless enabled pregnancy tests) and testing locations (e.g., Retail Health Clinics, new at-home testing formats), new types of specimens (e.g., cell free DNA), big biology/data (e.g., million genome projects), and new regulations (e.g., for laboratory developed tests). In addition, there are many emerging technologies (e.g., planar arrays, mass spectrometry) that might find even broader application in the future and therefore also disrupt current practice. One interesting source of disruptive technology may prove to be the Qualcomm Tricorder XPrize, currently in its final stages. PMID:27683538

  4. The disruption management model.

    Science.gov (United States)

    McAlister, James

    2011-10-01

    Within all organisations, business continuity disruptions present a set of dilemmas that managers may not have dealt with before in their normal daily duties. The disruption management model provides a simple but effective management tool to enable crisis management teams to stay focused on recovery in the midst of a business continuity incident. The model has four chronological primary headlines, which steer the team through a quick-time crisis decision-making process. The procedure facilitates timely, systematic, rationalised and justified decisions, which can withstand post-event scrutiny. The disruption management model has been thoroughly tested within an emergency services environment and is proven to significantly support clear and concise decision making in a business continuity context.

  5. Sustainable Disruption Management

    DEFF Research Database (Denmark)

    Vaaben, Bo Valdemar

    The world we live in is globalized. Goods are seldom made in the place where they are used or consumed, and we do increasingly travel to other countries for either business or pleasure. In our everyday lives we rely on well-functioning global transportations systems to continue the standard......, such as e.g. technical problems or congestions are also typical causes of delays. Returning a transportation system to its original plan of operation is referred to as Disruption Management. Disruptions are, however, not the only cause of concern to the transportation industry. Fuel is becoming...... when managing recovery from disruptions. The underlying work of this thesis is carried out as an industrial PhD project in co-operation with the company Jeppesen, which have the airline industry as its primary area of business and the maritime industry as its secondary area. For this reason the thesis...

  6. Search and Disrupt

    DEFF Research Database (Denmark)

    Ørding Olsen, Anders

    Extant research on external knowledge search and open innovation assumes that collaborators are aligned in their strategic interests towards solving innovation problems. However, disruptive innovation is known to threaten the competitive advantage of incumbent firms, thereby creating a potential...... conflict of interest between these firms and their collaborators. This paper explores the extent to which strategic interests influence joint problem solving in both complementary and disruptive technologies by analyzing the effects of incumbent collaboration. The analysis disentangles inability...... and strategic intent to find that non-incumbents experience suppression of problem solving likelihood within disruptive technologies when incumbent collaborators are not strategically committed. The paper contributes to extant theory by showing the influence of firms’ underlying strategic interests...

  7. Interruptions disrupt reading comprehension.

    Science.gov (United States)

    Foroughi, Cyrus K; Werner, Nicole E; Barragán, Daniela; Boehm-Davis, Deborah A

    2015-06-01

    Previous research suggests that being interrupted while reading a text does not disrupt the later recognition or recall of information from that text. This research is used as support for Ericsson and Kintsch's (1995) long-term working memory (LT-WM) theory, which posits that disruptions while reading (e.g., interruptions) do not impair subsequent text comprehension. However, to fully comprehend a text, individuals may need to do more than recognize or recall information that has been presented in the text at a later time. Reading comprehension often requires individuals to connect and synthesize information across a text (e.g., successfully identifying complex topics such as themes and tones) and not just make a familiarity-based decision (i.e., recognition). The goal for this study was to determine whether interruptions while reading disrupt reading comprehension when the questions assessing comprehension require participants to connect and synthesize information across the passage. In Experiment 1, interruptions disrupted reading comprehension. In Experiment 2, interruptions disrupted reading comprehension but not recognition of information from the text. In Experiment 3, the addition of a 15-s time-out prior to the interruption successfully removed these negative effects. These data suggest that the time it takes to process the information needed to successfully comprehend text when reading is greater than that required for recognition. Any interference (e.g., an interruption) that occurs during the comprehension process may disrupt reading comprehension. This evidence supports the need for transient activation of information in working memory for successful text comprehension and does not support LT-WM theory. PMID:25867225

  8. Concrete ensemble Kalman filters with rigorous catastrophic filter divergence.

    Science.gov (United States)

    Kelly, David; Majda, Andrew J; Tong, Xin T

    2015-08-25

    The ensemble Kalman filter and ensemble square root filters are data assimilation methods used to combine high-dimensional, nonlinear dynamical models with observed data. Ensemble methods are indispensable tools in science and engineering and have enjoyed great success in geophysical sciences, because they allow for computationally cheap low-ensemble-state approximation for extremely high-dimensional turbulent forecast models. From a theoretical perspective, the dynamical properties of these methods are poorly understood. One of the central mysteries is the numerical phenomenon known as catastrophic filter divergence, whereby ensemble-state estimates explode to machine infinity, despite the true state remaining in a bounded region. In this article we provide a breakthrough insight into the phenomenon, by introducing a simple and natural forecast model that transparently exhibits catastrophic filter divergence under all ensemble methods and a large set of initializations. For this model, catastrophic filter divergence is not an artifact of numerical instability, but rather a true dynamical property of the filter. The divergence is not only validated numerically but also proven rigorously. The model cleanly illustrates mechanisms that give rise to catastrophic divergence and confirms intuitive accounts of the phenomena given in past literature.

  9. Self-Organized Patchiness and Catastrophic Shifts in Ecosystems

    NARCIS (Netherlands)

    Rietkerk, Max; Dekker, Stefan C.; Ruiter, Peter C. de; Koppel, Johan van de

    2004-01-01

    Unexpected sudden catastrophic shifts may occur in ecosystems, with concomitant losses or gains of ecological and economic resources. Such shifts have been theoretically attributed to positive feedback and bistability of ecosystem states. However, verifications and predictive power with respect to c

  10. Self-organized patchiness and catastrophic shifts in ecosystems

    NARCIS (Netherlands)

    Rietkerk, M.; Dekker, S.C.; de Ruiter, P.C.; Van de Koppel, J.

    2004-01-01

    Unexpected sudden catastrophic shifts may occur in ecosystems, with concomitant losses or gains of ecological and economic resources. Such shifts have been theoretically attributed to positive feedback and bistability of ecosystem states. However, verifications and predictive power with respect to c

  11. Early warning signals also precede non-catastrophic transitions

    NARCIS (Netherlands)

    Kefi, S.; Dakos, V.; Scheffer, M.; Nes, E.H. van; Rietkerk, M.

    2013-01-01

    Ecosystem responses to external changes can surprise us by their abruptness and irreversibility. Models have helped identifying indicators of impending catastrophic shifts, referred to as ‘generic early warning signals’. These indicators are linked to a phenomenon known as ‘critical slowing down’ wh

  12. Catastrophe in diffusion-controlled annihilation dynamics: general scaling properties

    Science.gov (United States)

    Shipilevsky, Boris M.

    2015-11-01

    We present a systematic analytical and numerical study of the annihilation catastrophe phenomenon which develops in an open system, where species A and B diffuse from the bulk of restricted medium and die on its surface (desorb) by the reaction A + B → 0. This phenomenon arises in the diffusion-controlled limit as a result of self-organizing explosive growth (drop) of the surface concentrations of, respectively, slow and fast particles (concentration explosion) and manifests itself in the form of an abrupt singular jump of the desorption flux relaxation rate. In the recent work [B.M. Shipilevsky, Phys. Rev. E 76, 031126 (2007)] a closed scaling theory of catastrophe development has been given for the asymptotic limit when the characteristic time scale of explosion becomes much less than the characteristic time scales of diffusion of slow and fast particles at an arbitrary ratio of their diffusivities 0 < p < 1. In this paper we consider the behavior of the system at strong difference of species diffusivities p ≪ 1 and reveal a rich general pattern of catastrophe development for an arbitrary ratio of the characteristic time scales of explosion and fast particle diffusion. As striking results we find remarkable scaling properties of catastrophe evolution at the crossover between two limiting regimes with radically different dynamics.

  13. The Application of Catastrophe Theory to Medical Image Analysis

    NARCIS (Netherlands)

    Kuijper, Arjan; Florack, L.M.J.

    2002-01-01

    In order to investigate the deep structure of Gaussian scale space images, one needs to understand the behaviour of critical points under the influence of blurring. We show how the mathematical framework of catastrophe theory can be used to describe the various different types of annihilations and c

  14. The Application of Catastrophe Theory to Image Analysis

    NARCIS (Netherlands)

    Kuijper, Arjan; Florack, L.M.J.

    2002-01-01

    In order to investigate the deep structure of Gaussian scale space images, one needs to understand the behaviour of critical points under the in flence of blurring. We show how the mathematical framework of catastrophe theory can be used to describe the various different types of annihilations and t

  15. A catastrophe theory model of the conflict helix, with tests.

    Science.gov (United States)

    Rummel, R J

    1987-10-01

    Macro social field theory has undergone extensive development and testing since the 1960s. One of these has been the articulation of an appropriate conceptual micro model--called the conflict helix--for understanding the process from conflict to cooperation and vice versa. Conflict and cooperation are viewed as distinct equilibria of forces in a social field; the movement between these equilibria is a jump, energized by a gap between social expectations and power, and triggered by some minor event. Quite independently, there also has been much recent application of catastrophe theory to social behavior, but usually without a clear substantive theory and lacking empirical testing. This paper uses catastrophe theory--namely, the butterfly model--mathematically to structure the conflict helix. The social field framework and helix provide the substantive interpretation for the catastrophe theory; and catastrophe theory provides a suitable mathematical model for the conflict helix. The model is tested on the annual conflict and cooperation between India and Pakistan, 1948 to 1973. The results are generally positive and encouraging.

  16. Catastrophic Head Injuries in High School and Collegiate Sports.

    Science.gov (United States)

    Mueller, Frederick O.

    2001-01-01

    Describes the incidence of catastrophic head injuries within high school and college sports. Data from a national surveillance system indicated that a football-related fatality occurred every year except one from 1945-99, mainly related to head injuries. From 1984-99, 69 football head-related injuries resulted in permanent disability. Deaths and…

  17. Disruptive Co-Creation?

    DEFF Research Database (Denmark)

    Butler, Ivan; Christensen, David

    set up to foster innovative partnerships between civil society organizations, businesses and academia with the objective of supporting disruptive business model innovation in co-creation processes across these sectors. This paper delves into state-of-the-art concerning literature pertinent...

  18. Hadron production near threshold

    Indian Academy of Sciences (India)

    B K Jain; N G Kelkar; K P Khmemchandani

    2006-04-01

    Final state interaction effects in → + and → 3He reactions are explored near threshold to study the sensitivity of the cross-sections to the potential and the scattering matrix. The final state scattering wave functions between and and and 3He are described rigorously. The production is described by the exchange of one pion and a -meson between two protons in the incident channel. The production is described by a two-step model, where in the first step a pion is produced. This pion then produces an by interacting with another nucleon.

  19. Unstable Particles near Threshold

    CERN Document Server

    Chway, Dongjin; Kim, Hyung Do

    2015-01-01

    We explore physics of unstable particles when mother particle mass is around the sum of its daughter particle masses. In this case, the conventional wave function renormalization factor is ill-defined. We propose a simple resolution of the threshold singularity problem which still allows the use of narrow width approximation by defining branching ratio in terms of spectral density. The resonance peak and shape is different for different decay channels and no single decay width can be assigned to the unstable particles. Non-exponential decay happens in all time scales.

  20. Community resilience and decision theory challenges for catastrophic events.

    Science.gov (United States)

    Cox, Louis Anthony

    2012-11-01

    Extreme and catastrophic events pose challenges for normative models of risk management decision making. They invite development of new methods and principles to complement existing normative decision and risk analysis. Because such events are rare, it is difficult to learn about them from experience. They can prompt both too little concern before the fact, and too much after. Emotionally charged and vivid outcomes promote probability neglect and distort risk perceptions. Aversion to acting on uncertain probabilities saps precautionary action; moral hazard distorts incentives to take care; imperfect learning and social adaptation (e.g., herd-following, group-think) complicate forecasting and coordination of individual behaviors and undermine prediction, preparation, and insurance of catastrophic events. Such difficulties raise substantial challenges for normative decision theories prescribing how catastrophe risks should be managed. This article summarizes challenges for catastrophic hazards with uncertain or unpredictable frequencies and severities, hard-to-envision and incompletely described decision alternatives and consequences, and individual responses that influence each other. Conceptual models and examples clarify where and why new methods are needed to complement traditional normative decision theories for individuals and groups. For example, prospective and retrospective preferences for risk management alternatives may conflict; procedures for combining individual beliefs or preferences can produce collective decisions that no one favors; and individual choices or behaviors in preparing for possible disasters may have no equilibrium. Recent ideas for building "disaster-resilient" communities can complement traditional normative decision theories, helping to meet the practical need for better ways to manage risks of extreme and catastrophic events. PMID:22967051

  1. Threshold Generation of Signcryption

    Institute of Scientific and Technical Information of China (English)

    ZHANGFutai; JIDongyao; WANGYumin

    2003-01-01

    Signcryption is a new cryptographic primitive wiich simultaneously fulfills both the functions of digital signature and public key encryption in a logically singlestep,and with a cost significantly lower than that required by "signature followed by encryption".It has many applications in such areas as electronic cash payment systems,secure and authenticated key establishment,secure multicasting over the Internet,authenticated key recovery,etc..In secure and authenticated group communication there is a need for threshold generation of signcryption.In this paper,we propose a protocol for threshold generation of signcryption using the techniques of verifiable secret sharing(VSS)and secure multi-party computation (MPC).In the protocol,any t or more honest members can efficiently generate valid signcryption text of a given message,while the adversary whole corrupts up to t-1 group members cannot forge any valid signcryption text.The protocol of computing reciprocals of secrets presented by R.Gennaro,S.Jarecki,H.Krawczyk,and T.Rabin is also modified so that the efficiency is improved.

  2. Coloring geographical threshold graphs

    Energy Technology Data Exchange (ETDEWEB)

    Bradonjic, Milan [Los Alamos National Laboratory; Percus, Allon [Los Alamos National Laboratory; Muller, Tobias [EINDHOVEN UNIV. OF TECH

    2008-01-01

    We propose a coloring algorithm for sparse random graphs generated by the geographical threshold graph (GTG) model, a generalization of random geometric graphs (RGG). In a GTG, nodes are distributed in a Euclidean space, and edges are assigned according to a threshold function involving the distance between nodes as well as randomly chosen node weights. The motivation for analyzing this model is that many real networks (e.g., wireless networks, the Internet, etc.) need to be studied by using a 'richer' stochastic model (which in this case includes both a distance between nodes and weights on the nodes). Here, we analyze the GTG coloring algorithm together with the graph's clique number, showing formally that in spite of the differences in structure between GTG and RGG, the asymptotic behavior of the chromatic number is identical: {chi}1n 1n n / 1n n (1 + {omicron}(1)). Finally, we consider the leading corrections to this expression, again using the coloring algorithm and clique number to provide bounds on the chromatic number. We show that the gap between the lower and upper bound is within C 1n n / (1n 1n n){sup 2}, and specify the constant C.

  3. COLLISIONAL STRIPPING AND DISRUPTION OF SUPER-EARTHS

    International Nuclear Information System (INIS)

    The final stage of planet formation is dominated by collisions between planetary embryos. The dynamics of this stage determine the orbital configuration and the mass and composition of planets in the system. In the solar system, late giant impacts have been proposed for Mercury, Earth, Mars, and Pluto. In the case of Mercury, this giant impact may have significantly altered the bulk composition of the planet. Here we present the results of smoothed particle hydrodynamics simulations of high-velocity (up to ∼5v esc) collisions between 1 and 10 M + planets of initially terrestrial composition to investigate the end stages of formation of extrasolar super-Earths. As found in previous simulations of collisions between smaller bodies, when collision energies exceed simple merging, giant impacts are divided into two regimes: (1) disruption and (2) hit-and-run (a grazing inelastic collision and projectile escape). Disruption occurs when the impact parameter is near zero, when the projectile mass is small compared to the target, or at extremely high velocities. In the disruption regime, we derive the criteria for catastrophic disruption (when half the total colliding mass is lost), the transition energy between accretion and erosion, and a scaling law for the change in bulk composition (iron-to-silicate ratio) resulting from collisional stripping of a mantle.

  4. Catastrophic behavior of aphid population dynamics: An analysis of swallowtail model

    Directory of Open Access Journals (Sweden)

    Mkdk Piyaratne

    2014-09-01

    Full Text Available Catastrophe phenomena are frequent in insect ecology, especially in aphid populations. Complexity of this phenomenon urges different modeling frameworks other than traditional methodologies to understand the trajectories of their behavior. Situations like this can be best handled using catastrophe theory. A few numbers of experiments have been conducted to develop catastrophe models in insect ecology, especially for aphids, and most of them are based on cusp catastrophe theory which is a lower dimensional model. However few attempts using higher dimensional models such as swallowtail or butterfly theory to analyze aphid population dynamics are also exist. In this paper we tried to analyze a recently developed higher dimensional catastrophe theory model (APHIDSim in order to identify catastrophe regions, and used independent data to identify if catastrophic behavior is observed in the data and consequently to further verify the model. Here we found that identifying catastrophe regions is possible using catastrophe theory model, and it can be used to analyze catastrophes in insect ecology by graphically interpreting the simulated results. Increasing of insect population is intrinsically catastrophic and catastrophes (jumps occur between states even if the driving variables still change smoothly. The results further verified the previously developed model, and we suggest that insect management program developers should consider this phenomenon when they design the management strategies for insect controlling.

  5. 15 CFR 2301.10 - Applications resulting from catastrophic damage or emergency situations.

    Science.gov (United States)

    2010-01-01

    ... catastrophic damage or emergency situations. 2301.10 Section 2301.10 Commerce and Foreign Trade Regulations... Applications resulting from catastrophic damage or emergency situations. (a) An application may be filed with a... suffers catastrophic damage to the basic equipment essential to its continued operation as a result of...

  6. Endocrine disrupting compounds

    DEFF Research Database (Denmark)

    Bøgh, I B; Christensen, P; Dantzer, V;

    2001-01-01

    With the growing concern that environmental chemicals might impair human and animal fertility, it is important to investigate the possible influence of these substances on sexual differentiation and genital development of mammals. Many of these substances are suspected to interfere with endocrine...... processes, and exposure during critical periods of prenatal development might affect reproductive performance over several generations. Alkylphenols and their metabolites are lipophilic substances exerting apparent estrogenic action in in vitro and in vivo testing systems. With the widespread industrial use...... or embryo models for the evaluation of possible consequences of human exposure to endocrine disrupting compounds is discussed. Furthermore, possible consequences of exposure to endocrine disrupting compounds for the embryo transfer industry are addressed....

  7. Celibacy and Family Disruption

    OpenAIRE

    Emaletdinov B. M.

    2013-01-01

    Causes for celibacy, divorces and successful marriage are discussed in the article. Absence of true love and inability to build and keep it are the main reasons for family disruption. Amorousness, immature love and various forms of false or flawed love substitute the true feeling. It is caused by increased women’s independence, loss of mutual understanding and trust (due to infidelity or jealousy), incompatibility of characters or values. Celibacy is often conditioned by physical disability, ...

  8. Search and Disrupt

    OpenAIRE

    Ørding Olsen, Anders

    2015-01-01

    This paper analyzes how external search is affected by strategic interest alignment among knowledge sources. I focus on misalignment arising from the heterogeneous effects of disruptive technologies by analyzing the influence of incumbents on 2,855 non-incumbents? external knowledge search efforts. The efforts most likely to solve innovation problems obtained funding from the European Commission?s 7th Framework Program (2007-2013). The results show that involving incumbents improv...

  9. Schematically disruptive game design

    OpenAIRE

    Howell, Peter

    2011-01-01

    Many games focus their resources at satiating player ‘needs’, and meeting perceived expectations that players have of how games should behave and of what constitutes enjoyable, gratifying gameplay. This paper outlines an alternate position on game design – one which focuses on disrupting these expectations, on designing games that players cannot succeed in simply by relying on their pre-acquired gameplay experiences. A critique of current game design trends is offered, and possible future out...

  10. Stability threshold approach for complex dynamical systems

    Science.gov (United States)

    Klinshov, Vladimir V.; Nekorkin, Vladimir I.; Kurths, Jürgen

    2016-01-01

    A new measure to characterize the stability of complex dynamical systems against large perturbations is suggested, the stability threshold (ST). It quantifies the magnitude of the weakest perturbation capable of disrupting the system and switch it to an undesired dynamical regime. In the phase space, the ST corresponds to the ‘thinnest site’ of the attraction basin and therefore indicates the most ‘dangerous’ direction of perturbations. We introduce a computational algorithm for quantification of the ST and demonstrate that the suggested approach is effective and provides important insights. The generality of the obtained results defines their vast potential for application in such fields as engineering, neuroscience, power grids, Earth science and many others where the robustness of complex systems is studied.

  11. Monolayer dispersion thresholds and threshold effect displayed by supported catalysts

    Institute of Scientific and Technical Information of China (English)

    Cun DENG

    2008-01-01

    The principle of spontaneous monolayer dis-persion holds that active components of many supported catalysts will disperse spontaneously onto the surface of the carrier. The monolayer dispersion threshold of the active component on the surface of the carrier can be measured by X-ray diffraction phase-quantitative extra-polation method, etc. By measuring the monolayer disper-sion threshold, beneficial information on the surface structure and dispersion of supported catalysts can be obtained, and the optimal preparative processing condi-tions of the catalysts can be chosen. The proportion of the active component of many supported catalysts can be optimized while its monolayer dispersion threshold is observed. Mutation values of many physicochemical properties of supported catalysts are related to monolayer dispersion thresholds; the threshold effect on catalysts is apparent, and the proposal regarding the threshold effect provides instruction for the research on catalysts.

  12. Acceptance of governmental communication in catastrophes and media coverage

    International Nuclear Information System (INIS)

    Technology policy - like every political field - has to deal with conflicts, in which different partial interests are negotiated. Technological catastrophes are based on past decisions in technology policy. From there specific problems of acceptance in catastrophes can only be understood according to this social and temporal context. Acceptance deficits of the government result from the insufficient consideration of the interests non-governmental actors express(ed) with regard to technological risk decisions. Therefore governmental risk and crisis communication should communicate the rationales underlying technology decisions, at the same time giving other actors the possibility of further negotiation. The media coverage plays an important role in this communication process. Following their own specific rules the media create a public sphere, in order to give different groups and institutions an orientation for their social acting. Governmental communication should not consider journalism as a transmission belt for its information policy - rather, in order to be effective, it should respect the specific journalistic conduct. (orig.)

  13. Catastrophic failure of ceramic-polyethylene bearing total hip arthroplasty.

    Science.gov (United States)

    Needham, Justin; Burns, Travis; Gerlinger, Tad

    2008-06-01

    Complications of ceramic-polyethylene bearing total hip arthroplasty (THA) include osteolysis, loosening, dislocation, and component failure. Catastrophic acetabular component failure involves severe damage to both the polyethylene liner and metal shell. This case study presents the first reported complete wear-through of the acetabular portion of a ceramic-polyethylene arthroplasty presenting as a dislocation and a review of the literature. In this study, a patient's alumina ceramic femoral head penetrated the polyethylene liner and titanium shell and presented as a dislocated THA. The contributing factors for this catastrophic failure include young patient age, high activity level, thin polyethylene liner, backside wear, component positioning, polyethylene sterilization with gamma irradiation in air, and lack of appropriate follow-up. Revision THA was performed without complications. PMID:18514888

  14. The Kychtym accident or the story of a secret catastrophe

    International Nuclear Information System (INIS)

    This paper analyses the causes, the circumstances and the environmental consequences of the Kychtym catastrophe (Ural, USSR) that occurred in September 29, 1957 in the fuel recycle plant of the Tcheliabinsk military-industrial complex. A brief description of the separation process and of the installations used is given to understand the conclusions of the inquiry carried out by Russian and foreign experts. The violent redox reaction between nitrates and acetates that occurred, was due to a lack of cooling in the fission products storage ponds. The catastrophe produced a huge strontium 90-rich radioactive cloud which led to a 9000 to 15000 km2 surface contamination. A comparison with the PUREX separation process used in France is given to evaluate the risk of such industrial accidents in French fuel recycle centers. (J.S.). 1 fig., 2 photos

  15. Intraoperative endobronchial rupture of pulmonary hydatid cyst: An airway catastrophe

    Directory of Open Access Journals (Sweden)

    Richa Gupta

    2013-01-01

    Full Text Available Hydatid cyst disease of lungs may not be symptomatic. It may present as spontaneous rupture in pleura or a bronchus. During spontaneous breathing, cyst content of endobronchially ruptured pulmonary hydatid cyst is mostly evacuated by coughing. However, during positive pressure ventilation such extruded fragments may lodge into smaller airway leading to an airway catastrophe. We present such accidental endobronchial rupture of pulmonary hydatid cyst during surgery, its prompt detection, and management by rigid bronchoscopy.

  16. Bank strategies in catastrophe settings: empirical evidence and policy suggestions

    OpenAIRE

    Leonardo Becchetti; Stefano Castriota; Pierluigi Conzo

    2012-01-01

    The poor in developing countries are the most exposed to natural catastrophes and microfinance organizations may potentially ease their economic recovery. Yet, no evidence on MFIs strategies after natural disasters exists. We aim to fill this gap by building adataset which merges bank records of loans, issued before and after the 2004 Tsunami by a Sri Lankan MFI recapitalized by Western donors, with detailed survey data on the corresponding borrowers. Evidence of effective post-calamity inter...

  17. Iatrogenic diaphragmatic hernia in infants: Potentially catastrophic when overlooked

    Directory of Open Access Journals (Sweden)

    Yousef El-Gohary

    2014-11-01

    Full Text Available Acquired diaphragmatic hernias are a rare occurrence. They can result from blunt, penetrating or inadvertent iatrogenic injury. When overlooked they can potentially be catastrophic. We report a case of iatrogenic diaphragmatic hernia in a six-month old infant presenting with acute respiratory distress as a result of strangulated bowel herniating into the left hemithorax caused from a traumatic chest tube insertion in the neonatal period.

  18. Catastrophic Fault Recovery with Self-Reconfigurable Chips

    Science.gov (United States)

    Zheng, Will Hua; Marzwell, Neville I.; Chau, Savio N.

    2006-01-01

    Mission critical systems typically employ multi-string redundancy to cope with possible hardware failure. Such systems are only as fault tolerant as there are many redundant strings. Once a particular critical component exhausts its redundant spares, the multi-string architecture cannot tolerate any further hardware failure. This paper aims at addressing such catastrophic faults through the use of 'Self-Reconfigurable Chips' as a last resort effort to 'repair' a faulty critical component.

  19. Pricing Excess-of-loss Reinsurance Contracts Against Catastrophic Loss

    OpenAIRE

    J. David Cummins; Lewis, Christopher M.; Phillips, Richard D.

    1998-01-01

    This paper develops a pricing methodology and pricing estimates for the proposed Federal excess-of- loss (XOL) catastrophe reinsurance contracts. The contracts, proposed by the Clinton Administration, would provide per-occurrence excess-of-loss reinsurance coverage to private insurers and reinsurers, where both the coverage layer and the fixed payout of the contract are based on insurance industry losses, not company losses. In financial terms, the Federal government would be selling earthqua...

  20. Safeguards as catastrophic risk management: insights and projections

    International Nuclear Information System (INIS)

    The system of international agreements designed to prevent the use of nuclear weapons and to control the spread of nuclear weapons, materials and technologies (collectively referred to as the nuclear arms control and nonproliferation regimes) is posited as humanity.s first attempt to mitigate a man-made global catastrophic risk. By extrapolating general principles of government response to risk from the arms control and nonproliferation regimes, a model of international regime building for catastrophic risk mitigation is constructed. This model provides the context for an examination of the system of safeguards implemented by the International Atomic Energy Agency (IAEA), which serves as the nuclear nonproliferation regime.s verification and enforcement mechanism and thereby constitutes the regime's most completely developed discrete mechanism for risk mitigation (a 'system within a system'). An assessment of the history, evolution and effectiveness of the IAEA safeguards system in the context of the regimes-as-risk-mitigation model reveals some general principles for risk-mitigation regimes which are then applied to the safeguards system to identify ways in which it may be strengthened. Finally, the IAEA safeguards system is posited as the prototype verification/enforcement mechanism for future risk mitigation regimes that governments will be compelled to create in the face of new global catastrophic risks that technological advance will inevitably create. (author)

  1. The impact of possible climate catastrophes on global warming policy

    International Nuclear Information System (INIS)

    Recent studies on global warming have introduced the inherent uncertainties associated with the costs and benefits of climate policies and have often shown that abatement policies are likely to be less aggressive or postponed in comparison to those resulting from traditional cost-benefit analyses (CBA). Yet, those studies have failed to include the possibility of sudden climate catastrophes. The aim of this paper is to account simultaneously for possible continuous and discrete damages resulting from global warming, and to analyse their implications on the optimal path of abatement policies. Our approach is related to the new literature on investment under uncertainty, and relies on some recent developments of the real option in which we incorporated negative jumps (climate catastrophes) in the stochastic process corresponding to the net benefits associated with the abatement policies. The impacts of continuous and discrete climatic risks can therefore be considered separately. Our numerical applications lead to two main conclusions: (i) gradual, continuous uncertainty in the global warming process is likely to delay the adoption of abatement policies as found in previous studies, with respect to the standard CBA; however (ii) the possibility of climate catastrophes accelerates the implementation of these policies as their net discounted benefits increase significantly

  2. Catastrophic rupture of lunar rocks - A Monte Carlo simulation

    Science.gov (United States)

    Hoerz, F.; Schneider, E.; Gault, D. E.; Hartung, J. B.; Brownlee, D. E.

    1975-01-01

    A computer model based on Monte Carlo techniques was developed to simulate the destruction of lunar rocks by 'catastrophic rupture' due to meteoroid impact. Energies necessary to accomplish catastrophic rupture were derived from laboratory experiments. A crater-production rate derived from lunar rocks was utilized to calculate absolute time scales. Calculated median survival times for crystalline lunar rocks are 1.9, 4.6, 10.3, and 22 m.y. for rock masses of 10, 100, 1000, and 10,000 g, respectively. Corresponding times of 6, 14.5, 32, and 68 million years are required before the probability of destruction reaches 0.99. These results are consistent with absolute exposure ages measured on returned rocks. Some results also substantiate previous conclusions that the catastrophic-rupture process is significantly more effective in obliterating lunar rocks than mass wasting by single-particle abrasion. The view is also corroborated that most rocks presently on the lunar surface either are exhumed from the regolith or are fragments of much larger boulders rather than primary ejecta excavated from pristine bedrock.

  3. Molecular and Mechanical Causes of Microtubule Catastrophe and Aging.

    Science.gov (United States)

    Zakharov, Pavel; Gudimchuk, Nikita; Voevodin, Vladimir; Tikhonravov, Alexander; Ataullakhanov, Fazoil I; Grishchuk, Ekaterina L

    2015-12-15

    Tubulin polymers, microtubules, can switch abruptly from the assembly to shortening. These infrequent transitions, termed "catastrophes", affect numerous cellular processes but the underlying mechanisms are elusive. We approached this complex stochastic system using advanced coarse-grained molecular dynamics modeling of tubulin-tubulin interactions. Unlike in previous simplified models of dynamic microtubules, the catastrophes in this model arise owing to fluctuations in the composition and conformation of a growing microtubule tip, most notably in the number of protofilament curls. In our model, dynamic evolution of the stochastic microtubule tip configurations over a long timescale, known as the system's "aging", gives rise to the nonexponential distribution of microtubule lifetimes, consistent with experiment. We show that aging takes place in the absence of visible changes in the microtubule wall or tip, as this complex molecular-mechanical system evolves slowly and asymptotically toward the steady-state level of the catastrophe-promoting configurations. This new, to our knowledge, theoretical basis will assist detailed mechanistic investigations of the mechanisms of action of different microtubule-binding proteins and drugs, thereby enabling accurate control over the microtubule dynamics to treat various pathologies. PMID:26682815

  4. Does landscape diversity reduce the risk of catastrophic tipping points?

    Science.gov (United States)

    Temme, Arnaud; Baartman, Jantiene; Saco, Patricia; Nijp, Jelmer; Langston, Abigail

    2016-04-01

    Most studies about tipping points are based on computer simulations. These simulations, based on first principles of vegetation growth and competition, are not only able to explain a surprising number of vegetation patterns occurring in natural ecosystems, but they also predict shifts between multiple stable states that may be catastrophic. Initially, such studies were performed on simplistic 'non-landscapes' - flats or straight slopes. Recently, we have been able to resolve geomorphic redistribution processes more accurately, so that vegetation patterning can be simulated in more complex landscapes. Here, we present a first look into how such 'real landscapes' affect the risk of catastrophic shifts. We test the hypothesis that increasing complexity and organisation in a landscape reduce the risk of catastrophic shifts by effectively creating mini-refugia where vegetation persists over a wider range of boundary conditions such as precipitation. Depending on the extent of a study area, large complexity could even change the system from one with multiple stable states into one with only one stable state.

  5. Bifurcation and catastrophe of seepage flow system in broken rock

    Institute of Scientific and Technical Information of China (English)

    MIAO Xie-xing; LI Shun-cai; CHEN Zhan-qing

    2009-01-01

    The study of dynamical behavior of water or gas flows in broken rock is a basic research topic among a series of key projects about stability control of the surrounding rocks in mines and the prevention of some disasters such as water inrush or gas outburst and the protection of the groundwater resource. It is of great theoretical and engineering importance in respect of promo-tion of security in mine production and sustainable development of the coal industry. According to the non-Darcy property of seepage flow in broken rock dynamic equations of non-Darcy and non-steady flows in broken rock are established. By dimensionless transformation, the solution diagram of steady-states satisfying the given boundary conditions is obtained. By numerical analysis of low relaxation iteration, the dynamic responses corresponding to the different flow parameters have been obtained. The stability analysis of the steady-states indicate that a saddle-node bifurcaton exists in the seepage flow system of broken rock. Consequently, using catastrophe theory, the fold catastrophe model of seepage flow instability has been obtained. As a result, the bifurcation curves of the seepage flow systems with different control parameters are presented and the standard potential function is also given with respect to the generalized state variable for the fold catastrophe of a dynamic system of seepage flow in broken rock.

  6. MD 751: Train Instability Threshold

    CERN Document Server

    Carver, Lee Robert; Metral, Elias; Salvant, Benoit; Levens, Tom; Nisbet, David; Zobov, M; CERN. Geneva. ATS Department

    2016-01-01

    The purpose of this MD is to measure the octupole current thresholds for stability for a single bunch, and then make an immediate comparison (with the same operational settings) for a train of 72 bunches separated by 25ns. From theory, the expected thresholds should be similar. Any discrepancy between the two cases will be of great interest as it could indicate the presence of additional mechanisms that contribute to the instability threshold, for example electron cloud.

  7. Lower Hearing Threshold by Noise

    Institute of Scientific and Technical Information of China (English)

    龙长才; 邵峰; 张燕萍; 秦佑国

    2004-01-01

    We demonstrate that noise can be a benefit factor that enables us to hear weaker signals. We measured the hearing thresholds of subjects for pure tone in different noise levels. The results show that pure tone thresholds with noise of some levels are lower than that without noise. The largest down-shift of the threshold by noise among the examined subjects is 5. 7dB, and the smallest is 1.7dB.

  8. The 1985 Nevado del Ruiz volcano catastrophe: anatomy and retrospection

    Science.gov (United States)

    Voight, Barry

    1990-12-01

    This paper seeks to analyze in an objective way the circumstances and events that contributed to the 1985 Nevado del Ruiz catastrophe, in order to provide useful guidelines for future emergencies. The paper is organized into two principal parts. In the first part, an Anatomy of the catastrophe is developed as a step-by-step chronicle of events and actions taken by individuals and organizations during the period November 1984 through November 1985. This chronicle provides the essential background for the crucial events of November 13. This year-long period is broken down further to emphasize important chapters: the gradual awareness of the awakening of the volcano; a long period of institutional skepticism reflecting an absence of credibility; the closure of the credibility gap with the September 11 phreatic eruption, followed by an intensive effort to gird for the worst; and a detailed account of the day of reckoning. The second part of the paper, Retrospection, examines the numerous complicated factors that influenced the catastrophic outcome, and attempts to cull a few "lessons from Armero" in order to avoid similar occurrences in the future. In a nutshell, the government on the whole acted responsibly but was not willing to bear the economic or political costs of early evacuation or a false alarm. Science accurately foresaw the hazards but was insufficiently precise to render reliable warning of the crucial event at the last possible minute. Catastrophe was therefore a calculated risk, and this combination - the limitations of prediction/detection, the refusal to bear a false alarm and the lack of will to act on the uncertain information available - provided its immediate and most obvious causes. But because the crucial event occurred just two days before the Armero emergency management plan was to be critically examined and improved, the numerous circumstances which delayed progress of emergency management over the previous year also may be said to have

  9. Albania - Thresholds I and II

    Data.gov (United States)

    Millenium Challenge Corporation — From 2006 to 2011, the government of Albania (GOA) received two Millennium Challenge Corporation (MCC) Threshold Programs totaling $29.6 million. Albania received...

  10. Disruption - Access cards service

    CERN Multimedia

    2014-01-01

    We would like to inform you that between 10 November and 15 December 2014, the access cards service in Building 55 will be disrupted, as the GS Department has decided to improve the facilities for users of this building. During the work, you will find the registration, biometric registration and dosimeter exchange services on the second floor of Building 55 and the vehicle sticker service on the ground floor along with the access cards service. We thank you for your understanding and apologise for any inconvenience caused.

  11. Celibacy and Family Disruption

    Directory of Open Access Journals (Sweden)

    Emaletdinov B. M.

    2013-01-01

    Full Text Available Causes for celibacy, divorces and successful marriage are discussed in the article. Absence of true love and inability to build and keep it are the main reasons for family disruption. Amorousness, immature love and various forms of false or flawed love substitute the true feeling. It is caused by increased women’s independence, loss of mutual understanding and trust (due to infidelity or jealousy, incompatibility of characters or values. Celibacy is often conditioned by physical disability, revaluation of freedom and independence, huge requirements to partners, consumer attitude to life, infertility, alcohol and drug abuse, abnormalities in personality and sexuality.

  12. Cyanide enhances hydrogen peroxide toxicity by recruiting endogenous iron to trigger catastrophic chromosomal fragmentation.

    Science.gov (United States)

    Mahaseth, Tulip; Kuzminov, Andrei

    2015-04-01

    Hydrogen peroxide (HP) or cyanide (CN) are bacteriostatic at low-millimolar concentrations for growing Escherichia coli, whereas CN + HP mixture is strongly bactericidal. We show that this synergistic toxicity is associated with catastrophic chromosomal fragmentation. Since CN alone does not kill at any concentration, while HP alone kills at 20 mM, CN must potentiate HP poisoning. The CN + HP killing is blocked by iron chelators, suggesting Fenton's reaction. Indeed, we show that CN enhances plasmid DNA relaxation due to Fenton's reaction in vitro. However, mutants with elevated iron or HP pools are not acutely sensitive to HP-alone treatment, suggesting that, in addition, in vivo CN recruits iron from intracellular depots. We found that part of the CN-recruited iron pool is managed by ferritin and Dps: ferritin releases iron on cue from CN, while Dps sequesters it, quelling Fenton's reaction. We propose that disrupting intracellular iron trafficking is a common strategy employed by the immune system to kill microbes. PMID:25598241

  13. Relativistic tidal disruption events

    Directory of Open Access Journals (Sweden)

    Levan A.

    2012-12-01

    Full Text Available In March 2011 Swift detected an extremely luminous and long-lived outburst from the nucleus of an otherwise quiescent, low luminosity (LMC-like galaxy. Named Swift J1644+57, its combination of high-energy luminosity (1048 ergs s−1 at peak, rapid X-ray variability (factors of >100 on timescales of 100 seconds and luminous, rising radio emission suggested that we were witnessing the birth of a moderately relativistic jet (Γ ∼ 2 − 5, created when a star is tidally disrupted by the supermassive black hole in the centre of the galaxy. A second event, Swift J2058+0516, detected two months later, with broadly similar properties lends further weight to this interpretation. Taken together this suggests that a fraction of tidal disruption events do indeed create relativistic outflows, demonstrates their detectability, and also implies that low mass galaxies can host massive black holes. Here, I briefly outline the observational properties of these relativistic tidal flares observed last year, and their evolution over the first year since their discovery.

  14. Life below the threshold.

    Science.gov (United States)

    Castro, C

    1991-01-01

    This article explains that malnutrition, poor health, and limited educational opportunities plague Philippine children -- especially female children -- from families living below the poverty threshold. Nearly 70% of households in the Philippines do not meet the required daily level of nutritional intake. Because it is often -- and incorrectly -- assumed that women's nutritional requirements are lower than men's, women suffer higher rates of malnutrition and poor health. A 1987 study revealed that 11.7% of all elementary students were underweight and 13.9% had stunted growths. Among elementary-school girls, 17% were malnourished and 40% suffered from anemia (among lactating mothers, more than 1/2 are anemic). A 1988 Program for Decentralized Educational Development study showed that grade VI students learn only about 1/2 of what they are supposed to learn. 30% of the children enrolled in grade school drop out before they reach their senior year. The Department of Education, Culture and Sports estimates that some 2.56 million students dropped out of school in l989. That same year, some 3.7 million children were counted as part of the labor force. In Manila alone, some 60,000 children work the streets, whether doing odd jobs or begging, or turning to crime or prostitution. the article tells the story of a 12 year-old girl named Ging, a 4th grader at a public school and the oldest child in a poor family of 6 children. The undernourished Ging dreams of a good future for her family and sees education as a way out of poverty; unfortunately, her time after school is spend working in the streets or looking after her family. She considers herself luckier than many of the other children working in the streets, since she at least has a family.

  15. Life below the threshold.

    Science.gov (United States)

    Castro, C

    1991-01-01

    This article explains that malnutrition, poor health, and limited educational opportunities plague Philippine children -- especially female children -- from families living below the poverty threshold. Nearly 70% of households in the Philippines do not meet the required daily level of nutritional intake. Because it is often -- and incorrectly -- assumed that women's nutritional requirements are lower than men's, women suffer higher rates of malnutrition and poor health. A 1987 study revealed that 11.7% of all elementary students were underweight and 13.9% had stunted growths. Among elementary-school girls, 17% were malnourished and 40% suffered from anemia (among lactating mothers, more than 1/2 are anemic). A 1988 Program for Decentralized Educational Development study showed that grade VI students learn only about 1/2 of what they are supposed to learn. 30% of the children enrolled in grade school drop out before they reach their senior year. The Department of Education, Culture and Sports estimates that some 2.56 million students dropped out of school in l989. That same year, some 3.7 million children were counted as part of the labor force. In Manila alone, some 60,000 children work the streets, whether doing odd jobs or begging, or turning to crime or prostitution. the article tells the story of a 12 year-old girl named Ging, a 4th grader at a public school and the oldest child in a poor family of 6 children. The undernourished Ging dreams of a good future for her family and sees education as a way out of poverty; unfortunately, her time after school is spend working in the streets or looking after her family. She considers herself luckier than many of the other children working in the streets, since she at least has a family. PMID:12285009

  16. Disruptions in the TFTR tokamak

    International Nuclear Information System (INIS)

    For a successful reactor, it will be useful to predict the occurrence of disruptions and to understand disruption effects including how a plasma disrupts onto the wall and how reproducibly it does so. Studies of disruptions on TFTR at both high-βpol and high-density have shown that, in both types, a fast growing m/n=1/1 mode plays an important role. In highdensity disruptions, a newly observed fast m/n = 1/1 mode occurs early in the thermal decay phase. For the first time in TFTR q-profile measurements just prior to disruptions have been made. Experimental studies of heat deposition patterns on the first wall of TFTR due to disruptions have provided information on MHD phenomena prior to or during the disruption, how the energy is released to the wall, and the reproducibility of the heat loads from disruptions. This information is important in the design of future devices such as ITER. Several new processes of runaway electron generation are theoretically suggested and their application to TFTR and ITER is considered, together with a preliminary assessment of x-ray data from runaways generated during disruptions

  17. Chernobyl catastrophe: Information for people living in the contaminated areas

    International Nuclear Information System (INIS)

    The radioactive blow-outs after the Chernobyl Nuclear Power Plant catastrophe reached many states. The largest amount of them (according to experts' estimations - 70%) fell out on the Belarus territory. The estimation of radioecological, medico-biological, economic and social consequences of the Chernobyl catastrophe has shown that unimaginable damage was incurred on Belarus and its territory became the zone of ecological calamity. More than 14 years have passed since the Chernobyl NPP accident but some of the problems caused by the catastrophe have not been solved. This is bound up, first of all, with a high collective dosage absorbed by the population, with difficulties in forecasting and prophylactics of remote radiological effects, with ecological and economic crisis. The consequences of the disaster greatly affect all the aspects of vital activities of the affected regions and the state as a whole. Destructive tendencies have been revealed in all spheres of the life activity of people who experienced radiation effects. The processes of social adaptation and socio-psychological support of the population inhabiting the contaminated territory and resettled as well, require considerable optimisation. Negative factors of the Chernobyl catastrophe, which are significant for human health can be divided into two groups as follows: radiation-based, directly related to influence of ionising radiation and non radiation based, related to changes in habitat and prolonged psychological stress. The specific peculiarities of psychogenic disorders caused by the catastrophe are determined by the following reasons: insufficient knowledge of radiation effects; constant apprehension for the health and well-being of themselves and their families, especially children; unexpected change of the life stereotype (forced resettlement, the break of the former life, changing the place and the character of work, etc.); the necessity of constant keeping precaution measures and prophylactic

  18. Threshold Concepts and Information Literacy

    Science.gov (United States)

    Townsend, Lori; Brunetti, Korey; Hofer, Amy R.

    2011-01-01

    What do we teach when we teach information literacy in higher education? This paper describes a pedagogical approach to information literacy that helps instructors focus content around transformative learning thresholds. The threshold concept framework holds promise for librarians because it grounds the instructor in the big ideas and underlying…

  19. Second threshold in weak interactions

    NARCIS (Netherlands)

    Veltman, M.J.G.

    1977-01-01

    The point of view that weak interactions must have a second threshold below 300 – 600 GeV is developed. Above this threshold new physics must come in. This new physics may be the Higgs system, or some other nonperturbative system possibly having some similarities to the Higgs system. The limit of la

  20. Can we Detect Ecosystem Critical Transitions and Early Warning Signals of Catastrophic Shifts from Palaeo-Ecological Records?

    Science.gov (United States)

    Perga, M. E.; Taranu, Z. E.; Gregory-Eaves, I.; Frossard, V.; Thomas, Z.; Legendre, P.; Anderson, N. J.; Leavitt, P.; Gell, P.

    2015-12-01

    The observation that managed ecosystems often fail to respond smoothly to changing external pressures has shed some light on their complex non-linear dynamics. The concept of critical transitions (i.e., ecosystem regime shifts), thresholds and alternative stable states has since spread to the ecological and environmental management literature. Most recently, however, reviews have raised some skepticism about whether these catastrophic transitions are the exceptions rather than the rule. Overall, a better understanding of the occurrence and processes of such critical transitions requires more empirical testing and evidence on the mechanistic links between pressures and consequent ecological change. Many of the changes observed, or modeled, by ecologists extend beyond the monitoring record. Palaeo-ecological records thus represent a unique opportunity to extend our temporal perspective to the relevancy of critical transitions. Yet, paleo-ecological records have their own biases and shortcomings, such as sediment focusing, irregular temporal integration and often studied in a semi-quantitative way. As such, palaeo-ecological time series are not strictly analogous to instrumental datasets. In this work, we aimed to test, using both modeled and actual records, how different properties that are common in palaeo-ecological records affect our ability to detect past non-linear dynamics, such as early-warning signals of catastrophic shifts.

  1. Middle Yangtze sea-basin over Paleozoic-Mesozoic transition--Sedimental continuity and environmental catastrophe

    Institute of Scientific and Technical Information of China (English)

    黄定华; 段怡春; 李斌; 姚凌青; 张恒; 张凡; 王君慧; 郭浩; 殷鸿福

    2002-01-01

    On the centimeter scale of lithologic change,we conduct poly-statistic analysis on the sedimentary behavior and dynamic features of the stratigraphic sequence from upper Dalong formation to lower Daye formation,which across the Permian-Triassic boundary in East Hubei.From the perspective of stochastically dynamic system,the depositional process of upper Dalong formation can be regarded as a stable Markovian process with weakly stratigraphic correlation and randomly lithologic alteration.Compared to it,the depositional process of lower Daye formation was unstable Markovian process with much closer stratigraphic correlation and ordered lithologic change.As for the replacement style of the sedimental cycle,the former was chaotic,while the latter was periodical.Otherwise,although the overall depositional process of the two formations was continuous,their dynamic characteristics were obviously different.So this P-T sedimental boundary can also be regarded as a dynamic limit.It was a kind of depositional reaction in response to a catastrophic alteration when the geological environment was in continuous change but came over a certain threshold state.

  2. Catastrophic nanosecond laser induced damage in the bulk of potassium titanyl phosphate crystals

    Energy Technology Data Exchange (ETDEWEB)

    Wagner, Frank R., E-mail: frank.wagner@fresnel.fr; Natoli, Jean-Yves; Akhouayri, Hassan; Commandré, Mireille [Institut Fresnel, CNRS, Aix-Marseille Université, Ecole Centrale Marseille, Campus de St Jérôme, 13013 Marseille (France); Duchateau, Guillaume [CELIA, UMR 5107 Université Bordeaux 1-CNRS-CEA, 351 Cours de la Libération, 33405 Talence Cedex (France)

    2014-06-28

    Due to its high effective nonlinearity and the possibility to produce periodically poled crystals, potassium titanyl phosphate (KTiOPO{sub 4}, KTP) is still one of the economically important nonlinear optical materials. In this overview article, we present a large study on catastrophic nanosecond laser induced damage in this material and the very similar RbTiOPO{sub 4} (RTP). Several different systematic studies are included: multiple pulse laser damage, multi-wavelength laser damage in KTP, damage resistance anisotropy, and variations of the laser damage thresholds for RTP crystals of different qualities. All measurements were carried out in comparable experimental conditions using a 1064 nm Q-switched laser and some were repeated at 532 nm. After summarizing the experimental results, we detail the proposed model for laser damage in this material and discuss the experimental results in this context. According to the model, nanosecond laser damage is caused by light-induced generation of transient laser-damage precursors which subsequently provide free electrons that are heated by the same nanosecond pulse. We also present a stimulated Raman scattering measurement and confront slightly different models to the experimental data. Finally, the physical nature of the transient damage precursors is discussed and similarities and differences to laser damage in other crystals are pointed out.

  3. Ultrafast phase transition via catastrophic phonon collapse driven by plasmonic hot-electron injection.

    Science.gov (United States)

    Appavoo, Kannatassen; Wang, Bin; Brady, Nathaniel F; Seo, Minah; Nag, Joyeeta; Prasankumar, Rohit P; Hilton, David J; Pantelides, Sokrates T; Haglund, Richard F

    2014-03-12

    Ultrafast photoinduced phase transitions could revolutionize data-storage and telecommunications technologies by modulating signals in integrated nanocircuits at terahertz speeds. In quantum phase-changing materials (PCMs), microscopic charge, lattice, and orbital degrees of freedom interact cooperatively to modify macroscopic electrical and optical properties. Although these interactions are well documented for bulk single crystals and thin films, little is known about the ultrafast dynamics of nanostructured PCMs when interfaced to another class of materials as in this case to active plasmonic elements. Here, we demonstrate how a mesh of gold nanoparticles, acting as a plasmonic photocathode, induces an ultrafast phase transition in nanostructured vanadium dioxide (VO2) when illuminated by a spectrally resonant femtosecond laser pulse. Hot electrons created by optical excitation of the surface-plasmon resonance in the gold nanomesh are injected ballistically across the Au/VO2 interface to induce a subpicosecond phase transformation in VO2. Density functional calculations show that a critical density of injected electrons leads to a catastrophic collapse of the 6 THz phonon mode, which has been linked in different experiments to VO2 phase transition. The demonstration of subpicosecond phase transformations that are triggered by optically induced electron injection opens the possibility of designing hybrid nanostructures with unique nonequilibrium properties as a critical step for all-optical nanophotonic devices with optimizable switching thresholds.

  4. Defining catastrophic costs and comparing their importance for adverse tuberculosis outcome with multi-drug resistance: a prospective cohort study, Peru.

    Directory of Open Access Journals (Sweden)

    Tom Wingfield

    2014-07-01

    Full Text Available Even when tuberculosis (TB treatment is free, hidden costs incurred by patients and their households (TB-affected households may worsen poverty and health. Extreme TB-associated costs have been termed "catastrophic" but are poorly defined. We studied TB-affected households' hidden costs and their association with adverse TB outcome to create a clinically relevant definition of catastrophic costs.From 26 October 2002 to 30 November 2009, TB patients (n = 876, 11% with multi-drug-resistant [MDR] TB and healthy controls (n = 487 were recruited to a prospective cohort study in shantytowns in Lima, Peru. Patients were interviewed prior to and every 2-4 wk throughout treatment, recording direct (household expenses and indirect (lost income TB-related costs. Costs were expressed as a proportion of the household's annual income. In poorer households, costs were lower but constituted a higher proportion of the household's annual income: 27% (95% CI = 20%-43% in the least-poor houses versus 48% (95% CI = 36%-50% in the poorest. Adverse TB outcome was defined as death, treatment abandonment or treatment failure during therapy, or recurrence within 2 y. 23% (166/725 of patients with a defined treatment outcome had an adverse outcome. Total costs ≥20% of household annual income was defined as catastrophic because this threshold was most strongly associated with adverse TB outcome. Catastrophic costs were incurred by 345 households (39%. Having MDR TB was associated with a higher likelihood of incurring catastrophic costs (54% [95% CI = 43%-61%] versus 38% [95% CI = 34%-41%], p<0.003. Adverse outcome was independently associated with MDR TB (odds ratio [OR] = 8.4 [95% CI = 4.7-15], p<0.001, previous TB (OR = 2.1 [95% CI = 1.3-3.5], p = 0.005, days too unwell to work pre-treatment (OR = 1.01 [95% CI = 1.00-1.01], p = 0.02, and catastrophic costs (OR = 1.7 [95% CI = 1.1-2.6], p = 0.01. The

  5. Disruptive camouflage impairs object recognition

    OpenAIRE

    Richard J. Webster; Hassall, Christopher; Herdman, Chris M.; Godin, Jean-Guy J.; Sherratt, Thomas N.

    2013-01-01

    Whether hiding from predators, or avoiding battlefield casualties, camouflage is widely employed to prevent detection. Disruptive coloration is a seemingly well-known camouflage mechanism proposed to function by breaking up an object's salient features (for example their characteristic outline), rendering objects more difficult to recognize. However, while a wide range of animals are thought to evade detection using disruptive patterns, there is no direct experimental evidence that disruptive...

  6. Catastrophic events leading to de facto limits on liability

    International Nuclear Information System (INIS)

    This study conducts an overview of large technological systems in society to ascertain prevalence, if any, of situations that can lead to catastrophic effects where the resultant liabilities far exceed the insurances or assets subject to suit in court, thereby imposing de facto limits on liability. Several potential situations are examined: dam rupture, aircraft crash into a sports stadium, chemical plant accident, shipping disaster, and a toxic drug disaster. All of these events are estimated to have probabilities per year similar to or larger than a major nuclear accident and they are found to involve potential liability far exceeding the available resources, such as insurance, corporation assets, or government revenues

  7. Depolymerizing kinesins Kip3 and MCAK shape cellular microtubule architecture by differential control of catastrophe.

    Science.gov (United States)

    Gardner, Melissa K; Zanic, Marija; Gell, Christopher; Bormuth, Volker; Howard, Jonathon

    2011-11-23

    Microtubules are dynamic filaments whose ends alternate between periods of slow growth and rapid shortening as they explore intracellular space and move organelles. A key question is how regulatory proteins modulate catastrophe, the conversion from growth to shortening. To study this process, we reconstituted microtubule dynamics in the absence and presence of the kinesin-8 Kip3 and the kinesin-13 MCAK. Surprisingly, we found that, even in the absence of the kinesins, the microtubule catastrophe frequency depends on the age of the microtubule, indicating that catastrophe is a multistep process. Kip3 slowed microtubule growth in a length-dependent manner and increased the rate of aging. In contrast, MCAK eliminated the aging process. Thus, both kinesins are catastrophe factors; Kip3 mediates fine control of microtubule length by narrowing the distribution of maximum lengths prior to catastrophe, whereas MCAK promotes rapid restructuring of the microtubule cytoskeleton by making catastrophe a first-order random process.

  8. Threshold enhancement of diphoton resonances

    Science.gov (United States)

    Bharucha, Aoife; Djouadi, Abdelhak; Goudelis, Andreas

    2016-10-01

    We revisit a mechanism to enhance the decay width of (pseudo-)scalar resonances to photon pairs when the process is mediated by loops of charged fermions produced near threshold. Motivated by the recent LHC data, indicating the presence of an excess in the diphoton spectrum at approximately 750 GeV, we illustrate this threshold enhancement mechanism in the case of a 750 GeV pseudoscalar boson A with a two-photon decay mediated by a charged and uncolored fermion having a mass at the 1/2MA threshold and a small decay width, dark matter are discussed.

  9. Music effect on pain threshold evaluated with current perception threshold

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    AIM: Music relieves anxiety and psychotic tension. This effect of music is applied to surgical operation in the hospital and dental office. It is still unclear whether this music effect is only limited to the psychological aspect but not to the physical aspect or whether its music effect is influenced by the mood or emotion of audience. To elucidate these issues, we evaluated the music effect on pain threshold by current perception threshold (CPT) and profile of mood states (POMC) test. METHODS: Healthy 30 subjects (12 men, 18 women, 25-49 years old, mean age 34.9) were tested. (1)After POMC test, all subjects were evaluated pain threshold with CPT by Neurometer (Radionics, USA) under 6 conditions, silence, listening to the slow tempo classic music, nursery music, hard rock music, classic paino music and relaxation music with 30 seconds interval. (2)After Stroop color word test as the stresser, pain threshold was evaluated with CPT under 2 conditions, silence and listening to the slow tempo classic music. RESULTS: Under litening to the music, CPT sores increased, especially 2 000 Hz level related with compression, warm and pain sensation. Type of music, preference of music and stress also affected CPT score. CONCLUSION: The present study demonstrated that the concentration on the music raise the pain threshold and that stress and mood influence the music effect on pain threshold.

  10. 中国农业巨灾风险评估方法研究%Assessment Approach for Agricultural Catastrophic Risk in China

    Institute of Scientific and Technical Information of China (English)

    徐磊; 张峭

    2011-01-01

    [Objective] The purpose of this paper is to provide an evaluation method for agricultural catastrophic risk.[Method] Data on agricultural disaster loss were collected based on hectares covered by natural disasters, hectares affected by natural disasters, and hectares destroyed by natural disasters using the standard process, and Monte Carlo simulation was used to expand sample size. Peak over threshold (POT) approach based on the extreme value theory was used to model the distribution of agricultural catastrophic loss, and value at risk (VaR) was used to assess agricultural catastrophic risk. The paper cited drought catastrophe in Henan province of China as an example and assessed grain-production risk using the method proposed. [Result] The basic framework for assessment of agricultural catastrophic risk in China has been constructed. Drought catastrophe slightly affects grain-production in Henan province of China generally, and the mean loss of drought catastrophic is about 10%; however, the drought catastrophic risk is severe in the scenario of 50 years or 100 years for a return, and the grain loss caused by drought catastrophe will exceed 20%. More attention for policy designer must be taken into account. [Conclusion] The evaluation method of agricultural catastrophic risk is found to be appropriate and feasible.%[目的]研究中国农业巨灾风险评估的方法.[方法]利用农作物受灾面积、成灾面积和绝收面积获得中国农业灾害损失数据,同时运用蒙特卡罗模拟技术以解决样本数据不足的难题;运用极值POT模型实现对农业灾害损失尾部分布的有效拟合,建立农业巨灾损失的广义Pareto分布模型;建立基于VaR方法的农业巨灾风险的精确度量模型;选择河南省粮食生产的旱灾巨灾风险作为中国农业巨灾风险评估的案例.[结果]构建了中国农业巨灾风险评估的基本框架;旱灾巨灾对河南省粮食生产的影响总体上相对

  11. Catastrophe model of the accident process, safety climate, and anxiety.

    Science.gov (United States)

    Guastello, Stephen J; Lynn, Mark

    2014-04-01

    This study aimed (a) to address the evidence for situational specificity in the connection between safety climate to occupational accidents, (b) to resolve similar issues between anxiety and accidents, (c) to expand and develop the concept of safety climate to include a wider range of organizational constructs, (d) to assess a cusp catastrophe model for occupational accidents where safety climate and anxiety are treated as bifurcation variables, and environ-mental hazards are asymmetry variables. Bifurcation, or trigger variables can have a positive or negative effect on outcomes, depending on the levels of asymmetry, or background variables. The participants were 1262 production employees of two steel manufacturing facilities who completed a survey that measured safety management, anxiety, subjective danger, dysregulation, stressors and hazards. Nonlinear regression analyses showed, for this industry, that the accident process was explained by a cusp catastrophe model in which safety management and anxiety were bifurcation variables, and hazards, age and experience were asymmetry variables. The accuracy of the cusp model (R2 = .72) exceeded that of the next best log-linear model (R2 = .08) composed from the same survey variables. The results are thought to generalize to any industry where serious injuries could occur, although situationally specific effects should be anticipated as well.

  12. Zeeman catastrophe machines as a toolkit for teaching chaos

    International Nuclear Information System (INIS)

    The investigation of chaotic motions and cooperative systems offers a magnificent opportunity to involve modern physics in the basic course of mechanics taught to engineering students. In this paper, it will be demonstrated that the Zeeman machine can be a versatile and motivating tool for students to acquire introductory knowledge about chaotic motion via interactive simulations. The Zeeman catastrophe machine is a typical example of a quasi-static system with hysteresis. It works in a relatively simple way and its properties can be understood very easily. Since the machine can be built easily and the simulation of its movement is also simple, the experimental investigation and the theoretical description can be connected intuitively. Although the Zeeman machine is known mainly for its quasi-static and catastrophic behaviour, its dynamic properties are also of interest with its typical chaotic features. By means of a periodically driven Zeeman machine, a wide range of chaotic properties of the simple systems can be demonstrated, such as bifurcation diagrams, chaotic attractors, transient chaos, Lyapunov exponents and so on. This paper is organically linked to our website (http://csodafizika.hu/zeeman) where the discussed simulation programs can be downloaded. In a second paper, the novel construction of a network of Zeeman machines will be presented to study the properties of cooperative systems. (paper)

  13. Catastrophic failure in complex socio-technical systems

    International Nuclear Information System (INIS)

    This paper reviews the sequences leading to catastrophic failures in complex socio-technical systems. It traces some of the elements of an analytic framework to that proposed by Beer in Decision and Control, first published in 1966, and argues that these ideas are centrally relevant to a topic on which research interest has developed subsequently, the study of crises, catastrophes and disasters in complex socio-technical systems in high technology sectors. But while the system perspective is central, it is not by itself entirely adequate. The problems discussed cannot be discussed simply in terms of system parameters like variety, redundancy and complexity. Much empirical research supports the view that these systems typically operate in degraded mode. The degradations may be primarily initiated within the social components of the socio-technical system. Such variables as hierarchical position, actors' motivations and intentions are relevant to explain the ways in which communication systems typically operate to filter out messages from lower participants and to ignore the 'soft signals' issuing from small-scale and intermittent malfunctions. (author)

  14. Crisis Management Aspects of Bam Catastrophic Earthquake: Review Article

    Directory of Open Access Journals (Sweden)

    Homayoun Sadeghi-Bazargani

    2015-03-01

    Full Text Available Background: Bam earthquake was the most catastrophic natural disasters in recent years. The aim of this study was to review different aspects of crisis manage­ment during and after the catastrophic earthquake in Bam City, Iran.Methods: Data needed for this systematic review were collected through search­ing PubMed, EMBASE and SID databases, for the period from 2003 to 2011. Keywords included earthquake, Iran and Bam earthquake. The data were summarized and were analyzed using Content Analysis.Results: Out of 422 articles, 25 articles were included in the study. Crisis Manage­ment aspects and existing pitfalls were classified into seven categories including planning and organization, human resource management, management of logistics, international humanitarian aids, field performance of the military and security forces, health and medical service provision, and information manage­ment. Positive aspects and major pitfalls of crisis management have been introduced in all the mentioned categories. Conclusion: The available evidence indicated poor crisis management during Bam earthquake that resulted in aggravating the losses as well as diminishing the effect of interventions. Thus, concerning the importance of different aspects of the crisis management and the high prevalence of disasters in Iran, the observed vulnerability in disaster management process should be addressed.

  15. Catastrophic failure in complex socio-technical systems

    Energy Technology Data Exchange (ETDEWEB)

    Weir, D. [Intercultural Management, Rue Dostoievski, BP 085, 06902 Sophia Antipolis (France)]. E-mail: dweir@tinyworld.co.uk

    2004-07-01

    This paper reviews the sequences leading to catastrophic failures in complex socio-technical systems. It traces some of the elements of an analytic framework to that proposed by Beer in Decision and Control, first published in 1966, and argues that these ideas are centrally relevant to a topic on which research interest has developed subsequently, the study of crises, catastrophes and disasters in complex socio-technical systems in high technology sectors. But while the system perspective is central, it is not by itself entirely adequate. The problems discussed cannot be discussed simply in terms of system parameters like variety, redundancy and complexity. Much empirical research supports the view that these systems typically operate in degraded mode. The degradations may be primarily initiated within the social components of the socio-technical system. Such variables as hierarchical position, actors' motivations and intentions are relevant to explain the ways in which communication systems typically operate to filter out messages from lower participants and to ignore the 'soft signals' issuing from small-scale and intermittent malfunctions. (author)

  16. Observing a catastrophic thermokarst lake drainage in northern Alaska

    Science.gov (United States)

    Jones, Benjamin M.; Arp, Christopher D.

    2015-01-01

    The formation and drainage of thermokarst lakes have reshaped ice-rich permafrost lowlands in the Arctic throughout the Holocene. North of Teshekpuk Lake, on the Arctic Coastal Plain of northern Alaska, thermokarst lakes presently occupy 22.5% of the landscape, and drained thermokarst lake basins occupy 61.8%. Analysis of remotely sensed imagery indicates that nine lakes (>10 ha) have drained in the 1,750 km2 study area between 1955 and 2014. The most recent lake drainage was observed using in situ data loggers providing information on the duration and magnitude of the event, and a nearby weather station provided information on the environmental conditions preceding the lake drainage. Lake 195 (L195), an 80 ha thermokarst lake with an estimated water volume of ~872,000 m3, catastrophically drained on 05 July 2014. Abundant winter snowfall and heavy early summer precipitation resulted in elevated lake water levels that likely promoted bank overtopping, thermo-erosion along an ice-wedge network, and formation of a 9 m wide, 2 m deep, and 70 m long drainage gully. The lake emptied in 36 hours, with 75% of the water volume loss occurring in the first ten hours. The observed peak discharge of the resultant flood was 25 m3/s, which is similar to that in northern Alaska river basins whose areas are more than two orders of magnitude larger. Our findings support the catastrophic nature of sudden lake drainage events and the mechanistic hypotheses developed by J. Ross Mackay.

  17. "Till destruction sicken": the catastrophe of mind in Macbeth.

    Science.gov (United States)

    Tarantelli, Carole Beebe

    2010-12-01

    The author examines the tragedy of Macbeth from the vertex of its portrait of the effects of the hero's abandonment to the "blindest fury of destructiveness" (Freud, 1930, p. 121), using aspects of psychoanalytic thought to illuminate the theme. She affirms that Macbeth's immediate transformation in phantasy from loyal subject to future assassin threatens to flood his psyche with the uncontainable energy of destruction and thus to produce a psychic catastrophe. The remainder of the play is then examined as a representation of Macbeth's attempts to defend himself from that catastrophe: the only objects whose existence he can tolerate are those that cannot challenge his possession of the crown, which leads him to attempt to destroy all opposition. Since this is impossible, his alternative is to denude his mind of its perception of the reality in which the actions of others will inevitably produce future transformations which he is unable to control. The play's last soliloquy anticipates the final state, the repose of emptiness; it portrays a mind, emptied of emotion, looking at a world which it has denuded of meaning.

  18. Tatra's forests will recover from catastrophe for decades

    International Nuclear Information System (INIS)

    Windy tornado in Tatra's national park (TANAP, High Tatras, Slovakia) at the end of 2004 caused extensive ecological catastrophe and economic losses. Wind has totally damaged the trees in more than one fourth of forest area, which is administrated by state forests of TANAP. Next fourth of forest area has impaired structure. Mostly coniferous forests have fallen down not only in High Tatras, but also in Horehronie, Kysuce, Orava and Spis. According to estimates around 2.5 million cubic meters of wood have lain on the ground in High Tatras. This wood must be precipitately processed. In another regions totally from 800 to 900 thousands cubic meters are overcame by wind. Ecological catastrophe has come in High Tatras. Totally damaged large forests areas need to be recovered for long decades. 90 per cent of annual Slovakian wood cutting represents totally 2.5 million cubic meters. The state will invest in forest recovery from sale of calamity stuff. Reforestation of one hectare of forest costs from 80 to 90 thousands Slovak crowns (∼2666-3000 USD). Another remedies at the age to five years represent from 40 to 50 thousands Slovak crowns (1333-16666 USD). Around 1.6 billion Slovak crown (∼53.333 million USD) will be needed for reforestation of 12 thousands hectares of TANAP

  19. A gradient catastrophe mechanism in contexts of the phase change condition

    OpenAIRE

    Durmagambetov, A. A.

    2016-01-01

    The paper describes the mechanism of occurrence of a gradient catastrophe when changing phase. Materials shows that classical methods of estimation theory of functions do not fit the problem of studying the gradient catastrophe. We present material showing that the embedding theorem can not give an opportunity to study the process of a gradient catastrophe. In fact, work justifies pessimism Terence Tao in the insolvency of modern mathematics to solve the problem of the Navier-Stokes equations...

  20. Parton distributions with threshold resummation

    CERN Document Server

    Bonvini, Marco; Rojo, Juan; Rottoli, Luca; Ubiali, Maria; Ball, Richard D; Bertone, Valerio; Carrazza, Stefano; Hartland, Nathan P

    2015-01-01

    We construct a set of parton distribution functions (PDFs) in which fixed-order NLO and NNLO calculations are supplemented with soft-gluon (threshold) resummation up to NLL and NNLL accuracy respectively, suitable for use in conjunction with any QCD calculation in which threshold resummation is included at the level of partonic cross sections. These resummed PDF sets, based on the NNPDF3.0 analysis, are extracted from deep-inelastic scattering, Drell-Yan, and top quark pair production data, for which resummed calculations can be consistently used. We find that, close to threshold, the inclusion of resummed PDFs can partially compensate the enhancement in resummed matrix elements, leading to resummed hadronic cross-sections closer to the fixed-order calculation. On the other hand, far from threshold, resummed PDFs reduce to their fixed-order counterparts. Our results demonstrate the need for a consistent use of resummed PDFs in resummed calculations.

  1. Agricultural Mechanism of Spreading Catastrophe Risk in China and Legislation Conception

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    This paper introduces agricultural catastrophe and its characteristics,and conducts comparative analysis on existing mechanism of spreading agricultural catastrophe risk,indicating that the mechanism of administrative remedy has the greatest efficiency and highest cost;the mechanism of social assistance has the lowest cost,but its efficiency is lowest and there are unstable factors;market mechanism,namely the insurance of agricultural catastrophe,is the rational choice of agricultural department in mechanism of risk spreading.This paper analyzes the status quo of China’s insurance of agricultural catastrophe,indicating that the main body of management in China’s insurance of agricultural catastrophe is missing.In addition,the market demand is critically scanty,and insurance of agricultural catastrophe lacks external development environment.The gap of China’s insurance law of agricultural catastrophe has become the greatest obstacle to the development of insurance of agricultural catastrophe.From legislative purpose,basic principle,nature,main body of legal relations,management range,policy support,supervision and management and so on,the legislation conception of China’s insurance of agricultural catastrophe is put forward.

  2. Repartnering after First Union Disruption

    Science.gov (United States)

    Wu, Zheng; Schimmele, Christoph M.

    2005-01-01

    Using data from the 1995 General Social Survey (N= 2,639), this study examines two competing repartnering choices made by Canadians after first union disruption: marriage or cohabitation. About 42% of women and 54% of men form a second union 5 years after union disruption, with cohabitation being the most prevalent choice. The timing of second…

  3. Threshold models in radiation carcinogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Hoel, D.G.; Li, P. [Medical Univ. of South Carolina, Charleston, SC (United States). Dept. of Biometry and Epidemiology

    1998-09-01

    Cancer incidence and mortality data from the atomic bomb survivors cohort has been analyzed to allow for the possibility of a threshold dose response. The same dose-response models as used in the original papers were fit to the data. The estimated cancer incidence from the fitted models over-predicted the observed cancer incidence in the lowest exposure group. This is consistent with a threshold or nonlinear dose-response at low-doses. Thresholds were added to the dose-response models and the range of possible thresholds is shown for both solid tumor cancers as well as the different leukemia types. This analysis suggests that the A-bomb cancer incidence data agree more with a threshold or nonlinear dose-response model than a purely linear model although the linear model is statistically equivalent. This observation is not found with the mortality data. For both the incidence data and the mortality data the addition of a threshold term significantly improves the fit to the linear or linear-quadratic dose response for both total leukemias and also for the leukemia subtypes of ALL, AML, and CML.

  4. Disrupting Ethnography through Rhizoanalysis

    Directory of Open Access Journals (Sweden)

    Diana Masny

    2014-10-01

    Full Text Available This article interrogates principles of ethnography in education proposed by Mills and Morton: raw tellings, analytic pattern, vignette and empathy. This article adopts a position that is uncomfortable, unconventional and interesting. It involves a deterritorialization/ rupture of ethnography in education in order to reterritorialize a different concept: rhizoanalysis, a way to position theory and data that is multilayered, complex and messy. Rhizoanalysis, the main focus of this article is not a method. It is an approach to research conditioned by a reality in which Deleuze and Guattari disrupt representation, interpretation and subjectivity. In this article, Multiple Literacies Theory, a theoretical and practical framework, becomes a lens to examine a rhizomatic study of a Korean family recently arrived to Australia and attending English as a second language classes. Observations and interviews recorded the daily lives of the family. The vignettes were selected by reading data intensively and immanently through a process of palpation, an innovative approach to educational research. Rhizoanalysis proposes to abandon the given and invent different ways of thinking about and doing research and what might happen when reading data differently, intensively and immanently, through Multiple Literacies Theory. Rhizoanalysis, a game-changer in the way research can be conducted, affords a different lens to tackle issues in education through research.

  5. Guidelines for Auditory Threshold Measurement for Significant Threshold Shift.

    Science.gov (United States)

    Campbell, Kathleen; Hammill, Tanisha; Hoffer, Michael; Kil, Jonathan; Le Prell, Colleen

    2016-09-01

    The purpose of this article is to provide guidelines for determining a Significant Noise-Induced Threshold Shift in clinical trials involving human populations. The article reviews recommendations for the standards to be referenced for human subjects, equipment, test environment, and personnel. Additional guidelines for military populations are provided. Guidelines for the calibration of audiometers, sound booth noise levels, and immitance equipment are provided. In addition the guidance provides specific suggestions for the subjects history before study onset, and otoscopy.Test frequencies for threshold determination and methods of threshold determination are reviewed for both air conduction and bone conduction for both baseline testing and later determination of either a temporary (TTS) or permanent threshold shift (PTS). Once a Significant Noise-Induced Threshold Shift has been determined, subjects should be retested, conductive component should be ruled out or addressed, and the subject should be counseled or referred for additional medical evaluation. Guidance for reporting procedures and the computerized study database are described. Finally, experimental designs suggested for noise-induced otoprotection clinical trials are described. PMID:27518134

  6. A ground moving target emergency tracking method for catastrophe rescue

    Science.gov (United States)

    Zhou, X.; Li, D.; Li, G.

    2014-11-01

    In recent years, great disasters happen now and then. Disaster management test the emergency operation ability of the government and society all over the world. Immediately after the occurrence of a great disaster (e.g., earthquake), a massive nationwide rescue and relief operation need to be kicked off instantly. In order to improve the organizations efficiency of the emergency rescue, the organizers need to take charge of the information of the rescuer teams, including the real time location, the equipment with the team, the technical skills of the rescuers, and so on. One of the key factors for the success of emergency operations is the real time location of the rescuers dynamically. Real time tracking methods are used to track the professional rescuer teams now. But volunteers' participation play more and more important roles in great disasters. However, real time tracking of the volunteers will cause many problems, e.g., privacy leakage, expensive data consumption, etc. These problems may reduce the enthusiasm of volunteers' participation for catastrophe rescue. In fact, the great disaster is just small probability event, it is not necessary to track the volunteers (even rescuer teams) every time every day. In order to solve this problem, a ground moving target emergency tracking method for catastrophe rescue is presented in this paper. In this method, the handheld devices using GPS technology to provide the location of the users, e.g., smart phone, is used as the positioning equipment; an emergency tracking information database including the ID of the ground moving target (including the rescuer teams and volunteers), the communication number of the handheld devices with the moving target, and the usually living region, etc., is built in advance by registration; when catastrophe happens, the ground moving targets that living close to the disaster area will be filtered by the usually living region; then the activation short message will be sent to the selected

  7. The Remote Detection of Incipient Catastrophic Failure in Large Landslides

    Science.gov (United States)

    Petley, D.; Bulmer, M. H.; Murphy, W.; Mantovani, F.

    2001-12-01

    Landslide movement is commonly associated with brittle failure and ductile deformation. Kilburn and Petley (2001) proposed that cracking in landslides occurs due to downslope stress acting on the deforming horizon. If the assumption that a given crack event breaks a fixed distance of unbroken rock or soil the rate of cracking becomes equivalent to the number of crack events per unit time. Where crack growth (not nucleation) is occurring, the inverse rate of displacement changes linearly with time. Failure can be assumed to be the time at which displacement rates become infinitely large. Thus, for a slope heading towards catastrophic failure due to the development of a failure plane, this relationship would be linear, with the point at which failure will occur being the time when the line intercepts the x-axis. Increasing rates of deformation associated with ductile processes of crack nucleation would yield a curve with a negative gradient asymptopic to the x-axis. This hypothesis is being examined. In the 1960 movement of the Vaiont slide, Italy, although the rate of movement was accelerating, the plot of 1/deformation against time shows that it was increasing towards a steady state deformation. This movement has been associated with a low accumulated strain ductile phase of movement. In the 1963 movement event, the trend is linear. This was associated with a brittle phase of movement. A plot of 1/deformation against time for movement of the debris flow portion of the Tessina landslide (1998) shows a curve with a negative gradient asymptopic to the x-axis. This indicates that the debris flow moved as a result of ductile deformation processes. Plots of movement data for the Black Ven landslide over 1999 and 2001 also show curves that correlate with known deformation and catastrophic phases. The model results suggest there is a definable deformation pattern that is diagnostic of landslides approaching catastrophic failure. This pattern can be differentiated from

  8. Health-related financial catastrophe, inequality and chronic illness in Bangladesh.

    Directory of Open Access Journals (Sweden)

    Md Mizanur Rahman

    Full Text Available BACKGROUND: Bangladesh has a high proportion of households incurring catastrophic health expenditure, and very limited risk sharing mechanisms. Identifying determinants of out-of-pocket (OOP payments and catastrophic health expenditure may reveal opportunities to reduce costs and protect households from financial risk. OBJECTIVE: This study investigates the determinants of high healthcare expenditure and healthcare- related financial catastrophe. METHODS: A cross-sectional household survey was conducted in Rajshahi city, Bangladesh, in 2011. Catastrophic health expenditure was estimated separately based on capacity to pay and proportion of non-food expenditure. Determinants of OOP payments and financial catastrophe were estimated using double hurdle and Poisson regression models respectively. RESULTS: On average households spent 11% of their total budgets on health, half the residents spent 7% of the monthly per capita consumption expenditure for one illness, and nearly 9% of households faced financial catastrophe. The poorest households spent less on health but had a four times higher risk of catastrophe than the richest households. The risk of financial catastrophe and the level of OOP payments were higher for users of inpatient, outpatient public and private facilities respectively compared to using self-medication or traditional healers. Other determinants of OOP payments and catastrophic expenses were economic status, presence of chronic illness in the household, and illness among children and adults. CONCLUSION: Households that received inpatient or outpatient private care experienced the highest burden of health expenditure. The poorest members of the community also face large, often catastrophic expenses. Chronic illness management is crucial to reducing the total burden of disease in a household and its associated increased risk of level of OOP payments and catastrophic expenses. Households can only be protected from these situations by

  9. Tidal disruption event demographics

    Science.gov (United States)

    Kochanek, C. S.

    2016-09-01

    We survey the properties of stars destroyed in tidal disruption events (TDEs) as a function of black hole (BH) mass, stellar mass and evolutionary state, star formation history and redshift. For M_{BH} ≲ 10^7 M_{⊙}, the typical TDE is due to a M* ˜ 0.3 M⊙ M-dwarf, although the mass function is relatively flat for M_{ast } ≲ M_{⊙}. The contribution from older main-sequence stars and sub-giants is small but not negligible. From MBH ≃ 107.5-108.5 M⊙, the balance rapidly shifts to higher mass stars and a larger contribution from evolved stars, and is ultimately dominated by evolved stars at higher BH masses. The star formation history has little effect until the rates are dominated by evolved stars. TDE rates should decline very rapidly towards higher redshifts. The volumetric rate of TDEs is very high because the BH mass function diverges for low masses. However, any emission mechanism which is largely Eddington-limited for low BH masses suppresses this divergence in any observed sample and leads to TDE samples dominated by MBH ≃ 106.0-107.5 M⊙ BHs with roughly Eddington peak accretion rates. The typical fall-back time is relatively long, with 16 per cent having tfb plausible if tfb has any relation to the transient rise time. For almost any BH mass function, systematic searches for fainter, faster time-scale TDEs in smaller galaxies, and longer time-scale TDEs in more massive galaxies are likely to be rewarded.

  10. When Disruptive Approaches Meet Disruptive Technologies: Learning at a Distance.

    Science.gov (United States)

    Gibson, Chere Campbell

    2000-01-01

    Reviews research on constructivism in learning and selection of learning strategies. Suggests linking constructivism with instructional technologies for continuing medical education in order to "disrupt" reactive, habitual ways of learning and encourage active engagement. (SK)

  11. Industrial arsenic contamination causes catastrophic changes in freshwater ecosystems

    Science.gov (United States)

    Chen, Guangjie; Shi, Haibin; Tao, Jianshuang; Chen, Li; Liu, Yuanyuan; Lei, Guoliang; Liu, Xiaohai; Smol, John P.

    2015-11-01

    Heavy metal pollution is now widely recognized to pose severe health and environmental threats, yet much of what is known concerning its adverse impacts on ecosystem health is derived from short-term ecotoxicological studies. Due to the frequent absence of long-term monitoring data, little is known of the long-tem ecological consequences of pollutants such as arsenic. Here, our dated sediment records from two contaminated lakes in China faithfully document a 13.9 and 21.4-fold increase of total arsenic relative to pre-1950 background levels. Concurrently, coherent responses in keystone biota signal pronounced ecosystem changes, with a >10-fold loss in crustacean zooplankton (important herbivores in the food webs of these lake systems) and a >5-fold increase in a highly metal-tolerant alga. Such fundamental ecological changes will cascade through the ecosystem, causing potentially catastrophic consequences for ecosystem services in contaminated regions.

  12. On the governance of global and catastrophic risks

    DEFF Research Database (Denmark)

    Faber, Michael Havbro

    2011-01-01

    The focus of the present paper regards the identification and treatment of critical issues in the process of societal decision making concerning management of global and catastrophic risks. Taking basis in recent works by the author, the paper in particular addresses: 1) Which are the most relevant...... hazards in a holistic global perspective and how may these be categorised in view of strategies for their treatment?; 2) How might robust societal decisions on risk management subject to large uncertainties be formally supported?; 3) How may available economic resources be prioritised for the purpose...... of sustainable and global life safety and health improvements? Finally, new results and perspectives are presented on the issue of allocation of resources for the purpose of improving global public health and a discussion on global risk governance concludes the paper....

  13. Catastrophe analysis on pillar instability considered mining effect

    Institute of Scientific and Technical Information of China (English)

    LI Jiang-teng; CAO Ping

    2005-01-01

    The instability of the pillar was discussed based on the potential energy principle and the cusp catastrophe theory, and a simplified mechanical model of the pillar was established considering the mining effect. The necessary-sufficient conditions, the jump value of displacement of pillar and the released energy expressions were deduced. The results show that the instability of the pillar is related to the properties of the rock, the external force and the relative stiffness of the elastic area to the plastic area. The instability of system is like to occur with the enlarging of the softening area or the decreasing of E/λ. The calculation done shows that the estimated results correspond to practical experience.

  14. Catastrophes in nature and society mathematical modeling of complex systems

    CERN Document Server

    Khlebopros, Rem G; Fet, Abram I

    2007-01-01

    Many people are concerned about crises leading to disasters in nature, in social and economic life. The book offers a popular account of the causative mechanisms of critical states and breakdown in a broad range of natural and cultural systems - which obey the same laws - and thus makes the reader aware of the origin of catastrophic events and the ways to avoid and mitigate their negative consequences. The authors apply a single mathematical approach to investigate the revolt of cancer cells that destroy living organisms and population outbreaks that upset natural ecosystems, the balance between biosphere and global climate interfered lately by industry, the driving mechanisms of market and related economic and social phenomena, as well as the electoral system the proper use of which is an arduous accomplishment of democracy.

  15. MECHANISM AND CATASTROPHE THEORY ANALYSIS OF CIRCULAR TUNNEL ROCKBURST

    Institute of Scientific and Technical Information of China (English)

    PAN Yue; ZHANG Yong; YU Guang-ming

    2006-01-01

    Mechanism of circular tunnel rockburst is that, when the carrying capacity of the centralized zone of plastic deformation in limiting state reduces, the comparatively intact part in rock mass unloads by way of elasticity; rockburst occurs immediately when the elastic energy released by the comparatively intact part exceeds the energy dissipated by plastic deformation. The equivalent strain was taken as a state variable to establish a catastrophe model of tunnel rockburst, and the computation expression of the earthquake energy released by tunnel rockburst was given. The analysis shows that, the conditions of rockburst occurrence are relative to rock's ratio of elastic modulus to descendent modulus and crack growth degree of rocks; to rock mass with specific rockburst tendency, there exists a corresponding critical depth of softened zone, and rockburst occurs when the depth of softened zone reaches.

  16. Eradicating Catastrophic Collapse in Interdependent Networks via Reinforced Nodes

    CERN Document Server

    Yuan, Xin; Stanley, H Eugene; Havlin, Shlomo

    2016-01-01

    In interdependent networks, it is usually assumed, based on percolation theory, that nodes become nonfunctional if they lose connection to the network giant component. However, in reality, some nodes, equipped with alternative resources, together with their connected neighbors can still be functioning once disconnected from the giant component. Here we propose and study a generalized percolation model that introduces a fraction of reinforced nodes in the interdependent networks that can function and support their neighborhood. We analyze, both analytically and via simulations, the order parameter$-$the functioning component$-$comprising both the giant component and smaller components that include at least one reinforced node. Remarkably, we find that for interdependent networks, we need to reinforce only a small fraction of nodes to prevent abrupt catastrophic collapses. Moreover, we find that the universal upper bound of this fraction is 0.1756 for two interdependent Erd\\H{o}s-R\\'{e}nyi (ER) networks, regula...

  17. Catastrophic chromosomal restructuring during genome elimination in plants.

    Science.gov (United States)

    Tan, Ek Han; Henry, Isabelle M; Ravi, Maruthachalam; Bradnam, Keith R; Mandakova, Terezie; Marimuthu, Mohan Pa; Korf, Ian; Lysak, Martin A; Comai, Luca; Chan, Simon Wl

    2015-01-01

    Genome instability is associated with mitotic errors and cancer. This phenomenon can lead to deleterious rearrangements, but also genetic novelty, and many questions regarding its genesis, fate and evolutionary role remain unanswered. Here, we describe extreme chromosomal restructuring during genome elimination, a process resulting from hybridization of Arabidopsis plants expressing different centromere histones H3. Shattered chromosomes are formed from the genome of the haploid inducer, consistent with genomic catastrophes affecting a single, laggard chromosome compartmentalized within a micronucleus. Analysis of breakpoint junctions implicates breaks followed by repair through non-homologous end joining (NHEJ) or stalled fork repair. Furthermore, mutation of required NHEJ factor DNA Ligase 4 results in enhanced haploid recovery. Lastly, heritability and stability of a rearranged chromosome suggest a potential for enduring genomic novelty. These findings provide a tractable, natural system towards investigating the causes and mechanisms of complex genomic rearrangements similar to those associated with several human disorders. PMID:25977984

  18. Catastrophe characteristics of the condensation and pool boiling phenomena

    Science.gov (United States)

    Ma, Xuehu; Xu, Dunqi; Lin, Jifang

    1995-02-01

    Recently, Utaka proposed two types of the transition modes of dropwise condensation, i.e. the continuous and the jumping modes, and presented a criterion for determining the condensation transition mode. Stylianous and Rose proposed two hypotheses, the coalescence-limited transition and the nucleation site saturation transition. Neither Utaka's criterion nor Rose's hypotheses could clearly interpret the physical mechanisms of the transition both from filmwise to dropwise and from dropwise to pseudofilm condensation, and explicitly presented the main factors affecting the transitions. Kalinin hs given a general review of the transition boiling heat transfer. The catastrophe theory will be applied here to eluicidate the complex phenomena of the transitions of the condensation and boiling pattern states.

  19. Catastrophe Insurance Modeled by Shot-Noise Processes

    Directory of Open Access Journals (Sweden)

    Thorsten Schmidt

    2014-02-01

    Full Text Available Shot-noise processes generalize compound Poisson processes in the following way: a jump (the shot is followed by a decline (noise. This constitutes a useful model for insurance claims in many circumstances; claims due to natural disasters or self-exciting processes exhibit similar features. We give a general account of shot-noise processes with time-inhomogeneous drivers inspired by recent results in credit risk. Moreover, we derive a number of useful results for modeling and pricing with shot-noise processes. Besides this, we obtain some highly tractable examples and constitute a useful modeling tool for dynamic claims processes. The results can in particular be used for pricing Catastrophe Bonds (CAT bonds, a traded risk-linked security. Additionally, current results regarding the estimation of shot-noise processes are reviewed.

  20. Chasma Australe Mars: Structural Framework for a Catastrophic Outflow Origin

    Science.gov (United States)

    Anguita, F.; Babin, R.; Benito, G.; Collado, A.; Gomez, D.; Rice, J. W.

    1998-01-01

    Chasma Australe is the most remarkable of the martian south pole erosional reentrants carved in the polar layered deposits. Ms chasma originates near the south pole and runs across the polar troughs over a distance of about 500 km. Its width varies between 20 and 80 km and, with a depth up to 1000 m, it reaches the bedrock. Following an idea put forward originally for Chasma Boreale, we propose for the genesis of Chasma Australe a mechanism of catastrophic outflow preceded by a tectonically induced powerful sapping process. A detailed geomorphological analysis of Chasma Australe shows erosional and depositional features that can be interpreted as produced by the motion of a fluid. Like other polar reentrants, Chasma Australe is clearly assymetric, with a steep eastern margin where basal and lateral erosion prevailed, and a gentler western side, where the stepped topography and bedrock spurs favored deposition.

  1. Can non-ideal magnetohydrodynamics solve the magnetic braking catastrophe?

    CERN Document Server

    Wurster, James; Bate, Matthew R

    2015-01-01

    We investigate whether or not the low ionisation fractions in molecular cloud cores can solve the `magnetic braking catastrophe', where magnetic fields prevent the formation of circumstellar discs around young stars. We perform three-dimensional smoothed particle non-ideal magnetohydrodynamics (MHD) simulations of the gravitational collapse of one solar mass molecular cloud cores, incorporating the effects of ambipolar diffusion, Ohmic resistivity and the Hall effect alongside a self-consistent calculation of the ionisation chemistry assuming 0.1 micron grains. When including only ambipolar diffusion or Ohmic resistivity, discs do not form in the presence of strong magnetic fields, similar to the cases using ideal MHD. With the Hall effect included, disc formation depends on the direction of the magnetic field with respect to the rotation vector of the gas cloud. When the vectors are aligned, strong magnetic braking occurs and no disc is formed. When the vectors are anti-aligned, a disc with radius of 13AU ca...

  2. Variable Structure Control of Catastrophic Course in Airdropping Heavy Cargo

    Institute of Scientific and Technical Information of China (English)

    Zhang Huiyuan; Shi Zhongke

    2009-01-01

    The mathematical model of a transport aircraft would be subjected to a sudden change when heavy cargo is dropped off in airdropping, which exerts serious influences upon the safety of the aircraft. A variable structure controller is specially designed for handling the airdrop process. The nonlinear system is linearized by input-output feedback linearization using differential geometry theories. On this basis, an inner loop system for velocity and attitude tracking control is designed by using the exponentially approaching rule of the variable structure theory. The whole flight control system is integrated with the outer loop flight altitude control. Digital simulation evidences the applicability of the system to potentially catastrophic course in airdropping heavy cargo and provides robustness against system parameter perturbation.

  3. Stability of theoretical model for catastrophic weather prediction

    Institute of Scientific and Technical Information of China (English)

    SHI Wei-hui; WANG Yue-peng

    2007-01-01

    Stability related to theoretical model for catastrophic weather prediction,which includes non-hydrostatic perfect elastic model and anelastic model, is discussed and analyzed in detail. It is proved that non-hydrostatic perfect elastic equations set is stable in the class of infinitely differentiable function. However, for the anelastic equations set, its continuity equation is changed in form because of the particular hypothesis for fluid, so "the matching consisting of both viscosity coefficient and incompressible assumption" appears, thereby the most important equations set of this class in practical prediction shows the same instability in topological property as Navier-Stokes equation,which should be avoided first in practical numerical prediction. In light of this, the referenced suggestions to amend the applied model are finally presented.

  4. CUSP CATASTROPHE MODEL OF INSTABILITY OF PILLAR IN ASYMMETRIC MINING

    Institute of Scientific and Technical Information of China (English)

    LI Jiang-teng; CAO Ping

    2005-01-01

    A simplified mechanical model of pillar-hang wall was established in asymmetric mining and instability of the system was discussed by means of potential energy principle and cusp catastrophe theory. The necessary-sufficient condition and the jump value of displacement of pillar and the released energy expressions were derived,which established foundation for quantifying of the instability of system. The results show that instability of the system is related to load and its stiffness distribution. The critical load increases with the increasing relative stiffness, and the system is more stable. On the contrary, the instability of system is likely to occur, and the released energy is larger in instability process, and the harm is more tremendous accordingly.Furthermore, an example was calculated, and the estimated results are in good agreement with the practical experience, which provide basis for mining order and arranging stope.

  5. Heckling the Catastrophe. On the Holocaust Literary Criticism

    Directory of Open Access Journals (Sweden)

    Paweł Wolski

    2015-01-01

    Full Text Available The article discusses a special kind of narrative about the catastrophe, treated as a specific genre of writing: the theory of literature of the Holocaust. The article presents its two most significant (although not the only ones features: firstly, the conviction about its unusual character as compared to other genres/forms of writing, sometimes secretly described by such concepts as the uniqueness of the Holocaust (which metonymizes not only the event itself but also the narrations referring to it and, secondly, identifies all text-producing entities (narrator, author etc., simultaneously constituting the basic feature of the most important genre/modality of this kind of writing which is testimony. The article presents the examples of Polish and foreign scholars portraying this state of affairs.

  6. Coupled catastrophes: sudden shifts cascade and hop among interdependent systems

    CERN Document Server

    Brummitt, Charles D; D'Souza, Raissa M

    2014-01-01

    A profoundly important challenge in several disciplines today 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. We characterize these phenomena using a simple model grounded in the theory of fast--slow ordinary differential equations and in catastrophe theory. In the model, a system consists of multiple subsystems (e.g., countries in the global economy or patches of an ecosystem), each 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 quantities (e.g., trade couples economic output, diffusion couples populations); that coupling moves their bifurcations. The model elucidates two ways in which sudden changes can propaga...

  7. Endocrine Effects of Circadian Disruption.

    Science.gov (United States)

    Bedrosian, Tracy A; Fonken, Laura K; Nelson, Randy J

    2016-01-01

    Disruption of circadian rhythms, provoked by artificial lighting at night, inconsistent sleep-wake schedules, and transmeridian air travel, is increasingly prevalent in modern society. Desynchrony of biological rhythms from environmental light cycles has dramatic consequences for human health. In particular, disrupting homeostatic oscillations in endocrine tissues and the hormones that these tissues regulate can have cascading effects on physiology and behavior. Accumulating evidence suggests that chronic disruption of circadian organization of endocrine function may lead to metabolic, reproductive, sleep, and mood disorders. This review discusses circadian control of endocrine systems and the consequences of distorting rhythmicity of these systems. PMID:26208951

  8. Alternative solutions for public and private catastrophe funding in Austria

    Directory of Open Access Journals (Sweden)

    M. Gruber

    2008-07-01

    Full Text Available The impacts of natural hazards as well as their frequency of occurrence during the last decades have increased decisively. Therefore, the public as well as the private sector are expected to react to this development by providing sufficient funds, in particular for the improvement of protection measures and an enhanced funding of damage compensation for affected private individuals, corporate and public entities.

    From the public stance, the establishment of an appropriate regulatory environment seems to be indispensable. Structural and legal changes should, on the one hand, renew and improve the current distribution system of public catastrophe funds as well as the profitable investment of these financial resources, and on the other hand, facilitate the application of alternative mechanisms provided by the capital and insurance markets.

    In particular, capital markets have developed alternative risk transfer and financing mechanisms, such as captive insurance companies, risk pooling, contingent capital solutions, multi-trigger products and insurance securitisation for hard insurance market phases. These instruments have already been applied to catastrophic (re-insurance in other countries (mainly the US and off-shore domiciles, and may contribute positively to the insurability of extreme weather events in Austria by enhancing financial capacities. Not only private individuals and corporate entities may use alternative mechanisms in order to retain, thus, to finance certain risks, but also public institutions.

    This contribution aims at analysing potential solutions for an improved risk management of natural hazards in the private and the public sector by considering alternative mechanisms of the capital and insurance markets. Also the establishment of public-private-partnerships, which may contribute to a more efficient cat funding system in Austria, is considered.

  9. Overcoming challenges of catastrophe modelling in data poor regions

    Science.gov (United States)

    Grassby, L.; Millinship, I.; Breinl, K.

    2012-04-01

    There is an increasing demand for loss accumulation tools in expanding international insurance markets such as India, China and Thailand. This reflects the combination of an increase in exposures in these territories as industry intensifies and urban development expands, as well as several notable natural catastrophes affecting these areas over the past few years (e.g. extreme floods in Mumbai in 2006 and in Thailand in 2011). Large, global insurers and reinsurers are embracing the opportunity to underwrite these exposures but only where adequate tools are available to provide understanding of the hazards, exposures and potential losses. Unlike more developed countries, data availability in these regions is typically limited and of poor resolution, but model development is still required in order to analyse the risk. Some of the modelling challenges associated with data limitations include: (1) dealing with a lack of hydrological data which results in greater uncertainty of the flow rate and event frequency; (2) lower DTM resolution than that available across much of Europe, which underlies the hazard component of the catastrophe model; (3) limited accessibility to data that characterises the Built Environment including information on different building types and their susceptibility to damage; and (4) a lack of claims data from previous events or engineering research into the vulnerability of different building types. This is used to generate of country and structure specific vulnerability curves that explain the relationship between hazard intensity and damages. By presenting an industry specific flood model for data-poor India in collaboration with Allianz Re, we illustrate how we have overcome many of these challenges to allow loss accumulations to be made. The resulting model was successfully validated against the floods in Mumbai and Surat in 2006 and is being developed further with the availability of new data.

  10. The Chernobyl catastrophe is the most terrible civil nuclear incident

    International Nuclear Information System (INIS)

    Full text: The 4th nuclear reactor of the Chernobyl NPP exploded on 26 April 1986, 20 years ago. It's the most terrible nuclear civil accident of all times. The consequences of the Chernobyl accident led to contamination of 3,1 million ha of arable land, 1,5 million ha of natural pasture land, 3,5 million ha of forests and changed the lifestyle for millions of people in Belarus, Ukraine and Russia. It is well known that the mortality in the contaminated areas (infant mortality by cancer) drastically increased. The Chernobyl catastrophe is presented , such as a sad example for humanity, a complex political international, economical, social and, particular, ecological problem according to the traditional and new studies for the development of the nucleotide contaminated territories: 1. Financing of safety of stopped working 4th nuclear reactor (security of covering system) and of work another 3 blocks at the Chernobyl NPP. Detailed control of international financial support for guarantee the safety, security of the Chernobyl NPP and sustainable development for rehabilitation of the affected zones and people. 2. It should be marked increase in medical, demographic analysis and in social, economical protection of the people in the contaminated areas. 3. Analysis and synthesis, monitoring of the long-time data results due to environmental, ecological, social and political consequences of the Chernobyl disaster. 4. Protection from the possible terrorist (extra) actions and (inter) damage or incident function of the Chernobyl plant, such as an old generation nuclear power. 5. Planned budget for future studies in the affected territories and flexibility actually realization of budget (State and International). 6. Nuclear refuse and aria/water protection in the Ukraine, Belarus and Russia contaminated zones. 7. Risk evaluation of not good function of NPPs which are situated in Russia, Ukraine and in another places (always remembering that the Chernobyl catastrophe is the

  11. Alternative solutions for public and private catastrophe funding in Austria

    Science.gov (United States)

    Gruber, M.

    2008-07-01

    The impacts of natural hazards as well as their frequency of occurrence during the last decades have increased decisively. Therefore, the public as well as the private sector are expected to react to this development by providing sufficient funds, in particular for the improvement of protection measures and an enhanced funding of damage compensation for affected private individuals, corporate and public entities. From the public stance, the establishment of an appropriate regulatory environment seems to be indispensable. Structural and legal changes should, on the one hand, renew and improve the current distribution system of public catastrophe funds as well as the profitable investment of these financial resources, and on the other hand, facilitate the application of alternative mechanisms provided by the capital and insurance markets. In particular, capital markets have developed alternative risk transfer and financing mechanisms, such as captive insurance companies, risk pooling, contingent capital solutions, multi-trigger products and insurance securitisation for hard insurance market phases. These instruments have already been applied to catastrophic (re-)insurance in other countries (mainly the US and off-shore domiciles), and may contribute positively to the insurability of extreme weather events in Austria by enhancing financial capacities. Not only private individuals and corporate entities may use alternative mechanisms in order to retain, thus, to finance certain risks, but also public institutions. This contribution aims at analysing potential solutions for an improved risk management of natural hazards in the private and the public sector by considering alternative mechanisms of the capital and insurance markets. Also the establishment of public-private-partnerships, which may contribute to a more efficient cat funding system in Austria, is considered.

  12. Pain-related catastrophizing in pain patients and people with pain in the general population.

    NARCIS (Netherlands)

    Boer, M.J. de; Struys, M.M.; Versteegen, G.J.

    2012-01-01

    BACKGROUND: Catastrophizing is a defining factor in the pain experience and strongly contributes to the prediction of various aspects of health. Catastrophizing is not just present in pain patients, but may also be present in people with non-clinical pain. The aim of the present study is to investig

  13. Pain-related catastrophizing in pain patients and people with pain in the general population

    NARCIS (Netherlands)

    de Boer, M. J.; Struys, M. M. R. F.; Versteegen, G. J.

    2012-01-01

    Background Catastrophizing is a defining factor in the pain experience and strongly contributes to the prediction of various aspects of health. Catastrophizing is not just present in pain patients, but may also be present in people with non-clinical pain. The aim of the present study is to investiga

  14. Research on traffic flow forecasting model based on cusp catastrophe theory

    Institute of Scientific and Technical Information of China (English)

    张亚平; 裴玉龙

    2004-01-01

    This paper intends to describe the relationship between traffic parameters by using cusp catastrophe theory and to deduce highway capacity and corresponding speed forecasting value through suitable transformation of catastrophe model. The five properties of a catastrophe system are outlined briefly, and then the data collected on freeways of Zhujiang River Delta, Guangdong province, China are examined to ascertain whether they exhibit qualitative properties and attributes of the catastrophe model. The forecasting value of speed and capacity for freeway segments are given based on the catastrophe model. Furthermore, speed-flow curve on freeway is drawn by plotting out congested and uncongested traffic flow and the capacity value for the same freeway segment is also obtained from speed-flow curve to test the feasibility of the application of cusp catastrophe theory in traffic flow analysis. The calculating results of catastrophe model coincide with those of traditional traffic flow models regressed from field observed data, which indicates that the deficiency of traditional analysis of relationship between speed, flow and occupancy in two-dimension can be compensated by analysis of the relationship among speed, flow and occupancy based on catastrophe model in three-dimension. Finally, the prospects and problems of its application in traffic flow research in China are discussed.

  15. 12 CFR 741.214 - Report of crime or catastrophic act and Bank Secrecy Act compliance.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 6 2010-01-01 2010-01-01 false Report of crime or catastrophic act and Bank Secrecy Act compliance. 741.214 Section 741.214 Banks and Banking NATIONAL CREDIT UNION ADMINISTRATION... Unions § 741.214 Report of crime or catastrophic act and Bank Secrecy Act compliance. Any credit...

  16. Managing Catastrophic Disaster Risks Using Alternative Risk financing and Pooled Insurance Structures

    OpenAIRE

    Pollner, John D

    2001-01-01

    This report examines the constraints and opportunities in implementing a catastrophe insurance system which can resolve the key obstacles impeding broader implementation of a risk funding approach. The four main pillars in such a strategy involve: 1) strengthening insurance sector regulatory requirements and supervision; 2) establishing broad-based pooled catastrophe funding structures wit...

  17. Analysis of Interlayer Connection Catastrophe Characteristics in Internet AS level Topology

    Directory of Open Access Journals (Sweden)

    Si-yuan Jia

    2013-02-01

    Full Text Available Based on CAIDA’s (cooperative association for Internet data analysis statistics at AS-level collected from April 2009 to April 2010, it is found that network size, degree correlations and clustering have changed significantly three times. According to the definition of k-core, the Internet topology is divided into different levels. In this paper, by analyzing the changing connection on each level at the three time spots, we found that the connection difference between the highest and the lowest level varies cyclically. Before Internet has significant change, the connection difference between the highest and the lowest shell changes acutely. At that time point it is the later stage of the fluctuation period which is the accumulation of small fluctuation. The concept of catastrophe coefficient is proposed for quantifying the probability of Internet catastrophe so that the catastrophe coefficient of Internet could be calculated on real time, and the catastrophe time spots could be predicted. Using real data for verification, it turns out that catastrophe coefficient can accurately predict the "giant fluctuations" occurrence in the macroscopic structure. With the proposal of the concept of catastrophe coefficient, the research can play an important guiding role in understanding the actual network internal development and changes, analyzing the cause of Internet catastrophe, preventing devastating catastrophe, planning and further re-designing Ipv6.

  18. Household catastrophic healthcare expenditure and impoverishment due to rotavirus gastroenteritis requiring hospitalization in malaysia.

    OpenAIRE

    Tharani Loganathan; Way-Seah Lee; Kok-Foo Lee; Mark Jit; Chiu-Wan Ng

    2015-01-01

    Background While healthcare costs for rotavirus gastroenteritis requiring hospitalization may be burdensome on households in Malaysia, exploration on the distribution and catastrophic impact of these expenses on households are lacking. Objectives We assessed the economic burden, levels and distribution of catastrophic healthcare expenditure, the poverty impact on households and inequities related to healthcare payments for acute gastroenteritis requiring hospitalization in Malaysia. Methods A...

  19. Applying Catastrophe Theory to an Information-Processing Model of Problem Solving in Science Education

    Science.gov (United States)

    Stamovlasis, Dimitrios; Tsaparlis, Georgios

    2012-01-01

    In this study, we test an information-processing model (IPM) of problem solving in science education, namely the working memory overload model, by applying catastrophe theory. Changes in students' achievement were modeled as discontinuities within a cusp catastrophe model, where working memory capacity was implemented as asymmetry and the degree…

  20. Elicitation threshold of cobalt chloride

    DEFF Research Database (Denmark)

    Fischer, Louise A; Johansen, Jeanne D; Voelund, Aage;

    2016-01-01

    BACKGROUND: Cobalt is a strong skin sensitizer (grade 5 of 5 in the guinea-pig maximization test) that is used in various industrial and consumer applications. To prevent sensitization to cobalt and elicitation of allergic cobalt dermatitis, information about the elicitation threshold level of co...... individuals, and thereby the basis for future prevention of cobalt allergy.......BACKGROUND: Cobalt is a strong skin sensitizer (grade 5 of 5 in the guinea-pig maximization test) that is used in various industrial and consumer applications. To prevent sensitization to cobalt and elicitation of allergic cobalt dermatitis, information about the elicitation threshold level...... of cobalt is important. OBJECTIVE: To identify the dermatitis elicitation threshold levels in cobalt-allergic individuals. MATERIALS AND METHODS: Published patch test dose-response studies were reviewed to determine the elicitation dose (ED) levels in dermatitis patients with a previous positive patch test...

  1. Inclusive distributions near kinematic thresholds

    CERN Document Server

    Gardi, E

    2006-01-01

    The main challenge in computing inclusive cross sections and decay spectra in QCD is posed by kinematic thresholds. The threshold region is characterized by stringent phase-space constraints that are reflected in large perturbative corrections due to soft and collinear radiation as well as large non-perturbative effects. Major progress in addressing this problem was made in recent years by Dressed Gluon Exponentiation (DGE), a formalism that combines Sudakov and renormalon resummation in moment space. DGE has proven effective in extending the range of applicability of perturbation theory well into the threshold region and in identifying the relevant non-perturbative corrections. Here we review the method from a general perspective using examples from deep inelastic structure functions, event-shape distributions, heavy-quark fragmentation and inclusive decay spectra. A special discussion is devoted to the applications of DGE to radiative and semileptonic B decays that have proven valuable for the interpretatio...

  2. Predicting percolation thresholds in networks

    CERN Document Server

    Radicchi, Filippo

    2014-01-01

    We consider different methods, that do not rely on numerical simulations of the percolation process, to approximate percolation thresholds in networks. We perform a systematic analysis on synthetic graphs and a collection of 109 real networks to quantify their effectiveness and reliability as prediction tools. Our study reveals that the inverse of the largest eigenvalue of the non-backtracking matrix of the graph often provides a tight lower bound for true percolation threshold. However, in more than 40% of the cases, this indicator is less predictive than the naive expectation value based solely on the moments of the degree distribution. We find that the performance of all indicators becomes worse as the value of the true percolation threshold grows. Thus, none of them represents a good proxy for robustness of extremely fragile networks.

  3. Wing pathology of white-nose syndrome in bats suggests life-threatening disruption of physiology

    Science.gov (United States)

    Cryan, Paul M.; Meteyer, Carol U.; Boyles, Justin G.; Blehert, David S.

    2010-01-01

    White-nose syndrome (WNS) is causing unprecedented declines in several species of North American bats. The characteristic lesions of WNS are caused by the fungus Geomyces destructans, which erodes and replaces the living skin of bats while they hibernate. It is unknown how this infection kills the bats. We review here the unique physiological importance of wings to hibernating bats in relation to the damage caused by G. destructans and propose that mortality is caused by catastrophic disruption of wing-dependent physiological functions. Mechanisms of disease associated with G. destructans seem specific to hibernating bats and are most analogous to disease caused by chytrid fungus in amphibians.

  4. Neurotoxicity of Thyroid Disrupting Contaminants

    Science.gov (United States)

    Thyroid hormones playa critical role in the normal development ofthe mammalian brain. Thyroid disrupting chemicals (TDCs) are environmental contaminants that alter the structure or function ofthe thyroid gland, alter regulatory enzymes associated with thyroid hormone (TH) homeost...

  5. Vortex disruption by magnetohydrodynamic feedback

    CERN Document Server

    Mak, Julian; Hughes, D W

    2016-01-01

    In an electrically conducting fluid, vortices stretch out a weak, large-scale magnetic field to form strong current sheets on their edges. Associated with these current sheets are magnetic stresses, which are subsequently released through reconnection, leading to vortex disruption, and possibly even destruction. This disruption phenomenon is investigated here in the context of two-dimensional, homogeneous, incompressible magnetohydrodynamics. We derive a simple order of magnitude estimate for the magnetic stresses --- and thus the degree of disruption --- that depends on the strength of the background magnetic field (measured by the parameter $M$, a ratio between the Alfv\\'en speed and a typical flow speed) and on the magnetic diffusivity (measured by the magnetic Reynolds number $\\mbox{Rm}$). The resulting estimate suggests that significant disruption occurs when $M^{2}\\mbox{Rm} = O(1)$. To test our prediction, we analyse direct numerical simulations of vortices generated by the breakup of unstable shear flo...

  6. Gérard Brugnot, 2008, Les Catastrophes Naturelles, Paris, Le Cavalier Bleu, 127 p.

    Directory of Open Access Journals (Sweden)

    Stéphane Callens

    2009-01-01

    Full Text Available La collection « idées reçues » se propose de faire le point sur les savoirs et les croyances à propos d’un thème donné. Le thème des « catastrophes naturelles » est présenté par Gérard Brugnot, qui commente 16 idées reçues sur ces risques majeurs, regroupées dans quatre chapitres : 1/ « il y a toujours eu des catastrophes naturelles, il y en aura toujours », 2/ « Des catastrophes vraiment toutes naturelles ? », 3/ « On peut réduire les effets des catastrophes naturelles », 4/ « Catastrophes n...

  7. Yoga attitudes in chronic low back pain: Roles of catastrophizing and fear of movement.

    Science.gov (United States)

    Combs, Martha A; Thorn, Beverly E

    2015-08-01

    Chronic low back pain is a significant public health problem and, although underused, yoga may be an effective complementary treatment. The current study examined associations of pain catastrophizing and fear of movement with attitudes toward yoga in adults with chronic low back pain. Participants completed three quantitative questionnaires assessing specific constructs: beliefs about yoga, fear of movement, and pain catastrophizing. A semi-structured in-person interview was then conducted to obtain specific pain-related information. Hierarchical regression and mediational analyses were used to test hypotheses. Consistent with the fear-avoidance model of chronic pain, catastrophizing and fear of movement were negatively associated with yoga attitudes. Specifically, fear of movement was a mediator between catastrophizing and attitudes toward yoga. Individuals with higher levels of catastrophizing and fear of movement may be less likely to consider a pain treatment involving physical movement. PMID:26256134

  8. Baryon Form Factors at Threshold

    Energy Technology Data Exchange (ETDEWEB)

    Baldini Ferroli, Rinaldo [Museo Storico della Fisica e Centro Studi e Ricerche ' E. Fermi' , Rome (Italy); INFN, Laboratori Nazionali di Frascati, Frascati (Italy); Pacetti, Simone [INFN and Dipartimento di Fisica, Universita di Perugia, Perugia (Italy)

    2012-04-15

    An extensive study of the e{sup +}e{sup -}{yields}pp{sup Macron }BABAR cross section data is presented. Two unexpected outcomes have been found: the modulus of the proton form factor is normalized to one at threshold, i.e.: |G{sup p}(4M{sub p}{sup 2})|=1, as a pointlike fermion, and the resummation factor in the Sommerfeld formula is not needed. Other e{sup +}e{sup -} {yields} baryon-antibaryon cross sections show a similar behavior near threshold.

  9. On computational Gestalt detection thresholds.

    Science.gov (United States)

    Grompone von Gioi, Rafael; Jakubowicz, Jérémie

    2009-01-01

    The aim of this paper is to show some recent developments of computational Gestalt theory, as pioneered by Desolneux, Moisan and Morel. The new results allow to predict much more accurately the detection thresholds. This step is unavoidable if one wants to analyze visual detection thresholds in the light of computational Gestalt theory. The paper first recalls the main elements of computational Gestalt theory. It points out a precision issue in this theory, essentially due to the use of discrete probability distributions. It then proposes to overcome this issue by using continuous probability distributions and illustrates it on the meaningful alignment detector of Desolneux et al.

  10. Catastrophic caldera-forming eruptions II: The subordinate role of magma buoyancy as an eruption trigger

    Science.gov (United States)

    Gregg, Patricia M.; Grosfils, Eric B.; de Silva, Shanaka L.

    2015-10-01

    Recent analytical investigations have suggested that magma buoyancy is critical for triggering catastrophic caldera forming eruptions. Through detailed assessment of these approaches, we illustrate how analytical models have been misapplied for investigating buoyancy and are, therefore, incorrect and inconclusive. Nevertheless, the hypothesis that buoyancy is the critical trigger for larger eruptions warrants further investigation. As such, we utilize viscoelastic finite element models that incorporate buoyancy to test overpressure evolution and mechanical failure in the roof due to the coalescence of large buoyant magma bodies for two model cases. In the first case, we mimic empirical approaches and include buoyancy as an explicit boundary condition. In the second set of models, buoyancy is calculated implicitly due to the density contrast between the magma in the reservoir and the host rock. Results from these numerical experiments indicate that buoyancy promotes only minimal overpressurization of large silicic magma reservoirs (implementations and the results from the numerical experiments, we conclude that buoyancy does not provide an eruption triggering mechanism for large silicic systems. Therefore, correlations of buoyancy with magma residence times, the eruption frequency-volume relationship, and the dimensions of calderas are re-assessed. We find a causal relationship with magma reservoir volume that implicates the mechanical conditions of the host rock as a primary control on eruption frequency. As magma reservoirs grow in size (> 100 km3) they surpass a rheological threshold where their subsequent evolution is controlled by host rock mechanics. Consequently, this results in a thermomechanical division between small systems that are triggered "internally" by magmatic processes and large systems that are triggered "externally" by faulting related to roof uplift or tectonism. Finally, critical assessment of recent analytical approaches illustrates that care

  11. National Health Insurance Scheme: How Protected Are Households in Oyo State, Nigeria from Catastrophic Health Expenditure?

    Directory of Open Access Journals (Sweden)

    Olayinka Stephen Ilesanmi

    2014-05-01

    Full Text Available Background The major objective of the National Health Insurance Scheme (NHIS in Nigeria is to protect families from the financial hardship of large medical bills. Catastrophic Health Expenditure (CHE is rampart in Nigeria despite the take-off of the NHIS. This study aimed to determine if households enrolled in the NHIS were protected from having CHE. Methods The study took place among 714 households in urban communities of Oyo State. CHE was measured using a threshold of 40% of monthly non-food expenditure. Descriptive statistics were done, Principal Component Analysis was used to divide households into wealth quintiles. Chi-square test and binary logistic regression were done. Results The mean age of household respondent was 33.5 years. The median household income was 43,500 naira (290 US dollars and the range was 7,000–680,000 naira (46.7–4,533 US dollars in 2012. The overall median household healthcare cost was 890 naira (5.9 US dollars and the range was 10-17,700 naira (0.1–118 US dollars in 2012. In all, 67 (9.4% households were enrolled in NHIS scheme. Healthcare services was utilized by 637 (82.9% and CHE occurred in 42 (6.6% households. CHE occurred in 14 (10.9% of the households in the lowest quintile compared to 3 (2.5% in the highest wealth quintile (P= 0.004. The odds of CHE among households in lowest wealth quintile is about 5 times. They had Crude OR (CI: 4.7 (1.3–16.8, P= 0.022. Non enrolled households were two times likely to have CHE, though not significant Conclusion Households in the lowest wealth quintiles were at higher risk of CHE. Universal coverage of health insurance in Nigeria should be fast-tracked to give the expected financial risk protection and decreased incidence of CHE.

  12. Quark States Near a Threshold

    CERN Document Server

    Bashinsky, S V

    1996-01-01

    We reduce the problem of many-channel hadron scattering at nonrelativistic energies to calculations on the scale of a few fermis. Having thus disentangled kinematics from interior quark dynamics, we study their interplay when a quark state occurs near a hadronic threshold. Characteristic parameters, such as the observed peak width, the decay width, and the shape of a cross-section itself are highly affected by the threshold. A general pole-form expression for the S-matrix in an arbitrary background is given, and the pole structure of S is examined. We show that at a hadronic threshold two poles in S are generally important. We also classify the S-matrix pole structure considering an example where nonsingular coupled channels are closed at the threshold. The framework of our paper is the P-matrix formalism, which is reviewed and extended for use together with conventional methods of computing quark-gluon dynamics. Results and applications are illustrated for the doubly strange two-baryon system, the detailed a...

  13. Associated strangeness production at threshold

    CERN Document Server

    Kowina, P; Adam, H H; Budzanowski, A; Czyzykiewicz, R; Grzonka, D; Janusz, M; Jarczyk, L; Kamys, B; Khoukaz, A; Kilian, K; Lister, T A; Moskal, P; Oelert, Walter; Rozek, T; Santo, R; Schepers, G; Sefzick, T; Siemaszko, M; Smyrski, J; Steltenkamp, S; Strzalkowski, A; Winter, P; Wüstner, P; Zipper, W

    2003-01-01

    The associated strangeness dissociation at threshold has been studied at the COSY-11 facility measuring the hyperon - and the K+K- meson pair production. Measurements of the near threshold Lambda and Sigma0 production via the pp -> pK+ Lambda / Sigma0 reaction at COSY-11 have shown that the Lambda / Sigma0 cross section ratio exceeds the value at high excess energies (Q >= 300 MeV) by an order of magnitude. For a better understanding additional data have been taken between 13 MeV and 60 MeV excess energy. The near threshold production of the charged kaon-antikaon pair is related to the discussion about the nature of the scalar states in the 1 GeV/c^2 mass range, i.e. the f0(980) and a0(980). The interpretation as a K anti-K molecule is strongly dependent on the K anti-K interaction which can be studied via the production channel. A first total cross section value on the reaction pp -> ppK+K- at an excess energy of 17 MeV i.e. below the phi production threshold was measured.

  14. Threshold Concepts and Pedagogic Representation

    Science.gov (United States)

    Meyer, Jan H. F.

    2016-01-01

    Purpose: The purpose of this paper is to present a brief exposure to the development of the threshold concepts framework (TCF), the intention being to illuminate for interested readers a broader landscape of research activity than that perhaps conveyed by the individual contributions to this special edition. Design/Methodology/Approach: There is…

  15. The Nature of Psychological Thresholds

    NARCIS (Netherlands)

    Rouder, Jeffrey N.; Morey, Richard D.

    2009-01-01

    Following G. T. Fechner (1966), thresholds have been conceptualized as the amount of intensity needed to transition between mental states, such as between a states of unconsciousness and consciousness. With the advent of the theory of signal detection, however, discrete-state theory and the correspo

  16. A Secure Threshold Group Signature Scheme

    Institute of Scientific and Technical Information of China (English)

    Wang Xiaoming; Fu Fangwei

    2003-01-01

    The threshold group signature is an important kind of signature. So far, many threshold group signature schemes have been proposed, but most of them suffer from conspiracy attack and are insecure. In this paper, a secure threshold group signature scheme is proposed. It can not only satisfy the properties of the threshold group signature, but also withstand the conspiracy attack

  17. Dynamic Sublimation Pressure and the Catastrophic Breakup of Comet ISON

    CERN Document Server

    Steckloff, Jordan K; Bowling, Timothy; Melosh, H Jay; Minton, David; Lisse, Carey M; Battams, Karl

    2015-01-01

    Previously proposed mechanisms have difficulty explaining the disruption of Comet C/2012 S1 (ISON) as it approached the Sun. We describe a novel cometary disruption mechanism whereby comet nuclei fragment and disperse through dynamic sublimation pressure, which induces differential stresses within the interior of the nucleus. When these differential stresses exceed its material strength, the nucleus breaks into fragments. We model the sublimation process thermodynamically and propose that it is responsible for the disruption of Comet ISON. We estimate the bulk unconfined crushing strength of Comet ISON's nucleus and the resulting fragments to be 0.5 Pa and 1-9 Pa respectively, assuming typical Jupiter Family Comet (JFC) albedos. However, if Comet ISON has an albedo similar to Pluto, this strength estimate drops to 0.2 Pa for the intact nucleus and 0.6-4 Pa for its fragments. Regardless of assumed albedo, these are similar to previous strength estimates of JFCs. This suggests that, if Comet ISON is representat...

  18. Robust catastrophe-free space agriculture on Mars

    Science.gov (United States)

    Yamashita, Masamichi

    During the early stage of CELSS research, economy was a selling point of the bio-regenerative life support concept. Until system integration was exercised in detail at mission planing for the International Space Station, the turning point from open system to CELSS was estimated 10 years of operation for 10 crew member as a consensus. Initial investment and operational cost for the 10-10 regenerative system was believed to be cheaper than the integrated amount of consumables for running open system. Any drop-out from recycling loop of materials is counted as “penalty”. Under this context, degree of closure was raised as an index to measure “maturity” of CELSS technology. Once it was found quite difficult to achieve 100 % closure perfect, science merit of CELSS study was redefined as a small scaled model of terrestrial biosphere. Natural ecosystem has huge sink and backyard in its materials loop. They provide a basis for keeping member in the ecology without falling into catastrophe. Low productivity at high biological diversity is a common key feature at the climax phase of ecosystem. Artificial ecosystem on ground relies on “unpaid” backyard function of surrounding biosphere together with strong control for realizing high productivity at less degree of bio-diversity. It should be noted that top criteria in engineering manned space system is robustness and survivability of crew. All other item is secondary, and just better to have. Without verification of catastrophe free, space agriculture will never be implemented for space and stay as a fantasy on ground forever. There is a great gap between ecology and this requirement for manned space system. In order to fill this gap, we should remind how gatherer and hunter was civilized after the agricultural revolution about ten thousand years ago. Planting cereal crop was a great second step in agricultural innovation. Cereal grain can be stored more than one year after its harvest. Food processing and

  19. Gravothermal catastrophe in the framework of f(R) gravity

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Thiago B.R.F.; Santos, Janilo [Universidade Federal do Rio Grande do Norte (UFRN), RN (Brazil)

    2011-07-01

    , affects the so called gravothermal catastrophe in the context of f(R) gravity. As is well known, the thermodynamics of self-gravitating systems shows a stable branch for negative specific heat, a phenomenon known as gravothermal catastrophe. This can be derived from the virial theorem applied to astrophysical systems and has important consequences for the stability of nuclear burning in the cores of stars. (author)

  20. Spreading depression transiently disrupts myelin via interferon-gamma signaling.

    Science.gov (United States)

    Pusic, Aya D; Mitchell, Heidi M; Kunkler, Phillip E; Klauer, Neal; Kraig, Richard P

    2015-02-01

    Multiple sclerosis and migraine with aura are clinically correlated and both show imaging changes suggestive of myelin disruption. Furthermore, cortical myelin loss in the cuprizone animal model of multiple sclerosis enhances susceptibility to spreading depression, the likely underlying cause of migraine with aura. Since multiple sclerosis pathology involves inflammatory T cell lymphocyte production of interferon-gamma and a resulting increase in oxidative stress, we tested the hypothesis that spreading depression disrupts myelin through similar signaling pathways. Rat hippocampal slice cultures were initially used to explore myelin loss in spreading depression, since they contain T cells, and allow for controlled tissue microenvironment. These experiments were then translated to the in vivo condition in neocortex. Spreading depression in slice cultures induced significant loss of myelin integrity and myelin basic protein one day later, with gradual recovery by seven days. Myelin basic protein loss was abrogated by T cell depletion, neutralization of interferon-gamma, and pharmacological inhibition of neutral sphingomyelinase-2. Conversely, one day after exposure to interferon-gamma, significant reductions in spreading depression threshold, increases in oxidative stress, and reduced levels of glutathione, an endogenous neutral sphingomyelinase-2 inhibitor, emerged. Similarly, spreading depression triggered significant T cell accumulation, sphingomyelinase activation, increased oxidative stress, and reduction of gray and white matter myelin in vivo. Myelin disruption is involved in spreading depression, thereby providing pathophysiological links between multiple sclerosis and migraine with aura. Myelin disruption may promote spreading depression by enhancing aberrant excitability. Thus, preservation of myelin integrity may provide novel therapeutic targets for migraine with aura.

  1. Disruptive event analysis: volcanism and igneous intrusion

    International Nuclear Information System (INIS)

    Three basic topics are addressed for the disruptive event analysis: first, the range of disruptive consequences of a radioactive waste repository by volcanic activity; second, the possible reduction of the risk of disruption by volcanic activity through selective siting of a repository; and third, the quantification of the probability of repository disruption by volcanic activity

  2. Major disruptions, inverse cascades, and the Strauss equations

    International Nuclear Information System (INIS)

    Current-carrying plasmas in a strong dc magnetic field are subject to violent disruptions above certain thresholds. At present difficult to verify, explanations are typically sought in terms of tearing modes. An alternative explanation is in terms of inverse magnetic helicity cascades, generated from a variety of possible sources of small-scale MHD turbulence. Strongly anisotropic MHD plasmas may be described by the Strauss equations. Indications of turbulent inverse cascade behavior for the Strauss equations are sought, in parallel with earlier examples from MHD and fluid mechanics

  3. Quantifying the hurricane catastrophe risk to offshore wind power.

    Science.gov (United States)

    Rose, Stephen; Jaramillo, Paulina; Small, Mitchell J; Apt, Jay

    2013-12-01

    The U.S. Department of Energy has estimated that over 50 GW of offshore wind power will be required for the United States to generate 20% of its electricity from wind. Developers are actively planning offshore wind farms along the U.S. Atlantic and Gulf coasts and several leases have been signed for offshore sites. These planned projects are in areas that are sometimes struck by hurricanes. We present a method to estimate the catastrophe risk to offshore wind power using simulated hurricanes. Using this method, we estimate the fraction of offshore wind power simultaneously offline and the cumulative damage in a region. In Texas, the most vulnerable region we studied, 10% of offshore wind power could be offline simultaneously because of hurricane damage with a 100-year return period and 6% could be destroyed in any 10-year period. We also estimate the risks to single wind farms in four representative locations; we find the risks are significant but lower than those estimated in previously published results. Much of the hurricane risk to offshore wind turbines can be mitigated by designing turbines for higher maximum wind speeds, ensuring that turbine nacelles can turn quickly to track the wind direction even when grid power is lost, and building in areas with lower risk.

  4. Chandler wobble excitation by catastrophic flooding of the Black Sea

    Directory of Open Access Journals (Sweden)

    E. Boschi

    1999-06-01

    Full Text Available It is now widely accepted that during the late Quaternary glaciation the Black Sea formed an isolated inland lake (Ross et al., 1970. New geological data and the recognition of sudden population movements away from the Black Sea coasts suggest that the basin was rapidly flooded through the Bosphorus sill 7150 years bp, causing a sea level rise of ~ 135 m in a few years (Ryan et al., 1997. As shown here, such a catastrophic redistribution of mass has significantly altered the amplitude of the Chandler wobble, the free motion of the pole of rotation around the main inertia axis of the Earth (Lambeck, 1980. We also estimate that during the flooding the pole of rotation was diverted from its secular path and shifted by ~ 30 m, at a rate of several meters per year. These rotational variations are found to be orders of magnitude larger than those produced by other short-term geophysical processes, such as earthquakes seismic moment release (O'Connell and Dziewonski, 1979; Chao et al.,1996, anthropogenic water impoundment (Chao, 1995, and tectonic mass movements (Alfonsi and Spada, 1998. The Black Sea flooding may thus be responsible for the most drastic change in the rotational parameters of the Earth in the recent history of our planet.

  5. Catastrophic debris avalanche deposit of Socompa volcano, northern Chile

    Science.gov (United States)

    Francis, P. W.; Gardeweg, M.; Ramirez, C. F.; Rothery, D. A.

    1985-01-01

    Between 10,000 and 500 yr ago the Socompa volcano in northern Chile experienced a catastrophic collapse of a 70 deg sector of the original cone, causing a debris avalanche that descended nearly 3000 m vertically and traveled more than 35 km from the volcano. The deposits cover some 490 sq km and have a minimum volume of 15 cu km. Parts of the original cone slumped in a nearly coherent form and are now preserved as large blocks more than 400 m high. The primary avalanche traveled northwestward over sloping ground before coming to rest transiently, forming a prominent marginal ridge, and then slid away northeastward to form a secondary flow, overriding much of the primary avalanche deposit. Abundant, prismatic, jointed dacite blocks within the debris avalanche deposit and a thin, fine-grained pumiceous deposit beneath it suggest that the collapse was triggered by magmatic activity and may have been accompanied by a violent lateral blast. Collapse was followed by eruption of pumiceous pyroclastic flows and extrusion of voluminous dacite domes.

  6. Reconciling the infrared catastrophe and observations of SN 2011fe

    CERN Document Server

    Fransson, Claes

    2015-01-01

    The observational effects of the 'Infrared Catastrophe' are discussed in view of the very late observations of the Type Ia SN 2011fe. Our model spectra at 1000d take non-local radiative transfer into account, and find that this has a crucial impact on the spectral formation. Although rapid cooling of the ejecta to a few 100 K occurs also in these models, the late-time optical/NIR flux is brighter by 1-2 magnitudes due to redistribution of UV emissivity, resulting from non-thermal excitation and ionization. This effect brings models into better agreement with late-time observations of SN 2011fe and other Type Ia supernovae, and offers a solution to the long standing discrepancy between models and observations. The models show that spectral formation shifts from Fe II and Fe III at 300d to Fe I at 1000d, which explains the apparent wavelength shifts seen in SN2011fe. We discuss effects of time dependence and energy input from 57Co, finding both to be important at 1000d.

  7. Quantum resonance catastrophe for conductance through a periodically driven barrier

    Science.gov (United States)

    Thuberg, Daniel; Reyes, Sebastián A.; Eggert, Sebastian

    2016-05-01

    We consider the quantum conductance in a tight-binding chain with a locally applied potential which is oscillating in time. The steady state for such a driven impurity can be calculated exactly for any energy and applied potential using the Floquet formalism. The resulting transmission has a nontrivial, nonmonotonic behavior depending on incoming momentum, driving frequency, and the strength of the applied periodic potential. Hence there is an abundance of tuning possibilities, which allows finding the resonances of total reflection for any choice of incoming momentum and periodic potential. Remarkably, this implies that even for an arbitrarily small infinitesimal impurity potential it is always possible to find a resonance frequency at which there is a catastrophic breakdown of the transmission T =0 . The points of zero transmission are closely related to the phenomenon of Fano resonances at dynamically created bound states in the continuum. The results are relevant for a variety of one-dimensional systems where local AC driving is possible, such as quantum nanodot arrays, ultracold gases in optical lattices, photonic crystals, or molecular electronics.

  8. Evaluation of catastrophic failure risk in pressure vessels

    International Nuclear Information System (INIS)

    Within the Nordic countries a four-year research programme in the area of elastic-plastic fracture mechanics was initiated in 1985. Seven laboratories from Denmark, Finland, Norway and Sweden are participating in the programme. The main technical objective of the programme is to clarify how catastrophic fracture can be prevented in pressure vessels and piping by using the leak-before-break concept. The major experimental effort of the programme is destructive pressurization of a large size pressure vessel up to rupture. The vessel has dimensions similar to a nuclear reactor pressure vessel and it has been in operation for 20 years in a Finnish oil refinery plant. The materials characterization of the vessel has been partially carried out within an extensive Nordic round-robin programme. Two pressure tests have been carried out. In both tests an artificial sharp axial surface flaw was made on the inner wall of the vessel. The experimental details of the last test including repair welding of the vessel, flaw prepration, instrumentation and material characterization are described in this report. The fracture behaviour as well as experimental results are reported. The failure pressure is compared to estimates of the analytical pre-test calculations

  9. Fold catastrophe model of dynamic pillar failure in asymmetric mining

    Institute of Scientific and Technical Information of China (English)

    PAN Yue; LI Ai-wu; QI Yun-song

    2009-01-01

    A rock burst disaster not only destroys the pit facilities and results in economic loss but it also threatens the life of the miners. Pillar rock burst has a higher frequency of occurrence in the pit compared to other kinds of rock burst. Understanding the cause, magnitude and prevention of pillar rock burst is a significant undertaking. Equations describing the bending moment and displacement of the rock beam in asymmetric mining have been deduced for simplified asymmetric beam-pillar systems. Using the symbolic operation software MAPLE 9.5 a catastrophe model of the dynamic failure of an asymmetric rock-beam pillar system has been established. The differential form of the total potential function deduced from the law of conservation of energy was used for this deduction. The critical conditions and the initial and final positions of the pillar during failure have been given in analytical form. The amount of elastic energy released by the rock beam at the instant of failure is determined as well as. A diagrammatic form showing the pillar failure was plotted using MATLAB software. This plot contains a wealth of information and is important for understanding the behavior during each deformation phase of the rock-beam pillar system. The graphic also aids in distinguishing the equivalent stiffness of the rock beam in different directions.

  10. Catastrophe versus instability for the eruption of a toroidal solar magnetic flux rope

    CERN Document Server

    Kliem, B; Forbes, T G; Priest, E R; Török, T

    2014-01-01

    The onset of a solar eruption is formulated here as either a magnetic catastrophe or as an instability. Both start with the same equation of force balance governing the underlying equilibria. Using a toroidal flux rope in an external bipolar or quadrupolar field as a model for the current-carrying flux, we demonstrate the occurrence of a fold catastrophe by loss of equilibrium for several representative evolutionary sequences in the stable domain of parameter space. We verify that this catastrophe and the torus instability occur at the same point; they are thus equivalent descriptions for the onset condition of solar eruptions.

  11. TAD disruption as oncogenic driver.

    Science.gov (United States)

    Valton, Anne-Laure; Dekker, Job

    2016-02-01

    Topologically Associating Domains (TADs) are conserved during evolution and play roles in guiding and constraining long-range regulation of gene expression. Disruption of TAD boundaries results in aberrant gene expression by exposing genes to inappropriate regulatory elements. Recent studies have shown that TAD disruption is often found in cancer cells and contributes to oncogenesis through two mechanisms. One mechanism locally disrupts domains by deleting or mutating a TAD boundary leading to fusion of the two adjacent TADs. The other mechanism involves genomic rearrangements that break up TADs and creates new ones without directly affecting TAD boundaries. Understanding the mechanisms by which TADs form and control long-range chromatin interactions will therefore not only provide insights into the mechanism of gene regulation in general, but will also reveal how genomic rearrangements and mutations in cancer genomes can lead to misregulation of oncogenes and tumor suppressors. PMID:27111891

  12. 30 years life with Chernobyl, 5 years life with Fukushima. Health consequences of the nuclear catastrophes of Chernobyl and Fukushima

    International Nuclear Information System (INIS)

    The IPPNW report on health consequences of the nuclear catastrophes of Chernobyl and Fukushima covers the following issues: Part.: 30 years life with Chernobyl: Summarized consequences of Chernobyl, the accident progression, basic data of the catastrophe, estimation of health hazards as a consequence of the severe accident of Chernobyl, health consequences for the liquidators, health consequences for the contaminated population, mutagenic and teratogenic effects. Part B: 5 years life with Fukushima: The start of the nuclear catastrophe, emissions and contamination, consequences of the nuclear catastrophe on human health, thyroid surveys in the prefecture Fukushima, consequences of the nuclear catastrophe on the ecosystem, outlook.

  13. Threshold intensity factors as lower boundaries for crack propagation in ceramics

    Directory of Open Access Journals (Sweden)

    Walter Per-Ole

    2004-11-01

    Full Text Available Abstract Background Slow crack growth can be described in a v (crack velocity versus KI (stress intensity factor diagram. Slow crack growth in ceramics is attributed to corrosion assisted stress at the crack tip or at any pre-existing defect in the ceramic. The combined effect of high stresses at the crack tip and the presence of water or body fluid molecules (reducing surface energy at the crack tip induces crack propagation, which eventually may result in fatigue. The presence of a threshold in the stress intensity factor, below which no crack propagation occurs, has been the subject of important research in the last years. The higher this threshold, the higher the reliability of the ceramic, and consequently the longer its lifetime. Methods We utilize the Irwin K-field displacement relation to deduce crack tip stress intensity factors from the near crack tip profile. Cracks are initiated by indentation impressions. The threshold stress intensity factor is determined as the time limit of the tip stress intensity when the residual stresses have (nearly disappeared. Results We determined the threshold stress intensity factors for most of the all ceramic materials presently important for dental restorations in Europe. Of special significance is the finding that alumina ceramic has a threshold limit nearly identical with that of zirconia. Conclusion The intention of the present paper is to stress the point that the threshold stress intensity factor represents a more intrinsic property for a given ceramic material than the widely used toughness (bend strength or fracture toughness, which refers only to fast crack growth. Considering two ceramics with identical threshold limits, although with different critical stress intensity limits, means that both ceramics have identical starting points for slow crack growth. Fast catastrophic crack growth leading to spontaneous fatigue, however, is different. This growth starts later in those ceramic materials

  14. Establishment and Application of Assessment Indicator System of Agricultural Catastrophe Vulnerability

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    To give play to the role of agricultural catastrophe risk fund in spreading agricultural catastrophe risk,we select natural conditions,economic conditions,social conditions,as the external vulnerability assessment indicators;select commodity rate of agricultural products,substitutability of agricultural products,the extent of agricultural products being related to the national economy and the people’s livelihood,as the internal vulnerability assessment indicators.We assign weight to indicators using Analytic Hierarchy Process,and establish assessment indicator system of agricultural catastrophe vulnerability,to analyze the compensation for losses of different agricultural products arising from agricultural catastrophe in different regions.And we take the case of rice in Sichuan Province,to demonstrate the role this indicator system.

  15. Genome sequencing of pediatric medulloblastoma links catastrophic DNA rearrangements with TP53 mutations

    DEFF Research Database (Denmark)

    Rausch, Tobias; Jones, David T W; Zapatka, Marc;

    2012-01-01

    Genomic rearrangements are thought to occur progressively during tumor development. Recent findings, however, suggest an alternative mechanism, involving massive chromosome rearrangements in a one-step catastrophic event termed chromothripsis. We report the whole-genome sequencing-based analysis ...

  16. Psychometric properties of the Brazilian version of the Pain Catastrophizing Scale for acute low back pain

    Directory of Open Access Journals (Sweden)

    Renata Antunes Lopes

    2015-05-01

    Full Text Available Measurement instruments of pain catastrophizing for middle-aged and elderly individuals are needed to understand its impact on low back pain. The goals were to cross-culturally adapt the Pain Catastrophizing Scale, assess the construct validity through Rasch analysis, and verify reliability and convergent validity of pain catastrophizing with psychosocial factors. 131 individuals aged 55 years and older with acute low back pain were interviewed . The intra-rater reliability was Kp = 0.80 and interrater Kp = 0.75. The Rasch analysis found adequate reliability coefficients (0.95 for items and 0.90 for individuals . The separation index for the elderly was 2.95 and 4.59 items. Of the 13 items, one did not fit the model, which was justified in the sample evaluated. The pain catastrophizing correlated with most psychosocial factors. The instrument proved to be clinically useful. Subsequent studies should carry out the same analysis in different populations.

  17. Global Catastrophes in Earth History: An Interdisciplinary Conference on Impacts, Volcanism, and Mass Mortality

    Science.gov (United States)

    1988-01-01

    Topics addressed include: Cretaceous-Tertiary mass extinctions; geologial indicators for meteorite collisions; carbon dioxide catastrophes; volcanism; climatic changes; geochemistry; mineralogy; fossil records; biospheric traumas; stratigraphy; mathematical models; and ocean dynamics.

  18. Psychometric properties of the Brazilian version of the Pain Catastrophizing Scale for acute low back pain.

    Science.gov (United States)

    Lopes, Renata Antunes; Dias, Rosângela Corrêa; Queiroz, Bárbara Zille de; Rosa, Nayza Maciel de Britto; Pereira, Leani de Souza Máximo; Dias, João Marcos Domingues; Magalhães, Lívia de Castro

    2015-05-01

    Measurement instruments of pain catastrophizing for middle-aged and elderly individuals are needed to understand its impact on low back pain. The goals were to cross-culturally adapt the Pain Catastrophizing Scale, assess the construct validity through Rasch analysis, and verify reliability and convergent validity of pain catastrophizing with psychosocial factors. 131 individuals aged 55 years and older with acute low back pain were interviewed . The intra-rater reliability was Kp = 0.80 and interrater Kp = 0.75. The Rasch analysis found adequate reliability coefficients (0.95 for items and 0.90 for individuals ). The separation index for the elderly was 2.95 and 4.59 items. Of the 13 items, one did not fit the model, which was justified in the sample evaluated. The pain catastrophizing correlated with most psychosocial factors. The instrument proved to be clinically useful. Subsequent studies should carry out the same analysis in different populations. PMID:26017211

  19. Fully-coupled hydrometeorological prediction of catastrophic Mediterranean floods

    Science.gov (United States)

    Rebora, N.; Gabellani, S.; Rudari, R.; Silvestro, F.; Parodi, A.; Gochis, D.

    2012-12-01

    On November 4th, 2011, the city of Genoa, Italy, located between the Tyrrhenian Sea and the Apennine mountains, was witness to a catastrophic flash flood. About 500 millimeters of rain -a third of the average annual rainfall- fell in approximately six hours. The waters that flooded the town center equated to an approximately 300 year flood event. Six people perished, commercial property was inundated, cars were swept away and many trees were uprooted. We analyze the performance of cloud-permitting (1 km) model simulations of the convective system responsible for this extreme event using the Advanced Research Weather and Forecasting Model (ARW-WRF, version 3.3) with its associated hydrological modeling extension ('WRF-Hydro') focusing on the utility of model quantitative precipitation forecasts (QPFs) for flash flood prediction. WRF model skill is assessed with respect to specification of cloud microphysics, convection and land surface physics parameterizations. The QPF results strongly suggest an event dominated by comparatively shallow warm rain processes where local maxima were the product of both synoptic scale dynamics and orographic enhancement over the Apennine mountain range. Land and sea surface temperature forcing was assess but found to be secondary in importance. Streamflow prediction skill from the fully coupled WRF-Hydro modeling system was compared against observations and against offline or 'uncoupled' hydrological model runs, driven by several quantitative precipitation estimate (QPEs) products. The results illustrate the significant sensitivity of the predicted (simulated) streamflow event to QPF (QPE) skill and emphasize the importance of taking into account many factors and sources of error in the hydrometeorological prediction chain. The end product of this study is a comprehensive evaluation and justification for optimal configurations of the WRF-Hydro modeling system for high-impact Mediterranean flood events for use in future forecasting

  20. Catastrophic oxidation of Zr-TM (noble metals) glasses

    Energy Technology Data Exchange (ETDEWEB)

    Jastrow, Lioba; Koester, Uwe; Meuris, Monika

    2004-07-15

    Glassy Zr{sub 70}Pd{sub 30} as well as Zr{sub 70}Au{sub 30} prepared by melt-spinning exhibit a 'catastrophic' oxidation behavior in wet as well as synthetic air. For example, at a temperature of 270 deg. C, ribbons (about 30 {mu}m in thickness) are fully oxidized within a few hours. Thermogravimetric analysis reveals an oxidation kinetics by orders of magnitude faster than those in comparable Zr-Pt or Zr-Ni, Zr-Cu as well as related ternary or quaternary glasses. Detailed microstructural investigations, in particular cross-sectional microscopy, revealed details of this reaction and indicate for example for Zr-Au glasses at 25 deg. C an oxygen diffusivity in the developing zirconia scale of about 2x10{sup -17} m{sup 2} s{sup -1}; such a diffusivity is known to occur for stabilized ZrO{sub 2} only at about 300 deg. C. At the as-cast free surface of the ribbon nucleation of the oxidation process starts at defects like scratches or along the grooves at the contact side. The developing 'vulcano' like morphology (with diameters in the range of 10 {mu}m or more) can be explained assuming a diffusion controlled thickening of the scale, but linear lateral growth. It is of interest that the occurrence of extreme fast oxidation is correlated with significant changes in the zirconia microstructure as indicated by a decrease in the intensity of the low-indexed diffraction lines; TEM reveals a nanocrystalline structure with ZrO{sub 2} crystal diameters even below 5 nm. The results will be discussed in detail taking into account for example the different redox potentials of the noble metals, their catalytic activity, the Zr-noble metal bond strength as well as the density of states at the Fermi level of the glasses.

  1. Variable Threshold MOSFET Approach (Through Dynamic Threshold MOSFET) For Universal Logic Gates

    OpenAIRE

    Ragini, K.; DR.M. SATYAM; Dr. B.C. Jinaga

    2010-01-01

    In this article, we proposed a Variable threshold MOSFET(VTMOS)approach which is realized from Dynamic Threshold MOSFET(DTMOS), suitable for sub-threshold digital circuit operation. Basically the principle of sub- threshold logics is operating MOSFET in sub-threshold region and using the leakage current in that region for switching action, there by drastically decreasing power. To reduce the power consumption of sub-threshold circuits further, a novel body biasing technique termed VTMOS is in...

  2. Disruptive Innovation in Healthcare & Rehabilitation

    DEFF Research Database (Denmark)

    Brooks, Anthony Lewis

    2014-01-01

    will pay. Disruptive Innovation in context of the author’s body of work in healthcare and rehabilitation relates to how development of a cloud-based converged infrastructure resource, similar to that conceived in a national (Danish) study titled Humanics, can act as an accessible data and knowledge...

  3. Using Catastrophe-Linked Securities to Diversity Insurance Risk: A Financial Analysis of Cat Bonds

    OpenAIRE

    Henri Louberge; Evis Kellezi; Manfred Gilli

    1999-01-01

    Severe natural catastrophes in the early 1990s generated a lack of financial capacity in the catastrophe line of the global reinsurance market. The finance industry reacted to this situation by issuing innovative products designed to spread the excess risk more widely among international investors (risk securitization). The paper reviews these developments and emphasizes their significance with respect to the economic theory of risk exchanges. Special attention is devoted to the case of catas...

  4. Childhood Trauma and Pain and Pain Catastrophizing in Adulthood: A Cross-Sectional Survey Study

    OpenAIRE

    Sansone, Randy A.; Watts, Daron A.; Wiederman, Michael W.

    2013-01-01

    Objective: Previous studies have indicated relationships between trauma in childhood and pain in adulthood, although some studies have reported no such relationships and challenge the methodologies of large-scale community samples. In this study involving a clinical sample, we examined relationships among (1) childhood trauma at ages 12 or younger, (2) rated pain for 3 time points in adulthood, and (3) pain catastrophizing (ie, catastrophic thoughts and feelings about pain).

  5. A CATASTROPHIC-CUM-RESTORATIVE QUEUING SYSTEM WITH CORRELATED BATCH ARRIVALS AND VARIABLE CAPACITY

    Directory of Open Access Journals (Sweden)

    Rakesh Kumar

    2008-07-01

    Full Text Available In this paper, we study a catastrophic-cum-restorative queuing system with correlated batch arrivals and service in batches of variable sizes. We perform the transient analysis of the queuing model. We obtain the Laplace Transform of the probability generating function of system size. Finally, some particular cases of the model have been derived and discussed. Keywords: Queue length, Catastrophes, Correlated batch arrivals, Broadband services, Variable service capacity, and Restoration.

  6. Equilibrium balking strategies in the single server Markovian queue with catastrophes

    CERN Document Server

    Boudali, Olga

    2011-01-01

    We consider a Markovian queue subject to Poisson generated catastrophes. Whenever a catastrophe occurs, all customers are forced to abandon the system, the server is rendered inoperative and an exponential repair time is set on. We assume that the arriving customers decide whether to join the system or balk, based on a natural reward-cost structure. We study the balking behavior of the customers and derive the corresponding Nash equilibrium strategies.

  7. Use of catastrophe risk models in assessing sovereign food security for risk transfer

    OpenAIRE

    Sharma, Mohan; Hohl, Roman

    2015-01-01

    This paper discusses how catastrophe crop risk models can be used to assess food security needs at the sovereign level for the purpose of risk transfer. The rationale for a system to evaluate food security needs at the national level is discussed. The role of technology and remote sensing data availability as an enabler of catastrophe crop risk models is discussed followed by a description...

  8. Catastrophizing and fear of tinnitus predict quality of life in patients with chronic tinnitus

    OpenAIRE

    Cima, Rilana FF; Crombez, Geert; Vlaeyen, Johan WS

    2011-01-01

    Objectives: It is well established that catastrophic misinterpretations and fear are involved in the suffering and disability of patients with chronic pain. This study investigated whether similar processes explain suffering and disability in patients with chronic tinnitus. We hypothesized that patients who catastrophically (mis)interpret their tinnitus would be more fearful of tinnitus, more vigilant toward their tinnitus, and report less quality of life. Moreover, tinnitus-related fear was ...

  9. Catastrophic Health Expenditure and Household Impoverishment: a case of NCDs prevalence in Kenya

    Directory of Open Access Journals (Sweden)

    Daniel Mwai

    2016-03-01

    Full Text Available Introduction and problem: Non-Communicable Diseases (NCDs have become one of the leading causes of morbidity and mortality in Kenya. Their claim on financial and time resources adversely affects household welfare. Health care cost for NCDs in Kenya is predominantly paid by households as OOP. Health expenditure on NCD stands at 6.2% of Total Health Expenditure which is 0.4 % of the total gross domestic product of the country. This expenditure scenario could have implications on household welfare through catastrophic expenditure in Kenya. Most studies done on catastrophic expenditure in Kenya have not looked at the effect of NCD on poverty. Methodology: The paper has investigated the determinants of catastrophic health spending in a household with special focus on the NCDs. It has also investigated the effect of catastrophic expenditure on household welfare.A National household level survey data on expenditure and utilization is used. Controlling for endogeneity, the results revealed that NCDs and communicable diseases contribute significantly to the likelihood of a household incurring catastrophic expenditure. Results: Although all types of sicknesses have negative effects on household welfare, NCDs have more severe impacts on impoverishment. Policy wise, government and development partners should put in place a health financing plan entailing health insurance and resource pooling as a mean towards social protection. Key words:  Non-Communicable Diseases (NCD, Catastrophic Health Expenditure, endogeneity Impoverishment

  10. Polymorphism in serotonin receptor 3B is associated with pain catastrophizing.

    Directory of Open Access Journals (Sweden)

    Emilia Horjales-Araujo

    Full Text Available Pain catastrophizing, a coping style characterized by excessively negative thoughts and emotions in relation to pain, is one of the psychological factors that most markedly predicts variability in the perception of pain; however, only little is known about the underlying neurobiology. The aim of this study was to test for associations between psychological variables, such as pain catastrophizing, anxiety and depression, and selected polymorphisms in genes related to monoaminergic neurotransmission, in particular serotonin pathway genes. Three hundred seventy-nine healthy participants completed a set of psychological questionnaires: the Pain Catastrophizing Scale (PCS, the State-Trait Anxiety Inventory and Beck's Depression Inventory, and were genotyped for 15 single nucleotide polymorphisms (SNPs in nine genes. The SNP rs1176744 located in the serotonin receptor 3B gene (5-HTR3B was found to be associated with pain catastrophizing scores: both the global score and the subscales of magnification and helplessness. This is the first study to show an association between 5-HTR3B and PCS scores, thus suggesting a role of the serotonin pathway in pain catastrophizing. Since 5-HTR3B has previously been associated with descending pain modulation pathways, future studies will be of great interest to elucidate the molecular pathways involved in the relation between serotonin, its receptors and pain catastrophizing.

  11. Relationships Between Refraining From Catastrophic Thinking, Repetitive Negative Thinking, and Psychological Distress.

    Science.gov (United States)

    Sugiura, Tomoko; Sugiura, Yoshinori

    2016-10-01

    Skills to refrain from catastrophic thinking were negatively related to worry and a wide range of psychological distress. Repetitive negative thinking (including worry) is proposed as a common etiological factor for a wide range of psychological distress. Therefore, reduced repetitive negative thinking would mediate the negative relation between refraining from catastrophic thinking and psychological distress (depression, social anxiety, phobia, generalized anxiety, and obsessions and compulsions). As an overlap between five indices of psychological distress was expected, we first computed latent factors underlying them, which were then predicted by refraining from catastrophic thinking and repetitive negative thinking. Cross-sectional questionnaire data from 125 nonclinical voluntarily participating students (M age = 19.0 years, SD = 3.6; 54% women) supported the predictions: refraining from catastrophic thinking was negatively correlated with depression, social anxiety, phobia, generalized anxiety, and obsession and compulsion. Repetitive negative thinking mediated the negative relationship between refraining from catastrophic thinking and latent factors underlying psychological distress (Fear and Distress). Refraining from catastrophic thinking may be negatively correlated with psychological distress due to its negative relation to repetitive negative thinking. PMID:27511967

  12. 40 CFR 98.361 - Reporting threshold.

    Science.gov (United States)

    2010-07-01

    ...) MANDATORY GREENHOUSE GAS REPORTING Manure Management § 98.361 Reporting threshold. Livestock facilities must report GHG emissions under this subpart if the facility meets the reporting threshold as defined in...

  13. PMI Thresholds for GDP Growth

    OpenAIRE

    Kilinc, Zubeyir; Yucel, Eray

    2016-01-01

    In this study, we try to uncover the information capacity of the Purchasing Managers Index (PMI) as a leading indicator of GDP growth of euro area. Our results show that PMI carries a significant amount of information that can be used to forecast the growth rate in the current as well as subsequent quarters. In particular, having verified that a PMI level around 50 works as the threshold distinguishing between positive and negative rates of GDP growth, we establish a sequence of other PMI thr...

  14. Oscillation threshold of woodwind instruments

    OpenAIRE

    Grand, Noël; Gilbert, Joël; Laloë, Franck

    1997-01-01

    this version has figures at the end, which was not the case of version 1 We give a theoretical study of the nature of the bifurcations occurring at the oscillation threshold of woodwind instruments, or of physical systems obeying similar non-linear equations of motion. We start from the simplest description of the acoustical behavior these instruments, a mathematical model containing two equations only, one of which is linear but includes delays, while the other is non-linear but has no de...

  15. Ultra-low threshold polariton condensation

    CERN Document Server

    Steger, Mark; Alberi, Kirstin; Mascarenhas, Angelo; Snoke, David W; Pfeiffer, Loren N; West, Ken

    2016-01-01

    We demonstrate condensation of microcavity polaritons with a very sharp threshold occuring at two orders of magnitude lower pump intensity than previous demonstrations of condensation. The long cavity-lifetime and trapping and pumping geometries are crucial to the realization of this low threshold. Polariton condensation, or "polariton lasing" has long been proposed as a promising source of coherent light at lower threshold than traditional lasing, and these results suggest methods to bring this threshold even lower.

  16. Compositional threshold for Nuclear Waste Glass Durability

    Energy Technology Data Exchange (ETDEWEB)

    Kruger, Albert A. [Pacific Northwest National Lab., Richland, WA (United States); Farooqi, Rahmatullah [Pohang Univ. of Science and Technology, (Korea, Republic of); Hrma, Pavel R. [Pacific Northwest National Lab., Richland, WA (United States), Pohang Univ. of Science and Technology, (Korea, Republic of)

    2013-04-24

    Within the composition space of glasses, a distinct threshold appears to exist that separates "good" glasses, i.e., those which are sufficiently durable, from "bad" glasses of a low durability. The objective of our research is to clarify the origin of this threshold by exploring the relationship between glass composition, glass structure and chemical durability around the threshold region.

  17. Threshold Concepts in Finance: Student Perspectives

    Science.gov (United States)

    Hoadley, Susan; Kyng, Tim; Tickle, Leonie; Wood, Leigh N.

    2015-01-01

    Finance threshold concepts are the essential conceptual knowledge that underpin well-developed financial capabilities and are central to the mastery of finance. In this paper we investigate threshold concepts in finance from the point of view of students, by establishing the extent to which students are aware of threshold concepts identified by…

  18. Threshold enhancement of diphoton resonances

    CERN Document Server

    Bharucha, Aoife; Goudelis, Andreas

    2016-01-01

    The data collected by the LHC collaborations at an energy of 13 TeV indicates the presence of an excess in the diphoton spectrum that would correspond to a resonance of a 750 GeV mass. The apparently large production cross section is nevertheless very difficult to explain in minimal models. We consider the possibility that the resonance is a pseudoscalar boson $A$ with a two--photon decay mediated by a charged and uncolored fermion having a mass at the $\\frac12 M_A$ threshold and a very small decay width, $\\ll 1$ MeV; one can then generate a large enhancement of the $A\\gamma\\gamma$ amplitude which explains the excess without invoking a large multiplicity of particles propagating in the loop, large electric charges and/or very strong Yukawa couplings. The implications of such a threshold enhancement are discussed in two explicit scenarios: i) the Minimal Supersymmetric Standard Model in which the $A$ state is produced via the top quark mediated gluon fusion process and decays into photons predominantly through...

  19. Science for decision making: Transmitting hazard science using catastrophic scenarios

    Science.gov (United States)

    Wein, A.

    2010-12-01

    The ShakeOut and ARkStorm scenarios are scientifically-based, multi-disciplinary efforts to describe the damages and consequences of large, but plausible, natural disasters for use in emergency management and other planning. The ShakeOut earthquake scenario, completed in 2008, posits the occurrence of a major earthquake on the southern San Andreas Fault. It was used by more than 5,000 emergency personnel in a California statewide exercise, and it underpins the Federal Emergency Management Agency’s (FEMA) Catastrophic Plan for Southern California. The ARkStorm winter storm scenario, to be completed in 2010, posits the occurrence of a statewide disaster like the storm that occurred during 1861-1862. The ARkStorm scenario will culminate with two planning summits comprised of federal and state agencies, because such an event would exceed local response and recovery capabilities. This talk will address the following questions that are critical to transmitting science for decision making with examples and observations from the two scenarios: 1) Who are the end users of the scenarios, what types of decisions can scenarios inform, and how are stakeholders engaged? 2) What forms of information and processes work best to communicate and apply the hazard science? 3) What are the challenges of using science in decision making? 4) What future directions shall we pursue? From my perspective as coordinator of economic consequences analyses for the two scenarios, I will share insights to these questions. Framing stakeholder decisions in terms of scale (e.g., household to State) and disaster phase (e.g., emergency response, recovery, and mitigation) allows us to align methods of stakeholder engagement with stakeholder decision making. For these regional-scale scenarios, the methods of engagement included stakeholder participation in project vision, scenario construction workshops, presentations, conferences, and emergency response and recovery exercises. Champions (self

  20. Disrupting the habit of interviewing

    Directory of Open Access Journals (Sweden)

    Eileen Honan

    2014-06-01

    Full Text Available This paper contributes to the growing domain of ‘post-qualitative’ research and experiments with a new (representational form to move away from traditional and clichéd descriptions of research methods. In this paper, I want to interrogate the category of interview, and the habit of interviewing, to disrupt the clichés, so as to allow thinking of different ways of writing/speaking/representing the interactions between researcher and researched that will breathe new life into qualitative inquiries. I will attempt to flatten and shred, destabilise and disrupt our common-sense ideas about interview, including those held most sacred to the qualitative community, that of anonymity and confidentiality, as well as the privilege of the ‘transcript’ in re-presenting interview data.

  1. Optimal Disruption of Complex Networks

    CERN Document Server

    Zhao, Jin-Hua

    2016-01-01

    The collection of all the strongly connected components in a directed graph, among each cluster of which any node has a path to another node, is a typical example of the intertwining structure and dynamics in complex networks, as its relative size indicates network cohesion and it also composes of all the feedback cycles in the network. Here we consider finding an optimal strategy with minimal effort in removal arcs (for example, deactivation of directed interactions) to fragment all the strongly connected components into tree structure with no effect from feedback mechanism. We map the optimal network disruption problem to the minimal feedback arc set problem, a non-deterministically polynomial hard combinatorial optimization problem in graph theory. We solve the problem with statistical physical methods from spin glass theory, resulting in a simple numerical method to extract sub-optimal disruption arc sets with significantly better results than a local heuristic method and a simulated annealing method both...

  2. Thresholds in vegetation responses to drought: Implications for rainfall-runoff modeling

    Science.gov (United States)

    Tague, C.; Dugger, A. L.

    2011-12-01

    While threshold behavior is often associated with soil and subsurface runoff generation, dynamic vegetation responses to water stress may be an important contributor to threshold type behavior in rainfall runoff models. Vegetation water loss varies with vegetation type and biomass and transpiration dynamics in many settings are regulated by stomatal function. In water limited environments the timing and frequency of stomatal closure varies from year to year as a function of water stress. Stomatal closure and associated fine time scale (hourly to weekly) plant transpiration may appear as threshold (on/off) behavior. Total seasonal to annual plant water use, however, typically show a continuous relationship with atmospheric conditions and soil moisture. Thus while short-time scale behavior may demonstrate non-linear, threshold type behavior, continuous relationships at slightly longer time scales can be used to capture the role of vegetation mediated water loss and its associated impact on storage and runoff. Many rainfall runoff models rely on these types of relationships. However these relationships may change if water stress influences vegetation structure as it does in drought conditions. Forest dieback under drought is a dramatic example of a threshold event, and one that is expected to occur with increasing frequency under a warmer climate. Less dramatic but still important are changes in leaf and root biomass in response to drought. We demonstrate these effects using a coupled ecosystem carbon cycling and hydrology model and show that by accounting for drought driven changes in vegetation dynamics we improve our ability to capture inter-annual variation in streamflow for a semi-arid watershed in New Mexico. We also use the model to predict spatial patterns of more catastrophic vegetation dieback with moisture stress and show that we can accurately capture the spatial pattern of ponderosa pine dieback during a early 2000s drought in New Mexico. We use these

  3. Disruptive technologies in higher education

    Directory of Open Access Journals (Sweden)

    Michael Flavin

    2012-08-01

    Full Text Available This paper analyses the role of “disruptive” innovative technologies in higher education. In this country and elsewhere, Higher Education Institutions (HEIs have invested significant sums in learning technologies, with Virtual Learning Environments (VLEs being more or less universal, but these technologies have not been universally adopted and used by students and staff. Instead, other technologies not owned or controlled by HEIs are widely used to support learning and teaching. According to Christensen's theory of Disruptive Innovation, these disruptive technologies are not designed explicitly to support learning and teaching in higher education, but have educational potential. This study uses Activity Theory and Expansive Learning to analyse data regarding the impact of disruptive technologies. The data were obtained through a questionnaire survey about awareness and use of technologies, and through observation and interviews, exploring participants’ actual practice. The survey answers tended to endorse Disruptive Innovation theory, with participants establishing meanings for technologies through their use of them, rather than in keeping with a designer's intentions. Observation revealed that learners use a narrow range of technologies to support learning, but with a tendency to use resources other than those supplied by their HEIs. Interviews showed that participants use simple and convenient technologies to support their learning and teaching. This study identifies a contradiction between learning technologies made available by HEIs, and technologies used in practice. There is no evidence to suggest that a wide range of technologies is being used to support learning and teaching. Instead, a small range of technologies is being used for a wide range of tasks. Students and lecturers are not dependent on their HEIs to support learning and teaching. Instead, they self-select technologies, with use weighted towards established brands. The

  4. HOW TO IDENTIFY DISRUPTIVE NEW BUSINESSES

    OpenAIRE

    Elizabeth Robles

    2015-01-01

    In almost any industry, the most dramatic stories of growth and success were launched from a platform of disruptive innovation (Christensen et al., 2002). The probability of creating a successful, new growth business is 10 times greater if the innovators pursue a disruptive strategy rather than a sustaining one. Genuinely disruptive innovations are the ones that result in the creation of entirely new markets and business models. Few companies have introduced these innovations. Disruptive inno...

  5. Thyroid effects of endocrine disrupting chemicals

    DEFF Research Database (Denmark)

    Boas, Malene; Feldt-Rasmussen, Ulla; Main, Katharina M

    2012-01-01

    In recent years, many studies of thyroid-disrupting effects of environmental chemicals have been published. Of special concern is the exposure of pregnant women and infants, as thyroid disruption of the developing organism may have deleterious effects on neurological outcome. Chemicals may exert...... thyroid-disrupting effects, and there is emerging evidence that also phthalates, bisphenol A, brominated flame retardants and perfluorinated chemicals may have thyroid disrupting properties....

  6. Turbulence and disruptions in Tokamaks

    International Nuclear Information System (INIS)

    In the first part of this thesis, the possible explanation of the electron abnormal thermal conductivity with electromagnetic drift modes rather than simply electrostatic is discussed. A variational form is established in non collisional conditions; linear modes principal possibilities are reviewed, then quasilinear theory is used to calculate the transport phenomenon associated to each mode. They are compared to experimental results. Electron abnormal thermal conductibility is not better explained by electromagnetic modes than by electrostatic modes. In the second part, disruptions are examined; experimental manifestations are briefly recalled. Existing interpretations of these phenomenons are reviewed, which are based on magnetic islands non-linear evolution. A detailed analytical study of the case l=1, m=1 is made. Other disruptions are studied; it is shown that the disruptive process is indissociable from sudden apparition of small scale magnetic turbulence. The possibility of such a turbulence is studied. Its predictable effects are compared to experiment. Such a turbulence, is assumed to exist permanently in an attenuated form, which could justify the electronic transport anomalies in quiescent state

  7. Engineering analysis of TFTR disruption

    Energy Technology Data Exchange (ETDEWEB)

    Murray, J.G.; Rothe, K.E.; Bronner, G.

    1984-09-01

    This report covers an engineering approach quantifying the currents, forces, and times, as well as plasma position, for the worst-case disruption based on engineerign circuit assumptions for the plasma. As the plasma moves toward the wall during the current-decay phase of disruption, the wall currents affect the rate of movement and, hence, the decay time. The calculated structure-induced currents differ considerably from those calculated using a presently available criterion, which specifies that the plasma remains stationary in the center of the torus while decaying in 10 ms. This report outlines the method and basis for the engineering calculation used to determine the current and forces as a function of the circuit characteristics. It provides specific calculations for the Tokamak Fusion Test Reactor (TFTR) with variations in parameters such as the thermal decay time, the torus resistance, and plasma temperature during the current decay. The study reviews possible ways to reduce the disruption damage of TFTR by reducing the magnitude of the plasma external field energy that is absorbed by the plasma during the current decay.

  8. Pharmacological disruption of maladaptive memory.

    Science.gov (United States)

    Taylor, Jane R; Torregrossa, Mary M

    2015-01-01

    Many psychiatric disorders are characterized by intrusive, distracting, and disturbing memories that either perpetuate the illness or hinder successful treatment. For example, posttraumatic stress disorder (PTSD) involves such strong reemergence of memories associated with a traumatic event that the individual feels like the event is happening again. Furthermore, drug addiction is characterized by compulsive use and repeated relapse that is often driven by internal memories of drug use and/or by exposure to external stimuli that were associated with drug use. Therefore, identifying pharmacological methods to weaken the strength of maladaptive memories is a major goal of research efforts aimed at finding new treatments for these disorders. The primary mechanism by which memories could be pharmacologically disrupted or altered is through manipulation of memory reconsolidation. Reconsolidation occurs when an established memory is remembered or reactivated, reentering a labile state before again being consolidated into long-term memory storage. Memories are subject to disruption during this labile state. In this chapter we will discuss the preclinical and clinical studies identifying potential pharmacological methods for disrupting the integrity of maladaptive memory to treat mental illness. PMID:25977090

  9. Investigation of Shapes and Spins of Reaccumulated Remnants from Asteroid Disruption Simulations

    Science.gov (United States)

    Michel, Patrick; Ballouz, R.; Richardson, D. C.; Schwartz, S. R.

    2012-10-01

    Evidence that asteroids larger than a few hundred meters diameter can be gravitational aggregates of smaller, cohesive pieces comes, for instance, from images returned by the Hayabusa spacecraft of asteroid 25143 Itokawa (Fujiwara et al., 2006, Science 312, 1330). These images show an irregular 500-meter-long body with a boulder-strewn surface, as might be expected from reaccumulation following catastrophic disruption of a larger parent asteroid (Michel et al., 2001, Science 294, 1696). However, numerical simulations of this process to date essentially focus on the size/mass and velocity distributions of reaccumulated fragments, matching asteroid families. Reaccumulation was simplified by merging the objects into growing spheres. However, understanding shapes, spins and surface properties of gravitational aggregates formed by reaccumulation is required to interpret information from ground-based observations and space missions. E.g., do boulders on Itokawa originate from reaccumulation of material ejected from a catastrophic impact or from other processes (such as the Brazil-nut effect)? How does reaccumulation affect the observed shapes? A model was developed (Richardson et al., 2009, Planet. Space Sci. 57, 183) to preserve shape and spin information of reaccumulated bodies in simulations of asteroid disruption, by allowing fragments to stick on contact (and optionally bounce or fragment further, depending on user-selectable parameters). Such treatments are computationally expensive, and we could only recently start to explore the parameter space. Preliminary results will be presented, showing that some observed surface and shape features may be explained by how fragments produced by a disruption reaccumulate. Simulations of rubble pile collisions without particle cohesion, and an investigation of the influence of initial target rotation on the outcome will also be shown. We acknowledge the National Science Foundation (AST1009579) and NASA (NNX08AM39G).

  10. The disruptive instability in Tokamak plasmas

    NARCIS (Netherlands)

    Salzedas, F.J.B.

    2001-01-01

    Studies performed in RTP (Rijnhuizen Tokamak Project) of the most violent and dangerous instability in tokamak plasmas, the major disruption, are presented. A particular class of disruptions is analyzed, namely the density limit disruption, which occur in high density plasmas. The radiative te

  11. Disruptive innovation as an entrepreneurial process

    NARCIS (Netherlands)

    Y. Chandra; S.-J.S. Yang

    2008-01-01

    Research on conditions and causal mechanisms that influence disruptive innovation has been relatively unexplored in the extant research in disruptive innovation. By re-conceptualizing disruptive innovation as an entrepreneurial process at product, firm and industry levels, this paper draws on emergi

  12. Orientability thresholds for random hypergraphs

    CERN Document Server

    Gao, Pu

    2010-01-01

    Let $h>w>0$ be two fixed integers. Let $\\orH$ be a random hypergraph whose hyperedges are all of cardinality $h$. To {\\em $w$-orient} a hyperedge, we assign exactly $w$ of its vertices positive signs with respect to the hyperedge, and the rest negative. A $(w,k)$-orientation of $\\orH$ consists of a $w$-orientation of all hyperedges of $\\orH$, such that each vertex receives at most $k$ positive signs from its incident hyperedges. When $k$ is large enough, we determine the threshold of the existence of a $(w,k)$-orientation of a random hypergraph. The $(w,k)$-orientation of hypergraphs is strongly related to a general version of the off-line load balancing problem. The graph case, when $h=2$ and $w=1$, was solved recently by Cain, Sanders and Wormald and independently by Fernholz and Ramachandran, which settled a conjecture of Karp and Saks.

  13. Weights of Exact Threshold Functions

    DEFF Research Database (Denmark)

    Babai, László; Hansen, Kristoffer Arnsfelt; Podolskii, Vladimir V.;

    2010-01-01

    We consider Boolean exact threshold functions defined by linear equations, and in general degree d polynomials. We give upper and lower bounds on the maximum magnitude (absolute value) of the coefficients required to represent such functions. These bounds are very close and in the linear case...... in particular they are almost matching. The quantity is the same as the maximum magnitude of integer coefficients of linear equations required to express every possible intersection of a hyperplane in R n and the Boolean cube {0,1} n , or in the general case intersections of hypersurfaces of degree d in R n...... and the Boolean cube {0,1} n . In the process we construct new families of ill-conditioned matrices. We further stratify the problem (in the linear case) in terms of the dimension k of the affine subspace spanned by the solutions, and give upper and lower bounds in this case as well. Our bounds here in terms of k...

  14. Instability Threshold “Hysteresis”

    Directory of Open Access Journals (Sweden)

    Agnes Muszynska

    1999-01-01

    Full Text Available The transient process which starts at the instability threshold of a rotor rotating in a fluid environment, and ends up in the limit cycle of self-excited vibrations known as fluid whirl or fluid whip, is discussed in this paper. A one-lateral-mode, isotropic, nonlinear model of the rotor with fluid interaction allows for exact particular solutions and an estimation of the transient process. The fluid interacting with the rotor is contained in a small radial clearance area, such as in bearings, seals, or rotor-to-stator clearances, and its effects are represented by fluid film radial stiffness, damping, and fluid inertia rotating at a different angular velocities.

  15. Astronomy below the Survey Threshold

    CERN Document Server

    Zwart, Jonathan T L; Karim, Alexander; Jackson, Carole; Norris, Ray; Condon, Jim; Afonso, Jose; Heywood, Ian; Jarvis, Matt; Navarrete, Felipe; Prandoni, Isabella; Rigby, Emma; Rottgering, Huub; Santos, Mario; Sargent, Mark; Seymour, Nick; Taylor, Russ; Vernstrom, Tessa

    2014-01-01

    Astronomy at or below the 'survey threshold' has expanded significantly since the publication of the original 'Science with the Square Kilometer Array' in 1999 and its update in 2004. The techniques in this regime may be broadly (but far from exclusively) defined as 'confusion' or 'P(D)' analyses (analyses of one-point statistics), and 'stacking', accounting for the flux-density distribution of noise-limited images co-added at the positions of objects detected/isolated in a different waveband. Here we discuss the relevant issues, present some examples of recent analyses, and consider some of the consequences for the design and use of surveys with the SKA and its pathfinders.

  16. Threshold Signature Scheme Based on Discrete Logarithm and Quadratic Residue

    Institute of Scientific and Technical Information of China (English)

    FEI Ru-chun; WANG Li-na

    2004-01-01

    Digital signature scheme is a very important research field in computer security and modern cryptography.A(k,n) threshold digital signature scheme is proposed by integrating digital signature scheme with Shamir secret sharing scheme.It can realize group-oriented digital signature, and its security is based on the difficulty in computing discrete logarithm and quadratic residue on some special conditions.In this scheme, effective digital signature can not be generated by any k-1 or fewer legal users, or only by signature executive.In addition, this scheme can identify any legal user who presents incorrect partial digital signature to disrupt correct signature, or any illegal user who forges digital signature.A method of extending this scheme to an Abelian group such as elliptical curve group is also discussed.The extended scheme can provide rapider computing speed and stronger security in the case of using shorter key.

  17. Crossing thresholds: Analysis of hazardous tipping points in alpine catchments

    Science.gov (United States)

    Lutzmann, Silke; Sass, Oliver

    2016-04-01

    Steep mountain channels or torrents in small alpine catchments are characterized by high geomorphic activity with sediment dynamics being inherently nonlinear and threshold-mediated. Localized, high intensity rainstorms can drive torrential systems past a tipping point resulting in a sudden onset of hazardous events like (flash-) flooding, heavy bedload transport or debris flows. Such responses exhibit an abrupt switch in the fluvial system's mode (e.g. transport / supply limited). Changes in functional connectivity may persist beyond the tipping point. Torrential hazards cause costly damage in the densely populated Alpine Region. Thus, there is a rising interest in potential effects of climate change on torrential sediment dynamics. Understanding critical conditions close to tipping points is important to reduce uncertainty in predicting sediment fluxes. In this study we aim at (i) establishing threshold precipitation characteristics for the Eastern Alps of Austria. Precipitation is hypothesized to be the main forcing factor of torrential events. (ii) How do thresholds vary in space and time? (iii) The effect of external triggers is strongly mediated by the internal disposition of catchments to respond. Which internal conditions are critical for susceptibility? (iv) Is there a change in magnitude or frequency in the recent past and what can be expected for the future? The 71 km2 catchment of the river Schöttlbach in the East Alpine Region of Styria (Austria) is monitored since a heavy precipitation event resulted in a catastrophic flood in July 2011. Sediment mobilization from slopes as well as within-channel storage and bedload transport are regularly measured using photogrammetric methods and sediment impact sensors. Thus, detailed knowledge exists on magnitude and spatial propagation of sediment waves through the catchment. The associated hydro-meteorological (pre-) conditions can be inferred from a dense station network. Changing bedload transport rates and

  18. Catastrophe Bonds. From Structure to Strategy – A Cluster Analysis at European Level

    Directory of Open Access Journals (Sweden)

    Laura-Gabriela CONSTANTIN

    2014-12-01

    Full Text Available As a core activity and discipline of corporate management and corporate governance, risk management is, especially nowadays, a central part in pursuing the sustainable development desiderates, both from the perspective of the firm and of the society as a whole.Considering the negative impact natural catastrophes have on the companies’ and countries’ competitiveness, the development of sustainable financial products that make a contribution to transferring the risk and allocating the capital in case of disasters stands for a continual preoccupation, especially for the (reinsurance industry, while the study of catastrophe bonds – insurance-linked securities – is of interest in the specialized literature. In this context, the scope of the present research is to expand the empirical studies within this field while examining the link between the structure of the catastrophe bonds and the risk management approach employed while accessing the capital markets through this transactions.The methodology entailed clustering a selection of transactions developed by European cedents based on the size of each issue and correlating the results with an innovative score, developed to encompass several important catastrophe bonds structural components.The findings reflect that the general structural elements of the financial transactions reflect closely the corporate approach regarding the innovative risk intermediation instruments for the examined catastrophe bonds deals. The outcomes also emphasize, as expected, that companies with a stronger presence on this market seem to have a more sophisticated risk management approach.

  19. Catastrophe model and its experimental verification of static loading rock system under impact load

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    According to the catastrophe model for impact buckling of static loading structures, a new catastrophe model for impact loading failure of a static loading rock system was established, and one dimension (1D) catastrophe model was analyzed. The analysis results indicate that the furcation collection where catastrophe may take place is not only decided by mechanical system itself but also relates to exterior loading, which is different from the results obtained under mono-static loading where the bifurcation collection is only determined by mechanics of the system itself and has nothing to do with exterior loading. In addition, the corresponding 1D coupled static-dynamic loading experiment is designed to verify the analysis results of catastrophe model The test is done with Instron 1342 electroservo controlled testing system, in which medium strain rate is caused by monotony rising dynamic load. The parameters are obtained combining theoretical model with experiment. The experimental and theoretical curves of critical dynamic load vs static load are rather coincided, thus the new model is proved to be correct.

  20. Determinants of mitotic catastrophe on abrogation of the G2 DNA damage checkpoint by UCN-01.

    Science.gov (United States)

    On, Kin Fan; Chen, Yue; Ma, Hoi Tang; Chow, Jeremy P H; Poon, Randy Y C

    2011-05-01

    Genotoxic stress such as ionizing radiation halts entry into mitosis by activation of the G(2) DNA damage checkpoint. The CHK1 inhibitor 7-hydroxystaurosporine (UCN-01) can bypass the checkpoint and induce unscheduled mitosis in irradiated cells. Precisely, how cells behave following checkpoint abrogation remains to be defined. In this study, we tracked the fates of individual cells after checkpoint abrogation, focusing in particular on whether they undergo mitotic catastrophe. Surprisingly, while a subset of UCN-01-treated cells were immediately eliminated during the first mitosis after checkpoint abrogation, about half remained viable and progressed into G(1). Both the delay of mitotic entry and the level of mitotic catastrophe were dependent on the dose of radiation. Although the level of mitotic catastrophe was specific for different cell lines, it could be promoted by extending the mitosis. In supporting this idea, weakening of the spindle-assembly checkpoint, by either depleting MAD2 or overexpressing the MAD2-binding protein p31(comet), suppressed mitotic catastrophe. Conversely, delaying of mitotic exit by depleting either p31(comet) or CDC20 tipped the balance toward mitotic catastrophe. These results underscore the interplay between the level of DNA damage and the effectiveness of the spindle-assembly checkpoint in determining whether checkpoint-abrogated cells are eliminated during mitosis.

  1. Catastrophic Outcomes in Free Tissue Transfer: A Six-Year Review of the NSQIP Database

    Directory of Open Access Journals (Sweden)

    David W. Grant

    2014-01-01

    Full Text Available Background. No studies report robust data on the national incidence and risk factors associated with catastrophic medical outcomes following free tissue transfer. Methods. The American College of Surgeons (ACS multicenter, prospective National Surgical Quality Improvement Program (NSQIP database was used to identify patients who underwent free tissue transfer between 2006 and 2011. Multivariable logistic regression was used for statistical analysis. Results. Over the 6-year study period 2,349 patients in the NSQIP database underwent a free tissue transfer procedure. One hundred and twenty-two patients had at least one catastrophic medical outcome (5.2%. These 122 patients had 151 catastrophic medical outcomes, including 93 postoperative respiratory failure events (4.0%, 14 pulmonary emboli (0.6%, 13 septic shock events (0.5%, 12 myocardial infarctions (0.5%, 6 cardiac arrests (0.3%, 4 strokes (0.2%, 1 coma (0.0%, and 8 deaths (0.3%. Total length of hospital stay was on average 14.7 days longer for patients who suffered a catastrophic medical complication (P<0.001. Independent risk factors were identified. Conclusions. Free tissue transfer is a proven and safe technique. Catastrophic medical complications were infrequent but added significantly to length of hospital stay and patient morbidity.

  2. Pain-related Catastrophizing and Perceived Social Responses: Inter-relationships in the Context of Chronic Pain

    OpenAIRE

    Buenaver, Luis F.; Edwards, Robert R.; Haythornthwaite, Jennifer A.

    2006-01-01

    Pain-related coping, particularly catastrophizing, plays a significant role in shaping pain responses. One way catastrophizing is hypothesized to amplify pain and disability is via its effect on patients, social environments (e.g., communal coping model), though empirical support is limited. The present study tested whether the association between catastrophizing and deleterious pain-related outcomes was mediated by patients’ perceptions of significant others’ responses to their pain in a sam...

  3. Association between catastrophizing and self-rated pain and disability in patients with chronic low back pain

    OpenAIRE

    K. Meyer; Tschopp, A.; Sprott, H; Mannion, A. F.

    2009-01-01

    BACKGROUND: Catastrophizing plays an important role in models of pain chronicity, showing a consistent correlation with both pain intensity and disability. It is conceivable that these associations are mediated or confounded by other psychological attributes. OBJECTIVE: To examine the relative influence of catastrophizing and other psychological variables on pain and disability in patients with chronic low back pain. METHODS: Seventy-eight patients completed the Pain Catastrophizing Scale, Ro...

  4. Factors associated with increased risk for pain catastrophizing in patients with chronic neck pain: A retrospective cross-sectional study.

    Science.gov (United States)

    Park, Sang Jun; Lee, Rippy; Yoon, Duck Mi; Yoon, Kyung Bong; Kim, Kiwook; Kim, Shin Hyung

    2016-09-01

    Pain catastrophizing is becoming increasingly recognized as a clinically important psychological factor in chronic musculoskeletal pain. In this retrospective cross-sectional study, we have identified factors associated with an increased risk for pain catastrophizing in chronic neck pain (CNP) patients. We obtained data from our medical database on 331 patients who were treated for neck pain as their chief complaint at our clinic. The Pain Catastrophizing Scale (PCS) was used to define a high pain catastrophizing state (PCS score ≥21) in this study. Patient demographics, pain-related factors, and psychological factors were evaluated with logistic regression analysis to identify risk factors of high pain catastrophizing among patients with CNP. A total of 256 patients with CNP satisfied the study inclusion criteria and were included in the analyses. The median PCS score was 16 (range, 0-45), and 86 of 256 patients (33.5%) reported a PCS score ≥21. In multivariate analysis, high pain intensity, clinical insomnia, and a high level of depression/anxiety were strongly associated with high pain catastrophizing in patients with CNP. Depression was the strongest predictor of high pain catastrophizing, with an odds ratio of 7.35 (95% confidence interval 2.23-24.22). High pain catastrophizing was not significantly related to age, gender, comorbidities, or neck pain-related physical symptoms. In conclusion, poor psychological states should be addressed as an important part of pain management in CNP patients who are susceptible to high pain catastrophizing. PMID:27631217

  5. Public policy and risk financing strategies for global catastrophe risk management - the role of global risk initiatives

    Science.gov (United States)

    McSharry, Patrick; Mitchell, Andrew; Anderson, Rebecca

    2010-05-01

    Decision-makers in both public and private organisations depend on accurate data and scientific understanding to adequately address climate change and the impact of extreme events. The financial impacts of catastrophes on populations and infrastructure can be offset through effective risk transfer mechanisms, structured to reflect the specific perils and levels of exposure to be covered. Optimal strategies depend on the likely socio-econonomic impact, the institutional framework, the overall objectives of the covers placed and the level of both the frequency and severity of loss potential expected. The diversity of approaches across different countries has been documented by the Spanish "Consorcio de Compensación de Seguros". We discuss why international public/private partnerships are necessary for addressing the risk of natural catastrophes. International initiatives such as the Global Earthquake Model (GEM) and the World Forum of Catastrophe Programmes (WFCP) can provide effective guidelines for constructing natural catastrophe schemes. The World Bank has been instrumental in the creation of many of the existing schemes such as the Turkish Catastrophe Insurance Pool, the Caribbean Catastrophe Risk Insurance Facility and the Mongolian Index-Based Livestock Insurance Program. We review existing schemes and report on best practice in relation to providing protection against natural catastrophe perils. The suitability of catastrophe modelling approaches to support schemes across the world are discussed and we identify opportunities to improve risk assessment for such schemes through transparent frameworks for quantifying, pricing, sharing and financing catastrophe risk on a local and global basis.

  6. Stable states and catastrophic shifts in tidal eco-morphodynamics

    Science.gov (United States)

    Marani, M.; D'Alpaos, A.; Lanzoni, S.; Carniello, L.; Rinaldo, A.

    2007-12-01

    Changes in relative sea level, nutrient and sediment loading, and ecological characteristics expose tidal landforms and ecosystems to responses which may or may not be reversible. On this basis alone predicting the response of tidal geomorphology is important in view of the ecological, cultural and socio-economic importance of endangered tidal environments worldwide. Here we present a point model of the joint evolution of tidal landforms and biota including the dynamics of intertidal vegetation, benthic microbial assemblages, erosional and depositional processes, local and general hydrodynamics, and relative sea-level change. Alternative stable states and punctuated-equilibrium dynamics emerge, characterized by possible sudden transitions of the system, governed by marine transgressions or regressions, vegetation type, disturbances of the benthic biofilm and sediment availability. Multiple equilibria are the result of the interplay of erosion, deposition and biostabilization, highlighting the importance of the coupling between biological and sediment transport processes in determining the evolution of a tidal system as a whole. Hysteretic switches between stable states may arise because of differences in the threshold values of relative sea level rise inducing transitions from vegetated to unvegetated equilibria and viceversa. A similar hysteretic mechanism is also found to link successive periods of increased and decreased sediment availability.

  7. Catastrophic loss of stratospheric ozone in dense volcanic clouds

    Science.gov (United States)

    Prather, Michael

    1992-01-01

    Rapid, localized loss of ozone is predicted to occur in the midlatitude and tropical stratosphere in the presence of very large concentrations of sulfate aerosols. Volcanic eruptions can increase the effective surface area of sulfuric acid so that heterogeneous reactions involving ClONO2, and secondarily N2O5, are able to suppress NO(x) abundances by more than a factor of 10 relative to gas phase chemistry. When NO(x) levels fall below a threshold, e.g., 0.6 ppb at 24 km in mid-latitudes, the chlorine-catalyzed loss of O3 proceeds at rates comparable to those during the formation of the Antarctic ozone hole, more than 50 ppb per day. If such losses occurred following the eruption of Mount Pinatubo in the most volcanically perturbed regions over the tropics and mid-latitudes, this model predicts that they are driven primarily by the suppression of NO(x) below these critical levels. The increase in stratospheric chlorine since El Chichon has made Mount Pinatubo more than twice as effective in causing rapid O3 loss.

  8. Disruptive Innovation in Numerical Hydrodynamics

    Energy Technology Data Exchange (ETDEWEB)

    Waltz, Jacob I. [Los Alamos National Laboratory

    2012-09-06

    We propose the research and development of a high-fidelity hydrodynamic algorithm for tetrahedral meshes that will lead to a disruptive innovation in the numerical modeling of Laboratory problems. Our proposed innovation has the potential to reduce turnaround time by orders of magnitude relative to Advanced Simulation and Computing (ASC) codes; reduce simulation setup costs by millions of dollars per year; and effectively leverage Graphics Processing Unit (GPU) and future Exascale computing hardware. If successful, this work will lead to a dramatic leap forward in the Laboratory's quest for a predictive simulation capability.

  9. Loading-rate-independent delay of catastrophic avalanches in a bulk metallic glass

    Science.gov (United States)

    Chen, S. H.; Chan, K. C.; Wang, G.; Wu, F. F.; Xia, L.; Ren, J. L.; Li, J.; Dahmen, K. A.; Liaw, P. K.

    2016-02-01

    The plastic flow of bulk metallic glasses (BMGs) is characterized by intermittent bursts of avalanches, and this trend results in disastrous failures of BMGs. In the present work, a double-side-notched BMG specimen is designed, which exhibits chaotic plastic flows consisting of several catastrophic avalanches under the applied loading. The disastrous shear avalanches have, then, been delayed by forming a stable plastic-flow stage in the specimens with tailored distances between the bottoms of the notches, where the distribution of a complex stress field is acquired. Differing from the conventional compressive testing results, such a delaying process is independent of loading rate. The statistical analysis shows that in the specimens with delayed catastrophic failures, the plastic flow can evolve to a critical dynamics, making the catastrophic failure more predictable than the ones with chaotic plastic flows. The findings are of significance in understanding the plastic-flow mechanisms in BMGs and controlling the avalanches in relating solids.

  10. Evaluation of the propensity for coal spontaneous combustion based on catastrophe theory

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yu-tao; ZHANG Xi-chen; TIEN Jerry C; LI Ya-qing

    2011-01-01

    Generally,different prevention measures should be taken according to spontaneous combustion propensities.The current methods to evaluate the propensity of coal spontaneous combustion,such as chromatographic method of oxygen adsorption,oxidation kinetics method and activation energy method,are mostly affected by human factors.Their boundaries among different classes of propensities were all established by subjective judgments.A new evaluation method using catastrophe theory is introduced.This method can accurately depict the process of coal spontaneous combustion and the evaluation index,"catastrophe temperature",be obtained based on the model.In terms of catastrophe temperature,the spontaneous combustion propensity of different coals can be sequenced.Experimental data indicate that this method is appropriate to describe the spontaneous combustion process and to evaluate the propensity of coal spontaneous combustion.

  11. CALIFORNIA STATE UNIVERSITY CATASTROPHIC (CAT) LEAVE DONATION PROGRAM: DEMOGRAPHICS, ECONOMIC SECURITY, AND SOCIAL EQUITY.

    Science.gov (United States)

    Muller, Christina

    2015-01-01

    The California State University (CSU) Chancellor's Office reached an agreement with all CSU collective bargaining units and Employee Relations on a uniform Catastrophic (CAT) Leave Donation Program in 1992. The CAT Leave Donation Program allows employees to donate sick and/or vacation leave credits to employees who are incapacitated due to a catastrophic illness or injury and have exhausted all of their own leave credits. This also extends to employees with whom family illnesses are deemed catastrophic, thus requiring the employee to care for an immediate family member. Stakeholders include union represented employees who accrue leave credits as well as any employee who receives or donates hours of leave credits in the program. Other stakeholders include the family members and program administrators. PMID:26369237

  12. Iran: the next nuclear threshold state?

    OpenAIRE

    Maurer, Christopher L.

    2014-01-01

    Approved for public release; distribution is unlimited A nuclear threshold state is one that could quickly operationalize its peaceful nuclear program into one capable of producing a nuclear weapon. This thesis compares two known threshold states, Japan and Brazil, with Iran to determine if the Islamic Republic could also be labeled a threshold state. Furthermore, it highlights the implications such a status could have on U.S. nonproliferation policy. Although Iran's nuclear program is mir...

  13. VIBRATORY THRESHOLDS AND MOBILITY IN OLDER PERSONS

    OpenAIRE

    Buchman, Aron S; Wilson, Robert S.; Leurgans, Sue; David A Bennett

    2009-01-01

    We tested the hypothesis that vibratory thresholds in the elderly are related to mobility. 629 older persons without dementia underwent testing including 11 lower extremity performance measures and modified UPDRS, summarized as composite mobility and global Parkinsonian signs. Vibratory thresholds were measured at the ankle and toes bilaterally using the graduated Rydel-Seiffer tuning fork. In linear regression models adjusted for age, sex and education, vibratory threshold was associated wit...

  14. On the implications of thresholds for economic science and environmental policy

    Energy Technology Data Exchange (ETDEWEB)

    Aalbers, R.

    1999-05-11

    This thesis consists of four chapters on the topic of thresholds. Chapter 2 deals with the issue of a truly catastrophic threshold. Society has perfect information on both the location and the impact of crossing the threshold. The assumption is made that crossing the threshold will result in the destruction of all human utility on earth (which is not the same as the destruction of all human life on earth). On the basis of a simple neoclassical growth model the question is posed under what conditions society would like to cross the threshold, and hence, initiate a catastrophe. The trade-off for society is to have a relatively low consumption level for an infinite period of time, or to have a relatively high consumption level for a short period of time. Perhaps surprisingly, it turns out that the doomsday scenario may be optimal (in the sense of maximizing human utility). Chapter 3 extends the analysis of the second chapter by allowing society to spend resources either on consumption or on abatement. In chapter 4 the assumption of certainty of information about both the location and the impact of a threshold is relaxed. Instead it is assumed that a society has information - in the form of a probability density function - about both the location of the threshold and its impact. What then is the optimal strategy for that society? In addition, it will be analysed how society`s optimal strategy changes, if the uncertainty increases. We will see that if uncertainty about the impact of the threshold increases, society`s strategy will become more prudent. Moreover, it is argued that any form of cost-benefit analysis must - whenever thresholds cannot be excluded a priori from the analysis - necessarily be based on arbitrary, in the sense of non-empirically verifiable, assumptions about the shape of the damage function. Finally, the author examines the case in which society has not enough - quantitative or qualitative - information in order to obtain, or estimate, a

  15. Household catastrophic healthcare expenditure and impoverishment due to rotavirus gastroenteritis requiring hospitalization in Malaysia.

    Directory of Open Access Journals (Sweden)

    Tharani Loganathan

    Full Text Available While healthcare costs for rotavirus gastroenteritis requiring hospitalization may be burdensome on households in Malaysia, exploration on the distribution and catastrophic impact of these expenses on households are lacking.We assessed the economic burden, levels and distribution of catastrophic healthcare expenditure, the poverty impact on households and inequities related to healthcare payments for acute gastroenteritis requiring hospitalization in Malaysia.A two-year prospective, hospital-based study was conducted from 2008 to 2010 in an urban (Kuala Lumpur and rural (Kuala Terengganu setting in Malaysia. All children under the age of 5 years admitted for acute gastroenteritis were included. Patients were screened for rotavirus and information on healthcare expenditure was obtained.Of the 658 stool samples collected at both centers, 248 (38% were positive for rotavirus. Direct and indirect costs incurred were significantly higher in Kuala Lumpur compared with Kuala Terengganu (US$222 Vs. US$45; p<0.001. The mean direct and indirect costs for rotavirus gastroenteritis consisted 20% of monthly household income in Kuala Lumpur, as compared with only 5% in Kuala Terengganu. Direct medical costs paid out-of-pocket caused 141 (33% households in Kuala Lumpur to experience catastrophic expenditure and 11 (3% households to incur poverty. However in Kuala Terengganu, only one household (0.5% experienced catastrophic healthcare expenditure and none were impoverished. The lowest income quintile in Kuala Lumpur was more likely to experience catastrophic payments compared to the highest quintile (87% vs 8%. The concentration index for out-of-pocket healthcare payments was closer to zero at Kuala Lumpur (0.03 than at Kuala Terengganu (0.24.While urban households were wealthier, healthcare expenditure due to gastroenteritis had more catastrophic and poverty impact on the urban poor. Universal rotavirus vaccination would reduce both disease burden and health

  16. Percolation Threshold in Polycarbonate Nanocomposites

    Science.gov (United States)

    Ahuja, Suresh

    2014-03-01

    Nanocomposites have unique mechanical, electrical, magnetic, optical and thermal properties. Many methods could be applied to prepare polymer-inorganic nanocomposites, such as sol-gel processing, in-situ polymerization, particle in-situ formation, blending, and radiation synthesis. The analytical composite models that have been put forth include Voigt and Reuss bounds, Polymer nanocomposites offer the possibility of substantial improvements in material properties such as shear and bulk modulus, yield strength, toughness, film scratch resistance, optical properties, electrical conductivity, gas and solvent transport, with only very small amounts of nanoparticles Experimental results are compared against composite models of Hashin and Shtrikman bounds, Halpin-Tsai model, Cox model, and various Mori and Tanaka models. Examples of numerical modeling are molecular dynamics modeling and finite element modeling of reduced modulus and hardness that takes into account the modulus of the components and the effect of the interface between the hard filler and relatively soft polymer, polycarbonate. Higher nanoparticle concentration results in poor dispersion and adhesion to polymer matrix which results in lower modulus and hardness and departure from the existing composite models. As the level of silica increases beyond a threshold level, aggregates form which results in weakening of the structure. Polymer silica interface is found to be weak as silica is non-interacting promoting interfacial slip at silica-matrix junctions. Our experimental results compare favorably with those of nanocomposites of polyesters where the effect of nanoclay on composite hardness and modulus depended on dispersion of nanoclay in polyester.

  17. Efficient threshold for volumetric segmentation

    Science.gov (United States)

    Burdescu, Dumitru D.; Brezovan, Marius; Stanescu, Liana; Stoica Spahiu, Cosmin; Ebanca, Daniel

    2015-07-01

    Image segmentation plays a crucial role in effective understanding of digital images. However, the research on the existence of general purpose segmentation algorithm that suits for variety of applications is still very much active. Among the many approaches in performing image segmentation, graph based approach is gaining popularity primarily due to its ability in reflecting global image properties. Volumetric image segmentation can simply result an image partition composed by relevant regions, but the most fundamental challenge in segmentation algorithm is to precisely define the volumetric extent of some object, which may be represented by the union of multiple regions. The aim in this paper is to present a new method to detect visual objects from color volumetric images and efficient threshold. We present a unified framework for volumetric image segmentation and contour extraction that uses a virtual tree-hexagonal structure defined on the set of the image voxels. The advantage of using a virtual tree-hexagonal network superposed over the initial image voxels is that it reduces the execution time and the memory space used, without losing the initial resolution of the image.

  18. Enhance Confidentiality of Threshold Signature for MANET

    Institute of Scientific and Technical Information of China (English)

    GUO Wei; XIONG Zhongwei

    2006-01-01

    The participating wireless mobile node that mobile ad hoc network (MANET) communications need to forward may be malicious. That means not only adversary might be able to acquire some sensitive information of the threshold signatures from the compromised node, but also the partial signatures may be fabricated by malicious node, the advantages of threshold signatures would disappear. Signing and encrypting the sensitive information of the threshold signatures, and only the specified receiver can recover it, which will improve the confidentiality of threshold signatures. The security analysis shows the method is suitable for the secure characteristic of MANET that has the malicious nodes, and the message transmission is secure can against the attack.

  19. Nonlinear analysis of the cooperation of strategic alliances through stochastic catastrophe theory

    Science.gov (United States)

    Xu, Yan; Hu, Bin; Wu, Jiang; Zhang, Jianhua

    2014-04-01

    The excitation intervention of strategic alliance may change with the changes in the parameters of circumstance (e.g., external alliance tasks). As a result, the stable cooperation between members may suffer a complete unplanned betrayal at last. However, current perspectives on strategic alliances cannot adequately explain this transition mechanism. This study is a first attempt to analyze this nonlinear phenomenon through stochastic catastrophe theory (SCT). A stochastic dynamics model is constructed based on the cooperation of strategic alliance from the perspective of evolutionary game theory. SCT explains the discontinuous changes caused by the changes in environmental parameters. Theoretically, we identify conditions where catastrophe can occur in the cooperation of alliance members.

  20. Chronicle of a death foretold: a case of catastrophic vascular Behcet's disease.

    Science.gov (United States)

    Planer, David; Leibowitz, David; Elitzur, Yair; Korach, Amit; Hiller, Nurith; Chajek-Shaul, Tova

    2007-03-01

    A 20-year-old man with Behcet's disease characterized by recurrent arterial aneurysms presented with a new aortic root aneurysm. This patient previously had aneurysms of the coronary arteries and vein, as well as ruptured renal artery aneurysm. Chronic maintenance immunosuppressive therapy was recommended due to the catastrophic nature of the disease, which the patient refused to take. The patient died shortly after admission. This case demonstrates the unique catastrophic natural history of vascular Behcet's disease with recurrent life-threatening arterial events, and this case stresses the therapeutic dilemma of maintenance immunosuppressive therapy in selected patients. PMID:16767354

  1. Catastrophes and Conservation: Lessons from Sea Otters and the Exxon Valdez

    Directory of Open Access Journals (Sweden)

    Estes J.A.

    1992-02-01

    Full Text Available The Exxon Valdez spill is broadly perceived as an environmental catastrophe. However, expected catastrophic declines in the region's sea otter population cannot be demonstrated, not because they didn't occur but because the necessary information is lacking. Furthermore, efforts to rehabilitate oiled sea otters following the spill were extremely expensive and ineffective. Some improvements are possible with better planning. However, post-spill capture and rehabilitation probably can not be used to substantially reduce sea otter losses from future spills, and the use of such measures to conserve populations is unrealistic.

  2. Requiem for analytical psychology: a reflection on Jung's (anti)catastrophic psychology.

    Science.gov (United States)

    Barreto, Marco Heleno

    2014-02-01

    This article is an interpretation of analytical psychology in the light of the catastrophic vision and dreams that Jung had in 1913 and 1914. It is shown how the guiding spirit of Jung's psychological project is to be found in that psychic material. Then it is proposed that the completion of the symbolic catastrophe displayed in Jung's last vision (1961) points to the end of the psychological foundations upon which analytical psychology is built, and thus to its cultural obsolescence, extensive to any psychology grounded in Jung's notion of 'soul'. PMID:24467353

  3. Pain catastrophizing as a risk factor for chronic pain after total knee arthroplasty: a systematic review

    Directory of Open Access Journals (Sweden)

    Burns LC

    2015-01-01

    Full Text Available Lindsay C Burns,1–3 Sarah E Ritvo,1 Meaghan K Ferguson,1 Hance Clarke,3–5 Ze’ev Seltzer,3,5 Joel Katz1,3–5 1Department of Psychology, York University, Toronto, ON, Canada; 2Arthritis Research Centre of Canada, Vancouver, BC, Canada; 3Department of Anesthesia and Pain Management, Toronto General Hospital, Toronto, ON, Canada; 4Department of Anesthesia, University of Toronto, Toronto, ON, Canada; 5Centre for the Study of Pain, Faculties of Dentistry and Medicine, University of Toronto, Toronto, ON, Canada Background: Total knee arthroplasty (TKA is a common and costly surgical procedure. Despite high success rates, many TKA patients develop chronic pain in the months and years following surgery, constituting a public health burden. Pain catastrophizing is a construct that reflects anxious preoccupation with pain, inability to inhibit pain-related fears, amplification of the significance of pain vis-à-vis health implications, and a sense of helplessness regarding pain. Recent research suggests that it may be an important risk factor for untoward TKA outcomes. To clarify this impact, we systematically reviewed the literature to date on pain catastrophizing as a prospective predictor of chronic pain following TKA. Methods: We searched MEDLINE, EMBASE, and PsycINFO databases to identify articles related to pain catastrophizing, TKA, risk models, and chronic pain. We reviewed titles and abstracts to identify original research articles that met our specified inclusion criteria. Included articles were then rated for methodological quality. including methodological quality. Due to heterogeneity in follow-up, analyses, and outcomes reported across studies, a quantitative meta-analysis could not be performed. Results: We identified six prospective longitudinal studies with small-to-mid-sized samples that met the inclusion criteria. Despite considerable variability in reported pain outcomes, pain catastrophizing was identified as a significant

  4. Roll stability catastrophe mechanism of a flooded ship on regular sea waves

    International Nuclear Information System (INIS)

    Based on a typical one-free-degree ship roll motion equation, the cusp catastrophe model is built including the bifurcation set equation, splitting factor ‘u’ and regular factor ‘v’, where both ‘u’ and ‘v’ are further expressed with typical flooded ship parameters. Then, the roll catastrophe mechanism is analyzed mainly by means ‘u’, under the given parameters of a typical trawler boat. The aim of this research is to reveal the mutagenic mechanism of the roll stability and provide a reference for improving ship roll stability. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

  5. Requiem for analytical psychology: a reflection on Jung's (anti)catastrophic psychology.

    Science.gov (United States)

    Barreto, Marco Heleno

    2014-02-01

    This article is an interpretation of analytical psychology in the light of the catastrophic vision and dreams that Jung had in 1913 and 1914. It is shown how the guiding spirit of Jung's psychological project is to be found in that psychic material. Then it is proposed that the completion of the symbolic catastrophe displayed in Jung's last vision (1961) points to the end of the psychological foundations upon which analytical psychology is built, and thus to its cultural obsolescence, extensive to any psychology grounded in Jung's notion of 'soul'.

  6. Imaging findings in the rare catastrophic variant of the primary antiphospholipid syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Thuerl, Christina; Altehoefer, Carsten; Laubenberger, Joerg [Freiburg Univ. (Germany). Abt. Radiologie; Spyridonidis, Alexandros [Freiburg Univ. (DE). Abt. Innere Medizin 1 (Haematologie und Onkologie)

    2002-03-01

    We report imaging findings in a case of the rare catastrophic variant of antiphospholipid syndrome (CAPS) characterized by widespread microvascular occlusions, which may lead to multiple organ failure. We present a case of a 66-year-old woman with bone marrow necrosis, acute acalculous cholecystitis (AAC), focal liver necrosis, subtle patchy splenic infarctions, and bilateral adrenal infarction. The demonstration of multiple microvascular organ involvement (three or more) is crucial for the diagnosis of the catastrophic variant of APS. This can be performed radiologically intra-vitam. Imaging can even reveal subclinical microinfarctions, which are often only diagnosed at autopsy. (orig.)

  7. Model and algorithm for optimization of rescue center location of emergent catastrophe

    Institute of Scientific and Technical Information of China (English)

    WANG Ding-wei; ZHANG Guo-xiang

    2006-01-01

    The location of rescue centers is a key problem in optimal resource allocation and logistics in emergency response.We propose a mathematical model for rescue center location with the considerations of emergency occurrence probability,catastrophe diffusion function and rescue function.Because the catastrophe diffusion and rescue functions are both nonlinear and time-variable,it cannot be solved by common mathematical programming methods.We develop a heuristic embedded genetic algorithm for the special model solution.The computation based on a large number of examples with practical data has shown us satisfactory results.

  8. Climate change increases the likelihood of catastrophic avian mortality events during extreme heat waves.

    Science.gov (United States)

    McKechnie, Andrew E; Wolf, Blair O

    2010-04-23

    Severe heat waves have occasionally led to catastrophic avian mortality in hot desert environments. Climate change models predict increases in the intensity, frequency and duration of heat waves. A model of avian evaporative water requirements and survival times during the hottest part of day reveals that the predicted increases in maximum air temperatures will result in large fractional increases in water requirements (in small birds, equivalent to 150-200 % of current values), which will severely reduce survival times during extremely hot weather. By the 2080s, desert birds will experience reduced survival times much more frequently during mid-summer, increasing the frequency of catastrophic mortality events.

  9. Disruptive innovation for social change.

    Science.gov (United States)

    Christensen, Clayton M; Baumann, Heiner; Ruggles, Rudy; Sadtler, Thomas M

    2006-12-01

    Countries, organizations, and individuals around the globe spend aggressively to solve social problems, but these efforts often fail to deliver. Misdirected investment is the primary reason for that failure. Most of the money earmarked for social initiatives goes to organizations that are structured to support specific groups of recipients, often with sophisticated solutions. Such organizations rarely reach the broader populations that could be served by simpler alternatives. There is, however, an effective way to get to those underserved populations. The authors call it "catalytic innovation." Based on Clayton Christensen's disruptive-innovation model, catalytic innovations challenge organizational incumbents by offering simpler, good-enough solutions aimed at underserved groups. Unlike disruptive innovations, though, catalytic innovations are focused on creating social change. Catalytic innovators are defined by five distinct qualities. First, they create social change through scaling and replication. Second, they meet a need that is either overserved (that is, the existing solution is more complex than necessary for many people) or not served at all. Third, the products and services they offer are simpler and cheaper than alternatives, but recipients view them as good enough. Fourth, they bring in resources in ways that initially seem unattractive to incumbents. And fifth, they are often ignored, put down, or even encouraged by existing organizations, which don't see the catalytic innovators' solutions as viable. As the authors show through examples in health care, education, and economic development, both nonprofit and for-profit groups are finding ways to create catalytic innovation that drives social change.

  10. Long-range pulselength scaling of 351nm laser damage thresholds

    Science.gov (United States)

    Foltyn, S. R.; Jolin, L. J.

    1986-12-01

    In a series of experiments incorporating 351nm pulselength of 9, 26, 54, and 625ns, it was found that laser damage thresholds increased as (pulselength)/sup x/, and that the exponent averaged 0.36 and ranged, for different samples, from 0.23 to 0.48. Similar results were obtained when only catastrophic damage was considered. Samples included Al2O3/SiO2 in both AR and HR multilayers, HR's of Sc2O3/SiO2 and HfO2/SiO2, and Al-on-pyrex mirror; 9ns thresholds were between 0.2 to 5.6 J/sq cm. When these data were compared with a wide range of other results - for wavelengths from 0.25 to 10.6 microns and pulselengths down to 4ps - a remarkably consistent picture emerged. Damage thresholds, on average, increase approximately as the cube-root of pulselength from picoseconds to nearly a microsecond, and do so regardless of wavelength or material under test.

  11. Long-range pulse length scaling of 351 nm laser damage thresholds

    International Nuclear Information System (INIS)

    This paper reports how, in a series of experiments incorporating 351-nm pulselengths of 9, 26, 54, and 625 ns, it was found that laser damage thresholds increased as (pulselength)x, and that the exponent averaged 0.36 and ranged, for different samples, from 0.23 to 0.48. Similar results were obtained when only catastrophic damage was considered. Samples included Al2O3/SiO2 in both AR and HR multilayers. HR's of Sc2O3/SiO2 and HfO2/SiO2, and an Al- on-pyrex mirror; 9-ns thresholds were between 0.2-5.6 J/cm2. When these data were compared with a wide range of other results - for wavelengths from 0.25 to 10.6 μm and pulselengths down to 4 ps - a remarkably consistent picture emerged. Damage thresholds on average, increase approximately as the cube-root of pulselength from picoseconds to nearly a microsecond, and do so regardless of wavelength or material under test

  12. Dyadic analysis of child and parent trait and state pain catastrophizing in the process of children's pain communication.

    Science.gov (United States)

    Birnie, Kathryn A; Chambers, Christine T; Chorney, Jill; Fernandez, Conrad V; McGrath, Patrick J

    2016-04-01

    When explored separately, child and parent catastrophic thoughts about child pain show robust negative relations with child pain. The objective of this study was to conduct a dyadic analysis to elucidate intrapersonal and interpersonal influences of child and parent pain catastrophizing on aspects of pain communication, including observed behaviours and perceptions of child pain. A community sample of 171 dyads including children aged 8 to 12 years (89 girls) and parents (135 mothers) rated pain catastrophizing (trait and state versions) and child pain intensity and unpleasantness following a cold pressor task. Child pain tolerance was also assessed. Parent-child interactions during the cold pressor task were coded for parent attending, nonattending, and other talk, and child symptom complaints and other talk. Data were analyzed using the actor-partner interdependence model and hierarchical multiple regressions. Children reporting higher state pain catastrophizing had greater symptom complaints regardless of level of parent state pain catastrophizing. Children reporting low state pain catastrophizing had similar high levels of symptom complaints, but only when parents reported high state pain catastrophizing. Higher child and parent state and/or trait pain catastrophizing predicted their own ratings of higher child pain intensity and unpleasantness, with child state pain catastrophizing additionally predicting parent ratings. Higher pain tolerance was predicted by older child age and lower child state pain catastrophizing. These newly identified interpersonal effects highlight the relevance of the social context to children's pain expressions and parent perceptions of child pain. Both child and parent pain catastrophizing warrant consideration when managing child pain. PMID:26713422

  13. Viral-mediated Ntf3 overexpression disrupts innervation and hearing in nondeafened guinea pig cochleae.

    Science.gov (United States)

    Lee, Min Young; Kurioka, Takaomi; Nelson, Megan M; Prieskorn, Diane M; Swiderski, Donald L; Takada, Yohei; Beyer, Lisa A; Raphael, Yehoash

    2016-01-01

    Synaptopathy in the cochlea occurs when the connection between inner hair cells and the auditory nerve is disrupted, leading to impaired hearing and nerve degeneration. Experiments using transgenic mice have shown that overexpression of NT3 by supporting cells repairs synaptopathy caused by overstimulation. To accomplish such therapy in the clinical setting, it would be necessary to activate the neurotrophin receptor on auditory neurons by other means. Here we test the outcome of NT3 overexpression using viral-mediated gene transfer into the perilymph versus the endolymph of the normal guinea pig cochlea. We inoculated two different Ntf3 viral vectors, adenovirus (Adv) or adeno-associated virus (AAV) into the perilymph, to facilitate transgene expression in the mesothelial cells and cochlear duct epithelium, respectively. We assessed outcomes by comparing Auditory brainstem response (ABR) thresholds prior to that at baseline to thresholds at 1 and 3 weeks after inoculation, and then performed histologic evaluation of hair cells, nerve endings, and synaptic ribbons. We observed hearing threshold shifts as well as disorganization of peripheral nerve endings and disruption of synaptic connections between inner hair cells and peripheral nerve endings with both vectors. The data suggest that elevation of NT3 levels in the cochlear fluids can disrupt innervation and degrade hearing. PMID:27525291

  14. Improving SUSY Spectrum Determinations at the LHC with Wedgebox and Hidden Threshold Techniques

    CERN Document Server

    Bisset, M; Lü, R

    2008-01-01

    The LHC has the potential not only to discover supersymmetry (SUSY), but also to permit fairly precise measurements of at least a portion of the sparticle spectrum. Proposed mass reconstruction methods rely upon either inverting invariant mass endpoint expressions or upon solving systems of mass-shell equations. These methodologies suffer from the weakness that one certain specific sparticle decay chain is assumed to account for all the events in the sample.Taking two examples of techniques utilizing mass-shell equations, it is found that also applying wedgebox and hidden threshold (HT) techniques allows for the isolation of a purer event sample, thus avoiding errors, possibly catastrophic, due to mistaken assumptions about the decay chains involved and simultaneously improving accuracy. What is innovative is using endpoint measurements (with wedgebox and HT techniques) to obtain a more homogeneous, well-understood sample set rather than just using said endpoints to constrain the values of the masses (here fo...

  15. Current concepts in neuroendocrine disruption.

    Science.gov (United States)

    León-Olea, Martha; Martyniuk, Christopher J; Orlando, Edward F; Ottinger, Mary Ann; Rosenfeld, Cheryl S; Wolstenholme, Jennifer T; Trudeau, Vance L

    2014-07-01

    In the last few years, it has become clear that a wide variety of environmental contaminants have specific effects on neuroendocrine systems in fish, amphibians, birds and mammals. While it is beyond the scope of this review to provide a comprehensive examination of all of these neuroendocrine disruptors, we will focus on select representative examples. Organochlorine pesticides bioaccumulate in neuroendocrine areas of the brain that directly regulate GnRH neurons, thereby altering the expression of genes downstream of GnRH signaling. Organochlorine pesticides can also agonize or antagonize hormone receptors, adversely affecting crosstalk between neurotransmitter systems. The impacts of polychlorinated biphenyls are varied and in many cases subtle. This is particularly true for neuroedocrine and behavioral effects of exposure. These effects impact sexual differentiation of the hypothalamic-pituitary-gonadal axis, and other neuroendocrine systems regulating the thyroid, metabolic, and stress axes and their physiological responses. Weakly estrogenic and anti-androgenic pollutants such as bisphenol A, phthalates, phytochemicals, and the fungicide vinclozolin can lead to severe and widespread neuroendocrine disruptions in discrete brain regions, including the hippocampus, amygdala, and hypothalamus, resulting in behavioral changes in a wide range of species. Behavioral features that have been shown to be affected by one or more these chemicals include cognitive deficits, heightened anxiety or anxiety-like, sociosexual, locomotor, and appetitive behaviors. Neuroactive pharmaceuticals are now widely detected in aquatic environments and water supplies through the release of wastewater treatment plant effluents. The antidepressant fluoxetine is one such pharmaceutical neuroendocrine disruptor. Fluoxetine is a selective serotonin reuptake inhibitor that can affect multiple neuroendocrine pathways and behavioral circuits, including disruptive effects on reproduction and

  16. Detectability thresholds of general modular graphs

    CERN Document Server

    Kawamoto, Tatsuro

    2016-01-01

    We investigate the detectability thresholds of various modular structures in the stochastic block model. Our analysis reveals how the detectability threshold is related to the details of the modular pattern, including the hierarchy of the clusters. We show that certain planted structures are impossible to infer regardless of their fuzziness.

  17. Thresholding magnetic resonance images of human brain

    Institute of Scientific and Technical Information of China (English)

    Qing-mao HU; Wieslaw L NOWINSKI

    2005-01-01

    In this paper, methods are proposed and validated to determine low and high thresholds to segment out gray matter and white matter for MR images of different pulse sequences of human brain. First, a two-dimensional reference image is determined to represent the intensity characteristics of the original three-dimensional data. Then a region of interest of the reference image is determined where brain tissues are present. The non-supervised fuzzy c-means clustering is employed to determine: the threshold for obtaining head mask, the low threshold for T2-weighted and PD-weighted images, and the high threshold for T1-weighted, SPGR and FLAIR images. Supervised range-constrained thresholding is employed to determine the low threshold for T1-weighted, SPGR and FLAIR images. Thresholding based on pairs of boundary pixels is proposed to determine the high threshold for T2- and PD-weighted images. Quantification against public data sets with various noise and inhomogeneity levels shows that the proposed methods can yield segmentation robust to noise and intensity inhomogeneity. Qualitatively the proposed methods work well with real clinical data.

  18. Threshold Effects in Coral Reef Fisheries

    OpenAIRE

    Crépin, Anne Sophie

    2003-01-01

    Coral reefs may naturally flip between coral-dominated and algae-dominated states, when species' stocks trespass some threshold levels. This essay uses a stylized model of a coral reef to show how fishing may induce flips towards more algae-dominated states. Threshold effects have consequences for fisheries management, which are analyzed for open access fisheries and sole ownership.

  19. Intelligence and Creativity: Over the Threshold Together?

    Science.gov (United States)

    Welter, Marisete Maria; Jaarsveld, Saskia; van Leeuwen, Cees; Lachmann, Thomas

    2016-01-01

    Threshold theory predicts a positive correlation between IQ and creativity scores up to an IQ level of 120 and no correlation above this threshold. Primary school children were tested at beginning (N = 98) and ending (N = 70) of the school year. Participants performed the standard progressive matrices (SPM) and the Test of Creative…

  20. Applying Threshold Concepts to Finance Education

    Science.gov (United States)

    Hoadley, Susan; Wood, Leigh N.; Tickle, Leonie; Kyng, Tim

    2016-01-01

    Purpose: The purpose of this paper is to investigate and identify threshold concepts that are the essential conceptual content of finance programmes. Design/Methodology/Approach: Conducted in three stages with finance academics and students, the study uses threshold concepts as both a theoretical framework and a research methodology. Findings: The…

  1. Threshold Concepts, Systems and Learning for Sustainability

    Science.gov (United States)

    Sandri, Orana Jade

    2013-01-01

    This paper presents a framework for understanding the role that systems theory might play in education for sustainability (EfS). It offers a sketch and critique of Land and Meyer's notion of a "threshold concept", to argue that seeing systems as a threshold concept for sustainability is useful for understanding the processes of…

  2. Multistage Logistic Network Optimization under Disruption Risk

    OpenAIRE

    Rusman, Muhammad

    2013-01-01

    Getting over disruptions risk has been a challenging issue for many companies under the globalization that will link to potential external source such as demand uncertainties, natural disasters, and terrorist attacks. The disruption is an unexpected event that disturbs normal flows of products and materials within a supply chain. The disruption at one members of supply chain will propagate the offers and finally affect significant impacts on the entire chain. If we look back...

  3. Disrupted Sleep: From Molecules to Cognition

    OpenAIRE

    Someren, E.J.W.; Cirelli, C.; Dijk, D.-J.; Van Cauter, E; Schwartz, Sophie; Chee, M. W. L.

    2015-01-01

    Although the functions of sleep remain to be fully elucidated, it is clear that there are far-reaching effects of its disruption, whether by curtailment for a single night, by a few hours each night over a long period, or by disruption in sleep continuity. Epidemiological and experimental studies of these different forms of sleep disruption show deranged physiology from subcellular levels to complex affective behavior. In keeping with the multifaceted influence of sleep on health and well-bei...

  4. Disrupted Sleep: From Molecules to Cognition

    OpenAIRE

    Van Someren, Eus J. W.; Cirelli, Chiara; Dijk, Derk-Jan; Van Cauter, Eve; Schwartz, Sophie; Chee, Michael W. L.

    2015-01-01

    UNLABELLED: Although the functions of sleep remain to be fully elucidated, it is clear that there are far-reaching effects of its disruption, whether by curtailment for a single night, by a few hours each night over a long period, or by disruption in sleep continuity. Epidemiological and experimental studies of these different forms of sleep disruption show deranged physiology from subcellular levels to complex affective behavior. In keeping with the multifaceted influence of sleep on health ...

  5. Disruption management in passenger railway transportation.

    OpenAIRE

    Jespersen-Groth, J.; Potthoff, Daniel; Clausen, J.; Huisman, Dennis; Kroon, Leo; Maróti, Gábor; Nielsen, M.N.

    2007-01-01

    textabstractThis paper deals with disruption management in passenger railway transportation. In the disruption management process, many actors belonging to different organizations play a role. In this paper we therefore describe the process itself and the roles of the different actors. Furthermore, we discuss the three main subproblems in railway disruption management: timetable adjustment, and rolling stock and crew re-scheduling. Next to a general description of these problems, we give an o...

  6. Towards a Framework of Digital Platform Disruption

    OpenAIRE

    Kazan, Erol; Tan, Chee-Wee; Lim, Eric T. K.

    2014-01-01

    Digital platforms are disruptive information technology (IT) artifacts that erode conventional business logic associated with traditional market structures. This paper presents a framework for examining the disruptive potential of digital platforms whereby we postulate that the strategic interplay of governance regimes and platform layers is deterministic of whether disruptive derivatives are permitted to flourish. This framework has been employed in a comparative case study betwe...

  7. Action spectrum for photochemical retinal pigment epithelium (RPE) disruption in an in vivo monkey model

    Science.gov (United States)

    Zhang, Jie; Sabarinathan, Ranjani; Bubel, Tracy; Williams, David R.; Hunter, Jennifer J.

    2016-03-01

    Observations of RPE disruption and autofluorescence (AF) photobleaching at light levels below the ANSI photochemical maximum permissible exposure (MPE) (Morgan et al., 2008) indicates a demand to modify future light safety standards to protect the retina from harm. To establish safe light exposures, we measured the visible light action spectrum for RPE disruption in an in vivo monkey model with fluorescence adaptive optics retinal imaging. Using this high resolution imaging modality can provide insight into the consequences of light on a cellular level and allow for longitudinal monitoring of retinal changes. The threshold retinal radiant exposures (RRE) for RPE disruption were determined for 4 wavelengths (460, 488, 544, and 594 nm). The anaesthetized macaque retina was exposed to a uniform 0.5° × 0.5° field of view (FOV). Imaging within a 2° × 2° FOV was performed before, immediately after and at 2 week intervals for 10 weeks. At each wavelength, multiple RREs were tested with 4 repetitions each to determine the threshold for RPE disruption. For qualitative analysis, RPE disruption is defined as any detectable change from the pre exposure condition in the cell mosaic in the exposed region relative to the corresponding mosaic in the immediately surrounding area. We have tested several metrics to evaluate the RPE images obtained before and after exposure. The measured action spectrum for photochemical RPE disruption has a shallower slope than the current ANSI photochemical MPE for the same conditions and suggests that longer wavelength light is more hazardous than other measurements would suggest.

  8. Provably secure robust threshold partial blind signature

    Institute of Scientific and Technical Information of China (English)

    CAO Zhenfu; ZHU Haojin; LU Rongxing

    2006-01-01

    Threshold digital signature and blind signature are playing important roles in cryptography as well as in practical applications such as e-cash and e-voting systems.Over the past few years, many cryptographic researchers have made considerable headway in this field. However, to our knowledge, most of existing threshold blind signature schemes are based on the discrete logarithm problem. In this paper, we propose a new robust threshold partial blind signature scheme based on improved RSA cryptosystem.This scheme is the first threshold partial blind signature scheme based on factoring, and the robustness of threshold partial blind signature is also introduced. Moreover, in practical application, the proposed scheme will be especially suitable for blind signature-based voting systems with multiple administrators and secure electronic cash systems to prevent their abuse.

  9. Summary of DOE threshold limits efforts

    International Nuclear Information System (INIS)

    The Department of Energy (DOE) has been developing the concept of threshold quantities for use in determining which waste materials may be disposed of as nonradioactive waste in DOE sanitary landfills. Waste above a threshold level could be managed as radioactive or mixed waste (if hazardous chemicals are present); waste below this level would be handled as sanitary waste. After extensive review of a draft threshold guidance document in 1985, a second draft threshold background document was produced in March 1986. The second draft included a preliminary cost-benefit analysis and quality assurance considerations. The review of the second draft has been completed. Final changes to be incorporated include an in-depth cost-benefit analysis of two example sites and recommendations of how to further pursue (i.e. employ) the concept of threshold quantities within the DOE. 3 references

  10. Secure Undeniable Threshold Proxy Signature Scheme

    Directory of Open Access Journals (Sweden)

    Sattar J. Aboud

    2014-01-01

    Full Text Available the threshold proxy signature scheme allows the original signer to delegate a signature authority to the proxy group to cooperatively sign message on behalf of an original signer. In this paper, we propose a new scheme which includes the features and benefits of the RSA scheme. Also, we will evaluate the security of undeniable threshold proxy signature scheme with known signers. We find that the existing threshold proxy scheme is insecure against the original signer forgery. In this paper, we show the cryptanalysis of an existed scheme. Additional, we propose the secure, undeniable and known signers threshold proxy signature scheme which answers the drawback of an existed scheme. We also demonstrate that a threshold proxy signature suffers from a conspiracy of an original signer and a secret share dealer, that the scheme is commonly forgeable, and cannot offer undeniable. We claim that the proposed scheme offers the undeniable characteristic.

  11. Disrupting Entanglement of Black Holes

    CERN Document Server

    Leichenauer, Stefan

    2014-01-01

    We study entanglement in thermofield double states of strongly coupled CFTs by analyzing two-sided Reissner-Nordstrom solutions in AdS. The central object of study is the mutual information between a pair of regions, one on each asymptotic boundary of the black hole. For large regions the mutual information is positive and for small ones it vanishes; we compute the critical length scale, which goes to infinity for extremal black holes, of the transition. We also generalize the butterfly effect of Shenker and Stanford to a wide class of charged black holes, showing that mutual information is disrupted upon perturbing the system and waiting for a time of order $\\log E/\\delta E$ in units of the temperature. We conjecture that the parametric form of this timescale is universal.

  12. Formation of bi-lobed 67P/C-G-like shapes by sub-catastrophic collisions

    Science.gov (United States)

    Jutzi, Martin; Benz, Willy

    2016-10-01

    Small bodies with a bi-lobe shape such as comet 67P/C-G have been argued to form as the result of low velocity (v ≈ vesc) collisional mergers of similar-sized bodies very early on in the history of the solar system [1]. However, the recent analysis of the subsequent collisional survival of the global structure and shape of comet 67P/C-G strongly suggests that such a structure will not survive until today [2]. Hence, the comet must have acquired its present characteristics as a result of a collision occurring at later time when the relative velocities between small bodies are much higher (v >> vesc).One possible scenario would be that 67P/C-G-like bi-lobe structures form as the result of collisional disruptions of larger parent bodies [3]. Whether the internal properties of such larger parent bodies, the timing of such a collision, and the subsequent survival of the shape produced is compatible with observations will remain to be seen.Here, we propose a scenario in which the final bi-lobe shapes result from low-energy, sub-catastrophic impacts. We start with bodies of about the same mass as comet 67P/C-G, which are rotating and are slightly elongated (i.e., with properties which are consistent with the outcome of the disruptions of larger bodies). We use a SPH shock physics code to model the impacts, the subsequent re-accumulation of material and the reconfiguration into a stable final shape. Our modelling results suggest that these kind of collisions result in "splitting" events which frequently lead to formation of bi-lobe 67P/C-G-like shapes.The frequency of such small-scale impact events is consistent with a young (less than 1 Gy) age of the shape of comet 67P/C-G [2]. Equally important, the probability for such a shape-forming event to take place without a subsequent shape-destroying event occurring until today is reasonably high.Although the collisions considered in this work can alter the global shape, their respective energy is small enough not to lead to

  13. Assessing and modelling catastrophic risk perceptions and attitudes in agriculture: a review

    NARCIS (Netherlands)

    Ogurtsov, V.; Asseldonk, van M.A.P.M.; Huirne, R.B.M.

    2008-01-01

    Catastrophic risks result in high losses in agriculture. To cope with such losses farmers need to apply risk management strategies to balance their profits and risks. Therefore risk assessment and risk modelling are important to support farm-level decision-making. This paper (1) reviews the techniqu

  14. Collapsed Shape of Shallow Unlined Tunnels Based on Functional Catastrophe Theory

    Directory of Open Access Journals (Sweden)

    Chengping Zhang

    2015-01-01

    Full Text Available This paper investigates the collapse mechanisms and possible collapsing block shapes of shallow unlined tunnels under conditions of plane strain. The analysis is performed following the framework from a branch of catastrophe theory, functional catastrophe theory. First, the basic principles of functional catastrophe theory are introduced. Then, an analytical solution for the shape curve of the collapsing block of a shallow unlined tunnel is derived using functional catastrophe theory based on the nonlinear Hoek-Brown failure criterion. The effects of the rock mass parameters of the proposed method on the shape and weight of the collapsing block are examined. Moreover, a critical cover depth expression to classify deep and shallow tunnels is proposed. The analytical results are consistent with those obtained by numerical simulation using the particle flow code, demonstrating the validity of the proposed analytical method. The obtained formulas can be used to predict the height and width of the collapsing block of a shallow unlined tunnel and to provide a direct estimate of the overburden on the tunnel lining. The obtained formulas can be easily used by tunnel engineers and researchers due to their simplicity.

  15. Expected Utility and Catastrophic Risk in a Stochastic Economy-Climate Model

    NARCIS (Netherlands)

    Ikefuji, M.; Laeven, R.J.A.; Magnus, J.R.; Muris, C.H.M.

    2010-01-01

    In the context of extreme climate change, we ask how to conduct expected utility analysis in the presence of catastrophic risks. Economists typically model decision making under risk and uncertainty by expected util- ity with constant relative risk aversion (power utility); statisticians typi- cally

  16. Methodological aspects of health evaluation of the population suffered after the Chernobyl catastrophe

    International Nuclear Information System (INIS)

    Ecological situation in Belarus and the necessity of liquidation of medical consequences of the Chernobyl NPP Catastrophe demand many years' dynamic observation after the health condition of large people's contingents. At present this problem is being solved by the clinical follow up of the population undergone irradiation due to the Chernobyl catastrophe which is the basis of medical-prevention measures, directed to low medical consequences of the Chernobyl catastrophe. All the information on population's health received during the clinical follow up is put to a special State Data Base which was started for a clinical follow op information support, carrying out scientific researches and receiving reliable data on medical- biological consequences of the Chernobyl catastrophe. At present there's a problem of correct evaluation of health changes of the population who need clinical follow up on all its levels. The problem of comparative analyses of stored data hasn't been solved yet. It's necessary to underline that illness data of the population suffered after the Chernobyl catastrophe received due to intensive clinical follow up can't be compared with illness data of the population in general received due to ordinary applies to hospitals. It would be methodologically incorrect. Besides all said above, including into the research all the classes and forms of illnesses according to IDC-9, IDC-10 (International Disease Classification 9,10) what in a great degree enlarges volume of the research and its expenses is irrational. While studying the Chernobyl catastrophe medical consequences one must include to the analysis classes and nosologic illness forms which level and dynamic changes connected in some extend to radiation irradiation. By doing this one can minimize the volume and the expenses in the research like this. In this situation it's necessary to state such population health indexes which level exposed to a distortion in the lowest degree in the result of

  17. Catastrophic Failure and Fault-Tolerant Design of IGBT Power Electronic Converters - An Overview

    DEFF Research Database (Denmark)

    Wu, Rui; Blaabjerg, Frede; Wang, Huai;

    2013-01-01

    -event overstress. The wear out failure under field operation could be mitigated by scheduled maintenances based on lifetime prediction and condition monitoring. However, the catastrophic failure is difficult to be predicted and thus may lead to serious consequence of power electronic converters. To obtain a better...

  18. Physical limits of semiconductor laser operation: A time-resolved analysis of catastrophic optical damage

    DEFF Research Database (Denmark)

    Ziegler, Mathias; Hempel, Martin; Larsen, Henning Engelbrecht;

    2010-01-01

    The early stages of catastrophic optical damage (COD) in 808 nm emitting diode lasers are mapped by simultaneously monitoring the optical emission with a 1 ns time resolution and deriving the device temperature from thermal images. COD occurs in highly localized damage regions on a 30 to 400 ns...

  19. Insights into Participants' Behaviours in Educational Games, Simulations and Workshops: A Catastrophe Theory Application to Motivation.

    Science.gov (United States)

    Cryer, Patricia

    1988-01-01

    Develops models for participants' behaviors in games, simulations, and workshops based on Catastrophe Theory and Herzberg's two-factor theory of motivation. Examples are given of how these models can be used, both for describing and understanding the behaviors of individuals, and for eliciting insights into why participants behave as they do. (11…

  20. Potential for Application of a Probabilistic Catastrophe Risk Modelling Framework to Poverty Outcomes

    OpenAIRE

    Porter, Catherine; White, Emily

    2016-01-01

    This paper analyzes the potential to combine catastrophe risk modelling (CAT risk modeling) with economic analysis of vulnerability to poverty using the example of drought hazard impacts on the welfare of rural households in Ethiopia. The aim is to determine the potential for applying a derived set of damage (vulnerability) functions based on realized shocks and household expenditure/consu...

  1. Pain Catastrophizing is Associated with Dental Pain in a Stressful Context

    Science.gov (United States)

    Lin, C.-S.; Niddam, D.M.; Hsu, M.-L.; Hsieh, J.-C.

    2013-01-01

    Pain is associated with anxiety in a dental setting. It has remained unclear how cognitive-affective factors modulate pain and anxiety in a stressful context, such as receiving dental procedures. We hypothesized that both the situational factor (unpredictability about painful stimuli) and the trait factor (pain catastrophizing, i.e., the tendency to interpret pain in negative orientation) account for dental pain. Fifteen healthy participants were recruited to perform an associative learning task. They were asked to learn the pairing between visual cues and the intensity of incoming painful stimuli delivered at the right upper central incisor. Brain activation associated with pain was recorded by functional magnetic resonance imaging (fMRI). The participants reported increased anxiety and pain in the stressful context, where stimuli intensity was not predicted by the preceding cue. The score of the Pain Catastrophizing Scale was positively correlated with the increased pain modulated by unpredictability. Brain activation at the right posterior hippocampus, a region critically related to associative learning of aversive stimuli and context, was correlated with the individual catastrophizing level. Our findings suggest that both the situational factor (unpredictability) and the trait factor (catastrophizing) influence dental pain, highlighting the role of cognitive-affective factors in pain control of dental patients. PMID:23232145

  2. Perceptions of Challenge: The Role of Catastrophe Theory in Piano Learning

    Science.gov (United States)

    Bugos, Jennifer; Lee, William

    2015-01-01

    The purpose of this study is to evaluate the perceptions of private piano instructors on the role of challenge in teaching and learning the piano and to examine the potential application of catastrophe theory in understanding the role and outcomes of such challenges. A 23-item electronic questionnaire was administered to collect quantitative and…

  3. A Call to Action: Responding to Large-Scale Disasters, Catastrophes, and Traumas

    Science.gov (United States)

    Parham, William D.

    2011-01-01

    The ascendance of large-scale disasters, catastrophes, and traumas as a concentrated focus of academic inquiry in counseling psychology is timely, and this special issue and subsequent investigations represent welcome areas of scholarship. The observations and comments herein salute the authors for responding to a post-Katrina discovery by…

  4. Explaining health care utilization for panic attacks using cusp catastrophe modeling.

    Science.gov (United States)

    Katerndahl, David

    2008-10-01

    Despite increased health care utilization, patients with panic disorder continue to report unmet needs. The objective was to compare the fit of linear and Cusp Catastrophe Modeling in explaining changes in utilization of emergency, general and mental health settings, and self-treatments for panic symptoms. This community-based study surveyed 97 subjects with panic attacks drawn from a sample of randomly-selected adults from randomly-selected households. The stressor (splitting) variable used was Phobic Anxiety while predisposing variables included Family Health Care Utilization, Perceived Life Threat and Need For Treatment, and Treatment Experience. Outcomes consisted of the number of sites and self-treatments used for panic symptoms when first seeking care and during the 2 months prior to survey. Use of mental health sites and self-treatments demonstrated superior modeling with cusp catastrophe approaches using treatment experience as the predisposing variable, accounting for 47% and 38% of variances respectively, improving the fit by over 20% compared to the best linear models in both cases. Cusp catastrophe modeling accounted for more variance than all linear models when describing use of mental health settings and self-treatments. Cusp catastrophe may explain bimodal distributions in behavior, delays in behavior change, and sudden shifts in behavior in stressful situations. PMID:18765074

  5. Folding catastrophes due to viscosity in multiferroic domains: implications for room-temperature multiferroic switching

    Science.gov (United States)

    Scott, J. F.

    2015-12-01

    Unusual domains with curved walls and failure to satisfy the Landau-Lifshitz-Kittel Law are modeled as folding catastrophes (saddle-node bifurcations). This description of ballistic motion in a viscous medium is based upon early work by Dawber et al 2003 Appl. Phys. Lett. 82 436. It suggests that ferroelectric films can exhibit folds or vortex patterns but not both.

  6. Spatial ecology of peatland ecosystems: Spatial self-organization and catastrophic shifts in bogs

    NARCIS (Netherlands)

    Eppinga, M.B.

    2004-01-01

    Positive feedback interactions, as between plants and their abiotic environment, may have the consequence that an ecosystem has alternate stable equilibrium states. As a result, a gradual change in environmental conditions may lead to discontinuous, catastrophic shifts in such ecosystems. Until now,

  7. SOIL CONTAMINATION CAUSED BY EMERGENCY BIO-REDUCTION OF CATASTROPHIC LIVESTOCK MORTALITIES

    Science.gov (United States)

    Catastrophic regional losses of poultry and livestock have caused environmental officials in North America to seek emergency on-farm disposal alternatives that pose less pollution risk to soil and shallow groundwater than burial. Bio-decomposition of remains followed by land application of the resul...

  8. 78 FR 46256 - Security Program, Report of Suspected Crimes, Suspicious Transactions, Catastrophic Acts and Bank...

    Science.gov (United States)

    2013-07-31

    ... From the Federal Register Online via the Government Publishing Office NATIONAL CREDIT UNION ADMINISTRATION 12 CFR Part 748 Security Program, Report of Suspected Crimes, Suspicious Transactions, Catastrophic Acts and Bank Secrecy Act Compliance CFR Correction In Title 12 of the Code of Federal...

  9. 12 CFR Appendix B to Part 749 - Catastrophic Act Preparedness Guidelines

    Science.gov (United States)

    2010-01-01

    ... program address the following five elements: 1 See 12 CFR 748.1(b) concerning a FICU's reporting of any catastrophic act that occurs at its office to its regional director and 12 CFR 749.3 concerning the location of... addressed in 12 CFR 748.1(b); vi. Training and documentation of training to ensure all employees...

  10. Critical Periods and Catastrophic Interference Effects in the Development of Self-Organizing Feature Maps

    Science.gov (United States)

    Richardson, Fiona M.; Thomas, Michael S. C.

    2008-01-01

    The use of self-organizing feature maps (SOFM) in models of cognitive development has frequently been associated with explanations of "critical" or "sensitive periods". By contrast, error-driven connectionist models of development have been linked with "catastrophic interference" between new knowledge and old knowledge. We introduce a set of…

  11. Catastrophic Misinterpretations as a Predictor of Symptom Change during Treatment for Panic Disorder

    Science.gov (United States)

    Teachman, Bethany A.; Marker, Craig D.; Clerkin, Elise M.

    2010-01-01

    Objective: Cognitive models of panic disorder suggest that change in catastrophic misinterpretations of bodily sensations will predict symptom reduction. To examine change processes, we used a repeated measures design to evaluate whether the trajectory of change in misinterpretations over the course of 12-week cognitive behavior therapy is related…

  12. 灾难性医疗支出研究%Study on Catastrophic Health Expenditure

    Institute of Scientific and Technical Information of China (English)

    褚福灵

    2016-01-01

    Catastrophic heath expenditure occurs when the total out-of-pocket health payments are ≥40%of the household’s capacity to pay(non-living expenses). Studies have showed that the highest rate of catastrophic payments was 13%% in the world, and there were about 5% of poverty caused by serious illness. We should calculate the rate of catastrophic payment and poverty due to illness by using normative methods, and adopt comprehensive measures to prevent the occurrence of catastrophic health expenditure.%家庭的医疗费用支出等于或超过家庭支付能力(非生存支出)的40%时,该家庭即发生了灾难性医疗支出。世界范围内,家庭灾难性医疗支出发生率最高为13%,因病致贫发生率最高为5%。应采用规范的方法测算灾难性医疗支出发生率与因病致贫率,并采取综合措施防范灾难性医疗风险的发生。

  13. Pedagogy in Catastrophic Times: Giroux and the Tasks of Critical Public Intellectuals

    Science.gov (United States)

    Morris, Doug

    2012-01-01

    This article reflects on Henry Giroux's work as a critical public intellectual and the important role his work plays in fostering educated hope and insurgent possibilities during our present times of daily and longer term catastrophes. In addition to attempting to capture the experience of what it means and how it feels to read Giroux along with…

  14. Should catastrophic risks be included in a regulated competitive health insurance market?

    NARCIS (Netherlands)

    W.P.M.M. van de Ven (Wynand); F.T. Schut (Erik)

    1994-01-01

    textabstractIn 1988 the Dutch government launched a proposal for a national health insurance based on regulated competition. The mandatory benefits package should be offered by competing insurers and should cover both non-catastrophic risks (like hospital care, physician services and drugs) and cata

  15. Spectral signatures of compact sources in the inverse Compton catastrophe limit

    Science.gov (United States)

    Petropoulou, M.; Piran, T.; Mastichiadis, A.

    2015-09-01

    The inverse Compton catastrophe is defined as a dramatic rise in the luminosity of inverse Compton scattered photons. It is described by a non-linear loop of radiative processes that sets in for high values of the electron compactness and is responsible for the efficient transfer of energy from electrons to photons, predominantly through inverse Compton scatterings. We search for the conditions that drive a magnetized non-thermal source to the inverse Compton catastrophe regime and study its multiwavelength (MW) photon spectrum. We develop a generic analytical framework and use numerical calculations as a backup to the analytical predictions. We find that the escaping radiation from a source in the Compton catastrophe regime bears some unique features. The MW photon spectrum is a broken power law with a break at ˜mec2 due to the onset of the Klein-Nishina suppression. The spectral index below the break energy depends on the electron and magnetic compactnesses logarithmically, while it is independent of the electron power-law index (s). The maximum radiating power emerges typically in the γ-ray regime, at energies ˜mec2 (˜γmax mec2) for s > 2 (s ≲ 2), where γmax is the maximum Lorentz factor of the injected electron distribution. We apply the principles of the inverse Compton catastrophe to blazars and γ-ray bursts using the analytical framework we developed, and show how these can be used to impose robust constraints on the source parameters.

  16. Disrupted Brain Functional Network Architecture in Chronic Tinnitus Patients

    Science.gov (United States)

    Chen, Yu-Chen; Feng, Yuan; Xu, Jin-Jing; Mao, Cun-Nan; Xia, Wenqing; Ren, Jun; Yin, Xindao

    2016-01-01

    Purpose: Resting-state functional magnetic resonance imaging (fMRI) studies have demonstrated the disruptions of multiple brain networks in tinnitus patients. Nonetheless, several studies found no differences in network processing between tinnitus patients and healthy controls (HCs). Its neural bases are poorly understood. To identify aberrant brain network architecture involved in chronic tinnitus, we compared the resting-state fMRI (rs-fMRI) patterns of tinnitus patients and HCs. Materials and Methods: Chronic tinnitus patients (n = 24) with normal hearing thresholds and age-, sex-, education- and hearing threshold-matched HCs (n = 22) participated in the current study and underwent the rs-fMRI scanning. We used degree centrality (DC) to investigate functional connectivity (FC) strength of the whole-brain network and Granger causality to analyze effective connectivity in order to explore directional aspects involved in tinnitus. Results: Compared to HCs, we found significantly increased network centrality in bilateral superior frontal gyrus (SFG). Unidirectionally, the left SFG revealed increased effective connectivity to the left middle orbitofrontal cortex (OFC), left posterior lobe of cerebellum (PLC), left postcentral gyrus, and right middle occipital gyrus (MOG) while the right SFG exhibited enhanced effective connectivity to the right supplementary motor area (SMA). In addition, the effective connectivity from the bilateral SFG to the OFC and SMA showed positive correlations with tinnitus distress. Conclusions: Rs-fMRI provides a new and novel method for identifying aberrant brain network architecture. Chronic tinnitus patients have disrupted FC strength and causal connectivity mostly in non-auditory regions, especially the prefrontal cortex (PFC). The current findings will provide a new perspective for understanding the neuropathophysiological mechanisms in chronic tinnitus. PMID:27458377

  17. Numerical Simulations of Collisional Disruption of Rotating Gravitational Aggregates: Dependence on Material Properties

    CERN Document Server

    Ballouz, Ronald-Louis; Michel, Patrick; Schwartz, Stephen R; Yu, Yang

    2014-01-01

    Our knowledge of the strengths of small bodies in the Solar System is limited by our poor understanding of their internal structures, and this, in turn, clouds our understanding of the formation and evolution of these bodies. Observations of the rotational states of asteroids whose diameters are larger than a few hundreds of meters have revealed that they are dominated by gravity and that most are unlikely to be monoliths; however, there is a wide range of plausible internal structures. Numerical and analytical studies of shape and spin limits of gravitational aggregates and their collisional evolution show a strong dependence on shear strength. In order to study this effect, we carry out a systematic exploration of the dependence of collision outcomes on dissipation and friction parameters of the material components making up the bodies. We simulate the catastrophic disruption (leading to the largest remnant retaining 50% of the original mass) of km-size asteroids modeled as gravitational aggregates using pk...

  18. Wing pathology of white-nose syndrome in bats suggests life-threatening disruption of physiology

    Science.gov (United States)

    Cryan, P.M.; Meteyer, C.U.; Boyles, J.G.; Blehert, D.S.

    2010-01-01

    White-nose syndrome (WNS) is causing unprecedented declines in several species of North American bats. The characteristic lesions of WNS are caused by the fungus Geomyces destructans, which erodes and replaces the living skin of bats while they hibernate. It is unknown how this infection kills the bats. We review here the unique physiological importance of wings to hibernating bats in relation to the damage caused by G. destructans and propose that mortality is caused by catastrophic disruption of wing-dependent physiological functions. Mechanisms of disease associated with G. destructans seem specific to hibernating bats and are most analogous to disease caused by chytrid fungus in amphibians. ?? 2010 Cryan et al; licensee BioMed Central Ltd.

  19. Catastrophic injury in rugby union: is the level of risk acceptable?

    Science.gov (United States)

    Fuller, Colin W

    2008-01-01

    Rugby union is a full contact sport with a relatively high overall risk of injury and a small specific risk of fatal and catastrophic spinal injury. Although catastrophic injuries in rugby union cause public concern and generate strong emotive reactions, the magnitude of society's concern about this type of injury is often dominated by people's perceptions rather than by actual levels of risk. This article assesses published values for the risk of catastrophic injuries in rugby union, evaluates these against the risk standards of the UK Health and Safety Executive (HSE) and compares the values with the risks associated with other common sport and non-sport activities. The assessment showed that the risks of sustaining a catastrophic injury in rugby union in England (0.8/100,000 per year), Ireland (0.9/100,000 per year) and Argentina (1.9/100,000 per year) were within the HSE's 'acceptable' region of risk (0.1-2/100,000 per year), whilst the risks in New Zealand (4.2/100,000 per year), Australia (4.4/100,000 per year) and Fiji (13/100,000 per year) were within the 'tolerable' region of risk (2-100/100,000 per year). The risk of sustaining a catastrophic injury in rugby union was generally lower than or comparable with the levels reported for a wide range of other collision sports, such as ice hockey (4/100,000 per year), rugby league (2/100,000 per year) and American Football (2/100,000 per year). In addition, the risk of catastrophic injury in rugby union was comparable with that experienced by most people in work-based situations and lower than that experienced by motorcyclists, pedestrians and car occupants. Whilst ranking risks provides an effective way of assessing their acceptability, it is recognized that representing risks by a single risk value can be misleading, as account must also be taken of the public's perception of the risks and the inherent differences in the types of risk being considered. However, an acceptable level of risk is often regarded as

  20. Assessment of Flood Catastrophe Risk for Grain Production at the Provincial Scale in China Based on the BMM Method

    Institute of Scientific and Technical Information of China (English)

    XU Lei; ZHANG Qiao; ZHOU Ai-lian; HUO Ran

    2013-01-01

    Flood catastrophe risk assessment is imperative for the steady development of agriculture under the context of global climate change, and meanwhile, it is an urgent scientiifc issue need to be solved in agricultural risk assessment discipline. This paper developed the methodology of lfood catastrophe risk assessment, which can be shown as the standard process of crop loss calculation, Monte Carlo simulation, the generalized extreme value distribution (GEV) iftting, and risk evaluation. Data on crop loss were collected based on hectares covered by natural disasters, hectares affected by natural disasters, and hectares destroyed by natural disasters using the standard equation. Monte Carlo simulation based on appropriate distribution was used to expand sample size to overcome the insufifciency of crop loss data. Block maxima model (BMM) approach based on the extreme value theory was for modeling the generalized extreme value distribution (GEV) of lfood catastrophe loss, and then lfood catastrophe risk at the provincial scale in China was calculated. The Type III Extreme distribution (Weibull) has a weighted advantage of modeling lfood catastrophe risk for grain production. The impact of lfood catastrophe to grain production in China was signiifcantly serious, and high or very high risk of lfood catastrophe mainly concentrates on the central and eastern regions of China. Given the scenario of suffering once-in-a-century lfood disaster, for majority of the major-producing provinces, the probability of 10% reduction of grain output is more than 90%. Especially, the probabilities of more than 15% decline in grain production reach up to 99.99, 99.86, 99.69, and 91.60% respectively in Anhui, Jilin, Liaoning, and Heilongjiang. Flood catastrophe assessment can provide multifaceted information about lfood catastrophe risk that can help to guide management of lfood catastrophe.

  1. The impact of uncertain precipitation data on insurance loss estimates using a Flood Catastrophe Model

    Directory of Open Access Journals (Sweden)

    C. C. Sampson

    2014-01-01

    Full Text Available Catastrophe risk models used by the insurance industry are likely subject to significant uncertainty, but due to their proprietary nature and strict licensing conditions they are not available for experimentation. In addition, even if such experiments were conducted, these would not be repeatable by other researchers because commercial confidentiality issues prevent the details of proprietary catastrophe model structures from being described in public domain documents. However, such experimentation is urgently required to improve decision making in both insurance and re-insurance markets. In this paper we therefore construct our own catastrophe risk model for flooding in Dublin, Ireland in order to assess the impact of typical precipitation data uncertainty on loss predictions. As we consider only a city region rather than a whole territory and have access to detailed data and computing resources typically unavailable to industry modellers, our model is significantly more detailed than commercial products. The model consists of four components, a stochastic rainfall module, a hydrological and hydraulic flood hazard module, a vulnerability module and a financial loss module. Using these we undertake a series of simulations to test the impact of driving the stochastic event generator with four different rainfall data sets: ground gauge data, gauge corrected rainfall radar, meteorological re-analysis data (ERA-Interim and a satellite rainfall product (CMORPH. Catastrophe models are unusual because they use the upper three components of the modelling chain to generate a large synthetic database of unobserved and severe loss-driving events for which estimated losses are calculated. We find these loss estimates to be highly sensitive to uncertainties propagated from the driving observational datasets, suggesting that the range of uncertainty within catastrophe model structures may be greater than commonly believed.

  2. Reconstructing local population dynamics in noisy metapopulations--the role of random catastrophes and Allee effects.

    Science.gov (United States)

    Hart, Edmund M; Avilés, Leticia

    2014-01-01

    Reconstructing the dynamics of populations is complicated by the different types of stochasticity experienced by populations, in particular if some forms of stochasticity introduce bias in parameter estimation in addition to error. Identification of systematic biases is critical when determining whether the intrinsic dynamics of populations are stable or unstable and whether or not populations exhibit an Allee effect, i.e., a minimum size below which deterministic extinction should follow. Using a simulation model that allows for Allee effects and a range of intrinsic dynamics, we investigated how three types of stochasticity--demographic, environmental, and random catastrophes--affect our ability to reconstruct the intrinsic dynamics of populations. Demographic stochasticity aside, which is only problematic in small populations, we find that environmental stochasticity--positive and negative environmental fluctuations--caused increased error in parameter estimation, but bias was rarely problematic, except at the highest levels of noise. Random catastrophes, events causing large-scale mortality and likely to be more common than usually recognized, caused immediate bias in parameter estimates, in particular when Allee effects were large. In the latter case, population stability was predicted when endogenous dynamics were actually unstable and the minimum viable population size was overestimated in populations with small or non-existent Allee effects. Catastrophes also generally increased extinction risk, in particular when endogenous Allee effects were large. We propose a method for identifying data points likely resulting from catastrophic events when such events have not been recorded. Using social spider colonies (Anelosimus spp.) as models for populations, we show that after known or suspected catastrophes are accounted for, reconstructed growth parameters are consistent with intrinsic dynamical instability and substantial Allee effects. Our results are

  3. Reconstructing local population dynamics in noisy metapopulations--the role of random catastrophes and Allee effects.

    Directory of Open Access Journals (Sweden)

    Edmund M Hart

    Full Text Available Reconstructing the dynamics of populations is complicated by the different types of stochasticity experienced by populations, in particular if some forms of stochasticity introduce bias in parameter estimation in addition to error. Identification of systematic biases is critical when determining whether the intrinsic dynamics of populations are stable or unstable and whether or not populations exhibit an Allee effect, i.e., a minimum size below which deterministic extinction should follow. Using a simulation model that allows for Allee effects and a range of intrinsic dynamics, we investigated how three types of stochasticity--demographic, environmental, and random catastrophes--affect our ability to reconstruct the intrinsic dynamics of populations. Demographic stochasticity aside, which is only problematic in small populations, we find that environmental stochasticity--positive and negative environmental fluctuations--caused increased error in parameter estimation, but bias was rarely problematic, except at the highest levels of noise. Random catastrophes, events causing large-scale mortality and likely to be more common than usually recognized, caused immediate bias in parameter estimates, in particular when Allee effects were large. In the latter case, population stability was predicted when endogenous dynamics were actually unstable and the minimum viable population size was overestimated in populations with small or non-existent Allee effects. Catastrophes also generally increased extinction risk, in particular when endogenous Allee effects were large. We propose a method for identifying data points likely resulting from catastrophic events when such events have not been recorded. Using social spider colonies (Anelosimus spp. as models for populations, we show that after known or suspected catastrophes are accounted for, reconstructed growth parameters are consistent with intrinsic dynamical instability and substantial Allee effects. Our

  4. Mitigation of Earthquake-Induced Catastrophic Landslide Hazard on Gentle Slopes by Surface Loading

    Science.gov (United States)

    Trandafir, A. C.; Sidle, R. C.; Kamai, T.

    2005-05-01

    Catastrophic landslides have occurred repeatedly on gentle slopes during past earthquakes in Japan, sometimes causing great loss of life and significant environmental damage. Reconnaissance reports on the October 23, 2004, Chuetsu earthquake in Niigata Prefecture, Japan, also include collapse of gentle slopes associated with damage to roads and railways which lost foundation support. Additionally, investigations of the spatial distribution and features of landslides triggered by the Chuetsu earthquake revealed that 23% of the landslides mapped within a 2.9 km radius around the major earthquake epicenter occurred on slopes with gradients between 10 and 20 degrees. Past experience demonstrated that such earthquake-induced catastrophic landslides occurred along shear surfaces in saturated cohesionless materials, and the main factor controlling the high mobility of the slide mass after failure was the gradual loss in shear strength with progressive shear displacement. Given the high rainfall prior the earthquake, it is likely that the same failure mechanism characterizes the catastrophic landslides triggered on gentle slopes during the October 23, 2004, Chuetsu event in Niigata Prefecture. Thus, we introduce a procedure based on application of an additional confining stress to the surface to increase the stability of gentle slopes in saturated cohesionless soils subject to catastrophic failure during earthquakes. This surface pressure is achieved by concrete plates tied back with prestressed steel anchors which penetrate through the soil well below the potential sliding surface. Results of a dynamic analysis of undrained seismic performance conducted for a gentle infinite slope that experienced different levels of increase in effective confining stress due to a uniform load applied normal to the surface, illustrate the effectiveness of this measure in mitigating the earthquake-induced catastrophic landslide hazards.

  5. The Chernobyl catastrophe consequences in the Republic of Belarus. National report

    International Nuclear Information System (INIS)

    The estimation of radioecological, medico-biological, economic and social consequences of the Chernobyl catastrophe has shown that unimaginable damage was incurred on Belarus and its territory became the zone of ecological calamity. The Chernobyl NPP catastrophe has led to the contamination of almost the fourth part of the territory of Belarus where there lived 2,2 million people. The damage caused to the republic by the catastrophe makes up 32 annual budgets of the republic of the pre-accident period in account for the 30-years period for its overcoming. Radioecological situation in Belarus is characterized by complexity and heterogeneous contamination of the territory by different radionuclides and their presence on all the components of the environment. It stipulates the plurality of ways of external and internal irradiation of the population and jeopardizes its health. There is registered the worsening of the population's health, of evacuated and inhabiting the contaminated areas as well, with increase of a number of somatic diseases, including oncological diseases, there are disorders in the metabolic processes and functions of the main systems of the organism. The demographic indices are decreasing. Particular concern causes the children's morbidity growth and genetic consequences of the accident. The contamination of agricultural lands has stipulated in the neighboring the Chernobyl NPP zone the impossibility of their use for food production. On the other lands it has been required to re-profile the farms and create new technologies of the agricultural production. There have been revealed the destructive tendencies in all spheres of the life activity of people who experienced radiation effects. The processes of social adaptation and socio-psychological support of the population require considerable optimization. In spite of that for ten years passed after the catastrophe the discrepancy of its estimations has not been overcome completely. At the same time

  6. Scaled biotic disruption during early Eocene global warming events

    Directory of Open Access Journals (Sweden)

    S. J. Gibbs

    2012-11-01

    Full Text Available Late Paleocene and early Eocene hyperthermals are transient warming events associated with massive perturbations of the global carbon cycle, and are considered partial analogues for current anthropogenic climate change. Because the magnitude of carbon release varied between the events, they are natural experiments ideal for exploring the relationship between carbon cycle perturbations, climate change and biotic response. Here we quantify marine biotic variability through three million years of the early Eocene that include five hyperthermals, utilizing a method that allows us to integrate the records of different plankton groups through scenarios ranging from background to major extinction events. Our long time-series calcareous nannoplankton record indicates a scaling of biotic disruption to climate change associated with the amount of carbon released during the various hyperthermals. Critically, only the three largest hyperthermals, the Paleocene–Eocene Thermal Maximum (PETM, Eocene Thermal Maximum 2 (ETM2 and the I1 event, show above-background variance, suggesting that the magnitude of carbon input and associated climate change needs to surpass a threshold value to cause significant biotic disruption.

  7. Hyper-arousal decreases human visual thresholds.

    Directory of Open Access Journals (Sweden)

    Adam J Woods

    Full Text Available Arousal has long been known to influence behavior and serves as an underlying component of cognition and consciousness. However, the consequences of hyper-arousal for visual perception remain unclear. The present study evaluates the impact of hyper-arousal on two aspects of visual sensitivity: visual stereoacuity and contrast thresholds. Sixty-eight participants participated in two experiments. Thirty-four participants were randomly divided into two groups in each experiment: Arousal Stimulation or Sham Control. The Arousal Stimulation group underwent a 50-second cold pressor stimulation (immersing the foot in 0-2° C water, a technique known to increase arousal. In contrast, the Sham Control group immersed their foot in room temperature water. Stereoacuity thresholds (Experiment 1 and contrast thresholds (Experiment 2 were measured before and after stimulation. The Arousal Stimulation groups demonstrated significantly lower stereoacuity and contrast thresholds following cold pressor stimulation, whereas the Sham Control groups showed no difference in thresholds. These results provide the first evidence that hyper-arousal from sensory stimulation can lower visual thresholds. Hyper-arousal's ability to decrease visual thresholds has important implications for survival, sports, and everyday life.

  8. Reinterpreting several narrow `resonances' as threshold cusps

    CERN Document Server

    Bugg, D V

    2004-01-01

    The threshold pbar-p peak in BES data for J/\\Psi to gamma-pbar-p may be fitted as a cusp. It arises from the well known threshold peak in pbar-p elastic scattering due to annihilation. Several similar examples are discussed. The PS185 data for pbar-p to Lambdabar-Lambda require an almost identical cusp at the Lambdabar-Lambda threshold. There is also a cusp at the Sigma-N threshold in Kminus-d to piminus-Lambda-p. Similar cusps are likely to arise at thresholds for all 2-body de-excitation processes, providing the interaction is attractive; likely examples are Lambda-pbar, Sigma-pbar, and Kbar-Lambda. The narrow peak observed by Belle at 3872 MeV in piplus-piminus-J/Psi may be a 1++ cusp due to the Dbar-D* threshold. The narrow Xi*(1862) observed by NA49 may be due to a threshold cusp in Sigma(1385)-Kbar coupled to Xi-pi and Sigma-Kbar. The relation of cusps to known resonances such as fo(980) is discussed.

  9. Variable Threshold MOSFET Approach (Through Dynamic Threshold MOSFET) For Universal Logic Gates

    CERN Document Server

    Ragini, K; Jinaga, B C; 10.5121/vlsic.2010.1104

    2010-01-01

    In this article, we proposed a Variable threshold MOSFET(VTMOS)approach which is realized from Dynamic Threshold MOSFET(DTMOS), suitable for sub-threshold digital circuit operation. Basically the principle of sub- threshold logics is operating MOSFET in sub-threshold region and using the leakage current in that region for switching action, there by drastically decreasing power. To reduce the power consumption of sub-threshold circuits further, a novel body biasing technique termed VTMOS is introduced .VTMOS approach is realized from DTMOS approach. Dynamic threshold MOS (DTMOS) circuits provide low leakage and high current drive, compared to CMOS circuits, operated at lower voltages. The VTMOS is based on operating the MOS devices with an appropriate substrate bias which varies with gate voltage, by connecting a positive bias voltage between gate and substrate for NMOS and negative bias voltage between gate and substrate for PMOS. With VTMOS, there is a considerable reduction in operating current and power di...

  10. Voting on Thresholds for Public Goods

    DEFF Research Database (Denmark)

    Rauchdobler, Julian; Sausgruber, Rupert; Tyran, Jean-Robert

    2010-01-01

    Introducing a threshold in the sense of a minimal project size transforms a public-good game with an inefficient equilibrium into a coordination game with a set of Pareto-superior equilibria. Thresholds may therefore improve efficiency in the voluntary provision of public goods. In our one-shot e...... is approved in a referendum, because voting may facilitate coordination due to signaling and commitment effects. We find that voting does have signaling and commitment effects, but they are not strong enough to significantly improve the efficiency of thresholds....

  11. Voting on Thresholds for Public Goods

    DEFF Research Database (Denmark)

    Rauchdobler, Julian; Sausgruber, Rupert; Tyran, Jean-Robert

    Introducing a threshold in the sense of a minimal project size transforms a public goods game with an inefficient equilibrium into a coordination game with a set of Pareto-superior equilibria. Thresholds may therefore improve efficiency in the voluntary provision of public goods. In our one-shot ...... in a referendum, because voting may facilitate coordination due to signaling and commitment effects. We find that voting does have signaling and commitment effects but they are not strong enough to significantly improve the efficiency of thresholds....

  12. The tokamak density limit: A thermo-resistive disruption mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Gates, D. A.; Brennan, D. P.; Delgado-Aparicio, L.; White, R. B. [Plasma Physics Laboratory, Princeton University, P.O. Box 451, Princeton, New Jersey 08543 (United States)

    2015-06-15

    The behavior of magnetic islands with 3D electron temperature and the corresponding 3D resistivity effects on growth are examined for islands with near-zero net heating in the island interior. We refer to the resulting class of non-linearities as thermo-resistive effects. In particular, the effects of varying impurity mix on the previously proposed local island onset threshold [Gates and Delgado-Aparicio, Phys. Rev. Lett. 108, 165004 (2012)] are examined and shown to be consistent with the well established experimental scalings for tokamaks at the density limit. A surprisingly simple semi-analytic theory is developed which imposes the effects of heating/cooling in the island interior as well as the effects of island geometry. For the class of current profiles considered, it is found that a new term that accounts for the thermal effects of island asymmetry is required in the modified Rutherford equation. The resultant model is shown to exhibit a robust onset of a rapidly growing tearing mode—consistent with the disruption mechanism observed at the density limit in tokamaks. A fully non-linear 3D cylindrical calculation is performed that simulates the effect of net island heating/cooling by raising/suppressing the temperature in the core of the island. In both the analytic theory and the numerical simulation, the sudden threshold for rapid growth is found to be due to an interaction between three distinct thermal non-linearities which affect the island resistivity, thereby modifying the growth dynamics.

  13. Survey of disruption causes at JET

    NARCIS (Netherlands)

    de Vries, P. C.; Johnson, M. F.; Alper, B.; Buratti, P.; Hender, T. C.; Koslowski, H. R.; Riccardo, V.

    2011-01-01

    A survey has been carried out into the causes of all 2309 disruptions over the last decade of JET operations. The aim of this survey was to obtain a complete picture of all possible disruption causes, in order to devise better strategies to prevent or mitigate their impact. The analysis allows the e

  14. Rurality and Patterns of Social Disruption.

    Science.gov (United States)

    Wilkinson, Kenneth P.

    1984-01-01

    Argues that structural cleavages provoke social disruptions where opportunities are conducive. Thus, combinations of rurality with particular structural cleavages predict specific disruption patterns. Data from northeastern United States indicate that rurality, combined with other population characteristics (provocation, ascriptive inequality,…

  15. Network Formation under the Threat of Disruption

    NARCIS (Netherlands)

    Hoyer, B.

    2013-01-01

    The studies in this thesis are focused on the impact the presence of a network disruptor has on network formation models. In particular, we build two theoretical models to study the effect of network disruption on network formation and test the effect network disruption has on equilibrium selection

  16. Do firms with unique competencies for rescuing victims of human catastrophes have special obligations? Corporate responsibility and the AIDS catastrophe in sub-Saharan Africa.

    Science.gov (United States)

    Dunfee, Thomas W

    2006-04-01

    Firms possessing a unique competency to rescue the victims of a human catastrophe have a minimum moral obligation to devote substantial resources toward best efforts to aid victims. The minimum amount that firms should devote to rescue is the largest sum of their most recent year's investment in social initiatives, their five-year trend, their industry's average, or the national average. Financial exigency may justify a lower level of investment. Alternative social investments may be continued if they have an equally compelling rationale. These duties apply to the global pharmaceutical companies in the context of the AIDS pandemic in sub-Saharan Africa. PMID:17162832

  17. Investigating Ecohydrology and Connectivity Thresholds along a Precipitation Gradient in Australia

    Science.gov (United States)

    Saco, P. M.; Moreno-de las Heras, M.; Azadi, S.; Keesstra, S.

    2015-12-01

    Drylands are very sensitive to climatic or anthropogenic pressures and prone to critical degradation thresholds which make rehabilitation efforts considerably difficult. In these systems, the spatial structure of vegetation and the spatial redistribution of overland flow are tightly linked through feedbacks mechanisms. Disturbances, induced by human activities or climate change, can disrupt the spatial distribution of vegetation triggering erosion and substantial water losses by increasing landscape hydrological connectivity and damaging ecosystem function. Characterizing the integrity of these coevolving patterns is especially relevant for the detection of landscape degradation processes and possible threshold behaviour. Here we investigate the impact of degradation processes, induced by grazing pressure, across the Mulga Lands Bioregion in Australia. We combine remote sensing observations and a modelling approach to analyse changes in ecosystem connectivity and the existence of threshold behaviour along a precipitation gradient (250mm to 450mm annual average rainfall). Vegetation patterns are derived from high resolution remote sensing images, and Rainfall Use Efficiency (RUE) estimated from precipitation data and MODIS vegetation indices for a total of 40 plots along this gradient. A critical degradation threshold, associated to loss of vegetation cover appears for sites with lower mean annual precipitation. In these sites, hillslopes with high vegetation cover display low hydrologic connectivity and high RUE, and can be therefore classified as "functional". However, below a threshold vegetation cover we found highly "dysfunctional hillslopes" characterized by high connectivity and very low RUE. We found that this threshold behaviour tends to disappear for the north-western sites with higher mean annual rainfall. We further analytically investigate the dynamic response of these hillslopes using a coupled landform evolution-vegetation model to simulate coevolving

  18. Adaptive thresholding of digital subtraction angiography images

    Science.gov (United States)

    Sang, Nong; Li, Heng; Peng, Weixue; Zhang, Tianxu

    2005-10-01

    In clinical practice, digital subtraction angiography (DSA) is a powerful technique for the visualization of blood vessels in the human body. Blood vessel segmentation is a main problem for 3D vascular reconstruction. In this paper, we propose a new adaptive thresholding method for the segmentation of DSA images. Each pixel of the DSA images is declared to be a vessel/background point with regard to a threshold and a few local characteristic limits depending on some information contained in the pixel neighborhood window. The size of the neighborhood window is set according to a priori knowledge of the diameter of vessels to make sure that each window contains the background definitely. Some experiments on cerebral DSA images are given, which show that our proposed method yields better results than global thresholding methods and some other local thresholding methods do.

  19. Atherogenic risk factors and hearing thresholds

    DEFF Research Database (Denmark)

    Frederiksen, Thomas Winther; Ramlau-Hansen, Cecilia Høst; Stokholm, Zara Ann;

    2014-01-01

    The objective of this study was to evaluate the influence of atherogenic risk factors on hearing thresholds. In a cross-sectional study we analyzed data from a Danish survey in 2009-2010 on physical and psychological working conditions. The study included 576 white- and blue-collar workers from...... children's day care units, financial services and 10 manufacturing trades. Associations between atherogenic risk factors (blood lipids, glycosylated hemoglobin, smoking habits, body mass index (BMI), and ambulatory blood pressure) and hearing thresholds were analyzed using multiple linear regression models....... Adjusted results suggested associations between smoking, high BMI and triglyceride level and low high-density lipoprotein level and increased low-frequency hearing thresholds (average of pure-tone hearing thresholds at 0.25, 0.5 and 1 kHz). Furthermore, an increasing load of atherogenic risk factors seemed...

  20. Error Threshold of Fully Random Eigen Model

    Science.gov (United States)

    Li, Duo-Fang; Cao, Tian-Guang; Geng, Jin-Peng; Qiao, Li-Hua; Gu, Jian-Zhong; Zhan, Yong

    2015-01-01

    Species evolution is essentially a random process of interaction between biological populations and their environments. As a result, some physical parameters in evolution models are subject to statistical fluctuations. In this work, two important parameters in the Eigen model, the fitness and mutation rate, are treated as Gaussian distributed random variables simultaneously to examine the property of the error threshold. Numerical simulation results show that the error threshold in the fully random model appears as a crossover region instead of a phase transition point, and as the fluctuation strength increases the crossover region becomes smoother and smoother. Furthermore, it is shown that the randomization of the mutation rate plays a dominant role in changing the error threshold in the fully random model, which is consistent with the existing experimental data. The implication of the threshold change due to the randomization for antiviral strategies is discussed.

  1. 40 CFR 98.411 - Reporting threshold.

    Science.gov (United States)

    2010-07-01

    ...) MANDATORY GREENHOUSE GAS REPORTING Suppliers of Industrial Greenhouse Gases § 98.411 Reporting threshold. Any supplier of industrial greenhouse gases who meets the requirements of § 98.2(a)(4) must report GHG emissions....

  2. 40 CFR 98.181 - Reporting threshold.

    Science.gov (United States)

    2010-07-01

    ...) MANDATORY GREENHOUSE GAS REPORTING Lead Production § 98.181 Reporting threshold. You must report GHG emissions under this subpart if your facility contains a lead production process and the facility meets...

  3. 40 CFR 98.341 - Reporting threshold.

    Science.gov (United States)

    2010-07-01

    ...) MANDATORY GREENHOUSE GAS REPORTING Municipal Solid Waste Landfills § 98.341 Reporting threshold. You must report GHG emissions under this subpart if your facility contains a MSW landfill and the facility...

  4. 40 CFR 98.191 - Reporting threshold.

    Science.gov (United States)

    2010-07-01

    ...) MANDATORY GREENHOUSE GAS REPORTING Lime Manufacturing § 98.191 Reporting threshold. You must report GHG emissions under this subpart if your facility is a lime manufacturing plant as defined in § 98.190 and...

  5. 40 CFR 98.391 - Reporting threshold.

    Science.gov (United States)

    2010-07-01

    ...) MANDATORY GREENHOUSE GAS REPORTING Suppliers of Petroleum Products § 98.391 Reporting threshold. Any supplier of petroleum products who meets the requirements of § 98.2(a)(4) must report GHG emissions....

  6. 40 CFR 98.71 - Reporting threshold.

    Science.gov (United States)

    2010-07-01

    ...) MANDATORY GREENHOUSE GAS REPORTING Ammonia Manufacturing § 98.71 Reporting threshold. You must report GHG emissions under this subpart if your facility contains an ammonia manufacturing process and the...

  7. 40 CFR 98.271 - Reporting threshold.

    Science.gov (United States)

    2010-07-01

    ...) MANDATORY GREENHOUSE GAS REPORTING Pulp and Paper Manufacturing § 98.271 Reporting threshold. You must report GHG emissions under this subpart if your facility contains a pulp and paper manufacturing...

  8. 40 CFR 98.381 - Reporting threshold.

    Science.gov (United States)

    2010-07-01

    ...) MANDATORY GREENHOUSE GAS REPORTING Suppliers of Coal-based Liquid Fuels § 98.381 Reporting threshold. Any supplier of coal-to-liquid products who meets the requirements of § 98.2(a)(4) must report GHG emissions....

  9. 40 CFR 98.291 - Reporting threshold.

    Science.gov (United States)

    2010-07-01

    ...) MANDATORY GREENHOUSE GAS REPORTING Soda Ash Manufacturing § 98.291 Reporting threshold. You must report GHG emissions under this subpart if your facility contains a soda ash manufacturing process and the...

  10. 40 CFR 98.161 - Reporting threshold.

    Science.gov (United States)

    2010-07-01

    ...) MANDATORY GREENHOUSE GAS REPORTING Hydrogen Production § 98.161 Reporting threshold. You must report GHG emissions under this subpart if your facility contains a hydrogen production process and the facility...

  11. 40 CFR 98.31 - Reporting threshold.

    Science.gov (United States)

    2010-07-01

    ...) MANDATORY GREENHOUSE GAS REPORTING General Stationary Fuel Combustion Sources § 98.31 Reporting threshold. You must report GHG emissions under this subpart if your facility contains one or more stationary...

  12. 40 CFR 98.111 - Reporting threshold.

    Science.gov (United States)

    2010-07-01

    ...) MANDATORY GREENHOUSE GAS REPORTING Ferroalloy Production § 98.111 Reporting threshold. You must report GHG emissions under this subpart if your facility contains a ferroalloy production process and the...

  13. 40 CFR 98.41 - Reporting threshold.

    Science.gov (United States)

    2010-07-01

    ...) MANDATORY GREENHOUSE GAS REPORTING Electricity Generation § 98.41 Reporting threshold. You must report GHG emissions under this subpart if your facility contains one or more electricity generating units and...

  14. 40 CFR 98.151 - Reporting threshold.

    Science.gov (United States)

    2010-07-01

    ...) MANDATORY GREENHOUSE GAS REPORTING HCFC-22 Production and HFC-23 Destruction § 98.151 Reporting threshold. You must report GHG emissions under this subpart if your facility contains an HCFC-22 production...

  15. 40 CFR 98.81 - Reporting threshold.

    Science.gov (United States)

    2010-07-01

    ...) MANDATORY GREENHOUSE GAS REPORTING Cement Production § 98.81 Reporting threshold. You must report GHG emissions under this subpart if your facility contains a cement production process and the facility...

  16. 40 CFR 98.251 - Reporting threshold.

    Science.gov (United States)

    2010-07-01

    ...) MANDATORY GREENHOUSE GAS REPORTING Petroleum Refineries § 98.251 Reporting threshold. You must report GHG emissions under this subpart if your facility contains a petroleum refineries process and the facility...

  17. 40 CFR 98.281 - Reporting threshold.

    Science.gov (United States)

    2010-07-01

    ...) MANDATORY GREENHOUSE GAS REPORTING Silicon Carbide Production § 98.281 Reporting threshold. You must report GHG emissions under this subpart if your facility contains a silicon carbide production process...

  18. 40 CFR 98.211 - Reporting threshold.

    Science.gov (United States)

    2010-07-01

    ...) MANDATORY GREENHOUSE GAS REPORTING Miscellaneous Uses of Carbonate § 98.211 Reporting threshold. You must report GHG emissions from miscellaneous uses of carbonate if your facility uses carbonates as defined...

  19. 40 CFR 98.51 - Reporting threshold.

    Science.gov (United States)

    2010-07-01

    ...) MANDATORY GREENHOUSE GAS REPORTING Adipic Acid Production § 98.51 Reporting threshold. You must report GHG emissions under this subpart if your facility contains an adipic acid production process and the...

  20. 40 CFR 98.311 - Reporting threshold.

    Science.gov (United States)

    2010-07-01

    ...) MANDATORY GREENHOUSE GAS REPORTING Titanium Dioxide Production § 98.311 Reporting threshold. You must report GHG emissions under this subpart if your facility contains a titanium dioxide production process...