WorldWideScience

Sample records for poleward breaking rossby

  1. Lagrangian transport in poleward breaking Rossby waves in the North Atlantic - Europe tropopause region

    Energy Technology Data Exchange (ETDEWEB)

    Bartels, J.; Peters, D. [Rostock Univ. (Germany). Inst. fuer Atmosphaerenphysik

    1997-12-31

    The poleward advection of upper-tropospheric air is investigated for poleward Rossby wave breaking events. During boreal winter months the isentropic deformations of the tropopause are examined using maps of Ertel`s potential vorticity (EPV) and contour advection (CA) calculations. The role of ambient baro-tropic flow is further examined by idealized numerical models. In the vicinity of the tropopause the characteristic Lagrangian transport of air masses for ECMWF-analysis data are compared with high resolution (T106) ECHAM4 experiments. (author) 3 refs.

  2. Understanding Rossby wave trains forced by the Indian Ocean Dipole

    Science.gov (United States)

    McIntosh, Peter C.; Hendon, Harry H.

    2018-04-01

    Convective variations over the tropical Indian Ocean associated with ENSO and the Indian Ocean Dipole force a Rossby wave train that appears to emanate poleward and eastward to the south of Australia and which causes climate variations across southern Australia and more generally throughout the Southern Hemisphere extratropics. However, during austral winter, the subtropical jet that extends from the eastern Indian Ocean into the western Pacific at Australian latitudes should effectively prohibit continuous propagation of a stationary Rossby wave from the tropics into the extratropics because the meridional gradient of mean absolute vorticity goes to zero on its poleward flank. The observed wave train indeed exhibits strong convergence of wave activity flux upon encountering this region of vanishing vorticity gradient and with some indication of reflection back into the tropics, indicating the continuous propagation of the stationary Rossby wave train from low to high latitudes is inhibited across the south of Australia. However, another Rossby wave train appears to emanate upstream of Australia on the poleward side of the subtropical jet and propagates eastward along the waveguide of the eddy-driven (sub-polar) jet into the Pacific sector of the Southern Ocean. This combination of evanescent wave train from the tropics and eastward propagating wave train emanating from higher latitudes upstream of Australia gives the appearance of a continuous Rossby wave train propagating from the tropical Indian Ocean into higher southern latitudes. The extratropical Rossby wave source on the poleward side of the subtropical jet stems from induced changes in transient eddy activity in the main storm track of the Southern Hemisphere. During austral spring, when the subtropical jet weakens, the Rossby wave train emanating from Indian Ocean convection is explained more traditionally by direct dispersion from divergence forcing at low latitudes.

  3. Understanding Rossby wave trains forced by the Indian Ocean Dipole

    Science.gov (United States)

    McIntosh, Peter C.; Hendon, Harry H.

    2017-06-01

    Convective variations over the tropical Indian Ocean associated with ENSO and the Indian Ocean Dipole force a Rossby wave train that appears to emanate poleward and eastward to the south of Australia and which causes climate variations across southern Australia and more generally throughout the Southern Hemisphere extratropics. However, during austral winter, the subtropical jet that extends from the eastern Indian Ocean into the western Pacific at Australian latitudes should effectively prohibit continuous propagation of a stationary Rossby wave from the tropics into the extratropics because the meridional gradient of mean absolute vorticity goes to zero on its poleward flank. The observed wave train indeed exhibits strong convergence of wave activity flux upon encountering this region of vanishing vorticity gradient and with some indication of reflection back into the tropics, indicating the continuous propagation of the stationary Rossby wave train from low to high latitudes is inhibited across the south of Australia. However, another Rossby wave train appears to emanate upstream of Australia on the poleward side of the subtropical jet and propagates eastward along the waveguide of the eddy-driven (sub-polar) jet into the Pacific sector of the Southern Ocean. This combination of evanescent wave train from the tropics and eastward propagating wave train emanating from higher latitudes upstream of Australia gives the appearance of a continuous Rossby wave train propagating from the tropical Indian Ocean into higher southern latitudes. The extratropical Rossby wave source on the poleward side of the subtropical jet stems from induced changes in transient eddy activity in the main storm track of the Southern Hemisphere. During austral spring, when the subtropical jet weakens, the Rossby wave train emanating from Indian Ocean convection is explained more traditionally by direct dispersion from divergence forcing at low latitudes.

  4. Poleward intrusion in the northern Galician shelf

    Science.gov (United States)

    Alvarez, I.; Ospina-Alvarez, N.; deCastro, M.; Varela, M.; Gomez-Gesteira, M.; Prego, R.

    2010-05-01

    The evolution of a warm water mass related to the Iberian Poleward Current (IPC) was characterized along the northern Galician shelf in November 2008 by means of Sea Surface Temperature and wind data. It was observed that under upwelling favorable conditions water temperature decreased along the northern coast and a temperature break appeared between Cape Vilano and Cape Ortegal showing a relaxation of the poleward intrusion. The effect of the IPC was also analyzed inside the Northern Galician Rias taking into account the hydrographical and biogeochemical properties measured on November 18. Water driven by the IPC was observed close to the mouth of the rias, around Cape Estaca de Bares, causing a nutrient salts decrease. Inside the rias a slight biological activity was found near surface resulting from fluvial contributions.

  5. The Rossby wave instability in protoplanetary disks

    Directory of Open Access Journals (Sweden)

    Meheut H.

    2013-04-01

    Full Text Available The Rossby wave instability has been proposed as a mechanism to transport angular momentum in the dead zone of protoplanetary disks and to form vortices. These vortices are of particular interest to concentrate solids in their centres and eventually to form planetesimals. Here we summarize some recent results concerning the growth and structure of this instability in radially and vertically stratified disks, its saturation and non-linear evolution. We also discuss the concentration of solids in the Rossby vortices including vertical settling.

  6. Poleward propagation of boreal summer intraseasonal oscillations in a coupled model: role of internal processes

    Science.gov (United States)

    Ajayamohan, R. S.; Annamalai, H.; Luo, Jing-Jia; Hafner, Jan; Yamagata, Toshio

    2011-09-01

    The study compares the simulated poleward migration characteristics of boreal summer intraseasonal oscillations (BSISO) in a suite of coupled ocean-atmospheric model sensitivity integrations. The sensitivity experiments are designed in such a manner to allow full coupling in specific ocean basins but forced by temporally varying monthly climatological sea surface temperature (SST) adopted from the fully coupled model control runs (ES10). While the local air-sea interaction is suppressed in the tropical Indian Ocean and allowed in the other oceans in the ESdI run, it is suppressed in the tropical Pacific and allowed in the other oceans in the ESdP run. Our diagnostics show that the basic mean state in precipitation and easterly vertical shear as well as the BSISO properties remain unchanged due to either inclusion or exclusion of local air-sea interaction. In the presence of realistic easterly vertical shear, the continuous emanation of Rossby waves from the equatorial convection is trapped over the monsoon region that enables the poleward propagation of BSISO anomalies in all the model sensitivity experiments. To explore the internal processes that maintain the tropospheric moisture anomalies ahead of BSISO precipitation anomalies, moisture and moist static energy budgets are performed. In all model experiments, advection of anomalous moisture by climatological winds anchors the moisture anomalies that in turn promote the northward migration of BSISO precipitation. While the results indicate the need for realistic simulation of all aspects of the basic state, our model results need to be taken with caution because in the ECHAM family of coupled models the internal variance at intraseasonal timescales is indeed very high, and therefore local air-sea interactions may not play a pivotal role.

  7. On resonant Rossby-Haurwitz triads

    Science.gov (United States)

    Lynch, Peter

    2009-05-01

    The dynamics of non-divergent flow on a rotating sphere are described by the conservation of absolute vorticity. The analytical study of the non-linear barotropic vorticity equation is greatly facilitated by the expansion of the solution in spherical harmonics and truncation at low order. The normal modes are the well-known Rossby-Haurwitz (RH) waves, which represent the natural oscillations of the system. Triads of RH waves, which satisfy conditions for resonance, are of critical importance for the distribution of energy in the atmosphere. We show how non-linear interactions of resonant RH triads may result in dynamic instability of large-scale components. We also demonstrate a mathematical equivalence between the equations for an orographically forced triad and a simple mechanical system, the forced-damped swinging spring. This equivalence yields insight concerning the bounded response to a constant forcing in the absence of damping. An examination of triad interactions in atmospheric reanalysis data would be of great interest.

  8. Topographic Rossby Waves Generated by Tropical Cyclones

    Science.gov (United States)

    Dukhovskoy, D. S.; Morey, S. L.

    2013-05-01

    Analytical and numerical studies suggest that given appropriate slope, the ocean responds to a tropical storm with low-frequency motions trapped over a continental slope, the Coastal Trapped Waves. The presented study is focused on Topographic Rossby Waves (TRW), sub-inertial oscillations propagating over a sloping bottom. Generation and propagation of TRW under barotropic (Continental Shelf Waves or Shelf Waves) and baroclinic (Bottom Trapped Waves) approximations are discussed. A real-case model study of a storm surge in Apalachee Bay, northeastern Gulf of Mexico during Hurricane Dennis (July, 2005) is presented to demonstrate the role of the shelf waves in coastal inundation. The presentation also discusses excitation of baroclinic bottom-intensified wave motions on the continental slope by a tropical cyclone. An idealized model experiment demonstrates that a continental shelf that (1) responds to a storm as a baroclinic ocean and (2) has a slope steep enough to dominate the planetary β-effect (but small enough to prevent internal Kelvin-type modes) can support baroclinic topographic waves.

  9. On warm Rossby waves and their relations to ENSO events

    OpenAIRE

    Takeuchi, K.

    1989-01-01

    The hypothesis suggested by several simple air-sea coupled models is examined with an ocean numerical model driven by FSU wind stress for the period from 1963 to 1987. The examined hypothesis is that warm Rossby waves generated by stronger trades associated with cold events following warm episodes are responsible for triggering the next warm events as results, following are found. 1) Warm Rossby wawes are always found approaching the western boundary of the tropical Pacific in the preceding w...

  10. Symmetry group application for the (3+1)-dimensional Rossby waves

    Energy Technology Data Exchange (ETDEWEB)

    Kudryavtsev, A.G., E-mail: kudryavtsev_a_g@mail.r [Institute of Applied Mechanics, Russian Academy of Sciences, Moscow 119991 (Russian Federation); Myagkov, N.N., E-mail: NN_Myagkov@mail.r [Institute of Applied Mechanics, Russian Academy of Sciences, Moscow 119991 (Russian Federation)

    2011-01-17

    The (3+1)-dimensional nonlinear Charney-Obukhov equation is analyzed by means of the classical Lie group approach. The classical Lie symmetry group calculated allows one to obtain new exact Rossby wave solutions when a particular Rossby wave solution is known. New solutions obtained assist in the understanding how the Rossby waves change when the background wind changes.

  11. Enhanced poleward propagation of storms under climate change

    Science.gov (United States)

    Tamarin-Brodsky, Talia; Kaspi, Yohai

    2017-12-01

    Earth's midlatitudes are dominated by regions of large atmospheric weather variability—often referred to as storm tracks— which influence the distribution of temperature, precipitation and wind in the extratropics. Comprehensive climate models forced by increased greenhouse gas emissions suggest that under global warming the storm tracks shift poleward. While the poleward shift is a robust response across most models, there is currently no consensus on what the underlying dynamical mechanism is. Here we present a new perspective on the poleward shift, which is based on a Lagrangian view of the storm tracks. We show that in addition to a poleward shift in the genesis latitude of the storms, associated with the shift in baroclinicity, the latitudinal displacement of cyclonic storms increases under global warming. This is achieved by applying a storm-tracking algorithm to an ensemble of CMIP5 models. The increased latitudinal propagation in a warmer climate is shown to be a result of stronger upper-level winds and increased atmospheric water vapour. These changes in the propagation characteristics of the storms can have a significant impact on midlatitude climate.

  12. Is Climate Change Shifting the Poleward Limit of Mangroves?

    KAUST Repository

    Hickey, Sharyn M.

    2017-02-01

    Ecological (poleward) regime shifts are a predicted response to climate change and have been well documented in terrestrial and more recently ocean species. Coastal zones are amongst the most susceptible ecosystems to the impacts of climate change, yet studies particularly focused on mangroves are lacking. Recent studies have highlighted the critical ecosystem services mangroves provide, yet there is a lack of data on temporal global population response. This study tests the notion that mangroves are migrating poleward at their biogeographical limits across the globe in line with climate change. A coupled systematic approach utilising literature and land surface and air temperature data was used to determine and validate the global poleward extent of the mangrove population. Our findings indicate that whilst temperature (land and air) have both increased across the analysed time periods, the data we located showed that mangroves were not consistently extending their latitudinal range across the globe. Mangroves, unlike other marine and terrestrial taxa, do not appear to be experiencing a poleward range expansion despite warming occurring at the present distributional limits. Understanding failure for mangroves to realise the global expansion facilitated by climate warming may require a focus on local constraints, including local anthropogenic pressures and impacts, oceanographic, hydrological, and topographical conditions.

  13. Is the poleward migration of tropical cyclone maximum intensity associated with a poleward migration of tropical cyclone genesis?

    Science.gov (United States)

    Daloz, Anne Sophie; Camargo, Suzana J.

    2018-01-01

    A recent study showed that the global average latitude where tropical cyclones achieve their lifetime-maximum intensity has been migrating poleward at a rate of about one-half degree of latitude per decade over the last 30 years in each hemisphere. However, it does not answer a critical question: is the poleward migration of tropical cyclone lifetime-maximum intensity associated with a poleward migration of tropical cyclone genesis? In this study we will examine this question. First we analyze changes in the environmental variables associated with tropical cyclone genesis, namely entropy deficit, potential intensity, vertical wind shear, vorticity, skin temperature and specific humidity at 500 hPa in reanalysis datasets between 1980 and 2013. Then, a selection of these variables is combined into two tropical cyclone genesis indices that empirically relate tropical cyclone genesis to large-scale variables. We find a shift toward greater (smaller) average potential number of genesis at higher (lower) latitudes over most regions of the Pacific Ocean, which is consistent with a migration of tropical cyclone genesis towards higher latitudes. We then examine the global best track archive and find coherent and significant poleward shifts in mean genesis position over the Pacific Ocean basins.

  14. Structure and evolution of 3D Rossby Vortices

    Science.gov (United States)

    Richard, S.; Barge, P.

    2013-04-01

    Three dimensional compressible simulations of the Rossby Wave Instability are presented in a non-homentropic model of protoplanetary disk. The instability develops like in the two dimensional case, gradually coming to the formation of a single big vortex. This 3D vortex has a quasi-2D structure which looks like a vorticity column with only tiny vertical motions. The vortex survives hundred of rotations in a quasi-steady evolution and slowly migrates inward toward the star.

  15. Supplement to Resonant Rossby Wave Triads and the Swinging Spring.

    Science.gov (United States)

    Lynch, Peter

    2003-05-01

    The wave solutions discovered by Rossby are of fundamental importance for atmospheric dynamics. The nonlinear interactions between these waves determine the primary characteristics of the energy spectrum. These interactions take place between triplets of waves known as "resonant triads" and, for small amplitude, they are described by the three-wave equations. These same equations also govern the dynamics of a simple mechanical system, the elastic pendulum or swinging spring. This equivalence allows us to deduce properties, not otherwise evident, of resonant triads from the behavior of the mechanical system. In particular, the characteristic stepwise precession of the swing plane, so obvious from observation of the physical spring pendulum, is also found for the Rossby triads. This phenomenon has not been previously noted and is an example of the insight coming from the mathematical equivalence of the two systems. The implications of the precession for predictability of atmospheric motions are considered. The pattern of breakdown of unstable Rossby waves is very sensitive to unobservable details of the perturbations, making accurate prediction very difficult.

  16. Resonant Rossby Wave Triads and the Swinging Spring.

    Science.gov (United States)

    Lynch, Peter

    2003-05-01

    The wave solutions discovered by Rossby are of fundamental importance for atmospheric dynamics. The nonlinear interactions between these waves determine the primary characteristics of the energy spectrum. These interactions take place between triplets of waves known as "resonant triads" and, for a small amplitude, they are described by the three-wave equations. These same equations also govern the dynamics of a simple mechanical system, the elastic pendulum or swinging spring. This equivalence allows us to deduce properties, not otherwise evident, of resonant triads from the behavior of the mechanical system. In particular, the characteristic stepwise precession of the swing plane, so obvious from observation of the physical spring pendulum, is also found for the Rossby triads. This phenomenon has not been previously noted and is an example of the insight coming from the mathematical equivalence of the two systems. The implications of the precession for predictability of atmospheric motions are considered. The pattern of breakdown of unstable Rossby waves is very sensitive to unobservable details of the perturbations, making accurate prediction very difficult.

  17. An Analysis of Numerical Weather Prediction of the Diabatic Rossby Vortex

    Science.gov (United States)

    2014-06-01

    NUMERICAL WEATHER PREDICTION OF THE DIABATIC ROSSBY VORTEX by Matthew W. McKenzie June 2014 Thesis Advisor: Richard W. Moore Second Reader...TYPE AND DATES COVERED Master’s Thesis 4. TITLE AND SUBTITLE AN ANALYSIS OF NUMERICAL WEATHER PREDICTION OF THE DIABATIC ROSSBY VORTEX 5...public release; distribution is unlimited 12b. DISTRIBUTION CODE 13. ABSTRACT (maximum 200 words) This work examines diabatic Rossby vortex

  18. Formation and Development of Diabatic Rossby Vortices in a 10-Year Climatology

    Science.gov (United States)

    2012-06-01

    DEVELOPMENT OF DIABATIC ROSSBY VORTICES IN A 10-YEAR CLIMATOLOGY by Nengwei “Tom” Shih June 2012 Thesis Advisor: Richard W. Moore Second...TYPE AND DATES COVERED Master’s Thesis 4. TITLE AND SUBTITLE Formation and Development of Diabatic Rossby Vortices in a 10-Year Climatology 5...release; distribution is unlimited 12b. DISTRIBUTION CODE A 13. ABSTRACT (maximum 200 words) A diabatic Rossby vortex (DRV) is a short-scale

  19. Crop pests and pathogens move polewards in a warming world

    Science.gov (United States)

    Bebber, Daniel P.; Ramotowski, Mark A. T.; Gurr, Sarah J.

    2013-11-01

    Global food security is threatened by the emergence and spread of crop pests and pathogens. Spread is facilitated primarily by human transportation, but there is increasing concern that climate change allows establishment in hitherto unsuitable regions. However, interactions between climate change, crops and pests are complex, and the extent to which crop pests and pathogens have altered their latitudinal ranges in response to global warming is largely unknown. Here, we demonstrate an average poleward shift of 2.7+/-0.8kmyr-1 since 1960, in observations of hundreds of pests and pathogens, but with significant variation in trends among taxonomic groups. Observational bias, where developed countries at high latitudes detect pests earlier than developing countries at low latitudes, would result in an apparent shift towards the Equator. The observed positive latitudinal trends in many taxa support the hypothesis of global warming-driven pest movement.

  20. Mangrove expansion and saltmarsh decline at mangrove poleward limits

    Science.gov (United States)

    Saintilan, Neil; Wilson, Nicholas C.; Rogers, Kerrylee; Rajkaran, Anusha; Krauss, Ken W.

    2014-01-01

    Mangroves are species of halophytic intertidal trees and shrubs derived from tropical genera and are likely delimited in latitudinal range by varying sensitivity to cold. There is now sufficient evidence that mangrove species have proliferated at or near their poleward limits on at least five continents over the past half century, at the expense of salt marsh. Avicennia is the most cold-tolerant genus worldwide, and is the subject of most of the observed changes. Avicennia germinans has extended in range along the US Atlantic coast and expanded into salt marsh as a consequence of lower frost frequency and intensity in the southern USA. The genus has also expanded into salt marsh at its southern limit in Peru, and on the Pacific coast of Mexico. Mangroves of several species have expanded in extent and replaced salt marsh where protected within mangrove reserves in Guangdong Province. In south-eastern Australia, the expansion of Avicennia marina into salt marshes is now well documented, and Rhizophora stylosa has extended its range southward, while showing strong population growth within estuaries along its southern limits in northern New South Wales. Avicennia marina has extended its range southwards in South Africa. The changes are consistent with the pole-ward extension of temperature thresholds co-incident with sea-level rise, although the specific mechanism of range extension might be complicated by limitations on dispersal or other factors. The shift from salt marsh to mangrove dominance on subtropical and temperate shorelines has important implications for ecological structure, function, and global change adaptation.

  1. Discovery Of A Rossby Wave In Jupiter's South Equatorial Region

    Science.gov (United States)

    Simon-Miller, Amy A.; Choi, D. S.; Rogers, J. H.; Gierasch, P. J.

    2012-01-01

    A detailed study of the chevron-shaped dark spots on the strong southern equatorial wind jet near 7.5 deg S planetographic latitude shows variations in velocity with longitude and time. The chevrons move with velocities near the maximum wind jet velocity of approx.140 m/s, as deduced by the history of velocities at this latitude and the magnitude of the symmetric wind jet near 7 deg N latitude. Their repetitive nature is consistent with an inertia-gravity wave (n = 75-100) with phase speed up to 25 m/s, relative to the local flow, but the identity of this wave mode is not well constrained. However, high spatial resolution movies from Cassini images show that the chevrons oscillate in latitude with a approx.7-day period. This oscillating motion has a wavelength of approx.20 deg and a speed of approx.100 m/s, following a pattern similar to that seen in the Rossby wave plumes of the North Equatorial Zone, and possibly reinforced by it, though they are not perfectly in phase. The transient anticyclonic South Equatorial Disturbance (SED) may be a similar wave feature, but moves at slower velocity. All data show chevron latitude variability, but it is unclear if this Rossby wave is present during other epochs, without time series movies that fully delineate it. In the presence of multiple wave modes, the difference in dominant cloud appearance between 7 deg N and 7.5 deg S may be due to the presence of the Great Red Spot, either through changes in stratification and stability or by acting as a wave boundary.

  2. Genesis of Twin Tropical Cyclones as Revealed by a Global Mesoscale Model: The Role of Mixed Rossby Gravity Waves

    Science.gov (United States)

    Shen, Bo-Wen; Tao, Wei-Kuo; Lin, Yuh-Lang; Laing, Arlene

    2012-01-01

    In this study, it is proposed that twin tropical cyclones (TCs), Kesiny and 01A, in May 2002 formed in association with the scale interactions of three gyres that appeared as a convectively coupled mixed Rossby gravity (ccMRG) wave during an active phase of the Madden-Julian Oscillation (MJO). This is shown by analyzing observational data, including NCEP reanalysis data and METEOSAT 7 IR satellite imagery, and performing numerical simulations using a global mesoscale model. A 10-day control run is initialized at 0000 UTC 1 May 2002 with grid-scale condensation but no sub-grid cumulus parameterizations. The ccMRG wave was identified as encompassing two developing and one non-developing gyres, the first two of which intensified and evolved into the twin TCs. The control run is able to reproduce the evolution of the ccMRG wave and thus the formation of the twin TCs about two and five days in advance as well as their subsequent intensity evolution and movement within an 8-10 day period. Five additional 10-day sensitivity experiments with different model configurations are conducted to help understand the interaction of the three gyres, leading to the formation of the TCs. These experiments suggest the improved lead time in the control run may be attributed to the realistic simulation of the ccMRG wave with the following processes: (1) wave deepening (intensification) associated with a reduction in wavelength and/or the intensification of individual gyres, (2) poleward movement of gyres that may be associated with boundary layer processes, (3) realistic simulation of moist processes at regional scales in association with each of the gyres, and (4) the vertical phasing of low- and mid-level cyclonic circulations associated with a specific gyre.

  3. Rossby wave, drift wave and zonal flow turbulence

    Science.gov (United States)

    Slobinsky, Demian G.

    An extensive qualitative and quantitative study of Rossby wave, drift wave and zonal flow turbulence in the Charney-Hasegawa-Mima model is presented. This includes details of two generation mechanisms of the zonal flows, evidence of the nonlocal nature of this turbulence and of the energy exchange between the small and large scales. The modulational instability study shows that for strong primary waves the most unstable modes are perpendicular to the primary wave, which corresponds to the generation of a zonal flow if the primary wave is purely meridional. For weak waves, the maximum growth occurs for off-zonal modulations that are close to being in three-wave resonance with the primary wave. Nonlinear jet pinching is observed for all nonlinearity levels but the subsequent dynamics differ between strong and weak primary waves. The jets of the former further roll up into Karman-like vortex streets and saturate, while for the latter, the growth of the unstable mode reverses and the system oscillates between a dominant jet and a dominant primary wave. A critical level of nonlinearity is defined which separates the two regimes. Some of these characteristics are captured by truncated models. Numerical proof of the extra invariant in Rossby and drift wave turbulence is presented. While the theoretical derivations of this invariant stem from the wave kinetic equation which assumes weak wave amplitudes, it is shown to be relatively-well conserved for higher nonlinearities also. Together with the energy and enstrophy, these three invariants cascade into anisotropic sectors in the k-space as predicted by the Fjortoft argument. The cascades are characterised by the zonostrophy pushing the energy to the zonal scales. A small scale instability forcing applied to the model has demonstrated the wellknown drift wave - zonal flow feedback loop. The drift wave turbulence is generated from this primary instability. The zonal flows are then excited by either one of the generation

  4. The poleward shift of storm tracks under global warming: A Lagrangian perspective

    Science.gov (United States)

    Tamarin, T.; Kaspi, Y.

    2017-10-01

    Comprehensive models of climate change projections have shown that the latitudinal band of extratropical storms will likely shift poleward under global warming. Here we study this poleward shift from a Lagrangian storm perspective, through simulations with an idealized general circulation model. By employing a feature tracking technique to identify the storms, we demonstrate that the poleward motion of individual cyclones increases with increasing global mean temperature. A potential vorticity tendency analysis of the cyclone composites highlights two leading mechanisms responsible for enhanced poleward motion: nonlinear horizontal advection and diabatic heating associated with latent heat release. Our results imply that for a 4 K rise in the global mean surface temperature, the mean poleward displacement of cyclones increases by about 0.85° of latitude, and this occurs in addition to a poleward shift of about 0.6° in their mean genesis latitude. Changes in cyclone tracks may have a significant impact on midlatitude climate, especially in localized storm tracks such as the Atlantic and Pacific storm tracks, which may exhibit a more poleward deflected shape.

  5. The Poleward Shift of Storm Tracks Under Climate Change: Tracking Cyclones in CMIP5

    Science.gov (United States)

    Kaspi, Y.; Tamarin, T.

    2017-12-01

    Extratropical cyclones dominate the distribution of precipitation and wind in the midlatitudes, and therefore their frequency, intensity, and paths have a significant effect on weather and climate. Comprehensive climate models forced by enhanced greenhouse gas emissions suggest that under a climate change scenario, the latitudinal band of storm tracks would shift poleward. While the poleward shift is a robust response across most models, there is currently no consensus on what is the dominant dynamical mechanism. Here we use a Lagrangian approach to study the poleward shift, by employing a storm-tracking algorithm on an ensemble of CMIP5 models forced by increased CO2 emissions. We demonstrate that in addition to a poleward shift in the latitude of storm genesis, associated with the expansion of the Hadley cell, the averaged cyclonic storm also propagates more poleward until it reaches its maximum intensity. A mechanism for enhanced poleward motion of cyclones in a warmer climate is proposed, supported by idealized global warming experiments, and relates the shift to changes in upper level jet and atmospheric water vapour content. Our results imply that under the RCP8.5 climate change scenario, the averaged latitude of peak cyclone intensity shifts poleward by about 1.2○ (1.0○) in the Atlantic (Pacific) storm track in the Northern Hemisphere (NH), and by about 1.6○ in the Southern Hemisphere (SH) storm track. These changes in cyclone tracks can have a significant impact on midlatitude climate.

  6. Kinetochore-independent chromosome poleward movement during anaphase of meiosis II in mouse eggs.

    Directory of Open Access Journals (Sweden)

    Manqi Deng

    Full Text Available Kinetochores are considered to be the key structures that physically connect spindle microtubules to the chromosomes and play an important role in chromosome segregation during mitosis. Due to different mechanisms of spindle assembly between centrosome-containing mitotic cells and acentrosomal meiotic oocytes, it is unclear how a meiotic spindle generates the poleward forces to drive two rounds of meiotic chromosome segregation to achieve genome haploidization. We took advantage of the fact that DNA beads are able to induce bipolar spindle formation without kinetochores and studied the behavior of DNA beads in the induced spindle in mouse eggs during meiosis II. Interestingly, DNA beads underwent poleward movements that were similar in timing and speed to the meiotic chromosomes, although all the beads moved together to the same spindle pole. Disruption of dynein function abolished the poleward movements of DNA beads but not of the meiotic chromosomes, suggesting the existence of different dynein-dependent and dynein-independent force generation mechanisms for the chromosome poleward movement, and the latter may be dependent on the presence of kinetochores. Consistent with the observed DNA bead poleward movement, sperm haploid chromatin (which also induced bipolar spindle formation after injection to a metaphase egg without forming detectable kinetochore structures also underwent similar poleward movement at anaphase as DNA beads. The results suggest that in the chromatin-induced meiotic spindles, kinetochore attachments to spindle microtubules are not absolutely required for chromatin poleward movements at anaphase.

  7. Stationary drift-Rossby vortices in shear flows

    International Nuclear Information System (INIS)

    Horihata, Satoshi; Irie, Haruyuki; Sato, Masatomo

    1990-01-01

    Starting from Hasegawa-Mima equation with the generalized vorticity q which describes both electrostatic drift waves in plasmas and Rossby waves in the atmosphere of rotating planets, the stationary solutions of this equation in the (x, y) plane were considered assuming that the equilibrium density no depends on x and the electron temperature T 0 is constant. The arbitrary function F(φ) yielded from integration of transformed Hasegawa-Mima equation was taken either linear or nonlinear in φ, where φ is the stream function. When F is linear, vortex solutions were obtained by dividing the entire plane into internal and external regions by a closed boundary curve. Imposing the boundary conditions at the boundary curve, the constants in the solutions φ ex and φ in were determined. 4 examples are figured. When F is nonlinear, isolated (localized) vortex was considered. Deriving the equation to determine F, the equation for ψ, the internal vortical motion beyond the boundary was given. 2 examples are shown. (M.T.)

  8. Nonlinear features of equatorial baroclinic Rossby waves detected in Topex altimeter observations

    Directory of Open Access Journals (Sweden)

    R. E. Glazman

    1996-01-01

    Full Text Available Using a recently proposed technique for statistical analysis of non-gridded satellite altimeter data, regime of long equatorially-trapped baroclinic Rossby waves is studied. One-dimensional spatial and spatiotemporal autocorrelation functions of sea surface height (SSH variations yield a broad spectrum of baroclinic Rossby waves and permit determination of their propagation speed. The 1-d wavenumber spectrum of zonal variations is given by a power-law k-2 on scales from about 103 km to 104 km. We demonstrate that the observed wave regime exhibits features of soliton turbulence developing in the long baroclinic Rossby waves. However, being limited to second statistical moments, the present analysis does not allow us to rule out a possibility of weak wave turbulence.

  9. Breaking Bat

    Science.gov (United States)

    Aguilar, Isaac-Cesar; Kagan, David

    2013-01-01

    The sight of a broken bat in Major League Baseball can produce anything from a humorous dribbler in the infield to a frightening pointed projectile headed for the stands. Bats usually break at the weakest point, typically in the handle. Breaking happens because the wood gets bent beyond the breaking point due to the wave sent down the bat created…

  10. Decline and poleward shift in Indian summer monsoon synoptic activity in a warming climate.

    Science.gov (United States)

    Sandeep, S; Ajayamohan, R S; Boos, William R; Sabin, T P; Praveen, V

    2018-03-13

    Cyclonic atmospheric vortices of varying intensity, collectively known as low-pressure systems (LPS), travel northwest across central India and produce more than half of the precipitation received by that fertile region and its ∼600 million inhabitants. Yet, future changes in LPS activity are poorly understood, due in part to inadequate representation of these storms in current climate models. Using a high-resolution atmospheric general circulation model that realistically simulates the genesis distribution of LPS, here we show that Indian monsoon LPS activity declines about 45% by the late 21st century in simulations of a business-as-usual emission scenario. The distribution of LPS genesis shifts poleward as it weakens, with oceanic genesis decreasing by ∼60% and continental genesis increasing by ∼10%; over land the increase in storm counts is accompanied by a shift toward lower storm wind speeds. The weakening and poleward shift of the genesis distribution in a warmer climate are confirmed and attributed, via a statistical model, to the reduction and poleward shift of low-level absolute vorticity over the monsoon region, which in turn are robust features of most coupled model projections. The poleward shift in LPS activity results in an increased frequency of extreme precipitation events over northern India. Copyright © 2018 the Author(s). Published by PNAS.

  11. Poleward propagating subinertial alongshore surface currents off the U.S. West Coast

    KAUST Repository

    Kim, Sung Yong

    2013-12-01

    The network comprising 61 high-frequency radar systems along the U.S. West Coast (USWC) provides a unique, high resolution, and broad scale view of ocean surface circulation. Subinertial alongshore surface currents show poleward propagating signals with phase speeds of O(10) and O(100-300) km d -1 that are consistent with historical in situ observations off the USWC and that can be possibly interpreted as coastally trapped waves (CTWs). The propagating signals in the slow mode are partly observed in southern California, which may result from scattering and reflection of higher-mode CTWs due to curvature of shoreline and bathymetry near Point Conception, California. On the other hand, considering the order of the phase speed in the slow mode, the poleward propagating signals may be attributed to alongshore advection or pressure-driven flows. A statistical regression of coastal winds at National Data Buoy Center buoys on the observed surface currents partitions locally and remotely wind-forced components, isolates footprints of the equatorward propagating storm events in winter off the USWC, and shows the poleward propagating signals year round. Key Points A unique resource to examine synoptic-scale alongshore variability Isolation of equatorward wind events in winter using a statistical model Poleward propagating surface signals year-round © 2013. American Geophysical Union. All Rights Reserved.

  12. Decline and poleward shift in Indian summer monsoon synoptic activity in a warming climate

    Science.gov (United States)

    Sandeep, S.; Ajayamohan, R. S.; Boos, William R.; Sabin, T. P.; Praveen, V.

    2018-03-01

    Cyclonic atmospheric vortices of varying intensity, collectively known as low-pressure systems (LPS), travel northwest across central India and produce more than half of the precipitation received by that fertile region and its ˜600 million inhabitants. Yet, future changes in LPS activity are poorly understood, due in part to inadequate representation of these storms in current climate models. Using a high-resolution atmospheric general circulation model that realistically simulates the genesis distribution of LPS, here we show that Indian monsoon LPS activity declines about 45% by the late 21st century in simulations of a business-as-usual emission scenario. The distribution of LPS genesis shifts poleward as it weakens, with oceanic genesis decreasing by ˜60% and continental genesis increasing by ˜10%; over land the increase in storm counts is accompanied by a shift toward lower storm wind speeds. The weakening and poleward shift of the genesis distribution in a warmer climate are confirmed and attributed, via a statistical model, to the reduction and poleward shift of low-level absolute vorticity over the monsoon region, which in turn are robust features of most coupled model projections. The poleward shift in LPS activity results in an increased frequency of extreme precipitation events over northern India.

  13. Plants on the move: plant-soil interactions in poleward shifting plant species

    NARCIS (Netherlands)

    Grunsven, van R.H.A.

    2008-01-01

    As a result of recent global climate change, areas that have previously been climatically unsuitable for species have now become suitable new habitats. Many plant-species are expanding their range polewards, colonizing these newly available areas. If these species are able to expand their range

  14. Role of extratropical cyclones in the recently observed increase in poleward moisture transport into the Arctic Ocean

    Science.gov (United States)

    Villamil-Otero, Gian A.; Zhang, Jing; He, Juanxiong; Zhang, Xiangdong

    2018-01-01

    Poleward atmospheric moisture transport (AMT) into the Arctic Ocean can change atmospheric moisture or water vapor content and cause cloud formation and redistribution, which may change downward longwave radiation and, in turn, surface energy budgets, air temperatures, and sea-ice production and melt. In this study, we found a consistently enhanced poleward AMT across 60°N since 1959 based on the NCAR-NCEP reanalysis. Regional analysis demonstrates that the poleward AMT predominantly occurs over the North Atlantic and North Pacific regions, contributing about 57% and 32%, respectively, to the total transport. To improve our understanding of the driving force for this enhanced poleward AMT, we explored the role that extratropical cyclone activity may play. Climatologically, about 207 extratropical cyclones move across 60°N into the Arctic Ocean each year, among which about 66 (32% of the total) and 47 (23%) originate from the North Atlantic and North Pacific Ocean, respectively. When analyzing the linear trends of the time series constructed by using a 20-year running window, we found a positive correlation of 0.70 between poleward yearly AMT and the integrated cyclone activity index (measurement of cyclone intensity, number, and duration). This shows the consistent multidecadal changes between these two parameters and may suggest cyclone activity plays a driving role in the enhanced poleward AMT. Furthermore, a composite analysis indicates that intensification and poleward extension of the Icelandic low and accompanying strengthened cyclone activity play an important role in enhancing poleward AMT over the North Atlantic region.

  15. On the unstable mode merging of gravity-inertial waves with Rossby waves

    Directory of Open Access Journals (Sweden)

    J. F. McKenzie

    2011-08-01

    Full Text Available We recapitulate the results of the combined theory of gravity-inertial-Rossby waves in a rotating, stratified atmosphere. The system is shown to exhibit a "local" (JWKB instability whenever the phase speed of the low-frequency-long wavelength westward propagating Rossby wave exceeds the phase speed ("Kelvin" speed of the high frequency-short wavelength gravity-inertial wave. This condition ensures that mode merging, leading to instability, takes place in some intermediate band of frequencies and wave numbers. The contention that such an instability is "spurious" is not convincing. The energy source of the instability resides in the background enthalpy which can be released by the action of the gravitational buoyancy force, through the combined wave modes.

  16. Forced solitary Rossby waves under the influence of slowly varying topography with time

    International Nuclear Information System (INIS)

    Yang Hong-Wei; Yin Bao-Shu; Yang De-Zhou; Xu Zhen-Hua

    2011-01-01

    By using a weakly nonlinear and perturbation method, the generalized inhomogeneous Korteweg—de Vries (KdV)—Burgers equation is derived, which governs the evolution of the amplitude of Rossby waves under the influence of dissipation and slowly varying topography with time. The analysis indicates that dissipation and slowly varying topography with time are important factors in causing variation in the mass and energy of solitary waves. (general)

  17. Generalized investigation of the rotation-activity relation: favoring rotation period instead of Rossby number

    International Nuclear Information System (INIS)

    Reiners, A.; Passegger, V. M.; Schüssler, M.

    2014-01-01

    Magnetic activity in Sun-like and low-mass stars causes X-ray coronal emission which is stronger for more rapidly rotating stars. This relation is often interpreted in terms of the Rossby number, i.e., the ratio of rotation period to convective overturn time. We reconsider this interpretation on the basis of the observed X-ray emission and rotation periods of 821 stars with masses below 1.4 M ☉ . A generalized analysis of the relation between X-ray luminosity normalized by bolometric luminosity, L X /L bol , and combinations of rotational period, P, and stellar radius, R, shows that the Rossby formulation does not provide the solution with minimal scatter. Instead, we find that the relation L X /L bol ∝P –2 R –4 optimally describes the non-saturated fraction of the stars. This relation is equivalent to L X ∝P –2 , indicating that the rotation period alone determines the total X-ray emission. Since L X is directly related to the magnetic flux at the stellar surface, this means that the surface flux is determined solely by the star's rotation and is independent of other stellar parameters. While a formulation in terms of a Rossby number would be consistent with these results if the convective overturn time scales exactly as L bol −1/2 , our generalized approach emphasizes the need to test a broader range of mechanisms for dynamo action in cool stars.

  18. Instability of combined gravity-inertial-Rossby waves in atmospheres and oceans

    Directory of Open Access Journals (Sweden)

    J. F. McKenzie

    2011-06-01

    Full Text Available The properties of the instability of combined gravity-inertial-Rossby waves on a β-plane are investigated. The wave-energy exchange equation shows that there is an exchange of energy with the background stratified medium. The energy source driving the instability lies in the background enthalpy released by the gravitational buoyancy force. It is shown that if the phase speed of the westward propagating low frequency-long wavelength Rossby wave exceeds the Poincaré-Kelvin (or "equivalent" shallow water wave speed, instability arises from the merging of Rossby and Poincaré modes. There are two key parameters in this instability condition; namely, the equatorial/rotational Mach (or Froude number M and the latitude θ0 of the β-plane. In general waves equatorward of a critical latitude for given M can be driven unstable, with corresponding growth rates of the order of a day or so. Although these conclusions may only be safely drawn for short wavelengths corresponding to a JWKB wave packet propagating internally and located far from boundaries, nevertheless such a local instability may play a significant role in atmosphere-ocean dynamics.

  19. A note on poleward undercurrent along the southwest coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Muraleedharan, P.M.; RameshKumar, M.R.; Rao, L.V.G.

    . The climatological data supports this observation but the wind stress further south contradicts the climatological picture. Similarly the trend of the northerly wind from Cochin to Marmagao appears to be far from reality when compared to the climatological wind... and SALAT, 1981). If the narrowing of surface currents at Quilon is associated with the topography of the sea floor which could funnel or constrict the longshore current, it might augment the intensity of upwelling close to the coast• The poleward...

  20. Changing storm track diffusivity and the upper limit to poleward latent heat transport

    Science.gov (United States)

    Caballero, R.

    2010-12-01

    Poleward atmospheric energy transport plays a key role in the climate system by helping set the mean equator-pole temperature gradient. The mechanisms controlling the response of poleward heat flux to climate change are still poorly understood. Recent work shows that midlatitude poleward latent heat flux in atmospheric GCMs generally increases as the climate warms but reaches an upper limit at sufficiently high temperature and decreases with further warming. The reasons for this non-monotonic behavior have remained unclear. Simple arguments suggests that the latent heat flux Fl should scale as Fl ˜ vref qs, where vref is a typical meridional velocity in the baroclinic zone and qs is saturation humidity. While vref decreases with temperature, qs increases much more rapidly, so this scaling implies monotonically increasing moisture flux. We study this problem using a series of simulations employing NCAR’s CAM3 GCM coupled to a slab-ocean aquaplanet and spanning a wide range of atmospheric CO2 concentrations. We find that a modified scaling, Fl ˜ vref2 qs, describes the changes in moisture flux much more accurately. Using Lagrangian trajectory analysis, we explain the success of this scaling in terms of changes in the mixing length, which contracts proportionally to vref.

  1. MATLAB: break

    OpenAIRE

    2005-01-01

    Interactive Media Element This interactive tutorial on MATLAB covers the use of the break function. An example demonstrates how the break function affects a for loop with if instruction embedded in the loop. An example is provided with step-by-step animated explanation. The interactions involve entering MATLAB instructions and observing the outcomes. Self-check questions are provided to help learners determine their level of understanding of the content presented. EC1010 Introduction...

  2. The Effect of Surface Topography on the Nonlinear Dynamics of Rossby Waves

    Science.gov (United States)

    Abarzhi, S. I.; Desjardins, O.; Pitsch, H.

    2003-01-01

    Boussinesq convection in rotating systems attracts a sustained attention of the fluid dynamics community, because it has intricate non-linear dynamics (Cross & Hohenberg 1993) and plays an important role in geophysical and astrophysical applications, such as the motion of the liquid outer core of Earth, the Red Spot in Jupiter, the giant cells in the Sun etc. (Alridge et al. 1990). A fundamental distinction between the real geo- and astrophysical problems and the idealized laboratory studies is that natural systems are inhomogeneous (Alridge et al. 1990). Heterogeneities modulate the flow and influence significantly the dynamics of convective patterns (Alridge et al. 1990; Hide 1971). The effect of modulations on pattern formation and transition to turbulence in Boussinesq convection is far from being completely understood (Cross & Hohenberg 1993; Aranson & Kramer 2002). It is generally accepted that in the liquid outer core of the Earth the transport of the angular momentum and internal heat occurs via thermal Rossby waves (Zhang et al. 2001; Kuang & Bloxham 1999). These waves been visualized in laboratory experiments in rotating liquid-filled spheres and concentric spherical shells (Zhang et al. 2001; Kuang & Bloxham 1999). The basic dynamical features of Rossby waves have been reproduced in a cylindrical annulus, a system much simpler than the spherical ones (Busse & Or 1986; Or & Busse 1987). For convection in a cylindrical annulus, the fluid motion is two-dimensional, and gravity is replaced by a centrifugal force, (Busse & Or 1986; Or & Busse 1987). Hide (1971) has suggested that the momentum and heat transport in the core might be influenced significantly by so-called bumps, which are heterogeneities on the mantle-core boundary. To model the effect of surface topography on the transport of momentum and energy in the liquid outer core of the Earth, Bell & Soward (1996), Herrmann & Busse (1998) and Westerburg & Busse (2001) have studied the nonlinear dynamics

  3. Nonaxisymmetric Rossby vortex instability with toroidal magnetic fields in structured disks

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Cong [Los Alamos National Laboratory; Li, Hui [Los Alamos National Laboratory

    2009-01-01

    We investigate the global nonaxisymmetric Rossby vortex instability (RVI) in a differentially rotating, compressible magnetized accretion disk with radial density structures. Equilibrium magnetic fields are assumed to have only the toroidal component. Using linear theory analysis, we show that the density structure can be unstable to nonaxisymmetric modes. We find that, for the magnetic field profiles we have studied, magnetic fields always provide a stabilizing effect to the unstable RVI modes. We discuss the physical mechanism of this stabilizing effect. The threshold and properties of the unstable modes are also discussed in detail. In addition, we present linear stability results for the global magnetorotational instability when the disk is compressible.

  4. Nonlinear self-adjointness and invariant solutions of a 2D Rossby wave equation

    Science.gov (United States)

    Cimpoiasu, Rodica; Constantinescu, Radu

    2014-02-01

    The paper investigates the nonlinear self-adjointness of the nonlinear inviscid barotropic nondivergent vorticity equation in a beta-plane. It is a particular form of Rossby equation which does not possess variational structure and it is studied using a recently method developed by Ibragimov. The conservation laws associated with the infinite-dimensional symmetry Lie algebra models are constructed and analyzed. Based on this Lie algebra, some classes of similarity invariant solutions with nonconstant linear and nonlinear shears are obtained. It is also shown how one of the conservation laws generates a particular wave solution of this equation.

  5. Conservation laws of wave action and potential enstrophy for Rossby waves in a stratified atmosphere

    Science.gov (United States)

    Straus, D. M.

    1983-01-01

    The evolution of wave energy, enstrophy, and wave motion for atmospheric Rossby waves in a variable mean flow are discussed from a theoretical and pedagogic standpoint. In the absence of mean flow gradients, the wave energy density satisfies a local conservation law, with the appropriate flow velocity being the group velocity. In the presence of mean flow variations, wave energy is not conserved, but wave action is, provided the mean flow is independent of longitude. Wave enstrophy is conserved for arbitrary variations of the mean flow. Connections with Eliassen-Palm flux are also discussed.

  6. Structure, stability, and evolution of 3D Rossby vortices in protoplanetary disks

    Science.gov (United States)

    Richard, S.; Barge, P.; Le Dizès, S.

    2013-11-01

    Context. Large-scale persistent vortices could play a key role in the evolution of protoplanetary disks, particularly in the dead zone where no turbulence associated with a magnetic field is expected. These vortices are known to form easily in 2D disks via the Rossby wave or the baroclinic instability. In three dimensions, however, their formation and stability is a complex problem and still a matter of debate. Aims: We study the formation of vortices by the Rossby wave instability in a stratified inviscid disk and describe their 3D structure, stability, and long-term evolution. Methods: Numerical simulations were performed using a fully compressible hydrodynamical code based on a second-order finite volume method. We assumed a perfect-gas law and a non-homentropic adiabatic flow. Results: The Rossby wave instability is found to proceed in 3D in a similar way as in 2D. Vortices produced by the instability look like columns of vorticity in the whole disk thickness; the weak vertical motions are related to the weak inclination of the vortex axis that appears during the development of the RWI. Vortices with aspect ratios higher than 6 are unaffected by the elliptical instability. They relax into a quasi-steady columnar structure that survives hundreds of rotations while slowly migrating inward toward the star at a rate that reduces with the vortex aspect ratio. Vortices with a lower aspect ratio are by contrast affected by the elliptic instability. Short aspect ratio vortices (χ < 4) are completely destroyed in a few orbital periods. Vortices with an intermediate aspect ratio (4 < χ < 6) are partially destroyed by the elliptical instability in a region away from the midplane where the disk stratification is sufficiently strong. Conclusions: Elongated Rossby vortices can survive many orbital periods in protoplanetary disks in the form of vorticity columns. They could play a significant role in the evolution of the gas and the gathering of solid particles to form

  7. Are Calanus spp. shifting poleward in the North Atlantic? A habitat modelling approach

    KAUST Repository

    Chust, Guillem

    2013-09-16

    In the last decade, the analysis based on Continuous Plankton Recorder survey in the eastern North Atlantic Ocean detected one of the most striking examples of marine poleward migration related to sea warming. The main objective of this study is to verify the poleward shift of zooplankton species (Calanus finmarchicus, C. glacialis, C. helgolandicus, C. hyperboreus) for which distributional changes have been recorded in the North Atlantic Ocean and to assess how much of this shift was triggered by sea warming, using Generalized Additive Models. To this end, the population gravity centre of observed data was compared with that of a series of simulation experiments: (i) a model using only climate factors (i.e. niche-based model) to simulate species habitat suitability, (ii) a model using only temporal and spatial terms to reconstruct the population distribution, and (iii) a model using both factors combined, using a subset of observations as independent dataset for validation. Our findings show that only C. finmarchicus had a consistent poleward shift, triggered by sea warming, estimated in 8.1 km per decade in the North Atlantic (16.5 per decade for the northeast), which is substantially lower than previous works at the assemblage level and restricted to the Northeast Atlantic. On the contrary, C. helgolandicus is expanding in all directions, although its northern distribution limit in the North Sea has shifted northward. Calanus glacialis and C. hyperboreus, which have the geographic centres of populations mainly in the NW Atlantic, showed a slight southward shift, probably responding to cool water penetrating southward in the Labrador Current. Our approach, supported by high model accuracy, shows its power in detecting species latitudinal shifts and identifying its causes, since the trend of occurrence observed data is influenced by the sampling frequency, which has progressively concentrated to lower latitudes with time. © 2013 © 2013 International Council for

  8. The Break

    DEFF Research Database (Denmark)

    Strand, Anete Mikkala Camille

    2018-01-01

    The chapter elaborates on how to deal with one of the major challenges facing organizations worldwide; Stress. The Break enacts a quantum approach to meet the challenges by proposing a combination of three different quantum storytelling technologies; protreptic mentoring, walking and material sto...

  9. Supersymmetry breaking

    Indian Academy of Sciences (India)

    symmetry asks for the existence of a bosonic massless partner, which generically correspond to a non-compact flat direction. ... Hidden Sector nonren.int. Ti, 〈Fi〉 = 0. Let us define the strength of supersymmetry breaking by F2 = ∑ ... partners, not protected by the GIM mechanism. Solutions for FCNC problem: (i) Flavour ...

  10. An alternative view on the role of the β-effect in the Rossby wave propagation mechanism

    Directory of Open Access Journals (Sweden)

    Eyal Heifetz

    2014-11-01

    Full Text Available The role of the β-effect in the Rossby wave propagation mechanism is examined in the linearised shallow water equations directly in momentum–height variables, without recourse to potential vorticity (PV. Rigorous asymptotic expansion of the equations, with respect to the small non-dimensionalised β parameter, reveals in detail how the Coriolis force acting on the small ageostrophic terms translates the geostrophic leading-order solution to propagate westward in concert. This information cannot be obtained directly from the conventional PV perspective on the propagation mechanism. Furthermore, a comparison between the β-effect in planetary Rossby waves and the sloping-bottom effect in promoting topographic Rossby waves shows that the ageostrophic terms play different roles in the two cases. This is despite the fact that from the PV viewpoint whether the advection of mean PV gradient is set up by changes in planetary vorticity or by mean depth is inconsequential.

  11. Electroweak breaking and supersymmetry breaking

    Indian Academy of Sciences (India)

    We discuss the clash between the absence of fine tuning in the Higgs potential and a sufficient suppression of flavour changing neutral current transitions in supersymmetric extensions of the standard model. It is pointed out that horizontal U ( 1 ) symmetry combined with the D -term supersymmetry breaking provides a ...

  12. A new model for algebraic Rossby solitary waves in rotation fluid and its solution

    Science.gov (United States)

    Chen, Yao-Deng; Yang, Hong-Wei; Gao, Yu-Fang; Yin, Bao-Shu; Feng, Xing-Ru

    2015-09-01

    A generalized Boussinesq equation that includes the dissipation effect is derived to describe a kind of algebraic Rossby solitary waves in a rotating fluid by employing perturbation expansions and stretching transformations of time and space. Using this equation, the conservation laws of algebraic Rossby solitary waves are discussed. It is found that the mass, the momentum, the energy, and the velocity of center of gravity of the algebraic solitary waves are conserved in the propagation process. Finally, the analytical solution of the equation is generated. Based on the analytical solution, the properties of the algebraic solitary waves and the dissipation effect are discussed. The results point out that, similar to classic solitary waves, the dissipation can cause the amplitude and the speed of solitary waves to decrease; however, unlike classic solitary waves, the algebraic solitary waves can split during propagation and the decrease of the detuning parameter can accelerate the occurrence of the solitary waves fission phenomenon. Project supported by the Shandong Provincial Key Laboratory of Marine Ecology and Environment and Disaster Prevention and Mitigation Project, China (Grant No. 2012010), the National Natural Science Foundation of China (Grant Nos. 41205082 and 41476019), the Special Funds for Theoretical Physics of the National Natural Science Foundation of China (Grant No. 11447205), and the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD), China.

  13. MAGNETIC ROSSBY WAVES IN THE SOLAR TACHOCLINE AND RIEGER-TYPE PERIODICITIES

    International Nuclear Information System (INIS)

    Zaqarashvili, Teimuraz V.; Carbonell, Marc; Oliver, Ramon; Ballester, Jose Luis

    2010-01-01

    Apart from the eleven-year solar cycle, another periodicity around 155-160 days was discovered during solar cycle 21 in high-energy solar flares, and its presence in sunspot areas and strong magnetic flux has been also reported. This periodicity has an elusive and enigmatic character, since it usually appears only near the maxima of solar cycles, and seems to be related with a periodic emergence of strong magnetic flux at the solar surface. Therefore, it is probably connected with the tachocline, a thin layer located near the base of the solar convection zone, where a strong dynamo magnetic field is stored. We study the dynamics of Rossby waves in the tachocline in the presence of a toroidal magnetic field and latitudinal differential rotation. Our analysis shows that the magnetic Rossby waves are generally unstable and that the growth rates are sensitive to the magnetic field strength and to the latitudinal differential rotation parameters. Variation of the differential rotation and the magnetic field strength throughout the solar cycle enhance the growth rate of a particular harmonic in the upper part of the tachocline around the maximum of the solar cycle. This harmonic is symmetric with respect to the equator and has a period of 155-160 days. A rapid increase of the wave amplitude could give rise to a magnetic flux emergence leading to observed periodicities in solar activity indicators related to magnetic flux.

  14. QUASI-BIENNIAL OSCILLATIONS IN THE SOLAR TACHOCLINE CAUSED BY MAGNETIC ROSSBY WAVE INSTABILITIES

    International Nuclear Information System (INIS)

    Zaqarashvili, Teimuraz V.; Carbonell, Marc; Oliver, Ramon; Ballester, Jose Luis

    2010-01-01

    Quasi-biennial oscillations (QBOs) are frequently observed in solar activity indices. However, no clear physical mechanism for the observed variations has been suggested so far. Here, we study the stability of magnetic Rossby waves in the solar tachocline using the shallow water magnetohydrodynamic approximation. Our analysis shows that the combination of typical differential rotation and a toroidal magnetic field with a strength of ≥10 5 G triggers the instability of the m = 1 magnetic Rossby wave harmonic with a period of ∼2 years. This harmonic is antisymmetric with respect to the equator and its period (and growth rate) depends on the differential rotation parameters and magnetic field strength. The oscillations may cause a periodic magnetic flux emergence at the solar surface and consequently may lead to the observed QBO in solar activity features. The period of QBOs may change throughout a cycle, and from cycle to cycle, due to variations of the mean magnetic field and differential rotation in the tachocline.

  15. The poleward migration of the location of tropical cyclone maximum intensity.

    Science.gov (United States)

    Kossin, James P; Emanuel, Kerry A; Vecchi, Gabriel A

    2014-05-15

    Temporally inconsistent and potentially unreliable global historical data hinder the detection of trends in tropical cyclone activity. This limits our confidence in evaluating proposed linkages between observed trends in tropical cyclones and in the environment. Here we mitigate this difficulty by focusing on a metric that is comparatively insensitive to past data uncertainty, and identify a pronounced poleward migration in the average latitude at which tropical cyclones have achieved their lifetime-maximum intensity over the past 30 years. The poleward trends are evident in the global historical data in both the Northern and the Southern hemispheres, with rates of 53 and 62 kilometres per decade, respectively, and are statistically significant. When considered together, the trends in each hemisphere depict a global-average migration of tropical cyclone activity away from the tropics at a rate of about one degree of latitude per decade, which lies within the range of estimates of the observed expansion of the tropics over the same period. The global migration remains evident and statistically significant under a formal data homogenization procedure, and is unlikely to be a data artefact. The migration away from the tropics is apparently linked to marked changes in the mean meridional structure of environmental vertical wind shear and potential intensity, and can plausibly be linked to tropical expansion, which is thought to have anthropogenic contributions.

  16. Poleward upgliding Siberian atmospheric rivers over sea ice heat up Arctic upper air.

    Science.gov (United States)

    Komatsu, Kensuke K; Alexeev, Vladimir A; Repina, Irina A; Tachibana, Yoshihiro

    2018-02-13

    We carried out upper air measurements with radiosondes during the summer over the Arctic Ocean from an icebreaker moving poleward from an ice-free region, through the ice edge, and into a region of thick ice. Rapid warming of the Arctic is a significant environmental issue that occurs not only at the surface but also throughout the troposphere. In addition to the widely accepted mechanisms responsible for the increase of tropospheric warming during the summer over the Arctic, we showed a new potential contributing process to the increase, based on our direct observations and supporting numerical simulations and statistical analyses using a long-term reanalysis dataset. We refer to this new process as "Siberian Atmospheric Rivers (SARs)". Poleward upglides of SARs over cold air domes overlying sea ice provide the upper atmosphere with extra heat via condensation of water vapour. This heating drives increased buoyancy and further strengthens the ascent and heating of the mid-troposphere. This process requires the combination of SARs and sea ice as a land-ocean-atmosphere system, the implication being that large-scale heat and moisture transport from the lower latitudes can remotely amplify the warming of the Arctic troposphere in the summer.

  17. Poleward energy transport: is the standard definition physically relevant at all time scales?

    Science.gov (United States)

    Liang, Minyi; Czaja, Arnaud; Graversen, Rune; Tailleux, Remi

    2018-03-01

    Poleward energy transport in the atmosphere and oceans constitutes an important branch of the global energy budget, and its role in the climate system has been the subject of many studies. In the atmosphere, the transport is affected by "eddies" and large scale meridional cells, both with zero net mass transport across latitude circles, but also partly by processes associated with a net transport of mass across latitude circles. The latter must cease to operate in steady state, but they may be significant when time variability of the heat budget is considered. Indeed, examination of reanalysis data on short (daily to monthly) timescales shows that mass variations on these timescales result in surprisingly large fluctuations (in excess of 10^{15} W = 1 PW) in the poleward heat transport. These fluctuations are referred to as "extensive", for they primarily alter the mass integrated energy of the region considered, but not its averaged value. It is suggested that extensive fluctuations mask more meaningful climate signals present in the heat transport variability on monthly and interannual timescales, and a new formulation is proposed to isolate the latter. This new formulation is applied successfully to reanalysis data and climate model simulations.

  18. Breaking Symmetries

    Directory of Open Access Journals (Sweden)

    Kirstin Peters

    2010-11-01

    Full Text Available A well-known result by Palamidessi tells us that πmix (the π-calculus with mixed choice is more expressive than πsep (its subset with only separate choice. The proof of this result argues with their different expressive power concerning leader election in symmetric networks. Later on, Gorla offered an arguably simpler proof that, instead of leader election in symmetric networks, employed the reducibility of incestual processes (mixed choices that include both enabled senders and receivers for the same channel when running two copies in parallel. In both proofs, the role of breaking (initial symmetries is more or less apparent. In this paper, we shed more light on this role by re-proving the above result - based on a proper formalization of what it means to break symmetries without referring to another layer of the distinguishing problem domain of leader election. Both Palamidessi and Gorla rephrased their results by stating that there is no uniform and reasonable encoding from πmix into πsep. We indicate how the respective proofs can be adapted and exhibit the consequences of varying notions of uniformity and reasonableness. In each case, the ability to break initial symmetries turns out to be essential.

  19. Signatures of Kelvin and Rossby wave propagation in the northern Indian Ocean from TOPEX/POSEIDON Altimeter

    Digital Repository Service at National Institute of Oceanography (India)

    PrasannaKumar, S.; Unnikrishnan, A.S.; Muraleedharan, P.M.

    of sea level anomaly. The plots along 6 degrees, 12 degrees and 18 degrees N show the westward propagating (Rossby waves) features, the speed of which decreases from 7.74 cm s super(-1) at 12 degrees N to 4.50 cm s super(-1) at 18 degrees N. These speeds...

  20. The modified drift-Poisson model: Analogies with geophysical flows and Rossby waves

    International Nuclear Information System (INIS)

    Castillo-Negrete, D. del; Finn, J. M.; Barnes, D. C.

    1999-01-01

    We discuss an analogy between magnetically confined nonneutral plasmas and geophysical fluid dynamics. The analogy has its roots in the modified drift Poisson model, a recently proposed model that takes into account the plasma compression due to the variations of the plasma length [1]. The conservation of the line integrated density in the new model is analogous to the conservation of potential vorticity in the shallow water equations, and the variation of the plasma length is isomorphic to variations in the Coriolis parameter with latitude or to topography variations in the quasigeostrophic dynamics. We discuss a new class of linear and nonlinear waves that owe their existence to the variations of the plasma length. These modes are the analog of Rossby waves in geophysical flows

  1. A new technique based on the transformation of variables for nonlinear drift and Rossby vortices

    International Nuclear Information System (INIS)

    Orito, Kohtaro

    1996-07-01

    The quasi-two-dimensional nonlinear equations for drift and Rossby vortices have some stationary multipole solutions, and especially the dipole vortex solution is called modon. These solutions are valid only in the lowest order where the fluid velocity has a stream function. In order to investigate features of the multipole solutions more accurately, the effect of the higher order terms, for example the polarization drift in a plasma or the Coriolis force in a rotating planet, needs to be considered. It is shown that the higher order analysis through a new technique based on a transformation of variables is much easier than a straightforward iteration. The solutions in this analysis are obtained by inverse transformation to the original coordinates, where the profiles of potentials are distorted by the effects of higher order terms. (author)

  2. Rossby wave propagation and teleconnections for the Northern Hemisphere summer flow

    International Nuclear Information System (INIS)

    Ambrizzi, T.; Hoskins, B.J.

    1994-01-01

    To produce more confident predictions of global climate change, we have first to understand the climate itself. One way to do this is to use a numerical model in order to simulate a specific aspect observed in the atmosphere in an attempt to gain an insight into its dynamics. Teleconnection analysis comprises a global view of atmospheric circulation where local phenomena act to influence remote regions in the atmosphere. They have been used mainly to study large-scale low frequency fluctuations in the atmosphere. Their importance for long range weather forecasting, for instance, is obvious. The theory of Rossby wave propagation can largely explain patterns of wavetrains obtained in observations and in the results of models

  3. On the pattern of CO2 radiative forcing and poleward energy transport

    Science.gov (United States)

    Huang, Yi; Xia, Yan; Tan, Xiaoxiao

    2017-10-01

    A set of general circulation model experiments are conducted to analyze how the poleward energy transport (PET) is related to the spatial pattern of CO2 radiative forcing. The effects of forcing pattern are affirmed by comparing the conventional doubling CO2 experiment, in which the forcing pattern is inhomogeneous, to a set of forcing homogenization experiments, in which the top of atmosphere (TOA), surface, or atmospheric forcing distribution is homogenized respectively. In addition, we separate and compare the effects of CO2 forcing to various feedbacks on atmospheric and oceanic PETs, by using a set of radiative kernels that we have developed for both TOA and surface radiation fluxes. The results here show that both the enhancement of atmospheric PET and weakening of oceanic PET during global warming are directly driven by the meridional gradients of the CO2 forcing. Interestingly, the overall feedback effect is to reinforce the forcing effect, mainly through the cloud feedback in the case of atmospheric PET and the albedo feedback in the case of the oceanic PET. Contrary to previous studies, we find that the water vapor feedback only has a weak effect on atmospheric PET. The Arctic warming amplification, which strongly affects atmospheric PET, is sensitive to the CO2 forcing pattern.

  4. Instability of coupled gravity-inertial-Rossby waves on a β-plane in solar system atmospheres

    Directory of Open Access Journals (Sweden)

    J. F. McKenzie

    2009-11-01

    Full Text Available This paper provides an analysis of the combined theory of gravity-inertial-Rossby waves on a β-plane in the Boussinesq approximation. The wave equation for the system is fifth order in space and time and demonstrates how gravity-inertial waves on the one hand are coupled to Rossby waves on the other through the combined effects of β, the stratification characterized by the Väisälä-Brunt frequency N, the Coriolis frequency f at a given latitude, and vertical propagation which permits buoyancy modes to interact with westward propagating Rossby waves. The corresponding dispersion equation shows that the frequency of a westward propagating gravity-inertial wave is reduced by the coupling, whereas the frequency of a Rossby wave is increased. If the coupling is sufficiently strong these two modes coalesce giving rise to an instability. The instability condition translates into a curve of critical latitude Θc versus effective equatorial rotational Mach number M, with the region below this curve exhibiting instability. "Supersonic" fast rotators are unstable in a narrow band of latitudes around the equator. For example Θc~12° for Jupiter. On the other hand slow "subsonic" rotators (e.g. Mercury, Venus and the Sun's Corona are unstable at all latitudes except very close to the poles where the β effect vanishes. "Transonic" rotators, such as the Earth and Mars, exhibit instability within latitudes of 34° and 39°, respectively, around the Equator. Similar results pertain to Oceans. In the case of an Earth's Ocean of depth 4km say, purely westward propagating waves are unstable up to 26° about the Equator. The nonlinear evolution of this instability which feeds off rotational energy and gravitational buoyancy may play an important role in atmospheric dynamics.

  5. Instability of coupled gravity-inertial-Rossby waves on a β-plane in solar system atmospheres

    Directory of Open Access Journals (Sweden)

    J. F. McKenzie

    2009-11-01

    Full Text Available This paper provides an analysis of the combined theory of gravity-inertial-Rossby waves on a β-plane in the Boussinesq approximation. The wave equation for the system is fifth order in space and time and demonstrates how gravity-inertial waves on the one hand are coupled to Rossby waves on the other through the combined effects of β, the stratification characterized by the Väisälä-Brunt frequency N, the Coriolis frequency f at a given latitude, and vertical propagation which permits buoyancy modes to interact with westward propagating Rossby waves. The corresponding dispersion equation shows that the frequency of a westward propagating gravity-inertial wave is reduced by the coupling, whereas the frequency of a Rossby wave is increased. If the coupling is sufficiently strong these two modes coalesce giving rise to an instability. The instability condition translates into a curve of critical latitude Θc versus effective equatorial rotational Mach number M, with the region below this curve exhibiting instability. "Supersonic" fast rotators are unstable in a narrow band of latitudes around the equator. For example Θc~12° for Jupiter. On the other hand slow "subsonic" rotators (e.g. Mercury, Venus and the Sun's Corona are unstable at all latitudes except very close to the poles where the β effect vanishes. "Transonic" rotators, such as the Earth and Mars, exhibit instability within latitudes of 34° and 39°, respectively, around the Equator. Similar results pertain to Oceans. In the case of an Earth's Ocean of depth 4km say, purely westward propagating waves are unstable up to 26° about the Equator. The nonlinear evolution of this instability which feeds off rotational energy and gravitational buoyancy may play an important role in atmospheric dynamics.

  6. Multiscale numerical simulations of magnetoconvection at low magnetic Prandtl and Rossby numbers.

    Science.gov (United States)

    Maffei, S.; Calkins, M. A.; Julien, K. A.; Marti, P.

    2017-12-01

    The dynamics of the Earth's outer core is characterized by low values of the Rossby (Ro), Ekman and magnetic Prandtl numbers. These values indicate the large spectra of temporal and spatial scales that need to be accounted for in realistic numerical simulations of the system. Current direct numerical simulation are not capable of reaching this extreme regime, suggesting that a new class of models is required to account for the rich dynamics expected in the natural system. Here we present results from a quasi-geostrophic, multiscale model based on the scale separation implied by the low Ro typical of rapidly rotating systems. We investigate a plane layer geometry where convection is driven by an imposed temperature gradient and the hydrodynamic equations are modified by a large scale magnetic field. Analytical investigation shows that at values of thermal and magnetic Prandtl numbers relevant for liquid metals, the energetic requirements for the onset of convection is not significantly altered even in the presence of strong magnetic fields. Results from strongly forced nonlinear numerical simulations show the presence of an inverse cascade, typical of 2-D turbulence, when no or weak magnetic field is applied. For higher values of the magnetic field the inverse cascade is quenched.

  7. Climate change alters the structure of arctic marine food webs due to poleward shifts of boreal generalists

    Science.gov (United States)

    Kortsch, Susanne; Primicerio, Raul; Fossheim, Maria; Dolgov, Andrey V.; Aschan, Michaela

    2015-01-01

    Climate-driven poleward shifts, leading to changes in species composition and relative abundances, have been recently documented in the Arctic. Among the fastest moving species are boreal generalist fish which are expected to affect arctic marine food web structure and ecosystem functioning substantially. Here, we address structural changes at the food web level induced by poleward shifts via topological network analysis of highly resolved boreal and arctic food webs of the Barents Sea. We detected considerable differences in structural properties and link configuration between the boreal and the arctic food webs, the latter being more modular and less connected. We found that a main characteristic of the boreal fish moving poleward into the arctic region of the Barents Sea is high generalism, a property that increases connectance and reduces modularity in the arctic marine food web. Our results reveal that habitats form natural boundaries for food web modules, and that generalists play an important functional role in coupling pelagic and benthic modules. We posit that these habitat couplers have the potential to promote the transfer of energy and matter between habitats, but also the spread of pertubations, thereby changing arctic marine food web structure considerably with implications for ecosystem dynamics and functioning. PMID:26336179

  8. Climate change alters the structure of arctic marine food webs due to poleward shifts of boreal generalists.

    Science.gov (United States)

    Kortsch, Susanne; Primicerio, Raul; Fossheim, Maria; Dolgov, Andrey V; Aschan, Michaela

    2015-09-07

    Climate-driven poleward shifts, leading to changes in species composition and relative abundances, have been recently documented in the Arctic. Among the fastest moving species are boreal generalist fish which are expected to affect arctic marine food web structure and ecosystem functioning substantially. Here, we address structural changes at the food web level induced by poleward shifts via topological network analysis of highly resolved boreal and arctic food webs of the Barents Sea. We detected considerable differences in structural properties and link configuration between the boreal and the arctic food webs, the latter being more modular and less connected. We found that a main characteristic of the boreal fish moving poleward into the arctic region of the Barents Sea is high generalism, a property that increases connectance and reduces modularity in the arctic marine food web. Our results reveal that habitats form natural boundaries for food web modules, and that generalists play an important functional role in coupling pelagic and benthic modules. We posit that these habitat couplers have the potential to promote the transfer of energy and matter between habitats, but also the spread of pertubations, thereby changing arctic marine food web structure considerably with implications for ecosystem dynamics and functioning. © 2015 The Authors.

  9. Dynamic habitat suitability modelling reveals rapid poleward distribution shift in a mobile apex predator.

    Science.gov (United States)

    Hill, Nicholas J; Tobin, Andrew J; Reside, April E; Pepperell, Julian G; Bridge, Tom C L

    2016-03-01

    Many taxa are undergoing distribution shifts in response to anthropogenic climate change. However, detecting a climate signal in mobile species is difficult due to their wide-ranging, patchy distributions, often driven by natural climate variability. For example, difficulties associated with assessing pelagic fish distributions have rendered fisheries management ill-equipped to adapt to the challenges posed by climate change, leaving pelagic species and ecosystems vulnerable. Here, we demonstrate the value of citizen science data for modelling the dynamic habitat suitability of a mobile pelagic predator (black marlin, Istiompax indica) within the south-west Pacific Ocean. The extensive spatial and temporal coverage of our occurrence data set (n = 18 717), collected at high resolution (~1.85 km(2) ), enabled identification of suitable habitat at monthly time steps over a 16-year period (1998-2013). We identified considerable monthly, seasonal and interannual variability in the extent and distribution of suitable habitat, predominately driven by chlorophyll a and sea surface height. Interannual variability correlated with El Nino Southern Oscillation (ENSO) events, with suitable habitat extending up to ~300 km further south during La Nina events. Despite the strong influence of ENSO, our model revealed a rapid poleward shift in the geometric mean of black marlin habitat, occurring at 88.2 km decade(-1) . By incorporating multiple environmental factors at monthly time steps, we were able to demonstrate a rapid distribution shift in a mobile pelagic species. Our findings suggest that the rapid velocity of climate change in the south-west Pacific Ocean is likely affecting mobile pelagic species, indicating that they may be more vulnerable to climate change than previously thought. © 2015 John Wiley & Sons Ltd.

  10. On Liapunov and Exponential Stability of Rossby-Haurwitz Waves in Invariant Sets of Perturbations

    Science.gov (United States)

    Skiba, Yuri N.

    2018-01-01

    In this work, the stability of the Rossby-Haurwitz (RH) waves from the subspace H1\\oplus Hn is considered (n≥2 ) where Hk is the subspace of the homogeneous spherical polynomials of degree k. A conservation law for arbitrary perturbations of the RH wave is derived, and all perturbations are divided into three invariant sets M-n , M0n and M+n in which the mean spectral number χ (ψ ^' }) of any perturbation ψ ^' } is less than, equal to or greater than n(n+1) , respectively. In turn, the set M0n is divided into the invariant subsets Hn and M0n{\\setminus } Hn . Quotient spaces and norms of the perturbations are introduced, a hyperbolic law for the perturbations belonging to the sets M-n and M+n is derived, and a geometric interpretation of variations in the kinetic energy of perturbations is given. It is proved that any non-zonal RH wave from H1\\oplus Hn (n≥2 ) is Liapunov unstable in the invariant set M-n . Also, it is shown that a stationary RH wave from H1\\oplus Hn may be exponentially unstable only in the invariant set M0n{\\setminus } Hn , while any perturbation of the invariant set Hn conserves its form with time and hence is neutral. Since a Legendre polynomial flow aPn(μ ) and zonal RH wave - ω μ +aPn(μ ) are particular cases of the RH waves of H1\\oplus Hn , the major part of the stability results obtained here is also true for them.

  11. Body size, growth and life span: implications for the polewards range shift of Octopus tetricus in south-eastern Australia.

    Directory of Open Access Journals (Sweden)

    Jorge E Ramos

    Full Text Available Understanding the response of any species to climate change can be challenging. However, in short-lived species the faster turnover of generations may facilitate the examination of responses associated with longer-term environmental change. Octopus tetricus, a commercially important species, has undergone a recent polewards range shift in the coastal waters of south-eastern Australia, thought to be associated with the southerly extension of the warm East Australian Current. At the cooler temperatures of a polewards distribution limit, growth of a species could be slower, potentially leading to a bigger body size and resulting in a slower population turnover, affecting population viability at the extreme of the distribution. Growth rates, body size, and life span of O. tetricus were examined at the leading edge of a polewards range shift in Tasmanian waters (40°S and 147°E throughout 2011. Octopus tetricus had a relatively small body size and short lifespan of approximately 11 months that, despite cooler temperatures, would allow a high rate of population turnover and may facilitate the population increase necessary for successful establishment in the new extended area of the range. Temperature, food availability and gender appear to influence growth rate. Individuals that hatched during cooler and more productive conditions, but grew during warming conditions, exhibited faster growth rates and reached smaller body sizes than individuals that hatched into warmer waters but grew during cooling conditions. This study suggests that fast growth, small body size and associated rapid population turnover may facilitate the range shift of O. tetricus into Tasmanian waters.

  12. Body size, growth and life span: implications for the polewards range shift of Octopus tetricus in south-eastern Australia.

    Science.gov (United States)

    Ramos, Jorge E; Pecl, Gretta T; Moltschaniwskyj, Natalie A; Strugnell, Jan M; León, Rafael I; Semmens, Jayson M

    2014-01-01

    Understanding the response of any species to climate change can be challenging. However, in short-lived species the faster turnover of generations may facilitate the examination of responses associated with longer-term environmental change. Octopus tetricus, a commercially important species, has undergone a recent polewards range shift in the coastal waters of south-eastern Australia, thought to be associated with the southerly extension of the warm East Australian Current. At the cooler temperatures of a polewards distribution limit, growth of a species could be slower, potentially leading to a bigger body size and resulting in a slower population turnover, affecting population viability at the extreme of the distribution. Growth rates, body size, and life span of O. tetricus were examined at the leading edge of a polewards range shift in Tasmanian waters (40°S and 147°E) throughout 2011. Octopus tetricus had a relatively small body size and short lifespan of approximately 11 months that, despite cooler temperatures, would allow a high rate of population turnover and may facilitate the population increase necessary for successful establishment in the new extended area of the range. Temperature, food availability and gender appear to influence growth rate. Individuals that hatched during cooler and more productive conditions, but grew during warming conditions, exhibited faster growth rates and reached smaller body sizes than individuals that hatched into warmer waters but grew during cooling conditions. This study suggests that fast growth, small body size and associated rapid population turnover may facilitate the range shift of O. tetricus into Tasmanian waters.

  13. The dynamics of magnetic Rossby waves in spherical dynamo simulations: A signature of strong-field dynamos?

    Science.gov (United States)

    Hori, K.; Teed, R. J.; Jones, C. A.

    2018-03-01

    We investigate slow magnetic Rossby waves in convection-driven dynamos in rotating spherical shells. Quasi-geostrophic waves riding on a mean zonal flow may account for some of the geomagnetic westward drifts and have the potential to allow the toroidal field strength within the planetary fluid core to be estimated. We extend the work of Hori et al. (2015) to include a wider range of models, and perform a detailed analysis of the results. We find that a predicted dispersion relation matches well with the longitudinal drifts observed in our strong-field dynamos. We discuss the validity of our linear theory, since we also find that the nonlinear Lorentz terms influence the observed waveforms. These wave motions are excited by convective instability, which determines the preferred azimuthal wavenumbers. Studies of linear rotating magnetoconvection have suggested that slow magnetic Rossby modes emerge in the magnetostrophic regime, in which the Lorentz and Coriolis forces are in balance in the vorticity equation. We confirm this to be predominant balance for the slow waves we have detected in nonlinear dynamo systems. We also show that a completely different wave regime emerges if the magnetic field is not present. Finally we report the corresponding radial magnetic field variations observed at the surface of the shell in our simulations and discuss the detectability of these waves in the geomagnetic secular variation.

  14. LONG-TERM VARIATION IN THE SUN’S ACTIVITY CAUSED BY MAGNETIC ROSSBY WAVES IN THE TACHOCLINE

    Energy Technology Data Exchange (ETDEWEB)

    Zaqarashvili, Teimuraz V. [Space Research Institute, Austrian Academy of Sciences, Schmiedlstrasse 6, 8042 Graz (Austria); Oliver, Ramon; Ballester, Jose Luis [Departament de Física, Universitat de les Illes Balears, E-07122 Palma de Mallorca (Spain); Hanslmeier, Arnold [Institute für Physik, Geophysik Astrophysik und Meteorologie, University of Graz, Univ.-Platz 5, 8010 Graz (Austria); Carbonell, Marc [Departament de Matemàtiques i Informàtica, Universitat de les Illes Balears, E-07122 Palma de Mallorca (Spain); Gachechiladze, Tamar [Abastumani Astrophysical Observatory at Ilia State University, Tbilisi, Georgia (United States); Usoskin, Ilya G., E-mail: teimuraz.zaqarashvili@oeaw.ac.at [Sodankylä Geophysical Observatory and ReSoLVE Centre of Excellence, University of Oulu, FI-90014 Oulo (Finland)

    2015-06-01

    Long-term records of sunspot number and concentrations of cosmogenic radionuclides (10Be and 14C) on the Earth reveal the variation of the Sun's magnetic activity over hundreds and thousands of years. We identify several clear periods in sunspot, 10Be, and 14C data as 1000, 500, 350, 200, and 100 years. We found that the periods of the first five spherical harmonics of the slow magnetic Rossby mode in the presence of a steady toroidal magnetic field of 1200–1300 G in the lower tachocline are in perfect agreement with the timescales of observed variations. The steady toroidal magnetic field can be generated in the lower tachocline either due to the steady dynamo magnetic field for low magnetic diffusivity or due to the action of the latitudinal differential rotation on the weak poloidal primordial magnetic field, which penetrates from the radiative interior. The slow magnetic Rossby waves lead to variations of the steady toroidal magnetic field in the lower tachocline, which modulate the dynamo magnetic field and consequently the solar cycle strength. This result constitutes a key point for long-term prediction of the cycle strength. According to our model, the next deep minimum in solar activity is expected during the first half of this century.

  15. LONG-TERM VARIATION IN THE SUN’S ACTIVITY CAUSED BY MAGNETIC ROSSBY WAVES IN THE TACHOCLINE

    International Nuclear Information System (INIS)

    Zaqarashvili, Teimuraz V.; Oliver, Ramon; Ballester, Jose Luis; Hanslmeier, Arnold; Carbonell, Marc; Gachechiladze, Tamar; Usoskin, Ilya G.

    2015-01-01

    Long-term records of sunspot number and concentrations of cosmogenic radionuclides (10Be and 14C) on the Earth reveal the variation of the Sun's magnetic activity over hundreds and thousands of years. We identify several clear periods in sunspot, 10Be, and 14C data as 1000, 500, 350, 200, and 100 years. We found that the periods of the first five spherical harmonics of the slow magnetic Rossby mode in the presence of a steady toroidal magnetic field of 1200–1300 G in the lower tachocline are in perfect agreement with the timescales of observed variations. The steady toroidal magnetic field can be generated in the lower tachocline either due to the steady dynamo magnetic field for low magnetic diffusivity or due to the action of the latitudinal differential rotation on the weak poloidal primordial magnetic field, which penetrates from the radiative interior. The slow magnetic Rossby waves lead to variations of the steady toroidal magnetic field in the lower tachocline, which modulate the dynamo magnetic field and consequently the solar cycle strength. This result constitutes a key point for long-term prediction of the cycle strength. According to our model, the next deep minimum in solar activity is expected during the first half of this century

  16. Free and Forced Rossby Waves in the Western South China Sea Inferred from Jason-1 Satellite Altimetry Data

    Directory of Open Access Journals (Sweden)

    Dongxiao Wang

    2008-06-01

    Full Text Available Data from a subsurface mooring deployed in the western South China Sea shows clear intra-seasonal oscillations (ISO at the period of 40~70 days. Analysis of remotelysensed sea surface height (SSH anomalies in the same area indicates that these ISO signals propagate both eastward and westward. Time-longitude diagrams of ISO signals in SSH anomalies and wind-stress curl indicate that the eastward propagating SSH anomalies is forced by wind-stress curl. This is also confirmed by lag correlation between SSH anomalies and the wind-stress-curl index (wind stress curl averaged over 109.5ºE -115ºE and 12ºN -13.5ºN. Lag correlation of SSH anomaly suggests that the westward propagating signals are free Rossby waves.

  17. Structure of the poleward wall of the trough and the inclination of the geomagnetic field above the EISCAT radar

    Directory of Open Access Journals (Sweden)

    D. G. Jones

    Full Text Available A special high-resolution routine of the EISCAT radar has been used to investigate the structure and development of the poleward wall of a deep trough in electron density. The feature was tracked by the radar during a 7-hour period under very quiet geomagnetic conditions. The field-aligned nature of the structure enabled an estimate to be made of the inclination of the geomagnetic field above EISCAT that was in good agreement with the current model. Observations of narrow field-aligned enhancements in electron temperature demonstrated that the wall of this trough is a dynamic feature, reforming regularly as the electron density responds on a time scale of tens of minutes to energy input from soft-particle precipitation.

  18. Structure of the poleward wall of the trough and the inclination of the geomagnetic field above the EISCAT radar

    Directory of Open Access Journals (Sweden)

    D. G. Jones

    1997-06-01

    Full Text Available A special high-resolution routine of the EISCAT radar has been used to investigate the structure and development of the poleward wall of a deep trough in electron density. The feature was tracked by the radar during a 7-hour period under very quiet geomagnetic conditions. The field-aligned nature of the structure enabled an estimate to be made of the inclination of the geomagnetic field above EISCAT that was in good agreement with the current model. Observations of narrow field-aligned enhancements in electron temperature demonstrated that the wall of this trough is a dynamic feature, reforming regularly as the electron density responds on a time scale of tens of minutes to energy input from soft-particle precipitation.

  19. The future demographic niche of a declining grassland bird fails to shift poleward in response to climate change

    Science.gov (United States)

    McCauley, Lisa A.; Ribic, Christine; Pomara, Lars Y.; Zuckerberg, Benjamin

    2017-01-01

    ContextTemperate grasslands and their dependent species are exposed to high variability in weather and climate due to the lack of natural buffers such as forests. Grassland birds are particularly vulnerable to this variability, yet have failed to shift poleward in response to recent climate change like other bird species in North America. However, there have been few studies examining the effect of weather on grassland bird demography and consequent influence of climate change on population persistence and distributional shifts.ObjectivesThe goal of this study was to estimate the vulnerability of Henslow’s Sparrow (Ammodramus henslowii), an obligate grassland bird that has been declining throughout much of its range, to past and future climatic variability.MethodsWe conducted a demographic meta-analysis from published studies and quantified the relationship between nest success rates and variability in breeding season climate. We projected the climate-demography relationships spatially, throughout the breeding range, and temporally, from 1981 to 2050. These projections were used to evaluate population dynamics by implementing a spatially explicit population model.ResultsWe uncovered a climate-demography linkage for Henslow’s Sparrow with summer precipitation, and to a lesser degree, temperature positively affecting nest success. We found that future climatic conditions—primarily changes in precipitation—will likely contribute to reduced population persistence and a southwestward range contraction.ConclusionsFuture distributional shifts in response to climate change may not always be poleward and assessing projected changes in precipitation is critical for grassland bird conservation and climate change adaptation.

  20. 'BREAKS' Protocol for Breaking Bad News.

    Science.gov (United States)

    Narayanan, Vijayakumar; Bista, Bibek; Koshy, Cheriyan

    2010-05-01

    Information that drastically alters the life world of the patient is termed as bad news. Conveying bad news is a skilled communication, and not at all easy. The amount of truth to be disclosed is subjective. A properly structured and well-orchestrated communication has a positive therapeutic effect. This is a process of negotiation between patient and physician, but physicians often find it difficult due to many reasons. They feel incompetent and are afraid of unleashing a negative reaction from the patient or their relatives. The physician is reminded of his or her own vulnerability to terminal illness, and find themselves powerless over emotional distress. Lack of sufficient training in breaking bad news is a handicap to most physicians and health care workers. Adherence to the principles of client-centered counseling is helpful in attaining this skill. Fundamental insight of the patient is exploited and the bad news is delivered in a structured manner, because the patient is the one who knows what is hurting him most and he is the one who knows how to move forward. Six-step SPIKES protocol is widely used for breaking bad news. In this paper, we put forward another six-step protocol, the BREAKS protocol as a systematic and easy communication strategy for breaking bad news. Development of competence in dealing with difficult situations has positive therapeutic outcome and is a professionally satisfying one.

  1. Breaking down the contribution of different meteorological mechanisms

    Science.gov (United States)

    Dufour, Ambroise; Tilinina, Natalia; Zolina, Olga; Gulev, Sergey

    2017-04-01

    Several mechanisms are held responsible for extreme atmospheric moisture into the Arctic - our case study - : extratropical cyclones, breaking Rossby waves, blocking events, etc. Based on composite analysis, all these phenomena have been associated with above average meridional moisture transport. These individual conclusions call for a synthesis in order to share the credit between the different mechanisms. However, it is impossible to break down the respective contributions by simply using their composites due to the risk of double counting. Indeed, the different phenomena may occur simultaneously and have overlapping regions of influence. As a result, building composites for one phenomenon will likely count in a portion of the others as well. This ambiguity is raised within a probabilistic framework by viewing composites as conditional expectations. For a given event A, the composite is written as the sum of each event's contribution weighted by the event's conditional probability given A. The composites for a set of events can be interpreted as a linear system whose coefficents are conditional probabilities and whose solution is each event's individual contribution. Using data from ERA Interim and cyclone tracks from the Shirshov Institute of Oceanology, we solve the linear system in the case of moisture transport through 70°N. The main result is to downgrade the collective influence of extratropical cyclones due to the predominance of weak inconsequential cyclones. Transient eddies are nonetheless responsible for more than 90 % of the transport : it undermines the common but untested assumption that transient eddies are identical to extratropical cyclones.

  2. Consistency of Trend Break Point Estimator with Underspecified Break Number

    Directory of Open Access Journals (Sweden)

    Jingjing Yang

    2017-01-01

    Full Text Available This paper discusses the consistency of trend break point estimators when the number of breaks is underspecified. The consistency of break point estimators in a simple location model with level shifts has been well documented by researchers under various settings, including extensions such as allowing a time trend in the model. Despite the consistency of break point estimators of level shifts, there are few papers on the consistency of trend shift break point estimators in the presence of an underspecified break number. The simulation study and asymptotic analysis in this paper show that the trend shift break point estimator does not converge to the true break points when the break number is underspecified. In the case of two trend shifts, the inconsistency problem worsens if the magnitudes of the breaks are similar and the breaks are either both positive or both negative. The limiting distribution for the trend break point estimator is developed and closely approximates the finite sample performance.

  3. Mangrove expansion and contraction at a poleward range limit: climate extremes and land-ocean temperature gradients.

    Science.gov (United States)

    Osland, Michael J; Day, Richard H; Hall, Courtney T; Brumfield, Marisa D; Dugas, Jason L; Jones, William R

    2017-01-01

    Within the context of climate change, there is a pressing need to better understand the ecological implications of changes in the frequency and intensity of climate extremes. Along subtropical coasts, less frequent and warmer freeze events are expected to permit freeze-sensitive mangrove forests to expand poleward and displace freeze-tolerant salt marshes. Here, our aim was to better understand the drivers of poleward mangrove migration by quantifying spatiotemporal patterns in mangrove range expansion and contraction across land-ocean temperature gradients. Our work was conducted in a freeze-sensitive mangrove-marsh transition zone that spans a land-ocean temperature gradient in one of the world's most wetland-rich regions (Mississippi River Deltaic Plain; Louisiana, USA). We used historical air temperature data (1893-2014), alternative future climate scenarios, and coastal wetland coverage data (1978-2011) to investigate spatiotemporal fluctuations and climate-wetland linkages. Our analyses indicate that changes in mangrove coverage have been controlled primarily by extreme freeze events (i.e., air temperatures below a threshold zone of -6.3 to -7.6°C). We expect that in the past 121 yr, mangrove range expansion and contraction has occurred across land-ocean temperature gradients. Mangrove resistance, resilience, and dominance were all highest in areas closer to the ocean where temperature extremes were buffered by large expanses of water and saturated soil. Under climate change, these areas will likely serve as local hotspots for mangrove dispersal, growth, range expansion, and displacement of salt marsh. Collectively, our results show that the frequency and intensity of freeze events across land-ocean temperature gradients greatly influences spatiotemporal patterns of range expansion and contraction of freeze-sensitive mangroves. We expect that, along subtropical coasts, similar processes govern the distribution and abundance of other freeze

  4. Rossby and drift wave turbulence and zonal flows: The Charney-Hasegawa-Mima model and its extensions

    Science.gov (United States)

    Connaughton, Colm; Nazarenko, Sergey; Quinn, Brenda

    2015-12-01

    A detailed study of the Charney-Hasegawa-Mima model and its extensions is presented. These simple nonlinear partial differential equations suggested for both Rossby waves in the atmosphere and drift waves in a magnetically-confined plasma, exhibit some remarkable and nontrivial properties, which in their qualitative form, survive in more realistic and complicated models. As such, they form a conceptual basis for understanding the turbulence and zonal flow dynamics in real plasma and geophysical systems. Two idealised scenarios of generation of zonal flows by small-scale turbulence are explored: a modulational instability and turbulent cascades. A detailed study of the generation of zonal flows by the modulational instability reveals that the dynamics of this zonal flow generation mechanism differ widely depending on the initial degree of nonlinearity. The jets in the strongly nonlinear case further roll up into vortex streets and saturate, while for the weaker nonlinearities, the growth of the unstable mode reverses and the system oscillates between a dominant jet, which is slightly inclined to the zonal direction, and a dominant primary wave. A numerical proof is provided for the extra invariant in Rossby and drift wave turbulence-zonostrophy. While the theoretical derivations of this invariant stem from the wave kinetic equation which assumes weak wave amplitudes, it is shown to be relatively well-conserved for higher nonlinearities also. Together with the energy and enstrophy, these three invariants cascade into anisotropic sectors in the k-space as predicted by the Fjørtoft argument. The cascades are characterised by the zonostrophy pushing the energy to the zonal scales. A small scale instability forcing applied to the model has demonstrated the well-known drift wave-zonal flow feedback loop. The drift wave turbulence is generated from this primary instability. The zonal flows are then excited by either one of the generation mechanisms, extracting energy from

  5. Detection of Rossby Waves in Multi-Parameters in Multi-Mission Satellite Observations and HYCOM Simulations in the Indian Ocean

    Science.gov (United States)

    2009-01-01

    waves propagat- ing in every ocean basin , with amplitudes between 0.1 and 1.5 K. They noted that it seems most likely that the SST signature is...simulations of sea surface salinity (SSS) to dem - onstrate that Rossby waves can be seen as a signal in salinity as well. We anticipate the high-density...and includes monthly river runoff from 986 global rivers. There is a weak relaxation to monthly mean SSS from the Polar science center Hydrographic

  6. Strong Electroweak Symmetry Breaking

    CERN Document Server

    Grinstein, Benjamin

    2011-01-01

    Models of spontaneous breaking of electroweak symmetry by a strong interaction do not have fine tuning/hierarchy problem. They are conceptually elegant and use the only mechanism of spontaneous breaking of a gauge symmetry that is known to occur in nature. The simplest model, minimal technicolor with extended technicolor interactions, is appealing because one can calculate by scaling up from QCD. But it is ruled out on many counts: inappropriately low quark and lepton masses (or excessive FCNC), bad electroweak data fits, light scalar and vector states, etc. However, nature may not choose the minimal model and then we are stuck: except possibly through lattice simulations, we are unable to compute and test the models. In the LHC era it therefore makes sense to abandon specific models (of strong EW breaking) and concentrate on generic features that may indicate discovery. The Technicolor Straw Man is not a model but a parametrized search strategy inspired by a remarkable generic feature of walking technicolor,...

  7. Electroweak symmetry breaking

    Energy Technology Data Exchange (ETDEWEB)

    Chanowitz, M.S.

    1990-09-01

    The Higgs mechanism is reviewed in its most general form, requiring the existence of a new symmetry-breaking force and associated particles, which need not however be Higgs bosons. The first lecture reviews the essential elements of the Higgs mechanism, which suffice to establish low energy theorems for the scattering of longitudinally polarized W and Z gauge bosons. An upper bound on the scale of the symmetry-breaking physics then follows from the low energy theorems and partial wave unitarity. The second lecture reviews particular models, with and without Higgs bosons, paying special attention to how the general features discussed in lecture 1 are realized in each model. The third lecture focuses on the experimental signals of strong WW scattering that can be observed at the SSC above 1 TeV in the WW subenergy, which will allow direct measurement of the strength of the symmetry-breaking force. 52 refs., 10 figs.

  8. Plasma structure within poleward-moving cusp/cleft auroral transients: EISCAT Svalbard radar observations and an explanation in terms of large local time extent of events

    Directory of Open Access Journals (Sweden)

    M. Lockwood

    Full Text Available We report high-resolution observations of the southward-IMF cusp/cleft ionosphere made on December 16th 1998 by the EISCAT (European incoherent scatter Svalbard radar (ESR, and compare them with observations of dayside auroral luminosity, as seen at a wavelength of 630 nm by a meridian scanning photometer at Ny Ålesund, and of plasma flows, as seen by the CUTLASS (co-operative UK twin location auroral sounding system Finland HF radar. The optical data reveal a series of poleward-moving transient red-line (630 nm enhancements, events that have been associated with bursts in the rate of magnetopause reconnection generating new open flux. The combined observations at this time have strong similarities to predictions of the effects of soft electron precipitation modulated by pulsed reconnection, as made by Davis and Lockwood (1996; however, the effects of rapid zonal flow in the ionosphere, caused by the magnetic curvature force on the newly opened field lines, are found to be a significant additional factor. In particular, it is shown how enhanced plasma loss rates induced by the rapid convection can explain two outstanding anomalies of the 630 nm transients, namely how minima in luminosity form between the poleward-moving events and how events can re-brighten as they move poleward. The observations show how cusp/cleft aurora and transient poleward-moving auroral forms appear in the ESR data and the conditions which cause enhanced 630 nm emission in the transients: they are an important first step in enabling the ESR to identify these features away from the winter solstice when supporting auroral observations are not available.

    Key words: Ionosphere (polar ionosphere - Magnetospheric physics (magnetopause; cusp and boundary layers; solar wind-magnetosphere interactions

  9. Plasma structure within poleward-moving cusp/cleft auroral transients: EISCAT Svalbard radar observations and an explanation in terms of large local time extent of events

    Directory of Open Access Journals (Sweden)

    M. Lockwood

    2000-09-01

    Full Text Available We report high-resolution observations of the southward-IMF cusp/cleft ionosphere made on December 16th 1998 by the EISCAT (European incoherent scatter Svalbard radar (ESR, and compare them with observations of dayside auroral luminosity, as seen at a wavelength of 630 nm by a meridian scanning photometer at Ny Ålesund, and of plasma flows, as seen by the CUTLASS (co-operative UK twin location auroral sounding system Finland HF radar. The optical data reveal a series of poleward-moving transient red-line (630 nm enhancements, events that have been associated with bursts in the rate of magnetopause reconnection generating new open flux. The combined observations at this time have strong similarities to predictions of the effects of soft electron precipitation modulated by pulsed reconnection, as made by Davis and Lockwood (1996; however, the effects of rapid zonal flow in the ionosphere, caused by the magnetic curvature force on the newly opened field lines, are found to be a significant additional factor. In particular, it is shown how enhanced plasma loss rates induced by the rapid convection can explain two outstanding anomalies of the 630 nm transients, namely how minima in luminosity form between the poleward-moving events and how events can re-brighten as they move poleward. The observations show how cusp/cleft aurora and transient poleward-moving auroral forms appear in the ESR data and the conditions which cause enhanced 630 nm emission in the transients: they are an important first step in enabling the ESR to identify these features away from the winter solstice when supporting auroral observations are not available.Key words: Ionosphere (polar ionosphere - Magnetospheric physics (magnetopause; cusp and boundary layers; solar wind-magnetosphere interactions

  10. Simultaneous FPI and TMA Measurements of the Lower Thermospheric Wind in the Vicinity of the Poleward Expanding Aurora After Substorm Onset

    Science.gov (United States)

    Oyama, Shin-ichiro; Kubota, Ken; Morinaga, Takatoshi; Tsuda, Takuo T.; Kurihara, Junichi; Larsen, Miguel F.; Yamamoto, Masayuki; Cai, Lei

    2017-10-01

    Lower thermospheric wind fluctuations in the vicinity of an auroral arc immediately before and after a substorm onset were examined by analyzing data from a ground-based green line Fabry-Perot interferometer (FPI; optical wavelength of 557.7 nm) at Tromsø, Norway, and in situ measurements from a trimethyl aluminum (TMA) trail released from a sounding rocket launched during the Dynamics and Energetics of the Lower Thermosphere in Aurora 2 (DELTA-2) campaign on 26 January 2009. Soon after the rocket launch but before disappearance of the TMA trail, a substorm onset occurred. The DELTA-2 TMA experiment appears to be the first case in which the substorm onset occurred during the TMA wind measurement. It is known that energy dissipation induced by the ionospheric closure current is compacted at the poleward side of the discrete arc in the ionospheric morning cell. Both FPI and TMA measurements were made at the poleward side, but the FPI measured winds nearer to the poleward edge of the arc than the TMA by 110-130 km. The FPI winds at distance of 53-74 km relative to the arc edge showed clear fluctuations immediately after the substorm onset, but there was no obvious similar fluctuation in the TMA-measured winds. The difference in the response at the two locations suggests that energy dissipation sufficient to be detected as the FPI/TMA wind perturbations was confined to the area from the poleward edge of the arc to a relative distance shorter than 163-203 km but longer than 53-74 km in this event.

  11. Breaking the Waves

    DEFF Research Database (Denmark)

    Christensen, Poul Rind; Kirketerp, Anne

    2006-01-01

    The paper shortly reveals the history of a small school - the KaosPilots - dedicated to educate young people to carriers as entrepreneurs. In this contribution we want to explore how the KaosPilots managed to break the waves of institutionalised concepts and practices of teaching entrepreneurship...... pedagogical elements on which the education in entrepreneurship rests....

  12. Model Breaking Points Conceptualized

    Science.gov (United States)

    Vig, Rozy; Murray, Eileen; Star, Jon R.

    2014-01-01

    Current curriculum initiatives (e.g., National Governors Association Center for Best Practices and Council of Chief State School Officers 2010) advocate that models be used in the mathematics classroom. However, despite their apparent promise, there comes a point when models break, a point in the mathematical problem space where the model cannot,…

  13. The East Atlantic - West Russia Teleconnection in the North Atlantic: Climate Impact and Relation to Rossby Wave Propagation

    Science.gov (United States)

    Lim, Young-Kwon

    2014-01-01

    Large-scale winter teleconnection of the East Atlantic - West Russia (EA-WR) over the Atlantic and surrounding regions is examined in order to quantify its impacts on temperature and precipitation and identify the physical mechanisms responsible for its existence. A rotated empirical orthogonal function (REOF) analysis of the upper-tropospheric monthly height field captures successfully the EA-WR pattern and its interannual variation, with the North Atlantic Oscillation as the first mode. EA-WRs climate impact extends from eastern North America to Eurasia. The positive (negative) EA-WR produces positive (negative) temperature anomalies over the eastern US, western Europe and Russia east of Caspian Sea, with negative (positive) anomalies over eastern Canada, eastern Europe including Ural Mountains and the Middle East. These anomalies are largely explained by lower-tropospheric temperature advections. Positive (negative) precipitation anomalies are found over the mid-latitude Atlantic and central Russia around 60E, where lower-level cyclonic (anticyclonic) circulation anomaly is dominant. The eastern Canada and the western Europe are characterized by negative (positive) precipitation anomalies.The EA-WR is found to be closely associated with Rossby wave propagation. Wave activity fluxes show that it is strongly tied to large-scale stationary waves. Furthermore, a stationary wave model (SWM) forced with vorticity transients in the mid-latitude Atlantic (approximately 40N) or diabatic heat source over the subtropical Atlantic near the Caribbean Sea produces well-organized EA-WR-like wave patterns, respectively. Sensitivity tests with the SWM indicate improvement in the simulation of the EA-WR when the mean state is modified to have a positive NAO component that enhances upper-level westerlies between 40-60N.

  14. Breaking News as Radicalisation

    DEFF Research Database (Denmark)

    Hartley, Jannie Møller

    provides us with the following two research questions: How does the category of breaking news fit into Tuchmans typology related to time, planning and technology? What types of stories are providing journalistic capital and how are online news stories categorised relatively within the journalistic field?......The aim of the paper is to make explicit how the different categories are applied in the online newsroom and thus how new categories can be seen as positioning strategies in the form of radicalisations of already existing categories. Thus field theory provides us with tools to analyse how online...... journalists are using the categorisations to create hierarchies within the journalistic field in order to position themselves as specialists in what Tuchman has called developing news, aiming and striving for what today is know as breaking news and the “exclusive scoop,” as the trademark of online journalism...

  15. Routinizing Breaking News

    DEFF Research Database (Denmark)

    Hartley, Jannie Møller

    2011-01-01

    This chapter revisits seminal theoretical categorizations of news proposed three decades earlier by US sociologist Gaye Tuchman. By exploring the definition of ”breaking news” in the contemporary online newsrooms of three Danish news organisations, the author offers us a long overdue re......-theorization of journalistic practice in the online context and helpfully explores well-evidenced limitations to online news production, such as the relationship between original reporting and the use of ”shovelware.”...

  16. Propagation properties of Rossby waves for latitudinal β-plane variations of f and zonal variations of the shallow water speed

    Directory of Open Access Journals (Sweden)

    C. T. Duba

    2012-05-01

    Full Text Available Using the shallow water equations for a rotating layer of fluid, the wave and dispersion equations for Rossby waves are developed for the cases of both the standard β-plane approximation for the latitudinal variation of the Coriolis parameter f and a zonal variation of the shallow water speed. It is well known that the wave normal diagram for the standard (mid-latitude Rossby wave on a β-plane is a circle in wave number (ky,kx space, whose centre is displaced −β/2 ω units along the negative kx axis, and whose radius is less than this displacement, which means that phase propagation is entirely westward. This form of anisotropy (arising from the latitudinal y variation of f, combined with the highly dispersive nature of the wave, gives rise to a group velocity diagram which permits eastward as well as westward propagation. It is shown that the group velocity diagram is an ellipse, whose centre is displaced westward, and whose major and minor axes give the maximum westward, eastward and northward (southward group speeds as functions of the frequency and a parameter m which measures the ratio of the low frequency-long wavelength Rossby wave speed to the shallow water speed. We believe these properties of group velocity diagram have not been elucidated in this way before. We present a similar derivation of the wave normal diagram and its associated group velocity curve for the case of a zonal (x variation of the shallow water speed, which may arise when the depth of an ocean varies zonally from a continental shelf.

  17. Filamentary structure in chemical tracer distributions near the subtropical jet following a wave breaking event

    Directory of Open Access Journals (Sweden)

    J. Ungermann

    2013-10-01

    Full Text Available This paper presents a set of observations and analyses of trace gas cross sections in the extratropical upper troposphere/lower stratosphere (UTLS. The spatially highly resolved (≈0.5 km vertically and 12.5 km horizontally cross sections of ozone (O3, nitric acid (HNO3, and peroxyacetyl nitrate (PAN, retrieved from the measurements of the CRISTA-NF infrared limb sounder flown on the Russian M55-Geophysica, revealed intricate layer structures in the region of the subtropical tropopause break. The chemical structure in this region shows an intertwined stratosphere and troposphere. The observed filaments in all discussed trace gases are of a spatial scale of less than 0.8 km vertically and about 200 km horizontally across the jet stream. Backward trajectory calculations confirm that the observed filaments are the result of a breaking Rossby wave in the preceding days. An analysis of the trace gas relationships between PAN and O3 identifies four distinct groups of air mass: polluted subtropical tropospheric air, clean tropical upper-tropospheric air, the lowermost stratospheric air, and air from the deep stratosphere. The tracer relationships further allow the identification of tropospheric, stratospheric, and the transitional air mass made of a mixture of UT and LS air. Mapping of these air mass types onto the geo-spatial location in the cross sections reveals a highly structured extratropical transition layer (ExTL. Finally, the ratio between the measured reactive nitrogen species (HNO3 + PAN + ClONO2 and O3 is analysed to estimate the influence of tropospheric pollution on the extratropical UTLS. In combination, these diagnostics provide the first example of a multi-species two-dimensional picture of the inhomogeneous distribution of chemical species within the UTLS region. Since Rossby wave breaking occurs frequently in the region of the tropopause break, these observed fine-scale filaments are likely ubiquitous in the region. The

  18. Spontaneous breaking of supersymmetry

    Energy Technology Data Exchange (ETDEWEB)

    Zumino, B.

    1981-12-01

    There has been recently a revival of interest in supersymmetric gauge theories, stimulated by the hope that supersymmetry might help in clarifying some of the questions which remain unanswered in the so called Grand Unified Theories and in particular the gauge hierarchy problem. In a Grand Unified Theory one has two widely different mass scales: the unification mass M approx. = 10/sup 15/GeV at which the unification group (e.g. SU(5)) breaks down to SU(3) x SU(2) x U(1) and the mass ..mu.. approx. = 100 GeV at which SU(2) x U(1) is broken down to the U(1) of electromagnetism. There is at present no theoretical understanding of the extreme smallness of the ratio ..mu../M of these two numbers. This is the gauge hierarchy problem. This lecture attempts to review the various mechanisms for spontaneous supersymmetry breaking in gauge theories. Most of the discussions are concerned with the tree approximation, but what is presently known about radiative correction is also reviewed.

  19. Bootstrap Dynamical Symmetry Breaking

    Directory of Open Access Journals (Sweden)

    Wei-Shu Hou

    2013-01-01

    Full Text Available Despite the emergence of a 125 GeV Higgs-like particle at the LHC, we explore the possibility of dynamical electroweak symmetry breaking by strong Yukawa coupling of very heavy new chiral quarks Q . Taking the 125 GeV object to be a dilaton with suppressed couplings, we note that the Goldstone bosons G exist as longitudinal modes V L of the weak bosons and would couple to Q with Yukawa coupling λ Q . With m Q ≳ 700  GeV from LHC, the strong λ Q ≳ 4 could lead to deeply bound Q Q ¯ states. We postulate that the leading “collapsed state,” the color-singlet (heavy isotriplet, pseudoscalar Q Q ¯ meson π 1 , is G itself, and a gap equation without Higgs is constructed. Dynamical symmetry breaking is affected via strong λ Q , generating m Q while self-consistently justifying treating G as massless in the loop, hence, “bootstrap,” Solving such a gap equation, we find that m Q should be several TeV, or λ Q ≳ 4 π , and would become much heavier if there is a light Higgs boson. For such heavy chiral quarks, we find analogy with the π − N system, by which we conjecture the possible annihilation phenomena of Q Q ¯ → n V L with high multiplicity, the search of which might be aided by Yukawa-bound Q Q ¯ resonances.

  20. Glider observations of enhanced deep water upwelling at a shelf break canyon: A mechanism for cross-slope carbon and nutrient exchange

    Science.gov (United States)

    Porter, M.; Inall, M. E.; Hopkins, J.; Palmer, M. R.; Dale, A. C.; Aleynik, D.; Barth, J. A.; Mahaffey, C.; Smeed, D. A.

    2016-10-01

    Using underwater gliders we have identified canyon driven upwelling across the Celtic Sea shelf-break, in the vicinity of Whittard Canyon. The presence of this upwelling appears to be tied to the direction and strength of the local slope current, which is in itself highly variable. During typical summer time equatorward flow, an unbalanced pressure gradient force and the resulting disruption of geostrophic flow can lead to upwelling along the main axis of two small shelf break canyons. As the slope current reverts to poleward flow, the upwelling stops and the remnants of the upwelled features are mixed into the local shelf water or advected away from the region. The upwelled features are identified by the presence of sub-pycnocline high salinity water on the shelf, and are upwelled from a depth of 300 m on the slope, thus providing a mechanism for the transport of nutrients across the shelf break onto the shelf.

  1. Break the Pattern!

    DEFF Research Database (Denmark)

    Hasse, Cathrine; Trentemøller, Stine

    Break the Pattern! A critical enquiry into three scientific workplace cultures: Hercules, Caretakers and Worker Bees is the third publication of the international three year long project "Understanding Puzzles in the Gendered European Map" (UPGEM). By contrasting empirical findings from academic...... workplaces in the five UPGEM-countries (Denmark, Estonia, Finland, Italy and Poland) we identify three clusters of cultural patterns in physics as culture. We call these Hercules, Caretakers and Worker Bees. We also consider the influence of national cultural historical processes on the scientific culture...... (physics in culture) and discuss how physics as and in culture influence the perception of science, of work and family life, of the interplay between religion and science as well as how physics as culture can either hinder or promote the career of female scientists....

  2. Breaking soliton equations and negative-order breaking soliton ...

    Indian Academy of Sciences (India)

    Home; Journals; Pramana – Journal of Physics; Volume 87; Issue 5. Breaking soliton ... We use the simplified Hirota's method to obtain multiple soliton solutions for each developed breaking soliton equation. We also develop ... WAZWAZ1. Department of Mathematics, Saint Xavier University, Chicago, IL 60655, USA ...

  3. Breaking soliton equations and negative-order breaking soliton ...

    Indian Academy of Sciences (India)

    We develop breaking soliton equations and negative-order breaking soliton equations of typical and higher orders. The recursion operator of the KdV equation is used to derive these models.We establish the distinctdispersion relation for each equation. We use the simplified Hirota's method to obtain multiple soliton ...

  4. Break location effects on PWR small break LOCA phenomena

    International Nuclear Information System (INIS)

    Suzuki, Mitsuhiro

    1989-01-01

    The report presents experimental results of a small lower plenum break test of SB-PV-01 conducted at the large-Scale Test Facility (LSTF) of the Rig-of-Safety Assessment (ROSA)-IV program. This test simulates a loss-of-coolant accident (LOCA) caused by instrument tubes break (break area corresponds to 0.5% of the cold leg flow area) in a Westinghouse-type pressurized water reactor (PWR) assuming both manual actuation for all of the high pressure injection (HPI) systems and failure of the auxiliary feedwater systems. The report clarifies long-term system responses, especially the core cooling conditions related to the primary mass inventory. Also it clarifies break location effects on small break LOCA phenomena by comparing other five similar LOCA tests with break locations at cold leg, hot leg, upper head, pressurizer top (TMI-type) and SG U-tubes. It is coucluded that the lower plenum break is the severest on core heatup due to the highest break flow rate and the least primary mass recovery after the ECCS among the six tests. (author)

  5. Breaking soliton equations and negative-order breaking soliton ...

    Indian Academy of Sciences (India)

    2016-10-06

    Oct 6, 2016 ... Abstract. We develop breaking soliton equations and negative-order breaking soliton equations of typical and higher orders. The recursion operator of the KdV equation is used to derive these models. We establish the distinct dispersion relation for each equation. We use the simplified Hirota's method to ...

  6. Core break-off mechanism

    Science.gov (United States)

    Myrick, Thomas M. (Inventor)

    2003-01-01

    A mechanism for breaking off and retaining a core sample of a drill drilled into a ground substrate has an outer drill tube and an inner core break-off tube sleeved inside the drill tube. The break-off tube breaks off and retains the core sample by a varying geometric relationship of inner and outer diameters with the drill tube. The inside diameter (ID) of the drill tube is offset by a given amount with respect to its outer diameter (OD). Similarly, the outside diameter (OD) of the break-off tube is offset by the same amount with respect to its inner diameter (ID). When the break-off tube and drill tube are in one rotational alignment, the two offsets cancel each other such that the drill can operate the two tubes together in alignment with the drill axis. When the tubes are rotated 180 degrees to another positional alignment, the two offsets add together causing the core sample in the break-off tube to be displaced from the drill axis and applying shear forces to break off the core sample.

  7. supersymmetry breaking with extra dimensions

    Indian Academy of Sciences (India)

    This talk reviews some aspects of supersymmetry breaking in the presence of extra dimensions. The first part is a general introduction, recalling the motivations for supersymmetry and extra dimensions, as well as some unsolved problems of four-dimensional models of supersymmetry breaking. The central part is a more ...

  8. The use of the k - {epsilon} turbulence model within the Rossby Centre regional ocean climate model: parameterization development and results

    Energy Technology Data Exchange (ETDEWEB)

    Markus Meier, H.E. [Swedish Meteorological and Hydrological Inst., Norrkoeping (Sweden). Rossby Centre

    2000-09-01

    As mixing plays a dominant role for the physics of an estuary like the Baltic Sea (seasonal heat storage, mixing in channels, deep water mixing), different mixing parameterizations for use in 3D Baltic Sea models are discussed and compared. For this purpose two different OGCMs of the Baltic Sea are utilized. Within the Swedish regional climate modeling program, SWECLIM, a 3D coupled ice-ocean model for the Baltic Sea has been coupled with an improved version of the two-equation k - {epsilon} turbulence model with corrected dissipation term, flux boundary conditions to include the effect of a turbulence enhanced layer due to breaking surface gravity waves and a parameterization for breaking internal waves. Results of multi-year simulations are compared with observations. The seasonal thermocline is simulated satisfactory and erosion of the halocline is avoided. Unsolved problems are discussed. To replace the controversial equation for dissipation the performance of a hierarchy of k-models has been tested and compared with the k - {epsilon} model. In addition, it is shown that the results of the mixing parameterization depend very much on the choice of the ocean model. Finally, the impact of two mixing parameterizations on Baltic Sea climate is investigated. In this case the sensitivity of mean SST, vertical temperature and salinity profiles, ice season and seasonal cycle of heat fluxes is quite large.

  9. Inflation from supersymmetry breaking

    Energy Technology Data Exchange (ETDEWEB)

    Antoniadis, I. [UMR CNRS 7589 Sorbonne Universites, UPMC Paris 6, LPTHE, Paris (France); University of Bern, Albert Einstein Center, Institute for Theoretical Physics, Bern (Switzerland); Chatrabhuti, A.; Isono, H.; Knoops, R. [Chulalongkorn University, Department of Physics, Faculty of Science, Pathumwan, Bangkok (Thailand)

    2017-11-15

    We explore the possibility that inflation is driven by supersymmetry breaking with the superpartner of the goldstino (sgoldstino) playing the role of the inflaton. Moreover, we impose an R-symmetry that allows one to satisfy easily the slow-roll conditions, avoiding the so-called η-problem, and leads to two different classes of small-field inflation models; they are characterised by an inflationary plateau around the maximum of the scalar potential, where R-symmetry is either restored or spontaneously broken, with the inflaton rolling down to a minimum describing the present phase of our Universe. To avoid the Goldstone boson and be left with a single (real) scalar field (the inflaton), R-symmetry is gauged with the corresponding gauge boson becoming massive. This framework generalises a model studied recently by the present authors, with the inflaton identified by the string dilaton and R-symmetry together with supersymmetry restored at weak coupling, at infinity of the dilaton potential. The presence of the D-term allows a tuning of the vacuum energy at the minimum. The proposed models agree with cosmological observations and predict a tensor-to-scalar ratio of primordial perturbations 10{sup -9}

  10. Dynamic breaking of a single gold bond

    DEFF Research Database (Denmark)

    Pobelov, Ilya V.; Lauritzen, Kasper Primdal; Yoshida, Koji

    2017-01-01

    of a single Au-Au bond and show that the breaking force is dependent on the loading rate. We probe the temperature and structural dependencies of breaking and suggest that the paradox can be explained by fast breaking of atomic wires and slow breaking of point contacts giving very similar breaking forces....

  11. Long-term trends of typhoon-induced rainfall over Taiwan: in situ evidence of poleward shift of typhoons in western North Pacific in recent decades

    Science.gov (United States)

    Liang, Ting-Yu; Oey, Leo; Huang, Shiming; Chou, Simon

    2017-04-01

    Tracks of tropical cyclones or typhoons in the western North Pacific have recently been shown to shift northward in the past several decades; the poleward shift has been attributed to the expansion of the tropics due to climate warming. Here we use 64-year, hourly rainfall observations around Taiwan, and take advantage of the unique terrain and geographic location of the island with respect to typhoon tracks, to show that since 1950 the typhoon-related rainfalls have been rising on the western side of the island, but decreasing on the eastern side. We show that these extraordinary rainfall patterns, despite the smallness of Taiwan, are indicative of a northward shift of typhoons related to the changes in the wind fields and surface warming over the Indian and Pacific tropical/subtropical regions.

  12. What Has Controlled the Poleward Migration of Annual Averaged Location of Tropical Cyclone Lifetime Maximum Intensity Over the Western North Pacific Since 1961?

    Science.gov (United States)

    Song, Jinjie; Klotzbach, Philip J.

    2018-01-01

    The long-term tendency of the average latitude at which tropical cyclones (TCs) reach their lifetime maximum intensity (LMI) over the western North Pacific (WNP) is investigated in this study. Despite the post-1961 significant poleward shift in the annual mean LMI latitude, the migration rate is nonuniform on decadal timescales, having an insignificant trend and a significant increasing trend before and after 1980, respectively. Interdecadal fluctuations of TC genesis latitude (φG) as well as increases in latitudinal distance between genesis position and LMI location (Δφ) are both responsible for the observed LMI latitude trends. The former is linked to the Interdecadal Pacific Oscillation (IPO), which favors TCs forming in the northwestern (southeastern) quadrant of the WNP in negative (positive) IPO phases. The latter primarily results from the continuous warming of WNP sea surface temperature, which further increases the maximum potential intensity and extends the region favorable for TC development to higher latitudes.

  13. The effect of the low-level jet on the poleward water vapour transport in the central region of South America

    Science.gov (United States)

    Berri, Guillermo J.; Inzunza, Juan B.

    The low-level jet (LLJ) in the central region of South America is studied. This LLJ is generated by the daily cycle of convergence and divergence east of the Andes Mountains. We use the 1973-1974 radiosonde and pilot balloon data set from the upper air weather stations, Salta and Resistencia, in northern Argentina to select 10 LLJ cases and another 10 NoLLJ cases (when the LLJ is not present). We use the University of Utah Mesoscale Model to simulate these situations in order to obtain a high-resolution low-level wind field. These model predictions are then used to calculate the meridional water vapour transport across a vertical cross-section, along 26°S in central South America. The results reveal that the LLJs are a very effective mechanism for the poleward water vapour transport.

  14. Metastable supersymmetry breaking without scales

    Energy Technology Data Exchange (ETDEWEB)

    Bruemmer, Felix

    2010-11-15

    We construct new examples of models of metastable D=4 N=1 supersymmetry breaking in which all scales are generated dynamically. Our models rely on Seiberg duality and on the ISS mechanism of supersymmetry breaking in massive SQCD. Some of the electric quark superfields arise as composites of a strongly coupled gauge sector. This allows us to start with a simple cubic superpotential and an asymptotically free gauge group in the ultraviolet, and end up with an infrared effective theory which breaks supersymmetry dynamically in a metastable state. (orig.)

  15. Breaking beer bottles with cavitation

    Science.gov (United States)

    Jung, Sunny; Fontana, Jake; Palffy-Muhoray, Peter; Shelley, Michael

    2009-03-01

    Hitting the top of a beer bottle, nearly full of water, with an open hand can cause the bottle to break, with the bottom separating from upper section. We have studied this phenomenon using a high-speed camera, and observed the formation, coalescence and collapse of bubbles. The breaking of glass is due to cavitation, typically occurring near the bottom edge. We make numerical estimates of the relevant physical parameters, and compare these with experimental observations.

  16. On breaks of the Indian monsoon

    Indian Academy of Sciences (India)

    For over a century, the term break has been used for spells in which the rainfall over the Indian monsoon zone is interrupted. The phenomenon of `break monsoon' is of great interest because long intense breaks are often associated with poor monsoon seasons. Such breaks have distinct circulation characteristics (heat ...

  17. Coordinated Cluster, ground-based instrumentation and low-altitude satellite observations of transient poleward-moving events in the ionosphere and in the tail lobe

    Directory of Open Access Journals (Sweden)

    M. Lockwood

    Full Text Available During the interval between 8:00–9:30 on 14 January 2001, the four Cluster spacecraft were moving from the central magnetospheric lobe, through the dusk sector mantle, on their way towards intersecting the magnetopause near 15:00 MLT and 15:00 UT. Throughout this interval, the EISCAT Svalbard Radar (ESR at Longyearbyen observed a series of poleward-moving transient events of enhanced F-region plasma concentration ("polar cap patches", with a repetition period of the order of 10 min. Allowing for the estimated solar wind propagation delay of 75 ( ± 5 min, the interplanetary magnetic field (IMF had a southward component during most of the interval. The magnetic footprint of the Cluster spacecraft, mapped to the ionosphere using the Tsyganenko T96 model (with input conditions prevailing during this event, was to the east of the ESR beams. Around 09:05 UT, the DMSP-F12 satellite flew over the ESR and showed a sawtooth cusp ion dispersion signature that also extended into the electrons on the equatorward edge of the cusp, revealing a pulsed magnetopause reconnection. The consequent enhanced ionospheric flow events were imaged by the SuperDARN HF backscatter radars. The average convection patterns (derived using the AMIE technique on data from the magnetometers, the EISCAT and SuperDARN radars, and the DMSP satellites show that the associated poleward-moving events also convected over the predicted footprint of the Cluster spacecraft. Cluster observed enhancements in the fluxes of both electrons and ions. These events were found to be essentially identical at all four spacecraft, indicating that they had a much larger spatial scale than the satellite separation of the order of 600 km. Some of the events show a correspondence between the lowest energy magnetosheath electrons detected by the PEACE instrument on Cluster (10–20 eV and the topside ionospheric enhancements seen by the ESR (at 400–700 km. We suggest that a potential barrier at the

  18. Coordinated Cluster, ground-based instrumentation and low-altitude satellite observations of transient poleward-moving events in the ionosphere and in the tail lobe

    Directory of Open Access Journals (Sweden)

    M. Lockwood

    2001-09-01

    Full Text Available During the interval between 8:00–9:30 on 14 January 2001, the four Cluster spacecraft were moving from the central magnetospheric lobe, through the dusk sector mantle, on their way towards intersecting the magnetopause near 15:00 MLT and 15:00 UT. Throughout this interval, the EISCAT Svalbard Radar (ESR at Longyearbyen observed a series of poleward-moving transient events of enhanced F-region plasma concentration ("polar cap patches", with a repetition period of the order of 10 min. Allowing for the estimated solar wind propagation delay of 75 ( ± 5 min, the interplanetary magnetic field (IMF had a southward component during most of the interval. The magnetic footprint of the Cluster spacecraft, mapped to the ionosphere using the Tsyganenko T96 model (with input conditions prevailing during this event, was to the east of the ESR beams. Around 09:05 UT, the DMSP-F12 satellite flew over the ESR and showed a sawtooth cusp ion dispersion signature that also extended into the electrons on the equatorward edge of the cusp, revealing a pulsed magnetopause reconnection. The consequent enhanced ionospheric flow events were imaged by the SuperDARN HF backscatter radars. The average convection patterns (derived using the AMIE technique on data from the magnetometers, the EISCAT and SuperDARN radars, and the DMSP satellites show that the associated poleward-moving events also convected over the predicted footprint of the Cluster spacecraft. Cluster observed enhancements in the fluxes of both electrons and ions. These events were found to be essentially identical at all four spacecraft, indicating that they had a much larger spatial scale than the satellite separation of the order of 600 km. Some of the events show a correspondence between the lowest energy magnetosheath electrons detected by the PEACE instrument on Cluster (10–20 eV and the topside ionospheric enhancements seen by the ESR (at 400–700 km. We suggest that a potential barrier at the

  19. Isospin breaking from diquark clustering

    Science.gov (United States)

    Gibbs, W. R.; Dedonder, Jean-Pierre

    2017-09-01

    Background: Although SU(2) isospin symmetry is generally assumed in the basic theory of the strong interaction, a number of significant violations have been observed in scattering and bound states of nucleons. Many of these violations can be attributed to the electromagnetic interaction but the question of how much of the violation is due to it remains open. Purpose: To establish the connection between diquark clustering in the two-nucleon system and isospin breaking from the Coulomb interaction between the members of diquark pairs. Method: A schematic model based on clustering of quarks in the interior of the confinement region of the two-nucleon system is introduced and evaluated. In this model the Coulomb interaction is the source of all isospin breaking. It draws on a picture of the quark density based on the diquark-quark model of hadron structure which has been investigated by a number of groups. Results: The model produces three isospin breaking potentials connecting the unbroken value of the low-energy scattering amplitude to those of the p p , n n , and n p singlet channels. A simple test of the potentials in the three-nucleon energy difference problem yields results in agreement with the known binding energy difference. Conclusion: The illustrative model suggests that the breaking seen in the low-energy nucleon-nucleon (NN) interaction may be understood in terms of the Coulomb force between members of diquark clusters. It allows the prediction of the charge symmetry breaking interaction and the n n scattering length from the well measured n p singlet scattering length. Values of the n n scattering length around -18 fm are favored. Since the model is based on the quark picture, it can be easily extended, in the SU(3) limit, to calculate isospin breaking in the strange sector in the corresponding channels. A natural consequence of isospin breaking from diquark clustering is that the breaking in the strange sector, as measured by the separation energy

  20. Rossby wave dynamics of the North Pacific extra-tropical response to El Nino: importance of the basic state in coupled GCMs

    Energy Technology Data Exchange (ETDEWEB)

    Dawson, Andrew; Stevens, David P. [University of East Anglia, School of Mathematics, Norwich (United Kingdom); Matthews, Adrian J. [University of East Anglia, School of Mathematics, Norwich (United Kingdom); University of East Anglia, School of Environmental Sciences, Norwich (United Kingdom)

    2011-07-15

    The extra-tropical response to El Nino in a ''low'' horizontal resolution coupled climate model, typical of the Intergovernmental Panel on Climate Change fourth assessment report simulations, is shown to have serious systematic errors. A high resolution configuration of the same model has a much improved response that is similar to observations. The errors in the low resolution model are traced to an incorrect representation of the atmospheric teleconnection mechanism that controls the extra-tropical sea surface temperatures (SSTs) during El Nino. This is due to an unrealistic atmospheric mean state, which changes the propagation characteristics of Rossby waves. These erroneous upper tropospheric circulation anomalies then induce erroneous surface circulation features over the North Pacific. The associated surface wind speed and direction errors create erroneous surface flux and upwelling anomalies which finally lead to the incorrect extra-tropical SST response to El Nino in the low resolution model. This highlights the sensitivity of the climate response to a single link in a chain of complex climatic processes. The correct representation of these processes in the high resolution model indicates the importance of horizontal resolution in resolving such processes. (orig.)

  1. Causes and consequences of mid–21st-century rapid ice loss events simulated by the Rossby centre regional atmosphere-ocean model

    Directory of Open Access Journals (Sweden)

    Jean-Philippe Paquin

    2013-08-01

    Full Text Available Recent observations and modelling studies suggest that the Arctic climate is undergoing important transition. One manifestation of this change is seen in the rapid sea-ice cover decrease as experienced in 2007 and 2012. Although most numerical climate models cannot adequately reproduce the recent changes, some models produce similar Rapid Ice Loss Events (RILEs during the mid–21st-century. This study presents an analysis of four specific RILEs clustered around 2040 in three transient climate projections performed with the coupled Rossby Centre regional Atmosphere-Ocean model (RCAO. The analysis shows that long-term thinning causes increased vulnerability of the Arctic Ocean sea-ice cover. In the Atlantic sector, pre-conditioning (thinning of sea ice combined with anomalous atmospheric and oceanic heat transport causes large ice loss, while in the Pacific sector of the Arctic Ocean sea-ice albedo feedback appears important, particularly along the retreating sea-ice margin. Although maximum sea-ice loss occurs in the autumn, response in surface air temperature occurs in early winter, caused by strong increase in ocean-atmosphere surface energy fluxes, mainly the turbulent fluxes. Synchronicity of the events around 2040 in the projections is caused by a strong large-scale atmospheric circulation anomaly at the Atlantic lateral boundary of the regional model. The limited impact on land is caused by vertical propagation of the surface heat anomaly rather than horizontal, caused by the absence of low-level temperature inversion over the ocean.

  2. A direct estimate of poleward volume, heat and fresh water flux at 59.5°N between Greenland and Scotland

    Science.gov (United States)

    Rossby, Thomas; Reverdin, Gilles; Chafik, Leon; Søiland, Henrik

    2017-04-01

    The meridional overturning circulation (MOC) in the North Atlantic plays a major role in the transport of heat from low latitudes to high. In this study we combine recent measurements of currents from the surface to >700 m from a shipboard acoustic Doppler current profiler on the Nuka Arctica, a freighter in regular service between Greenland and Denmark with Argo profiles (to 2000 m) to estimate poleward volume, heat and freshwater flux at 59.5°N between Greenland and Scotland. For the period late 2012 to early 2016 the de-seasoned mean meridional overturning circulation reaches a 14.9±1.7 Sv maximum at the σθ = 27.55 kg m-3 isopycnal, which varies in depth from near the surface in the western Irminger Sea to 1000 m in Rockall Trough. The surface to bottom transport has a -0.44 Sv (southward) residual, which is not significantly different from zero. The total heat and fresh water fluxes across 59.5°N = 307 PW and 0.15 Sv, both with a 12% uncertainty principally due to uncertainties of the MOC. Comparing this ADCP dataset with an earlier one of comparable size from 1999-2002 (to 400 m depth only) shows strikingly similar transports in both west and east of the Reykjanes Ridge suggesting at least for these two periods 13 years apart very little difference in the strength of the MOC.

  3. A direct estimate of poleward volume, heat, and freshwater fluxes at 59.5°N between Greenland and Scotland

    Science.gov (United States)

    Rossby, T.; Reverdin, Gilles; Chafik, Leon; Søiland, Henrik

    2017-07-01

    The meridional overturning circulation (MOC) in the North Atlantic plays a major role in the transport of heat from low to high latitudes. In this study, we combine recent measurements of currents from the surface to >700 m from a shipboard acoustic Doppler current profiler with Argo profiles (to 2000 m) to estimate poleward volume, heat, and freshwater flux at 59.5°N between Greenland and Scotland. This is made possible thanks to the vessel Nuka Arctica that operates on a 3 week schedule between Greenland and Denmark. For the period late 2012 to early 2016, the deseasoned mean meridional overturning circulation reaches a 18.4 ± 3.4 Sv maximum at the σθ = 27.55 kg m-3 isopycnal, which varies in depth from near the surface in the western Irminger Sea to 1000 m in Rockall Trough. The total heat and freshwater fluxes across 59.5°N = 399 ± 74 TW and -0.20 ± 0.04 Sv, where the uncertainties are principally due to that of the MOC. Analysis of altimetric sea surface height variations along exactly the same route reveals a somewhat stronger geostrophic flow north during this period compared to the 23 year mean suggesting that for a long-term mean the above flux estimates should be reduced slightly to 17.4 Sv, 377 TW, and -0.19 Sv, respectively, with the same estimate uncertainties. The ADCP program is ongoing.

  4. Breaking Rules – Making Bonds

    Indian Academy of Sciences (India)

    IAS Admin

    RESONANCE | January 2016. GENERAL | ARTICLE. Breaking Rules – Making Bonds. A G Samuelson. Boron-containing molecules discovered recently have new types of dative bonds between carbenes and borylenes. At the same time, they show that traditional thumb rules regarding acids and bases are no longer valid.

  5. Oil prices: Breaks and trends

    International Nuclear Information System (INIS)

    Noguera, José

    2013-01-01

    This paper contributes to the literature of the stationarity of financial time series and the literature on oil and macroeconomics in several ways. First, it uses Kejriwal and Perron (2010) sequential procedure to endogenously determine multiple structural changes in real oil prices without facing the circular testing problem between structural changes and stationary assumptions of previous tests. Second, it performs a diagnostic check to detect the significance and magnitude of the potential breaks. Third, it uses the above information to test for the existence of stochastic trends in real oil prices, and fourth, it speculates about possible explanations for the break dates found in order to encourage further work and discussions. The exercise uses monthly data from January 1861 to August 2011. - Highlights: ► The model endogenously determine multiple structural changes in real oil prices. ► The methods used does not face the circular testing problem. ► It also detect the significance and magnitude of the breaks detected. ► It tests for the existence of stochastic trends. ► It explains the reasons for the break dates found

  6. Breaking Bad News to Parents.

    Science.gov (United States)

    Miller, Susan A.

    1996-01-01

    Discusses the difficulty of breaking bad news to parents, whether the news pertains to center policy or a child's behavior. Provides strategies for presenting news and for helping parents to overcome difficult situations, including gathering facts in advance, arranging an appropriate time, and having resource materials available for parents. (MOK)

  7. Inflationary implications of supersymmetry breaking

    NARCIS (Netherlands)

    Borghese, Andrea; Roest, Diederik; Zavala, Ivonne

    2013-01-01

    We discuss a general bound on the possibility to realise inflation in any minimal supergravity with F-terms. The derivation crucially depends on the sGoldstini, the scalar field directions that are singled out by spontaneous supersymmetry breaking. The resulting bound involves both slow-roll

  8. Code breaking in the pacific

    CERN Document Server

    Donovan, Peter

    2014-01-01

    Covers the historical context and the evolution of the technically complex Allied Signals Intelligence (Sigint) activity against Japan from 1920 to 1945 Describes, explains and analyzes the code breaking techniques developed during the war in the Pacific Exposes the blunders (in code construction and use) made by the Japanese Navy that led to significant US Naval victories

  9. Aluminum break-point contacts

    NARCIS (Netherlands)

    Heinemann, Martina; Groot, R.A. de

    1997-01-01

    Ab initio molecular dynamics is used to study the contribution of a single Al atom to an aluminum breakpoint contact during the final stages of breaking and the initial stages of the formation of such a contact. A hysteresis effect is found in excellent agreement with experiment and the form of the

  10. Breaking Rules–Making Bonds

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 21; Issue 1. Breaking Rules - Making Bonds. A G Samuelson. General Article Volume 21 Issue 1 January 2016 pp 43- ... Author Affiliations. A G Samuelson1. Department of Inorganic and Physical Chemistry, Indian Institute of Science, Bengaluru 560 012 ...

  11. Sediment transport under breaking waves

    DEFF Research Database (Denmark)

    Christensen, Erik Damgaard; Hjelmager Jensen, Jacob; Mayer, Stefan

    2000-01-01

    generated at the surface where the wave breaks as well as the turbulence generated near the bed due to the wave-motion and the undertow. In general, the levels of turbulent kinetic energy are found to be higher than experiments show. This results in an over prediction of the sediment transport. Nevertheless...

  12. Tight bounds for break minimization

    NARCIS (Netherlands)

    Brouwer, Andries E.; Post, Gerhard F.; Woeginger, Gerhard

    We consider round-robin sports tournaments with n teams and n − 1 rounds. We construct an infinite family of opponent schedules for which every home-away assignment induces at least 1/4 n(n−2) breaks. This construction establishes a matching lower bound for a corresponding upper bound from the

  13. supersymmetry breaking with extra dimensions

    Indian Academy of Sciences (India)

    mechanism for (super)symmetry breaking, proposed first by Scherk and Schwarz, where extra dimensions play a crucial role. The last part is devoted to the description of some recent results and of some open problems. Keywords. Supersymmetry; supergravity; extra dimensions. PACS Nos 11.25.Мj; 11.25.Wx; 11.25.

  14. Breaking Carbon Lock-in

    DEFF Research Database (Denmark)

    Driscoll, Patrick Arthur

    2014-01-01

    This central focus of this paper is to highlight the ways in which path dependencies and increasing returns (network effects) serve to reinforce carbon lock-in in large-scale road transportation infrastructure projects. Breaking carbon lock-in requires drastic changes in the way we plan future...

  15. Parental Break-Ups and Stress

    DEFF Research Database (Denmark)

    Dissing, Agnete S.; Dich, Nadya; Nybo Andersen, Anne-Marie

    2017-01-01

    Background: Parental break-up is wide spread, and the effects of parental break-up on children’s well-being are known. The evidence regarding child age at break-up and subsequent family arrangements is inconclusive. Aim: to estimate the effects of parental break-up on stress in pre-adolescent chi......Background: Parental break-up is wide spread, and the effects of parental break-up on children’s well-being are known. The evidence regarding child age at break-up and subsequent family arrangements is inconclusive. Aim: to estimate the effects of parental break-up on stress in pre......-adolescent children with a specific focus on age at break-up and post-breakup family arrangements. Methods: We used data from the Danish National Birth Cohort. Participants included 44 509 children followed from birth to age 11. Stress was self-reported by children at age 11, when the children also reported...... on parental break-up and post break-up family arrangements. Results: Twenty-one percent of the children had experienced a parental break-up at age 11, and those who had experienced parental break-up showed a higher risk of stress (OR:1.72, 95%CI:1.55;1.91) regardless of the child’s age at break-up. Children...

  16. A model of intrinsic symmetry breaking

    International Nuclear Information System (INIS)

    Ge, Li; Li, Sheng; George, Thomas F.; Sun, Xin

    2013-01-01

    Different from the symmetry breaking associated with a phase transition, which occurs when the controlling parameter is manipulated across a critical point, the symmetry breaking presented in this Letter does not need parameter manipulation. Instead, the system itself suddenly undergoes symmetry breaking at a certain time during its evolution, which is intrinsic symmetry breaking. Through a polymer model, it is revealed that the origin of the intrinsic symmetry breaking is nonlinearity, which produces instability at the instance when the evolution crosses an inflexion point, where this instability breaks the original symmetry

  17. Motion of the dayside polar cap boundary during substorm cycles: II. Generation of poleward-moving events and polar cap patches by pulses in the magnetopause reconnection rate

    Directory of Open Access Journals (Sweden)

    M. Lockwood

    2005-12-01

    Full Text Available Using data from the EISCAT (European Incoherent Scatter VHF and CUTLASS (Co-operative UK Twin-Located Auroral Sounding System HF radars, we study the formation of ionospheric polar cap patches and their relationship to the magnetopause reconnection pulses identified in the companion paper by Lockwood et al. (2005. It is shown that the poleward-moving, high-concentration plasma patches observed in the ionosphere by EISCAT on 23 November 1999, as reported by Davies et al. (2002, were often associated with corresponding reconnection rate pulses. However, not all such pulses generated a patch and only within a limited MLT range (11:00-12:00 MLT did a patch result from a reconnection pulse. Three proposed mechanisms for the production of patches, and of the concentration minima that separate them, are analysed and evaluated: (1 concentration enhancement within the patches by cusp/cleft precipitation; (2 plasma depletion in the minima between the patches by fast plasma flows; and (3 intermittent injection of photoionisation-enhanced plasma into the polar cap. We devise a test to distinguish between the effects of these mechanisms. Some of the events repeat too frequently to apply the test. Others have sufficiently long repeat periods and mechanism (3 is shown to be the only explanation of three of the longer-lived patches seen on this day. However, effect (2 also appears to contribute to some events. We conclude that plasma concentration gradients on the edges of the larger patches arise mainly from local time variations in the subauroral plasma, via the mechanism proposed by Lockwood et al. (2000.

  18. Post accidental small breaks analysis

    International Nuclear Information System (INIS)

    Depond, G.; Gandrille, J.

    1980-04-01

    EDF ordered to FRAMATOME by 1977 to complete post accidental long term studies on 'First Contrat-Programme' reactors, in order to demonstrate the safety criteria long term compliance, to get information on NSSS behaviour and to improve the post accidental procedures. Convenient analytical models were needed and EDF and FRAMATOME respectively developped the AXEL and FRARELAP codes. The main results of these studies is that for the smallest breaks, it is possible to manually undertake cooling and pressure reducing actions by dumping the steam generators secondary side in order to meet the RHR operating specifications and perform long term cooling through this system. A specific small breaks procedure was written on this basis. The EDF and FRAMATOME codes are continuously improved; the results of a French set of separate effects experiments will be incorporated as well as integral system verification

  19. Prophylactic treatment of retinal breaks

    DEFF Research Database (Denmark)

    Blindbæk, Søren Leer; Grauslund, Jakob

    2015-01-01

    Prophylactic treatment of retinal breaks has been examined in several studies and reviews, but so far, no studies have successfully applied a systematic approach. In the present systematic review, we examined the need of follow-up after posterior vitreous detachment (PVD) - diagnosed by slit...... published before 2012. Four levels of screening identified 13 studies suitable for inclusion in this systematic review. No meta-analysis was conducted as no data suitable for statistical analysis were identified. In total, the initial examination after symptomatic PVD identified 85-95% of subsequent retinal......-47% of cases, respectively. The cumulated incidence of RRD despite prophylactic treatment was 2.1-8.8%. The findings in this review suggest that follow-up after symptomatic PVD is only necessary in cases of incomplete retinal examination at presentation. Prophylactic treatment of symptomatic retinal breaks...

  20. Breaking through the tranfer tunnel

    CERN Document Server

    Laurent Guiraud

    2001-01-01

    This image shows the tunnel boring machine breaking through the transfer tunnel into the LHC tunnel. Proton beams will be transferred from the SPS pre-accelerator to the LHC at 450 GeV through two specially constructed transfer tunnels. From left to right: LHC Project Director, Lyn Evans; CERN Director-General (at the time), Luciano Maiani, and Director for Accelerators, Kurt Hubner.

  1. Models of electroweak symmetry breaking

    CERN Document Server

    Pomarol, Alex

    2015-01-01

    This chapter present models of electroweak symmetry breaking arising from strongly interacting sectors, including both Higgsless models and mechanisms involving a composite Higgs. These scenarios have also been investigated in the framework of five-dimensional warped models that, according to the AdS/CFT correspondence, have a four-dimensional holographic interpretation in terms of strongly coupled field theories. We explore the implications of these models at the LHC.

  2. Supersymmetry breaking at finite temperature

    International Nuclear Information System (INIS)

    Kratzert, K.

    2002-11-01

    The mechanism of supersymmetry breaking at finite temperature is still only partly understood. Though it has been proven that temperature always breaks supersymmetry, the spontaneous nature of this breaking remains unclear, in particular the role of the Goldstone fermion. The aim of this work is to unify two existing approaches to the subject. From a hydrodynamic point of view, it has been argued under very general assumptions that in any supersymmetric quantum field theory at finite temperature there should exist a massless fermionic collective excitation, named phonino because of the analogy to the phonon. In the framework of a self-consistent resummed perturbation theory, it is shown for the example of the Wess-Zumino model that this mode fits very well into the quantum field theoretical framework pursued by earlier works. Interpreted as a bound state of boson and fermion, it contributes to the supersymmetric Ward-Takahashi identities in a way showing that supersymmetry is indeed broken spontaneously with the phonino playing the role of the Goldstone fermion. The second part of the work addresses the case of supersymmetric quantum electrodynamics. It is shown that also here the phonino exists and must be interpreted as the Goldstone mode. This knowledge allows a generalization to a wider class of models. (orig.)

  3. Dynamic breaking of a single gold bond

    DEFF Research Database (Denmark)

    Pobelov, Ilya V.; Lauritzen, Kasper Primdal; Yoshida, Koji

    2017-01-01

    . Conversely, if the force is loaded rapidly it is more likely that the maximum breaking force is measured. Paradoxically, no clear differences in breaking force were observed in experiments on gold nanowires, despite being conducted under very different conditions. Here we explore the breaking behaviour...

  4. Validation of measured poleward TEC gradient using multi-station GPS with Artificial Neural Network based TEC model in low latitude region for developing predictive capability of ionospheric scintillation

    Science.gov (United States)

    Sur, D.; Paul, A.

    2017-12-01

    The equatorial ionosphere shows sharp diurnal and latitudinal Total Electron Content (TEC) variations over a major part of the day. Equatorial ionosphere also exhibits intense post-sunset ionospheric irregularities. Accurate prediction of TEC in these low latitudes is not possible from standard ionospheric models. An Artificial Neural Network (ANN) based Vertical TEC (VTEC) model has been designed using TEC data in low latitude Indian longitude sector for accurate prediction of VTEC. GPS TEC data from the stations Calcutta (22.58°N, 88.38°E geographic, magnetic dip 32°), Baharampore (24.09°N, 88.25°E geographic, magnetic dip 35°) and Siliguri (26.72°N, 88.39°E geographic; magnetic dip 40°) are used as training dataset for the duration of January 2007-September 2011. Poleward VTEC gradients from northern EIA crest to region beyond EIA crest have been calculated from measured VTEC and compared with that obtained from ANN based VTEC model. TEC data from Calcutta and Siliguri are used to compute VTEC gradients during April 2013 and August-September 2013. It has been observed that poleward VTEC gradient computed from ANN based TEC model has shown good correlation with measured values during vernal and autumnal equinoxes of high solar activity periods of 2013. Possible correlation between measured poleward TEC gradients and post-sunset scintillations (S4 ≥ 0.4) from northern crest of EIA has been observed in this paper. From the observation, a suitable threshold poleward VTEC gradient has been proposed for possible occurrence of post-sunset scintillations at northern crest of EIA along 88°E longitude. Poleward VTEC gradients obtained from ANN based VTEC model are used to forecast possible ionospheric scintillation after post-sunset period using the threshold value. It has been observed that these predicted VTEC gradients obtained from ANN based VTEC model can forecast post-sunset L-band scintillation with an accuracy of 67% to 82% in this dynamic low latitude

  5. Inflationary implications of supersymmetry breaking

    Energy Technology Data Exchange (ETDEWEB)

    Borghese, Andrea; Roest, Diederik; Zavala, Ivonne [Centre for Theoretical Physics, University of Groningen, Nijenborgh 4, 9747 AG Groningen (Netherlands)

    2013-07-23

    We discuss a general bound on the possibility to realise inflation in any minimal supergravity with F-terms. The derivation crucially depends on the sGoldstini, the scalar field directions that are singled out by spontaneous supersymmetry breaking. The resulting bound involves both slow-roll parameters and the geometry of the Kähler manifold of the chiral scalars. We analyse the inflationary implications of this bound, and in particular discuss to what extent the requirements of single field and slow-roll can both be met in F-term inflation.

  6. Leaders break ground for INFINITY

    Science.gov (United States)

    2008-01-01

    Community leaders from Mississippi and Louisiana break ground for the new INFINITY at NASA Stennis Space Center facility during a Nov. 20 ceremony. Groundbreaking participants included (l to r): Gottfried Construction representative John Smith, Mississippi Highway Commissioner Wayne Brown, INFINITY board member and Apollo 13 astronaut Fred Haise, Stennis Director Gene Goldman, Studio South representative David Hardy, Leo Seal Jr. family representative Virginia Wagner, Hancock Bank President George Schloegel, Mississippi Rep. J.P. Compretta, Mississippi Band of Choctaw Indians representative Charlie Benn and Louisiana Sen. A.G. Crowe.

  7. Characteristics of merging at the magnetopause inferred from dayside 557.7-nm all-sky images: IMF drivers of poleward moving auroral forms

    Directory of Open Access Journals (Sweden)

    N. C. Maynard

    2006-11-01

    Full Text Available We combine in situ measurements from Cluster with high-resolution 557.7 nm all-sky images from South Pole to investigate the spatial and temporal evolution of merging on the dayside magnetopause. Variations of 557.7 nm emissions were observed at a 6 s cadence at South Pole on 29 April 2003 while significant changes in the Interplanetary Magnetic Field (IMF clock angle were reaching the magnetopause. Electrons energized at merging sites are the probable sources for 557.7 nm cusp emissions. At the same time Cluster was crossing the pre-noon cusp in the Northern Hemisphere. The combined observations confirm results of a previous study that merging events can occur at multiple sites simultaneously and vary asynchronously on time scales of 10 s to 3 min (Maynard et al., 2004. The intensity of the emissions and the merging rate appear to vary with changes in the IMF clock angle, IMF BX and the dynamic pressure of the solar wind. Most poleward moving auroral forms (PMAFs reflect responses to changes in interplanetary medium rather than to local processes. The changes in magnetopause position required by increases in dynamic pressure are mediated by merging and result in the generation of PMAFs. Small (15–20% variations in dynamic pressure of the solar wind are sufficient to launch PMAFs. Changes in IMF BX create magnetic flux compressions and rarefactions in the solar wind. Increases (decreases in IMF BX strengthens |B| near northern (southern hemisphere merging sites thereby enhancing merging rates and triggering PMAFs. When correlating responses in the two hemispheres, the presence of significant IMF BX also requires that different lag-times be applied to ACE measurements acquired ~0.1 AU upstream of Earth. Cluster observations set lag times for merging at Northern Hemisphere sites; post-noon optical emissions set times of Southern Hemisphere merging. All-sky images and magnetohydrodynamic simulations indicate that merging occurs in multiple

  8. The pulsating nature of large-scale Saharan dust transport as a result of interplays between mid-latitude Rossby waves and the North African Dipole Intensity

    Science.gov (United States)

    Cuevas, E.; Gómez-Peláez, A. J.; Rodríguez, S.; Terradellas, E.; Basart, S.; García, R. D.; García, O. E.; Alonso-Pérez, S.

    2017-10-01

    It was previously shown that during August the export of Saharan dust to the Atlantic was strongly affected by the difference of the 700-hPa geopotential height anomaly between the subtropics and the tropics over North Africa, which was termed the North African Dipole Intensity (NAFDI). In this work a more comprehensive analysis of the NAFDI is performed, focusing on the entire summer dust season (June-September), and examining the interactions between the mid-latitude Rossby waves (MLRWs) and NAFDI. Widespread and notable aerosol optical depth (AOD) monthly anomalies are found for each NAFDI-phase over the dust corridors off the Sahara, indicating that NAFDI presents intra-seasonal variability and drives dust transport over both the Mediterranean basin and the North Atlantic. Those summer months with the same NAFDI-phase show similar AOD-anomaly patterns. Variations in NAFDI-phase also control the displacement of the Saharan Heat Low (SHL) westwards or eastwards through horizontal advection of temperature over Morocco-Western Sahara or eastern Algeria-Western Libya, respectively. The connection between the SHL and the NAFDI is quantified statistically by introducing two new daily indexes that account for their respective phases (NAFDI daily index -NAFDIDI-, and SHL longitudinal shift index -SHLLSI-) and explained physically using the energy equation of the atmospheric dynamics. The Pearson's correlation coefficient between the one-day-lag SHLLSI and the NAFDIDI for an extended summer season (1980-2013) is 0.78. A positive NAFDI is associated with the West-phase of the SHL, dust sources intensification on central Algeria, and positive AOD anomalies over this region and the Subtropical North Atlantic. A negative NAFDI is associated with the East-phase of the SHL, and positive AOD anomalies over central-eastern Sahara and the central-western Mediterranean Sea. The results point out that the phase changes of NAFDI at intra-seasonal time scale are conducted by those

  9. Lorentz Symmetry Breaking in Quantum Electrodynamics

    OpenAIRE

    Oliveira, D. M.

    2010-01-01

    In this dissertation, we study the implications generated by the Lorentz breaking symmetry in quantum electrodynamics. We analyze fermions interacting with an electromagnetic field in the contexts of quantum mechanics and make radiative corrections. In quantum mechanics, the terms of the Lorentz breaking symmetry were treated as perturbations to the Dirac equation, and their expected values were obtained in a vacuum. In the radiative corrections, the Lorentz breaking symmetry was introduced i...

  10. Rock breaking methods to replace blasting

    Science.gov (United States)

    Zhou, Huisheng; Xie, Xinghua; Feng, Yuqing

    2018-03-01

    The method of breaking rock by blasting has a high efficiency and the cost is relatively low, but the associated vibration, flyrock, production of toxic gases since the 1970’s, the Western developed countries began to study the safety of breaking rock. This paper introduces different methods and their progress to safely break rock. Ideally, safe rock breaking would have little vibration, no fly stone, and no toxic gases, which can be widely used in municipal engineering, road excavation, high-risk mining, quarrying and complex environment.

  11. NPP Krsko small break LOCA analysis

    International Nuclear Information System (INIS)

    Mavko, B.; Petelin, S.; Peterlin, G.

    1987-01-01

    Parametric analysis of small break loss of coolant accident for the Krsko NPP was calculated by using RELAP5/MOD1 computer code. The model that was used in our calculations has been improved over several years and was previously tested in simulation (s) of start-up tests and known NPP Krsko transients. In our calculations we modelled automatic actions initiated by control, safety and protection systems. We also modelled the required operator actions as specified in emergency operating instructions. In small-break LOCA calculations, we varied break sizes in the cold leg. The influence of steam generator tube plugging on small break LOCA accidents was also analysed. (author)

  12. Give me a better break: Choosing workday break activities to maximize resource recovery.

    Science.gov (United States)

    Hunter, Emily M; Wu, Cindy

    2016-02-01

    Surprisingly little research investigates employee breaks at work, and even less research provides prescriptive suggestions for better workday breaks in terms of when, where, and how break activities are most beneficial. Based on the effort-recovery model and using experience sampling methodology, we examined the characteristics of employee workday breaks with 95 employees across 5 workdays. In addition, we examined resources as a mediator between break characteristics and well-being. Multilevel analysis results indicated that activities that were preferred and earlier in the work shift related to more resource recovery following the break. We also found that resources mediated the influence of preferred break activities and time of break on health symptoms and that resource recovery benefited person-level outcomes of emotional exhaustion, job satisfaction, and organizational citizenship behavior. Finally, break length interacted with the number of breaks per day such that longer breaks and frequent short breaks were associated with more resources than infrequent short breaks. (c) 2016 APA, all rights reserved).

  13. Lie-algebra approach to symmetry breaking

    International Nuclear Information System (INIS)

    Anderson, J.T.

    1981-01-01

    A formal Lie-algebra approach to symmetry breaking is studied in an attempt to reduce the arbitrariness of Lagrangian (Hamiltonian) models which include several free parameters and/or ad hoc symmetry groups. From Lie algebra it is shown that the unbroken Lagrangian vacuum symmetry can be identified from a linear function of integers which are Cartan matrix elements. In broken symmetry if the breaking operators form an algebra then the breaking symmetry (or symmetries) can be identified from linear functions of integers characteristic of the breaking symmetries. The results are applied to the Dirac Hamiltonian of a sum of flavored fermions and colored bosons in the absence of dynamical symmetry breaking. In the partially reduced quadratic Hamiltonian the breaking-operator functions are shown to consist of terms of order g 2 , g, and g 0 in the color coupling constants and identified with strong (boson-boson), medium strong (boson-fermion), and fine-structure (fermion-fermion) interactions. The breaking operators include a boson helicity operator in addition to the familiar fermion helicity and ''spin-orbit'' terms. Within the broken vacuum defined by the conventional formalism, the field divergence yields a gauge which is a linear function of Cartan matrix integers and which specifies the vacuum symmetry. We find that the vacuum symmetry is chiral SU(3) x SU(3) and the axial-vector-current divergence gives a PCAC -like function of the Cartan matrix integers which reduces to PCAC for SU(2) x SU(2) breaking. For the mass spectra of the nonets J/sup P/ = 0 - ,1/2 + ,1 - the integer runs through the sequence 3,0,-1,-2, which indicates that the breaking subgroups are the simple Lie groups. Exact axial-vector-current conservation indicates a breaking sum rule which generates octet enhancement. Finally, the second-order breaking terms are obtained from the second-order spin tensor sum of the completely reduced quartic Hamiltonian

  14. Effects of Rest-Break Intention on Rest-Break Frequency and Work-Related Fatigue.

    Science.gov (United States)

    Blasche, Gerhard; Pasalic, Sanja; Bauböck, Verena-Maria; Haluza, Daniela; Schoberberger, Rudolf

    2017-03-01

    The present paper presents findings from two studies addressing the effects of the employee's intention to have rest breaks on rest-break frequency and the change of well-being during a workday. Rest breaks are effective in avoiding an accumulation of fatigue during work. However, little is known about individual differences in rest-break behavior. In Study 1, the association between rest-break intention and the daily number of rest breaks recorded over 4 consecutive workdays was determined by generalized linear model in a sample of employees ( n = 111, 59% females). In Study 2, professional geriatric nurses ( n = 95 females) who worked over two consecutive 12-hour day shifts recorded well-being (fatigue, distress, effort motivation) at the beginning and the end of their shifts. The effect of rest-break intention on the change of well-being was determined by multilevel modeling. Rest-break intention was positively associated with the frequency of rest breaks (Study 1) and reduced the increase of fatigue and distress over the workday (Study 2). The results indicate that individual differences account for the number of breaks an employee takes and, as a consequence, for variations in the work-related fatigue and distress. Strengthening rest-break intentions may help to increase rest-break behavior to avoid the buildup of fatigue and distress over a workday.

  15. Breaking antidunes: Cyclic behavior due to hysteresis

    DEFF Research Database (Denmark)

    Deigaard, Rolf

    2006-01-01

    The cyclic behavior of breaking antidunes (growth, breaking of surface wave, obliteration) is investigated by use of a numerical model. The model includes the transition between supercritical and transcritical flow. As the antidune grows the flow becomes transcritical and a hydraulic jump is form...

  16. Breaking Bad News - Perceptions of Pediatric Residents.

    Science.gov (United States)

    Geeta, M G; Krishnakumar, P

    2017-08-15

    The present study evaluated the perceptions and practice of 92 final year pediatric residents with regard to breaking bad news. Only 16% of residents had received any training in communication skills. Majority (65%) of the residents were not comfortable while breaking bad news.

  17. Symmetry breaking signaling mechanisms during cell polarization

    NARCIS (Netherlands)

    Bruurs, LJM

    2017-01-01

    Breaking of cellular symmetry in order to establish an apico-basal polarity axis initiates de novo formation of cell polarity. However, symmetry breaking provides a formidable challenge from a signaling perspective, because by definition no spatial cues are present to instruct axis establishment.

  18. Structural Break Tests Robust to Regression Misspecification

    NARCIS (Netherlands)

    Abi Morshed, Alaa; Andreou, E.; Boldea, Otilia

    2016-01-01

    Structural break tests developed in the literature for regression models are sensitive to model misspecification. We show - analytically and through simulations - that the sup Wald test for breaks in the conditional mean and variance of a time series process exhibits severe size distortions when the

  19. Strongly coupled semidirect mediation of supersymmetry breaking

    International Nuclear Information System (INIS)

    Ibe, M.; Izawa, K.-I.; Nakai, Y.

    2009-01-01

    Strongly coupled semidirect gauge mediation models of supersymmetry breaking through massive mediators with standard-model charges are investigated by means of composite degrees of freedom. Sizable mediation is realized to generate the standard-model gaugino masses for a small mediator mass without breaking the standard-model symmetries.

  20. On breaks of the Indian monsoon

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    2000) but little overlap with breaks identified by Webster et al (1998). Further, there are three or four active-break cycles in a season according to Webster et al (1998) which implies a time scale of about 40 days for which Goswami and Mohan ...

  1. Dynamical study of symmetries: breaking and restauration

    International Nuclear Information System (INIS)

    Schuck, P.

    1986-09-01

    First symmetry breaking (spontaneous) is explained and the physical implication discussed for infinite systems. The relation with phase transitions is indicated. Then the specific aspects of symmetry breaking in finite systems is treated and illustrated in detail for the case of translational invariance with the help of an oversimplified but exactly solvable model. The method of projection (restauration of symmetry) is explained for the static case and also applied to the model. Symmetry breaking in the dynamical case and for instance the notion of a soft mode responsible for the symmetry breaking is discussed in the case of superfluidity and another exactly solvable model is introduced. The Goldstone mode is treated in detail. Some remarks on analogies with the breaking of chiral symmetry are made. Some recent developments in the theory of symmetry restauration are briefly outlined [fr

  2. Research progress on dam-break floods

    KAUST Repository

    Wu, Jiansong

    2011-08-01

    Because of the catastrophic effects downstream of dam-break failure, more and more researchers around the world have been working on the study of dam-break flows to accurately forecast the downstream inundation mapping. With the rapid development of computer hardware and computing techniques, numerical study on dam-break flows has been a popular research subject. In the paper, the numerical methodologies used to solve the governing partial differential equations of dam-break flows are classified and summarized, and their characteristics and applications are discussed respectively. Furthermore, the fully-developed mathematical models developed in recent decades are reviewed, and also introduced the authors\\' on-going work. Finally, some possible future developments on modeling the dam-break flows and some solutions are presented and discussed. © 2011 IEEE.

  3. Supersymmetry and electroweak breaking in the interval

    International Nuclear Information System (INIS)

    Diego, David; Gersdorff, Gero von; Quiros, Mariano

    2005-01-01

    Hypermultiplets are considered in the five-dimensional interval where all fields are continuous and the boundary conditions are dynamically obtained from the action principle. The orbifold boundary conditions are obtained as particular cases. We can interpret the Scherk-Schwarz supersymmetry breaking as a misalignment of boundary conditions while a new source of supersymmetry breaking corresponding to a mismatch of different boundary parameters is identified. The latter can be viewed as coming from boundary supersymmetry breaking masses for hyperscalars and the nature of the corresponding supersymmetry breaking parameter is analyzed. For some regions of the parameter space where supersymmetry is broken (either by Scherk-Schwarz boundary conditions or by boundary hyperscalar masses) electroweak symmetry breaking can be triggered at the tree level

  4. Chiral symmetry and chiral-symmetry breaking

    International Nuclear Information System (INIS)

    Peskin, M.E.

    1982-12-01

    These lectures concern the dynamics of fermions in strong interaction with gauge fields. Systems of fermions coupled by gauge forces have a very rich structure of global symmetries, which are called chiral symmetries. These lectures will focus on the realization of chiral symmetries and the causes and consequences of thier spontaneous breaking. A brief introduction to the basic formalism and concepts of chiral symmetry breaking is given, then some explicit calculations of chiral symmetry breaking in gauge theories are given, treating first parity-invariant and then chiral models. These calculations are meant to be illustrative rather than accurate; they make use of unjustified mathematical approximations which serve to make the physics more clear. Some formal constraints on chiral symmetry breaking are discussed which illuminate and extend the results of our more explicit analysis. Finally, a brief review of the phenomenological theory of chiral symmetry breaking is presented, and some applications of this theory to problems in weak-interaction physics are discussed

  5. Big break for charge symmetry

    CERN Document Server

    Miller, G A

    2003-01-01

    Two new experiments have detected charge-symmetry breaking, the mechanism responsible for protons and neutrons having different masses. Symmetry is a crucial concept in the theories that describe the subatomic world because it has an intimate connection with the laws of conservation. The theory of the strong interaction between quarks - quantum chromodynamics - is approximately invariant under what is called charge symmetry. In other words, if we swap an up quark for a down quark, then the strong interaction will look almost the same. This symmetry is related to the concept of sup i sospin sup , and is not the same as charge conjugation (in which a particle is replaced by its antiparticle). Charge symmetry is broken by the competition between two different effects. The first is the small difference in mass between up and down quarks, which is about 200 times less than the mass of the proton. The second is their different electric charges. The up quark has a charge of +2/3 in units of the proton charge, while ...

  6. Regionally Varying Assessments of Tropical Width in Reanalyses and CMIP5 Models Using a Tropopause Break Metric

    Science.gov (United States)

    Homeyer, C. R.; Martin, E. R.; McKinzie, R.; McCarthy, K.

    2017-12-01

    The boundary between the tropics and the extratropics in each hemisphere is not fixed in space or time. Variations in the north-south width of the tropics are directly connected to changes in weather and climate. These fluctuations have been shown to impact tropical biodiversity, the spread of vector borne diseases, atmospheric chemistry, and additional natural and human sectors. However, there is no unanimous definition of the tropical boundary. This has led to a disagreement on the magnitude of changes in the tropical width during the past 30 years and a lack of understanding concerning its spatial and temporal variability. This study identifies the variability of the tropical width in modern reanalyses (ERA-Interim, JRA-55, CFSR, MERRA, and MERRA-2) and CMIP5 models (all models with available 6-hourly output) using a novel analysis metric: the tropopause "break" (i.e., the sharp discontinuity in tropopause altitude between the tropics and extratropics). Similarities and differences are found amongst the reanalyses, with some degree of tropical narrowing in the Eastern Pacific between 1981 and 2010. Historical simulations from the CMIP5 models agree well with the tropopause break latitudes depicted by the reanalyses, with considerable differences in estimated trends over the relatively short overlapping time period of the datasets. For future projections under the RCP8.5 scenario from 2006 to 2100, CMIP5 models generally show statistically significant increases in tropical width (at the 99% level) throughout each hemisphere, with regional variability of 1-2 degrees in poleward latitude trends. The impact of CMIP5 model grid resolution and other factors on the results of the tropopause break analysis will be discussed.

  7. Improving long term driving comfort by taking breaks - How break activity affects effectiveness.

    Science.gov (United States)

    Sammonds, George M; Mansfield, Neil J; Fray, Mike

    2017-11-01

    During long duration journeys, drivers are encouraged to take regular breaks. The benefits of breaks have been documented for safety; breaks may also be beneficial for comfort. The activity undertaken during a break may influence its effectiveness. Volunteers completed 3 journeys on a driving simulator. Each 130 min journey included a 10 min break after the first hour. During the break volunteers either stayed seated, left the simulator and sat in an adjacent room, or took a walk on a treadmill. The results show a reduction in driver discomfort during the break for all 3 conditions, but the effectiveness of the break was dependent on activity undertaken. Remaining seated in the vehicle provided some improvement in comfort, but more was experienced after leaving the simulator and sitting in an adjacent room. The most effective break occurred when the driver walked for 10 min on a treadmill. The benefits from taking a break continued until the end of the study (after a further hour of driving), such that comfort remained the best after taking a walk and worst for those who remained seated. It is concluded that taking a break and taking a walk is an effective method for relieving driving discomfort. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. The magnetic strip(s) in the advanced phases of stellar evolution. Theoretical convective turnover timescale and Rossby number for low- and intermediate-mass stars up to the AGB at various metallicities

    Science.gov (United States)

    Charbonnel, C.; Decressin, T.; Lagarde, N.; Gallet, F.; Palacios, A.; Aurière, M.; Konstantinova-Antova, R.; Mathis, S.; Anderson, R. I.; Dintrans, B.

    2017-09-01

    Context. Recent spectropolarimetric observations of otherwise ordinary (in terms e.g. of surface rotation and chemical properties) G, K, and M giants have revealed localized magnetic strips in the Hertzsprung-Russell diagram coincident with the regions where the first dredge-up and core helium burning occur. Aims: We seek to understand the origin of magnetic fields in such late-type giant stars, which is currently unexplained. In analogy with late-type dwarf stars, we focus primarily on parameters known to influence the generation of magnetic fields in the outer convective envelope. Methods: We compute the classical dynamo parameters along the evolutionary tracks of low- and intermediate-mass stars at various metallicities using stellar models that have been extensively tested by spectroscopic and asteroseismic observations. Specifically, these include convective turnover timescales and convective Rossby numbers, computed from the pre-main sequence (PMS) to the tip of the red giant branch (RGB) or the early asymptotic giant branch (AGB) phase. To investigate the effects of the very extended outer convective envelope, we compute these parameters both for the entire convective envelope and locally, that is, at different depths within the envelope. We also compute the turnover timescales and corresponding Rossby numbers for the convective cores of intermediate-mass stars on the main sequence. Results: Our models show that the Rossby number of the convective envelope becomes lower than unity in the well-delimited locations of the Hertzsprung-Russell diagram where magnetic fields have indeed been detected. Conclusions: We show that α - Ω dynamo processes might not be continuously operating, but that they are favored in the stellar convective envelope at two specific moments along the evolution tracks, that is, during the first dredge-up at the base of the RGB and during central helium burning in the helium-burning phase and early-AGB. This general behavior can explain

  9. Key Impact Factors on Dam Break Fatalities

    Science.gov (United States)

    Huang, D.; Yu, Z.; Song, Y.; Han, D.; Li, Y.

    2016-12-01

    Dam failures can lead to catastrophes on human society. However, there is a lack of research about dam break fatalities, especially on the key factors that affect fatalities. Based on the analysis of historical dam break cases, most studies have used the regression analysis to explore the correlation between those factors and fatalities, but without implementing optimization to find the dominating factors. In order to understand and reduce the risk of fatalities, this study has proposed a new method to select the impact factors on the fatality. It employs an improved ANN (Artificial Neural Network) combined with LOOCV (Leave-one-out cross-validation) and SFS (Stepwise Forward Selection) approach to explore the nonlinear relationship between impact factors and life losses. It not only considers the factors that have been widely used in the literature but also introduces new factors closely involved with fatalities. Dam break cases occurred in China from 1954 to 2013 are summarized, within which twenty-five cases are selected with a comprehensive coverage of geographic position and temporal variation. Twelve impact factors are taken into account as the inputs, i.e., severity of dam break flood (SF), population at risk (PR), public understanding of dam break (UB), warning time (TW), evacuation condition (EC), weather condition during dam break (WB), dam break mode (MB), water storage (SW), building vulnerability (VB), dam break time (TB), average distance from the affected area to the dam (DD) and preventive measures by government (PG).From those, three key factors of SF, MB and TB are chosen. The proposed method is able to extract the key factors, and the derived fatality model performs well in various types of dam break conditions.

  10. Particle production from symmetry breaking after inflation

    CERN Document Server

    García-Bellido, J; Garcia-Bellido, Juan; Morales, Ester Ruiz

    2002-01-01

    Recent studies suggest that the process of symmetry breaking after inflation typically occurs very fast, within a single oscillation of the symmetry-breaking field, due to the spinodal growth of its long-wave modes, otherwise known as `tachyonic preheating'. In this letter we show how this sudden transition from the false to the true vacuum can induce a significant production of particles, bosons and fermions, coupled to the symmetry-breaking field. We find that this new mechanism of particle production in the early Universe may have interesting consequences for the origin of dark matter and the generation of the observed baryon asymmetry through leptogenesis.

  11. Unconventional supersymmetry and its breaking

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez, Pedro D., E-mail: alvarez@physics.ox.ac.uk [Centro de Estudios Científicos (CECS), Av. Arturo Prat 514, Valdivia (Chile); Universidad Andrés Bello, Av. República 440, Santiago (Chile); Rudolf Peierls Centre for Theoretical Physics, University of Oxford, Oxford (United Kingdom); Pais, Pablo, E-mail: pais@cecs.cl [Centro de Estudios Científicos (CECS), Av. Arturo Prat 514, Valdivia (Chile); Universidad Andrés Bello, Av. República 440, Santiago (Chile); Zanelli, Jorge, E-mail: z@cecs.cl [Centro de Estudios Científicos (CECS), Av. Arturo Prat 514, Valdivia (Chile); Universidad Andrés Bello, Av. República 440, Santiago (Chile)

    2014-07-30

    We present a gauge theory for a superalgebra that includes an internal gauge (G) and local Lorentz (so(1,D−1)) algebras. These two symmetries are connected by fermionic supercharges. The field content of the system includes a (non-)abelian gauge potential A, a spin-1/2 Dirac spinor ψ, the Lorentz connection ω{sup ab}, and the vielbein e{sub μ}{sup a}. The connection one-form A is in the adjoint representation of G, while ψ is in the fundamental. In contrast to standard supersymmetry and supergravity, the metric is not a fundamental field and is in the center of the superalgebra: it is not only invariant under the internal gauge group, G, and under Lorentz transformations, SO(1,D−1), but is also invariant under supersymmetry. The distinctive features of this theory that mark the difference with standard supersymmetries are: i) the number of fermionic and bosonic states is not necessarily the same; ii) there are no superpartners with equal mass; iii) although this supersymmetry originates in a local gauge theory and gravity is included, there is no gravitino; iv) fermions acquire mass from their coupling to the background or from higher order self-couplings, while bosons remain massless. In odd dimensions, the Chern–Simons (CS) form provides an action that is (quasi-)invariant under the entire superalgebra. In even dimensions, the Yang–Mills (YM) form is the only natural option and the symmetry breaks down to G⊗SO(1,D−1). In four dimensions, the construction follows the Townsend–Mac Dowell–Mansouri approach, starting with an osp(4|2)∼usp(2,2|1) connection. Due to the absence of osp(4|2)-invariant traces in four dimensions, the resulting Lagrangian is only invariant under u(1)⊕so(3,1), which includes a Nambu–Jona-Lasinio (NJL) term. In this case, the Lagrangian depends on a single dimensionful parameter that fixes Newton's constant, the cosmological constant and the NJL coupling.

  12. Tidal Mixing at the Shelf Break

    National Research Council Canada - National Science Library

    Hogg, Nelson; Legg, Sonya

    2005-01-01

    The aim of this project was to study mixing forced by tidal flow over sudden changes in topographic slope such as near the shelf-break, using high-resolution nonhydrostatic numerical simulations employing the MIT gem...

  13. Water Breaking: Understand This Sign of Labor

    Science.gov (United States)

    Healthy Lifestyle Labor and delivery, postpartum care Water breaking worries? Prepare yourself for childbirth by getting the facts about this important sign of labor. By Mayo Clinic Staff If you're ...

  14. Higgsless grand unified theory breaking and trinification

    International Nuclear Information System (INIS)

    Carone, Christopher D.; Conroy, Justin M.

    2004-01-01

    Boundary conditions on an extra dimensional interval can be chosen to break bulk gauge symmetries and to reduce the rank of the gauge group. We consider this mechanism in models with gauge trinification. We determine the boundary conditions necessary to break the trinified gauge group directly down to that of the standard model. Working in an effective theory for the gauge-symmetry-breaking parameters on a boundary, we examine the limit in which the grand-unified theory-breaking-sector is Higgsless and show how one may obtain the low-energy particle content of the minimal supersymmetric standard model. We find that gauge unification is preserved in this scenario, and that the differential gauge coupling running is logarithmic above the scale of compactification. We compare the phenomenology of our model to that of four dimensional 'trinified' theories

  15. Proposed changes in intermediate pipe break criteria

    International Nuclear Information System (INIS)

    Schmitz, R.P.

    1984-01-01

    Bechtel Power Corporation proposed to the US NRC in 1983 that the NRC eliminate from their criteria all intermediate breaks. Bechtel's rationale for the proposal and support for their position are presented

  16. The problem of symmetry breaking hierarchy

    International Nuclear Information System (INIS)

    Natale, A.A.

    1983-01-01

    The problem of symmetry breaking hierarchy in grand unified theories is discussed, proving the impossibility to get a big hierarchy of interactions, in a natural way within the framework of perturbation theory. (L.C.) [pt

  17. Phil Anderson and Gauge Symmetry Breaking

    Science.gov (United States)

    Witten, Edward

    In this article, I describe the celebrated paper that Phil Anderson wrote in 1962 with early contributions to the idea of gauge symmetry breaking in particle physics. To set the stage, I describe the work of Julian Schwinger to which Anderson was responding, and also some of Anderson's own work on superconductivity that provided part of the context. After describing Anderson's work I describe the later work of others, leading to the modern understanding of gauge symmetry breaking in weak interactions...

  18. Hydraulic Response of Caisson Breakwaters in Multidirectional Breaking and Non-Breaking Waves

    DEFF Research Database (Denmark)

    Grønbech, J.; Kofoed, Jens Peter; Hald, Tue

    1998-01-01

    The present paper concerns the results and findings of a physical study on wave impacts on vertical caisson breakwaters situated in irregular, multidirectional breaking seas. The study has taken place as part of the framework programme "Dynamic of Structures" financially supported by the Danish...... induced loading and overtopping on caisson breakwaters situated in breaking seas. Regarding the wave forces only minor differences between breaking and non breaking waves in deep water were observed, and it was found that the prediction formula of Goda also seems to apply well for multidirectionally...

  19. Chiral symmetry and chiral-symmetry breaking

    Energy Technology Data Exchange (ETDEWEB)

    Peskin, M.E.

    1982-12-01

    These lectures concern the dynamics of fermions in strong interaction with gauge fields. Systems of fermions coupled by gauge forces have a very rich structure of global symmetries, which are called chiral symmetries. These lectures will focus on the realization of chiral symmetries and the causes and consequences of thier spontaneous breaking. A brief introduction to the basic formalism and concepts of chiral symmetry breaking is given, then some explicit calculations of chiral symmetry breaking in gauge theories are given, treating first parity-invariant and then chiral models. These calculations are meant to be illustrative rather than accurate; they make use of unjustified mathematical approximations which serve to make the physics more clear. Some formal constraints on chiral symmetry breaking are discussed which illuminate and extend the results of our more explicit analysis. Finally, a brief review of the phenomenological theory of chiral symmetry breaking is presented, and some applications of this theory to problems in weak-interaction physics are discussed. (WHK)

  20. Modelling oil price volatility with structural breaks

    International Nuclear Information System (INIS)

    Salisu, Afees A.; Fasanya, Ismail O.

    2013-01-01

    In this paper, we provide two main innovations: (i) we analyze oil prices of two prominent markets namely West Texas Intermediate (WTI) and Brent using the two recently developed tests by Narayan and Popp (2010) and Liu and Narayan, 2010 both of which allow for two structural breaks in the data series; and (ii) the latter method is modified to include both symmetric and asymmetric volatility models. We identify two structural breaks that occur in 1990 and 2008 which coincidentally correspond to the Iraqi/Kuwait conflict and the global financial crisis, respectively. We find evidence of persistence and leverage effects in the oil price volatility. While further extensions can be pursued, the consideration of asymmetric effects as well as structural breaks should not be jettisoned when modelling oil price volatility. - Highlights: ► We analyze oil price volatility using NP (2010) and LN (2010) tests. ► We modify the LN (2010) to account for leverage effects in oil price. ► We find two structural breaks that reflect major global crisis in the oil market. ► We find evidence of persistence and leverage effects in oil price volatility. ► Leverage effects and structural breaks are fundamental in oil price modelling.

  1. Jet simulations and gamma-ray burst afterglow jet breaks

    NARCIS (Netherlands)

    van Eerten, H.J.; Meliani, Z.; Wijers, R.A.M.J.; Keppens, R.

    2011-01-01

    The conventional derivation of the gamma-ray burst afterglow jet break time uses only the blast wave fluid Lorentz factor and therefore leads to an achromatic break. We show that in general gamma-ray burst afterglow jet breaks are chromatic across the self-absorption break. Depending on

  2. 19 CFR 149.4 - Bulk and break bulk cargo.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 2 2010-04-01 2010-04-01 false Bulk and break bulk cargo. 149.4 Section 149.4... TREASURY (CONTINUED) IMPORTER SECURITY FILING § 149.4 Bulk and break bulk cargo. (a) Bulk cargo exempted.... (b) Break bulk cargo exempted from time requirement. For break bulk cargo that is exempt from the...

  3. Calculation of the limiting CESSAR Feedwater Line-Break and Steam Line-Break transients

    International Nuclear Information System (INIS)

    Peeler, G.B.; Kennedy, M.F.; Caraher, D.L.; Guttmann, J.; Chung, K.S.

    1983-01-01

    Argonne National Laboratory (ANL), under contract to the Nuclear Regulatory Commission, performed audit calculations of the limiting Feedwater Line Break (FLB) and Steam Line Break (SLB) transients presented in the CESSAR FSAR. The results of the FLB and SLB calculations are discussed

  4. Rule-making, rule breaking? Law breaking by government in the Netherlands and the United Kingdom

    NARCIS (Netherlands)

    Huberts, L.W.J.C.; van Montfort, A.J.G.M.; Doig, A.; Clark, D.

    2006-01-01

    This article concerns a relatively novel issue: rule breaking and unlawful conduct by government bodies; to which degree does it occur, what is the nature of this misconduct, what are the underlying motives, and what are the consequences and possible solutions? Rule and law breaking is harmful for

  5. Break-glass handling exceptional situations in access control

    CERN Document Server

    Petritsch, Helmut

    2014-01-01

    Helmut Petritsch describes the first holistic approach to Break-Glass which covers the whole life-cycle: from access control modeling (pre-access), to logging the security-relevant system state during Break-Glass accesses (at-access), and the automated analysis of Break-Glass accesses (post-access). Break-Glass allows users to override security restrictions in exceptional situations. While several Break-Glass models specific to given access control models have already been discussed in research (e.g., extending RBAC with Break-Glass), the author introduces a generic Break-Glass model. The pres

  6. Workshop on electroweak symmetry breaking: proceedings

    International Nuclear Information System (INIS)

    Hinchliffe, I.

    1984-10-01

    A theoretical workshop on electroweak symmetry breaking at the Superconducting Supercollider was held at Lawrence Berkeley Laboratory, June 4-22, 1984. The purpose of the workshop was to focus theoretical attention on the ways in which experimentation at the SSC could reveal manifestations of the phenomenon responsible for electroweak symmetry breaking. This issue represents, at present, the most compelling scientific argument for the need to explore the energy region to be made accessible by the SSC, and a major aim of the workshop was to involve a broad cross section of particle theorists in the ongoing process of sharpening the requirements for both accelerator and detector design that will ensure detection and identification of meaningful signals, whatever form the electroweak symmetry breaking phenomenon should actually take. Separate entries were prepared for the data base for the papers presented

  7. Workshop on electroweak symmetry breaking: proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Hinchliffe, I. (ed.)

    1984-10-01

    A theoretical workshop on electroweak symmetry breaking at the Superconducting Supercollider was held at Lawrence Berkeley Laboratory, June 4-22, 1984. The purpose of the workshop was to focus theoretical attention on the ways in which experimentation at the SSC could reveal manifestations of the phenomenon responsible for electroweak symmetry breaking. This issue represents, at present, the most compelling scientific argument for the need to explore the energy region to be made accessible by the SSC, and a major aim of the workshop was to involve a broad cross section of particle theorists in the ongoing process of sharpening the requirements for both accelerator and detector design that will ensure detection and identification of meaningful signals, whatever form the electroweak symmetry breaking phenomenon should actually take. Separate entries were prepared for the data base for the papers presented.

  8. A break in the obesity epidemic?

    DEFF Research Database (Denmark)

    Visscher, T L S; Heitmann, B L; Rissanen, A

    2015-01-01

    epidemic. However, follow-ups of short duration may, in part, explain the apparent break or decrease in the obesity epidemic. On the other hand, a single focus on body mass index (BMI) ⩾25 or ⩾30 kg m(-)(2) is likely to mask a real increase in the obesity epidemic. And, in both children and adults, trends......Recent epidemiologic papers are presenting prevalence data suggesting breaks and decreases in obesity rates. However, before concluding that the obesity epidemic is not increasing anymore, the validity of the presented data should be discussed more thoroughly. We had a closer look...... into the literature presented in recent reviews to address the major potential biases and distortions, and to develop insights about how to interpret the presented suggestions for a potential break in the obesity epidemic. Decreasing participation rates, the use of reported rather than measured data and small sample...

  9. Breaking bad news in cancer patients.

    Science.gov (United States)

    Konstantis, Apostolos; Exiara, Triada

    2015-01-01

    In a regional hospital, many patients are newly diagnosed with cancer. Breaking the bad news in these patients and their relatives is a tough task. Many doctors are not experienced in talking to patients about death or death-related diseases. In recent years, there have been great efforts to change the current situation. The aim of this study was to investigate the experience and education of medical personnel in breaking bad news in a secondary hospital. 59 doctors from General Hospital of Komotini, Greece were included in the study. All the doctors were in clinical specialties that treated cancer patients. A brief questionnaire was developed based on current guidelines such as Baile/SPIKES framework and the ABCDE mnemonic. Residents are involved in delivering bad news less frequently than specialists. Only 21 doctors (35.59%) had specific training on breaking bad news. 20 doctors (33.90%) were aware of the available techniques and protocols on breaking bad news. 47 doctors (79.66%) had a consistent plan for breaking bad news. 57 (96.61%) delivered bad news in a quiet place, 53 (89.83%) ensured no interruptions and enough time, 53 (89.83%) used simple words and 54 (91.53%) checked for understanding and did not rush through the news. 46 doctors (77.97%) allowed relatives to determine patient's knowledge about the disease. There were low rates of specific training in breaking bad news. However, the selected location, the physician's speech and their plan were according to current guidelines.

  10. Breaking bad news in cancer patients

    Directory of Open Access Journals (Sweden)

    Apostolos Konstantis

    2015-01-01

    Full Text Available Objective: In a regional hospital, many patients are newly diagnosed with cancer. Breaking the bad news in these patients and their relatives is a tough task. Many doctors are not experienced in talking to patients about death or death-related diseases. In recent years, there have been great efforts to change the current situation. The aim of this study was to investigate the experience and education of medical personnel in breaking bad news in a secondary hospital. Materials and Methods: 59 doctors from General Hospital of Komotini, Greece were included in the study. All the doctors were in clinical specialties that treated cancer patients. A brief questionnaire was developed based on current guidelines such as Baile/SPIKES framework and the ABCDE mnemonic. Results: Residents are involved in delivering bad news less frequently than specialists. Only 21 doctors (35.59% had specific training on breaking bad news. 20 doctors (33.90% were aware of the available techniques and protocols on breaking bad news. 47 doctors (79.66% had a consistent plan for breaking bad news. 57 (96.61% delivered bad news in a quiet place, 53 (89.83% ensured no interruptions and enough time, 53 (89.83% used simple words and 54 (91.53% checked for understanding and did not rush through the news. 46 doctors (77.97% allowed relatives to determine patient′s knowledge about the disease. Conclusions: There were low rates of specific training in breaking bad news. However, the selected location, the physician′s speech and their plan were according to current guidelines.

  11. Implications of career break from personal and company perspectives

    OpenAIRE

    Vuorinen, Niina

    2017-01-01

    The objective of this study is to show the implications that career breaks have on individuals and employers. The intensions are to identify personal motivations for career breaks, and if the breaks change the careers of the people taking them. Furthermore, this study intends to understand how career breaks are viewed by employers, and if career breaks are becoming more acceptable internationally. The theoretical framework was based on description of work and careers both from employee an...

  12. Introduction to symmetry breaking and spin

    International Nuclear Information System (INIS)

    Ng, J.N.

    1992-05-01

    These lectures form an elementary introduction to the physics of symmetry breaking and the role polarization experiments play in the study of gauge symmetry breaking. Included here is an introduction to testing the electroweak sector of the standard model to one-loop and the use of oblique corrections as a probe of new physics. The second part of the lectures consists of an introduction to multiple Higgs models as sources of spontaneous CP violation. A brief discussion of using spin measurements in meson decays to study these sources of CP violation is also included. (author)

  13. Detecting Structural Breaks using Hidden Markov Models

    DEFF Research Database (Denmark)

    Ntantamis, Christos

    Testing for structural breaks and identifying their location is essential for econometric modeling. In this paper, a Hidden Markov Model (HMM) approach is used in order to perform these tasks. Breaks are defined as the data points where the underlying Markov Chain switches from one state to another....... The estimation of the HMM is conducted using a variant of the Iterative Conditional Expectation-Generalized Mixture (ICE-GEMI) algorithm proposed by Delignon et al. (1997), that permits analysis of the conditional distributions of economic data and allows for different functional forms across regimes...

  14. Electromagnetic radiation under explicit symmetry breaking.

    Science.gov (United States)

    Sinha, Dhiraj; Amaratunga, Gehan A J

    2015-04-10

    We report our observation that radiation from a system of accelerating charges is possible only when there is explicit breaking of symmetry in the electric field in space within the spatial configuration of the radiating system. Under symmetry breaking, current within an enclosed area around the radiating structure is not conserved at a certain instant of time resulting in radiation in free space. Electromagnetic radiation from dielectric and piezoelectric material based resonators are discussed in this context. Finally, it is argued that symmetry of a resonator of any form can be explicitly broken to create a radiating antenna.

  15. The experimental investigation of supersymmetry breaking

    Energy Technology Data Exchange (ETDEWEB)

    Peskin, M.E.

    1996-04-01

    If Nature is supersymmetric at the weak interaction scale, what can we hope to learn from experiments on supersymmetric particles? The most mysterious aspect of phenomenological supersymmetry is the mechanism of spontaneous supersymmetry breaking. This mechanism ties the observable pattern of supersymmetric particle masses to aspects of the underlying unified theory at very small distance scales. In this article, I will discuss a systematic experimental program to determine the mechanism of supersymmetry breaking. Both pp and e{sup +}e{sup -} colliders of the next generation play an essential role.

  16. The experimental investigation of supersymmetry breaking

    International Nuclear Information System (INIS)

    Peskin, M.E.

    1996-04-01

    If Nature is supersymmetric at the weak interaction scale, what can we hope to learn from experiments on supersymmetric particles? The most mysterious aspect of phenomenological supersymmetry is the mechanism of spontaneous supersymmetry breaking. This mechanism ties the observable pattern of supersymmetric particle masses to aspects of the underlying unified theory at very small distance scales. In this article, I will discuss a systematic experimental program to determine the mechanism of supersymmetry breaking. Both pp and e + e - colliders of the next generation play an essential role

  17. Stratospheric Influence on Summer Monsoon and Associated Planetary Wave Breaking and Mixing in the Subtropical Tropopause Region

    Science.gov (United States)

    Lubis, S. W.; Nakamura, N.

    2017-12-01

    Previous studies have shown that the monsoonal circulation plays an important role in planetary wave breaking (PWB). The highest frequency of breaking events occurs just downstream (east) of the monsoon region in summer. PWB induces mixing of potential vorticity (PV) and hence, alter the horizontal mixing in the atmosphere. Here, the authors hypothesize that the stratospheric easterlies in the boreal summer also play a significant role in the PWB and mixing associated with the summer monsoon. If the stratospheric winds were westerly in boreal summer, the frequency of PWB would be decreased due to more waves penetrating in the stratosphere, resulting in less horizontal PWB and thus reduced mixing in the subtropical tropopause region. The hypothesis is examined by using a set of idealized moist GFDL simulations. The monsoon circulation is produced by adding a land-sea contrast with a Gaussian-shaped mountains positioned in the midlatitudes. Other key ingredients for the monsoon, including albedo, oceanic warm pool, and Q-flux, were also ideally imposed in all simulations. Our control simulation produces a summer monsoon-like circulation similar to the observation. In particular, the thermally forced monsoonal circulation forms a prominent closed upper-level anticyclone that dominates the summertime upper-level flow. Associated with this circulation is an upward-bulging tropopause that forms a large reservoir of anomalously low PV. Consistent with previous studies, the well-defined tropospheric jet lies just poleward of the upper-level anticyclone, and acts as a dynamical barrier between the low-PV reservoir over the monsoonal region and the high-PV reservoir in the extratropics. This barrier disappears just northeast of the monsoon area in the jet exit region, allowing more quasi-planetary waves to break in this region. Repetitive wave breaking further weakens the PV gradient, leading to the formation of the surf zone and stronger mixing in this region. To quantify

  18. Peaking cladding temperature and break equivalent size of intermediate break loss of coolant accident

    International Nuclear Information System (INIS)

    Luo Bangqi

    2012-01-01

    The analysis results of intermediate break loss of coolant accident for the nuclear power plant of million kw level showed to be as following: (1) At the begin of life, the break occur simultaneity reactor shutdown with L(X)P. it's equivalent break size and peaking cladding temperature is respectively 20 cm and 849℃. (2) At the begin of life, the break occur simultaneity reactor shutdown without loop. the reactor coolant pumps will be stop after reactor shutdown 10 minutes, it's equivalent break size and peaking cladding temperature is respectively 10.5 cm and 921℃. (3) At the bur up of 31 GWd/t(EOC1). the break occur simultaneity reactor shutdown without loop, the reactor coolant pumps will be stop after reactor shutdown 20 minutes, it's equivalent break size and peaking cladding temperature is respectively 8 cm and 1145℃. The above analysis results showed that the peaking cladding temperature of intermediate break loss of coolant accident is not only related with the break equivalent size and core bur up, and is closely related with the stop time of coolant pumps because the coolant pumps would drive the coolant from safety system to produce the seal loop in break loop and affect the core coolant flow, results in the fuel cladding temperature increasing or damaging. Therefore, the break spectrum, burn up spectrum, the stop time of coolant pumps and operator action time will need to detail analysis and provide appropriate operating procedure, otherwise the peaking cladding temperature will exceed 1204℃ and threaten the safety of the reactor core when the intermediate break loss of coolant accident occur in some break equivalent size, burn up, stop pumps time and operator action not appropriate. The pressurizer pressure low signal simultaneity containment pressure higher signal were used as the operator manual close the signal of reactor coolant pumps after reactor shutdown of 20 minutes. have successful solved the operator intervention time from 10 minutes

  19. Remote Sensing Characteristics of Wave Breaking Rollers

    Science.gov (United States)

    Haller, M. C.; Catalan, P.

    2006-12-01

    The wave roller has a primary influence on the balances of mass and momentum in the surf zone (e.g. Svendsen, 1984; Dally and Brown, 1995; Ruessink et al., 2001). In addition, the roller area and its angle of inclination on the wave front are important quantities governing the dissipation rates in breaking waves (e.g Madsen et al., 1997). Yet, there have been very few measurements published of individual breaking wave roller geometries in shallow water. A number of investigators have focused on observations of the initial jet-like motion at the onset of breaking before the establishment of the wave roller (e.g. Basco, 1985; Jansen, 1986), while Govender et al. (2002) provide observations of wave roller vertical cross-sections and angles of inclination for a pair of laboratory wave conditions. Nonetheless, presently very little is known about the growth, evolution, and decay of this aerated region of white water as it propagates through the surf zone; mostly due to the inherent difficulties in making the relevant observations. The present work is focused on analyzing observations of the time and space scales of individual shallow water breaking wave rollers as derived from remote sensing systems. Using a high-resolution video system in a large-scale laboratory facility, we have obtained detailed measurements of the growth and evolution of the wave breaking roller. In addition, by synchronizing the remote video with in-situ wave gages, we are able to directly relate the video intensity signal to the underlying wave shape. Results indicate that the horizontal length scale of breaking wave rollers differs significantly from the previous observations of Duncan (1981), which has been a traditional basis for roller model parameterizations. The overall approach to the video analysis is new in the sense that we concentrate on individual breaking waves, as opposed to the more commonly used time-exposure technique. In addition, a new parameter of interest, denoted Imax, is

  20. Does artificial UV use prior to spring break protect students from sunburns during spring break?

    Science.gov (United States)

    Dennis, Leslie K; Lowe, John B

    2013-06-01

    Dark-skinned individuals are less likely than light-skinned individuals to become sunburned or develop skin cancer. Some have extrapolated this relationship and surmised that developing and maintaining a tan will reduce the risk of sunburns and melanoma. In order to examine whether this strategy indeed protects against sunburns, we surveyed college students about both their tanning habits prior to spring break and their spring break activities. Sorority and fraternity students were recruited after spring break. Analyses examined associations between potential risk factors and the development of one or more sunburns during spring break. As expected, the risk of obtaining a sunburn increased with: time spent in the sun during spring break; light complexion, as assessed by various sun-sensitivity factors; and lack of sunscreen use. We also found that tanning using an artificial UV source during the 10 weeks prior to spring break was not associated with reduced risk of sunburns during spring-break, but rather with a marginal increase in this risk. These data provide evidence that maintaining a tan may not provide protection from sunburns. Public health messages need to address this misconception, stating clearly that a tan does not protect against or reduce the chances of developing a sunburn. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  1. Atmospheric noise of a breaking tidal bore.

    Science.gov (United States)

    Chanson, Hubert

    2016-01-01

    A tidal bore is a surge of waters propagating upstream in an estuary as the tidal flow turns to rising and the flood tide propagates into a funnel-shaped system. Large tidal bores have a marked breaking roller. The sounds generated by breaking tidal bores were herein investigated in the field (Qiantang River) and in laboratory. The sound pressure record showed two dominant periods, with some similarity with an earlier study [Chanson (2009). J. Acoust. Soc. Am. 125(6), 3561-3568]. The two distinct phases were the incoming tidal bore when the sound amplitude increased with the approaching bore, and the passage of the tidal bore in front of the microphone when loud and powerful noises were heard. The dominant frequency ranged from 57 to 131 Hz in the Qiantang River bore. A comparison between laboratory and prototype tidal bores illustrated both common features and differences. The low pitch sound of the breaking bore had a dominant frequency close to the collective oscillations of bubble clouds, which could be modeled with a bubble cloud model using a transverse dimension of the bore roller. The findings suggest that this model might be over simplistic in the case of a powerful breaking bore, like that of the Qiantang River.

  2. Dynamical Symmetry Breaking in RN Quantum Gravity

    Directory of Open Access Journals (Sweden)

    A. T. Kotvytskiy

    2011-01-01

    Full Text Available We show that in the RN gravitation model, there is no dynamical symmetry breaking effect in the formalism of the Schwinger-Dyson equation (in flat background space-time. A general formula for the second variation of the gravitational action is obtained from the quantum corrections hμν (in arbitrary background metrics.

  3. Duality and supersymmetry breaking in string theory

    Energy Technology Data Exchange (ETDEWEB)

    Ferrara, S. (European Organization for Nuclear Research, Geneva (Switzerland) California Univ., Los Angeles (USA)); Magnoli, N.; Veneziano, G. (European Organization for Nuclear Research, Geneva (Switzerland)); Taylor, T.R. (Northeastern Univ., Boston, MA (USA))

    1990-08-16

    Target-space duality is incorporated in previously proposed effective actions describing non-perturbative supersymmetry breaking in string theory via gaugino condensation. Duality-preserving vacua with broken supersymmetry and fixed unified coupling constant do generically occur. The question of the vanishing of the cosmological constant is also briefly addressed. (orig.).

  4. Physician-patient communication: breaking bad news.

    Science.gov (United States)

    Fields, Scott A; Johnson, W Michael

    2012-01-01

    Physicians often struggle with how to manage the task of breaking bad news with patients. Moreover, the arduous nature of the task can contribute to physician detachment from the patient or an avoidance of breaking the news in a timely manner. A plan of action can only improve physician confidence in breaking bad news, and also make the task more manageable. Over a decade ago, Rabow and McPhee offered a strategy; the ABCDE plan, which provided a patient centered framework from which to deliver troubling news to patients and families. At the heart of this plan was the creation of a safe environment, the demonstration of timely communication skills, and the display of empathy on the physician's part. Careful consideration of the doctor's own reactions to death and dying also played an important role. A close review of the five tenets of this plan indicates the relevance of Rabow and McPhee's strategy today. The patient base in our nation and state continues to be older, on average, and physicians are faced with numerous patients who have terminal illness. A constructive plan with specific ideas for breaking bad news can help physicians effectively navigate this difficult task.

  5. Bereavement Part 2: Breaking bad news.

    Science.gov (United States)

    Kendrick, K D

    1998-11-01

    Breaking bad news, whether telling a patient about a poor prognosis or informing relatives of the sudden death of a loved one, is one of the most daunting tasks facing nurses. It requires a sensitive approach, based on individuals' right to know the truth.

  6. Density Functional Simulation of a Breaking Nanowire

    DEFF Research Database (Denmark)

    Nakamura, A.; Brandbyge, Mads; Hansen, Lars Bruno

    1999-01-01

    We study the deformation and breaking of an atomic-sized sodium wire using density functional simulations. The wire deforms through sudden atomic rearrangements and smoother atomic displacements. The conductance of the wire exhibits plateaus at integer values in units of 2e(2)/h corresponding...

  7. Firm break-up and performance

    Czech Academy of Sciences Publication Activity Database

    Kočenda, Evžen; Hanousek, Jan

    2012-01-01

    Roč. 13, č. 2 (2012), s. 121-143 ISSN 1435-6104 R&D Projects: GA ČR GA402/09/1595 Institutional support: PRVOUK-P23 Keywords : break-up of firms * corporate performance * ownership changes Subject RIV: AH - Economics Impact factor: 0.588, year: 2012

  8. Path-breaking books in regional science

    NARCIS (Netherlands)

    Waldorf, BS

    This article presents a collection of regional science books that long-standing members of the Regional Science Association International (RSAI) identified as path-breaking books. The most frequently nominated books include the "classics" by Isard, the seminal books in urban economics by Alonso,

  9. The issue of supersymmetry breaking in strings

    International Nuclear Information System (INIS)

    Binetruy, P.

    1989-12-01

    We discuss the central role that supersymmetry plays in string models, both in spacetime and at the level of the string world-sheet. The problems associated with supersymmetry-breaking are reviewed together with some of the attempts to solve them, in the string as well as the field theory approach

  10. Critical wind speed at which trees break

    Science.gov (United States)

    Virot, E.; Ponomarenko, A.; Dehandschoewercker, É.; Quéré, D.; Clanet, C.

    2016-02-01

    Data from storms suggest that the critical wind speed at which trees break is constant (≃42 m /s ), regardless of tree characteristics. We question the physical origin of this observation both experimentally and theoretically. By combining Hooke's law, Griffith's criterion, and tree allometry, we show that the critical wind speed indeed hardly depends on the height, diameter, and elastic properties of trees.

  11. Fragmentation in DNA double-strand breaks

    International Nuclear Information System (INIS)

    Wei Zhiyong; Suzhou Univ., Suzhou; Zhang Lihui; Li Ming; Fan Wo; Xu Yujie

    2005-01-01

    DNA double strand breaks are important lesions induced by irradiations. Random breakage model or quantification supported by this concept is suitable to analyze DNA double strand break data induced by low LET radiation, but deviation from random breakage model is more evident in high LET radiation data analysis. In this work we develop a new method, statistical fragmentation model, to analyze the fragmentation process of DNA double strand breaks. After charged particles enter the biological cell, they produce ionizations along their tracks, and transfer their energies to the cells and break the cellular DNA strands into fragments. The probable distribution of the fragments is obtained under the condition in which the entropy is maximum. Under the approximation E≅E 0 + E 1 l + E 2 l 2 , the distribution functions are obtained as exp(αl + βl 2 ). There are two components, the one proportional to exp(βl 2 ), mainly contributes to the low mass fragment yields, the other component, proportional to exp(αl), decreases slowly as the mass of the fragments increases. Numerical solution of the constraint equations provides parameters α and β. Experimental data, especially when the energy deposition is higher, support the statistical fragmentation model. (authors)

  12. Mechanisms of supersymmetry breaking in the minimal ...

    Indian Academy of Sciences (India)

    We provide a bird's eyeview of current ideas on supersymmetry breaking mechanisms in the MSSM. The essentials of gauge, gravity, anomaly and gaugino/higgsino mediation mechanisms are covered briefly and the phenomenology of the associated models is touched upon. A few statement are also made on braneworld ...

  13. SUSY breaking mediation by throat fields

    International Nuclear Information System (INIS)

    Bruemmer, F.; Hebecker, A.; Trapletti, M.

    2006-01-01

    We investigate, in the general framework of KKLT, the mediation of supersymmetry breaking by fields propagating in the strongly warped region of the compactification manifold ('throat fields'). Such fields can couple both to the supersymmetry breaking sector at the IR end of the throat and to the visible sector at the UV end. We model the supersymmetry breaking sector by a chiral superfield which develops an F term vacuum expectation value (also responsible for the uplift). It turns out that the mediation effect of vector multiplets propagating in the throat can compete with modulus-anomaly mediation. Moreover, such vector fields are naturally present as the gauge fields arising from isometries of the throat (most notably the SO(4) isometry of the Klebanov-Strassler solution). Their mediation effect is important in spite of their large 4d mass. The latter is due to the breaking of the throat isometry by the compact manifold at the UV end of the throat. The contribution from heavy chiral superfields is found to be subdominant

  14. Mechanisms of supersymmetry breaking in the minimal ...

    Indian Academy of Sciences (India)

    Preliminary remarks. This will be a somewhat theoretical review of models and mechanisms for generating soft explicit supersymmetry breaking terms in the MSSM. There will not be much signal phe- nomenology except in a few illustrative cases. Also, I shall be somewhat antihistorical in first talking about gauge mediation ...

  15. Electroweak symmetry breaking beyond the Standard Model

    Indian Academy of Sciences (India)

    In this paper, two key issues related to electroweak symmetry breaking are addressed. First, how fine-tuned different models are that trigger this phenomenon? Second, even if a light Higgs boson exists, does it have to be necessarily elementary? After a brief introduction, the fine-tuning aspects of the MSSM, NMSSM, ...

  16. Unified gauge theories with spontaneous symmetry breaking

    International Nuclear Information System (INIS)

    MacDowell, S.W.

    1975-01-01

    Unified gauge theories with spontaneous symmetry breaking are studied with a view to renormalize quantum field theory. Georgi-Glashow and Weinberg-Salam models to unify weak and electromagnetic interactions are discussed in detail. Gauge theories of strong interactions are also considered [pt

  17. Symmetry breaking and restoration in gauge theories

    International Nuclear Information System (INIS)

    Natale, A.A.

    A review is made of the utilization of the Higgs mechanism in spontaneous symmetry breaking. It is shown that such as ideas came from an analogy with the superconductivity phenomenological theory based on a Ginzburg-Landau lagrangean. The symmetry restoration through the temperature influence is studied. (L.C.) [pt

  18. Pulsed flows at the high-altitude cusp poleward boundary, and associated ionospheric convection and particle signatures, during a Cluster - FAST - SuperDARN- Søndrestrøm conjunction under a southwest IMF

    Directory of Open Access Journals (Sweden)

    C. J. Farrugia

    2004-09-01

    Full Text Available Particle and magnetic field observations during a magnetic conjunction Cluster 1-FAST-Søndrestrøm within the field of view of SuperDARN radars on 21 January 2001 allow us to draw a detailed, comprehensive and self-consistent picture at three heights of signatures associated with transient reconnection under a steady south-westerly IMF (clock angle ≈130°. Cluster 1 was outbound through the high altitude (~12RE exterior northern cusp tailward of the bifurcation line (geomagnetic Bx>0 when a solar wind dynamic pressure release shifted the spacecraft into a boundary layer downstream of the cusp. The centerpiece of the investigation is a series of flow bursts observed there by the spacecraft, which were accompanied by strong field perturbations and tailward flow deflections. Analysis shows these to be Alfvén waves. We interpret these flow events as being due to a sequence of reconnected flux tubes, with field-aligned currents in the associated Alfvén waves carrying stresses to the underlying ionosphere, a view strengthened by the other observations. At the magnetic footprint of the region of Cluster flow bursts, FAST observed an ion energy-latitude disperison of the stepped cusp type, with individual cusp ion steps corresponding to individual flow bursts. Simultaneously, the SuperDARN Stokkseyri radar observed very strong poleward-moving radar auroral forms (PMRAFs which were conjugate to the flow bursts at Cluster. FAST was traversing these PMRAFs when it observed the cusp ion steps. The Søndrestrøm radar observed pulsed ionospheric flows (PIFs just poleward of the convection reversal boundary. As at Cluster, the flow was eastward (tailward, implying a coherent eastward (tailward motion of the hypothesized open flux tubes. The joint Søndrestrøm and FAST observations indicate that the open/closed field line boundary was equatorward of the convection reversal boundary by ~2°. The unprecedented accuracy of the conjunction argues strongly

  19. Breaking bad news among cancer physicians

    Directory of Open Access Journals (Sweden)

    Sami Ayed Alshammary

    2017-01-01

    Full Text Available Background: Breaking bad news to patients with cancer diagnosis is not an easy task for physicians. The diagnosis must be explicitly stated and understood, and prognosis must be well-discussed in the most gentle and comfortable manner. It is important that the disclosure is performed in a way that patients will not lose all hope and get very depressed, leading them to undergo an abrupt change of their outlook in life. Objective: The aim of this study was to explore the physicians' perceptions and perspectives of breaking bad news to cancer patients. Methods: A cross-sectional survey of all comprehensive cancer centre physicians currently working in a university teaching hospital in the Middle East was conducted from August to September 2016. Results: Sixty-eight percent responded to the survey. Eighty-four percent were comfortable with breaking bad news, and 70% had training in breaking bad news. Eighty-six percent of responders stated that patients should be told about their cancer. Almost 30% of the respondents stated that they would still disclose the diagnosis to patients even if it would be against the preference of the relatives. Nearly 61% said that they would only tell the details to the patients if asked while 67% of them disagreed that patients should be told about the diagnoses only if the relatives consent. About 51% of physicians wanted to discuss the bad news with the family members and patient together, whereas 24% stated that the patient alone should be involved in the discussion. Conclusion: Physicians face a dilemma when families do not wish the patient to know the cancer diagnosis and this highlights the necessity of taking into consideration the social circumstances in healthcare. When taking these into considerations, curriculum in the medical school must, therefore, be updated and must integrate the acquisition of skills in breaking bad news early in training.

  20. Quantum break-time of de Sitter

    Science.gov (United States)

    Dvali, Gia; Gómez, César; Zell, Sebastian

    2017-06-01

    The quantum break-time of a system is the time-scale after which its true quantum evolution departs from the classical mean field evolution. For capturing it, a quantum resolution of the classical background—e.g., in terms of a coherent state—is required. In this paper, we first consider a simple scalar model with anharmonic oscillations and derive its quantum break-time. Next, following [1], we apply these ideas to de Sitter space. We formulate a simple model of a spin-2 field, which for some time reproduces the de Sitter metric and simultaneously allows for its well-defined representation as quantum coherent state of gravitons. The mean occupation number N of background gravitons turns out to be equal to the de Sitter horizon area in Planck units, while their frequency is given by the de Sitter Hubble parameter. In the semi-classical limit, we show that the model reproduces all the known properties of de Sitter, such as the redshift of probe particles and thermal Gibbons-Hawking radiation, all in the language of quantum S-matrix scatterings and decays of coherent state gravitons. Most importantly, this framework allows to capture the 1/N-effects to which the usual semi-classical treatment is blind. They violate the de Sitter symmetry and lead to a finite quantum break-time of the de Sitter state equal to the de Sitter radius times N. We also point out that the quantum-break time is inversely proportional to the number of particle species in the theory. Thus, the quantum break-time imposes the following consistency condition: older and species-richer universes must have smaller cosmological constants. For the maximal, phenomenologically acceptable number of species, the observed cosmological constant would saturate this bound if our Universe were 10100 years old in its entire classical history.

  1. Breaking Bad News in Veterinary Medicine.

    Science.gov (United States)

    Nickels, Bonnie McCracken; Feeley, Thomas Hugh

    2017-06-16

    The patient-provider relationship in the context of veterinary medicine represents a unique opportunity for studying how bad news is communicated to pet owners by conducting structured interviews with veterinarians. A sample of 44 veterinarians' responses was recorded and content-analyzed in an effort to identify themes among providers in their clinical experience of breaking bad news (BBN). Two coders revealed several themes in the data that were organized by three overarching areas: (1) breaking bad news in general, (2) euthanasia, and (3) social support. The findings from interviews indicated the COMFORT model (Villagran, Goldsmith, Wittenberg-Lyles, & Baldwin, 2010) in medical education provided a useful framework to organize the communication of BBN in veterinary medicine. Results were discussed in relation to future research in patient-provider communication and COMFORT's potential value for training students in veterinarian education.

  2. Dual realizations of dynamical symmetry breaking

    International Nuclear Information System (INIS)

    Dudas, Emilian; Papineau, Chloe

    2006-01-01

    We show the infrared equivalence between a recently proposed model containing a six dimensional scalar field with a four-dimensional localized Higgs type potential and the four-dimensional Nambu-Jona-Lasinio (NJL) model. In the dual NJL description, the fermions are localized at the origin of a large two-dimensional compact space. Due to a classical running effect above the compactification scale, the four-fermion coupling of the NJL model increases from the cutoff scale down to the compactification scale, providing the large Fermi coupling needed for the dynamical symmetry breaking. We also present a string theory embedding of our field-theory construction. On more general grounds, our results suggest that 4d models with dynamical symmetry breaking can be given a higher dimensional description in terms of field theories with nontrivial boundary conditions in the internal space

  3. [Breaking bad news in clinical practice].

    Science.gov (United States)

    Herrera, Andrea; Ríos, Matías; Manríquez, José Manuel; Rojas, Gonzalo

    2014-10-01

    Breaking bad news is a complex task that requires multiple communication skills from health professionals. Clinical practice demands to communicate all type of bad news, from a diagnosis of cancer to adverse effects of a treatment. On the other hand, since the beginning of the health reform in 2003, the need to improve the quality of services was proposed, among which the concern about the rights and duties of patients stands out. Therefore, the health care provider-patient relationship becomes again the subject of discussion and study, and a topic of great importance for clinical work. We revise the consequences of breaking bad news for the patient and for the health care provider, as well as the current protocols available for this purpose. The importance of developing communication skills both for future health professionals as for those who currently work in the area is emphasized.

  4. Unit roots, nonlinearities and structural breaks

    DEFF Research Database (Denmark)

    Haldrup, Niels; Kruse, Robinson; Teräsvirta, Timo

    One of the most influential research fields in econometrics over the past decades concerns unit root testing in economic time series. In macro-economics much of the interest in the area originate from the fact that when unit roots are present, then shocks to the time series processes have...... a selective review of contributions to the field of unit root testing over the past three decades. We discuss the nature of stochastic and deterministic trend processes, including break processes, that are likely to affect unit root inference. A range of the most popular unit root tests are presented...... and their modifications to situations with breaks are discussed. We also review some results on unit root testing within the framework of non-linear processes....

  5. Electroweak symmetry breaking: Higgs/whatever

    International Nuclear Information System (INIS)

    Chanowitz, M.S.

    1989-01-01

    In the first of these two lectures the Higgs mechanism is reviewed in its most general form, which does not necessarily require the existence of Higgs bosons. The general consequences of the hypothesis that electroweak symmetry breaking is due to the Higgs mechanism are deduced just from gauge invariance and unitarity. In the second lecture the general properties are illustrated with three specific models: the Weinberg-Salam model, its minimal supersymmetric extension, and technicolor. The second lecture concludes with a discussion of the experiment signals for strong WW scattering, whose presence or absence will allow us to determine whether the symmetry breaking sector lies above or below 1 TeV. 57 refs

  6. Mechanochemical symmetry breaking in Hydra aggregates.

    Science.gov (United States)

    Mercker, Moritz; Köthe, Alexandra; Marciniak-Czochra, Anna

    2015-05-05

    Tissue morphogenesis comprises the self-organized creation of various patterns and shapes. Although detailed underlying mechanisms are still elusive in many cases, an increasing amount of experimental data suggests that chemical morphogen and mechanical processes are strongly coupled. Here, we develop and test a minimal model of the axis-defining step (i.e., symmetry breaking) in aggregates of the Hydra polyp. Based on previous findings, we combine osmotically driven shape oscillations with tissue mechanics and morphogen dynamics. We show that the model incorporating a simple feedback loop between morphogen patterning and tissue stretch reproduces a wide range of experimental data. Finally, we compare different hypothetical morphogen patterning mechanisms (Turing, tissue-curvature, and self-organized criticality). Our results suggest the experimental investigation of bigger (i.e., multiple head) aggregates as a key step for a deeper understanding of mechanochemical symmetry breaking in Hydra. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  7. Selecting a model of supersymmetry breaking mediation

    International Nuclear Information System (INIS)

    AbdusSalam, S. S.; Allanach, B. C.; Dolan, M. J.; Feroz, F.; Hobson, M. P.

    2009-01-01

    We study the problem of selecting between different mechanisms of supersymmetry breaking in the minimal supersymmetric standard model using current data. We evaluate the Bayesian evidence of four supersymmetry breaking scenarios: mSUGRA, mGMSB, mAMSB, and moduli mediation. The results show a strong dependence on the dark matter assumption. Using the inferred cosmological relic density as an upper bound, minimal anomaly mediation is at least moderately favored over the CMSSM. Our fits also indicate that evidence for a positive sign of the μ parameter is moderate at best. We present constraints on the anomaly and gauge mediated parameter spaces and some previously unexplored aspects of the dark matter phenomenology of the moduli mediation scenario. We use sparticle searches, indirect observables and dark matter observables in the global fit and quantify robustness with respect to prior choice. We quantify how much information is contained within each constraint.

  8. Analysis of chiral symmetry breaking mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Xin-Heng, Guo [Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, RJ (Brazil); Tao, Huang [Academia Sinica, Beijing, BJ (China). Inst. of High Energy Physics; Chuang, Wang

    1997-07-01

    The renormalization group invariant quark condensate {mu} is determinate both from the consistent equation for quark condensate in the chiral limit and from the Schwinger-Dyson (SD) equation improved by the intermediate range QCD force singular like {delta} (q) which is associated with the gluon condensate. The solutions of {mu} in these two equations are consistent. We also obtain the critical strong coupling constant {alpha}c above which chiral symmetry breaks in two approaches. The nonperturbative kernel of the SD equation makes {alpha}c smaller and {mu} bigger. An intuitive picture of the condensation above {alpha}c is discussed. In addition, with the help of the Slavnov-Taylor-Ward (STW) identity we derive the equations for the nonperturbative quark propagator from SD equation in the presence of the intermediate-range force is also responsible for dynamical chiral symmetry breaking. (author) 32 refs., 2 figs.

  9. Dynamics of Symmetry Breaking and Tachyonic Preheating

    CERN Document Server

    Felder, G; Greene, P B; Kofman, L A; Linde, Andrei D; Tkachev, Igor I; Felder, Gary; Garcia-Bellido, Juan; Greene, Patrick B.; Kofman, Lev; Linde, Andrei; Tkachev, Igor

    2001-01-01

    We reconsider the old problem of the dynamics of spontaneous symmetry breaking using 3d lattice simulations, and develop a theory of tachyonic preheating, which occurs due to the spinodal instability of the scalar field. Tachyonic preheating is so efficient that symmetry breaking typically completes within a single oscillation of the field distribution as it rolls towards the minimum of its effective potential. As an application of this theory we consider preheating in the hybrid inflation scenario, including SUSY-motivated F-term and D-term inflationary models. We show that preheating in hybrid inflation is typically tachyonic and the stage of oscillations of a homogeneous component of the scalar fields driving inflation ends after a single oscillation. Our results may also be relevant for the theory of the formation of disoriented chiral condensates in heavy ion collisions.

  10. Qinshan NPP large break LOCA safety analysis

    International Nuclear Information System (INIS)

    Shi Guobao; Tang Jiahuan; Zhou Quanfu; Wang Yangding

    1997-01-01

    Qinshan NPP is the first nuclear power plant in the mainland of China, a 300 MW(e) two-loop PWR. Large break LOCA is the design-basis accident of Qinshan NPP. Based on available computer codes, the own analysis method which complies with Appendix k of 10 CFR 50 has been established. The RELAP4/MOD7 code is employed for the calculations of blowdown, refill and reflood phase of the RCS respectively. The CONTEMPT-LT/028 code is used for the containment pressure and temperature analysis. The temperature transient in the hot rod is calculated using the FRAP-6T code. Conservative initial and functional assumptions were adopted during Qinshan NPP large break LOCA analysis. The results of the analysis show the applicable acceptance criteria for the loss-of-coolant accident are met

  11. Microwave-assisted rock breaking modelling and application

    CSIR Research Space (South Africa)

    Monchusi, B

    2012-10-01

    Full Text Available As part of the ongoing development of novel mining methods, the CSIR has developed alternative methods to break rocks. In this case, we show the application of microwave energy to break narrow tabular ore bodies....

  12. Breaking democracy with non renormalizable mass terms

    CERN Document Server

    Silva-Marcos, Joaquim I

    2001-01-01

    The exact democratic structure for the quark mass matrix, resulting from the action of the family symmetry group $A_{3L}\\times A_{3R}$, is broken by the vacuum expectation values of heavy singlet fields appearing in non renormalizable dimension 6 operators. Within this specific context of breaking of the family symmetry we formulate a very simple ansatz which leads to correct quark masses and mixings.

  13. Dynamical symmetry breaking in quantum field theories

    CERN Document Server

    Miransky, Vladimir A

    1993-01-01

    The phenomenon of dynamical symmetry breaking (DSB) in quantum field theory is discussed in a detailed and comprehensive way. The deep connection between this phenomenon in condensed matter physics and particle physics is emphasized. The realizations of DSB in such realistic theories as quantum chromodynamics and electroweak theory are considered. Issues intimately connected with DSB such as critical phenomenona and effective lagrangian approach are also discussed.

  14. Supersymmetry breaking in a magnetic field

    International Nuclear Information System (INIS)

    Akyeampong, D.A.

    1981-10-01

    The one-loop effective potential of an abelian supersymmetric model in an environment provided by a constant external magnetic field is derived. It is shown that magnetic field breaks supersymmetry and that the value of the resulting minimum potential is lower than that of the tree level. This could be relevant to the question of possible restoration of the symmetry at higher loops. (author)

  15. Music and Video Gaming during Breaks

    OpenAIRE

    Liu, Shuyan; Schad, Daniel J.; Kuschpel, Maxim S.; Rapp, Michael A.; Heinz, Andreas

    2016-01-01

    Different systems for habitual versus goal-directed control are thought to underlie human decision-making. Working memory is known to shape these decision-making systems and their interplay, and is known to support goal-directed decision making even under stress. Here, we investigated if and how decision systems are differentially influenced by breaks filled with diverse everyday life activities known to modulate working memory performance. We used a within-subject design where young adult...

  16. Missed retinal breaks in rhegmatogenous retinal detachment

    Directory of Open Access Journals (Sweden)

    Brijesh Takkar

    2016-12-01

    Full Text Available AIM: To evaluate the causes and associations of missed retinal breaks (MRBs and posterior vitreous detachment (PVD in patients with rhegmatogenous retinal detachment (RRD. METHODS: Case sheets of patients undergoing vitreo retinal surgery for RRD at a tertiary eye care centre were evaluated retrospectively. Out of the 378 records screened, 253 were included for analysis of MRBs and 191 patients were included for analysis of PVD, depending on the inclusion criteria. Features of RRD and retinal breaks noted on examination were compared to the status of MRBs and PVD detected during surgery for possible associations. RESULTS: Overall, 27% patients had MRBs. Retinal holes were commonly missed in patients with lattice degeneration while missed retinal tears were associated with presence of complete PVD. Patients operated for cataract surgery were significantly associated with MRBs (P=0.033 with the odds of missing a retinal break being 1.91 as compared to patients with natural lens. Advanced proliferative vitreo retinopathy (PVR and retinal bullae were the most common reasons for missing a retinal break during examination. PVD was present in 52% of the cases and was wrongly assessed in 16%. Retinal bullae, pseudophakia/aphakia, myopia, and horse shoe retinal tears were strongly associated with presence of PVD. Traumatic RRDs were rarely associated with PVD. CONCLUSION: Pseudophakic patients, and patients with retinal bullae or advanced PVR should be carefully screened for MRBs. Though Weiss ring is a good indicator of PVD, it may still be over diagnosed in some cases. PVD is associated with retinal bullae and pseudophakia, and inversely with traumatic RRD.

  17. Canard cycles with two breaking parameters

    OpenAIRE

    DUMORTIER, Freddy; Roussarie, Robert

    2007-01-01

    We consider two-dimensional slow-fast systems with a layer equation exhibiting canard cycles. The canard cycles under consideration contain both a turning point and a fast orbit connecting two jump points. At both the turning point and the connecting fast orbit we suppose the presence of a parameter permitting generic breaking. Such canard cycles depend on two parameters, that we call phase parameters. We study the relaxation oscillations near the canard cycles by means of a map from the plan...

  18. Breaking Bad News in Oncology: A Metasynthesis.

    Science.gov (United States)

    Bousquet, Guilhem; Orri, Massimiliano; Winterman, Sabine; Brugière, Charlotte; Verneuil, Laurence; Revah-Levy, Anne

    2015-08-01

    The delivery of bad news by oncologists to their patients is a key moment in the physician-patient relationship. We performed a systematic review of qualitative studies (a metasynthesis) that focused on the experiences and points of view of oncologists about breaking bad news to patients. We searched international publications to identify relevant qualitative research exploring oncologists' perspectives about this topic. Thematic analysis, which compensates for the potential lack of generalizability of the primary studies by their conjoint interpretation, was used to identify key themes and synthesize them. NVivo qualitative analysis software was used. We identified 40 articles (> 600 oncologists) from 12 countries and assessed their quality as good according to the Critical Appraisal Skills Programme (CASP). Two main themes emerged: the patient-oncologist encounter during the breaking of bad news, comprising essential aspects of the communication, including the process of dealing with emotions; and external factors shaping the patient-oncologist encounter, composed of factors that influence the announcement beyond the physician-patient relationship: the family, systemic and institutional factors, and cultural factors. Breaking bad news is a balancing act that requires oncologists to adapt continually to different factors: their individual relationships with the patient, the patient's family, the institutional and systemic environment, and the cultural milieu. Extending the development of the ability to personalize and adapt therapeutic treatment to this realm of communications would be a major step forward from the stereotyped way that oncologists are currently trained in communication skills. © 2015 by American Society of Clinical Oncology.

  19. Phenomenological Constraints on Patterns of Supersymmetry Breaking

    CERN Document Server

    Ellis, Jonathan Richard; Santoso, Y; Spanos, V C

    2003-01-01

    Specific models of supersymmetry breaking predict relations between the trilinear and bilinear soft supersymmetry breaking parameters A_0 and B_0 at the input scale. In such models, the value of tan beta can be calculated as a function of the scalar masses m_0 and the gaugino masses m_{1/2}, which we assume to be universal. The experimental constraints on sparticle and Higgs masses, b to s gamma decay and the cold dark matter density Omega_{CDM} h^2 can then be used to constrain tan beta in such specific models of supersymmetry breaking. In the simplest Polonyi model with A_0 = (3 - sqrt{3})m_0 = B_0 + m_0, we find 11 0 (mu 0, and the range 1.25 < A_0/m_0 < 4.8 for mu < 0. In these models, we find no solutions in the rapid-annihilation `funnels' or in the `focus-point' region. We also discuss the allowed range of tan beta in the no-scale model with A_0 = B_0 = 0. In all these models, most of the allowed regions are in the chi - stau_1 coannihilation `tail'.

  20. Phenomenology of GUT-less Supersymmetry Breaking

    CERN Document Server

    Ellis, Jonathan Richard; Sandick, Pearl

    2007-01-01

    We study models in which supersymmetry breaking appears at an intermediate scale, M_{in}, below the GUT scale. We assume that the soft supersymmetry-breaking parameters of the MSSM are universal at M_{in}, and analyze the morphology of the constraints from cosmology and collider experiments on the allowed regions of parameter space as M_{in} is reduced from the GUT scale. We present separate analyses of the (m_{1/2},m_0) planes for tan(beta)=10 and tan(beta)=50, as well as a discussion of non-zero trilinear couplings, A_0. Specific scenarios where the gaugino and scalar masses appear to be universal below the GUT scale have been found in mirage-mediation models, which we also address here. We demand that the lightest neutralino be the LSP, and that the relic neutralino density not conflict with measurements by WMAP and other observations. At moderate values of M_{in}, we find that the allowed regions of the (m_{1/2},m_0) plane are squeezed by the requirements of electroweak symmetry breaking and that the ligh...

  1. Radiative breaking of cosmologically acceptable grand unified theories

    International Nuclear Information System (INIS)

    Gato, B.; Leon, J.; Quiros, M.

    1984-01-01

    We present a cosmologically acceptable grand unified model where the breaking of SU(5) proceeds through radiative corrections induced by supergravity soft-breaking terms. The breaking scale is determined by dimensional transmutation. The model is compatible with the radiative breaking of SU(2)sub(L)xU(1)sub(Y) which provides an experimentally accessible low energy particle spectrum and small top quark mass. (orig.)

  2. 9 CFR 590.522 - Breaking room operations.

    Science.gov (United States)

    2010-01-01

    ... EGG PRODUCTS INSPECTION INSPECTION OF EGGS AND EGG PRODUCTS (EGG PRODUCTS INSPECTION ACT) Sanitary... breaking room and prior to receiving clean equipment after breaking an inedible egg. (c) Paper towels or tissues shall be used at breaking tables, and shall not be reused. Cloth towels are not permitted. (d...

  3. Active and break spells of the Indian summer monsoon

    Indian Academy of Sciences (India)

    et al 2006) for identifying the active and break spells. The threshold used for identifying the spells was one-half of the standard deviation of the. IMR index. Gadgil and Joseph (2003) have defined breaks (and active spells) on the basis of the daily rainfall over the monsoon trough zone. They defined a break (active) day as a ...

  4. Morphological composition of web-break inducing shives in ...

    African Journals Online (AJOL)

    Web-breaks during paper production cause a serious inconvenience in production process and increase cost of production. Earlier studies indicate that web breaks occur at tensions far below the ultimate tensile strength values determined by tensile testing in the laboratory. It was also reported that most of the web-breaks ...

  5. 24 CFR 982.315 - Family break-up.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 4 2010-04-01 2010-04-01 false Family break-up. 982.315 Section... SECTION 8 TENANT BASED ASSISTANCE: HOUSING CHOICE VOUCHER PROGRAM Leasing a Unit § 982.315 Family break-up... assistance in the program if the family breaks up. The PHA administrative plan must state PHA policies on how...

  6. Vacuum instability in low-energy supersymmetry breaking

    International Nuclear Information System (INIS)

    Dasgupta, I.; Dobrescu, B.A.; Randall, L.

    1997-01-01

    We show that for the simplest models of gauge mediated supersymmetry breaking, including all existing models, the true vacuum will not preserve QCD if it communicates supersymmetry breaking to the visible sector. We show that the desired supersymmetry breaking color preserving vacuum can nonetheless be stable cosmologically, but only if certain couplings are sufficiently small. We also present simple modifications to the sector which communicates supersymmetry breaking in which the true vacuum is acceptable, suggesting desirable properties to be sought in dynamical models of supersymmetry breaking. (orig.)

  7. Sparticle spectrum and constraints in anomaly mediated supersymmetry breaking models

    International Nuclear Information System (INIS)

    Huitu, K.; Laamanen, J.; Pandita, P.N.

    2002-01-01

    We study in detail the particle spectrum in anomaly mediated supersymmetry breaking models in which supersymmetry breaking terms are induced by the super-Weyl anomaly. We investigate the minimal anomaly mediated supersymmetry breaking models, gaugino assisted supersymmetry breaking models, as well as models with additional residual nondecoupling D-term contributions due to an extra U(1) gauge symmetry at a high energy scale. We derive sum rules for the sparticle masses in these models which can help in differentiating between them. We also obtain the sparticle spectrum numerically, and compare and contrast the results so obtained for the different types of anomaly mediated supersymmetry breaking models

  8. A Preliminary Investigation of Caffeinated Alcohol Use During Spring Break.

    Science.gov (United States)

    Linden-Carmichael, Ashley N; Lau-Barraco, Cathy

    2016-06-06

    Caffeinated alcoholic beverages (e.g., Red Bull and vodka) are popular but associated with negative consequences. CABs may be particularly popular during Spring Break, a potentially risky social event. We aimed to identify the prevalence of Spring Break caffeinated alcohol use, determine how caffeinated alcohol use Spring Break drinking habits differ from usual, and examine the association between Spring Break caffeinated alcohol use and alcohol-related problems. Data were collected from 95 college students during March of 2013 and 2014. Students completed questionnaires of their alcohol and caffeinated alcohol use before and during Spring Break and Spring Break alcohol-related problems. Approximately 54% of students used caffeinated alcohol during Spring Break. Spring Break caffeinated alcohol use was associated with more alcohol-related problems, even after controlling for other alcohol consumed and Spring Break vacation status. Caffeinated alcoholic beverages are commonly consumed during Spring Break and their use uniquely predicted harms. Prevention efforts placed on caffeinated alcoholic beverage users may be helpful in reducing Spring Break-related harms.

  9. Breaking the News in Spinal Cord Injury

    Science.gov (United States)

    Kirshblum, Steven; Fichtenbaum, Joyce

    2008-01-01

    Summary: Breaking the bad news in terms of prognosis for significant motor recovery following a neurologically complete spinal cord injury (SCI) is one of the most difficult tasks for the spinal cord medicine specialist. Learning the skills to facilitate this communication is extremely important to better assist patients to understand their prognosis as well as foster hope for their future. If bad news is delivered poorly it can cause confusion and long-lasting distress and resentment; if done well, it may assist understanding, adjustment, and acceptance. This article provides the physician who cares for patients with SCI with some concepts to consider when discussing prognosis with patients and their families. PMID:18533406

  10. Rotation Breaking Induced by ELMs on EAST

    DEFF Research Database (Denmark)

    Xiong, H.; Xu, G.; Sun, Y.

    Spontaneous rotation has been observed in LHCD H-mode plasmas with type III ELMs (edge localized modes) on EAST, and it revealed that type III ELMs can induce the loss of both core and edge toroidal rotation. Here we work on the breaking mechanism during the ELMs. Several large tokamaks have...... of magnetic surface, thus generate NTV (neoclassical toroidal viscosity) torque that affects toroidal rotation. We adopt 1cm maximum edge magnetic surface displacement from experimental observation, and our calculation shows that the edge torque is about 0.35 N/m2, and the core very small. The expected...

  11. Breaking Barriers in Polymer Additive Manufacturing

    Energy Technology Data Exchange (ETDEWEB)

    Love, Lonnie J [ORNL; Duty, Chad E [ORNL; Post, Brian K [ORNL; Lind, Randall F [ORNL; Lloyd, Peter D [ORNL; Kunc, Vlastimil [ORNL; Peter, William H [ORNL; Blue, Craig A [ORNL

    2015-01-01

    Additive Manufacturing (AM) enables the creation of complex structures directly from a computer-aided design (CAD). There are limitations that prevent the technology from realizing its full potential. AM has been criticized for being slow and expensive with limited build size. Oak Ridge National Laboratory (ORNL) has developed a large scale AM system that improves upon each of these areas by more than an order of magnitude. The Big Area Additive Manufacturing (BAAM) system directly converts low cost pellets into a large, three-dimensional part at a rate exceeding 25 kg/h. By breaking these traditional barriers, it is possible for polymer AM to penetrate new manufacturing markets.

  12. Electroweak Symmetry Breaking (1/3)

    CERN Multimedia

    CERN. Geneva

    2012-01-01

    The focus of the lectures will be on the role of the Higgs boson in the mechanism of electroweak symmetry breaking, both in the Standard Model and in models of New Physics. In particular, I will discuss how a determination of its couplings to matter and gauge fields can give important information on the nature and origin of the Higgs boson. I will thus review the picture on Higgs couplings implied by the current experimental data and examine further interesting processes that can be measured in the future.

  13. Electroweak Symmetry Breaking (2/3)

    CERN Multimedia

    CERN. Geneva

    2012-01-01

    The focus of the lectures will be on the role of the Higgs boson in the mechanism of electroweak symmetry breaking, both in the Standard Model and in models of New Physics. In particular, I will discuss how a determination of its couplings to matter and gauge fields can give important information on the nature and origin of the Higgs boson. I will thus review the picture on Higgs couplings implied by the current experimental data and examine further interesting processes that can be measured in the future.

  14. Electroweak Symmetry Breaking (3/3)

    CERN Multimedia

    CERN. Geneva

    2012-01-01

    The focus of the lectures will be on the role of the Higgs boson in the mechanism of electroweak symmetry breaking, both in the Standard Model and in models of New Physics. In particular, I will discuss how a determination of its couplings to matter and gauge fields can give important information on the nature and origin of the Higgs boson. I will thus review the picture on Higgs couplings implied by the current experimental data and examine further interesting processes that can be measured in the future.

  15. Report of Break Out Group 1

    DEFF Research Database (Denmark)

    Alward, Randy; Carley, Kathleen M.; Madsen, Fredrik Huitfeldt

    2006-01-01

    To help understand a network and its ability to continue operating when under attack, the break out group discussed issues that need to be considered when presenting network vulnerability information to an analyst, manager or commander in effective support of that person's "observe, orient, decid...... of characterizing a vulnerability. This would take into account the potential for the vulnerability to be exploited as well as the potential impact on the operations supported by the network, and on the network structure itself, of a successful exploit of that vulnerability....

  16. Cosmoparticle physics of family symmetry breaking

    International Nuclear Information System (INIS)

    Khlopov, M.Yu.

    1993-07-01

    The foundations of both particle theory and cosmology are hidden at super energy scale and can not be tested by direct laboratory means. Cosmoparticle physics is developed to probe these foundations by the proper combination of their indirect effects, thus providing definite conclusions on their reliability. Cosmological and astrophysical tests turn to be complementary to laboratory searches of rare processes, induced by new physics, as it can be seen in the case of gauge theory of broken symmetry of quark and lepton families, ascribing to the hierarchy of the horizontal symmetry breaking the observed hierarchy of masses and the mixing between quark and lepton families. 36 refs

  17. Phenomenology of flavor-mediated supersymmetry breaking

    International Nuclear Information System (INIS)

    Kaplan, D. Elazzar; Kribs, Graham D.

    2000-01-01

    The phenomenology of a new economical supersymmetric model that utilizes dynamical supersymmetry breaking and gauge mediation for the generation of the sparticle spectrum and the hierarchy of fermion masses is discussed. Similarities between the communication of supersymmetry breaking through a messenger sector and the generation of flavor using the Froggatt-Nielsen (FN) mechanism are exploited, leading to the identification of vector-like messenger fields with FN fields and the messenger U(1) as a flavor symmetry. An immediate consequence is that the first and second generation scalars acquire flavor-dependent masses, but do not violate flavor changing neutral current bounds since their mass scale, consistent with ''effective supersymmetry,'' is of order 10 TeV. We define and advocate a ''minimal flavor-mediated model'' (MFMM), recently introduced in the literature, which successfully accommodates the small flavor-breaking parameters of the standard model using order 1 couplings and ratios of flavon field VEVs. The mediation of supersymmetry breaking occurs via two-loop logarithm-enhanced gauge-mediated contributions, as well as several one-loop and two-loop Yukawa-mediated contributions for which we provide analytical expressions. The MFMM is parametrized by a small set of masses and couplings, with values restricted by several model constraints and experimental data. Full two-loop renormalization group evolution is performed, correctly taking into account the negative two-loop gauge contributions from heavy first and second generations. Electroweak symmetry is radiatively broken with the value of μ determined by matching to the Z mass. The weak scale spectrum is generally rather heavy, except for the lightest Higgs boson, the lightest stau, the lightest chargino, the lightest two neutralinos, and of course a very light gravitino. The next-to-lightest sparticle always has a decay length that is larger than the scale of a detector, and is either the lightest stau

  18. Dense Gravity Currents with Breaking Internal Waves

    Science.gov (United States)

    Tanimoto, Yukinobu; Hogg, Charlie; Ouellette, Nicholas; Koseff, Jeffrey

    2017-11-01

    Shoaling and breaking internal waves along a pycnocline may lead to mixing and dilution of dense gravity currents, such as cold river inflows into lakes or brine effluent from desalination plants in near-coastal environments. In order to explore the interaction between gravity currents and breaking interfacial waves a series of laboratory experiments was performed in which a sequence of internal waves impinge upon a shelf-slope gravity current. The waves are generated in a two-layer thin-interface ambient water column under a variety of conditions characterizing both the waves and the gravity currents. The mixing of the gravity current is measured through both intrusive (CTD probe) and nonintrusive (Planar-laser inducted fluorescence) techniques. We will present results over a full range of Froude number (characterizing the waves) and Richardson number (characterizing the gravity current) conditions, and will discuss the mechanisms by which the gravity current is mixed into the ambient environment including the role of turbulence in the process. National Science Foundation.

  19. Chiral symmetry breakings in supersymmetric QCD

    Energy Technology Data Exchange (ETDEWEB)

    Shinmura, Mamoru; Yamawaki, Koichi (Nagoya Univ. (Japan). Dept. of Physics)

    1984-05-01

    It is argued that spontaneous chiral symmetry breaking in supersymmetric QCD is due to the boson pair condensation instead of the fermion pair condensation in sharp contrast to the ordinary QCD. We further construct a low energy effective Lagrangian for supersymmetric QCD, which realizes the symmetry breaking, SU(N) sub(L) x SU(N) sub(R) x U(1) sub(V) x U(1) sub(X) down to SU(N) sub(V) x U(1) sub(V), in the massless limit. Our Lagrangian has no singular behaviour in the massless limit, supersymmetry being preserved independently of the quark mass m. It is shown that linear masses (instead of quadratic masses) of the pseudo-Nambu-Goldstone bosons are proportional to the quark mass and supersymmetric variants of Dashen's formulae are all saturated by the condensations -- O(m..lambda../sup 2/) and -- O (..lambda../sup 2/) for m -- 0.

  20. Large-field inflation and supersymmetry breaking

    International Nuclear Information System (INIS)

    Buchmueller, Wilfried; Wieck, Clemens; Dudas, Emilian; Heurtier, Lucien; Ecole Polytechnique, Palaiseau

    2014-07-01

    Large-field inflation is an interesting and predictive scenario. Its non-trivial embedding in supergravity was intensively studied in the recent literature, whereas its interplay with supersymmetry breaking has been less thoroughly investigated. We consider the minimal viable model of chaotic inflation in supergravity containing a stabilizer field, and add a Polonyi field. Furthermore, we study two possible extensions of the minimal setup. We show that there are various constraints: first of all, it is very hard to couple an O'Raifeartaigh sector with the inflaton sector, the simplest viable option being to couple them only through gravity. Second, even in the simplest model the gravitino mass is bounded from above parametrically by the inflaton mass. Therefore, high-scale supersymmetry breaking is hard to implement in a chaotic inflation setup. As a separate comment we analyze the simplest chaotic inflation construction without a stabilizer field, together with a supersymmetrically stabilized Kaehler modulus. Without a modulus, the potential of such a model is unbounded from below. We show that a heavy modulus cannot solve this problem.

  1. Dimensional reduction, monopoles and dynamical symmetry breaking

    Science.gov (United States)

    Dolan, Brian P.; Szabo, Richard J.

    2009-03-01

    We consider SU(2)-equivariant dimensional reduction of Yang-Mills-Dirac theory on manifolds of the form M × Bbb CP1, with emphasis on the effects of non-trivial magnetic flux on Bbb CP1. The reduction of Yang-Mills fields gives a chain of coupled Yang-Mills-Higgs systems on M with a Higgs potential leading to dynamical symmetry breaking, as a consequence of the monopole fields. The reduction of SU(2)-symmetric fermions gives massless Dirac fermions on M transforming under the low-energy gauge group with Yukawa couplings, again as a result of the internal U(1) fluxes. The tower of massive fermionic Kaluza-Klein states also has Yukawa interactions and admits a natural SU(2)-equivariant truncation by replacing Bbb CP1 with a fuzzy sphere. In this approach it is possible to obtain exactly massless chiral fermions in the effective field theory with Yukawa interactions, without any further requirements. We work out the spontaneous symmetry breaking patterns and determine the complete physical particle spectrum in a number of explicit examples.

  2. Chiral Gauge Dynamics and Dynamical Supersymmetry Breaking

    Energy Technology Data Exchange (ETDEWEB)

    Poppitz, Erich; /Toronto U.; Unsal, Mithat; /SLAC /Stanford U.

    2009-05-07

    We study the dynamics of a chiral SU(2) gauge theory with a Weyl fermion in the I = 3/2 representation and of its supersymmetric generalization. In the former, we find a new and exotic mechanism of confinement, induced by topological excitations that we refer to as magnetic quintets. The supersymmetric version was examined earlier in the context of dynamical supersymmetry breaking by Intriligator, Seiberg, and Shenker, who showed that if this gauge theory confines at the origin of moduli space, one may break supersymmetry by adding a tree level superpotential. We examine the dynamics by deforming the theory on S{sup 1} x R{sup 3}, and show that the infrared behavior of this theory is an interacting CFT at small S{sup 1}. We argue that this continues to hold at large S{sup 1}, and if so, that supersymmetry must remain unbroken. Our methods also provide the microscopic origin of various superpotentials in SQCD on S{sup 1} x R{sup 3}--which were previously obtained by using symmetry and holomorphy--and resolve a long standing interpretational puzzle concerning a flux operator discovered by Affleck, Harvey, and Witten. It is generated by a topological excitation, a 'magnetic bion', whose stability is due to fermion pair exchange between its constituents. We also briefly comment on composite monopole operators as leading effects in two dimensional antiferromagnets.

  3. Electromagnetic scattering from large steady breaking waves

    Energy Technology Data Exchange (ETDEWEB)

    Coakley, D.B.; Haldeman, P.M.; Morgan, D.G.; Nicolas, K.R.; Penndorf, D.R.; Wetzel, L.B.; Weller, C.S. [David Taylor Model Basin, Naval Surface Warfare Center Carderock Div., West Bethesda, MD (United States)

    2001-05-01

    A submerged hydrofoil generated large steady breaking waves of 0.3 m and 0.4 m height in a circulating water channel. We measured water fraction in the breakers with conductivity probes. We observed the radar cross-section of the breakers at X-band with a pulsed step-frequency instrumentation radar with high spatial resolution in the downstream direction. The normalized radar cross-section increases with increasing elevation angle of observation for both vertical and horizontal polarization. This variation is consistent with a simple interpretation of the breaking wave as a diffuse (Lambertian) surface. However, the observed sizes and shapes of fluid elements in the breakers clearly show that construction of a theory for electromagnetic scattering from first principles will be challenging. We also obtained the velocity spectrum of the scattering features within the breakers. This spectrum indicates that slower moving small liquid elements rather than the faster moving large disturbances are responsible for most of the electromagnetic scattering. (orig.)

  4. 'Jet breaks' and 'missing breaks' in the X-Ray afterglow of Gamma Ray Bursts

    CERN Document Server

    Dado, Shlomo; De Rújula, Alvaro

    2008-01-01

    The X-ray afterglows (AGs) of Gamma-Ray Bursts (GRBs) and X-Ray Flashes (XRFs) have, after the fast decline phase of their prompt emission, a temporal behaviour varying between two extremes. A large fraction of these AGs has a 'canonical' light curve which, after an initial shallow-decay 'plateau' phase, 'breaks smoothly' into a fast power-law decline. Very energetic GRBs, contrariwise, appear not to have a 'break', their AG declines like a power-law from the start of the observations. Breaks and 'missing breaks' are intimately related to the geometry and deceleration of the jets responsible for GRBs. In the frame of the 'cannonball' (CB) model of GRBs and XRFs, we analyze the cited extreme behaviours (canonical and pure power-law) and intermediate cases spanning the observed range of X-ray AG shapes. We show that the entire panoply of X-ray light-curve shapes --measured with Swift and other satellites-- are as anticipated, on very limpid grounds, by the CB model. We test the expected correlations between the...

  5. Structural changes in Central and Eastern European economies: breaking news or breaking the ice?

    Czech Academy of Sciences Publication Activity Database

    Égert, B.; Jiménez-Rodríguez, R.; Kočenda, Evžen; Morales-Zumaquero, A.

    2006-01-01

    Roč. 39, 1-2 (2006), s. 85-103 ISSN 1573-9414 R&D Projects: GA MŠk LC542 Institutional research plan: CEZ:MSM0021620846 Keywords : Central and Eastern Europe an (CEE) countries * multiple structural breaks * volatility Subject RIV: AH - Economic s

  6. Tear film break-up time in rabbits.

    Science.gov (United States)

    Wei, Xiaojia E; Markoulli, Maria; Zhao, Zhenjun; Willcox, Mark D P

    2013-01-01

    Rabbits have a longer inter-blink time (approximately 10 minutes) compared with humans (five to eight seconds), suggesting that rabbits have a much more stable tear film. Using fluorescein, the tear break-up time of rabbits has been reported to be similar to that of humans. This study set out to measure the tear break-up time in rabbits using non-invasive methods and to establish the pattern of tear break-up compared to humans. The tear break-up time was measured and the pattern of tear break-up was observed in six New Zealand White rabbits on two separate occasions using both the Keeler Tearscope-plus(TM) and a slitlamp biomicroscope. The mean rabbit tear break-up time was 29.8 ± 3.4 (SD) minutes. This contrasts with the reports of human tear break-up time of eight to 30 seconds. The tear breaking spread very slowly and was often restricted to the area of the initial break. Rabbit tears have a significantly higher tear break-up time than humans and this aligns with previously demonstrated differences in inter-blink time between rabbits and humans. Understanding the underlying mechanisms of tear stability may lead to novel ways of increasing human tear film stability. © 2012 The Authors. Clinical and Experimental Optometry © 2012 Optometrists Association Australia.

  7. Breaks in Play: Do They Achieve Intended Aims?

    Science.gov (United States)

    Blaszczynski, Alexander; Cowley, Elizabeth; Anthony, Christina; Hinsley, Kate

    2016-06-01

    Breaks in play represent a responsible gambling strategy designed to disrupt states of dissociation and enhance the likelihood of drawing attention to a player's session behaviour and expenditure with respect to time and money. The aim of the break in play is to motivate the player to modify or cease gambling so the activity remains within affordable levels. The aim of this study was to investigate whether imposed breaks in play in the absence of accompanying warning messages were effective in reducing cravings. Participants (141 university students) were randomly allocated to one of three conditions: 15 min computer simulated Black Jack play followed by no break, a 3 or 8 min break in play. Participants were administered a battery of measures to assess problem gambling card play, cravings, and dissociation to assess the effects of length of break on cravings. Results indicated that cravings increased rather than decreased with imposed breaks in play, and that the strength of cravings were higher following the eight- compared to 3-min break. It was concluded that breaks in play in isolation might produce counterproductive, unintended, and even perverse effects. The policy implications for responsible gambling strategies is that breaks in play ought to be accompanied with warning and/or personal appraisal messages if optimal effects in reducing within session gambling expenditure are to be achieved.

  8. Symmetry Breaking in MILP Formulations for Unit Commitment Problems

    KAUST Repository

    Lima, Ricardo

    2015-12-11

    This paper addresses the study of symmetry in Unit Commitment (UC) problems solved by Mixed Integer Linear Programming (MILP) formulations, and using Linear Programming based Branch & Bound MILP solvers. We propose three sets of symmetry breaking constraints for UC MILP formulations exhibiting symmetry, and its impact on three UC MILP models are studied. The case studies involve the solution of 24 instances by three widely used models in the literature, with and without symmetry breaking constraints. The results show that problems that could not be solved to optimality within hours can be solved with a relatively small computational burden if the symmetry breaking constraints are assumed. The proposed symmetry breaking constraints are also compared with the symmetry breaking methods included in two MILP solvers, and the symmetry breaking constraints derived in this work have a distinct advantage over the methods in the MILP solvers.

  9. Proteins Breaking Bad: A Free Energy Perspective.

    Science.gov (United States)

    Valle-Orero, Jessica; Tapia-Rojo, Rafael; Eckels, Edward C; Rivas-Pardo, Jaime Andrés; Popa, Ionel; Fernández, Julio M

    2017-08-03

    Protein aging may manifest as a mechanical disease that compromises tissue elasticity. As proved recently, while proteins respond to changes in force with an instantaneous elastic recoil followed by a folding contraction, aged proteins break bad, becoming unstructured polymers. Here, we explain this phenomenon in the context of a free energy model, predicting the changes in the folding landscape of proteins upon oxidative aging. Our findings validate that protein folding under force is constituted by two separable components, polymer properties and hydrophobic collapse, and demonstrate that the latter becomes irreversibly blocked by oxidative damage. We run Brownian dynamics simulations on the landscape of protein L octamer, reproducing all experimental observables, for a naive and damaged polyprotein. This work provides a unique tool to understand the evolving free energy landscape of elastic proteins upon physiological changes, opening new perspectives to predict age-related diseases in tissues.

  10. Symmetry breaking during seeded growth of nanocrystals.

    Science.gov (United States)

    Xia, Xiaohu; Xia, Younan

    2012-11-14

    Currently, most of the reported noble-metal nanocrystals are limited to a high level of symmetry, as constrained by the inherent, face-centered cubic (fcc) lattice of these metals. In this paper, we report, for the first time, a facile and versatile approach (backed up by a clear mechanistic understanding) for breaking the symmetry of an fcc lattice and thus obtaining nanocrystals with highly unsymmetrical shapes. The key strategy is to induce and direct the growth of nanocrystal seeds into unsymmetrical modes by manipulating the reduction kinetics. With silver as an example, we demonstrated that the diversity of possible shapes taken by noble-metal nanocrystals could be greatly expanded by incorporating a series of new shapes drastically deviated from the fcc lattice. This work provides a new method to investigate shape-controlled synthesis of metal nanocrystal.

  11. Higgsless approach to electroweak symmetry breaking

    CERN Document Server

    Grojean, Christophe

    2007-01-01

    Higgsless models are an attempt to achieve a breaking of the electroweak symmetry via boundary conditions at the end-points of a fifth dimension compactified on an interval, as an alternative to the usual Higgs mechanism. There is no physical Higgs scalar in the spectrum and the perturbative unitarity violation scale is delayed via the exchange of massive spin-1 KK resonances. The correct mass spectrum is reproduced in a model in warped space, which inherits a custodial symmetry from a left–right gauge symmetry in the bulk. Phenomenological challenges as well as collider signatures are presented. From the AdS/CFT perspective, this model appears as a weakly coupled dual to walking technicolour models.

  12. Passive appendages generate drift through symmetry breaking

    Science.gov (United States)

    Lācis, U.; Brosse, N.; Ingremeau, F.; Mazzino, A.; Lundell, F.; Kellay, H.; Bagheri, S.

    2014-10-01

    Plants and animals use plumes, barbs, tails, feathers, hairs and fins to aid locomotion. Many of these appendages are not actively controlled, instead they have to interact passively with the surrounding fluid to generate motion. Here, we use theory, experiments and numerical simulations to show that an object with a protrusion in a separated flow drifts sideways by exploiting a symmetry-breaking instability similar to the instability of an inverted pendulum. Our model explains why the straight position of an appendage in a fluid flow is unstable and how it stabilizes either to the left or right of the incoming flow direction. It is plausible that organisms with appendages in a separated flow use this newly discovered mechanism for locomotion; examples include the drift of plumed seeds without wind and the passive reorientation of motile animals.

  13. Passive appendages aid locomotion through symmetry breaking

    Science.gov (United States)

    Bagheri, Shervin; Lacis, Ugis; Mazzino, Andrea; Kellay, Hamid; Brosse, Nicolas; Lundell, Fredrik; Ingremeau, Francois

    2014-11-01

    Plants and animals use plumes, barbs, tails, feathers, hairs, fins, and other types of appendages to aid locomotion. Despite their enormous variation, passive appendages may contribute to locomotion by exploiting the same physical mechanism. We present a new mechanism that applies to body appendages surrounded by a separated flow, which often develops behind moving bodies larger than a few millimeters. We use theory, experiments, and numerical simulations to show that bodies with protrusions turn and drift by exploiting a symmetry-breaking instability similar to the instability of an inverted pendulum. Our model explains why the straight position of an appendage in flowing fluid is unstable and how it stabilizes either to the left or right of the incoming fluid flow direction. The discovery suggests a new mechanism of locomotion that may be relevant for certain organisms; for example, how plumed seeds may drift without wind and how motile animals may passively reorient themselves.

  14. Break the silence: Let's talk about AIDS.

    Science.gov (United States)

    1999-10-11

    The organizers of the Confederation of East and Central Africa Football Associations¿ (CECAFA) Youth Tournament in Kenya will organize a campaign on AIDS prevention. ¿Break the Silence: Let¿s Talk About AIDS¿ is the campaign slogan, which will be used before, during, and after the 2-week football tournament. The campaign will involve an estimated 300 players and coaches and millions of fans who will attend, watch television, or listen to radios. AIDS prevention efforts linked to the tournament include: radio and television AIDS prevention spots featuring famous football players; campaign orientation and training in AIDS outreach and education for coaches and team managers; telephone hotlines for HIV/AIDS counseling through public phone booths and health information booths; AIDS information caravans to support community awareness rallies about AIDS prevention; and a minute of silence at the beginning of all matches to commemorate soccer heroes and other loved ones who have died of AIDS.

  15. Symmetry breaking: The standard model and superstrings

    International Nuclear Information System (INIS)

    Gaillard, M.K.

    1988-01-01

    The outstanding unresolved issue of the highly successful standard model is the origin of electroweak symmetry breaking and of the mechanism that determines its scale, namely the vacuum expectation value (vev)v that is fixed by experiment at the value v = 4m//sub w//sup 2///g 2 = (√2G/sub F/)/sup /minus/1/ ≅ 1/4 TeV. In this talk I will discuss aspects of two approaches to this problem. One approach is straightforward and down to earth: the search for experimental signatures, as discussed previously by Pierre Darriulat. This approach covers the energy scales accessible to future and present laboratory experiments: roughly (10/sup /minus/9/ /minus/ 10 3 )GeV. The second approach involves theoretical speculations, such as technicolor and supersymmetry, that attempt to explain the TeV scale. 23 refs., 5 figs

  16. Symmetry breaking: The standard model and superstrings

    Energy Technology Data Exchange (ETDEWEB)

    Gaillard, M.K.

    1988-08-31

    The outstanding unresolved issue of the highly successful standard model is the origin of electroweak symmetry breaking and of the mechanism that determines its scale, namely the vacuum expectation value (vev)v that is fixed by experiment at the value v = 4m//sub w//sup 2///g/sup 2/ = (..sqrt..2G/sub F/)/sup /minus/1/ approx. = 1/4 TeV. In this talk I will discuss aspects of two approaches to this problem. One approach is straightforward and down to earth: the search for experimental signatures, as discussed previously by Pierre Darriulat. This approach covers the energy scales accessible to future and present laboratory experiments: roughly (10/sup /minus/9/ /minus/ 10/sup 3/)GeV. The second approach involves theoretical speculations, such as technicolor and supersymmetry, that attempt to explain the TeV scale. 23 refs., 5 figs.

  17. Dirac gauginos in low scale supersymmetry breaking

    International Nuclear Information System (INIS)

    Goodsell, Mark D.; Tziveloglou, Pantelis

    2014-01-01

    It has been claimed that Dirac gaugino masses are necessary for realistic models of low-scale supersymmetry breaking, and yet very little attention has been paid to the phenomenology of a light gravitino when gauginos have Dirac masses. We begin to address this deficit by investigating the couplings and phenomenology of the gravitino in the effective Lagrangian approach. We pay particular attention to the phenomenology of the scalar octets, where new decay channels open up. This leads us to propose a new simplified effective scenario including only light gluinos, sgluons and gravitinos, allowing the squarks to be heavy – with the possible exception of the third generation. Finally, we comment on the application of our results to Fake Split Supersymmetry

  18. Symmetry breaking bifurcations of a current sheet

    International Nuclear Information System (INIS)

    Parker, R.D.; Dewar, R.L.; Johnson, J.L.

    1988-08-01

    Using a time evolution code with periodic boundary conditions, the viscoresistive hydromagnetic equations describing an initially static, planar current sheet with large Lundquist number have been evolved for times long enough to reach a steady state. A cosh 2 x resistivity model was used. For long periodicity lengths, L p , the resistivity gradient drives flows which cause forced reconnection at X point current sheets. Using L p as a bifurcation parameter, two new symmetry breaking bifurcations were found - a transition to an asymmetric island chain with nonzero, positive or negative phase velocity, and a transition to a static state with alternating large and small islands. These states are reached after a complex transient behavior which involves a competition between secondary current sheet instability and coalescence. 31 refs., 6 figs

  19. Supersymmetry Breaking, Gauge Mediation, and the LHC

    International Nuclear Information System (INIS)

    Shih, David

    2015-01-01

    Gauge mediated SUSY breaking (GMSB) is a promising class of supersymmetric models that automatically satisfies the precision constraints. Prior work of Meade, Seiberg and Shih in 2008 established the full, model-independent parameter space of GMSB, which they called 'General Gauge Mediation' (GGM). During the first half of 2010-2015, Shih and his collaborators thoroughly explored the parameter space of GGM and established many well-motivated benchmark models for use by the experimentalists at the LHC. Through their work, the current constraints on GGM from LEP, the Tevatron and the LHC were fully elucidated, together with the possible collider signatures of GMSB at the LHC. This ensured that the full discovery potential for GGM could be completely realized at the LHC.

  20. Spontaneous spherical symmetry breaking in atomic confinement

    Science.gov (United States)

    Sveshnikov, Konstantin; Tolokonnikov, Andrey

    2017-07-01

    The effect of spontaneous breaking of initial SO(3) symmetry is shown to be possible for an H-like atom in the ground state, when it is confined in a spherical box under general boundary conditions of "not going out" through the box surface (i.e. third kind or Robin's ones), for a wide range of physically reasonable values of system parameters. The most novel and nontrivial result, which has not been reported previously, is that such an effect takes place not only for attractive, but also for repulsive interactions of atomic electrons with the cavity environment. Moreover, in the limit of a large box size R ≫ aB the regime of an atom, soaring over a plane with boundary condition of "not going out", is reproduced, rather than a spherically symmetric configuration, which would be expected on the basis of the initial SO(3) symmetry of the problem.

  1. Physical Model of Cellular Symmetry Breaking

    Science.gov (United States)

    van der Gucht, Jasper; Sykes, Cécile

    2009-01-01

    Cells can polarize in response to external signals, such as chemical gradients, cell–cell contacts, and electromagnetic fields. However, cells can also polarize in the absence of an external cue. For example, a motile cell, which initially has a more or less round shape, can lose its symmetry spontaneously even in a homogeneous environment and start moving in random directions. One of the principal determinants of cell polarity is the cortical actin network that underlies the plasma membrane. Tension in this network generated by myosin motors can be relaxed by rupture of the shell, leading to polarization. In this article, we discuss how simplified model systems can help us to understand the physics that underlie the mechanics of symmetry breaking. PMID:20066077

  2. A (critical) overview of electroweak symmetry breaking

    International Nuclear Information System (INIS)

    Csaki, Csaba

    2010-01-01

    This presentation discusses the following points: The standard Higgs, big vs. little hierarchy; Electroweak Symmetry Breaking in supersymmetry and little hierarchy of Minimal Supersymmetric Standard Model (MSSM): Buried Higgs, Bigger quartic (D-terms, Next-to-Minimal Supersymmetric Standard Model (NMSSM), fat Higgs,..); Strong dynamics and related models: Technicolor, Monopole condensate, Warped extra dimensions, Realistic RS, Higgs-less, Composite Higgs, Little Higgs. In summary, we do not understand how Higgs is light and still no trace of new physics. In Supersymmetry (SUSY) it calls for extension of MSSM. In strong dynamics models: electroweak penguin (EWP) usually issue (Warped extra dimension - composite Higgs, Higgs-less, Little Higgs, Technicolor, monopole condensation,..). None of them is fully convincing but LHC should settle these

  3. Applicability of the leak before break concept

    International Nuclear Information System (INIS)

    1993-06-01

    Within the framework of the IAEA Extrabudgetary Programme on the Safety of WWER-440 Model 230 NPPs, a list of safety issues requiring broad studies of general interest have been agreed upon by an Advisory Group which met in Vienna in September 1990. The information on the status of the issues, and on amount of work already completed and under way in various countries, needs to be compiled. Moreover, an evaluation of what further work is required to resolve each of the issues is also necessary. In view of this, the IAEA has started the preparation of a series of status reports on the various issues. This report on the generic safety issue ''Applicability of the Leak Before Break Concept'' presents a comprehensive survey of technical information available in the field and identifies those which require further investigation. 50 refs, 15 figs, 2 tabs

  4. Small Neutrino Masses from Supersymmetry Breaking

    Energy Technology Data Exchange (ETDEWEB)

    Arkani-Hamed, Nima; Hall, Lawrence; Murayama, Hitoshi; Smith, David; Weiner, Neal

    2000-06-27

    An alternative to the conventional see-saw mechanism is proposed to explain the origin of small neutrino masses in supersymmetric theories. The masses and couplings of the right-handed neutrino field are suppressed by supersymmetry breaking, in a way similar to the suppression of the Higgs doublet mass, $\\mu$. New mechanisms for light Majorana, Dirac and sterile neutrinos arise, depending on the degree of suppression. Superpartner phenomenology is greatly altered by the presence of weak scale right-handed sneutrinos, which may have a coupling to a Higgs boson and a left-handed sneutrino. The sneutrino spectrum and couplings are quite unlike the conventional case - the lightest sneutrino can be the dark matter and predictions are given for event rates at upcoming halo dark matter direct detection experiments. Higgs decays and search strategies are changed. Copious Higgs production at hadron colliders can result from cascade decays of squarks and gluinos.

  5. Supersymmetry Breaking, Gauge Mediation, and the LHC

    Energy Technology Data Exchange (ETDEWEB)

    Shih, David [Rutgers Univ., New Brunswick, NJ (United States)

    2015-04-14

    Gauge mediated SUSY breaking (GMSB) is a promising class of supersymmetric models that automatically satisfies the precision constraints. Prior work of Meade, Seiberg and Shih in 2008 established the full, model-independent parameter space of GMSB, which they called "General Gauge Mediation" (GGM). During the first half of 2010-2015, Shih and his collaborators thoroughly explored the parameter space of GGM and established many well-motivated benchmark models for use by the experimentalists at the LHC. Through their work, the current constraints on GGM from LEP, the Tevatron and the LHC were fully elucidated, together with the possible collider signatures of GMSB at the LHC. This ensured that the full discovery potential for GGM could be completely realized at the LHC.

  6. Breaking Gaussian incompatibility on continuous variable quantum systems

    Energy Technology Data Exchange (ETDEWEB)

    Heinosaari, Teiko, E-mail: teiko.heinosaari@utu.fi [Turku Centre for Quantum Physics, Department of Physics and Astronomy, University of Turku, FI-20014 Turku (Finland); Kiukas, Jukka, E-mail: jukka.kiukas@aber.ac.uk [Department of Mathematics, Aberystwyth University, Penglais, Aberystwyth, SY23 3BZ (United Kingdom); Schultz, Jussi, E-mail: jussi.schultz@gmail.com [Turku Centre for Quantum Physics, Department of Physics and Astronomy, University of Turku, FI-20014 Turku (Finland); Dipartimento di Matematica, Politecnico di Milano, Piazza Leonardo da Vinci 32, I-20133 Milano (Italy)

    2015-08-15

    We characterise Gaussian quantum channels that are Gaussian incompatibility breaking, that is, transform every set of Gaussian measurements into a set obtainable from a joint Gaussian observable via Gaussian postprocessing. Such channels represent local noise which renders measurements useless for Gaussian EPR-steering, providing the appropriate generalisation of entanglement breaking channels for this scenario. Understanding the structure of Gaussian incompatibility breaking channels contributes to the resource theory of noisy continuous variable quantum information protocols.

  7. Wave-breaking and generic singularities of nonlinear hyperbolic equations

    International Nuclear Information System (INIS)

    Pomeau, Yves; Le Berre, Martine; Guyenne, Philippe; Grilli, Stephan

    2008-01-01

    Wave-breaking is studied analytically first and the results are compared with accurate numerical simulations of 3D wave-breaking. We focus on the time dependence of various quantities becoming singular at the onset of breaking. The power laws derived from general arguments and the singular behaviour of solutions of nonlinear hyperbolic differential equations are in excellent agreement with the numerical results. This shows the power of the analysis by methods using generic concepts of nonlinear science. (open problem)

  8. Covalent bond symmetry breaking and protein secondary structure

    OpenAIRE

    Lundgren, Martin; Niemi, Antti J.

    2011-01-01

    Both symmetry and organized breaking of symmetry have a pivotal r\\^ole in our understanding of structure and pattern formation in physical systems, including the origin of mass in the Universe and the chiral structure of biological macromolecules. Here we report on a new symmetry breaking phenomenon that takes place in all biologically active proteins, thus this symmetry breaking relates to the inception of life. The unbroken symmetry determines the covalent bond geometry of a sp3 hybridized ...

  9. Unified models of the QCD axion and supersymmetry breaking

    Science.gov (United States)

    Harigaya, Keisuke; Leedom, Jacob M.

    2017-08-01

    Similarities between the gauge meditation of supersymmetry breaking and the QCD axion model suggest that they originate from the same dynamics. We present a class of models where supersymmetry and the Peccei-Quinn symmetry are simultaneously broken. The messengers that mediate the effects of these symmetry breakings to the Standard Model are identical. Since the axion resides in the supersymmetry breaking sector, the saxion and the axino are heavy. We show constraints on the axion decay constant and the gravitino mass.

  10. Age of Seychelles India break-up

    Science.gov (United States)

    Collier, J. S.; Sansom, V.; Ishizuka, O.; Taylor, R. N.; Minshull, T. A.; Whitmarsh, R. B.

    2008-07-01

    Many continental flood basalt provinces are spatially and temporally linked with continental break-up. Establishing the relative timing of the two events is a key step in determining their causal relationship. Here we investigate the example of the Deccan Traps and the separation of India and the Seychelles. Whilst there has been a growing consensus as to the age of the main phase of the Deccan emplacement (65.5 ± 1 Ma, chron 29r), the age of the rifting has remained unclear. We resolve this issue through detailed seafloor magnetic anomaly modeling (supported by wide-angle and reflection seismic results) of the north Seychelles and conjugate Laxmi Ridge/Gop Rift margins, and geochemistry and 40Ar/ 39Ar geochronology of rocks from the north Seychelles margin. We show that syn-rift volcanics offshore the Seychelles Islands in the form of seaward-dipping reflectors were most likely erupted during chron 28n, and the first organized seafloor spreading at the Carlsberg Ridge also initiated during this chron at 63.4 Ma. The severing of the Seychelles occurred by a south-eastward ridge propagation that was completed by the start of chron 27n (~ 62 Ma). A brief, pre-28r phase of seafloor spreading occurred in the Gop Rift, possibly as early as 31r-32n (~ 71 Ma). Initial extension at the margin therefore preceded or was contemporaneous with the Deccan emplacement, and separation of the Seychelles was achieved less than 3.5 Ma afterwards. This is the shortest time interval between flood basalt emplacement and break-up yet reported for any continental flood basalt-rifted margin pair. A contributing factor to the apparently short interval in the Deccan case may be that rifting occurred by a ridge jump into already thinned continental lithosphere. However, we conclude that external plate-boundary forces, rather than the impact of a mantle plume, were largely responsible for the rifting of the Seychelles from India.

  11. Phenomenology of induced electroweak symmetry breaking

    International Nuclear Information System (INIS)

    Chang, Spencer; Galloway, Jamison; Luty, Markus A.; Salvioni, Ennio; Tsai, Yuhsin

    2015-01-01

    We study the phenomenology of models of electroweak symmetry breaking where the Higgs potential is destabilized by a tadpole arising from the coupling to an “auxiliary” Higgs sector. The auxiliary Higgs sector can be either perturbative or strongly coupled, similar to technicolor models. Since electroweak symmetry breaking is driven by a tadpole, the cubic and quartic Higgs couplings can naturally be significantly smaller than their values in the standard model. The theoretical motivation for these models is that they can explain the 125 GeV Higgs mass in supersymmetry without fine-tuning. The auxiliary Higgs sector contains additional Higgs states that cannot decouple from standard model particles, so these models predict a rich phenomenology of Higgs physics beyond the standard model. In this paper we analyze a large number of direct and indirect constraints on these models. We present the current constraints after the 8 TeV run of the LHC, and give projections for the sensitivity of the upcoming 14 TeV run. We find that the strongest constraints come from the direct searches A 0 →Zh, A 0 →tt-bar, with weaker constraints from Higgs coupling fits. For strongly-coupled models, additional constraints come from ρ + →WZ where ρ + is a vector resonance. Our overall conclusion is that a significant parameter space for such models is currently open, allowing values of the Higgs cubic coupling down to 0.4 times the standard model value for weakly coupled models and vanishing cubic coupling for strongly coupled models. The upcoming 14 TeV run of the LHC will stringently test this scenario and we identify several new searches with discovery potential for this class of models.

  12. Unstable volatility functions: the break preserving local linear estimator

    DEFF Research Database (Denmark)

    Casas, Isabel; Gijbels, Irene

    The objective of this paper is to introduce the break preserving local linear (BPLL) estimator for the estimation of unstable volatility functions. Breaks in the structure of the conditional mean and/or the volatility functions are common in Finance. Markov switching models (Hamilton, 1989......) and threshold models (Lin and Terasvirta, 1994) are amongst the most popular models to describe the behaviour of data with structural breaks. The local linear (LL) estimator is not consistent at points where the volatility function has a break and it may even report negative values for finite samples...

  13. Best estimate analysis of GDH break in RBMK-1500

    International Nuclear Information System (INIS)

    Vileiniskis, V.; Kaliatka, A.; Uspuras, E.

    2004-01-01

    The RBMK-1500 is a multichannel boiling water and graphite moderated nuclear reactor. Two identical cooling loops compose the main circulation circuit, which consists of 1661 parallel fuel channels (FC) and numerous components, such as collectors, headers, pumps, etc. There are 20 group distribution headers (GDH) in the each cooling loop. Guillotine or partial break of one GDH, which in turn feeds 38-43 FC, leads to the sharp coolant flow rate decrease in the FC connected to the affected GDH. In the case of partial GDH break the short-term flow stagnation in the group of fuel channels connected to ruptured GDH can occur. Thus, any GDH break is accompanied by fuel cladding and fuel channel temperature increase. This paper presents best estimate analysis of possible GDH breaks in Ignalina Nuclear Power Plant RBMK-1500 reactor: Guillotine break upstream check valve, Guillotine break downstream check valve, Partial break. Best estimate code RELAP5/MOD3.2 was used for deterministic analysis. According to the international practice if a best estimate code is used for the analysis, the uncertainty and sensitivity analysis should be performed. Sensitivity and uncertainty analysis was performed employing System for Uncertainty and Sensitivity Analysis (SUSA) developed at GRS (Germany). Results of the analysis shows that acceptance criterion for fuel cladding temperature is violated only short time period in the case of GDH guillotine break, in the case of partial GDH break the reactor core will be reliably cooled.(author)

  14. Rossby Waves in the Arctic Ocean

    DEFF Research Database (Denmark)

    Hjorth, Poul G.; Schmith, Torben

    The Arctic Ocean has a characteristic stable stratification with fresh and cold water occupying the upper few hundred meters and the warm and more saline Atlantic waters underneath. These water masses are separated by the cold halocline. The stability of the cold halocline regulates the upward...... directed turbulent heat flux from the Atlantic water to the Arctic water. This heat flux is a part of the arctic energy budget and is important for large scale sea ice formation and melting. Due to the strong vertical stratification combined with its almost circular boundary, the Arctic Ocean supports...

  15. On resonant Rossby-Haurwitz triads

    OpenAIRE

    Lynch, Peter

    2009-01-01

    The dynamics of non-divergent flow on a rotating sphere are described by the conservation of absolute vorticity. The analytical study of the non-linear barotropic vorticity equation is greatly facilitated by the expansion of the solution in spherical harmonics and truncation at low order. The normal modes are the well-known Rossby–Haurwitz (RH) waves, which represent the natural oscillations of the system. Triads of RH waves, which satisfy conditions for resonance, are of critical...

  16. Relationship between Age and the Ability to Break Scored Tablets.

    Science.gov (United States)

    Notenboom, Kim; Vromans, Herman; Schipper, Maarten; Leufkens, Hubert G M; Bouvy, Marcel L

    2016-01-01

    Practical problems with the use of medicines, such as difficulties with breaking tablets, are an often overlooked cause for non-adherence. Tablets frequently break in uneven parts and loss of product can occur due to crumbling and powdering. Health characteristics, such as the presence of peripheral neuropathy, decreased grip strength and manual dexterity, can affect a patient's ability to break tablets. As these impairments are associated with aging and age-related diseases, such as Parkinson's disease and arthritis, difficulties with breaking tablets could be more prevalent among older adults. The objective of this study was to investigate the relationship between age and the ability to break scored tablets. A comparative study design was chosen. Thirty-six older adults and 36 young adults were systematically observed with breaking scored tablets. Twelve different tablets were included. All participants were asked to break each tablet by three techniques: in between the fingers with the use of nails, in between the fingers without the use of nails and pushing the tablet downward with one finger on a solid surface. It was established whether a tablet was broken or not, and if broken, whether the tablet was broken accurately or not. The older adults experienced more difficulties to break tablets compared to the young adults. On average, the older persons broke 38.1% of the tablets, of which 71.0% was broken accurately. The young adults broke 78.2% of the tablets, of which 77.4% was broken accurately. Further analysis by mixed effects logistic regression revealed that age was associated with the ability to break tablets, but not with the accuracy of breaking. Breaking scored tablets by hand is less successful in an elderly population compared to a group of young adults. Health care providers should be aware that tablet breaking is not appropriate for all patients and for all drugs. In case tablet breaking is unavoidable, a patient's ability to break tablets should

  17. Breaking waves on a dynamic Hele-Shaw beach

    NARCIS (Netherlands)

    Bokhove, Onno; van der Horn, Bram; van der Horn, Avraham/Bram; van der Meer, Roger M.; Zweers, Wout; Thornton, Anthony Richard

    We report the formation of quasi-steady beaches and dunes via breaking waves in our tabletop ‘Hele-Shaw’ beach experiment. Breaking waves are generated by a wave maker, and zeolite particles act as sand. The tank is narrow, just over one-particle diameter wide, creating a quasi-2D set-up. Classical

  18. 75 FR 80073 - Reasonable Break Time for Nursing Mothers

    Science.gov (United States)

    2010-12-21

    ... law to provide break time and space for nursing mother employees who are working at other sites. d... DEPARTMENT OF LABOR Wage and Hour Division RIN 1235-ZA00 Reasonable Break Time for Nursing Mothers... and a place for nursing mothers to express breast milk for one year after their child's birth. The...

  19. Young Children's Interpretations of Page Breaks in Contemporary Picture Storybooks

    Science.gov (United States)

    Sipe, Lawrence R.; Brightman, Anne E.

    2009-01-01

    This article reports on a study of the responses of a second-grade class to the page breaks in contemporary picturebooks. In a picturebook, the text and accompanying illustrations are divided into a series of facing pages called openings, and the divisions between the openings are called page breaks or turns. Unlike a novel, in which the page…

  20. Partial Symmetry Breaking by Local Search in the Group

    NARCIS (Netherlands)

    Prestwich, S.; Hnich, B.; Simonis, H.; Rossi, R.; Tarim, S.A.

    2012-01-01

    The presence of symmetry in constraint satisfaction problems can cause a great deal of wasted search effort, and several methods for breaking symmetries have been reported. In this paper we describe a new method called Symmetry Breaking by Nonstationary Optimisation, which interleaves local search

  1. Global increase in record-breaking monthly-mean temperatures

    NARCIS (Netherlands)

    Coumou, Dim; Robinson, Alexander; Rahmstorf, Stefan

    The last decade has produced record-breaking heat waves in many parts of the world. At the same time, it was globally the warmest since sufficient measurements started in the 19th century. Here we show that, worldwide, the number of local record-breaking monthly temperature extremes is now on

  2. DNA breaks early in replication in B cell cancers

    Science.gov (United States)

    Research by scientists at the NCI has identified a new class of DNA sites in cells that break early in the replication process. They found that these break sites correlate with damage often seen in B cell cancers, such as diffuse large B cell lymphoma.

  3. Gauge principle, vector-meson dominance, and spontaneous symmetry breaking

    International Nuclear Information System (INIS)

    Nambu, Yoichiro

    1989-01-01

    The author concentrates on certain theoretical developments of the late 1950s which are concerned with the meaning and role of symmetries and symmetry breaking, and especially work done in Chicago, and notes his own involvement in this debate. He worked on symmetry-breaking in superconductivity, using a four-fermion interaction model. (UK)

  4. 27 CFR 19.282 - Breaking Government locks.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Breaking Government locks... Breaking Government locks. Where affixed, Government locks shall not be removed without the authorization... obtain authorization from an appropriate TTB officer, Government locks may be removed, by the proprietor...

  5. Symmetry breaking in collective honeybee foraging: a simulation study

    NARCIS (Netherlands)

    Vries, Han de; Biesmeijer, J.C.

    2002-01-01

    Symmetry breaking is the phenomenon that the numbers of foragers exploiting two equally profitable food sources will diverge. This phenomenon has been investigated in ants [1,4,5], but hardly in honeybees. It is even not clear whether in honeybees symmetry breaking can occur [3, p.190]. We present

  6. Physical pictures of symmetry breaking in quenched QED4

    International Nuclear Information System (INIS)

    Kogut, J.B.; Argonne National Lab., IL

    1989-01-01

    We discuss 'collapse of the wavefunction' as the phenomenon underlying chiral symmetry breaking in quenched QED4. The 1/r singularity in the 'collapsed' qanti q wavefunction causes 'catalyzed symmetry breaking' which is the field theoretic analog of 'monopole induced proton decay'. The evasion of mean field exponents by the quenched theory's chiral phase transition is emphasized. (orig.)

  7. Breaking Bad News for Patients with Gastro-Intestinal Malignancy ...

    African Journals Online (AJOL)

    No patient was told about the prognosis and the chances of cure. Conclusion: Sympathy over-ride empathy in communicating bad news to Sudanese patients suffering of cancer. Patient education and training in breaking the bad news is needed. Key words: Communication skills, breaking bad news, truth telling, Sudan.

  8. MORPlIOLOGICAL COMPOSITION OF WEB-BREAK INDUCING ...

    African Journals Online (AJOL)

    Sears et al reported that web breaks occur at tensions far below the ultimate tensile strength values determinecf by tensile testing in the laboratory[7}:. More than. 3200 breaks were investigated and in more than 98. ... of approximately cross machine orientation, length beMeen 3-4 nun and thickness equal to a considerable.

  9. Electroweak symmetry breaking and Higgs physics: basic concepts

    International Nuclear Information System (INIS)

    Gomez-Bock, M; Mondragon, M; Muehlleitner, M; Noriega-Papaqui, R; Pedraza, I; Spira, M; Zerwas, P M

    2005-01-01

    We present an introduction to the basic concepts of electroweak symmetry breaking and Higgs physics within the Standard Model and its sypersymmetric extensions. A brief overview will also be given on alternative mechanisms of symmetry breaking. In addition to the theoretical basis, the present experimental status of Higgs physics and implications for future experiments at the LHC and e + e - linear colliders are discussed

  10. Implications of dynamical symmetry breaking for high energy experiments

    International Nuclear Information System (INIS)

    Ali, A.

    1981-06-01

    A scenario of dynamical symmetry breaking as an alternative to the canonical Higgs mechanism with elementary spin-O fields is described, and its implications for high energy experiments contrasted with those of the canonical theory. The potential role of e + e - annihilation physics in unravelling the nature of spontaneous symmetry breaking is emphasized. (orig.)

  11. Breaking Bad News To Patients | Adisa | Journal of Medical ...

    African Journals Online (AJOL)

    A review of the English literature on proven methods of breaking bad news to patients was carried out. Numerous study results show that patients generally desire frank and empathetic disclosure of a terminal diagnosis or other bad news Focused training in communication skills and techniques to facilitate breaking bad ...

  12. Should I Give the Exam before or after the Break?

    Science.gov (United States)

    O'Connor, Kevin J.

    2014-01-01

    This study was designed to help faculty make decisions about when to administer an exam in relation to an in-semester break. Students in multiple sections of an undergraduate educational psychology class were assigned to take an exam either before or after a scheduled 5-day break (Thursday-Monday). A multiple regression analysis revealed the break…

  13. Evaluation of the break-out square post breakaway system.

    Science.gov (United States)

    2015-02-01

    Determine the effectiveness of the Break-Out Square (BOS) Post coupler as a : possible alternative to other breakaway devices. This product is designed to (upon : impact) break flush with grade with no damage apparent to base or anchor and offer a : ...

  14. "Old Dead Guys": Using Activity Breaks to Teach History

    Science.gov (United States)

    Holles, Joseph H.

    2009-01-01

    The people and history of chemical engineering surround us: Gibbs free energy, Arrhenius Equation, and Reynolds number. Since these seminal figures appear in almost every classroom lecture, they provide an opportunity for a historically focused activity break. Each activity break provides the students with an image of the historical figure along…

  15. Breaking the spores of Ganoderma lucidum by fermentation with ...

    African Journals Online (AJOL)

    In this paper, fermentation of G. lucidum with Lactobacillus plantarum was applied to break down the sporoderm. Scanning electron microscope (SEM) was used to characterize the spores. The broken spores were found on the 3rd day and complete breaking on the 5th day of fermentation. Lactic acid, acetic acid and ...

  16. A synopsis of experimental activities on small-break LOCA

    International Nuclear Information System (INIS)

    Hein, D.

    1984-01-01

    Through reactor safety studies like WASH 1400 or the ''Deutsche Risiko-Studie'' the attention has turned from large break loss of coolant accidents to small breaks because of the high contribution of this type of accidents to core meltdown. But only after the TMI-2 accident were also the main activities in the experimental fields shifted world-wide to the small break LOCAs. Since TMI numerous research programs have either been finished or are underway. This review paper presents: a classification of the various types of transients according to break size; a discussion of major physical phenomena associated with a small break LOCA, and a description of a few selected research programs and the most important results achieved. (author)

  17. ANALISA BREAK EVENT POINT (BEP TERHADAP LABA PERUSAHAAN

    Directory of Open Access Journals (Sweden)

    Muhammad Yusuf

    2015-09-01

    Full Text Available Break event point or the break-even point can be defined as a situation where the operating company does not make a profit and not a loss. The goal is to provide the knowledge to increase knowledge about the break event point (the point of principal and its relationship with the company profit and to know how the results of the. Analysis break event point is very important for the leadership of the company to determine the production rate how much the cost will be equal to the amount of sales or in other words to determine the break event point we will determine the relationship between sales, production, selling price, cost, loss or profit, making it easier for leaders to take discretion.DOI: 10.15408/ess.v4i1.1955 

  18. Breaking gold nano-junctions simulation and analysis

    DEFF Research Database (Denmark)

    Lauritzen, Kasper Primdal

    Simulating the movements of individual atoms allows us to look at and investigate the physical processes that happen in an experiment. In this thesis I use simulations to support and improve experimental studies of breaking gold nano-junctions. By using molecular dynamics to study gold nanowires, I...... can investigate their breaking forces under varying conditions, like stretching rate or temperature. This resolves a confusion in the literature, where the breaking forces of two different breaking structures happen to coincide. The correlations between the rupture and reformation of a gold junction......, to predict the structure of a gold junction just as it breaks. This method is based on artificial neural networks and can be used on experimental data, even when it is trained purely on simulated data. The method is extended to other types of experimental traces, where it is trained without the use...

  19. Smiles count but minutes matter: responses to classroom exercise breaks.

    Science.gov (United States)

    Howie, Erin K; Newman-Norlund, Roger D; Pate, Russell R

    2014-09-01

    To determine the subjective responses of teachers and students to classroom exercise breaks, and how responses varied by duration. This mixed-methods experimental study included focus groups with teachers (N = 8) and 4(th)- and 5(th)-grade students (N = 96). Students participated in 5-, 10-, and 20-minute exercise breaks and 10 minutes of sedentary activity. In an additional exploratory analysis, video-tapes of each condition were coded and compared for positive affect. Students and teachers discussed multiple benefits, but teachers discussed barriers to implementing regular breaks of 5-minutes or more. Students exhibited higher positive affect during each exercise condition. Classroom exercise breaks are an enjoyable way to increase physical activity, but additional support may be needed to encourage teachers to implement breaks of 5 minutes or longer.

  20. Detecting structural breaks in time series via genetic algorithms

    DEFF Research Database (Denmark)

    Doerr, Benjamin; Fischer, Paul; Hilbert, Astrid

    2016-01-01

    Detecting structural breaks is an essential task for the statistical analysis of time series, for example, for fitting parametric models to it. In short, structural breaks are points in time at which the behaviour of the time series substantially changes. Typically, no solid background knowledge...... of the time series under consideration is available. Therefore, a black-box optimization approach is our method of choice for detecting structural breaks. We describe a genetic algorithm framework which easily adapts to a large number of statistical settings. To evaluate the usefulness of different crossover...... operator alone. Moreover, we present a specific fitness function which exploits the sparse structure of the break points and which can be evaluated particularly efficiently. The experiments on artificial and real-world time series show that the resulting algorithm detects break points with high precision...

  1. Warped Electroweak Breaking Without Custodial Symmetry

    CERN Document Server

    Cabrer, Joan A; Quiros, Mariano

    2010-01-01

    We propose an alternative to the introduction of an extra gauge (custodial) symmetry to suppress the contribution of KK modes to the T parameter in warped theories of electroweak breaking. The mechanism is based on a general class of warped 5D metrics and a Higgs propagating in the bulk. The metrics are nearly AdS in the UV region but depart from AdS in the IR region, towards where KK fluctuations are mainly localized, and have a singularity outside the slice between the UV and IR branes. This gravitational background is generated by a bulk stabilizing scalar field which triggers a natural solution to the hierarchy problem. Depending on the model parameters, gauge-boson KK modes can be consistent with present bounds on EWPT for m > 1 TeV at 95% CL. The model contains a light Higgs mode which unitarizes the four-dimensional theory. The reduction in the precision observables can be traced back to a large wave function renormalization for this mode.

  2. Golden Probe of Electroweak Symmetry Breaking

    CERN Document Server

    Chen, Yi; Spiropulu, Maria; Stolarski, Daniel; Vega-Morales, Roberto

    2016-12-09

    The ratio of the Higgs couplings to $WW$ and $ZZ$ pairs, $\\lambda_{WZ}$, is a fundamental parameter in electroweak symmetry breaking as well as a measure of the (approximate) custodial symmetry possessed by the gauge boson mass matrix. We show that Higgs decays to four leptons are sensitive, via tree level/1-loop interference effects, to both the magnitude and, in particular, overall sign of $\\lambda_{WZ}$. Determining this sign requires interference effects, as it is nearly impossible to measure with rate information. Furthermore, simply determining the sign effectively establishes the custodial representation of the Higgs boson. We find that $h\\to4\\ell$ ($4\\ell \\equiv 2e2\\mu, 4e, 4\\mu$) decays have excellent prospects of directly establishing the overall sign at a high luminosity 13 TeV LHC. We also examine the ultimate LHC sensitivity in $h\\to4\\ell$ to the magnitude of $\\lambda_{WZ}$. Our results are independent of other measurements of the Higgs boson couplings and, in particular, largely free of assumpti...

  3. Breaking of electroweak symmetry: origin and effects

    International Nuclear Information System (INIS)

    Delaunay, C.

    2008-10-01

    The Higgs boson appears as the corner stone of high energy physics, it might be the cause of the excess of matter that led to the formation of the structures of the universe and it seems that it drives the breaking of the electroweak symmetry. Moreover, when the stability at low energies of the Higgs boson is assured by an extra space dimension, it appears that this extra dimension can explain most issues in the flavor physics that are not understood by the standard model. The first chapter presents the main tools of effective field theories, the role of experimental data in the construction of theories valid beyond the standard model is discussed. The second chapter focuses on the electroweak baryogenesis that allows the testing of new physics via the electroweak phase transition. We detail the calculation of a Higgs potential at finite temperature. We follow the dynamics of the phase transition including nucleation an supercooling. Finally we investigate the prospects of gravity wave detection to see the effects of a strong electroweak phase transition. The 2 last chapters are dedicated to the physics of extra-dimension. The properties of the dynamics of scalar, vector fields with a 1/2 spin plunged in a 5 d. Anti de Sitter geometry are reviewed. We present a model of lepton masses and mixings based on the A 4 non-Abelian discrete symmetry. It is shown that this model does not contradict the tests of electroweak precision. (A.C.)

  4. Rice Research to Break Yield Barriers

    Science.gov (United States)

    Verma, Vivek; Ramamoorthy, Rengasamy; Kohli, Ajay; Kumar, Prakash P.

    2015-10-01

    The world’s population continues to expand and it is expected to cross 9 billion by 2050. This would significantly amplify the demand for food, which will pose serious threats to global food security. Additional challenges are being imposed due to a gradual decrease in the total arable land and global environmental changes. Hence, it is of utmost importance to review and revise the existing food production strategies by incorporating novel biotechnological approaches that can help to break the crop yield barriers in the near future. In this review, we highlight some of the concerns hampering crop yield enhancements. The review also focuses on modern breeding techniques based on genomics as well as proven biotechnological approaches that enable identification and utilization of candidate genes. Another aspect of discussion is the important area of research, namely hormonal regulation of plant development, which is likely to yield valuable regulatory genes for such crop improvement efforts in the future. These strategies can serve as potential tools for developing elite crop varieties for feeding the growing billions.

  5. Electron transfer and bond breaking: Recent advances

    Science.gov (United States)

    Costentin, Cyrille; Robert, Marc; Savéant, Jean-Michel

    2006-05-01

    After a reminder of concerted/stepwise mechanistic dichotomy and other basic concepts and facts in the field, a series of recent advances is discussed. Particular emphasis is laid on the interactions between the fragments formed upon bond cleavage. These interactions may persist even in polar solvents and have important consequences on dissociative electron transfer kinetics and on the competition between concerted and stepwise pathways. Cleavage of ion radicals and its reverse reaction are examples of single electron transfer reactions concerted with bond cleavage and bond formation, respectively. The case of aromatic carbon-heteroatom bonds is particularly worth examination since symmetry restrictions impose circumventing a conical intersection. Reductive dehalogenases are involved in 'dehalorespiration' of anaerobic bacteria in which the role of dioxygen in aerobic organisms is played by major polychloride pollutants such as tetrachloroethylene. They offer an interesting illustration of how the coupling of electron transfer with bond breaking may be an important issue in natural processes. Applications of dissociative electron transfer concepts and models to mechanistic analysis in this class of enzymes will be discussed.

  6. Generalized geometry and partial supersymmetry breaking

    Energy Technology Data Exchange (ETDEWEB)

    Triendl, Hagen Mathias

    2010-08-15

    This thesis consists of two parts. In the first part we use the formalism of (exceptional) generalized geometry to derive the scalar field space of SU(2) x SU(2)-structure compactifications. We show that in contrast to SU(3) x SU(3) structures, there is no dynamical SU(2) x SU(2) structure interpolating between an SU(2) structure and an identity structure. Furthermore, we derive the scalar manifold of the low-energy effective action for consistent Kaluza-Klein truncations as expected from N = 4 supergravity. In the second part we then determine the general conditions for the existence of stable Minkowski and AdS N = 1 vacua in spontaneously broken gauged N = 2 supergravities and construct the general solution under the assumption that two appropriate commuting isometries exist in the hypermultiplet sector. Furthermore, we derive the low-energy effective action below the scale of partial supersymmetry breaking and show that it satisfies the constraints of N = 1 supergravity. We then apply the discussion to special quaternionic-Kaehler geometries which appear in the low-energy limit of SU(3) x SU(3)-structure compactifications and construct Killing vectors with the right properties. Finally we discuss the string theory realizations for these solutions. (orig.)

  7. LHC Report: a break from luminosity production

    CERN Multimedia

    Jan Uythoven for the LHC team

    2016-01-01

    The LHC has been in great shape over the last few months, delivering over 20 fb-1 of integrated luminosity before the ICHEP conference in Chicago at the beginning of August. This is not much below the 25 fb-1 target for the whole of 2016. With this success in mind, a break in luminosity production was taken for six days, starting on 26 July 2016, for a machine development period.   This year, 20 days of the LHC schedule are devoted to machine development with the aim of carrying out detailed studies of the accelerator. The 20 days are divided over five different periods, called MD blocks. They can be seen as an investment in the future, so the machine can produce collisions more efficiently in the months and years to come. A detailed programme is worked out for each MD block, whereby different specialist teams are assigned periods of four to twelve hours, depending on the topic, to perform their previously approved tests. The MD program continues 24 hours per day, as in normal physics operation. One...

  8. Electroweak symmetry breaking: Higgs/whatever

    International Nuclear Information System (INIS)

    Chanowitz, M.S.

    1990-01-01

    In these two lectures the author discusses electroweak symmetry breaking from a general perspective, stressing properties that are model independent and follow just from the assumption that the electroweak interactions are described by a spontaneously broken gauge theory. This means he assumes the Higgs mechanism though not necessarily the existence of Higgs bosons. The first lecture presents the general framework of a spontaneously broken gauge theory: (1) the Higgs mechanism sui generis, with or without Higgs boson(s) and (2) the implications of symmetry and unitarity for the mass scale and interaction strength of the new physics that the Higgs mechanism requires. In addition he reviews a softer theoretical argument based on the naturalness problem which leads to a prejudice against Higgs bosons unless they are supersymmetric. This is a prejudice, not a theorem, and it could be overturned in the future by a clever new idea. In the second lecture he illustrates the general framework by reviewing some specific models: (1) the Weinberg-Salam model of the Higgs sector; (2) the minimal supersymmetric extension of the Weinberg-Salam model; and (3) technicolor as an example of the Higgs mechanism without Higgs bosons. He concludes the second lecture with a discussion of strong WW scattering that must occur if L SB lives above 1 TeV. In particular he describes some of the experimental signals and backgrounds at the SSC. 57 refs., 12 figs

  9. Cilia in Left-Right Symmetry Breaking.

    Science.gov (United States)

    Shinohara, Kyosuke; Hamada, Hiroshi

    2017-10-03

    Visceral organs of vertebrates show left-right (L-R) asymmetry with regard to their position and morphology. Cilia play essential role in generating L-R asymmetry. A number of genes required for L-R asymmetry have now been identified in vertebrates, including human, many of which contribute to the formation and motility of cilia. In the mouse embryo, breaking of L-R symmetry occurs in the ventral node, where two types of cilia (motile and immotile) are present. Motile cilia are located at the central region of the node, and generate a leftward fluid flow. These motile cilia at the node are unique in that they rotate in the clockwise direction, unlike other immotile cilia such as airway cilia that show planar beating. The second type of cilia essential for L-R asymmetry is immotile cilia that are peripherally located immotile cilia. They sense a flow-dependent signal, which is either chemical or mechanical in nature. Although Ca 2+ signaling is implicated in flow sensing, the precise mechanism remains unknown. Copyright © 2017 Cold Spring Harbor Laboratory Press; all rights reserved.

  10. Isospin symmetry breaking in sd shell nuclei

    International Nuclear Information System (INIS)

    Lam, Y.W.

    2011-12-01

    In the thesis, we develop a microscopic approach to describe the isospin-symmetry breaking effects in sd-shell nuclei. The work is performed within the nuclear shell model. A realistic isospin-conserving Hamiltonian is perfected by a charge-dependent part consisting of the Coulomb interaction and Yukawa-type meson exchange potentials to model charge-dependent forces of nuclear origin. The extended database of the experimental isobaric mass multiplet equation coefficients was compiled during the thesis work and has been used in a fit of the Hamiltonian parameters. The constructed Hamiltonian provides an accurate theoretical description of the isospin mixing nuclear states. A specific behaviour of the IMME (Isobaric Multiplet Mass Equation) coefficients have been revealed. We present two important applications: (i) calculations of isospin-forbidden proton emission amplitudes, which is often of interest for nuclear astrophysics, and (ii) calculation on corrections to nuclear Fermi beta decay, which is crucial for the tests of fundamental symmetries of the weak interaction. (author)

  11. Generalized geometry and partial supersymmetry breaking

    International Nuclear Information System (INIS)

    Triendl, Hagen Mathias

    2010-08-01

    This thesis consists of two parts. In the first part we use the formalism of (exceptional) generalized geometry to derive the scalar field space of SU(2) x SU(2)-structure compactifications. We show that in contrast to SU(3) x SU(3) structures, there is no dynamical SU(2) x SU(2) structure interpolating between an SU(2) structure and an identity structure. Furthermore, we derive the scalar manifold of the low-energy effective action for consistent Kaluza-Klein truncations as expected from N = 4 supergravity. In the second part we then determine the general conditions for the existence of stable Minkowski and AdS N = 1 vacua in spontaneously broken gauged N = 2 supergravities and construct the general solution under the assumption that two appropriate commuting isometries exist in the hypermultiplet sector. Furthermore, we derive the low-energy effective action below the scale of partial supersymmetry breaking and show that it satisfies the constraints of N = 1 supergravity. We then apply the discussion to special quaternionic-Kaehler geometries which appear in the low-energy limit of SU(3) x SU(3)-structure compactifications and construct Killing vectors with the right properties. Finally we discuss the string theory realizations for these solutions. (orig.)

  12. When does taking a break help in negotiations? The influence of breaks and social motivation on negotiation processes and outcomes

    NARCIS (Netherlands)

    Harinck, F.; de Dreu, C.K.W.

    2011-01-01

    Most negotiations are interrupted from time to time to reflect on the negotiation or to do other pressing tasks. This study investigated how these breaks and the thoughts during these breaks influence subsequent negotiation behavior. Prosocially motivated dyads, with a tendency to think

  13. Nutrition. You can break the diarrhoea circle.

    Science.gov (United States)

    1993-01-01

    During a diarrheal episode, the body cannot absorb nutrients as well as it can when it is healthy. Nutrient intake may fall as much as 33% during the first days of a diarrheal episode. Loss of appetite or vomiting often occurs, or mothers may follow traditional beliefs or incorrect recommendations and feed the child less. This contributes to malnutrition, which, in turn, facilitates infections (e.g., diarrhea) because the body does not have the nutrients to fight infections. In fact, malnourished children usually have longer and more severe episodes of acute diarrhea (14 days) than well-nourished children. Good nutrition before, during, and after diarrhea can break the cycle of malnutrition and diarrhea. If a child develops dehydration, oral rehydration therapy (ORT) should be administered and feeding (other than breast feeding) should be suspended for a few hours. ORT may include home fluids (e.g., soup). Caretakers should resume feeding within 4-6 hours after ORT begins. The children should receive at least 6 small meals a day during and after diarrhea. Severely malnourished children should continue to receive food, especially potassium-rich foods (e.g., bananas and coconut water) during ORT. Rehydration should last longer (12-24 hours) in severely malnourished children. Growth slows down during diarrhea regardless of food intake. During the recovery period, the very hungry children may consume as much as 2 times the amount normally eaten. Caretakers should provide an extra meal for a recovering child for 2 weeks. Breast feeding should continue at least at the same level during diarrhea. Non-breast-fed infants should continue to receive undiluted animal milk or formula during acute diarrhea. Older infants (=or 4 months) who are already receiving soft or solid foods should continue to receive them during diarrhea. Adding 1-2 teaspoonfuls of vegetable oil (e.g., red palm oil) to staple foods increases the energy content.

  14. Breaking Bad News to Togolese Patients.

    Science.gov (United States)

    Kpanake, Lonzozou; Sorum, Paul Clay; Mullet, Etienne

    2016-11-01

    The aim of this study was to map Togolese people's positions regarding the breaking of bad news to elderly patients. Two hundred eleven participants who had in the past received bad medical news were presented with 72 vignettes depicting communication of bad news to elderly female patients and asked to indicate the acceptability of the physician's conduct in each case. The vignettes were all combinations of five factors: (a) the severity of the disease, (b) the patient's wishes about disclosure, (c) the level of social support during hospitalization, (d) the patient's psychological robustness, and (e) the physician's decision about how to communicate the bad news. Five qualitatively different positions were found. Two percent of the participants preferred that the physician always tell the full truth to both the patient and her relatives, 8% preferred that the truth be told depending on the physician's perception of the situation, 15% preferred that the physician tell the truth but understood that in some cases nondisclosure to the patient was not inappropriate, 33% preferred that the physician tell the full truth to the relatives but not as much information to the patient, and 42% preferred that the physician tell the full truth to the relatives only. These findings present a challenge to European physicians taking care of African patients living in Europe or working in African hospitals, and to African physicians trained in Europe and now working in their home countries. If these physicians respect the imperative of always telling the truth directly to their patients, their behavior may trigger anger and considerable misunderstanding among African patients and their families.

  15. Leak before break piping evaluation diagram

    International Nuclear Information System (INIS)

    Fabi, R.J.; Peck, D.A.

    1994-01-01

    Traditionally Leak Before Break (LBB) has been applied to the evaluation of piping in existing nuclear plants. This paper presents a simple method for evaluating piping systems for LBB during the design process. This method produces a piping evaluation diagram (PED) which defines the LBB requirements to the piping designer for use during the design process. Several sets of LBB analyses are performed for each different pipe size and material considered in the LBB application. The results of this method are independent of the actual pipe routing. Two complete LBB evaluations are performed to determine the maximum allowable stability load, one evaluation for a low normal operating load, and the other evaluation for a high normal operating load. These normal operating loads span the typical loads for the particular system being evaluated. In developing the allowable loads, the appropriate LBB margins are included in the PED preparation. The resulting LBB solutions are plotted as a set of allowable curves for the maximum design basis load, such is the seismic load versus the normal operating load. Since the required margins are already accounted for in the LBB PED, the piping designer can use the diagram directly with the results of the piping analysis and determine immediately if the current piping arrangement passes LBB. Since the LBB PED is independent of pipe routing, changes to the piping system can be evaluated using the existing PED. For a particular application, all that remains is to confirm that the actual materials and pipe sizes assumed in creating the particular design are built into the plant

  16. PCB-Based Break-Out Box

    Science.gov (United States)

    Lee, Jason H.

    2011-01-01

    Break-out boxes (BOBs) are necessary for all electrical integration/cable checkouts and troubleshooting. Because the price of a BOB is high, and no work can be done without one, often the procedure stops, simply waiting for a BOB. A less expensive BOB would take less time in the integration, testing, and troubleshooting process. The PCB-based BOB works and looks the same as a standard JPL BOB, called Gold Boxes. The only differences between the old BOB and the new PCB-based BOB is that the new one has 80 percent of its circuitry in a printed circuit board. This process reduces the time for fabrication, thus making the BOBs less expensive. Moreover, because of its unique design, the new BOBs can be easily assembled and fixed. About 80 percent of the new PCB-based BOB is in a $22 (at the time of this reporting) custom-designed, yet commercially available PCB. This device has been used successfully to verify that BOB cables were properly made. Also, upon completion, the BOB was beeped out via a multimeter to ensure that all sockets on the connectors were properly connected to the respective banana jack. When compared to the Gold Box BOBs, the new BOB has many advantages. It is much more cost efficient, it delivers equal usability at substantially lower cost of the BOB, and the Gold Box is much heavier when compared to the new BOB. The new BOB is also a bit longer and much more versatile in that connectors are easily changeable and if a banana jack is broken, it can be replaced instead of throwing away an entire BOB.

  17. Attributing Changing Rates of Temperature Record Breaking to Anthropogenic Influences

    Science.gov (United States)

    King, Andrew D.

    2017-11-01

    Record-breaking temperatures attract attention from the media, so understanding how and why the rate of record breaking is changing may be useful in communicating the effects of climate change. A simple methodology designed for estimating the anthropogenic influence on rates of record breaking in a given time series is proposed here. The frequency of hot and cold record-breaking temperature occurrences is shown to be changing due to the anthropogenic influence on the climate. Using ensembles of model simulations with and without human-induced forcings, it is demonstrated that the effect of climate change on global record-breaking temperatures can be detected as far back as the 1930s. On local scales, a climate change signal is detected more recently at most locations. The anthropogenic influence on the increased occurrence of hot record-breaking temperatures is clearer than it is for the decreased occurrence of cold records. The approach proposed here could be applied in rapid attribution studies of record extremes to quantify the influence of climate change on the rate of record breaking in addition to the climate anomaly being studied. This application is demonstrated for the global temperature record of 2016 and the Central England temperature record in 2014.

  18. Simulation of breaking waves using the high-order spectral method with laboratory experiments: Wave-breaking onset

    Science.gov (United States)

    Seiffert, Betsy R.; Ducrozet, Guillaume; Bonnefoy, Félicien

    2017-11-01

    This study investigates a wave-breaking onset criteria to be implemented in the non-linear potential flow solver HOS-NWT. The model is a computationally efficient, open source code, which solves for the free surface in a numerical wave tank using the High-Order Spectral (HOS) method. The goal of this study is to determine the best method to identify the onset of random single and multiple breaking waves over a large domain at the exact time they occur. To identify breaking waves, a breaking onset criteria based on the ratio of local energy flux velocity to the local crest velocity, introduced by Barthelemy et al. (2017) is selected. The breaking parameter is uniquely applied in the numerical model in that calculations of the breaking onset criteria ratio are not made only at the location of the wave crest, but at every point in the domain and at every time step. This allows the model to calculate the onset of a breaking wave the moment it happens, and without knowing anything about the wave a priori. The application of the breaking criteria at every point in the domain and at every time step requires the phase velocity to be calculated instantaneously everywhere in the domain and at every time step. This is achieved by calculating the instantaneous phase velocity using the Hilbert transform and dispersion relation. A comparison between more traditional crest-tracking techniques shows the calculation of phase velocity using Hilbert transform at the location of the breaking wave crest provides a good approximation of crest velocity. The ability of the selected wave breaking criteria to predict single and multiple breaking events in two dimensions is validated by a series of large-scale experiments. Breaking waves are generated by energy focusing and modulational instability methods, with a wide range of primary frequencies. Steep irregular waves which lead to breaking waves, and irregular waves with an energy focusing wave superimposed are also generated. This set of

  19. An automatic system for elaboration of chip breaking diagrams

    DEFF Research Database (Denmark)

    Andreasen, Jan Lasson; De Chiffre, Leonardo

    1998-01-01

    A laboratory system for fully automatic elaboration of chip breaking diagrams has been developed and tested. The system is based on automatic chip breaking detection by frequency analysis of cutting forces in connection with programming of a CNC-lathe to scan different feeds, speeds and cutting...... depths. An evaluation of the system based on a total of 1671 experiments has shown that unfavourable snarled chips can be detected with 98% certainty which indeed makes the system a valuable tool in chip breakability tests. Using the system, chip breaking diagrams can be elaborated with a previously...

  20. NPP Krsko Containment Response Following Main Steam Line Break

    International Nuclear Information System (INIS)

    Spalj, S.; Grgic, D.; Cavlina, N.

    2000-01-01

    This paper presents the calculation of thermohydraulic environmental parameters (pressure and temperature) inside containment of Krsko NPP after postulated Main Steam Line Break (MSLB) accident. This analysis was done as a part of the ambient parameters specification in the frame of the NPP Krsko Equipment Qualification (EQ) project. The RELAP5/mod2 computer code was used for the determination of MSLB mass and energy release and computer code GOTHIC was used to calculate pressure and temperature profiles inside NPP Krsko containment. The analysis was performed for spectrum of break sizes to account for possible steam superheating during accidents with smaller break sizes. (author)

  1. Flavour breaking effects in the pseudoscalar meson decay constants

    Directory of Open Access Journals (Sweden)

    V.G. Bornyakov

    2017-04-01

    Full Text Available The SU(3 flavour symmetry breaking expansion in up, down and strange quark masses is extended from hadron masses to meson decay constants. This allows a determination of the ratio of kaon to pion decay constants in QCD. Furthermore when using partially quenched valence quarks the expansion is such that SU(2 isospin breaking effects can also be determined. It is found that the lowest order SU(3 flavour symmetry breaking expansion (or Gell-Mann–Okubo expansion works very well. Simulations are performed for 2+1 flavours of clover fermions at four lattice spacings.

  2. Unified models of the QCD axion and supersymmetry breaking

    Directory of Open Access Journals (Sweden)

    Keisuke Harigaya

    2017-08-01

    Full Text Available Similarities between the gauge meditation of supersymmetry breaking and the QCD axion model suggest that they originate from the same dynamics. We present a class of models where supersymmetry and the Peccei–Quinn symmetry are simultaneously broken. The messengers that mediate the effects of these symmetry breakings to the Standard Model are identical. Since the axion resides in the supersymmetry breaking sector, the saxion and the axino are heavy. We show constraints on the axion decay constant and the gravitino mass.

  3. Amino acid chirality breaking by N-phosphorylation

    International Nuclear Information System (INIS)

    Zhao Yufen; Yan Qingjin.

    1995-01-01

    The chirality breaking of amino acid is a focus issue in the origin of life. For chemists, there are some interesting chemical approaches to solve the symmetry breaking problem. Our previous experiments indicated that when amino acids were phosphorylated, there were many bio-mimic reactions happened. In this paper, it was found that there had significant difference between the N-phosphoryl L- and D- amino acids such as serine and threonine. The optical rotation tracing experiments of the racemic N-phosphoamino acids also showed the similar results. The chirality breaking of amino acids by N-phosphorylation was a novel phenomena. (author). 3 refs, 1 fig. Abstract only

  4. Spontaneous symmetry breaking, self-trapping, and Josephson oscillations

    CERN Document Server

    2013-01-01

    This volume collects a a number of contributions on spontaneous symmetry breaking. Current studies in this general field are going ahead at a full speed. The book present review chapters which give an overview on the major break throughs of recent years. It covers a number of different physical settings which are introduced when a nonlinearity is added to the underlying symmetric problems and its strength exceeds a certain critical value. The corresponding loss of symmetry, called spontaneous symmetry breaking, alias self-trapping into asymmetric states is extensively discussed in this book.

  5. Simulation of breaking waves using the high-order spectral method with laboratory experiments: wave-breaking energy dissipation

    Science.gov (United States)

    Seiffert, Betsy R.; Ducrozet, Guillaume

    2018-01-01

    We examine the implementation of a wave-breaking mechanism into a nonlinear potential flow solver. The success of the mechanism will be studied by implementing it into the numerical model HOS-NWT, which is a computationally efficient, open source code that solves for the free surface in a numerical wave tank using the high-order spectral (HOS) method. Once the breaking mechanism is validated, it can be implemented into other nonlinear potential flow models. To solve for wave-breaking, first a wave-breaking onset parameter is identified, and then a method for computing wave-breaking associated energy loss is determined. Wave-breaking onset is calculated using a breaking criteria introduced by Barthelemy et al. (J Fluid Mech https://arxiv.org/pdf/1508.06002.pdf, submitted) and validated with the experiments of Saket et al. (J Fluid Mech 811:642-658, 2017). Wave-breaking energy dissipation is calculated by adding a viscous diffusion term computed using an eddy viscosity parameter introduced by Tian et al. (Phys Fluids 20(6): 066,604, 2008, Phys Fluids 24(3), 2012), which is estimated based on the pre-breaking wave geometry. A set of two-dimensional experiments is conducted to validate the implemented wave breaking mechanism at a large scale. Breaking waves are generated by using traditional methods of evolution of focused waves and modulational instability, as well as irregular breaking waves with a range of primary frequencies, providing a wide range of breaking conditions to validate the solver. Furthermore, adjustments are made to the method of application and coefficient of the viscous diffusion term with negligible difference, supporting the robustness of the eddy viscosity parameter. The model is able to accurately predict surface elevation and corresponding frequency/amplitude spectrum, as well as energy dissipation when compared with the experimental measurements. This suggests the model is capable of calculating wave-breaking onset and energy dissipation

  6. Genetic and environmental influence on DNA strand break repair

    DEFF Research Database (Denmark)

    Garm, Christian; Moreno-Villanueva, Maria; Bürkle, Alexander

    2013-01-01

    factors are likely to influence DNA repair capacity. In order to gain more insight into the genetic and environmental contribution to the molecular basis of DNA repair, we have performed a human twin study, where we focused on the consequences of some of the most abundant types of DNA damage (single-strand...... breaks), and some of the most hazardous lesions (DNA double-strand breaks). DNA damage signaling response (Gamma-H2AX signaling), relative amount of endogenous damage, and DNA-strand break repair capacities were studied in peripheral blood mononuclear cells from 198 twins (94 monozygotic and 104...... dizygotic). We did not detect genetic effects on the DNA-strand break variables in our study. Environ. Mol. Mutagen., 2013. © 2013 Wiley Periodicals, Inc....

  7. Recurring genomic breaks in independent lineages support genomic fragility

    Directory of Open Access Journals (Sweden)

    Hannenhalli Sridhar

    2006-11-01

    Full Text Available Abstract Background Recent findings indicate that evolutionary breaks in the genome are not randomly distributed, and that certain regions, so-called fragile regions, are predisposed to breakages. Previous approaches to the study of genomic fragility have examined the distribution of breaks, as well as the coincidence of breaks with segmental duplications and repeats, within a single species. In contrast, we investigate whether this regional fragility is an inherent genomic characteristic and is thus conserved over multiple independent lineages. Results We do this by quantifying the extent to which certain genomic regions are disrupted repeatedly in independent lineages. Our investigation, based on Human, Chimp, Mouse, Rat, Dog and Chicken, suggests that the propensity of a chromosomal region to break is significantly correlated among independent lineages, even when covariates are considered. Furthermore, the fragile regions are enriched for segmental duplications. Conclusion Based on a novel methodology, our work provides additional support for the existence of fragile regions.

  8. [Breaking bad news in oncology: the Belgian experience].

    Science.gov (United States)

    Delevallez, F; Lienard, A; Gibon, A-S; Razavi, D

    2014-10-01

    Breaking bad news is a complex and frequent clinical task for physicians working in oncology. It can have a negative impact on patients and their relatives who are often present during breaking bad news consultations. Many factors influence how the delivery of bad news will be experienced especially the communication skills used by physicians. A three-phase process (post-delivery phase, delivery phase, pre-delivery phase) has been developed to help physician to handle this task more effectively. Communication skills and specific breaking bad news training programs are both necessary and effective. A recent study conducted in Belgium has shown their impact on the time allocated to each of the three phases of this process, on the communication skills used, on the inclusion of the relative in the consultation and on physicians' physiological arousal. These results underscore the importance of promoting intensive communication skills and breaking bad news training programs for health care professionals.

  9. Mind the Gap: Women in STEM Career Breaks

    Directory of Open Access Journals (Sweden)

    Catherine Mavriplis

    2010-03-01

    Full Text Available There are two issues related to women and pathways to STEM careers. Recruitment to the field is one aspect. The second issue is the retention of women in STEM fields. This paper reports on the structured interviews with 14 women who have taken career breaks sometime after receiving their PhD in order to understand the pressures in place to take such breaks, how women remain connected (or not to their field during the break and issues related to re-entering the field after a career break. Suggestions based on the interviews include enhancements for women’s preparation for STEM fields and changes to the STEM culture itself. We suggest the inclusion workshops to detail what they might expect in their career and a provision for networking opportunities. We urge changes in the fee structure for society membership, differences in how resumes are reviewed as well as changes in maternity and child care leave.

  10. Chip breaking for an automated accurate turning system

    Energy Technology Data Exchange (ETDEWEB)

    Burnham, M.W. (BDM Corp., Albuquerque, NM (USA)); Abbatiello, L.A. (Oak Ridge Y-12 Plant, TN (USA))

    1988-01-01

    Based upon a survey of chip breakup information, the various methods have been evaluated for application to automated accurate turning systems. Many chip breaking methods work well on shafts or cylinders but fail to break chips for an entire inside or outside contouring cut. Many metals produce straight or snarled chip forms at small depths of cut, feed rates, or moderate surface speeds. These chip forms can be a cause of workpiece and tool damage. Such forms also interfere with on-machine gaging, part transfer, and tool change. Often the chip wraps around the tool holder and is difficult to remove even in manual operation. Computer analysis now makes it possible to get the most of each types of chip breaking system. Reliable ship breaking is urgently needed for automated systems, especially those operating in an unmanned mode. 83 refs., 10 figs., 2 tabs.

  11. Chip breaking and control for a precision automated turning system

    Energy Technology Data Exchange (ETDEWEB)

    Burnham, M.W. (BDM International, Inc., McLean, VA (USA)); Abbatiello, L.A. (Martin Marietta Energy Systems, Inc., Oak Ridge, TN (USA))

    1990-01-01

    Chip breaking and control is essential to automatic operation of precision turning systems. Failure to transfer parts and system jams can occur if chip fragments are not continuously removed. Surface damage and tool breakage also result from chips that are permitted to wrap around the tool. Also, with increasing environmental concerns, chip handling and recycling are becoming major issues in manufacturing. New information on a variety of mechanisms for breaking chips and methods for removal from the system are discussed. Some of the chip breaking methods are evaluated for the range of cutting in which they are effective. Chip curl and chip breaking analyzed carefully by Nakayama and others is expanded to more fully understand the ways in which chips can be broken. 23 figs.

  12. Approximate equations at breaking for nearshore wave transformation coefficients

    Digital Repository Service at National Institute of Oceanography (India)

    Chandramohan, P.; Nayak, B.U.; SanilKumar, V.

    Based on small amplitude wave theory approximate equations are evaluated for determining the coefficients of shoaling, refraction, bottom friction, bottom percolation and viscous dissipation at breaking. The results obtainEd. by these equations...

  13. STRESS FRACTURE OF THE ULNA IN A BREAK-DANCER

    Directory of Open Access Journals (Sweden)

    Yu-Hsu Chen

    2008-12-01

    Full Text Available Break dancing is a popular activity in teenagers and is associated with severe trauma to bones and tissues. We report the first known case of a break dancer with an ulnar stress fracture. Such injuries occur in a variety of sports due to substantial stress on the ulna and repetitive excessive rotation of the forearm. In this study we describe a patient who experienced an ulnar stress fracture during break dancing training. The diagnosis was established by history and physical examination. Initial radiographic findings were negative. However, radiographs taken 3 months after initial presented revealed callus formation over the ulnar shaft. This suggested that readjustment is required in break dancing training protocols. It is important to increase awareness of this injury among physicians to expedite the diagnosis and to prevent the possibility of conversion to an overt fracture in the future

  14. Some geological and geophysical aspects in electric rock breaking

    CSIR Research Space (South Africa)

    Henry, G

    2011-08-01

    Full Text Available This presentation looks at the way rocks break and the geological and geophysical aspects thereof. It it important to know that rocks are much weaker under tension (10 times) than under compression. Geological and geophysical factors play...

  15. Symmetry breaking and the geometry of reduced density matrices

    Science.gov (United States)

    Zauner, V.; Draxler, D.; Vanderstraeten, L.; Haegeman, J.; Verstraete, F.

    2016-11-01

    The concept of symmetry breaking and the emergence of corresponding local order parameters constitute the pillars of modern day many body physics. We demonstrate that the existence of symmetry breaking is a consequence of the geometric structure of the convex set of reduced density matrices of all possible many body wavefunctions. The surfaces of these convex bodies exhibit non-analyticities, which signal the emergence of symmetry breaking and of an associated order parameter and also show different characteristics for different types of phase transitions. We illustrate this with three paradigmatic examples of many body systems exhibiting symmetry breaking: the quantum Ising model, the classical q-state Potts model in two-dimensions at finite temperature and the ideal Bose gas in three-dimensions at finite temperature. This state based viewpoint on phase transitions provides a unique novel tool for studying exotic many body phenomena in quantum and classical systems.

  16. Ras activation and symmetry breaking during Dictyostelium chemotaxis

    NARCIS (Netherlands)

    Kortholt, Arjan; Keizer-Gunnink, Ineke; Kataria, Rama; Van Haastert, Peter J. M.

    2013-01-01

    Central to chemotaxis is the molecular mechanism by which a shallow spatial gradient of chemoattractant induces symmetry breaking of activated signaling molecules. Previously, we have used Dictyostelium mutants to investigate the minimal requirements for chemotaxis, and identified a basal signaling

  17. Spontaneous Breaking of Spatial and Spin Symmetry in Spinor Condensates

    DEFF Research Database (Denmark)

    Scherer, M.; Lücke, B.; Gebreyesus, G.

    2010-01-01

    Parametric amplification of quantum fluctuations constitutes a fundamental mechanism for spontaneous symmetry breaking. In our experiments, a spinor condensate acts as a parametric amplifier of spin modes, resulting in a twofold spontaneous breaking of spatial and spin symmetry in the amplified...... broken, but phase squeezing prevents spin-symmetry breaking. If, however, nondegenerate spin modes contribute to the amplification, quantum interferences lead to spin-dependent density profiles and hence spontaneously formed patterns in the longitudinal magnetization....... clouds. Our experiments permit a precise analysis of the amplification in specific spatial Bessel-like modes, allowing for the detailed understanding of the double symmetry breaking. On resonances that create vortex-antivortex superpositions, we show that the cylindrical spatial symmetry is spontaneously...

  18. Thumb Sucking: Help Your Child Break the Habit

    Science.gov (United States)

    ... older kids who continue to suck their thumbs, peer pressure at school usually ends the habit. Remember, though, ... an incredibly difficult habit to break. Remember, though, peer pressure typically leads kids to stop daytime sucking habits ...

  19. Yukawa unification in moduli-dominant SUSY breaking

    International Nuclear Information System (INIS)

    Khalil, S.; Tatsuo Kobayashi

    1997-07-01

    We study Yukawa in string models with moduli-dominant SUSY breaking. This type of SUSY breaking in general leads to non-universal soft masses, i.e. soft scalar masses and gaugino masses. Such non-universality is important for phenomenological aspects of Yukawa unification, i.e., successful electroweak breaking, SUSY corrections to the bottom mass and the branching ratio of b → sγ. We show three regions in the whole parameter space which lead to successful electroweak breaking and allow small SUSY corrections to the bottom mass. For these three regions we investigated the b → sγ decay and mass spectra. (author). 26 refs, 6 figs

  20. Dam-Break Flood Analysis Upper Hurricane Reservoir, Hartford, Vermont

    National Research Council Canada - National Science Library

    Acone, Scott

    1995-01-01

    .... Various dam break flood conditions were modeled and inundation maps developed. Based on this analysis the dam is rated a Class 2 or significant hazard category in terms of its potential to cause downstream damage...

  1. Lorentz symmetry breaking effects on relativistic EPR correlations

    Energy Technology Data Exchange (ETDEWEB)

    Belich, H. [Universidade Federal do Espirito Santo, Departamento de Fisica e Quimica, Vitoria, ES (Brazil); Furtado, C.; Bakke, K. [Universidade Federal da Paraiba, Departamento de Fisica, Caixa Postal 5008, Joao Pessoa, PB (Brazil)

    2015-09-15

    Lorentz symmetry breaking effects on relativistic EPR (Einstein-Podolsky-Rosen) correlations are discussed. From the modified Maxwell theory coupled to gravity, we establish a possible scenario of the Lorentz symmetry violation and write an effective metric for the Minkowski spacetime. Then we obtain the Wigner rotation angle via the Fermi-Walker transport of spinors and consider the WKB (Wentzel-Kramers-Brillouin) approximation in order to study the influence of Lorentz symmetry breaking effects on the relativistic EPR correlations. (orig.)

  2. Supersymmetry breaking from superstrings and the gauge hierarchy

    Energy Technology Data Exchange (ETDEWEB)

    Gaillard, M.K. (Lawrence Berkeley Lab., CA (USA) California Univ., Berkeley, CA (USA). Dept. of Physics)

    1990-07-11

    The gauge hierarchy problem is reviewed and a class of effective field theories obtained from superstrings is described. These are characterized by a classical symmetry, related to the space-time duality of string theory, that is responsible for the suppression of observable supersymmetry breaking effects. At the quantum level, the symmetry is broken by anomalies that provide the seed of observable supersymmetry breaking, and an acceptably large gauge hierarchy may be generated. 39 refs.

  3. Anomalous U(1) as a mediator of Supersymmetry Breaking

    CERN Document Server

    Dvali, Gia; Dvali, Gia; Pomarol, Alex

    1996-01-01

    We point out that an anomalous gauge U(1) symmetry is a natural candida= te for being the mediator and messenger of supersymmetry breaking. It facilitate= s dynamical supersymmetry breaking even in the flat limit. Soft masses are induced by both gravity and the U(1) gauge interactions giving an unusual= mass hierarchy in the sparticle spectrum which suppresses flavor violations. T= his scenario does not suffer from the Polonyi problem.

  4. 11Li structural information from inclusive break-up measurements

    Directory of Open Access Journals (Sweden)

    Fernández-García J. P.

    2015-01-01

    Full Text Available Structure information of 11Li halo nucleus has been obtained from the inclusive break-up measurements of the 11Li+208Pb reactions at energies around the Coulomb barrier (Elab = 24.3 and 29.8 MeV. The effective break-up energy and the slope of B(E1 distribution close to the threshold have been extracted from the experimental data.

  5. Concepts of electroweak symmetry breaking and Higgs physics

    Energy Technology Data Exchange (ETDEWEB)

    Gomez-Bock, M. [Benemerita Univ., Puebla (Mexico). Inst. de Fisica; Mondragon, M. [Universidad Nacional Autonoma de Mexico, Mexico City (Mexico). Inst. de Fisica; Muehlleitner, M. [Laboratoire d' Annecy-Le-Vieux de Physique Theorique, 74 (France)]|[CERN - European Organization for Nuclear Research, Geneva (Switzerland). Theory Div.; Spira, M. [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Zerwas, P.M. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)]|[RWTH Aachen (Germany). Inst. Theor. Physik E]|[Univ. Paris- Sud, Orsay (France). Laboratoire de Physique Theorique

    2007-12-15

    We present an introduction to the basic concepts of electroweak symmetry breaking and Higgs physics within the Standard Model and its supersymmetric extensions. A brief overview will also be given on alternative mechanisms of electroweak symmetry breaking. In addition to the theoretical basis, the present experimental status of Higgs physics and prospects at the Tevatron, the LHC and e{sup +}e{sup -} linear colliders are discussed. (orig.)

  6. Supersymmetry breaking from superstrings and the gauge hierarchy

    International Nuclear Information System (INIS)

    Gaillard, M.K.; California Univ., Berkeley, CA

    1990-01-01

    The gauge hierarchy problem is reviewed and a class of effective field theories obtained from superstrings is described. These are characterized by a classical symmetry, related to the space-time duality of string theory, that is responsible for the suppression of observable supersymmetry breaking effects. At the quantum level, the symmetry is broken by anomalies that provide the seed of observable supersymmetry breaking, and an acceptably large gauge hierarchy may be generated. 39 refs

  7. Majorana Fermions, Supersymmetry Breaking, and Born-Infeld Theory

    CERN Document Server

    Ferrara, Sergio; Yeranyan, Armen

    2015-01-01

    This review is devoted to highlight some aspects of the relevance of Majorana fermions in rigid supersymmetry breaking in four spacetime dimensions. After introducing some basic facts on spinors, and on their symmetries and reality properties, we consider Goldstino actions describing partial breaking of rigid supersymmetry, then focussing on Born-Infeld non-linear theory, its duality symmetry, and its supersymmetric extensions, also including multi-field generalizations exhibiting doubly self-duality.

  8. Fuel weight and removal costs in fuel-break construction

    Science.gov (United States)

    James L. Murphy

    1966-01-01

    Three major fuel types were sampled during fuel-break construction on the west side of the Sierra Nevada, California. Fuel weight per acre ranged from 12.2. to 420.6 tons per acre on average. Fuel-break construction removed 27.9 to 40.5 percent of teh total fuel; costs ranged from $141.29 to $148.38 per acre and $1.16 to $4.43 per ton.

  9. Automatic first-break picking using the instantaneous traveltime attribute

    KAUST Repository

    Saragiotis, Christos

    2012-01-01

    Picking the first breaks is an important step in seismic processing. The large volume of the seismic data calls for automatic and objective picking. We introduce a new automatic first-break picker, which uses specifically designed time windows and an iterative procedure based on the instantaneous traveltime attribute. The method is fast as it only uses a few FFT\\'s per trace. We demonstrate the effectiveness of this automatic method by applying it on real test data.

  10. Dynamical symmetry breaking in models with strong Yukawa interactions

    Czech Academy of Sciences Publication Activity Database

    Beneš, Petr

    2012-01-01

    Roč. 62, 1-2 (2012), s. 1-274 ISSN 0323-0465 R&D Projects: GA ČR GA202/06/0734; GA MŠk LA08015 Institutional support: RVO:61389005 Keywords : spontaneus symmetry breaking * Gauge symmetries * nonperturbative techniques * radiative symmetry breaking * Quark and lepton masses * Cabibbo-Kobayashi-Maskawa matrix elements * extensions of electroweak Higgs sector Subject RIV: BE - Theoretical Physics Impact factor: 1.333, year: 2012

  11. Concepts of electroweak symmetry breaking and Higgs physics

    International Nuclear Information System (INIS)

    Gomez-Bock, M.; Zerwas, P.M.; RWTH Aachen; Univ. Paris- Sud, Orsay

    2007-12-01

    We present an introduction to the basic concepts of electroweak symmetry breaking and Higgs physics within the Standard Model and its supersymmetric extensions. A brief overview will also be given on alternative mechanisms of electroweak symmetry breaking. In addition to the theoretical basis, the present experimental status of Higgs physics and prospects at the Tevatron, the LHC and e + e - linear colliders are discussed. (orig.)

  12. Break-even zones for cable yarding by log size

    Science.gov (United States)

    Chris B. LeDoux

    1984-01-01

    The use of cable logging to extract small pieces of residue wood may result in low rates of production and a high cost per unit of wood produced. However, the logging manager can improve yarding productivity and break-even in cable residue removal operations by using the proper planning techniques. In this study, break-even zones for specific young-growth stands were...

  13. A geometric hierarchy for the supersymmetry breaking scale

    International Nuclear Information System (INIS)

    Oakley, C.; Ross, G.G.

    1983-01-01

    F type supersymmetry breaking through O'Raifeartaigh-Fayet (Nucl. Phys.; B96:331 (1975) and Phys. Lett.; 580:67 (1975)) potentials is considered. It is shown how a class of models gives rise to a supersymmetry breaking scale reduced relative to the fundamental scale M of the potential by powers of (M/Msub(Planck)). The role of R invariance in such potentials is discussed. (author)

  14. On SUSY breaking and χSB from string duals

    International Nuclear Information System (INIS)

    Gomis, Jaume

    2002-01-01

    We find regular string duals of three-dimensional N=1 SYM with a Chern-Simons interaction at level k for SO and Sp gauge groups. Using the string dual we exactly reproduce the conjectured pattern of supersymmetry breaking proposed by Witten by showing that there is dynamical supersymmetry breaking for k 2h →Z 2 by analyzing the symmetries of the string solution

  15. Symmetry Breaking in the Parton Distribution Functions of the Nucleon

    Science.gov (United States)

    Cao, Fu-Guang; Signal, A. I.

    We study flavour symmetry breaking in the nucleon's parton distribution functions (PDF) using the meson cloud model and `Pauli blocking' mechanism. It was found that the `Pauli blocking' contribution to the integrated polarized asymmetry is much larger than the meson cloud, in contrast to approximate equality in the unpolarized case. We also investigate charge symmetry breaking in the nucleon's PDF using the meson cloud model. Our results are very different from the quark model calculations.

  16. Framework for an asymptotically safe standard model via dynamical breaking

    DEFF Research Database (Denmark)

    Abel, Steven; Sannino, Francesco

    2017-01-01

    We present a consistent embedding of the matter and gauge content of the Standard Model into an underlying asymptotically safe theory that has a well-determined interacting UV fixed point in the large color/flavor limit. The scales of symmetry breaking are determined by two mass-squared parameters...... with the breaking of electroweak symmetry being driven radiatively. There are no other free parameters in the theory apart from gauge couplings....

  17. Evidence for SU(3) symmetry breaking from hyperon production

    International Nuclear Information System (INIS)

    Yang Jianjun

    2002-01-01

    We examine the SU(3) symmetry breaking in hyperon semileptonic decays (HSD) by considering two typical sets of quark contributions to the spin content of the octet baryons: set 1 with SU(3) flavor symmetry and set 2 with SU(3) flavor symmetry breaking in the HSD. The quark distributions of the octet baryons are calculated with a successful statistical model. Using an approximate relation between the quark fragmentation functions and the quark distributions, we predict the polarizations of the octet baryons produced in e + e - annihilation and semi-inclusive deep lepton-nucleon scattering in order to reveal the SU(3) symmetry breaking effect on the spin structure of the octet baryons. We find that the SU(3) symmetry breaking significantly affects the hyperon polarization. The available experimental data on the Λ polarization seem to favor the theoretical predictions with SU(3) symmetry breaking. We conclude that there is a possibility to get collateral evidence for SU(3) symmetry breaking from hyperon production. The theoretical errors for our predictions are discussed

  18. Effects of symmetry breaking in finite quantum systems

    Energy Technology Data Exchange (ETDEWEB)

    Birman, J.L. [Department of Physics, City College, City University of New York, New York, NY 10031 (United States); Nazmitdinov, R.G. [Departament de Fisica, Universitat de les Illes Balears, Palma de Mallorca 07122 (Spain); Bogolubov Laboratory of Theoretical Physics, Joint Institute for Nuclear Research, Dubna 141980 (Russian Federation); Yukalov, V.I., E-mail: yukalov@theor.jinr.ru [Bogolubov Laboratory of Theoretical Physics, Joint Institute for Nuclear Research, Dubna 141980 (Russian Federation)

    2013-05-15

    The review considers the peculiarities of symmetry breaking and symmetry transformations and the related physical effects in finite quantum systems. Some types of symmetry in finite systems can be broken only asymptotically. However, with a sufficiently large number of particles, crossover transitions become sharp, so that symmetry breaking happens similarly to that in macroscopic systems. This concerns, in particular, global gauge symmetry breaking, related to Bose–Einstein condensation and superconductivity, or isotropy breaking, related to the generation of quantum vortices, and the stratification in multicomponent mixtures. A special type of symmetry transformation, characteristic only for finite systems, is the change of shape symmetry. These phenomena are illustrated by the examples of several typical mesoscopic systems, such as trapped atoms, quantum dots, atomic nuclei, and metallic grains. The specific features of the review are: (i) the emphasis on the peculiarities of the symmetry breaking in finite mesoscopic systems; (ii) the analysis of common properties of physically different finite quantum systems; (iii) the manifestations of symmetry breaking in the spectra of collective excitations in finite quantum systems. The analysis of these features allows for the better understanding of the intimate relation between the type of symmetry and other physical properties of quantum systems. This also makes it possible to predict new effects by employing the analogies between finite quantum systems of different physical nature.

  19. [Factors related to intraoperative retinal breaks in macular hole surgery].

    Science.gov (United States)

    Kumagai, K; Ogino, N; Demizu, S; Atsumi, K; Kurihara, H; Iwaki, M; Ishigooka, H; Tachi, N

    2001-02-01

    To evaluate the factors of intraoperative retinal breaks in macular hole surgery. This study included 558 eyes of 506 patients who underwent idiopathic macular hole surgery by one surgeon. Multiple regression was performed using the variables of gender, age, affected eye, lens status, stage, duration of symptoms, hole size, axial length, and lattice degeneration. The rate of retinal breaks was higher in stage 3 (16.0%) than in stage 4 (8.2%) (p = 0.014). In eyes with lattice degeneration intraoperative retinal breaks occurred in about 40% of the cases. Major factors were as follows: lattice degeneration (r = 0.24, p lattice degeneration, and gender (r = -0.18, p = 0.035) in eyes of stage 4 without lattice degeneration. The factors of intraoperative retinal breaks in macular hole surgery were lattice degeneration in all eyes and stage 3 in eyes without lattice degeneration. The high incidence of intraoperative retinal breaks in stage 3 was mainly due to the occurrence of posterior vitreous detachment. Male gender was a significant factor associated with intraoperative retinal breaks.

  20. The Mid-Lecture Break: When Less Is More

    Science.gov (United States)

    Olmsted, John, III

    1999-04-01

    Chemistry courses that operate in the traditional mode typically involve 50-minute presentations, even though human attention spans are substantially shorter. Decline of attention toward mid-lecture can be avoided by inserting an interactive "intermission", the mid-lecture break. Change of pace, student involvement, and in-class assessment are the three essential features of mid-lecture breaks. These can be implemented in a variety of ways, depending on the instructor's interests and ingenuity. Most of the mid-lecture breaks that I use fall into three general categories: brief in-class assessment questions, feedback concerning previously collected information, and "news breaks". An in-class assessment poses a single question for students to answer in writing. Feedback provides the class with information about student responses to classroom research questions.. News breaks convey announcements and chemistry-related news. Examples of each of these are described. Student response to this instructional feature, as determined by in-class surveys, is overwhelmingly positive. At the end of a recent semester, students ranked the mid-lecture break on a par with detailed problem solving as the most effective instructional strategies.

  1. Ensuring the Right to Rest: City Rest Break Ordinances and Access to Rest Breaks in the Construction Industry.

    Science.gov (United States)

    Scott, Jennifer; Boggess, Bethany; Timm, Emily

    2017-10-23

    To evaluate the effectiveness of city Rest Break Ordinance (RBO) policies in expanding access to rest at work. We use data from surveys of construction workers in Austin and Dallas, Texas, in 2009, 2012 and 2015 (n = 557) to calculate the odds of receiving a rest break in pre- versus post-RBO Austin and in post-RBO Austin versus pre-RBO Dallas, controlling for demographic and employment characteristics. Construction workers were 35% more likely to report receiving a rest break in Austin post-RBO and 16% less likely in Dallas without a RBO as compared to Austin with a RBO. The increased likelihood of receiving rest breaks at work in a RBO city suggests that, in the absence of enforceable national standards, city-level RBOs can be an important first step to effective prevention of HRIs and heat-related fatalities at work.

  2. A primary school active break programme (ACTI-BREAK): study protocol for a pilot cluster randomised controlled trial.

    Science.gov (United States)

    Watson, Amanda; Timperio, Anna; Brown, Helen; Hesketh, Kylie D

    2017-09-19

    Levels of overall physical activity have been shown to decline across childhood. Schools are considered ideal settings to promote physical activity as children spend a large amount of their waking hours at school. Time-efficient physical activity strategies that demonstrate a positive impact on academic-related outcomes are needed to enable physical activity to be prioritised in the school day. The ACTI-BREAK programme requires classroom teachers to integrate active breaks; 5-min bursts of moderate-intensity physical activity into their classroom routine. Active breaks have been shown to be effective in improving academic-related outcomes, a potentially appealing aspect for teachers and schools. The primary aim of this study is to assess the feasibility and potential efficacy of the ACTI-BREAK programme on children's academic achievement. Secondary aims are to explore the impact of ACTI-BREAK on children's on-task behaviour and objectively measured physical activity levels. ACTI-BREAK is a 6-week, classroom-based, physical activity intervention. This pilot trial of the programme will be evaluated using a cluster randomised controlled design. Government primary schools in metropolitan Melbourne, Australia will be invited to participate in the programme in 2017. Randomisation will occur at the school level, with the aim to recruit six schools (three intervention and three control). The ACTI-BREAK programme is theoretically grounded, and was developed with input and guidance from current primary school teachers. Teachers from the intervention schools will receive a 45-min training session and be asked to incorporate ACTI-BREAKS into their classroom routine three times per day for 6 weeks. Intervention support will be provided via assisted delivery. The primary outcomes will be children's academic achievement in mathematics and reading. Children's on-task behaviour and school-day physical activity will be assessed as secondary outcomes. Process evaluation will also be

  3. Explicit Supersymmetry Breaking on Boundaries of Warped Extra Dimensions

    Energy Technology Data Exchange (ETDEWEB)

    Hall, Lawrence J.; Nomura, Yasunori; Okui, Takemichi; Oliver, Steven J.

    2003-02-25

    Explicit supersymmetry breaking is studied in higher dimensional theories by having boundaries respect only a subgroup of the bulk symmetry. If the boundary symmetry is the maximal subgroup allowed by the boundary conditions imposed on the fields, then the symmetry can be consistently gauged; otherwise gauging leads to an inconsistent theory. In a warped fifth dimension, an explicit breaking of all bulk supersymmetries by the boundaries is found to be inconsistent with gauging; unlike the case of flat 5D, complete supersymmetry breaking by boundary conditions is not consistent with supergravity. Despite this result, the low energy effective theory resulting from boundary supersymmetry breaking becomes consistent in the limit where gravity decouples, and such models are explored in the hope that some way of successfully incorporating gravity can be found. A warped constrained standard model leads to a theory with one Higgs boson with mass expected close to the experimental limit. A unified theory in a warped fifth dimension is studied with boundary breaking of both SU(5) gauge symmetry and supersymmetry. The usual supersymmetric predictionfor gauge coupling unification holds even though the TeV spectrum is quite unlike the MSSM. Such a theory may unify matter and Higgs in the same SU(5) hypermultiplet.

  4. Duality, exchange-degeneracy breaking, and exotic states

    International Nuclear Information System (INIS)

    Goldstein, G.R.; Haridas, P.

    1979-01-01

    We study the connection between exchange-degeneracy breaking and multiquark states within the framework of a highly constrained dual approach. We show that M 4 (baryonium) states emerge at the daughter trajectory level as a consequence of small exchange-degeneracy breaking in the meson-meson system (approx.delta) and larger exchange-degeneracy breaking of the baryon trajectories in the meson-baryon system (approx.epsilon). The M 4 states are coupled weakly to external mesons in proportion to the breaking parameter delta. Assuming M 4 couplings to B-barB channels are strong, as determined by duality with normal mesons in the B-barB system, consistency requires epsilon approx. √delta-bar, thereby relating the larger breaking of baryon trajectories to the violation of the Okubo-Zweig-Iizuka-type rule for M 4 . It is shown that exotic baryon states, B 5 , also emerge from this scheme at the daughter level and that dibaryons will appear at the second daughter level

  5. On the ether-like Lorentz-breaking actions

    International Nuclear Information System (INIS)

    Petrov, A.Yu; Nascimento, J.R.; Gomes, M.; Silva, A. J. da

    2011-01-01

    We demonstrate the generation of the CPT-even, ether-like Lorentz-breaking actions for the scalar and electro-magnetic fields via their appropriate Lorentz-breaking coupling to spinor fields in three, four and five space-time dimensions. Besides, we show that the ether-like terms for the spinor field also can be generated as a consequence of the same couplings. The key result which will be presented here is the finiteness of the ether-like term for the electromagnetic field not only in three and five space-time dimensions where it is natural due to known effects of the dimensional regularization but also in four space-time dimensions. Moreover, we present the calculation of the last result within different calculational schemes and conclude that the result for the four-dimensional ether-like term for the electromagnetic field essentially depending on the calculation scheme, similarly to the result for the Carroll-Field-Jackiw (CFJ) term which probably signalizes a possibility for arising of a new anomaly. Also we discuss the dispersion relations in the theories with ether-like Lorentz-breaking terms which allows to discuss the consistency of the Lorentz-breaking modified theories for different (space-like or time-like) Lorentz-breaking vectors and find the tree-level effective (Breit) potential for fermion scattering and the one-loop effective potential corresponding to the action of the scalar field. (author)

  6. Dam Break Analysis of Embankment Dams Considering Breach Characteristics

    Directory of Open Access Journals (Sweden)

    Abolfazl Shamsaei

    2004-05-01

    Full Text Available The study of dam's break, needs the definition of various parameters such as the break cause, its type, its dimension and the duration of breach development. The precise forecast for different aspects of the breach is one of the most important factors for analyzing it in embankment dam. The characteristics of the breach and determination of their vulnerability has the most effect on the waves resulting from dam break. Investigating, about the parameters of the breach in "Silveh" earth dam have been determined using the suitable model. In Silve dam a trapezoid breach with side slope z=0.01m and the average base line b=80m was computed. The duration of the breaches development is 1.9 hour. Regarding the above results and the application of DAM Break software the consequences of the probable break of the dam was determined. The analysis of the results of water covering of the city of Piranshahr located 12km from silve dam confirms that in 3 hours the water will reach the height (level of 1425 meters.

  7. Electroweak symmetry breaking via UV insensitive anomaly mediation

    International Nuclear Information System (INIS)

    Kitano, Ryuichiro; Kribs, Graham D.; Murayama, Hitoshi

    2004-01-01

    Anomaly mediation solves the supersymmetric flavor and CP problems. This is because the superconformal anomaly dictates that supersymmetry breaking is transmitted through nearly flavor-blind infrared physics that is highly predictive and UV insensitive. Slepton mass squareds, however, are predicted to be negative. This can be solved by adding D-terms for U(1) Y and U(1) B-L while retaining the UV insensitivity. In this paper we consider electroweak symmetry breaking via UV insensitive anomaly mediation in several models. For the minimal supersymmetric standard model we find a stable vacuum when tan β<1, but in this region the top Yukawa coupling blows up only slightly above the supersymmetry breaking scale. For the next-to-minimal supersymmetric standard model (NMSSM), we find a stable electroweak breaking vacuum but with a chargino that is too light. Replacing the cubic singlet term in the NMSSM superpotential with a term linear in the singlet we find a stable vacuum and viable spectrum. Most of the parameter region with correct vacua requires a large superpotential coupling, precisely what is expected in the 'Fat Higgs' model in which the superpotential is generated dynamically. We have therefore found the first viable UV complete, UV insensitive supersymmetry breaking model that solves the flavor and CP problems automatically: the Fat Higgs model with UV insensitive anomaly mediation. Moreover, the cosmological gravitino problem is naturally solved, opening up the possibility of realistic thermal leptogenesis

  8. Flux-induced SUSY-breaking soft terms

    CERN Document Server

    Camara, Pablo G.; Uranga, A.M.

    2003-01-01

    We describe the computation of SUSY-breaking terms on a D3-brane in a quite general type IIB supergravity background. We apply it to study the SUSY-breaking induced on the D3-brane world-volume by the presence of NSNS and RR 3-form fluxes. We provide explicit general formulae for the SUSY-breaking soft terms valid for the different types of fluxes, leading to different patterns of soft terms. Imaginary anti-selfdual fluxes with G_3 a pure (3,0)-form lead to soft terms corresponding to dilaton-dominated SUSY-breaking. More general SUSY-breaking patterns are discussed, arising from more general fluxes, or from distant anti-D3-branes. The known finiteness properties of dilaton-dominated soft terms are understood in terms of holography. The above results are interpreted in the context of the 4d effective supergravity theory, where flux components correspond to auxiliary fields of e.g. the 4d dilaton and overall volume modulus. We present semirealistic Type IIB orientifold examples with (meta)stable vacua leading ...

  9. Break-induced telomere synthesis underlies alternative telomere maintenance.

    Science.gov (United States)

    Dilley, Robert L; Verma, Priyanka; Cho, Nam Woo; Winters, Harrison D; Wondisford, Anne R; Greenberg, Roger A

    2016-11-03

    Homology-directed DNA repair is essential for genome maintenance through templated DNA synthesis. Alternative lengthening of telomeres (ALT) necessitates homology-directed DNA repair to maintain telomeres in about 10-15% of human cancers. How DNA damage induces assembly and execution of a DNA replication complex (break-induced replisome) at telomeres or elsewhere in the mammalian genome is poorly understood. Here we define break-induced telomere synthesis and demonstrate that it utilizes a specialized replisome, which underlies ALT telomere maintenance. DNA double-strand breaks enact nascent telomere synthesis by long-tract unidirectional replication. Proliferating cell nuclear antigen (PCNA) loading by replication factor C (RFC) acts as the initial sensor of telomere damage to establish predominance of DNA polymerase δ (Pol δ) through its POLD3 subunit. Break-induced telomere synthesis requires the RFC-PCNA-Pol δ axis, but is independent of other canonical replisome components, ATM and ATR, or the homologous recombination protein Rad51. Thus, the inception of telomere damage recognition by the break-induced replisome orchestrates homology-directed telomere maintenance.

  10. Physical activity breaks and facilities in US secondary schools.

    Science.gov (United States)

    Hood, Nancy E; Colabianchi, Natalie; Terry-McElrath, Yvonne M; O'Malley, Patrick M; Johnston, Lloyd D

    2014-11-01

    Research on physical activity breaks and facilities (indoor and outdoor) in secondary schools is relatively limited. School administrators and students in nationally representative samples of 8th (middle school) and 10th/12th grade (high school) students were surveyed annually from 2008-2009 to 2011-2012. School administrators reported information about physical activity breaks and facilities. Students self-reported height, weight, and physical activity. The prevalence of physical activity breaks and indoor and outdoor facilities (dichotomized by median split) differed significantly by region of the country, school size, student race/ethnicity, and school socioeconomic status (SES). Breaks were associated with lower odds of overweight (adjusted odds ratio [AOR] = 0.91, 95% confidence interval [CI]: 0.83-1.00) and obesity (AOR = 0.86, 95% CI: 0.75-0.99) among middle school students. Among low-SES middle school students and schools, higher indoor facilities were associated with lower rates of overweight and obesity. Among high school students, higher indoor and outdoor facilities were associated with 19-42% higher odds of moderate-to-vigorous physical activity. Physical activity breaks and school facilities may help to address high rates of overweight/obesity and low physical activity levels among secondary students, especially lower-SES students. Students in all schools should have equal access to these resources. © 2014, American School Health Association.

  11. Long-term evaluation of laser retinopexy in retinal breaks: a review ...

    African Journals Online (AJOL)

    Purpose: To evaluate the effects of laser retinopexy in retinal breaks and the recurrence cases. Materials and Methods: 45 eyes of 25 patients who underwent laser retinopexy in retinal breaks between the period of July 2009 and January 2013 are included. All the breaks and suspicious areas for possible breaks are treated ...

  12. 26 CFR 1.410(a)-8T - Year of service; break in service (temporary).

    Science.gov (United States)

    2010-04-01

    ... 26 Internal Revenue 5 2010-04-01 2010-04-01 false Year of service; break in service (temporary). 1...)-8T Year of service; break in service (temporary). (a)-(b) (c) Breaks in service. (1) (2) Employees...-year break in service under a plan which provides that after not more than 2 years of service each...

  13. Break the "wall" and become creative: Enacting embodied metaphors in virtual reality.

    Science.gov (United States)

    Wang, Xinyue; Lu, Kelong; Runco, Mark A; Hao, Ning

    2018-03-19

    This study investigated whether the experience of "breaking the walls", the embodiment of the metaphor "breaking the rules", could enhance creative performance. The virtual reality technology was used to simulate the scenario where participants could "break the walls" while walking in a corridor. Participants were asked to solve the creativity-demanding problems (ie., alternative uses tasks, AUT) in either the "break" condition in which they had to break the walls to move forward in VR, or the "no-break" condition where no barrier walls would appear. Results showed higher AUT originality and AUT fluency in the "break" condition than in the "no-break" condition. Moreover, the effects of "breaking the walls" on AUT originality were fully mediated by cognitive flexibility and persistence. These findings may indicate that enacting metaphors such as "breaking the rules" contribute to creative performance. The enhanced cognitive flexibility and persistence may account for the benefits. Copyright © 2018 Elsevier Inc. All rights reserved.

  14. Experimental and Numerical Investigation of Pre-Breaking and Breaking Vorticity within a Plunging Breaker

    Directory of Open Access Journals (Sweden)

    Diana De Padova

    2018-03-01

    Full Text Available The characteristics of vorticity induced just prior and at the splash-down of a plunging breaker on a 1:10 planar slope have been studied using wave flume experiments and numerical simulations. Laboratory experiments involved detailed measurements in the outer surf zone of both fluid velocities below trough level, achieved by a fibre-optic laser-Doppler anemometer, and water surface elevations, obtained by an ultrasound probe. A Weakly-Compressible Smoothed Particle (WCSPH model, coupled with a two-equation model for turbulent stresses, has been employed for the numerical simulations. A thorough calibration of the SPH’s numerical parameters has been first performed, through comparison between numerical and experimental wave elevation and velocity data. Then, considering that time-averaged laboratory data shows a significant vorticity beneath the free surface in the wave pre-breaking region, the vorticity generation mechanism has been thoroughly analyzed by means of the numerical model. In the attempt of explaining the generation of vorticity as induced by flow separation, we also inspected the role of the streamwise flow deceleration and surface-parallel vorticity flux. In analogy with the case of spilling breakers a cause-effect relation has been observed between streamwise flow deceleration and vorticity generation. Numerical findings are positively confirmed by the experimental results.

  15. Estimation of LOCA break size using cascaded Fuzzy neural networks

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Geon Pil; Yoo, Kwae Hwan; Back, Ju Hyun; Na, Man Gyun [Dept. of Nuclear Engineering, Chosun University, Gwangju (Korea, Republic of)

    2017-04-15

    Operators of nuclear power plants may not be equipped with sufficient information during a loss-of-coolant accident (LOCA), which can be fatal, or they may not have sufficient time to analyze the information they do have, even if this information is adequate. It is not easy to predict the progression of LOCAs in nuclear power plants. Therefore, accurate information on the LOCA break position and size should be provided to efficiently manage the accident. In this paper, the LOCA break size is predicted using a cascaded fuzzy neural network (CFNN) model. The input data of the CFNN model are the time-integrated values of each measurement signal for an initial short-time interval after a reactor scram. The training of the CFNN model is accomplished by a hybrid method combined with a genetic algorithm and a least squares method. As a result, LOCA break size is estimated exactly by the proposed CFNN model.

  16. Dynamical chiral symmetry breaking and Bethe-Salpeter equation

    Energy Technology Data Exchange (ETDEWEB)

    Naito, Kenichi [Tokyo Inst. of Tech. (Japan)

    1998-08-01

    {pi} meson, (pseudo) Nambu-Goldstone particle caused by a spontaneous breaking of chiral symmetry, was studied by use of Bethe-Salpeter (BS) equation in the limits of effective model as a bound state of quark and antiquark. The effective model has nonlocal interaction and proved to satisfy the Gell-Mann-Oaks-Renner (GMOR) mass formula by treating correct Noether current in spite of loss of local chiral invariance of interaction term. GMOR mass formula: M{sub {pi}}{sup 2}f{sub {pi}}{sup 2}{approx_equal}-2m{sub 0} was realized as the result of the dynamical breaking and the clear breaking of chiral symmetry. M{sub {pi}}, f{sub {pi}}, m{sub 0}, and indicate mass of pseudo scalar meson, decay constant, mass of quark and vacuum condensation of quark and antiquark. (S.Y.)

  17. Dynamical Supergravity Breaking via the Super-Higgs Effect Revisited

    CERN Document Server

    Alexandre, Jean; Mavromatos, Nick E

    2013-01-01

    We investigate the dynamical breaking of local supersymmetry (supergravity), including the Deser-Zumino super-Higgs effect, via the corresponding one-loop effective potential for the simple but quite representative cases of N=1, D=4 simple supergravity and a (simplified) conformal version of it. We find solutions to the effective equations which indicate dynamical generation of a gravitino mass, thus breaking supergravity. In the case of conformal supergravity models, the gravitino mass can be much lower than the Planck scale, for global supersymmetry breaking scales below the Grand Unification scale. The absence of instabilities in the effective potential arising from the quantum fluctuations of the metric field is emphasised, contrary to previous claims in the literature.

  18. Inverse Supersymmetry Breaking in S1 × R3

    Directory of Open Access Journals (Sweden)

    Vasilis Oikonomou

    2010-03-01

    Full Text Available In this paper, we study the influence of hard supersymmetry breaking terms in a N = 1, d = 4 supersymmetric model, in S1 × R3 spacetime topology. It is shown that when the radius of the compact dimension is large supersymmetry is unbroken, and dynamically breaks as the radius decreases. We point out that this resembles the inverse symmetry breaking of continuous symmetries at finite temperature (however, in the case of supersymmetry, the role of the temperature is played by the compact dimension’s radius. Furthermore, we also find a universality in the dependence of the critical length Lc as a function of a coupling g3, after comparing all cases.

  19. Modulated Tool-Path (MTP) Chip Breaking System

    Energy Technology Data Exchange (ETDEWEB)

    Graham, K. B.

    2010-04-01

    The Modulated Tool-Path (MTP) Chip Breaking System produces user-selectable chip lengths and workpiece finishes and is compatible with any material, workpiece shape, and depth of cut. The MTP chip breaking system consistently creates the desired size of chips regardless of workpiece size, shape, or material, and the machine operator does not need to make any adjustments during the machining operation. The system's programmer configures the part program that commands the machine tool to move in a specific fashion to deliver the desired part size, shape, chip length, and workpiece surface finish. The MTP chip breaking system helps manufacturers avoid the detrimental effects of continuous chips, including expensive repair costs, delivery delays, and hazards to personnel.

  20. Nonlinear wave breaking in self-gravitating viscoelastic quantum fluid

    Energy Technology Data Exchange (ETDEWEB)

    Mitra, Aniruddha, E-mail: anibabun@gmail.com [Center for Plasma Studies, Department of Instrumentation Science, Jadavpur University, Kolkata, 700 032 (India); Roychoudhury, Rajkumar, E-mail: rajdaju@rediffmail.com [Advanced Centre for Nonlinear and Complex Phenomena, 1175 Survey Park, Kolkata 700075 (India); Department of Mathematics, Bethune College, Kolkata 700006 (India); Bhar, Radhaballav [Center for Plasma Studies, Department of Instrumentation Science, Jadavpur University, Kolkata, 700 032 (India); Khan, Manoranjan, E-mail: mkhan.ju@gmail.com [Center for Plasma Studies, Department of Instrumentation Science, Jadavpur University, Kolkata, 700 032 (India)

    2017-02-12

    The stability of a viscoelastic self-gravitating quantum fluid has been studied. Symmetry breaking instability of solitary wave has been observed through ‘viscosity modified Ostrovsky equation’ in weak gravity limit. In presence of strong gravitational field, the solitary wave breaks into shock waves. Response to a Gaussian perturbation, the system produces quasi-periodic short waves, which in terns predicts the existence of gravito-acoustic quasi-periodic short waves in lower solar corona region. Stability analysis of this dynamical system predicts gravity has the most prominent effect on the phase portraits, therefore, on the stability of the system. The non-existence of chaotic solution has also been observed at long wavelength perturbation through index value theorem. - Highlights: • In weak gravitational field, viscoelastic quantum fluid exhibits symmetry breaking instability. • Gaussian perturbation produces quasi-periodic gravito-acoustic waves into the system. • There exists no chaotic state of the system against long wavelength perturbations.

  1. Nurses' views about returning to practice after a career break.

    Science.gov (United States)

    Durand, Mary Alison; Randhawa, Gurch

    Shortages in nursing staff have led to recruitment campaigns targeting nurses who have left the profession. The present study explored reasons why career-break nurses decide for or against a return to practice, as well as perceptions of nursing following return. Semistructured interview were conducted with 24 nurses who had returned recently to the profession and 28 nurses on a "career break". Findings revealed that those who returned did so when their personal circumstances allowed, and half returned as bank nurses in order to work flexible, family-friendly hours. Some non-returners reported that they could not afford to return because of childcare costs. Although still a caring one, the nurse's role is seen by returners as becoming increasingly technologically and administratively demanding. Flexibility with regard to working practices, increased salaries and demonstrating that it values its staff, were highlighted by interviewees generally as priority issues for the NHS if it wishes to recruit career-break nurses.

  2. D7 brane embeddings and chiral symmetry breaking

    International Nuclear Information System (INIS)

    Evans, Nick; Waterson, Tom; Shock, Jonathan P.

    2005-01-01

    We study the embedding of D7 brane probes in five geometries that are deformations of AdS 5 xS 5 . Each case corresponds to the inclusion of quark fields in a dual gauge theory where we are interested in investigating whether chiral symmetry breaking occurs. We use a supersymmetric geometry describing an N=2 theory on its moduli space and a dilaton driven non-supersymmetric flow to establish criteria for a chiral symmetry breaking embedding. We develop a simple spherical D7 embedding that tests the repulsion of the core of the geometry and signals dynamical symmetry breaking. We then use this tool in more complicated geometries to show that an N=2* theory and a non-supersymmetric theory with scalar masses do not induce a chiral condensate. Finally we provide evidence that the Yang Mills* geometry does. (author)

  3. Microfluidic droplet generator with controlled break-up mechanism

    KAUST Repository

    Gonzalez, David Conchouso

    2017-04-13

    Droplet generation devices and systems that parallelize droplet generation devices are provided. The droplet generation devices can include a symmetric block-and-break system and a tapered droplet generation zone. The symmetric block-and-break system can include a pair of break channels and a pair of bypass channels symmetrically arranged with respect to the dispersed-phase input channel and the output channel. The droplet generation devices can generate monodisperse droplets with a predefined volume over a range of flow rates, pressures, and fluid properties. The droplet generation devices are therefore capable of parallelization to achieve large-capacity droplet generation, e.g. greater than 1 L/hr, with small overall coefficients of variation.

  4. DNA turnover and strand breaks in Escherichia coli

    International Nuclear Information System (INIS)

    Hanawalt, P.; Grivell, A.; Nakayama, H.

    1975-01-01

    The extent of DNA turnover has been measured in a dnaB mutant of Escherichia coli, temperature sensitive for semiconservative DNA replication. At the nonpermissive temperature about 0.02 percent of the deoxynucleotides in DNA are exchanged per generation period. This turnover rate is markedly depressed in the presence of rifampicin. During thymine starvation strand breaks accumulate in the DNA of E. coli strains that are susceptible to thymineless death. Rifampicin suppresses the appearance of these breaks, consistent with our hypothesis that transcription may be accompanied by repairable single-strand breaks in DNA. DNA turnover is enhanced severalfold in strands containing 5-bromodeoxyuridine in place of thymidine, possibly because the analog (or the deoxyuridine, following debromination) is sometimes recognized and excised

  5. Spontaneous Symmetry Breaking in 5D Conformally Invariant Gravity

    Directory of Open Access Journals (Sweden)

    Taeyoon Moon

    2016-01-01

    Full Text Available We explore the possibility of the spontaneous symmetry breaking in 5D conformally invariant gravity, whose action consists of a scalar field nonminimally coupled to the curvature with its potential. Performing dimensional reduction via ADM decomposition, we find that the model allows an exact solution giving rise to the 4D Minkowski vacuum. Exploiting the conformal invariance with Gaussian warp factor, we show that it also admits a solution which implements the spontaneous breaking of conformal symmetry. We investigate its stability by performing the tensor perturbation and find the resulting system is described by the conformal quantum mechanics. Possible applications to the spontaneous symmetry breaking of time-translational symmetry along the dynamical fifth direction and the brane-world scenario are discussed.

  6. Chiral symmetry breaking in superfluid 3He-A.

    Science.gov (United States)

    Ikegami, H; Tsutsumi, Y; Kono, K

    2013-07-05

    Spontaneous symmetry breaking is an important concept in many branches of physics. In helium-3 ((3)He), the breaking of symmetry leads to the orbital chirality in the superfluid phase known as (3)He-A. Chirality is a fundamental property of (3)He-A, but its direct detection has been challenging. We report direct detection of chirality by transport measurements of electrons trapped below a free surface of (3)He-A. In particular, we observed the so-called intrinsic Magnus force experienced by a moving electron; the direction of the force directly reflected the chirality. We further showed that, at the superfluid transition, the system selected either right- or left-handed chirality. The observation of such selection directly demonstrates chiral symmetry breaking.

  7. Introduction to symmetry-breaking phenomena in physics

    CERN Multimedia

    CERN. Geneva. Audiovisual Unit

    2001-01-01

    The notion of broken symmetries started slowly to emerge in the 19th century. The early studies of Pasteur on the parity asymmetry of life, the studies of Curie on piezoelectricity and on the symmetries of effects versus the symmetry of causes ( which clearly excluded spontaneous symmetry breaking), are important historical landmarks. However the possibility of spontaneous symmetry breaking within the usual principles of statistical mechanics, waited for the work of Peierls and Onsager. The whole theory of phase transitions and critical phenomena, as well as the construction of field theoretic models as long distance limit of yet unknown physics, relies nowadays on the concept of criticality associated to spontaneous symmetry breaking. The phenomena of Goldstone bosons, of Meissner-Higgs effects, are central to the theory of condensed matter as well as to particle physics. In cosmology as well, the various inflationary scenarios begin similarly with this same concept. The three lectures will provide a simple ...

  8. Symmetry breaking in occupation number based slave-particle methods

    Science.gov (United States)

    Georgescu, Alexandru B.; Ismail-Beigi, Sohrab

    2017-10-01

    We describe a theoretical approach to finding spontaneously symmetry-broken electronic phases due to strong electronic interactions when using recently developed slave-particle (slave-boson) approaches based on occupation numbers. We describe why, to date, spontaneous symmetry breaking has proven difficult to achieve in such approaches. We then provide a total energy based approach for introducing auxiliary symmetry-breaking fields into the solution of the slave-particle problem that leads to lowered total energies for symmetry-broken phases. We point out that not all slave-particle approaches yield energy lowering: the slave-particle model being used must explicitly describe the degrees of freedom that break symmetry. Finally, our total energy approach permits us to greatly simplify the formalism used to achieve a self-consistent solution between spinon and slave modes while increasing the numerical stability and greatly speeding up the calculations.

  9. Application of break preclusion concept in German nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    Roos, E. [Energie-Versorgung Schwaben AG, Stuttgart (Germany); Maier, V. [Bayernwerk AG, Muenchen (Germany); Nagel, G. [PraussenElektra AG, Hannover (Germany)] [and others

    1997-04-01

    The break preclusion concept is based on {open_quotes}KTA rules{close_quotes}, {open_quotes}RSK guidelines{close_quotes} and {open_quotes}Rahmenspeziflkation Basissicherheit{close_quotes}. These fundamental rules containing for example requirements on material, design, calculation, manufacturing and testing procedures are explained and the technical realisation is shown by means of examples. The proof of the quality of these piping systems can be executed by means of fracture mechanics calculations by showing that in every case the leakage monitoring system already detect cracks which are clearly smaller than the critical crack. Thus the leak before break behavior and the break preclusion concept is implicitly affirmed. In order to further diminish conservativities in the fracture mechanics procedures, specific research projects are executed which are explained in this contribution.

  10. Commercial breaks vs. product placement: what works for young consumers?

    Directory of Open Access Journals (Sweden)

    Ovidiu Mircea ŢIEREAN

    2015-06-01

    Full Text Available The article presents the results of a quantitative marketing research conducted on young consumers from Braşov County regarding their perceptions about commercial breaks and product placement during the most important reality shows. The purpose of this research is to determine to what extent young consumers watch the evening shows and to what extent they remember the brands advertised during commercial breaks and product placement within the shows. For young consumers, the evening shows are time spent with family and friends. A large majority do not watch the commercial breaks and they mostly remember brands that also practice product placement during the shows. There is a direct corelation between numbers of shows watched and the percentage of consumers who remember the main sponsors for evening shows.

  11. CNN for breaking text-based CAPTCHA with noise

    Science.gov (United States)

    Liu, Kaixuan; Zhang, Rong; Qing, Ke

    2017-07-01

    A CAPTCHA ("Completely Automated Public Turing test to tell Computers and Human Apart") system is a program that most humans can pass but current computer programs could hardly pass. As the most common type of CAPTCHAs , text-based CAPTCHA has been widely used in different websites to defense network bots. In order to breaking textbased CAPTCHA, in this paper, two trained CNN models are connected for the segmentation and classification of CAPTCHA images. Then base on these two models, we apply sliding window segmentation and voting classification methods realize an end-to-end CAPTCHA breaking system with high success rate. The experiment results show that our method is robust and effective in breaking text-based CAPTCHA with noise.

  12. Sensitivity Analyses in Small Break LOCA with HPI-Failure: Effect of Break-Size in Secondary-Side Depressurization

    Science.gov (United States)

    Kinoshita, Ikuo; Torige, Toshihide; Yamada, Minoru

    2014-06-01

    In the case of total failure of the high pressure injection (HPI) system following small break loss of coolant accident (SBLOCA) in pressurized water reactor (PWR), the break size is so small that the primary system does not depressurize to the accumulator (ACC) injection pressure before the core is uncovered extensively. Therefore, steam generator (SG) secondary-side depressurization is necessary as an accident management in order to grant accumulator system actuation and core reflood. A thermal-hydraulic analysis using RELAP5/MOD3 was made on SBLOCA with HPI-failure for Oi Units 3/4 operated by Kansai Electoric Power Co., which are conventional 4 loop PWR plants. The effectiveness of SG secondary-side depressurization procedure was investigated for the real plant design and operational characteristics. The sensitivity analyses using RELAP5/MOD3.2 showed that the accident management was effective for a wide range of break sizes, various orientations and positions. The critical break can be 3 inch cold-leg bottom break.

  13. Spring break versus spring broken: predictive utility of spring break alcohol intentions and willingness at varying levels of extremity.

    Science.gov (United States)

    Litt, Dana M; Lewis, Melissa A; Patrick, Megan E; Rodriguez, Lindsey; Neighbors, Clayton; Kaysen, Debra L

    2014-02-01

    Within the domain of risk-related behavior, many times the decision to engage is not a product of premeditation or intention. The prototype willingness model was created to capture and explain the unintended element of risk behavior. The present study aimed to evaluate the importance of willingness versus intention, two important constructs within the prototype willingness model, in relation to spring break drinking behavior when assessed at both high and low extremities. College undergraduates (N = 275) completed questionnaires prior to spring break regarding their anticipated spring break activities. Willingness and intention were assessed for different levels of risk. Specifically, participants indicated the extent to which they intended to (a) get drunk and (b) drink enough to black out or pass out; and the extent to which they were willing to (a) get drunk and (b) drink enough to black out or pass out. When classes resumed following spring break, the students indicated the extent to which they actually (a) got drunk and (b) drank enough to black out or pass out. Results demonstrated that when the health-related risk was lower (i.e., getting drunk), intention was a stronger predictor of behavior than was willingness. However, as the level of risk increased (i.e., getting drunk enough to black out or pass out), willingness more strongly predicted behavior. The present study suggests that willingness and intentions differentially predict spring break alcohol-related behavior depending on the extremity of behavior in question. Implications regarding alcohol interventions are discussed.

  14. EARLY BUD-BREAK1 (EBB1) defines a conserved mechanism for control of bud-break in woody perennials.

    Science.gov (United States)

    Busov, Victor; Carneros, Elena; Yakovlev, Igor

    2016-01-01

    Bud-break is an environmentally and economically important trait in trees, shrubs and vines from temperate latitudes. Poor synchronization of bud-break timing with local climates can lead to frost injuries, susceptibility to pests and pathogens and poor crop yields in fruit trees and vines. The rapid climate changes outpace the adaptive capacities of plants to respond through natural selection. This is particularly true for trees which have long generation cycle and thus the adaptive changes are significantly delayed. Therefore, to devise appropriate breeding and conservation strategies, it is imperative to understand the molecular underpinnings that govern dormancy mechanisms. We have recently identified and characterized the poplar EARLY BUD-BREAK 1 (EBB1) gene. EBB1 is a positive regulator of bud-break and encodes a transcription factor from the AP2/ERF family. Here, using comparative and functional genomics approaches we show that EBB1 function in regulation of bud-break is likely conserved across wide range of woody perennial species with importance to forestry and agriculture.

  15. Paediatric SpRs' experiences of breaking bad news.

    Science.gov (United States)

    Horwitz, N; Ellis, J

    2007-09-01

    To ascertain the level of support and training available to paediatric specialist registrars (SpRs) in breaking bad news and their self-reported confidence in this task. A questionnaire-based survey. Paediatric SpRs working in North Thames region. Specialist registrars (n = 206) were sent a questionnaire relating to the level of support and training available to them in breaking bad news and their attitudes to this task. A repeat questionnaire was sent out 2 weeks later. The response rate was 54.9%. The study sample included 78 females and 34 males. The median year of qualification was 1995 [interquartile range (IQR) 1993-1997] and the median year of Calman training was Year 3 (IQR 2-4). Only 15.9% of participants had guidelines where they worked and 91.2% had received training in breaking bad news. Median self-perceived confidence in breaking bad news was rated as 4 out of 5. Only 21.2% of all respondents had both disclosed a diagnosis of Down syndrome and received feedback on their performance from their seniors. Few SpRs were able to adhere to all evidence-based recommendations for breaking bad news. Most SpRs had received training in breaking bad news and self-reported confidence in this skill was high, although their hands-on experience was limited. Recent research shows, however, that parental dissatisfaction with the way in which bad news is broken remains high. The potential discrepancy between self-reported confidence and actual competence casts doubt on the value of self-evaluation.

  16. Defining Nitrogen Kinetics for Air Break in Prebreathe

    Science.gov (United States)

    Conkin, Johnny

    2009-01-01

    Actual tissue nitrogen (N2) kinetics are complex; the uptake and elimination is often approximated with a single half-time compartment in statistical descriptions of denitrogenation [prebreathe (PB)] protocols. Air breaks during PB complicate N2 kinetics. A comparison of symmetrical versus asymmetrical N2 kinetics was performed using the time to onset of hypobaric decompression sickness (DCS) as a surrogate for actual venous N2 tension. Published results of 12 tests involving 179 hypobaric exposures in altitude chambers after PB, with and without air breaks, provide the complex protocols from which to model N2 kinetics. DCS survival time for combined control and air breaks were described with an accelerated log logistic model where N2 uptake and elimination before, during, and after the air break was computed with a simple exponential function or a function that changed half-time depending on ambient N2 partial pressure. P1N2-P2 = delta P defined DCS dose for each altitude exposure, where P2 was the test altitude and P1N2 was computed N2 pressure at the beginning of the altitude exposure. The log likelihood (LL) without DCS dose (null model) was -155.6, and improved (best-fit) to -97.2 when dose was defined with a 240 min half-time for both N2 elimination and uptake during the PB. The description of DCS survival time was less precise with asymmetrical N2 kinetics, for example, LL was -98.9 with 240 min half-time elimination and 120 min half-time uptake. The statistical regression described survival time mechanistically linked to symmetrical N2 kinetics during PBs that also included air breaks. The results are data-specific, and additional data may change the conclusion. The regression is useful to compute additional PB time to compensate for an air break in PB within the narrow range of tested conditions.

  17. Perceptions of rule-breaking related to marine ecosystem health.

    Directory of Open Access Journals (Sweden)

    Matthew J Slater

    Full Text Available Finding effective solutions to manage marine resources is high on political and conservation agendas worldwide. This is made more urgent by the rate of increase in the human population and concomitant resource pressures in coastal areas. This paper links empirical socio-economic data about perceptions of marine resource health to the breaking of marine management rules, using fisheries as a case study. The relationship between perceived rule-breaking (non-compliance with regulations controlling fishing and perceived health of inshore marine environments was investigated through face-to-face interviews with 299 heads of households in three Tanzanian coastal communities in November and December 2011. Awareness of rules controlling fishing activity was high among all respondents. Fishers were able to describe more specific rules controlling fishing practices than non-fishers (t = 3.5, df = 297, p<0.01. Perceived breaking of fishing regulations was reported by nearly half of all respondents, saying "some" (32% of responses or "most" (15% of responses people break fishing rules. Ordinal regression modelling revealed a significant linkage (z= -3.44, p<0.001 in the relationship between respondents' perceptions of deteriorating marine health and their perception of increased rule-breaking. In this paper, inferences from an empirical study are used to identify and argue the potential for using perceptions of ecosystem health and level of rule-breaking as a means to guide management measures. When considering different management options (e.g. Marine Protected Areas, policy makers are advised to take account of and utilise likely egoistic or altruistic decision-making factors used by fishers to determine their marine activities.

  18. Long Memory and Structural Breaks in Realized Volatility: An Irreversible Markov Switching Approach

    DEFF Research Database (Denmark)

    Nonejad, Nima

    This paper proposes a model that simultaneously captures long memory and structural breaks. We model structural breaks through irreversible Markov switching or so-called change-point dynamics. The parameters subject to structural breaks and the unobserved states which determine the position...... to daily S&P 500 data, one finds strong evidence of three structural breaks. The evidence of these breaks is robust to different specifications including a GARCH specification for the conditional variance of volatility....

  19. Structural breaks in mean temperature over agroclimatic zones in India.

    Science.gov (United States)

    Paul, Ranjit Kumar; Birthal, P S; Khokhar, Ankit

    2014-01-01

    Amongst Asian countries India is one of the most vulnerable countries to climate change. During the past century, surface temperature in India has shown a significant increasing trend. In this paper, we have investigated behavior of mean monthly temperature during the period 1901-2001 over four agroclimatic zones of India and also tried to detect structural change in the temperature series. A structural break in the series has been observed at the national as well regional levels between 1970 and 1980. An analysis of trends before and after the structural break shows a significant increase in July temperature in the arid zone since 1972.

  20. Breaking Bad News: An essential skill for doctors.

    Science.gov (United States)

    Abdul Hafidz, M I; Zainudin, L D

    2016-02-01

    Breaking bad news is a process of delivering news, which may negatively affect a patient's view of the future, however is an essential skill for doctors. There are a multitude of benefits if doctors can execute this task well, and will improve the disease journey for the patient. There are several published models including the SPIKES and ABCDE models to help guide the doctor to break bad news effectively. This important skill can be taught through various methods but the most effective may be actually observing a session by senior clinicians.

  1. Finding strongly interacting symmetry breaking at the SSC

    International Nuclear Information System (INIS)

    Golden, M.

    1989-02-01

    Pairs of gauge bosons, W and Z, are a probe of the electroweak symmetry-breaking sector, since the numbers of two gauge boson events are much larger in strongly coupled models than weak. The doubly charged channels W + W + and W/sup /minus//W/sup/minus// are cleanest, since they do not suffer from q/bar q/ or gg fusion backgrounds. The like-charged gauge boson events are observable only if the symmetry breaking sector is strongly interacting. 19 refs., 4 figs., 2 tabs

  2. Margins in high temperature leak-before-break assessments

    International Nuclear Information System (INIS)

    Budden, P.J.; Hooton, D.G.

    1997-01-01

    Developments in the defect assessment procedure R6 to include high-temperature mechanisms in Leak-before-Break arguments are described. In particular, the effect of creep on the time available to detect a leak and on the crack opening area, and hence leak rate, is discussed. The competing influence of these two effects is emphasized by an example. The application to Leak-before-Break of the time-dependent failure assessment diagram approach for high temperature defect assessment is then outlined. The approach is shown to be of use in assessing the erosion of margins by creep

  3. On radiative gauge symmetry breaking in the minimal supersymmetric model

    International Nuclear Information System (INIS)

    Gamberini, G.; Ridolfi, G.; Zwirner, F.

    1990-01-01

    We present a critical reappraisal of radiative gauge symmetry breaking in the minimal supersymmetric standard model. We show that a naive use of the renormalization group improved tree-level potential can lead to incorrect conclusions. We specify the conditions under which the above method gives reliable results, by performing a comparison with the results obtained from the full one-loop potential. We also point out how the stability constraint and the conditions for the absence of charge- and colour-breaking minima should be applied. Finally, we comment on the uncertainties affecting the model predictions for physical observables, in particular for the top quark mass. (orig.)

  4. Breaking wave impacts on offshore wind turbine foundations

    DEFF Research Database (Denmark)

    Bredmose, Henrik; Jacobsen, Niels Gjøl

    2010-01-01

    Extreme wave loads from breaking waves on a monopile foundation are computed within a 3D CFD model. The wave impacts are obtained by application of focused wave groups. For a fixed position of the monopile, the focus location of the wave group is varied to produce impacts with front shapes...... that for the impacts of spilling breakers the peak force gets smaller the more developed the breaking is. This is in qualitative agreement with a finding from shallow water impacts on vertical walls: the strongest wave loads are associated with breakers that hit the structure with slightly overturning front...

  5. Non-universal SUSY breaking, hierarchy and squark degeneracty

    International Nuclear Information System (INIS)

    Murayama, Hitoshi.

    1995-01-01

    I discuss non-trivial effects in the soft SUSY breaking terms which appear when one integrates out heavy fields. The effects exist only when the SUSY breaking terms are non-universal. They may spoil (1) the hierarchy between the weak and high-energy scales, or (2) degeneracy among the squark masses even in the presense of a horizontal symmetry. I argue, in the end, that such new effects may be useful in probing physics at high-energy scales from TeV-scale experiments

  6. Non-local symmetry breaking in Kaluza-Klein theories

    CERN Document Server

    Masiero, A; Serone, M; Silvestrini, L

    2001-01-01

    Scherk-Schwarz gauge symmetry breaking of a D-dimensional field theory model compactified on a circle is analyzed. It is explicitly shown that forbidden couplings in the unbroken theory appear in the one-loop effective action only in a non-local way, implying that they are finite at all orders in perturbation theory. This result can be understood as a consequence of the local gauge symmetry, but holds true also in the global limit. Similar results for Scherk-Schwarz supersymmetry breaking are expected to hold.

  7. E-mail, decisional styles, and rest breaks.

    Science.gov (United States)

    Baker, James R; Phillips, James G

    2007-10-01

    E-mail is a common but problematic work application. A scale was created to measure tendencies to use e-mail to take breaks (e-breaking); and self-esteem and decisional style (vigilance, procrastination, buck-passing, hypervigilance) were used to predict the self-reported and actual e-mail behaviors of 133 participants (students and marketing employees). Individuals who were low in defensive avoidance (buck-passing) engaged in more e-mailing per week, both in time spent on e-mail and message volume. E-breakers were more likely to engage in behavioral procrastination and spent more time on personal e-mail.

  8. Observations on the partial breaking of N=2 rigid supersymmetry

    Directory of Open Access Journals (Sweden)

    Laura Andrianopoli

    2015-05-01

    Full Text Available We study the partial breaking of N=2 rigid supersymmetry for a generic rigid special geometry of n abelian vector multiplets in the presence of Fayet–Iliopoulos terms induced by the hyper-Kähler momentum map. By exhibiting the symplectic structure of the problem we give invariant conditions for the breaking to occur, which rely on a quartic invariant of the Fayet–Iliopoulos charges as well as on a modification of the N=2 rigid symmetry algebra by a vector central charge.

  9. Charge and CP symmetry breaking in two Higgs doublet models

    International Nuclear Information System (INIS)

    Barroso, A.; Ferreira, P.M.; Santos, R.

    2006-01-01

    We show that, for the most generic model with two Higgs doublets possessing a minimum that preserves the U(1) em symmetry, charge breaking (CB) cannot occur. If CB does not occur, the potential could have two different minima, and there is in principle no general argument to show which one is the deepest. The depth of the potential at a stationary point that breaks CB or CP, relative to the U(1) em preserving minimum, is proportional to the squared mass of the charged or pseudoscalar Higgs, respectively

  10. Neutronic calculations for Angra-1 steam line break accident

    International Nuclear Information System (INIS)

    Ponzoni Filho, Pedro; Sato, Sadakatu

    2000-01-01

    The reduction of boron concentration in the Boron Injection Tank (BIT), to the room temperature solubility level, makes necessary a reanalysis of the steam line break accident of Angra 1 NPP. This paper describes the neutronic calculation related to this reanalysis. The main steps of the work were: review of reactivity parameters used in the accident simulation; search of xenon profiles that cause the most severe core power distribution; calculation of hot channel factors and other neutronic parameters necessary for DNBR determination. The final conclusion, related to the steam line break accident, states the BIT concentration may be reduced to 2000 ppm. (author)

  11. Dynamical evolution of supernova remnants breaking through molecular clouds

    OpenAIRE

    Cho, Wankee; Kim, Jongsoo; Koo, Bon-Chul

    2015-01-01

    We carry out three-dimensional hydrodynamic simulations of the supernova remnants (SNRs) produced inside molecular clouds (MCs) near their surface using the HLL code (Harten et al. 1983). We explore the dynamical evolution and the X-ray morphology of SNRs after breaking through the MC surface for ranges of the explosion depths below the surface and the density ratios of the clouds to the intercloud media (ICM). We find that if an SNR breaks out through an MC surface in its Sedov stage, the ou...

  12. What can break the Wandzura--Wilczek relation?

    Energy Technology Data Exchange (ETDEWEB)

    Alessandro Bacchetta, Alberto Accardi, Wolodymyr Melnitchouk, Marc Schlegel

    2009-11-01

    We analyze the breaking of the Wandzura--Wilczek relation for the g_2 structure function, emphasizing its connection with transverse momentum dependent parton distribution functions. We find that the relation is broken by two distinct twist-3 terms, and clarify how these can be separated in measurements of double-spin asymmetries in semi-inclusive deep inelastic scattering. Through a quantitative analysis of available g_2 data we also show that the breaking of the Wandzura--Wilczek relation can be as large as 15--30% of the size of g_2.

  13. Observations on the Partial Breaking of $N=2$ Rigid Supersymmetry

    CERN Document Server

    Andrianopoli, Laura; Ferrara, Sergio; Trigiante, Mario

    2015-01-01

    We study the partial breaking of $N=2$ rigid supersymmetry for a generic rigid special geometry of $n$ abelian vector multiplets in the presence of Fayet-Iliopoulos terms induced by the Hyper-K\\"ahler momentum map. By exhibiting the symplectic structure of the problem we give invariant conditions for the breaking to occur, which rely on a quartic invariant of the Fayet-Iliopoulos charges as well as on a modification of the $N=2$ rigid symmetry algebra by a vector central charge.

  14. Strong evidence for spontaneous chiral symmetry breaking in (quenched) QCD

    International Nuclear Information System (INIS)

    Barbour, I.M.; Gibbs, P.; Schierholz, G.; Teper, M.; Gilchrist, J.P.; Schneider, H.

    1983-09-01

    We calculate the chiral condensate for all quark masses using Kogut-Susskind fermions in lattice-regularized quenched QCD. The large volume behaviour of at small quark masses demonstrates that the explicit U(1) chiral symmetry is spontaneously broken. We perform the calculation for β = 5.1 to 5.9 and find very good continuum renormalization group behaviour. We infer that the spontaneous breaking we observe belongs to continuum QCD. This constitutes the first unambiguous demonstration of spontaneous chiral symmetry breaking in continuum quenched QCD. (orig.)

  15. Effect of symmetry breaking on transition strength distributions

    International Nuclear Information System (INIS)

    Mitchell, G.E.; Shriner, J.F. Jr.

    2001-01-01

    The quantum numbers of over 100 states in 30 P have been determined from the ground state to 8 MeV. Previous measurements had provided complete spectroscopy in 26 Al. For these N=Z=odd nuclei, states of isospin T=0 and T=1 coexist at all energies. These spectra provide a unique opportunity to test the effect of symmetry breaking (of the approximate symmetry isospin) on the level statistics and on the transition strength distributions. The level statistics are strongly affected by the small symmetry breaking and the transition strength distributions differ from the Porter-Thomas distribution

  16. Margins in high temperature leak-before-break assessments

    Energy Technology Data Exchange (ETDEWEB)

    Budden, P.J.; Hooton, D.G.

    1997-04-01

    Developments in the defect assessment procedure R6 to include high-temperature mechanisms in Leak-before-Break arguments are described. In particular, the effect of creep on the time available to detect a leak and on the crack opening area, and hence leak rate, is discussed. The competing influence of these two effects is emphasized by an example. The application to Leak-before-Break of the time-dependent failure assessment diagram approach for high temperature defect assessment is then outlined. The approach is shown to be of use in assessing the erosion of margins by creep.

  17. Chiral symmetry breaking in a semilocalized magnetic field

    Science.gov (United States)

    Cao, Gaoqing

    2018-03-01

    In this work, we explore the pattern of chiral symmetry breaking and restoration in a solvable magnetic field configuration within the Nambu-Jona-Lasinio model. The special semilocalized static magnetic field can roughly mimic the realistic situation in peripheral heavy ion collisions; thus, the study is important for the dynamical evolution of quark matter. We find that the magnetic-field-dependent contribution from discrete spectra usually dominates over the contribution from continuum spectra and chiral symmetry breaking is locally catalyzed by both the magnitude and scale of the magnetic field. The study is finally extended to the case with finite temperature or chemical potential.

  18. Dark matter in theories of gauge-mediated supersymmetry breaking

    CERN Document Server

    Dimopoulos, Savas K; Pomarol, A

    1996-01-01

    In gauge-mediated theories supersymmetry breaking originates in a strongly interacting sector and is communicated to the ordinary sparticles via SU(3)\\timesSU(2)\\timesU(1) carrying ``messenger'' particles. Stable baryons of the strongly interacting supersymmetry breaking sector naturally weigh \\sim 100 TeV and are viable cold dark matter candidates. They interact too weakly to be observed in dark matter detectors. The lightest messenger particle is a viable cold dark matter candidate under particular assumptions. It weighs less than 5 TeV, has zero spin and is easily observable in dark matter detectors.

  19. Gamma-ray induced double-strand breaks in DNA resulting from randomly-inflicted single-strand breaks: temporal local denaturation, a new radiation phenomenon?

    NARCIS (Netherlands)

    Schans, G.P. van der

    1978-01-01

    The induction of single- and double-strand breaks in DNA by γ-rays has been measured. The maximum number of nucleotide paris (a) between two independently induced single-strand breaks in opposite strands of the DNA which cannot prevent the occurrence of a double-strand break was found to amount to

  20. Gas Transfer Velocity in the Presence of Wave Breaking

    Science.gov (United States)

    Li, S.

    2016-02-01

    Wave breaking is known to intensify the gas exchange across the air-sea interface through air entrainment and enhancement of the near-surface turbulence. We proposed a composite model for the gas transfer velocity by examining the near-surface turbulence induced by wave breaking, which was determined based on the combination of the vertical distribution of the turbulence in the wave-affected layer and the breaking wave energy dissipation rate in the wave-breaking layer. The gas transfer velocity was calculated as a function of the air frictional velocity, wave age, and whitecap coverage. The model was validated for both the wind and wave-age dependence against field and laboratory measurements. The results supported the hypothesis that the large uncertainties in the traditional wind speed-based gas transfer velocities at moderate to high wind speeds can be ascribed to the neglect of the wind-wave effect, which is mainly attributed to the whitecap coverage as a function of the wind-wave Reynolds number.

  1. Onyekulufa and Atu-Mma: breaking the barriers of gender ...

    African Journals Online (AJOL)

    Onyekulufa and Atu-Mma: breaking the barriers of gender discrimination in health-related indigenous masquerade performances in Nigeria. ... It recommends a culture-centred approach to the transformation and repositioning of masquerade performances for effective health communication in rural communities. Keywords: ...

  2. Tie-breaking in games of perfect information

    DEFF Research Database (Denmark)

    Tranæs, Torben

    1998-01-01

    The paper suggests that ties in an extensive form game have strategic implications if they represent credible threats or promises. We consider a subset of subgame-perfect Nash equilibria obtained by breaking ties according to their strategic implications, and show that the subset is nonempty for ...... for finite extensive form games of perfect information....

  3. Breaking into the World of Coaching: The Graduate Student Coach.

    Science.gov (United States)

    Zeidler, Tom; Kirch, Michael W.

    A pilot study examined whether there is a "caste system" within the forensics community; what graduate students, faculty coaches, and tournament administrators can do to foster a sense of community and break down the caste system; and the role that formal and informal mentoring can play in this process. A survey was completed by 17…

  4. Effect of breaking bad news on patients' perceptions of doctors

    Science.gov (United States)

    Barnett, Mandy M

    2002-01-01

    The breaking of bad news is a routine but difficult task for many health professionals. There are numerous anecdotes of insensitive practice but the subject has attracted little systematic research. We therefore interviewed 106 patients with advanced cancer (from an original sample of 195) to assess their perceptions of the doctors involved in their care. Aspects of the ‘breaking bad news’ event were recorded during discussion of the illness history and were subsequently rated. Participants were also asked to nominate doctors under the headings ‘most helpful’ and ‘less helpful’, and completed standardized psychological screening questionnaires. In 94 of the 106 cases the bad news had been given by a doctor, usually a surgeon. Of the 13 doctors categorized as ‘most helpful’ when breaking bad news, 8 were general practitioners; of the 7 categorized as ‘less helpful’ all were surgeons. 69% of patients were neutral or positive about the bad-news consultation, but 20% were negative and 6% very negative. Doctors in surgical specialties were significantly more likely to be rated poorly than non-surgical specialists or general practitioners. Surgeons were the group of doctors most likely to break bad news, but non-surgical doctors were rated more positively in performance of the task. This finding has implications for training. PMID:12091508

  5. ‘BREAKS’ Protocol for Breaking Bad News

    Science.gov (United States)

    Narayanan, Vijayakumar; Bista, Bibek; Koshy, Cheriyan

    2010-01-01

    Information that drastically alters the life world of the patient is termed as bad news. Conveying bad news is a skilled communication, and not at all easy. The amount of truth to be disclosed is subjective. A properly structured and well-orchestrated communication has a positive therapeutic effect. This is a process of negotiation between patient and physician, but physicians often find it difficult due to many reasons. They feel incompetent and are afraid of unleashing a negative reaction from the patient or their relatives. The physician is reminded of his or her own vulnerability to terminal illness, and find themselves powerless over emotional distress. Lack of sufficient training in breaking bad news is a handicap to most physicians and health care workers. Adherence to the principles of client-centered counseling is helpful in attaining this skill. Fundamental insight of the patient is exploited and the bad news is delivered in a structured manner, because the patient is the one who knows what is hurting him most and he is the one who knows how to move forward. Six-step SPIKES protocol is widely used for breaking bad news. In this paper, we put forward another six-step protocol, the BREAKS protocol as a systematic and easy communication strategy for breaking bad news. Development of competence in dealing with difficult situations has positive therapeutic outcome and is a professionally satisfying one. PMID:21811349

  6. Breaking bad news: issues relating to nursing practice.

    Science.gov (United States)

    Warnock, Clare

    2014-07-15

    The breaking of bad news was traditionally regarded to be the time when a doctor and nurse sat down with a patient and family members to provide information about, for example, a life-limiting diagnosis or a poor prognosis. However, breaking bad news is now generally accepted as a process, not a one-off event, and is considered to refer to any bad, sad or difficult information that alters patients' perceptions of their present and future. Nurses have an important role in the process of providing information and helping patients prepare for, receive, understand and cope with the bad news they have been given. This article aims to help nurses understand the process of breaking bad news and discuss the challenges and difficulties that nurses can face when they are involved with patients who have been given bad news. It also provides guidance with regard to preparing for breaking bad news, giving difficult information, responding to possible reactions, and supporting patients and their relatives after they have received bad news.

  7. Survivors' Voices Breaking the Silence: Owning the Past.

    Science.gov (United States)

    Benton, Carol L.

    For the adult survivor of incest, the evolution from victim to survivor occurs in complex and creative ways. Often journal writing can be a means of exposing and exploring past abuse. The process of journal writing is special in that it allows the adult survivor to break the silence and shame imposed by the perpetrator while remaining essentially…

  8. The Making and Breaking of Trust in Pension Providers

    NARCIS (Netherlands)

    van Dalen, H.P.; Henkens, K.

    2017-01-01

    Trust in pension institutions is pivotal in making pension decisions, like saving or enrolling in pension programs. But which traits of pension institutions matter in making or breaking trust in providers like pension funds, banks or insurance companies? This paper presents an empirical analysis of

  9. Breaking bread with female 'criminals': towards generation of ...

    African Journals Online (AJOL)

    Breaking bread with incarcerated women incarcerated in prisons is a decolonising methodological framework which aims to bring the voices of an otherwise silenced population into the mainstream criminological discourse. In throwing their voices, women were able to single out what was and still is significant in their lives ...

  10. Breaking bad news: A guide for effective and empathetic communication

    Science.gov (United States)

    Rosenzweig, Margaret Quinn

    2017-01-01

    Breaking negative news to patients is a common occurrence for nurse practitioners. This difficult task requires patience and refined communication skills, and must be approached with empathy for all parties involved. There are several ways to deliver bad news to patients successfully using patient-centered communication techniques and methods. PMID:22252021

  11. Breaking up with Deleuze: Desire and Valuing the Irreconcilable

    Science.gov (United States)

    Tuck, Eve

    2010-01-01

    In this article, Eve Tuck grapples with Gilles Deleuze's conceptualization of desire, finding it simultaneously generative and unsatisfying. Recognizing that Deleuze will not "say" what Tuck wants him to say about desire--that it is smart, and constitutes expertise--Tuck reasons that there is only one thing she can do: break up with Deleuze. The…

  12. Systematics in break-up fusion reactions at low energies

    International Nuclear Information System (INIS)

    Singh, B.P.

    2017-01-01

    The reaction mechanism of heavy-ion interactions at low projectile energies is still not well understood. Both the fusion as well as break-up fusion of projectile have been observed at these energies. In the break-up fusion, also referred to as the incomplete fusion (ICF), a part of the incident ion fuses with the target nucleus while the remnant moves forward with the same velocity as that of projectile. Several models have been proposed, however, none of them could reproduce the data on ICF process. In order to study the break-up fusion reactions and to study its influence on various entrance channel parameters, several experiments have been carried out using pelletron accelerator facility at the Inter University Accelerator Centre (IUAC), New Delhi. The analysis of data has indicated significant break-up fusion contributions at energies ≈ 4-7 MeV/nucleon. Important systematic for incomplete or breakup fusion reactions have been observed and will be presented. (author)

  13. Minimally doubled fermions and spontaneous chiral symmetry breaking

    Directory of Open Access Journals (Sweden)

    Osmanaj (Zeqirllari Rudina

    2018-01-01

    Full Text Available Chiral symmetry breaking in massless QCD is a very important feature in the current understanding of low energy physics. Low - lying Dirac modes are suitable to help us understand the spontaneous chiral symmetry breaking, since the formation of a non zero chiral condensate is an effect of their accumulation near zero. The Banks – Casher relation links the spectral density of the Dirac operator to the condensate with an identity that can be read in both directions. In this work we propose a spectral method to achieve a reliable determination of the density of eigenvalues of Dirac operator near zero using the Gauss – Lanczos quadrature. In order to understand better the dynamical chiral symmetry breaking and use the method we propose, we have chosen to work with minimally doubled fermions. These kind of fermions have been proposed as a strictly local discretization of the QCD fermions action, which preserves chiral symmetry at finite cut-off. Being chiral fermions, is easier to work with them and their low - lying Dirac modes and to understand the dynamical spontaneous chiral symmetry breaking.

  14. The origin of a primordial genome through spontaneous symmetry breaking

    NARCIS (Netherlands)

    Takeuchi, Nobuto|info:eu-repo/dai/nl/304836966; Hogeweg, P|info:eu-repo/dai/nl/073710725; Kaneko, Kunihiko

    2017-01-01

    The heredity of a cell is provided by a small number of non-catalytic templates-The genome. How did genomes originate? Here, we demonstrate the possibility that genome-like molecules arise from symmetry breaking between complementary strands of self-replicating molecules. Our model assumes a

  15. Effects of different methods of breaking dormancy and seed ...

    African Journals Online (AJOL)

    Seed dormancy in palms, date palm inclusive have continued to be challenging especially when cultivating through seeds. This study evaluated different methods of breaking dormancy and seed germination rate in P. dactylifera. Using Completely Randomize Design, two varieties of P. dactylifera were treated with three ...

  16. Comparison of two culture media for breaking seed dormancy and ...

    African Journals Online (AJOL)

    The aim of this study was to compare the effects of different treatments in breaking dormancy and to increase germination percentage and days to germination in two media of water with agar and Murashige and Skoog (MS) growth medium in four species of Linum L. namely, L. mucronatum, L. nervosum, L. album and L.

  17. ArtBreak: A Creative Group Counseling Program for Children

    Science.gov (United States)

    Ziff, Katherine; Pierce, Lori; Johanson, Susan; King, Margaret

    2012-01-01

    This article describes the pilot of a school-based creative group-counseling program for children called ArtBreak, a choice-based studio art experience based on the restorative possibilities of art making delineated in the expressive therapies continuum (ETC; Kagin & Lusebrink, 1978). The ETC features a developmental hierarchy in relation to how…

  18. Fuel breaks affect nonnative species abundance in Californian plant communities

    Science.gov (United States)

    Kyle E Merriam; Jon E. Keeley; Jan L. Beyers

    2006-01-01

    We evaluated the abundance of nonnative plants on fuel breaks and in adjacent untreated areas to determine if fuel treatments promote the invasion of nonnative plant species. Understanding the relationship between fuel treatments and nonnative plants is becoming increasingly important as federal and state agencies are currently implementing large fuel treatment...

  19. Maintaining cold chain integrity: Temperature breaks within fruit ...

    African Journals Online (AJOL)

    Seventy percent (70%) of South African fruit exports are shipped through the Cape Town Container Terminal (CTCT). This in-depth case study provides a better understanding of the signifi cant challenges within the CTCT. This research revealed that 81% of the temperature breaks in fruit reefer containers carrying summer ...

  20. Towards breaking temperature equilibrium in multi-component Eulerian schemes

    Energy Technology Data Exchange (ETDEWEB)

    Grove, John W [Los Alamos National Laboratory; Masser, Thomas [Los Alamos National Laboratory

    2009-01-01

    We investigate the effects ofthermal equilibrium on hydrodynamic flows and describe models for breaking the assumption ofa single temperature for a mixture of components in a cell. A computational study comparing pressure-temperature equilibrium simulations of two dimensional implosions with explicit front tracking is described as well as implementation and J-D calculations for non-equilibrium temperature methods.

  1. Electroweak Symmetry Breaking without Higgs Bosons at LHC

    CERN Document Server

    Delsart, P A

    2007-01-01

    It is possible that Electroweak Symmetry Breaking does not occur in Nature through the Higgs mechanism. Several alternate scenarios are studied at LHC experiment and this presentation review some of them : Technicolor searches in CMS and and Vector Boson Scattering in the Chiral Lagrangian model or in extra-dimension model in Atlas.

  2. Breaking down barriers between research and action | IDRC ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    2016-06-08

    Jun 8, 2016 ... An IDRC-funded project contributed to breaking down barriers between the practice of participatory action research (PAR) and academic training and thinking in the field. The project also supported Southern leadership of regional and thematic communities of practice dedicated to PAR.

  3. Print to Paint: Breaking Away from Singular Images

    Science.gov (United States)

    Alexander, Kristi

    2010-01-01

    Each fall, the author presents a printmaking unit, starting with simple techniques such as rubbings, stamping and stenciling. In this article, the author describes a linoleum printmaking lesson wherein students are challenged to break away from singular images of peace signs and initials, and create illustrative plates that could communicate a…

  4. Simple mathematical models of symmetry breaking. Application to particle physics

    International Nuclear Information System (INIS)

    Michel, L.

    1976-01-01

    Some mathematical facts relevant to symmetry breaking are presented. A first mathematical model deals with the smooth action of compact Lie groups on real manifolds, a second model considers linear action of any group on real or complex finite dimensional vector spaces. Application of the mathematical models to particle physics is considered. (B.R.H.)

  5. Minimally doubled fermions and spontaneous chiral symmetry breaking

    Science.gov (United States)

    Osmanaj (Zeqirllari), Rudina; Hyka (Xhako), Dafina

    2018-03-01

    Chiral symmetry breaking in massless QCD is a very important feature in the current understanding of low energy physics. Low - lying Dirac modes are suitable to help us understand the spontaneous chiral symmetry breaking, since the formation of a non zero chiral condensate is an effect of their accumulation near zero. The Banks - Casher relation links the spectral density of the Dirac operator to the condensate with an identity that can be read in both directions. In this work we propose a spectral method to achieve a reliable determination of the density of eigenvalues of Dirac operator near zero using the Gauss - Lanczos quadrature. In order to understand better the dynamical chiral symmetry breaking and use the method we propose, we have chosen to work with minimally doubled fermions. These kind of fermions have been proposed as a strictly local discretization of the QCD fermions action, which preserves chiral symmetry at finite cut-off. Being chiral fermions, is easier to work with them and their low - lying Dirac modes and to understand the dynamical spontaneous chiral symmetry breaking.

  6. When Rhodes met Mandela: History breaks down into images, not ...

    African Journals Online (AJOL)

    canberry

    from the residence had decided to break ranks and try out for the university soccer team. It was just a fortnight ... many of us in the residence were reading books on South Africa's political history. Especially, the journal ...... same time, while taxes to the rich have been cut and unemployment reaches catastrophic propor tions ...

  7. Short wave breaking effects on low frequency waves

    NARCIS (Netherlands)

    Daly, C.; Roelvink, J.A.; Van Dongeren, A.; Van Thiel de Vries, J.S.M.; McCall, R.T.

    2010-01-01

    The effect of short wave breaking on low frequency waves is investigated using two breaker formulations implemented in a time-dependent numerical model (XBeach): (1) an advective-deterministic approach (ADA) and (2) the probabilistic breaker formulation of Roelvink (1993). Previous research has

  8. Gauge symmetry breaking in gauge theories -- in search of clarification

    NARCIS (Netherlands)

    Friederich, Simon

    2013-01-01

    The paper investigates the spontaneous breaking of gauge symmetries in gauge theories from a philosophical angle, taking into account the fact that the notion of a spontaneously broken local gauge symmetry, though widely employed in textbook expositions of the Higgs mechanism, is not supported by

  9. Curvature-induced symmetry breaking in nonlinear Schrodinger models

    DEFF Research Database (Denmark)

    Gaididei, Yuri Borisovich; Mingaleev, S. F.; Christiansen, Peter Leth

    2000-01-01

    We consider a curved chain of nonlinear oscillators and show that the interplay of curvature and nonlinearity leads to a symmetry breaking when an asymmetric stationary state becomes energetically more favorable than a symmetric stationary state. We show that the energy of localized states decrea...

  10. Fabiola Gianotti - "Women in science: breaking the cliché"

    CERN Multimedia

    Brice, Maximilien

    2017-01-01

    On 4 May 2017, Fabiola Gianotti joined the panel "Breaking the cliché - Women in science" co-organised by the International Gender Champions, the Mission permanente de la France auprès de l'ONU à Genève and the World Meteorological Organization.

  11. Breaking into the Cellulosic Ethanol Market: Capacity and Storage Strategies

    OpenAIRE

    Darby, Paul M.; Mark, Tyler B.; Salassi, Michael E.

    2010-01-01

    This paper examines the possibilities of breaking into the cellulosic ethanol market in south Louisiana via strategic feedstock choices and the leveraging of the area’s competitive advantages. A small plant strategy is devised whereby the first-mover problem might be solved, and several scenarios are tested using Net Present Value analysis.

  12. Radiative symmetry breaking from interacting UV fixed points

    DEFF Research Database (Denmark)

    Abel, Steven; Sannino, Francesco

    2017-01-01

    It is shown that the addition of positive mass-squared terms to asymptotically safe gauge-Yukawa theories with perturbative UV fixed points leads to calculable radiative symmetry breaking in the IR. This phenomenon, and the multiplicative running of the operators that lies behind it, is akin...

  13. RETINAL BREAKS IN VITRECTOMY FOR RETAINED LENS FRAGMENTS

    NARCIS (Netherlands)

    Tan, H. Stevie; Mura, Marco; Oberstein, Sarit Y. Lesnik; Bijl, Heico M.

    2012-01-01

    Purpose: To describe the incidence and outcome of retinal breaks in vitrectomy for retained lens fragments. Methods: This is a retrospective noncomparative interventional case series. Medical records of consecutive cases of vitrectomy for retained lens fragments over a period of 4 years were

  14. Enantioselective Symmetry Breaking Directed by the Order of Process Steps

    NARCIS (Netherlands)

    Noorduin, Wim L.; Meekes, Hugo; Enckevort, Willem J.P. van; Kaptein, Bernard; Kellogg, Richard M.; Vlieg, Elias

    2010-01-01

    Going forward in reverse: The configuration of the product of grinding-induced symmetry breaking can be controlled simply by the order in which the different reaction-mixture components are combined. The underlying mechanism is based on a subtle balance between enantioselective crystal growth and

  15. Optimal Spatial Harvesting Strategy and Symmetry-Breaking

    International Nuclear Information System (INIS)

    Kurata, Kazuhiro; Shi Junping

    2008-01-01

    A reaction-diffusion model with logistic growth and constant effort harvesting is considered. By minimizing an intrinsic biological energy function, we obtain an optimal spatial harvesting strategy which will benefit the population the most. The symmetry properties of the optimal strategy are also discussed, and related symmetry preserving and symmetry breaking phenomena are shown with several typical examples of habitats

  16. Using Breaking Bad to teach about defense mechanisms.

    Science.gov (United States)

    Johnson, Justin M; Beresin, Eugene V; Stern, Theodore A

    2014-12-01

    Defense mechanisms represent an important component of medical education that should be taught to all medical students, psychiatry residents, and other mental health trainees. Teaching about defense mechanisms can become more engaging by analyzing popular media. Using Breaking Bad, a well-known television show, we recommend specific scenes and episodes that can be used in teaching about defense mechanisms.

  17. Anatomy of new SUSY breaking holographic RG flows

    Energy Technology Data Exchange (ETDEWEB)

    Argurio, Riccardo [Physique Théorique et Mathématique andInternational Solvay Institutes, Université Libre de Bruxelles,C.P. 231, 1050 Brussels (Belgium); Musso, Daniele [International Center of Theoretical Physics (ICTP),Strada Costiera 11, I 34014 Trieste (Italy); Redigolo, Diego [Physique Théorique et Mathématique andInternational Solvay Institutes, Université Libre de Bruxelles,C.P. 231, 1050 Brussels (Belgium); Sorbonne Universités, UPMC University Paris 06, UMR 7589, LPTHE,F-75005, Paris (France); CNRS, UMR 7589, LPTHE,F-75005, Paris (France)

    2015-03-17

    We find and thoroughly study new supergravity domain wall solutions which are holographic realizations of supersymmetry breaking strongly coupled gauge theories. We set ourselves in an N=2 gauged supergravity with a minimal content in order to reproduce a dual N=1 effective SCFT which has a U(1){sub R} symmetry, a chiral operator whose components are responsible for triggering the RG flow, and an additional U(1){sub F} symmetry. We present a full three dimensional parameter space of solutions, which generically break supersymmetry. Some known solutions are recovered for specific sets of values of the parameters, with the new solutions interpolating between them. The generic backgrounds being singular, we provide a stability test of their dual theories by showing that there are no tachyonic resonances in the two point correlators. We compute the latter by holographic renormalization. We also carefully analyze the appearance of massless modes, such as the dilaton and the R axion, when the respective symmetries are spontaneously broken, and their lifting when the breaking is explicit. We further comment on the application of such class of backgrounds as archetypes of strongly coupled hidden sectors for gauge mediation of supersymmetry breaking. In particular, we show that it is possible to model in this way all types of hierarchies between the visible sector gaugino and sfermion masses.

  18. 24 CFR 904.108 - Break-even amount.

    Science.gov (United States)

    2010-04-01

    ...) OFFICE OF ASSISTANT SECRETARY FOR PUBLIC AND INDIAN HOUSING, DEPARTMENT OF HOUSING AND URBAN DEVELOPMENT... in the same manner as other Project income. (c) Deficit in monthly payment. When the homebuyer's required monthly payment is less than the applicable break-even amount, the deficit shall be applied as a...

  19. ′BREAKS′ protocol for breaking bad news

    Directory of Open Access Journals (Sweden)

    Vijayakumar Narayanan

    2010-01-01

    Full Text Available Information that drastically alters the life world of the patient is termed as bad news. Conveying bad news is a skilled communication, and not at all easy. The amount of truth to be disclosed is subjective. A properly structured and well-orchestrated communication has a positive therapeutic effect. This is a process of negotiation between patient and physician, but physicians often find it difficult due to many reasons. They feel incompetent and are afraid of unleashing a negative reaction from the patient or their relatives. The physician is reminded of his or her own vulnerability to terminal illness, and find themselves powerless over emotional distress. Lack of sufficient training in breaking bad news is a handicap to most physicians and health care workers. Adherence to the principles of client-centered counseling is helpful in attaining this skill. Fundamental insight of the patient is exploited and the bad news is delivered in a structured manner, because the patient is the one who knows what is hurting him most and he is the one who knows how to move forward. Six-step SPIKES protocol is widely used for breaking bad news. In this paper, we put forward another six-step protocol, the BREAKS protocol as a systematic and easy communication strategy for breaking bad news. Development of competence in dealing with difficult situations has positive therapeutic outcome and is a professionally satisfying one.

  20. Model for dynamical chiral symmetry breaking and quark condensate

    International Nuclear Information System (INIS)

    Nekrasov, M.L.; Rochev, V.E.

    1986-01-01

    In the framework of the model, proposed earlier to describe nonperturbative QCD, the singularity of the type 1/k 4 in the gluon propagator is shown to result in dynamical chiral symmetry breaking and appearance of quark condensate. The value, obtained for quark condensate, is close to the phenomenological one

  1. Spontaneous symmetry breaking in spinor Bose-Einstein condensates

    DEFF Research Database (Denmark)

    Scherer, Manuel; Lücke, Bernd; Peise, Jan

    2013-01-01

    We present an analytical model for the theoretical analysis of spin dynamics and spontaneous symmetry breaking in a spinor Bose-Einstein condensate (BEC). This allows for an excellent intuitive understanding of the processes and provides good quantitative agreement with the experimental results...

  2. Time-reversal symmetry breaking by ac field: Effect of ...

    Indian Academy of Sciences (India)

    possesses an interesting dualism: the periodic ac fields that are least effective in suppress- ing conductance fluctuations by dephasing, turn out to be the most effective in breaking the time-reversal symmetry. An important exception is the periodic ac field that is anti- symmetric with respect to a shift by a half-period τ/2.

  3. Strong electroweak symmetry breaking signals in WW scattering at TESLA

    CERN Document Server

    Chierici, R; Kobel, M

    2000-01-01

    A realistic study of the sensitivity to signals of strong electroweak symmetry breaking at TESLA energies using ee to WW nu nu and ee to ZZ nu nu processes is presented. Limits on alpha /sub 4/ and alpha /sub 5/, parameters of the electroweak chiral lagrangian, are given and discussed. (8 refs).

  4. Chiral symmetry breaking and the pion quark structure

    International Nuclear Information System (INIS)

    Bernard, V.

    1986-01-01

    The mechanism of dynamical breaking of chiral symmetry in hadronic matter is first studied in the framework of the Nambu and Jona-Lasinio model on one hand and its generalisation to finite hadron size on the other hand. The analysis uses a variational procedure modelled after the BCS superconductor. Our study indicates for example, a great sensitivity of various quantities characterizing the breaking of symmetry to the shape of the interaction. Also the mechanism of breaking of chiral symmetry is essentially related to the mechanism of confinement. When a symmetry is spontaneously broken, there exists a Goldstone particle of zero mass. This is true in our model. This particle, the pion, is obtained as solution of a Bethe Salpeter equation for a qantiq bound state. This enables us to establish a connection between the pion as a Goldstone boson related to spontaneous symmetry breaking and the quark-antiquark structure of the pion. The finite mass of the physical pion is obtained with non zero current quark mass. Various properties of this particle are then studied in the RPA formalism. One important point of our model is the highly collective character of the pion. 85 refs [fr

  5. Wave Impacts on Caisson Breakwaters Situated in Multidirectionally Breaking Seas

    DEFF Research Database (Denmark)

    Grønbech, J.; Burcharth, Hans F.; Frigaard, Peter

    1999-01-01

    Attention has been addressed to the effects of wave obliquity and multidirectionality on the wave loads on vertical caisson breakwaters situated in non breaking seas. Within the joint European (MAST-LIP-TAW) research project, a 3D model investigation was carried out at Delft Hydraulics to assess...

  6. Sgoldstino-less inflation and low energy SUSY breaking

    Energy Technology Data Exchange (ETDEWEB)

    Argurio, Riccardo [Physique Théorique et Mathématique and International Solvay Institutes, Université Libre de Bruxelles, CP231, B-1050 Brussels (Belgium); Coone, Dries; Mariotti, Alberto [Theoretische Natuurkunde and IIHE/ELEM, Vrije Universiteit Brussel, and International Solvay Institutes, Pleinlaan 2, B-1050 Brussels (Belgium); Heurtier, Lucien, E-mail: rargurio@ulb.ac.be, E-mail: a.a.coone@rug.nl, E-mail: lucien.heurtier@ulb.ac.be, E-mail: alberto.mariotti@vub.ac.be [Service de Physique Théorique, Université Libre de Bruxelles, CP225, B-1050 Brussels (Belgium)

    2017-07-01

    We assess the range of validity of sgoldstino-less inflation in a scenario of low energy supersymmetry breaking. We first analyze the consistency conditions that an effective theory of the inflaton and goldstino superfields should satisfy in order to be faithfully described by a sgoldstino-less model. Enlarging the scope of previous studies, we investigate the case where the effective field theory cut-off, and hence also the sgoldstino mass, are inflaton-dependent. We then introduce a UV complete model where one can realize successfully sgoldstino-less inflation and gauge mediation of supersymmetry breaking, combining the α-attractor mechanism and a weakly coupled model of spontaneous breaking of supersymmetry. In this class of models we find that, given current limits on superpartner masses, the gravitino mass has a lower bound of the order of the MeV, i.e. we cannot reach very low supersymmetry breaking scales. On the plus side, we recognize that in this framework, one can derive the complete superpartner spectrum as well as compute inflation observables, the reheating temperature, and address the gravitino overabundance problem. We then show that further constraints come from collider results and inflation observables. Their non trivial interplay seems a staple feature of phenomenological studies of supersymmetric inflationary models.

  7. A Benders approach for the constrained minimum break problem

    DEFF Research Database (Denmark)

    Rasmussen, Rasmus Vinther; Trick, Michael

    2007-01-01

    This paper presents a hybrid IP/CP algorithm for designing a double round robin schedule with a minimal number of breaks. Both mirrored and non-mirrored schedules with and without place constraints are considered. The algorithm uses Benders cuts to obtain feasible home-away pattern sets in few...

  8. "Child Divorce": A Break from Parental Responsibilities and Rights ...

    African Journals Online (AJOL)

    In a recent ground-breaking case the South African courts were for the first time requested to use their discretion to interfere in the parent-child relationship due to the traditional socio-cultural beliefs of the parents. In what has been described as "every parent's nightmare; the fancy of many teenagers", a 16 year-old ...

  9. Chromatin remodelers in the DNA double strand break response

    NARCIS (Netherlands)

    Smeenk, Godelieve

    2012-01-01

    During my PhD project, I studied the role of several chromatin remodelers in the DNA double strand break (DSB) response. We discovered that both CHD4 and SMARCA5 are required for ubiquitin signaling through the E3 ubiquitin ligases RNF8 and RNF168, which is a central signaling event in the response

  10. Breaking the Silence Surrounding Mental Health on Campus

    Science.gov (United States)

    Roper, Larry D.

    2013-01-01

    Mentally ill students are able to participate in higher education at unprecedented rates. While colleges and universities have been responsive to the therapeutic needs, we have failed to successfully create supportive campus climates. Campus leaders are challenged to demonstrate ethical leadership that breaks the silence and confronts the stigma…

  11. Time-reversal symmetry breaking by ac field: Effect of ...

    Indian Academy of Sciences (India)

    Time-reversal symmetry breaking by ac field: Effect of commensurability in the frequency domain. V E KRAVTSOV. Present address: The Abdus Salam International Centre for Theoretical Physics, P.O. Box 586, 34100. Trieste, Italy. Landau Institute for Theoretical Physics, 2 Kosygina Street, 117940 Moscow, Russia.

  12. TESTING FOR A BREAK IN OUTPUT - NEW INTERNATIONAL EVIDENCE

    NARCIS (Netherlands)

    ZELHORST, D; DEHAAN, J

    In this note we present the outcomes of two unit root tests, which allow for the existence of a break in real GDP for 12 industrial countries, using data for the period 1870-1989. We conclude that in the majority of the countries real per capita GDP has no unit root and that both tests yield very

  13. Using break quantities for tactical optimisation in multistage distribution systems

    NARCIS (Netherlands)

    M.J. Kleijn (Marcel); R. Dekker (Rommert)

    1997-01-01

    textabstractIn this chapter we discuss a tactical optimisation problem that arises in a multistage distribution system where customer orders can be delivered from any stockpoint. A simple rule to allocate orders to locations is a break quantity rule, which routes large orders to higher-stage

  14. Positive role of peptidoglycan breaks in lactococcal biofilm formation

    NARCIS (Netherlands)

    Mercier, C; Durrieu, C; Briandet, R; Domakova, E; Tremblay, J; Buist, G; Kulakauskas, S

    2002-01-01

    Bacterial attachment to solid matrices depends on adhesive molecules present on the cell surface. Here we establish a positive correlation between peptidoglycan (PG) breaks, rather than particular molecules, and biofilm-forming capacity in the Gram-positive bacterium Lactococcus lactis. The L.

  15. Charge symmetry breaking in the A=4 hypernuclei

    Czech Academy of Sciences Publication Activity Database

    Gazda, Daniel; Gal, A.

    2016-01-01

    Roč. 954, OCT (2016), s. 161-175 ISSN 0375-9474 R&D Projects: GA ČR(CZ) GA15-04301S Institutional support: RVO:61389005 Keywords : hypernuclei * hyperon-nucleon interactions * charge symmetry breaking Subject RIV: BE - Theoretical Physics Impact factor: 1.916, year: 2016

  16. Secondary School Students with Disabilities at Break Time

    Directory of Open Access Journals (Sweden)

    Josué ARTILES RODRÍGUEZ

    2017-01-01

    Full Text Available Break time fulfills an important role in the social development of students, providing free time for interaction where they are able to practice their abilities of making contact with others. Students with disabilities do not see themselves in the same light because they consider this activity an unstructured one to get on with. Break planning and mediation carried out by other pupils eases relationships between both groups and offers a natural learning environment among students, according to inclusive education principles. This research has been carried out by investigating multiple cases in three special education classrooms which belong to secondary schools, with a total of 19 students with disabilities. Over the course of three months of observation, 3,420 interaction instances were obtained which were linked with the students’ interviews. The results show a lower number of relationships between students belonging to classrooms with no planned breaks in their schedule and those classrooms which did plan their breaks and peer mediation. The practical implications are discussed.

  17. Dam break flood wave under different reservoir's capacities and ...

    Indian Academy of Sciences (India)

    Farhad Hooshyaripor

    2017-07-14

    Jul 14, 2017 ... the ultimate flash flood risk management plan. In order to improve the inputs and advance our ... dam break flood risk management will be shown by a robust flume test. In the next section the methodology ..... The quality of ADV data in the velocity time series was monitored by two criteria: signal strength of ...

  18. Comparison of two culture media for breaking seed dormancy and ...

    African Journals Online (AJOL)

    vahid04

    2012-03-08

    Mar 8, 2012 ... The aim of this study was to compare the effects of different treatments in breaking dormancy and to increase germination percentage and days to germination in two media of water with agar and. Murashige and Skoog (MS) growth medium in four species of Linum L. namely, L. mucronatum, L. nervosum, L.

  19. Time-reversal symmetry breaking in quantum billiards

    International Nuclear Information System (INIS)

    Schaefer, Florian

    2009-01-01

    The present doctoral thesis describes experimentally measured properties of the resonance spectra of flat microwave billiards with partially broken timereversal invariance induced by an embedded magnetized ferrite. A vector network analyzer determines the complex scattering matrix elements. The data is interpreted in terms of the scattering formalism developed in nuclear physics. At low excitation frequencies the scattering matrix displays isolated resonances. At these the effect of the ferrite on isolated resonances (singlets) and pairs of nearly degenerate resonances (doublets) is investigated. The hallmark of time-reversal symmetry breaking is the violation of reciprocity, i.e. of the symmetry of the scattering matrix. One finds that reciprocity holds in singlets; it is violated in doublets. This is modeled by an effective Hamiltonian of the resonator. A comparison of the model to the data yields time-reversal symmetry breaking matrix elements in the order of the level spacing. Their dependence on the magnetization of the ferrite is understood in terms of its magnetic properties. At higher excitation frequencies the resonances overlap and the scattering matrix elements fluctuate irregularly (Ericson fluctuations). They are analyzed in terms of correlation functions. The data are compared to three models based on random matrix theory. The model by Verbaarschot, Weidenmueller and Zirnbauer describes time-reversal invariant scattering processes. The one by Fyodorov, Savin and Sommers achieves the same for systems with complete time-reversal symmetry breaking. An extended model has been developed that accounts for partial breaking of time-reversal invariance. This extended model is in general agreement with the data, while the applicability of the other two models is limited. The cross-correlation function between forward and backward reactions determines the time-reversal symmetry breaking matrix elements of the Hamiltonian to up to 0.3 mean level spacings. Finally

  20. Time-reversal symmetry breaking in quantum billiards

    Energy Technology Data Exchange (ETDEWEB)

    Schaefer, Florian

    2009-01-26

    The present doctoral thesis describes experimentally measured properties of the resonance spectra of flat microwave billiards with partially broken timereversal invariance induced by an embedded magnetized ferrite. A vector network analyzer determines the complex scattering matrix elements. The data is interpreted in terms of the scattering formalism developed in nuclear physics. At low excitation frequencies the scattering matrix displays isolated resonances. At these the effect of the ferrite on isolated resonances (singlets) and pairs of nearly degenerate resonances (doublets) is investigated. The hallmark of time-reversal symmetry breaking is the violation of reciprocity, i.e. of the symmetry of the scattering matrix. One finds that reciprocity holds in singlets; it is violated in doublets. This is modeled by an effective Hamiltonian of the resonator. A comparison of the model to the data yields time-reversal symmetry breaking matrix elements in the order of the level spacing. Their dependence on the magnetization of the ferrite is understood in terms of its magnetic properties. At higher excitation frequencies the resonances overlap and the scattering matrix elements fluctuate irregularly (Ericson fluctuations). They are analyzed in terms of correlation functions. The data are compared to three models based on random matrix theory. The model by Verbaarschot, Weidenmueller and Zirnbauer describes time-reversal invariant scattering processes. The one by Fyodorov, Savin and Sommers achieves the same for systems with complete time-reversal symmetry breaking. An extended model has been developed that accounts for partial breaking of time-reversal invariance. This extended model is in general agreement with the data, while the applicability of the other two models is limited. The cross-correlation function between forward and backward reactions determines the time-reversal symmetry breaking matrix elements of the Hamiltonian to up to 0.3 mean level spacings. Finally