WorldWideScience

Sample records for catastrophic disruption threshold

  1. Catastrophic Disruption of Comet ISON

    Science.gov (United States)

    Keane, Jacqueline V.; Milam, Stefanie N.; Coulson, Iain M.; Kleyna, Jan T.; Sekanina, Zdenek; Kracht, Rainer; Riesen, Timm-Emmanuel; Meech, Karen J.; Charnley, Steven B.

    2016-01-01

    We report submillimeter 450 and 850 microns dust continuum observations for comet C/2012 S1 (ISON) obtained at heliocentric distances 0.31-0.08 au prior to perihelion on 2013 November 28 (rh?=?0.0125 au). These observations reveal a rapidly varying dust environment in which the dust emission was initially point-like. As ISON approached perihelion, the continuum emission became an elongated dust column spread out over as much as 60? (greater than 10(exp 5) km in the anti-solar direction. Deconvolution of the November 28.04 850 microns image reveals numerous distinct clumps consistent with the catastrophic disruption of comet ISON, producing approximately 5.2?×?10(exp 10) kg of submillimeter-sized dust. Orbital computations suggest that the SCUBA-2 emission peak coincides with the comet's residual nucleus.

  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

    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...

  4. Defending the Pittsburgh Waterways Against Catastrophic Disruption

    OpenAIRE

    2012-01-01

    This thesis develops an Operatorâ s Model that mimics the real-world behavior of coal transport in the Port of Pittsburgh and allows for systematic investigation of â what ifâ disruption scenarios. We model the multi-modal flow of coal using a network of nodes and arcs representing river transport, with support from a surrounding system of rail lines and roads. Each mode of shipment has finite capacities with varying costs. Our model routes flows in order to satisfy contracted...

  5. The Properties of Fragments from Catastrophic Disruption Events

    Science.gov (United States)

    Giblin, I.; Martelli, G.; Farinella, P.; Paolicchi, P.; Di Martino, M.; Smith, P. N.

    1998-07-01

    We report and discuss the results from a series of catastrophic disruption experiments involving 21-cm spherical targets of alumina cement. These experiments were performed in the open air using a contact charge technique to simulate an impact at ∼6 km/s, typical of collision velocities between asteroids in the main belt. The 1992 experiments reported here, the most recent in an extensive experimental program initiated by Giuseppe Martelli before his death in 1994, follow directly from those described in I. Giblinet al.(1994a,Icarus110, 203-224), with a number of improvements to our instrumentation and analysis. By using two high-speed cameras at a mutual angle of 60° we have made possible a three-dimensional analysis of fragment velocities alongside the standard size, shape, ejection angle and rotation rate measurements which can easily be made from appropriately oriented single film records. In this paper we report on the results of the 1992 experiments, together with various unpublished data from 1989. We make a comparison between these sets of data and between our data and those of other researchers in this field. Also, we compare our results to those of the most recent semi-empirical model (SEM) of P. Paolicchiet al.(1996,Icarus121, 126-157) and to appropriate data concerning real asteroids, focusing on the dynamical families, which are believed to be remnants from the catastrophic disruption of precursor asteroids. A secondary purpose of this paper is to document our experiences and techniques in the implementation and analysis of these experiments. We find considerable variation in the slope of the fragment size distribution, even between closely similar experiments. Fragments are found to be slightly flatter and/or more elongated than those from some previous work, but in agreement with the previous study mentioned above. Fragment velocities are generally between 4 and 20 m/s with a few fast fragments observed up to 35 m/s. Only a weak correlation is

  6. 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 ...

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

    Directory of Open Access Journals (Sweden)

    David D. Briske

    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.

  8. Catastrophic shifts and lethal thresholds in a propagating front model of unstable tumor progression

    Science.gov (United States)

    Amor, Daniel R.; Solé, Ricard V.

    2014-08-01

    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.

  9. 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.

  10. Disruption?

    DEFF Research Database (Denmark)

    2016-01-01

    This is a short video on the theme disruption and entrepreneurship. It takes the form of an interview with John Murray......This is a short video on the theme disruption and entrepreneurship. It takes the form of an interview with John Murray...

  11. 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.

  12. 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.)

  13. 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.

  14. Volcanic Catastrophes

    Science.gov (United States)

    Eichelberger, J. C.

    2003-12-01

    The big news from 20th century geophysics may not be plate tectonics but rather the surprise return of catastrophism, following its apparent 19th century defeat to uniformitarianism. Divine miracles and plagues had yielded to the logic of integrating observations of everyday change over time. Yet the brilliant interpretation of the Cretaceous-Tertiary Boundary iridium anomaly introduced an empirically based catastrophism. Undoubtedly, decades of contemplating our own nuclear self-destruction played a role in this. Concepts of nuclear winter, volcanic winter, and meteor impact winter are closely allied. And once the veil of threat of all-out nuclear exchange began to lift, we could begin to imagine slower routes to destruction as "global change". As a way to end our world, fire is a good one. Three-dimensional magma chambers do not have as severe a magnitude limitation as essentially two-dimensional faults. Thus, while we have experienced earthquakes that are as big as they get, we have not experienced volcanic eruptions nearly as great as those preserved in the geologic record. The range extends to events almost three orders of magnitude greater than any eruptions of the 20th century. Such a calamity now would at the very least bring society to a temporary halt globally, and cause death and destruction on a continental scale. At maximum, there is the possibility of hindering photosynthesis and threatening life more generally. It has even been speculated that the relative genetic homogeneity of humankind derives from an evolutionary "bottleneck" from near-extinction in a volcanic cataclysm. This is somewhat more palatable to contemplate than a return to a form of Original Sin, in which we arrived at homogeneity by a sort of "ethnic cleansing". Lacking a written record of truly great eruptions, our sense of human impact must necessarily be aided by archeological and anthropological investigations. For example, there is much to be learned about the influence of

  15. Dose-Dependent Thresholds of 10-ns Electric Pulse Induced Plasma Membrane Disruption and Cytotoxicity in Multiple Cell Lines

    Science.gov (United States)

    2011-01-01

    SJ, Fox PM, Rec LJ, Somers K, Stark RH, et al. (2002) Nanosecond Pulsed Electric Field (nsPEF) Effects on Cells and Tissues: Apoptosis Induction and...and a case report of intense nanosecond pulsed electric field as a local therapy for human malignancies. Int J Cancer 121: 675–682. 22. Nuccitelli R...Chen X, Pakhomov AG, Baldwin WH, Sheikh S, et al. (2009) A new pulsed electric field therapy for melanoma disrupts the tumor’s blood supply and causes

  16. Numerical simulations of catastrophic disruption: Recent results

    Science.gov (United States)

    Benz, W.; Asphaug, E.; Ryan, E. V.

    1994-01-01

    Numerical simulations have been used to study high velocity two-body impacts. In this paper, a two-dimensional Largrangian finite difference hydro-code and a three-dimensional smooth particle hydro-code (SPH) are described and initial results reported. These codes can be, and have been, used to make specific predictions about particular objects in our solar system. But more significantly, they allow us to explore a broad range of collisional events. Certain parameters (size, time) can be studied only over a very restricted range within the laboratory; other parameters (initial spin, low gravity, exotic structure or composition) are difficult to study at all experimentally. The outcomes of numerical simulations lead to a more general and accurate understanding of impacts in their many forms.

  17. 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...

  18. 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.

  19. 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.

  20. [The abdominal catastrophe].

    Science.gov (United States)

    Seiler, Christian A

    2011-08-01

    Patients with an abdominal catastrophe are in urgent need of early, interdisciplinary medical help. The treatment plan should be based on medical priorities and clear leadership. First priority should be given to achieve optimal oxygenation of blood and stabilization of circulation during all treatment-phases. The sicker the patient, the less invasive the (surgical) treatment should to be, which means "damage control only". This short article describes 7 important, pragmatic rules that will help to increase the survival of a patient with an abdominal catastrophe. Preexisting morbidity and risk factors must be included in the overall risk-evaluation for every therapeutic intervention. The challenge in patients with an abdominal catastrophe is to carefully balance the therapeutic stress and the existing resistance of the individual patient. The best way to avoid abdominal disaster, however, is its prevention.

  1. The Ongoing Catastrophe

    DEFF Research Database (Denmark)

    Kublitz, Anja

    2015-01-01

    were expelled from their homeland. However, according to my interlocutors, al-Nakba never stopped, but continues in the present. To understand this phenomenon, I suggest that it is conducive to think of al-Nakba as a reverse national myth, a figure of un-becoming, which is replicated in the present. I...... argue that, unlike the spectacular catastrophes in Palestine and later in Lebanon, life in the Danish camps is characterized by minor mundane catastrophes that are each so small that they barely register or elicit a moral response, but nevertheless erode the lives of my interlocutors....

  2. 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

  3. 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.

  4. [Catastrophic antiphospholipid syndrome].

    Science.gov (United States)

    Wisłowska, Małgorzata

    2015-01-01

    Catastrophic antiphospholipid syndrome is the most dangerous form of the antiphospholipid syndrome, which is characterized by rapid onset of thrombosis in small vessels of many organs and intravascular coagulation, thrombocytopenia and hemolytic anemia. The syndrome develops over a short period of time with acute multi-organ failure, including kidney, respiratory, cardiovascular, central nervous system and adrenal glands, often associated with disseminated thrombotic microangiopathy. The catastrophic antiphospholipid syndrome involves three or more systems, organs and/or tissues, the development of symptoms must occur within less than one week, it is necessary to confirm the histopathological vascular occlusion in at least one organ or tissue, and laboratory confirmation of the presence of antiphospholipid antibodies in the serum on two occasions over an interval of 12 weeks. This syndrome is characterized by a high mortality despite the use of optimal treatment. Early diagnosis and aggressive treatment of patients with catastrophic antiphospholipid syndrome is essential to save the life of these patients. In the last 10 years, the mortality in this disease decreased from 50% to 30% with simultaneous treatment with anticoagulants, corticosteroids, plasmapheresis and immunoglobulins.

  5. 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

  6. 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.

  7. 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.

  8. 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.

  9. 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) GMT2/RT +(3 / 5) Gmp2/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).

  10. Situational vs. dispositional measurement of catastrophizing: Associations with pain responses in multiple samples

    Science.gov (United States)

    Campbell, Claudia M.; Kronfli, Tarek; Buenaver, Luis F.; Smith, Michael T.; Berna, Chantal; Haythornthwaite, Jennifer A.; Edwards, Robert R.

    2009-01-01

    Catastrophizing is widely recognized as an important risk factor for adverse pain-related outcomes. However, questions remain surrounding the details of its assessment. In particular, recent laboratory studies suggest that evaluation of “situational” catastrophizing (i.e., catastrophizing measured during or directly after the administration of noxious stimulation) may provide information distinct from that obtained by standard, or “dispositional” measures which assess individuals’ recall of catastrophizing in daily life. However, comparatively little research has systematically investigated the inter-relationships and properties of these two different forms of pain-related catastrophizing. The current study evaluated both situational and dispositional catastrophizing measures within multiple samples: healthy individuals (N=84), patients with painful temporomandibular joint disorders (TMD; N=48), and patients with painful arthritis (N=43). All participants first completed the Pain Catastrophizing Scale (PCS)49, and then underwent psychophysical pain testing, which included heat, cold, and pressure pain. Participants then completed a situational catastrophizing measure with reference to the laboratory pain he/she had just undergone. Situational catastrophizing scores were not significantly correlated with dispositional PCS scores in the healthy participants and arthritis patients, though they were associated in TMD patients. Situational catastrophizing was more strongly associated with experimental pain responses than dispositional PCS scores for the healthy subjects and arthritis patients. In general, higher levels of situational catastrophizing were associated with lower pain thresholds and higher pain ratings across all 3 samples. The findings highlight the importance of multi-dimensional assessment of pain-related catastrophizing, and suggests a role for measuring catastrophizing related to specific, definable events. PMID:20439057

  11. Death, Catastrophe, and the Significance of Tragedy

    Directory of Open Access Journals (Sweden)

    Jennifer Ballengee

    2014-05-01

    Full Text Available This NANO note will examine the tension between representation, memorial, and the catastrophe of death that emerges in the space of tragedy, as the problem arises in two quite different works: Oedipus at Colonus, a fairly typical fifth-century Greek tragedy, and Falling Man, Don DeLillo’s novel that, in its attempt to address the events of 9/11, reflects in form and subject matter many of Aristotle’s terms of tragic representation. It is not the intent of this note to engage with the recent proliferation of work in “performance theory.” Rather than being concerned with an imagined exchange between audience and actor, this study examines how the supplementary relationship of gesture and speech in tragedy disrupts the public/private distinction, and how this articulation effects and enables the public memorialization of death. Thus, this paper will consider the representation of death as an event whose catastrophic, and somewhat mysterious, collision of the public and the private lends it its tragic significance.

  12. 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

  13. 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...

  14. Catastrophizing and perceived partner responses to pain.

    Science.gov (United States)

    Boothby, Jennifer L; Thorn, Beverly E; Overduin, Lorraine Y; Ward, L Charles

    2004-06-01

    This study examined the relationship between catastrophizing and patient-perceived partner responses to pain behaviors. The Catastrophizing subscale of the Cognitive Coping Strategy Inventory and the West Haven-Yale Multidimensional Pain Inventory were completed by 62 adult chronic pain patients. Consistent with past research, catastrophizing and patient-perceived solicitous partner behaviors were positively correlated with negative pain outcomes. The communal coping theory of catastrophizing suggests that catastrophizing might be undertaken to solicit support and empathy from others. However, catastrophizing was not related to perceived solicitous partner behavior in this study. Rather, catastrophizing was associated with perceived punishing partner responses. Implications are that catastrophizing and perceived solicitous partner behaviors are independently associated with pain and that catastrophizing may not be reinforced by empathy from significant others.

  15. 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.

  16. Guidance for Catastrophic Emergency Situations Involving Asbestos

    Science.gov (United States)

    This document addresses the types of asbestos issues that may arise during catastrophic events and how EPA has addressed such issues. It replaces the Guidelines for Catastrophic Emergency Situations Involving Asbestos which was issued in 1992.

  17. 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.

  18. 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.

  19. 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......” within the realm of public climate change communication. For that reason, the essay centers on the interplay between news media and entertainment. It argues that blockbuster disaster films represent an inversion of traditional risk and disaster news....

  20. Is Geothermal Simulation a "Catastrophe"?

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, V.V.; Pinder, George F.

    1980-12-16

    All numerical simulators of geothermal reservoirs depend upon an accurate representation of the thermodynamics of steam-water systems. These relationships are required to render tractable the system of balance equations derived from the physics of flow through porous media. While it is generally recognized that the steam-water system (i.e. two phase) is not in thermodynamic equilibrium, equihbrium thermodynamics are employed in its description. In this paper, we present an alternative view based on non-equilibrium thermodynamics. The underpinnings of this approach are found in a branch of topology generally referred to as "catastrophe theory". [Thom, 1975

  1. 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.

  2. 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...

  3. Increase in error threshold for quasispecies by heterogeneous replication accuracy

    Science.gov (United States)

    Aoki, Kazuhiro; Furusawa, Mitsuru

    2003-09-01

    In this paper we investigate the error threshold for quasispecies with heterogeneous replication accuracy. We show that the coexistence of error-free and error-prone polymerases can greatly increase the error threshold without a catastrophic loss of genetic information. We also show that the error threshold is influenced by the number of replicores. Our research suggests that quasispecies with heterogeneous replication accuracy can reduce the genetic cost of selective evolution while still producing a variety of mutants.

  4. 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.

  5. 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.

  6. 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...

  7. 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.

  8. 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.

  9. Does catastrophic thinking enhance oesophageal pain sensitivity?

    DEFF Research Database (Denmark)

    Martel, M O; Olesen, A E; Jørgensen, D;

    2016-01-01

    that catastrophic thinking exerts an influence on oesophageal pain sensitivity, but not necessarily on the magnitude of acid-induced oesophageal sensitization. WHAT DOES THIS STUDY ADD?: Catastrophizing is associated with heightened pain sensitivity in the oesophagus. This was substantiated by assessing responses...

  10. 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

  11. 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.

  12. 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...

  13. 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...

  14. 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 ...

  15. 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.

  16. 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.

  17. Catastrophic antiphospholipid syndrome: task force report summary.

    Science.gov (United States)

    Cervera, R; Rodríguez-Pintó, I

    2014-10-01

    The Task Force on Catastrophic Antiphospholipid Syndrome (CAPS) aimed to assess the current knowledge on pathogenesis, clinical and laboratory features, diagnosis and classification, precipitating factors and treatment of CAPS. This article summarizes the main aspects of its final report.

  18. 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.

  19. 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.

  20. Politisk disruption

    DEFF Research Database (Denmark)

    Tække, Jesper

    2017-01-01

    Dette blogindlæg giver en kort analyse af hvordan de sociale medier ved at give en ny tid har åbnet for den disruption af de politiske processer som især Trump stå som et eksempel på.......Dette blogindlæg giver en kort analyse af hvordan de sociale medier ved at give en ny tid har åbnet for den disruption af de politiske processer som især Trump stå som et eksempel på....

  1. 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...

  2. 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.

  3. 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.

  4. 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.

  5. Creating catastrophes in the classroom

    Science.gov (United States)

    Andersson, Thommy

    2013-04-01

    Buildings, infrastructure and human life are being destroyed by wind and landslides. To interest and motivate pupils and to help them understand abstract knowledge, a practical experiment could be useful. These experiments will show why strong winds circulate around tropical cyclones and how fluvial geological processes affect nature and communities. The experiments are easy to set up and the equipment is not expensive. Experiment 1: Exogenic processes of water are often slow processes. This experiment will simulate water processes that can take thousands of years, in less than 40 minutes. This experiment can be presented for and understood by pupils at all levels. Letting the pupils build up the scenery will make them more curious about the course of events. During that time they will see the geomorphological genesis of landforms such as landslides, sandurs, deltas, canyons sedimentations, selective erosions. Placing small houses, bridges etc. we can lead to discussions about natural catastrophes and community planning. Material needed for the experiment is a water bucket, erosion gutter, clay (simulating rock), sand and smaller pebbles (simulating the soil), houses of "Monopoly" size and tubes. By using a table with wheels it is easy to reuse the result for other lessons. Installation of a pump can make the experiment into a closed loop system. This installation can be used for presentations outside the classroom. Experiment 2: The Coriolis Effect explains why the wind (moving objects) deflects when moving. In the northern hemisphere the deflection is clockwise and anti-clockwise in the southern hemisphere. This abstract effect is often hard for upper secondary pupils to understand. This experiment will show the effect and thus make the theory real and visible. Material needed for this experiment is a bucket, pipes, a string. At my school we had cooperation with pupils from the Industrial Technology programme who made a copper pipe construction. During the

  6. 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.

  7. 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...

  8. Disruptive innovations

    OpenAIRE

    Viglia, Giampaolo; Werthner, H.; Buhalis, Dimitrios

    2016-01-01

    The diffusion of disrupting innovations has generated significant market changes, modifying the dominant logic and affecting the strategic positioning of companies. This structural change is affecting market structure, the networks and the services that tourism players are supposed to use (Gretzel et al. 2015). One can also refer to the notion of digital infrastructure, which provides a nice framework that connects the different stakeholders, their relations as well as internal dynamics. At t...

  9. 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.

  10. Catastrophic expenditure on medicines in Brazil

    Science.gov (United States)

    Luiza, Vera Lucia; Tavares, Noemia Urruth Leão; Oliveira, Maria Auxiliadora; Arrais, Paulo Sergio Dourado; Ramos, Luiz Roberto; Pizzol, Tatiane da Silva Dal; Mengue, Sotero Serrate; Farias, Mareni Rocha; Bertoldi, Andréa Dâmaso

    2016-01-01

    ABSTRACT OBJECTIVE To describe the magnitude of the expenditure on medicines in Brazil according to region, household size and composition in terms of residents in a situation of dependency. METHODS Population-based data from the national household survey were used, with probabilistic sample, applied between September 2013 and February 2014 in urban households. The expenditure on medicines was the main outcome of interest. The prevalence and confidence intervals (95%CI) of the outcomes were stratified according to socioeconomic classification and calculated according to the region, the number of residents dependent on income, the presence of children under five years and residents in a situation of dependency by age. RESULTS In about one of every 17 households (5.3%) catastrophic health expenditure was reported and, in 3.2%, the medicines were reported as one of the items responsible for this situation. The presence of three or more residents (3.6%) and resident in a situation of dependency (3.6%) were the ones that most reported expenditure on medicines. Southeast was the region with the lowest prevalence of expenditure on medicines. The prevalence of households with catastrophic health expenditure and on medicines in relation to the total of households showed a regressive tendency for economic classes. CONCLUSIONS Catastrophic health expenditure was present in 5.3%, and catastrophic expenditure on medicines in 3.2% of the households. Multi-person households, presence of residents in a situation of economic dependency and belonging to the class D or E had the highest proportion of catastrophic expenditure on medicines. Although the problem is important, permeated by aspects of iniquity, Brazilian policies seem to be protecting families from catastrophic expenditure on health and on medicine. PMID:27982383

  11. On a new global catastrophic ICT model

    DEFF Research Database (Denmark)

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

    2011-01-01

    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....

  12. 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)

  13. 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

  14. Catastrophizing and Causal Beliefs in Whiplash

    NARCIS (Netherlands)

    Buitenhuis, J.; de Jong, P. J.; Jaspers, J. P. C.; Groothoff, J. W.

    2008-01-01

    Study Design. Prospective cohort study. Objective. This study investigates the role of pain catastrophizing and causal beliefs with regard to severity and persistence of neck complaints after motor vehicle accidents. Summary of Background Data. In previous research on low back pain, somatoform disor

  15. Extension of catastrophe theory to Dulac unfoldings

    NARCIS (Netherlands)

    Broer, HW; Naudot, [No Value; Roussarie, R; Dumortier, F; Broer, H; Mawhin, J; Vanderbauwhede, A; Lunel, SV

    2005-01-01

    We consider a perturbation of a Hamiltonian planar vector field. The bifurcation set of limit cycles is studied. If the vector field is defined in an annulus, limit cycles are in one to one correspondence to the zeros of a polynomial. Catastrophe theory is relevant for the study of the ensuing bifur

  16. Thoracic aortic catastrophes : towards the endovascular solution

    NARCIS (Netherlands)

    Jonker, F.H.W.

    2010-01-01

    Descending thoracic aortic catastrophes include a variety of acute pathologies of the descending thoracic aorta, which are all associated with high morbidity and mortality rates, requiring immediate intervention. For this thesis, we explored the management and outcomes of several thoracic aortic cat

  17. 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.

  18. 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

  19. 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...

  20. Fitting the Cusp Catastrophe in R: A cusp Package Primer

    Directory of Open Access Journals (Sweden)

    Raoul P. P. P. Grasman

    2009-11-01

    Full Text Available Of the seven elementary catastrophes in catastrophe theory, the “cusp” model is the most widely applied. Most applications are however qualitative. Quantitative techniques for catastrophe modeling have been developed, but so far the limited availability of flexible software has hindered quantitative assessment. We present a package that implements and extends the method of Cobb (Cobb and Watson 1980; Cobb, Koppstein, and Chen 1983, and makes it easy to quantitatively fit and compare different cusp catastrophe models in a statistically principled way. After a short introduction to the cusp catastrophe, we demonstrate the package with two instructive examples.

  1. 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.

  2. 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 ...

  3. Performance studies – the theory of catastrophes?

    Directory of Open Access Journals (Sweden)

    Konrad Wojnowski

    2014-01-01

    Full Text Available The author of Performatyka – teoria katastrof? [“Performance studies – the theory of catastrophes?”], which is a cross-sectional investigation into performance studies, tracks the trains of thought about catastrophes in different theories of performativity, ranging from J. L. Austin’s to Jon McKenzie’s ideas. Of particular interest is how particular theoreticians integrate the term ‘catastrophe’ into their conceptual frameworks and how they evaluate it. By criticizing the approach taken by Judith Butler, who postulates “melancholic performance studies”, which brings to mind Adorno’s idea that is explicated in Minima Moralia (traurige Wissenschaft, the author tries to show how we can productively use Austin’s theses that are presented in the first chapters of his famous How to Do Things with Words. In the author’s opinion, Austin allows us to approach communicational catastrophes from a different perspective, which is often forgotten, i.e. of the functioning of contextual systems. It is shown that the tension between felicity and infelicity may be at the core of the popularity of performativity which is understood as a tool for researching contemporary cultural phenomena.

  4. 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...

  5. 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).

  6. 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.

  7. Fire phenomena and nonlinearity (II). Catastrophic fire dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Z. [University of Science and Technology, Hefei (China). State Key Laboratory of Fire Science

    2000-09-01

    As one of the most important non-linear mechanisms to cause fire or exacerbate fire disaster, there is a great deal of catastrophe behaviours existing in fire processes. The main tasks of the study of catastrophic fire dynamics are: 1) analysis of the catastrophe mechanisms of discontinuity behaviours in fire systems; 2) investigation of the controlling methods of discontinuity behaviours of fire system; 3) qualitative analysis of the dynamical characteristics of fire systems; and 4) catastrophe classifying of discontinuity phenomena in fire system. The other disciplines, such as physics, chemistry, biology, geoscience, astronomy, or even social sciences (for instance, political, economics, strategics and management science), may also take the similar method to establish the corresponding branch discipline of catastrophe science and catastrophe classification method. It is pointed out that an ignition behaviour of the uniform temperature thermal explosion system under the control of radiation has cusp catastrophe mechanism. 10 refs., 3 figs.

  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. Catastrophizing and symptoms of sleep disturbances in children.

    Science.gov (United States)

    Gregory, Alice M; Noone, Deirdre M; Eley, Thalia C; Harvey, Allison G

    2010-03-01

    Catastrophizing about sleeplessness is a cognitive process associated with sleep disturbance in adults. This study aimed to (1) examine whether children catastrophize about the consequences of not sleeping; (2) define the topics that children catastrophize about; (3) assess whether there is a link between catastrophizing and sleep disturbance in children; and (4) examine whether an association between catastrophizing and sleep in children is mediated by anxiety and depression symptoms. Children completed the sleep self-report and a catastrophizing interview. Testing took place in two inner-city schools in London, UK and participants comprised 123 children aged between 8 and 10 years (49% male). Thirty-four (28%) participants reported concerns in response to the catastrophizing questionnaire. The main topics being catastrophized were concerns about sleep, physiological issues and one's own emotions. Catastrophes predicted sleep disturbance after controlling for age and sex (beta = 0.35, P anxiety and depression symptoms (beta = 0.15, P = 0.106). Symptoms of anxiety (Sobel test = 3.30, P sleep. A proportion of children catastrophized about the consequences of sleeplessness and this was associated with sleep disturbance, an association which was mediated through anxiety and depression symptoms.

  10. Bodily illusions disrupt tactile sensations.

    Science.gov (United States)

    D'Amour, Sarah; Pritchett, Lisa M; Harris, Laurence R

    2015-02-01

    To accurately interpret tactile information, the brain needs to have an accurate representation of the body to which to refer the sensations. Despite this, body representation has only recently been incorporated into the study of tactile perception. Here, we investigate whether distortions of body representation affect tactile sensations. We perceptually altered the length of the arm and the width of the waist using a tendon vibration illusion and measured spatial acuity and sensitivity. Surprisingly, we found reduction in both tactile acuity and sensitivity thresholds when the arm or waist was perceptually altered, which indicates a general disruption of low-level tactile processing. We postulate that the disruptive changes correspond to the preliminary stage as the body representation starts to change and may give new insights into sensory processing in people with long-term or sudden abnormal body representation such as are found in eating disorders or following amputation.

  11. 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

  12. Bladder Pneumatosis From a Catastrophic Vascular Event

    Directory of Open Access Journals (Sweden)

    Ian J. Cooke

    2016-09-01

    Full Text Available Air within the bladder wall, or bladder pneumatosis, is a very rare finding typically resulting from an infectious etiology, as in emphysematous cystitis (EC. However, there have been reports of bladder pneumatosis occurring without clear infectious origins. We present a case of a female patient found to have concurrent bladder and ileal pneumatosis secondary to a catastrophic vascular event. Prompt recognition of non-infectious etiologies of bladder pneumatosis is essential as this distinction may dramatically alter clinical decision-making.

  13. 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.

  14. 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.

  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. 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

  17. 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…

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

    OpenAIRE

    Muris, Peter; Meesters, Cor; van den Hout, Mari F. C. M.; Wessels, Sylvia; Franken, Ingmar; 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 for Children, as well as scales for measuring sensitivity of the behavioral inhibition and behavioral activation systems (BIS-BAS), and various reactive and regulative temperament traits. Results de...

  19. 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.

  20. 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.

  1. 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.

  2. 5. Nonmalignant diseases after the Chernobyl catastrophe.

    Science.gov (United States)

    Yablokov, Alexey V

    2009-11-01

    This section describes the spectrum and the scale of the nonmalignant diseases that have been found among exposed populations. Adverse effects as a result of Chernobyl irradiation have been found in every group that has been studied. Brain damage has been found in individuals directly exposed--liquidators and those living in the contaminated territories, as well as in their offspring. Premature cataracts; tooth and mouth abnormalities; and blood, lymphatic, heart, lung, gastrointestinal, urologic, bone, and skin diseases afflict and impair people, young and old alike. Endocrine dysfunction, particularly thyroid disease, is far more common than might be expected, with some 1,000 cases of thyroid dysfunction for every case of thyroid cancer, a marked increase after the catastrophe. There are genetic damage and birth defects especially in children of liquidators and in children born in areas with high levels of radioisotope contamination. Immunological abnormalities and increases in viral, bacterial, and parasitic diseases are rife among individuals in the heavily contaminated areas. For more than 20 years, overall morbidity has remained high in those exposed to the irradiation released by Chernobyl. One cannot give credence to the explanation that these numbers are due solely to socioeconomic factors. The negative health consequences of the catastrophe are amply documented in this chapter and concern millions of people.

  3. 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.

  4. 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...

  5. Catastrophic Consequences of Kicking the Chameleon

    CERN Document Server

    Erickcek, Adrienne L; 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 consequences for the chameleon during the Universe's first minutes. The chameleon couples to the trace of the stress-energy tensor, which is temporarily non-zero in a radiation-dominated universe whenever a particle species becomes non-relativistic. These "kicks" impart a significant velocity to the chameleon field, causing its effective mass to vary non-adiabatically and resulting in the copious production of quantum fluctuations. Dissipative effects strongly modify the background evolution of the chameleon field, invalidati...

  6. Simple scaling of catastrophic landslide dynamics.

    Science.gov (United States)

    Ekström, Göran; Stark, Colin P

    2013-03-22

    Catastrophic landslides involve the acceleration and deceleration of millions of tons of rock and debris in response to the forces of gravity and dissipation. Their unpredictability and frequent location in remote areas have made observations of their dynamics rare. Through real-time detection and inverse modeling of teleseismic data, we show that landslide dynamics are primarily determined by the length scale of the source mass. When combined with geometric constraints from satellite imagery, the seismically determined landslide force histories yield estimates of landslide duration, momenta, potential energy loss, mass, and runout trajectory. Measurements of these dynamical properties for 29 teleseismogenic landslides are consistent with a simple acceleration model in which height drop and rupture depth scale with the length of the failing slope.

  7. Neurosurgical management for complicated catastrophic antiphospholipid syndrome.

    Science.gov (United States)

    Drazin, Doniel; Westley Phillips, H; Shirzadi, Ali; Drazin, Noam; Schievink, Wouter

    2014-04-01

    Antiphospholipid syndrome (APS) is an autoimmune condition involving arterial and venous thrombosis. An unusual APS variant, catastrophic antiphospholipid syndrome (CAPS), includes rapid multi-organ failure from widespread small vessel thrombosis. Central nervous system complications arise in one-third of CAPS patients. In rare cases, CAPS co-manifests with cerebellar hemorrhage presenting a neurosurgical emergency. We present a 65-year-old woman with CAPS-related cerebellar hematoma, co-morbid idiopathic thrombocytopenic purpura, deep vein thrombosis and altered mental status, with treatment complicated by thrombocytopenia. The patient suddenly deteriorated, secondary to a cerebellar subdural hematoma, and underwent decompression and excision of the hematoma. After recovery in the intensive care unit, she developed a new spontaneous epidural hematoma requiring additional surgery. Management of these patients is hematologically complex and often requires a multi-disciplinary team of physicians. This patient provides an important learning point for clinicians - consider CAPS when hemorrhage and thrombosis are present.

  8. 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

  9. 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...

  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. Catastrophe, gender and urban experience 1648-1920

    DEFF Research Database (Denmark)

    Employing a broad definition of catastrophe, this book examines how urban communities conceived, adapted to and were transformed by catastrophes. Competing views of gender figure in the telling and retelling of these trag- edies, which are mediated by myth and memory. This is a nuanced account...

  12. 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,

  13. 'Performative narrativity': Palestinian identity and the performance of catastrophe

    NARCIS (Netherlands)

    Saloul, I.

    2008-01-01

    The day Israel annually celebrates as its "Day of Independence" Palestinians commemorate as their day of catastrophe (al-nakba). To most Palestinians, the catastrophic loss of Palestine in 1948 represents the climactic formative event of their lives. In the aftermath of this loss, the Palestinian so

  14. Catastrophic healthcare expenditure - drivers and protection: the Portuguese case.

    Science.gov (United States)

    Kronenberg, Christoph; Barros, Pedro Pita

    2014-03-01

    The objective of this paper is to assess the extent of catastrophic healthcare expenditure, which can lead to impoverishment, even in a country with a National Health Service, such as Portugal. The level of catastrophic healthcare expenditure will be identified before the determinants of these catastrophic payments are analyzed. Afterwards, the effects of existing exemptions to copayments in health care use will be tested and the relationship between catastrophe and impoverishment will be discussed. Catastrophe is calculated from the Portuguese Household Budget Surveys of 2000 and 2005, and then analyzed using logistic regression models. The results show that catastrophe due to healthcare out-of-pocket payments are a sizeable issue in Portugal. Exemptions from out-of-pocket expenses for medical care should be created to prevent vulnerable groups from facing catastrophic healthcare spending. These vulnerable groups include children, people with disabilities and individuals suffering from chronic conditions. Disability proxies offer straightforward policy options for an exemption for the elderly with recognized disabilities. An exemption of retired people with disabilities is therefore recommended to policymakers as it targets a vulnerable group with high risk of facing catastrophic healthcare expenditure.

  15. 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.

  16. 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.

  17. 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

  18. Effects of target shape and impact speed on the outcome of catastrophic disruptions

    Science.gov (United States)

    Campo~Bagatin, A.; Durda, D.; Alemañ, R.; Flynn, G.; Strait, M.; Clayton, A.; Patmore, E.

    2014-07-01

    Because of the propensity of previous laboratory investigations to focus on idealized spherical targets, there is a bit of ambiguity in decoupling the relative importance/influence of low speed or spherical shape in producing the 'onion shell' fragment shape outcomes found in impacts into spherical targets [1,2]. If due primarily to impact speed/energy density as suggested by [3], this could play an important role in main-belt impacts due to the presence of non-spherical targets and non-negligible probability of low-speed (i.e., below about 3-4 km/s, subsonic in rock) impacts [4]. Also, [5] and [6] suggested that the shape of targets may affect the outcome of shattering processes, both in terms of fragment shape and mass distribution. To examine explicitly the effects of target shape in impact outcomes, we chose to conduct impact experiments on both spherical and naturally-occurring irregularly-shaped basalt targets. We impacted a total of six targets (two spheres and four irregular targets). We focused on shots with impact speeds in the ˜4 to 6 km/s range by 3/16th-inch diameter Al-sphere projectiles fired at the NASA AVGR. Following each shot, the debris were recovered (>95 %) and large fragments (>0.20 g) were individually weighed, allowing us to carefully measure the mass-frequency distribution from each impact experiment. The 36 largest fragments of each shot were photographed and their largest axes accurately measured by the program ''ImageJ''. Their shortest axes were measured by means of a digital caliber. High-speed video of each impact was obtained to aid interpretation of the fragmentation mode of the targets. Images clearly show that shell-like fragments can be produced in shattering events not in the target's surface. Instead, those fragments may form around the core, well inside the target structure, independently on the target shape itself. This is a feature not reported to date. In order to understand what the bulk macro-porosity of a non-coherent set of fragments is, we gathered randomly together the fragments with weighed mass mimicking the post-shattering gravitational re-accumulation of fragments into an asteroid rubble-pile. For each set, we wrapped the fragments in a thin plastic film and measured the bulk volume by hanging and plunging the assemblage into distilled water. The volume is calculated straightforward from the density of water at the given temperature. Cumulative mass distributions are derived and exponents 0.75m)=A m^{-β} (m is the fragment mass, A is the corresponding constant) in the stationary part of the distribution. The exponent of each distribution and the mass of each largest fragment are found to be related to the corresponding specific energy of each impact as expected [3]. The mass distributions seem to show slightly larger values of β in the case of spherical targets when comparing two sets of close specific energy impacts. However, this feature needs further sets of impact experiments to be properly investigated. As for the shapes of fragments, b/a and c/a ratios were calculated along with the shape metrics Ψ=[ c^2/(ab)]^{1/3}, F=(a-b)/(a-c) for deviation from the spherical shape and relative flatness, respectively [7,8]. The average relationship between a, b, and c axes is 1:0.7:0.4, slightly different (flatter) than reported by former investigations (1:0.7:0.5) carried on in the 70s and 80s [7]. This result is quite stable and no differences are found in average shapes among spherical and irregular targets nor for different specific energy up to a factor of ˜3. This does not mean that fragments look like triaxial ellipsoids, instead they are quite irregular but their average relative sizes are distributed very nicely as described. Finally, the study of the macro-porosities of randomly aggregated fragments shows values in the 45 to 50 % range. This result may be useful in the interpretation of small asteroids' bulk densities and in the calibration of numerical modelling of internal structures.

  19. 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…

  20. Empirical Bayes Credibility Models for Economic Catastrophic Losses by Regions

    Directory of Open Access Journals (Sweden)

    Jindrová Pavla

    2017-01-01

    Full Text Available Catastrophic events affect various regions of the world with increasing frequency and intensity. The number of catastrophic events and the amount of economic losses is varying in different world regions. Part of these losses is covered by insurance. Catastrophe events in last years are associated with increases in premiums for some lines of business. The article focus on estimating the amount of net premiums that would be needed to cover the total or insured catastrophic losses in different world regions using Bühlmann and Bühlmann-Straub empirical credibility models based on data from Sigma Swiss Re 2010-2016. The empirical credibility models have been developed to estimate insurance premiums for short term insurance contracts using two ingredients: past data from the risk itself and collateral data from other sources considered to be relevant. In this article we deal with application of these models based on the real data about number of catastrophic events and about the total economic and insured catastrophe losses in seven regions of the world in time period 2009-2015. Estimated credible premiums by world regions provide information how much money in the monitored regions will be need to cover total and insured catastrophic losses in next year.

  1. The relation between catastrophizing and the communication of pain experience.

    Science.gov (United States)

    Sullivan, M J L; Martel, M O; Tripp, D; Savard, A; Crombez, G

    2006-06-01

    The Communal Coping Model of pain catastrophizing proposes that pain catastrophizers enact pain behaviors in order to solicit support or empathy from their social environment. By this account, pain catastrophizers might be expected to engage in behavior aimed at maximizing the probability that their pain will be perceived by others in their social environment. To test this prediction, 40 undergraduates were videotaped during a cold pressor procedure. A separate sample of 20 (10 men, 10 women) undergraduates were asked to view the video sequences and infer the pain ratings of the cold pressor participants. Correlational analyses revealed that higher levels of pain catastrophizing of the cold pressor participants were associated with observer inferences of more intense pain, r=.39, ppain catastrophizing and observer inferences of pain intensity was mediated by the cold pressor participants' pain behavior. Although pain catastrophizing was associated with observers' inferences of more intense pain, cold pressor participants' level of pain catastrophizing was not associated with observers' accuracy in inferring self-reported pain. Implications of the findings for theory and clinical practice are addressed.

  2. 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...

  3. 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.

  4. The Potential for Space Intervention in Global Catastrophes

    Science.gov (United States)

    Hempsell, M.

    There is a growing understanding of the risks facing mankind of global catastrophe, which is defined as an event that kills a quarter the world population and risks destruction of organised society. Such catastrophes can be triggered by either naturally occurring, or arthropogenic, initiating events. And history shows that catastrophes with a natural origin do occur, with a mean separation time of around 1000 years. Anthropogenic initiated events are a recent possibility resulting from an expansion of technology capabilities, economic activity and population and, while they clearly significantly increase the total risk level above the natural background, it is more difficult to determine quantitatively by how much. Some initiating events and be directly tackled by an appropriate space capability. For example intercepting Near Earth Object before collision, or using Solar Power Satellites to eliminating carbon dioxide production in the power generation process to which many attribute global warming. Obviously prevention is the preferred option and so, not surprisingly, these particular uses of space as a means of preventing global catastrophe have received considerable attention. However space capability has a much wider potential for intervention in global catastrophes, even in those where the initiating event itself cannot be prevented. Previous work highlighting the risks through consideration of historic catastrophes has identified that global catastrophes have a complex structure with the initiating event triggering chains of vectors, which in turn trigger death causing agents. The work also highlighted that the vectors and agents during a catastrophe are similar regardless of the initiating event. This opens the possibility that space systems capable of addressing generic vectors and agents on a global scale can help deal with any global catastrophe regardless of its cause. The paper lists known (and credible) components to global catastrophes and highlight

  5. 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.

  6. Universal threshold enhancement

    CERN Document Server

    Patkós, András; Szépfalusy, P; Szep, Zs.

    2003-01-01

    By assuming certain analytic properties of the propagator, it is shown that universal features of the spectral function including threshold enhancement arise if a pole describing a particle at high temperature approaches in the complex energy plane the threshold position of its two-body decay with the variation of T. The case is considered, when one can disregard any other decay processes. The quality of the proposed description is demonstrated by comparing it with the detailed large N solution of the linear sigma model around the pole-threshold coincidence.

  7. 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

  8. Gradient catastrophe and Fermi-edge resonances in Fermi gas.

    Science.gov (United States)

    Bettelheim, E; Kaplan, Y; Wiegmann, P

    2011-04-22

    Any smooth spatial disturbance of a degenerate Fermi gas inevitably becomes sharp. This phenomenon, called the gradient catastrophe, causes the breakdown of a Fermi sea to multiconnected components characterized by multiple Fermi points. We argue that the gradient catastrophe can be probed through a Fermi-edge singularity measurement. In the regime of the gradient catastrophe the Fermi-edge singularity problem becomes a nonequilibrium and nonstationary phenomenon. We show that the gradient catastrophe transforms the single-peaked Fermi-edge singularity of the tunneling (or absorption) spectrum to a sequence of multiple asymmetric singular resonances. An extension of the bosonic representation of the electronic operator to nonequilibrium states captures the singular behavior of the resonances.

  9. 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.

  10. 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.

  11. Catastrophic antiphospholipid antibody syndrome in a child with thrombotic microangiopathy.

    Science.gov (United States)

    Prasad, N; Bhadauria, D; Agarwal, N; Gupta, A; Gupta, P; Jain, M; Lal, H

    2012-07-01

    Thrombotic microangiopathic hemolytic anemia (TMHA) is not uncommon in clinical nephrology practice while antiphospholipid syndrome (APS) is uncommon. Although less than 1% of patients with APS develop catastrophic APS (CAPS), its potential lethal outcome because of thrombosis in multiple organs and subsequent multiorgan failure emphasizes its importance in nephrology practice. Here is a case of catastrophic APS in a 7-year-old girl, who presented to us with TMHA associated with antiphospholipid antibodies and subsequently died because of CAPS.

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

    OpenAIRE

    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 frequen...

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

    OpenAIRE

    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...

  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. Catastrophic antiphospholipid syndrome in obstetric practice

    Directory of Open Access Journals (Sweden)

    Валерий Николаевич Запорожан

    2015-05-01

    Full Text Available Thus, the Catastrophic antiphospholipid syndrome (CAPS is much more common than has been assumed until now, in all patients the authors strongly recommend screening for AFA. Furthermore, eclampsia, HELLP-syndrome premature detachment of normally located placentae (PDNSP can develop in the presence of other defects of hemostasis, in particular in mutation FV Leiden, MTHFR C677T, deficiency of protein C (PC, protein S (PS. The combination of acquired thrombophilia due to APS, with genetic defects worsen hemostasis during the pathological process leading to the development of thrombotic complications. Perhaps a combination of hereditary thrombophilia and APS creates a favorable environment in which, under certain conditions, possible decompensation of the hemostatic system and the development of CAPS. Patients with APS constitute a group of very high risk of thromboembolic complications in the perioperative period. Even a minimally invasive intervention (biopsy, curettage, tooth extraction may trigger the development of CAPS. Thus, according to Erkan et al. (2003, 40% of patients develop CAPS was provoked by surgery. The main reasons for the development of thrombotic complications in connection with surgical intervention is the damage to the vessel wall, blood stasis and the abolition of indirect anticoagulants. In the study on the presence of genetic thrombophilia was found heterozygous form of FV Leiden mutation and homozygous mutation of MTHFR C677T. He was diagnosed with pregnancy 14 weeks, APS, mixed form of thrombophilia (a combination of acquisitions and multigenic thrombophilia, hyperhomocysteinemia, weighed down by obstetric and somatic history.It is very urgent and important problem remains diagnosis CAPS, which is inconceivable without the determination of AFA. The latter should be mandatory for all pregnant women with preeclampsia habitual miscarriage, Premature detachment of normally situated placenta (PDNSP, genital herpes history

  18. 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

  19. Sustainable Disruption Management

    DEFF Research Database (Denmark)

    Vaaben, Bo Valdemar

    papers combining disruption management and flight planning through an integrated optimization approach. An additional contribution of the thesis is to show how flexible flight speeds can be used to improve recovery from disruptions, while at the same time allowing an airline to trade off fuel costs...... of flights between different regions is centrally managed in order to reduce the negative impact of airspace congestions. A final contribution of the thesis is an approach and a model, which combines disruption management with flexible flight trajectories. In a situation, where a specific area......, 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...

  20. Polynomial threshold functions and Boolean threshold circuits

    DEFF Research Database (Denmark)

    Hansen, Kristoffer Arnsfelt; Podolskii, Vladimir V.

    2013-01-01

    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...... 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...

  1. Super Massive Star Clusters: From Superwinds to a Cooling Catastrophe and the Re-processing of the Injected Gas

    CERN Document Server

    Silich, S; Muñoz-Tunón, C; Palous, J

    2006-01-01

    Different hydrodynamic regimes for the gaseous outflows generated by multiple supernovae explosions and stellar winds occurring within compact and massive star clusters are discussed. It is shown that there exists the threshold energy that separates clusters whose outflows evolve in the quasi-adiabatic or radiative regime from those within which catastrophic cooling and a positive feedback star-forming mode sets in. The role of the surrounding ISM and the observational appearance of the star cluster winds evolving in different hydrodynamic regimes are also discussed.

  2. 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.

  3. 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

  4. Confronting the disruptive physician.

    Science.gov (United States)

    Linney, B J

    1997-01-01

    Ignoring disruptive behavior is no longer an option in today's changing health care environment. Competition and managed care have caused more organizations to deal with the disruptive physician, rather than look the other way as many did in years past. But it's not an easy task, possibly the toughest of your management career. How should you confront a disruptive physician? By having clearly stated expectations for physician behavior and policies in place for dealing with problem physicians, organizations have a context from which to address the situation.

  5. Shifting Relations with the More-than-Human: Six Threshold Concepts for Transformative Sustainability Learning

    Science.gov (United States)

    Barrett, M. J.; Harmin, Matthew; Maracle, Bryan; Patterson, Molly; Thomson, Christina; Flowers, Michelle; Bors, Kirk

    2017-01-01

    Using the iterative process of action research, we identify six portals of understanding, called threshold concepts, which can be used as curricular guideposts to disrupt the socially constituted separation, and hierarchy, between humans and the more-than-human. The threshold concepts identified in this study provide focal points for a curriculum…

  6. 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...

  7. 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.

  8. 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...

  9. 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.

  10. 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 ...

  11. Stagewise cognitive development: an application of catastrophe theory.

    Science.gov (United States)

    van der Maas, H L; Molenaar, P C

    1992-07-01

    In this article an overview is given of traditional methodological approaches to stagewise cognitive developmental research. These approaches are evaluated and integrated on the basis of catastrophe theory. In particular, catastrophe theory specifies a set of common criteria for testing the discontinuity hypothesis proposed by Piaget. Separate criteria correspond to distinct methods used in cognitive developmental research. Such criteria are, for instance, the detection of spurts in development, bimodality of test scores, and increased variability of responses during transitional periods. When a genuine stage transition is present, these criteria are expected to be satisfied. A revised catastrophe model accommodating these criteria is proposed for the stage transition in cognitive development from the preoperational to the concrete operational stage.

  12. 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.

  13. 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.

  14. Heritability of pain catastrophizing and associations with experimental pain outcomes: a twin study.

    Science.gov (United States)

    Trost, Zina; Strachan, Eric; Sullivan, Michael; Vervoort, Tine; Avery, Ally R; Afari, Niloofar

    2015-03-01

    This study used a twin paradigm to examine genetic and environmental contributions to pain catastrophizing and the observed association between pain catastrophizing and cold-pressor task (CPT) outcomes. Male and female monozygotic (n = 206) and dizygotic twins (n = 194) from the University of Washington Twin Registry completed a measure of pain catastrophizing and performed a CPT challenge. As expected, pain catastrophizing emerged as a significant predictor of several CPT outcomes, including cold-pressor Immersion Tolerance, Pain Tolerance, and Delayed Pain Rating. The heritability estimate for pain catastrophizing was found to be 37% with the remaining 63% of variance attributable to unique environmental influence. Additionally, the observed associations between pain catastrophizing and CPT outcomes were not found attributable to shared genetics or environmental exposure, which suggests a direct relationship between catastrophizing and experimental pain outcomes. This study is the first to examine the heritability of pain catastrophizing and potential processes by which pain catastrophizing is related to experimental pain response.

  15. 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.

  16. Catastrophic antiphospholipid syndrome presenting as fever of unknown origin.

    Science.gov (United States)

    Al-Beladi, Fatma I

    2012-01-01

    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.

  17. Predicting catastrophes in nonlinear dynamical systems by compressive sensing.

    Science.gov (United States)

    Wang, Wen-Xu; Yang, Rui; Lai, Ying-Cheng; Kovanis, Vassilios; Grebogi, Celso

    2011-04-15

    An extremely challenging problem of significant interest is to predict catastrophes in advance of their occurrences. We present a general approach to predicting catastrophes in nonlinear dynamical systems under the assumption that the system equations are completely unknown and only time series reflecting the evolution of the dynamical variables of the system are available. Our idea is to expand the vector field or map of the underlying system into a suitable function series and then to use the compressive-sensing technique to accurately estimate the various terms in the expansion. Examples using paradigmatic chaotic systems are provided to demonstrate our idea.

  18. Predicting catastrophes in nonlinear dynamical systems by compressive sensing

    CERN Document Server

    Wang, Wen-Xu; Lai, Ying-Cheng; Kovanis, Vassilios; Grebogi, Celso

    2011-01-01

    An extremely challenging problem of significant interest is to predict catastrophes in advance of their occurrences. We present a general approach to predicting catastrophes in nonlinear dynamical systems under the assumption that the system equations are completely unknown and only time series reflecting the evolution of the dynamical variables of the system are available. Our idea is to expand the vector field or map of the underlying system into a suitable function series and then to use the compressive-sensing technique to accurately estimate the various terms in the expansion. Examples using paradigmatic chaotic systems are provided to demonstrate our idea.

  19. Efficient Threshold Signature Scheme

    Directory of Open Access Journals (Sweden)

    Sattar J Aboud

    2012-01-01

    Full Text Available In this paper, we introduce a new threshold signature RSA-typed scheme. The proposed scheme has the characteristics of un-forgeable and robustness in random oracle model. Also, signature generation and verification is entirely non-interactive. In addition, the length of the entity signature participate is restricted by a steady times of the length of the RSA signature modulus. Also, the signing process of the proposed scheme is more efficient in terms of time complexity and interaction.

  20. Pain catastrophizing predicts verbal expression among children with chronic pain and their mothers

    Directory of Open Access Journals (Sweden)

    Shelby L Langer

    2016-03-01

    Full Text Available This study examined intra- and inter-personal associations between pain catastrophizing and verbal expression in 70 children with recurrent abdominal pain and their mothers. Participants independently completed the Pain Catastrophizing Scale. Mothers and children then talked about the child’s pain. Speech was categorized using a linguistic analysis program. Catastrophizing was positively associated with the use of negative emotion words by both mothers and children. In addition, mothers’ catastrophizing was positively associated with both mothers’ and children’s anger word usage, whereas children’s catastrophizing was inversely associated with mothers’ anger word usage. Findings extend the literature on behavioral and interpersonal aspects of catastrophizing.

  1. 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.

  2. A case of seronegative catastrophic antiphospholipid antibody syndrome.

    Science.gov (United States)

    Shreders, Amanda; Bar, Michael

    2013-02-01

    Catastrophic antiphospholipid antibody syndrome (CAPS) is a rare syndrome associated with multiorgan failure that carries a high mortality rate. It has been defined previously by the presence of autoantibodies in a patient with acute multiorgan failure as a result of small vessel occlusion by multiple thrombi. We report a patient who meets all criteria of CAPS except for persistent seronegativity.

  3. 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

  4. Enabling Unity of Effort in Response Activities during Complex Catastrophes

    Science.gov (United States)

    2013-03-01

    catastrophe (including any hurricane, tornado, storm, high water , winddriven water , tidal wave, tsunami, earthquake, volcanic eruption , landslide...the Insurrection Act, and the Stafford Act. Perhaps the most efficient means to achieve unity of effort would be to consolidate all forces under a...possible under our federalist system of government, where respective authorities are divided between federal, state and local jurisdictions. The most

  5. Alignment of Lyapunov Vectors: A Quantitative Criterion to Predict Catastrophes?

    Science.gov (United States)

    Beims, Marcus W.; Gallas, Jason A. C.

    2016-11-01

    We argue that the alignment of Lyapunov vectors provides a quantitative criterion to predict catastrophes, i.e. the imminence of large-amplitude events in chaotic time-series of observables generated by sets of ordinary differential equations. Explicit predictions are reported for a Rössler oscillator and for a semiconductor laser with optoelectronic feedback.

  6. Catastrophe Theory: A Unified Model for Educational Change.

    Science.gov (United States)

    Cryer, Patricia; Elton, Lewis

    1990-01-01

    Catastrophe Theory and Herzberg's theory of motivation at work was used to create a model of change that unifies and extends Lewin's two separate stage and force field models. This new model is used to analyze the behavior of academics as they adapt to the changing university environment. (Author/MLW)

  7. Vaginismus : Heightened Harm Avoidance and Pain Catastrophizing Cognitions

    NARCIS (Netherlands)

    Borg, Charmaine; Peters, Madelon L.; Schultz, Willibrord Weijmar; de Jong, Peter J.

    2012-01-01

    Introduction. Catastrophic appraisal of experienced pain may promote hypervigilance and intense pain, while the personality trait of harm avoidance (HA) might prevent the occurrence of correcting such experiences. Women inflicted with vaginismus may enter a self-perpetuating downward spiral of incre

  8. Catastrophic fire deaths: the numbers are back up.

    Science.gov (United States)

    Tremblay, K J

    1994-01-01

    The number of catastrophic multiple-death fires in the United States rose in 1993 from the record low of 1992 to a level more consistent with that of recent years. Despite our efforts to highlight risk factors, we continue to see the same problems year after year.

  9. 7 CFR 402.4 - Catastrophic Risk Protection Endorsement Provisions.

    Science.gov (United States)

    2010-01-01

    ... total household income at or below the national poverty level for a family of four, or less than 50..., provided that you execute a High Risk Land Exclusion Option and obtain a catastrophic risk protection... the landowners must agree in writing to such arrangement and have their social security number...

  10. 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.

  11. 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…

  12. 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

  13. [Establishing the personal identity of the victims in aviation catastrophes].

    Science.gov (United States)

    Abramov, S S; Alekseev, I V; Gedygushev, I A; Zaĭtsev, A B; Isaev, Iu S; Nedel'ko, N F; Miller, V V; Proskurin, V N; Khaĭrulin, E G; Shilin, A V

    1999-01-01

    Algorithm of organization measures and expert investigations is proposed, based on experience gained in expert studies during liquidation of aircraft catastrophes. It permits effective classification, differentiation, and identification of victims and is based on traditional and high technological methods of investigation.

  14. Concrete ensemble Kalman filters with rigorous catastrophic filter divergence

    Science.gov (United States)

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

    2015-01-01

    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. PMID:26261335

  15. 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...

  16. 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

  17. 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.

  18. 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.

  19. Endocrine disrupting chemicals

    DEFF Research Database (Denmark)

    Mandrup, Karen

    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...... and genistein, a mixture of phytoestrogens, and a mixture of environmentally relevant estrogenic EDCs of various origins. Moreover, mixtures of antiandrogenic chemicals were investigated. These include a mixture of pesticides and a mixture of environmentally relevant anti-androgenic EDCs of various origins...

  20. 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.

  1. Catastrophic neurological complications of emergent endotracheal intubation: report of 2 cases.

    Science.gov (United States)

    Oppenlander, Mark E; Hsu, Forrest D; Bolton, Patrick; Theodore, Nicholas

    2015-05-01

    Although exceedingly rare, catastrophic neurological decline may result from endotracheal intubation of patients with preexisting cervical spine disease. The authors report on 2 cases of quadriplegia resulting from emergent endotracheal intubation in the intensive care unit. A 68-year-old man with ankylosing spondylitis became quadriplegic after emergent intubation. A new C6-7 fracturedislocation was identified, and the patient underwent emergent open reduction and C4-T2 posterior fixation and fusion. The patient remained quadriplegic and ultimately died of pneumonia 1 year later. This is the first report with radiographic documentation of a cervical fracture-dislocation resulting from intubation in a patient with ankylosing spondylitis. A 73-year-old man underwent posterior C6-T1 decompression and fixation for a C6-7 fracture. On postoperative Day 12, emergent intubation for respiratory distress resulted in C6-level quadriplegia. Imaging revealed acute spondyloptosis at C6-7, and the patient underwent emergent open reduction with revision and extension of posterior fusion from C-3 to T-2. He remained quadriplegic and ventilator dependent. Five days after the second operation, care was withdrawn. This is the first report of intubation as a cause of significant neurological decline related to disruption of a recently fixated cervical fracture. Risk factors are identified and pertinent literature is reviewed for cases of catastrophic neurological complications after emergent endotracheal intubation. Strategies for obtaining airway control in patients with cervical spine pathology are also identified. Awareness of the potential dangers of airway management in patients with cervical spine pathology is critical for all involved subspecialty team members.

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

    Science.gov (United States)

    Feng, Xiao-Li; Gu, Jian-Zhong; Li, Yu-Xiao; Zhuo, Yi-Zhong

    2007-10-01

    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 quasi-species 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.

  3. 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.

  4. 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.

  5. 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.

  6. Managing Supply Chain Disruptions

    Science.gov (United States)

    2008-08-09

    additional resources such as increased levels of inventory to restore operations following a disruption (Stonebraker & Afifi , 2004; Zsidisin et al...Other Disciplines to Logistics. International Journal of Physical Distribution & Logistics Management, 27(9/10), pp 515. Stonebraker, P. W. & Afifi

  7. $\\eta'$ photoproduction near threshold

    CERN Document Server

    Zhao, Q

    2000-01-01

    In this work, the $\\eta^\\prime$ meson photoproduction near threshold is studied in the quark model framework. A pseudovector effective Lagrangian is introduced for the $\\eta^\\prime NN$ coupling and the newly published data from the SAPHIR Collaboration provide good constraints to this parameter. Corrections of order $O(1/m_q^2)$ for the electromagnetic interaction vertex are taken into account, which produce corrections of order $O(1/m_q^3)$ to the transition amplitude for $\\gamma p\\to \\eta^\\prime p$. Some low-lying resonances, $S_{11}(1535)$, $P_{13}(1720)$, and $P_{13}(1900)$ are found to have significant contributions. A bump structure around $E_\\gamma\\approx$ 2 GeV is found arising from the $n=3$ terms in the harmonic oscillator basis. The beam polarization asymmetries are predicted and can be tested against the forthcoming data from GRAAL.

  8. Le gouvernement mondial des catastrophes « naturelles »

    Directory of Open Access Journals (Sweden)

    Sandrine Revet

    2015-01-01

    Full Text Available Depuis la fin des années 1980, une tentative de gouvernement international des catastrophes dites « naturelles » a progressivement vu le jour. Celui-ci prétend coordonner à l’échelle internationale des actions relevant à la fois de la prévention des risques et de la gestion de crise. L’article propose de décrire ce processus en en retraçant les grandes étapes, depuis la Décennie internationale pour la prévention des catastrophes naturelles de l’ONU (1990-1999 jusqu’aux négociations ayant mené au Cadre d’action de Hyogo (CAH, 2005-2015. Il mettra en lumière les grandes tensions qui ont animé ce processus et qui révèlent les différentes approches adoptées face aux catastrophes naturelles : mettre en place des politiques de prévention qui misent sur la transformation en profondeur des choix de développement ou insister sur les capacités technologiques de prévision, de communication de l’alerte et de gestion des crises provoquées par les catastrophes lorsqu’elles surviennent ? Nous nous intéresserons enfin aux enjeux qui seront soulevés en 2015 par les négociations du prochain cadre d’action international CAH2 lors de la conférence mondiale qui se tiendra à Sendaï au Japon.

  9. Optimising threshold levels for information transmission in binary threshold networks: Independent multiplicative noise on each threshold

    Science.gov (United States)

    Zhou, Bingchang; McDonnell, Mark D.

    2015-02-01

    The problem of optimising the threshold levels in multilevel threshold system subject to multiplicative Gaussian and uniform noise is considered. Similar to previous results for additive noise, we find a bifurcation phenomenon in the optimal threshold values, as the noise intensity changes. This occurs when the number of threshold units is greater than one. We also study the optimal thresholds for combined additive and multiplicative Gaussian noise, and find that all threshold levels need to be identical to optimise the system when the additive noise intensity is a constant. However, this identical value is not equal to the signal mean, unlike the case of additive noise. When the multiplicative noise intensity is instead held constant, the optimal threshold levels are not all identical for small additive noise intensity but are all equal to zero for large additive noise intensity. The model and our results are potentially relevant for sensor network design and understanding neurobiological sensory neurons such as in the peripheral auditory system.

  10. 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.

  11. Catastrophic subsidence: An environmental hazard, shelby county, Alabama

    Science.gov (United States)

    Lamoreaux, Philip E.; Newton, J. G.

    1986-03-01

    Induced sinkholes (catastrophic subsidence) are those caused or accelerated by human activities These sinkholes commonly result from a water level decline due to pumpage Construction activities in a cone of depression greatly increases the likelihood of sinkhole occurrence Almost all occur where cavities develop in unconsolidated deposits overlying solution openings in carbonate rocks. Triggering mechanisms resulting from water level declines are (1) loss of buoyant support of the water, (2) increased gradient and water velocity, (3) water-level fluctuations, and (4) induced recharge Construction activities triggering sinkhole development include ditching, removing overburden, drilling, movement of heavy equipment, blasting and the diversion and impoundment of drainage Triggering mechanisms include piping, saturation, and loading Induced sinkholes resulting from human water development/management activities are most predictable in a youthful karst area impacted by groundwater withdrawals Shape, depth, and timing of catastrophic subsidence can be predicted in general terms Remote sensing techniques are used in prediction of locations of catastrophic subsidence. This provides a basis for design and relocation of structures such as a gas pipeline, dam, or building Utilization of techniques and a case history of the relocation of a pipeline are described

  12. Evidence for Middle Amazonian catastrophic flooding and glaciation on Mars

    Science.gov (United States)

    Rodríguez, J. Alexis P.; Gulick, Virginia C.; Baker, Victor R.; Platz, Thomas; Fairén, Alberto G.; Miyamoto, Hideaki; Kargel, Jeffrey S.; Rice, James W.; Glines, Natalie

    2014-11-01

    Early geologic investigations of Mars revealed some of the largest channels in the Solar System (outflow channels), which appear to have mostly developed ∼3 byr ago. These channels have been the subject of much scientific inquiry since the 1970s and proposed formative processes included surface erosion by catastrophic floods, glaciers, debris flows and lava flows. Based on the analysis of newly acquired Mars Reconnaissance Orbiter (MRO) Context (CTX, 5.15-5.91 m/pixel) and High Resolution Imaging Science Experiment (HiRISE, 25-50 cm/pixel) image data, we have identified a few locations contained within relatively narrow canyons of the southern circum-Chryse outflow channels that retain well-preserved decameter/hectometer-scale landform assemblages. These terrains include landforms consistent in shape, dimension and overall assemblage to those produced by catastrophic floods, and at one location, to glacial morphologies. Impact crater statistics for four of these surfaces, located within upstream, midstream and downstream outflow channel surfaces, yield an age estimate of ∼600 myr. This suggests that the southern circum-Chryse outflow channels were locally resurfaced by some of the most recent catastrophic floods on the planet, and that these floods coexisted within regional glacier environments as recently as during the Middle Amazonian.

  13. 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...

  14. 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.

  15. 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.

  16. Albania - Thresholds I and II

    Data.gov (United States)

    Millennium 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...

  17. 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.

  18. 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.

  19. 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.

  20. Manuel's asteroid disruption technique.

    Science.gov (United States)

    John, Manuel; Ipe, Abraham; Jacob, Ivan

    2015-06-01

    A seventy-year-old male presented with dense asteroid hyalosis in both eyes. He had undergone cataract extraction in one eye 3 years ago, and the other eye had immature cataract. Both the autorefractor and dilated streak retinoscopy did not give readings and subjective visual improvement could not be achieved. Immediately following YAG posterior capsulotomy and anterior vitreous asteroid disruption, the vision improved to 20/20 with recordable auto refractor and streak retinoscopy values. Our initial experience indicates that the treatment is simple, safe and effective but needs controlled and prospective studies to confirm its long-term safety.

  1. 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.

  2. Disruptive Space Technology

    OpenAIRE

    Benson, Jim

    2004-01-01

    In 1997 "The Innovator’s Dilemma" by Clayton M. Christensen became a popular book in the small satellite and launch vehicle communities. But like the weather, every one talks about “Disruptive Technology” but few do anything about it. In the ‘70s and ‘80s, people were looking for “Paradigm Shifts,” and since the resurrection of Donald Rumsfeld, a recent watchword has been “Transformational Technology.” But today’s buzzword is now “Responsive Space Systems.”

  3. 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…

  4. 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

  5. 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

  6. 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.

  7. 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.

  8. Blue sky catastrophe as applied to modeling of cardiac rhythms

    Science.gov (United States)

    Glyzin, S. D.; Kolesov, A. Yu.; Rozov, N. Kh.

    2015-07-01

    A new mathematical model for the electrical activity of the heart is proposed. The model represents a special singularly perturbed three-dimensional system of ordinary differential equations with one fast and two slow variables. A characteristic feature of the system is that its solution performs nonclassical relaxation oscillations and simultaneously undergoes a blue sky catastrophe bifurcation. Both these factors make it possible to achieve a phenomenological proximity between the time dependence of the fast component in the model and an ECG of the human heart.

  9. ATR Prohibits Replication Catastrophe by Preventing Global Exhaustion of RPA

    DEFF Research Database (Denmark)

    Toledo Lazaro, Luis Ignacio; Altmeyer, Matthias; Rask, Maj-Britt;

    2013-01-01

    induced breakage of stalled forks even in cells with active ATR. Thus, ATR-mediated suppression of dormant origins shields active forks against irreversible breakage via preventing exhaustion of nuclear RPA. This study elucidates how replicating genomes avoid destabilizing DNA damage. Because cancer cells...... origin firing generates an excess of single-stranded DNA that exhausts the nuclear pool of RPA. Partial reduction of RPA accelerated fork breakage, and forced elevation of RPA was sufficient to delay such "replication catastrophe" even in the absence of ATR activity. Conversely, unscheduled origin firing...

  10. 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.

  11. Cell disruption for microalgae biorefineries.

    Science.gov (United States)

    Günerken, E; D'Hondt, E; Eppink, M H M; Garcia-Gonzalez, L; Elst, K; Wijffels, R H

    2015-01-01

    Microalgae are a potential source for various valuable chemicals for commercial applications ranging from nutraceuticals to fuels. Objective in a biorefinery is to utilize biomass ingredients efficiently similarly to petroleum refineries in which oil is fractionated in fuels and a variety of products with higher value. Downstream processes in microalgae biorefineries consist of different steps whereof cell disruption is the most crucial part. To maintain the functionality of algae biochemicals during cell disruption while obtaining high disruption yields is an important challenge. Despite this need, studies on mild disruption of microalgae cells are limited. This review article focuses on the evaluation of conventional and emerging cell disruption technologies, and a comparison thereof with respect to their potential for the future microalgae biorefineries. The discussed techniques are bead milling, high pressure homogenization, high speed homogenization, ultrasonication, microwave treatment, pulsed electric field treatment, non-mechanical cell disruption and some emerging technologies.

  12. Do we need a communal coping model of pain catastrophizing? An alternative explanation

    OpenAIRE

    2006-01-01

    In this topical review, a case is made for placing pain catastrophizing within the transactional stress and coping model of Lazarus and Folkman (1984). It is argued that the CCM in its current formulation might actually contribute to the conceptual confusion around the construct of pain catastrophizing that was mentioned previously. This finally leads to the question of whether we actually need a CCM of catastrophizing.

  13. Plasma Exchange in the Management of Catastrophic Antiphospholipid Syndrome

    Directory of Open Access Journals (Sweden)

    Dimitri Titeca-Beauport

    2016-01-01

    Full Text Available Objective. Report of a case of catastrophic antiphospholipid syndrome (CAPS with multiple organ involvement leading to a life-threatening condition despite early combination corticosteroid and heparin therapy. Initiation of plasma exchange led to rapid improvement of the patient’s general condition. Design. Case report. Setting. University teaching hospital medical intensive care unit. Patient. Single case: 52-year-old man hospitalized for catastrophic antiphospholipid syndrome (CAPS with cardiac, renal, and cutaneous involvement. Despite early methylprednisolone and heparin therapy, the patient’s condition progressively deteriorated, resulting in acute renal failure, right adrenal hemorrhage, and pulmonary involvement, leading to acute respiratory distress on day 6, requiring high-flow nasal cannula oxygen therapy with FiO2 of 1.0. Interventions. Plasma exchange was started on day 6. Endpoints and Main Results. A marked improvement of the patient’s general condition was observed after initiation of plasma exchange, with successful weaning of oxygen therapy and normalization of platelet count, troponin, and serum creatinine within four days. Conclusions. This case illustrates the efficacy of plasma exchange in CAPS and the difficulty for physicians to determine the optimal timing of plasma exchange.

  14. "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.

  15. Plasma Exchange in the Management of Catastrophic Antiphospholipid Syndrome

    Science.gov (United States)

    Salle, Valery; Kontar, Loay; Maizel, Julien

    2016-01-01

    Objective. Report of a case of catastrophic antiphospholipid syndrome (CAPS) with multiple organ involvement leading to a life-threatening condition despite early combination corticosteroid and heparin therapy. Initiation of plasma exchange led to rapid improvement of the patient's general condition. Design. Case report. Setting. University teaching hospital medical intensive care unit. Patient. Single case: 52-year-old man hospitalized for catastrophic antiphospholipid syndrome (CAPS) with cardiac, renal, and cutaneous involvement. Despite early methylprednisolone and heparin therapy, the patient's condition progressively deteriorated, resulting in acute renal failure, right adrenal hemorrhage, and pulmonary involvement, leading to acute respiratory distress on day 6, requiring high-flow nasal cannula oxygen therapy with FiO2 of 1.0. Interventions. Plasma exchange was started on day 6. Endpoints and Main Results. A marked improvement of the patient's general condition was observed after initiation of plasma exchange, with successful weaning of oxygen therapy and normalization of platelet count, troponin, and serum creatinine within four days. Conclusions. This case illustrates the efficacy of plasma exchange in CAPS and the difficulty for physicians to determine the optimal timing of plasma exchange. PMID:27833765

  16. 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)

  17. 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.

  18. Iodine and thyroid gland with or without nuclear catastrophe

    Directory of Open Access Journals (Sweden)

    Kovačev-Zavišić Branka

    2012-01-01

    Full Text Available Introduction. Iodine, as a trace element, is a necessary and limiting substrate for thyroid gland hormone synthesis. It is an essential element that enables the thyroid gland to produce thyroid hormones thyroxine (T4 and triiodothyronine (T3. Synthesis of Thyroid Hormones and Iodine Metabolism. Three iodine molecules are added to make triiodothyronine, and four for thyroxine - the two key hormones produced by the thyroid gland. Iodine deficiency. The proper daily amount of iodine is required for optimal thyroid function. Iodine deficiency can cause hypothyroidism, developmental brain disorders and goiter. Iodine deficiency is the single most common cause of preventable mental retardation and brain damage in the world. It also decreases child survival, causes goiters, and impairs growth and development. Iodine deficiency disorders in pregnant women cause miscarriages, stillbirths, and other complications. Children with iodine deficiency disorders can grow up stunted, apathetic, mentally retarded, and incapable of normal movements, speech or hearing. Excessive Iodine Intake. Excessive iodine intake, which can trigger autoimmune thyroid disease and dysfunction, is on the other side. Iodine use in Case of Nuclear Catastrophe. In addition to other severe consequences of radioactivity, high amount of radioactive iodine causes significant increase in incidence of thyroid gland carcinoma after some of the nuclear catastrophes (Hiroshima, Nagasaki, Chernobyl, Fukushima. The incidence of thyroid carcinoma was increased mostly in children. This paper was aimed at clarifying some of the possibilities of prevention according to the recommendations given by the World Health Organization.

  19. Relationship of Fault Geometry to Catastrophic Outflow on Mars

    Science.gov (United States)

    Davatzes, A.; Gulick, V.

    2006-12-01

    We present results from studies of large outflow channels on Mars that suggest fault morphology is a critical factor for the trapping and catastrophic release of water on Mars, resulting in large flooding events. On Earth, hot springs are commonly concentrated around fault relays, bends, and fault tips, where jointing forms in zones of concentrated stress promoting tensile failure. Examples of fault controlled hydrothermal activity have been documented in the Coso Geothermal Field in California, Southern Seismic Zone in Iceland, Waiotapu Geothermal Field in New Zealand, Killoran Fault in Ireland, and throughout the southwestern United States. On Earth, abrupt changes in the water table, as well as the formation of sand-boils and springs, are associated with earthquakes, and their spatial distribution is related to the geometry of the earthquake slip patch. A similar process may occur on Mars, where hydrothermal waters collect in highly fractured zones at fault relays, and are released catastrophically during an earthquake event. Two examples of large outflow channels on Mars, Mangala and Athabasca Valles, appear to be sourced in a relay zone. Other Martian examples show sourcing at fault bends and fault tips. Data from the instruments on Mars Reconnaissance Orbiter will help us to further understand this mechanism by which large flood events may occur. High resolution images from HiRISE will be used to map these fault systems and estimate outflow rates, and data from CRISM will be used to identify regions of past high temperature fluid flow on the surface of Mars.

  20. 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.

  1. Endocrine disrupters as obesogens.

    Science.gov (United States)

    Grün, Felix; Blumberg, Bruce

    2009-05-25

    The recent dramatic rise in obesity rates is an alarming global health trend that consumes an ever increasing portion of health care budgets in Western countries. The root cause of obesity is thought to be a prolonged positive energy balance. Hence, the major focus of preventative programs for obesity has been to target overeating and inadequate physical exercise. Recent research implicates environmental risk factors, including nutrient quality, stress, fetal environment and pharmaceutical or chemical exposure as relevant contributing influences. Evidence points to endocrine disrupting chemicals that interfere with the body's adipose tissue biology, endocrine hormone systems or central hypothalamic-pituitary-adrenal axis as suspects in derailing the homeostatic mechanisms important to weight control. This review highlights recent advances in our understanding of the molecular targets and mechanisms of action for these compounds and areas of future research needed to evaluate the significance of their contribution to obesity.

  2. Rituximab use in the catastrophic antiphospholipid syndrome: descriptive analysis of the CAPS registry patients receiving rituximab.

    Science.gov (United States)

    Berman, Horacio; Rodríguez-Pintó, Ignasi; Cervera, Ricard; Morel, Nathalie; Costedoat-Chalumeau, Nathalie; Erkan, Doruk; Shoenfeld, Yehuda; Espinosa, Gerard

    2013-09-01

    The catastrophic variant of the antiphospholipid syndrome (APS) is characterized by thrombosis in multiple organs developing over a short period of time. First-line treatment for the catastrophic APS is the combination of anticoagulation plus corticosteroids plus plasma exchange and/or intravenous immunoglobulin. Despite this regimen, the mortality remains high and new treatment options are needed. By a systematic review of the Catastrophic APS Registry (CAPS Registry), we identified 20 patients treated with rituximab. The purpose of this study is to describe the clinical manifestations, laboratory features, and outcomes of rituximab-treated CAPS patients. In addition, the rationale for using rituximab in catastrophic APS is discussed.

  3. 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.

  4. Pain Catastrophizing and Its Relationship with Health Outcomes: Does Pain Intensity Matter?

    Science.gov (United States)

    García-Palacios, Azucena; Botella, Cristina; Ribera-Canudas, Maria Victoria

    2017-01-01

    Pain catastrophizing is known to contribute to physical and mental functioning, even when controlling for the effect of pain intensity. However, research has yet to explore whether the strength of the relationship between pain catastrophizing and pain-related outcomes varies across pain intensity levels (i.e., moderation). If this was the case, it would have important implications for existing models of pain and current interventions. The present investigation explored whether pain intensity moderates the relationship between pain catastrophizing and pain-related outcomes. Participants were 254 patients (62% women) with heterogeneous chronic pain. Patients completed a measure of pain intensity, pain interference, pain catastrophizing, and physical and mental health. Pain intensity moderated the relationship between pain catastrophizing and pain interference and between pain catastrophizing and physical health status. Specifically, the strength of the correlation between pain catastrophizing and these outcomes decreased considerably as pain intensity increased. In contrast, pain intensity did not moderate the relationship between pain catastrophizing and mental health. Study findings provide a new insight into the role of pain intensity (i.e., moderator) in the relationship between pain catastrophizing and various pain-related outcomes, which might help develop existent models of pain. Clinical implications are discussed in the context of personalized therapy.

  5. Task Force on Catastrophic Antiphospholipid Syndrome (APS) and Non-criteria APS Manifestations (I): catastrophic APS, APS nephropathy and heart valve lesions.

    Science.gov (United States)

    Cervera, R; Tektonidou, M G; Espinosa, G; Cabral, A R; González, E B; Erkan, D; Vadya, S; Adrogué, H E; Solomon, M; Zandman-Goddard, G; Shoenfeld, Y

    2011-02-01

    The objectives of the 'Task Force on Catastrophic Antiphospholipid Syndrome (APS) and Non-criteria APS Manifestations' were to assess the clinical utility of the international consensus statement on classification criteria and treatment guidelines for the catastrophic APS, to identify and grade the studies that analyse the relationship between the antiphospholipid antibodies and the non-criteria APS manifestations and to present the current evidence regarding the accuracy of these non-criteria APS manifestations for the detection of patients with APS. This article summarizes the studies analysed on the catastrophic APS, APS nephropathy and heart valve lesions, and presents the recommendations elaborated by the Task Force after this analysis.

  6. The characteristics of railway service disruption: implications for disruption management.

    Science.gov (United States)

    Golightly, D; Dadashi, N

    2017-03-01

    Rail disruption management is central to operational continuity and customer satisfaction. Disruption is not a unitary phenomenon - it varies by time, cause, location and complexity of coordination. Effective, user-centred technology for rail disruption must reflect this variety. A repertory grid study was conducted to elicit disruption characteristics. Construct elicitation with a group of experts (n = 7) captured 26 characteristics relevant to rail disruption. A larger group of operational staff (n = 28) rated 10 types of rail incident against the 26 characteristics. The results revealed distinctions such as business impact and public perception, and the importance of management of the disruption over initial detection. There were clear differences between those events that stop the traffic, as opposed to those that only slow the traffic. The results also demonstrate the utility of repertory grid for capturing the characteristics of complex work domains. Practitioner Summary: The aim of the paper is to understand how variety in rail disruption influences socio-technical design. It uses repertory grid to identify and prioritise 26 constructs, and group 10 disruption types, identifying critical factors such as whether an incident stops or merely slows the service, and business reputation.

  7. 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.

  8. 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

  9. 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.

  10. Catastrophic Antiphospholipid Syndrome Presenting as Bilateral Central Retinal Artery Occlusions

    Directory of Open Access Journals (Sweden)

    Steven S. Saraf

    2015-01-01

    Full Text Available A previously healthy 22-year-old African American woman presented with bilateral vision loss associated with headache. Her ocular examination was significant for bilateral retinal arterial “boxcarring,” retinal whitening, retinal hemorrhages, and cherry red spots. She was diagnosed with bilateral central retinal artery occlusions and was hospitalized due to concomitant diagnosis of stroke and hypercoagulable state. She was also found to be in heart failure and kidney failure. Rheumatology was consulted and she was diagnosed with catastrophic antiphospholipid syndrome in association with systemic lupus erythematosus. Approximately 7 months after presentation, the patient’s vision improved and remained stable at 20/200 and 20/80.

  11. 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.

  12. 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...

  13. 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.

  14. 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...

  15. The role of infectious diseases in the catastrophic antiphospholipid syndrome.

    Science.gov (United States)

    Garcia-Carrasco, M; Mendoza-Pinto, C; Macias-Diaz, S; Vazquez de Lara, F; Etchegaray-Morales, I; Galvez-Romero, J L; Mendez-Martinez, S; Cervera, R

    2015-11-01

    Catastrophic antiphospholipid syndrome (CAPS), also called "Asherson syndrome", is a variant of the antiphospholipid syndrome (APS) that occurs in less than 1% of APS cases. The etiology of CAPS is uncertain; however, several triggering factors have been recognized. The most common of these are infectious diseases, particularly those of the respiratory tract. CAPS pathogenesis is incompletely understood, but several theories have been proposed, such as the molecular mimicry theory, which describes the production of anti-β2-glycoprotein I (GP1) antibody in response to infection. The process is complex and involves the activation of Toll-like receptor 4 (TLR-4), which triggers a cytokine storm, followed by endothelial alterations that induce a procoagulant state.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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...

  3. On the governance of global and catastrophic risks

    DEFF Research Database (Denmark)

    Faber, Michael Havbro

    2011-01-01

    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.......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...

  4. Improving Catastrophe Modeling for Business Interruption Insurance Needs.

    Science.gov (United States)

    Rose, Adam; Huyck, Charles K

    2016-10-01

    While catastrophe (CAT) modeling of property damage is well developed, modeling of business interruption (BI) lags far behind. One reason is the crude nature of functional relationships in CAT models that translate property damage into BI. Another is that estimating BI losses is more complicated because it depends greatly on public and private decisions during recovery with respect to resilience tactics that dampen losses by using remaining resources more efficiently to maintain business function and to recover more quickly. This article proposes a framework for improving hazard loss estimation for BI insurance needs. Improved data collection that allows for analysis at the level of individual facilities within a company can improve matching the facilities with the effectiveness of individual forms of resilience, such as accessing inventories, relocating operations, and accelerating repair, and can therefore improve estimation accuracy. We then illustrate the difference this can make in a case study example of losses from a hurricane.

  5. 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.

  6. 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.

  7. 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.

  8. Dynamic growth of slip surfaces in catastrophic landslides.

    Science.gov (United States)

    Germanovich, Leonid N; Kim, Sihyun; Puzrin, Alexander M

    2016-01-01

    This work considers a landslide caused by the shear band that emerges along the potential slip (rupture) surface. The material above the band slides downwards, causing the band to grow along the slope. This growth may first be stable (progressive), but eventually becomes dynamic (catastrophic). The landslide body acquires a finite velocity before it separates from the substrata. The corresponding initial-boundary value problem for a dynamic shear band is formulated within the framework of Palmer & Rice's (Proc. R. Soc. Lond. A332, 527-548. (doi:10.1098/rspa.1973.0040)) approach, which is generalized to the dynamic case. We obtain the exact, closed-form solution for the band velocity and slip rate. This solution assesses when the slope fails owing to a limiting condition near the propagating tip of the shear band. Our results are applicable to both submarine and subaerial landslides of this type. It appears that neglecting dynamic (inertia) effects can lead to a significant underestimation of the slide size, and that the volumes of catastrophic slides can exceed the volumes of progressive slides by nearly a factor of 2. As examples, we consider the Gaviota and Humboldt slides offshore of California, and discuss landslides in normally consolidated sediments and sensitive clays. In particular, it is conceivable that Humboldt slide is unfinished and may still displace a large volume of sediments, which could generate a considerable tsunami. We show that in the case of submarine slides, the effect of water resistance on the shear band dynamics may frequently be limited during the slope failure stage. For a varying slope angle, we formulate a condition of slide cessation.

  9. 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.

  10. Threshold proxy quantum signature scheme with threshold shared verification

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    A threshold proxy quantum signature scheme with threshold shared verification is proposed. An original signer could authorize a group as its proxy signers. Then only t or more of n persons in the proxy group can generate the proxy signature on behalf of the original signer and any t-1 or fewer ones cannot do that. When the proxy signature needs to be verified,any t or more of n persons belonging to the verification group can verify the message and any t-1 or fewer ones cannot verify the validity of the proxy signature.

  11. Further evidence for the super-catastrophic destruction of asteroids at small yet nontrivial perihelion distances

    Science.gov (United States)

    Granvik, Mikael

    2016-10-01

    For the past two decades or so the consensus in the near-Earth-object (NEO) community was that the majority of the NEOs are destroyed when they plunge into the Sun (Farinella et al. 1994, Nature 371, 314). There is now growing evidence suggesting that NEOs are completely destroyed at nontrivial distances from the Sun as proposed by Granvik et al. (2016, Nature 530, 303). The majority of meteor streams at small perihelion distances lack obvious parent bodies (Brown et al. 2010, Icarus 207, 66), potentially suggesting that the remaining fragments are too small to be telescopically detected from the Earth. Furthermore, orbital estimates for meter-scale Earth-impactors based on airburst observations show that the space interior to the orbit of Mercury is essentially void of objects in that size range and this cannot be explained by observational selection effects (Brown et al. 2016, Icarus 266, 96). This suggest that the remaining fragments must be substantially less than one meter in diameter. The mechanism(s) that could cause such a complete destruction of the parent asteroid is currently not well understood. The analysis by Granvik et al. (2016) found that smaller NEOs are destroyed at larger distances and that the albedo estimates by NEOWISE imply that NEOs with low albedos are destroyed at larger distances compared to their high-albedo counterparts. The discovery of the first asteroid in the process of being destroyed (Knight et al. 2016, ApJL 823(1), L6) and an ongoing observation campaign targeting NEOs at small perihelion distances will hopefully lead to further insight regarding the destruction mechanism. I will synthesize what is currently known about the destruction of asteroids at small perihelion distances, and explain how these super-catastrophic disruptions may be used to statistically constrain the interior structure of asteroids.

  12. Inhibition of PLK1 in glioblastoma multiforme induces mitotic catastrophe and enhances radiosensitization

    Science.gov (United States)

    Tandle, Anita T.; Kramp, Tamalee; Kil, Whoon J; Halthore, Aditya; Gehlhaus, Kristen; Shankavaram, Uma; Tofilon, Philip J.; Caplen, Natasha J.; Camphausen, Kevin

    2013-01-01

    Glioblastoma multiforme (GBM) is the most common primary brain tumor in the USA with a median survival of approximately 14 months. Low survival rates are attributable to the aggressiveness of GBM and a lack of understanding of the molecular mechanisms underlying GBM. The disruption of signaling pathways regulated either directly or indirectly by protein kinases is frequently observed in cancer cells and thus the development of inhibitors of specific kinases has become a major focus of drug discovery in oncology. To identify protein kinases required for the survival of GBM we performed a siRNA-based RNAi screen focused on the human kinome in GBM. Inhibition of the polo-like kinase 1 (PLK1) induced a reduction in the viability in two different GBM cell lines. To assess the potential of inhibiting PLK1 as a treatment strategy for GBM we examined the effects of a small molecule inhibitor of PLK1, GSK461364A, on the growth of GBM cells. PLK1 inhibition arrested cells in the mitotic phase of the cell cycle and induced cell kill by mitotic catastrophe. GBM engrafts treated with GSK461364A showed statistically significant inhibition of tumor growth. Further, exposure of different GBM cells to RNAi or GSK461364A prior to radiation resulted in an increase in their radiosensitivity with dose enhancement factor ranging from 1.40 to 1.53 with no effect on normal cells. As a measure of DNA double strand breaks, γH2AX levels were significantly higher in the combined modality as compared to the individual treatments. This study suggests that PLK1 is an important therapeutic target for GBM and can enhance radiosensitivity in GBM. PMID:23790466

  13. Inhibition of polo-like kinase 1 in glioblastoma multiforme induces mitotic catastrophe and enhances radiosensitisation.

    Science.gov (United States)

    Tandle, Anita T; Kramp, Tamalee; Kil, Whoon J; Halthore, Aditya; Gehlhaus, Kristen; Shankavaram, Uma; Tofilon, Philip J; Caplen, Natasha J; Camphausen, Kevin

    2013-09-01

    Glioblastoma multiforme (GBM) is the most common primary brain tumour in the United States of America (USA) with a median survival of approximately 14 months. Low survival rates are attributable to the aggressiveness of GBM and a lack of understanding of the molecular mechanisms underlying GBM. The disruption of signalling pathways regulated either directly or indirectly by protein kinases is frequently observed in cancer cells and thus the development of inhibitors of specific kinases has become a major focus of drug discovery in oncology. To identify protein kinases required for the survival of GBM we performed a siRNA-based RNAi screen focused on the human kinome in GBM. Inhibition of the polo-like kinase 1 (PLK1) induced a reduction in the viability in two different GBM cell lines. To assess the potential of inhibiting PLK1 as a treatment strategy for GBM we examined the effects of a small molecule inhibitor of PLK1, GSK461364A, on the growth of GBM cells. PLK1 inhibition arrested cells in the mitotic phase of the cell cycle and induced cell kill by mitotic catastrophe. GBM engrafts treated with GSK461364A showed statistically significant inhibition of tumour growth. Further, exposure of different GBM cells to RNAi or GSK461364A prior to radiation resulted in an increase in their radiosensitivity with dose enhancement factor ranging from 1.40 to 1.53 with no effect on normal cells. As a measure of DNA double strand breaks, γH2AX levels were significantly higher in the combined modality as compared to the individual treatments. This study suggests that PLK1 is an important therapeutic target for GBM and can enhance radiosensitivity in GBM.

  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. Spatial structure induced by marine reserves shapes population responses to catastrophes in mathematical models.

    Science.gov (United States)

    McGilliard, Carey R; Punt, André E; Hilborn, Ray

    2011-06-01

    Catastrophic events such as oil spills, hypoxia, disease, and major predation events occur in marine ecosystems and affect fish populations. Previous evaluations of the performance of spatial management alternatives have not considered catastrophic events. We investigate the effects of local and global catastrophic events on populations managed with and without no-take marine reserves and with fishing mortality rates that are optimized accounting for reserves. A spatial population dynamics model is used to explore effects of large, catastrophic natural mortality events. The effects of the spatial spread, magnitude, probability of catastrophe, and persistence of a catastrophic event through time are explored. Catastrophic events affecting large spatial areas and those that persist through time have the greatest effects on population dynamics because they affect natural mortality nonlinearly, whereas the probability and magnitude of catastrophic events result in only linear increases in natural mortality. The probability of falling below 10% or 20% of unfished abundance was greatest when a no-take marine reserve was implemented with no additional fishing regulations and least when a no-take marine reserve was implemented in addition to the maintenance of optimal fishing mortality in fished areas. In the absence of implementation error, maintaining abundance across space using restrictions on fishing mortality rates, regardless of the existence of a no-take marine reserve, decreased the probability of falling below 10% or 20% of unfished abundance.

  16. 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.

  17. 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…

  18. 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...

  19. 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

  20. 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

  1. 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...

  2. 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.

  3. 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.

  4. 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...

  5. Effects of Accelerated Aging on Fiber Damage Thresholds

    Energy Technology Data Exchange (ETDEWEB)

    Setchell, R.E.

    1999-02-15

    Laser-induced damage mechanisms that can occur during high-intensity fiber transmission have been under study for a number of years. Our particular interest in laser initiation of explosives has led us to examine damage processes associated with the transmission of Q-switched, Nd:YAG pulses at 1.06 {micro}m through step-index, multimode, fused silica fiber. Laser breakdown at the fiber entrance face is often the first process to limit fiber transmission but catastrophic damage can also occur at either fiber end face, within the initial entry segment of the fiber, and at other internal sites along the fiber path. Past studies have examined how these various damage mechanisms depend upon fiber end-face preparation, fiber fixturing and routing, laser characteristics, and laser-to-fiber injection optics. In some applications of interest, however, a fiber transmission system may spend years in storage before it is used. Consequently, an important additional issue for these applications is whether or not there are aging processes that can result in lower damage thresholds over time. Fiber end-face contamination would certainly lower breakdown and damage thresholds at these surfaces, but careful design of hermetic seals in connectors and other end-face fixtures can minimize this possibility. A more subtle possibility would be a process for the slow growth of internal defects that could lead to lower thresholds for internal damage. In the current study, two approaches to stimulating the growth of internal defects were used in an attempt to produce observable changes in internal damage thresholds. In the first approach test fibers were subjected to a very high tensile stress for a time sufficient for some fraction to fail from static fatigue. In the second approach, test fibers were subjected to a combination of high tensile stress and large, cyclic temperature variations. Both of these approaches were rather arbitrary due to the lack of an established growth mechanism for

  6. Precursory landforms and geologic structures of catastrophic landslides induced by typhoon Talas 2011 Japan (Invited)

    Science.gov (United States)

    Chigira, M.; Matsushi, Y.; Tsou, C.

    2013-12-01

    Our experience of catastrophic landslides induced by rainstorms and earthquakes in recent years suggests that many of them are preceded by deep-seated gravitational slope deformation. Deep-seated gravitational slope deformation continues slowly and continually and some of them transform into catastrophic failures, which cause devastating damage in wide areas. Some other types, however, do not change into catastrophic failure. Deep-seated gravitational slope deformation that preceded catastrophic failures induced by typhoon Talas 2011 Japan, had been surveyed with airborne laser scanner beforehand, of which high-resolution DEMs gave us an important clue to identify which type of topographic features of gravitational slope deformation is susceptible to catastrophic failure. We found that 26 of 39 deep-seated catastrophic landslides had small scarps along the heads of future landslides. These scarps were caused by gravitational slope deformation that preceded the catastrophic failure. Although the scarps may have been enlarged by degradation, their sizes relative to the whole slopes suggest that minimal slope deformation had occurred in the period immediately before the catastrophic failure. The scarp ratio, defined as the ratio of length of a scarp to that of the whole slope both measured along the slope line, ranged from 1% to 23%. 38% of the landslides with small scarps had scarp ratios less than 4%, and a half less than 8%. This fact suggests that the gravitational slope deformation preceded catastrophic failure was relatively small and may suggest that those slopes were under critical conditions just before catastrophic failure. The above scarp ratios may be characteristic to accretional complex with undulating, anastomosing thrust faults, which were major sliding surfaces of the typhoon-induced landslides. Eleven of the remaining 13 landslides occurred in landslide scars of previous landslides or occurred as an extension of landslide scars at the lower parts of

  7. 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.

  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. 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.

  10. Parent Pain and Catastrophizing Are Associated With Pain, Somatic Symptoms, and Pain-Related Disability Among Early Adolescents

    OpenAIRE

    Wilson, Anna C; Moss, Ashley; Palermo, Tonya M.; Fales, Jessica L.

    2013-01-01

    Objective To examine associations between parental history of pain and catastrophizing and their adolescent’s pain, somatic symptoms, catastrophizing, and disability. Methods Participants included 178 youths aged 11–14 years recruited through public schools. Adolescents completed measures assessing pain characteristics, somatic symptoms, and pain catastrophizing. Parents reported on their own pain, and catastrophizing about their adolescent’s pain. Results About one quarter of the adolescents...

  11. 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...

  12. 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...

  13. Tidal disruption of inviscid protoplanets

    Science.gov (United States)

    Boss, Alan P.; Cameron, A. G. W.; Benz, W.

    1991-01-01

    Roche showed that equilibrium is impossible for a small fluid body synchronously orbiting a primary within a critical radius now termed the Roche limit. Tidal disruption of orbitally unbound bodies is a potentially important process for planetary formation through collisional accumulation, because the area of the Roche limit is considerably larger then the physical cross section of a protoplanet. Several previous studies were made of dynamical tidal disruption and different models of disruption were proposed. Because of the limitation of these analytical models, we have used a smoothed particle hydrodynamics (SPH) code to model the tidal disruption process. The code is basically the same as the one used to model giant impacts; we simply choose impact parameters large enough to avoid collisions. The primary and secondary both have iron cores and silicate mantles, and are initially isothermal at a molten temperature. The conclusions based on the analytical and numerical models are summarized.

  14. 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

  15. Threshold enhancement of diphoton resonances

    Directory of Open Access Journals (Sweden)

    Aoife Bharucha

    2016-10-01

    Full Text Available 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 12MA threshold and a small decay width, <1 MeV. 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 loops of charginos with masses close to 12MA and ii a two Higgs doublet model in which A is again produced by gluon fusion but decays into photons through loops of vector-like charged heavy leptons. In both these scenarios, while the mass of the charged fermion has to be adjusted to be extremely close to half of the A resonance mass, the small total widths are naturally obtained if only suppressed three-body decay channels occur. Finally, the implications of some of these scenarios for dark matter are discussed.

  16. 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…

  17. 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...

  18. Disruptive innovation: the demand side.

    Science.gov (United States)

    Havighurst, Clark C

    2008-01-01

    The notion of disruptive innovation provides a welcome framework for considering the prospects for low-cost alternatives in American medicine. Such innovations as have been seen, however, are largely the result of demand by patients paying their own bills because they have high-deductible coverage or are uninsured. Many other cost-saving innovations are discouraged by financing systems that are themselves largely immune to competition from disruptive innovators.

  19. 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...

  20. 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

  1. Experimental reduction of pain catastrophizing modulates pain report but not spinal nociception as verified by mediation analyses.

    Science.gov (United States)

    Terry, Ellen L; Thompson, Kathryn A; Rhudy, Jamie L

    2015-08-01

    Pain catastrophizing is associated with enhanced pain; however, the mechanisms by which it modulates pain are poorly understood. Evidence suggests that catastrophizing modulates supraspinal processing of pain but does not modulate spinal nociception (as assessed by nociceptive flexion reflex [NFR]). Unfortunately, most NFR studies have been correlational. To address this, this study experimentally reduced catastrophizing to determine whether it modulates spinal nociception (NFR). Healthy pain-free participants (N = 113) were randomly assigned to a brief 30-minute catastrophizing reduction manipulation or a control group that received pain education. Before and after manipulations, 2 types of painful stimuli were delivered to elicit (1) NFR (single trains of stimuli) and (2) temporal summation of NFR (3 stimulations at 2 Hz). After each set of stimuli, participants were asked to report their pain intensity and unpleasantness, as well as their situation-specific catastrophizing. Manipulation checks verified that catastrophizing was effectively reduced. Furthermore, pain intensity and unpleasantness to both stimulation types were reduced by the catastrophizing manipulation, effects that were mediated by catastrophizing. Although NFRs were not affected by the catastrophizing manipulation, temporal summation of NFR was reduced. However, this effect was not mediated by catastrophizing. These results indicate that reductions in catastrophizing lead to reductions in pain perception but do not modulate spinal nociception and provides further evidence that catastrophizing modulates pain at the supraspinal, not the spinal, level.

  2. Second Order Catalytic Quasispecies Yields Discontinuous Mean Fitness at Error Threshold

    Science.gov (United States)

    Wagner, Nathaniel; Tannenbaum, Emmanuel; Ashkenasy, Gonen

    2010-05-01

    The quasispecies model describes processes related to the origin of life and viral evolutionary dynamics. We discuss how the error catastrophe that reflects the transition from localized to delocalized quasispecies population is affected by catalytic replication of different reaction orders. Specifically, we find that second order mechanisms lead to a discontinuity in the mean fitness of the population at the error threshold. This is in contrast to the behavior of the first order, autocatalytic replication mechanism considered in the standard quasispecies model. This suggests that quasispecies models with higher order replication mechanisms produce discontinuities in the mean fitness, and hence the viable population fraction as well, at the error threshold, while lower order replication mechanisms yield a continuous mean fitness function. We discuss potential implications for understanding replication in the RNA world and in virology.

  3. [2016 review on catastrophic antiphospholipid syndrome].

    Science.gov (United States)

    Costedoat-Chalumeau, Nathalie; Coutte, Laetitia; Le Guern, Véronique; Morel, Nathalie; Leroux, Gaelle; Paule, Romain; Mouthon, Luc; Piette, Jean-Charles

    2016-12-01

    The catastrophic antiphospholipid syndrome (CAPS) develops in at least 1% of patients with antiphospholipid syndrome, either primary or associated with systemic lupus erythematosus. CAPS reveals the antiphospholipid syndrome in about 50% of cases. The CAPS is characterized by rapidly-progressive widespread thromboses mainly affecting the microvasculature in the presence of antiphospholipid antibodies. In a few days, the patients develop multiorgan failure with renal insufficiency with severe hypertension, pulmonary, cerebral, cardiac, digestive and/or cutaneous involvement. The vital prognosis is frequently engaged. CAPS is often precipitated by infectious diseases, surgical procedures and/or withdrawal or modification of the anticoagulation. CAPS overall mortality rate has decreased and is currently below 30%. The main differential diagnoses are other thrombotic microangiopathies, and heparin-induced thrombocytopenia. The treatment of CAPS consists of the association of anticoagulation and steroids, plus plasma exchange and/or intravenous immunoglobulins. Cyclophosphamide is added only in patients with active systemic lupus erythematosus. The potential contribution of some additional therapies (rituximab, eculizumab or sirolimus) needs to be assessed. The prevention of CAPS is essential and is based upon the adequate management of the perioperative period when surgery cannot be avoided, the prompt treatment and the prevention with immunization of infections and the education of patients with antiphospholipid syndrome, especially for the management of oral anticoagulants.

  4. 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.

  5. A depth refugium from catastrophic coral bleaching prevents regional extinction.

    Science.gov (United States)

    Smith, Tyler B; Glynn, Peter W; Maté, Juan L; Toth, Lauren T; Gyory, Joanna

    2014-06-01

    Species intolerant of changing climate might avoid extinction within refugia buffered from extreme conditions. Refugia have been observed in the fossil record but are not well documented or understood on ecological time scales. Using a 37-year record from the eastern Pacific across the two most severe El Niño events on record (1982-1983 and 1997 1998) we show how an exceptionally thermally sensitive reef-building hydrocoral, Millepora intricata, twice survived catastrophic bleaching in a deeper-water refuge (> 11 m depth). During both events, M. intricata was extirpated across its range in shallow water, but showed recovery within several years, while two other hydrocorals without deep-water populations were driven to regional extinction. Evidence from the subfossil record in the same area showed shallow-water persistence of abundant M. intricata populations from 5000 years ago, through severe El Niño-Southern Oscillation cycles, suggesting a potential depth refugium on a millennial timescale. Our data confirm the deep refuge hypothesis for corals under thermal stress.

  6. Role of senescence and mitotic catastrophe in cancer therapy

    Directory of Open Access Journals (Sweden)

    Shukla Yogeshwer

    2010-01-01

    Full Text Available Abstract Senescence and mitotic catastrophe (MC are two distinct crucial non-apoptotic mechanisms, often triggered in cancer cells and tissues in response to anti-cancer drugs. Chemotherapeuticals and myriad other factors induce cell eradication via these routes. While senescence drives the cells to a state of quiescence, MC drives the cells towards death during the course of mitosis. The senescent phenotype distinguishes tumor cells that survived drug exposure but lost the ability to form colonies from those that recover and proliferate after treatment. Although senescent cells do not proliferate, they are metabolically active and may secrete proteins with potential tumor-promoting activities. The other anti-proliferative response of tumor cells is MC that is a form of cell death that results from abnormal mitosis and leads to the formation of interphase cells with multiple micronuclei. Different classes of cytotoxic agents induce MC, but the pathways of abnormal mitosis differ depending on the nature of the inducer and the status of cell-cycle checkpoints. In this review, we compare the two pathways and mention that they are activated to curb the growth of tumors. Altogether, we have highlighted the possibilities of the use of senescence targeting drugs, mitotic kinases and anti-mitotic agents in fabricating novel strategies in cancer control.

  7. On growth rate hysteresis and catastrophic crystal growth

    Science.gov (United States)

    Ferreira, Cecília; Rocha, Fernando A.; Damas, Ana M.; Martins, Pedro M.

    2013-04-01

    Different crystal growth rates as supersaturation is increasing or decreasing in impure media is a phenomenon called growth rate hysteresis (GRH) that has been observed in varied systems and applications, such as protein crystallization or during biomineralization. We have recently shown that the transient adsorption of impurities onto newly formed active sites for growth (or kinks) is sensitive to the direction and rate of supersaturation variation, thus providing a possible explanation for GRH [6]. In the present contribution, we expand on this concept by deriving the analytical expressions for transient crystal growth based on the energetics of growth hillock formation and kink occupation by impurities. Two types of GRH results are described according to the variation of kink density with supersaturation: for nearly constant density, decreasing or increasing supersaturation induce, respectively, growth promoting or inhibiting effects relative to equilibrium conditions. This is the type of GRH measured by us during the crystallization of egg-white lysozyme. For variable kink density, slight changes in the supersaturation level may induce abrupt variations in the crystal growth rate. Different literature examples of this so-called 'catastrophic' crystal growth are discussed in terms of their fundamental consequences.

  8. Catastrophic antiphospholipid syndrome with concurrent thrombotic and hemorrhagic manifestations.

    Science.gov (United States)

    Rangel, M L; Alghamdi, I; Contreras, G; Harrington, T; Thomas, D B; Barisoni, L; Andrews, D; Wolf, M; Asif, A; Nayer, A

    2013-07-01

    Antiphospholipid syndrome (APS) is a distinct autoimmune prothrombotic disorder due to pathogenic autoantibodies directed against proteins that bind to phospholipids. APS is characterized by arterial and venous thrombosis and their clinical sequelae. Catastrophic antiphospholipid syndrome (CAPS) is a rare and often fatal form of APS characterized by disseminated intravascular thrombosis and ischemic injury resulting in multiorgan failure. Rarely, intravascular thrombosis in CAPS is accompanied by hemorrhagic manifestations such as diffuse alveolar hemorrhage. Here, we report a 43-year-old woman who presented with anemia, acute gastroenteritis, abnormal liver function tests, bilateral pulmonary infiltrates, and a systemic inflammatory response syndrome. The patient developed respiratory failure as a result of diffuse alveolar hemorrhage followed by acute renal failure. Laboratory tests disclosed hematuria, proteinuria, and reduced platelet count. Microbiologic tests were negative. A renal biopsy demonstrated acute thrombotic microangiopathy and extensive interstitial hemorrhage. Serologic tests disclosed antinuclear antibodies and reduced serum complement C4 concentration. Coagulation studies revealed the lupus anticoagulant and autoantibodies against cardiolipin, beta 2-glycoprotein I, and prothrombin. High-dose glucocorticoids and plasma exchange resulted in rapid resolution of pulmonary, renal, and hematological manifestations. This rare case emphasizes that CAPS can present with concurrent thrombotic and hemorrhagic manifestations. Rapid diagnosis and treatment may result in complete recovery.

  9. Investigating the outcomes of SPH models of catastrophic destruction

    Science.gov (United States)

    Dell'Oro, A.; Cellino, A.; Paolicchi, P.; Tanga, P.

    Smooth particle hydro-dynamics (SPH) codes have proved able to simulate satisfactorily the shattering processes in high-energy collisions among asteroids, reproducing the major observational evidences. In particular, SPH models reproduce fairly well the size distributions of the members of some asteroid families. A considerable difference between SPH models and Semi-Empirical Models (SEM) is that in the former the asteroids are ground up into very small fragments, the size of which is limited by the resolution of the code. Moreover, the subsequent ballistic dynamical evolution, driven by their mutual gravitational attraction, would result in a significant re-accumulation into many bodies. On the contrary, ejection velocity fields predicted by SEM allow the reaccumulation into very few bodies, sometimes only the largest remnant. This difference is a critical issue for the interpretation of the observational data in order to understand the physics of the catastrophic destruction process, and the physical characteristics of the asteroids themselves. We present a new analysis of some SPH velocity fields aiming to shed light on the intrinsic differences between SPH models and SEMs.

  10. 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.

  11. Catastrophic rockfalls and rockslides in the Sierra Nevada, USA

    Science.gov (United States)

    Wieczorek, Gerald F.; Evans, Stephen G.; DeGraff, Jerome V.

    2002-01-01

    Despite having a low recorded historical incidence of landsliding, the Sierra Nevada has undergone large prehistoric and historical rockfalls and rockslides that could be potentially catastrophic if they occurred today in the more densely populated parts of the region. Several large documented rockfall and rockslides have been triggered either by strong seismic shaking or long periods of unusually wet weather; however, in several instances no obvious triggering event can be identified. The glaciated topography of the higher elevations of the SierraNevada has produced many relatively small falls and slides within relatively hard, massively jointed, granitic rocks; however, where exposed to weathering for long periods after glaciation, the oversteepened rock slopes are prone to uncommonly large falls and slides. At lower elevations on the nonglaciated slopes of the Sierra Nevada, rockslides commonly occur within more weathered granitic rocks, where the strength of the rock mass is typically affected by joint weathering and alteration of the intact rock to saprolite. Historical large rock-falls and rockslides in the Sierra Nevada have created additional secondary natural hazards, including debris flows and floods from the breaching of landslide dams that can be as hazardous as the initial rockfalls and rockslides.

  12. 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.

  13. Chromothripsis: how does such a catastrophic event impact human reproduction?

    Science.gov (United States)

    Pellestor, Franck

    2014-03-01

    The recent discovery of a new kind of massive chromosomal rearrangement, baptized chromothripsis (chromo for chromosomes, thripsis for shattering into pieces), greatly modifies our understanding of molecular mechanisms implicated in the repair of DNA damage and the genesis of complex chromosomal rearrangements. Initially described in cancers, and then in constitutional rearrangements, chromothripsis is characterized by the shattering of one (or a few) chromosome(s) segments followed by a chaotic reassembly of the chromosomal fragments, occurring during one unique cellular event. The diversity and the high complexity of chromothripsis events raise questions about their origin, their ties to chromosome instability and their impact in pathology. Several causative mechanisms, involving abortive apoptosis, telomere erosion, mitotic errors, micronuclei formation and p53 inactivation, have been proposed. The remarkable point is that all these mechanisms have been identified in the field of human reproduction as causal factors for reproductive failures and chromosomal abnormalities. Consequently, it seems important to consider this unexpected catastrophic phenomenon in the context of fertilization and early embryonic development in order to discuss its potential impact on human reproduction.

  14. 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.

  15. 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.

  16. Catastrophe models and the expansion method: A review of issues and an application to the econometric modeling of economic growth

    Directory of Open Access Journals (Sweden)

    Emilio Casetti

    1997-01-01

    Full Text Available Many negative reactions to Catastrophe Theory have been triggered by overly simplistic applications unintended and unsuited for statistical-econometric estimation, inference, and testing. In this paper it is argued that stochastic catastrophe models constructed using the Expansion Method hold the most promise to widen the acceptance of Catastrophe Theory by analytically oriented scholars in the social sciences and elsewhere. The paper presents a typology of catastrophe models, and demonstrates the construction and estimation of an econometric expanded cusp catastrophe model of economic growth.

  17. 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 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...... reaction to cobalt. A logistic dose-response model was applied to data collected from the published literature to estimate ED values. The 95% confidence interval (CI) for the ratio of mean doses that can elicit a reaction in 10% (ED(10)) of a population was calculated with Fieller's method. RESULTS...

  18. Online Education Cast as "Disruptive Innovation"

    Science.gov (United States)

    Totter, Andrew

    2008-01-01

    Technology-based forces of "disruptive innovation" are gathering around public education and will overhaul the way K-12 students learn--with potentially dramatic consequences for established public schools, according to an upcoming book that draws parallels to disruptions in other industries. In his "Disrupting Class: How Disruptive Innovation…

  19. 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, photons predominantly through loops of charginos with masses close to 1/2MA and ii) a two Higgs doublet model in which A is again produced by gluon fusion but decays into photons through loops of vector-like charged heavy leptons. In both these scenarios, while the mass of the charged fermion has to be adjusted to be extremely close to half of the A resonance mass, the small total widths are naturally obtained if only suppressed three-body decay channels occur. Finally, the implications of some of these scenarios for dark matter are discussed.

  20. 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.

  1. 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.

  2. 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.

  3. Study on Catastrophic Air Current Early-warning and Control System of Coalmines

    Directory of Open Access Journals (Sweden)

    L.F. Fang

    2016-02-01

    Full Text Available Catastrophic air current significantly influences the stability of ventilation system, and existing studies have not considered the flow characteristics of catastrophic air current when designing the control systems. To analyze the effects of different kinds of coalmine accidents on safety production, grey relation entropy theory was used to analyze the hazard assessment of coalmine accidents. Fluent software was employed to study the flow characteristics of catastrophic air current, and the catastrophic air current early-warning and control system of coalmine was researched according to the theoretical analysis and numerical simulation. The threat of fire accidents and roof accidents were larger than other accidents. The influence of temperature and CO volume fraction distribution of fire accidents to the tailwind side was larger than that of the weather side, and gradient decreased on the weather side. This system can effectively control the spread of fire and poisonous gas,

  4. The role of positive traits and pain catastrophizing in pain perception.

    Science.gov (United States)

    Pulvers, Kim; Hood, Anna

    2013-05-01

    A variety of biological, psychological, and social factors interact to influence pain. This article focuses on two distinct, but connected, psychological factors--positive personality traits and pain catastrophizing--and their link with pain perception in healthy and clinical populations. First, we review the protective link between positive personality traits, such as optimism, hope, and self-efficacy, and pain perception. Second, we provide evidence of the well-established relationship between pain catastrophizing and pain perception and other related outcomes. Third, we outline the inverse relationship between positive traits and pain catastrophizing, and offer a model that explains the inverse link between positive traits and pain perception through lower pain catastrophizing. Finally, we discuss clinical practice recommendations based on the aforementioned relationships.

  5. Tidal disruption of inviscid planetesimals

    Science.gov (United States)

    Boss, A. P.; Cameron, A. G. W.; Benz, W.

    1991-01-01

    In view of previous efforts' demonstration that strongly dissipative planetesimals are immune to tidal disruption, an examination is presently conducted of the complementary case of inviscid planetesimals arising from collisions that are sufficiently energetic to entirely melt the resulting planetesimal and debris. The tidal disruption is numerically simulated by means of the smoothed particle hydrodynamics (SPH) code of Cameron and Benz (1991), concentrating on the tidal disruption of 0.01 earth-mass planetesimals passing by the earth with variations in the impact parameter at perigee and velocity at infinity. The SPH models show that tidal forces during a close encounter can efficiently convert orbital angular momentum into spin angular momentum, thereby initiating equatorial mass-shedding to inviscid planetesimals that have been spun up beyond the limit of rotational stability.

  6. Pediatric catastrophic antiphospholipid syndrome: descriptive analysis of 45 patients from the "CAPS Registry".

    Science.gov (United States)

    Berman, Horacio; Rodríguez-Pintó, Ignasi; Cervera, Ricard; Gregory, Simone; de Meis, Ernesto; Rodrigues, Carlos Ewerton Maia; Aikawa, Nádia Emi; de Carvalho, Jozélio Freire; Springer, Janusz; Niedzwiecki, Maciej; Espinosa, Gerard

    2014-02-01

    Given the lack of information about catastrophic antiphospholipid syndrome (APS) in pediatric patients, the objective of the current study was to describe the clinical characteristics, laboratory features, treatment, and outcome of pediatric patients with catastrophic APS and compare them with the adult patients with catastrophic APS. We identified patients who were under 18years of age at time of catastrophic APS diagnosis included in the international registry of patients with catastrophic APS (CAPS Registry). Their main demographic and clinical characteristics, laboratory features, treatment, and outcome were described and compared with those of adult patients with catastrophic APS. From the 446 patients included in the CAPS Registry as of May 2013, 45 (10.3%) patients developed 46 catastrophic events before 18years of age (one patient presented two episodes). Overall, 32 (71.1%) patients were female and the mean age was 11.5±4.6years (range, 3months-18years). A total of 31 (68.9%) patients suffered from primary APS and 13 (28.9%) from systemic lupus erythematosus (SLE). The main differences between the two groups of patients were the higher prevalence of infections as precipitating factor for catastrophic event in the pediatric population (60.9% versus 26.8% in the adult population, p<0.001) and of peripheral vessel thrombosis (52.2% versus 34.3%, p=0.017). In addition, catastrophic APS was the first manifestation of APS more frequently in pediatric patients (86.6% versus 45.2%, p<0.001). Interestingly, pediatric patients showed a trend of lower mortality, although the difference was not statistically significant (26.1% versus 40.2%; odds ratio, 1.9; 95% confidence interval, 0.96-3.79; p=0.063). No differences were found neither in the laboratory features nor in the isolated or combination treatments between groups. Catastrophic APS in pediatric patients is a rare disease. There are minimal differences in the clinical and laboratory features, treatment, and

  7. 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

  8. DISRUPTIVE BEHAVIOUR AMONGST DOCTORS, MYTH OR REALITY?

    OpenAIRE

    Avtar Singh

    2014-01-01

    BACKGROUND : Disruptive behavior in a medical setting is defined as objectionable or offensive interpersonal behavior that leads to disruption of professional activities in the workplace. 1 It has been observed that majority of doctors do not show disruptive behavior in their day today conduct and only few doctors are identified for their disruptive behavior . Special commi ttee on professional conduct and ethics defines disruptive behavio...

  9. 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.

  10. Floating worlds and their phantoms in the aftermath of social catastrophes.

    Science.gov (United States)

    Kimbles, Samuel

    2017-02-01

    In this paper the author describes certain kinds of images (phantoms) that appear in the aftermath of social catastrophes. These phantoms come with an underlying narrative structure, which the author describes as phantom narratives. Phantom narratives show how the unconscious, working at the group and individual levels, provides political and social contexts within which the individual may find a different kind of containment for these catastrophes. In this way their suffering may be potentially processed psychologically and related to symbolically.

  11. Metacognitive beliefs moderate the relationship between catastrophic misinterpretation and health anxiety.

    Science.gov (United States)

    Bailey, Robin; Wells, Adrian

    2015-08-01

    Catastrophic misinterpretations of bodily symptoms have a central role in cognitive-behavioural models of health anxiety. However, the metacognitive (S-REF) model postulates that psychological disturbance is linked more to beliefs about thinking i.e., metacognition. Equally the relationship between catastrophic misinterpretation and health anxiety should be moderated by metacognition, in particular negative beliefs about the uncontrollability and danger of thinking (MCQNeg). Participants (N = 351) completed measures to examine the relationship between these variables. Results indicated positive relationships between metacognition, catastrophic misinterpretation, and health anxiety. Moderation analysis showed that the effect of catastrophic misinterpretations on health anxiety was explained by the proposed interaction with metacognition. Follow-up regression analysis demonstrated the interaction term explained variance in health anxiety when controlling for other variables, and was a stronger unique predictor of health anxiety than catastrophic misinterpretation. Metacognition appears to be an important factor in the relationship between catastrophic misinterpretation and health anxiety, and would have important implications for existing models and treatment.

  12. 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

  13. 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.

  14. 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...

  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. Threshold Effects And Perturbative Unification

    CERN Document Server

    Bastero-Gil, M; Pérez-Mercader, J

    1995-01-01

    We discuss the effect of the renormalization procedure in the computation of the unification point for running coupling constants. We explore the effects of threshold--crossing on the $\\beta$--functions. We compute the running of the coupling constants of the Standard Model, between $m_Z$ and $M_P$, using a mass dependent subtraction procedure, and then compare the results with $\\bar{MS}$, and with the $\\theta$-- function approximation. We also do this for the Minimal Supersymmetric extension of the Standard Model. In the latter, the bounds on susy masses that one obtains by requiring perturbative unification are dependent, to some extent, on the procedure.

  17. Circular threshold quantum secret sharing

    Institute of Scientific and Technical Information of China (English)

    Yang Yu-Guang; Wen Qiao-Yan

    2008-01-01

    This paper proposes a circular threshold quantum secret sharing (TQSS) scheme with polarized single photons.A polarized single photon sequence runs circularly among any t or more of n parties and any t or more of n parties can reconstruct the secret key when they collaborate.It shows that entanglement is not necessary for quantum secret sharing.Moreover,the theoretic efficiency is improved to approach 100% as the single photons carrying the secret key are deterministically forwarded among any t or more of n parties,and each photon can carry one bit of information without quantum storage.This protocol is feasible with current technology.

  18. Jogging Can Modify Disruptive Behaviors.

    Science.gov (United States)

    Allen, Jill I.

    1980-01-01

    Jogging was used to modify disruptive behavior as part of the classroom routine for 12 learning disabled elementary-grade boys. The number of incidents of each of five negative behaviors were reduced by half following the 10-minute jogging routine. (SBH)

  19. Strategic network disruption and defence

    NARCIS (Netherlands)

    Hoyer, Britta; De Jaegher, K.J.M.

    2016-01-01

    We study a game between a network designer, who uses costly links to connect nodes in a network, and a network disruptor who tries to disrupt the resulting network as much as possible by deleting either nodes or links. For low linking costs networks with all nodes in symmetric positions are a best r

  20. 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…

  1. Magnetic contrast in threshold photoemission electron microscopy

    NARCIS (Netherlands)

    Veghel, Marinus Godefridus Adrianus van

    2004-01-01

    In threshold photoemission electron microscopy (threshold PEEM), photoelectrons are excited by UV photons with an energy just above the photoemission threshold. The lateral intensity distribution of these electrons is then imaged by an electrostatic lens system. In this thesis, the possibilities o

  2. 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

  3. Fisheries-induced disruptive selection.

    Science.gov (United States)

    Landi, Pietro; Hui, Cang; Dieckmann, Ulf

    2015-01-21

    Commercial harvesting is recognized to induce adaptive responses of life-history traits in fish populations, in particular by shifting the age and size at maturation through directional selection. In addition to such evolution of a target stock, the corresponding fishery itself may adapt, in terms of fishing policy, technological progress, fleet dynamics, and adaptive harvest. The aim of this study is to assess how the interplay between natural and artificial selection, in the simplest setting in which a fishery and a target stock coevolve, can lead to disruptive selection, which in turn may cause trait diversification. To this end, we build an eco-evolutionary model for a size-structured population, in which both the stock׳s maturation schedule and the fishery׳s harvest rate are adaptive, while fishing may be subject to a selective policy based on fish size and/or maturity stage. Using numerical bifurcation analysis, we study how the potential for disruptive selection changes with fishing policy, fishing mortality, harvest specialization, life-history tradeoffs associated with early maturation, and other demographic and environmental parameters. We report the following findings. First, fisheries-induced disruptive selection is readily caused by commonly used fishing policies, and occurs even for policies that are not specific for fish size or maturity, provided that the harvest is sufficiently adaptive and large individuals are targeted intensively. Second, disruptive selection is more likely in stocks in which the selective pressure for early maturation is naturally strong, provided life-history tradeoffs are sufficiently consequential. Third, when a fish stock is overexploited, fisheries targeting only large individuals might slightly increase sustainable yield by causing trait diversification (even though the resultant yield always remains lower than the maximum sustainable yield that could be obtained under low fishing mortality, without causing disruptive

  4. Threshold temperature optical fibre sensors

    Science.gov (United States)

    Stasiewicz, K. A.; Musial, J. E.

    2016-12-01

    This paper presents a new approach to manufacture a threshold temperature sensor based on a biconical optical fibre taper. The presented sensor employs the influence of variable state of concentration of some isotropic materials like wax or paraffin. Application of the above- mentioned materials is an attempt to prove that there is a possibility to obtain a low-cost, repeatable and smart sensor working as an in-line element. Optical fibre taper was obtained from a standard single mode fibre (SMF28®) by using a low pressure gas burner technique. The diameter of the manufactured tapers was 6.0 ± 0.5 μm with the length of elongation equal to 30.50 ± 0.16 mm. The applied technology allowed to produce tapers with the losses of 0.183 ± 0.015 dB. Application of materials with different temperature transition points made it possible to obtain the threshold work at the temperatures connected directly with their conversion temperature. External materials at the temperatures above their melting points do not influence the propagation losses. For each of them two types of the protection area and position of the optical fibre taper were applied.

  5. Catastrophe model for the exposure to blood-borne pathogens and other accidents in health care settings.

    Science.gov (United States)

    Guastello, S J; Gershon, R R; Murphy, L R

    1999-11-01

    Catastrophe models, which describe and predict discontinuous changes in system state variables, were used to model the exposure to blood and bodily fluids and more conventional occupational accidents among 1708 health care workers. Workers at three hospitals completed a survey measuring HIV-relevant exposures (needlesticks, cuts, splashes, contact with open wounds), the accident rate for broadly-defined injuries, and several occupationally relevant themes: safety climate, shift work, depression symptoms, work pace, verbal abuse, and professional group membership. A cusp (cubic polynomial) model predicting HIV-relevant exposures specifically was more accurate (R2 = 0.56) than a comparable linear model containing the same variables (R2 = 0.07). Some of the foregoing variables predisposed workers to greater differences in HIV-relevant and general accident exposures: shiftwork, climate, depressive symptoms, and work pace. Other variables governed how close an individual was to a critical threshold where a harmful incident would take place: verbal abuse, professional group membership. Similarly, a cusp model for accident incidents predicted from HIV-relevant exposures and occupational variables was also more accurate (R2 = 0.75) than comparison models. Two variables predisposed the worker to a greater accident risk: depression symptoms and shift work. Four other variables predisposed the worker to lesser accident risk: job satisfaction, safety climate, environmental stressors, and work pace. Compliance with the universal precautions and HIV-related training were not relevant to either of the models.

  6. Stochastic simulations suggest that HIV-1 survives close to its error threshold.

    Directory of Open Access Journals (Sweden)

    Kushal Tripathi

    Full Text Available The use of mutagenic drugs to drive HIV-1 past its error threshold presents a novel intervention strategy, as suggested by the quasispecies theory, that may be less susceptible to failure via viral mutation-induced emergence of drug resistance than current strategies. The error threshold of HIV-1, μ c, however, is not known. Application of the quasispecies theory to determine μ c poses significant challenges: Whereas the quasispecies theory considers the asexual reproduction of an infinitely large population of haploid individuals, HIV-1 is diploid, undergoes recombination, and is estimated to have a small effective population size in vivo. We performed population genetics-based stochastic simulations of the within-host evolution of HIV-1 and estimated the structure of the HIV-1 quasispecies and μ c. We found that with small mutation rates, the quasispecies was dominated by genomes with few mutations. Upon increasing the mutation rate, a sharp error catastrophe occurred where the quasispecies became delocalized in sequence space. Using parameter values that quantitatively captured data of viral diversification in HIV-1 patients, we estimated μ c to be 7 x 10(-5-1 x 10(-4 substitutions/site/replication, ≈ 2-6 fold higher than the natural mutation rate of HIV-1, suggesting that HIV-1 survives close to its error threshold and may be readily susceptible to mutagenic drugs. The latter estimate was weakly dependent on the within-host effective population size of HIV-1. With large population sizes and in the absence of recombination, our simulations converged to the quasispecies theory, bridging the gap between quasispecies theory and population genetics-based approaches to describing HIV-1 evolution. Further, μ c increased with the recombination rate, rendering HIV-1 less susceptible to error catastrophe, thus elucidating an added benefit of recombination to HIV-1. Our estimate of μ c may serve as a quantitative guideline for the use of

  7. Does changing pain-related knowledge reduce pain and improve function through changes in catastrophizing?

    Science.gov (United States)

    Lee, Hopin; McAuley, James H; Hübscher, Markus; Kamper, Steven J; Traeger, Adrian C; Moseley, G Lorimer

    2016-04-01

    Evidence from randomized controlled studies shows that reconceptualizing pain improves patients' knowledge of pain biology, reduces catastrophizing thoughts, and improves pain and function. However, causal relationships between these variables remain untested. It is hypothesized that reductions in catastrophizing could mediate the relationship between improvements in pain knowledge and improvements in pain and function. To test this causal mechanism, we conducted longitudinal mediation analyses on a cohort of 799 patients who were exposed to a pain education intervention. Patients provided responses to the neurophysiology of pain questionnaire, catastrophic thoughts about pain scale, visual analogue pain scale, and the patient specific functional scale, at baseline, 1-month, 6-month, and 12-month follow-up. With adjustment for potential confounding variables, an improvement in pain biology knowledge was significantly associated with a reduction in pain intensity (total effect = -2.20, 95% confidence interval [CI] = -2.96 to -1.44). However, this effect was not mediated by a reduction in catastrophizing (indirect effect = -0.16, 95% CI = -0.36 to 0.02). This might be due to a weak, nonsignificant relationship between changes in catastrophizing and pain intensity (path b = 0.19, 95% CI = -0.03 to 0.41). Similar trends were found in models with function as the outcome. Our findings indicate that change in catastrophizing did not mediate the effect of pain knowledge acquisition on change in pain or function. The strength of this conclusion is moderated, however, if patient-clinician relational factors are conceptualized as a consequence of catastrophizing, rather than a cause.

  8. Avoidance of disruptions at high βN in ASDEX Upgrade with off-axis ECRH

    Science.gov (United States)

    Esposito, B.; Granucci, G.; Maraschek, M.; Nowak, S.; Gude, A.; Igochine, V.; Lazzaro, E.; McDermott, R.; Poli, E.; Stober, J.; Suttrop, W.; Treutterer, W.; Zohm, H.; Brunetti, D.; ASDEX Upgrade Team

    2011-08-01

    Experiments on disruption avoidance have been carried out in H-mode ASDEX Upgrade plasmas: the localized perpendicular injection of ECRH (1.5 MW ~ 0.2Ptot) onto the q = 2 resonant surface has led to the delay and/or complete avoidance of disruptions in a high βN scenario (Ip = 1 MA, Bt = 2.1 T, q95 ~ 3.6, with NBI ~7.5 MW). In these discharges (at low q95 and low density) neoclassical tearing modes (NTMs) are excited: the growth and locking of the m/n = 2/1 mode leads to the disruption. The scheme of the experiment is successfully applied in the same way as in previous disruption avoidance experiments in FTU and ASDEX Upgrade. As soon as the disruption precursor signal (the locked mode detector and/or the loop voltage) reaches the preset threshold, the ECRH power is triggered by real-time control. A poloidal scan in deposition location (ρdep) has been carried out by setting the poloidal launching mirrors at different angles in each discharge. The results depend on ρdep: complete disruption avoidance can be achieved when the power is injected close to or onto the 2/1 island. When ECRH is injected outside the island (either at radii inside or outside the q = 2 surface), the discharge is disrupted as in the reference case.

  9. Collisional Disruption of Ice by High-Velocity Impact

    Science.gov (United States)

    Arakawa, Masahiko

    1999-11-01

    High-velocity impact among icy planetesimals is a physical phenomenon important to the planetary evolution process in the outer Solar System. In order to study this phenomenon, impact experiments on water ice were made by using a two-stage light gas gun installed in a cold room (-10°C) to clarify the elementary processes of collisional disruption and to study the reaccumulation and the escape conditions of the impact fragments. Cubic ice targets ranging in size from 15 to 100 mm were impacted by a nylon projectile of 7 mg with an impact velocity ( vi) from 2.3 to 4.7 km/s. The corresponding mass ratio of the projectile to the target ( mp/ Mt) ranged from 10 -3 to 10 -6, which is two orders of magnitude lower than that used in previous studies (Arakawa et al. 1995, Icarus118, 341-354). As a result, we obtained data on elementary processes such as attenuation of the shock wave and fragmentation dynamics. We found that the shock pressure attenuates in the ice target according to the relation of P∝( Lp/ r2, irrespective of the mass ratio between 10 -3 and 10 -5, where Lp is the projectile size and r is a propagation distance. The largest fragment mass ( ml) normalized by the original target mass has a good relationship to a nondimensional impact stress ( PI, NDIS) defined as the ratio of the antipodal pressure to the material strength. This relationship is described as ml/ Mt ∝ PI-1.7 for a wide range of impact conditions (50 m/s20 km) reaccumulated. On the other hand, when smaller icy bodies (radius<2 km) disrupted catastrophically, all fragments escaped and a rubble pile was never formed.

  10. 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.

  11. Connectivity threshold for Bluetooth graphs

    CERN Document Server

    Broutin, Nicolas; Fraiman, Nicolas; Lugosi, Gábor

    2011-01-01

    We study the connectivity properties of random Bluetooth graphs that model certain "ad hoc" wireless networks. The graphs are obtained as "irrigation subgraphs" of the well-known random geometric graph model. There are two parameters that control the model: the radius $r$ that determines the "visible neighbors" of each node and the number of edges $c$ that each node is allowed to send to these. The randomness comes from the underlying distribution of data points in space and from the choices of each vertex. We prove that no connectivity can take place with high probability for a range of parameters $r, c$ and completely characterize the connectivity threshold (in $c$) for values of $r$ close the critical value for connectivity in the underlying random geometric graph.

  12. 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...

  13. 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.

  14. 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

  15. 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.

  16. Abrupt Climate Change. Lessons from Integrated Catastrophic Risk Management. Interim Report

    Energy Technology Data Exchange (ETDEWEB)

    Ermolieva, T.; Obersteiner, M.

    2003-05-06

    This paper is an extended version of the talks 'Uncertainty and Robust Solutions: Lessons from IIASA Case Studies on Catastrophic Risk Management and Economic Growth under Shocks' given on 12 June 2002 and 'Sink Technologies and Climate Risk Management' given on 15 May 2002 at IIASA's Greenhouse Gas Initiative seminars. Risks of disaster arise out of the combination of natural hazards and human activities. We argue that by divorcing the natural disaster issues from social and economic development, half of this disaster equation is ignored. The current pace of disaster development is undermining the markets and safety nets not only of developing countries. Far greater policy coherence is needed between economists, development planners, natural scientists and disaster managers in order to prevent catastrophic losses to human lives, livelihoods, and natural and economic assets. In this paper we present an integrated approach to catastrophic risk management that aims at more coherence and comprehensiveness. The models presented take into account spatial and temporal heterogeneity of catastrophes as well as institutional heterogeneity within a model of economic growth. Loss and gains profiles are functions of various strategies/requirements/goals of agents such as individuals, governments, producers, insurers and investors. GIS-based catastrophe models and stochastic optimization methods allow to guide policy analyses with respect to location specific risk exposures.

  17. Rate-weakening friction characterizes both slow sliding and catastrophic failure of landslides.

    Science.gov (United States)

    Handwerger, Alexander L; Rempel, Alan W; Skarbek, Rob M; Roering, Joshua J; Hilley, George E

    2016-09-13

    Catastrophic landslides cause billions of dollars in damages and claim thousands of lives annually, whereas slow-moving landslides with negligible inertia dominate sediment transport on many weathered hillslopes. Surprisingly, both failure modes are displayed by nearby landslides (and individual landslides in different years) subjected to almost identical environmental conditions. Such observations have motivated the search for mechanisms that can cause slow-moving landslides to transition via runaway acceleration to catastrophic failure. A similarly diverse range of sliding behavior, including earthquakes and slow-slip events, occurs along tectonic faults. Our understanding of these phenomena has benefitted from mechanical treatments that rely upon key ingredients that are notably absent from previous landslide descriptions. Here, we describe landslide motion using a rate- and state-dependent frictional model that incorporates a nonlocal stress balance to account for the elastic response to gradients in slip. Our idealized, one-dimensional model reproduces both the displacement patterns observed in slow-moving landslides and the acceleration toward failure exhibited by catastrophic events. Catastrophic failure occurs only when the slip surface is characterized by rate-weakening friction and its lateral dimensions exceed a critical nucleation length [Formula: see text] that is shorter for higher effective stresses. However, landslides that are extensive enough to fall within this regime can nevertheless slide slowly for months or years before catastrophic failure. Our results suggest that the diversity of slip behavior observed during landslides can be described with a single model adapted from standard fault mechanics treatments.

  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. 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.

  20. 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.

  1. Rate-weakening friction characterizes both slow sliding and catastrophic failure of landslides

    Science.gov (United States)

    Handwerger, Alexander L.; Rempel, Alan W.; Skarbek, Rob M.; Roering, Joshua J.; Hilley, George E.

    2016-09-01

    Catastrophic landslides cause billions of dollars in damages and claim thousands of lives annually, whereas slow-moving landslides with negligible inertia dominate sediment transport on many weathered hillslopes. Surprisingly, both failure modes are displayed by nearby landslides (and individual landslides in different years) subjected to almost identical environmental conditions. Such observations have motivated the search for mechanisms that can cause slow-moving landslides to transition via runaway acceleration to catastrophic failure. A similarly diverse range of sliding behavior, including earthquakes and slow-slip events, occurs along tectonic faults. Our understanding of these phenomena has benefitted from mechanical treatments that rely upon key ingredients that are notably absent from previous landslide descriptions. Here, we describe landslide motion using a rate- and state-dependent frictional model that incorporates a nonlocal stress balance to account for the elastic response to gradients in slip. Our idealized, one-dimensional model reproduces both the displacement patterns observed in slow-moving landslides and the acceleration toward failure exhibited by catastrophic events. Catastrophic failure occurs only when the slip surface is characterized by rate-weakening friction and its lateral dimensions exceed a critical nucleation length h*h* that is shorter for higher effective stresses. However, landslides that are extensive enough to fall within this regime can nevertheless slide slowly for months or years before catastrophic failure. Our results suggest that the diversity of slip behavior observed during landslides can be described with a single model adapted from standard fault mechanics treatments.

  2. 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

  3. 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.

  4. Revealing catastrophic failure of leaf networks under stress.

    Science.gov (United States)

    Brodribb, Timothy J; Bienaimé, Diane; Marmottant, Philippe

    2016-04-26

    The intricate patterns of veins that adorn the leaves of land plants are among the most important networks in biology. Water flows in these leaf irrigation networks under tension and is vulnerable to embolism-forming cavitations, which cut off water supply, ultimately causing leaf death. Understanding the ways in which plants structure their vein supply network to protect against embolism-induced failure has enormous ecological and evolutionary implications, but until now there has been no way of observing dynamic failure in natural leaf networks. Here we use a new optical method that allows the initiation and spread of embolism bubbles in the leaf network to be visualized. Examining embolism-induced failure of architecturally diverse leaf networks, we found that conservative rules described the progression of hydraulic failure within veins. The most fundamental rule was that within an individual venation network, susceptibility to embolism always increased proportionally with the size of veins, and initial nucleation always occurred in the largest vein. Beyond this general framework, considerable diversity in the pattern of network failure was found between species, related to differences in vein network topology. The highest-risk network was found in a fern species, where single events caused massive disruption to leaf water supply, whereas safer networks in angiosperm leaves contained veins with composite properties, allowing a staged failure of water supply. These results reveal how the size structure of leaf venation is a critical determinant of the spread of embolism damage to leaves during drought.

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

    OpenAIRE

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

    2015-01-01

    [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 matc...

  6. 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.

  7. Disruption and Distinctiveness in Higher Education

    Science.gov (United States)

    Purcell, Wendy

    2014-01-01

    "Disruption"--while an evocative word triggering feelings of anxiety and perhaps even fear--also signals renewal and growth. The Higher Education (HE) sector in England has experienced some profound disruption over the years, and yet has emerged stronger and renewed in many ways. The impact of recent disruptive forces, from fees to the…

  8. Disruptive innovation as an entrepreneurial process

    NARCIS (Netherlands)

    Chandra, Y.; Yang, S.-J.S.; Singh, P.; Prajogo, D.; O'Neill, P.; Rahman, S.

    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

  9. Dealing with Disruptive Behavior of Adult Learners

    Science.gov (United States)

    Dobmeier, Robert; Moran, Joseph

    2008-01-01

    The adult education literature on disruptive behavior of adult learners was reviewed and a survey on disruptive behavior of adult learners was conducted with adult educators. The findings are synthesized in a conceptual framework for understanding the types and causes of disruptive behavior, which fall into the categories of inattention,…

  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. Tailored disconnection based on presurgical evidence in catastrophic epilepsy: report of 2 cases.

    Science.gov (United States)

    Park, Jun T; Manjila, Sunil V; Tangen, Rachel B; Cohen, Mark L; Shahid, Asim M; Sweet, Jennifer A; Tuxhorn, Ingrid E; Miller, Jonathan P

    2016-06-01

    Catastrophic epilepsy in infants, often due to extensive cortical dysplasia, has devastating consequences with respect to brain development. Conventional lobar, multilobar, or hemispheric resection in these infants is challenging, carrying an increased operative risk compared with that in older children. Removing a larger tissue volume versus removing or disconnecting the epileptogenic region does not always guarantee better seizure outcome. The authors describe 2 infants with catastrophic epilepsy who benefited from individually tailored disconnections based on a hypothesized epileptogenic zone following intensive presurgical evaluation. Two infants with catastrophic epilepsy and epileptic spasms underwent leukotomies between 3 and 12 months of age. They were followed up postoperatively for 19-36 months. Both patients had 90%-100% seizure reduction and a significantly improved neurodevelopmental outcome without postoperative complication. Cortical malformation was seen in both patients. Modifications of established surgical disconnection techniques, tailored to each patient's specific epileptogenic zone, optimized seizure and neurodevelopmental outcomes while minimizing the risks associated with more extensive resections.

  12. 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.

  13. On the foreshocks of strong earthquakes in the light of catastrophe theory

    CERN Document Server

    Guglielmi, A V; Sobisevich, L E; Lavrov, I P

    2013-01-01

    It is useful to consider the earthquakes in terms of catastrophe theory. In the paper, we illustrate this statement by analysis foreshocks preceding the strong earthquakes. We focused on the so-called catastrophe flags, and on the triggers that cause the critical transitions. The analysis shows a sharp increase of foreshock activity 3 h before the mainshock. This result is reminiscent of the well-known activation of the ULF magnetic precursors of earthquakes. Furthermore, we found that the characteristic frequency of foreshock sequence decreases a few hours before the mainshock, which is consistent with a prediction of the catastrophe theory. Finally, the analysis testifies that the strong foreshocks seems may be triggers of mainshocks. The idea is that the surface waves propagating outwards from the foreshock return back to the vicinity of the epicenter after having made a complete revolution around the Earth and induce there the mainshock.

  14. Analgesic effect of perioperative escitalopram in high pain catastrophizing patients after total knee arthroplasty

    DEFF Research Database (Denmark)

    Lunn, Troels H; Frokjaer, Vibe G; Hansen, Torben Bæk

    2015-01-01

    has not previously been investigated. The authors hypothesized that perioperative escitalopram would reduce pain after TKA in high pain catastrophizing patients. METHODS: A total of 120 pain catastrophizing patients (selected using the pain catastrophizing scale as preoperative screening tool......) scheduled for TKA were randomized in a double-blind manner to either 10 mg escitalopram or placebo daily from preanesthesia to postoperative day 6 in addition to a standardized analgesic regime. The primary outcome was pain upon ambulation 24 h after surgery. Secondary outcomes were overall pain during well......-defined mobilizations and at rest from 2 to 48 h and from days 2 to 6, morphine equivalents, anxiety, depression, and side effects. RESULTS: Pain upon ambulation (mean [95% CI]) 24 h after surgery in the escitalopram versus placebo group was 58 (53 to 64) versus 64 (58 to 69), the mean difference being -5 (-13 to 3), P...

  15. 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

  16. 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

  17. Changing perspectives in medical practice: disruptive innovation.

    Science.gov (United States)

    Paterick, Zachary R; Pradhan, Sala R; Paterick, Timothy E; Waterhouse, Blake E

    2009-01-01

    Disruptive innovation represents a business model that identifies a market location and increases consumer options. Retail clinics may represent a disruptive healthcare innovation that identifies strategies to reduce the cost of healthcare at the primary care level. The future of healthcare demands disruptive innovation that will allow for the 50 million uninsured members of our society to receive medical care. Disruptive innovative solutions need to ensure access, quality, and reasonable cost. Retail clinics represent the tip of the iceberg in disruptive innovative thinking. The obstacles that retail clinics must solve will be lessons learned for those that identify future innovative techniques.

  18. 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.

  19. 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'.

  20. 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.)

  1. 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

  2. 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.

  3. 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.

  4. 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.

  5. Threshold electric field in unconventional density waves

    Science.gov (United States)

    Dóra, Balázs; Virosztek, Attila; Maki, Kazumi

    2001-07-01

    As it is well known most charge-density waves (CDW's) and spin-density waves exhibit nonlinear transport with well-defined threshold electric field ET. Here we study theoretically the threshold electric field of unconventional density waves. We find that the threshold field increases monotonically with temperature without divergent behavior at Tc, unlike the one in conventional CDW. The present result in the three-dimensional weak pinning limit appears to describe rather well the threshold electric field observed recently in the low-temperature phase of α-(BEDT-TTF)2KHg(SCN)4.

  6. Finance, growth and threshold effects

    Directory of Open Access Journals (Sweden)

    Allegret Jean-Pierre

    2012-01-01

    Full Text Available In this paper, we test the existence of financial development threshold effects, firstly, between financial development and long-term growth, and, secondly, between financial development and long-term GDP. We also ask whether such effects may explain the link financial development - convergence/ divergence to the advanced countries’ growth. Our work builds on that of Aghion, Howitt, and Mayer-Foulkes (2004. It differs from previous work about assumptions and methodology. Estimates are performed with GMM dynamic panel data techniques for 112 emerging and developing countries from 1975 to 2007. The results show a positive but vanishing effect of financial development on steady-state GDP, from a critical (an average level of financial development. They do not validate, however, the assumption that the marginal impact of financial development on the steady-state growth rate is more favorable than the degree of financial development is low. We support only partially the role that the financial development could play in the acceleration of the convergence of emerging and developing economies towards the world frontier growth.

  7. Forecasting scenarios of collision catastrophes produced by celestial body falls

    Science.gov (United States)

    Shor, V.; Kochetova, O.; Chernetenko, Y.; Zheleznov, N.; Deryugin, V.; Zaitsev, A.

    2014-07-01

    The subject under discussion arose in the course of developing a computer program, which gives the possibility for numerical and graphical modeling of the scenarios of catastrophes caused by collisions of cosmic bodies with the Earth. It is expected that this program can be used for computer-assisted training of the personnel of units of the Ministry for Emergency Situations in the case of a situation caused by the fall of a celestial body on the Earth. Also, it is anticipated that the program can be used in real situations when a dangerous body is discovered on an orbit leading to an imminent collision with the Earth. From the scientific point of view, both variants of use require solving of analogous tasks. In what follows, we discuss both variants. 1. The computation of the circumstances for a fall on the Earth (or approach within short distance) of a real body begins with the determination of its orbit from the observations available using the least-squares method. The mean square error of the representation of the observations on the base of the initial values of the coordinates and the velocities is computed, as well as their covariance matrix. Then, the trajectory of the body's motion is followed by numerical integration starting from the osculating epoch to the collision with the Earth or to its flyby. The computer program takes into account the various cases: at the initial moment, the body can move away from or approach the Earth, it can be outside the sphere of action or inside it. At the moment, when the body enters the sphere of action, the coordinates of the center of the dispersion ellipse on the target plane are computed as well as the dimensions of its axes. Using these data, the probability of collision with the Earth is calculated. Then, the point of penetration of the body into the Earth's atmosphere at a given height above the level of the Earth geoid is determined. In case the body is passing by the Earth, the minimum distance of the body from

  8. 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.

  9. 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.

  10. Incumbent response to disruptive innovation

    DEFF Research Database (Denmark)

    Kaulio, Matti; Thorén, Kent; Rohrbeck, René

    changes, however successful in minor business model adaptions. An implication hereof is that the business model concept as such has low predictive power in explaining success and failure and is in the need of an operationalization. In addition, the article discusses the relationship between technological...... in relation to disruptive change. In relation to technical change the case company has successfully in transferred its technology from one generation to the next during more than 20 years. In relation to business model change the case company has been proactive but not successful in major business model...... innovation and business innovation....

  11. Properties and evolution of NEO families created by tidal disruption at Earth

    CERN Document Server

    Schunová, Eva; Walsh, Kevin J; Granvik, Mikael; Wainscoat, Richard J; Haghighipour, Nader

    2014-01-01

    We have calculated the coherence and detectable lifetimes of synthetic near-Earth object (NEO) families created by catastrophic disruption of a progenitor as it suffers a very close Earth approach. The closest or slowest approaches yield the most violent `s-class' disruption events. We found that the average slope of the absolute magnitude (H) distribution, $N(H)\\propto10^{(0.55\\pm0.04)\\,H}$, for the fragments in the s-class families is steeper than the slope of the NEO population \\citep{mainzer2011} in the same size range. The families remain coherent as statistically significant clusters of orbits within the NEO population for an average of $\\bar\\tau_c = (14.7\\pm0.6)\\times10^3$ years after disruption. The s-class families are detectable with the techniques developed by \\citet{fu2005} and \\citet{Schunova2012} for an average duration ($\\bar\\tau_{det}$) ranging from about 2,000 to about 12,000 years for progenitors in the absolute magnitude ($H_p$) range from 20 to 13 corresponding to diameters in the range fr...

  12. 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.

  13. Disentangling phase transitions and critical points in the proton–neutron interacting boson model by catastrophe theory

    Directory of Open Access Journals (Sweden)

    J.E. García-Ramos

    2014-09-01

    Full Text Available We introduce the basic concepts of catastrophe theory needed to derive analytically the phase diagram of the proton–neutron interacting boson model (IBM-2. Previous studies [1–3] were based on numerical solutions. We here explain the whole IBM-2 phase diagram including the precise order of the phase transitions in terms of the cusp catastrophe.

  14. Disentangling phase transitions and critical points in the proton–neutron interacting boson model by catastrophe theory

    Energy Technology Data Exchange (ETDEWEB)

    García-Ramos, J.E., E-mail: enrique.ramos@dfaie.uhu.es [Departamento de Física Aplicada, Universidad de Huelva, 21071 Huelva (Spain); Unidad Asociada de la Universidad de Huelva al IEM (CSIC), Madrid (Spain); Arias, J.M., E-mail: ariasc@us.es [Departamento de Física Atómica, Molecular y Nuclear, Universidad de Sevilla, Apdo 1065, 41080 Sevilla (Spain); Unidad Asociada de la Universidad de Sevilla al IEM (CSIC), Madrid (Spain); Dukelsky, J., E-mail: dukelsky@iem.cfmac.csic.es [Instituto de Estructura de la Materia, CSIC, Serrano 123, 28006 Madrid (Spain)

    2014-09-07

    We introduce the basic concepts of catastrophe theory needed to derive analytically the phase diagram of the proton–neutron interacting boson model (IBM-2). Previous studies [1–3] were based on numerical solutions. We here explain the whole IBM-2 phase diagram including the precise order of the phase transitions in terms of the cusp catastrophe.

  15. Relationship of depression and catastrophizing to pain, disability, and medication adherence in patients with HIV-associated sensory neuropathy.

    Science.gov (United States)

    Lucey, Brendan P; Clifford, David B; Creighton, Jason; Edwards, Robert R; McArthur, Justin C; Haythornthwaite, Jennifer

    2011-08-01

    Few studies have examined how patients with chronic HIV infection cope with pain and how pain relates to medication adherence. Pain coping strategies such as catastrophizing are often associated with increased pain and disability and may also influence adherence to medications. The goal of our study is to assess the relationship of catastrophizing and depression to pain, disability, and medication adherence through questionnaires administered to a cross-section of patients with HIV-associated sensory neuropathy. In our study, 46 HIV-seropositive subjects completed questionnaires evaluating neuropathic pain severity, pain catastrophizing, pain-related disability, depressive symptoms, severity of antiretroviral therapy (ART) side effects, and common reasons for medication nonadherence. Hierarchical regression analysis indicated that pain catastrophizing correlated with severity of neuropathic pain independent of depressive symptoms. Furthermore, depressive symptoms were not associated with multiple factors independent of pain catastrophizing such as severity of neuropathic pain and pain-related disability. Pain catastrophizing, but not depressive symptoms, correlated with increased pain disability even after controlling for the effects of age and neuropathic pain. We also found that poor adherence attributed to fear of side effects or forgetfulness was associated with increased severity of neuropathic pain, while depressive symptoms but not catastrophizing correlated with ART side effects. These findings suggest that both catastrophizing and depressive symptoms are important factors to consider in the management of pain from HIV neuropathy and adherence to ART.

  16. Thresholds for odor and nasal pungency.

    Science.gov (United States)

    Cometto-Muñiz, J E; Cain, W S

    1990-11-01

    Detection thresholds were measured repeatedly for 11 chemicals in normosmic and anosmic subjects. The stimuli comprised the first eight members of the series of n-aliphatic alcohols, phenyl ethyl alcohol, pyridine, and menthol. Results showed that anosmics could detect, via pungency, all but phenyl ethyl alcohol reliably. In the aliphatic series, both odor and pungency thresholds declined with chain length in a way that implied dependence of both in part on phase distribution in the mucosa. Odor thresholds, however, declined more rapidly than pungency thresholds: the ratio of anosmics threshold/normosmics threshold increased from 23 for methanol to 10,000 for 1-octanol. The outcome of a scaling experiment employing normosmic subjects indicated that, with the exception of methanol and ethanol, pungency arose when perceived intensity reached a narrowly tuned criterion level. When thresholds were expressed as percentages of saturated vapor, an index of thermodynamic activity, thereby accounting for differences in solubility and in phase distribution in the mucosa among the various stimuli, both odor and pungency thresholds depicted a striking constancy across stimuli.

  17. 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...

  18. 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…

  19. 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...

  20. 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.

  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. 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.

  3. 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

  4. 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。

  5. 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...

  6. 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

  7. Subamolide a induces mitotic catastrophe accompanied by apoptosis in human lung cancer cells.

    Science.gov (United States)

    Hung, Jen-Yu; Wen, Ching-Wen; Hsu, Ya-Ling; Lin, En-Shyh; Huang, Ming-Shyan; Chen, Chung-Yi; Kuo, Po-Lin

    2013-01-01

    This study investigated the anticancer effects of subamolide A (Sub-A), isolated from Cinnamomum subavenium, on human nonsmall cell lung cancer cell lines A549 and NCI-H460. Treatment of cancer cells with Sub-A resulted in decreased cell viability of both lung cancer cell lines. Sub-A induced lung cancer cell death by triggering mitotic catastrophe with apoptosis. It triggered oxidant stress, indicated by increased cellular reactive oxygen species (ROS) production and decreased glutathione level. The elevated ROS triggered the activation of ataxia-telangiectasia mutation (ATM), which further enhanced the ATF3 upregulation and subsequently enhanced p53 function by phosphorylation at Serine 15 and Serine 392. The antioxidant, EUK8, significantly decreased mitotic catastrophe by inhibiting ATM activation, ATF3 expression, and p53 phosphorylation. The reduction of ATM and ATF3 expression by shRNA decreased Sub-A-mediated p53 phosphorylation and mitotic catastrophe. Sub-A also caused a dramatic 70% reduction in tumor size in an animal model. Taken together, cell death of lung cancer cells in response to Sub-A is dependent on ROS generation, which triggers mitotic catastrophe followed by apoptosis. Therefore, Sub-A may be a novel anticancer agent for the treatment of nonsmall cell lung cancer.

  8. Subamolide A Induces Mitotic Catastrophe Accompanied by Apoptosis in Human Lung Cancer Cells

    Directory of Open Access Journals (Sweden)

    Jen-Yu Hung

    2013-01-01

    Full Text Available This study investigated the anticancer effects of subamolide A (Sub-A, isolated from Cinnamomum subavenium, on human nonsmall cell lung cancer cell lines A549 and NCI-H460. Treatment of cancer cells with Sub-A resulted in decreased cell viability of both lung cancer cell lines. Sub-A induced lung cancer cell death by triggering mitotic catastrophe with apoptosis. It triggered oxidant stress, indicated by increased cellular reactive oxygen species (ROS production and decreased glutathione level. The elevated ROS triggered the activation of ataxia-telangiectasia mutation (ATM, which further enhanced the ATF3 upregulation and subsequently enhanced p53 function by phosphorylation at Serine 15 and Serine 392. The antioxidant, EUK8, significantly decreased mitotic catastrophe by inhibiting ATM activation, ATF3 expression, and p53 phosphorylation. The reduction of ATM and ATF3 expression by shRNA decreased Sub-A-mediated p53 phosphorylation and mitotic catastrophe. Sub-A also caused a dramatic 70% reduction in tumor size in an animal model. Taken together, cell death of lung cancer cells in response to Sub-A is dependent on ROS generation, which triggers mitotic catastrophe followed by apoptosis. Therefore, Sub-A may be a novel anticancer agent for the treatment of nonsmall cell lung cancer.

  9. Morphological response of a barrier island system on a catastrophic event

    DEFF Research Database (Denmark)

    Fruergaard, Mikkel; Kroon, Aart

    2016-01-01

    The AD 1634 North Sea storm is one of the most catastrophic storms along the Wadden Sea coast of Denmark. In this study we show how pre-1634 storm morphology exerted a strong control on the resulting post-storm coastal morphology. Erosional responses associated with the storm were barrier breachi...

  10. Do we need a communal coping model of pain catastrophizing? An alternative explanation

    NARCIS (Netherlands)

    Severeijns, R.; Vlaeyen, J.W.S.; Hout, M.A. van den

    2006-01-01

    In this topical review, a case is made for placing pain catastrophizing within the transactional stress and coping model of Lazarus and Folkman (1984). It is argued that the CCM in its current formulation might actually contribute to the conceptual confusion around the construct of pain catastrophiz

  11. The nonlinear dynamical hypothesis in science education problem solving: a catastrophe theory approach.

    Science.gov (United States)

    Stamovlasis, Dimitrios

    2006-01-01

    The current study tests the nonlinear dynamical hypothesis in science education problem solving by applying catastrophe theory. Within the neo-Piagetian framework a cusp catastrophe model is proposed, which accounts for discontinuities in students' performance as a function of two controls: the functional M-capacity as asymmetry and the degree of field dependence/independence as bifurcation. The two controls have functional relation with two opponent processes, the processing of relevant information and the inhibitory process of dis-embedding irrelevant information respectively. Data from achievement scores of freshmen at a technological college were measured at two points in time, and were analyzed using dynamic difference equations and statistical regression techniques. The cusp catastrophe model proved superior (R(2)=0.77) comparing to the pre-post linear counterpart (R(2)=0.46). Besides the empirical evidence, theoretical analyses are provided, which attempt to build bridges between NDS-theory concepts and science education problem solving and to neo-Piagetian theories as well. This study sets a framework for the application of catastrophe theory in education.

  12. Potential for Application of a Probabilistic Catastrophe Risk Modelling Framework to Poverty Outcomes

    OpenAIRE

    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...

  13. 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.

  14. The 13 August 2010 catastrophic debris flows after the 2008 Wenchuan earthquake, China

    NARCIS (Netherlands)

    Xu, Q.; Zhang, S.; Li, W.L.; Asch, Th.W.J. van

    2012-01-01

    From 12 to 14 August 2010, heavy rainstorms occurred in the Sichuan province in SW China in areas which were affected by the 2008 Wenchuan Earthquake, inducing catastrophic debris flows. This disaster is named as “the 8.13 debris flows”. The results of the research presented in this paper show that

  15. 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…

  16. Rapid growth of an infectious intracranial aneurysm with catastrophic intracranial hemorrhage.

    Science.gov (United States)

    Koffie, Robert M; Stapleton, Christopher J; Torok, Collin M; Yoo, Albert J; Leslie-Mazwi, Thabele M; Codd, Patrick J

    2015-03-01

    Infectious intracranial aneurysms are rare vascular lesions that classically occur in patients with infective endocarditis. We present a 49-year-old man with altered mental status and headache with rapid growth and rupture of an infectious intracranial aneurysm with catastrophic intracranial hemorrhage, and review issues related to open neurosurgical and endovascular interventions.

  17. Stochastic simulation of catastrophic hail and windstorm indemnities in the Dutch greenhouse sector

    NARCIS (Netherlands)

    Asseldonk, van M.A.P.M.; Meuwissen, M.P.M.; Huirne, R.B.M.

    2001-01-01

    A risk analysis was performed to examine the effect of changes in the Dutch greenhouse sector on the probability of occurrence and magnitude of indemnities induced by catastrophic natural hazards. Analyzed historical indemnities, which included direct and consequential losses resulting from severe h

  18. 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…

  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. 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...

  1. 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

    Reliability is one of the key issues for the application of Insulated Gate Bipolar Transistors (IGBTs) in power electronic converters. Many efforts have been devoted to the reduction of IGBT wear out failure induced by accumulated degradation and catastrophic failure triggered by single-event ove......Reliability is one of the key issues for the application of Insulated Gate Bipolar Transistors (IGBTs) in power electronic converters. Many efforts have been devoted to the reduction of IGBT wear out failure induced by accumulated degradation and catastrophic failure triggered by single......-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...... understanding of catastrophic failure of IGBTs, the state-of-the-art research on their failure behaviors and failure mechanisms is presented in this paper. Moreover, various fault-tolerant design methods, to prevent converter level malfunctions in the event of IGBT failure, are also reviewed....

  2. 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…

  3. 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.

  4. Vector Broadcast Channels: Optimal Threshold Selection Problem

    CERN Document Server

    Samarasinghe, Tharaka; Evans, Jamie

    2011-01-01

    Threshold feedback policies are well known and provably rate-wise optimal selective feedback techniques for communication systems requiring partial channel state information (CSI). However, optimal selection of thresholds at mobile users to maximize information theoretic data rates subject to feedback constraints is an open problem. In this paper, we focus on the optimal threshold selection problem, and provide a solution for this problem for finite feedback systems. Rather surprisingly, we show that using the same threshold values at all mobile users is not always a rate-wise optimal feedback strategy, even for a system with identical users experiencing statistically the same channel conditions. By utilizing the theory of majorization, we identify an underlying Schur-concave structure in the rate function and obtain sufficient conditions for a homogenous threshold feedback policy to be optimal. Our results hold for most fading channel models, and we illustrate an application of our results to familiar Raylei...

  5. Optimism Moderates the Influence of Pain Catastrophizing on Shoulder Pain Outcome: A Longitudinal Analysis.

    Science.gov (United States)

    Coronado, Rogelio A; Simon, Corey B; Lentz, Trevor A; Gay, Charles W; Mackie, Lauren N; George, Steven Z

    2017-01-01

    Study Design Secondary analysis of prospectively collected data. Background An abundance of evidence has highlighted the influence of pain catastrophizing and fear avoidance on clinical outcomes. Less is known about the interaction of positive psychological resources with these pain-associated distress factors. Objective To assess whether optimism moderates the influence of pain catastrophizing and fear avoidance on 3-month clinical outcomes in patients with shoulder pain. Methods Data from 63 individuals with shoulder pain (mean ± SD age, 38.8 ± 14.9 years; 30 female) were examined. Demographic, psychological, and clinical characteristics were obtained at baseline. Validated measures were used to assess optimism (Life Orientation Test-Revised), pain catastrophizing (Pain Catastrophizing Scale), fear avoidance (Fear-Avoidance Beliefs Questionnaire physical activity subscale), shoulder pain intensity (Brief Pain Inventory), and shoulder function (Pennsylvania Shoulder Score function subscale). Shoulder pain and function were reassessed at 3 months. Regression models assessed the influence of (1) pain catastrophizing and optimism and (2) fear avoidance and optimism. The final multivariable models controlled for factors of age, sex, education, and baseline scores, and included 3-month pain intensity and function as separate dependent variables. Results Shoulder pain (mean difference, -1.6; 95% confidence interval [CI]: -2.1, -1.2) and function (mean difference, 2.4; 95% CI: 0.3, 4.4) improved over 3 months. In multivariable analyses, there was an interaction between pain catastrophizing and optimism (β = 0.19; 95% CI: 0.02, 0.35) for predicting 3-month shoulder function (F = 16.8, R(2) = 0.69, Pshoulder pain (P = .090) or function (P = .092). Conclusion Optimism decreased the negative influence of pain catastrophizing on shoulder function, but not pain intensity. Optimism did not alter the influence of fear-avoidance beliefs on these outcomes. Level of Evidence

  6. 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

  7. 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.

  8. 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.

  9. Error and repair catastrophes: A two-dimensional phase diagram in the quasispecies model

    Science.gov (United States)

    Tannenbaum, Emmanuel; Shakhnovich, Eugene I.

    2004-01-01

    This paper develops a two-gene, single fitness peak model for determining the equilibrium distribution of genotypes in a unicellular population which is capable of genetic damage repair. The first gene, denoted by σvia, yields a viable organism with first-order growth rate constant k>1 if it is equal to some target “master” sequence σvia,0. The second gene, denoted by σrep, yields an organism capable of genetic repair if it is equal to some target “master” sequence σrep,0. This model is analytically solvable in the limit of infinite sequence length, and gives an equilibrium distribution which depends on μ≡Lɛ, the product of sequence length and per base pair replication error probability, and ɛr, the probability of repair failure per base pair. The equilibrium distribution is shown to exist in one of the three possible “phases.” In the first phase, the population is localized about the viability and repairing master sequences. As ɛr exceeds the fraction of deleterious mutations, the population undergoes a “repair” catastrophe, in which the equilibrium distribution is still localized about the viability master sequence, but is spread ergodically over the sequence subspace defined by the repair gene. Below the repair catastrophe, the distribution undergoes the error catastrophe when μ exceeds ln k/ɛr, while above the repair catastrophe, the distribution undergoes the error catastrophe when μ exceeds ln k/fdel, where fdel denotes the fraction of deleterious mutations.

  10. 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.

  11. 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

  12. 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.

  13. Manufacturing doubt about endocrine disrupter science

    DEFF Research Database (Denmark)

    Bergman, Åke; Becher, Georg; Blumberg, Bruce;

    2015-01-01

    We present a detailed response to the critique of "State of the Science of Endocrine Disrupting Chemicals 2012" (UNEP/WHO, 2013) by financial stakeholders, authored by Lamb et al. (2014). Lamb et al.'s claim that UNEP/WHO (2013) does not provide a balanced perspective on endocrine disruption...... not intimately familiar with the topic of endocrine disruption and therefore susceptible to false generalizations of bias and subjectivity....

  14. 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.

  15. Tumor vascular disruption using various radiation types

    Directory of Open Access Journals (Sweden)

    JJ Bevelacqua

    2014-04-01

    Full Text Available The feasibility of disrupting a tumor’s vascular structure with various radiation types and radionuclides is investigated. Calculated absorbed dose profiles for photons and 4He ions suggest that low-energy beta-gamma and alpha emitting radionuclides can deposit sufficient absorbed dose to disrupt a tumor’s vascular structure while minimizing the dose outside the blood vessel. Candidate radionuclides uniformly distributed in microspheres are theoretically investigated with respect to their vascular disruption potential and to offer an alternative to 90Y microsphere therapy. Requisite activities of candidate low-energy beta-gamma and alpha emitting radionuclides to facilitate vascular disruption are calculated.

  16. Automatic location of disruption times in JET.

    Science.gov (United States)

    Moreno, R; Vega, J; Murari, A

    2014-11-01

    The loss of stability and confinement in tokamak plasmas can induce critical events known as disruptions. Disruptions produce strong electromagnetic forces and thermal loads which can damage fundamental components of the devices. Determining the disruption time is extremely important for various disruption studies: theoretical models, physics-driven models, or disruption predictors. In JET, during the experimental campaigns with the JET-C (Carbon Fiber Composite) wall, a common criterion to determine the disruption time consisted of locating the time of the thermal quench. However, with the metallic ITER-like wall (JET-ILW), this criterion is usually not valid. Several thermal quenches may occur previous to the current quench but the temperature recovers. Therefore, a new criterion has to be defined. A possibility is to use the start of the current quench as disruption time. This work describes the implementation of an automatic data processing method to estimate the disruption time according to this new definition. This automatic determination allows both reducing human efforts to locate the disruption times and standardizing the estimates (with the benefit of being less vulnerable to human errors).

  17. Resistance to disruption in a classroom setting.

    Science.gov (United States)

    Parry-Cruwys, Diana E; Neal, Carrie M; Ahearn, William H; Wheeler, Emily E; Premchander, Raseeka; Loeb, Melissa B; Dube, William V

    2011-01-01

    Substantial experimental evidence indicates that behavior reinforced on a denser schedule is more resistant to disruption than is behavior reinforced on a thinner schedule. The present experiment studied resistance to disruption in a natural educational environment. Responding during familiar activities was reinforced on a multiple variable-interval (VI) 7-s VI 30-s schedule for 6 participants with developmental disabilities. Resistance to disruption was measured by presenting a distracting item. Response rates in the disruption components were compared to within-session response rates in prior baseline components. Results were consistent with the predictions of behavioral momentum theory for 5 of 6 participants.

  18. Dipolarization front and current disruption

    Science.gov (United States)

    Lui, A. T. Y.

    2016-10-01

    The modification of current density on the dawn-dusk cross section of the magnetotail with the earthward approach of a dipolarization front (DF) is examined through the recently published results of a three-dimensional (3-D) particle-in-cell (PIC) simulation. It is found that the current density intensifies by 37% abruptly within 1.5 ion gyrotime as the DF approaches and shows localized regions with north-south extrusions. After reaching its peak value, it undergoes a drastic current reduction (DCR) by 65% within 2 ion gyrotime. Breakdown of the frozen-in condition occurs in the neutral sheet region in association with DCR, demonstrating the non-MHD behavior of the phenomenon. The evolution of current density from this 3-D PIC simulation bears several similarities to those observed for the current disruption (CD) phenomenon, such as explosive growth and disruption of the current density leading to a breakdown of the frozen-in condition. The evolution is also similar to those from a previous two-dimensional (2-D) PIC simulation specially designed to investigate the nonlinear evolution of the cross-field current instability for CD. One interpretation of these findings is that CD and substorm triggering can be associated with earthward intrusion of a DF into the near-Earth plasma sheet as indicated by previous Cluster and Time History of Events and Macroscale Interactions during Substorms observations. An alternative interpretation is that both DF and CD are consequences of a global evolution from an ion-tearing-like instability of the magnetotail.

  19. 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.

  20. Hyper-arousal decreases human visual thresholds.

    Science.gov (United States)

    Woods, Adam J; Philbeck, John W; Wirtz, Philip

    2013-01-01

    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.

  1. Experimental realization of chaos control by thresholding.

    Science.gov (United States)

    Murali, K; Sinha, Sudeshna

    2003-07-01

    We report the experimental verification of thresholding as a versatile tool for efficient and flexible chaos control. The strategy here simply involves monitoring a single state variable and resetting it when it exceeds a threshold. We demonstrate the success of the technique in rapidly controlling different chaotic electrical circuits, including a hyperchaotic circuit, onto stable fixed points and limit cycles of different periods, by thresholding just one variable. The simplicity of this controller entailing no run-time computation, and the ease and rapidity of switching between different targets it offers, suggests a potent tool for chaos based applications.

  2. Scaled biotic disruption during early Eocene global warming events

    Directory of Open Access Journals (Sweden)

    S. J. Gibbs

    2012-01-01

    Full Text Available Late Paleocene and early Eocene hyperthermals are transient global warming events associated with massive carbon injection or carbon redistribution in the ocean-atmosphere system, 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, including 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.

  3. 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.

  4. Depressive symptoms and pain evaluations among persons with chronic pain: catastrophizing, but not pain acceptance, shows significant effects.

    Science.gov (United States)

    Richardson, Elizabeth J; Ness, Timothy J; Doleys, Daniel M; Baños, James H; Cianfrini, Leanne; Richards, J Scott

    2009-12-15

    Cognitive factors such as catastrophic thoughts regarding pain, and conversely, one's acceptance of that pain, may affect emotional functioning among persons with chronic pain conditions. The aims of the present study were to examine the effects of both catastrophizing and acceptance on affective ratings of experimentally induced ischemic pain and also self-reports of depressive symptoms. Sixty-seven individuals with chronic back pain completed self-report measures of catastrophizing, acceptance, and depressive symptoms. In addition, participants underwent an ischemic pain induction procedure and were asked to rate the induced pain. Catastrophizing showed significant effects on sensory and intensity but not affective ratings of the induced pain. Acceptance did not show any significant associations, when catastrophizing was also in the model, with any form of ratings of the induced pain. Catastrophizing, but not acceptance, was also significantly associated with self-reported depressive symptoms when these two variables were both included in a regression model. Overall, results indicate negative thought patterns such as catastrophizing appear to be more closely related to outcomes of perceived pain severity and affect in persons with chronic pain exposed to an experimental laboratory pain stimulus than does more positive patterns as reflected in measures of acceptance.

  5. Effective theories and thresholds in particle physics

    Energy Technology Data Exchange (ETDEWEB)

    Gaillard, M.K.

    1991-06-07

    The role of effective theories in probing a more fundamental underlying theory and in indicating new physics thresholds is discussed, with examples from the standard model and more speculative applications to superstring theory. 38 refs.

  6. Nonlinear theory of kinetic instabilities near threshold

    Energy Technology Data Exchange (ETDEWEB)

    Berk, H.L.; Pekker, M.S. [Univ. of Texas, Austin, TX (United States). Inst. for Fusion Studies; Breizman, B.N. [Texas Univ., Austin, TX (United States). Inst. for Fusion Studies]|[Budker Inst. of Nuclear Physics, Novosibirsk (Russian Federation)

    1997-05-01

    A new nonlinear equation has been derived and solved for the evolution of an unstable collective mode in a kinetic system close to the threshold of linear instability. The resonant particle response produces the dominant nonlinearity, which can be calculated iteratively in the near-threshold regime as long as the mode doe snot trap resonant particles. With sources and classical relaxation processes included, the theory describes both soft nonlinear regimes, where the mode saturation level is proportional to an increment above threshold, and explosive nonlinear regimes, where the mode grows to a level that is independent of the closeness to threshold. The explosive solutions exhibit mode frequency shifting. For modes that exist in the absence of energetic particles, the frequency shift is both upward and downward. For modes that require energetic particles for their existence, there is a preferred direction of the frequency shift. The frequency shift continues even after the mode traps resonant particles.

  7. Secure information management using linguistic threshold approach

    CERN Document Server

    Ogiela, Marek R

    2013-01-01

    This book details linguistic threshold schemes for information sharing. It examines the opportunities of using these techniques to create new models of managing strategic information shared within a commercial organisation or a state institution.

  8. 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....

  9. 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...

  10. 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...

  11. 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...

  12. 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....

  13. 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...

  14. 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...

  15. 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....

  16. 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...

  17. 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...

  18. 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...

  19. 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...

  20. 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...

  1. 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...

  2. 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...

  3. 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...

  4. 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...

  5. 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...

  6. 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...

  7. 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...

  8. 40 CFR 98.221 - Reporting threshold.

    Science.gov (United States)

    2010-07-01

    ...) MANDATORY GREENHOUSE GAS REPORTING Nitric Acid Production § 98.221 Reporting threshold. You must report GHG emissions under this subpart if your facility contains a nitric acid train and the facility meets...

  9. 40 CFR 98.261 - Reporting threshold.

    Science.gov (United States)

    2010-07-01

    ...) MANDATORY GREENHOUSE GAS REPORTING Phosphoric Acid Production § 98.261 Reporting threshold. You must report GHG emissions under this subpart if your facility contains a phosphoric acid production process...

  10. 40 CFR 98.171 - Reporting threshold.

    Science.gov (United States)

    2010-07-01

    ...) MANDATORY GREENHOUSE GAS REPORTING Iron and Steel Production § 98.171 Reporting threshold. You must report GHG emissions under this subpart if your facility contains an iron and steel production process...

  11. 40 CFR 98.331 - Reporting threshold.

    Science.gov (United States)

    2010-07-01

    ...) MANDATORY GREENHOUSE GAS REPORTING Zinc Production § 98.331 Reporting threshold. You must report GHG emissions under this subpart if your facility contains a zinc production process and the facility meets...

  12. 40 CFR 98.141 - Reporting threshold.

    Science.gov (United States)

    2010-07-01

    ...) MANDATORY GREENHOUSE GAS REPORTING Glass Production § 98.141 Reporting threshold. You must report GHG emissions under this subpart if your facility contains a glass production process and the facility meets...

  13. 40 CFR 98.241 - Reporting threshold.

    Science.gov (United States)

    2010-07-01

    ...) MANDATORY GREENHOUSE GAS REPORTING Petrochemical Production § 98.241 Reporting threshold. You must report GHG emissions under this subpart if your facility contains a petrochemical process as specified...

  14. 40 CFR 98.61 - Reporting threshold.

    Science.gov (United States)

    2010-07-01

    ...) MANDATORY GREENHOUSE GAS REPORTING Aluminum Production § 98.61 Reporting threshold. You must report GHG emissions under this subpart if your facility contains an aluminum production process and the facility...

  15. Remembering pain after surgery: a longitudinal examination of the role of pain catastrophizing in children's and parents' recall.

    Science.gov (United States)

    Noel, Melanie; Rabbitts, Jennifer A; Tai, Gabrielle G; Palermo, Tonya M

    2015-05-01

    Children's memories for pain play a powerful role in their pain experiences. Parents' memories may also influence children's pain experiences, by influencing parent-child interactions about pain and children's cognitions and behaviors. Pain catastrophizing of children and parents has been implicated as a factor underlying memory biases; however, this has not been empirically examined. The current longitudinal study is the first to examine the role of pain catastrophizing of children and parents in the development of their pain memories after surgery. Participants were 49 youth (32 girls) aged 10 to 18 years undergoing major surgery and their parents. One week before surgery, children and parents completed measures of pain catastrophizing. Two weeks after surgery (the acute recovery period), children and parents completed measures of child pain intensity and affect. Two to 4 months after surgery, children's and parents' memories of child pain intensity and affect were elicited. Hierarchical linear regression models revealed that over and above covariates, parent catastrophizing about their child's pain (magnification, rumination) accounted for a significant portion of variance in children's affective and parents' sensory pain memories. Although parent catastrophizing had a direct effect on pain memories, mediation analyses revealed that child catastrophizing (helplessness) indirectly influenced children's and parents' pain memories through the child's postoperative pain experience. Findings highlight that aspects of catastrophic thinking about child pain before surgery are linked to distressing pain memories several months later. Although both child and parent catastrophizing influence pain memory development, parent catastrophizing is most influential to both children's and parents' evolving cognitions about child pain.

  16. Resistance to Disruption in a Classroom Setting

    Science.gov (United States)

    Parry-Cruwys, Diana E.; Neal, Carrie M.; Ahearn, William H.; Wheeler, Emily E.; Premchander, Raseeka; Loeb, Melissa B.; Dube, William V.

    2011-01-01

    Substantial experimental evidence indicates that behavior reinforced on a denser schedule is more resistant to disruption than is behavior reinforced on a thinner schedule. The present experiment studied resistance to disruption in a natural educational environment. Responding during familiar activities was reinforced on a multiple…

  17. 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

  18. 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 ...

  19. Design of Threshold Controller Based Chaotic Circuits

    DEFF Research Database (Denmark)

    Mohamed, I. Raja; Murali, K.; Sinha, Sudeshna;

    2010-01-01

    We propose a very simple implementation of a second-order nonautonomous chaotic oscillator, using a threshold controller as the only source of nonlinearity. We demonstrate the efficacy and simplicity of our design through numerical and experimental results. Further, we show that this approach of ...... of using a threshold controller as a nonlinear element, can be extended to obtain autonomous and multiscroll chaotic attractor circuits as well....

  20. Optimizing Retransmission Threshold in Wireless Sensor Networks.

    Science.gov (United States)

    Bi, Ran; Li, Yingshu; Tan, Guozhen; Sun, Liang

    2016-05-10

    The retransmission threshold in wireless sensor networks is critical to the latency of data delivery in the networks. However, existing works on data transmission in sensor networks did not consider the optimization of the retransmission threshold, and they simply set the same retransmission threshold for all sensor nodes in advance. The method did not take link quality and delay requirement into account, which decreases the probability of a packet passing its delivery path within a given deadline. This paper investigates the problem of finding optimal retransmission thresholds for relay nodes along a delivery path in a sensor network. The object of optimizing retransmission thresholds is to maximize the summation of the probability of the packet being successfully delivered to the next relay node or destination node in time. A dynamic programming-based distributed algorithm for finding optimal retransmission thresholds for relay nodes along a delivery path in the sensor network is proposed. The time complexity is O n Δ · max 1 ≤ i ≤ n { u i } , where u i is the given upper bound of the retransmission threshold of sensor node i in a given delivery path, n is the length of the delivery path and Δ is the given upper bound of the transmission delay of the delivery path. If Δ is greater than the polynomial, to reduce the time complexity, a linear programming-based ( 1 + p m i n ) -approximation algorithm is proposed. Furthermore, when the ranges of the upper and lower bounds of retransmission thresholds are big enough, a Lagrange multiplier-based distributed O ( 1 ) -approximation algorithm with time complexity O ( 1 ) is proposed. Experimental results show that the proposed algorithms have better performance.

  1. Polar catastrophe at the MgO(100)/SnO2(110) interface

    KAUST Repository

    Albar, Arwa

    2016-11-14

    First principles calculations, based on density functional theory, are used to investigate the structural and electronic properties of the epitaxial MgO(100)/SnO2(110) interface of wide band gap insulators. Depending on the interface termination, nonmagnetic metallic and half-metallic interface states are observed. The formation of these states is explained by a polar catastrophe model for nonpolar-polar interfaces. Strong lattice distortions and buckling develop in SnO2, which influence the interface properties as the charge discontinuity is partially screened. Already a single unit cell of SnO2 is sufficient to drive the polar catastrophe scenario. © 2016 The Royal Society of Chemistry.

  2. Repeated catastrophic valley infill following medieval earthquakes in the Nepal Himalaya.

    Science.gov (United States)

    Schwanghart, Wolfgang; Bernhardt, Anne; Stolle, Amelie; Hoelzmann, Philipp; Adhikari, Basanta R; Andermann, Christoff; Tofelde, Stefanie; Merchel, Silke; Rugel, Georg; Fort, Monique; Korup, Oliver

    2016-01-08

    Geomorphic footprints of past large Himalayan earthquakes are elusive, although they are urgently needed for gauging and predicting recovery times of seismically perturbed mountain landscapes. We present evidence of catastrophic valley infill following at least three medieval earthquakes in the Nepal Himalaya. Radiocarbon dates from peat beds, plant macrofossils, and humic silts in fine-grained tributary sediments near Pokhara, Nepal's second-largest city, match the timing of nearby M > 8 earthquakes in ~1100, 1255, and 1344 C.E. The upstream dip of tributary valley fills and x-ray fluorescence spectrometry of their provenance rule out local sources. Instead, geomorphic and sedimentary evidence is consistent with catastrophic fluvial aggradation and debris flows that had plugged several tributaries with tens of meters of calcareous sediment from a Higher Himalayan source >60 kilometers away.

  3. Error catastrophe and phase transition in the empirical fitness landscape of HIV

    Science.gov (United States)

    Hart, Gregory R.; Ferguson, Andrew L.

    2015-03-01

    We have translated clinical sequence databases of the p6 HIV protein into an empirical fitness landscape quantifying viral replicative capacity as a function of the amino acid sequence. We show that the viral population resides close to a phase transition in sequence space corresponding to an "error catastrophe" beyond which there is lethal accumulation of mutations. Our model predicts that the phase transition may be induced by drug therapies that elevate the mutation rate, or by forcing mutations at particular amino acids. Applying immune pressure to any combination of killer T-cell targets cannot induce the transition, providing a rationale for why the viral protein can exist close to the error catastrophe without sustaining fatal fitness penalties due to adaptive immunity.

  4. Evaluating core technology capacity based on an improved catastrophe progression method: the case of automotive industry

    Science.gov (United States)

    Zhao, Shijia; Liu, Zongwei; Wang, Yue; Zhao, Fuquan

    2017-01-01

    Subjectivity usually causes large fluctuations in evaluation results. Many scholars attempt to establish new mathematical methods to make evaluation results consistent with actual objective situations. An improved catastrophe progression method (ICPM) is constructed to overcome the defects of the original method. The improved method combines the merits of the principal component analysis' information coherence and the catastrophe progression method's none index weight and has the advantage of highly objective comprehensive evaluation. Through the systematic analysis of the influencing factors of the automotive industry's core technology capacity, the comprehensive evaluation model is established according to the different roles that different indices play in evaluating the overall goal with a hierarchical structure. Moreover, ICPM is developed for evaluating the automotive industry's core technology capacity for the typical seven countries in the world, which demonstrates the effectiveness of the method.

  5. Catastrophe Bonds Structures at European Level – A Cluster Analysis Approach

    Directory of Open Access Journals (Sweden)

    Nadotti Loris Lino Maria

    2014-12-01

    Full Text Available The present paper aims at examining several characteristics of the catastrophe bonds (CB market by focusing on emblematic transactions with the objective of stressing the choices of the European-based (reinsurance groups in terms of the CB tranches structure. For the purpose of highlighting the common individualities regarding the configuration of the catastrophe bonds, there are recognized homogenous groups in terms of covered perils and size of the each CB tranche, while emphasizing some stringent aspects linked to their trigger mechanism (like the basis risk, their rating, or tenor. The research identifies several profiles regarding the structural characteristics of the CB during the entire analysed period (1999-2014 and the main periods of development of the market. Accommodating categorical and continuous data, the structural patterns are determined and analysed by applying the two-step cluster methodology.

  6. Catastrophic model for stability analysis of high pile-column bridge pier

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    According to the engineering features of higher pile-column bridge pier in mountainous area, a clamped beam mechanical model was set up by synthetically analyzing the higher pile-column bridge pier buckling mechanism. Based on the catastrophe theory, the cusp catastrophe model of higher pile-column bridge pier was established by the determination of its potential function and bifurcation set equation, the necessary instability conditions of high pile-column bridge pier were deduced, and the determination method for column-buckling and lateral displacement of high pile-column bridge pier was derived. The comparison between the experimental and calculated results show that the calculated curves agree with testing curves and the method is reasonable and effective.

  7. Changes in Climate Extremes and Catastrophic Events in the Mongolian Plateau from 1951 to 2012

    DEFF Research Database (Denmark)

    Wang, Lei; Yao, Zhi-Jun; Jiang, Liguang;

    2016-01-01

    The spatiotemporal changes in 21 indices of extreme temperature and precipitation for the Mongolian Plateau from 1951 to 2012 were investigated on the basis of daily temperature and precipitation data from 70 meteorological stations. Changes in catastrophic events, such as droughts, floods...... was shown for total precipitation from west to east as based on the spatial distribution of decadal trends. Drought was the most serious extreme disaster, and prolonged drought for longer than 3 yr occurred about every 7-11 yr. An increasing trend in the disaster area was apparent for flood events from 1951......, and snowstorms, were also investigated for the same period. The correlations between catastrophic events and the extreme indices were examined. The results show that the Mongolian Plateau experienced an asymmetric warming trend. Both the cold extremes and warm extremes showed greater warming at night than...

  8. INVESTIGATING FINANCIAL INNOVATION AND EUROPEAN CAPITAL MARKETS. THE CASE OF CATASTROPHE BONDS AND LISTED REINSURANCE COMPANIES

    Directory of Open Access Journals (Sweden)

    CONSTANTIN LAURA-GABRIELA

    2014-12-01

    Full Text Available Focusing on the financial innovation – stock market interconnections, the present research studies the association between the insurance-linked market activity of European (reinsurance companies and their evolution on the capital markets. With the aim of emphasizing the connections from the perspective of the stock performance and their risk, the empirical analysis is based on vector autoregression (VAR and Granger causality analyses. The proposed examination is further developed by considering both impulse response functions and variance decomposition insights. The proxies of the catastrophe bond market, as financial innovation, there are employed both the size and the number of catastrophe bonds transactions, while the stock returns and their standard deviation stand for representatives of the evolution of the reinsurance companies on the capital markets in terms of financial performance and risk. The main results confirm other studies, suggesting that the effects of issuing cat bonds on the ceding companies is reflected rather in terms of stocks’ risk diminishing

  9. INVESTIGATING FINANCIAL INNOVATION AND EUROPEAN CAPITAL MARKETS. THE CASE OF CATASTROPHE BONDS AND LISTED REINSURANCE COMPANIES

    Directory of Open Access Journals (Sweden)

    CONSTANTIN LAURA-GABRIELA

    2014-12-01

    Full Text Available Focusing on the financial innovation – stock market interconnections, the present research studies the association between the insurance-linked market activity of European (reinsurance companies and their evolution on the capital markets. With the aim of emphasizing the connections from the perspective of the stock performance and their risk, the empirical analysis is based on vector autoregression (VAR and Granger causality analyses. The proposed examination is further developed by considering both impulse response functions and variance decomposition insights. The proxies of the catastrophe bond market, as financial innovation, there are employed both the size and the number of catastrophe bonds transactions, while the stock returns and their standard deviation stand for representatives of the evolution of the reinsurance companies on the capital markets in terms of financial performance and risk. The main results confirm other studies, suggesting that the effects of issuing cat bonds on the ceding companies is reflected rather in terms of stocks’ risk diminishing.

  10. Catastrophic Incident Recovery: Long-Term Recovery from an Anthrax Event Symposium

    Energy Technology Data Exchange (ETDEWEB)

    Lesperance, Ann M.

    2008-06-30

    On March 19, 2008, policy makers, emergency managers, and medical and Public Health officials convened in Seattle, Washington, for a workshop on Catastrophic Incident Recovery: Long-Term Recovery from an Anthrax Event. The day-long symposium was aimed at generating a dialogue about restoration and recovery through a discussion of the associated challenges that impact entire communities, including people, infrastructure, and critical systems.

  11. Civil Support: Actions Are Needed to Improve DOD’s Planning for a Complex Catastrophe

    Science.gov (United States)

    2013-09-01

    tsunami, earthquake, volcanic eruption , landslide, mudslide, snowstorm, or drought), or regardless of cause, any fire, flood, or explosion, in any...and emergencies. A major disaster is any natural catastrophe (including any hurricane, tornado, storm, high water , wind-driven water , tidal wave...damage under imminently serious conditions in response to a request from civil authorities when time does not permit approval from higher DOD

  12. Subamolide A Induces Mitotic Catastrophe Accompanied by Apoptosis in Human Lung Cancer Cells

    OpenAIRE

    Jen-Yu Hung; Ching-Wen Wen; Ya-Ling Hsu; En-Shyh Lin; Ming-Shyan Huang; Chung-Yi Chen; Po-Lin Kuo

    2013-01-01

    This study investigated the anticancer effects of subamolide A (Sub-A), isolated from Cinnamomum subavenium, on human nonsmall cell lung cancer cell lines A549 and NCI-H460. Treatment of cancer cells with Sub-A resulted in decreased cell viability of both lung cancer cell lines. Sub-A induced lung cancer cell death by triggering mitotic catastrophe with apoptosis. It triggered oxidant stress, indicated by increased cellular reactive oxygen species (ROS) production and decreased glutathione le...

  13. Factors that determine catastrophic expenditure for tuberculosis care: a patient survey in China

    Institute of Scientific and Technical Information of China (English)

    Chengchao Zhou; Qian Long; Jiaying Chen; Li Xiang; Qiang Li; Shenglan Tang; Fei Huang

    2016-01-01

    Background:Tuberculosis (TB) often causes catastrophic economic effects on both the individual suffering the disease and their households.A number of studies have analyzed patient and household expenditure on TB care,but there does not appear to be any that have assessed the incidence,intensity and determinants of catastrophic health expenditure (CHE) relating to TB care in China.That will be the objective of this paper.Methods:The data used for this study were derived from the baseline survey of the China Government-Gates Foundation TB Phase Ⅱ program.Our analysis included 747 TB cases.Catastrophic health expenditure for TB care was estimated using two approaches,with households defined as experiencing CHE if their annual expenditure on TB care:(a) exceeded 10 % of total household income;and (b) exceeded 40 % of their non-food expenditure (capacity to pay).Chi-square tests were used to identify associated factors and logistic regression analysis to identify the determinants of CHE.Results:The incidence of CHE was 66.8 % using the household income measure and 54.7 % using non-food expenditure (capacity to pay).An inverse association was observed between CHE rates and household income level.Significant determinants of CHE were:age,household size,employment status,health insurance status,patient income as a percentage of total household income,hospitalization and status as a minimum living security household.Factors including gender,marital status and type of TB case had no significant associations with CHE.Conclusions:Catastrophic health expenditure incidence from TB care is high in China.An integrated policy expanding the free treatment package and ensuring universal coverage,especially the height of UHC for TB patients,is needed.Financial and social protection interventions are essential for identified at-risk groups.

  14. Risque extensif et risque quotidien dans le Chaco bolivien : sources de crise et catastrophe

    Directory of Open Access Journals (Sweden)

    Lilian R. Reyes Pando

    2012-04-01

    Full Text Available Les risques de catastrophe suivent un continuum qui va des risques structurels initiaux (de pré-impact aux risques futurs ou directement liés aux pratiques de reconstruction et à une récupération1 inadéquate, en passant par les risques contingents (résultant directement de l’impact. Ces différentes catégories sont souvent construites à partir de risques chroniques déjà existants. Elles sont utilisées pour démontrer l’évolution cyclique des catastrophes de 2009 et 2011, associées à la sécheresse et au gel, ayant affectés le Chaco bolivien. Par ailleurs, cet article vise à montrer en quoi une analyse des facteurs de causalité et des impacts post-catastrophe déjà connus est nécessaire. Ces notions sont souvent associées aux aléas à grande échelle pouvant survenir brutalement, mais elles occultent la compréhension des besoins lors de crises qui surviennent à causes d’aléas diffus, extensifs, liés aux styles de vie. Il s’agit également de révéler en quoi les tentatives d’appréhender les catégories successives de risques, apparemment séquencées, en utilisant des mécanismes et des cadres institutionnels indépendants, sont vouées à l’échec. De fait, des relations existent entre risques principaux, risques contingents et risques futurs, et la gestion des risques de catastrophe ainsi que les mécanismes de développement nécessaires pour les réduire.

  15. CATASTROPHIC ABDOMINAL INJURY WITH EVISCERATION OF JEJUNUM AND ILEUM IN A DRAUGHT DONKEY

    Directory of Open Access Journals (Sweden)

    M. H. Hussain, M. Athar, A. Yousaf, G. Muhammad and M. Saqib

    2003-12-01

    Full Text Available The present report describes a catastrophic penetrating abdominal injury associated with a roadside accident in a draught donkey. Though repair of the eviscerated, damaged portion of the small intestine was accomplished successfully, the animal could not be saved. After postmortem it was concluded that hypovolemia and respiratory distress resulted in the death of the wounded donkey before any resuscitating attempt could be made.

  16. Terrestrial catastrophe caused by cometary impact at the end of Cretaceous

    Science.gov (United States)

    Hsü, Kenneth J.

    1980-05-01

    Evidence is presented indicating that the extinction, at the end of the Cretaceous, of large terrestrial animals was caused by atmospheric heating during a cometary impact and that the extinction of calcareous marine plankton was a consequence of poisoning by cyanide released by the fallen comet and of a catastrophic rise in calcite-compensation depth in the oceans after the detoxification of the cyanide.

  17. Catastrophe of coronal magnetic flux ropes in fully open magnetic field

    Institute of Scientific and Technical Information of China (English)

    LI; Guoqiang(李国强); HU; Youqiu(胡友秋)

    2002-01-01

    The catastrophe of coronal magnetic flux ropes is closely related to solar explosive phenomena, such as prominence eruptions, coronal mass ejections, and two-ribbon solar flares. Using a 2-dimensional, 3-component ideal MHD model in Cartesian coordinates, numerical simulations are carried out to investigate the equilibrium property of a coronal magnetic flux rope which is embedded in a fully open background magnetic field. The flux rope emerges from the photosphere and enters the corona with its axial and annular magnetic fluxes controlled by a single "emergence parameter". For a flux rope that has entered the corona, we may change its axial and annular fluxes artificially and let the whole system reach a new equilibrium through numerical simulations. The results obtained show that when the emergence parameter, the axial flux, or the annular flux is smaller than a certain critical value, the flux rope is in equilibrium and adheres to the photosphere. On the other hand, if the critical value is exceeded, the flux rope loses equilibrium and erupts freely upward, namely, a catastrophe takes place. In contrast with the partly-opened background field, the catastrophic amplitude is infinite for the case of fully-opened background field.

  18. Depletion of Paraspeckle Protein 1 Enhances Methyl Methanesulfonate-Induced Apoptosis through Mitotic Catastrophe.

    Directory of Open Access Journals (Sweden)

    Xiangjing Gao

    Full Text Available Previously, we have shown that paraspeckle protein 1 (PSPC1, a protein component of paraspeckles that was involved in cisplatin-induced DNA damage response (DDR, probably functions at the G1/S checkpoint. In the current study, we further examined the role of PSPC1 in another DNA-damaging agent, methyl methanesulfonate (MMS-induced DDR, in particular, focusing on MMS-induced apoptosis in HeLa cells. First, it was found that MMS treatment induced the expression of PSPC1. While MMS treatment alone can induce apoptosis, depletion of PSPC1 expression using siRNA significantly increased the level of apoptosis following MMS exposure. In contrast, overexpressing PSPC1 decreased the number of apoptotic cells. Interestingly, morphological observation revealed that many of the MMS-treated PSPC1-knockdown cells contained two or more nuclei, indicating the occurrence of mitotic catastrophe. Cell cycle analysis further showed that depletion of PSPC1 caused more cells entering the G2/M phase, a prerequisite of mitosis catastrophe. On the other hand, over-expressing PSPC1 led to more cells accumulating in the G1/S phase. Taken together, these observations suggest an important role for PSPC1 in MMS-induced DDR, and in particular, depletion of PSPC1 can enhance MMS-induced apoptosis through mitotic catastrophe.

  19. Induction of mitotic catastrophe by PKC inhibition in Nf1-deficient cells.

    Science.gov (United States)

    Zhou, Xiaodong; Kim, Sung-Hoon; Shen, Ling; Lee, Hyo-Jung; Chen, Changyan

    2014-01-01

    Mutations of tumor suppressor Nf1 gene deregulate Ras-mediated signaling, which confers the predisposition for developing benign or malignant tumors. Inhibition of protein kinase C (PKC) was shown to be in synergy with aberrant Ras for the induction of apoptosis in various types of cancer cells. However, it has not been investigated whether loss of PKC is lethal for Nf1-deficient cells. In this study, using HMG (3-hydroxy-3-methylgutaryl, a PKC inhibitor), we demonstrate that the inhibition of PKC by HMG treatment triggered a persistently mitotic arrest, resulting in the occurrence of mitotic catastrophe in Nf1-deficient ST8814 cells. However, the introduction of the Nf1 effective domain gene into ST8814 cells abolished this mitotic crisis. In addition, HMG injection significantly attenuated the growth of the xenografted ST8814 tumors. Moreover, Chk1 was phosphorylated, accompanied with the persistent increase of cyclin B1 expression in HMG-treated ST8814 cells. The knockdown of Chk1 by the siRNA prevented the Nf1-deficient cells from undergoing HMG-mediated mitotic arrest as well as mitotic catastrophe. Thus, our data suggested that the suppression of PKC activates the Chk1-mediated mitotic exit checkpoint in Nf1-deficient cells, leading to the induction of apoptosis via mitotic catastrophe. Collectively, the study indicates that targeting PKC may be a potential option for developing new strategies to treat Nf1-deficiency-related diseases.

  20. Incorporating Family Function into Chronic Pain Disability: The Role of Catastrophizing

    Directory of Open Access Journals (Sweden)

    Fatemeh Akbari

    2016-01-01

    Full Text Available Background. Observers’ responses to pain are recently investigated to more comprehensively explain chronic pain (CP and disability. However, the role of family context, defined as interference in roles, communication, and problem-solving, and how (i.e., through which mechanisms these variables contribute to CP related disability have yet to be examined. Objectives. The aim of the present study is to examine family context in relationship to pain catastrophizing, fear of movement, and depression and its role in understanding CP disability. Three different models were examined. Methods. A total sample of 142 patients with musculoskeletal chronic pain was recruited to examine the role of fear of movement, pain intensity, pain catastrophizing, and depression in relationship to family functioning as predictors of disability. Results. Findings indicated that two models showed acceptable fit, but one of them revealed superior fit indices. Results of the model with superior fit indices indicated that family dysfunction may contribute to catastrophic thinking, which, in turn, contributes to patients’ disability through increasing fear of movement and depression. Discussion. The current study provides further support for the notion that the impact of emotional and cognitive variables upon CP-related disability can be better understood when we consider the social context of pain patients and family function in particular.

  1. Pain affects spouses too: personal experience with pain and catastrophizing as correlates of spouse distress.

    Science.gov (United States)

    Leonard, Michelle T; Cano, Annmarie

    2006-12-15

    Chronic pain has adverse effects on individuals with chronic pain (ICPs) as well as their family members. Borrowing from an empathy model described by Goubert et al. (2005), we examined top-down and bottom-up factors that may be related to psychological well-being in the spouses of ICPs. A diverse community sample of 113 middle-aged spouses of individuals with chronic pain (ICPs) completed measures on pain severity and spouse pain catastrophizing (PCS-S; Cano et al., 2005). Results showed that almost half (48.7%) of spouses reported chronic pain themselves and that pain in the spouse accounted for within-couple differences on psychological distress. That is, in couples where only the ICP reported pain, ICP psychological distress was greater than their spouses. However, when both partners reported chronic pain, there was no significant difference in psychological distress between partners. Hierarchical regression analyses showed that spouse magnification catastrophizing was associated with depressive and anxiety symptoms, and that helplessness catastrophizing was associated with depressive symptoms for spouses of ICPs who also reported chronic pain but not for spouses of ICPs without chronic pain. The results are discussed in light of interpersonal processes that may affect spouses' distress.

  2. Dynamics of microtubule asters in microfabricated chambers: The role of catastrophes

    Science.gov (United States)

    Faivre-Moskalenko, Cendrine; Dogterom, Marileen

    2002-01-01

    Recent in vivo as well as in vitro experiments have indicated that microtubule pushing alone is sufficient to position a microtubule-organizing center within a cell. Here, we investigate the effect of catastrophes on the dynamics of microtubule asters within microfabricated chambers that mimic the confining geometry of living cells. The use of a glass bead as the microtubule-organizing center allows us to manipulate the aster by using optical tweezers. In the case in which microtubules preexist, we show that because of microtubule buckling, repositioning almost never occurs after relocation with the optical tweezers, although initial microtubule growth always leads the aster to the geometrical center of the chamber. When a catastrophe promoter is added, we find instead that the aster is able to efficiently explore the chamber geometry even after being relocated with the optical tweezers. As predicted by theoretical calculations, the results of our in vitro experiments clearly demonstrate the need for catastrophes for proper positioning in a confining geometry. These findings correlate with recent observations of nuclear positioning in fission yeast cells. PMID:12486218

  3. Pain catastrophizing predicts pain intensity during a neurodynamic test for the median nerve in healthy participants.

    Science.gov (United States)

    Beneciuk, Jason M; Bishop, Mark D; George, Steven Z

    2010-08-01

    Psychological factors within the Fear-Avoidance Model of Musculoskeletal Pain (FAM) predict clinical and experimental pain in both symptomatic and asymptomatic individuals. Clinicians routinely examine individuals with provocative testing procedures that evoke symptoms. The purpose of this study was to investigate which FAM factors were associated with evoked pain intensity, non-painful symptom intensity, and range of motion during an upper-limb neurodynamic test. Healthy participants (n = 62) completed psychological questionnaires for pain catastrophizing, fear of pain, kinesiophobia, and anxiety prior to neurodynamic testing. Pain intensity, non-painful sensation intensity, and elbow range of motion (ROM) were collected during testing and served as dependent variables in separate simultaneous regression models. All the psychological predictors in the model accounted for 18% of the variance in evoked pain intensity (p = .02), with only pain catastrophizing (beta = .442, p neurodynamic testing for healthy subjects. Although these findings cannot be directly translated to clinical practice, the influence of pain catastrophizing on evoked pain responses should be considered during neurodynamic testing.

  4. Overfishing reduces resilience of kelp beds to climate-driven catastrophic phase shift.

    Science.gov (United States)

    Ling, S D; Johnson, C R; Frusher, S D; Ridgway, K R

    2009-12-29

    A key consideration in assessing impacts of climate change is the possibility of synergistic effects with other human-induced stressors. In the ocean realm, climate change and overfishing pose two of the greatest challenges to the structure and functioning of marine ecosystems. In eastern Tasmania, temperate coastal waters are warming at approximately four times the global ocean warming average, representing the fastest rate of warming in the Southern Hemisphere. This has driven range extension of the ecologically important long-spined sea urchin (Centrostephanus rodgersii), which has now commenced catastrophic overgrazing of productive Tasmanian kelp beds leading to loss of biodiversity and important rocky reef ecosystem services. Coincident with the overgrazing is heavy fishing of reef-based predators including the spiny lobster Jasus edwardsii. By conducting experiments inside and outside Marine Protected Areas we show that fishing, by removing large predatory lobsters, has reduced the resilience of kelp beds against the climate-driven threat of the sea urchin and thus increased risk of catastrophic shift to widespread sea urchin barrens. This shows that interactions between multiple human-induced stressors can exacerbate nonlinear responses of ecosystems to climate change and limit the adaptive capacity of these systems. Management actions focused on reducing the risk of catastrophic phase shift in ecosystems are particularly urgent in the face of ongoing warming and unprecedented levels of predator removal from the world's oceans.

  5. Termination of Protofilament Elongation by Eribulin Induces Lattice Defects that Promote Microtubule Catastrophes.

    Science.gov (United States)

    Doodhi, Harinath; Prota, Andrea E; Rodríguez-García, Ruddi; Xiao, Hui; Custar, Daniel W; Bargsten, Katja; Katrukha, Eugene A; Hilbert, Manuel; Hua, Shasha; Jiang, Kai; Grigoriev, Ilya; Yang, Chia-Ping H; Cox, David; Horwitz, Susan Band; Kapitein, Lukas C; Akhmanova, Anna; Steinmetz, Michel O

    2016-07-11

    Microtubules are dynamic polymers built of tubulin dimers that attach in a head-to-tail fashion to form protofilaments, which further associate laterally to form a tube. Asynchronous elongation of individual protofilaments can potentially lead to an altered microtubule-end structure that promotes sudden depolymerization, termed catastrophe [1-4]. However, how the dynamics of individual protofilaments relates to overall growth persistence has remained unclear. Here, we used the microtubule targeting anti-cancer drug Eribulin [5-7] to explore the consequences of stalled protofilament elongation on microtubule growth. Using X-ray crystallography, we first revealed that Eribulin binds to a site on β-tubulin that is required for protofilament plus-end elongation. Based on the structural information, we engineered a fluorescent Eribulin molecule. We demonstrate that single Eribulin molecules specifically interact with microtubule plus ends and are sufficient to either trigger a catastrophe or induce slow and erratic microtubule growth in the presence of EB3. Interestingly, we found that Eribulin increases the frequency of EB3 comet "splitting," transient events where a slow and erratically progressing comet is followed by a faster comet. This observation possibly reflects the "healing" of a microtubule lattice. Because EB3 comet splitting was also observed in control microtubules in the absence of any drugs, we propose that Eribulin amplifies a natural pathway toward catastrophe by promoting the arrest of protofilament elongation.

  6. Identifying Threshold Concepts for Information Literacy: A Delphi Study

    Directory of Open Access Journals (Sweden)

    Lori Townsend

    2016-06-01

    Full Text Available This study used the Delphi method to engage expert practitioners on the topic of threshold concepts for information literacy. A panel of experts considered two questions. First, is the threshold concept approach useful for information literacy instruction? The panel unanimously agreed that the threshold concept approach holds potential for information literacy instruction. Second, what are the threshold concepts for information literacy instruction? The panel proposed and discussed over fifty potential threshold concepts, finally settling on six information literacy threshold concepts.

  7. Microalgal cell disruption via ultrasonic nozzle spraying.

    Science.gov (United States)

    Wang, M; Yuan, W

    2015-01-01

    The objective of this study was to understand the effect of operating parameters, including ultrasound amplitude, spraying pressure, nozzle orifice diameter, and initial cell concentration on microalgal cell disruption and lipid extraction in an ultrasonic nozzle spraying system (UNSS). Two algal species including Scenedesmus dimorphus and Nannochloropsis oculata were evaluated. Experimental results demonstrated that the UNSS was effective in the disruption of microalgal cells indicated by significant changes in cell concentration and Nile red-stained lipid fluorescence density between all treatments and the control. It was found that increasing ultrasound amplitude generally enhanced cell disruption and lipid recovery although excessive input energy was not necessary for best results. The effect of spraying pressure and nozzle orifice diameter on cell disruption and lipid recovery was believed to be dependent on the competition between ultrasound-induced cavitation and spraying-generated shear forces. Optimal cell disruption was not always achieved at the highest spraying pressure or biggest nozzle orifice diameter; instead, they appeared at moderate levels depending on the algal strain and specific settings. Increasing initial algal cell concentration significantly reduced cell disruption efficiency. In all UNSS treatments, the effectiveness of cell disruption and lipid recovery was found to be dependent on the algal species treated.

  8. Plasma current asymmetries during disruptions in JET

    Science.gov (United States)

    Gerasimov, S. N.; Hender, T. C.; Morris, J.; Riccardo, V.; Zakharov, L. E.; EFDA Contributors, JET

    2014-07-01

    A key feature of disruptions during vertical displacement events, discovered in JET in 1996, is the toroidal variation in the measured plasma current Ip, i.e. the plasma current asymmetries, lasting for almost the entire current quench. The unique magnetic diagnostics at JET (full set of poloidal coils and saddle loops recorded either from two toroidally opposite or from four toroidally orthogonal locations) allow for a comprehensive analysis of asymmetrical disruptions with a large scale database. This paper presents an analysis of 4854 disruptions over an 18 year period that includes both the JET carbon (C) wall and the ITER-like (IL) wall (a mixed beryllium/tungsten first wall). In spite of the Ip quench time significantly increasing for the IL-wall compared to C-wall disruptions, the observed toroidal asymmetry time integral (˜ sideways force impulse), did not increase for IL-wall disruptions. The Ip asymmetry has a dominantly n = 1 structure. Its motion in the toroidal direction has a sporadic behaviour, in general. The distributions of the number of rotation periods are found to be very similar for both C- and IL-wall disruptions, and multi-turn rotation was sometimes observed. The Ip asymmetry amplitude has no degradation with rotation frequency for either the C- or IL-wall disruption. Therefore dynamic amplification remains a potentially serious issue for ITER due to possible mechanical resonance of the machine components with the rotating asymmetry.

  9. Disrupted Stars in Unusual Galaxies

    Science.gov (United States)

    Kohler, Susanna

    2016-03-01

    Tidal disruption events (TDEs) occur when a star passes a little too close to a supermassive black hole at the center of a galaxy. Tidal forces from the black hole cause the passing star to be torn apart, resulting in a brief flare of radiation as the stars material accretes onto the black hole. A recent study asks the following question: do TDEs occur most frequently in an unusual type of galaxy?A Trend in DisruptionsSo far, we have data from eight candidate TDEs that peaked in optical and ultraviolet wavelengths. The spectra from these observations have shown an intriguing trend: many of these TDEs host galaxies exhibit weak line emission (indicating little or no current star-formation activity), and yet they show strong Balmer absorption lines (indicating star formation activity occurred within the last Gyr). These quiescent, Balmer-strong galaxies likely underwent a period of intense star formation that recently ended.To determine if TDEs are overrepresented in such galaxies, a team of scientists led by Decker French (Steward Observatory, University of Arizona) has quantified the fraction of galaxies in the Sloan Digital Sky Survey (SDSS) that exhibit similar properties to those of TDE hosts.Quantifying OverrepresentationSpectral characteristics of SDSS galaxies (gray) and TDE candidate host galaxies (colored points): line emission vs. Balmer absorption. The lower right-hand box identifies thequiescent, Balmer-strong galaxies which contain most TDE events, yet are uncommon among the galaxy sample as a whole. Click for a better look! [French et al. 2016]French and collaborators compare the optical spectra of the TDE host galaxies to those of nearly 600,000 SDSS galaxies, using two different cutoffs for the Balmer absorption the indicator of past star formation. Their strictest cut, filtering for very high Balmer absorption, selected only 0.2% of the SDSS galaxies, yet 38% of the TDEs are hosted in such galaxies. Using a more relaxed cutoff selects 2.3% of

  10. Analysis of Environmental Contamination resulting from Catastrophic Incidents: Part two: Building Laboratory Capability by Selecting and Developing Analytical Methodologies

    Science.gov (United States)

    Catastrophic incidents can generate a large number of samples with analytically diverse types including forensic, clinical, environmental, food, and others. Environmental samples include water, wastewater, soil, air, urban building and infrastructure materials, and surface resid...

  11. GLACIER DEGRADATION AND CATASTROPHIC MUDFLOWS ORIGIN FROM THE MODERN GLACIAL-MORAINE BODIES IN THE ELBRUS REGION

    Directory of Open Access Journals (Sweden)

    E. A. Zolotarev

    2012-01-01

    Full Text Available Mechanism of formation of the catastrophic mudflows in different glacial valleys of Elbrus region at the present stage of glacial degradation is described. The important role of the buried ice in the formation of catastrophic mudflows that affected Tyrnyauz in the XX century was revealed as a result of remote monitoring of changes in glacial-moraine complex of Kayarta river. The dynamics of glacial lakes in the Adyl-Su valley in the Bashkara Glacier region was described and probability of their breakthrough was estimated. The quantitative indicators of the dynamics of the landslide in the Kubasanty valley were obtained as a result of remote monitoring, and its influence on the formation of catastrophic mudflows is discovered. Various possible methods of catastrophic mudflows prevention not requiring expensive protective constructions are discussed.

  12. Virtual reality exposure therapy as treatment for pain catastrophizing in fibromyalgia patients: proof-of-concept study (Study Protocol

    Directory of Open Access Journals (Sweden)

    Spottiswoode Bruce

    2011-04-01

    Full Text Available Abstract Background Albeit exercise is currently advocated as one of the most effective management strategies for fibromyalgia syndrome (FMS; the implementation of exercise as a FMS treatment in reality is significantly hampered by patients' poor compliance. The inference that pain catastrophizing is a key predictor of poor compliance in FMS patients, justifies considering the alteration of pain catastrophizing in improving compliance towards exercises in FMS patients. The aim of this study is to provide proof-of-concept for the development and testing of a novel virtual reality exposure therapy (VRET program as treatment for exercise-related pain catastrophizing in FMS patients. Methods Two interlinked experimental studies will be conducted. Study 1 aims to objectively ascertain if neurophysiological changes occur in the functional brain areas associated with pain catastrophizing, when catastrophizing FMS subjects are exposed to visuals of exercise activities. Study 2 aims to ascertain the preliminary efficacy and feasibility of exposure to visuals of exercise activities as a treatment for exercise-related pain catastrophizing in FMS subjects. Twenty subjects will be selected from a group of FMS patients attending the Tygerberg Hospital in Cape Town, South Africa and randomly allocated to either the VRET (intervention group or waiting list (control group. Baseline neurophysiological activity for subjects will be collected in study 1 using functional magnetic resonance imaging (fMRI. In study 2, clinical improvement in pain catastrophizing will be measured using fMRI (objective and the pain catastrophizing scale (subjective. Discussion The premise is if exposing FMS patients to visuals of various exercise activities trigger the functional brain areas associated with pain catastrophizing; then as a treatment, repeated exposure to visuals of the exercise activities using a VRET program could possibly decrease exercise-related pain catastrophizing

  13. IMAGE WAVELET DENOISING USING THE ROBUST LOCAL THRESHOLD

    Institute of Scientific and Technical Information of China (English)

    LinKezheng; ZhouHongyu; 等

    2002-01-01

    This paper suggests a scheme of image denoising based on two-dimensional discrete wavelet transform.The denoising algorithm is described with some operatiors.By thresholding the wavelet transform coefficients of noisy images, the original image can be reconstructed cor-rectly.Different threshold selections and thresholding methods are discussed.A new robust local threshold scheme is proposed.Quantifying the performance of image denoising schemes by using the mean square error, the performance of the robust local threshold scheme is demonstrated and is compared with the universal threshold scheme.The experiment shows that image denoising using the robust local threshold performs better than that using the universal threshold.

  14. IMAGE WAVELET DENOISING USING THE ROBUST LOCAL THRESHOLD

    Institute of Scientific and Technical Information of China (English)

    Lin Kezheng; Zhou Hongyu; Li Dianpu

    2002-01-01

    This paper suggests a scheme of image denoising based on two-dimensional discrete wavelet transform. The denoising algorithm is described with some operators. By thresholding the wavelet transform coefficients of noisy images, the original image can be reconstructed correctly. Different threshold selections and thresholding methods are discussed. A new robust local threshold scheme is proposed. Quantifying the performance of image denoising schemes by using the mean square error, the performance of the robust local threshold scheme is demonstrated and is compared with the universal threshold scheme. The experiment shows that image denoising using the robust local threshold performs better than that using the universal threshold.

  15. Application of Threshold Techniques for Readability Improvement of Jawi Historical Manuscript Images

    CERN Document Server

    Som, Hafizan Mat; Ghazali, Amzari Jihadi; 10.5121/acij.2011.2206

    2011-01-01

    Historical documents such as old books and manuscripts have a high aesthetic value and highly appreciated. Unfortunately, there are some documents cannot be read due to quality problems like faded paper, ink expand, uneven colour tone, torn paper and other elements disruption such as the existence of small spots. The study aims to produce a copy of manuscript that shows clear wordings so they can easily be read and the copy can also be displayed for visitors. 16 samples of Jawi historical manuscript with different quality problems were obtained from The Royal Museum of Pahang, Malaysia. We applied three binarization techniques; Otsu's method represents global threshold technique; Sauvola and Niblack method which are categorized as local threshold techniques. We compared the binarized images with the original manuscript to be visually inspected by the museum's curator. The unclear features were marked and analyzed. Most of the examined images show that with optimal parameters and effective pre processing techn...

  16. Delayed cell death associated with mitotic catastrophe in γ-irradiated stem-like glioma cells

    Directory of Open Access Journals (Sweden)

    Esser Norbert

    2011-06-01

    Full Text Available Abstract Background and Purpose Stem-like tumor cells are regarded as highly resistant to ionizing radiation (IR. Previous studies have focused on apoptosis early after irradiation, and the apoptosis resistance observed has been attributed to reduced DNA damage or enhanced DNA repair compared to non-stem tumor cells. Here, early and late radioresponse of patient-derived stem-like glioma cells (SLGCs and differentiated cells directly derived from them were examined for cell death mode and the influence of stem cell-specific growth factors. Materials and methods Primary SLGCs were propagated in serum-free medium with the stem-cell mitogens epidermal growth factor (EGF and fibroblast growth factor-2 (FGF-2. Differentiation was induced by serum-containing medium without EGF and FGF. Radiation sensitivity was evaluated by assessing proliferation, clonogenic survival, apoptosis, and mitotic catastrophe. DNA damage-associated γH2AX as well as p53 and p21 expression were determined by Western blots. Results SLGCs failed to apoptose in the first 4 days after irradiation even at high single doses up to 10 Gy, but we observed substantial cell death later than 4 days postirradiation in 3 of 6 SLGC lines treated with 5 or 10 Gy. This delayed cell death was observed in 3 of the 4 SLGC lines with nonfunctional p53, was associated with mitotic catastrophe and occurred via apoptosis. The early apoptosis resistance of the SLGCs was associated with lower γH2AX compared to differentiated cells, but we found that the stem-cell culture cytokines EGF plus FGF-2 strongly reduce γH2AX levels. Nonetheless, in two p53-deficient SLGC lines examined γIR-induced apoptosis even correlated with EGF/FGF-induced proliferation and mitotic catastrophe. In a line containing CD133-positive and -negative stem-like cells, the CD133-positive cells proliferated faster and underwent more γIR-induced mitotic catastrophe. Conclusions Our results suggest the importance of delayed

  17. The role of catastrophic geomorphic events in central Appalachian landscape evolution

    Science.gov (United States)

    Jacobson, R.B.; Miller, A.J.; Smith, J.A.

    1989-01-01

    Catastrophic geomorphic events are taken as those that are large, sudden, and rare on human timescales. In the nonglaciated, low-seismicity central Appalachians, these are dominantly floods and landslides. Evaluation of the role of catastrophic events in landscape evolution includes assessment of their contributions to denudation and formation of prominent landscape features, and how they vary through space and time. Tropical storm paths and topographic barriers at the Blue Ridge and Allegheny Front create significant climatic variability across the Appalachians. For moderate floods, the influence of basin geology is apparent in modifying severity of flooding, but for the most extreme events, flood discharges relate mainly to rainfall characteristics such as intensity, duration, storm size, and location. Landslide susceptibility relates more directly to geologic controls that determine what intensity and duration of rainfall will trigger slope instability. Large floods and landslides are not necessarily effective in producing prominent geomorphic features. Large historic floods in the Piedmont have been minimally effective in producing prominent and persistent geomorphic features. In contrast, smaller floods in the Valley and Ridge produced erosional and depositional features that probably will require thousands of years to efface. Scars and deposits of debris slide-avalanches triggered on sandstone ridges recover slowly and persist much longer than scars and deposits of smaller landslides triggered on finer-grained regolith, even though the smaller landslides may have eroded greater aggregate volume. The surficial stratigraphic record can be used to extend the spatial and temporal limits of our knowledge of catastrophic events. Many prominent alluvial and colluvial landforms in the central Appalachians are composed of sediments that were deposited by processes similar to those observed in historic catastrophic events. Available stratigraphic evidence shows two

  18. Cost-effectiveness thresholds: pros and cons.

    Science.gov (United States)

    Bertram, Melanie Y; Lauer, Jeremy A; De Joncheere, Kees; Edejer, Tessa; Hutubessy, Raymond; Kieny, Marie-Paule; Hill, Suzanne R

    2016-12-01

    Cost-effectiveness analysis is used to compare the costs and outcomes of alternative policy options. Each resulting cost-effectiveness ratio represents the magnitude of additional health gained per additional unit of resources spent. Cost-effectiveness thresholds allow cost-effectiveness ratios that represent good or very good value for money to be identified. In 2001, the World Health Organization's Commission on Macroeconomics in Health suggested cost-effectiveness thresholds based on multiples of a country's per-capita gross domestic product (GDP). In some contexts, in choosing which health interventions to fund and which not to fund, these thresholds have been used as decision rules. However, experience with the use of such GDP-based thresholds in decision-making processes at country level shows them to lack country specificity and this - in addition to uncertainty in the modelled cost-effectiveness ratios - can lead to the wrong decision on how to spend health-care resources. Cost-effectiveness information should be used alongside other considerations - e.g. budget impact and feasibility considerations - in a transparent decision-making process, rather than in isolation based on a single threshold value. Although cost-effectiveness ratios are undoubtedly informative in assessing value for money, countries should be encouraged to develop a context-specific process for decision-making that is supported by legislation, has stakeholder buy-in, for example the involvement of civil society organizations and patient groups, and is transparent, consistent and fair.

  19. Threshold concepts in finance: conceptualizing the curriculum

    Science.gov (United States)

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

    2015-08-01

    Graduates with well-developed capabilities in finance are invaluable to our society and in increasing demand. Universities face the challenge of designing finance programmes to develop these capabilities and the essential knowledge that underpins them. Our research responds to this challenge by identifying threshold concepts that are central to the mastery of finance and by exploring their potential for informing curriculum design and pedagogical practices to improve student outcomes. In this paper, we report the results of an online survey of finance academics at multiple institutions in Australia, Canada, New Zealand, South Africa and the United Kingdom. The outcomes of our research are recommendations for threshold concepts in finance endorsed by quantitative evidence, as well as a model of the finance curriculum incorporating finance, modelling and statistics threshold concepts. In addition, we draw conclusions about the application of threshold concept theory supported by both quantitative and qualitative evidence. Our methodology and findings have general relevance to the application of threshold concept theory as a means to investigate and inform curriculum design and delivery in higher education.

  20. Disruptive School Peers and Student Outcomes

    DEFF Research Database (Denmark)

    Kristoffersen, Jannie H. G.; Krægpøth, Morten; Nielsen, Helena Skyt

    2015-01-01

    This paper estimates how peers’ achievement gains are affected by the presence of potentially disruptive and emotionally sensitive children in the school-cohort. We exploit that some children move between schools and thus generate variation in peer composition in the receiving school-cohort. We...... identify three groups of potentially disruptive and emotionally sensitive children from detailed Danish register data: children with divorced parents, children with parents convicted of crime, and children with a psychiatric diagnosis. We find that adding potentially disruptive children lowers the academic...