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Sample records for breaking resolution limits

  1. Breaking Abbe's diffraction resolution limit in fluorescence microscopy with stimulated emission depletion beams of various shapes.

    Science.gov (United States)

    Klar, T A; Engel, E; Hell, S W

    2001-12-01

    We report on the generation of various hole-centered beams in the focal region of a lens and investigate their effectiveness to break the diffraction barrier in fluorescence microscopy by stimulated emission. Patterning of the phase of the stimulating beam across the entrance pupil of the objective lens produces point-spread-functions with twofold, fourfold, and circular symmetry, which narrow down the focal spot to 65-100 nm. Comparison with high-resolution confocal images exhibits a resolution much beyond the diffraction barrier. Particles that are only 65-nm apart are resolved with focused light.

  2. Modular structure of brain functional networks: breaking the resolution limit by Surprise.

    Science.gov (United States)

    Nicolini, Carlo; Bifone, Angelo

    2016-01-14

    The modular organization of brain networks has been widely investigated using graph theoretical approaches. Recently, it has been demonstrated that graph partitioning methods based on the maximization of global fitness functions, like Newman's Modularity, suffer from a resolution limit, as they fail to detect modules that are smaller than a scale determined by the size of the entire network. Here we explore the effects of this limitation on the study of brain connectivity networks. We demonstrate that the resolution limit prevents detection of important details of the brain modular structure, thus hampering the ability to appreciate differences between networks and to assess the topological roles of nodes. We show that Surprise, a recently proposed fitness function based on probability theory, does not suffer from these limitations. Surprise maximization in brain co-activation and functional connectivity resting state networks reveals the presence of a rich structure of heterogeneously distributed modules, and differences in networks' partitions that are undetectable by resolution-limited methods. Moreover, Surprise leads to a more accurate identification of the network's connector hubs, the elements that integrate the brain modules into a cohesive structure.

  3. Origins Space Telescope: Breaking the Confusion Limit

    Science.gov (United States)

    Wright, Edward L.; Origins Space Telescope Science and Technology Definition Team

    2018-01-01

    The Origins Space Telescope (OST) is the mission concept for the Far-Infrared Surveyor, one of the four science and technology definition studies of NASA Headquarters for the 2020 Astronomy and Astrophysics Decadal survey. Origins will enable flagship-quality general observing programs led by the astronomical community in the 2030s.OST will have a background-limited sensitivity for a background 27,000 times lower than the Herschel background caused by thermal emission from Herschel's warm telescope. For continuum observations the confusion limit in a diffraction-limited survey can be reached in very short integration times at longer far-infrared wavelengths. But the confusion limit can be pierced for both the nearest and the farthest objects to be observed by OST. For outer the Solar System the targets' motion across the sky will provide a clear signature in surveys repeated after an interval of days to months. This will provide a size-frequency distribution of TNOs that is not biased toward high albedo objects.For the distant Universe the first galaxies and the first metals will provide a third dimension of spectral information that can be measured with a long-slit, medium resolution spectrograph. This will allow 3Dmapping to measure source densities as a function of redshift. The continuum shape associated with sourcesat different redshifts can be derived from correlation analyses of these 3D maps.Fairly large sky areas can be scanned by moving the spacecraft at a constant angular rate perpendicular to the orientation of the long slit of the spectrograph, avoiding the high overhead of step-and-stare surveying with a large space observatory.We welcome you to contact the Science and Technology Definition Team (STDT) with your science needs and ideas by emailing us at ost_info@lists.ipac.caltech.edu

  4. Limits to Drift Chamber Resolution

    CERN Document Server

    Riegler, Werner

    1998-01-01

    ATLAS (A Large Toroidal LHC Apparatus) will be a general-purpose experiment at the Large Hadron Collider that will be operational at CERN in the year 2004. The ATLAS muon spectrometer aims for a momentum resolution of 10% for a transverse momentum of pT=1TeV. The precision tracking devices in the muon system will be high pressure drift tubes (MDTs) with a single wire resolution of 1100 chambers covering an area of ≈ 2500m2. The high counting rates in the spectrometer as well as the aim for excellent spatial resolution and high efficiency put severe constraints on the MDT operating parameters. This work describes a detailed study of all the resolution limiting factors in the ATLAS environment. A ’full chain’ simulation of the MDT response to photons and charged particles as well as quantitative comparisons with measurements was performed. The good agreement between simulation and measurements resulted in a profound understanding of the drift chamber processes and the individual contributions to the spat...

  5. Resolution, LER, and sensitivity limitations of photoresists

    Science.gov (United States)

    Gallatin, Gregg M.; Naulleau, Patrick; Niakoula, Dimitra; Brainard, Robert; Hassanein, Elsayed; Matyi, Richard; Thackeray, Jim; Spear, Kathleen; Dean, Kim

    2008-03-01

    Recent experimental results and modeling both indicate that whereas it is possible to optimize a photoresist and process to achieve separately a desired resolution or line edge roughness or sensitivity, it will be difficult if not impossible to achieve all three simultaneously using current standard chemically amplified photoresists and processes. This tradeoff among Resolution, Line Edge Roughness (LER) and Sensitivity is termed the RLS tradeoff. Here we review the progress to date of a SEMATECH-funded program to develop an experimentally verified model of the relationship among resolution, LER and sensitivity and use it to determine approaches for "breaking" the RLS tradeoff.

  6. Resolution limits in imaging ladar systems

    Science.gov (United States)

    Khoury, Jed; Woods, Charles L.; Lorenzo, Joseph; Kierstead, John; Pyburn, Dana; Sengupta, Sandip K.

    2006-02-01

    We introduce a new design concept of laser radar systems that combines both phase comparison and time-of-flight methods. We show from signal-to-noise ratio considerations that there is a fundamental limit to the overall resolution in three-dimensional imaging range laser radar (ladar). We introduce a new metric, volume of resolution, and we show from quantum noise considerations that there is a maximum resolution volume that can be achieved for a given set of system parameters. Consequently, there is a direct trade-off between range resolution and spatial resolution. Thus, in a ladar system, range resolution may be maximized at the expense of spatial image resolution and vice versa. We introduce resolution efficiency etar as a new figure of merit for ladar that describes system resolution under the constraints of a specific design, compared with its optimal resolution performance derived from quantum noise considerations. We analyze how the resolution efficiency could be utilized to improve the resolution performance of a ladar system. Our analysis could be extended to all ladars, regardless of whether they are imaging or scanning laser systems.

  7. Spatial resolution limits of an optical profiler

    Science.gov (United States)

    Creath, Katherine

    1990-07-01

    Interferometric optical profilers have a spatial resolution which is either limited by the detector array sample spacing and element size or by the optical resolution of the system. To test the working spatial resolution of an optical profiler a sinsusoidal grating with 300 lines/mm was measured using an optical profiler at lOx 2Ox 40x and 200x with detector arrays having element-to-element spacings of 6. 8 j. tm and 40 tm. The highest magnification gave the greatest and most accurate depth for the grating for all of the detectors. At 40x as long as there were more than about 8 sample points per cycle as there were with the two smaller detector spacings the grating depth can be measured quite accurately. With fewer points the peak-to-valley height measurement of the grating is too low even though the optical resolution of the system is sufficient enough to resolve the grating. The results of this work show that for accurate representation of surface heights containing high frequency structures oversampling is desirable. Summary The spatial resolution of an interferometric optical proffler depends upon both the optical resolution of the system and the characteristics of the detector array used to sample the image. The limiting resolution wifi be the larger of the optical and detector resolution. One means of defining optical resolution is the Sparrow criterion which states that the image of two points is just

  8. Breaking Cryo-EM Resolution Barriers to Facilitate Drug Discovery.

    Science.gov (United States)

    Merk, Alan; Bartesaghi, Alberto; Banerjee, Soojay; Falconieri, Veronica; Rao, Prashant; Davis, Mindy I; Pragani, Rajan; Boxer, Matthew B; Earl, Lesley A; Milne, Jacqueline L S; Subramaniam, Sriram

    2016-06-16

    Recent advances in single-particle cryoelecton microscopy (cryo-EM) are enabling generation of numerous near-atomic resolution structures for well-ordered protein complexes with sizes ≥ ∼200 kDa. Whether cryo-EM methods are equally useful for high-resolution structural analysis of smaller, dynamic protein complexes such as those involved in cellular metabolism remains an important question. Here, we present 3.8 Å resolution cryo-EM structures of the cancer target isocitrate dehydrogenase (93 kDa) and identify the nature of conformational changes induced by binding of the allosteric small-molecule inhibitor ML309. We also report 2.8-Å- and 1.8-Å-resolution structures of lactate dehydrogenase (145 kDa) and glutamate dehydrogenase (334 kDa), respectively. With these results, two perceived barriers in single-particle cryo-EM are overcome: (1) crossing 2 Å resolution and (2) obtaining structures of proteins with sizes EM can be used to investigate a broad spectrum of drug-target interactions and dynamic conformational states. Published by Elsevier Inc.

  9. Resolution limits for wave equation imaging

    KAUST Repository

    Huang, Yunsong

    2014-08-01

    Formulas are derived for the resolution limits of migration-data kernels associated with diving waves, primary reflections, diffractions, and multiple reflections. They are applicable to images formed by reverse time migration (RTM), least squares migration (LSM), and full waveform inversion (FWI), and suggest a multiscale approach to iterative FWI based on multiscale physics. That is, at the early stages of the inversion, events that only generate low-wavenumber resolution should be emphasized relative to the high-wavenumber resolution events. As the iterations proceed, the higher-resolution events should be emphasized. The formulas also suggest that inverting multiples can provide some low- and intermediate-wavenumber components of the velocity model not available in the primaries. Finally, diffractions can provide twice or better the resolution than specular reflections for comparable depths of the reflector and diffractor. The width of the diffraction-transmission wavepath is approximately λ at the diffractor location for the diffraction-transmission wavepath. © 2014 Elsevier B.V.

  10. Breaking the concentration limit of optical single-molecule detection.

    Science.gov (United States)

    Holzmeister, Phil; Acuna, Guillermo P; Grohmann, Dina; Tinnefeld, Philip

    2014-02-21

    Over the last decade, single-molecule detection has been successfully utilized in the life sciences and materials science. Yet, single-molecule measurements only yield meaningful results when working in a suitable, narrow concentration range. On the one hand, diffraction limits the minimal size of the observation volume in optical single-molecule measurements and consequently a sample must be adequately diluted so that only one molecule resides within the observation volume. On the other hand, at ultra-low concentrations relevant for sensing, the detection volume has to be increased in order to detect molecules in a reasonable timespan. This in turn results in the loss of an optimal signal-to-noise ratio necessary for single-molecule detection. This review discusses the requirements for effective single-molecule fluorescence applications, reflects on the motivation for the extension of the dynamic concentration range of single-molecule measurements and reviews various approaches that have been introduced recently to solve these issues. For the high-concentration limit, we identify four promising strategies including molecular confinement, optical observation volume reduction, temporal separation of signals and well-conceived experimental designs that specifically circumvent the high concentration limit. The low concentration limit is addressed by increasing the measurement speed, parallelization, signal amplification and preconcentration. The further development of these ideas will expand our possibilities to interrogate research questions with the clarity and precision provided only by the single-molecule approach.

  11. Breaking the black-body limit with resonant surfaces

    Directory of Open Access Journals (Sweden)

    Valagiannopoulos Constantinos A.

    2017-01-01

    Full Text Available The speed with which electromagnetic energy can be wirelessly transferred from a source to the user is a crucial indicator for the performance of a large number of electronic and photonic devices. We expect that energy transfer can be enhanced using special materials. In this paper, we determine the constituent parameters of a medium which can support theoretically infinite energy concentration close to its boundary; such a material combines properties of Perfectly Matched Layers (PML and Double-Negative (DNG media. It realizes conjugate matching with free space for every possible mode including, most importantly, all evanescent modes; we call this medium Conjugate Matched Layer (CML. Sources located outside such layer deliver power to the conjugate-matched body exceptionally effectively, impressively overcoming the black-body absorption limit which takes into account only propagating waves. We also expand this near-field concept related to the infinitely fast absorption of energy along the air-medium interface to enhance the far-field radiation. This becomes possible with the use of small particles randomly placed along the boundary; the induced currents due to the extremely high-amplitude resonating fields can play the role of emission “vessels”, by sending part of the theoretically unlimited near-field energy far away from the CML structure.

  12. Resolution, coverage, and geometry beyond traditional limits

    Energy Technology Data Exchange (ETDEWEB)

    Ronen, Shuki; Ferber, Ralf

    1998-12-31

    The presentation relates to the optimization of the image of seismic data and improved resolution and coverage of acquired data. Non traditional processing methods such as inversion to zero offset (IZO) are used. To realize the potential of saving acquisition cost by reducing in-fill and to plan resolution improvement by processing, geometry QC methods such as DMO Dip Coverage Spectrum (DDCS) and Bull`s Eyes Analysis are used. The DDCS is a 2-D spectrum whose entries consist of the DMO (Dip Move Out) coverage for a particular reflector specified by it`s true time dip and reflector normal strike. The Bull`s Eyes Analysis relies on real time processing of synthetic data generated with the real geometry. 4 refs., 6 figs.

  13. Limiting liability via high resolution image processing

    Energy Technology Data Exchange (ETDEWEB)

    Greenwade, L.E.; Overlin, T.K.

    1996-12-31

    The utilization of high resolution image processing allows forensic analysts and visualization scientists to assist detectives by enhancing field photographs, and by providing the tools and training to increase the quality and usability of field photos. Through the use of digitized photographs and computerized enhancement software, field evidence can be obtained and processed as `evidence ready`, even in poor lighting and shadowed conditions or darkened rooms. These images, which are most often unusable when taken with standard camera equipment, can be shot in the worst of photographic condition and be processed as usable evidence. Visualization scientists have taken the use of digital photographic image processing and moved the process of crime scene photos into the technology age. The use of high resolution technology will assist law enforcement in making better use of crime scene photography and positive identification of prints. Valuable court room and investigation time can be saved and better served by this accurate, performance based process. Inconclusive evidence does not lead to convictions. Enhancement of the photographic capability helps solve one major problem with crime scene photos, that if taken with standard equipment and without the benefit of enhancement software would be inconclusive, thus allowing guilty parties to be set free due to lack of evidence.

  14. Statistical Angular Resolution Limit for Ultrawideband MIMO Noise Radar

    Directory of Open Access Journals (Sweden)

    Xiaoli Zhou

    2015-01-01

    Full Text Available The two-dimensional angular resolution limit (ARL of elevation and azimuth for MIMO radar with ultrawideband (UWB noise waveforms is investigated using statistical resolution theory. First, the signal model of monostatic UWB MIMO noise radar is established in a 3D reference frame. Then, the statistical angular resolution limits (SARLs of two closely spaced targets are derived using the detection-theoretic and estimation-theoretic approaches, respectively. The detection-theoretic approach is based on the generalized likelihood ratio test (GLRT with given probabilities of false alarm and detection, while the estimation-theoretic approach is based on Smith’s criterion which involves the Cramér-Rao lower bound (CRLB. Furthermore, the relationship between the two approaches is presented, and the factors affecting the SARL, that is, detection parameters, transmit waveforms, array geometry, signal-to-noise ratio (SNR, and parameters of target (i.e., radar cross section (RCS and direction, are analyzed. Compared with the conventional radar resolution theory defined by the ambiguity function, the SARL reflects the practical resolution ability of radar and can provide an optimization criterion for radar system design.

  15. A practical definition of eye-limited display system resolution

    Science.gov (United States)

    Lloyd, Charles J.; Winterbottom, M.; Gaska, J.; Williams, L.

    2015-05-01

    Over the past few decades the term "eye-limited resolution" has seen significant use. However, several variations in the definition of the term have been employed and estimates of the display pixel pitch required to achieve it differ significantly. This paper summarizes the results of published evaluations and experiments conducted in our laboratories relating to resolution requirements. The results of several evaluations employing displays with sufficient antialiasing indicate a pixel pitch of 0.5 to 0.93 arcmin will produce 90% of peak performance for observers with 20/20 or better acuity for a variety of visual tasks. If insufficient antialiasing is employed, spurious results can indicate that a finer pixel pitch is required due to the presence of sampling artifacts. The paper reconciles these findings with hyperacuity task performance which a number of authors have suggested may require a much finer pixel pitch. The empirical data provided in this paper show that hyperacuity task performance does not appear to be a driver of eye-limited resolution. Asymptotic visual performance is recommended as the basis of eye-limited resolution because it provides the most stable estimates and is well aligned with the needs of the display design and acquisition communities.

  16. Noise and physical limits to maximum resolution of PET images

    Energy Technology Data Exchange (ETDEWEB)

    Herraiz, J.L.; Espana, S. [Dpto. Fisica Atomica, Molecular y Nuclear, Facultad de Ciencias Fisicas, Universidad Complutense de Madrid, Avda. Complutense s/n, E-28040 Madrid (Spain); Vicente, E.; Vaquero, J.J.; Desco, M. [Unidad de Medicina y Cirugia Experimental, Hospital GU ' Gregorio Maranon' , E-28007 Madrid (Spain); Udias, J.M. [Dpto. Fisica Atomica, Molecular y Nuclear, Facultad de Ciencias Fisicas, Universidad Complutense de Madrid, Avda. Complutense s/n, E-28040 Madrid (Spain)], E-mail: jose@nuc2.fis.ucm.es

    2007-10-01

    In this work we show that there is a limit for the maximum resolution achievable with a high resolution PET scanner, as well as for the best signal-to-noise ratio, which are ultimately related to the physical effects involved in the emission and detection of the radiation and thus they cannot be overcome with any particular reconstruction method. These effects prevent the spatial high frequency components of the imaged structures to be recorded by the scanner. Therefore, the information encoded in these high frequencies cannot be recovered by any reconstruction technique. Within this framework, we have determined the maximum resolution achievable for a given acquisition as a function of data statistics and scanner parameters, like the size of the crystals or the inter-crystal scatter. In particular, the noise level in the data as a limitation factor to yield high-resolution images in tomographs with small crystal sizes is outlined. These results have implications regarding how to decide the optimal number of voxels of the reconstructed image or how to design better PET scanners.

  17. Teenagers' and parents' views on a short-break service for children with life-limiting conditions: a qualitative study.

    Science.gov (United States)

    Swallow, Veronica; Forrester, Tracey; Macfadyen, Ann

    2012-04-01

    Few opportunities exist outside the home for children and teenagers with life-limiting conditions to have a break in a setting specifically designed and adequately staffed and resourced to meet their complex clinical, practical and emotional needs; until recently provision focused primarily on providing respite for parents/carers. Based on policy recommendations, a short-break service was established with the aim of working in partnership with families and voluntary and statutory agencies to provide a fun break for children and teenagers with life-limiting conditions and complement the range of services available. This qualitative study used interviews and focus groups to determine teenagers' and parents' views of the service. Three themes emerged: accessibility and communication; needs and boundaries; and shaping the service. Teenagers enjoyed regular planned residential breaks, access to skilled staff and bespoke facilities to support their needs, opportunities to meet others with life-limiting conditions and fun time away from home, thereby giving parents peace of mind, a regular planned break from care-giving, opportunities to meet other parents and to spend exclusive time with their other children. If specialist short-break services become part of the national range of services available, children and teenagers with life-limiting conditions and their parents and siblings could all benefit.

  18. Population Bottlenecks Increase Additive Genetic Variance But Do Not Break a Selection Limit in Rainforest Drosophila

    DEFF Research Database (Denmark)

    van Heerwaarden, Belinda; Willi, Yvonne; Kristensen, Torsten N

    2008-01-01

    According to neutral quantitative genetic theory, population bottlenecks are expected to decrease standing levels of additive genetic variance of quantitative traits. However, some empirical and theoretical results suggest that, if nonadditive genetic effects influence the trait, bottlenecks may...... effects were responsible for the divergence in desiccation resistance between the original control and a bottlenecked line exhibiting increased additive genetic variance for desiccation resistance. However, when bottlenecked lines were selected for increased desiccation resistance, there was only a small...... actually increase additive genetic variance. This has been an important issue in conservation genetics where it has been suggested that small population size might actually experience an increase rather than a decrease in the rate of adaptation. Here we test if bottlenecks can break a selection limit...

  19. Adaptive resolution simulation of supramolecular water : The concurrent making, breaking, and remaking of water bundles

    NARCIS (Netherlands)

    Zavadlav, Julija; Marrink, Siewert J; Praprotnik, Matej

    2016-01-01

    The adaptive resolution scheme (AdResS) is a multiscale molecular dynamics simulation approach that can concurrently couple atomistic (AT) and coarse-grained (CG) resolution regions, i.e., the molecules can freely adapt their resolution according to their current position in the system. Coupling to

  20. Thermodynamic limitations on the resolution obtainable with metal replicas.

    Science.gov (United States)

    Woodward, J T; Zasadzinski, J A

    1996-12-01

    The major factor limiting resolution of metal-shadowed surfaces for electron and scanning tunnelling microscopy is the granularity of the metal film. This granularity had been believed to result from a recrystallization of the evaporated film, and hence could be limited by use of higher melting point materials for replication, or inhibited by adding carbon or other impurities to the film. However, evaporated and sputtered films of amorphous metal alloys that do not crystallize also show a granularity that decreases with increasing alloy melting point. A simple thermodynamic analysis shows that the granularity results from a dewetting of the typically low surface energy sample by the high surface energy metal film, similar to the beading up of drops of spilled mercury. The metal granularity and the resulting resolution of the metal-coated surface is proportional to the mobility of the metal on the surface after evaporation, which is related to the difference in temperature between the melting point of the metal and the sample surface temperature.

  1. Harnessing singlet exciton fission to break the Shockley-Queisser limit

    Science.gov (United States)

    Rao, Akshay; Friend, Richard H.

    2017-11-01

    Singlet exciton fission is a carrier multiplication process in organic semiconductors that generates two electron-hole pairs for each photon absorbed. Singlet fission occurs on sub-100 fs timescales with yields of up to 200%, and photovoltaic devices based on singlet fission have achieved external quantum efficiencies above 100%. The major challenge for the field is to use singlet fission to improve the efficiency of conventional inorganic solar cells, such as silicon, and to break the Shockley-Queisser limit on the efficiency of single-junction photovoltaics. Achieving this goal requires a broader and more collaborative effort than the one used at present. Synthetic chemists, spectroscopists, theorists, materials scientists, device physicists and engineers will need to work together. In this Review, we critically assess the current status of the field, highlight the key results and identify the challenges ahead. In doing so, we seek to open the field to new expertise and ideas, which will in turn promote both fundamental science and device applications.

  2. Breaking the diffraction limit of light-sheet fluorescence microscopy by RESOLFT.

    Science.gov (United States)

    Hoyer, Patrick; de Medeiros, Gustavo; Balázs, Bálint; Norlin, Nils; Besir, Christina; Hanne, Janina; Kräusslich, Hans-Georg; Engelhardt, Johann; Sahl, Steffen J; Hell, Stefan W; Hufnagel, Lars

    2016-03-29

    We present a plane-scanning RESOLFT [reversible saturable/switchable optical (fluorescence) transitions] light-sheet (LS) nanoscope, which fundamentally overcomes the diffraction barrier in the axial direction via confinement of the fluorescent molecular state to a sheet of subdiffraction thickness around the focal plane. To this end, reversibly switchable fluorophores located right above and below the focal plane are transferred to a nonfluorescent state at each scanning step. LS-RESOLFT nanoscopy offers wide-field 3D imaging of living biological specimens with low light dose and axial resolution far beyond the diffraction barrier. We demonstrate optical sections that are thinner by 5-12-fold compared with their conventional diffraction-limited LS analogs.

  3. Fundamental limitations in antenna resolution by maximum entropy methods

    Energy Technology Data Exchange (ETDEWEB)

    Bevensee, R.M.

    1984-08-01

    This paper summarizes work done during the past few years on antenna super-resolution of distant radiating sources, both incoherent with and without additive noise and coherent with and without additive noise.

  4. Breaking The Millisecond Barrier On SpiNNaker: Implementing Asynchronous Event-Based Plastic Models With Microsecond Resolution

    Directory of Open Access Journals (Sweden)

    Xavier eLagorce

    2015-06-01

    Full Text Available Spike-based neuromorphic sensors such as retinas and cochleas, change the way in which the world is sampled. Instead of producing data sampled at a constant rate, these sensors output spikes that are asynchronous and event driven. The event-based nature of neuromorphic sensors implies a complete paradigm shift in current perception algorithms towards those that emphasize the importance of precise timing. The spikes produced by these sensors usually have a time resolution in the order of microseconds. This high temporal resolution is a crucial factor in learning tasks. It is also widely used in the field of biological neural networks. Sound localization for instance relies on detecting time lags between the two ears which, in the barn owl, reaches a temporal resolution of 5 microseconds. Current available neuromorphic computation platforms such as SpiNNaker often limit their users to a time resolution in the order of milliseconds that is not compatible with the asynchronous outputs of neuromorphic sensors. To overcome these limitations and allow for the exploration of new types of neuromorphic computing architectures, we introduce a novel software framework on the SpiNNaker platform. This framework allows for simulations of spiking networks and plasticity mechanisms using a completely asynchronous and event-based scheme running with a microsecond time resolution. Results on two example networks using this new implementation are presented.

  5. Two-dimensional, high-resolution modeling of urban dam-break flooding: A case study of Baldwin Hills, California

    Science.gov (United States)

    Gallegos, Humberto A.; Schubert, Jochen E.; Sanders, Brett F.

    2009-08-01

    Modeling of dam-break flooding in an urban residential area in southern California is presented. Modeling is performed using BreZo, an unstructured grid, Godunov-type, finite volume model that solves the shallow-water equations. The model uses terrain data from a 1.5 m Light Detection and Ranging (LiDAR) Digital Terrain Model (DTM) and contour data depicting the reservoir and breach geometry. A spatially distributed Manning coefficient based on a landcover classification derived from digital orthophotos and vector data (e.g., parcel outlines) is also used, and the interception of flow by storm drains is modeled with sink terms in the 2D continuity equation. The model is validated with flood extent and stream flow measurements, and a sensitivity analysis is completed to identify the necessary level of data and model complexity for accuracy purposes. Results show street depressions in the land surface should be resolved by the computational mesh for flood extent and stream flow accuracy. A ca. 5 m resolution mesh that spans streets by approximately 3 cells achieves a good balance between accuracy and computational effort. Results also show that heterogeneous resistance is important for stream flow accuracy, and the interception of overland flow by storm sewers is important for flood extent accuracy. The sensitivity of predictions to several additional factors such as the reservoir level, breach geometry and DTM source (LiDAR, National Elevation Data, Shuttle Radar Topography Mission Data) is also reported.

  6. Breaking Lorentz reciprocity to overcome the time-bandwidth limit in physics and engineering

    Science.gov (United States)

    Tsakmakidis, K. L.; Shen, L.; Schulz, S. A.; Zheng, X.; Upham, J.; Deng, X.; Altug, H.; Vakakis, A. F.; Boyd, R. W.

    2017-06-01

    A century-old tenet in physics and engineering asserts that any type of system, having bandwidth Δω, can interact with a wave over only a constrained time period Δt inversely proportional to the bandwidth (Δt·Δω ~ 2π). This law severely limits the generic capabilities of all types of resonant and wave-guiding systems in photonics, cavity quantum electrodynamics and optomechanics, acoustics, continuum mechanics, and atomic and optical physics but is thought to be completely fundamental, arising from basic Fourier reciprocity. We propose that this “fundamental” limit can be overcome in systems where Lorentz reciprocity is broken. As a system becomes more asymmetric in its transport properties, the degree to which the limit can be surpassed becomes greater. By way of example, we theoretically demonstrate how, in an astutely designed magnetized semiconductor heterostructure, the above limit can be exceeded by orders of magnitude by using realistic material parameters. Our findings revise prevailing paradigms for linear, time-invariant resonant systems, challenging the doctrine that high-quality resonances must invariably be narrowband and providing the possibility of developing devices with unprecedentedly high time-bandwidth performance.

  7. Breaking Lorentz reciprocity to overcome the time-bandwidth limit in physics and engineering.

    Science.gov (United States)

    Tsakmakidis, K L; Shen, L; Schulz, S A; Zheng, X; Upham, J; Deng, X; Altug, H; Vakakis, A F; Boyd, R W

    2017-06-23

    A century-old tenet in physics and engineering asserts that any type of system, having bandwidth Δω, can interact with a wave over only a constrained time period Δ t inversely proportional to the bandwidth (Δ t ·Δω ~ 2π). This law severely limits the generic capabilities of all types of resonant and wave-guiding systems in photonics, cavity quantum electrodynamics and optomechanics, acoustics, continuum mechanics, and atomic and optical physics but is thought to be completely fundamental, arising from basic Fourier reciprocity. We propose that this "fundamental" limit can be overcome in systems where Lorentz reciprocity is broken. As a system becomes more asymmetric in its transport properties, the degree to which the limit can be surpassed becomes greater. By way of example, we theoretically demonstrate how, in an astutely designed magnetized semiconductor heterostructure, the above limit can be exceeded by orders of magnitude by using realistic material parameters. Our findings revise prevailing paradigms for linear, time-invariant resonant systems, challenging the doctrine that high-quality resonances must invariably be narrowband and providing the possibility of developing devices with unprecedentedly high time-bandwidth performance. Copyright © 2017 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

  8. Recurrent myopic foveoschisis: resolution after internal limiting membrane removal

    Directory of Open Access Journals (Sweden)

    Renato Antunes Schiave Germano

    2015-02-01

    Full Text Available We report a case of a 66-year-old man with a history of high myopia and who was referred for acute decreased visual acuity of the right eye. Fundus examination and optical coherence tomography (OCT showed a mild epiretinal membrane (ERM and splitting of retinal layers. Pars plana vitrectomy was performed with intravitreous triamcinolone injection, posterior hyaloid and ERM peeling, and 12% perfluoropropane (C3F8 gas tamponade. After remaining asymptomatic for 17 months, the patient reported a new episode of sudden decreased visual acuity in his right eye, and OCT showed recurrent myopic foveoschisis (MF. He underwent vitrectomy and internal limiting membrane (ILM peeling. Six months later, the patient’s best corrected visual acuity had improved to 20/25. Optical coherence tomography showed a remarkably improved macular anatomy, with residual traction along the inferotemporal arcade, which was attributed to the vessel stiffness itself. We conclude that removing the internal limiting membrane is a challenging maneuver in myopic foveoschisis, even with staining approaches. Although myopic foveoschisis may be resolved without peeling the internal limiting membrane, its removal should be considered if the condition recurs.

  9. Quantitative Proteomics via High Resolution MS Quantification: Capabilities and Limitations.

    Science.gov (United States)

    Higgs, Richard E; Butler, Jon P; Han, Bomie; Knierman, Michael D

    2013-01-01

    Recent improvements in the mass accuracy and resolution of mass spectrometers have led to renewed interest in label-free quantification using data from the primary mass spectrum (MS1) acquired from data-dependent proteomics experiments. The capacity for higher specificity quantification of peptides from samples enriched for proteins of biological interest offers distinct advantages for hypothesis generating experiments relative to immunoassay detection methods or prespecified peptide ions measured by multiple reaction monitoring (MRM) approaches. Here we describe an evaluation of different methods to post-process peptide level quantification information to support protein level inference. We characterize the methods by examining their ability to recover a known dilution of a standard protein in background matrices of varying complexity. Additionally, the MS1 quantification results are compared to a standard, targeted, MRM approach on the same samples under equivalent instrument conditions. We show the existence of multiple peptides with MS1 quantification sensitivity similar to the best MRM peptides for each of the background matrices studied. Based on these results we provide recommendations on preferred approaches to leveraging quantitative measurements of multiple peptides to improve protein level inference.

  10. Spatiotemporal Imaging of Magnetization Dynamics at the Nanoscale: Breaking the Diffraction Limit

    Science.gov (United States)

    2016-03-09

    engineering high performance spintronic memory and logic devices that are simultaneously high-speed, high-density, low-power, and radiation hard. Although...this project we studied approaches to exceeding the diffraction limit for optical magnetic microscopy while still retaining the excellent temporal...magnetic devices on fundamental scales to magnetism is of particular importance to engineering high performance spintronic memory and logic devices that

  11. Diffractive optics and nanophotonics resolution below the diffraction limit

    CERN Document Server

    Minin, Igor

    2016-01-01

    In this book the authors present several examples of techniques used to overcome the Abby diffraction limit using flat and 3D diffractive optical elements, photonic crystal lenses, photonic jets, and surface plasmon diffractive optics. The structures discussed can be used in the microwave and THz range and also as scaled models for optical frequencies. Such nano-optical microlenses can be integrated, for example, into existing semiconductor heterostructure platforms for next-generation optoelectronic applications. Chapter 1 considers flat diffractive lenses and innovative 3D radiating structures including a conical millimeter-wave Fresnel zone plate (FZP) lens proposed for subwavelength focusing. In chapter 2 the subwavelength focusing properties of diffractive photonic crystal lenses are considered and it is shown that at least three different types of photonic crystal lens are possible.  With the aim of achieving subwavelength focusing, in chapter 3 an alternative mechanism to produce photonic jets at Tera...

  12. Use DAS algorithm to break through the device limitations of switched-capacitor-based DAC in an ADC consisting of pipelined SAR and TDC

    Science.gov (United States)

    Fu, Zhongyi; Tang, Xian; Pun, Kong-Pang

    2017-12-01

    Switched capacitors are widely used in integrated circuits for discrete-time signal processing. Metal-Insulator-Metal (MIM) capacitors and MOSFET switches are commonly used for switched-capacitor circuits. They impose limitations in the power consumption and the bandwidth of the circuits. For instance, the switched-capacitor digital-to-analog converter (DAC) is the critical circuit block that determines the performance in a successive approximation register (SAR) analog-to-digital converters (ADC). In this paper, a design using the detect-and-skip (DAS) algorithm to break through the device limitations of switched-capacitor-based DACs is analyzed in a coarse-fine SAR ADC architecture. When it is shown that compared with the state-of-the-art Vcm-based capacitive DAC (CDAC), the DAS algorithm reduces 55% of the energy and extends the valid bandwidth from 2 MHz to 16 MHz with a 6-bit resolution under the same setting and technology. Besides, a time-to-digital converter (TDC)-assisted pipelined SAR ADC architecture using the DAS algorithm is proposed. Implemented in a 180 nm CMOS process, the 10-bit 10-MS/s prototype measures an energy efficiency of 57.8 fJ/conv.-step.

  13. Quantifying high resolution transitional breaks in plant and mammal distributions at regional extent and their association with climate, topography and geology.

    Science.gov (United States)

    Di Virgilio, Giovanni; Laffan, Shawn W; Ebach, Malte C

    2013-01-01

    We quantify spatial turnover in communities of 1939 plant and 59 mammal species at 2.5 km resolution across a topographically heterogeneous region in south-eastern Australia to identify distributional breaks and low turnover zones where multiple species distributions overlap. Environmental turnover is measured to determine how climate, topography and geology influence biotic turnover differently across a variety of biogeographic breaks and overlaps. We identify the genera driving turnover and confirm the versatility of this approach across spatial scales and locations. Directional moving window analyses, rotated through 360°, were used to measure spatial turnover variation in different directions between gridded cells containing georeferenced plant and mammal occurrences and environmental variables. Generalised linear models were used to compare taxic turnover results with equivalent analyses for geology, regolith weathering, elevation, slope, solar radiation, annual precipitation and annual mean temperature, both uniformly across the entire study area and by stratifying it into zones of high and low turnover. Identified breaks and transitions were compared to a conservation bioregionalisation framework widely used in Australia. Detailed delineations of plant and mammal turnover zones with gradational boundaries denoted subtle variation in species assemblages. Turnover patterns often diverged from bioregion boundaries, though plant turnover adhered most closely. A prominent break zone contained either comparable or greater numbers of unique genera than adjacent overlaps, but these were concentrated in a small subsection relatively under-protected by conservation reserves. The environmental correlates of biotic turnover varied for different turnover zones in different subsections of the study area. Topography and temperature showed much stronger relationships with plant turnover in a topographically complex overlap, relative to a lowland overlap where weathering

  14. Surpassing the Path-Limited Resolution of a Fourier Transform Spectrometer with Frequency Combs

    CERN Document Server

    Maslowski, Piotr; Johansson, Alexandra C; Khodabakhsh, Amir; Kowzan, Grzegorz; Rutkowski, Lucile; Mills, Andrew A; Mohr, Christian; Jiang, Jie; Fermann, Martin E; Foltynowicz, Aleksandra

    2015-01-01

    Fourier transform spectroscopy based on incoherent light sources is a well-established tool in research fields from molecular spectroscopy and atmospheric monitoring to material science and biophysics. It provides broadband molecular spectra and information about the molecular structure and composition of absorptive media. However, the spectral resolution is fundamentally limited by the maximum delay range ({\\Delta}$_{max}$) of the interferometer, so acquisition of high-resolution spectra implies long measurement times and large instrument size. We overcome this limit by combining the Fourier transform spectrometer with an optical frequency comb and measuring the intensities of individual comb lines by precisely matching the {\\Delta}$_{max}$ to the comb line spacing. This allows measurements of absorption lines narrower than the nominal (optical path-limited) resolution without ringing effects from the instrumental lineshape and reduces the acquisition time and interferometer length by orders of magnitude.

  15. Resolution limits of migration and linearized waveform inversion images in a lossy medium

    KAUST Repository

    Schuster, Gerard T.

    2017-03-10

    The vertical-and horizontal-resolution limits Delta x(lossy) and Delta z(lossy) of post-stack migration and linearized waveform inversion images are derived for lossy data in the far-field approximation. Unlike the horizontal resolution limit Delta x proportional to lambda z/L in a lossless medium which linearly worsens in depth z, Delta x(lossy) proportional to z(2)/QL worsens quadratically with depth for a medium with small Q values. Here, Q is the quality factor, lambda is the effective wavelength, L is the recording aperture, and loss in the resolution formulae is accounted for by replacing lambda with z/Q. In contrast, the lossy vertical-resolution limit Delta z(lossy) only worsens linearly in depth compared to Delta z proportional to lambda for a lossless medium. For both the causal and acausal Q models, the resolution limits are linearly proportional to 1/Q for small Q. These theoretical predictions are validated with migration images computed from lossy data.

  16. WAVE BREAKING OVER LOCAL TOPOGRAPHY DURING THE MAP IOP 15 MISTRAL EVENT: OBSERVATIONS AND HIGH-RESOLUTION NUMERICAL SIMULATIONS

    OpenAIRE

    Guénard, Vincent; Tedeschi, Gilles; Drobinski, Philippe; Caccia, Jean Luc

    2005-01-01

    Abstract: This study investigates the fundamental processes involved in the severe Mistral’s windstorm occurring during the MAP IOP 15 (from 06 to 09 November 1999). It is based on numerical high-resolution simulations performed with the RAMS non-hydrostatic model at 3 km resolution. The simulation is found able to capture the flow complexity both upstream of the Alps and in coastal regions affected by the Mistral. The simulations accurately reproduce dynamical and thermodynamical fields obse...

  17. Physical limitations to the spatial resolution of solid-state detectors

    CERN Document Server

    Boronat, M; Frey, A; Garcia, I; Schwenker, B; Vos, M; Wilk, F

    2015-01-01

    In this paper we explore the effect of -ray emission and fluctuations in the signal deposition on the detection of charged particles in silicon-based detectors. We show that these two effects ultimately limit the resolution that can be achieved by interpolation of the signal in finely segmented position-sensitive solid-state devices.

  18. 78 FR 41716 - Hours of Service; Limited 90-Day Waiver From the 30-Minute Rest Break Requirement for the...

    Science.gov (United States)

    2013-07-11

    ... livestock trucks during drivers' mandatory 30-minute break, especially in light of long-range weather... and Carrier Operations Division, Office of Bus and Truck Standards and Operations, Federal Motor...: Agricultural and Food Transporters Conference of the American Trucking Associations; American Farm Bureau...

  19. 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.

  20. Mapping atomic motions with ultrabright electrons: towards fundamental limits in space-time resolution.

    Science.gov (United States)

    Manz, Stephanie; Casandruc, Albert; Zhang, Dongfang; Zhong, Yinpeng; Loch, Rolf A; Marx, Alexander; Hasegawa, Taisuke; Liu, Lai Chung; Bayesteh, Shima; Delsim-Hashemi, Hossein; Hoffmann, Matthias; Felber, Matthias; Hachmann, Max; Mayet, Frank; Hirscht, Julian; Keskin, Sercan; Hada, Masaki; Epp, Sascha W; Flöttmann, Klaus; Miller, R J Dwayne

    2015-01-01

    The long held objective of directly observing atomic motions during the defining moments of chemistry has been achieved based on ultrabright electron sources that have given rise to a new field of atomically resolved structural dynamics. This class of experiments requires not only simultaneous sub-atomic spatial resolution with temporal resolution on the 100 femtosecond time scale but also has brightness requirements approaching single shot atomic resolution conditions. The brightness condition is in recognition that chemistry leads generally to irreversible changes in structure during the experimental conditions and that the nanoscale thin samples needed for electron structural probes pose upper limits to the available sample or "film" for atomic movies. Even in the case of reversible systems, the degree of excitation and thermal effects require the brightest sources possible for a given space-time resolution to observe the structural changes above background. Further progress in the field, particularly to the study of biological systems and solution reaction chemistry, requires increased brightness and spatial coherence, as well as an ability to tune the electron scattering cross-section to meet sample constraints. The electron bunch density or intensity depends directly on the magnitude of the extraction field for photoemitted electron sources and electron energy distribution in the transverse and longitudinal planes of electron propagation. This work examines the fundamental limits to optimizing these parameters based on relativistic electron sources using re-bunching cavity concepts that are now capable of achieving 10 femtosecond time scale resolution to capture the fastest nuclear motions. This analysis is given for both diffraction and real space imaging of structural dynamics in which there are several orders of magnitude higher space-time resolution with diffraction methods. The first experimental results from the Relativistic Electron Gun for Atomic

  1. Plasma beta dependence of the ion-scale spectral break of solar wind turbulence: high-resolution 2D hybrid simulations

    CERN Document Server

    Franci, Luca; Matteini, Lorenzo; Verdini, Andrea; Hellinger, Petr

    2016-01-01

    We investigate properties of the ion-scale spectral break of solar wind turbulence by means of two-dimensional high-resolution hybrid particle-in-cell simulations. We impose an initial ambient magnetic field perpendicular to the simulation box and add a spectrum of in-plane, large-scale, magnetic and kinetic fluctuations. We perform a set of simulations with different values of the plasma beta, distributed over three orders of magnitude, from 0.01 to 10. In all the cases, once turbulence is fully developed, we observe a power-law spectrum of the fluctuating magnetic field on large scales (in the inertial range) with a spectral index close to -5/3, while in the sub-ion range we observe another power-law spectrum with a spectral index systematically varying with $\\beta$ (from around -3.6 for small values to around -2.9 for large ones). The two ranges are separated by a spectral break around ion scales. The length scale at which this transition occurs is found to be proportional to the ion inertial length, $d_i$...

  2. Progressive Refinement of Beamforming Vectors for High-Resolution Limited Feedback

    Directory of Open Access Journals (Sweden)

    Robert W. Heath

    2009-01-01

    Full Text Available Limited feedback enables the practical use of channel state information in multiuser multiple-input multiple-output (MIMO wireless communication systems. Using the limited feedback concept, channel state information at the receiver is quantized by choosing a representative element from a codebook known to both the receiver and transmitter. Unfortunately, achieving the high resolution required with multiuser MIMO communication is challenging due to the large number of codebook entries required. This paper proposes to use a progressively scaled local codebook to enable high resolution quantization and reconstruction for multiuser MIMO with zero-forcing precoding. Several local codebook designs are proposed including one based on a ring and one based on mutually unbiased bases; both facilitate efficient implementation. Structure in the local codebooks is used to reduce search complexity in the progressive refinement algorithm. Simulation results illustrate sum rate performance as a function of the number of refinements.

  3. Some Fundamental Limits on SAW RFID Tag Information Capacity and Collision Resolution

    Science.gov (United States)

    Barton, Richard J.

    2013-01-01

    In this paper, we apply results from multi-user information theory to study the limits of information capacity and collision resolution for SAW RFID tags. In particular, we derive bounds on the achievable data rate per tag as a function of fundamental parameters such as tag time-bandwidth product, tag signal-to-noise ratio (SNR), and number of tags in the environment. We also discuss the implications of these bounds for tag waveform design and tag interrogation efficiency

  4. Printable Nanoscopic Metamaterial Absorbers and Images with Diffraction-Limited Resolution

    CERN Document Server

    Richner, Patrizia; Kress, Stephan J P; Schmid, Martin; Norris, David J; Poulikakos, Dimos

    2016-01-01

    The fabrication of functional metamaterials with extreme feature resolution finds a host of applications such as the broad area of surface/light interaction. Non-planar features of such structures can significantly enhance their performance and tunability, but their facile generation remains a challenge. Here, we show that carefully designed out-of-plane nanopillars made of metal-dielectric composites integrated in a metal-dielectric-nanocomposite configuration, can absorb broadband light very effectively. We further demonstrate that electrohydrodynamic printing in a rapid nanodripping mode, is able to generate precise out-of-plane forests of such composite nanopillars with deposition resolutions at the diffraction limit on flat and non-flat substrates. The nanocomposite nature of the printed material allows the fine-tuning of the overall visible light absorption from complete absorption to complete reflection by simply tuning the pillar height. Almost perfect absorption (~95%) over the entire visible spectru...

  5. Community detection in weighted brain connectivity networks beyond the resolution limit.

    Science.gov (United States)

    Nicolini, Carlo; Bordier, Cécile; Bifone, Angelo

    2017-02-01

    Graph theory provides a powerful framework to investigate brain functional connectivity networks and their modular organization. However, most graph-based methods suffer from a fundamental resolution limit that may have affected previous studies and prevented detection of modules, or "communities", that are smaller than a specific scale. Surprise, a resolution-limit-free function rooted in discrete probability theory, has been recently introduced and applied to brain networks, revealing a wide size-distribution of functional modules (Nicolini and Bifone, 2016), in contrast with many previous reports. However, the use of Surprise is limited to binary networks, while brain networks are intrinsically weighted, reflecting a continuous distribution of connectivity strengths between different brain regions. Here, we propose Asymptotical Surprise, a continuous version of Surprise, for the study of weighted brain connectivity networks, and validate this approach in synthetic networks endowed with a ground-truth modular structure. We compare Asymptotical Surprise with leading community detection methods currently in use and show its superior sensitivity in the detection of small modules even in the presence of noise and intersubject variability such as those observed in fMRI data. We apply our novel approach to functional connectivity networks from resting state fMRI experiments, and demonstrate a heterogeneous modular organization, with a wide distribution of clusters spanning multiple scales. Finally, we discuss the implications of these findings for the identification of connector hubs, the brain regions responsible for the integration of the different network elements, showing that the improved resolution afforded by Asymptotical Surprise leads to a different classification compared to current methods. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  6. 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…

  7. Fine-resolution conservation planning with limited climate-change information.

    Science.gov (United States)

    Shah, Payal; Mallory, Mindy L; Ando, Amy W; Guntenspergen, Glenn R

    2017-04-01

    Climate-change induced uncertainties in future spatial patterns of conservation-related outcomes make it difficult to implement standard conservation-planning paradigms. A recent study translates Markowitz's risk-diversification strategy from finance to conservation settings, enabling conservation agents to use this diversification strategy for allocating conservation and restoration investments across space to minimize the risk associated with such uncertainty. However, this method is information intensive and requires a large number of forecasts of ecological outcomes associated with possible climate-change scenarios for carrying out fine-resolution conservation planning. We developed a technique for iterative, spatial portfolio analysis that can be used to allocate scarce conservation resources across a desired level of subregions in a planning landscape in the absence of a sufficient number of ecological forecasts. We applied our technique to the Prairie Pothole Region in central North America. A lack of sufficient future climate information prevented attainment of the most efficient risk-return conservation outcomes in the Prairie Pothole Region. The difference in expected conservation returns between conservation planning with limited climate-change information and full climate-change information was as large as 30% for the Prairie Pothole Region even when the most efficient iterative approach was used. However, our iterative approach allowed finer resolution portfolio allocation with limited climate-change forecasts such that the best possible risk-return combinations were obtained. With our most efficient iterative approach, the expected loss in conservation outcomes owing to limited climate-change information could be reduced by 17% relative to other iterative approaches. © 2016 Society for Conservation Biology.

  8. A high resolution IR/visible imaging system for the W7-X limiter

    Energy Technology Data Exchange (ETDEWEB)

    Wurden, G. A., E-mail: wurden@lanl.gov; Dunn, J. P. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Stephey, L. A. [University of Wisconsin, Madison, Wisconsin 53706 (United States); Biedermann, C.; Jakubowski, M. W.; Gamradt, M. [Max Planck Institut für Plasma Physik, Wendelsteinstrasse 1, 17491 Greifswald (Germany)

    2016-11-15

    A high-resolution imaging system, consisting of megapixel mid-IR and visible cameras along the same line of sight, has been prepared for the new W7-X stellarator and was operated during Operational Period 1.1 to view one of the five inboard graphite limiters. The radial line of sight, through a large diameter (184 mm clear aperture) uncoated sapphire window, couples a direct viewing 1344 × 784 pixel FLIR SC8303HD camera. A germanium beam-splitter sends visible light to a 1024 × 1024 pixel Allied Vision Technologies Prosilica GX1050 color camera. Both achieve sub-millimeter resolution on the 161 mm wide, inertially cooled, segmented graphite tiles. The IR and visible cameras are controlled via optical fibers over full Camera Link and dual GigE Ethernet (2 Gbit/s data rates) interfaces, respectively. While they are mounted outside the cryostat at a distance of 3.2 m from the limiter, they are close to a large magnetic trim coil and require soft iron shielding. We have taken IR data at 125 Hz to 1.25 kHz frame rates and seen that surface temperature increases in excess of 350 °C, especially on leading edges or defect hot spots. The IR camera sees heat-load stripe patterns on the limiter and has been used to infer limiter power fluxes (∼1–4.5 MW/m{sup 2}), during the ECRH heating phase. IR images have also been used calorimetrically between shots to measure equilibrated bulk tile temperature, and hence tile energy inputs (in the range of 30 kJ/tile with 0.6 MW, 6 s heating pulses). Small UFO’s can be seen and tracked by the FLIR camera in some discharges. The calibrated visible color camera (100 Hz frame rate) has also been equipped with narrow band C-III and H-alpha filters, to compare with other diagnostics, and is used for absolute particle flux determination from the limiter surface. Sometimes, but not always, hot-spots in the IR are also seen to be bright in C-III light.

  9. A high resolution IR/visible imaging system for the W7-X limiter

    Science.gov (United States)

    Wurden, G. A.; Stephey, L. A.; Biedermann, C.; Jakubowski, M. W.; Dunn, J. P.; Gamradt, M.

    2016-11-01

    A high-resolution imaging system, consisting of megapixel mid-IR and visible cameras along the same line of sight, has been prepared for the new W7-X stellarator and was operated during Operational Period 1.1 to view one of the five inboard graphite limiters. The radial line of sight, through a large diameter (184 mm clear aperture) uncoated sapphire window, couples a direct viewing 1344 × 784 pixel FLIR SC8303HD camera. A germanium beam-splitter sends visible light to a 1024 × 1024 pixel Allied Vision Technologies Prosilica GX1050 color camera. Both achieve sub-millimeter resolution on the 161 mm wide, inertially cooled, segmented graphite tiles. The IR and visible cameras are controlled via optical fibers over full Camera Link and dual GigE Ethernet (2 Gbit/s data rates) interfaces, respectively. While they are mounted outside the cryostat at a distance of 3.2 m from the limiter, they are close to a large magnetic trim coil and require soft iron shielding. We have taken IR data at 125 Hz to 1.25 kHz frame rates and seen that surface temperature increases in excess of 350 °C, especially on leading edges or defect hot spots. The IR camera sees heat-load stripe patterns on the limiter and has been used to infer limiter power fluxes (˜1-4.5 MW/m2), during the ECRH heating phase. IR images have also been used calorimetrically between shots to measure equilibrated bulk tile temperature, and hence tile energy inputs (in the range of 30 kJ/tile with 0.6 MW, 6 s heating pulses). Small UFO's can be seen and tracked by the FLIR camera in some discharges. The calibrated visible color camera (100 Hz frame rate) has also been equipped with narrow band C-III and H-alpha filters, to compare with other diagnostics, and is used for absolute particle flux determination from the limiter surface. Sometimes, but not always, hot-spots in the IR are also seen to be bright in C-III light.

  10. Limits in point to point resolution of MOS based pixels detector arrays

    Science.gov (United States)

    Fourches, N.; Desforge, D.; Kebbiri, M.; Kumar, V.; Serruys, Y.; Gutierrez, G.; Leprêtre, F.; Jomard, F.

    2018-01-01

    In high energy physics point-to-point resolution is a key prerequisite for particle detector pixel arrays. Current and future experiments require the development of inner-detectors able to resolve the tracks of particles down to the micron range. Present-day technologies, although not fully implemented in actual detectors, can reach a 5-μm limit, this limit being based on statistical measurements, with a pixel-pitch in the 10 μm range. This paper is devoted to the evaluation of the building blocks for use in pixel arrays enabling accurate tracking of charged particles. Basing us on simulations we will make here a quantitative evaluation of the physical and technological limits in pixel size. Attempts to design small pixels based on SOI technology will be briefly recalled here. A design based on CMOS compatible technologies that allow a reduction of the pixel size below the micrometer is introduced here. Its physical principle relies on a buried carrier-localizing collecting gate. The fabrication process needed by this pixel design can be based on existing process steps used in silicon microelectronics. The pixel characteristics will be discussed as well as the design of pixel arrays. The existing bottlenecks and how to overcome them will be discussed in the light of recent ion implantation and material characterization experiments.

  11. Fundamental Limits on Spatial Resolution in Ultrafast X-ray Diffraction

    Directory of Open Access Journals (Sweden)

    Adam Kirrander

    2017-05-01

    Full Text Available X-ray Free-Electron Lasers have made it possible to record time-sequences of diffraction images to determine changes in molecular geometry during ultrafast photochemical processes. Using state-of-the-art simulations in three molecules (deuterium, ethylene, and 1,3-cyclohexadiene, we demonstrate that the nature of the nuclear wavepacket initially prepared by the pump laser, and its subsequent dispersion as it propagates along the reaction path, limits the spatial resolution attainable in a structural dynamics experiment. The delocalization of the wavepacket leads to a pronounced damping of the diffraction signal at large values of the momentum transfer vector q, an observation supported by a simple analytical model. This suggests that high-q measurements, beyond 10–15 Å − 1 , provide scant experimental payback, and that it may be advantageous to prioritize the signal-to-noise ratio and the time-resolution of the experiment as determined by parameters such as the repetition-rate, the photon flux, and the pulse durations. We expect these considerations to influence future experimental designs, including source development and detection schemes.

  12. Nuclear structure at the limits of resolution: Looking through individual wave functions

    Energy Technology Data Exchange (ETDEWEB)

    Zelevinsky, V.G. [Michigan State Univ., East Lansing, MI (United States)

    1996-12-31

    60 years ago Niels Bohr suggested the idea of the compound nucleus. Bohr`s picture strongly resembles that of quantum chaos. Here one comes to the limits of resolution studying particular stationary states at high level density. Present knowledge comes from the experiment and from theoretical constructions, confirmed by the experiment at lower energies and extrapolated into the region where fine resolution measurements are not feasible. Such an analysis was carried out recently for heavy atoms and shell model nuclei. Among complicated states with the same values of integrals of motion, either (i) adjacent states have different structure or (ii) they {open_quotes}look the same{close_quotes} on the microscopic scale. Only (ii) corresponds to strong mixing assumed in the compound nucleus theory. Many-body chaos in nuclei is caused by residual interactions rather than by specific shape of the {open_quotes}container{close_quotes} as in quantum billiards. The shell model, including all degrees of freedom (in truncated space) along with the symmetry requirements, guarantees the correct level density up to some excitation energy. Therefore one can extrapolate the calculations into terra incognita of high lying states.

  13. Combination of high spatial resolution and low minimum detection limit using thinned specimens in cutting-edge electron probe microanalysis

    Energy Technology Data Exchange (ETDEWEB)

    Kubo, Yugo, E-mail: kubo-yugo@sei.co.jp; Hamada, Kotaro

    2015-10-15

    The effect of sample thickness on the spatial resolution and minimum detection limit (MDL) has been investigated for field-emission electron probe microanalysis with wavelength dispersive X-ray spectroscopy (FE-EPMA–WDX). Indium gallium phosphide samples thinned to thicknesses of about 100, 130, 210, 310, and 430 nm provided effective thin-sample FE-EPMA–WDX in the resolution range of 40–350 nm and MDL range of 13,000–600 ppm (mass). A comparison of the FE-EPMA results for thin and bulk samples demonstrated that thin-sample FE-EPMA can achieve both higher sensitivity and better spatial resolution than is possible using bulk samples. Most of the X-rays that determine the MDL are generated in a surface region of the sample with a depth of approximately 300 nm. The spatial resolution and MDL can be tuned by the sample thickness. Furthermore, analysis of small amounts of Cl in SiO{sub 2} indicated that thin-sample FE-EPMA can realize a spatial resolution and MDL of 41 nm and 446 ppm at I{sub prob}=50 nA, respectively, whereas bulk-sample FE-EPMA offers a resolution of only 348 nm and MDL of 426 ppm. - Highlights: • Mechanism for FE-EPMA combining high spatial resolution with a low detection limit. • Spatial resolution and minimum detection limit controllable by sample thickness. • Achievement of a combined resolution and detection limit of 41 nm and 446 ppm. • Spatial resolution and detection limit for FE-EPMA–WDX and FE-SEM–EDX.

  14. Fundamental Limitations of Resolution And Accuracy of Tomographic Regional Wave Q Models

    Science.gov (United States)

    Xie, J.; Chen, Y.

    2016-12-01

    Imaging lateral variations of seismic Q is much more difficult than imaging those of velocity. The foremost reason for the difficulty is that 1/Q values are measured with "reduced amplitude" data rather than observed ground motion amplitudes. The reduced amplitudes are derived using logarithm of the ground motion amplitudes, after a 1D geometrical spreading term is removed. The reduced amplitudes contain modeling errors arising from the effects of the true 3D geometrical spreading and pre-arrival, ambient and coda noises. Statistical distribution of the modeling error has not been systematically explored, except being assumed to be normally distributed. This assumption brings the convenience of formulating Q tomography as a least-squares problem. Here we develop a statistical treatise of modeling error, which permits the calibration of the probability function, mean and variance of the error using real data. We develop a matrix operation methodology to solve for the inverse, error and resolution matrices associated with the two-station tomographic Q model. We apply this methodology to regional Lg wave data collected from SW China, and compare the resolution and error of the model with those associated with typical tomographic velocity models derived from the much simpler travel time data. Another fundamental limitation in Q tomography is caused by the inherently large variability of Q. In velocity and Q tomography, the laterally varying quantity that is solved for by linear equations is the inverse of velocity (slowness) or Q (attenuation coefficient), respectively. Variations of slowness are a small fraction of the mean slowness, so a tomographic slowness model can be robustly converted to a tomographic velocity model. The Q values in the Earth, on the other hand, vary drastically by up to an order of magnitude. The conversion between the attenuation coefficients and the Q values in such a large range is highly non-linear. High Q values corresponding to small

  15. Breaking the speed limit--comparative sprinting performance of brook trout (Salvelinus fontinalis) and brown trout (Salmo trutta)

    Science.gov (United States)

    Castro-Santos, Theodore; Sanz-Ronda, Francisco Javier; Ruiz-Legazpi, Jorge

    2013-01-01

    Sprinting behavior of free-ranging fish has long been thought to exceed that of captive fish. Here we present data from wild-caught brook trout (Salvelinus fontinalis) and brown trout (Salmo trutta), volitionally entering and sprinting against high-velocity flows in an open-channel flume. Performance of the two species was nearly identical, with the species attaining absolute speeds > 25 body lengths·s−1. These speeds far exceed previously published observations for any salmonid species and contribute to the mounting evidence that commonly accepted estimates of swimming performance are low. Brook trout demonstrated two distinct modes in the relationship between swim speed and fatigue time, similar to the shift from prolonged to sprint mode described by other authors, but in this case occurring at speeds > 19 body lengths·s−1. This is the first demonstration of multiple modes of sprint swimming at such high swim speeds. Neither species optimized for distance maximization, however, indicating that physiological limits alone are poor predictors of swimming performance. By combining distributions of volitional swim speeds with endurance, we were able to account for >80% of the variation in distance traversed by both species.

  16. Comparison between subjective and quantitative methods for assessing the resolution limit of radiographic systems; Comparacao entre metodos subjetivos e quantitativos na medida da resolucao limite de sistemas radiograficos

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez, Matheus; Oliveira, Marcela de; Miranda, Jose R.A. [Universidade Estadual Paulista Julio de Mesquita Filho (UNESP), Botucatu, SP (Brazil). Inst. de Biociencias de Botucatu; Pina, Diana R., E-mail: matheus@ibb.unesp.br [UNESP, Botucatu, SP (Brazil). Faculdade de Medicina. Dept. de Doencas Tropicais e Diagnostico por Imagem

    2012-07-01

    The aim of this study was to compare two ways of measuring the resolution limit of radiographic systems, one subjective and one quantitative. To this end, nine images were acquired with different radiographic techniques using a pattern of bars and aluminum plates. With these images were acquired modulation transfer function (MTF) through the edge image obtained by the aluminum plate - the MTF 10% was measured on all images - and the variation of these points, which was faced with the evaluation obtained by the resolution limit of the standard bar. Although we have observed a greater variation between measurements obtained using the bar-pattern, the simplicity of this measuring technique favors the common use of the same. We concluded that, to optimize the quality control of radiographic equipment, it is suggested to measure the MTF at least in periods of time while the annual pattern of bars to be used in shorter time periods to measure changes in resolution of the system. (author)

  17. What Limits an Altimeter's Resolution of Along-Track Geoid Slope? Insights from Saral and Cryosat

    Science.gov (United States)

    Smith, W. H. F.

    2014-12-01

    Satellite altimeter data collected along densely spaced ground tracks can map the marine gravity field, revealing the tectonic fabric of the sea floor. This application requires high accuracy of the along-track derivative of sea surface height over distances shorter than 80 km, and so is very sensitive to the instrument's range precision and any factors that produce short-scale along-track correlation of range measurement errors. To date the altimeters that have collected data over a dense network of ground tracks all acquired their largest data sets in Ku band and employing conventional (incoherent) processing. Two new altimeters go beyond conventional Ku instruments. SARAL AltiKa operates as an incoherent altimeter at Ka-band, and CryoSat collects some Ku-band data in a SAR mode to permit coherent processing for aperture synthesis and delay-Doppler calculations. The along-track range noise correlation characteristics of each of these new measurements are different from what has been seen in previous altimeters. SARAL AltiKa has a lower noise floor than pre-Cryosat Ku-band instruments and its noise spectrum shows decorrelation at different wavelengths, in partial agreement with theoretical work on speckle noise decorrelation over homogeneous surfaces. This improved noise performance results in demonstrable improvement in the resolution of geoid anomalies over small seamounts. Retracking of Cryosat's SAR mode multi-looked waveform yields a decorrelation of range errors unlike that found in conventional instruments, such that it doesn't require two-pass retracking to get the best geoid slope resolution. This is due mainly to the waveform's shape, which yields partial derivatives with respect to geophysical parameter estimates that are more nearly orthogonal than in conventional Ku-band Brown model waveforms. Further understanding of the limits on range precision in these instruments will require understanding of the heterogeneities in reflecting surfaces that are

  18. Spatial resolution limits for the isotropic-3D PET detector X’tal cube

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, Eiji, E-mail: rush@nirs.go.jp; Tashima, Hideaki; Hirano, Yoshiyuki; Inadama, Naoko; Nishikido, Fumihiko; Murayama, Hideo; Yamaya, Taiga

    2013-11-11

    Positron emission tomography (PET) has become a popular imaging method in metabolism, neuroscience, and molecular imaging. For dedicated human brain and small animal PET scanners, high spatial resolution is needed to visualize small objects. To improve the spatial resolution, we are developing the X’tal cube, which is our new PET detector to achieve isotropic 3D positioning detectability. We have shown that the X’tal cube can achieve 1 mm{sup 3} uniform crystal identification performance with the Anger-type calculation even at the block edges. We plan to develop the X’tal cube with even smaller 3D grids for sub-millimeter crystal identification. In this work, we investigate spatial resolution of a PET scanner based on the X’tal cube using Monte Carlo simulations for predicting resolution performance in smaller 3D grids. For spatial resolution evaluation, a point source emitting 511 keV photons was simulated by GATE for all physical processes involved in emission and interaction of positrons. We simulated two types of animal PET scanners. The first PET scanner had a detector ring 14.6 cm in diameter composed of 18 detectors. The second PET scanner had a detector ring 7.8 cm in diameter composed of 12 detectors. After the GATE simulations, we converted the interacting 3D position information to digitalized positions for realistic segmented crystals. We simulated several X’tal cubes with cubic crystals from (0.5 mm){sup 3} to (2 mm){sup 3} in size. Also, for evaluating the effect of DOI resolution, we simulated several X’tal cubes with crystal thickness from (0.5 mm){sup 3} to (9 mm){sup 3}. We showed that sub-millimeter spatial resolution was possible using cubic crystals smaller than (1.0 mm){sup 3} even with the assumed physical processes. Also, the weighted average spatial resolutions of both PET scanners with (0.5 mm){sup 3} cubic crystals were 0.53 mm (14.6 cm ring diameter) and 0.48 mm (7.8 cm ring diameter). For the 7.8 cm ring diameter, spatial

  19. Potential and limitations of high resolution multitemporal sar images in river morphology

    Science.gov (United States)

    Mitidieri, Francesco; Nicolina Papa, Maria; Amitrano, Donato; Ruello, Giuseppe

    2017-04-01

    In this study we test the capability of satellite synthetic aperture radar (SAR) images to enrich the monitoring of river geomorphological processes. A case study on the Italian River Orco is presented; a set of 100 COSMO-SkyMed stripmap images (from October 2008 to December 2016) from Italian Space Agency was employed. All the data, acquired with medium look angle (almost 30°) and HH polarization for increasing the land-water contrast, were processed in order to calibrate, register and reduce the speckle effect. Moreover, the optimal weighting multi-temporal De Grandi filter was adopted to allow an effective extraction of the water surfaces contour. This method was applied to extract water contours over the entire historical series of SAR datasets available. Thanks to the generated information we were able to monitor the lateral dynamic of the water channels and infer on the relations between low or peak flow and river morphology. Multi-temporal SAR images were compared to orthophotos and in situ measurements (performed at the same time of a SAR acquisition) in terms of river features extraction (e.g. active channel, vegetated islands) and measurements of morphometric parameters (e.g. reach length, channel width, curvature and sinuosity). Results of this comparison highlighted the potential offered by the use of SAR technology, with some limitations. In particular, good performances were reached by the extraction of the active channel and vegetated island compared to the ones obtained using the orthophotos. On the other hand, some issues were encountered in extracting water surfaces where riffles exhibit surface waves having heights greater than the wavelength of the electromagnetic signal of SAR, which causes a low land-water contrast. Hence, given the high spatial (3 m) and temporal resolution (15 days) of SAR images and the all-weather all-time acquisition conditions, a significant enhancement in the river management capabilities is possible, in particular

  20. 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...... storytelling to enact fruitful breakings of patterns unbecoming. The claim being, that the hamster wheel of Work-life anno 2016 needs reconfiguration and the simple yet fruitful manner by which this is done is through acknowledging the benefits of bodies, spaces and artifacts – and the benefits of actually...... taking a break, discontinuing for a moment in order to continue better, wiser and more at ease. Both within and as part of the daily routines, and – now and then – outside these routines in the majesty of nature with time to explore and redirect the course of life in companionships with fellow man...

  1. Pushing back the limits of Raman imaging by coupling super-resolution and chemometrics for aerosols characterization

    Science.gov (United States)

    Offroy, Marc; Moreau, Myriam; Sobanska, Sophie; Milanfar, Peyman; Duponchel, Ludovic

    2015-07-01

    The increasing interest in nanoscience in many research fields like physics, chemistry, and biology, including the environmental fate of the produced nano-objects, requires instrumental improvements to address the sub-micrometric analysis challenges. The originality of our approach is to use both the super-resolution concept and multivariate curve resolution (MCR-ALS) algorithm in confocal Raman imaging to surmount its instrumental limits and to characterize chemical components of atmospheric aerosols at the level of the individual particles. We demonstrate the possibility to go beyond the diffraction limit with this algorithmic approach. Indeed, the spatial resolution is improved by 65% to achieve 200 nm for the considered far-field spectrophotometer. A multivariate curve resolution method is then coupled with super-resolution in order to explore the heterogeneous structure of submicron particles for describing physical and chemical processes that may occur in the atmosphere. The proposed methodology provides new tools for sub-micron characterization of heterogeneous samples using far-field (i.e. conventional) Raman imaging spectrometer.

  2. Clumpy galaxies seen in H α: inflated observed clump properties due to limited spatial resolution and sensitivity

    Science.gov (United States)

    Tamburello, Valentina; Rahmati, Alireza; Mayer, Lucio; Cava, Antonio; Dessauges-Zavadsky, Miroslava; Schaerer, Daniel

    2017-07-01

    High-resolution simulations of star-forming massive galactic discs have shown that clumps form with a characteristic baryonic mass in the range 107-108 M⊙, with a small tail exceeding 109 M⊙ produced by clump-clump mergers. This is in contrast with the observed kpc-size clumps with masses up to 1010 M⊙ in high-redshift star-forming galaxies. In this paper, we show that the comparison between simulated and observed star-forming clumps is hindered by limited observational spatial resolution and sensitivity. We post-process high-resolution hydrodynamical simulations of clumpy discs using accurate radiative transfer to model the effect of ionizing radiation from young stars and to compute H α emission maps. By comparing the intrinsic clump size and mass distributions with those inferred from convolving the H α maps with different Gaussian apertures, we mimic the typical resolution used in observations. We found that with 100 pc resolution, mock observations can recover the intrinsic clump radii and stellar masses, in agreement with those found by lensing observations. Instead, using a 1 kpc resolution smears out individual clumps, resulting in their apparent merging. This causes significant overestimations of the clump radii and therefore masses derived using methods that use their observed sizes. We show that limited sensitivity can also force observations to significantly overestimate the clump masses. We conclude that a significant fraction of giant clumps detected in the observations may result from artificially inflated radii and masses, and that ≈100 pc spatial resolution is required to capture correctly the physical characteristics of star-forming clumps if they are coherent structures produced by disc fragmentation.

  3. The limit of time resolution in frequency modulation atomic force microscopy by a pump-probe approach

    Science.gov (United States)

    Schumacher, Zeno; Spielhofer, Andreas; Miyahara, Yoichi; Grutter, Peter

    2017-01-01

    Atomic force microscopy (AFM) routinely achieves structural information in the sub-nm length scale. Measuring time resolved properties on this length scale to understand kinetics at the nm scale remains an elusive goal. We present a general analysis of the lower limit for time resolution in AFM. Our finding suggests that the time resolution in AFM is ultimately limited by the well-known thermal limit of AFM and not as often proposed by the mechanical response time of the force sensing cantilever. We demonstrate a general pump-probe approach using the cantilever as a detector responding to the averaged signal. This method can be applied to any excitation signal such as electrical, thermal, magnetic or optical. Experimental implementation of this method allows us to measure a photocarrier decay time of ˜1 ps in low temperature grown GaAs using a cantilever with a resonant frequency of 280 kHz.

  4. 28 CFR 14.6 - Dispute resolution techniques and limitations on agency authority.

    Science.gov (United States)

    2010-07-01

    ... disputed factual questions regarding claims against the United States under the FTCA, including 28 U.S.C... resolution techniques or processes should not be adopted arbitrarily but rather should be based upon a... 28 U.S.C. 2672 only after consultation with the Department of Justice when, in the opinion of the...

  5. Stacking it up: Exploring the limits of ultra-high resolution atomic force microscopy

    NARCIS (Netherlands)

    van der Heijden, N.J.|info:eu-repo/dai/nl/369392205

    2017-01-01

    Atomic force microscopy (AFM) is a technique wherein an atomically sharp needle raster scans across a surface, detecting forces between it and the sample. In state-of-the-art AFM experiments the measured forces are typically on the order of pico-Newtons, and the lateral resolution is on the order of

  6. Limits on the spatial resolution of monolithic scintillators read out by APD arrays

    NARCIS (Netherlands)

    Laan, D.J.J. van der; Maas, M.C.; Bruyndonckx, P.; Schaart, D.R.

    2012-01-01

    Cramér-Rao theory can be used to derive the lower bound on the spatial resolution achievable with position-sensitive scintillation detectors as a function of the detector geometry and the pertinent physical properties of the scintillator, the photosensor and the readout electronics. Knowledge of the

  7. Group-focused morality is associated with limited conflict detection and resolution capacity: Neuroanatomical evidence.

    Science.gov (United States)

    Nash, Kyle; Baumgartner, Thomas; Knoch, Daria

    2017-02-01

    Group-focused moral foundations (GMFs) - moral values that help protect the group's welfare - sharply divide conservatives from liberals and religiously devout from non-believers. However, there is little evidence about what drives this divide. Moral foundations theory and the model of motivated social cognition both associate group-focused moral foundations with differences in conflict detection and resolution capacity, but in opposing directions. Individual differences in conflict detection and resolution implicate specific neuroanatomical differences. Examining neuroanatomy thus affords an objective and non-biased opportunity to contrast these influential theories. Here, we report that increased adherence to group-focused moral foundations was strongly associated (whole-brain corrected) with reduced gray matter volume in key regions of the conflict detection and resolution system (anterior cingulate cortex and lateral prefrontal cortex). Because reduced gray matter is reliably associated with reduced neural and cognitive capacity, these findings support the idea outlined in the model of motivated social cognition that belief in group-focused moral values is associated with reduced conflict detection and resolution capacity. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. CT energy weighting in the presence of scatter and limited energy resolution

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, Taly Gilat [Department of Biomedical Engineering, Marquette University, Milwaukee, Wisconsin 53201 (United States)

    2010-03-15

    Purpose: Energy-resolved CT has the potential to improve the contrast-to-noise ratio (CNR) through optimal weighting of photons detected in energy bins. In general, optimal weighting gives higher weight to the lower energy photons that contain the most contrast information. However, low-energy photons are generally most corrupted by scatter and spectrum tailing, an effect caused by the limited energy resolution of the detector. This article first quantifies the effects of spectrum tailing on energy-resolved data, which may also be beneficial for material decomposition applications. Subsequently, the combined effects of energy weighting, spectrum tailing, and scatter are investigated through simulations. Methods: The study first investigated the effects of spectrum tailing on the estimated attenuation coefficients of homogeneous slab objects. Next, the study compared the CNR and artifact performance of images simulated with varying levels of scatter and spectrum tailing effects, and reconstructed with energy integrating, photon-counting, and two optimal linear weighting methods: Projection-based and image-based weighting. Realistic detector energy-response functions were simulated based on a previously proposed model. The energy-response functions represent the probability that a photon incident on the detector at a particular energy will be detected at a different energy. Realistic scatter was simulated with Monte Carlo methods. Results: Spectrum tailing resulted in a negative shift in the estimated attenuation coefficient of slab objects compared to an ideal detector. The magnitude of the shift varied with material composition, increased with material thickness, and decreased with photon energy. Spectrum tailing caused cupping artifacts and CT number inaccuracies in images reconstructed with optimal energy weighting, and did not impact images reconstructed with photon counting weighting. Spectrum tailing did not significantly impact the CNR in reconstructed images

  9. 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 ...

  10. Crossing the Resolution Limit in Near-Infrared Imaging of Silicon Chips: Targeting 10-nm Node Technology

    Directory of Open Access Journals (Sweden)

    Krishna Agarwal

    2015-05-01

    Full Text Available The best reported resolution in optical failure analysis of silicon chips is 120-nm half pitch demonstrated by Semicaps Private Limited, whereas the current and future industry requirement for 10-nm node technology is 100-nm half pitch. We show the first experimental evidence for resolution of features with 100-nm half pitch buried in silicon (λ/10.6, thus fulfilling the industry requirement. These results are obtained using near-infrared reflection-mode imaging using a solid immersion lens. The key novel feature of our approach is the choice of an appropriately sized collection pinhole. Although it is usually understood that, in general, resolution is improved by using the smallest pinhole consistent with an adequate signal level, it is found that in practice for silicon chips there is an optimum pinhole size, determined by the generation of induced currents in the sample. In failure analysis of silicon chips, nondestructive imaging is important to avoid disturbing the functionality of integrated circuits. High-resolution imaging techniques like SEM or TEM require the transistors to be exposed destructively. Optical microscopy techniques may be used, but silicon is opaque in the visible spectrum, mandating the use of near-infrared light and thus poor resolution in conventional optical microscopy. We expect our result to change the way semiconductor failure analysis is performed.

  11. Testing the limits of high-resolution whole-rock δ13Ccarb stratigraphy

    Science.gov (United States)

    McLaughlin, P.; Emsbo, P.; Brett, C.; Hurth, M.; Sell, B. K.; Johnson, C. A.

    2014-12-01

    Uncertainty about the effects of "diagenetic noise" on primary δ13Ccarb signals has been a principal obstacle in interpreting whole-rock δ13Ccarb stratigraphy. We have evaluated the fidelity of the whole-rock δ13Ccarb signal through a high-resolution sampling of correlative marine Paleozoic sections in North America and Europe across facies transitions spanning pure limestone to calcareous black shale and sandstone. Sections altered by metosomatic (diagenetic and hydrothermal) processes were specifically targeted for comparison with pristine unaltered sections. Precise stratigraphic correlations were confirmed using bentonite fingerprinting/dating, Sr-isotope stratigraphy, and whole-rock XRF chemistry. Our results demonstrate that whole-rock δ13Ccarb is an extraordinarily robust signal of global marine δ13C compositions. Correlative sections show strikingly similar δ13Ccarb values and patterns regardless of location, facies and rock type. Closely spaced successions of pristine limestone show highly reproducible δ13Ccarb profiles. Remarkably, δ13Ccarb trends cut across zones of alteration with no offset, and sections completely replaced by diagenetic/hydrothermal dolomite produce the same δ13Ccarb profiles as their unaltered counterparts. Our study confirms that whole-rock δ13Ccarb is an unprecedented chronostratigraphic tool. Our high-resolution approach identified abrupt offsets in δ13Ccarb profiles that correspond with unconformity horizons (supported by sedimentologic features) that can be correlated throughout different basins around the globe. A systematic covariation between shallowing-deepening trends and δ13Ccarb demonstrates its primary origin. The fidelity of the high-resolution record provides previously unattainable fine-scale temporal correlation - a resolution that, ultimately, will be required to fully understand the processes that fractionate the global carbon reservoir and have led to its overarching control on Earths evolution.

  12. The Break

    DEFF Research Database (Denmark)

    Strand, Anete Mikkala Camille; Larsen, Jens

    2015-01-01

    that language and the social has been granted too much power on the dispense of the bodily, physical and biological – or in short, in dispense of the material. The break To be or not to be poses the theoretical notion of dis-/continuity (Barad, 2007, 2010) from the quantum approach to storytelling (Strand 2012...... and euro each year. The paper tries to explore new ways to deal with these challenges through a quantum approach to storytelling where the enactment of core values, bodies, spaces and artifacts positions managers and CEO’s from major Scandinavian organizations in sites where they can re-evaluate their life...... stones on a table in an office of a municipality in Denmark. Silence….. Rebuilding rooms for taking breaks with the inclusion of different activities such as a game of soccer or a hike seems to provide the tools to rework these imbalances or enslaving patterns. Break……. The attempt at meeting...

  13. Cooperative folding near the downhill limit determined with amino acid resolution by hydrogen exchange

    Science.gov (United States)

    Yu, Wookyung; Baxa, Michael C.; Gagnon, Isabelle; Freed, Karl F.; Sosnick, Tobin R.

    2016-01-01

    The relationship between folding cooperativity and downhill, or barrier-free, folding of proteins under highly stabilizing conditions remains an unresolved topic, especially for proteins such as λ-repressor that fold on the microsecond timescale. Under aqueous conditions where downhill folding is most likely to occur, we measure the stability of multiple H bonds, using hydrogen exchange (HX) in a λYA variant that is suggested to be an incipient downhill folder having an extrapolated folding rate constant of 2 × 105 s−1 and a stability of 7.4 kcal·mol−1 at 298 K. At least one H bond on each of the three largest helices (α1, α3, and α4) breaks during a common unfolding event that reflects global denaturation. The use of HX enables us to both examine folding under highly stabilizing, native-like conditions and probe the pretransition state region for stable species without the need to initiate the folding reaction. The equivalence of the stability determined at zero and high denaturant indicates that any residual denatured state structure minimally affects the stability even under native conditions. Using our ψ analysis method along with mutational ϕ analysis, we find that the three aforementioned helices are all present in the folding transition state. Hence, the free energy surface has a sufficiently high barrier separating the denatured and native states that folding appears cooperative even under extremely stable and fast folding conditions. PMID:27078098

  14. Limits on the spatial resolution of monolithic scintillators read out by APD arrays.

    Science.gov (United States)

    van der Laan, D J Jan; Maas, Marnix C; Bruyndonckx, Peter; Schaart, Dennis R

    2012-10-21

    Cramér-Rao theory can be used to derive the lower bound on the spatial resolution achievable with position-sensitive scintillation detectors as a function of the detector geometry and the pertinent physical properties of the scintillator, the photosensor and the readout electronics. Knowledge of the Cramér-Rao lower bound (CRLB) can for example be used to optimize the detector design and to test the performance of the method used to derive position information from the detector signals. Here, this approach is demonstrated for monolithic scintillator detectors for positron emission tomography. Two detector geometries are investigated: a 20 × 10 × 10 mm(3) and a 20 × 10 × 20 mm(3) monolithic LYSO:Ce(3+) crystal read out by one or two Hamamatsu S8550SPL avalanche photodiode (APD) arrays, respectively. The results indicate that in these detectors the CRLB is primarily determined by the APD excess noise factor and the number of scintillation photons detected. Furthermore, it is shown that the use of a k-nearest neighbor (k-NN) algorithm for position estimation allows the experimentally obtained spatial resolution to closely approach the CRLB. The approach outlined in this work can in principle be applied to any scintillation detector in which position information is encoded in the distribution of the scintillation light over multiple photosensor elements.

  15. Theoretical limits to sensitivity and resolution in magneto-acousto-electrical tomography

    Science.gov (United States)

    Ghalichi, Elyar; Güneri Gençer, Nevzat

    2017-10-01

    In this study, the performance of magneto-acousto-electrical tomography (MAET) is investigated quantitatively by considering interrelations between its sensitivity, resolution and conductivity contrast. An analytical solution for the forward problem of MAET is derived for two-dimensional (2D) concentric bodies by the separation of variables method. The electric potential and the acoustic pressure are separated into their angular and radial components. The series coefficients for these solutions are obtained from their respective boundary conditions. The electric potential on the boundary is related to the acoustic boundary acceleration analytically. From this relation, a sensitivity expression is derived relating fractional change in conductivity contrast to fractional change in the measured electric potential. This expression is a function of the resolution and conductivity contrast of the imaging system. It also depends on the acoustic wave number and the dimensions of the body. The pair-wise relations between these parameters are presented. The sensitivity behavior of MAET is compared with applied current electrical impedance tomography and the improvements for small inhomogeneities are presented. For eccentric bodies, a modified expression for the sensitivity is obtained by conformal mapping. For arbitrary periodic boundary excitations, the sensitivity expressions for harmonic cases are combined to obtain a unified sensitivity expression.

  16. Global high resolution versus Limited Area Model climate change projections over Europe

    DEFF Research Database (Denmark)

    Déqué, Michel; Jones, R. G.; Wild, M.

    2005-01-01

    the 2071-2100 and the 1961-1990 means is compared with the same diagnostic obtained with nine Regional Climate Models (RCM) all driven by the Hadley Centre atmospheric GCM. The seasonal mean response for 2m temperature and precipitation is investigated. For temperature, GCMs and RCMs behave similarly......, except that GCMs exhibit a larger spread. However, during summer, the spread of the RCMs - in particular in terms of precipitation - is larger than that of the GCMs. This indicates that the European summer climate is strongly controlled by parameterized physics and/or high-resolution processes....... The temperature response is larger than the systematic error. The situation is different for precipitation. The model bias is twice as large as the climate response. The confidence in PRUDENCE results comes from the fact that the models have a similar response to the IPCC-SRES A2 forcing, whereas their systematic...

  17. Central Printing Management System: A case study of Contact Resolution Nigeria Limited

    OpenAIRE

    RASAQ, MORUF OLALEKAN

    2016-01-01

    At a period when all entry in the budget is under intense scrutiny, Organizations searches for a strategy to minimize cost. This necessitates Contact solution limited to actively give consideration to office printing as a significant opportunity. Advancement in technology and compliance to meet information security challenges in printing, faxing, email, scanning and device integrity drives the company to centralize, scrutinize and standardize office output. The aim of this project is to ...

  18. Image quality assessment for determining efficacy and limitations of Super-Resolution Convolutional Neural Network (SRCNN)

    Science.gov (United States)

    Ward, Chris M.; Harguess, Joshua; Crabb, Brendan; Parameswaran, Shibin

    2017-09-01

    Traditional metrics for evaluating the efficacy of image processing techniques do not lend themselves to under- standing the capabilities and limitations of modern image processing methods - particularly those enabled by deep learning. When applying image processing in engineering solutions, a scientist or engineer has a need to justify their design decisions with clear metrics. By applying blind/referenceless image spatial quality (BRISQUE), Structural SIMilarity (SSIM) index scores, and Peak signal-to-noise ratio (PSNR) to images before and after im- age processing, we can quantify quality improvements in a meaningful way and determine the lowest recoverable image quality for a given method.

  19. 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.

  20. Optical Sideband Generation: a Longitudinal Electron Beam Diagnostic Beyond the Laser Bandwidth Resolution Limit

    Energy Technology Data Exchange (ETDEWEB)

    Lawrence Berkeley National Laboratory; Tilborg, J. van; Matlis, N. H.; Plateau, G. R.; Leemans, W. P.

    2010-06-01

    Electro-optic sampling (EOS) is widely used as a technique to measure THz-domain electric field pulses such asthe self-fields of femtosecond electron beams. We present an EOS-based approach for single-shot spectral measurement that excels in simplicity (compatible with fiber integration) and bandwidth coverage (overcomes the laser bandwidth limitation), allowing few-fs electron beams or single-cycle THz pulses to be characterized with conventional picosecond probes. It is shown that the EOS-induced optical sidebands on the narrow-bandwidth optical probe are spectrally-shifted replicas of the THz pulse. An experimental demonstration on a 0-3 THz source is presented.

  1. Upper limits for stratospheric H2O2 and HOCl from high resolution balloon-borne infrared solar absorption spectra

    Science.gov (United States)

    Larsen, J. C.; Rinsland, C. P.; Goldman, A.; Murcray, D. G.; Murcray, F. J.

    1985-01-01

    Solar absorption spectra from two stratospheric balloon flights have been analyzed for the presence of H2O2 and HOCl absorption in the 1230.0 to 1255.0 per cm region. The data were recorded at 0.02 per cm resolution during sunset with the University of Denver interferometer system on October 27, 1978 and March 23, 1981. Selected spectral regions were analyzed with the technique of nonlinear least squares spectral curve fitting. Upper limits of 0.33 ppbv for H2O2 and 0.36 ppbv for HOCl near 28 km are derived from the 1978 flight data while upper limits of 0.44 ppbv for H2O2 and 0.43 ppbv for HOCl at 29.5 km are obtained from the 1981 flight data.

  2. 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.”...

  3. Fine-resolution conservation planning with limited climate-change information

    Science.gov (United States)

    Shah, Payal; Mallory, Mindy L.; Ando , Amy W.; Guntenspergen, Glenn R.

    2017-01-01

    Climate change related uncertainty in future spatial patterns of conservation-related outcomes make it difficult to implement standard conservation and land-use planning paradigms. A recent study translates Markowitz’s risk diversification strategy from finance to conservation settings, enabling policy makers and conservation agents to use this diversification strategy for allocating conservation and restoration investments across space to overcome such uncertainty. However this method is information intensive and requires a large number of climate change scenarios for carrying out fine scale conservation planning. We develop an iterative portfolio 47 analysis technique that enables policy makers and conservation agents to allocate scarce conservation resources across a desired level of sub-regions in a planning landscape in the absence of sufficient number of climate scenarios. We use a case study of the Prairie Pothole Region to show that lack of sufficient information prevents a conservation agent from attaining the most efficient risk-return conservation outcomes. However, our iterative approach enables a decision maker to do fine-scale portfolio allocation with limited available climate change forecasts in a manner that obtains the best possible risk-return combinations, especially when targeting low risk opportunities.

  4. Heterogeneous pattern of retinal nerve fiber layer in multiple sclerosis. High resolution optical coherence tomography: potential and limitations.

    Science.gov (United States)

    Serbecic, Nermin; Aboul-Enein, Fahmy; Beutelspacher, Sven C; Graf, Martin; Kircher, Karl; Geitzenauer, Wolfgang; Brannath, Werner; Lang, Priska; Kristoferitsch, Wolfgang; Lassmann, Hans; Reitner, Andreas; Schmidt-Erfurth, Ursula

    2010-11-08

    Recently the reduction of the retinal nerve fibre layer (RNFL) was suggested to be associated with diffuse axonal damage in the whole CNS of multiple sclerosis (MS) patients. However, several points are still under discussion. (1) Is high resolution optical coherence tomography (OCT) required to detect the partly very subtle RNFL changes seen in MS patients? (2) Can a reduction of RNFL be detected in all MS patients, even in early disease courses and in all MS subtypes? (3) Does an optic neuritis (ON) or focal lesions along the visual pathways, which are both very common in MS, limit the predication of diffuse axonal degeneration in the whole CNS? The purpose of our study was to determine the baseline characteristics of clinical definite relapsing-remitting (RRMS) and secondary progressive (SPMS) MS patients with high resolution OCT technique. Forty-two RRMS and 17 SPMS patients with and without history of uni- or bilateral ON, and 59 age- and sex-matched healthy controls were analysed prospectively with the high resolution spectral-domain OCT device (SD-OCT) using the Spectralis 3.5mm circle scan protocol with locked reference images and eye tracking mode. Furthermore we performed tests for visual and contrast acuity and sensitivity (ETDRS, Sloan and Pelli-Robson-charts), for color vision (Lanthony D-15), the Humphrey visual field and visual evoked potential testing (VEP). All 4 groups (RRMS and SPMS with or without ON) showed significantly reduced RNFL globally, or at least in one of the peripapillary sectors compared to age-/sex-matched healthy controls. In patients with previous ON additional RNFL reduction was found. However, in many RRMS patients the RNFL was found within normal range. We found no correlation between RNFL reduction and disease duration (range 9-540 months). RNFL baseline characteristics of RRMS and SPMS are heterogeneous (range from normal to markedly reduced levels).

  5. Heterogeneous pattern of retinal nerve fiber layer in multiple sclerosis. High resolution optical coherence tomography: potential and limitations.

    Directory of Open Access Journals (Sweden)

    Nermin Serbecic

    Full Text Available BACKGROUND: Recently the reduction of the retinal nerve fibre layer (RNFL was suggested to be associated with diffuse axonal damage in the whole CNS of multiple sclerosis (MS patients. However, several points are still under discussion. (1 Is high resolution optical coherence tomography (OCT required to detect the partly very subtle RNFL changes seen in MS patients? (2 Can a reduction of RNFL be detected in all MS patients, even in early disease courses and in all MS subtypes? (3 Does an optic neuritis (ON or focal lesions along the visual pathways, which are both very common in MS, limit the predication of diffuse axonal degeneration in the whole CNS? The purpose of our study was to determine the baseline characteristics of clinical definite relapsing-remitting (RRMS and secondary progressive (SPMS MS patients with high resolution OCT technique. METHODOLOGY: Forty-two RRMS and 17 SPMS patients with and without history of uni- or bilateral ON, and 59 age- and sex-matched healthy controls were analysed prospectively with the high resolution spectral-domain OCT device (SD-OCT using the Spectralis 3.5mm circle scan protocol with locked reference images and eye tracking mode. Furthermore we performed tests for visual and contrast acuity and sensitivity (ETDRS, Sloan and Pelli-Robson-charts, for color vision (Lanthony D-15, the Humphrey visual field and visual evoked potential testing (VEP. PRINCIPAL FINDINGS: All 4 groups (RRMS and SPMS with or without ON showed significantly reduced RNFL globally, or at least in one of the peripapillary sectors compared to age-/sex-matched healthy controls. In patients with previous ON additional RNFL reduction was found. However, in many RRMS patients the RNFL was found within normal range. We found no correlation between RNFL reduction and disease duration (range 9-540 months. CONCLUSIONS: RNFL baseline characteristics of RRMS and SPMS are heterogeneous (range from normal to markedly reduced levels.

  6. A Prior Knowledge-Based Method to Derivate High-Resolution Leaf Area Index Maps with Limited Field Measurements

    Directory of Open Access Journals (Sweden)

    Yuechan Shi

    2016-12-01

    Full Text Available High-resolution leaf area index (LAI maps from remote sensing data largely depend on empirical models, which link field LAI measurements to the vegetation index. The existing empirical methods often require the field measurements to be sufficient for constructing a reliable model. However, in many regions of the world, there are limited field measurements available. This paper presents a prior knowledge-based (PKB method to derivate LAI with limited field measurements, in an effort to improve the accuracy of empirical model. Based on the assumption that the experimental sites with the same vegetation type can be represented by similar models, a priori knowledge for crops was extracted from the published models in various cropland sites. The knowledge, composed of an initial guess of each model parameter with the associated uncertainty, was then combined with the local field measurements to determine a semi-empirical model using the Bayesian inversion method. The proposed method was evaluated at a cropland site in the Huailai region of Hebei Province, China. Compared with the regression method, the proposed PKB method can effectively improve the accuracy of empirical model and LAI estimation, when the field measurements were limited. The results demonstrate that a priori knowledge extracted from the universal sites can provide important auxiliary information to improve the representativeness of the empirical model in a given study area.

  7. Quantifying Efficacy and Limits of Unmanned Aerial Vehicle (UAV) Technology for Weed Seedling Detection as Affected by Sensor Resolution

    Science.gov (United States)

    Peña, José M.; Torres-Sánchez, Jorge; Serrano-Pérez, Angélica; de Castro, Ana I.; López-Granados, Francisca

    2015-01-01

    In order to optimize the application of herbicides in weed-crop systems, accurate and timely weed maps of the crop-field are required. In this context, this investigation quantified the efficacy and limitations of remote images collected with an unmanned aerial vehicle (UAV) for early detection of weed seedlings. The ability to discriminate weeds was significantly affected by the imagery spectral (type of camera), spatial (flight altitude) and temporal (the date of the study) resolutions. The colour-infrared images captured at 40 m and 50 days after sowing (date 2), when plants had 5–6 true leaves, had the highest weed detection accuracy (up to 91%). At this flight altitude, the images captured before date 2 had slightly better results than the images captured later. However, this trend changed in the visible-light images captured at 60 m and higher, which had notably better results on date 3 (57 days after sowing) because of the larger size of the weed plants. Our results showed the requirements on spectral and spatial resolutions needed to generate a suitable weed map early in the growing season, as well as the best moment for the UAV image acquisition, with the ultimate objective of applying site-specific weed management operations. PMID:25756867

  8. Quantifying efficacy and limits of unmanned aerial vehicle (UAV) technology for weed seedling detection as affected by sensor resolution.

    Science.gov (United States)

    Peña, José M; Torres-Sánchez, Jorge; Serrano-Pérez, Angélica; de Castro, Ana I; López-Granados, Francisca

    2015-03-06

    In order to optimize the application of herbicides in weed-crop systems, accurate and timely weed maps of the crop-field are required. In this context, this investigation quantified the efficacy and limitations of remote images collected with an unmanned aerial vehicle (UAV) for early detection of weed seedlings. The ability to discriminate weeds was significantly affected by the imagery spectral (type of camera), spatial (flight altitude) and temporal (the date of the study) resolutions. The colour-infrared images captured at 40 m and 50 days after sowing (date 2), when plants had 5-6 true leaves, had the highest weed detection accuracy (up to 91%). At this flight altitude, the images captured before date 2 had slightly better results than the images captured later. However, this trend changed in the visible-light images captured at 60 m and higher, which had notably better results on date 3 (57 days after sowing) because of the larger size of the weed plants. Our results showed the requirements on spectral and spatial resolutions needed to generate a suitable weed map early in the growing season, as well as the best moment for the UAV image acquisition, with the ultimate objective of applying site-specific weed management operations.

  9. Infection propagator approach to compute epidemic thresholds on temporal networks: impact of immunity and of limited temporal resolution

    CERN Document Server

    Valdano, Eugenio; Colizza, Vittoria

    2015-01-01

    The epidemic threshold of a spreading process indicates the condition for the occurrence of the wide spreading regime, thus representing a predictor of the network vulnerability to the epidemic. Such threshold depends on the natural history of the disease and on the pattern of contacts of the network with its time variation. Based on the theoretical framework introduced in (Valdano et al. PRX 2015) for a susceptible-infectious-susceptible model, we formulate here an infection propagator approach to compute the epidemic threshold accounting for more realistic effects regarding a varying force of infection per contact, the presence of immunity, and a limited time resolution of the temporal network. We apply the approach to two temporal network models and an empirical dataset of school contacts. We find that permanent or temporary immunity do not affect the estimation of the epidemic threshold through the infection propagator approach. Comparisons with numerical results show the good agreement of the analytical ...

  10. Breaking Bad

    DEFF Research Database (Denmark)

    Harlev, Mikkel Alexander; Sun Yin, Haohua; Langenheldt, Klaus Christian

    2018-01-01

    Bitcoin is a cryptocurrency whose transactions are recorded on a distributed, openly accessible ledger. On the Bitcoin Blockchain, an entity’s real-world identity is hidden behind a pseudonym, a so-called address. Therefore, Bitcoin is widely assumed to provide a high degree of anonymity, which...... is a driver for its frequent use for illicit activities. This paper presents a novel approach for reducing the anonymity of the Bitcoin Blockchain by using Supervised Machine Learning to predict the type of yet-unidentified entities. We utilised a sample of 434 entities with ≈ 200 million transactions...... discuss our novel approach of Supervised Machine Learning for uncovering Blockchain anonymity and its potential applications to forensics and financial compliance and its societal implications, outline study limitations and propose future research directions....

  11. Particles with similar LET values generate DNA breaks of different complexity and reparability: a high-resolution microscopy analysis of γH2AX/53BP1 foci.

    Science.gov (United States)

    Jezkova, Lucie; Zadneprianetc, Mariia; Kulikova, Elena; Smirnova, Elena; Bulanova, Tatiana; Depes, Daniel; Falkova, Iva; Boreyko, Alla; Krasavin, Evgeny; Davidkova, Marie; Kozubek, Stanislav; Valentova, Olga; Falk, Martin

    2018-01-18

    Biological effects of high-LET (linear energy transfer) radiation have received increasing attention, particularly in the context of more efficient radiotherapy and space exploration. Efficient cell killing by high-LET radiation depends on the physical ability of accelerated particles to generate complex DNA damage, which is largely mediated by LET. However, the characteristics of DNA damage and repair upon exposure to different particles with similar LET parameters remain unexplored. We employed high-resolution confocal microscopy to examine phosphorylated histone H2AX (γH2AX)/p53-binding protein 1 (53BP1) focus streaks at the microscale level, focusing on the complexity, spatiotemporal behaviour and repair of DNA double-strand breaks generated by boron and neon ions accelerated at similar LET values (∼135 keV μm-1) and low energies (8 and 47 MeV per n, respectively). Cells were irradiated using sharp-angle geometry and were spatially (3D) fixed to maximize the resolution of these analyses. Both high-LET radiation types generated highly complex γH2AX/53BP1 focus clusters with a larger size, increased irregularity and slower elimination than low-LET γ-rays. Surprisingly, neon ions produced even more complex γH2AX/53BP1 focus clusters than boron ions, consistent with DSB repair kinetics. Although the exposure of cells to γ-rays and boron ions eliminated a vast majority of foci (94% and 74%, respectively) within 24 h, 45% of the foci persisted in cells irradiated with neon. Our calculations suggest that the complexity of DSB damage critically depends on (increases with) the particle track core diameter. Thus, different particles with similar LET and energy may generate different types of DNA damage, which should be considered in future research.

  12. Statistical resolution limit for the multidimensional harmonic retrieval model: hypothesis test and Cramér-Rao Bound approaches

    Directory of Open Access Journals (Sweden)

    El Korso Mohammed

    2011-01-01

    Full Text Available Abstract The statistical resolution limit (SRL, which is defined as the minimal separation between parameters to allow a correct resolvability, is an important statistical tool to quantify the ultimate performance for parametric estimation problems. In this article, we generalize the concept of the SRL to the multidimensional SRL (MSRL applied to the multidimensional harmonic retrieval model. In this article, we derive the SRL for the so-called multidimensional harmonic retrieval model using a generalization of the previously introduced SRL concepts that we call multidimensional SRL (MSRL. We first derive the MSRL using an hypothesis test approach. This statistical test is shown to be asymptotically an uniformly most powerful test which is the strongest optimality statement that one could expect to obtain. Second, we link the proposed asymptotic MSRL based on the hypothesis test approach to a new extension of the SRL based on the Cramér-Rao Bound approach. Thus, a closed-form expression of the asymptotic MSRL is given and analyzed in the framework of the multidimensional harmonic retrieval model. Particularly, it is proved that the optimal MSRL is obtained for equi-powered sources and/or an equi-distributed number of sensors on each multi-way array.

  13. Integral-field spectroscopy at the resolution limit of large telescopes: the science program of OSIRIS at Keck

    Science.gov (United States)

    Quirrenbach, Andreas; Larkin, James E.; Krabbe, Alfred; Barczys, Matthew; LaFreniere, David

    2003-03-01

    OSIRIS (OH-Suppressing InfraRed Integral-field Spectrograph) is a new facility instrument for the Keck Observatory. Starting in 2004, it will provide the capability of performing three-dimensional spectroscopy in the near-infrared z, J, H, and K bands at the resolution limit of the Keck II telescope, which is equipped with adaptive optics and a laser guide star. The innovative capabilities of OSIRIS will enable many new observing projects. Galaxies in the early Universe will be among the most interesting targets for OSIRIS, which will perform detailed studies of their stellar content and dynamical properties. In more exotic objects, such as quasars, radio galaxies, and more nearby active galactic nuclei, OSIRIS can elucidate the relation of the central black hole to the properties of the host galaxy, and the mechanism by which gas is fed into the central engine. In the center of our own Galaxy, it will be possible to search for signatures of interaction between the massive black hole and stars in its immediate vicinity. Closer to home, OSIRIS will perform spectroscopic observations of young stars and their environment, and of brown dwarfs. Imaging spectroscopy of the giant planets, their moons, and asteroids will shed new light on meteorology, mineralogy, and volcanism in the Solar System. OSIRIS observations of Kuiper Belt objects will provide sufficient sensitivity to establish their surface composition, which will contribute substantially to our understanding of the history of the Solar System.

  14. Local density of electromagnetic states in plasmonic nanotapers: spatial resolution limits with nitrogen-vacancy centers in diamond nanospheres.

    Science.gov (United States)

    Salas-Montiel, Rafael; Berthel, Martin; Beltran-Madrigal, Josslyn; Huant, Serge; Drezet, Aurélien; Blaize, Sylvain

    2017-05-19

    One of the most explored single quantum emitters for the development of nanoscale fluorescence lifetime imaging is the nitrogen-vacancy (NV) color center in diamond. An NV center does not experience fluorescence bleaching or blinking at room temperature. Furthermore, its optical properties are preserved when embedded into nanodiamond hosts. This paper focuses on the modeling of the local density of states (LDOS) in a plasmonic nanofocusing structure with an NV center acting as local illumination sources. Numerical calculations of the LDOS near such a nanostructure were done with a classical electric dipole radiation placed inside a diamond sphere as well as near-field optical fluorescence lifetime imaging of the structure. We found that Purcell factors higher than ten can be reached with diamond nanospheres of radius less than 5 nm and at a distance of less than 20 nm from the surface of the structure. Although the spatial resolution of the experiment is limited by the size of the nanodiamond, our work supports the analysis and interpretation of a single NV color center in a nanodiamond as a probe for scanning near-field optical microscopy.

  15. Breaking the diffraction barrier in fluorescence microscopy by optical shelving.

    Science.gov (United States)

    Bretschneider, Stefan; Eggeling, Christian; Hell, Stefan W

    2007-05-25

    We report the breaking of the diffraction resolution barrier in far-field fluorescence microscopy by transiently shelving the fluorophore in a metastable dark state. Using a relatively modest light intensity of several kW/cm(2) in a focal distribution featuring a local zero, we confine the fluorescence emission to a spot whose diameter is a fraction of the wavelength of light. Nanoscale far-field optical resolution down to 50 nm is demonstrated by imaging microtubules in a mammalian cell and proteins on the plasma membrane of a neuron. The presence of dark states in virtually any fluorescent molecule opens up a new venue for far-field microscopy with resolution that is no longer limited by diffraction.

  16. Universality of the Break-up Profile for the KdV Equation in the Small Dispersion Limit Using the Riemann-Hilbert Approach

    Science.gov (United States)

    Claeys, T.; Grava, T.

    2009-03-01

    We obtain an asymptotic expansion for the solution of the Cauchy problem for the Korteweg-de Vries (KdV) equation u_t+6uu_x+ɛ2u_{xxx}=0,quad u(x,t=0,ɛ)=u_0(x), for {ɛ} small, near the point of gradient catastrophe ( x c , t c ) for the solution of the dispersionless equation u t + 6 uu x = 0. The sub-leading term in this expansion is described by the smooth solution of a fourth order ODE, which is a higher order analogue to the Painlevé I equation. This is in accordance with a conjecture of Dubrovin, suggesting that this is a universal phenomenon for any Hamiltonian perturbation of a hyperbolic equation. Using the Deift/Zhou steepest descent method applied on the Riemann-Hilbert problem for the KdV equation, we are able to prove the asymptotic expansion rigorously in a double scaling limit.

  17. Position resolution limits in pure noble gaseous detectors for X-ray energies from 1 to 60 keV

    Directory of Open Access Journals (Sweden)

    C.D.R. Azevedo

    2015-02-01

    Full Text Available The calculated position resolutions for X-ray photons (1–60 keV in pure noble gases at atmospheric pressure are presented. In this work we show the influence of the atomic shells and the detector dimensions on the intrinsic position resolution of the used noble gas. The calculated results were obtained by using a new software tool, Degrad, and compared to the available experimental data.

  18. Breaking Through the Multi-Mesa-Channel Width Limited of Normally Off GaN HEMTs Through Modulation of the Via-Hole-Length

    Science.gov (United States)

    Chien, Cheng-Yen; Wu, Wen-Hsin; You, Yao-Hong; Lin, Jun-Huei; Lee, Chia-Yu; Hsu, Wen-Ching; Kuan, Chieh-Hsiung; Lin, Ray-Ming

    2017-06-01

    We present new normally off GaN high-electron-mobility transistors (HEMTs) that overcome the typical limitations in multi-mesa-channel (MMC) width through modulation of the via-hole-length to regulate the charge neutrality screen effect. We have prepared enhancement-mode (E-mode) GaN HEMTs having widths of up to 300 nm, based on an enhanced surface pinning effect. E-mode GaN HEMTs having MMC structures and widths as well as via-hole-lengths of 100 nm/2 μm and 300 nm/6 μm, respectively, exhibited positive threshold voltages ( V th) of 0.79 and 0.46 V, respectively. The on-resistances of the MMC and via-hole-length structures were lower than those of typical tri-gate nanoribbon GaN HEMTs. In addition, the devices not only achieved the E-mode but also improved the power performance of the GaN HEMTs and effectively mitigated the device thermal effect. We controlled the via-hole-length sidewall surface pinning effect to obtain the E-mode GaN HEMTs. Our findings suggest that via-hole-length normally off GaN HEMTs have great potential for use in next-generation power electronics.

  19. PROVIDING STRINGENT STAR FORMATION RATE LIMITS OF z ∼ 2 QSO HOST GALAXIES AT HIGH ANGULAR RESOLUTION

    Energy Technology Data Exchange (ETDEWEB)

    Vayner, Andrey; Wright, Shelley A. [Department of Astronomy and Astrophysics, University of Toronto, 50 St. George Street, Toronto, ON, M5S 3H4 (Canada); Do, Tuan [Dunlap Institute for Astronomy and Astrophysics, University of Toronto, 50 St. George Street, Toronto, ON, M5S 3H4 (Canada); Larkin, James E. [Department of Physics and Astronomy, University of California, Los Angeles, CA 90095 (United States); Armus, Lee [Spitzer Science Center, California Institute of Technology, 1200 E. California Boulevard, Pasadena, CA 91125 (United States); Gallagher, S. C. [Department of Physics and Astronomy, The University of Western Ontario, London, ON N6A 3K7 (Canada)

    2016-04-10

    We present integral field spectrograph (IFS) with laser guide star adaptive optics (LGS-AO) observations of z ∼ 2 quasi-stellar objects (QSOs) designed to resolve extended nebular line emission from the host galaxy. Our data was obtained with W. M. Keck and Gemini North Observatories, using OSIRIS and NIFS coupled with the LGS-AO systems, respectively. We have conducted a pilot survey of five QSOs, three observed with NIFS+AO and two observed with OSIRIS+AO at an average redshift of z = 2.2. We demonstrate that the combination of AO and IFSs provides the necessary spatial and spectral resolutions required to separate QSO emission from its host. We present our technique for generating a point-spread function (PSF) from the broad-line region of the QSO and performing PSF subtraction of the QSO emission to detect the host galaxy emission at a separation of ∼0.″2 (∼1.4 kpc). We detect Hα narrow-line emission for two sources, SDSS J1029+6510 (z{sub Hα} = 2.182) and SDSS J0925+0655 (z{sub Hα} = 2.197), that have evidence for both star formation and extended narrow-line emission. Assuming that the majority of narrow-line Hα emission is from star formation, we infer a star formation rate (SFR) for SDSS J1029+6510 of 78.4 M{sub ⊙} yr{sup −1} originating from a compact region that is kinematically offset by 290–350 km s{sup −1}. For SDSS J0925+0655 we infer a SFR of 29 M{sub ⊙} yr{sup −1} distributed over three clumps that are spatially offset by ∼7 kpc. The null detections on three of the QSOs are used to infer surface brightness limits and we find that at 1.4 kpc from the QSO the un-reddened star formation limit is ≲0.3 M{sub ⊙} yr{sup −1} kpc{sup −2}. If we assume typical extinction values for z = 2 type-1 QSOs, the dereddened SFR for our null detections would be ≲0.6 M{sub ⊙} yr{sup −1} kpc{sup −2}. These IFS observations indicate that while the central black hole is accreting mass at 10%–40% of the Eddington rate, if

  20. Super-resolution photoacoustic imaging of single gold nanoparticles

    Science.gov (United States)

    Lee, Seunghyun; Kwon, Owoong; Jeon, Mansik; Song, Jaejung; Jo, Minguk; Kim, Sungjee; Son, Junwoo; Kim, Yunseok; Kim, Chulhong

    2016-03-01

    Photoacoustic imaging (PAI) is an emerging hybrid imaging modality that can provide a strong optical absorption contrast using the photoacoustic (PA) effect, and breaks through the fundamental imaging depth limit of existing optical microscopy such as optical coherence tomography (OCT), confocal or two-photon microscopy. In PAI, a short-pulsed laser is illuminated to the tissue, and the PA waves are generated by thermoelastic expansion. Despite the high lateral resolution of optical-resolution photoacoustic microscopy (OR-PAM) thanks to the tight optical focus, the lateral resolution of OR-PAM is limited to the optical diffraction limit, which is approximately a half of the excitation wavelength. Here, we demonstrate a new super-resolution photoacoustic microscopy (SR-PAM) system by breaking the optical diffraction limit. The conventional microscopes with nanoscale resolutions such as a scanning electron microscope (SEM) and transmission electron microscope (TEM) are typically used to image the structures of nanomaterials, but these systems should work in a high vacuum environment and cannot provide the optical properties of the materials. Our newly developed SR-PAM system provides the optical properties with a nanoscale resolution in a normal atmosphere. We have photoacoustically imaged single gold nanoparticles with an average size of 80 nm in diameter and shown their PA expansion properties individually. The lateral resolution of this system was approximately 20 nm. Therefore, this tool will provide an unprecedented optical absorption property with an accurate nanoscale resolution and greatly impact on materials science and nanotechnology field.

  1. Automatic Delineation of Sea-Cliff Limits Using Lidar-Derived High-Resolution DEMs in Southern California

    Science.gov (United States)

    Palaseanu, M.; Danielson, J.; Foxgrover, A. C.; Barnard, P.; Thatcher, C.; Brock, J. C.

    2014-12-01

    Seacliff erosion is a serious hazard with implications for coastal management, and is often estimated using successive hand digitized cliff tops or bases (toe) to assess cliff retreat. Traditionally the recession of the cliff top or cliff base is obtained from aerial photographs, topographic maps, or in situ surveys. Irrespective of how or what is measured to categorize cliff erosion, the position of the cliff top and cliff base is important. Habitually, the cliff top and base are hand digitized even when using high resolution lidar derived DEMs. Even if efforts were made to standardize and eliminate as much as possible any digitizing subjectivity, the delineation of cliffs is time consuming, and depends on the analyst's interpretation. We propose an automatic procedure to delineate the cliff top and base from high resolution bare-earth DEMs. The method is based on bare-earth high-resolution DEMs, generalized coastal shorelines and approximate measurements of distance between the shoreline and the cliff top. The method generates orthogonal transects and profiles with a minimum spacing equal to the DEM resolution and extracts for each profile xyz coordinates for cliff's top and toe, as well as second major positive and negative inflections (second top and toe) along the profile. The difference between the automated and digitized top and toe, respectively, is smaller than the DEM error margin for over 82% of the top points and 86% of the toe points along a stretch of coast in Del Mar, CA. The larger errors were due either to the failure to remove all vegetation from the bare-earth DEM or errors of interpretation during hand digitizing. The automatic method was further applied between Point Conception and Los Angeles Harbor, CA. This automatic method is repeatable, takes advantage of the bare-earth high-resolution, and is more efficient.

  2. Genome-wide mapping of DNA strand breaks.

    Directory of Open Access Journals (Sweden)

    Frédéric Leduc

    Full Text Available Determination of cellular DNA damage has so far been limited to global assessment of genome integrity whereas nucleotide-level mapping has been restricted to specific loci by the use of specific primers. Therefore, only limited DNA sequences can be studied and novel regions of genomic instability can hardly be discovered. Using a well-characterized yeast model, we describe a straightforward strategy to map genome-wide DNA strand breaks without compromising nucleotide-level resolution. This technique, termed "damaged DNA immunoprecipitation" (dDIP, uses immunoprecipitation and the terminal deoxynucleotidyl transferase-mediated dUTP-biotin end-labeling (TUNEL to capture DNA at break sites. When used in combination with microarray or next-generation sequencing technologies, dDIP will allow researchers to map genome-wide DNA strand breaks as well as other types of DNA damage and to establish a clear profiling of altered genes and/or intergenic sequences in various experimental conditions. This mapping technique could find several applications for instance in the study of aging, genotoxic drug screening, cancer, meiosis, radiation and oxidative DNA damage.

  3. Resolution enhancement by extrapolation of coherent diffraction images: a quantitative study on the limits and a numerical study of nonbinary and phase objects.

    Science.gov (United States)

    Latychevskaia, T; Chushkin, Y; Fink, H-W

    2016-10-01

    In coherent diffractive imaging, the resolution of the reconstructed object is limited by the numerical aperture of the experimental setup. We present here a theoretical and numerical study for achieving super-resolution by postextrapolation of coherent diffraction images, such as diffraction patterns or holograms. We demonstrate that a diffraction pattern can unambiguously be extrapolated from only a fraction of the entire pattern and that the ratio of the extrapolated signal to the originally available signal is linearly proportional to the oversampling ratio. Although there could be in principle other methods to achieve extrapolation, we devote our discussion to employing iterative phase retrieval methods and demonstrate their limits. We present two numerical studies; namely, the extrapolation of diffraction patterns of nonbinary and that of phase objects together with a discussion of the optimal extrapolation procedure. © 2016 The Authors Journal of Microscopy © 2016 Royal Microscopical Society.

  4. 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

  5. Fundamental limits of image registration performance: Effects of image noise and resolution in CT-guided interventions.

    Science.gov (United States)

    Ketcha, M D; de Silva, T; Han, R; Uneri, A; Goerres, J; Jacobson, M; Vogt, S; Kleinszig, G; Siewerdsen, J H

    2017-02-11

    In image-guided procedures, image acquisition is often performed primarily for the task of geometrically registering information from another image dataset, rather than detection / visualization of a particular feature. While the ability to detect a particular feature in an image has been studied extensively with respect to image quality characteristics (noise, resolution) and is an ongoing, active area of research, comparatively little has been accomplished to relate such image quality characteristics to registration performance. To establish such a framework, we derived Cramer-Rao lower bounds (CRLB) for registration accuracy, revealing the underlying dependencies on image variance and gradient strength. The CRLB was analyzed as a function of image quality factors (in particular, dose) for various similarity metrics and compared to registration accuracy using CT images of an anthropomorphic head phantom at various simulated dose levels. Performance was evaluated in terms of root mean square error (RMSE) of the registration parameters. Analysis of the CRLB shows two primary dependencies: 1) noise variance (related to dose); and 2) sum of squared image gradients (related to spatial resolution and image content). Comparison of the measured RMSE to the CRLB showed that the best registration method, RMSE achieved the CRLB to within an efficiency factor of 0.21, and optimal estimators followed the predicted inverse proportionality between registration performance and radiation dose. Analysis of the CRLB for image registration is an important step toward understanding and evaluating an intraoperative imaging system with respect to a registration task. While the CRLB is optimistic in absolute performance, it reveals a basis for relating the performance of registration estimators as a function of noise content and may be used to guide acquisition parameter selection (e.g., dose) for purposes of intraoperative registration.

  6. Active and break spells of the Indian summer monsoon

    Indian Academy of Sciences (India)

    In this paper, we suggest criteria for the identification of active and break events of the Indian summer monsoon on the basis of recently derived high resolution daily gridded rainfall dataset over India (1951–2007). Active and break events are defined as periods during the peak monsoon months of July and August, in which ...

  7. Microsphere-aided optical microscopy and its applications for super-resolution imaging

    Science.gov (United States)

    Upputuri, Paul Kumar; Pramanik, Manojit

    2017-12-01

    The spatial resolution of a standard optical microscope (SOM) is limited by diffraction. In visible spectrum, SOM can provide ∼ 200 nm resolution. To break the diffraction limit several approaches were developed including scanning near field microscopy, metamaterial super-lenses, nanoscale solid immersion lenses, super-oscillatory lenses, confocal fluorescence microscopy, techniques that exploit non-linear response of fluorophores like stimulated emission depletion microscopy, stochastic optical reconstruction microscopy, etc. Recently, photonic nanojet generated by a dielectric microsphere was used to break the diffraction limit. The microsphere-approach is simple, cost-effective and can be implemented under a standard microscope, hence it has gained enormous attention for super-resolution imaging. In this article, we briefly review the microsphere approach and its applications for super-resolution imaging in various optical imaging modalities.

  8. Discussion of limit values for mobile telecommunication systems as exemplified by the resolution of the Buergerforum ''Elektrosmog''; Diskussion von Richtwerten fuer den Mobilfunk am Beispiel der Resolution des Buergerforums ''Elektrosmog''

    Energy Technology Data Exchange (ETDEWEB)

    Hutter, H.P.; Moshammer, H.; Wallner, P.; Kundi, M. [Vienna Univ. (Austria). Inst. fuer Umwelthygiene

    2000-07-01

    The present state of knowledge still does not unequivocally support the derivation of limit values in the field of pulsed high frequency radiation (neither for base stations nor for mobile phones). The standpoint of preventative medicine calls for an exposure minimization strategy (ALARA-principle). The preliminary value used in Salzburg/Austria (1 mW/m{sup 2} at the nearest neighbour of a base station) corresponds, in our opinion, to a reasonable basis for handling modern mobile telecommunication technology. Furthermore, this value has the advantage that it can be achieved with current technology. An Austrian resolution, which was passed on to parliament on 30.11.1999, contains the requirement that this value be adopted for the whole of Austria. We believe that a further reduction, as proposed in the German resolution, cannot be justified in the light of current medical evidence. On the contrary, such a step is likely to be counterproductive and would result in a hardening of presently held opinions. However, the requirement that the local public should be involved in the process of establishing a base station, as demanded in both resolutions, is at least as important as the debate on the definition of limit values. (orig.) [German] Im gepulsten Hochfrequenzbereich ist derzeit noch keine endgueltige Grenzwertsetzung (weder fuer Sendeanlagen noch fuer Mobiltelefone) auf medizinischer Basis moeglich. Aufgrund der vorliegenden Befunde ist es aber vorsorgemedizinisch gesehen unumgaenglich, sich am Minimierungsprinzip (ALARA-Prinzip) zu orientieren. Der Gesundheitsvorsorgewert des Landes Salzburg (Leistungsflussdichte von 1 mW/m{sup 2} in der Wohnung des naechsten Nachbarn einer Sendeanlage) entspricht unserer Ansicht nach der Forderung nach einem vorsichtigen Umgang mit dem Mobilfunk. Dieser Wert hat gleichzeitig den Vorteil, dass es sich auch mit derzeit verfuegbarer Technik umsetzen laesst, ohne auf die moderne Kommunikationstechnologie verzichten zu muessen. Eine

  9. Measurement of trabecular bone thickness in the limited resolution regime of in vivo MRI by fuzzy distance transform.

    Science.gov (United States)

    Saha, Punam K; Wehrli, Felix W

    2004-01-01

    Trabecular or cancellous bone, the type of bone found in the vertebrae and near the joints of long bones, consists of a network of plates and struts. Accurate measurement of trabecular thickness is of significant interest, for example, to assess the effectiveness of anabolic (bone forming) agents of patients with osteoporosis. Here, we introduce a new fuzzy distance transform (FDT)-based thickness computation method that obviates binary segmentation and that can effectively deal with images acquired at a voxel size comparable to the typical trabecular bone thickness. The method's robustness is shown on the basis of micro-CT images of human trabecular bone, resampled at progressively coarser resolution and after application of rotation and addition of noise as a means to simulate the in vivo situation. Reproducibility of the method is demonstrated with micro-CT images by comparing histograms of thickness within and between data sets and with micro-MRI volume data sets of human volunteers imaged repeatedly. Finally, with in vivo micro-MR images from a prior study in rabbits subjected to corticosteroid exposure, it is demonstrated that short-term treatment resulting in trabecular thinning can be quantified with the new method.

  10. Atlantic hurricanes and associated insurance loss potentials in future climate scenarios: limitations of high-resolution AGCM simulations

    Directory of Open Access Journals (Sweden)

    Thomas F. Stocker

    2012-01-01

    Full Text Available Potential future changes in tropical cyclone (TC characteristics are among the more serious regional threats of global climate change. Therefore, a better understanding of how anthropogenic climate change may affect TCs and how these changes translate in socio-economic impacts is required. Here, we apply a TC detection and tracking method that was developed for ERA-40 data to time-slice experiments of two atmospheric general circulation models, namely the fifth version of the European Centre model of Hamburg model (MPI, Hamburg, Germany, T213 and the Japan Meteorological Agency/ Meteorological research Institute model (MRI, Tsukuba city, Japan, TL959. For each model, two climate simulations are available: a control simulation for present-day conditions to evaluate the model against observations, and a scenario simulation to assess future changes. The evaluation of the control simulations shows that the number of intense storms is underestimated due to the model resolution. To overcome this deficiency, simulated cyclone intensities are scaled to the best track data leading to a better representation of the TC intensities. Both models project an increased number of major hurricanes and modified trajectories in their scenario simulations. These changes have an effect on the projected loss potentials. However, these state-of-the-art models still yield contradicting results, and therefore they are not yet suitable to provide robust estimates of losses due to uncertainties in simulated hurricane intensity, location and frequency.

  11. Wave breaking in the surf zone and deep-water in a non-hydrostatic RANS model. Part 1: Organized wave motions

    Science.gov (United States)

    Derakhti, Morteza; Kirby, James T.; Shi, Fengyan; Ma, Gangfeng

    2016-11-01

    We examine wave-breaking predictions ranging from shallow- to deep-water conditions using a non-hydrostatic σ-coordinate RANS model NHWAVE as described in Derakhti et al. (2016a), comparing results both with corresponding experiments and with the results of a volume-of-fluid (VOF)/Navier-Stokes solver (Ma et al., 2011; Derakhti and Kirby, 2014a,b). Our study includes regular and irregular depth-limited breaking waves on planar and barred beaches as well as steepness-limited unsteady breaking focused wave packets in intermediate and deep water. In Part 1 of this paper, it is shown that the model resolves organized wave motions in terms of free-surface evolution, spectral evolution, organized wave velocity evolution and wave statistics, using a few vertical σ-levels. In addition, the relative contribution of modeled physical dissipation and numerical dissipation to the integral breaking-induced wave energy loss is discussed. In steepness-limited unsteady breaking focused wave packets, the turbulence model has not been triggered, and all the dissipation is imposed indirectly by the numerical scheme. Although the total wave-breaking-induced energy dissipation is underestimated in the unsteady wave packets, the model is capable of predicting the dispersive and nonlinear properties of different wave packet components before and after the break point, as well as the overall wave height decay and the evolution of organized wave velocity field and power spectrum density over the breaking region. In Part 2 (Derakhti et al., 2016b), model reproduction of wave-breaking-induced turbulence and mean circulation is examined in detail. The same equations and numerical methods are used for the various depth regimes, and no ad-hoc treatment, such as imposing hydrostatic conditions, is involved in triggering breaking. Vertical grid resolution in all simulated cases is at least an order of magnitude coarser than that of typical VOF-based simulations.

  12. A Simple Approach for Obtaining High Resolution, High Sensitivity ¹H NMR Metabolite Spectra of Biofluids with Limited Mass Supply

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Jian Zhi; Rommereim, Donald N.; Wind, Robert A.; Minard, Kevin R.; Sears, Jesse A.

    2006-11-01

    A simple approach is reported that yields high resolution, high sensitivity ¹H NMR spectra of biofluids with limited mass supply. This is achieved by spinning a capillary sample tube containing a biofluid at the magic angle at a frequency of about 80Hz. A 2D pulse sequence called ¹H PASS is then used to produce a high-resolution ¹H NMR spectrum that is free from magnetic susceptibility induced line broadening. With this new approach a high resolution ¹H NMR spectrum of biofluids with a volume less than 1.0 µl can be easily achieved at a magnetic field strength as low as 7.05T. Furthermore, the methodology facilitates easy sample handling, i.e., the samples can be directly collected into inexpensive and disposable capillary tubes at the site of collection and subsequently used for NMR measurements. In addition, slow magic angle spinning improves magnetic field shimming and is especially suitable for high throughput investigations. In this paper first results are shown obtained in a magnetic field of 7.05T on urine samples collected from mice using a modified commercial NMR probe.

  13. A Shadowing Problem in the Detection of Overlapping Communities: Lifting the Resolution Limit through a Cascading Procedure.

    Directory of Open Access Journals (Sweden)

    Jean-Gabriel Young

    Full Text Available Community detection is the process of assigning nodes and links in significant communities (e.g. clusters, function modules and its development has led to a better understanding of complex networks. When applied to sizable networks, we argue that most detection algorithms correctly identify prominent communities, but fail to do so across multiple scales. As a result, a significant fraction of the network is left uncharted. We show that this problem stems from larger or denser communities overshadowing smaller or sparser ones, and that this effect accounts for most of the undetected communities and unassigned links. We propose a generic cascading approach to community detection that circumvents the problem. Using real and artificial network datasets with three widely used community detection algorithms, we show how a simple cascading procedure allows for the detection of the missing communities. This work highlights a new detection limit of community structure, and we hope that our approach can inspire better community detection algorithms.

  14. A Shadowing Problem in the Detection of Overlapping Communities: Lifting the Resolution Limit through a Cascading Procedure.

    Science.gov (United States)

    Young, Jean-Gabriel; Allard, Antoine; Hébert-Dufresne, Laurent; Dubé, Louis J

    2015-01-01

    Community detection is the process of assigning nodes and links in significant communities (e.g. clusters, function modules) and its development has led to a better understanding of complex networks. When applied to sizable networks, we argue that most detection algorithms correctly identify prominent communities, but fail to do so across multiple scales. As a result, a significant fraction of the network is left uncharted. We show that this problem stems from larger or denser communities overshadowing smaller or sparser ones, and that this effect accounts for most of the undetected communities and unassigned links. We propose a generic cascading approach to community detection that circumvents the problem. Using real and artificial network datasets with three widely used community detection algorithms, we show how a simple cascading procedure allows for the detection of the missing communities. This work highlights a new detection limit of community structure, and we hope that our approach can inspire better community detection algorithms.

  15. Effect of Considering Sub-Grid Scale Uncertainties on the Forecasts of a High-Resolution Limited Area Ensemble Prediction System

    Science.gov (United States)

    Kim, SeHyun; Kim, Hyun Mee

    2017-05-01

    The ensemble prediction system (EPS) is widely used in research and at operation center because it can represent the uncertainty of predicted atmospheric state and provide information of probabilities. The high-resolution (so-called "convection-permitting") limited area EPS can represent the convection and turbulence related to precipitation phenomena in more detail, but it is also much sensitive to small-scale or sub-grid scale processes. The convection and turbulence are represented using physical processes in the model and model errors occur due to sub-grid scale processes that were not resolved. This study examined the effect of considering sub-grid scale uncertainties using the high-resolution limited area EPS of the Korea Meteorological Administration (KMA). The developed EPS has horizontal resolution of 3 km and 12 ensemble members. The initial and boundary conditions were provided by the global model. The Random Parameters (RP) scheme was used to represent sub-grid scale uncertainties. The EPSs with and without the RP scheme were developed and the results were compared. During the one month period of July, 2013, a significant difference was shown in the spread of 1.5 m temperature and the Root Mean Square Error and spread of 10 m zonal wind due to application of the RP scheme. For precipitation forecast, the precipitation tended to be overestimated relative to the observation when the RP scheme was applied. Moreover, the forecast became more accurate for heavy precipitations and the longer forecast lead times. For two heavy rainfall cases occurred during the research period, the higher Equitable Threat Score was observed for heavy precipitations in the system with the RP scheme compared to the one without, demonstrating consistency with the statistical results for the research period. Therefore, the predictability for heavy precipitation phenomena that affected the Korean Peninsula increases if the RP scheme is used to consider sub-grid scale uncertainties

  16. Intrinsic limits on resolutions in muon- and electron-neutrino charged-current events in the KM3NeT/ORCA detector

    Science.gov (United States)

    Adrián-Martínez, S.; Ageron, M.; Aiello, S.; Albert, A.; Ameli, F.; Anassontzis, E. G.; Andre, M.; Androulakis, G.; Anghinolfi, M.; Anton, G.; Ardid, M.; Avgitas, T.; Barbarino, G.; Barbarito, E.; Baret, B.; Barrios-Mart, J.; Belias, A.; Berbee, E.; van den Berg, A.; Bertin, V.; Beurthey, S.; van Beveren, V.; Beverini, N.; Biagi, S.; Biagioni, A.; Billault, M.; Bondì, M.; Bormuth, R.; Bouhadef, B.; Bourlis, G.; Bourret, S.; Boutonnet, C.; Bouwhuis, M.; Bozza, C.; Bruijn, R.; Brunner, J.; Buis, E.; Buompane, R.; Busto, J.; Cacopardo, G.; Caillat, L.; Calamai, M.; Calvo, D.; Capone, A.; Caramete, L.; Cecchini, S.; Celli, S.; Champion, C.; Cherubini, S.; Chiarella, V.; Chiarelli, L.; Chiarusi, T.; Circella, M.; Classen, L.; Cobas, D.; Cocimano, R.; Coelho, J. A. B.; Coleiro, A.; Colonges, S.; Coniglione, R.; Cordelli, M.; Cosquer, A.; Coyle, P.; Creusot, A.; Cuttone, G.; D'Amato, C.; D'Amico, A.; D'Onofrio, A.; De Bonis, G.; De Sio, C.; Di Palma, I.; Díaz, A. F.; Distefano, C.; Donzaud, C.; Dornic, D.; Dorosti-Hasankiadeh, Q.; Drakopoulou, E.; Drouhin, D.; Durocher, M.; Eberl, T.; Eichie, S.; van Eijk, D.; El Bojaddaini, I.; Elsaesser, D.; Enzenhöfer, A.; Favaro, M.; Fermani, P.; Ferrara, G.; Frascadore, G.; Furini, M.; Fusco, L. A.; Gal, T.; Galatà, S.; Garufi, F.; Gay, P.; Gebyehu, M.; Giacomini, F.; Gialanella, L.; Giordano, V.; Gizani, N.; Gracia, R.; Graf, K.; Grégoire, T.; Grella, G.; Grmek, A.; Guerzoni, M.; Habel, R.; Hallmann, S.; van Haren, H.; Harissopulos, S.; Heid, T.; Heijboer, A.; Heine, E.; Henry, S.; Hernández-Rey, J. J.; Hevinga, M.; Hofestädt, J.; Hugon, C. M. F.; Illuminati, G.; James, C. W.; Jansweijerf, P.; Jongen, M.; de Jong, M.; Kadler, M.; Kalekin, O.; Kappes, A.; Katz, U. F.; Keller, P.; Kieft, G.; Kießling, D.; Koffeman, E. N.; Kooijman, P.; Kouchner, A.; Kreter, M.; Kulikovskiy, V.; Lahmann, R.; Lamare, P.; Larosa, G.; Leisos, A.; Leone, F.; Leonora, E.; Lindsey Clark, M.; Liolios, A.; Llorens Alvarez, C. D.; Lo Presti, D.; Löhner, H.; Lonardo, A.; Lotze, M.; Loucatos, S.; Maccioni, E.; Mannheim, K.; Manzali, M.; Margiotta, A.; Margotti, A.; Marinelli, A.; Maris, O.; Markou, C.; Martínez-Mora, J. A.; Martini, A.; Marzaioli, F.; Mele, R.; Melis, K. W.; Michael, T.; Migliozzi, P.; Migneco, E.; Mijakowski, P.; Miraglia, A.; Mollo, C. M.; Mongelli, M.; Morganti, M.; Moussa, A.; Musico, P.; Musumeci, M.; Navas, S.; Nicolau, C. A.; Olcina, I.; Olivetto, C.; Orlando, A.; Orzelli, A.; Pancaldi, G.; Papaikonomou, A.; Papaleo, R.; Păvălas, G. E.; Peek, H.; Pellegrini, G.; Pellegrino, C.; Perrina, C.; Pfutzner, M.; Piattelli, P.; Pikounis, K.; Pleinert, M.-O.; Poma, G. E.; Popa, V.; Pradier, T.; Pratolongo, F.; Pühlhofer, G.; Pulvirenti, S.; Quinn, L.; Racca, C.; Raffaelli, F.; Randazzo, N.; Rauch, T.; Real, D.; Resvanis, L.; Reubelt, J.; Riccobene, G.; Rossi, C.; Rovelli, A.; Saldaña, M.; Salvadori, I.; Samtleben, D. F. E.; Sánchez García, A.; Sánchez Losa, A.; Sanguineti, M.; Santangelo, A.; Santonocito, D.; Sapienza, P.; Schimmel, F.; Schmelling, J.; Schnabel, J.; Sciacca, V.; Sedita, M.; Seitz, T.; Sgura, I.; Simeone, F.; Sipala, V.; Spisso, B.; Spurio, M.; Stavropoulos, G.; Steijger, J.; Stellacci, S. M.; Stransky, D.; Taiuti, M.; Tayalati, Y.; Terrasi, F.; Tézier, D.; Theraube, S.; Timmer, P.; Tönnis, C.; Trasatti, L.; Travaglini, R.; Trovato, A.; Tsirigotis, A.; Tzamarias, S.; Tzamariudaki, E.; Vallage, B.; Van Elewyck, V.; Vermeulen, J.; Versari, F.; Vicini, P.; Viola, S.; Vivolo, D.; Volkert, M.; Wiggers, L.; Wilms, J.; de Wolf, E.; Zachariadou, K.; Zani, S.; Zornoza, J. D.; Zúñiga, J.

    2017-05-01

    Studying atmospheric neutrino oscillations in the few-GeV range with a multi-megaton detector promises to determine the neutrino mass hierarchy. This is the main science goal pursued by the future KM3NeT/ORCA water Cherenkov detector in the Mediterranean Sea. In this paper, the processes that limit the obtainable resolution in both energy and direction in charged-current neutrino events in the ORCA detector are investigated. These processes include the composition of the hadronic fragmentation products, the subsequent particle propagation and the photon-sampling fraction of the detector. GEANT simulations of neutrino interactions in seawater produced by GENIE are used to study the effects in the 1-20 GeV range. It is found that fluctuations in the hadronic cascade in conjunction with the variation of the inelasticity y are most detrimental to the resolutions. The effect of limited photon sampling in the detector is of significantly less importance. These results will therefore also be applicable to similar detectors/media, such as those in ice. [Figure not available: see fulltext.

  17. Estimation of unknown structure parameters from high-resolution (S)TEM images: what are the limits?

    Science.gov (United States)

    den Dekker, A J; Gonnissen, J; De Backer, A; Sijbers, J; Van Aert, S

    2013-11-01

    Statistical parameter estimation theory is proposed as a quantitative method to measure unknown structure parameters from electron microscopy images. Images are then purely considered as data planes from which structure parameters have to be determined as accurately and precisely as possible using a parametric statistical model of the observations. For this purpose, an efficient algorithm is proposed for the estimation of atomic column positions and intensities from high angle annular dark field (HAADF) scanning transmission electron microscopy (STEM) images. Furthermore, the so-called Cramér-Rao lower bound (CRLB) is reviewed to determine the limits to the precision with which continuous parameters such as atomic column positions and intensities can be estimated. Since this lower bound can only be derived for continuous parameters, alternative measures using the principles of detection theory are introduced for problems concerning the estimation of discrete parameters such as atomic numbers. An experimental case study is presented to show the practical use of these measures for the optimization of the experiment design if the purpose is to decide between the presence of specific atom types using STEM images. © 2013 Elsevier B.V. All rights reserved.

  18. Macrophages in Injured Skeletal Muscle: A Perpetuum Mobile Causing and Limiting Fibrosis, Prompting or Restricting Resolution and Regeneration

    Science.gov (United States)

    Bosurgi, Lidia; Manfredi, Angelo A.; Rovere-Querini, Patrizia

    2011-01-01

    Macrophages are present in regenerating skeletal muscles and participate in the repair process. This is due to a unique feature of macrophages, i.e., their ability to perceive signals heralding ongoing tissue injury and to broadcast the news to cells suited at regenerating the tissue such as stem and progenitor cells. Macrophages play a complex role in the skeletal muscle, probably conveying information on the pattern of healing which is appropriate to ensure an effective healing of the tissue, yielding novel functional fibers. Conversely, they are likely to be involved in limiting the efficacy of regeneration, with formation of fibrotic scars and fat replacement of the tissue when the original insult persists. In this review we consider the beneficial versus the detrimental actions of macrophages during the response to muscle injury, with attention to the available information on the molecular code macrophages rely on to guide, throughout the various phases of muscle healing, the function of conventional and unconventional stem cells. Decrypting this code would represent a major step forward toward the establishment of novel targeted therapies for muscle diseases. PMID:22566851

  19. Macrophages in injured skeletal muscle: a perpetuum mobile causing and limiting fibrosis, prompting or restricting resolution and regeneration

    Directory of Open Access Journals (Sweden)

    Lidia eBosurgi

    2011-11-01

    Full Text Available Macrophages are present in regenerating skeletal muscles and participate in the repair process. This is due to a unique feature of macrophages, i.e. their ability to perceive signals heralding ongoing tissue injury and to broadcast the news to cells suited at regenerating the tissue such as stem and progenitor cells. Macrophages play a complex role in the skeletal muscle, probably conveying information on the pattern of healing which is appropriate to ensure an effective healing of the tissue, yielding novel functional fibers. Conversely, they are likely to be involved in limiting the efficacy of regeneration, with formation of fibrotic scars and fat replacement of the tissue when the original insult persists. In this review we consider the beneficial versus the detrimental actions of macrophages during the response to muscle injury, with attention to the available information on the molecular code macrophages rely on to guide, throughout the various phases of muscle healing, the function of conventional and unconventional stem cells. Decrypting this code would represent a major step forward towards the establishment of novel targeted therapies for muscle diseases.

  20. Super-resolution differential interference contrast microscopy by structured illumination.

    Science.gov (United States)

    Chen, Jianling; Xu, Yan; Lv, Xiaohua; Lai, Xiaomin; Zeng, Shaoqun

    2013-01-14

    We propose a structured illumination differential interference contrast (SI-DIC) microscopy, breaking the diffraction resolution limit of differential interference contrast (DIC) microscopy. SI-DIC extends the bandwidth of coherent transfer function of the DIC imaging system, thus the resolution is improved. With 0.8 numerical aperture condenser and objective, the reconstructed SI-DIC image of 53 nm polystyrene beads reveals lateral resolution of approximately 190 nm, doubling that of the conventional DIC image. We also demonstrate biological observations of label-free cells with improved spatial resolution. The SI-DIC microscopy can provide sub-diffraction resolution and high contrast images with marker-free specimens, and has the potential for achieving sub-diffraction resolution quantitative phase imaging.

  1. Resolution Limit in Community Detection

    National Research Council Canada - National Science Library

    Santo Fortunato; Marc Barthélemy

    2007-01-01

    Detecting community structure is fundamental for uncovering the links between structure and function in complex networks and for practical applications in many disciplines such as biology and sociology...

  2. 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,…

  3. Resolution and super-resolution.

    Science.gov (United States)

    Sheppard, Colin J R

    2017-06-01

    Many papers have claimed the attainment of super-resolution, i.e. resolution beyond that achieved classically, by measurement of the profile of a feature in the image. We argue that measurement of the contrast of the image of a dark bar on a bright background does not give a measure of resolution, but of detection sensitivity. The width of a bar that gives an intensity at the center of the bar of 0.735 that in the bright region (the same ratio as in the Rayleigh resolution criterion) is λ/(13.9×numerical aperture) for the coherent case with central illumination. This figure, which compares with λ/(numerical aperture) for the Abbe resolution limit with central illumination, holds for the classical case, and so is no indication of super-resolution. Theoretical images for two points, two lines, arrays of lines, arrays of bars, and grating objects are compared. These results can be used a reference for experimental results, to determine if super-resolution has indeed been attained. The history of the development of the theory of microscope resolution is outlined. © 2017 Wiley Periodicals, Inc.

  4. Exo-metabolome of Pseudovibrio sp. FO-BEG1 analyzed by ultra-high resolution mass spectrometry and the effect of phosphate limitation.

    Directory of Open Access Journals (Sweden)

    Stefano Romano

    Full Text Available Oceanic dissolved organic matter (DOM is an assemblage of reduced carbon compounds, which results from biotic and abiotic processes. The biotic processes consist in either release or uptake of specific molecules by marine organisms. Heterotrophic bacteria have been mostly considered to influence the DOM composition by preferential uptake of certain compounds. However, they also secrete a variety of molecules depending on physiological state, environmental and growth conditions, but so far the full set of compounds secreted by these bacteria has never been investigated. In this study, we analyzed the exo-metabolome, metabolites secreted into the environment, of the heterotrophic marine bacterium Pseudovibrio sp. FO-BEG1 via ultra-high resolution mass spectrometry, comparing phosphate limited with phosphate surplus growth conditions. Bacteria belonging to the Pseudovibrio genus have been isolated worldwide, mainly from marine invertebrates and were described as metabolically versatile Alphaproteobacteria. We show that the exo-metabolome is unexpectedly large and diverse, consisting of hundreds of compounds that differ by their molecular formulae. It is characterized by a dynamic recycling of molecules, and it is drastically affected by the physiological state of the strain. Moreover, we show that phosphate limitation greatly influences both the amount and the composition of the secreted molecules. By assigning the detected masses to general chemical categories, we observed that under phosphate surplus conditions the secreted molecules were mainly peptides and highly unsaturated compounds. In contrast, under phosphate limitation the composition of the exo-metabolome changed during bacterial growth, showing an increase in highly unsaturated, phenolic, and polyphenolic compounds. Finally, we annotated the detected masses using multiple metabolite databases. These analyses suggested the presence of several masses analogue to masses of known bioactive

  5. Breaking News as Radicalisation

    DEFF Research Database (Denmark)

    Hartley, Jannie Møller

    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...... in a media environment where immediacy rules (Domingo 2008a). Following this research the primary focus of this paper is the category breaking news and Tuchmans developing news, but as they are all connected the analysis will also draw upon the other categories in Tuchmans typology. The theoretical framework...

  6. Model for chiral symmetry breaking in QCD

    Energy Technology Data Exchange (ETDEWEB)

    Govaerts, J.; Weyers, J.; Mandula, J.E.

    1984-04-30

    A recently proposed model for dynamical breaking of chiral symmetry in QCD is extended and developed for the calculation of pion and chiral symmetry breaking parameters. The pion is explicitly realized as a massless Goldstone boson and as a bound state of the constituent quarks. We compute, in the limit of exact chiral symmetry, Msub(Q), the constituent quark mass, fsub(..pi..), the pion decay coupling, , the constituent quark loop density, ..mu..sub(..pi..)/sup 2//msub(q), the ratio of the Goldstone boson mass squared to the bare quark mass, and sub(..pi..), the pion electromagnetic charge radius squared.

  7. Temporal characterization of the wave-breaking flash in a laser plasma accelerator

    Science.gov (United States)

    Miao, Bo; Feder, Linus; Goers, Andrew; Hine, George; Salehi, Fatholah; Wahlstrand, Jared; Woodbury, Daniel; Milchberg, Howard

    2017-10-01

    Wave-breaking injection of electrons into a relativistic plasma wake generated in near-critical density plasma by sub-terawatt laser pulses generates an intense ( 1 μJ) and ultra-broadband (Δλ 300 nm) radiation flash. In this work we demonstrate the spectral coherence of this radiation and measure its temporal width using single-shot supercontinuum spectral interferometry (SSSI). The measured temporal width is limited by measurement resolution to 50 fs. Spectral coherence is corroborated by PIC simulations which show that the spatial extent of the acceleration trajectory at the trapping region is small compared to the radiation center wavelength. To our knowledge, this is the first temporal and coherence characterization of wave-breaking radiation. This work is supported by the US Department of Energy, the National Science Foundation, and the Air Force Office of Scientific Research.

  8. The high overtone and combination levels of SF6 revisited at Doppler-limited resolution: A global effective rovibrational model for highly excited vibrational states

    Science.gov (United States)

    Faye, M.; Boudon, V.; Loëte, M.; Roy, P.; Manceron, L.

    2017-03-01

    Sulfur hexafluoride is an important prototypal molecule for modeling highly excited vibrational energy flow and multi quanta absorption processes in hexafluoride molecules of technological importance. It is also a strong greenhouse gas of anthropogenic origin. This heavy species, however, features many hot bands at room temperature (at which only 30% of the molecules lie in the ground vibrational state), especially those originating from the lowest, v6=1 vibrational state. Using a cryogenic long path cell with variable optical path length and temperatures regulated between 120 and 163 K, coupled to Synchrotron Radiation and a high resolution interferometer, Doppler-limited spectra of the 2ν1 +ν3 , ν1 +ν2 +ν3 , ν1 +ν3 , ν2 +ν3 , 3ν3, ν2 + 3ν3 and ν1 + 3ν3 from 2000 to 4000 cm-1 near-infrared region has been recorded. Low temperature was used to limit the presence of hot bands. The spectrum has been analyzed thanks to the XTDS software package. Combining with previously observed weak difference bands in the far infrared region involving the v1, v2, v3=1 states, we are thus able to use the tensorial model to build a global fit of spectroscopic parameters for v1=1,2, v2=1, v3=1,2,3. The model constitutes a consistent set of molecular parameters and enable spectral rovibrational simulation for all multi-quanta transitions involving v1, v2 and v3 up to v1-3 = 3 . Tests simulation on rovibrational transitions not yet rovibrationally assigned are presented and compared to new experimental data.

  9. 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 ...... (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....

  10. 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.

  11. Multiple Break-Points Detection in Array CGH Data via the Cross-Entropy Method.

    Science.gov (United States)

    Priyadarshana, W J R M; Sofronov, Georgy

    2015-01-01

    Array comparative genome hybridization (aCGH) is a widely used methodology to detect copy number variations of a genome in high resolution. Knowing the number of break-points and their corresponding locations in genomic sequences serves different biological needs. Primarily, it helps to identify disease-causing genes that have functional importance in characterizing genome wide diseases. For human autosomes the normal copy number is two, whereas at the sites of oncogenes it increases (gain of DNA) and at the tumour suppressor genes it decreases (loss of DNA). The majority of the current detection methods are deterministic in their set-up and use dynamic programming or different smoothing techniques to obtain the estimates of copy number variations. These approaches limit the search space of the problem due to different assumptions considered in the methods and do not represent the true nature of the uncertainty associated with the unknown break-points in genomic sequences. We propose the Cross-Entropy method, which is a model-based stochastic optimization technique as an exact search method, to estimate both the number and locations of the break-points in aCGH data. We model the continuous scale log-ratio data obtained by the aCGH technique as a multiple break-point problem. The proposed methodology is compared with well established publicly available methods using both artificially generated data and real data. Results show that the proposed procedure is an effective way of estimating number and especially the locations of break-points with high level of precision. Availability: The methods described in this article are implemented in the new R package breakpoint and it is available from the Comprehensive R Archive Network at http://CRAN.R-project.org/package=breakpoint.

  12. 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...... breaks. Additional retinal breaks were only revealed at follow-up in patients where a full retinal examination was compromised at presentation by, for example, vitreous haemorrhage. Asymptomatic and symptomatic retinal breaks progressed to rhegmatogenous retinal detachment (RRD) in 0-13.8% and 35...

  13. Electroweak breaking in supersymmetric models

    CERN Document Server

    Ibáñez, L E

    1992-01-01

    We discuss the mechanism for electroweak symmetry breaking in supersymmetric versions of the standard model. After briefly reviewing the possible sources of supersymmetry breaking, we show how the required pattern of symmetry breaking can automatically result from the structure of quantum corrections in the theory. We demonstrate that this radiative breaking mechanism works well for a heavy top quark and can be combined in unified versions of the theory with excellent predictions for the running couplings of the model. (To be published in ``Perspectives in Higgs Physics'', G. Kane editor.)

  14. Seeing the forest tree by tree: super-resolution light microscopy meets the neurosciences.

    Science.gov (United States)

    Maglione, Marta; Sigrist, Stephan J

    2013-07-01

    Light microscopy can be applied in vivo and can sample large tissue volumes, features crucial for the study of single neurons and neural circuits. However, light microscopy per se is diffraction-limited in resolution, and the substructure of core signaling compartments of neuronal circuits--axons, presynaptic active zones, postsynaptic densities and dendritic spines-can be only insufficiently characterized by standard light microscopy. Recently, several forms of super-resolution light microscopy breaking the diffraction-imposed resolution limit have started to allow highly resolved, dynamic imaging in the cell-biologically highly relevant 10-100 nanometer range ('mesoscale'). New, sometimes surprising answers concerning how protein mobility and protein architectures shape neuronal communication have already emerged. Here we start by briefly introducing super-resolution microscopy techniques, before we describe their use in the analysis of neuronal compartments. We conclude with long-term prospects for super-resolution light microscopy in the molecular and cellular neurosciences.

  15. Limited copy number-high resolution melting (LCN-HRM) enables the detection and identification by sequencing of low level mutations in cancer biopsies

    National Research Council Canada - National Science Library

    Do, Hongdo; Dobrovic, Alexander

    2009-01-01

    .... High resolution melting (HRM) is more sensitive than sequencing but identification of the mutation is desirable, particularly when it is important to discriminate false positives due to PCR errors or template degradation from true...

  16. 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 ...

  17. 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.

  18. 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.

  19. Development of an iterative reconstruction method to overcome 2D detector low resolution limitations in MLC leaf position error detection for 3D dose verification in IMRT

    NARCIS (Netherlands)

    Visser, Ruurd; Godart, J.; Wauben, D. J. L.; Langendijk, J. A.; van't Veld, A. A.; Korevaar, E. W.

    2016-01-01

    The objective of this study was to introduce a new iterative method to reconstruct multi leaf collimator (MLC) positions based on low resolution ionization detector array measurements and to evaluate its error detection performance. The iterative reconstruction method consists of a fluence model, a

  20. 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.

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

    Science.gov (United States)

    Abel, Steven; Sannino, Francesco

    2017-09-01

    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.

  2. Nonlinear super-resolution nano-optics and applications

    CERN Document Server

    Wei, Jingsong

    2015-01-01

    This book covers many advances in the subjects of nano-optics and nano photonics. The author describes the principle and technical schematics of common methods for breaking through the optical diffraction limit and focuses on realizing optical super-resolution with nonlinear effects of thin film materials. The applications of nonlinear optical super-resolution effects in nano-data storage, nanolithography, and nano-imaging are also presented. This book is useful to graduate students majoring in optics and nano science and also serves as a reference book for academic researchers, engineers, technical professionals in the fields of super-resolution optics and laser techniques, nano-optics and nano photonics, nano-data storage, nano imaging, micro/nanofabrication and nanolithography and nonlinear optics.

  3. Testing the limits of Paleozoic chronostratigraphic correlation via high-resolution (13Ccarb) biochemostratigraphy across the Llandovery–Wenlock (Silurian) boundary: Is a unified Phanerozoic time scale achievable?

    Science.gov (United States)

    Cramer, Bradley D.; Loydell, David K.; Samtleben, Christian; Munnecke, Axel; Kaljo, Dimitri; Mannik, Peep; Martma, Tonu; Jeppsson, Lennart; Kleffner, Mark A.; Barrick, James E.; Johnson, Craig A.; Emsbo, Poul; Joachimski, Michael M.; Bickert, Torsten; Saltzman, Matthew R.

    2010-01-01

    The resolution and fidelity of global chronostratigraphic correlation are direct functions of the time period under consideration. By virtue of deep-ocean cores and astrochronology, the Cenozoic and Mesozoic time scales carry error bars of a few thousand years (k.y.) to a few hundred k.y. In contrast, most of the Paleozoic time scale carries error bars of plus or minus a few million years (m.y.), and chronostratigraphic control better than ??1 m.y. is considered "high resolution." The general lack of Paleozoic abyssal sediments and paucity of orbitally tuned Paleozoic data series combined with the relative incompleteness of the Paleozoic stratigraphic record have proven historically to be such an obstacle to intercontinental chronostratigraphic correlation that resolving the Paleozoic time scale to the level achieved during the Mesozoic and Cenozoic was viewed as impractical, impossible, or both. Here, we utilize integrated graptolite, conodont, and carbonate carbon isotope (??13Ccarb) data from three paleocontinents (Baltica, Avalonia, and Laurentia) to demonstrate chronostratigraphic control for upper Llando very through middle Wenlock (Telychian-Sheinwoodian, ~436-426 Ma) strata with a resolution of a few hundred k.y. The interval surrounding the base of the Wenlock Series can now be correlated globally with precision approaching 100 k.y., but some intervals (e.g., uppermost Telychian and upper Shein-woodian) are either yet to be studied in sufficient detail or do not show sufficient biologic speciation and/or extinction or carbon isotopic features to delineate such small time slices. Although producing such resolution during the Paleozoic presents an array of challenges unique to the era, we have begun to demonstrate that erecting a Paleozoic time scale comparable to that of younger eras is achievable. ?? 2010 Geological Society of America.

  4. Breaking the Rules in Style.

    Science.gov (United States)

    Romano, Tom

    1988-01-01

    Describes how allowing students to break the rules of standard writing can increase students' creativity in their written expression. Discusses several traits of this alternate style, or "Grammar B," including sentence fragments, double voice, lists, and spelling variations. (MM)

  5. Breaking the race barrier.

    Science.gov (United States)

    Minrath, M

    1985-08-01

    Through the reflective process of analyzing one's own feelings and reactions to the ethnic minority patient, the white therapist develops an inner clarity that serves as a resource to cope with the unique conflicts one must confront in interracial practice. Only when the therapist has come to some resolution of his or her own feelings about the plight of ethnic minorities in this country can this acumen develop. Although the therapeutic skills applied in psychotherapy with ethnic minorities are in no way different from overall therapeutic skills, certain techniques may be especially useful in interracial practice. For instance, a discussion of the meaning of race and ethnicity in the relationship may curtail racial distortion, prevent stereotyping, and lead to the creation of a therapeutic alliance. When dealing with transference and countertransference issues, the therapist must be particularly attentive to the representation of these same distortions and stereotypes. Formulating clinical problems from dual perspectives, theoretical and sociocultural, is an arduous, but necessary task. Finally, the white therapist must be able to view ethnic minority patients as individuals. Although these patients cope with special problems which must be acknowledged and dealt with in therapy, the therapist must realize there is a common ground on which to communicate. On this common ground, therapists discover the foundation of interracial clinical practice is the ability to accept and respect their patients and themselves as individuals who may have similar anxieties, problems, experiences, and goals. It is through the recognition and sharing of the fundamental human bond that ethnic and racial differences, which may have detrimental effects on interpersonal relationships, are transcended.

  6. Nearshore bars and the break-point hypothesis

    Science.gov (United States)

    Sallenger, A.H.; Howd, P.A.

    1989-01-01

    The set of hypotheses calling for bar formation at the break point was tested with field data. During two different experiments, waves were measured across the surf zone coincident with the development of a nearshore bar. We use a criterion, based on the wave height to depth ratio, to determine the offshore limit of the inner surf zone. During the first experiment, the bar became better developed and migrated offshore while remaining well within the inner surf zone. During the second experiment, the surf zone was narrower and we cannot rule out the possibility of break point processes contributing to bar development. We conclude that bars are not necessarily coupled with the break point and can become better developed and migrate offshore while being in the inner surf zone landward from initial wave breaking in the outer surf zone. ?? 1989.

  7. Non-minimal scalar multiplets, supersymmetry breaking and dualities

    Energy Technology Data Exchange (ETDEWEB)

    Farakos, Fotis; Hulík, Ondřej; Kočí, Pavel; Unge, Rikard von [Institute for Theoretical Physics, Masaryk University,611 37 Brno (Czech Republic)

    2015-09-25

    We study supersymmetry breaking in theories with non-minimal multiplets (such as the complex linear or CNM multiplets), by using superspace higher derivative terms which give rise to new supersymmetry breaking vacuum solutions on top of the standard supersymmetric vacuum. We illustrate the decoupling of the additional massive sectors inside the complex linear and the CNM multiplets and show that only the Goldstino sector is left in the low energy limit. We also discuss the duality between non-minimal scalar multiplets and chiral multiplets in the presence of superspace higher derivatives. From the superspace Noether procedure we calculate the supercurrents, and we show that in the supersymmetry breaking vacuum the chiral superfield X which enters the Ferrara-Zumino supercurrent conservation equation does indeed flow in the IR to the chiral constrained Goldstino superfield. We also provide a description of the Goldstino sector in terms of the Samuel-Wess superfield for the supersymmetry breaking mechanism at hand.

  8. On breaks of the Indian monsoon

    Indian Academy of Sciences (India)

    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 (2000), and Annamalai and Slingo (2001) have studied breaks and active minus break fluctuations. On the other hand, neither the traditional breaks ...

  9. Development of an iterative reconstruction method to overcome 2D detector low resolution limitations in MLC leaf position error detection for 3D dose verification in IMRT.

    Science.gov (United States)

    Visser, R; Godart, J; Wauben, D J L; Langendijk, J A; Van't Veld, A A; Korevaar, E W

    2016-05-21

    The objective of this study was to introduce a new iterative method to reconstruct multi leaf collimator (MLC) positions based on low resolution ionization detector array measurements and to evaluate its error detection performance. The iterative reconstruction method consists of a fluence model, a detector model and an optimizer. Expected detector response was calculated using a radiotherapy treatment plan in combination with the fluence model and detector model. MLC leaf positions were reconstructed by minimizing differences between expected and measured detector response. The iterative reconstruction method was evaluated for an Elekta SLi with 10.0 mm MLC leafs in combination with the COMPASS system and the MatriXX Evolution (IBA Dosimetry) detector with a spacing of 7.62 mm. The detector was positioned in such a way that each leaf pair of the MLC was aligned with one row of ionization chambers. Known leaf displacements were introduced in various field geometries ranging from  -10.0 mm to 10.0 mm. Error detection performance was tested for MLC leaf position dependency relative to the detector position, gantry angle dependency, monitor unit dependency, and for ten clinical intensity modulated radiotherapy (IMRT) treatment beams. For one clinical head and neck IMRT treatment beam, influence of the iterative reconstruction method on existing 3D dose reconstruction artifacts was evaluated. The described iterative reconstruction method was capable of individual MLC leaf position reconstruction with millimeter accuracy, independent of the relative detector position within the range of clinically applied MU's for IMRT. Dose reconstruction artifacts in a clinical IMRT treatment beam were considerably reduced as compared to the current dose verification procedure. The iterative reconstruction method allows high accuracy 3D dose verification by including actual MLC leaf positions reconstructed from low resolution 2D measurements.

  10. Intrinsic limits on resolutions in muon- and electron-neutrino charged-current events in the KM3NeT/ORCA detector

    NARCIS (Netherlands)

    The KM3NeT collaboration; Adrián-Martínez, S.; Ageron, M.; Aiello, S.; Albert, A.; Ameli, F.; Anassontzis, E.G.; Andre, M.; Androulakis, G.; Anghinolfi, M.; Anton, G.; Ardid, M.; Avgitas, T.; Barbarino, G.; Barbarito, E.; Baret, B.; Barrios-Mart, J.; Belias, A.; Berbee, E.; Berg, A. van den; Bertin, V.; Beurthey, S.; Beveren, V. van; Beverini, N.; Biagi, S.; Biagioni, A.; Billault, M.; Bondì, M.; Bormuth, R.; Bouhadef, B.; Bourlis, G.; Bourret, S.; Boutonnet, C.; Bouwhuis, M.; Bozza, C.; Bruijn, R.; Brunner, J.; Buis, E.; Buompane, R.; Busto, J.; Cacopardo, G.; Caillat, L.; Calamai, M.; Calvo, D.; Capone, A.; Caramete, L.; Cecchini, S.; Celli, S.; Champion, C.; Cherubini, S.; Chiarella, V.; Chiarelli, L.; Chiarusi, T.; Circella, M.; Classen, L.; Cobas, D.; Cocimano, R.; Coelho, J.A.B.; Coleiro, A.; Colonges, S.; Coniglione, R.; Cordelli, M.; Cosquer, A.; Coyle, P.; Creusot, A.; Cuttone, G.; D’Amato, C.; D’Amico, A.; D’Onofrio, A.; De Bonis, G.; De Sio, C.; Di Palma, I.; Díaz, A.F.; Distefano, C.; Donzaud, C.; Dornic, D.; Dorosti-Hasankiadeh, Q.; Drakopoulou, E.; Drouhin, D.; Durocher, M.; Eberl, T.; Eichie, S.; Eijk, D. van; El Bojaddaini, I.; Elsaesser, D.; Enzenhöfer, A.; Favaro, M.; Fermani, P.; Ferrara, G.; Frascadore, G.; Furini, M.; Fusco, L.A.; Gal, T.; Galatà, S.; Garufi, F.; Gay, P.; Gebyehu, M.; Giacomini, F.; Gialanella, L.; Giordano, V.; Gizani, N.; Gracia, R.; Graf, K.; Grégoire, T.; Grella, G.; Grmek, A.; Guerzoni, M.; Habel, R.; Hallmann, S.; Haren, H. van; Harissopulos, S.; Heid, T.; Heijboer, A.; Heine, E.; Henry, S.; Hernández-Rey, J.J.; Hevinga, M.; Hofestädt, J.; Hugon, C.M.F.; Illuminati, G.; James, C.W.; Jansweijerf, P.; Jongen, M.; Jong, M. de; Kadler, M.; Kalekin, O.; Kappes, A.; Katz, U.F.; Keller, P.; Kieft, G.; Kießling, D.; Koffeman, E.N.; Kooijman, P.; Kouchner, A.; Kreter, M.; Kulikovskiy, V.; Lahmann, R.; Lamare, P.; Larosa, G.; Leisos, A.; Leone, F.; Leonora, E.; Lindsey Clark, M.; Liolios, A.; Llorens Alvarez, C.D.; Lo Presti, D.; Löhner, H.; Lonardo, A.; Lotze, M.; Loucatos, S.; Maccioni, E.; Mannheim, K.; Manzali, M.; Margiotta, A.; Margotti, A.; Marinelli, A.; Maris, O.; Markou, C.; Martínez-Mora, J.A.; Martini, A.; Marzaioli, F.; Mele, R.; Melis, K.W.; Michael, T.; Migliozzi, P.; Migneco, E.; Mijakowski, P.; Miraglia, A.; Mollo, C.M.; Mongelli, M.; Morganti, M.; Moussa, A.; Musico, P.; Musumeci, M.; Navas, S.; Nicolau, C.A.; Olcina, I.; Olivetto, C.; Orlando, A.; Orzelli, A.; Pancaldi, G.; Papaikonomou, A.; Papaleo, R.; Păvălas, G.E.; Peek, H.; Pellegrini, G.; Pellegrino, C.; Perrina, C.; Pfutzner, M.; Piattelli, P.; Pikounis, K.; Pleinert, M.O.; Poma, G.E.; Popa, V.; Pradier, T.; Pratolongo, F.; Pühlhofer, G.; Pulvirenti, S.; Quinn, L.; Racca, C.; Raffaelli, F.; Randazzo, N.; Rauch, T.; Real, D.; Resvanis, L.; Reubelt, J.; Riccobene, G.; Rossi, C.; Rovelli, A.; Saldaña, M.; Salvadori, I.; Samtleben, D.F.E.; Sánchez García, A.; Sánchez Losa, A.; Sanguineti, M.; Santangelo, A.; Santonocito, D.; Sapienza, P.; Schimmel, F.; Schmelling, J.; Schnabel, J.; Sciacca, V.; Sedita, M.; Seitz, T.; Sgura, I.; Simeone, F.; Sipala, V.; Spisso, B.; Spurio, M.; Stavropoulos, G.; Steijger, J.; Stellacci, S.M.; Stransky, D.; Taiuti, M.; Tayalati, Y.; Terrasi, F.; Tézier, D.; Theraube, S.; Timmer, P.; Tönnis, C.; Trasatti, L.; Travaglini, R.; Trovato, A.; Tsirigotis, A.; Tzamarias, S.; Tzamariudaki, E.; Vallage, B.; Elewyck, V. van; Vermeulen, J.; Versari, F.; Vicini, P.; Viola, S.; Vivolo, D.; Volkert, M.; Wiggers, L.; Wilms, J.; Wolf, E. de; Zachariadou, K.; Zani, S.; Zornoza, J.D.; Zúñiga, J.

    2017-01-01

    Studying atmospheric neutrino oscillations in the few-GeV range with a multi-megaton detector promises to determine the neutrino mass hierarchy. This is the main science goal pursued by the future KM3NeT/ORCA water Cherenkov detector in the Mediterranean Sea. In this paper, the processes that limit

  11. Prospects of high-resolution resonant X-ray inelastic scattering studies on solid materials, liquids and gases at diffraction-limited storage rings

    NARCIS (Netherlands)

    Schmitt, Thorsten; de Groot, Frank M. F.; Rubensson, Jan-Erik

    The spectroscopic technique of resonant inelastic X-ray scattering (RIXS) will particularly profit from immensely improved brilliance of diffraction-limited storage rings (DLSRs). In RIXS one measures the intensities of excitations as a function of energy and momentum transfer. DLSRs will allow for

  12. 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

    2017-11-01

    successfully for a wide range of breaking conditions. The model is also able to successfully calculate the transfer of energy between frequencies due to wave focusing and wave breaking. This study is limited to unidirectional waves but provides a valuable basis for future application of the wave-breaking model to a multidirectional wave field. By including parameters for removing energy due to wave-breaking into a nonlinear potential flow solver, the risk of developing numerical instabilities due to an overturning wave is decreased, thereby increasing the application range of the model, including calculating more extreme sea states. A computationally efficient and accurate model for the generation of a nonlinear random wave field is useful for predicting the dynamic response of offshore vessels and marine renewable energy devices, predicting loads on marine structures, and in the study of open ocean wave generation and propagation in a realistic environment.

  13. 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

    successfully for a wide range of breaking conditions. The model is also able to successfully calculate the transfer of energy between frequencies due to wave focusing and wave breaking. This study is limited to unidirectional waves but provides a valuable basis for future application of the wave-breaking model to a multidirectional wave field. By including parameters for removing energy due to wave-breaking into a nonlinear potential flow solver, the risk of developing numerical instabilities due to an overturning wave is decreased, thereby increasing the application range of the model, including calculating more extreme sea states. A computationally efficient and accurate model for the generation of a nonlinear random wave field is useful for predicting the dynamic response of offshore vessels and marine renewable energy devices, predicting loads on marine structures, and in the study of open ocean wave generation and propagation in a realistic environment.

  14. 78 FR 76757 - Regulatory Guidance on Hours of Service of Drivers Rest Break Requirement; Drivers Who Become...

    Science.gov (United States)

    2013-12-19

    ... Service of Drivers Rest Break Requirement; Drivers Who Become Ineligible for the ``Short-Haul'' Exception... guidance. SUMMARY: This regulatory guidance addresses application of the 30- minute break rule to... exempt from the break rule, but who occasionally exceed the short haul distance or time limits. Such...

  15. 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.

  16. supersymmetry breaking with extra dimensions

    Indian Academy of Sciences (India)

    physics pp. 497-511 supersymmetry breaking with extra dimensions. FABIO ZWIRNER. Theory Division, CERN, CH-1211 Geneva 23, Switzerland. On leave from: Physics ... theory which accounts for all the observed interactions at the presently available ... For some standard reviews of sUsY and of the MssM, with lists.

  17. 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

  18. 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

  19. 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...

  20. Baryon and chiral symmetry breaking

    Energy Technology Data Exchange (ETDEWEB)

    Gorsky, A. [Institute for Theoretical and Experimental Physics (ITEP), Moscow, Russia and Moscow Institute of Physics and Technology (MIPT), Dolgoprudny (Russian Federation); Krikun, A. [NORDITA, KTH Royal Institute of Technology and Stockholm University Stockholm, Sweden and Institute for Theoretical and Experimental Physics (ITEP), Moscow (Russian Federation)

    2014-07-23

    We briefly review the generalized Skyrmion model for the baryon recently suggested by us. It takes into account the tower of vector and axial mesons as well as the chiral symmetry breaking. The generalized Skyrmion model provides the qualitative explanation of the Ioffe’s formula for the baryon mass.

  1. 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 43-48. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/021/01/0043-0048. Keywords.

  2. Small Break Air Ingress Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Chang Oh; Eung Soo Kim

    2011-09-01

    The small break air-ingress experiment, described in this report, is designed to investigate air-ingress phenomena postulated to occur in pipes in a very high temperature gas-cooled reactor (VHTRs). During this experiment, air-ingress rates were measured for various flow and break conditions through small holes drilled into a pipe of the experimental apparatus. The holes were drilled at right angles to the pipe wall such that a direction vector drawn from the pipe centerline to the center of each hole was at right angles with respect to the pipe centerline. Thus the orientation of each hole was obtained by measuring the included angle between the direction vector of each hole with respect to a reference line anchored on the pipe centerline and pointing in the direction of the gravitational force. Using this reference system, the influence of several important parameters on the air ingress flow rate were measured including break orientation, break size, and flow velocity . The approach used to study the influence of these parameters on air ingress is based on measuring the changes in oxygen concentrations at various locations in the helium flow circulation system as a function of time using oxygen sensors (or detectors) to estimate the air-ingress rates through the holes. The test-section is constructed of a stainless steel pipe which had small holes drilled at the desired locations.

  3. 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...

  4. Strong coupling electroweak symmetry breaking

    Energy Technology Data Exchange (ETDEWEB)

    Barklow, T.L. [Stanford Linear Accelerator Center, Menlo Park, CA (United States); Burdman, G. [Univ. of Wisconsin, Madison, WI (United States). Dept. of Physics; Chivukula, R.S. [Boston Univ., MA (United States). Dept. of Physics

    1997-04-01

    The authors review models of electroweak symmetry breaking due to new strong interactions at the TeV energy scale and discuss the prospects for their experimental tests. They emphasize the direct observation of the new interactions through high-energy scattering of vector bosons. They also discuss indirect probes of the new interactions and exotic particles predicted by specific theoretical models.

  5. Breaking up Sedentary Behavior: Perceptions from Cancer Survivors

    Science.gov (United States)

    Paxton, Raheem J.; Anderson, Alexandra; Sakar, Sonali; Taylor, Wendell C.

    2015-01-01

    Background Limited data exist on the benefits of, barriers to, and potential strategies to break up time spent sitting in cancer survivors. Such data will be meaningful given the consequences of prolonged sitting. Objectives To conduct a mixed method research study consisting of semi-structured telephone interviews to identify recurrent themes associated with prolonged sitting in cancer survivors. Methods African American breast cancer survivors (N = 31) were recruited from a local tumor registry. Telephone interviews were conducted and group consensus processes were used to identify recurrent themes. The a priori categories were benefits, barriers, and potential strategies to breaking up prolonged periods of sitting. Results Recurrent themes contributing most to prolonged sitting were leisure time interest (45%: e.g., watching television and reading) and health challenges (27%: e.g., pain and fatigue). Most (66%) women perceived improved health as benefits to breaking up time spent sitting. Nonetheless, many (41%) survivors reported health (e.g., pain and fatigue) as the biggest challenge to breaking up time spent sitting. Engaging in light intensity activities (e.g., staying active, keep moving) was the most commonly reported strategy for breaking up prolonged sitting. Conclusions African American breast cancer survivors identified the benefits and barriers to breaking up time spent sitting as well as potential strategies to breaking up time-spent sitting. Implications for practice Clinicians are integral in promoting breaks from prolonged sitting throughout the initial phases of the cancer continuum. Successful studies will begin with early intervention in the clinical setting, following with interventions during the recovery phase. PMID:26713501

  6. High-resolution magneto stratigraphic of the Eocene-Oligocene boundary in the Umbria-Marche sequence; Stratigrafia magnetica ad alta risoluzione del limite Eocene-Oligocene nella successione Umbro-Marchigiana

    Energy Technology Data Exchange (ETDEWEB)

    Lanci, L.; Lowrie, W.; Montanari, A.

    1998-12-31

    High-resolution magneto stratigraphy across the Eocene-Olicene boundary has been employed in a detailed investigation of the nature of low-amplitude, short-wavelength oceanic magnetic anomalies. [Italiano] La stratigrafia magnetica ad alta risoluzione del limite Eocene-Oligocene ed il magnetismo delle rocce sono stati studiati in dettaglio per verificare la presenza di eventuali inversioni di polarita` brevi (short chrons) e variazioni delle intensita` del campo geomagnetico che possano essere messe in relazione con le anomalie oceaniche a bassa ampiezza e corto periodo.

  7. Fluorescent dyes with large Stokes shifts for super-resolution optical microscopy of biological objects: A review.

    OpenAIRE

    Sednev, M.; Belov, V.; Hell, S.

    2015-01-01

    The review deals with commercially available organic dyes possessing large Stokes shifts and their applications as fluorescent labels in optical microscopy based on stimulated emission depletion (STED). STED microscopy breaks Abbe’s diffraction barrier and provides optical resolution beyond the diffraction limit. STED microscopy is non-invasive and requires photostable fluorescent markers attached to biomolecules or other objects of interest. Up to now, in most biology-related STED experiment...

  8. Super-resolution Luminescence Micro-Spectroscopy : A nano-scale view of solar cell material photophysics

    OpenAIRE

    Merdasa, Aboma

    2017-01-01

    Optical microscopy is a fundamental tool in a range of disciplines encompassed by the physical and biological sciences. At the dawn of this millennium, a break-through was made in optical microscopy where super-resolution methods emerged and declared imaging beyond the optical diffraction limit a possibility. Most of these methods are based on fluorescence detection of single molecules. These methods found particular prominence in the life sciences where small structures could be observed ins...

  9. A model of intrinsic symmetry breaking

    Energy Technology Data Exchange (ETDEWEB)

    Ge, Li [Research Center for Quantum Manipulation, Department of Physics, Fudan University, Shanghai 200433 (China); Li, Sheng [Department of Physics, Zhejiang Normal University, Zhejiang 310004 (China); George, Thomas F., E-mail: tfgeorge@umsl.edu [Office of the Chancellor and Center for Nanoscience, Department of Chemistry and Biochemistry, University of Missouri-St. Louis, St. Louis, MO 63121 (United States); Department of Physics and Astronomy, University of Missouri-St. Louis, St. Louis, MO 63121 (United States); Sun, Xin, E-mail: xin_sun@fudan.edu.cn [Research Center for Quantum Manipulation, Department of Physics, Fudan University, Shanghai 200433 (China)

    2013-11-01

    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.

  10. Parasites as Biological Tags for Stock Discrimination of Beaked Redfish (Sebastes mentella: Parasite Infra-Communities vs. Limited Resolution of Cytochrome Markers.

    Directory of Open Access Journals (Sweden)

    Regina Klapper

    Full Text Available The use of parasites as biological tags for discrimination of fish stocks has become a commonly used approach in fisheries management. Metazoan parasite community analysis and anisakid nematode population genetics based on a mitochondrial cytochrome marker were applied in order to assess the usefulness of the two parasitological methods for stock discrimination of beaked redfish Sebastes mentella of three fishing grounds in the North East Atlantic. Multivariate, model-based approaches demonstrated that the metazoan parasite fauna of beaked redfish from East Greenland differed from Tampen, northern North Sea, and Bear Island, Barents Sea. A joint model (latent variable model was used to estimate the effects of covariates on parasite species and identified four parasite species as main source of differences among fishing grounds; namely Chondracanthus nodosus, Anisakis simplex s.s., Hysterothylacium aduncum, and Bothriocephalus scorpii. Due to its high abundance and differences between fishing grounds, Anisakis simplex s.s. was considered as a major biological tag for host stock differentiation. Whilst the sole examination of Anisakis simplex s.s. on a population genetic level is only of limited use, anisakid nematodes (in particular, A. simplex s.s. can serve as biological tags on a parasite community level. This study confirmed the use of multivariate analyses as a tool to evaluate parasite infra-communities and to identify parasite species that might serve as biological tags. The present study suggests that S. mentella in the northern North Sea and Barents Sea is not sub-structured.

  11. Doppler-limited high-resolution spectrum and VPT2 assisted assignment of the C-H stretch of CH2Br2.

    Science.gov (United States)

    Sadiek, Ibrahim; Friedrichs, Gernot

    2017-06-15

    The Doppler limited non-saturated rotationally resolved infrared spectra of the symmetric and asymmetric CH-stretch bands of CH 2 Br 2 have been measured. A continuous wave cavity ringdown setup with a widely tunable Mid-IR-OPO laser light source yielded a single-shot minimum absorption of 4.9×10 -8 cm -1 . In contrast to the heavily congested ν 1 band, the ν 6 band showed partially resolved rotational features that may serve as suitable absorption targets in future environmental detection schemes for CH 2 Br 2 . A straightforward, VPT2 (second-order vibrational perturbation theory) assisted quantum-chemical approach for assigning the rotational structure has been tested using different model chemistries. The molecular structures, anharmonic frequencies and the structural changes upon vibrational excitation of CH 2 Br 2 have been investigated. The predicted changes of the anharmonic rotational constants have been used together with available spectroscopic ground state constants to simulate the rovibrational structures of the ν 1 and ν 6 bands of CH 2 Br 2 . A refined analysis of the ν 6 band is presented yielding accurate values for the band origin and the rotational constants. A fit of the line positions of 312 prominent transitions of the three isotopologues revealed a low standard error of 0.00056cm -1 , hence within the absolute 0.0009cm -1 wavelength accuracy of the used spectrometer setup. A combined analysis of the predicted line strengths and positions of the strong Q sub-branches of the ν 6 band has been performed to test the ability of the different density functionals for VPT2 prediction of anharmonic molecular constants. The M06/6-311++G(d,p) model chemistry turned out to yield reliable state-dependent rotational constants that are accurate enough to reproduce the overall rotational structure even without fitting. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Doppler-limited high-resolution spectrum and VPT2 assisted assignment of the C-H stretch of CH2Br2

    Science.gov (United States)

    Sadiek, Ibrahim; Friedrichs, Gernot

    2017-06-01

    The Doppler limited non-saturated rotationally resolved infrared spectra of the symmetric and asymmetric CH-stretch bands of CH2Br2 have been measured. A continuous wave cavity ringdown setup with a widely tunable Mid-IR-OPO laser light source yielded a single-shot minimum absorption of 4.9 × 10-8 cm-1. In contrast to the heavily congested ν1 band, the ν6 band showed partially resolved rotational features that may serve as suitable absorption targets in future environmental detection schemes for CH2Br2. A straightforward, VPT2 (second-order vibrational perturbation theory) assisted quantum-chemical approach for assigning the rotational structure has been tested using different model chemistries. The molecular structures, anharmonic frequencies and the structural changes upon vibrational excitation of CH2Br2 have been investigated. The predicted changes of the anharmonic rotational constants have been used together with available spectroscopic ground state constants to simulate the rovibrational structures of the ν1 and ν6 bands of CH2Br2. A refined analysis of the ν6 band is presented yielding accurate values for the band origin and the rotational constants. A fit of the line positions of 312 prominent transitions of the three isotopologues revealed a low standard error of 0.00056 cm-1, hence within the absolute 0.0009 cm-1 wavelength accuracy of the used spectrometer setup. A combined analysis of the predicted line strengths and positions of the strong Q sub-branches of the ν6 band has been performed to test the ability of the different density functionals for VPT2 prediction of anharmonic molecular constants. The M06/6-311++G(d,p) model chemistry turned out to yield reliable state-dependent rotational constants that are accurate enough to reproduce the overall rotational structure even without fitting.

  13. Breaking through the tranfer tunnel

    CERN Multimedia

    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.

  14. 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.

  15. Mechanics of lithographically defined break junctions

    NARCIS (Netherlands)

    Vrouwe, SAG; van der Giessen, E; van der Molen, SJ; Dulic, D; Trouwborst, ML; van Wees, BJ

    We investigate the mechanics of lithographically defined mechanically controllable break junctions, both theoretically and experimentally. It is shown that the relationship between controlled deflection and junction opening depends on the details of the break junction geometry. As a result the

  16. A model for chiral symmetry breaking in QCD

    Science.gov (United States)

    Govaerts, J.; Mandula, J. E.; Weyers, J.

    1984-04-01

    A recently proposed model for dynamical breaking of chiral symmetry in QCD is extended and developed for the calculation of pion and chiral symmetry breaking parameters. The pion is explicitly realized as a massless Goldstone boson and as a bound state of the constituent quarks. We compute, in the limit of exact chiral symmetry, MQ, the constituent quark mass ƒ π the pion decay coupling, , the constituent quark loop density, μπ2/ mq, the ratio of the Goldstone boson mass squared to the bare quark mass, and π, the pion electromagnetic charge radius squared.

  17. Superconcentration of light: circumventing the classical limit to achievable irradiance.

    Science.gov (United States)

    Roth, Stephan; Sheppard, Colin J R; Heintzmann, Rainer

    2016-05-01

    Concentration of light is limited by a fundamental physical principle, which ensures that étendue, the product of area and solid angle, can never decrease in an optical system. In microscopy, many superresolving methods, which can overcome the classical resolution limit, have recently emerged. We propose, and demonstrate experimentally, that it is also possible to circumvent the classical light concentration limit. Actually, most superresolution methods exhibit a common drawback: with respect to the total number of emitted photons, they are less efficient than standard widefield microscopy. Most methods "shave"' the point spread function (PSF) by discarding the disturbing signal from its edge. We show, that in contrast to PSF-shaving, methods related to reassignment microscopy (image scanning microscopy, optical photon reassignment, rescan confocal, instant structured illumination microscopy) concentrate all detected photons in their superresolving images and thereby increase the detected signal per sample area compared to widefield microsopy. We term this behavior superconcentration, as it breaks the classical light concentration limit.

  18. Impact of rest-break interventions on the neck and shoulder posture of symptomatic VDU operators during prolonged computer work.

    Science.gov (United States)

    Chaikumarn, Montakarn; Nakphet, Nuttika; Janwantanakul, Prawit

    2018-06-01

    There is limited research on the effects of different types of rest-break interventions for visual display unit (VDU) operators on neck and shoulder postures. This study examined the effect of rest-break interventions on the neck and shoulder postures of symptomatic VDU operators during prolonged computer work. Thirty subjects were randomly and equally assigned to breaks with stretching, breaks with dynamic movement and passive breaks. Subjects performed the typing task for 60 min and received 3-min breaks after 20 min of work. The craniovertebral and forward shoulder angles were obtained from a 3D motion analysis system. Results showed that there were no significant differences in the craniovertebral and forward shoulder angles among any types of rest breaks. It can be concluded that the three types of rest-break interventions had positive effects on neck and shoulder posture during prolonged computer terminal work.

  19. A deep search for the release of volcanic gases on Mars using ground-based high-resolution infrared and submillimeter spectroscopy: Sensitive upper limits for OCS and SO2

    Science.gov (United States)

    Khayat, A.; Villanueva, G. L.; Mumma, M. J.; Tokunaga, A. T.

    2017-11-01

    Recent volcanic activity has long been considered a distinct possibility that would place major constraints on the evolution of Mars' interior. Volcanic activity would result in the outgassing of sulfur-bearing species. As part of our multi-band search for active release of volcanic gases on Mars, we looked for carbonyl sulfide (OCS) at its combination band (ν1 +ν3) at 3.42 μ m (2924 cm-1), and sulfur dioxide (SO2) at 346.652 GHz, in two successive Mars years during its late Northern spring and mid Northern summer seasons (Ls= 43°-144°). The targeted volcanic districts, Tharsis and Syrtis Major, were observed during the two intervals, 15 Dec. 2011 to 6 Jan. 2012 in the first year, and 23 May 2014 to 12 June 2014 in the second year using the high resolution infrared spectrometer CSHELL on the NASA Infrared Telescope Facility, and the high resolution heterodyne receiver HARP at the James Clerk Maxwell Telescope atop Maunakea, Hawaii. No active release of such gases was detected, and we report 2σ upper limits of 1.8 ppbv and 3.1 ppbv for OCS and SO2, respectively, compared to 0.3 ppbv for SO2 (Encrenaz, T. et al. [2011] Astron. & Astrophys. 530, A37; Krasnopolsky, V.A. [2012] Icarus 217, 144-152) over the disk of Mars. Our retrieved upper limit on the SO2 outgassing rate of 156 tons/day (1.8 kg/s), corresponds to a mass rate of magma that is able to degas the SO2 of 104 kilotons/day (1200 kg/s), or 40,000 m3/day (0.46 m3/s). Our campaign places stringent limits on the concentration of sulfur-bearing species into the atmosphere of Mars.

  20. 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...

  1. 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.)

  2. Breaking strain of neutron star crust and gravitational waves.

    Science.gov (United States)

    Horowitz, C J; Kadau, Kai

    2009-05-15

    Mountains on rapidly rotating neutron stars efficiently radiate gravitational waves. The maximum possible size of these mountains depends on the breaking strain of the neutron star crust. With multimillion ion molecular dynamics simulations of Coulomb solids representing the crust, we show that the breaking strain of pure single crystals is very large and that impurities, defects, and grain boundaries only modestly reduce the breaking strain to around 0.1. Because of the collective behavior of the ions during failure found in our simulations, the neutron star crust is likely very strong and can support mountains large enough so that their gravitational wave radiation could limit the spin periods of some stars and might be detectable in large-scale interferometers. Furthermore, our microscopic modeling of neutron star crust material can help analyze mechanisms relevant in magnetar giant flares and microflares.

  3. 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.

  4. 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 ...

  5. 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.

  6. Taking breaks from work: an exploratory inquiry.

    Science.gov (United States)

    Strongman, K T; Burt, C D

    2000-05-01

    Two studies concerned with taking breaks from either mental or physical work are presented. In the first study, a questionnaire was given to 101 students in which they answered questions about their own break taking and that of others. They also completed a time management questionnaire and scales about procrastination, self-esteem, and work overload. In the second study, 17 students kept detailed diaries of their daily break-taking behavior over a 6-week period. Results are discussed in terms of the types of reasons given for taking breaks and the possible discrepancies between such reasons and the actual activities engaged in during breaks.

  7. Intrinsic spatial resolution limitations due to differences between positron emission position and annihilation detection localization; Limitacoes da resolucao espacial intrinseca devido as diferencas entre a posicao da emissao do positron e a deteccao da localizacao de aniquilacao

    Energy Technology Data Exchange (ETDEWEB)

    Perez, Pedro; Malano, Francisco; Valente, Mauro, E-mail: valente@famaf.unc.edu.ar [Universidad Nacional de Cordoba, Cordoba (Argentina). Fac. de Matematica, Astronomia y Fisica (FaMAF)

    2012-07-01

    Since its successful implementation for clinical diagnostic, positron emission tomography (PET) represents the most promising medical imaging technique. The recent major growth of PET imaging is mainly due to its ability to trace the biologic pathways of different compounds in the patient's body, assuming the patient can be labeled with some PET isotope. Regardless of the type of isotope, the PET imaging method is based on the detection of two 511-keV gamma photons being emitted in opposite directions, with almost 180 deg between them, as a consequence of electron-positron annihilation. Therefore, this imaging method is intrinsically limited by random uncertainties in spatial resolutions, related with differences between the actual position of positron emission and the location of the detected annihilation. This study presents an approach with the Monte Carlo method to analyze the influence of this effect on different isotopes of potential implementation in PET. (author)

  8. 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.

  9. History of electroweak symmetry breaking

    CERN Document Server

    Kibble, T W B

    2015-01-01

    In this talk, I recall the history of the development of the unified electroweak theory, incorporating the symmetry-breaking Higgs mechanism, as I saw it from my standpoint as a member of Abdus Salam's group at Imperial College. I start by describing the state of physics in the years after the Second World War, explain how the goal of a unified gauge theory of weak and electromagnetic interactions emerged, the obstacles encountered, in particular the Goldstone theorem, and how they were overcome, followed by a brief account of more recent history, culminating in the historic discovery of the Higgs boson in 2012.

  10. Boundary breaking for interdisciplinary learning

    Directory of Open Access Journals (Sweden)

    Adi Kidron

    2015-10-01

    Full Text Available The purpose of this work is to contribute to the body of knowledge on processesby which students develop interdisciplinary understanding of contents, as well as to suggest technology-enhanced means for supporting them in these processes in the context of higher education. In doing so, we suggest a rethinking of three traditional practices that tend to characterise typical higher education instruction: (1 compartmentalisation of disciplines; (2 traditional pedagogy; and (3 traditional hierarchies based on levels of expertise. Our high-level conjecture was that meaningful dialogue with peers and experts supports both the deepening of ideas in one knowledge domain and the formation of connections between ideas from several domains, both of which are required for the development of interdisciplinary understanding. We developed the Boundary Breaking for Interdisciplinary Learning (BBIL model, which harnesses technology to break boundaries between disciplines, learners and organisational levels of hierarchy. Findings indicate that 36 undergraduate students who participated in an interdisciplinary online course that implemented the BBIL model have significantly improved their interdisciplinary understanding of the course contents. This study illustrates how innovative use of available, free and low-cost technology can produce a ‘positive disruption’ in higher education instruction.

  11. A comparison between ultrasonic array beamforming and super resolution imaging algorithms for non-destructive evaluation.

    Science.gov (United States)

    Fan, Chengguang; Caleap, Mihai; Pan, Mengchun; Drinkwater, Bruce W

    2014-09-01

    In this paper the total focusing method, the so called gold standard in classical beamforming, is compared with the widely used time-reversal MUSIC super resolution technique in terms of its ability to resolve closely spaced scatterers in a solid. The algorithms are tested with simulated and experimental array data, each containing different noise levels. The performance of the algorithms is evaluated in terms of lateral resolution and sensitivity to noise. It is shown that for the weak noise situation (SNR>20 dB), time-reversal MUSIC provides significantly enhanced lateral resolution when compared to the total focusing method, breaking the diffraction limit. However, for higher noise levels, the total focusing method is shown to be robust, whilst the performance of time-reversal MUSIC is degraded. The influence of multiple scattering on the imaging algorithms is also investigated and shown to be small. Copyright © 2014 The Authors. Published by Elsevier B.V. All rights reserved.

  12. High-resolution imaging in a deep turbid medium based on an ultrasound-switchable fluorescence technique

    Science.gov (United States)

    Yuan, Baohong; Uchiyama, Seiichi; Liu, Yuan; Nguyen, Kytai T.; Alexandrakis, George

    2012-07-01

    The spatial resolution of fluorescence imaging techniques in deep optically turbid media such as tissues is limited by photon diffusion. To break the diffusion limit and achieve high-resolution and deep-tissue fluorescence imaging, a fundamentally different method was demonstrated based on a concept of ultrasound-switchable fluorescence. The results showed that a small fluorescent tube with a diameter of ˜180 μm at a depth of ˜20 mm in an optical scattering medium (μs'≈3.2 and μa≈0.026 cm-1) can be clearly imaged with a size of ˜260 μm. The depth-to-resolution ratio is shown to be about one order of magnitude better than other deep-tissue fluorescence imaging techniques.

  13. 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...... 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...... living in a new family with stepparents (OR = 1.63, 95%CI:1.38;1.92), or shared between the parents (OR = 1.48, 95%CI:1.26;1.75) reported higher stress than children of intact families. Single parent families reported markedly higher stress levels than children in intact families (OR = 2.18, 95%CI:1...

  14. 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).

  15. MTE1 Functions with MPH1 in Double-Strand Break Repair.

    Science.gov (United States)

    Yimit, Askar; Kim, TaeHyung; Anand, Ranjith P; Meister, Sarah; Ou, Jiongwen; Haber, James E; Zhang, Zhaolei; Brown, Grant W

    2016-05-01

    Double-strand DNA breaks occur upon exposure of cells to ionizing radiation and certain chemical agents or indirectly through replication fork collapse at DNA damage sites. If left unrepaired, double-strand breaks can cause genome instability and cell death, and their repair can result in loss of heterozygosity. In response to DNA damage, proteins involved in double-strand break repair by homologous recombination relocalize into discrete nuclear foci. We identified 29 proteins that colocalize with recombination repair protein Rad52 in response to DNA damage. Of particular interest, Ygr042w/Mte1, a protein of unknown function, showed robust colocalization with Rad52. Mte1 foci fail to form when the DNA helicase gene MPH1 is absent. Mte1 and Mph1 form a complex and are recruited to double-strand breaks in vivo in a mutually dependent manner. MTE1 is important for resolution of Rad52 foci during double-strand break repair and for suppressing break-induced replication. Together our data indicate that Mte1 functions with Mph1 in double-strand break repair. Copyright © 2016 by the Genetics Society of America.

  16. Effective photon mass by Super and Lorentz symmetry breaking

    Science.gov (United States)

    Bonetti, Luca; dos Santos Filho, Luís R.; Helayël-Neto, José A.; Spallicci, Alessandro D. A. M.

    2017-01-01

    In the context of Standard Model Extensions (SMEs), we analyse four general classes of Super Symmetry (SuSy) and Lorentz Symmetry (LoSy) breaking, leading to observable imprints at our energy scales. The photon dispersion relations show a non-Maxwellian behaviour for the CPT (Charge-Parity-Time reversal symmetry) odd and even sectors. The group velocities exhibit also a directional dependence with respect to the breaking background vector (odd CPT) or tensor (even CPT). In the former sector, the group velocity may decay following an inverse squared frequency behaviour. Thus, we extract a massive Carroll-Field-Jackiw photon term in the Lagrangian and show that the effective mass is proportional to the breaking vector and moderately dependent on the direction of observation. The breaking vector absolute value is estimated by ground measurements and leads to a photon mass upper limit of 10-19 eV or 2 ×10-55 kg, and thereby to a potentially measurable delay at low radio frequencies.

  17. Sgoldstino-less inflation and low energy SUSY breaking

    Science.gov (United States)

    Argurio, Riccardo; Coone, Dries; Heurtier, Lucien; Mariotti, Alberto

    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.

  18. Effective photon mass by Super and Lorentz symmetry breaking

    Directory of Open Access Journals (Sweden)

    Luca Bonetti

    2017-01-01

    Full Text Available In the context of Standard Model Extensions (SMEs, we analyse four general classes of Super Symmetry (SuSy and Lorentz Symmetry (LoSy breaking, leading to observable imprints at our energy scales. The photon dispersion relations show a non-Maxwellian behaviour for the CPT (Charge-Parity-Time reversal symmetry odd and even sectors. The group velocities exhibit also a directional dependence with respect to the breaking background vector (odd CPT or tensor (even CPT. In the former sector, the group velocity may decay following an inverse squared frequency behaviour. Thus, we extract a massive Carroll–Field–Jackiw photon term in the Lagrangian and show that the effective mass is proportional to the breaking vector and moderately dependent on the direction of observation. The breaking vector absolute value is estimated by ground measurements and leads to a photon mass upper limit of 10−19 eV or 2×10−55 kg, and thereby to a potentially measurable delay at low radio frequencies.

  19. On Supersymmetry Breaking in String Theory and its Realization in Brane Worlds

    CERN Document Server

    Mayr, Peter

    2001-01-01

    We use string duality to describe instanton induced spontaneous supersymmetry breaking in string compactifications with additional background fields. Dynamical supersymmetry breaking by space-time instantons in the heterotic string theory is mapped to a tree level breaking in the type II string which can be explicitly calculated by geometric methods. It is argued that the instanton corrections resurrect the no-go theorem on partial supersymmetry breaking. The point particle limit describes the non-perturbative scalar potential of a SYM theory localized on a hypersurface of space-time. The N=0 vacuum displays condensation of magnetic monopoles and confinement. The supersymmetry breaking scale is determined by $M_{str}$, which can be in the TeV range, and the geometry transverse to the gauge theory.

  20. 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.

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

    Indian Academy of Sciences (India)

    Mechanisms of supersymmetry breaking in the minimal supersymmetric standard model ... Supersymmetry breaking; MSSM; mechanisms. ... The essentials of gauge, gravity, anomaly and gaugino/higgsino mediation mechanisms are covered briefly and the phenomenology of the associated models is touched upon.

  2. SU(3) breaking in hyperon beta decays

    Energy Technology Data Exchange (ETDEWEB)

    Roos, M. (Helsinki Univ. (Finland). Dept. of High Energy Physics)

    1990-08-23

    The symmetry breaking in the hyperon semi-leptonic decays is analyzed with the constraint that vertical strokeV{sub us}vertical stroke is given by K{sub e3}. The mechanism of symmetry breaking of Donoghue, Holstein and Klimt and the one-loop corrected vector form factors of Krause are compared with data. (orig.).

  3. SU(3) breaking in hyperon beta decays

    Science.gov (United States)

    Roos, M.

    1990-08-01

    The symmetry breaking in the hyperon semi-leptonic decays is analyzed with the constraint the | us| is given by K e3. The mechanisms of symmetry breaking of Donoghue, Holstein and Klimt and the one-loop corrected vector form factors of Krause are compared with data.

  4. 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

  5. Mathematical models of spontaneous symmetry breaking

    OpenAIRE

    Sardanashvily, G.

    2008-01-01

    The Higgs mechanism of mass generation is the main ingredient in the contemporary Standard Model and its various generalizations. However, there is no comprehensive theory of spontaneous symmetry breaking. We summarize the relevant mathematical results characterizing spontaneous symmetry breaking phenomena in algebraic quantum theory, axiomatic quantum field theory, group theory, and classical gauge theory.

  6. Symmetry breaking signaling mechanisms during cell polarization

    NARCIS (Netherlands)

    Bruurs, LJM|info:eu-repo/dai/nl/413640779

    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.

  7. Symmetry Breaking in Hofstadter's Butterfly in graphene

    Science.gov (United States)

    Forsythe, Carlos; Dean, Cory; Wang, Lei; Maher, Patrick; Ghahari, Fereshte; Moon, Pilkyung; Koshino, Mikito; Taniguchi, Takashi; Watanabe, Kenji; Shepard, Ken; Hone, Jim; Kim, Philip

    2013-03-01

    We will present magnetotransport measurements in hBN encapsulated bilayer graphene devices where one of hBN substrates provides a weak modulation of lattice potential. Under a strong magnetic field, interplay between periodic electric potential and quantizing magnetic field lead to a fractal energy spectrum known as Hofstadter's butterfly. In graphene, while spin and layer symmetry breakings are expected in dual gated devices under large magnetic fields, valley symmetry breaking in the Hofstadter regime is not so easily understood. We will present the observance of these measured gaps along with a discussion of symmetry breaking in our BLG-hBN devices. Further quantitative analysis of these breakings will be presented through the temperature dependence of quantized conductance at these gaps. Through careful modulation of temperature and electron density, we have extracted a range of activation energies associated with symmetry breakings. the speaker acknowledges support from the Columbia Optics and Quantum Electronics IGERT under NSF grant DGE-1069420

  8. 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.

  9. 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 ...

  10. Comparison of occlusion break responses and vacuum rise times of phacoemulsification systems.

    Science.gov (United States)

    Sharif-Kashani, Pooria; Fanney, Douglas; Injev, Val

    2014-07-30

    Occlusion break surge during phacoemulsification cataract surgery can lead to potential surgical complications. The purpose of this study was to quantify occlusion break surge and vacuum rise time of current phacoemulsification systems used in cataract surgery. Occlusion break surge at vacuum pressures between 200 and 600 mmHg was assessed with the Infiniti® Vision System, the WhiteStar Signature® Phacoemulsification System, and the Centurion® Vision System using gravity-fed fluidics. Centurion Active FluidicsTM were also tested at multiple intraoperative pressure target settings. Vacuum rise time was evaluated for Infiniti, WhiteStar Signature, Centurion, and Stellaris® Vision Enhancement systems. Rise time to vacuum limits of 400 and 600 mmHg was assessed at flow rates of 30 and 60 cc/minute. Occlusion break surge was analyzed by 2-way analysis of variance. The Centurion system exhibited substantially less occlusion break surge than the other systems tested. Surge area with Centurion Active Fluidics was similar to gravity fluidics at an equivalent bottle height. At all Centurion Active Fluidics intraoperative pressure target settings tested, surge was smaller than with Infiniti and WhiteStar Signature. Infiniti had the fastest vacuum rise time and Stellaris had the slowest. No system tested reached the 600-mmHg vacuum limit. In this laboratory study, Centurion had the least occlusion break surge and similar vacuum rise times compared with the other systems tested. Reducing occlusion break surge may increase safety of phacoemulsification cataract surgery.

  11. Breaking the Ceiling of Human Maximal Lifespan.

    Science.gov (United States)

    Ben-Haim, Moshe Shay; Kanfi, Yariv; Mitchel, Sarah J; Maoz, Noam; Vaughan, Kelli; Amariglio, Ninette; Lerrer, Batia; de Cabo, Rafael; Rechavi, Gideon; Cohen, Haim Y

    2017-11-07

    While average human life expectancy has increased dramatically in the last century, the maximum lifespan has only modestly increased. These observations prompted the notion that human lifespan might have reached its maximal natural limit of ~115 years. To evaluate this hypothesis, we conducted a systematic analysis of all-cause human mortality throughout the 20 th century. Our analyses revealed that, once cause of death is accounted for, there is a proportional increase in both median age of death and maximum lifespan. To examine whether pathway targeted aging interventions affected both median and maximum lifespan, we analyzed hundreds of interventions performed in multiple organisms (yeast, worms, flies, and rodents). Three criteria: median, maximum, and last survivor lifespans were all significantly extended, and to a similar extent. Altogether, these findings suggest that targeting the biological/genetic causes of aging can allow breaking the currently observed ceiling of human maximal lifespan. © The Author 2017. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  12. 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.)

  13. 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.

  14. Detecting breast microcalcifications using super-resolution and wave-equation ultrasound imaging: a numerical phantom study

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Lianjie [Los Alamos National Laboratory; Simonetti, Francesco [IMPERIAL COLLEGE LONDON; Huthwaite, Peter [IMPERIAL COLLEGE LONDON; Rosenberg, Robert [UNM; Williamson, Michael [UNM

    2010-01-01

    Ultrasound image resolution and quality need to be significantly improved for breast microcalcification detection. Super-resolution imaging with the factorization method has recently been developed as a promising tool to break through the resolution limit of conventional imaging. In addition, wave-equation reflection imaging has become an effective method to reduce image speckles by properly handling ultrasound scattering/diffraction from breast heterogeneities during image reconstruction. We explore the capabilities of a novel super-resolution ultrasound imaging method and a wave-equation reflection imaging scheme for detecting breast microcalcifications. Super-resolution imaging uses the singular value decomposition and a factorization scheme to achieve an image resolution that is not possible for conventional ultrasound imaging. Wave-equation reflection imaging employs a solution to the acoustic-wave equation in heterogeneous media to backpropagate ultrasound scattering/diffraction waves to scatters and form images of heterogeneities. We construct numerical breast phantoms using in vivo breast images, and use a finite-difference wave-equation scheme to generate ultrasound data scattered from inclusions that mimic microcalcifications. We demonstrate that microcalcifications can be detected at full spatial resolution using the super-resolution ultrasound imaging and wave-equation reflection imaging methods.

  15. Unary resolution

    DEFF Research Database (Denmark)

    Aubert, Clément; Bagnol, Marc; Seiller, Thomas

    2016-01-01

    We give a characterization of deterministic polynomial time computation based on an algebraic structure called the resolution semiring, whose elements can be understood as logic programs or sets of rewriting rules over first-order terms. This construction stems from an interactive interpretation ...

  16. 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.

  17. arXiv Framework for an asymptotically safe Standard Model via dynamical breaking

    CERN Document Server

    Abel, Steven

    2017-09-15

    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.

  18. Breaking of longitudinal Akhiezer-Polovin waves.

    Science.gov (United States)

    Verma, Prabal Singh; Sengupta, Sudip; Kaw, Predhiman

    2012-03-23

    The breaking of longitudinal Akhiezer-Polovin (AP) waves is demonstrated using a one-dimensional simulation based on the Dawson sheet model. It is found that the AP longitudinal waves break through the process of phase mixing at an amplitude well below the breaking amplitude for AP waves, when subjected to arbitrarily small longitudinal perturbations. Results from the simulation show a good agreement with the Dawson phase mixing formula modified to include relativistic mass variation effects. This result may be of direct relevance to the laser- or particle-beam plasma wakefield experiments.

  19. Keeping It Real: Exploring an Interdisciplinary Breaking Bad News Role-Play as an Integrative Learning Opportunity

    Science.gov (United States)

    Sweeney, Catherine; O'Sullivan, Eleanor; McCarthy, Marian

    2015-01-01

    Palliative care is a complex area of healthcare best delivered by an interdisciplinary team approach. Breaking bad news is an inherent part of caring for people with life-limiting conditions. This study aims to explore an interdisciplinary breaking bad news role-play in a palliative care module. Participants were undergraduate medical and nursing…

  20. Downslope flow across the Ross Sea shelf break (Antarctica)

    Science.gov (United States)

    Bergamasco, A.; Budillon, G.; Carniel, S.; Defendi, V.; Meloni, R.; Paschini, E.; Sclavo, M.; Spezie, G.

    2003-12-01

    The analysis of some high-resolution hydrological data sets acquired during the 1997, 1998, 2001 and 2003 austral summers across the Ross Sea continental shelf break are here presented. The main focus of these cruises carried out in the framework of the Italian National Antarctic Program was the investigation of the downslope flow of the dense waters originated inside the Ross Sea. Such dense waters, flow near the bottom and, reaching the continental shelf break, ventilate the deep ocean. Two Antarctic continental shelf mechanisms can originate dense and deep waters. The former mechanism involves the formation, along the Victoria Land coasts, of a dense and saline water mass, the High Salinity Shelf Water (HSSW). The HSSW formation is linked to the rejection of salt into the water column as sea ice freezes, especially during winter, in the polynya areas, where the ice is continuously pushed offshore by the strong katabatic winds. The latter one is responsible of the formation of a supercold water mass, the Ice Shelf Water (ISW). The salt supplied by the HSSW recirculated below the Ross Ice Shelf, the latent heat of melting and the heat sink provided by the Ross Ice Shelf give rise to plumes of ISW, characterized by temperatures below the sea-surface freezing point. The dense shelf waters migrate to the continental shelf-break, spill over the shelf edge and descend the continental slope as a shelf-break gravity current, subject to friction and possibly enhanced by topographic channelling. Friction, in particular, breaks the constraint of potential vorticity conservation, counteracting the geostrophic tendency for along slope flow. The density-driven downslope motion or cascading entrains ambient water, namely the lower layer of the CDW, reaches a depth where density is the same and spreads off-slope. In fact, the cascading event is inhibited by friction without entrainment. The downslope processes are important for the ocean and climate system because they play a

  1. Sub-nanometer drift correction for super-resolution imaging.

    Science.gov (United States)

    Tang, Y; Wang, X; Zhang, X; Li, J; Dai, L

    2014-10-01

    Spatial resolution of conventional far-field fluorescence microscopy is limited by diffraction of light. Single-molecule localization microscopy (SMLM), such as (direct) stochastic optical reconstruction microscopy (dSTORM/STORM), and (fluorescence) photoactivation localization microscopy (fPALM/PALM), can break this barrier by localizing single emitters and reconstructing super-resolution image with much higher precision. Nevertheless, a SMLM measurement needs to record a large number of image frames and takes considerable recording time. In this process, sample drift becomes a critical problem and cannot be neglected. In this Letter, we present a sub-nanometer precision, low-cost sample drift correction method based on minimizing normalized root-mean-square error (NRMSE) between bright field images. Two optical configurations are suggested for recording bright field and fluorescence images simultaneously or alternately. The method was demonstrated on simulated data, and better than 0.3 nm drift correction precision was achieved. It was also applied on dSTORM imaging of F-actins of 3T3 cell, and the quality of reconstructed super-resolution image was improved observably. This method does not require special hardware, extra labelling or markers, and no precision decline due to photobleaching. It can be applied as an add-on for SMLM setups and achieves sub-nanometer precision drift correction for post-measurement or real time drift compensation.

  2. Break-up of droplets in a concentrated emulsion flowing through a narrow constriction.

    Science.gov (United States)

    Rosenfeld, Liat; Fan, Lin; Chen, Yunhan; Swoboda, Ryan; Tang, Sindy K Y

    2014-01-21

    This paper describes the break-up of droplets in a concentrated emulsion during its flow as a 2D monolayer in a microchannel consisting of a narrow constriction. Analysis of the behavior of a large number of drops (N > 4000) shows that the number of break-ups increases with increasing flow rate, entrance angle to the constriction, and size of the drops relative to the width of the constriction. As single drops do not break at the highest flow rate used in the system, break-ups arise primarily from droplet-droplet interactions. Analysis of droplet properties at a high temporal resolution of 10 microseconds makes it possible to relate droplet deformation with droplet break-up probability. Similar to previous studies on single drops, no break-up is observed below a set of critical flow rates and droplet deformations. Unlike previous studies, however, not all drops undergo break-up above the critical values. Instead, the probability of droplet break-up increases with flow rate and the deformation of the drops. The probabilistic nature of the break-up process arises from the stochastic variations in the packing configuration of the drops as they enter the constriction. Local break-up dynamics involves two primary drops. A close look at the interactions between the pair of drops reveals that the competing time scales of droplet rearrangement relative to the relaxation of the opposing drop govern whether break-up occurs or not. Practically, these results can be used to calculate the maximum throughput of the serial interrogation process often employed in droplet microfluidics. For 40 pL-drops, the highest throughput with less than 1% droplet break-up was measured to be approximately 7000 drops per second. In addition, the results presented are useful for understanding the behavior of concentrated emulsions in applications such as mobility control in enhanced oil recovery, and for extrapolating critical parameters such as injection rates to ensure the stability of the

  3. 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 ...

  4. Breaking Free with Wireless Networks.

    Science.gov (United States)

    Fleischman, John

    2002-01-01

    Discusses wireless local area networks (LANs) which typically consist of laptop computers that connect to fixed access points via infrared or radio signals. Topics include wide area networks; personal area networks; problems, including limitations of available bandwidth, interference, and security concerns; use in education; interoperability;…

  5. 10 microsecond time resolution studies of Cygnus X-1

    Energy Technology Data Exchange (ETDEWEB)

    Wen, H. C. [Stanford Univ., CA (United States)

    1997-06-01

    Time variability analyses have been applied to data composed of event times of X-rays emitted from the binary system Cygnus X-1 to search for unique black hole signatures. The X-ray data analyzed was collected at ten microsecond time resolution or better from two instruments, the High Energy Astrophysical Observatory (HEAO) A-1 detector and the Rossi X-ray Timing Explorer (XTE) Proportional Counter Array (PCA). HEAO A-1 and RXTE/PCA collected data from 1977--79 and from 1996 on with energy sensitivity from 1--25 keV and 2--60 keV, respectively. Variability characteristics predicted by various models of an accretion disk around a black hole have been searched for in the data. Drop-offs or quasi-periodic oscillations (QPOs) in the Fourier power spectra are expected from some of these models. The Fourier spectral technique was applied to the HEAO A-1 and RXTE/PCA data with careful consideration given for correcting the Poisson noise floor for instrumental effects. Evidence for a drop-off may be interpreted from the faster fall off in variability at frequencies greater than the observed breaks. Both breaks occur within the range of Keplerian frequencies associated with the inner edge radii of advection-dominated accretion disks predicted for Cyg X-1. The break between 10--20 Hz is also near the sharp rollover predicted by Nowak and Wagoner`s model of accretion disk turbulence. No QPOs were observed in the data for quality factors Q > 9 with a 95% confidence level upper limit for the fractional rms amplitude at 1.2% for a 16 M⊙ black hole.

  6. Booster Breaks in the workplace: participants’ perspectives on health-promoting work breaks

    Science.gov (United States)

    Taylor, Wendell C.; King, Kathryn E.; Shegog, Ross; Paxton, Raheem J.; Evans-Hudnall, Gina L.; Rempel, David M.; Chen, Vincent; Yancey, Antronette K.

    2013-01-01

    Increasing sedentary work has been associated with greater cardiovascular and metabolic risk, as well as premature mortality. Interrupting the sedentary workday with health-promoting work breaks can counter these negative health effects. To examine the potential sustainability of work-break programs, we assessed the acceptance of these breaks among participants in a Booster Break program. We analyzed qualitative responses from 35 participants across five worksites where one 15-min physical activity break was taken each workday. Two worksites completed a 1-year intervention and three worksites completed a 6-month intervention. Responses to two open-ended questions about the acceptance and feasibility of Booster Breaks were obtained from a survey administered after the intervention. Three themes for benefits and two themes for barriers were identified. The benefit themes were (i) reduced stress and promoted enjoyment, (ii) increased health awareness and facilitated behavior change, and (iii) enhanced workplace social interaction. The barrier themes were the need for (iv) greater variety in Booster Break routines and (v) greater management support. This study provides empirical support for the acceptance and feasibility of Booster Breaks during the workday. Emphasizing the benefits and minimizing the barriers are strategies that can be used to implement Booster Breaks in other workplaces. PMID:23466367

  7. Breaking bad news: a communication competency for ophthalmology training programs

    Science.gov (United States)

    Hilkert, Sarah M.; Cebulla, Colleen M.; Jain, Shelly Gupta; Pfeil, Sheryl A.; Benes, Susan C.; Robbins, Shira L.

    2016-01-01

    As the ophthalmology accreditation system undergoes major changes, training programs must evaluate residents in the 6 core competencies, including appropriately communicating bad news. Although the literature is replete with recommendations for breaking bad news across various non-ophthalmology specialties, no formal training programs exist for ophthalmology. There are many valuable lessons to be learned from our non-ophthalmology colleagues regarding this important skill. We examine the historic basis for breaking bad news, explores current recommendations among other specialties, and then evaluate a pilot study to teach breaking bad news to ophthalmology residents. The results of this study are limited by a small number of residents at a single academic center. Future studies from multiple training programs should be conducted to further evaluate the need and efficacy of formal communication skills training in this area, as well as the generalizability of our pilot training program. If validated, this work could serve as a template for future ophthalmology resident training and evaluation in this core competency. PMID:27134009

  8. Role of specific geographic landscapes in city break destinations

    Directory of Open Access Journals (Sweden)

    Štetić Snežana

    2009-01-01

    Full Text Available Urban tourist destinations or City Break destinations are representing one of main destination products on tourist market. City Break destinations are big cities, administrative, economic and political centers of states and regions. These cities are 'open' 24 hours per day, seven days in week. Inside these tourist destination we can find different range of products (culture, entertainment, recreation, leisure, history, modern infrastructure. In these destinations season is not present and it lasts trough out the year. Promotional campaigns in City Break destinations are truing to create distinguished images in tourists mind as also as on investors, consumers and future residents. They emphasize advantages that those cities are delivering to their consumers, but often we forget that all these cities are having specific geographic landscapes. In the era of limiting of mass tourism to preserve resources for future generations and emphasizing the importance of sustainable development for tourism perspectives, the importance of specific geographic landscapes inside urban destinations for their further development as tourist destinations an their overall development is slightly neglected.

  9. A Theoretical Model for the Prediction of Siphon Breaking Phenomenon

    Energy Technology Data Exchange (ETDEWEB)

    Bae, Youngmin; Kim, Young-In; Seo, Jae-Kwang; Kim, Keung Koo; Yoon, Juhyeon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-10-15

    A siphon phenomenon or siphoning often refers to the movement of liquid from a higher elevation to a lower one through a tube in an inverted U shape (whose top is typically located above the liquid surface) under the action of gravity, and has been used in a variety of reallife applications such as a toilet bowl and a Greedy cup. However, liquid drainage due to siphoning sometimes needs to be prevented. For example, a siphon breaker, which is designed to limit the siphon effect by allowing the gas entrainment into a siphon line, is installed in order to maintain the pool water level above the reactor core when a loss of coolant accident (LOCA) occurs in an open-pool type research reactor. In this paper, we develop a theoretical model to predict the siphon breaking phenomenon. In this paper, a theoretical model to predict the siphon breaking phenomenon is developed. It is shown that the present model predicts well the fundamental features of the siphon breaking phenomenon and undershooting height.

  10. Breaking bad news: A communication competency for ophthalmology training programs.

    Science.gov (United States)

    Hilkert, Sarah M; Cebulla, Colleen M; Jain, Shelly Gupta; Pfeil, Sheryl A; Benes, Susan C; Robbins, Shira L

    As the ophthalmology accreditation system undergoes major changes, training programs must evaluate residents in the 6 core competencies, including appropriately communicating bad news. Although the literature is replete with recommendations for breaking bad news across various non-ophthalmology specialties, no formal training programs exist for ophthalmology. There are many valuable lessons to be learned from our colleagues regarding this important skill. We examine the historic basis for breaking bad news, explore current recommendations among other specialties, and then evaluate a pilot study in breaking bad news for ophthalmology residents. The results of this study are limited by a small number of residents at a single academic center. Future studies from multiple training programs should be conducted to further evaluate the need and efficacy of formal communication skills training in this area, as well as the generalizability of our pilot training program. If validated, this work could serve as a template for future ophthalmology resident training and evaluation in this core competency. Copyright © 2016 Elsevier Inc. All rights reserved.

  11. Breaking Object Correspondence Across Saccadic Eye Movements Deteriorates Object Recognition.

    Science.gov (United States)

    Poth, Christian H; Herwig, Arvid; Schneider, Werner X

    2015-01-01

    Visual perception is based on information processing during periods of eye fixations that are interrupted by fast saccadic eye movements. The ability to sample and relate information on task-relevant objects across fixations implies that correspondence between presaccadic and postsaccadic objects is established. Postsaccadic object information usually updates and overwrites information on the corresponding presaccadic object. The presaccadic object representation is then lost. In contrast, the presaccadic object is conserved when object correspondence is broken. This helps transsaccadic memory but it may impose attentional costs on object recognition. Therefore, we investigated how breaking object correspondence across the saccade affects postsaccadic object recognition. In Experiment 1, object correspondence was broken by a brief postsaccadic blank screen. Observers made a saccade to a peripheral object which was displaced during the saccade. This object reappeared either immediately after the saccade or after the blank screen. Within the postsaccadic object, a letter was briefly presented (terminated by a mask). Observers reported displacement direction and letter identity in different blocks. Breaking object correspondence by blanking improved displacement identification but deteriorated postsaccadic letter recognition. In Experiment 2, object correspondence was broken by changing the object's contrast-polarity. There were no object displacements and observers only reported letter identity. Again, breaking object correspondence deteriorated postsaccadic letter recognition. These findings identify transsaccadic object correspondence as a key determinant of object recognition across the saccade. This is in line with the recent hypothesis that breaking object correspondence results in separate representations of presaccadic and postsaccadic objects which then compete for limited attentional processing resources (Schneider, 2013). Postsaccadic object recognition is

  12. Bulk gauge fields in warped space and localized supersymmetry breaking

    Energy Technology Data Exchange (ETDEWEB)

    Chacko, Z.; Ponton, Eduardo

    2003-11-01

    We consider five dimensional supersymmetric warped scenarios in which the Standard Model quark and lepton fields are localized on the ultraviolet brane, while the Standard Model gauge fields propagate in the bulk. Supersymmetry is assumed to be broken on the infrared brane. The relative sizes of supersymmetry breaking effects are found to depend on the hierarchy between the infrared scale and the weak scale. If the infrared scale is much larger than the weak scale the leading supersymmetry breaking effect on the visible brane is given by gaugino mediation. The gaugino masses at the weak scale are proportional to the square of the corresponding gauge coupling, while the dominant contribution to the scalar masses arises from logarithmically enhanced radiative effects involving the gaugino mass that are cutoff at the infrared scale. While the LSP is the gravitino, the NLSP which is the stau is stable on collider time scales. If however the infrared scale is close to the weak scale then the effects of hard supersymmetry breaking operators on the scalar masses can become comparable to those from gaugino mediation. These operators alter the relative strengths of the couplings of gauge bosons and gauginos to matter, and give loop contributions to the scalar masses that are also cutoff at the infrared scale. The gaugino masses, while exhibiting a more complicated dependence on the corresponding gauge coupling, remain hierarchical and become proportional to the corresponding gauge coupling in the limit of strong supersymmetry breaking. The scalar masses are finite and a loop factor smaller than the gaugino masses. The LSP remains the gravitino.

  13. Breaking object correspondence across saccadic eye movements deteriorates object recognition

    Directory of Open Access Journals (Sweden)

    Christian H. Poth

    2015-12-01

    Full Text Available Visual perception is based on information processing during periods of eye fixations that are interrupted by fast saccadic eye movements. The ability to sample and relate information on task-relevant objects across fixations implies that correspondence between presaccadic and postsaccadic objects is established. Postsaccadic object information usually updates and overwrites information on the corresponding presaccadic object. The presaccadic object representation is then lost. In contrast, the presaccadic object is conserved when object correspondence is broken. This helps transsaccadic memory but it may impose attentional costs on object recognition. Therefore, we investigated how breaking object correspondence across the saccade affects postsaccadic object recognition. In Experiment 1, object correspondence was broken by a brief postsaccadic blank screen. Observers made a saccade to a peripheral object which was displaced during the saccade. This object reappeared either immediately after the saccade or after the blank screen. Within the postsaccadic object, a letter was briefly presented (terminated by a mask. Observers reported displacement direction and letter identity in different blocks. Breaking object correspondence by blanking improved displacement identification but deteriorated postsaccadic letter recognition. In Experiment 2, object correspondence was broken by changing the object’s contrast-polarity. There were no object displacements and observers only reported letter identity. Again, breaking object correspondence deteriorated postsaccadic letter recognition. These findings identify transsaccadic object correspondence as a key determinant of object recognition across the saccade. This is in line with the recent hypothesis that breaking object correspondence results in separate representations of presaccadic and postsaccadic objects which then compete for limited attentional processing resources (Schneider, 2013. Postsaccadic

  14. Goldstone mode and pair-breaking excitations in atomic Fermi superfluids

    Science.gov (United States)

    Hoinka, Sascha; Dyke, Paul; Lingham, Marcus G.; Kinnunen, Jami J.; Bruun, Georg M.; Vale, Chris J.

    2017-10-01

    Spontaneous symmetry breaking is a central paradigm of elementary particle physics, magnetism, superfluidity and superconductivity. According to Goldstone's theorem, phase transitions that break continuous symmetries lead to the existence of gapless excitations in the long-wavelength limit. These Goldstone modes can become the dominant low-energy excitation, showing that symmetry breaking has a profound impact on the physical properties of matter. Here, we present a comprehensive study of the elementary excitations in a homogeneous strongly interacting Fermi gas through the crossover from a Bardeen-Cooper-Schrieffer (BCS) superfluid to a Bose-Einstein condensate (BEC) of molecules using two-photon Bragg spectroscopy. The spectra exhibit a discrete Goldstone mode, associated with the broken-symmetry superfluid phase, as well as pair-breaking single-particle excitations. Our techniques yield a direct determination of the superfluid pairing gap and speed of sound in close agreement with strong-coupling theories.

  15. Turbulence generation by mountain wave breaking in flows with directional wind shear

    Science.gov (United States)

    Vittoria Guarino, Maria; Teixeira, Miguel A. C.

    2016-04-01

    In this study, wave breaking, and the potential for the generation of turbulence in the atmosphere, is investigated using high-resolution numerical simulations of idealized atmospheric flows with directional wind shear over a three-dimensional isolated mountain. These simulations, which use the WRF-ARW model, differ in degree of flow non-linearity and directional wind shear intensity, quantified through the dimensionless mountain height and the Richardson number of the incoming flow. The aim is to predict wave breaking occurrence based on large-scale variables. The simulation results have been used to produce a regime diagram representing a description of wave breaking behavior in parameter space. By selecting flow overturning occurrence as a discriminating factor, it was possible to split the regime diagram in two sub-regions representing: a non-wave breaking regime and a wave breaking regime. The regime diagram shows that in the presence of directional shear wave breaking may occur over lower mountains that in a constant-wind case. When mountain waves break, the associated convective instability can lead to turbulence generation (known as Clear Air Turbulence or CAT in a non-cloudy atmosphere), thus, regions within the simulation domain where wave breaking and potential development of CAT are expected have been identified. The extent of these regions is variable and increases with the background shear intensity. In contrast with constant-wind flows, where wave breaking occurs in the stream-wise direction aligned with the mountain, for the helical wind profiles considered in this study as prototypes of flows with directional wind shear, flow overturning regions have a more three-dimensional geometry. The analysis of the model outputs, supported by theoretical arguments, suggest the existence of a link between wave breaking and the relative orientation of the incoming wind vector and the horizontal velocity perturbation vector. In particular, in a wave breaking

  16. Can phenological models predict tree phenology accurately in the future? The unrevealed hurdle of endodormancy break.

    Science.gov (United States)

    Chuine, Isabelle; Bonhomme, Marc; Legave, Jean-Michel; García de Cortázar-Atauri, Iñaki; Charrier, Guillaume; Lacointe, André; Améglio, Thierry

    2016-10-01

    The onset of the growing season of trees has been earlier by 2.3 days per decade during the last 40 years in temperate Europe because of global warming. The effect of temperature on plant phenology is, however, not linear because temperature has a dual effect on bud development. On one hand, low temperatures are necessary to break bud endodormancy, and, on the other hand, higher temperatures are necessary to promote bud cell growth afterward. Different process-based models have been developed in the last decades to predict the date of budbreak of woody species. They predict that global warming should delay or compromise endodormancy break at the species equatorward range limits leading to a delay or even impossibility to flower or set new leaves. These models are classically parameterized with flowering or budbreak dates only, with no information on the endodormancy break date because this information is very scarce. Here, we evaluated the efficiency of a set of phenological models to accurately predict the endodormancy break dates of three fruit trees. Our results show that models calibrated solely with budbreak dates usually do not accurately predict the endodormancy break date. Providing endodormancy break date for the model parameterization results in much more accurate prediction of this latter, with, however, a higher error than that on budbreak dates. Most importantly, we show that models not calibrated with endodormancy break dates can generate large discrepancies in forecasted budbreak dates when using climate scenarios as compared to models calibrated with endodormancy break dates. This discrepancy increases with mean annual temperature and is therefore the strongest after 2050 in the southernmost regions. Our results claim for the urgent need of massive measurements of endodormancy break dates in forest and fruit trees to yield more robust projections of phenological changes in a near future. © 2016 John Wiley & Sons Ltd.

  17. Future summer mega-heatwave and record-breaking temperatures in a warmer France climate

    Science.gov (United States)

    Bador, Margot; Terray, Laurent; Boé, Julien; Somot, Samuel; Alias, Antoinette; Gibelin, Anne-Laure; Dubuisson, Brigitte

    2017-07-01

    This study focuses on future very hot summers associated with severe heatwaves and record-breaking temperatures in France. Daily temperature observations and a pair of historical and scenario (greenhouse gas radiative concentration pathway 8.5) simulations with the high-resolution (∼12.5 km) ALADIN regional climate model provide a robust framework to examine the spatial distribution of these extreme events and their 21st century evolution. Five regions are identified with an extreme event spatial clustering algorithm applied to observed temperatures. They are used to diagnose the 21st century heatwave spatial patterns. In the 2070s, we find a simulated mega-heatwave as severe as the 2003 observed heatwave relative to its contemporaneous climate. A 20-member initial condition ensemble is used to assess the sensitivity of this future heatwave to the internal variability in the regional climate model and to pre-existing land surface conditions. Even in a much warmer and drier climate in France, late spring dry land conditions may lead to a significant amplification of summer extreme temperatures and heatwave intensity through limitations in evapotranspiration. By 2100, the increase in summer temperature maxima exhibits a range from 6 °C to almost 13 °C in the five regions in France, relative to historical maxima. These projections are comparable with the estimates given by a large number of global climate models.

  18. Minimal but non-minimal inflation and electroweak symmetry breaking

    Energy Technology Data Exchange (ETDEWEB)

    Marzola, Luca [National Institute of Chemical Physics and Biophysics,Rävala 10, 10143 Tallinn (Estonia); Institute of Physics, University of Tartu,Ravila 14c, 50411 Tartu (Estonia); Racioppi, Antonio [National Institute of Chemical Physics and Biophysics,Rävala 10, 10143 Tallinn (Estonia)

    2016-10-07

    We consider the most minimal scale invariant extension of the standard model that allows for successful radiative electroweak symmetry breaking and inflation. The framework involves an extra scalar singlet, that plays the rôle of the inflaton, and is compatibile with current experimental bounds owing to the non-minimal coupling of the latter to gravity. This inflationary scenario predicts a very low tensor-to-scalar ratio r≈10{sup −3}, typical of Higgs-inflation models, but in contrast yields a scalar spectral index n{sub s}≃0.97 which departs from the Starobinsky limit. We briefly discuss the collider phenomenology of the framework.

  19. Leak before break application in French PWR plants under operation

    Energy Technology Data Exchange (ETDEWEB)

    Faidy, C. [EDF SEPTEN, Villeurbanne (France)

    1997-04-01

    Practical applications of the leak-before break concept are presently limited in French Pressurized Water Reactors (PWR) compared to Fast Breeder Reactors. Neithertheless, different fracture mechanic demonstrations have been done on different primary, auxiliary and secondary PWR piping systems based on similar requirements that the American NUREG 1061 specifications. The consequences of the success in different demonstrations are still in discussion to be included in the global safety assessment of the plants, such as the consequences on in-service inspections, leak detection systems, support optimization,.... A large research and development program, realized in different co-operative agreements, completes the general approach.

  20. Expected track length estimation using track break statistics

    Science.gov (United States)

    Arambel, Pablo O.; Finn, Lucas I.

    2012-06-01

    We consider the problem of estimating the performance of a system that tracks moving objects on the ground using airborne sensors. Expected Track Life (ETL) is a measure of performance that indicates the ability of a tracker to maintain track for extended periods of time. The most desirable method for computing ETL would involve the use of large sets of real data with accompanying truth. This accurately accounts for sensor artifacts and data characteristics, which are difficult to simulate. However, datasets with these characteristics are difficult to collect because the coverage area of the sensors is limited, the collection time is limited, and the number of objects that can realistically be truthed is also limited. Thus when using real datasets, many tracks are terminated because the objects leave the field of view or the end of the dataset is reached. This induces a bias in the estimation when the ETL is computed directly from the tracks. An alternative to direct ETL computation is the use of Markov-Chain models that use track break statistics to estimate ETL. This method provides unbiased ETL estimates from datasets much shorter than what would be required for direct computation. In this paper we extend previous work in this area and derive an explicit expression of the ETL as a function of track break statistics. An example illustrates the properties and advantages of the method.

  1. Type III Guyon Syndrome in 'B Boy' Break-Dancer: A Case Report.

    Science.gov (United States)

    Hu, Soo-Young; Choi, Jin-Gyu; Son, Byung-Chul

    2015-10-01

    Although the musculoskeletal injuries associated with break-dancing which is gaining more popularity among adolescent and young people has been reported, the report regarding a peripheral nerve injury associated with breakdance is scarce. We report a rare case of a young amateur break-dancer, 'b-boy' who suffered from a painful paresthesia in his left hand, later diagnosed as type III Guyon's canal syndrome. A 23-year-old, right handed college man presented with a tenderness over the left hypothenar eminence and painful paresthesia over the ring and little fingers of 3 months duration. He trained himself as an amateur 'b boy' break-dancer for the last 10 months. Conservative management under the diagnosis of wrist sprain before presentation did not improve his hand pain. An magnetic resonance imaging and electrodiagnostic study revealed that painful paresthesia was caused by type III Guyon's canal syndrome, and 4 weeks of corticosteroid treatment was given with resolution of pain and paresthesia.

  2. 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)

  3. 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

  4. Project Trust: breaking down barriers between middle school children.

    Science.gov (United States)

    Batiuk, Mary Ellen; Boland, James A; Wilcox, Norma

    2004-01-01

    This paper analyzes the success of a camp retreat weekend called Project Trust involving middle school students and teachers. The goal of the camp is to break down barriers between cliques identified as active in the school. The camp focuses on building team relationships across clique membership and incorporates elements of peace education and conflict resolution. A treatment group (campers) and comparison group (noncampers) were administered an adaptation of the Bogardus Social Distance Test and the Piers-Harris Children's Self-Concept Scale before and after the camp. Attendance was found to lower social distance scores for nine of the ten groups/cliques. Campers also had higher self-concept scores after the retreat.

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

    NARCIS (Netherlands)

    van Eerten, H. J.; Meliani, Z.; Wijers, Ramj; 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

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

    NARCIS (Netherlands)

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

    2010-01-01

    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

  7. 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...

  8. 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

  9. Gap Resolution

    Energy Technology Data Exchange (ETDEWEB)

    2017-04-25

    Gap Resolution is a software package that was developed to improve Newbler genome assemblies by automating the closure of sequence gaps caused by repetitive regions in the DNA. This is done by performing the follow steps:1) Identify and distribute the data for each gap in sub-projects. 2) Assemble the data associated with each sub-project using a secondary assembler, such as Newbler or PGA. 3) Determine if any gaps are closed after reassembly, and either design fakes (consensus of closed gap) for those that closed or lab experiments for those that require additional data. The software requires as input a genome assembly produce by the Newbler assembler provided by Roche and 454 data containing paired-end reads.

  10. Breaks in MODIS time series portend vegetation change: verification using long-term data in an arid grassland ecosystem.

    Science.gov (United States)

    Browning, Dawn M; Maynard, Jonathan J; Karl, Jason W; Peters, Debra C

    2017-07-01

    Frequency and severity of extreme climatic events are forecast to increase in the 21st century. Predicting how managed ecosystems may respond to climatic extremes is intensified by uncertainty associated with knowing when, where, and how long effects of extreme events will be manifest in an ecosystem. In water-limited ecosystems with high inter-annual variability in rainfall, it is important to be able to distinguish responses that result from seasonal fluctuations in rainfall from long-term directional increases or decreases in precipitation. A tool that successfully distinguishes seasonal from directional biomass responses would allow land managers to make informed decisions about prioritizing mitigation strategies, allocating human resource monitoring efforts, and mobilizing resources to withstand extreme climatic events. We leveraged long-term observations (2000-2013) of quadrat-level plant biomass at multiple locations across a semiarid landscape in southern New Mexico to verify the use of Normalized Difference Vegetation Index (NDVI) time series derived from 250-m Moderate Resolution Imaging Spectroradiometer (MODIS) data as a proxy for changes in aboveground productivity. This period encompassed years of sustained drought (2000-2003) and record-breaking high rainfall (2006 and 2008) followed by subsequent drought years (2011 through 2013) that resulted in a restructuring of plant community composition in some locations. Our objective was to decompose vegetation patterns derived from MODIS NDVI over this period into contributions from (1) the long-term trend, (2) seasonal cycle, and (3) unexplained variance using the Breaks for Additive Season and Trend (BFAST) model. BFAST breakpoints in NDVI trend and seasonal components were verified with field-estimated biomass at 15 sites that differed in species richness, vegetation cover, and soil properties. We found that 34 of 45 breaks in NDVI trend reflected large changes in mean biomass and 16 of 19 seasonal

  11. 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.

  12. 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...

  13. Supersymmetry breaking in spatially modulated vacua

    Science.gov (United States)

    Nitta, Muneto; Sasaki, Shin; Yokokura, Ryo

    2017-11-01

    We study spontaneous supersymmetry breaking in spatially modulated stable or metastable vacua in supersymmetric field theories. Such spatial modulation can be realized in a higher derivative chiral model for which vacuum energies are positive, negative, or zero, depending on the model parameters. There appears a Nambu-Goldstone boson associated with the spontaneous breaking of the translational and U (1 ) symmetries without the quadratic kinetic term and with a quartic derivative term in the modulated direction, and a gapless Higgs mode. We show that there appears a Goldstino associated with the supersymmetry breaking at a metastable vacuum, where energy is positive, while it becomes a fermionic ghost in the negative energy vacuum, and zero norm state and disappears from the physical sector in the zero energy vacuum.

  14. On Supersymmetry Breaking in Intersecting Brane Models

    Energy Technology Data Exchange (ETDEWEB)

    Klein, M

    2004-01-13

    We discuss a framework to analyze the transmission of supersymmetry breaking in models of intersecting D-branes. Generically, different intersections preserve different fractions of an extended bulk supersymmetry, thus breaking supersymmetry completely but in a nonlocal way. We analyze this mechanism in a 5D toy model where two brane intersections, which are separated in the fifth dimension, break different halves of an extended {Nu} = 2 supersymmetry. The sector of the theory on one brane intersection feels the breakdown of the residual {Nu} = 1 supersymmetry only through two-loop interactions involving a coupling to fields from the other intersection. We compute the diagrams that contribute to scalar masses on one intersection and find that the masses are proportional to the compactification scale up to logarithmic corrections. We also compute the three-loop diagrams relevant to the Casimir energy between the two intersections and find a repulsive Casimir force.

  15. 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.

  16. 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...

  17. 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.

  18. La poetica degli spazi di Breaking Bad

    Directory of Open Access Journals (Sweden)

    Sara Martin

    2015-12-01

    Full Text Available Breaking Bad (2008-2013 produced, thanks to the creativity of Vince Gilligan and his writing room, some of the most emblematic characters in the history of contemporary television. Also, the writers of Breaking Bad were able to devise places and spaces that play important symbolic functions: spaces of mediation, spaces of transit, sacred spaces. This article investigates the meanings and characteristics of some of these settings: the swimming pool, the White family home, the meth lab. The analysis considers also the relation between characters and spaces, paying particular attention to the places inhabited by the main character, Walter White.

  19. Superconducting properties of lithographic lead break junctions

    Science.gov (United States)

    Weber, David; Scheer, Elke

    2018-01-01

    We have fabricated mechanically controlled break junction samples made of lead (Pb) by means of state-of-the-art nanofabrication methods: electron beam lithography and physical vapour deposition. The electrical and magnetic properties were characterized in a {}3{He} cryostat and showed a hard superconducting gap. Temperature and magnetic field dependence of tunnel contacts were compared and quantitatively described by including either thermal broadening of the density of states or pair breaking in the framework of a Skalski model, respectively. We show point contact spectra of few-atom contacts and present tunneling spectra exhibiting a superconducting double-gap structure.

  20. Spontaneous symmetry breaking in gauge theories.

    Science.gov (United States)

    Kibble, T W B

    2015-01-13

    The aim of this historical article is to describe the development of the idea of spontaneous symmetry breaking in gauge theories as seen from my perspective as a member of Abdus Salam's group at Imperial College London, UK. Beginning with an account of particle physics in the years after the Second World War, I describe early attempts at constructing a unified theory of weak and electromagnetic interactions, the obstacles encountered and how they were eventually overcome with the mass-generating mechanism incorporating the idea of spontaneous symmetry breaking, one of whose features is the now-famous Higgs boson.

  1. 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...

  2. A swath across the great divide: Kelp forests across the Samalga Pass biogeographic break

    Science.gov (United States)

    Konar, Brenda; Edwards, Matthew S.; Bland, Aaron; Metzger, Jacob; Ravelo, Alexandra; Traiger, Sarah; Weitzman, Ben

    2017-07-01

    Biogeographic breaks are often described as locations where a large number of species reach their geographic range limits. Samalga Pass, in the eastern Aleutian Archipelago, is a known biogeographic break for the spatial distribution of several species of offshore-pelagic communities, including numerous species of cold-water corals, zooplankton, fish, marine mammals, and seabirds. However, it remains unclear whether Samalga Pass also serves as a biogeographic break for nearshore benthic communities. The occurrence of biogeographic breaks across multiple habitats has not often been described. In this study, we examined if the biogeographic break for offshore-pelagic communities applies to nearshore kelp forests. To examine whether Samalga Pass serves as a biogeographic break for kelp forest communities, this study compared abundance, biomass and percent bottom cover of species associated with kelp forests on either side of the pass. We observed marked differences in kelp forest community structure, with some species reaching their geographic range limits on the opposing sides of the pass. In particular, the habitat-forming kelp Nereocystis luetkeana, and the predatory sea stars Pycnopodia helianthoides and Orthasterias koehleri all occurred on the eastern side of Samalga Pass but were not observed west of the pass. In contrast, the sea star Leptasterias camtschatica dispar was observed only on the western side of the pass. We also observed differences in overall abundance and biomass of numerous associated fish, invertebrate and macroalgal species on opposing sides of the pass. We conclude that Samalga Pass is important biogeographic break for kelp forest communities in the Aleutian Archipelago and may demark the geographic range limits of several ecologically important species.

  3. A swath across the great divide: Kelp forests across the Samalga Pass biogeographic break

    Science.gov (United States)

    Konar, Brenda H.; Edwards, Matthew S.; Bland, Aaron; Metzger, Jacob; Ravelo, Alexandra; Traiger, Sarah; Weitzman, Ben P.

    2017-01-01

    Biogeographic breaks are often described as locations where a large number of species reach their geographic range limits. Samalga Pass, in the eastern Aleutian Archipelago, is a known biogeographic break for the spatial distribution of several species of offshore-pelagic communities, including numerous species of cold-water corals, zooplankton, fish, marine mammals, and seabirds. However, it remains unclear whether Samalga Pass also serves as a biogeographic break for nearshore benthic communities. The occurrence of biogeographic breaks across multiple habitats has not often been described. In this study, we examined if the biogeographic break for offshore-pelagic communities applies to nearshore kelp forests. To examine whether Samalga Pass serves as a biogeographic break for kelp forest communities, this study compared abundance, biomass and percent bottom cover of species associated with kelp forests on either side of the pass. We observed marked differences in kelp forest community structure, with some species reaching their geographic range limits on the opposing sides of the pass. In particular, the habitat-forming kelp Nereocystis luetkeana, and the predatory sea stars Pycnopodia helianthoides and Orthasterias koehleri all occurred on the eastern side of Samalga Pass but were not observed west of the pass. In contrast, the sea star Leptasterias camtschatica dispar was observed only on the western side of the pass. We also observed differences in overall abundance and biomass of numerous associated fish, invertebrate and macroalgal species on opposing sides of the pass. We conclude that Samalga Pass is important biogeographic break for kelp forest communities in the Aleutian Archipelago and may demark the geographic range limits of several ecologically important species.

  4. Bud break responds more strongly to daytime than night-time temperature under asymmetric experimental warming.

    Science.gov (United States)

    Rossi, Sergio; Isabel, Nathalie

    2017-01-01

    Global warming is diurnally asymmetric, leading to a less cold, rather than warmer, climate. We investigated the effects of asymmetric experimental warming on plant phenology by testing the hypothesis that daytime warming is more effective in advancing bud break than night-time warming. Bud break was monitored daily in Picea mariana seedlings belonging to 20 provenances from Eastern Canada and subjected to daytime and night-time warming in growth chambers at temperatures varying between 8 and 16 °C. The higher advancements of bud break and shorter times required to complete the phenological phases occurred with daytime warming. Seedlings responded to night-time warming, but still with less advancement of bud break than under daytime warming. No advancement was observed when night-time warming was associated with a daytime cooling. The effect of the treatments was uniform across provenances. Our observations realized under controlled conditions allowed to experimentally demonstrate that bud break can advance under night-time warming, but to a lesser extent than under daytime warming. Prediction models using daily timescales could neglect the diverging influence of asymmetric warming and should be recalibrated for higher temporal resolutions. © 2016 John Wiley & Sons Ltd.

  5. 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.

  6. The Solar System According to General Relativity: The Sun's Space Breaking Meets the Asteroid Strip

    Directory of Open Access Journals (Sweden)

    Borissova L.

    2010-04-01

    Full Text Available This study deals with the exact solution of Einstein’s field equations for a sphere of incompressible liquid without the additional limitation initially introduced in 1916 by Schwarzschild, by which the space-time metric must have no singularities. The ob- tained exact solution is then applied to the Universe, the Sun, and the planets, by the assumption that these objects can be approximated as spheres of incompressible liq- uid. It is shown that gravitational collapse of such a sphere is permitted for an object whose characteristics (mass, density, and size are close to the Universe. Meanwhile, there is a spatial break associated with any of the mentioned stellar objects: the break is determined as the approaching to infinity of one of the spatial components of the metric tensor. In particular, the break of the Sun’s space meets the Asteroid strip, while Jupiter’s space break meets the Asteroid strip from the outer side. Also, the space breaks of Mercury, Venus, Earth, and Mars are located inside the Asteroid strip (inside the Sun’s space break.

  7. The transcription fidelity factor GreA impedes DNA break repair.

    Science.gov (United States)

    Sivaramakrishnan, Priya; Sepúlveda, Leonardo A; Halliday, Jennifer A; Liu, Jingjing; Núñez, María Angélica Bravo; Golding, Ido; Rosenberg, Susan M; Herman, Christophe

    2017-10-12

    Homologous recombination repairs DNA double-strand breaks and must function even on actively transcribed DNA. Because break repair prevents chromosome loss, the completion of repair is expected to outweigh the transcription of broken templates. However, the interplay between DNA break repair and transcription processivity is unclear. Here we show that the transcription factor GreA inhibits break repair in Escherichia coli. GreA restarts backtracked RNA polymerase and hence promotes transcription fidelity. We report that removal of GreA results in markedly enhanced break repair via the classic RecBCD-RecA pathway. Using a deep-sequencing method to measure chromosomal exonucleolytic degradation, we demonstrate that the absence of GreA limits RecBCD-mediated resection. Our findings suggest that increased RNA polymerase backtracking promotes break repair by instigating RecA loading by RecBCD, without the influence of canonical Chi signals. The idea that backtracked RNA polymerase can stimulate recombination presents a DNA transaction conundrum: a transcription fidelity factor that compromises genomic integrity.

  8. The Solar System is According to General Relativity: The Sun's Space Breaking Meets the Asteroid Strip

    Directory of Open Access Journals (Sweden)

    Borissova L.

    2010-04-01

    Full Text Available This study deals with the exact solution of Einstein's field equations for a sphere of incompressible liquid without the additional limitation initially introduced in 1916 by Schwarzschild, by which the space-time metric must have no singularities. The obtained exact solution is then applied to the Universe, the Sun, and the planets, by the assumption that these objects can be approximated as spheres of incompressible liquid. It is shown that gravitational collapse of such a sphere is permitted for an object whose characteristics (mass, density, and size are close to the Universe. Meanwhile, there is a spatial break associated with any of the mentioned stellar objects: the~break is determined as the approaching to infinity of one of the spatial components of the metric tensor. In particular, the break of the Sun's space meets the Asteroid strip, while Jupiter's space break meets the Asteroid strip from the outer side. Also, the space breaks of Mercury, Venus, Earth, and Mars are located inside the Asteroid strip (inside the Sun's space break.

  9. Record-Breaking Eclipsing Binary

    Science.gov (United States)

    Kohler, Susanna

    2016-05-01

    A new record holder exists for the longest-period eclipsing binary star system: TYC-2505-672-1. This intriguing system contains a primary star that is eclipsed by its companion once every 69 years with each eclipse lasting several years!120 Years of ObservationsIn a recent study, a team of scientists led by Joseph Rodriguez (Vanderbilt University) characterizes the components of TYC-2505-672-1. This binary star system consists of an M-type red giant star that undergoes a ~3.45-year-long, near-total eclipse with a period of ~69.1 years. This period is more than double that of the previous longest-period eclipsing binary!Rodriguez and collaborators combined photometric observations of TYC-2505-672-1 by the Kilodegree Extremely Little Telescope (KELT) with a variety of archival data, including observations by the American Association of Variable Star Observers (AAVSO) network and historical data from the Digital Access to a Sky Century @ Harvard (DASCH) program.In the 120 years spanned by these observations, two eclipses are detected: one in 1942-1945 and one in 2011-2015. The authors use the observations to analyze the components of the system and attempt to better understand what causes its unusual light curve.Characterizing an Unusual SystemObservations of TYC-2505-672-1 plotted from 1890 to 2015 reveal two eclipses. (The blue KELT observations during the eclipse show upper limits only.) [Rodriguez et al. 2016]By modeling the systems emission, Rodriguez and collaborators establish that TYC-2505-672-1 consists of a 3600-K primary star thats the M giant orbited by a small, hot, dim companion thats a toasty 8000 K. But if the companion is small, why does the eclipse last several years?The authors argue that the best model of TYC-2505-672-1 is one in which the small companion star is surrounded by a large, opaque circumstellar disk. Rodriguez and collaborators suggest that the companion could be a former red giant whose atmosphere was stripped from it, leaving behind

  10. 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

  11. On breaks of the Indian monsoon

    Indian Academy of Sciences (India)

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

    of rainfall over the monsoon zone. The rainfall criteria are chosen so as to ensure a large over- lap with the traditional breaks documented by Ramamurthy (1969) and De et al (1998). We have identified these rainbreaks for 1901–89. We have also identified active spells on the basis of rainfall over the Indian monsoon zone.

  12. 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...

  13. 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.

  14. 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.).

  15. 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,

  16. Spontaneous Symmetry Breaking in Nonrelativistic Systems

    Science.gov (United States)

    Watanabe, Haruki

    The subject of condensed matter physics is very rich --- there are an infinite number of parameters producing a diversity of exciting phenomena. As a theorist, my goal is to distill general principles out of this complexity --- to construct theories that can coherently explain many known examples altogether. This thesis is composed of several attempts to develop such theories in topics related to spontaneously symmetry breaking. A remarkable feature of many-body interacting systems is that although they are described by equations respecting various symmetries, they may spontaneously organize into a state that explicitly breaks symmetries. Examples are numerous: various types of crystalline and magnetic orders, Bose-Einstein condensates of cold atoms, superfluids of liquid helium, chiral symmetry in QCD, neutron stars, and cosmic inflation. These systems with spontaneously broken continuous symmetries have gapless excitations, so called Nambu-Goldstone bosons (NGBs). Although the properties of NGBs are well understood in Lorentz-invariant systems, surprisingly, some basic properties of NGBs such as their number and dispersion in nonrelativistic systems have not been discussed from a general perspective. In the first part of this thesis, we solve this issue by developing and analyzing an effective Lagrangian that coherently captures the low-energy, long-distance physics of many different symmetry-breaking states all at once. Next, we examine whether these NGBs originating from spontaneous symmetry breaking remain to be well-defined excitations inside a metal, where low-energy electrons near Fermi surface can collide with them. Our result is a one equation criterion that specifies whether the interactions between electrons and NGBs can be ignored, or whether it completely changes their character. In the latter case, unusual phases of matter such as non-Fermi liquids may arise; in that case, NGBs are overdamped and cannot form particle-like excitations in spite of the

  17. High-resolution neutron tomography

    Energy Technology Data Exchange (ETDEWEB)

    Mikerov, V.I. [P.N. Lebedev Physical Inst., RAN, Moscow (Russian Federation); Zhitnik, I.A. [P.N. Lebedev Physical Inst., RAN, Moscow (Russian Federation); Ignat`ev, A.P. [P.N. Lebedev Physical Inst., RAN, Moscow (Russian Federation); Isakov, A.I. [P.N. Lebedev Physical Inst., RAN, Moscow (Russian Federation); Korneev, V.V. [P.N. Lebedev Physical Inst., RAN, Moscow (Russian Federation); Krutov, V.V. [P.N. Lebedev Physical Inst., RAN, Moscow (Russian Federation); Kuzin, S.V. [P.N. Lebedev Physical Inst., RAN, Moscow (Russian Federation); Oparin, S.N. [P.N. Lebedev Physical Inst., RAN, Moscow (Russian Federation); Pertsov, A.A. [P.N. Lebedev Physical Inst., RAN, Moscow (Russian Federation); Podolyak, E.R. [P.N. Lebedev Physical Inst., RAN, Moscow (Russian Federation); Sobel`man, I.I. [P.N. Lebedev Physical Inst., RAN, Moscow (Russian Federation); Tindo, I.P. [P.N. Lebedev Physical Inst., RAN, Moscow (Russian Federation); Tukarev, B.A. [P.N. Lebedev Physical Inst., RAN, Moscow (Russian Federation)

    1995-12-31

    A neutron tomography technique with a coordinate resolution of several tens of micrometers has been developed. Our results indicate that the technique resolves details with dimensions less than 100 {mu}m and measures a linear attenuation of less than {approx} 0.1 cm{sup -1}. Tomograms can be reconstructed using incomplete data. Limits on the resolution of the restored pattern are analyzed, and ways to improve the sensitivity of the technique are discussed. (orig.).

  18. Further Study of BRST-Symmetry Breaking on the Lattice

    CERN Document Server

    Cucchieri, Attilio

    2016-01-01

    We evaluate the so-called Bose-ghost propagator Q(p^2) for SU(2) gauge theory in minimal Landau gauge, considering lattice volumes up to 120^4 and physical lattice extents up to 13.5 f. In particular, we investigate discretization effects, as well as the infinite-volume and continuum limits. We recall that a nonzero value for this quantity provides direct evidence of BRST-symmetry breaking, related to the restriction of the functional measure to the first Gribov region. Our results show that the prediction (from cluster decomposition) for Q(p^2) in terms of gluon and ghost propagators is better satisfied as the continuum limit is approached.

  19. KINOFORM LENSES - TOWARD NANOMETER RESOLUTION.

    Energy Technology Data Exchange (ETDEWEB)

    STEIN, A.; EVANS-LUTTERODT, K.; TAYLOR, A.

    2004-10-23

    While hard x-rays have wavelengths in the nanometer and sub-nanometer range, the ability to focus them is limited by the quality of sources and optics, and not by the wavelength. A few options, including reflective (mirrors), diffractive (zone plates) and refractive (CRL's) are available, each with their own limitations. Here we present our work with kinoform lenses which are refractive lenses with all material causing redundant 2{pi} phase shifts removed to reduce the absorption problems inherently limiting the resolution of refractive lenses. By stacking kinoform lenses together, the effective numerical aperture, and thus the focusing resolution, can be increased. The present status of kinoform lens fabrication and testing at Brookhaven is presented as well as future plans toward achieving nanometer resolution.

  20. Neutrino masses from SUSY breaking in radiative seesaw models

    Energy Technology Data Exchange (ETDEWEB)

    Figueiredo, Antonio J.R. [University of Lisbon, Centro de Fisica Teorica de Particulas (CFTP), Instituto Superior Tecnico, Lisbon (Portugal)

    2015-03-01

    Radiatively generated neutrino masses (m{sub ν}) are proportional to supersymmetry (SUSY) breaking, as a result of the SUSY non-renormalisation theorem. In this work, we investigate the space of SUSY radiative seesaw models with regard to their dependence on SUSY breaking (SUSY). In addition to contributions from sources of SUSY that are involved in electroweak symmetry breaking (SUSY{sub EWSB} contributions), and which are manifest from left angle F{sub H}{sup †} right angle = μ left angle anti H right angle ≠ 0 and left angle D right angle = g sum {sub H} left angle H{sup †} x {sub H} H right angle ≠ 0, radiatively generated m{sub ν} can also receive contributions from SUSY sources that are unrelated to EWSB (SUSY{sub EWS} contributions). We point out that recent literature overlooks pure-SUSY{sub EWSB} contributions (∝ μ/M) that can arise at the same order of perturbation theory as the leading order contribution from SUSY{sub EWS}. We show that there exist realistic radiative seesaw models in which the leading order contribution to m{sub ν} is proportional to SUSY{sub EWS}. To our knowledge no model with such a feature exists in the literature. We give a complete description of the simplest model topologies and their leading dependence on SUSY. We show that in one-loop realisations LLHH operators are suppressed by at least μ m{sub soft}/M{sup 3} or m{sub soft}{sup 2}/M{sup 3}. We construct a model example based on a oneloop type-II seesaw. An interesting aspect of these models lies in the fact that the scale of soft-SUSY effects generating the leading order m{sub ν} can be quite small without conflicting with lower limits on the mass of new particles. (orig.)

  1. Failure Diameter Resolution Study

    Energy Technology Data Exchange (ETDEWEB)

    Menikoff, Ralph [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-12-19

    Previously the SURFplus reactive burn model was calibrated for the TATB based explosive PBX 9502. The calibration was based on fitting Pop plot data, the failure diameter and the limiting detonation speed, and curvature effect data for small curvature. The model failure diameter is determined utilizing 2-D simulations of an unconfined rate stick to find the minimum diameter for which a detonation wave propagates. Here we examine the effect of mesh resolution on an unconfined rate stick with a diameter (10mm) slightly greater than the measured failure diameter (8 to 9 mm).

  2. Automatic detection of tulip breaking virus (TBV) in tulip fields using machine vision

    NARCIS (Netherlands)

    Polder, G.; Heijden, van der G.W.A.M.; Doorn, van J.; Baltissen, A.H.M.C.

    2012-01-01

    Tulip breaking virus (TBV) causes severe economic losses for the Netherlands. Infected plants must be removed from the field as soon as possible to prevent further spread by aphids. Until now screening is done by visual inspection in the field. As the availability of human experts is limited there

  3. Aspects of semilocal BPS vortex in systems with Lorentz symmetry breaking

    Energy Technology Data Exchange (ETDEWEB)

    Villalobos, C.H.C.; Silva, J.M.H. da; Hott, M.B. [UNESP, Univ Estadual Paulista, Departamento de Fisica e Quimica, Guaratingueta, SP (Brazil); Belich, H. [Universidade Federal do Espi rito Santo (UFES), Departamento de Fisica e Quimica, Vitoria, ES (Brazil)

    2014-03-15

    The existence is shown of a static self-dual semilocal vortex configuration for the Maxwell-Higgs system with a Lorentz-violating CPT-even term. The dependence of the vorticity upper limit on the Lorentz-symmetry-breaking term is also investigated. (orig.)

  4. The (Untold) Drama of the Turning Page: The Role of Page Breaks in Understanding Picture Books

    Science.gov (United States)

    Jacobs, Katrina Emily Bartow

    2016-01-01

    While scholars have recognized the importance of page breaks in both the construction and comprehension of narrative within picture books, there has previously been limited research that focused directly on how children discuss and make sense of these spaces in the text. Yet, because of their nature as dramatic gaps in the narrative, page breaks…

  5. Large-radius Holstein polaron and the problem of spontaneous symmetry breaking

    Science.gov (United States)

    Lakhno, V. D.

    2014-07-01

    A translation-invariant solution is found for a large-radius Holstein polaron whose energy in the strong coupling limit is lower than that obtained by Holstein [T. Holstein, Annals Phys., 8, 325 (1959)]. The wave function corresponding to this solution is delocalized. A conclusion is drawn about the absence of spontaneous symmetry breaking in the quantum system discussed.

  6. Record-breaking luminosity boosts discovery potential at Fermilab's Tevatron collider

    CERN Multimedia

    Fermi National Accelerator Laboratory. Batavia

    2006-01-01

    The record-breaking performance of the Tevatron colklider at the Department of Energy's Fermi National Accelerator Laboratory is pushing tje search fpr dark matter, supersymmetric particles and extra dimensions to new limits. Repeatedly smashing peak luminosity records, the Tevatron has created record numbers of proton-antiproton collisions that provide the means to unveil the secrets of the universe

  7. 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...... discovered ELMs' filamentary structures. It revealed that the ELMs are filamentary perturbations of positive density formed along the local field lines close to the LCFS. Currents flowing in the filaments induce magnetic perturbations, which break symmetry of magnetic field strength and lead to deformation...... 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...

  8. 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.

  9. Kondo Effect in Bare Electromigrated Break Junctions

    Science.gov (United States)

    Houck, Andrew; Labaziewicz, Jarek

    2005-03-01

    Electromigrated break junctions are one of only a very few systems currently available that provide sub-nanometer electrode gaps in a gated geometry. They have been used in several experiments over the past few years to measure transport through nanometer-scale objects such as single molecules. Our measurements show that the electromigrated electrode system--even by itself, without added nanoparticles-- is richer than previously thought. This talk will present gate- dependent transport measurements of Kondo impurities in bare gold break junctions, generated with high yield using an electromigration process that is actively controlled. An unexpected behavior of the splitting is observed in the crossover regime, where spin splitting is of the same order as the Kondo temperature. The Kondo resonances observed here may be due to atomic-scale metallic grains formed during electromigration.

  10. 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.

  11. Multiscale Simulation of Breaking Wave Impacts

    DEFF Research Database (Denmark)

    Lindberg, Ole

    The purpose of this project is to make an accurate, robust, geometric flexible and efficient model for calculation of forces on structures from nonlinear ocean waves and breaking wave impacts. Accurate prediction of the extreme forces on wind turbine foundations, breakwaters and tidal or wave power...... devises are important for enhancement structural designs. The proposed model is based on an incompressible and inviscid flow approximation and the governing equations are applied in an arbitrary Lagrangian-Eulerian moving frame of reference (ALE). The Runge-Kutta method (RK) is used for time integration...... compare reasonably well. The incompressible and inviscid ALE-WLS model is coupled with the potential flow model of Engsig-Karup et al. [2009], to perform multiscale calculation of breaking wave impacts on a vertical breakwater. The potential flow model provides accurate calculation of the wave...

  12. Soft Supersymmetry Breaking in KKLT Flux Compactification

    CERN Document Server

    Choi, Kiwoon; Nilles, Hans Peter; Olechowski, Marek; Choi, Kiwoon; Falkowski, Adam; Nilles, Hans Peter; Olechowski, Marek

    2005-01-01

    We examine the structure of soft supersymmetry breaking terms in KKLT models of flux compactification with low energy supersymmetry. Moduli are stabilized by fluxes and nonperturbative dynamics while a de Sitter vacuum is obtained by adding supersymmetry breaking anti-branes. We discuss the characteristic pattern of mass scales in such a set-up as well as some features of 4D N=1 supergravity breakdown by anti-branes. Anomaly mediation is found to always give an important contribution and one can easily arrange for flavor-independent soft terms. In its most attractive realization, the modulus mediation is comparable to the anomaly mediation, yielding a quite distinctive sparticle spectrum. In addition, the axion component of the modulus/dilaton superfield dynamically cancels the relative CP phase between the contributions of anomaly and modulus mediation, thereby avoiding dangerous SUSY CP violation.

  13. 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.

  14. Continental underplating after slab break-off

    Science.gov (United States)

    Magni, V.; Allen, M. B.; van Hunen, J.; Bouilhol, P.

    2017-09-01

    We present three-dimensional numerical models to investigate the dynamics of continental collision, and in particular what happens to the subducted continental lithosphere after oceanic slab break-off. We find that in some scenarios the subducting continental lithosphere underthrusts the overriding plate not immediately after it enters the trench, but after oceanic slab break-off. In this case, the continental plate first subducts with a steep angle and then, after the slab breaks off at depth, it rises back towards the surface and flattens below the overriding plate, forming a thick horizontal layer of continental crust that extends for about 200 km beyond the suture. This type of behaviour depends on the width of the oceanic plate marginal to the collision zone: wide oceanic margins promote continental underplating and marginal back-arc basins; narrow margins do not show such underplating unless a far field force is applied. Our models show that, as the subducted continental lithosphere rises, the mantle wedge progressively migrates away from the suture and the continental crust heats up, reaching temperatures >900 °C. This heating might lead to crustal melting, and resultant magmatism. We observe a sharp peak in the overriding plate rock uplift right after the occurrence of slab break-off. Afterwards, during underplating, the maximum rock uplift is smaller, but the affected area is much wider (up to 350 km). These results can be used to explain the dynamics that led to the present-day crustal configuration of the India-Eurasia collision zone and its consequences for the regional tectonic and magmatic evolution.

  15. Systems with Symmetry Breaking and Restoration

    Directory of Open Access Journals (Sweden)

    Vyacheslav I. Yukalov

    2010-01-01

    Full Text Available Statistical systems, in which spontaneous symmetry breaking can be accompanied by spontaneous local symmetry restoration, are considered. A general approach to describing such systems is formulated, based on the notion of weighted Hilbert spaces and configuration averaging. The approach is illustrated by the example of a ferroelectric with mesoscopic fluctuations of paraelectric phase. The influence of the local symmetry restoration on the system characteristics, such as sound velocity and Debye-Waller factor, is discussed.

  16. 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.

  17. 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....

  18. BreakingNews: Article Annotation by Image and Text Processing.

    Science.gov (United States)

    Ramisa, Arnau; Yan, Fei; Moreno-Noguer, Francesc; Mikolajczyk, Krystian

    2017-06-30

    Current approaches lying in the intersection of computer vision and NLP have achieved unprecedented breakthroughs in tasks like automatic captioning or image retrieval. Most of these methods, though, rely on training sets of images associated with annotations that specifically describe the visual content. This paper proposes going a step further and explores more complex cases where textual descriptions are loosely related to images. We focus on the particular domain of News. We introduce new deep learning methods that address source and popularity prediction, article illustration, and article geolocation. An adaptive CNN is proposed, that shares most of the structure for all tasks, and is suitable for multitask and transfer learning. Deep CCA is deployed for article illustration, and a new loss function based on Great Circle Distance is proposed for geolocation. Furthermore, we present BreakingNews, a novel dataset with approximately 100K news articles including images, text, captions, and enriched with heterogeneous meta-data. BreakingNews allows exploring all aforementioned problems, for which we provide baseline performances using various CNN architectures, and different representations of the textual and visual features. We report promising results and bring to light several limitations of current state-of-the-art, which we hope will help spur progress in the field.

  19. Current conduction mechanism and electrical break-down in InN grown on GaN

    Science.gov (United States)

    Kuzmik, J.; Fleury, C.; Adikimenakis, A.; Gregušová, D.; Ťapajna, M.; Dobročka, E.; Haščík, Š.; Kučera, M.; Kúdela, R.; Androulidaki, M.; Pogany, D.; Georgakilas, A.

    2017-06-01

    Current conduction mechanism, including electron mobility, electron drift velocity (vd) and electrical break-down have been investigated in a 0.5 μm-thick (0001) InN layer grown by molecular-beam epitaxy on a GaN/sapphire template. Electron mobility (μ) of 1040 cm2/Vs and a free electron concentration (n) of 2.1 × 1018 cm-3 were measured at room temperature with only a limited change down to 20 K, suggesting scattering on dislocations and ionized impurities. Photoluminescence spectra and high-resolution X-ray diffraction correlated with the Hall experiment showing an emission peak at 0.69 eV, a full-width half-maximum of 30 meV, and a dislocation density Ndis ˜ 5.6 × 1010 cm-2. Current-voltage (I-V) characterization was done in a pulsed (10 ns-width) mode on InN resistors prepared by plasma processing and Ohmic contacts evaporation. Resistors with a different channel length ranging from 4 to 15.8 μm obeyed the Ohm law up to an electric field intensity Eknee ˜ 22 kV/cm, when vd ≥ 2.5 × 105 m/s. For higher E, I-V curves were nonlinear and evolved with time. Light emission with a photon energy > 0.7 eV has been observed already at modest Erad of ˜ 8.3 kV/cm and consequently, a trap-assisted interband tunneling was suggested to play a role. At Eknee ˜ 22 kV/cm, we assumed electron emission from traps, with a positive feed-back for the current enhancement. Catastrophic break-down appeared at E ˜ 25 kV/cm. Reduction of Ndis was suggested to fully exploit InN unique prospects for future high-frequency devices.

  20. Dormancy Breaking in Ormosia arborea Seeds

    Directory of Open Access Journals (Sweden)

    Edilma Pereira Gonçalves

    2011-01-01

    Full Text Available Ormosia arborea is a tree species planted in urban areas and used to restore degraded areas. Its seeds are dormant and propagation is difficult. This study compares different dormancy breaking methods and physiological seed quality and seedling production. The seeds were germinated in sand in the laboratory of the Universidade Estadual de Santa Cruz, Ilhéus, Bahia, Brazil. The following dormancy breaking treatments were applied: control (intact seeds, 100°C water immersion; boiling water immersion followed by 24 hours of soaking; scarification with number 100 and number 50 sandpaper opposite from root emergence; sulfuric acid immersion for 1 hour, 50, 45, and 30 minutes. Seed immersion in 100°C and boiling water did not break the dormancy. The study species showed a greater vigor of seedling when its seeds were submitted to treatments associated with tegument rupturing by sandpaper or sulfuric acid. On the other hand, seed scarification with sulfuric acid for 1 hour, 50, 45, and 30 minutes or sandpaper favored seed germination and vigor.

  1. 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...

  2. 75 FR 80073 - Reasonable Break Time for Nursing Mothers

    Science.gov (United States)

    2010-12-21

    ... public comment on any and all issues concerning the reasonable break time for nursing mothers law. The... Hour Division RIN 1235-ZA00 Reasonable Break Time for Nursing Mothers AGENCY: Wage and Hour Division... Standards Act (FLSA) that requires employers to provide reasonable break time and a place for nursing...

  3. 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 ...

  4. 24 CFR 904.108 - Break-even amount.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 4 2010-04-01 2010-04-01 false Break-even amount. 904.108 Section... LOW RENT HOUSING HOMEOWNERSHIP OPPORTUNITIES Turnkey III Program Description § 904.108 Break-even amount. (a) Definition. The term “break-even amount” as used herein means the minimum average monthly...

  5. Dynamical Symmetry Breaking on Langevin Equation : Nambu-Jona-Lasinio Model : Particles and Fields

    OpenAIRE

    Kenji, IKEGAMI; Riuji, MOCHIZUKI; Kazuhiro, YOSHIDA; Graduate School of Science and Technology, Chiba University; Department of Physics, Faculty of Science, Chiba University; Department of Physics, Faculty of Science, Chiba University

    1993-01-01

    In order to investigate dynamical symmetry breaking,we study Nambu-Jona-Lasinio model in the large-N limit in the stochastic quantization method. Here in order to solve the Langevin equation, we impose specified initial conditions and construct "effective Langevin equation" in the large-N limit and give the same non-perturbative results as path-integral approach gives. Moreover we discuss stability of vacuum by means of "effective potential"

  6. The evolution of the break preclusion concept for nuclear power plants in Germany

    Energy Technology Data Exchange (ETDEWEB)

    Schulz, H. [Gesellschaft fuer Anlagen- und Reaktorsicherheit, Koeln (Germany)

    1997-04-01

    In the updating of the Guidelines for PWR`s of the {open_quotes}Reaktor-Sicherheitskommission{close_quotes} (RSK) in 1981 the requirements on the design have been changed with respect to the postulated leaks and breaks in the primary pressure boundary. The major change was a revision in the requirements for pipe whip protection. As a logical consequence of the {open_quotes}concept of basic safety{close_quotes} a guillotine type break or any other break type resulting in a large opening is not postulated any longer for the calculation of reaction and jet forces. As an upper limit for a leak an area of 0, 1 A (A = open cross section of the pipe) is postulated. This decision was based on a general assessment of the present PWR system design in Germany. Since then a number of piping systems have been requalified in the older nuclear power plants to comply with the break preclusion concept. Also a number of extensions of the concept have been developed to cover also leak-assumptions for branch pipes. Furthermore due considerations have been given to other aspects which could contribute to a leak development in the primary circuit, like vessel penetrations, manhole covers, flanges, etc. Now the break preclusion concept originally applied to the main piping has been developed into an integrated concept for the whole pressure boundary within the containment and will be applied also in the periodic safety review of present nuclear power plants.

  7. Photoacoustic imaging of voltage responses beyond the optical diffusion limit

    National Research Council Canada - National Science Library

    Bin Rao; Ruiying Zhang; Lei Li; Jin-Yu Shao; Lihong V Wang

    2017-01-01

    .... Although photoacoustic tomography breaks this limit by exciting the targets with diffused photons and detecting the resulting acoustic responses, it has not been demonstrated as a modality for imaging voltage responses...

  8. Boundary and analytic attitude: reflections on a summer holiday break.

    Science.gov (United States)

    Wright, Susanna

    2016-06-01

    The effect of a boundary in analytic work at the summer holiday break is discussed in relation to archetypal experiences of exclusion, loss and limitation. Some attempts by patients to mitigate an analyst's act of separation are reviewed as enactments, and in particular the meanings of a gift made by one patient. Analytic attitude towards enactment from within different schools of practice is sketched, with reference to the effect on the analyst of departing from the received practice of their own allegiance. A theory is adumbrated that the discomfort of 'contravening the rules' has a useful effect in sparking the analyst into consciousness, with greater attention to salient features in an individual case. Interpretation as an enactment is briefly considered, along with the possible effects of containing the discomfort of a patient's enactment in contrast to confronting it with interpretation. © 2016, The Society of Analytical Psychology.

  9. Validity of self-reported measures of workplace sitting time and breaks in sitting time.

    Science.gov (United States)

    Clark, Bronwyn K; Thorp, Alicia A; Winkler, Elisabeth A H; Gardiner, Paul A; Healy, Genevieve N; Owen, Neville; Dunstan, David W

    2011-10-01

    To understand the prevalence and potential health effect of prolonged workplace sedentary (sitting) time, valid measures are required. Here, we examined the criterion validity of a brief self-reported measure of workplace sitting time and breaks in sitting time. An interviewer-administered questionnaire was used to assess workplace sitting time (h·d(-1)) and breaks from sitting per hour at work in a convenience sample of 121 full-time workers (36% men, mean age = 37 yr, 53% office based). These self-reported measures were compared with accelerometer-derived sedentary time (hours per day, times, ≥100 counts per minute) during work hours. Self-reported sitting time was significantly correlated with accelerometer-derived sedentary time (Pearson r = 0.39, 95% confidence interval = 0.22-0.53), with an average sitting time 0.45 h·d(-1) higher than average sedentary time. Bland-Altman plots and regression analysis showed positive associations between the difference in sitting and sedentary time and the average of sitting and sedentary time (mean difference = -2.75 h + 0.47 × average sitting and sedentary time; limits of agreement = ±2.25 h·d(-1)). The correlation of self-reported breaks per sitting hour with accelerometer-derived breaks per sedentary hour was also statistically significant (Spearman rs = 0.26, 95% confidence interval = 0.11-0.44). This study is the first to examine the criterion validity of an interviewer-administered questionnaire measure of workplace sitting time and breaks in sitting time using objective criterion measures. The workplace sitting measure has acceptable properties for use in observational studies concerned with sedentary behavior in groups of workers; however, the wide limits of agreement suggest caution in estimating individuals' sitting time with high precision. Using self-reported measures to capture patterns of workplace sitting (such as breaks in sitting time) requires further development.

  10. Current limiters

    Energy Technology Data Exchange (ETDEWEB)

    Loescher, D.H. [Sandia National Labs., Albuquerque, NM (United States). Systems Surety Assessment Dept.; Noren, K. [Univ. of Idaho, Moscow, ID (United States). Dept. of Electrical Engineering

    1996-09-01

    The current that flows between the electrical test equipment and the nuclear explosive must be limited to safe levels during electrical tests conducted on nuclear explosives at the DOE Pantex facility. The safest way to limit the current is to use batteries that can provide only acceptably low current into a short circuit; unfortunately this is not always possible. When it is not possible, current limiters, along with other design features, are used to limit the current. Three types of current limiters, the fuse blower, the resistor limiter, and the MOSFET-pass-transistor limiters, are used extensively in Pantex test equipment. Detailed failure mode and effects analyses were conducted on these limiters. Two other types of limiters were also analyzed. It was found that there is no best type of limiter that should be used in all applications. The fuse blower has advantages when many circuits must be monitored, a low insertion voltage drop is important, and size and weight must be kept low. However, this limiter has many failure modes that can lead to the loss of over current protection. The resistor limiter is simple and inexpensive, but is normally usable only on circuits for which the nominal current is less than a few tens of milliamperes. The MOSFET limiter can be used on high current circuits, but it has a number of single point failure modes that can lead to a loss of protective action. Because bad component placement or poor wire routing can defeat any limiter, placement and routing must be designed carefully and documented thoroughly.

  11. 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.

  12. Large eddy simulation of breaking waves

    DEFF Research Database (Denmark)

    Christensen, Erik Damgaard; Deigaard, Rolf

    2001-01-01

    . The incoming waves are specified by a flux boundary condition. The waves are approaching in the shore-normal direction and are breaking on a plane, constant slope beach. The first few wave periods are simulated by a two-dimensional model in the vertical plane normal to the beach line. The model describes...... of the turbulence (the characteristic size of the eddies resolved by the model) is similar in the horizontal and the vertical direction. It is found to be of the order one half of the water depth....

  13. Parity breaking medium and squeeze operators

    Science.gov (United States)

    Andrianov, A. A.; Kolevatov, S. S.; Soldati, R.

    2017-04-01

    The transition between a Minkowski space region and a parity breaking medium domain is thoroughly discussed. The requirement of continuity of the field operator content across the separating boundary of the two domains leads to Bogolyubov transformations, squeezed pairs states and squeeze operators that turn out to generate a functional SU(2) algebra. According to this algebraic approach, the reflection and transmission probability amplitude across the separating boundary are computed. The probability rate of the emission or absorption of squeezed pairs out of the vacuum (generalization of the Sauter-Schwinger-Nikishov formula) is obtained.

  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. 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.

  16. 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.

  17. Unit roots, nonlinearities and structural breaks

    DEFF Research Database (Denmark)

    Haldrup, Niels; Kruse, Robinson; Teräsvirta, Timo

    a persistent effect with resulting policy implications. From a statistical perspective on the other hand, the presence of unit roots has dramatic implications for econometric model building, estimation, and inference in order to avoid the so-called spurious regression problem. The present paper provides...... 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...

  18. 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....

  19. NASA Shared Services Center breaks ground

    Science.gov (United States)

    2006-01-01

    NASA officials and elected leaders were on hand for the groundbreaking ceremony of the NASA Shared Services Center Feb. 24, 2006, on the grounds of Stennis Space Center. The NSSC provides agency centralized administrative processing, human resources, procurement and financial services. From left, Louisiana Economic Development Secretary Mike Olivier, Stennis Space Center Director Rick Gilbrech, Computer Sciences Corp. President Michael Laphen, NASA Deputy Administrator Shana Dale, Rep. Gene Taylor, Sen. Trent Lott, Mississippi Gov. Haley Barbour, NASA Administrator Mike Griffin and Shared Services Center Executive Director Arbuthnot use golden shovels to break ground at the site.

  20. On inflation, cosmological constant, and SUSY breaking

    Energy Technology Data Exchange (ETDEWEB)

    Linde, Andrei [Department of Physics and SITP, Stanford University, Stanford, California 94305 (United States)

    2016-11-02

    We consider a broad class of inflationary models of two unconstrained chiral superfields, the stabilizer S and the inflaton Φ, which can describe inflationary models with nearly arbitrary potentials. These models include, in particular, the recently introduced theories of cosmological attractors, which provide an excellent fit to the latest Planck data. We show that by adding to the superpotential of the fields S and Φ a small term depending on a nilpotent chiral superfield P one can break SUSY and introduce a small cosmological constant without affecting main predictions of the original inflationary scenario.

  1. SU(3) flavour breaking and baryon structure

    Energy Technology Data Exchange (ETDEWEB)

    Cooke, A.N.; Horsley, R. [Edinburgh Univ. (United Kingdom). School of Physics and Astronomy; Nakamura, Y. [RIKEN Advanced Institute for Computational Science, Kobe, Hyogo (Japan); Pleiter, D. [Forschungszentrum Juelich GmbH (Germany). Juelich Supercomputing Centre (JSC); Regensburg Univ. (Germany). Institut fuer Theoretische Physik; Rakow, P.E.L. [Liverpool Univ. (United Kingdom). Theoretical Physics Div.; Shanahan, P.; Zanotti, J.M. [Adelaide Univ., SA (Australia). CSSM, School of Chemistry and Physics; Schierholz, G. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Stueben, H. [Hamburg Univ. (Germany). Regionales Rechenzentrum; Collaboration: QCDSF/UKQCD Collaboration

    2013-11-15

    We present results from the QCDSF/UKQCD collaboration for hyperon electromagnetic form factors and axial charges obtained from simulations using N{sub f}=2+1 flavours of O(a)-improved Wilson fermions. We also consider matrix elements relevant for hyperon semileptonic decays. We find flavour-breaking effects in hyperon magnetic moments which are consistent with experiment, while our results for the connected quark spin content indicates that quarks contribute more to the spin of the {Xi} baryon than they do to the proton.

  2. Super-resolution by pupil plane phase filtering

    Indian Academy of Sciences (India)

    Abstract. Resolution capability of any optical imaging system is limited by residual aberrations as well as diffraction effects. Overcoming this fundamental limit is called super-resolution. Several new paradigms for super-resolution in optical systems use 'a posteriori' digital image processing. In these ventures the ...

  3. Nanometer resolution imaging and tracking of fluorescent molecules with minimal photon fluxes

    CERN Document Server

    Balzarotti, Francisco; Gwosch, Klaus C; Gynnå, Arvid H; Westphal, Volker; Stefani, Fernando D; Elf, Johan; Hell, Stefan W

    2016-01-01

    We introduce MINFLUX, a concept for localizing photon emitters in space. By probing the emitter with a local intensity minimum of excitation light, MINFLUX minimizes the fluorescence photons needed for high localization precision. A 22-fold reduction of photon detections over that required in popular centroid-localization is demonstrated. In superresolution microscopy, MINFLUX attained ~1 nm precision, resolving molecules only 6 nm apart. Tracking single fluorescent proteins by MINFLUX increased the temporal resolution and the localizations per trace by 100-fold, as demonstrated with diffusing 30S ribosomal subunits in living E. coli. Since conceptual limits have not been reached, we expect this localization modality to break new ground for observing the dynamics, distribution, and structure of macromolecules in living cells and beyond.

  4. Large-scale Vortex Generation and Evolution in Short-crested Isolated Wave Breaking

    Science.gov (United States)

    Derakhti, M.; Kirby, J. T., Jr.

    2016-12-01

    Peregrine (1999), in discussing the effect of localization of wave energy dissipation as a generation mechanism for vorticity at the scale of individual waves, spurred a wave of study of vorticity dynamics and mixing processes in the wave-driven ocean. In deep water, the limited depth of penetration of breaking effects leads to the conceptual forcing of a "smoke-ring" resulting from the localized cross-section of impulsive forcing (Pizzo and Melville, 2013). In shallow water, depth limitations favor the generation of a quasi-two-dimensional field of vertical vortex structures, with a resulting inverse cascade of energy to low wavenumbers and the evolution of flows such as transient rip currents (Johnson and Pattiaratchi, 2006). In this study, we are examining a more detailed picture of the vorticity field evolving during a localized breaking event, with particular interest in the span from deep water to shallow water, with special attention to the transition from weak to strong bottom control. Using an LES/VOF model (Derakhti and Kirby, 2014), we examine the evolution of coherent vortex structures whose initial scales are determined by the width of the breaking region, and are much larger than the locally-controlled reverse horseshoe structures seen in typical studies of along-crest uniform breaking. We study the persistence of three-dimensionality of these structures and their contribution to the development of depth-integrated vertical vorticity, and comment on the suitability of 2D or quasi-3D models to represent nearshore flow fields.

  5. Emulsion for hydraulically breaking the gas layer

    Energy Technology Data Exchange (ETDEWEB)

    Matveev, D.F.; Kendis, M.Sh.; Polkovnichenko, I.T.; Yaroshenko, N.A.; Zhadanova, K.M.

    1981-05-25

    Acid monoesters and diesters of alkyl phosphates based on primary fatty alcohols of the C /sub 12/ -C /sub 16/ fraction are added as emulsifiers to an emulsion for hydraulically breaking the gas layer with a view to increasing its thermal stability. The components have the following ratio: hydrocarbon mixture, 9.8-20.6%; acid monoesters and diesters, 0.3-0.6%; aqueous fraction, 25.7-38.8%, and sand, 40-60%. In preparing the composition, the emulsifier is dissolved in a hydrocarbon liquid at 50/sup 0/C. Then, an aqueous phase is gradually added while stirring at a rate of 8,000-10,000 revolutions per minute for 30 min. Afterwards, sand is added. Tests of the mixtures for hydraulic breakage have been carried out in the laboratory by the KTs-5 consistometer. The plastic viscosity of the emulsions were determined in the absence of sand by the Reotest-2 device. The mixture which is proposed has heightened (up to 130/sup 0/C) thermal stability as compared with the known one (diesel fuel, water, ethanolamide of free fatty acids): the emulsions in a mixture with sand decompose at 70/sup 0/C. The high thermal stability of the mixture makes it possible to use hydraulic breakage in a wider range. The gas yield of the borehole doubles as a result of hydraulically breaking the productive layer by the given mixture.

  6. Rock Directed Breaking Under the Impulse Load

    Science.gov (United States)

    Khomeriki, Sergo; Mataradze, Edgar; Chikhradze, Nikoloz; Losaberidze, Marine; Khomeriki, Davit; Shatberashvili, Grigol

    2016-10-01

    In the work the problem of directed chipping of facing stone material by means of managing of explosion process is considered. The technology of the mining of decorative stone by the use of explosion energy means the very rapid transfer of potential energy of elastic deformations to kinetic energy. As a result, the explosion impulse, in the expanse of the inertia of rock massive, does not cause the increase of existing cracks. In the course of explosion, the shock wave is propagated by ultrasonic velocity and in this case the medium parameters (pressure, density, temperature, velocity) increase in spurts. In spite of this fact the all three conservation laws of mechanics remain valid on basis of three laws the equations are derived by which the parameters of shock wave may be defined by means of the rock physical-mechanical properties. The load on the body volume at breaking under explosion acts over very small period of the time. Therefore, stressed-deformed state of the rock was studied when the impulse load acts on the boundary. It was considered that the mining of the blocks of facing stone is performed from the hard rocks. This means that the breaking proceeds in the zone of elastic deformation. In the conditions of mentioned assumptions, the expression of the stress tensor and displacement of vector components initiated by stressed-deformed state in the rock are written.

  7. Break-induced replication is highly inaccurate.

    Directory of Open Access Journals (Sweden)

    Angela Deem

    2011-02-01

    Full Text Available DNA must be synthesized for purposes of genome duplication and DNA repair. While the former is a highly accurate process, short-patch synthesis associated with repair of DNA damage is often error-prone. Break-induced replication (BIR is a unique cellular process that mimics normal DNA replication in its processivity, rate, and capacity to duplicate hundreds of kilobases, but is initiated at double-strand breaks (DSBs rather than at replication origins. Here we employed a series of frameshift reporters to measure mutagenesis associated with BIR in Saccharomyces cerevisiae. We demonstrate that BIR DNA synthesis is intrinsically inaccurate over the entire path of the replication fork, as the rate of frameshift mutagenesis during BIR is up to 2,800-fold higher than during normal replication. Importantly, this high rate of mutagenesis was observed not only close to the DSB where BIR is less stable, but also far from the DSB where the BIR replication fork is fast and stabilized. We established that polymerase proofreading and mismatch repair correct BIR errors. Also, dNTP levels were elevated during BIR, and this contributed to BIR-related mutagenesis. We propose that a high level of DNA polymerase errors that is not fully compensated by error-correction mechanisms is largely responsible for mutagenesis during BIR, with Pol δ generating many of the mutagenic errors. We further postulate that activation of BIR in eukaryotic cells may significantly contribute to accumulation of mutations that fuel cancer and evolution.

  8. Monitoring structural breaks in vegetation dynamics of the nature reserve Königsbrücker Heide

    Science.gov (United States)

    Wessollek, Christine; Karrasch, Pierre

    2017-10-01

    Nowadays remote sensing is a well-established method and technique of providing data. The current development shows the availability of systems with very high geometric resolution for the monitoring of vegetation. At the same time, however, the value of temporally high-resolution data is underestimated, particularly in applications focusing on the detection of short-term changes. These can be natural processes like natural disasters as well as changes caused by anthropogenic interventions. These include economic activities such as forestry, agriculture or mining but also processes which are intended to convert previously used areas into natural or near-natural surfaces. The K¨onigsbr¨ucker Heide is a former military training site located about 30 km north of the Saxon state capitol Dresden. After the withdrawal of the Soviet forces in 1992 and after nearly 100 years of military use this site was declared as nature reserve in 1996. The management of the whole protection area is implemented in three different management zone. Based on MODIS-NDVI time series between 2000 and 2016 different developments are apparent in the nature development zone and the zone of controlled succession. Nevertheless, the analyses also show that short-term changes, so called breaks in the vegetation development cannot be described using linear trend models. The complete understanding of vegetation trends is only given if discontinuities in vegetation development are considered. Structural breaks in the NDVI time series can be found simultaneously in the whole study area. Hence it can be assumed that these breaks have a more natural character, caused for example by climatic conditions like temperature or precipitation. Otherwise, especially in the zone of controlled succession structural breaks can be detected which cannot be traced back to natural conditions. Final analyses of the spatial distribution of breakpoints as well as their frequency depending on the respective protection zone

  9. Limiting Skepticism

    DEFF Research Database (Denmark)

    Hendricks, Vincent Fella; Symons, John

    2011-01-01

    Skeptics argue that the acquisition of knowledge is impossible given the standing possibility of error. We present the limiting convergence strategy for responding to skepticism and discuss the relationship between conceivable error and an agent’s knowledge in the limit. We argue that the skeptic...

  10. '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...

  11. 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.

  12. High resolution surface plasmon imaging of nanoparticles

    Science.gov (United States)

    Berguiga, Lotfi; Roland, Thibault; Fahys, Audrey; Elezgaray, Juan; Argoul, Françoise

    2010-05-01

    We report a technique of surface plasmon resonance imaging (SPRi) called SSPM (Scanning Surface Plasmon Microscopy) which pushes down the resolution limit to sub-micronic scales. To confirm the sensitivity and resolution of this non labeling microscopy we show images of gold and dielectric nanoparticules detected in air. The contrast mechanism is discussed versus the defocusing and versus the nature of the particules.

  13. A numerical model for super resolution effect in optical discs

    NARCIS (Netherlands)

    Assafrao, A.C.; Pereira, S.F.; Urbach, H.P.; Fery, C.; Von Riewel, L.; Knappmann, S.

    2010-01-01

    A simplified computational model for super resolution effect in optical discs is proposed and simulations are compared with experimental results, providing basic understanding of this phenomenon. Simulations show that resolution beyond the diffraction limit is achieved and signal destruction occurs

  14. Inverse Limits

    CERN Document Server

    Ingram, WT

    2012-01-01

    Inverse limits provide a powerful tool for constructing complicated spaces from simple ones. They also turn the study of a dynamical system consisting of a space and a self-map into a study of a (likely more complicated) space and a self-homeomorphism. In four chapters along with an appendix containing background material the authors develop the theory of inverse limits. The book begins with an introduction through inverse limits on [0,1] before moving to a general treatment of the subject. Special topics in continuum theory complete the book. Although it is not a book on dynamics, the influen

  15. Case study of wave breaking with high-resolution turbulence measurements with LITOS and WRF simulations

    Science.gov (United States)

    Schneider, Andreas; Wagner, Johannes; Söder, Jens; Gerding, Michael; Lübken, Franz-Josef

    2017-06-01

    Measurements of turbulent energy dissipation rates obtained from wind fluctuations observed with the balloon-borne instrument LITOS (Leibniz-Institute Turbulence Observations in the Stratosphere) are combined with simulations with the Weather Research and Forecasting (WRF) model to study the breakdown of waves into turbulence. One flight from Kiruna (68° N, 21° E) and two flights from Kühlungsborn (54° N, 12° E) are analysed. Dissipation rates are of the order of 0. 1 mW kg-1 (˜ 0.01 K d-1) in the troposphere and in the stratosphere below 15 km, increasing in distinct layers by about 2 orders of magnitude. For one flight covering the stratosphere up to ˜ 28 km, the measurement shows nearly no turbulence at all above 15 km. Another flight features a patch with highly increased dissipation directly below the tropopause, collocated with strong wind shear and wave filtering conditions. In general, small or even negative Richardson numbers are affirmed to be a sufficient condition for increased dissipation. Conversely, significant turbulence has also been observed in the lower stratosphere under stable conditions. Observed energy dissipation rates are related to wave patterns visible in the modelled vertical winds. In particular, the drop in turbulent fraction at 15 km mentioned above coincides with a drop in amplitude in the wave patterns visible in the WRF. This indicates wave saturation being visible in the LITOS turbulence data.

  16. Wave breaking in the surf zone and deep-water in a non-hydrostatic RANS model. Part 2: Turbulence and mean circulation

    Science.gov (United States)

    Derakhti, Morteza; Kirby, James T.; Shi, Fengyan; Ma, Gangfeng

    2016-11-01

    Field-scale modeling of wave-breaking-induced turbulence and mean circulation is still challenging. Although Boussinesq-type models have been successfully used to study field-scale wave transformation and wave-breaking-driven circulation, they cannot provide turbulence or the vertical structure of the velocity field. In addition, the applicability of such models is limited to shallow water. In Part 1 (Derakhti et al., 2016b) of this study, we showed that the non-hydrostatic σ-coordinate RANS model NHWAVE, as described by Derakhti et al. (2016a), accurately predicts organized wave motions and total wave-breaking-induced energy dissipation from deep-water up to the swash zone using a few vertical σ-layers. In this paper, our goal is to examine what level of detail of wave-breaking-induced turbulence and mean circulation, both in depth- and steepness-limited breaking waves, can be reproduced by NHWAVE. Further, effects of modeled turbulent eddy viscosity on the predicted time-averaged velocity distribution is discussed. We establish that NHWAVE is capable of predicting the structure of the mean velocity and vorticity fields including large-scale breaking-induced coherent vortices in deep-water breaking events; where the absence of turbulence-induced eddy viscosity results in the overprediction of the velocity and vorticity field in the breaking region. We show that NHWAVE reduces the required CPU time up to two orders of magnitude in comparison with a comparable VOF-based simulation.

  17. Super-resolution methods for fluorescence microscopy

    OpenAIRE

    Mandula, Ondrej

    2013-01-01

    Fluorescence microscopy is an important tool for biological research. However, the resolution of a standard fluorescence microscope is limited by diffraction, which makes it difficult to observe small details of a specimen’s structure. We have developed two fluorescence microscopy methods that achieve resolution beyond the classical diffraction limit. The first method represents an extension of localisation microscopy. We used nonnegative matrix factorisation (NMF) to model ...

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. Quantum Measurement Driven by Spontaneous Symmetry Breaking

    Science.gov (United States)

    Morikawa, M.; Nakamichi, A.

    2006-10-01

    Quantum mechanics cannot be applied within a closed system. Inevitable measurement process in quantum mechanics is usually treated separately from the basic principles of the framework and requires outside observer of the system. In this paper, we propose that the quantum measurement process is actually a physical process associated with the ubiquitous mechanism of spontaneous symmetry breaking. Based on this proposal, we construct a quantum measurement model in which the mixed state evolves into a pure state as the dynamical pro-coherence process. Furthermore, the classically distinguishable pointer parameter emerges as the c-number order parameter in the formalism of closed time-path quantum field theory. We also discuss the precision of the measurement and the possible deduction of the Born probability postulate.

  3. Spontaneous breaking of continuous translational invariance

    Science.gov (United States)

    Watanabe, Haruki; Brauner, Tomáš

    2012-04-01

    Unbroken continuous translational invariance is often taken as a basic assumption in discussions of spontaneous symmetry breaking (SSB), which singles out SSB of translational invariance itself as an exceptional case. We present a framework that allows us to treat translational invariance on the same footing as other symmetries. It is shown that existing theorems on SSB can be straightforwardly extended to this general case. As a concrete application, we analyze the Nambu-Goldstone modes in a (ferromagnetic) supersolid. We prove on the ground of the general theorems that the Bogoliubov mode stemming from a spontaneously broken internal U(1) symmetry and the longitudinal phonon due to a crystalline order are distinct physical modes.

  4. 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

  5. Superradiance with local phase-breaking effects

    Science.gov (United States)

    Shammah, Nathan; Lambert, Neill; Nori, Franco; De Liberato, Simone

    2017-08-01

    We study the superradiant evolution of a set of N two-level systems spontaneously radiating under the effect of phase-breaking mechanisms. We investigate the dynamics generated by nonradiative losses and pure dephasing, and their interplay with spontaneous emission. Our results show that in the parameter region relevant to many solid-state cavity quantum electrodynamics experiments, even with a dephasing rate much faster than the radiative lifetime of a single two-level system, a suboptimal collective superfluorescent burst is still observable. We also apply our theory to the dilute excitation regime, often used to describe optical excitations in solid-state systems. In this regime, excitations can be described in terms of bright and dark bosonic quasiparticles. We show how the effect of dephasing and losses in this regime translate into intermode scattering rates and quasiparticle lifetimes.

  6. 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.

  7. 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.

  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. High Resolution Pulse Compression Imaging Using Super Resolution FM-Chirp Correlation Method (SCM)

    Science.gov (United States)

    Fujiwara, M.; Okubo, K.; Tagawa, N.

    This study addresses the issue of the super-resolution pulse compression technique (PCT) for ultrasound imaging. Time resolution of multiple ultrasonic echoes using the FM-Chirp PCT is limited by the bandwidth of the sweep-frequency. That is, the resolution depends on the sharpness of auto-correlation function. We propose the Super resolution FM-Chirp correlation Method (SCM) and evaluate its performance. This method is based on the multiple signal classification (MUSIC) algorithm. Our simulations were made for the model assuming multiple signals reflected from some scatterers. We confirmed that SCM detects time delay of complicated reflected signals successfully with high resolution.

  10. 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.

  11. Fast sensitive amplifier for two-probe conductance measurements in single molecule break junctions

    Science.gov (United States)

    Johnson, Tyler K.; Ivie, Jeffrey A.; Jaruvang, Jason; Monti, Oliver L. A.

    2017-03-01

    We demonstrate an amplifier based on the Wheatstone bridge designed specifically for use in single molecule break junctions. This amplifier exhibits superior performance due to its large bandwidth, flat frequency response, and high sensitivity. The amplifier is capable of measuring conductance values from 102 to 10-6G0 (G0 = 2e2/h), while maintaining a bandwidth in excess of 20 kHz, and shows remarkable resolution in the molecular conductance regime of 10-2 to 10-5 G0.

  12. Line-breaking algorithm enhancement in inverse typesetting paradigma

    Directory of Open Access Journals (Sweden)

    Jan Přichystal

    2007-01-01

    Full Text Available High quality text preparing using computer desktop publishing systems usually uses line-breaking algorithm which cannot make provision for line heights and typeset paragraph accurately when composition width, page break, line index or other object appears. This article deals with enhancing of line-breaking algorithm based on optimum-fit algorithm. This algorithm is enhanced with calculation of immediate typesetting width and thus solves problem of forced change. Line-breaking algorithm enhancement causes expansion potentialities of high-quality typesetting in cases that have not been yet covered with present typesetting systems.

  13. Optical chirality breaking in a bilayered chiral metamaterial.

    Science.gov (United States)

    Zhao, Jianxing; Fu, Yuegang; Liu, Zhiying; Zhou, Jianhong

    2017-09-18

    We propose a planar optical bilayered chiral metamaterial, which consists of periodic metallic arrays of two L-shaped structures and a nanorod twisted on both sides of a dielectric slab, to investigate the optical chirality breaking effect by using finite-difference time-domain (FDTD) method. Even the metamaterial is with chiral symmetry, an optical chirality breaking window in the asymmetric transmission pass band is obtained in chiral metamaterial structure. We analyze the plasmonic mode properties and attribute the mechanism of the optical chirality breaking effect to the plasmonic analogue of EIT. The optical chirality breaking window can be modulated by changing the geometric parameters of the nanorods in the structure.

  14. Soft supersymmetry-breaking terms from supergravity and superstring models

    CERN Document Server

    Brignole, A; Muñoz, C

    1998-01-01

    We review the origin of soft supersymmetry-breaking terms in N=1 supergravity models of particle physics. We first consider general formulae for those terms in general models with a hidden sector breaking supersymmetry at an intermediate scale. The results for some simple models are given. We then consider the results obtained in some simple superstring models in which particular assumptions about the origin of supersymmetry breaking are made. These are models in which the seed of supersymmetry breaking is assumed to be originated in the dilaton/moduli sector of the theory.

  15. Quantum-limit spectroscopy

    CERN Document Server

    Ficek, Zbigniew

    2017-01-01

    This book covers the main ideas, methods, and recent developments of quantum-limit optical spectroscopy and applications to quantum information, resolution spectroscopy, measurements beyond quantum limits, measurement of decoherence, and entanglement. Quantum-limit spectroscopy lies at the frontier of current experimental and theoretical techniques, and is one of the areas of atomic spectroscopy where the quantization of the field is essential to predict and interpret the existing experimental results. Currently, there is an increasing interest in quantum and precision spectroscopy both theoretically and experimentally, due to significant progress in trapping and cooling of single atoms and ions. This progress allows one to explore in the most intimate detail the ways in which light interacts with atoms and to measure spectral properties and quantum effects with high precision. Moreover, it allows one to perform subtle tests of quantum mechanics on the single atom and single photon scale which were hardly eve...

  16. Symmetry breaking and finite size scaling in antiferromagnets

    Science.gov (United States)

    Azaria, P.; Delamotte, B.; Mouhanna, D.

    1993-02-01

    We show that the finite size scaling analysis of the quantum non linear sigma model O(3)/O(2) associated with antiferromagnets justifies the existence of the tower of excited states first proposed by Anderson to explain the symmetry breaking of quantum antiferromagnets in the thermodynamical limit. Finite size formulas for the ground state energy and for the ground state expectation value of the order parameter are explicitly given. Nous montrons que l'analyse du comportement à taille finie du modèle sigma non linéaire quantique O(3)/O(2) adapté aux antiferromagnétiques justifie l'existence d'une tour d'états excités proposée pour la première fois par Anderson pour expliquer la brisure de symétrie des antiferromagnétiques quantiques dans la limite thermodynamique. Nous donnons également les formules de taille finie pour l'énergie du fondamental et pour la valeur moyenne dans le vide du paramètre d'ordre.

  17. Ultrahigh-resolution CT and DR scanner

    Science.gov (United States)

    DiBianca, Frank A.; Gupta, Vivek; Zou, Ping; Jordan, Lawrence M.; Laughter, Joseph S.; Zeman, Herbert D.; Sebes, Jeno I.

    1999-05-01

    A new technique called Variable-Resolution X-ray (VRX) detection that dramatically increases the spatial resolution in computed tomography (CT) and digital radiography (DR) is presented. The technique is based on a principle called 'projective compression' that allows the resolution element of a CT detector to scale with the subject or field size. For very large (40 - 50 cm) field sizes, resolution exceeding 2 cy/mm is possible and for very small fields, microscopy is attainable with resolution exceeding 100 cy/mm. Several effects that could limit the performance of VRX detectors are considered. Experimental measurements on a 16-channel, CdWO4 scintillator + photodiode test array yield a limiting MTF of 64 cy/mm (8(mu) ) in the highest-resolution configuration reported. Preliminary CT images have been made of small anatomical specimens and small animals using a storage phosphor screen in the VRX mode. Measured detector resolution of the CT projection data exceeds 20 cy/mm (less than 25 (mu) ); however, the final, reconstructed CT images produced thus far exhibit 10 cy/mm (50 (mu) ) resolution because of non-flatness of the storage phosphor plates, focal spot effects and the use of a rudimentary CT reconstruction algorithm. A 576-channel solid-state detector is being fabricated that is expected to achieve CT image resolution in excess of that of the 26-channel test array.

  18. Breaks in the Breaks: An Analysis of Divorce Rates in Europe

    OpenAIRE

    González-Val, Rafael; Marcén, Miriam

    2010-01-01

    This paper explores the frequency of permanent shocks in divorce rates for 16 European countries during the period 1930 to 2006, by examining whether the divorce rate is a stationary series, exhibits a unit root, or is stationary around a process subject to structural breaks. A clear finding from this analysis is that not all shocks have transitory effects on the divorce rate. Results provide evidence of both stationarity around occasional shocks which have permanent effects, and of a unit ro...

  19. Low-scale SUSY breaking and the (s)goldstino physics

    CERN Document Server

    Antoniadis, I.

    2013-01-01

    For a 4D N=1 supersymmetric model with a low SUSY breaking scale (f) and general Kahler potential K(Phi^i,Phi_j^*) and superpotential W(Phi^i) we study, in an effective theory approach, the relation of the goldstino superfield to the (Ferrara-Zumino) superconformal symmetry breaking chiral superfield X. In the presence of more sources of supersymmetry breaking, we verify the conjecture that the goldstino superfield is the (infrared) limit of X for zero-momentum and Lambda->\\infty. (Lambda is the effective cut-off scale). We then study the constraint X^2=0, which in the one-field case is known to decouple a massive sgoldstino and thus provide an effective superfield description of the Akulov-Volkov action for the goldstino. In the presence of additional fields that contribute to SUSY breaking we identify conditions for which X^2=0 remains valid, in the effective theory below a large but finite sgoldstino mass. The conditions ensure that the effective expansion (in 1/Lambda) of the initial Lagrangian is not in ...

  20. Efficient dam break flood simulation methods for developing a preliminary evacuation plan after the Wenchuan Earthquake

    Directory of Open Access Journals (Sweden)

    Y. Li

    2012-01-01

    Full Text Available The Xiaojiaqiao barrier lake, which was the second largest barrier lake formed by the Wenchuan Earthquake had seriously threatened the lives and property of the population downstream. The lake was finally dredged successfully on 7 June 2008. Because of the limited time available to conduct an inundation potential analysis and make an evacuation plan, barrier lake information extraction and real-time dam break flood simulation should be carried out quickly, integrating remote sensing and geographic information system (GIS techniques with hydrologic/hydraulic analysis. In this paper, a technical framework and several key techniques for this real-time preliminary evacuation planning are introduced. An object-oriented method was used to extract hydrological information on the barrier lake from unmanned aerial vehicle (UAV remote sensing images. The real-time flood routine was calculated by using shallow-water equations, which were solved by means of a finite volume scheme on multiblock structured grids. The results of the hydraulic computations are visualized and analyzed in a 3-D geographic information system for inundation potential analysis, and an emergency response plan is made. The results show that if either a full-break or a half-break situation had occurred for the Chapinghe barrier lake on 19 May 2008, then the Xiaoba Town region and the Sangzao Town region would have been affected, but the downstream towns would have been less influenced. Preliminary evacuation plans under different dam break situations can be effectively made using these methods.

  1. Breaking sod or breaking even? Flax on the northern Great Plains and Prairies, 1889-1930.

    Science.gov (United States)

    MacFayden, Joshua D

    2009-01-01

    A new thirst for paint and color in cities made extensive flax production profitable in the northern Great Plains and Prairies and contributed to the cultivation of the most fragile grassland ecosystems. The production of flax seed for linseed oil became an early spin-off of the Prairie wheat economy but, unlike wheat, flax vanished from old land after one or two rotations and reappeared in districts with the most new breaking. Officials explained the migrant crop as preparing native grasslands for cultivation or exhausting soil in old land, but farmers brought flax to their new breaking for other reasons. Producers would only put flax on any land when a range of economic and environmental conditions were in place. It was never sown without promise of adequately high prices or in the absence of affordable seed and other inputs. When price allowed, it usually appeared on new breaking because it could be planted later and transported further without upsetting the balance of other activities and without farmers learning many new techniques. Scientists discovered that diseased soil drove flax off old land, not soil exhaustion. Circumventing the disease was possible but costly, and farmers simply replaced flax with the next most lucrative commodity.

  2. 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

  3. Skills Associated with Line Breaks in Elite Rugby Union

    Directory of Open Access Journals (Sweden)

    Steve den Hollander, James Brown, Michael Lambert, Paul Treu, Sharief Hendricks

    2016-09-01

    Full Text Available The ability of the attacking team to break through the defensive line is a key indicator of success as it creates opportunities to score tries. The aim of this study was to analyse line breaks and identify the associated skills and playing characteristics. The 2013 Super Rugby season (125 games was analysed, in which 362 line breaks were identified and coded using variables that assessed team patterns and non-contact attacking skills in the phases preceding the line break. There was an average of 3 line breaks per game, with 39% of line breaks resulting in a try. Line breaks occurred when the ball-carrier was running fast [61%, x2(4 = 25.784, p = 0.000, Cramer’s v = 0.1922, weak]. At a moderate distance, short lateral passes (19% and skip passes (15% attributed to the highest percentage of line breaks [x2(26 = 50.899, p = 0.036, Cramer’s v = 0.2484, moderate]. Faster defensive line speeds resulted in more line breaks [x2(12 = 61.703, p < 0.001, Cramer’s v = 0.3026, moderate]. Line breaks are associated with overall team success and try scoring opportunities. Awareness of the defenders line speed and depth, fast running speed when receiving the ball and quick passing between attackers to the outside backs creates line break opportunities. During training, coaches should emphasise the movement speed of the ball between attackers and manipulate the speed and distance of the defenders.

  4. Visualization of the drop deformation and break-up process in a high pressure homogenizer

    Energy Technology Data Exchange (ETDEWEB)

    Innings, F. [Tetra Pak Processing Systems, Ruben Rausings gata, SE-221 86 Lund (Sweden); Traegaardh, C. [Lund University, Box 124, SE-221 00 Lund (Sweden)

    2005-08-01

    For the creation of sub-micron emulsions in fluids of low viscosity the high pressure homogenizer (HPH) is usually chosen. One way of obtaining deeper knowledge of exactly what happens in the active region is to visualize it. In this work, a drop deformation and break-up visualization system based on a modified Particle Image Velocimetry (PIV) system is described. The system reproduces the gap in a HPH and has been used with pressures up to 18 MPa and drops as small as 5 {mu}m. The optics of the system are analyzed taking into account limiting factors such as the lens resolving power, the focal depth, and the duration of the laser pulses. It is shown that it is possible to resolve drops down to a few {mu}m moving in excess of 100 m/s, and that the main limitations are the resolving power and in the focal depth of the objectives. Examples are shown from capillary drop creation and from the deformation and break-up of drops in a HPH. It can be concluded that in a HPH, the drops are only deformed to a limited extent in the inlet of the gap, and that all drop break-up occurs far downstream of the gap. (Abstract Copyright [2005], Wiley Periodicals, Inc.)

  5. Large-eddy simulation of cavitating nozzle flow and primary jet break-up

    Energy Technology Data Exchange (ETDEWEB)

    Örley, F., E-mail: felix.oerley@aer.mw.tum.de; Trummler, T.; Mihatsch, M. S.; Schmidt, S. J.; Adams, N. A. [Institute of Aerodynamics and Fluid Mechanics, Technische Universität München, Boltzmannstr. 15, 85748 Garching bei München (Germany); Hickel, S. [Institute of Aerodynamics and Fluid Mechanics, Technische Universität München, Boltzmannstr. 15, 85748 Garching bei München (Germany); Chair of Computational Aerodynamics, Faculty of Aerospace Engineering, TU Delft, Kluyverweg 1, 2629 HS Delft (Netherlands)

    2015-08-15

    We employ a barotropic two-phase/two-fluid model to study the primary break-up of cavitating liquid jets emanating from a rectangular nozzle, which resembles a high aspect-ratio slot flow. All components (i.e., gas, liquid, and vapor) are represented by a homogeneous mixture approach. The cavitating fluid model is based on a thermodynamic-equilibrium assumption. Compressibility of all phases enables full resolution of collapse-induced pressure wave dynamics. The thermodynamic model is embedded into an implicit large-eddy simulation (LES) environment. The considered configuration follows the general setup of a reference experiment and is a generic reproduction of a scaled-up fuel injector or control valve as found in an automotive engine. Due to the experimental conditions, it operates, however, at significantly lower pressures. LES results are compared to the experimental reference for validation. Three different operating points are studied, which differ in terms of the development of cavitation regions and the jet break-up characteristics. Observed differences between experimental and numerical data in some of the investigated cases can be caused by uncertainties in meeting nominal parameters by the experiment. The investigation reveals that three main mechanisms promote primary jet break-up: collapse-induced turbulent fluctuations near the outlet, entrainment of free gas into the nozzle, and collapse events inside the jet near the liquid-gas interface.

  6. Investigating HST/WFC3 Selected Lyman Break Galaxies at z=1-3

    Science.gov (United States)

    Hathi, Nimish P.; McCarthy, P. J.; Cohen, S. H.; Ryan, R. E.; Windhorst, R. A.; Yan, H.; Rutkowski, M. J.; Koekemoer, A. M.; O'Connell, R. W.; SOC, WFC3

    2013-01-01

    The Lyman break technique is widely used to select high redshift (z>3) galaxies, but the lack of Lyman break galaxies (LBGs) at zlight on the physical properties of higher redshift LBGs, whose spectroscopic and photometric studies are very challenging because of their faint magnitudes and lack of high resolution rest-frame optical photometry. The peak epoch of global star-formation rate at z=1-3 is now accessible using the dropout technique with the WFC3 UVIS channel. The availability of extensive multi-wavelength photometric data, and access to rest-frame optical spectroscopy at z=1-3 will tremendously increase our physical understanding of LBGs. We have selected LBG candidates using the WFC3 UVIS filters (F225W, F275W, F336W) that bracket the Lyman break at z=1-3 in the GOODS-S field using the WFC3 Early Release Science Observations. I will present results from our studies of rest-UV luminosity functions and SED analysis of these LBGs at z=1-3, and infer possible evolutionary trends. This work is based on Early Release Science observations made by the WFC3 Scientific Oversight Committee (STScI/NASA grant HST-GO-11359.08-A). This research is (partially) supported by a grant from the American Astronomical Society.

  7. Crowdsourced online dispute resolution

    NARCIS (Netherlands)

    Dimov, D.V.

    2017-01-01

    Solving disputes often takes a considerable amount of time and money. That holds for everyone involved. A new type of dispute resolution called Crowdsourced Online Dispute Resolution (CODR) seems to have the potential to offer a cheap, fast, and democratic dispute resolution procedure. Since it is

  8. Pushing the physical limits of spectroscopic imaging for new biology and better medicine (Conference Presentation)

    Science.gov (United States)

    Cheng, Ji-Xin

    2017-02-01

    In vivo molecular spectroscopic imaging is not a simple addition of a spectrometer to a microscope. Innovations are needed to break the physical limits in sensitivity, depth, speed and resolution perspectives. I will present our most recent advances in modality development, biological application, and clinical translation. My talk will focus on the development of mid-infrared photothermal microscope for depth-resolved vibrational imaging of living cells (Science Advances, in press), the discovery of a metabolic signature in cancer stem cells by hyperspectral stimulated Raman scattering imaging (Cell Stem Cell, in press), and the development of an intravascular vibrational photoacoustic catheter for label-free sensing of lipid laden plaques (Scientific Report 2016, 6:25236).

  9. 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.

  10. 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

  11. Radiative symmetry breaking from interacting UV fixed points

    Science.gov (United States)

    Abel, Steven; Sannino, Francesco

    2017-09-01

    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 to the radiative symmetry breaking that occurs in the supersymmetric standard model.

  12. 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...

  13. 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…

  14. 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.

  15. Distributed Decision Making in Combined Vehicle Routing and Break Scheduling

    NARCIS (Netherlands)

    Meyer, Christoph Manuel; Kopfer, Herbert; Kok, A.L.; Schutten, Johannes M.J.

    2009-01-01

    The problem of combined vehicle routing and break scheduling comprises three subproblems: clustering of customer requests, routing of vehicles, and break scheduling. In practice, these subproblems are usually solved in the interaction between planners and drivers. We consider the case that the

  16. 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 ...

  17. 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 ...

  18. The Year Zero: Iconoclastic Breaks with the Past

    NARCIS (Netherlands)

    de Baets, Antoon

    2015-01-01

    Some regimes try to force a complete break with the past and even to start from the year zero. Throughout history, such iconoclastic breaks were meant to erase, once and for all, the entire past or to destroy as many of its relics and symbols as possible, and either to reach orregain some faraway

  19. 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

  20. Late-breaking papers of EuroGP-99

    NARCIS (Netherlands)

    W.B. Langdon; R. Poli; P. Nordin; T. Fogarty

    1999-01-01

    textabstractThis booklet contains the late-breaking papers of the Second European Workshop on Genetic Programming (EuroGP'99) held in G'oteborg Sweden 26--27~May~1999. EuroGP'99 was one of the EvoNet workshops on evolutionary computing, EvoWorkshops'99. The purpose of the late-breaking papers was to

  1. 36 CFR 7.52 - Cedar Breaks National Monument.

    Science.gov (United States)

    2010-07-01

    ... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false Cedar Breaks National Monument. 7.52 Section 7.52 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR SPECIAL REGULATIONS, AREAS OF THE NATIONAL PARK SYSTEM § 7.52 Cedar Breaks National Monument. (a...

  2. Breaking Wave Impact Pressure on a Vertical Wall

    Directory of Open Access Journals (Sweden)

    C. Rajasekaran

    2010-09-01

    Full Text Available Offshore and coastal structures experience wave impact loads particularly due to breaking waves throughout its design period. In the present paper, an experimental program has been devised to improve our perceptive of the physics and the characteristics of impact pressures due to breaking waves on a vertical wall. The salient features of the study such as model details, breaking wave simulation, the impact and dynamic pressure variation along the depth of the wall are presented. The maximum impact pressure magnitude is found to be of the order of ten times that of the non-breaking dynamic pressure and it always occurred above the still water level for different intensities of breaking waves considered. The minimum pressure rise time is observed to be 0.235 ms.

  3. 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 

  4. Stochastic chiral symmetry breaking process besides the deterministic one.

    Science.gov (United States)

    Silva-Dias, L; López-Castillo, A

    2017-11-08

    In chiral symmetry breaking, populations with initial enantiomeric excess (EE) are probabilistically favored if statistical fluctuation is present, as in nature. Stochastic methods correctly describe chiral symmetry breaking by taking into account the quantitative enantiomeric difference (excess or deficiency) and the statistical fluctuation amplitude, which is inversely proportional to the absolute size of the populations involved. From this, we obtain a law, which indicates that such a favoring probability decreases exponentially [P(EE) = 1/(e(αEE) + 1)] with an initial enantiomeric deficiency mediated by statistical fluctuation. Obviously, chiral symmetry breaking equally favors populations without enantiomeric excess [P(0) = 1/2]. However, if deterministic methods are considered, chiral symmetry breaking will strictly favor the population with an initial enantiomeric excess (EE). To study these stochastic chiral symmetry breaking processes the autocatalytic Frank model was considered. Summarizing, our results show that the initial enantiomeric excesses are not entirely responsible for the final state configuration of autocatalytic finite systems.

  5. 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....... The estimator presented in this paper generalises the classical LL. The BPLL maintains the desirable properties of the LL with regard to the bias and the boundary estimation, it estimates the breaks consistently and it ensures that the volatility estimates are always positive....

  6. 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.

  7. 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.

  8. 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...

  9. Dynamical Local Chirality and Chiral Symmetry Breaking

    CERN Document Server

    Alexandru, Andrei

    2013-01-01

    We present some of the reasoning and results substantiating the notion that spontaneous chiral symmetry breaking (SChSB) in QCD is encoded in local chiral properties of Dirac eigenmodes. Such association is possible when viewing chirality as a dynamical effect, measured with respect to the benchmark of statistically independent left-right components. Following this rationale leads to describing local chiral behavior by a taylor-made correlation, namely the recently introduced correlation coefficient of polarization C_A. In this language, correlated modes (C_A>0) show dynamical preference for local chirality while anti-correlated modes (C_A<0) favor anti-chirality. Our conclusion is that SChSB in QCD can be viewed as dominance of low-energy correlation (chirality) over anti-correlation (anti-chirality) of Dirac sea. The spectral range of local chirality, chiral polarization scale Lambda_ch, is a dynamically generated scale in the theory associated with SChSB. One implication of these findings is briefly dis...

  10. Chiral symmetry breaking in unstirred crystallization

    Energy Technology Data Exchange (ETDEWEB)

    Szurgot, M. [Center of Mathematics and Physics, Technical University of Lodz (Poland)

    2012-01-15

    Statistics of nucleation of chiral forms of sodium bromate from unstirred aqueous solutions was studied. It was established that bimodal, trimodal and unimodal distributions of enantiomers are obtained in unstirred crystallization. It was also found out that probabilities of the creation of L or D crystals and racemates R, as well as the presence of D, L, and R peaks in distributions depend on crystallizer size, supersaturation and temperature. Nucleation at low supersaturations in small, closed crystallizers leads to the formation of pure enantiomers, and to bimodal distributions with D and L peaks at any temperature. At high supersaturations in large, open crystallizers the formation of racemates and unimodal distributions with racemate R peaks results. In open crystallizers at the lowest temperatures and at the highest temperatures used in crystallization from aqueous solution racemates of sodium bromate are preferentially formed, but in a wide range of intermediate-temperatures apart from racemates, pure enantiomers are efficiently formed which leads to trimodal distributions. The spontaneous formation of pure enantiomers in crystallization from unstirred, unseeded solutions is caused by the chiral symmetry breaking phenomenon, the same as that discovered in stirred crystallization. The conservation of chiral symmetry is, in unstirred crystallization, one of the two possibilities, and the other one is the breakage of symmetry. Both of them occur in nature. (copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  11. 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.

  12. 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...

  13. Record breaking bursts in a fiber bundle model of creep rupture

    Directory of Open Access Journals (Sweden)

    Zsuzsa eDanku

    2014-02-01

    Full Text Available We investigate the statistics of record breaking events in the time series of cracklingbursts in a fiber bundle model of the creep rupture of heterogeneous materials. In the model fibers break due to two mechanisms: slowly accumulating damage triggers bursts of immediate breakings analogousto acoustic emissions in experiments. The rupture process accelerates such that the size of breaking avalanches increases while the waiting time between consecutive events decreases towards failure.Record events are defined as bursts which have a larger size than all previous events in the time series.We analyze the statistics of records focusing on the limit of equal load sharing (ELS of the model and compare the results to the record statistics of sequences of independent identically distributed random variables. Computer simulations revealed that the number of records grows with the logarithm of the event number except for the close vicinity of macroscopic failure where an exponential dependence isevidenced. The two regimes can be attributed to the dominance of disorder with small burst sizesand to stress enhancements giving rise efficient triggering of extended bursts, respectively.Both the size of records and the increments between consecutive record eventsare characterized by power law distributions with a common exponent 1.33 significantly differentfrom the usual ELS burst size exponents of fiber bundles. The distribution of waiting times followsthe same behavior, however, with two distinct exponents for low and high loads. Studying the evolution of records we identify a load dependent characteristic scale of the systemwhich separates slow down and acceleration of record breaking as failure is approached.

  14. Record breaking bursts in a fiber bundle model of creep rupture

    Science.gov (United States)

    Danku, Zsuzsa; Kun, Ferenc

    2014-02-01

    We investigate the statistics of record breaking events in the time series of cracklingbursts in a fiber bundle model of the creep rupture of heterogeneous materials. In the model fibers break due to two mechanisms: slowly accumulating damage triggers bursts of immediate breakings analogousto acoustic emissions in experiments. The rupture process accelerates such that the size of breaking avalanches increases while the waiting time between consecutive events decreases towards failure.Record events are defined as bursts which have a larger size than all previous events in the time series.We analyze the statistics of records focusing on the limit of equal load sharing (ELS) of the model and compare the results to the record statistics of sequences of independent identically distributed random variables. Computer simulations revealed that the number of records grows with the logarithm of the event number except for the close vicinity of macroscopic failure where an exponential dependence isevidenced. The two regimes can be attributed to the dominance of disorder with small burst sizesand to stress enhancements giving rise efficient triggering of extended bursts, respectively.Both the size of records and the increments between consecutive record eventsare characterized by power law distributions with a common exponent 1.33 significantly differentfrom the usual ELS burst size exponents of fiber bundles. The distribution of waiting times followsthe same behavior, however, with two distinct exponents for low and high loads. Studying the evolution of records we identify a load dependent characteristic scale of the systemwhich separates slow down and acceleration of record breaking as failure is approached.

  15. 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

  16. RANS-VOF modeling of hydrodynamics and sand transport under full-scale non-breaking and breaking waves

    NARCIS (Netherlands)

    Fernandez Mora, Maria de Los Angeles; Ribberink, Jan S.; van der Zanden, Joep; van der Werf, Jebbe J.; Jacobsen, N.G.; Lynett, P.; Lynett, Patrick

    2017-01-01

    A 2D RANS-VOF model is used to simulate the flow and sand transport for two different full-scale laboratory experiments: i) non-breaking waves over a horizontal sand bed (Schretlen et al., 2011) and ii) plunging breaking waves over a barred mobile bed profile (Van der Zanden et al., 2016). For the

  17. Limits on $\

    CERN Document Server

    Perego, D L

    2002-01-01

    A limit on the tau neutrino mass is obtained using all the $Z^{0} \\to \\tau^{+} \\tau^{-}$ data collected at LEP by the DELPHI detector between 1992 and 1995. In this analysis events in which one of the taus decays into one charged particle, while the second $\\tau$ decays into f{}ive charged pions (1-5 topology) have been used. The neutrino mass is determined from a bidimensional \\fit ~on the invariant mass $m^{*}_{5 \\pi}$ and on the energy $E_{5 \\pi}$ of the f{}ive $\\pi^{\\pm}$ system. The result found is $m_{\

  18. Photon-Limited Information in High Resolution Laser Ranging

    Science.gov (United States)

    2014-05-28

    mirrors rotate at about 12 degrees from the corners so the deflected light comes off at odd angles . In order for the beam to come off the DMD straight...15 Figure 15 The picture on the left is of the digital mirror device DMD that is used to generate the transmit images. The image...collected for every pattern transmitted. Despite the relatively low contrast shown here, we believe the contrast can be improved and in addition we believe

  19. Tele-AAC Resolution.

    Science.gov (United States)

    Anderson, Kate; Boisvert, Michelle K; Doneski-Nicol, Janis; Gutmann, Michelle L; Hall, Nerissa C; Morelock, Cynthia; Steele, Richard; Cohn, Ellen R

    2012-01-01

    Approximately 1.3% of all people, or about 4 million Americans, cannot rely on their natural speech to meet their daily communication needs. Telepractice offers a potentially cost-effective service delivery mechanism to provide clinical AAC services at a distance to the benefit of underserved populations in the United States and worldwide. Tele-AAC is a unique cross-disciplinary clinical service delivery model that requires expertise in both telepractice and augmentative and alternative communication (AAC) systems. The Tele-AAC Working Group of the 2012 ISAAC Research Symposium therefore drafted a resolution underscoring the importance of identifying and characterizing the unique opportunities and constraints of Tele-AAC in all aspects of service delivery. These include, but are not limited to: needs assessments; implementation planning; device/system procurement, set-up and training; quality assurance, client progress monitoring, and follow-up service delivery. Tele-AAC, like other telepractice applications, requires adherence to the ASHA Code of Ethics and other policy documents, and state, federal, and international laws, as well as a competent technological infrastructure. The Working Group recommends that institutions of higher education and professional organizations provide training in Tele-AAC service provision. In addition, research and development are needed to create validity measures across Tele-AAC practices (i.e., assessment, implementation, and consultation); determine the communication competence levels achieved by Tele-AAC users; discern stakeholders' perceptions of Tele-AAC services (e.g., acceptability and viability); maximize Tele-AAC's capacity to engage multiple team members in AAC assessment and ongoing service; identify the limitations and barriers of Tele-AAC provision; and develop potential solutions.

  20. Tele-AAC Resolution

    Directory of Open Access Journals (Sweden)

    Kate Anderson

    2012-12-01

    Full Text Available Approximately 1.3% of all people, or about 4 million Americans, cannot rely on their natural speech to meet their daily communication needs. Telepractice offers a potentially cost-effective service delivery mechanism to provide clinical AAC services at a distance to the benefit of underserved populations in the United States and worldwide.  Tele-AAC is a unique cross-disciplinary clinical service delivery model that requires expertise in both telepractice and augmentative and alternative communication (AAC systems.  The Tele-AAC Working Group of the 2012 ISAAC Research Symposium therefore drafted a resolution underscoring the importance of identifying and characterizing the unique opportunities and constraints of Tele-AAC in all aspects of service delivery. These include, but are not limited to: needs assessments; implementation planning; device/system procurement, set-up and training; quality assurance, client progress monitoring, and follow-up service delivery. Tele-AAC, like other telepractice applications, requires adherence to the ASHA Code of Ethics and other policy documents, and state, federal, and international laws, as well as a competent technological infrastructure. The Working Group recommends that institutions of higher education and professional organizations provide training in Tele-AAC service provision. In addition, research and development are needed to create validity measures across Tele-AAC practices (i.e., assessment, implementation, and consultation; determine the communication competence levels achieved  by Tele-AAC users; discern stakeholders’  perceptions of Tele-AAC services (e.g., acceptability and viability; maximize Tele-AAC’s capacity to engage multiple team members in AAC assessment and ongoing service; identify the limitations and barriers of Tele-AAC provision; and develop potential solutions. 

  1. Spontaneous deadlock breaking on amoeba-based neurocomputer.

    Science.gov (United States)

    Aono, Masashi; Hara, Masahiko

    2008-01-01

    Any artificial concurrent computing system involves a potential risk of "deadlock" that its multiple processes sharing common computational resources are stuck in starved conditions, if simultaneous accesses of the processes to the resources were unconditionally permitted. To avoid the deadlock, it is necessary to set up some form of central control protocol capable of appropriately regulating the resource allocation. On the other hand, many decentralized biological systems also perform concurrent computing based on interactions of components sharing limited amounts of available resources. Despite the absence of a central control unit, they appear to be free from the deadlock implying their death, as long as they are alive. Should we consider that biological computing paradigms are essentially different from artificial ones? Here we employ a photosensitive amoeboid cell known as a model organism for studying cellular information processing and construct an experimental system to explore how the amoeba copes with deadlock-like situations induced by optical feedback control. The feedback control is implemented by a recurrent neural network algorithm for leading the amoeba to solve a particular constraint satisfaction problem. We show that the amoeba is capable of breaking through the deadlock-like situations because its oscillating cellular membrane spontaneously produces a wide variety of spatiotemporal patterns. The result implies that our system can be developed to a neurocomputer that works as logical circuit, associative memory device, combinatorial optimization problem solver, and chaotic computer capable of spontaneous transition among multiple solutions.

  2. Influence of Crack Morphology on Leak Before Break Margins

    Energy Technology Data Exchange (ETDEWEB)

    Weilin Zang (Inspecta Technology AB, Stockholm (SE))

    2007-11-15

    The purpose of the project is to evaluate the deterministic LBB-margins for different pipe systems in a Swedish PWR-plant and using different crack morphology parameters. Results: - The influence of crack morphology on Leak Before Break (LBB) margins is studied. The subject of the report is a number of LBB-submittals to SKI where deterministic LBB-margins are reported. These submittals typically uses a surface roughness of 0.0762 mm (300 microinch) and number of turns equal to zero and an in-house code for the leak rate evaluations. The present report has shown that these conditions give the largest LBB-margins both in terms of the quotient between the critical crack length and the leakage crack size and for the leak rate margin. - Crack morphology parameters have a strong influence on the leak rate evaluations. Using the SQUIRT code and more recent recommendations for crack morphology parameters, it is shown that in many cases the evaluated margins, using 1 gpm as the reference leak rate detection limit, are below the safety factor of 2 on crack size and 10 on leak rate, which is generally required for LBB approval. - The effect of including weld residual stresses on the LBB margins is also investigated. It is shown that for the two examples studied, weld residual stresses were important for the small diameter thin wall pipe whereas it was negligible for the large diameter thick wall pipe which had a self-balanced weld residual stress distribution

  3. Radiative breaking of the minimal supersymmetric left–right model

    Directory of Open Access Journals (Sweden)

    Nobuchika Okada

    2016-05-01

    Full Text Available We study a variation to the SUSY Left–Right symmetric model based on the gauge group SU(3c×SU(2L×SU(2R×U(1BL. Beyond the quark and lepton superfields we only introduce a second Higgs bidoublet to produce realistic fermion mass matrices. This model does not include any SU(2R triplets. We calculate renormalization group evolutions of soft SUSY parameters at the one-loop level down to low energy. We find that an SU(2R slepton doublet acquires a negative mass squared at low energies, so that the breaking of SU(2R×U(1BL→U(1Y is realized by a non-zero vacuum expectation value of a right-handed sneutrino. Small neutrino masses are produced through neutrino mixings with gauginos. Mass limits on the SU(2R×U(1BL sector are obtained by direct search results at the LHC as well as lepton-gaugino mixing bounds from the LEP precision data.

  4. Major Limitations of Satellite images

    OpenAIRE

    Al-Wassai, Firouz A.; Kalyankar, N. V.

    2013-01-01

    Remote sensing has proven to be a powerful tool for the monitoring of the Earth surface to improve our perception of our surroundings has led to unprecedented developments in sensor and information technologies. However, technologies for effective use of the data and for extracting useful information from the data of Remote sensing are still very limited since no single sensor combines the optimal spectral, spatial and temporal resolution. This paper briefly reviews the limitations of satelli...

  5. 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...... Technical Research Council, during the period of January '97 to December '97. The tests were carried out in the 3D wave basin at the Hydraulics and Coastal Engineering Laboratory, Aalborg University. The objective of the study was to asses the effects of wave obliquity and multidirectionality on the wave...

  6. Breaks in the Breaks: A Time-Series Analysis of Divorce Rates

    OpenAIRE

    González-Val, Rafael; Marcén, Miriam

    2009-01-01

    The economic literature examining changes in divorce rates is not conclusive since legal reforms have been found to have permanent, transitory or no effect on divorce rates. This paper studies differences in divorce rates among 16 European countries from 1930 to 2006, by exploiting time-series analysis. We find that 37.5% of the divorce rate’s series are stationary, so that any shock had a transitory effect. However, we also detect structural breaks in the average divorce rate for each countr...

  7. Solution of classical evolutionary models in the limit when the diffusion approximation breaks down

    Science.gov (United States)

    Saakian, David B.; Hu, Chin-Kun

    2016-10-01

    The discrete time mathematical models of evolution (the discrete time Eigen model, the Moran model, and the Wright-Fisher model) have many applications in complex biological systems. The discrete time Eigen model rather realistically describes the serial passage experiments in biology. Nevertheless, the dynamics of the discrete time Eigen model is solved in this paper. The 90% of results in population genetics are connected with the diffusion approximation of the Wright-Fisher and Moran models. We considered the discrete time Eigen model of asexual virus evolution and the Wright-Fisher model from population genetics. We look at the logarithm of probabilities and apply the Hamilton-Jacobi equation for the models. We define exact dynamics for the population distribution for the discrete time Eigen model. For the Wright-Fisher model, we express the exact steady state solution and fixation probability via the solution of some nonlocal equation then give the series expansion of the solution via degrees of selection and mutation rates. The diffusion theories result in the zeroth order approximation in our approach. The numeric confirms that our method works in the case of strong selection, whereas the diffusion method fails there. Although the diffusion method is exact for the mean first arrival time, it provides incorrect approximation for the dynamics of the tail of distribution.

  8. Practical Covertly Secure MPC for Dishonest Majority – or: Breaking the SPDZ Limits

    DEFF Research Database (Denmark)

    Damgård, Ivan Bjerre; Keller, Marcel; Larraia, Enrique

    2013-01-01

    SPDZ (pronounced “Speedz”) is the nickname of the MPC protocol of Damg°ard et al. from Crypto 2012. SPDZ provided various efficiency innovations on both the theoretical and practical sides compared to previous work in the preprocessing model. In this paper we both resolve a number of open problem...

  9. 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.

  10. 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.

  11. Chiral symmetry breaking in QCD with two light flavors.

    Science.gov (United States)

    Engel, Georg P; Giusti, Leonardo; Lottini, Stefano; Sommer, Rainer

    2015-03-20

    A distinctive feature of the presence of spontaneous chiral symmetry breaking in QCD is the condensation of low modes of the Dirac operator near the origin. The rate of condensation must be equal to the slope of M(π)(2)F(π)(2)/2 with respect to the quark mass m in the chiral limit, where M(π) and F(π) are the mass and the decay constant of the Nambu-Goldstone bosons. We compute the spectral density of the (Hermitian) Dirac operator, the quark mass, the pseudoscalar meson mass, and decay constant by numerical simulations of lattice QCD with two light degenerate Wilson quarks. We use lattices generated by the Coordinated Lattice Simulation (CLS) group at three values of the lattice spacing in the range 0.05-0.08 fm, and for several quark masses corresponding to pseudoscalar mesons masses down to 190 MeV. Thanks to this coverage of parameters space, we can extrapolate all quantities to the chiral and continuum limits with confidence. The results show that the low quark modes do condense in the continuum as expected by the Banks-Casher mechanism, and the rate of condensation agrees with the Gell-Mann-Oakes-Renner relation. For the renormalization-group-invariant ratios we obtain [Σ(RGI)](1/3)/F=2.77(2)(4) and Λ(M̅S)/F=3.6(2), which correspond to [Σ(M̅S)(2  GeV)](1/3)=263(3)(4)  MeV and F=85.8(7)(20)  MeV if F(K) is used to set the scale by supplementing the theory with a quenched strange quark.

  12. 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...

  13. Flavour breaking effects in the pseudoscalar meson decay constants

    Energy Technology Data Exchange (ETDEWEB)

    Bornyakov, V.G. [Institute for High Energy Physics, Protvino (Russian Federation); Institute of Theoretical and Experimental Physics, Moscow (Russian Federation); Far Eastern Federal Univ., Vladivostok (Russian Federation). School of Biomedicine; Horsley, R. [Edinburgh Univ. (United Kingdom). School of Physics and Astronomy; Nakamura, Y. [RIKEN Advanced Institute for Computational Science, Hyogo (Japan); Perlt, H.; Schiller, A. [Leipzig Univ. (Germany). Inst. fuer Theoretische Physik; Pleiter, D. [Forschungszentrum Juelich (Germany). Juelich Supercomputing Centre; Regensburg Univ. (Germany). Inst. fuer Theoretische Physik; Rakow, P.E.L. [Liverpool Univ. (United Kingdom). Theoretical Physics Division; Schierholz, G. [DESY Hamburg (Germany); Stueben, H. [Hamburg Univ. (Germany). Regionales Rechenzentrum; Zanotti, J.M. [Adelaide Univ. (Australia). CSSM, Dept. of Physics; Collaboration: QCDSF-UKQCD Collaborations

    2016-12-14

    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.

  14. 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...... in the creation efficiency of these atom pairs can be traced back to excitation modes of this confinement. The understanding of these excitation modes allows for a detailed characterization of the symmetry-breaking mechanism, showing how a twofold spontaneous breaking of spatial and spin symmetry can occur....... In addition, a detailed account of the experimental methods for the preparation and analysis of spinor quantum gases is given....

  15. Automatic assessment of tear film break-up dynamics.

    Science.gov (United States)

    Ramos, L; Barreira, N; Pena-Verdeal, H; Giráldez, M J

    2014-01-01

    Dry eye syndrome is a common disorder of the tear film which affects a remarkable percentage of the population. The Break-Up Time (BUT) is a clinical test used for the diagnosis of this disease, which computes the time the first tear film break-up appears. This work describes a fully automatic methodology to compute the BUT measurement and evaluate the break-up dynamics until the final blink. This analysis provides useful additional information for the assessment of tear film stability.

  16. Breaking bad news to people with a learning disability.

    Science.gov (United States)

    Read, S

    This article identifies the difficulties often associated with breaking bad news, from a nursing perspective. The additional considerations involved in breaking bad news to people with learning disabilities are identified, and a six-step protocol (Buckman, 1991) is introduced and explored in relation to this client group. Effective communication is seen to be crucial when working with people with a learning disability, and a system for accurate listening is offered (Conboy-Hill, 1992). Finally, recommendations for helping professionals to learn how to break bad news sensitively to this client group are suggested. They include multi-agency working, education and training opportunities, standard statements, resources, support and research initiatives.

  17. 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.

  18. 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.

  19. Resolution of Reflection Seismic Data Revisited

    DEFF Research Database (Denmark)

    Hansen, Thomas Mejer; Mosegaard, Klaus; Zunino, Andrea

    lower vertical resolution of reflection seismic data. In the following we will revisit think layer model and demonstrate that there is in practice no limit to the vertical resolution using the parameterization of Widess (1973), and that the vertical resolution is limited by the noise in the data...... wavelength of the wavelet within the thin layer. Using a simple thin-layer parameterization Widess (1973) demonstrated that thin layers with thickness less that around λb/8 cannot be resolved from seismic data independent of the noise level. This has results since been widely adopted as a commonly accepted....... In general, we discuss that the resolution of reflection seismic data is controlled by the noise level and the a priori information available...

  20. Axial Super-resolution Evanescent Wave Tomography

    CERN Document Server

    Pendharker, Sarang; Newman, Ward; Ogg, Stephen; Nazemifard, Neda; Jacob, Zubin

    2016-01-01

    Optical tomographic reconstruction of a 3D nanoscale specimen is hindered by the axial diffraction limit, which is 2-3 times worse than the focal plane resolution. We propose and experimentally demonstrate an axial super-resolution evanescent wave tomography (AxSET) method that enables the use of regular evanescent wave microscopes like Total Internal Reflection Fluorescence Microscope (TIRF) beyond surface imaging, and achieve tomographic reconstruction with axial super-resolution. Our proposed method based on Fourier reconstruction achieves axial super-resolution by extracting information from multiple sets of three-dimensional fluorescence images when the sample is illuminated by an evanescent wave. We propose a procedure to extract super-resolution features from the incremental penetration of an evanescent wave and support our theory by 1D (along the optical axis) and 3D simulations. We validate our claims by experimentally demonstrating tomographic reconstruction of microtubules in HeLa cells with an axi...

  1. Concepts for nanoscale resolution in fluorescence microscopy.

    Science.gov (United States)

    Hell, Stefan W; Dyba, Marcus; Jakobs, Stefan

    2004-10-01

    Spatio-temporal visualization of cellular structures by fluorescence microscopy has become indispensable in biology. However, the resolution of conventional fluorescence microscopy is limited by diffraction to about 180 nm in the focal plane and to about 500 nm along the optic axis. Recently, concepts have emerged that overcome the diffraction resolution barrier fundamentally. Formed on the basis of reversible saturable optical transitions, these concepts might eventually allow us to investigate hitherto inaccessible details within live cells.

  2. The 2015 super-resolution microscopy roadmap

    Science.gov (United States)

    Hell, Stefan W.; Sahl, Steffen J.; Bates, Mark; Zhuang, Xiaowei; Heintzmann, Rainer; Booth, Martin J.; Bewersdorf, Joerg; Shtengel, Gleb; Hess, Harald; Tinnefeld, Philip; Honigmann, Alf; Jakobs, Stefan; Testa, Ilaria; Cognet, Laurent; Lounis, Brahim; Ewers, Helge; Davis, Simon J.; Eggeling, Christian; Klenerman, David; Willig, Katrin I.; Vicidomini, Giuseppe; Castello, Marco; Diaspro, Alberto; Cordes, Thorben

    2015-11-01

    Far-field optical microscopy using focused light is an important tool in a number of scientific disciplines including chemical, (bio)physical and biomedical research, particularly with respect to the study of living cells and organisms. Unfortunately, the applicability of the optical microscope is limited, since the diffraction of light imposes limitations on the spatial resolution of the image. Consequently the details of, for example, cellular protein distributions, can be visualized only to a certain extent. Fortunately, recent years have witnessed the development of ‘super-resolution’ far-field optical microscopy (nanoscopy) techniques such as stimulated emission depletion (STED), ground state depletion (GSD), reversible saturated optical (fluorescence) transitions (RESOLFT), photoactivation localization microscopy (PALM), stochastic optical reconstruction microscopy (STORM), structured illumination microscopy (SIM) or saturated structured illumination microscopy (SSIM), all in one way or another addressing the problem of the limited spatial resolution of far-field optical microscopy. While SIM achieves a two-fold improvement in spatial resolution compared to conventional optical microscopy, STED, RESOLFT, PALM/STORM, or SSIM have all gone beyond, pushing the limits of optical image resolution to the nanometer scale. Consequently, all super-resolution techniques open new avenues of biomedical research. Because the field is so young, the potential capabilities of different super-resolution microscopy approaches have yet to be fully explored, and uncertainties remain when considering the best choice of methodology. Thus, even for experts, the road to the future is sometimes shrouded in mist. The super-resolution optical microscopy roadmap of Journal of Physics D: Applied Physics addresses this need for clarity. It provides guidance to the outstanding questions through a collection of short review articles from experts in the field, giving a thorough

  3. Ice breaking in GPCR structural biology

    Science.gov (United States)

    Zhao, Qiang; Wu, Bei-li

    2012-01-01

    G-protein-coupled receptors (GPCRs) are one of the most challenging targets in structural biology. To successfully solve a high-resolution GPCR structure, several experimental obstacles must be overcome, including expression, extraction, purification, and crystallization. As a result, there are only a handful of unique structures reported from this protein superfamily, which consists of over 800 members. In the past few years, however, there has been an increase in the amount of solved GPCR structures, and a few high-impact structures have been determined: the peptide receptor CXCR4, the agonist bound receptors, and the GPCR-G protein complex. The dramatic progress in GPCR structural studies is not due to the development of any single technique, but a combination of new techniques, new tools and new concepts. Here, we summarize the progress made for GPCR expression, purification, and crystallization, and we highlight the technical advances that will facilitate the future determination of GPCR structures. PMID:22286917

  4. Swiss-cheese D3- D7 soft SUSY breaking

    Science.gov (United States)

    Misra, Aalok; Shukla, Pramod

    2010-03-01

    We address issues related to (i) a proposal for resolving a long-standing tension between large volume cosmology and phenomenology as regards reconciliation of requirements of different gravitino masses within the same string-theoretic framework, as well as (ii) evaluation of soft supersymmetry breaking terms and open-string moduli masses in the context of type IIB large volume compactifications involving orientifolds of the Swiss-cheese Calabi-Yau WCP[1,1,1,6,9] with a single mobile space-time filling D3-brane and stacks of D7-branes wrapping the "big" divisor Σ as well as supporting D7-brane fluxes. In addition, we also include perturbative α-corrections and non-perturbative world-sheet instanton corrections to the Kähler potential as well as Euclidean D3-instanton superpotential. First, using the toric data for the aforementioned Swiss-cheese Calabi-Yau and GLSM techniques, we obtain in the large volume limit, the geometric Kähler potential for the big (and small) divisor(s) in terms of derivatives of genus-two Siegel theta functions. Next, we show that as the mobile space-time filling D3-brane moves from a particular non-singular elliptic curve embedded in the Swiss-cheese Calabi-Yau to another non-singular elliptic curve, it is possible to obtain 10 12 GeV gravitino during the primordial inflationary era as well as, e.g., a TeV gravitino in the present era, within the same set up for the same volume of the Calabi-Yau stabilized at around 10ls6. Then by constructing local (i.e. localized around the location of the mobile D3-brane in the Calabi-Yau) appropriate involutively-odd harmonic one-form on the big divisor that lies in coker(H∂¯,-(0,1)(CY)→iH∂¯,-(0,1)(Σ)) and extremizing the potential, we show that it is possible to obtain an O(1)g from the wrapping of D7-branes on the big divisor due to competing contributions from the Wilson line moduli relative to the divisor volume modulus. To permit gaugino condensation, we take the rigid limit of the

  5. Resolution enhancement using simultaneous couple illumination

    Science.gov (United States)

    Hussain, Anwar; Martínez Fuentes, José Luis

    2016-10-01

    A super-resolution technique based on structured illumination created by a liquid crystal on silicon spatial light modulator (LCOS-SLM) is presented. Single and simultaneous pairs of tilted beams are generated to illuminate a target object. Resolution enhancement of an optical 4f system is demonstrated by using numerical simulations. The resulting intensity images are recorded at a charged couple device (CCD) and stored in the computer memory for further processing. One dimension enhancement can be performed with only 15 images. Two dimensional complete improvement requires 153 different images. The resolution of the optical system is extended three times compared to the band limited system.

  6. Faunal breaks and species composition of Indo-Pacific corals: the role of plate tectonics, environment and habitat distribution.

    Science.gov (United States)

    Keith, S A; Baird, A H; Hughes, T P; Madin, J S; Connolly, S R

    2013-07-22

    Species richness gradients are ubiquitous in nature, but the mechanisms that generate and maintain these patterns at macroecological scales remain unresolved. We use a new approach that focuses on overlapping geographical ranges of species to reveal that Indo-Pacific corals are assembled within 11 distinct faunal provinces. Province limits are characterized by co-occurrence of multiple species range boundaries. Unexpectedly, these faunal breaks are poorly predicted by contemporary environmental conditions and the present-day distribution of habitat. Instead, faunal breaks show striking concordance with geological features (tectonic plates and mantle plume tracks). The depth range over which a species occurs, its larval development rate and genus age are important determinants of the likelihood that species will straddle faunal breaks. Our findings indicate that historical processes, habitat heterogeneity and species colonization ability account for more of the present-day biogeographical patterns of corals than explanations based on the contemporary distribution of reefs or environmental conditions.

  7. High resolution quantum metrology via quantum interpolation

    Science.gov (United States)

    Ajoy, Ashok; Liu, Yixiang; Saha, Kasturi; Marseglia, Luca; Jaskula, Jean-Christophe; Cappellaro, Paola

    2016-05-01

    Nitrogen Vacancy (NV) centers in diamond are a promising platform for quantum metrology - in particular for nanoscale magnetic resonance imaging to determine high resolution structures of single molecules placed outside the diamond. The conventional technique for sensing of external nuclear spins involves monitoring the effects of the target nuclear spins on the NV center coherence under dynamical decoupling (the CPMG/XY8 pulse sequence). However, the nuclear spin affects the NV coherence only at precise free evolution times - and finite timing resolution set by hardware often severely limits the sensitivity and resolution of the method. In this work, we overcome this timing resolution barrier by developing a technique to supersample the metrology signal by effectively implementing a quantum interpolation of the spin system dynamics. This method will enable spin sensing at high magnetic fields and high repetition rate, allowing significant improvements in sensitivity and spectral resolution. We experimentally demonstrate a resolution boost by over a factor of 100 for spin sensing and AC magnetometry. The method is shown to be robust, versatile to sensing normal and spurious signal harmonics, and ultimately limited in resolution only by the number of pulses that can be applied.

  8. Robust microbubble tracking for super resolution imaging in ultrasound

    DEFF Research Database (Denmark)

    Hansen, Kristoffer B.; Villagómez Hoyos, Carlos Armando; Brasen, Jens Christian

    2016-01-01

    Currently ultrasound resolution is limited by diffraction to approximately half the wavelength of the sound wave employed. In recent years, super resolution imaging techniques have overcome the diffraction limit through the localization and tracking of a sparse set of microbubbles through the vas...

  9. 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

  10. Effective photon mass by Super and Lorentz symmetry breaking

    National Research Council Canada - National Science Library

    Bonetti, Luca; dos Santos Filho, Luís R; Helayël-Neto, José A; Spallicci, Alessandro D.A.M

    2017-01-01

    .... Thus, we extract a massive Carroll–Field–Jackiw photon term in the Lagrangian and show that the effective mass is proportional to the breaking vector and moderately dependent on the direction of observation...

  11. 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.

  12. 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.

  13. Footprints of Buildings at Cedar Breaks National Monument, Utah (footprints)

    Data.gov (United States)

    National Park Service, Department of the Interior — This is an Arc/INFO coverage consisting of 10 polygons representing the buildings' footprints at Cedar Breaks National Monument, Utah. The footprints were collected...

  14. 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...

  15. Could dynamical Lorentz symmetry breaking induce the superluminal neutrinos?

    Energy Technology Data Exchange (ETDEWEB)

    Nojiri, Shin' ichi [Nagoya University, Department of Physics, Nagoya (Japan); Nagoya University, Kobayashi-Maskawa Institute for the Origin of Particles and the Universe, Nagoya (Japan); Odintsov, Sergei D. [Facultat de Ciencies, Institucio Catalana de Recerca i Estudis Avancats (ICREA) and Institut de Ciencies de l' Espai (IEEC-CSIC), Campus UAB, Bellaterra (Barcelona) (Spain); Tomsk State Pedagogical University, Tomsk (Russian Federation)

    2011-11-15

    A toy fermion model coupled to the Lagrange multiplier constraint field is proposed. The possibility of superluminal neutrino propagation as a result of dynamical Lorentz symmetry breaking is studied. (orig.)

  16. 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.

  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. Breaking supercontinents; no need to choose between passive or active

    Science.gov (United States)

    Wolstencroft, Martin; Davies, J. Huw

    2017-08-01

    Much debate has centred on whether continental break-up is predominantly caused by active upwelling in the mantle (e.g. plumes) or by long-range extensional stresses in the lithosphere. We propose the hypothesis that global supercontinent break-up events should always involve both. The fundamental principle involved is the conservation of mass within the spherical shell of the mantle, which requires a return flow for any major upwelling beneath a supercontinent. This shallow horizontal return flow away from the locus of upwelling produces extensional stress. We demonstrate this principle with numerical models, which simultaneously exhibit both upwellings and significant lateral flow in the upper mantle. For non-global break-up the impact of the finite geometry of the mantle will be less pronounced, weakening this process. This observation should motivate future studies of continental break-up to explicitly consider the global perspective, even when observations or models are of regional extent.

  19. Stroma Breaking Theranostic Nanoparticles for Targeted Pancreatic Cancer Therapy

    Science.gov (United States)

    This project develops a dual-targeted and stroma breaking theranostic nanoparticle platform to address an unmet, clinical challenge of poor drug delivery efficiency in the application of nanomedicine to cancer therapy.

  20. ATLAS diboson excess from low scale supersymmetry breaking

    Energy Technology Data Exchange (ETDEWEB)

    Petersson, Christoffer [Department of Fundamental Physics, Chalmers University of Technology,412 96 Göteborg (Sweden); Physique Théorique et Mathématique, Université Libre de Bruxelles,C.P. 231, 1050 Brussels (Belgium); International Solvay Institutes,1050 Brussels (Belgium); Torre, Riccardo [Dipartimento di Fisica e Astronomia, Università di Padova and INFN Sezione di Padova,Via Marzolo 8, I-35131 Padova (Italy)

    2016-01-18

    We provide an interpretation of the recent ATLAS diboson excess in terms of a class of supersymmetric models in which the scale of supersymmetry (SUSY) breaking is in the few TeV range. The particle responsible for the excess is the scalar superpartner of the Goldstone fermion associated with SUSY breaking, the sgoldstino. This scalar couples strongly to the Standard Model vector bosons and weakly to the fermions, with all coupling strengths determined by ratios of soft SUSY breaking parameters over the SUSY breaking scale. Explaining the ATLAS excess selects particular relations and ranges for the gaugino masses, while imposing no constraints on the other superpartner masses. Moreover, this signal hypothesis predicts a rate in the Zγ final state that is expected to be observable at the LHC Run II already with a few fb{sup −1} of integrated luminosity.

  1. A two-dimensional dam-break flood plain model

    Science.gov (United States)

    Hromadka, T.V.; Berenbrock, C.E.; Freckleton, J.R.; Guymon, G.L.

    1985-01-01

    A simple two-dimensional dam-break model is developed for flood plain study purposes. Both a finite difference grid and an irregular triangle element integrated finite difference formulation are presented. The governing flow equations are approximately solved as a diffusion model coupled to the equation of continuity. Application of the model to a hypothetical dam-break study indicates that the approach can be used to predict a two-dimensional dam-break flood plain over a broad, flat plain more accurately than a one-dimensional model, especially when the flow can break-out of the main channel and then return to the channel at other downstream reaches. ?? 1985.

  2. Utilities at Cedar Breaks National Monument, Utah (utilpnt)

    Data.gov (United States)

    National Park Service, Department of the Interior — This feature class represents various types of utilities, including water- and power-related utilities, at Cedar Breaks National Monument, Utah. The utilities were...

  3. 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...

  4. 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.

  5. 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

  6. Electroweak symmetry breaking beyond the Standard Model

    Indian Academy of Sciences (India)

    reduced gauge coupling which helps it to evade the LEP-2 limit. This again implies that we can employ a lighter stop in the loop, ..... It is also called a holographic Higgs [29]. The holographic 5D-to-4D translation involves the presence of ... rial representation 4 of SO(5). The spectrum of new particles can therefore reveal the.

  7. High Resolution Imaging with AEOS

    Energy Technology Data Exchange (ETDEWEB)

    Patience, J; Macintosh, B A; Max, C E

    2001-08-27

    The U. S. Air Force Advanced Electro-Optical System (AEOS) which includes a 941 actuator adaptive optics system on a 3.7m telescope has recently been made available for astronomical programs. Operating at a wavelength of 750 nm, the diffraction-limited angular resolution of the system is 0.04 inches; currently, the magnitude limit is V {approx} 7 mag. At the distances of nearby open clusters, diffraction-limited images should resolve companions with separations as small as 4-6 AU--comparable to the Sun-Jupiter distance. The ability to study such close separations is critical, since most companions are expected to have separations in the few AU to tens of AU range. With the exceptional angular resolution of the current AEOS setup, but restricted target magnitude range, we are conducting a companion search of a large, well-defined sample of bright early-type stars in nearby open clusters and in the field. Our data set will both characterize this relatively new adaptive optics system and answer questions in binary star formation and stellar X-ray activity. We will discuss our experience using AEOS, the data analysis involved, and our initial results.

  8. Bank Resolution in Europe

    DEFF Research Database (Denmark)

    N. Gordon, Jeffery; Ringe, Georg

    2015-01-01

    Bank resolution is a key pillar of the European Banking Union. This column argues that the current structure of large EU banks is not conducive to an effective and unbiased resolution procedure. The authors would require systemically important banks to reorganise into a ‘holding company’ structure...

  9. abour Dispute Resolution System

    African Journals Online (AJOL)

    for Conciliation, Mediation and Arbitration (CCMA). Even though the Labour. Relations Act 66/95 (LRA) has brought statutory dispute resolution within reach of the ordinary worker, it might actually have compounded the problems relating to dispute resolution in the country. The high rate of individual unfair dismissal cases ...

  10. Automated conflict resolution issues

    Science.gov (United States)

    Wike, Jeffrey S.

    1991-01-01

    A discussion is presented of how conflicts for Space Network resources should be resolved in the ATDRSS era. The following topics are presented: a description of how resource conflicts are currently resolved; a description of issues associated with automated conflict resolution; present conflict resolution strategies; and topics for further discussion.

  11. 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.

  12. Wave Kinematics and Sediment Suspension at Wave Breaking Point.

    Science.gov (United States)

    1982-06-01

    Cayley , A. 1895, An Elementary Treatise on Elliptic Functions, George BeTl an Sons, London. Dally, W. R., 1980, A Numerical Model for Beach Profile...were studied in the laboratory. - The flow field concerns mainly the drift velocity on sloping beach. The drift velocity profiles as well as the mean...to treat the breaking point as a natural boundary for various studies of surf zone problems. The breaking point itself, however, has not been widely

  13. Some geological and geophysical aspects in electric rock breaking

    CSIR Research Space (South Africa)

    Henry, G

    2011-08-01

    Full Text Available in mining Novel mining methods autonomous narrow reef miner (<50 cm high) CMI Carlow Road Campus Rock breaker (non-explosive; ore processor) 3D scanner ? mapping Roof sounding device Underground navigation How rock breaks ? CSIR 2011 Slide 3... Marx generator transformer From: Ilgner (2006) Single ?shot high voltage electric rock breaking (2003) ? CSIR 2011 Slide10 Inefficient Comminution by Compression (-) (+) Water Direct Comminution by Explosion (-) (+) 6 mm Screen Water...

  14. 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.

  15. Measurement of Entrained Air Bubbles and Vortices in Breaking Waves

    OpenAIRE

    大塚, 淳一; 渡部, 靖憲; Junichi, Otsuka; Yasunori, Watanabe; 北海道大学大学院工学研究科; School of Engineering, Hokkaido University

    2007-01-01

    Breaking waves produce numbers of vortices through a jet splashing process and also entrain many air bubbles, forming complicated air-water two-phase turbulent flow field in a surf zone. In this research, a simultaneous velocity measurement technique of water and bubble flows in breaking waves is developed for characterizing water-bubble interactions within vortices in a surf zone. The bubbles and neutral buoyant tracers are separately recorded by two different digital video cameras on the ba...

  16. 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.

  17. 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.)

  18. 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.

  19. Concepts of Electroweak Symmetry Breaking and Higgs Physics

    CERN Document Server

    Gomez-Bock, M; Mühlleitner, M; Spira, M; Zerwas, P M

    2008-01-01

    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.

  20. 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.)

  1. Teaching medical students how to break bad news

    OpenAIRE

    Garg, A. (Abhishek); Buckman, R.; Kason, Y

    1997-01-01

    PROGRAM OBJECTIVE: To teach medical students to break bad news to patients and their families empathically and competently. SETTING: Seven teaching hospitals affiliated with the University of Toronto since 1987. PARTICIPANTS: All medical students in their third preclinical year. PROGRAM: The course presents a 6-point protocol to guide students in breaking bad news and comprises 2 half-day (3-hour) teaching sessions. Each session incorporates a video presentation, a discussion period and small...

  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. 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...

  4. Blinking and tear break-up during four visual tasks.

    Science.gov (United States)

    Himebaugh, Nikole L; Begley, Carolyn G; Bradley, Arthur; Wilkinson, Jenni A

    2009-02-01

    This study investigates the relationship between blinking, tear film break-up, and ocular symptoms for normal and dry eye subjects performing four different visual tasks. Sixteen control and sixteen dry eye subjects performed four visual tasks (looking straight ahead, watching a movie, identifying rapidly changing letters, and playing a computer game) while blink patterns and fluorescein images of the tear film were videotaped. Pre and posttesting symptom questionnaires, querying the intensity of nine symptoms of ocular irritation, were completed by all subjects. Blink rate and blink amplitude were computed from digitized videos. The percentage of tear film break-up before the blink was calculated. Dry eye subjects had a significantly higher blink rate (p = 0.017, t-test). Both groups blinked significantly less during the game and letter tasks (p break-up in normal subjects was typically inferior; whereas dry eye subjects showed more tear break-up centrally and superiorly. Real-time video recording of tear break-up and blink behavior pointed to complex interaction between the two. Dry eye subjects shifted more toward intense ocular symptoms at posttesting (p break-up during normal visual tasks may explain the increased level of ocular discomfort symptoms reported at the end of the day, particularly in dry eye patients.

  5. 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.

  6. To Break or Not To Break: Sex Chromosome Hemizygosity During Meiosis in Caenorhabditis.

    Science.gov (United States)

    Van, Mike V; Larson, Braden J; Engebrecht, JoAnne

    2016-11-01

    Meiotic recombination establishes connections between homologous chromosomes to promote segregation. Hemizygous regions of sex chromosomes have no homologous chromosome to recombine with, yet must be transmitted through meiosis. An extreme case of hemizygosity exists in the genus Caenorhabditis, where males have a single X chromosome that completely lacks a homologous partner. To determine whether similar strategies have evolved to accommodate hemizygosity of the X during male meiosis in Caenorhabditis with distinct modes of sexual reproduction, we examined induction and processing of meiotic double strand breaks (DSBs) in androdioecious (hermaphrodite/male) Caenorhabditis elegans and C. briggsae, and gonochoristic (female/male) C. remanei and C. brenneri Analysis of the recombinase RAD-51 suggests more meiotic DSBs are induced in gonochoristic vs. androdioecious species. However, in late prophase in all species, chromosome pairs are restructured into bivalents around a single axis, suggesting that the holocentric nature of Caenorhabditis chromosomes dictates a single crossover per bivalent regardless of the number of DSBs induced. Interestingly, RAD-51 foci were readily observed on the X chromosome of androdioecious male germ cells, while very few were detected in gonochoristic male germ cells. As in C. elegans, the X chromosome in C. briggsae male germ cells undergoes transient pseudosynapsis and flexibility in DSB repair pathway choice. In contrast, in C. remanei and C. brenneri male germ cells, the X chromosome does not undergo pseudosynapsis and appears refractory to SPO-11-induced breaks. Together our results suggest that distinct strategies have evolved to accommodate sex chromosome hemizygosity during meiosis in closely related Caenorhabditis species. Copyright © 2016 by the Genetics Society of America.

  7. Limits of social mobilization.

    Science.gov (United States)

    Rutherford, Alex; Cebrian, Manuel; Dsouza, Sohan; Moro, Esteban; Pentland, Alex; Rahwan, Iyad

    2013-04-16

    The Internet and social media have enabled the mobilization of large crowds to achieve time-critical feats, ranging from mapping crises in real time, to organizing mass rallies, to conducting search-and-rescue operations over large geographies. Despite significant success, selection bias may lead to inflated expectations of the efficacy of social mobilization for these tasks. What are the limits of social mobilization, and how reliable is it in operating at these limits? We build on recent results on the spatiotemporal structure of social and information networks to elucidate the constraints they pose on social mobilization. We use the DARPA Network Challenge as our working scenario, in which social media were used to locate 10 balloons across the United States. We conduct high-resolution simulations for referral-based crowdsourcing and obtain a statistical characterization of the population recruited, geography covered, and time to completion. Our results demonstrate that the outcome is plausible without the presence of mass media but lies at the limit of what time-critical social mobilization can achieve. Success relies critically on highly connected individuals willing to mobilize people in distant locations, overcoming the local trapping of diffusion in highly dense areas. However, even under these highly favorable conditions, the risk of unsuccessful search remains significant. These findings have implications for the design of better incentive schemes for social mobilization. They also call for caution in estimating the reliability of this capability.

  8. Symmetry associated with symmetry break: Revisiting ants and humans escaping from multiple-exit rooms

    Science.gov (United States)

    Ji, Q.; Xin, C.; Tang, S. X.; Huang, J. P.

    2018-02-01

    Crowd panic has incurred massive injuries or deaths throughout the world, and thus understanding it is particularly important. It is now a common knowledge that crowd panic induces "symmetry break" in which some exits are jammed while others are underutilized. Amazingly, here we show, by experiment, simulation and theory, that a class of symmetry patterns come to appear for ants and humans escaping from multiple-exit rooms while the symmetry break exists. Our symmetry pattern is described by the fact that the ratio between the ensemble-averaging numbers of ants or humans escaping from different exits is equal to the ratio between the widths of the exits. The mechanism lies in the effect of heterogeneous preferences of agents with limited information for achieving the Nash equilibrium. This work offers new insights into how to improve public safety because large public areas are always equipped with multiple exits, and it also brings an ensemble-averaging method for seeking symmetry associated with symmetry breaking.

  9. Selective breaking of bonds in water with intense, 2-cycle, infrared laser pulses

    Energy Technology Data Exchange (ETDEWEB)

    Mathur, D., E-mail: atmol1@tifr.res.in; Dharmadhikari, A. K. [Tata Institute of Fundamental Research, 1 Homi Bhabha Road, Mumbai 400 005 (India); Dota, K. [Tata Institute of Fundamental Research, 1 Homi Bhabha Road, Mumbai 400 005 (India); Centre for Atomic and Molecular Physics, Manipal University, Manipal 576 104 (India); Dey, D.; Tiwari, A. K. [Indian Institute of Science Education and Research Kolkata, Mohanpur 741 246 (India); Dharmadhikari, J. A. [Centre for Atomic and Molecular Physics, Manipal University, Manipal 576 104 (India); De, S. [Saha Institute of Nuclear Physics, Bidhan Nagar, Kolkata 700 064 (India); Vasa, P. [Department of Physics, Indian Institute of Technology Bombay, Mumbai 400 076 (India)

    2015-12-28

    One of the holy grails of contemporary science has been to establish the possibility of preferentially breaking one of several bonds in a molecule. For instance, the two O–H bonds in water are equivalent: given sufficient energy, either one of them is equally likely to break. We report bond-selective molecular fragmentation upon application of intense, 2-cycle pulses of 800 nm laser light: we demonstrate up to three-fold enhancement for preferential bond breaking in isotopically substituted water (HOD). Our experimental observations are rationalized by means of ab initio computations of the potential energy surfaces of HOD, HOD{sup +}, and HOD{sup 2+} and explorations of the dissociation limits resulting from either O–H or O–D bond rupture. The observations we report present a formidable theoretical challenge that need to be taken up in order to gain insights into molecular dynamics, strong field physics, chemical physics, non-adiabatic processes, mass spectrometry, and time-dependent quantum chemistry.

  10. Test circuit for verifying dielectric performance of phase-to-enclosure during capacitive current breaking

    Directory of Open Access Journals (Sweden)

    Jung-Hyeon Ryu

    2016-01-01

    Full Text Available In the case of Extra High Voltage and Ultra High Voltage circuit breaker, almost all of testing laboratories adopt the single-phase testing method for verifying the performance of capacitive breaking capability, based on IEC 62271-100 Annex O, due to the limitation of testing facilities. For dead-tank breaker, the tests for the insulating properties of phase-to-enclosure are recommended as a non-mandatory testing item. However, IEC MT36 has proposed the change of standard to specify as a mandatory in its next version planned in 2016. The peak of recovery voltages, occurring just after interrupting the some type of capacitive currents, arrives at different values on supply and load sides. With the technical background, the new capacitive current breaking test circuits are proposed to fulfill the next edition of IEC 62271-100 to be newly published. This paper illustrates the testing methods and simulation results for the single phase test circuits of capacitive current breaking, applicable to the circuit-breakers from 145 to 362 kV.

  11. Spatial resolution considerations for urban hydrological modelling

    Science.gov (United States)

    Krebs, G.; Kokkonen, T.; Valtanen, M.; Setälä, H.; Koivusalo, H.

    2014-05-01

    Hydrological model simulations can be applied to evaluate the performance of low impact development (LID) tools in urban areas. However, the assessment for large-scale urban areas remains a challenge due to the required high spatial resolution and limited availability of field measurements for model calibration. This study proposes a methodology to parameterize a hydrological model (SWMM) with sufficiently high spatial resolution and direct accessibility of model parameters for LID performance simulation applicable to a large-scale ungauged urban area. Based on calibrated high-resolution models for three small-scale study catchments (6-12 ha), we evaluated how constraints implied by large-scale urban modelling, such as data limitations, affect the model results. The high-resolution surface representation, resulting in subcatchments of uniform surface types, reduced the number of calibration parameters. Calibration conducted independently for all catchments yielded similar parameter values for same surface types in each study catchment. These results suggest the applicability of the parameter values calibrated for high resolution models to be regionalized to larger, ungauged urban areas. The accessibility of surface specific model parameters for LID simulation is then also retained. Conducted perturbations in spatial resolution through sewer network truncation showed that while the runoff volume was mostly unaffected by resolution perturbations, lower resolutions resulted in over-simulation of peak flows due to excessively rapid catchment response to storm events. Our results suggest that a hydrological model where parameter values are adopted from high-resolution models and that is developed based on a minimum conduit diameter of 300 mm provides good simulation performance and is applicable to large-scale urban areas with reasonable effort.

  12. Effects of imperfect elements on resolution and sensitivity of quantum metrology using two-mode squeezed vacuum state.

    Science.gov (United States)

    Zhang, Jiandong; Zhang, Zijing; Cen, Longzhu; Yu, Miao; Li, Shuo; Wang, Feng; Zhao, Yuan

    2017-10-16

    It has been demonstrated that using two-mode squeezed vacuum state for phase estimation can break the Heisenberg limit. Our results reveal that the two-mode squeezed vacuum state is also applied to the optical rotation angle measurement. In our scheme, the resolution and sensitivity of the optical rotation angle signal are the same as the case of phase estimation. For the parameter estimation, phase or rotation angle, we discuss the influences of several imperfect factors on the resolution and sensitivity. First, the effect that the upper limit of photon-number resolving has on the maximum amount of available quantum Fisher information has been analyzed. Then, we have also studied the impacts of both the transmission efficiency in the transmission process and the detection efficiency on the detection results. Finally, conditions where all of the above imperfect elements are taken into account at the same time have also been explored. Additionally, other imperfect factors such as squeezing efficiency and dark counts are briefly discussed.

  13. Resolution exchange simulation.

    Science.gov (United States)

    Lyman, Edward; Ytreberg, F Marty; Zuckerman, Daniel M

    2006-01-20

    We extend replica-exchange simulation in two ways and apply our approaches to biomolecules. The first generalization permits exchange simulation between models of differing resolution--i.e., between detailed and coarse-grained models. Such "resolution exchange" can be applied to molecular systems or spin systems. The second extension is to "pseudoexchange" simulations, which require little CPU usage for most levels of the exchange ladder and also substantially reduce the need for overlap between levels. Pseudoexchanges can be used in either replica or resolution exchange simulations. We perform efficient, converged simulations of a 50-atom peptide to illustrate the new approaches.

  14. Super-resolution microscopy by movable thin-films with embedded microspheres: Resolution analysis

    Energy Technology Data Exchange (ETDEWEB)

    Allen, Kenneth W.; Farahi, Navid; Astratov, Vasily N. [Department of Physics and Optical Science, Center for Optoelectronics and Optical Communications, University of North Carolina at Charlotte, Charlotte, NC, 28223-0001 (United States); Air Force Research Laboratory, Sensors Directorate, Wright-Patterson AFB, OH (United States); Li, Yangcheng [Department of Physics and Optical Science, Center for Optoelectronics and Optical Communications, University of North Carolina at Charlotte, Charlotte, NC, 28223-0001 (United States); Limberopoulos, Nicholaos I.; Walker, Dennis E. Jr. [Air Force Research Laboratory, Sensors Directorate, Wright-Patterson AFB, OH (United States); Urbas, Augustine M. [Air Force Research Laboratory, Materials and Manufacturing Directorate, Wright Patterson AFB, OH (United States); Liberman, Vladimir [Lincoln Laboratory, Massachusetts Institute of Technology, Lexington, Massachusetts 02420 (United States)

    2015-08-15

    Microsphere-assisted imaging has emerged as an extraordinary simple technique of obtaining optical super-resolution. This work addresses two central problems in developing this technology: (i) methodology of the resolution measurements and (ii) limited field-of-view provided by each sphere. It is suggested that a standard method of resolution analysis in far-field microscopy based on convolution with the point-spread function can be extended into the super-resolution area. This allows developing a unified approach to resolution measurements, which can be used for comparing results obtained by different techniques. To develop the surface scanning functionality, the high-index (n ∝ 2) barium titanate glass microspheres were embedded in polydimethylsiloxane (PDMS) thin-films. It is shown that such films adhere to the surface of nanoplasmonic structures so that the tips of embedded spheres experience the objects' optical near-fields. Based on rigorous criteria, the resolution ∝λ/6-λ/7 (where λ is the illumination wavelength) is demonstrated for arrays of Au dimers and bowties. Such films can be translated along the surface of investigated samples after liquid lubrication. It is shown that just after lubrication the resolution is diffraction limited, however the super-resolution gradually recovers as the lubricant evaporates. (copyright 2015 by WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  15. Model Building to Facilitate Understanding of Holliday Junction and Heteroduplex Formation, and Holliday Junction Resolution

    Science.gov (United States)

    Selvarajah, Geeta; Selvarajah, Susila

    2016-01-01

    Students frequently expressed difficulty in understanding the molecular mechanisms involved in chromosomal recombination. Therefore, we explored alternative methods for presenting the two concepts of the double-strand break model: Holliday junction and heteroduplex formation, and Holliday junction resolution. In addition to a lecture and…

  16. Percepção de limitações de atividades comunicativas, resolução temporal e figura-fundo em perda auditiva unilateral Perception of limitations on communicative activities, temporal resolution and figure-to-ground in unilateral hearing loss

    Directory of Open Access Journals (Sweden)

    Márcia Ribeiro Vieira

    2011-12-01

    Full Text Available OBJETIVO: Avaliar os comportamentos auditivos de figura-fundo e resolução temporal, e a auto-percepção das limitações de atividades comunicativas de crianças e adolescentes portadores de perda auditiva unilateral. MÉTODOS: Participaram do estudo 38 indivíduos, com idades entre 8 e 19 anos, divididos em: grupo estudo (portadores de perda auditiva unilateral e grupo controle (ouvintes normais, cada um formado por 19 indivíduos, pareados conforme gênero, idade e escolaridade. Todos foram submetidos à anamnese, avaliação audiológica e aos procedimentos do estudo: questionário de auto-avaliação das limitações de atividades comunicativas, testes de processamento auditivo Gaps-in-Noise e Pediatric Speech Intelligibility Test. A análise estatística foi realizada por meio de testes não paramétricos. RESULTADOS: No grupo estudo, a perda auditiva unilateral na maioria dos participantes foi de grau profundo, com início na fase pré-escolar, com etiologias desconhecidas ou identificadas como meningite, traumas, caxumba e sarampo. A maioria dos indivíduos apresentou queixa de dificuldades de aprendizagem e mostrou limitações de atividades comunicativas de grau moderado predominantemente, e principalmente em situações ruidosas. No grupo estudo foram observadas as piores respostas tanto para os limiares de detecção de gap como no teste Pediatric Speech Intelligibility Test obtidas na orelha normal. Não houve correlação significativa entre os limiares de detecção de gap na orelha normal e o lado da orelha com perda auditiva. CONCLUSÃO: Indivíduos com perda auditiva unilateral apresentam limitações de atividades comunicativas, principalmente em ambientes ruidosos associadas a piores habilidades auditivas de resolução temporal e de figura-fundo.PURPOSE: To evaluate the hearing behavior of figure-to-ground and temporal resolution, and the self-perception of limitations on communicative activities of children and

  17. Parity breaking transport in Lifshitz hydrodynamics

    Energy Technology Data Exchange (ETDEWEB)

    Hoyos, Carlos [Department of Physics, Universidad de Oviedo, Avda. Calvo Sotelo 18, 33007, Oviedo (Spain); Meyer, Adiel; Oz, Yaron [Raymond and Beverly Sackler School of Physics and Astronomy, Tel Aviv University, Tel Aviv 69978 (Israel)

    2015-09-07

    We derive the constitutive relations of first order charged hydrodynamics for theories with Lifshitz scaling and broken parity in 2+1 and 3+1 spacetime dimensions. In addition to the anomalous (in 3+1) or Hall (in 2+1) transport of relativistic hydrodynamics, there is an additional non-dissipative transport allowed by the absence of boost invariance. We analyze the non-relativistic limit and use a phenomenological model of a strange metal to argue that these effects can be measured in principle by using electromagnetic fields with non-zero gradients.

  18. LHCb VELO Tracking Resolutions

    CERN Multimedia

    Alexander, Michael

    2011-01-01

    The excellent tracking performance of the Vertex Locator (VELO) at LHCb is presented. The resolutions it achieves on single hits, impact parameters, and primary vertex positions are shown, with particular attention paid to measurement of impact parameters.

  19. High Resolution Elevation Contours

    Data.gov (United States)

    Minnesota Department of Natural Resources — This dataset contains contours generated from high resolution data sources such as LiDAR. Generally speaking this data is 2 foot or less contour interval.

  20. 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

  1. Scalable Resolution Display Walls

    KAUST Repository

    Leigh, Jason

    2013-01-01

    This article will describe the progress since 2000 on research and development in 2-D and 3-D scalable resolution display walls that are built from tiling individual lower resolution flat panel displays. The article will describe approaches and trends in display hardware construction, middleware architecture, and user-interaction design. The article will also highlight examples of use cases and the benefits the technology has brought to their respective disciplines. © 1963-2012 IEEE.

  2. Ultra high resolution tomography

    Energy Technology Data Exchange (ETDEWEB)

    Haddad, W.S.

    1994-11-15

    Recent work and results on ultra high resolution three dimensional imaging with soft x-rays will be presented. This work is aimed at determining microscopic three dimensional structure of biological and material specimens. Three dimensional reconstructed images of a microscopic test object will be presented; the reconstruction has a resolution on the order of 1000 A in all three dimensions. Preliminary work with biological samples will also be shown, and the experimental and numerical methods used will be discussed.

  3. Dynamic systemic resolution.

    Science.gov (United States)

    Sakulsombat, Morakot; Zhang, Yan; Ramström, Olof

    2012-01-01

    Dynamic Systemic Resolution is a powerful technique for selecting optimal constituents from dynamic systems by applying selection pressures, either externally by addition of target entities, or internally within the system constraints. This concept is a subset of Constitutional Dynamic Chemistry, and the dynamic systems are generally based on reversible covalent interactions between a range of components where the systems are maintained under thermodynamic control. In the present chapter, the concept will be described in detail, and a range of examples will be given for both selection classes. For external pressure generation, target enzymes, in aqueous and/or organic solution, have been used to demonstrate the resolution processes. In a first example, a dynamic transthiolesterification system was generated in aqueous solution at neutral pH, and resolved by hydrolysis using serine hydrolases (cholinesterases). In organic solution, lipase-catalyzed acylation was chosen to demonstrate asymmetric resolution in different dynamic systems, generating chiral ester and amide structures. By use of such biocatalysts, the optimal constituents were selectively chosen and amplified from the dynamic systems in one-pot processes. In internal selection pressure resolution, self-transformation and crystallization-induced diastereomeric resolution have been successfully used to challenge dynamic systems. The technique was, for example, used to identify the best diastereomeric substrate from a large and varied dynamic system in a single resolution reaction.

  4. Direct detection of a break in the teraelectronvolt cosmic-ray spectrum of electrons and positrons

    Science.gov (United States)

    DAMPE Collaboration; Ambrosi, G.; An, Q.; Asfandiyarov, R.; Azzarello, P.; Bernardini, P.; Bertucci, B.; Cai, M. S.; Chang, J.; Chen, D. Y.; Chen, H. F.; Chen, J. L.; Chen, W.; Cui, M. Y.; Cui, T. S.; D'Amone, A.; de Benedittis, A.; De Mitri, I.; di Santo, M.; Dong, J. N.; Dong, T. K.; Dong, Y. F.; Dong, Z. X.; Donvito, G.; Droz, D.; Duan, K. K.; Duan, J. L.; Duranti, M.; D'Urso, D.; Fan, R. R.; Fan, Y. Z.; Fang, F.; Feng, C. Q.; Feng, L.; Fusco, P.; Gallo, V.; Gan, F. J.; Gao, M.; Gao, S. S.; Gargano, F.; Garrappa, S.; Gong, K.; Gong, Y. Z.; Guo, D. Y.; Guo, J. H.; Hu, Y. M.; Huang, G. S.; Huang, Y. Y.; Ionica, M.; Jiang, D.; Jiang, W.; Jin, X.; Kong, J.; Lei, S. J.; Li, S.; Li, X.; Li, W. L.; Li, Y.; Liang, Y. F.; Liang, Y. M.; Liao, N. H.; Liu, H.; Liu, J.; Liu, S. B.; Liu, W. Q.; Liu, Y.; Loparco, F.; Ma, M.; Ma, P. X.; Ma, S. Y.; Ma, T.; Ma, X. Q.; Ma, X. Y.; Marsella, G.; Mazziotta, M. N.; Mo, D.; Niu, X. Y.; Peng, X. Y.; Peng, W. X.; Qiao, R.; Rao, J. N.; Salinas, M. M.; Shang, G. Z.; H. Shen, W.; Shen, Z. Q.; Shen, Z. T.; Song, J. X.; Su, H.; Su, M.; Sun, Z. Y.; Surdo, A.; Teng, X. J.; Tian, X. B.; Tykhonov, A.; Vagelli, V.; Vitillo, S.; Wang, C.; Wang, H.; Wang, H. Y.; Wang, J. Z.; Wang, L. G.; Wang, Q.; Wang, S.; Wang, X. H.; Wang, X. L.; Wang, Y. F.; Wang, Y. P.; Wang, Y. Z.; Wen, S. C.; Wang, Z. M.; Wei, D. M.; Wei, J. J.; Wei, Y. F.; Wu, D.; Wu, J.; Wu, L. B.; Wu, S. S.; Wu, X.; Xi, K.; Xia, Z. Q.; Xin, Y. L.; Xu, H. T.; Xu, Z. L.; Xu, Z. Z.; Xue, G. F.; Yang, H. B.; Yang, P.; Yang, Y. Q.; Yang, Z. L.; Yao, H. J.; Yu, Y. H.; Yuan, Q.; Yue, C.; Zang, J. J.; Zhang, C.; Zhang, D. L.; Zhang, F.; Zhang, J. B.; Zhang, J. Y.; Zhang, J. Z.; Zhang, L.; Zhang, P. F.; Zhang, S. X.; Zhang, W. Z.; Zhang, Y.; Zhang, Y. J.; Zhang, Y. Q.; Zhang, Y. L.; Zhang, Y. P.; Zhang, Z.; Zhang, Z. Y.; Zhao, H.; Zhao, H. Y.; Zhao, X. F.; Zhou, C. Y.; Zhou, Y.; Zhu, X.; Zhu, Y.; Zimmer, S.

    2017-12-01

    High-energy cosmic-ray electrons and positrons (CREs), which lose energy quickly during their propagation, provide a probe of Galactic high-energy processes and may enable the observation of phenomena such as dark-matter particle annihilation or decay. The CRE spectrum has been measured directly up to approximately 2 teraelectronvolts in previous balloon- or space-borne experiments, and indirectly up to approximately 5 teraelectronvolts using ground-based Cherenkov γ-ray telescope arrays. Evidence for a spectral break in the teraelectronvolt energy range has been provided by indirect measurements, although the results were qualified by sizeable systematic uncertainties. Here we report a direct measurement of CREs in the energy range 25 gigaelectronvolts to 4.6 teraelectronvolts by the Dark Matter Particle Explorer (DAMPE) with unprecedentedly high energy resolution and low background. The largest part of the spectrum can be well fitted by a ‘smoothly broken power-law’ model rather than a single power-law model. The direct detection of a spectral break at about 0.9 teraelectronvolts confirms the evidence found by previous indirect measurements, clarifies the behaviour of the CRE spectrum at energies above 1 teraelectronvolt and sheds light on the physical origin of the sub-teraelectronvolt CREs.

  5. Lyman Break Analogs: Constraints on the Formation of Extreme Starbursts at Low and High Redshift

    Science.gov (United States)

    Goncalves, Thiago S.; Overzier, Roderik; Basu-Zych, Antara; Martin, D. Christopher

    2011-01-01

    Lyman Break Analogs (LBAs), characterized by high far-UV luminosities and surface brightnesses as detected by GALEX, are intensely star-forming galaxies in the low-redshift universe (z approximately equal to 0.2), with star formation rates reaching up to 50 times that of the Milky Way. These objects present metallicities, morphologies and other physical properties similar to higher redshift Lyman Break Galaxies (LBGs), motivating the detailed study of LBAs as local laboratories of this high-redshift galaxy population. We present results from our recent integral-field spectroscopy survey of LBAs with Keck/OSIRIS, which shows that these galaxies have the same nebular gas kinematic properties as high-redshift LBGs. We argue that such kinematic studies alone are not an appropriate diagnostic to rule out merger events as the trigger for the observed starburst. Comparison between the kinematic analysis and morphological indices from HST imaging illustrates the difficulties of properly identifying (minor or major) merger events, with no clear correlation between the results using either of the two methods. Artificial redshifting of our data indicates that this problem becomes even worse at high redshift due to surface brightness dimming and resolution loss. Whether mergers could generate the observed kinematic properties is strongly dependent on gas fractions in these galaxies. We present preliminary results of a CARMA survey for LBAs and discuss the implications of the inferred molecular gas masses for formation models.

  6. A LYMAN BREAK GALAXY IN THE EPOCH OF REIONIZATION FROM HUBBLE SPACE TELESCOPE GRISM SPECTROSCOPY

    Energy Technology Data Exchange (ETDEWEB)

    Rhoads, James E.; Malhotra, Sangeeta; Cohen, Seth; Zheng Zhenya [School of Earth and Space Exploration, Arizona State University, Tempe, AZ 85287 (United States); Stern, Daniel [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States); Dickinson, Mark [National Optical Astronomy Observatory, Tucson, AZ (United States); Pirzkal, Norbert; Grogin, Norman; Koekemoer, Anton; Peth, Michael A. [Space Telescope Science Institute, Baltimore, MD (United States); Spinrad, Hyron [University of California, Berkeley, CA (United States); Reddy, Naveen [University of California, Riverside, CA (United States); Hathi, Nimish [Observatories of the Carnegie Institution of Washington, Pasadena, CA (United States); Budavari, Tamas [Johns Hopkins University, Baltimore, MD (United States); Ferreras, Ignacio [Mullard Space Science Laboratory, University College London, Holmbury St Mary, Dorking, Surrey RH5 6NT (United Kingdom); Gardner, Jonathan P. [NASA Goddard Space Flight Center, Astrophysics Science Division, Observational Cosmology Laboratory, Code 665, Greenbelt, MD 20771 (United States); Gronwall, Caryl [Department of Astronomy and Astrophysics, and Institute for Gravitation and the Cosmos, The Pennsylvania State University, University Park, PA 16802 (United States); Haiman, Zoltan [Columbia University, New York, NY (United States); Kuemmel, Martin [Universitaets-Sternwarte Muenchen, Scheinerstr. 1, D-81679 Muenchen (Germany); Meurer, Gerhardt, E-mail: James.Rhoads@asu.edu [International Centre for Radio Astronomy Research, University of Western Australia, M468, 35 Stirling Highway, Crawley, WA 6009 (Australia); and others

    2013-08-10

    We present observations of a luminous galaxy at z = 6.573-the end of the reionization epoch-which has been spectroscopically confirmed twice. The first spectroscopic confirmation comes from slitless Hubble Space Telescope Advanced Camera for Surveys grism spectra from the PEARS survey (Probing Evolution And Reionization Spectroscopically), which show a dramatic continuum break in the spectrum at rest frame 1216 A. The second confirmation is done with Keck + DEIMOS. The continuum is not clearly detected with ground-based spectra, but high wavelength resolution enables the Ly{alpha} emission line profile to be determined. We compare the line profile to composite line profiles at z = 4.5. The Ly{alpha} line profile shows no signature of a damping wing attenuation, confirming that the intergalactic gas is ionized at z = 6.57. Spectra of Lyman breaks at yet higher redshifts will be possible using comparably deep observations with IR-sensitive grisms, even at redshifts where Ly{alpha} is too attenuated by the neutral intergalactic medium to be detectable using traditional spectroscopy from the ground.

  7. Local Activity Principle:. the Cause of Complexity and Symmetry Breaking

    Science.gov (United States)

    Mainzer, Klaus

    2013-01-01

    The principle of local activity is precisely the missing concept to explain the emergence of complex patterns in a homogeneous medium. Leon O. Chua discovered and defined this principle in the theory of nonlinear electronic circuits in a mathematically rigorous way. The local principle can be generalized and proven at least for the class of nonlinear reaction-diffusion systems in physics, chemistry, biology and brain research. Recently, it was realized by memristors for nanoelectronic device applications in technical brains. In general, the emergence of complex patterns and structures is explained by symmetry breaking in homogeneous media. The principle of local activity is the cause of symmetry breaking in homogeneous media. We argue that the principle of local activity is really fundamental in science and can even be identified in quantum cosmology as symmetry breaking of local gauge symmetries generating the complexity of matter and forces in our universe. Finally, we consider applications in economic, financial, and social systems with the emergence of equilibrium states, symmetry breaking at critical points of phase transitions and risky acting at the edge of chaos. In any case, the driving causes of symmetry breaking and the emergence of complexity are locally active elements, cells, units, or agents.

  8. Analysis of break test of 54 cluster fuels

    Energy Technology Data Exchange (ETDEWEB)

    Matsumoto, Mitsuo; Kawamata, Nobuhiro; Kamoshida, Hiroshi

    1998-03-01

    A break test of down pipe and main steam tube of 54 cluster fuels were carried out in the Power Reactor and Nuclear Fuel Development Corporation (PNC) in fiscal 1996. The safety evaluation code for `Fugen` was investigated by analysing the break tests by RELAP 5 code. The tests were carried out by ATR safety experimental facility which was consisted of steam drum, lower header, pressure tube, inlet tube, riser, recirculation pump and non-return valve. Break is modified by breaking a rupture disk in both cases of test. Pressure, pressure difference, temperature, water level and flow rate at channel inlet were measured. The results proved the following: The safety evaluation code for `Fugen` estimated the higher temperature of cladding tube after dry out. A return model of the best evaluation for `Fugen` was confirmed to make reappear dry out and quenching phenomena of temperature behavior of cladding tube under the experimental conditions. RELAP 5 code made a reproduction of heat transfer fluid phenomena of LOCA experiment modifying break of down pipe of Fugen. The result proved that the code is also able to use for LOCA analysis of ATR system. (S.Y.)

  9. Double strand break repair functions of histone H2AX

    Energy Technology Data Exchange (ETDEWEB)

    Scully, Ralph, E-mail: rscully@bidmc.harvard.edu; Xie, Anyong

    2013-10-15

    Chromosomal double strand breaks provoke an extensive reaction in neighboring chromatin, characterized by phosphorylation of histone H2AX on serine 139 of its C-terminal tail (to form “γH2AX”). The γH2AX response contributes to the repair of double strand breaks encountered in a variety of different contexts, including those induced by ionizing radiation, physiologically programmed breaks that characterize normal immune cell development and the pathological exposure of DNA ends triggered by telomere dysfunction. γH2AX also participates in the evolutionarily conserved process of sister chromatid recombination, a homologous recombination pathway involved in the suppression of genomic instability during DNA replication and directly implicated in tumor suppression. At a biochemical level, the γH2AX response provides a compelling example of how the “histone code” is adapted to the regulation of double strand break repair. Here, we review progress in research aimed at understanding how γH2AX contributes to double strand break repair in mammalian cells.

  10. 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.

  11. Explicit chiral symmetry breaking in Gross-Neveu type models

    Energy Technology Data Exchange (ETDEWEB)

    Boehmer, Christian

    2011-07-25

    This thesis is devoted to the study of a 1+1-dimensional, fermionic quantum field theory with Lagrangian L= anti {psi}i{gamma}{sup {mu}}{partial_derivative}{sub {mu}}{psi}-m{sub 0} anti {psi}{psi}+(g{sup 2})/(2)(anti {psi}{psi}){sup 2}+(G{sup 2})/(2)(anti {psi}i{gamma}{sub 5}{psi}){sup 2} in the limit of an infinite number of flavors, using semiclassical methods. The main goal of the present work was to see what changes if we allow for explicit chiral symmetry breaking, either by a bare mass term, or a splitting of the scalar and pseudo-scalar coupling constants, or both. In the first case, this becomes the massive NJL{sub 2} model. In the 2nd and 3rd cases we are dealing with a model largely unexplored so far. The first half of this thesis deals with the massive NJL{sub 2} model. Before attacking the phase diagram, it was necessary to determine the baryons of the model. We have carried out full numerical Hartree-Fock calculations including the Dirac sea. The most important result is the first complete phase diagram of the massive NJL{sub 2} model in ({mu},T,{gamma}) space, where {gamma} arises from m{sub 0} through mass renormalization. In the 2nd half of the thesis we have studied a generalization of the massless NJL{sub 2} model with two different (scalar and pseudoscalar) coupling constants, first in the massless version. Renormalization of the 2 coupling constants leads to the usual dynamical mass by dynamical transmutation, but in addition to a novel {xi} parameter interpreted as chiral quenching parameter. As far as baryon structure is concerned, the most interesting result is the fact that the new baryons interpolate between the kink of the GN model and the massless baryon of the NJL{sub 2} model, always carrying fractional baryon number 1/2. The phase diagram of the massless model with 2 coupling constants has again been determined numerically. At zero temperature we have also investigated the massive, generalized GN model with 3 parameters. It is well

  12. A compromise to break the climate impasse

    Science.gov (United States)

    Grasso, Marco; Roberts, Timmons

    2014-07-01

    To overcome the current impasse in global climate negotiations we propose a compromise for sharing the remaining carbon budget, based on four elements. First, limiting initial action to the Major Economies Forum members would streamline negotiations greatly. Second, using consumption-based carbon accounting would overcome important fairness concerns of key developing countries. Similarly, applying equity principles of responsibility and capability to apportion the burden of emissions reductions within the group can address concerns of both the global north and south. And fourth, promptly bringing this compromise back to the United Nations negotiations for wider adoption will be critical. Based on an indicative carbon budget of 420 gigatonnes carbon dioxide over the period 2012-2050, our analysis shows that ambitious but feasible emissions reductions will be needed, with sharp differences by world economic groups. The compromise offers effectiveness, feasibility and fairness.

  13. Far-field super-resolution imaging of resonant multiples

    KAUST Repository

    Guo, Bowen

    2016-05-20

    We demonstrate for the first time that seismic resonant multiples, usually considered as noise, can be used for super-resolution imaging in the far-field region of sources and receivers. Tests with both synthetic data and field data show that resonant multiples can image reflector boundaries with resolutions more than twice the classical resolution limit. Resolution increases with the order of the resonant multiples. This procedure has important applications in earthquake and exploration seismology, radar, sonar, LIDAR (light detection and ranging), and ultrasound imaging, where the multiples can be used to make high-resolution images.

  14. DNA-PKcs structure suggests an allosteric mechanism modulating DNA double-strand break repair.

    Science.gov (United States)

    Sibanda, Bancinyane L; Chirgadze, Dimitri Y; Ascher, David B; Blundell, Tom L

    2017-02-03

    DNA-dependent protein kinase catalytic subunit (DNA-PKcs) is a central component of nonhomologous end joining (NHEJ), repairing DNA double-strand breaks that would otherwise lead to apoptosis or cancer. We have solved its structure in complex with the C-terminal peptide of Ku80 at 4.3 angstrom resolution using x-ray crystallography. We show that the 4128-amino acid structure comprises three large structural units: the N-terminal unit, the Circular Cradle, and the Head. Conformational differences between the two molecules in the asymmetric unit are correlated with changes in accessibility of the kinase active site, which are consistent with an allosteric mechanism to bring about kinase activation. The location of KU80ct194 in the vicinity of the breast cancer 1 (BRCA1) binding site suggests competition with BRCA1, leading to pathway selection between NHEJ and homologous recombination. Copyright © 2017, American Association for the Advancement of Science.

  15. A Lyman Break Galaxy in the Epoch of Reionization from Hubble Space Telescope (HST) Grism Spectroscopy

    Science.gov (United States)

    Rhoads, James E.; Malhotra, Sangeeta; Stern, Daniel K.; Gardner, Jonathan P.; Dickinson, Mark; Pirzkal, Norbert; Spinrad, Hyron; Reddy, Naveen; Dey, Arjun; Hathi, Nimish; hide

    2013-01-01

    Slitless grism spectroscopy from space offers dramatic advantages for studying high redshift galaxies: high spatial resolution to match the compact sizes of the targets, a dark and uniform sky background, and simultaneous observation over fields ranging from five square arcminutes (HST) to over 1000 square arcminutes (Euclid). Here we present observations of a galaxy at z = 6.57 the end of the reioinization epoch identified using slitless HST grism spectra from the PEARS survey (Probing Evolution And Reionization Spectroscopically) and reconfirmed with Keck + DEIMOS. This high redshift identification is enabled by the depth of the PEARS survey. Substantially higher redshifts are precluded for PEARS data by the declining sensitivity of the ACS grism at greater than lambda 0.95 micrometers. Spectra of Lyman breaks at yet higher redshifts will be possible using comparably deep observations with IR-sensitive grisms.

  16. 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...

  17. FluBreaks: early epidemic detection from Google flu trends.

    Science.gov (United States)

    Pervaiz, Fahad; Pervaiz, Mansoor; Abdur Rehman, Nabeel; Saif, Umar

    2012-10-04

    . Regions with larger populations (regions 4 and 6) had higher values of EA than region 10 (which had the smallest population) for negative binomial- and Poisson-based algorithms. The difference was 12.5% and 13.5% on average in negative binomial- and Poisson-based algorithms, respectively. We present the first detailed comparative analysis of popular early epidemic detection algorithms on Google Flu Trends data. We note that realizing this opportunity requires moving beyond the cumulative sum and historical limits method-based normal distribution approaches, traditionally employed by the CDC, to negative binomial- and Poisson-based algorithms to deal with potentially noisy search query data from regions with varying population and Internet penetrations. Based on our work, we have developed FluBreaks, an early warning system for flu epidemics using Google Flu Trends.

  18. Conflict Prevention and Resolution Center

    Science.gov (United States)

    The Conflict Prevention and Resolution Center is EPA's primary resource for services and expertise in the areas of consensus-building, collaborative problem solving, alternative dispute resolution, and environmental collaboration and conflict resolution.

  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. Analysis of dam break waves; Analyse av dambruddsboelger

    Energy Technology Data Exchange (ETDEWEB)

    Midttoemme, Grethe Holm (ed.)

    2010-06-15

    The project objective was to improve knowledge and methodology for dam break wave calculations in relation to current practice and NVE's current requirements. The reason was the experience of flood in Troendelag in 2006, which indicated that NVE's policies was not good enough for small and / or erosion prone rivers. The project has shown that erosion processes can be at least as large consequences as the dam break flood, and that degree of detail with respect to terrain data and the choice of roughness is important for the results in a watercourse as Lauvsnes waterway. It is also shown that the results from the use of 2D model may differ significantly from results from the 1D model. The report is making recommendations for updating guidelines for dam break wave calculations. (AG)